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Sample records for acid h3bo2 zinc

  1. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN...

  2. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN...

  3. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN...

  4. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN...

  5. 40 CFR 721.3032 - Boric acid (H3BO2), zinc salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO2), zinc salt. 721... Substances § 721.3032 Boric acid (H3BO2), zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO2), zinc salt (PMN...

  6. Effect of folic acid on zinc absorption

    SciTech Connect

    Wada, L.; Keating, S.; King, J.C.; Stokstad, E.L.R.

    1986-03-05

    The effect of folic acid on zinc uptake was studied in the human and in the rat. The serum zinc response to a 25 mg oral dose or zinc was measured with and without a 10 mg dose of folic acid. Serum zinc levels were measured prior to the oral dose of zinc and at hourly intervals up to 4 hours after the dose. When zinc was given along, the increases in serum zinc from baseline at hours 1, 2, 3 and 4 were 92, 118, 92 and 66 ..mu..g/dl, respectively. When both zinc and folic acid were given, the increases in serum zinc at hours 1, 2, 3 and 4 were 100, 140, 110 and 75 ..mu..g/dl, respectively. When the increases in serum zinc were plotted against time, there was no significant difference between the areas under the two curves. The everted jejunal sac from the rat was used to study the effect of folate on zinc transport using 100 ..mu..M zinc in the mucosal buffer. The addition of folic acid at levels up to 10/sup -3/M had no significant effect on zinc transport to the serosal side solution or on uptake by the intestinal mucosa. This in vivo study with humans and in vitro study with rat intestine does not support a direct adverse effect of folic acid on zinc absorption.

  7. Selective Acidic Leaching of Spent Zinc-Carbon Batteries Followed by Zinc Electrowinning

    NASA Astrophysics Data System (ADS)

    Shalchian, Hossein; Rafsanjani-Abbasi, Ali; Vahdati-Khaki, Jalil; Babakhani, Abolfazl

    2015-02-01

    In this work, a selective acidic leaching procedure was employed for recycling zinc from spent zinc-carbon batteries. Leaching experiments were carried out in order to maximize zinc recovery and minimize manganese recovery in diluted sulfuric acid media. Response surface methodology and analysis of variance were employed for experimental design, data analysis, and leaching optimization. The experimental design has 28 experiments that include 24 main runs and four replicate in center point. The optimal conditions obtained from the selective acidic leaching experiments, were sulfuric acid concentration of 1 pct v/v, leaching temperature of 343 K (70 °C), pulp density of 8 pct w/v, and stirring speed of 300 rpm. The results show that the zinc and manganese recoveries after staged selective leaching are about 92 and 15 pct, respectively. Finally, metallic zinc with purity of 99.9 pct and electrolytic manganese dioxide were obtained by electrowinning.

  8. Phytic acid reduction in soy protein improves zinc bioavailability

    SciTech Connect

    Zhou, J.R.; Wong, M.S.; Burns, R.A.; Erdman, J.W. Jr. Mead Johnson Research Center, Evansville, IN )

    1991-03-15

    The objective of this study was to confirm previous studies that have suggested that reduction of phytic acid in soy improved zinc bioavailability (BV). Two commercially-produced soybean isolates containing either a normal phytic acid level or a reduced level were formulated into diets so as to provide 6 or 9 ppm zinc. Control diets were egg white protein-based and contained 3, 6 or 9 ppm zinc from zinc carbonate. Weanling male rats were fed these diets for 21 days and food intake and weight gain monitored. Slope ratio analysis of total tibia zinc content compared to total zinc intake revealed that zinc BV from reduced phytic acid soy isolate-containing diets was indistinguishable from control egg white diets. In contrast, zinc BV from normal soy isolate diets was significantly reduced compared to reduced phytic acid and control diets. These results coupled with other results indicate that phytic acid is the inhibitory factor in soybean products that results in reduced zinc BV.

  9. Exposure to sulfuric acid in zinc production.

    PubMed

    Bråtveit, Magne; Haaland, Inger Margrethe; Moen, Bente E; Målsnes, Agnar

    2004-03-01

    This study characterized workers' exposure to sulfuric acid in two cell houses of a zinc production plant. We also aimed at estimating previous exposure to sulfuric acid by simulating the process conditions from before 1975 to produce exposure data for an epidemiological study on cancer in this industry. Further, we compared different sampling methods for aerosols in the cell houses. Personal sampling with a 37 mm Millipore cassette showed that the geometric means of the exposure levels for the workers in the two cell houses were 0.07 mg/m3 (range 0.01-0.48 mg/m3) and 0.04 mg/m3 (range 0.01-0.15 mg/m3). Norway's newly revised limit value of 0.1 mg/m3 was exceeded in 39.0 and 12.9% of the samples in the two cell houses. After the foam layer was removed from the electrolyte surface to simulate the production process from before 1975, the concentration of sulfuric acid increased from 0.11 to 6.04 mg/m3 in stationary measurement by the Millipore sampler. Stationary sampling showed that the Millipore sampler and the inhalable fraction of the Respicon impactor underestimated the sulfuric acid concentration by factors of 1.5 and 2.1 compared with the Institute of Occupational Medicine (IOM) sampler. Sampling with the Respicon impactor showed that the respirable, tracheobronchial and extrathoracic fractions constituted 3.0, 18.7 and 71.7% of the inhalable sulfuric acid aerosol, respectively. Today's exposure levels are lower than those reported to be associated with an increased prevalence of laryngeal cancer in other industries, but the levels prior to 1975 seem to have been much higher. By mass, most of the inhalable aerosol was in the size fractions considered to be highly relevant for the effects of sulfuric acid on the respiratory system. The risk of cancer among the cell house workers should be investigated in an epidemiological study.

  10. Zinc-induced oligomerization of zinc α2 glycoprotein reveals multiple fatty acid-binding sites.

    PubMed

    Zahid, Henna; Miah, Layeque; Lau, Andy M; Brochard, Lea; Hati, Debolina; Bui, Tam T T; Drake, Alex F; Gor, Jayesh; Perkins, Stephen J; McDermott, Lindsay C

    2016-01-01

    Zinc α2 glycoprotein (ZAG) is an adipokine with a class I MHC protein fold and is associated with obesity and diabetes. Although its intrinsic ligand remains unknown, ZAG binds the dansylated C11 fatty acid 11-(dansylamino)undecanoic acid (DAUDA) in the groove between the α1 and α2 domains. The surface of ZAG has approximately 15 weak zinc-binding sites deemed responsible for precipitation from human plasma. In the present study the functional significance of these metal sites was investigated. Analytical ultracentrifugation (AUC) and CD showed that zinc, but not other divalent metals, causes ZAG to oligomerize in solution. Thus ZAG dimers and trimers were observed in the presence of 1 and 2 mM zinc. Molecular modelling of X-ray scattering curves and sedimentation coefficients indicated a progressive stacking of ZAG monomers, suggesting that the ZAG groove may be occluded in these. Using fluorescence-detected sedimentation velocity, these ZAG-zinc oligomers were again observed in the presence of the fluorescent boron dipyrromethene fatty acid C16-BODIPY (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-hexadecanoic acid). Fluorescence spectroscopy confirmed that ZAG binds C16-BODIPY. ZAG binding to C16-BODIPY, but not to DAUDA, was reduced by increased zinc concentrations. We conclude that the lipid-binding groove in ZAG contains at least two distinct fatty acid-binding sites for DAUDA and C16-BODIPY, similar to the multiple lipid binding seen in the structurally related immune protein CD1c. In addition, because high concentrations of zinc occur in the pancreas, the perturbation of these multiple lipid-binding sites by zinc may be significant in Type 2 diabetes where dysregulation of ZAG and zinc homoeostasis occurs.

  11. Intercalation studies of zinc hydroxide chloride: Ammonia and amino acids

    SciTech Connect

    Arizaga, Gregorio Guadalupe Carbajal

    2012-01-15

    Zinc hydroxide chloride (ZHC) is a layered hydroxide salt with formula Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}2H{sub 2}O. It was tested as intercalation matrix for the first time and results were compared with intercalation products of the well-known zinc hydroxide nitrate and a Zn/Al layered double hydroxide. Ammonia was intercalated into ZHC, while no significant intercalation occurred in ZHN. Aspartic acid intercalation was only achieved by co-precipitation at pH=10 with ZHC and pH=8 with zinc hydroxide nitrate. Higher pH resistance in ZHC favored total deprotonation of both carboxylic groups of the Asp molecule. ZHC conferred more thermal protection against Asp combustion presenting exothermic peaks even at 452 Degree-Sign C while the exothermic event in ZHN was 366 Degree-Sign C and in the LDH at 276 Degree-Sign C. - Graphical abstract: The zinc hydroxide chloride (ZHC) with formula Zn{sub 5}(OH){sub 8}Cl{sub 2}{center_dot}2H{sub 2}O was tested as intercalation matrix. In comparison with the well-known zinc hydroxide nitrate (ZHN) and layered double hydroxides (LDH), ZHC was the best matrix for thermal protection of Asp combustion, presenting exothermic peaks even at 452 Degree-Sign C, while the highest exothermic event in ZHN was at 366 Degree-Sign C, and in the LDH it was at 276 Degree-Sign C. Highlights: Black-Right-Pointing-Pointer Zinc hydroxide chloride (ZHC) was tested as intercalation matrix for the first time. Black-Right-Pointing-Pointer ZHC has higher chemical and thermal stability than zinc hydroxide nitrate and LDH. Black-Right-Pointing-Pointer NH{sub 3} molecules can be intercalated into ZHC. Black-Right-Pointing-Pointer The amino group of amino acids limits the intercalation by ion-exchange.

  12. Intestinal transport of zinc and folic acid: a mutual inhibitory effect

    SciTech Connect

    Ghishan, F.K.; Said, H.M.; Wilson, P.C.; Murrell, J.E.; Greene, H.L.

    1986-02-01

    Recent observations suggest an inverse relationship between folic acid intake and zinc nutriture and indicate an interaction between folic acid and zinc at the intestinal level. To define that interaction, we designed in vivo and in vitro transport studies in which folic acid transport in the presence of zinc, as well as zinc transport in the presence of folic acid was examined. These studies show that zinc transport is significantly decreased when folate is present in the intestinal lumen. Similarly folic acid transport is significantly decreased with the presence of zinc. To determine whether this intestinal inhibition is secondary to zinc and folate-forming complexes, charcoal-binding studies were performed. These studies indicate that zinc and folate from complexes at pH 2.0, but that at pH 6.0, these complexes dissolve. Therefore, our studies suggest that under normal physiological conditions a mutual inhibition between folate and zinc exists at the site of intestinal transport.

  13. Kinetic Aspects of Leaching Zinc from Waste Galvanizing Zinc by Using Hydrochloric Acid Solutions

    NASA Astrophysics Data System (ADS)

    Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

    2016-10-01

    In this work, the results of acid leaching of flux skimmings coming from two plants are presented. Sample A contained two phases, Zn(OH)Cl and NH4Cl. In sample B, the presence of three phases, Zn5(OH)8Cl2·H2O, (NH4)2(ZnCl4) and ZnCl2(NH3)2, was proved. The aqueous solution of hydrochloric acid and distilled water was used as the leaching medium. The effects of the leaching time, temperature and concentration of the leaching medium on the zinc extraction were investigated. The apparent activation energy, E a = 4.61 kJ mol-1, and apparent reaction order n = 0.18 for sample A, and the values E a = 6.28 kJ mol-1 and n = 0.33 for sample B were experimentally determined. Zinc leaching in acid medium is a diffusion-controlled process.

  14. Fishy business: effect of omega-3 fatty acids on zinc transporters and free zinc availability in human neuronal cells.

    PubMed

    De Mel, Damitha; Suphioglu, Cenk

    2014-08-15

    Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer's disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration.

  15. Fishy Business: Effect of Omega-3 Fatty Acids on Zinc Transporters and Free Zinc Availability in Human Neuronal Cells

    PubMed Central

    De Mel, Damitha; Suphioglu, Cenk

    2014-01-01

    Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration. PMID:25195602

  16. The interaction of zinc(II) and hydroxamic acids and a metal-triggered Lossen rearrangement.

    PubMed

    Duchácková, Lucie; Roithová, Jana

    2009-12-14

    The structure and reactivity of a complex of zinc(II), water, acetic acid, and acetohydroxamic acid, in which one of the acids is deprotonated, is investigated by means of mass spectrometry, labeling studies, and density functional calculations to unravel the exceptional binding properties of hydroxamic acids towards zinc-containing enzymes at the molecular level. It is shown that acetohydroxamic acid is deprotonated in the complex, whereas acetic acid is present in its neutral form. The binding energies of the ligands towards zinc increase in the following order: wateracidacid. The structure of the complex and its fragmentation provide experimental evidence for the proposed mode of operation of drugs based on hydroxamic acids. Furthermore, coordinatively unsaturated complexes of zinc and acetohydroxamic acid undergo a zinc-assisted Lossen rearrangement followed by elimination of water if acetohydroxamic acid is present as a neutral ligand, or by loss of methylisocyanate if acetohydroxamic acid is deprotonated. PMID:19937618

  17. Zinc

    MedlinePlus

    ... ulcers and promoting weight gain in people with eating disorders such as anorexia nervosa. Some people use zinc ... is abnormal): 25-100 mg zinc. For the eating disorder anorexia nervosa: 100 mg of zinc gluconate daily. ...

  18. Dietary zinc deficiency affects blood linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio; a sensitive physiological marker of zinc status in vivo (Gallus gallus).

    PubMed

    Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P; Tako, Elad

    2014-03-20

    Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn⁺ (zinc adequate control, 42.3 μg/g zinc), and Zn⁻ (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn⁺ control versus Zn⁻ group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn⁺ control group (p < 0.05), and hepatic Δ⁶ desaturase was significantly higher in the Zn⁺ group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn⁻ group compared to the Zn⁺ group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation.

  19. Dietary Zinc Deficiency Affects Blood Linoleic Acid: Dihomo-γ-linolenic Acid (LA:DGLA) Ratio; a Sensitive Physiological Marker of Zinc Status in Vivo (Gallus gallus)

    PubMed Central

    Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P.; Tako, Elad

    2014-01-01

    Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn(+) (zinc adequate control, 42.3 μg/g zinc), and Zn(−) (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn(+) control versus Zn(−) group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn(+) control group (p < 0.05), and hepatic Δ6 desaturase was significantly higher in the Zn(+) group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn(−) group compared to the Zn(+) group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation. PMID:24658588

  20. Does zinc moderate essential fatty acid and amphetamine treatment of attention-deficit/hyperactivity disorder?

    PubMed

    Arnold, L E; Pinkham, S M; Votolato, N

    2000-01-01

    Zinc is an important co-factor for metabolism relevant to neurotransmitters, fatty acids, prostaglandins, and melatonin, and indirectly affects dopamine metabolism, believed intimately involved in attention-deficit/hyperactivity disorder (ADHD). To explore the relationship of zinc nutrition to essential fatty acid supplement and stimulant effects in treatment of ADHD, we re-analyzed data from an 18-subject double-blind, placebo-controlled crossover treatment comparison of d-amphetamine and Efamol (evening primrose oil, rich in gamma-linolenic acid). Subjects were categorized as zinc-adequate (n = 5), borderline zinc (n = 5), and zinc-deficient (n = 8) by hair, red cell, and urine zinc levels; for each category, placebo-active difference means were calculated on teachers' ratings. Placebo-controlled d-amphetamine response appeared linear with zinc nutrition, but the relationship of Efamol response to zinc appeared U-shaped; Efamol benefit was evident only with borderline zinc. Placebo-controlled effect size (Cohen's d) for both treatments ranged up to 1.5 for borderline zinc and dropped to 0.3-0.7 with mild zinc deficiency. If upheld by prospective research, this post-hoc exploration suggests that zinc nutrition may be important for treatment of ADHD even by pharmacotherapy, and if Efamol benefits ADHD, it likely does so by improving or compensating for borderline zinc nutrition. PMID:10933121

  1. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN...

  2. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN...

  3. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN...

  4. 40 CFR 721.10135 - Phosphinic acid, P,P-diethyl-, zinc salt (2:1).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phosphinic acid, P,P-diethyl-, zinc... Specific Chemical Substances § 721.10135 Phosphinic acid, P,P-diethyl-, zinc salt (2:1). (a) Chemical... acid, P,P-diethyl-, zinc salt (2:1) (PMN P-05-11; CAS No. 284685-45-6) is subject to reporting...

  5. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN...

  6. 40 CFR 721.10135 - Phosphinic acid, P,P-diethyl-, zinc salt (2:1).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phosphinic acid, P,P-diethyl-, zinc... Specific Chemical Substances § 721.10135 Phosphinic acid, P,P-diethyl-, zinc salt (2:1). (a) Chemical... acid, P,P-diethyl-, zinc salt (2:1) (PMN P-05-11; CAS No. 284685-45-6) is subject to reporting...

  7. 40 CFR 721.10135 - Phosphinic acid, P,P-diethyl-, zinc salt (2:1).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phosphinic acid, P,P-diethyl-, zinc... Specific Chemical Substances § 721.10135 Phosphinic acid, P,P-diethyl-, zinc salt (2:1). (a) Chemical... acid, P,P-diethyl-, zinc salt (2:1) (PMN P-05-11; CAS No. 284685-45-6) is subject to reporting...

  8. 40 CFR 721.10135 - Phosphinic acid, P,P-diethyl-, zinc salt (2:1).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phosphinic acid, P,P-diethyl-, zinc... Specific Chemical Substances § 721.10135 Phosphinic acid, P,P-diethyl-, zinc salt (2:1). (a) Chemical... acid, P,P-diethyl-, zinc salt (2:1) (PMN P-05-11; CAS No. 284685-45-6) is subject to reporting...

  9. 40 CFR 721.10135 - Phosphinic acid, P,P-diethyl-, zinc salt (2:1).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phosphinic acid, P,P-diethyl-, zinc... Specific Chemical Substances § 721.10135 Phosphinic acid, P,P-diethyl-, zinc salt (2:1). (a) Chemical... acid, P,P-diethyl-, zinc salt (2:1) (PMN P-05-11; CAS No. 284685-45-6) is subject to reporting...

  10. 40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN...

  11. Zinc.

    PubMed

    Barceloux, D G

    1999-01-01

    The use of zinc in metal alloys and medicinal lotions dates back before the time of Christ. Currently, most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. Some studies support the use of zinc gluconate lozenges to treat the common cold, but there are insufficient data at this time to recommend the routine use of these lozenges. Zinc is an essential co-factor in a variety of cellular processes including DNA synthesis, behavioral responses, reproduction, bone formation, growth, and wound healing. Zinc is a relatively common metal with an average concentration of 50 mg/kg soil and a range of 10-300 mg/kg soil. Meat, seafood, dairy products, nuts, legumes, and whole grains contain relatively high concentrations of zinc. The mobility of zinc in anaerobic environments is poor and therefore severe zinc contamination occurs primarily near points sources of zinc release. The recommended daily allowance for adults is 15 mg zinc. The ingestion of 1-2 g zinc sulfate produces emesis. Zinc compounds can produce irritation and corrosion of the gastrointestinal tract, along with acute renal tubular necrosis and interstitial nephritis. Inhalation of high concentrations of zinc chloride from smoke bombs detonated in closed spaces may cause chemical pneumonitis and adult respiratory distress syndrome. In the occupational setting inhalation of fumes from zinc oxide is the most common cause of metal fume fever (fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste, salivation). Zinc compounds are not suspected carcinogens. Treatment of zinc toxicity is supportive. Calcium disodium ethylenediaminetetraacetate (CaNa2EDTA) is the chelator of choice based on case reports that demonstrate normalization of zinc concentrations, but there are few clinical data to confirm the efficacy of this agent. PMID:10382562

  12. Discotic liquid crystal derived from zinc tetraaminophthalocyanine and perfluorooctanoic acid

    NASA Astrophysics Data System (ADS)

    Meng, Fanbao; Zhou, Naiyu; Diao, Na; Du, Chang

    2013-12-01

    A novel kind of metallo-phthalocyanine derivative, zinc 2,9,16,23-tetraaminophthalocyanine perfluorooctanoate (Zn-APc-pFOA), was synthesized from zinc tetraaminophthalocyanine and perfluorooctanoic acid. The chemical structure, liquid crystalline behavior, and electrorheological properties were characterized by the use of various experimental techniques, methods, and instruments, including FT-IR and UV-vis spectroscopy, 1H-NMR, x-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, polarized optical microscopy, the four-point method, a relative permittivity test instrument, and a rotating viscometer. Zn-APc-pFOA shows a discotic hexagonal columnar mesophase over a wide temperature range. The dielectric constant and conductivity of Zn-APc-pFOA are 11.4 and 6.34 × 10-3 S cm-1, respectively. The 20 V% silicone oil-Zn-APc-pFOA fluid shows an electrorheological (ER) effect. Zn-APc-pFOA is a semiconductor with a high dielectric constant, causing a mismatch of conductivity and dielectric constant between the Zn-APc-pFOA and silicone oil. Furthermore, some synergistic effect could occur between the semiconducting property and the molecular orientation of the discotic liquid crystals in Zn-APc-pFOA suspensions, resulting in a high ER effect.

  13. Evaluation of zinc electrodeposition kinetics from acidic zinc sulfate solutions using a UPD-modified platinum substrate

    NASA Astrophysics Data System (ADS)

    Guerra, Eduard

    In general, underpotential deposition, UPD, describes the formation of a two-dimensional layer of metal onto a foreign substrate at a potential more positive than that for overpotential deposition, OPD, of the metal. Use of this phenomenon is proposed as a novel technique for generating smooth and reproducible electrode surfaces of reactive metals, using zinc UPD on platinum as a model case. The technique involves polarization of a polished platinum electrode to cause zinc UPD followed by a pulsed polarization step to grow a bulk zinc metal deposit on the electrode. The steady-state zinc deposition rate is recorded as a function of the applied potential. Mass transfer effects are controlled by the use of a rotating disc electrode. After each potential step, the electrode is polarized to a potential near the UPD potential, which dissolves the bulk zinc and regenerates the original smooth electrode. In this manner the voltage-current density relationship for the zinc deposition reaction may be mapped for a particular solution composition. Experiments were conducted to characterize UPD of zinc on platinum in magnesium sulphate and sulphuric acid supporting electrolytes. UPD of zinc on platinum occurs at a voltage approximately 1 V more positive than that of bulk zinc deposition with an estimated charge density of 260 +/- 30 muC cm-2, which is in the order of a monolayer of zinc. The UPD layer was determined to evolve into a Pt-Zn alloy which further inhibited hydrogen evolution, relative to the freshly deposited UPD layer. Bulk zinc deposition experiments were carried out in pure zinc sulphate solutions at 25°C, using the developed technique, and kinetic parameters were evaluated and compared to previously reported values. The Tafel slope for zinc deposition from pH neutral electrolytes was determined to be ca. 60 mV dec-1, while in highly acid electrolytes was ca. 30 mV dec-1, due to the inhibiting effect of hydrogen adsorption. The transition of zinc deposit

  14. Zinc

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

  15. Effect of zinc sulphate on acetic acid-induced gastric ulceration in rats.

    PubMed

    Li, K M

    1990-09-01

    The effects of zinc sulphate on gastric ulcer healing rate and mucosal mucus content of acetic acid-induced ulceration in rats have been assessed. Daily treatment with zinc sulphate progressively accelerated ulcer healing in a dose-dependent manner with a significant increase observed on day 15 after ulcer induction in rats treated with 44 and 88 mg kg-1 zinc sulphate. A significant increase in gastric mucosal adherent mucus was also observed in those animals treated with 88 mg kg-1 zinc sulphate. The results suggest that a minimum treatment period of 15 days is needed for the zinc sulphate to be effective, and that zinc ions may promote gastric ulcer healing by enhancing mucus formation to prevent acid back-diffusion into the gastric mucosa.

  16. Zinc recovery by ultrasound acid leaching of double kiln treated electric arc furnace dust

    SciTech Connect

    Barrera Godinez, J.A.

    1989-01-01

    The need to convert 70,000 tons a year of electric arc furnace (EAF) dust into an environmentally safe or recyclable product has encouraged studies to reclaim zinc from this waste material. Successful characterization of a double-kiln calcine, produced from EAF dust, has shown that the calcine pellets consisted mainly of zinc oxide plates with some iron oxide particles. Preliminary leaching tests using hydrochloric and sulfuric acids indicated that this calcine is suitable for selective ultrasound leaching of zinc. A factorially designed screening test using hydrochloric acid showed that ultrasound significantly lowered iron dissolution and increased zinc dissolution, thus enhancing the selective leaching of zinc. Ultrasound, temperature, air bubbling rate and acidity increased the sulfuric acid selectivity, while fluorosilicic acid was not selective. Reactor characterization through ultrasonic field measurements led to the selection of reactor and ultrasound bath, which were utilized to enhance the selectivity of a laboratory scale sulfuric acid leaching of a double-kiln treated electric arc furnace dust. Results indicated that ultrasonic leaching of this calcine is a satisfactory technique to selectively separate zinc from iron. After further iron removal by precipitation and cementation of nickel, it was possible to electrowin zinc from the leach liquor under common industrial conditions, with current efficiencies from 86% through 92% being observed. Calcine washing showed that a substantial chloride removal is possible, but fluoride ion in the electrolyte caused deposit sticking during electrowinning.

  17. Bioavailability of iron, zinc, folic acid, and vitamin A from fortified maize.

    PubMed

    Moretti, Diego; Biebinger, Ralf; Bruins, Maaike J; Hoeft, Birgit; Kraemer, Klaus

    2014-04-01

    Several strategies appear suitable to improve iron and zinc bioavailability from fortified maize, and fortification per se will increase the intake of bioavailable iron and zinc. Corn masa flour or whole maize should be fortified with sodium iron ethylenediaminetetraacetate (NaFeEDTA), ferrous fumarate, or ferrous sulfate, and degermed corn flour should be fortified with ferrous sulfate or ferrous fumarate. The choice of zinc fortificant appears to have a limited impact on zinc bioavailability. Phytic acid is a major inhibitor of both iron and zinc absorption. Degermination at the mill will reduce phytic acid content, and degermed maize appears to be a suitable vehicle for iron and zinc fortification. Enzymatic phytate degradation may be a suitable home-based technique to enhance the bioavailability of iron and zinc from fortified maize. Bioavailability experiments with low phytic acid-containing maize varieties have suggested an improved zinc bioavailability compared to wild-type counterparts. The bioavailability of folic acid from maize porridge was reported to be slightly higher than from baked wheat bread. The bioavailability of vitamin A provided as encapsulated retinyl esters is generally high and is typically not strongly influenced by the food matrix, but has not been fully investigated in maize.

  18. Zinc

    MedlinePlus

    ... deficiency also causes hair loss, diarrhea, eye and skin sores and loss of appetite. Weight loss, problems ... pneumonia and other infections. Zinc also helps the skin stay healthy. Some people who have skin ulcers ...

  19. A field investigation of the relationship between zinc and acid volatile sulfide concentrations in freshwater sediments

    USGS Publications Warehouse

    Ankley, Gerald T.; Liber, Karsten; Call, Daniel J.; Markee, Thomas P.; Canfield, Timothy J.; Ingersoll, Christopher G.

    1996-01-01

    Understanding relationships between cationic metals such as cadmium, copper, nickel, lead and zinc, and amorphous iron sulfides, measured as acid volatile sulfide (AVS), is key to predicting metal bioavailability and toxicity insediments. The objective of the present study was to assess seasonal and spatial variations of AVS in freshwater sediments contaminated with zinc. Sediments were sampled from three streams with varying levels of zinc contamination at two different times, March and June of 1995, representing cold- and warm-weather situations. Interstitial (pore) water concentrations of zinc, and solid phase concentrations of AVS and zinc were measured in surficial and deep sediment horizons. Toxicity tests (10-d) with the amphipodHyalella azteca were conducted using intact cores. Sediment zinc concentrations from six sites within the primary test stream differed by about five-fold, and also varied seasonally. Acid volatile sulfide concentrations were generally lower than those of zinc, and pore water zinc concentrations typically were elevated. There was a positive correlation between solid-phase AVS and zinc concentrations, suggesting that the system was dominated by zinc, as opposed to iron sulfides. In contrast to expectations arising from some studies of seasonal variations of AVS in iron-dominated systems, AVS concentrations were smaller in June than in March. However, this was likely due to a major storm event and associated sediment scouring before the June sampling, rather than to seasonal processes related to variations in temperature and dissolved oxygen. Based upon an indirect analysis of depth variations in AVS, there was some indication that zinc sulfide might be less prone to oxidation than iron sulfide. There was a strong correlation between toxicity of the sediment samples toH. azteca and interstitial water concentrations of zinc; however, the possible contribution of other contaminants to sediment toxicity cannot be dismissed.

  20. Kinetics of Reductive Acid Leaching of Cadmium-Bearing Zinc Ferrite Mixture Using Hydrazine Sulfate

    NASA Astrophysics Data System (ADS)

    Zhang, Chun; Zhang, Jianqiang; Min, Xiaobo; Wang, Mi; Zhou, Bosheng; Shen, Chen

    2015-09-01

    The reductive acid leaching kinetics of synthetic cadmium-bearing zinc ferrite was investigated, and the influence of reaction temperature, sulfuric acid and hydrazine sulfate were studied. The results illustrated that an increase in the reaction temperature, initial sulfuric acid and hydrazine sulfate significantly enhanced the extraction efficiencies of cadmium, zinc and iron. The leaching kinetics were controlled by a surface chemical reaction based on a shrinking core model. The empirical equation applied was found to fit well with the kinetics analysis; the leaching processes of cadmium, zinc and iron were similar and the activation energies were 79.9 kJ/mol, 77.9 kJ/mol and 79.7 kJ/mol, respectively. The apparent orders of cadmium-bearing zinc ferrite dissolution with respect to sulfuric acid concentration were 0.83, 0.83 and 0.84 for Cd, Zn and Fe, respectively.

  1. Synthesis and characterization of zinc chloride containing poly(acrylic acid) hydrogel by gamma irradiation

    NASA Astrophysics Data System (ADS)

    Park, Jong-Seok; Kuang, Jia; Gwon, Hui-Jeong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Seob Khil, Myung; Nho, Young-Chang

    2013-07-01

    In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV-vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity.

  2. The (unusual) aspartic acid in the metal coordination sphere of the prokaryotic zinc finger domain.

    PubMed

    D'Abrosca, Gianluca; Russo, Luigi; Palmieri, Maddalena; Baglivo, Ilaria; Netti, Fortuna; de Paola, Ivan; Zaccaro, Laura; Farina, Biancamaria; Iacovino, Rosa; Pedone, Paolo Vincenzo; Isernia, Carla; Fattorusso, Roberto; Malgieri, Gaetano

    2016-08-01

    The possibility of choices of protein ligands and coordination geometries leads to diverse Zn(II) binding sites in zinc-proteins, allowing a range of important biological roles. The prokaryotic Cys2His2 zinc finger domain (originally found in the Ros protein from Agrobacterium tumefaciens) tetrahedrally coordinates zinc through two cysteine and two histidine residues and it does not adopt a correct fold in the absence of the metal ion. Ros is the first structurally characterized member of a family of bacterial proteins that presents several amino acid changes in the positions occupied in Ros by the zinc coordinating residues. In particular, the second position is very often occupied by an aspartic acid although the coordination of structural zinc by an aspartate in eukaryotic zinc fingers is very unusual. Here, by appropriately mutating the protein Ros, we characterize the aspartate role within the coordination sphere of this family of proteins demonstrating how the presence of this residue only slightly perturbs the functional structure of the prokaryotic zinc finger domain while it greatly influences its thermodynamic properties. PMID:27238756

  3. Zinc complexes as fluorescent chemosensors for nucleic acids: new perspectives for a "boring" element.

    PubMed

    Terenzi, Alessio; Lauria, Antonino; Almerico, Anna Maria; Barone, Giampaolo

    2015-02-28

    Zinc(II) complexes are effective and selective nucleic acid-binders and strongly fluorescent molecules in the low energy range, from the visible to the near infrared. These two properties have often been exploited to quantitatively detect nucleic acids in biological samples, in both in vitro and in vivo models. In particular, the fluorescent emission of several zinc(II) complexes is drastically enhanced or quenched by the binding to nucleic acids and/or upon visible light exposure, in a different fashion in bulk solution and when bound to DNA. The twofold objective of this perspective is (1) to review recent utilisations of zinc(II) complexes as selective fluorescent probes for nucleic acids and (2) to highlight their novel potential applications as diagnostic tools based on their photophysical properties.

  4. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid

    EPA Science Inventory

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2•6H2O functionalization of zeolite. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The adsorption capacity of the adsorbents at 21...

  5. Effect of folic acid and zinc sulphate on endocrine parameters and seminal antioxidant level after varicocelectomy.

    PubMed

    Nematollahi-Mahani, S N; Azizollahi, G H; Baneshi, M R; Safari, Z; Azizollahi, S

    2014-04-01

    Varicocele is among the most common problems which may lead to male infertility. Spermatogenesis is impaired as a consequence of this vascular defect, through mechanisms that are not well described. This study aimed to evaluate serum hormonal level (inhibin B, FSH and testosterone) and seminal plasma antioxidant defence levels after folic acid and zinc sulphate administration in varicocelectomised patients. Participants were randomly allocated to four experimental groups. Our randomisation schedule was as follows: zinc sulphate/folic acid, folic acid, zinc sulphate and placebo. The patients underwent varicocelectomy, before which a blood and semen sample were obtained and also three and six months after varicocelectomy for evaluation of blood hormonal level (FSH, testosterone, inhibin B) and seminal oxidative stress status (nitric oxide, superoxide dismutase, total antioxidant capacity). Patients in different groups took orally one capsule per day after dinner following varicocelectomy for 6 months. A significant rise in peripheral blood inhibin B and seminal plasma activity was detected in the zinc sulphate/folic acid group after 6 months. The present clinical trial indicates a change in the hormonal status of varicocelectomised patients following long-term administration of zinc sulphate and folic acid.

  6. Effect of supplemental folic acid on valproic acid-induced embryotoxicity and tissue zinc levels in vivo.

    PubMed

    Hansen, D K; Grafton, T F; Dial, S L; Gehring, T A; Siitonen, P H

    1995-11-01

    Valproic acid (VPA) is an anti-convulsant drug known to cause spina bifida in humans. Administration of the vitamin, folic acid, has been shown to decrease the recurrence and possibly also the occurrence of neural tube defects, primarily spina bifida, in humans. Additionally, treatment with a derivative (folinic acid) of folic acid has been reported to decrease the frequency of VPA-induced exencephaly in mice treated with the drug in vivo. A protective effect by folinic acid has not been observed in vitro. The purpose of this investigation was to reexamine the ability of folinic acid to decrease the incidence of VPA-induced neural tube defects in vivo. We also examined the effect of increased intake of folic acid on zinc levels in various maternal and embryonic tissues. Folinic acid, whether administered by intraperitoneal injection or in osmotic mini-pumps, did not decrease the number of mouse fetuses with VPA-induced exencephaly. Dietary supplementation with 10-20 times the daily required intake of folic acid in rodents also failed to decrease the embryotoxicity of VPA. Such dietary supplementation had no effect on zinc levels in maternal liver, brain, or kidney, nor in embryonic tissues. These results indicate that folic acid is not able to reverse the embryotoxicity induced by the anticonvulsant, that there is no apparent effect of high dietary folate intake on maternal or embryonic zinc levels and suggest that folate is probably not involved in the mechanism of VPA-induced embryotoxicity. PMID:8838251

  7. Specific zinc-finger architecture required for HIV-1 nucleocapsid protein's nucleic acid chaperone function

    PubMed Central

    Williams, Mark C.; Gorelick, Robert J.; Musier-Forsyth, Karin

    2002-01-01

    The nucleocapsid protein (NC) of HIV type 1 (HIV-1) is a nucleic acid chaperone that facilitates the rearrangement of nucleic acid secondary structure during reverse transcription. HIV-1 NC contains two CCHC-type zinc binding domains. Here, we use optical tweezers to stretch single λ-DNA molecules through the helix-to-coil transition in the presence of wild-type and several mutant forms of HIV-1 NC with altered zinc-finger domains. Although all forms of NC lowered the cooperativity of the DNA helix–coil transition, subtle changes in the zinc-finger structures reduced NC's effect on the transition. The change in cooperativity of the DNA helix–coil transition correlates strongly with in vitro nucleic acid chaperone activity measurements and in vivo HIV-1 replication studies using the same NC mutants. Moreover, Moloney murine leukemia virus NC, which contains a single zinc finger, had little effect on transition cooperativity. These results suggest that a specific two-zinc-finger architecture is required to destabilize nucleic acids for optimal chaperone activity during reverse transcription in complex retroviruses such as HIV-1. PMID:12084921

  8. Studies on zinc nodules electrodeposited from acid electrolytes

    SciTech Connect

    Anderson, R.; Tobias, C.W.

    1984-12-01

    The development of morphology of electrodeposited zinc was investigated by studying the initial stages of deposition. Zinc was deposited galvanostatically from 1.0 M ZnCl/sub 2/ electrolyte (0.7 < pH < 4.6) on rotating disc electrodes at current densities from 5 to 130 ma/cm/sup 2/. Pine glassy carbon, Union Carbide pyrolytic graphite, Gould pyrolytic graphite, Exxon graphite loaded polymer, and platinum substrates were used. The number densities of nodules (diameter greater than 1 ..mu..m), typically encountered during incipient morphological development, were measured using scanning electron microscopy and image analysis. Nodule densities up to 7 x 10/sup 4/ nodules/mm/sup 2/ were measured.

  9. Zinc-Mediated Binding of Nucleic Acids to Amyloid-β Aggregates: Role of Histidine Residues.

    PubMed

    Khmeleva, Svetlana A; Radko, Sergey P; Kozin, Sergey A; Kiseleva, Yana Y; Mezentsev, Yuri V; Mitkevich, Vladimir A; Kurbatov, Leonid K; Ivanov, Alexis S; Makarov, Alexander A

    2016-09-01

    Amyloid-β peptide (Aβ) plays a central role in Alzheimer's disease (AD) pathogenesis. Besides extracellular Aβ, intraneuronal Aβ (iAβ) has been suggested to contribute to AD onset and development. Based on reported in vitro Aβ-DNA interactions and nuclear localization of iAβ, the interference of iAβ with the normal DNA expression has recently been proposed as a plausible pathway by which Aβ can exert neurotoxicity. Employing the sedimentation assay, thioflavin T fluorescence, and dynamic light scattering we have studied effects of zinc ions on binding of RNA and single- and double-stranded DNA molecules to Aβ42 aggregates. It has been found that zinc ions significantly enhance the binding of RNA and DNA molecules to pre-formed β-sheet rich Aβ42 aggregates. Another type of Aβ42 aggregates, the zinc-induced amorphous aggregates, was demonstrated to also bind all types of nucleic acids tested. To evaluate the role of the Aβ metal-binding domain's histidine residues in Aβ-nucleic acid interactions mediated by zinc, Aβ16 mutants with substitutions H6R and H6A-H13A and rat Aβ16 lacking histidine residue 13 were used. The zinc-induced interaction of Aβ16 with DNA was shown to critically depend on histidine residues 6 and 13. However, the inclusion of H6R mutation in Aβ42 peptide did not affect DNA binding to Aβ42 aggregates. Since oxidative and/or nitrosative stresses implicated in AD pathogenesis are known to release zinc ions from metallothioneins in cytoplasm and cell nuclei, our findings suggest that intracellular zinc can be an important player in iAβ-nucleic acid interactions. PMID:27567853

  10. Zinc distribution and acid-base mobilisation in vineyard soils and sediments.

    PubMed

    Fernández-Calviño, David; Pateiro-Moure, Mirian; Nóvoa-Muñoz, Juan Carlos; Garrido-Rodríguez, Beatriz; Arias-Estévez, Manuel

    2012-01-01

    Nineteen vineyard stands located in steep-slope areas of three wine-growing regions in northwest Spain were selected for this study. In each stand, a representative soil sample (19) and one or two sediment samples (24) were collected. In these samples, the Zn distribution in the solid phase was assessed. Moreover, the effect of pH on the release of zinc was determined using a batch-type experiment. The mean zinc concentration (109 mg kg(-1)) of the samples was lower than the maximum concentrations allowed by the European Union. Moreover, most of the zinc that appeared in vineyard soils was residual zinc, suggesting a tendency for zinc in these soils to be irreversibly bound to soil components, reducing its potential environmental impact. In sediments, the mean total Zn concentration (126 mg kg(-1)) was higher than those in the original soils and in the mobile fractions, which could mean a higher risk of liberation. Zinc release was higher under acidic conditions, in which release depends mainly on labile fractions. Under basic conditions, the release of Zn was lower and depended on Zn bound to crystalline oxyhydroxides.

  11. Combined iron and folic acid supplementation with or without zinc reduces time to walking unassisted among Zanzibari infants 5-11 months old

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Iron and zinc deficiencies have been associated with delayed motor development in nutritionally at-risk children, albeit inconsistently. In this community-based, randomized double-blind trial, iron+folic acid (FeFA) (12.5 mg Fe + 50 'g folic acid), zinc (Zn) (10 mg), and iron+folic acid+zinc (FeFA+Z...

  12. Superiority of zinc complex of acetylsalicylic acid to acetylsalicylic acid in preventing postischemic myocardial dysfunction.

    PubMed

    Korkmaz, Sevil; Atmanli, Ayhan; Li, Shiliang; Radovits, Tamás; Hegedűs, Peter; Barnucz, Enikő; Hirschberg, Kristóf; Loganathan, Sivakkanan; Yoshikawa, Yutaka; Yasui, Hiroyuki; Karck, Matthias; Szabó, Gábor

    2015-09-01

    The pathophysiology of ischemic myocardial injury involves cellular events, reactive oxygen species, and an inflammatory reaction cascade. The zinc complex of acetylsalicylic acid (Zn(ASA)2) has been found to possess higher anti-inflammatory and lower ulcerogenic activities than acetylsalicylic acid (ASA). Herein, we studied the effects of both ASA and Zn(ASA)2 against acute myocardial ischemia. Rats were pretreated with ASA (75 mg/kg) or Zn(ASA)2 (100 mg/kg) orally for five consecutive days. Isoproterenol (85 mg/kg, subcutaneously [s.c.]) was applied to produce myocardial infarction. After 17-22 h, animals were anesthetized with sodium pentobarbital (60 mg/kg, intraperitoneally [i.p.]) and both electrical and mechanical parameters of cardiac function were evaluated in vivo. Myocardial histological and gene expression analyses were performed. In isoproterenol-treated rats, Zn(ASA)2 treatment normalized significantly impaired left-ventricular contractility index (Emax 2.6 ± 0.7 mmHg/µL vs. 4.6 ± 0.5 mmHg/µL, P < 0.05), increased stroke volume (30 ± 3 µL vs. 50 ± 6 µL, P < 0.05), decreased systemic vascular resistance (7.2 ± 0.7 mmHg/min/mL vs. 4.2 ± 0.5 mmHg/min/mL, P < 0.05) and reduced inflammatory infiltrate into the myocardial tissues. ECG revealed a restoration of elevated ST-segment (0.21 ± 0.03 mV vs. 0.09 ± 0.02 mV, P < 0.05) and prolonged QT-interval (79.2 ± 3.2 ms vs. 69.5 ± 2.5 ms, P < 0.05) by Zn(ASA)2. ASA treatment did not result in an improvement of these parameters. Additionally, Zn(ASA)2 significantly increased the mRNA-expression of superoxide dismutase 1 (+73 ± 15%), glutathione peroxidase 4 (+44 ± 12%), and transforming growth factor (TGF)-β1 (+102 ± 22%). In conclusion, our data demonstrate that oral administration of zinc and ASA in the form of bis(aspirinato)zinc(II) complex is superior to ASA in preventing electrical

  13. Superiority of zinc complex of acetylsalicylic acid to acetylsalicylic acid in preventing postischemic myocardial dysfunction

    PubMed Central

    Korkmaz, Sevil; Atmanli, Ayhan; Li, Shiliang; Radovits, Tamás; Hegedűs, Peter; Hirschberg, Kristóf; Loganathan, Sivakkanan; Yoshikawa, Yutaka; Yasui, Hiroyuki; Karck, Matthias; Szabó, Gábor

    2015-01-01

    The pathophysiology of ischemic myocardial injury involves cellular events, reactive oxygen species, and an inflammatory reaction cascade. The zinc complex of acetylsalicylic acid (Zn(ASA)2) has been found to possess higher anti-inflammatory and lower ulcerogenic activities than acetylsalicylic acid (ASA). Herein, we studied the effects of both ASA and Zn(ASA)2 against acute myocardial ischemia. Rats were pretreated with ASA (75 mg/kg) or Zn(ASA)2 (100 mg/kg) orally for five consecutive days. Isoproterenol (85 mg/kg, subcutaneously [s.c.]) was applied to produce myocardial infarction. After 17–22 h, animals were anesthetized with sodium pentobarbital (60 mg/kg, intraperitoneally [i.p.]) and both electrical and mechanical parameters of cardiac function were evaluated in vivo. Myocardial histological and gene expression analyses were performed. In isoproterenol-treated rats, Zn(ASA)2 treatment normalized significantly impaired left-ventricular contractility index (Emax 2.6 ± 0.7 mmHg/µL vs. 4.6 ± 0.5 mmHg/µL, P < 0.05), increased stroke volume (30 ± 3 µL vs. 50 ± 6 µL, P < 0.05), decreased systemic vascular resistance (7.2 ± 0.7 mmHg/min/mL vs. 4.2 ± 0.5 mmHg/min/mL, P < 0.05) and reduced inflammatory infiltrate into the myocardial tissues. ECG revealed a restoration of elevated ST-segment (0.21 ± 0.03 mV vs. 0.09 ± 0.02 mV, P < 0.05) and prolonged QT-interval (79.2 ± 3.2 ms vs. 69.5 ± 2.5 ms, P < 0.05) by Zn(ASA)2. ASA treatment did not result in an improvement of these parameters. Additionally, Zn(ASA)2 significantly increased the mRNA-expression of superoxide dismutase 1 (+73 ± 15%), glutathione peroxidase 4 (+44 ± 12%), and transforming growth factor (TGF)-β1 (+102 ± 22%). In conclusion, our data demonstrate that oral administration of zinc and ASA in the form of bis(aspirinato)zinc(II) complex is superior to ASA in preventing electrical

  14. Effects of zinc, copper, and lead toxicity on. cap alpha. -aminolevulinic acid dehydratase activity. [Rats

    SciTech Connect

    Shafiq-ur-Rehman

    1984-07-01

    The distribution of lead, zinc and copper in the human environment has been recognized as a major toxicological factor. Lead ions have been shown to inhibit the activity of delta-aminolevulinic acid dehydratase (delta-ALAD), which is involved in the biosynthesis of heme. Copper also has its inhibitory effect on delta-ALAD activity. A study has shown that the delta-ALAD was activated by zinc ions at physiological concentrations. In view of these reports, it was considered worthwhile to study the poisoning effects of lead, zinc and copper on delta-ALAD activity along with the concentrations of these metal ions in the blood. A possible role of Zn/sup + +/, Cu/sup + +/, and Pb/sup + +/ interaction and their influence on delta-ALAD has been explored in the present paper.

  15. Effects of surfactants on low-molecular-weight organic acids to wash soil zinc.

    PubMed

    Chen, Yue; Zhang, Shirong; Xu, Xiaoxun; Yao, Ping; Li, Ting; Wang, Guiyin; Gong, Guoshu; Li, Yun; Deng, Ouping

    2016-03-01

    Soil washing is an effective approach to the removal of heavy metals from contaminated soil. In this study, the effects of the surfactants sodium dodecyl sulfate, Triton X-100, and non-ionic polyacrylamide (NPAM) on oxalic acid, tartaric acid, and citric acid used to remove zinc from contaminated soils were investigated. The Zn removal efficiencies of all washing solutions showed a logarithmic increase with acid concentrations from 0.5 to 10.0 g/L, while they decreased as pH increased from 4 to 9. Increasing the reaction time enhanced the effects of surfactants on Zn removal efficiencies by the acids during washing and significantly (P < 0.05) improved the removal under some mixed cases. Oxalic acid suffered antagonistic effects from the three surfactants and seriously damaged soil nutrients during the removal of soil Zn. Notably, the three surfactants caused synergistic effects on tartaric and citric acid during washing, with NPAM leading to an increase in Zn removal by 5.0 g/L citric acid of 10.60 % (P < 0.05) within 2 h. NPAM also alleviated the loss of cation exchange capacity of washed soils and obviously improved soil nitrogen concentrations. Overall, combining citric acid with NPAM offers a promising approach to the removal of zinc from contaminated soil.

  16. Cements containing syringic acid esters -- o-ethoxybenzoic acid and zinc oxide.

    PubMed

    Brauer, G M; Stansbury, J W

    1984-02-01

    Fissure caries is reduced when syringic acid is incorporated into a cariogenic diet of rats. It was therefore of interest to synthesize n-hexyl and 2-ethylhexyl syringate and to evaluate the properties of cements with these compounds as ingredients. Liquids containing the esters dissolved in o-ethoxybenzoic acid (EBA) - when mixed with powders made up from zinc oxide, aluminum oxide, and hydrogenated rosin - hardened in from four to nine min. Properties of the cements were determined, when possible, according to ANSI/ADA specification tests. Depending on the powder-liquid ratio employed, we obtained compositions with varying physical properties desirable for different dental applications. The syringate cements, compared with the commonly used ZOE materials, have improved compressive and tensile strength, lower water solubility, do not inhibit polymerization, and are compatible with acrylic monomers. These cements pass, and mostly greatly exceed, the requirements for ZOE-type restorative materials. They also bond significantly to resins, composites, and non-precious metals. The bond strength is somewhat less than that of n-hexyl vanillate-EBA cement, but greatly exceeds the adhesion to various substrates of ZOE luting agents. Cements containing n-hexyl syringate were somewhat brittle. Best results were obtained with liquid compositions containing 5% 2-ethylhexyl syringate, 7% n-hexyl vanillate, and 88% EBA, which yielded non-brittle materials. These cements, because of the syringate ingredient, may possess caries-reducing properties. Thus, perhaps in conjunction with fluoride additives, they would be useful as insulating bases, pulp capping agents, root canal sealers, soft tissue packs, or intermediate restoratives.

  17. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-,...

  18. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-,...

  19. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-,...

  20. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-,...

  1. 40 CFR 721.5252 - 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-, zinc salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-methylenebis [3-hydroxy-, zinc salt. 721.5252 Section 721.5252 Protection of Environment ENVIRONMENTAL...′-methylenebis [3-hydroxy-, zinc salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 2-Naphthalenecarboxylic acid, 4,4′-methylenebis [3-hydroxy-,...

  2. Clinical Evaluation of Hyaluronic Acid Sponge with Zinc versus Placebo for Scar Reduction after Breast Surgery

    PubMed Central

    Mahedia, Monali; Shah, Nilay

    2016-01-01

    Background: Scar formation is a major source of dissatisfaction among patients and surgeons. Individually, hyaluronan, or hyaluronic acid (HA), and zinc have been shown to reduce scarring. The authors evaluated the safety and efficacy of an HA sponge with zinc compared with placebo when applied to bilateral breast surgery scars; specifically, they evaluated whether the use of this product modulates inflammation and immediate scarring in treated patients after bilateral breast surgery. Methods: This double-blind, randomized, prospective study was approved by the local institutional review board. Bilateral breast surgery patients with right and left incision lines were randomly assigned to receive HA sponge with zinc or placebo within 2 to 4 days after their procedure. Participants were followed up at 6 weeks, 12 weeks, and 1 year and evaluated at 12 weeks. Three blinded evaluators reviewed photographs of the incision lines and assessed the scars using a visual analog scale, new scale, and a patient satisfaction survey. Results: Nineteen bilateral breast surgery patients were enrolled in the study. Statistical analysis was performed on 14 patients who completed the follow-up. The mean visual analog scale score was lower for the side receiving the HA sponge with zinc (2.6) than for the side receiving placebo (3.0), indicating a better outcome (t test; P = 0.08). The HA sponge with zinc was found to have significant positive findings on a patient satisfaction survey (P = 0.01). Conclusions: This is a preliminary study that shows zinc hyaluronan was associated with high patient satisfaction in achieving a better scar after bilateral breast surgery, irrespective of skin color. It seems to be safe and effective for early scars. PMID:27536470

  3. Identification of glutamic acid 646 as a zinc-coordinating residue in endopeptidase-24.11.

    PubMed

    Le Moual, H; Devault, A; Roques, B P; Crine, P; Boileau, G

    1991-08-25

    Neutral endopeptidase (EC 3.424.11, NEP) is a membrane-bound zinc-metallopeptidase. The substrate specificity and catalytic activity of NEP resemble those of thermolysin, a bacterial zinc-metalloprotease. Comparison of the primary structure of both enzymes suggests that several amino acids present in the active site of thermolysin are also found in NEP. Using site-directed mutagenesis of the cDNA encoding the NEP sequence, we have already shown that His residues 583 and 587 are two of the three zinc ligands. In order to identify the third zinc ligand, we have substituted Val or Asp for Glu616 or Glu646. Val616 NEP showed the same kinetic parameters as the non-mutated NEP. In contrast, the mutant Val646 NEP was almost completely devoid of catalytic activity and unable to bind the tritiated inhibitor [3H]N-[2(R,S)-3-hydroxyaminocarbonyl-2-benzyl-1-oxypropyl]gl ycine, the binding of which is dependent on the presence of the zinc ion. Replacing Glu for Asp at position 646 conserved the negative charge, and the mutant enzyme exhibited the same Km value as the non-mutated enzyme, but kCat was decreased to less than 3% of the value of the non-mutated enzyme. When compared to the non-mutated enzyme Asp646 NEP showed a higher susceptibility to chelating agents, but bound the tritiated inhibitor with the same affinity. Taken together, these observations strongly suggest that Glu646 of NEP is the third zinc-coordinating residue and is equivalent to Glu166 in thermolysin.

  4. Functional assessment of zinc nutriture using changes in plasma zinc after exercise in men supplemented with folic acid

    SciTech Connect

    Lukaski, H.C.; Bolonchuk, W.W.; Milne, D.B.

    1986-03-05

    Recently, the authors proposed that changes in plasma zinc (Zn) and copper (Cu) content after maximal exercise could be a functional test of human trace element nutriture. To test this hypothesis, they studied the effect of folic acid (FA) supplements, previously shown to affect zinc absorption on the exercise-induced changes in plasma Zn and Cu in 7 men aged 28.6 +/- 1.2 yr (mean +/- SEM). The men were fed a constant diet with intakes of Cu (1.01 +/- 0.06 mg/d), Zn (12.7 +/- 0.3 mg/d) and FA (200 mg/d) for two 4 wk periods. This basal diet was supplemented with 400 or 800 mg/d FA and it was fed for 4 wk periods alternating with the unsupplemented diet. Pre and post-exercise hematocrit (Hct), hemoglobin (Hb), and plasma Zn and Cu were not affected by FA supplements. To correct for hemoconcentration during exercise, the van Beaumont quotient was calculated from pre and post-exercise Hct, Hb, and plasma Zn and Cu. When the basal diet was fed, the quotient for Zn was 3.4 +/- 1.4 and 2.3 +/- 1.4%, and it declined (p < 0.05) to -5.93 +/- 1.9% and -7.4 +/- 1.8% with 400 and 800 mg/d supplementation, resp. FA supplementation had no effect on the quotient for plasma Cu. These data suggest that Zn mobilization from stores during exercise is impaired with high intakes of FA.

  5. Acidic leaching both of zinc and iron from basic oxygen furnace sludge.

    PubMed

    Trung, Zuzana Hoang; Kukurugya, Frantisek; Takacova, Zita; Orac, Dusan; Laubertova, Martina; Miskufova, Andrea; Havlik, Tomas

    2011-09-15

    During the steel production in the basic oxygen furnace (BOF), approximately 7-15 kg of dust per tonne of produced steel is generated. This dust contains approximately 1.4-3.2% Zn and 54-70% Fe. Regarding the zinc content, the BOF dust is considered to be highly problematic, and therefore new technological processes for recycling dusts and sludge from metallurgical production are still searched for. In this study the hydrometallurgical processing of BOF sludge in the sulphuric acid solutions under atmospheric pressure and temperatures up to 100 °C is investigated on laboratory scale. The influence of sulphuric acid concentration, temperature, time and liquid to solid ratio (L:S) on the leaching process was studied. The main aim of this study was to determine optimal conditions when the maximum amount of zinc passes into the solution whilst iron remains in a solid residue.

  6. Rapid, efficient charging of lead-acid and nickel-zinc traction cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1978-01-01

    Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate tapered direct current (HRTDC) charge method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, in these preliminary tests, 300 amp-hour nickel-zinc traction cells were given a HRTDC (initial current 500 amps, final current 100 amps) to 78 percent of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92 percent and an energy efficiency of 52 percent. Three hundred amp-hour lead-acid traction cells were charged to 69 percent of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91 percent with an energy efficiency of 64 percent. In order to find ways to further decrease the recharge times, the effect of periodically (0 to 400 Hz) pulse discharging cells during a constant current charging process (94% duty cycle) was investigated. Preliminary data indicate no significant effect of this type of pulse discharging during charge on charge acceptance of lead-acid or nickel-zinc cells.

  7. Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin

    NASA Astrophysics Data System (ADS)

    Kliber, Marta; Broda, Małgorzata A.; Nackiewicz, Joanna

    2016-02-01

    Effect of selected amino acids (glycine, L-histidine, L-cysteine, L-serine, L-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366 nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC: amino acids complexes in the gas phase and in water environment as well as the BSSE corrected interaction energies indicates that the more likely is the formation of equatorial complexes in which H-bonds are formed between the COOH groups of the phthalocyanine and carboxyl or amino groups of amino acids. UV-Vis spectra calculated by employing time dependent density functional theory (TD-DFT) are also consistent with this conclusion.

  8. Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin.

    PubMed

    Kliber, Marta; Broda, Małgorzata A; Nackiewicz, Joanna

    2016-02-15

    Effect of selected amino acids (glycine, l-histidine, l-cysteine, l-serine, l-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC: amino acids complexes in the gas phase and in water environment as well as the BSSE corrected interaction energies indicates that the more likely is the formation of equatorial complexes in which H-bonds are formed between the COOH groups of the phthalocyanine and carboxyl or amino groups of amino acids. UV-Vis spectra calculated by employing time dependent density functional theory (TD-DFT) are also consistent with this conclusion.

  9. Elution of zinc in dust discharged from electric arc furnace in carbonic acid solution

    NASA Astrophysics Data System (ADS)

    Yokoyama, S.; Sasaki, T.; Sasano, J.; Izaki, M.

    2012-03-01

    The dust discharged from an electric arc furnace (EAF) is a valuable resource of zinc. As a fundamental study of extraction of zinc, iron and chlorine in the EAF dust, the elution behavior of them in carbonic acid solution was studied. The influence of the weight of the EAF dust on the elution behavior was examined in this study. Experiment was carried out putting the EAF dust from 1 g to 200 g in weight into 1 L of water that was introduced by CO2. Generally, the pH in the aqueous solution increased with an increase in weight of the additive EAF dust. Maximums of the eluted concentrations of zinc and chloride ion increased with an increase in the weight of the additive EAF dust whereas the extraction ratios of both of them decreased with an increase in the weight of the additive EAF dust. Iron in the EAF dust remained in the dust without elution. The limit of extraction of zinc from the EAF dust to water was given by the solubilities of ZnFe2O4 and ZnO expressed by eq. (6) and eq. (9) respectively.

  10. Discovery of arjunolic acid as a novel non-zinc binding carbonic anhydrase II inhibitor.

    PubMed

    Kalyanavenkataraman, Subhalakshmi; Nanjan, Pandurangan; Banerji, Asoke; Nair, Bipin G; Kumar, Geetha B

    2016-06-01

    Elevated levels of carbonic anhydrase II (CA II) have been shown to be associated with cardiac hypertrophy and heart failure. Although arjunolic acid (AA) has a diverse range of therapeutic applications including cardio-protection, there have been no reports on the effect of AA on CA II. The present study describes for the first time, the novel zinc independent inhibition of CA II by AA. The molecular docking studies of AA indicated that the hydroxyl group at C2 of the A-ring, which hydrogen bonds with the catalytic site residues (His64, Asn62 and Asn67), along with the gem-dimethyl group at C20 of the E-ring, greatly influences the inhibitory activity, independent of the catalytic zinc, unlike the inhibition observed with most CA II inhibitors. Among the triterpenoids tested viz. arjunolic acid, arjunic acid, asiatic acid, oleanolic acid and ursolic acid, AA was the most potent in inhibiting CA II in vitro with an IC50 of 9μM. It was interesting to note, that in spite of exhibiting very little differences in their structures, these triterpenoids exhibited vast differences in their inhibitory activities, with IC50 values ranging from 9μM to as high as 333μM. Furthermore, AA also inhibited the cytosolic activity of CA in H9c2 cardiomyocytes, as reflected by the decrease in acidification of the intracellular pH (pHi). The decreased acidification reduced the intracellular calcium levels, which further prevented the mitochondrial membrane depolarization. Thus, these studies provide a better understanding for establishing the novel molecular mechanism involved in CA II inhibition by the non-zinc binding inhibitor AA. PMID:27038848

  11. Model studies of zinc bonding with humic acid in the presence of UV-VIS-NIR radiation.

    PubMed

    Koczorowska, Elzbieta; Slawinski, Janusz

    2003-06-01

    Model experiments were performed to determine the influence of UV-VIS-NIR radiation on zinc bonded with humic acid (HA). The samples of HA or HA-65Zn radioisotope were overlayed on quartz sand in a glass column and subjected to elution that simulated natural conditions. The zinc concentration was chosen to that occurring in the sewage of the Central Sewage Work in Poznań. Zinc was washed with water to simulate the influence of rain. The recovery of injected radiotraces ions in the eluates was found to depend on pH, zinc and HA concentrations and on radiation exposure. The results help to evaluate the migration behavior of zinc in the presence of HA and UV-VIS-NIR radiation. From the first part of the investigation appears that radiation induces a degradation of HA-Zn layer and that the degradation process depends on pH of the environment. A decrease in pH causes an increase in photodegradation and the degree of zinc binding in the humic layer. Simultaneously, the ultra-weak luminescence (UWL) of plants was monitored to estimate the influence of zinc and HA on their development. The results show effects of HA and zinc on UWL and growth of bean and watercress which characterize the rate of plants metabolism and perturbation of their homeostasis. It was observed that high concentrations of zinc ions and HA considerably affect the development process of the plants.

  12. Effects of acid-volatile sulfide on zinc bioavailability and toxicity to benthic macroinvertebrates: A spiked sediment field experiment

    SciTech Connect

    Liber, K.; Call, D.J.; Markee, T.P.; Schmude, K.L.; Balcer, M.D.; Whiteman, F.W.; Ankley, G.T.

    1996-12-01

    Acid-volatile sulfide (AVS) has been proposed as the primary normalization phase for the development of sediment quality criteria for certain cationic metals. This study was designed to assist in this development by providing necessary field data on the relationships among season, AVS concentrations, and zinc bioavailability and toxicity in freshwater sediments. Zinc was spiked into uncontaminated sediments collected from a local pond, creating five simultaneously extracted metal (SEM) concentrations ranging from 0.8 to 12.0 {micro}mol/g dry weight. The spiked sediments were transferred to 4-L plastic trays, returned to the bottom of the pond, and sampled on five dates during 1993--1994. Results revealed a pronounced increase in AVS concentration with increasing zinc concentration. Acid-volatile sulfide concentrations in zinc-spiked sediments displayed only minor seasonal variation but were lowest in surficial (0--2 cm) sediments. Acid-volatile sulfide concentrations always exceeded SEM concentrations at {le}6.0 {micro}mol SEM/g; only at 12.0 {micro}mol SEM/g did SEM/AVS ratios exceed 1.0. Zinc was rarely detected in pore water at any treatment and never at concentrations which should have posed a hazard to benthic macroinvertebrates. No substantial effect on colonization of zinc-spiked sediments by benthic macroinvertebrates was observed. Only oligochaetes (Naididae) were significantly reduced in abundance at the high zinc treatment, although reductions were occasionally evident for other taxa. Lack of noteworthy pore-water zinc concentrations and lack of associated, ecologically meaningful effects were attributed to the increase in AVS levels observed with increasing SEM zinc sediment concentration. The increases in AVS theoretically resulted from a replacement of natural iron and manganese sulfides with the more stable zinc sulfide complex.

  13. Ultrasound effects on zinc recovery from EAF dust by sulfuric acid leaching

    NASA Astrophysics Data System (ADS)

    Brunelli, K.; Dabalà, M.

    2015-04-01

    In this work, an ultrasound-assisted leaching process was studied for the recovery of zinc from electric arc furnace (EAF) dust, in which zinc was mainly present in the form of franklinite (60%). Hydrometallurgy is emerging as a preferred process for the recovery of a variety of metals, and the use of ultrasound could offer advantages over the conventional leaching process, especially for the dissolution of franklinite. Franklinite is a refractory phase that is difficult to leach and represents the main obstacle in conventional hydrometallurgy processing. Atmospheric leaching with different sulfuric acid concentrations (0.2-2.0 M) at two temperatures (323 and 353 K) was performed. The tests were conducted using both conventional and ultrasound-assisted leaching. After the leaching tests, the solid residues were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, whereas the leach liquor was analyzed by inductively coupled plasma spectroscopy (ICP). The use of ultrasound facilitated the dissolution of franklinite at low acid concentrations and resulted in a greater zinc recovery under all of the investigated operating conditions.

  14. Bioavailability of iron, vitamin A, zinc, and folic acid when added to condiments and seasonings.

    PubMed

    Degerud, Eirik M; Manger, Mari Skar; Strand, Tor A; Dierkes, Jutta

    2015-11-01

    Seasonings and condiments can be candidate vehicles for micronutrient fortification if consumed consistently and if dietary practices ensure bioavailability of the nutrient. In this review, we identify factors that may affect the bioavailability of iron, vitamin A, zinc, and folic acid when added to seasonings and condiments and evaluate their effects on micronutrient status. We take into consideration the chemical and physical properties of different forms of the micronutrients, the influence of the physical and chemical properties of foods and meals to which fortified seasonings and condiments are typically added, and interactions between micronutrients and the physiological and nutritional status of the target population. Bioavailable fortificants of iron have been developed for use in dry or fluid vehicles. For example, sodium iron ethylenediaminetetraacetic acid (NaFeEDTA) and ferrous sulfate with citric acid are options for iron fortification of fish and soy sauce. Furthermore, NaFeEDTA, microencapsulated ferrous fumarate, and micronized elemental iron are potential fortificants in curry powder and salt. Dry forms of retinyl acetate or palmitate are bioavailable fortificants of vitamin A in dry candidate vehicles, but there are no published studies of these fortificants in fluid vehicles. Studies of zinc and folic acid bioavailability in seasonings and condiments are also lacking.

  15. Bioavailability of iron, vitamin A, zinc, and folic acid when added to condiments and seasonings.

    PubMed

    Degerud, Eirik M; Manger, Mari Skar; Strand, Tor A; Dierkes, Jutta

    2015-11-01

    Seasonings and condiments can be candidate vehicles for micronutrient fortification if consumed consistently and if dietary practices ensure bioavailability of the nutrient. In this review, we identify factors that may affect the bioavailability of iron, vitamin A, zinc, and folic acid when added to seasonings and condiments and evaluate their effects on micronutrient status. We take into consideration the chemical and physical properties of different forms of the micronutrients, the influence of the physical and chemical properties of foods and meals to which fortified seasonings and condiments are typically added, and interactions between micronutrients and the physiological and nutritional status of the target population. Bioavailable fortificants of iron have been developed for use in dry or fluid vehicles. For example, sodium iron ethylenediaminetetraacetic acid (NaFeEDTA) and ferrous sulfate with citric acid are options for iron fortification of fish and soy sauce. Furthermore, NaFeEDTA, microencapsulated ferrous fumarate, and micronized elemental iron are potential fortificants in curry powder and salt. Dry forms of retinyl acetate or palmitate are bioavailable fortificants of vitamin A in dry candidate vehicles, but there are no published studies of these fortificants in fluid vehicles. Studies of zinc and folic acid bioavailability in seasonings and condiments are also lacking. PMID:26469774

  16. Bioavailability of iron, vitamin A, zinc, and folic acid when added to condiments and seasonings

    PubMed Central

    Degerud, Eirik M.; Manger, Mari Skar; Strand, Tor A.

    2015-01-01

    Seasonings and condiments can be candidate vehicles for micronutrient fortification if consumed consistently and if dietary practices ensure bioavailability of the nutrient. In this review, we identify factors that may affect the bioavailability of iron, vitamin A, zinc, and folic acid when added to seasonings and condiments and evaluate their effects on micronutrient status. We take into consideration the chemical and physical properties of different forms of the micronutrients, the influence of the physical and chemical properties of foods and meals to which fortified seasonings and condiments are typically added, and interactions between micronutrients and the physiological and nutritional status of the target population. Bioavailable fortificants of iron have been developed for use in dry or fluid vehicles. For example, sodium iron ethylenediaminetetraacetic acid (NaFeEDTA) and ferrous sulfate with citric acid are options for iron fortification of fish and soy sauce. Furthermore, NaFeEDTA, microencapsulated ferrous fumarate, and micronized elemental iron are potential fortificants in curry powder and salt. Dry forms of retinyl acetate or palmitate are bioavailable fortificants of vitamin A in dry candidate vehicles, but there are no published studies of these fortificants in fluid vehicles. Studies of zinc and folic acid bioavailability in seasonings and condiments are also lacking. PMID:26469774

  17. Molar ratio iron: zinc and folic acid in Brazilian biscuits and snacks and test for classification using principal component analyses.

    PubMed

    Godoy, Adriana Teixeira; Rebelatto, Ana Paula; Borin-Nogueira, Alessandra; Lima-Pallone, Juliana Azevedo

    2014-06-01

    The aim of the present work was to evaluate molar ratio iron: zinc and the levels of folic acid in biscuit and snacks commercialized in Brazil, prepared with folic acid and iron fortified flours. These nutrients are important for human nutrition; however, iron can have a negative effect on zinc absorption. Molar ratio iron:zinc can indicate if there will be any problems for absorption of these nutrients. The folic acid content varied from 58 to 433 μg/100 g and iron and zinc levels varied from 2.9 to 9.4 mg/100 g and from 0.2 to 1.3 mg/100 g, respectively, for 75 analyzed samples. The average iron contents observed in the products and molar ratio iron:zinc (in average 8:1 for biscuits and 12.8:1 for snacks) could result in problems with the zinc absorption. Moreover, principal compo- nent analyses (PCA) indicated low uniformity in the distribution of minerals and vitamin in the majority of the samples, mainly among brands. The results indicated that for the majority of the samples tested folic acid and iron content was higher than expected for flours and could be useful to governmental authorities in their evaluation program of flour fortification.

  18. Differential binding of monomethylarsonous acid compared to arsenite and arsenic trioxide with zinc finger peptides and proteins.

    PubMed

    Zhou, Xixi; Sun, Xi; Mobarak, Charlotte; Gandolfi, A Jay; Burchiel, Scott W; Hudson, Laurie G; Liu, Ke Jian

    2014-04-21

    Arsenic is an environmental toxin that enhances the carcinogenic effect of DNA-damaging agents, such as ultraviolet radiation and benzo[a]pyrene. Interaction with zinc finger proteins has been shown to be an important molecular mechanism for arsenic toxicity and cocarcinogenesis. Arsenicals such as arsenite, arsenic trioxide (ATO), and monomethylarsonous acid (MMA(III)) have been reported to interact with cysteine residues of zinc finger domains, but little is known about potential differences in their selectivity of interaction. Herein we analyzed the interaction of arsenite, MMA(III), and ATO with C2H2, C3H1, and C4 configurations of zinc fingers using UV-vis, cobalt, fluorescence, and mass spectrometry. We observed that arsenite and ATO both selectively bound to C3H1 and C4 zinc fingers, while MMA(III) interacted with all three configurations of zinc finger peptides. Structurally and functionally, arsenite and ATO caused conformational changes and zinc loss on C3H1 and C4 zinc finger peptide and protein, respectively, whereas MMA(III) changed conformation and displaced zinc on all three types of zinc fingers. The differential selectivity was also demonstrated in zinc finger proteins isolated from cells treated with these arsenicals. Our results show that trivalent inorganic arsenic compounds, arsenite and ATO, have the same selectivity and behavior when interacting with zinc finger proteins, while methylation removes the selectivity. These findings provide insights on the molecular mechanisms underlying the differential effects of inorganic versus methylated arsenicals, as well as the role of in vivo arsenic methylation in arsenic toxicity and carcinogenesis.

  19. Lactic acid aided electrochemical deposition of c -axis preferred orientation of zinc oxide thin films: Structural and morphological features

    NASA Astrophysics Data System (ADS)

    Whang, Thou-Jen; Hsieh, Mu-Tao; Tsai, Jia-Ming; Lee, Shyan-Jer

    2011-09-01

    Compact and homogeneous c-axis preferred orientation of zinc oxide (ZnO) films on indium tin oxide (ITO) coated glass have been prepared electrochemically at -1.2 V vs. Ag|AgCl in a weak acidic condition from 0.06 M Zn(NO 3) 2 with 3 mM lactic acid (LA) added. LA was found having strong influence on the electrodeposition of c-axis preferred orientation of zinc oxide films. Other experimental variables such as deposition temperature, potential, and precursor concentration were also conducted in this article. Among these variables, it was found that precursor concentration of zinc nitrate influenced significantly on growth direction and crystal diameter of zinc oxide. Cyclic voltammetry was used to observe the electrochemistry of the deposition. Crystallinities of the films were examined by X-ray diffractometer. The morphologies of zinc oxide films were observed with a field emitting scanning electron microscope. Optical characteristics of zinc oxide layers were measured with UV-vis spectrophotometer. The band gap of the deposited zinc oxide thin films was evaluated from the Tauc relationship of ( αhν) 2 vs. hν, which was found to be 3.31 eV.

  20. effect of fulvic acids of the syr Dar'ya River on the behavior of the radionuclides mercury-203, cadmium-109, and zinc-65 in solutions

    SciTech Connect

    Kulmatov, R.A.; Kist, A.A.; Rakmatov, V.; Volkov, A.A.

    1986-07-01

    The interaction of fulvic acids isolated from natural waters of arid zone with the radionuclides mercury-203, cadmium-109, and zinc-65 is studied by radiogel chromatography. It is shown that mercury-203 and cadmium-109 form complexes with the high-molecular-weight fractions of fulvic acids. Zinc-65 does not form complexes with fulvic acids.

  1. Relationship between acid volatile sulfide and the toxicity of zinc, lead and copper in marine sediments

    SciTech Connect

    Casas, A.M. . School of Fisheries); Crecelius, E.A. )

    1994-03-01

    It has been proposed that acid volatile sulfide (AVS) is an important sediment phase for determining the toxicity of certain trace metals. By evaluating the ratio of the molar quantities of simultaneously extracted metal (SEM) to AVS, the toxicity of metals to organisms in contact with sediment can be predicted. This study examines the role of AVS in prediction the toxicity of zinc, lead, and copper in marine sediments. Sediment samples were titrated with zinc, lead, and copper and subsequently analyzed for SEM, pore-water (PW) metal, and AVS retention. In most cases, metal was not detected in the pore waters until the AVS was exceeded, suggesting that AVS is an adequate measure of the metal-blinding capacity of a sediment. The [SEM]-to-[AVS] ratios were calculated and toxicities predicted for each spiking concentration where [SEM]/[AVS] > 1. A 10-d, flow-though, acute bioassay using the marine polychaete Capitella capita was conducted to examine the prediction of toxicity from the metal titrations and the bioassay sediment chemistry data. In most cases, mortalities occurred as predicted. AVS and the [SEM]-to-[AVS] ratio proved useful as predictors of toxicity for zinc, lead, and perhaps copper. Another tool for predicting metal toxicity in sediments may be the [PW]/LC50 value; in every case where this ratio was > 1, mortalities occurred.

  2. Simultaneous sulfate and zinc removal from acid wastewater using an acidophilic and autotrophic biocathode.

    PubMed

    Teng, Wenkai; Liu, Guangli; Luo, Haiping; Zhang, Renduo; Xiang, Yinbo

    2016-03-01

    The aim of this study was to develop microbial electrolysis cell (MEC) with a novel acidophilic and autotrophic biocathode for treatment of acid wastewater. A biocathode was developed using acidophilic sulfate-reducing bacteria as the catalyst. Artificial wastewater with 200mgL(-1) sulfate and different Zn concentrations (0, 15, 25, and 40 mg L(-1)) was used as the MEC catholyte. The acidophilic biocathode dominated by Desulfovibrio sp. with an abundance of 66% (with 82% of Desulfovibrio sequences similar to Desulfovibrio simplex) and achieved a considerable sulfate reductive rate of 32 gm(-3)d(-1). With 15 mg L(-1) Zn added, the sulfate reductive rate of MEC improved by 16%. The formation of ZnS alleviated the inhibition from sulfide and sped the sulfate reduction. With 15 and 25 mgL(-1) Zn added, more than 99% of Zn was removed from the wastewater. Dissolved Zn ions in the catholyte were converted into insoluble Zn compounds, such as zinc sulfide and zinc hydroxide, due to the sulfide and elevated pH produced by sulfate reduction. The MEC with acidophilic and autotrophic biocathode can be used as an alternative to simultaneously remove sulfate and metals from acid wastewaters, such as acid mine drainage.

  3. Simultaneous sulfate and zinc removal from acid wastewater using an acidophilic and autotrophic biocathode.

    PubMed

    Teng, Wenkai; Liu, Guangli; Luo, Haiping; Zhang, Renduo; Xiang, Yinbo

    2016-03-01

    The aim of this study was to develop microbial electrolysis cell (MEC) with a novel acidophilic and autotrophic biocathode for treatment of acid wastewater. A biocathode was developed using acidophilic sulfate-reducing bacteria as the catalyst. Artificial wastewater with 200mgL(-1) sulfate and different Zn concentrations (0, 15, 25, and 40 mg L(-1)) was used as the MEC catholyte. The acidophilic biocathode dominated by Desulfovibrio sp. with an abundance of 66% (with 82% of Desulfovibrio sequences similar to Desulfovibrio simplex) and achieved a considerable sulfate reductive rate of 32 gm(-3)d(-1). With 15 mg L(-1) Zn added, the sulfate reductive rate of MEC improved by 16%. The formation of ZnS alleviated the inhibition from sulfide and sped the sulfate reduction. With 15 and 25 mgL(-1) Zn added, more than 99% of Zn was removed from the wastewater. Dissolved Zn ions in the catholyte were converted into insoluble Zn compounds, such as zinc sulfide and zinc hydroxide, due to the sulfide and elevated pH produced by sulfate reduction. The MEC with acidophilic and autotrophic biocathode can be used as an alternative to simultaneously remove sulfate and metals from acid wastewaters, such as acid mine drainage. PMID:26561748

  4. Use of poly(lactic acid) amendments to promote the bacterial fixation of metals in zinc smelter tailings.

    PubMed

    Edenborn, H M

    2004-04-01

    The ability of poly(lactic acid) (PLA) to serve as a long-term source of lactic acid for bacterial sulfate reduction activity in zinc smelter tailings was investigated. Solid PLA polymers mixed in water hydrolyzed abiotically to release lactic acid into solution over an extended period of time. The addition of both PLA and gypsum was required for indigenous bacteria to lower redox potential, raise pH, and stimulate sulfate reduction activity in highly oxidized smelter tailings after one year of treatment. Bioavailable cadmium, copper, lead and zinc were all lowered significantly in PLA/gypsum treated soil, but PLA amendments alone increased the bioavailability of lead, nickel and zinc. Similar PLA amendments may be useful in constructed wetlands and reactive barrier walls for the passive treatment of mine drainage, where enhanced rates of bacterial sulfate reduction are desirable.

  5. The impact of zinc sulfate addition on the dynamic metabolic profiling of Saccharomyces cerevisiae subjected to long term acetic acid stress treatment and identification of key metabolites involved in the antioxidant effect of zinc.

    PubMed

    Wan, Chun; Zhang, Mingming; Fang, Qing; Xiong, Liang; Zhao, Xinqing; Hasunuma, Tomohisa; Bai, Fengwu; Kondo, Akihiko

    2015-02-01

    The mechanisms of how zinc protects the cells against acetic acid toxicity and acts as an antioxidant are still not clear. Here we present results of the metabolic profiling of the eukaryotic model yeast species Saccharomyces cerevisiae subjected to long term high concentration acetic acid stress treatment in the presence and absence of zinc supplementation. Zinc addition decreased the release of reactive oxygen species (ROS) in the presence of chronic acetic acid stress. The dynamic changes in the accumulation of intermediates in central carbon metabolism were observed, and higher contents of intracellular alanine, valine and serine were observed by zinc supplementation. The most significant change was observed in alanine content, which is 3.51-fold of that of the control culture in cells in the stationary phase. Subsequently, it was found that 0.5 g L(-1) alanine addition resulted in faster glucose consumption in the presence of 5 g L(-1) acetic acid, and apparently decreased ROS accumulation in zinc-supplemented cells. This indicates that alanine exerted its antioxidant effect at least partially through the detoxification of acetic acid. In addition, intracellular glutathione (GSH) accumulation was enhanced by zinc addition, which is related to the protection of yeast cells from the oxidative injury caused by acetic acid. Our studies revealed for the first time that zinc modulates cellular amino acid metabolism and redox balance, especially biosynthesis of alanine and glutathione to exert its antioxidant effect.

  6. Dietary zinc deficiency affects blood linoleic acid: dihomo-gamma-linolenic acid (LA:DGLA) ratio; a reactive physiological marker of zinc status in vivo (Gallus gallus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary Zinc (Zn) deficiency affects approximately 30% of the world’s population. Zinc is a vital micronutrient and is important for the body’s ability to function. To date, accurate biological markers of the Zn subject’s status are still needed. The aim of this study was to evaluate the chicken mod...

  7. The micronutrient supplements, zinc sulphate and folic acid, did not ameliorate sperm functional parameters in oligoasthenoteratozoospermic men.

    PubMed

    Raigani, M; Yaghmaei, B; Amirjannti, N; Lakpour, N; Akhondi, M M; Zeraati, H; Hajihosseinal, M; Sadeghi, M R

    2014-01-01

    We investigated the effects of folic acid and zinc sulphate supplementation on the improvement of sperm function in subfertile oligoasthenoteratozoospermic (OAT) men. Eighty-three OAT men participated in a 16-week intervention randomised, double-blind clinical trial with daily treatment of folic acid (5 mg day(-1) ) and zinc sulphate (220 mg day(-1) ), or placebo. Before and after treatment, semen and blood samples were obtained for determining sperm concentration, motility, and morphology, sperm viability, sperm mitochondrial function, sperm chromatin status using toluidine blue, aniline blue, acridine orange and chromomycin A3 staining; and semen and blood folate, zinc, B12 , total antioxidant capacity (TAC) and malondialdehyde (MDA) concentrations. Sperm concentration (×10(6)  ml(-1) ) increased in subfertile men receiving the combined treatment of folic acid and zinc sulphate and also in the group receiving only folic acid treatment; however, it was not statistically significant (P = 0.056 and P = 0.05, respectively). Sperm chromatin integrity (%) increased significantly in subfertile men receiving only zinc sulphate treatment (P = 0.048). However, this improvement in sperm quality was not significant after adjusting placebo effect. This study showed that zinc sulphate and folic acid supplementation did not ameliorate sperm quality in infertile men with severely compromised sperm parameters, OAT. Male infertility is a multifactorial disorder, and also nutritional factors play an important role in results of administration of supplementation on sperm parameters. However, these results should be confirmed by multiple studies in larger populations of OAT men.

  8. Effect of essential fatty acid and zinc supplementation during pregnancy on birth intervals, neonatal piglet brain myelination, stillbirth, and preweaning mortality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Omega fatty acids and zinc contribute to physiological pathways that could affect the farrowing process, stillbirth, preweaning mortality and postweaning return to estrus. To determine effects of omega fatty acids and zinc on these reproductive traits, gilts were mated and fed either a control diet,...

  9. A highly sensitive electrochemical biosensor based on zinc oxide nanotetrapods for L-lactic acid detection.

    PubMed

    Lei, Yang; Luo, Ning; Yan, Xiaoqin; Zhao, Yanguang; Zhang, Gong; Zhang, Yue

    2012-06-01

    An amperometric biosensor based on zinc oxide (ZnO) nanotetrapods was designed to detect L-lactic acid. The lactate oxidase was immobilized on the surface of ZnO nanotetrapods by electrostatic adsorption. Unlike traditional detectors, the special four-leg individual ZnO nanostructure, as an adsorption layer, provides multiterminal charge transfer channels. Furthermore, a large amount of ZnO tetrapods are randomly stacked to form a three-dimensional network naturally that facilitates the exchange of electrons and ions in the phosphate buffer solution. Utilizing amperometric response measurements, the prepared ZnO nanotetrapod L-lactic acid biosensor displayed a detection limit of 1.2 μM, a low apparent Michaelis-Menten constant of 0.58 mM, a high sensitivity of 28.0 μA cm(-2) mM(-1) and a good linear relationship in the range of 3.6 μM-0.6 mM for the L-lactic acid detection. This study shows that the biosensor based on ZnO tetrapod nanostructures is highly sensitive and able to respond rapidly in detecting lactic acid. PMID:22538963

  10. Leaching of lead from zinc leach residue in acidic calcium chloride aqueous solution

    NASA Astrophysics Data System (ADS)

    Wang, Le; Mu, Wen-ning; Shen, Hong-tao; Liu, Shao-ming; Zhai, Yu-chun

    2015-05-01

    A process with potentially reduced environmental impacts and occupational hazards of lead-bearing zinc plant residue was studied to achieve a higher recovery of lead via a cost-effective and environmentally friendly process. This paper describes an optimization study on the leaching of lead from zinc leach residue using acidic calcium chloride aqueous solution. Six main process conditions, i.e., the solution pH value, stirring rate, concentration of CaCl2 aqueous solution, liquid-to-solid (L/S) ratio, leaching temperature, and leaching time, were investigated. The microstructure and components of the residue and tailing were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). On the basis of experimental results, the optimum reaction conditions were determined to be a solution pH value of 1, a stirring rate of 500 r·min-1, a CaCl2 aqueous solution concentration of 400 g·L-1, a liquid-to-solid mass ratio of 7:1, a leaching temperature of 80°C, and a leaching time of 45 min. The leaching rate of lead under these conditions reached 93.79%, with an iron dissolution rate of 19.28%. Silica did not take part in the chemical reaction during the leaching process and was accumulated in the residue.

  11. Amphipathic Benzoic Acid Derivativies: Synthesis and Binding in the Hydrophobic Tunnel of the Zinc Deacetylase LpxC

    SciTech Connect

    Shin,H.; Gennadios, H.; Whittington, D.; Christianson, D.

    2007-01-01

    The first committed step in lipid A biosynthesis is catalyzed by uridine diphosphate-(3-O-(R-3-hydroxymyristoyl))-N-acetylglucosamine deacetylase (LpxC), a zinc-dependent deacetylase, and inhibitors of LpxC may be useful in the development of antibacterial agents targeting a broad spectrum of Gram-negative bacteria. Here, we report the design of amphipathic benzoic acid derivatives that bind in the hydrophobic tunnel in the active site of LpxC. The hydrophobic tunnel accounts for the specificity of LpxC toward substrates and substrate analogues bearing a 3-O-myristoyl substituent. Simple benzoic acid derivatives bearing an aliphatic 'tail' bind in the hydrophobic tunnel with micromolar affinity despite the lack of a glucosamine ring like that of the substrate. However, although these benzoic acid derivatives each contain a negatively charged carboxylate 'warhead' intended to coordinate to the active site zinc ion, the 2.25 {angstrom} resolution X-ray crystal structure of LpxC complexed with 3-(heptyloxy)benzoate reveals 'backward' binding in the hydrophobic tunnel, such that the benzoate moiety does not coordinate to zinc. Instead, it binds at the outer end of the hydrophobic tunnel. Interestingly, these ligands bind with affinities comparable to those measured for more complicated substrate analogue inhibitors containing glucosamine ring analogues and hydroxamate 'warheads' that coordinate to the active site zinc ion. We conclude that the intermolecular interactions in the hydrophobic tunnel dominate enzyme affinity in this series of benzoic acid derivatives.

  12. UV screening of ferulic acid-zinc basic salt nanohybrid with controlled release rate.

    PubMed

    Biswick, Timothy; Park, Dae-Hwan; Shul, Yong-Gun; Hwang, Seong-Ju; Choy, Jin-Ho

    2011-01-01

    Ferulic acid (FA), an organic UV absorber and free radical scavenger, was intercalated into an inorganic zinc basic salt (ZBS) matrix to prepare a UV screening material. FA molecules were vertically oriented bilayer in the ZBS lattice with an expansion of approximately 22.7 angstroms along the c-axis. The FA-ZBS nanohybrid exhibited a superior UV-A approximately UV-B screening ability and an antioxidant activity that was comparable to that of a pure FA molecule. The in vitro release test showed the biphasic release of the FA molecules from the FA-ZBS nanohybrid that consisted of an initial burst, followed by a slow and sustained release. PMID:21446466

  13. An innovative zinc oxide-coated zeolite adsorbent for removal of humic acid.

    PubMed

    Wang, Lingling; Han, Changseok; Nadagouda, Mallikarjuna N; Dionysiou, Dionysios D

    2016-08-01

    Zinc oxide (ZnO)-coated zeolite adsorbents were developed by both nitric acid modification and Zn(NO3)2·6H2O functionalization of zeolite 4A. The developed adsorbents were used for the removal of humic acid (HA) from aqueous solutions. The synthesized materials were characterized by porosimetry analysis, scanning electron microscopy, X-Ray diffraction analysis, and high resolution transmission electron microscopy. The maximum adsorption capacity of the adsorbents at 21±1°C was about 60mgCg(-1). The results showed that the positive charge density of ZnO-coated zeolite adsorbents was proportional to the amount of ZnO coated on zeolite and thus, ZnO-coated zeolite adsorbents exhibited a greater affinity for negatively charged ions. Furthermore, the adsorption capacity of ZnO-coated zeolite adsorbents increased markedly after acid modification. Adsorption experiments demonstrated ZnO-coated zeolite adsorbents possessed high adsorption capacity to remove HA from aqueous solutions mainly due to strong electrostatic interactions between negative functional groups of HA and the positive charges of ZnO-coated zeolite adsorbents.

  14. Transient neonatal zinc deficiency.

    PubMed

    Krieger, I; Alpern, B E; Cunnane, S C

    1986-06-01

    We report an infant who developed clinical manifestations of zinc deficiency during the first month of life although the diet was adequate for zinc and no other causes could be ascertained. The diagnosis was confirmed by low plasma-zinc concentrations and a positive response to zinc treatment. The fatty acid profile of plasma phospholipids was typical of zinc deficiency (ie, arachidonic acid was markedly decreased). The transient nature of this disorder was evident when no relapse occurred after cessation of zinc therapy and plasma-zinc and arachidonic acid concentrations remained normal. Several explanations for the development of transient neonatal zinc deficiency are offered. The observation demonstrates that occasional infants may have requirements for zinc that are beyond the intakes of the conventional RDA. PMID:3717070

  15. A Far-Red Emitting Probe for Unambiguous Detection of Mobile Zinc in Acidic Vesicles and Deep Tissue†

    PubMed Central

    Rivera-Fuentes, Pablo; Wrobel, Alexandra T.; Zastrow, Melissa L.; Khan, Mustafa; Georgiou, John; Luyben, Thomas T.; Roder, John C.; Okamoto, Kenichi

    2015-01-01

    Imaging mobile zinc in acidic environments remains challenging because most small-molecule optical probes display pH-dependent fluorescence. Here we report a reaction-based sensor that detects mobile zinc unambiguously at low pH. The sensor responds reversibly and with a large dynamic range to exogenously applied Zn2+ in lysosomes of HeLa cells, endogenous Zn2+ in insulin granules of MIN6 cells, and zinc-rich mossy fiber boutons in hippocampal tissue from mice. This long-wavelength probe is compatible with the green-fluorescent protein, enabling multicolor imaging, and facilitates visualization of mossy fiber boutons at depths of >100 µm, as demonstrated by studies in live tissue employing two-photon microscopy. PMID:25815162

  16. Continuous monitoring of the zinc-phosphate acid-base cement setting reaction by proton nuclear magnetic relaxation

    NASA Astrophysics Data System (ADS)

    Apih, T.; Lebar, A.; Pawlig, O.; Trettin, R.

    2001-06-01

    Proton nuclear magnetic relaxation is a well-established technique for continuous and non destructive monitoring of hydration of conventional Portland building cements. Here, we demonstrate the feasibility of nuclear magnetic resonance (NMR) monitoring of the setting reaction of zinc-phosphate acid-base dental cements, which harden in minutes as compared to days, as in the case of Portland cements. We compare the setting of cement powder (mainly, zinc oxide) prepared with clinically used aluminum-modified orthophosphoric acid solution with the setting of a model system where cement powder is mixed with pure orthophosphoric acid solution. In contrast to previously published NMR studies of setting Portland cements, where a decrease of spin-lattice relaxation time is attributed to enhanced relaxation at the growing internal surface, spin-lattice relaxation time T1 increases during the set of clinically used zinc-phosphate cement. Comparison of these results with a detailed study of diffusion, viscosity, and magnetic-field dispersion of T1 in pure and aluminum-modified orthophosphoric acid demonstrates that the increase of T1 in the setting cement is connected with the increase of molecular mobility in the residual phosphoric acid solution. Although not taken into account so far, such effects may also significantly influence the relaxation times in setting Portland cements, particularly when admixtures with an effect on water viscosity are used.

  17. Influence of humic acid on the stability and bacterial toxicity of zinc oxide nanoparticles in water.

    PubMed

    Akhil, K; Chandran, Preethy; Sudheer Khan, S

    2015-12-01

    The present study investigated the stability of zinc oxide nanoparticles (ZnO NPs) by the adsorption of humic acid (HA) and the mechanism of adsorption. The effect of humic acid on NP toxicity was determined by Escherichia coli (ATCC 13534), E. coli (ATCC 25922), and Pseudomonas putida (MTCC 4910). The nanoparticles showed low zeta potential and were least stable in the absence of HA. However, the negative surface charge of the particles increased in the presence of HA (0-50mg/L) that reduced the propensity of nanoparticles to aggregate in water. A decrease in absorbance of ZnO NPs at 375 nm (plasmon peak) was noted in the presence of HA by UV-visible spectrophotometric analysis. A blue shift towards 370 nm was noted when the concentration of HA was above 20mg/L. The HA adsorbed ZnO NPs showed higher zeta potential (>-30 mV) and were highly stable. HA reduced the photocatalytic activity of ZnO and at the same time increased the photostability of ZnO.

  18. Effect of high dietary zinc oxide on the caecal and faecal short-chain fatty acids and tissue zinc and copper concentration in pigs is reversible after withdrawal of the high zinc oxide from the diet.

    PubMed

    Janczyk, P; Büsing, K; Dobenecker, B; Nöckler, K; Zeyner, A

    2015-04-01

    Zinc oxide (ZnO) used in high ('pharmacological') levels to prevent diarrhoea in pigs is assumed to reduce copper (Cu) in tissues and inhibits large intestinal microbial fermentation. To test it, German Landrace pigs were weaned on d28 of age and fed diets containing either 100 (LowZinc, LZn, n = 10) or 3100 mg ZnO/kg (HighZinc, HZn, n = 10). The mixed feed (13.0 MJ ME, 18.5% crude protein) was based on wheat, barley, soya bean meal and maize. After 4 weeks, the HZn group was further fed 100 mg ZnO/kg for another 2 weeks. Caecal contents, faeces and tissues were collected after 4 weeks (n = 5 and n = 10 respectively) and 6 weeks (n = 5 and n = 5 respectively). Faeces and caecal content were analysed for dry matter (DM), pH, ammonia, lactic acid (LA) and short-chain fatty acids (SCFA) on native water basis. anova was performed to elucidate significant differences at p < 0.05. No diarrhoea occurred. After 4 weeks, the caecal contents' pH increased (p < 0.001) and butyric (p < 0.05) and valeric acid (p < 0.01) decreased in the HZn group in comparison with LZn. In faeces, a decrease of acetic (p = 0.009), butyric (p = 0.007) and valeric acid (p = 0.046), as well as reduced acetic:propionic acid (A:P) ratio (p = 0.025) was observed in the HZn group in comparison with LZn. Faecal ammonia decreased in HZn (p = 0.018). No differences (p > 0.05) were recorded in caecal contents after 6 weeks. In faeces, acetic acid remained lower in the HZn group in comparison with LZn (p = 0.006), as did the A:P ratio (p = 0.004). Zn concentration in liver, kidneys and ribs, and Cu concentrations in kidneys increased in HZn. Withdrawal of ZnO resulted in reversibility of the changes. The effect on butyric acid should be discussed critically regarding the energetic support for the enterocytes. High Zn and Cu tissue concentrations should be considered by pet food producers. PMID:25865418

  19. Effect of high dietary zinc oxide on the caecal and faecal short-chain fatty acids and tissue zinc and copper concentration in pigs is reversible after withdrawal of the high zinc oxide from the diet.

    PubMed

    Janczyk, P; Büsing, K; Dobenecker, B; Nöckler, K; Zeyner, A

    2015-04-01

    Zinc oxide (ZnO) used in high ('pharmacological') levels to prevent diarrhoea in pigs is assumed to reduce copper (Cu) in tissues and inhibits large intestinal microbial fermentation. To test it, German Landrace pigs were weaned on d28 of age and fed diets containing either 100 (LowZinc, LZn, n = 10) or 3100 mg ZnO/kg (HighZinc, HZn, n = 10). The mixed feed (13.0 MJ ME, 18.5% crude protein) was based on wheat, barley, soya bean meal and maize. After 4 weeks, the HZn group was further fed 100 mg ZnO/kg for another 2 weeks. Caecal contents, faeces and tissues were collected after 4 weeks (n = 5 and n = 10 respectively) and 6 weeks (n = 5 and n = 5 respectively). Faeces and caecal content were analysed for dry matter (DM), pH, ammonia, lactic acid (LA) and short-chain fatty acids (SCFA) on native water basis. anova was performed to elucidate significant differences at p < 0.05. No diarrhoea occurred. After 4 weeks, the caecal contents' pH increased (p < 0.001) and butyric (p < 0.05) and valeric acid (p < 0.01) decreased in the HZn group in comparison with LZn. In faeces, a decrease of acetic (p = 0.009), butyric (p = 0.007) and valeric acid (p = 0.046), as well as reduced acetic:propionic acid (A:P) ratio (p = 0.025) was observed in the HZn group in comparison with LZn. Faecal ammonia decreased in HZn (p = 0.018). No differences (p > 0.05) were recorded in caecal contents after 6 weeks. In faeces, acetic acid remained lower in the HZn group in comparison with LZn (p = 0.006), as did the A:P ratio (p = 0.004). Zn concentration in liver, kidneys and ribs, and Cu concentrations in kidneys increased in HZn. Withdrawal of ZnO resulted in reversibility of the changes. The effect on butyric acid should be discussed critically regarding the energetic support for the enterocytes. High Zn and Cu tissue concentrations should be considered by pet food producers.

  20. Effect of Fluid Flow on Zinc Electrodeposits from Acid Chloride Electrolytes. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Abdelmassir, A. A.

    1982-01-01

    Zinc was deposited potentiostatically from acid chloride baths. Once bath chemistry and electrochemistry were controlled, the study was focused on convective mass transfer at horizontal electrodes and its effect on cell performance. A laser schlieren imaging technique allowed in situ observations of flow patterns and their correlation with current transients. Convection was turbulent and mass transfer as a function of Rayleigh number was well correlated by: Sh = 0.14 R to the 1/3 power. Similarly, convection initiation time was correlated by DT/d squared = 38 Ra to the -2/3 power. Time scale of fluctuations was about half the initiation time. Taking the boundary layer thickness as a characteristic length, a critical Rayleigh number for the onset of convection was deduced: Ra sub CR = 5000. Placing the anode on the top of the cathode completely changed the flow pattern but kept the I-t curves identical whereas the use of a cathode grid doubled the limiting current. A well defined plateau in the current voltage curves suggested that hydrogen evolution has been successfully inhibited. Finally, long time deposition showed that convection at horizontal electrodes increased the induction time for dentrite growth by at least a factor of 2 with respect to a vertical wire.

  1. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD): part I: Characterization and leaching by diluted sulphuric acid.

    PubMed

    Oustadakis, P; Tsakiridis, P E; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The present paper is the first of a series of two articles dealing with the development of an integrated process for the recovery of zinc from electric arc furnace dust (EAFD), a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Part I presents the EAFD characterization and its leaching process by diluted sulphuric acid, whereas Part II deals with the purification of the leach liquor and the recovery of zinc by solvent extraction/electrowinning. The characterization of the examined electric arc furnace dust was carried out by using granulometry analysis, chemical analysis, X-ray diffraction (XRD), thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The leaching process was based on the Zn extraction with diluted sulphuric acid from EAFD under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The zinc recovery efficiency on the basis of EAFD weight reached 80%. X-ray diffraction and scanning electron microscopy were used for the characterization of the leached residues. PMID:20129730

  2. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD): part I: Characterization and leaching by diluted sulphuric acid.

    PubMed

    Oustadakis, P; Tsakiridis, P E; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The present paper is the first of a series of two articles dealing with the development of an integrated process for the recovery of zinc from electric arc furnace dust (EAFD), a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Part I presents the EAFD characterization and its leaching process by diluted sulphuric acid, whereas Part II deals with the purification of the leach liquor and the recovery of zinc by solvent extraction/electrowinning. The characterization of the examined electric arc furnace dust was carried out by using granulometry analysis, chemical analysis, X-ray diffraction (XRD), thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The leaching process was based on the Zn extraction with diluted sulphuric acid from EAFD under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The zinc recovery efficiency on the basis of EAFD weight reached 80%. X-ray diffraction and scanning electron microscopy were used for the characterization of the leached residues.

  3. Dynamic HypA zinc site is essential for acid viability and proper urease maturation in Helicobacter pylori

    PubMed Central

    Johnson, Ryan C.; Hu, Heidi Q.; Merrell, D. Scott; Maroney, Michael J.

    2015-01-01

    Helicobacter pylori requires urease activity in order to survive in the acid environment of the human stomach. Urease is regulated in part by nickelation, a process that requires the HypA protein, which is a putative nickel metallochaperone that is generally associated with hydrogenase maturation. However, in H. pylori, HypA plays a dual role. In addition to an N-terminal nickel binding site, HypA proteins also contain a structural zinc site that is coordinated by two rigorously conserved CXXC sequences, which in H. pylori are flanked by His residues. These structural Zn sites are known to be dynamic, converting from Zn(Cys)4 centers at pH 7.2 to Zn(Cys)2(His)2 centers at pH 6.3 in the presence of Ni(II) ions. In this study, mutant strains of H. pylori that express zinc site variants of the HypA protein are used to show that the structural changes in the zinc site are important for the acid viability of the bacterium, and that a reduction in acid viability in these variants can be traced in large measure to deficient urease activity. This in turn leads to a model that connects the Zn(Cys)4 coordination to urease maturation. PMID:25608738

  4. Effects of supplemental zinc amino acid complex on gut integrity in heat-stressed growing pigs.

    PubMed

    Sanz Fernandez, M V; Pearce, S C; Gabler, N K; Patience, J F; Wilson, M E; Socha, M T; Torrison, J L; Rhoads, R P; Baumgard, L H

    2014-01-01

    Heat stress (HS) jeopardizes livestock health and productivity and both may in part be mediated by reduced intestinal integrity. Dietary zinc improves a variety of bowel diseases, which are characterized by increased intestinal permeability. Study objectives were to evaluate the effects of supplemental zinc amino acid complex (ZnAA) on intestinal integrity in heat-stressed growing pigs. Crossbred gilts (43±6 kg BW) were ad libitum fed one of three diets: (1) control (ZnC; 120 ppm Zn as ZnSO4; n=13), (2) control+100 ppm Zn as ZnAA (Zn220; containing a total of 220 ppm Zn; n=14), and (3) control+200 ppm Zn as ZnAA (Zn320; containing a total of 320 ppm Zn; n=16). After 25 days on their respective diets, all pigs were exposed to constant HS conditions (36°C, ∼50% humidity) for either 1 or 7 days. At the end of the environmental exposure, pigs were euthanized and blood and intestinal tissues were harvested immediately after sacrifice. As expected, HS increased rectal temperature (P⩽0.01; 40.23°C v. 38.93°C) and respiratory rate (P⩽0.01; 113 v. 36 bpm). Pigs receiving ZnAA tended to have increased rectal temperature (P=0.07; +0.27°C) compared with ZnC-fed pigs. HS markedly reduced feed intake (FI; P⩽0.01; 59%) and caused BW loss (2.10 kg), but neither variable was affected by dietary treatment. Fresh intestinal segments were assessed ex vivo for intestinal integrity. As HS progressed from days 1 to 7, both ileal and colonic transepithelial electrical resistance (TER) decreased (P⩽0.05; 34% and 22%, respectively). This was mirrored by an increase in ileal and colonic permeability to the macromolecule dextran (P⩽0.01; 13- and 56-fold, respectively), and increased colonic lipopolysaccharide permeability (P⩽0.05; threefold) with time. There was a quadratic response (P⩽0.05) to increasing ZnAA on ileal TER, as it was improved (P⩽0.05; 56%) in Zn220-fed pigs compared with ZnC. This study demonstrates that HS progressively compromises the intestinal

  5. Dynamics of linker residues modulate the nucleic acid binding properties of the HIV-1 nucleocapsid protein zinc fingers.

    PubMed

    Zargarian, Loussiné; Tisné, Carine; Barraud, Pierre; Xu, Xiaoqian; Morellet, Nelly; René, Brigitte; Mély, Yves; Fossé, Philippe; Mauffret, Olivier

    2014-01-01

    The HIV-1 nucleocapsid protein (NC) is a small basic protein containing two zinc fingers (ZF) separated by a short linker. It is involved in several steps of the replication cycle and acts as a nucleic acid chaperone protein in facilitating nucleic acid strand transfers occurring during reverse transcription. Recent analysis of three-dimensional structures of NC-nucleic acids complexes established a new property: the unpaired guanines targeted by NC are more often inserted in the C-terminal zinc finger (ZF2) than in the N-terminal zinc finger (ZF1). Although previous NMR dynamic studies were performed with NC, the dynamic behavior of the linker residues connecting the two ZF domains remains unclear. This prompted us to investigate the dynamic behavior of the linker residues. Here, we collected 15N NMR relaxation data and used for the first time data at several fields to probe the protein dynamics. The analysis at two fields allows us to detect a slow motion occurring between the two domains around a hinge located in the linker at the G35 position. However, the amplitude of motion appears limited in our conditions. In addition, we showed that the neighboring linker residues R29, A30, P31, R32, K33 displayed restricted motion and numerous contacts with residues of ZF1. Our results are fully consistent with a model in which the ZF1-linker contacts prevent the ZF1 domain to interact with unpaired guanines, whereas the ZF2 domain is more accessible and competent to interact with unpaired guanines. In contrast, ZF1 with its large hydrophobic plateau is able to destabilize the double-stranded regions adjacent to the guanines bound by ZF2. The linker residues and the internal dynamics of NC regulate therefore the different functions of the two zinc fingers that are required for an optimal chaperone activity.

  6. Does Short-Term Dietary Omega-3 Fatty Acid Supplementation Influence Brain Hippocampus Gene Expression of Zinc Transporter-3?

    PubMed

    Sopian, Nur Farhana Ahmad; Ajat, Mokrish; Shafie, Nurul' Izzati; Noor, Mohd Hezmee Mohd; Ebrahimi, Mehdi; Rajion, Mohamed Ali; Meng, Goh Yong; Ahmad, Hafandi

    2015-01-01

    Dietary omega-3 fatty acids have been recognized to improve brain cognitive function. Deficiency leads to dysfunctional zinc metabolism associated with learning and memory impairment. The objective of this study is to explore the effect of short-term dietary omega-3 fatty acids on hippocampus gene expression at the molecular level in relation to spatial recognition memory in mice. A total of 24 male BALB/c mice were randomly divided into four groups and fed a standard pellet as a control group (CTL, n = 6), standard pellet added with 10% (w/w) fish oil (FO, n = 6), 10% (w/w) soybean oil (SO, n = 6) and 10% (w/w) butter (BT, n = 6). After 3 weeks on the treatment diets, spatial-recognition memory was tested on a Y-maze. The hippocampus gene expression was determined using a real-time PCR. The results showed that 3 weeks of dietary omega-3 fatty acid supplementation improved cognitive performance along with the up-regulation of α-synuclein, calmodulin and transthyretin genes expression. In addition, dietary omega-3 fatty acid deficiency increased the level of ZnT3 gene and subsequently reduced cognitive performance in mice. These results indicate that the increased the ZnT3 levels caused by the deficiency of omega-3 fatty acids produced an abnormal zinc metabolism that in turn impaired the brain cognitive performance in mice. PMID:26184176

  7. Does Short-Term Dietary Omega-3 Fatty Acid Supplementation Influence Brain Hippocampus Gene Expression of Zinc Transporter-3?

    PubMed

    Sopian, Nur Farhana Ahmad; Ajat, Mokrish; Shafie, Nurul' Izzati; Noor, Mohd Hezmee Mohd; Ebrahimi, Mehdi; Rajion, Mohamed Ali; Meng, Goh Yong; Ahmad, Hafandi

    2015-07-13

    Dietary omega-3 fatty acids have been recognized to improve brain cognitive function. Deficiency leads to dysfunctional zinc metabolism associated with learning and memory impairment. The objective of this study is to explore the effect of short-term dietary omega-3 fatty acids on hippocampus gene expression at the molecular level in relation to spatial recognition memory in mice. A total of 24 male BALB/c mice were randomly divided into four groups and fed a standard pellet as a control group (CTL, n = 6), standard pellet added with 10% (w/w) fish oil (FO, n = 6), 10% (w/w) soybean oil (SO, n = 6) and 10% (w/w) butter (BT, n = 6). After 3 weeks on the treatment diets, spatial-recognition memory was tested on a Y-maze. The hippocampus gene expression was determined using a real-time PCR. The results showed that 3 weeks of dietary omega-3 fatty acid supplementation improved cognitive performance along with the up-regulation of α-synuclein, calmodulin and transthyretin genes expression. In addition, dietary omega-3 fatty acid deficiency increased the level of ZnT3 gene and subsequently reduced cognitive performance in mice. These results indicate that the increased the ZnT3 levels caused by the deficiency of omega-3 fatty acids produced an abnormal zinc metabolism that in turn impaired the brain cognitive performance in mice.

  8. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae)

    NASA Astrophysics Data System (ADS)

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-04-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation.

  9. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae).

    PubMed

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-12-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation. PMID:27107771

  10. The Effect of Copper And Zinc Nanoparticles on the Growth Parameters, Contents of Ascorbic Acid, and Qualitative Composition of Amino Acids and Acylcarnitines in Pistia stratiotes L. (Araceae).

    PubMed

    Olkhovych, Olga; Volkogon, Mykola; Taran, Nataliya; Batsmanova, Lyudmyla; Kravchenko, Inna

    2016-12-01

    The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant's ability to use free fatty acids as the oxidation substrate for cell reparation.

  11. Highly microporous carbons derived from a complex of glutamic acid and zinc chloride for use in supercapacitors

    NASA Astrophysics Data System (ADS)

    Dong, Xiao-Ling; Lu, An-Hui; He, Bin; Li, Wen-Cui

    2016-09-01

    The selection of carbon precursor is an important factor when designing carbon materials. In this study, a complex derived from L-glutamic acid and zinc chloride was used to prepare highly microporous carbons via facile pyrolysis. L-glutamic acid, a new carbon precursor with nitrogen functionality, coordinated with zinc chloride resulted in a homogeneous distribution of Zn2+ on the molecular level. During pyrolysis, the evaporation of the in situ formed zinc species creates an abundance of micropores together with the inert gases. The obtained carbons exhibit high specific surface area (SBET: 1203 m2 g-1) and a rich nitrogen content (4.52 wt%). In excess of 89% of the pore volume consists of micropores with pore size ranging from 0.5 to 1.2 nm. These carbons have been shown to be suitable for use as supercapacitor electrodes, and have been tested in 6 M KOH where a capacitance of 217 F g-1 was achieved at a current density of 0.5 A g-1. A long cycling life of 30 000 cycles was achieved at a current density of 1 A g-1, with only a 9% loss in capacity. The leakage current through a two-electrode device was measured as 2.3 μA per mg of electrode and the self-discharge characteristics were minimal.

  12. Synthesis of framework isomer MOFs containing zinc and 4-tetrazolyl benzenecarboxylic acid via a structure directing solvothermal approach

    DOE PAGES

    Ordonez, Carlos; Kinnibrugh, Tiffany L.; Xu, Hongwu; Lindline, Jennifer; Timofeeva, Tatiana; Wei, Qiang

    2015-04-02

    The solvothermal synthesis of framework isomers was carried out using the hybrid carboxylate and tetrazolate functional ligand, 4-tetrazolyl benzenecarboxylic acid (H₂TBC, TBC = 4-tetrazolyl benzenecarboxylate) and zinc. H₂TBC was also synthesized with the solvothermal approach, and is referred herein as structure 1. Using single-crystal X-ray diffraction, we found that the tetrazolate groups of TBC show an unusual “opposite-on” coordination mode with zinc. Three previously characterized metal-organic frameworks (MOFs) were obtained by systematically changing the solvents of the H₂TBC-Zn reaction, (1) ZnTBC, 2, which has a non-porous structure; (2) Zn₂(TBC)₂(H2O), 3, which has an amphiphilic pore structure and (3) Zn₂(TBC)₂{guest}, 4,more » which is porous and has channels containing uncoordinated N heteroatoms. Fluorescence spectra of 4 reveal a strong blue emission mainly from the TBC ligands.« less

  13. Synthesis of framework isomer MOFs containing zinc and 4-tetrazolyl benzenecarboxylic acid via a structure directing solvothermal approach

    SciTech Connect

    Ordonez, Carlos; Kinnibrugh, Tiffany L.; Xu, Hongwu; Lindline, Jennifer; Timofeeva, Tatiana; Wei, Qiang

    2015-04-02

    The solvothermal synthesis of framework isomers was carried out using the hybrid carboxylate and tetrazolate functional ligand, 4-tetrazolyl benzenecarboxylic acid (H₂TBC, TBC = 4-tetrazolyl benzenecarboxylate) and zinc. H₂TBC was also synthesized with the solvothermal approach, and is referred herein as structure 1. Using single-crystal X-ray diffraction, we found that the tetrazolate groups of TBC show an unusual “opposite-on” coordination mode with zinc. Three previously characterized metal-organic frameworks (MOFs) were obtained by systematically changing the solvents of the H₂TBC-Zn reaction, (1) ZnTBC, 2, which has a non-porous structure; (2) Zn₂(TBC)₂(H2O), 3, which has an amphiphilic pore structure and (3) Zn₂(TBC)₂{guest}, 4, which is porous and has channels containing uncoordinated N heteroatoms. Fluorescence spectra of 4 reveal a strong blue emission mainly from the TBC ligands.

  14. Zinc(II) complexes with heterocyclic ether, acid and amide. Crystal structure, spectral, thermal and antibacterial activity studies

    NASA Astrophysics Data System (ADS)

    Jabłońska-Wawrzycka, Agnieszka; Rogala, Patrycja; Czerwonka, Grzegorz; Hodorowicz, Maciej; Stadnicka, Katarzyna

    2016-02-01

    The reaction of zinc salts with heterocyclic ether (1-ethoxymethyl-2-methylimidazole (1-ExMe-2-MeIm)), acid (pyridine-2,3-dicarboxylic acid (2,3-pydcH2)) and amide (3,5-dimethylpyrazole-1-carboxamide (3,5-DMePzCONH2)) yielded three new zinc complexes formulated as [Zn(1-ExMe-2-MeIm)2Cl2] 1, fac-[Zn(H2O)6][Zn(2,3-pydcH)3]22 and [Zn(3,5-DMePz)2(NCO)2] 3. Complexes of 1 and 3 are four-coordinated with a tetrahedron as coordination polyhedron. However, compound 2 forms an octahedral cation-anion complex. The complex 3 was prepared by eliminating of the carboxamide group from the ligand and then the 3,5-dimethylpyrazole (3,5-DMePz) and isocyanates formed were employed as new ligands. The IR and X-ray studies have confirmed a bidentate fashion of coordination of the 2,3-pydcH and monodentate fashion of coordination of the 1-ExMe-2-MeIm and 3,5-DMePz to the Zn(II) ions. The crystal packing of Zn(II) complexes are stabilized by intermolecular classical hydrogen bonds of O-H⋯O and N-H⋯O types. The most interesting feature of the supramolecular architecture of complexes is the existence of C-H⋯O, C-H⋯Cl and C-H⋯π interactions and π⋯π stacking, which also contributes to structural stabilisation. The correlation between crystal structure and thermal stability of zinc complexes is observed. In all compounds the fragments of ligands donor-atom containing go in the last steps. Additionally, antimicrobial activities of compounds were carried out against certain Gram-positive and Gram-negative bacteria and counts of CFU (colony forming units) were also determined. The achieved results confirmed a significant antibacterial activity of some tested zinc complexes. On the basis of the Δ log CFU values the antibacterial activity of zinc complexes follows the order: 3 > 2 > 1. Influence a number of N-donor atoms in zinc environment on antibacterial activity is also observed.

  15. Separation of zinc and nickel ions in a strong acid through liquid-liquid extraction.

    PubMed

    Park, Young Jun; Fray, Derek J

    2009-04-15

    Many solid wastes contain both zinc and nickel at the same time. For recycling or recovery of metals, it is essential to separate materials. Among those materials, zinc and nickel are very difficult to be separated because there is not so much difference in the chemical and physical properties. This paper focuses on the separation of zinc and nickel ions in a diluted aqua regia solution. Liquid-liquid extraction by TBP, Cyanex 272 and Cyanex 301 was used and a distribution coefficient (D), a separation factor (S) and a relative purity (R) were induced to evaluate the degree of separation. All of the extractions were proportional to the concentration of the extractants, and zinc ions were extracted more easily than nickel ions. Among the extractants, Cyanex 301 showed the best characteristics regarding Zn/Ni separation. In particular, the extraction of zinc ions in the range of pHzinc was about 99 wt.% without a pH control, pH -1.1. PMID:18675511

  16. Changes in pulmonary lavage fluid of guinea pigs exposed to ultrafine zinc oxide with adsorbed sulfuric acid

    SciTech Connect

    Conner, M.W.; Flood, W.H.; Rogers, A.E.; Amdur, M.O.

    1989-01-01

    Ultrafine metal oxide particles (diameters less than 0.1 microns) and sulfur dioxide are important products of coal combustion. Interaction of these products in the effluent stream results in formation of ultrafine particles with adsorbed sulfur compounds, including sulfuric acid. The toxicity of ultrafine zinc oxide particles with adsorbed sulfuric acid was evaluated by comparing pulmonary lavage fluid from guinea pigs exposed for 1, 2, 3, 4, or 5 consecutive daily 3-h periods to ultrafine zinc oxide generated in the presence of sulfur dioxide (ZnO + SO/sub 2/) to pulmonary lavage fluid from guinea pigs exposed to an equivalent concentration of ultrafine ZnO. Two groups of guinea pigs exposed either to SO/sub 2/ or to particle-free furnace gas served as additional controls. Cells, protein, and activities of lactate dehydrogenase, acid phosphatase, and alkaline phosphatase were increased in lavage fluid obtained from guinea pigs exposed to ZnO + SO/sub 2/ as compared to guinea pigs exposed to ZnO. These results demonstrate the potential importance of ultrafine metal oxides as carries of sulfuric acid derived from fossil fuel combustion.

  17. Effect of dietary phytic acid and cadmium on the availability of cadmium, zinc, copper, iron, and manganese to rats

    SciTech Connect

    Turecki, T.; Ewan, R.C.; Stahr, H.M.

    1995-05-01

    The main route of cadmium intake for general population, both human and animal, is via ingestion. The intestinal absorption of cadmium is relatively low, 6% of a single oral dose for humans and less than 2% for various animal species. However, due to poor excretion, accumulation of cadmium occurs, primarily in kidney. The chronic exposure even to low levels of dietary cadmium can lead to the development of renal disturbances. Fox (1988) suggests that phytic acid might be a dietary component capable to influence the intestinal absorption of cadmium. Phytic acid naturally occurs as the major phosphorus storage constituent of most cereals, legumes, and oilseeds. At physiological pH, phytic acid is ionized and has a strong affinity for divalent cations. The potential of phytic acid to decrease the availability of Zn has been for long time of concern for nutritionists. Phytic acid has also been reported to decrease the availability of other trace metals. For nonessential elements, reduced availability of lead has been observed. The experimental data concerning the effect of dietary phytic acid on the availability of dietary cadmium are limited to the work of Rose and Quarterman (1984). The objective of this experiment was to examine: (1) the effect of dietary phytic acid on the availability of cadmium under conditions of chronic dietary exposure of rats to cadmium, and (2) the effect of dietary phytic acid and of chronic dietary exposure to cadmium on the availability of zinc, copper, iron, and manganese to rats. 19 refs., 4 tabs.

  18. Influence of two different alcohols in the esterification of fatty acids over layered zinc stearate/palmitate.

    PubMed

    de Paiva, Eduardo José Mendes; Corazza, Marcos Lúcio; Sierakowski, Maria Rita; Wärnå, Johan; Murzin, Dmitry Yu; Wypych, Fernando; Salmi, Tapio

    2015-10-01

    In this work, esterification of fatty acids (oleic, linoleic and stearic acid) with a commercial zinc carboxylate (a layered compound formed by simultaneous intercalation of stearate and palmitate anions) was performed. Kinetic modeling using a quasi-homogeneous approach successfully fitted experimental data at different molar ratio of fatty acids/alcohols (1-butanol and 1-hexanol) and temperature. An apparent first-order reaction related to all reactants was found and activation energy of 66 kJ/mol was reported. The catalyst showed to be unique, as it can be easily recovered like a heterogeneous catalysts behaving like ionic liquids. In addition, this catalyst demonstrated a peculiar behavior, because higher reactivity was observed with the increase in the alcohols chain length compared to the authors' previous work using ethanol.

  19. Selective extraction of zinc(II) over iron(II) from spent hydrochloric acid pickling effluents by liquid-liquid extraction.

    PubMed

    Mansur, Marcelo Borges; Rocha, Sônia Denise Ferreira; Magalhães, Fernando Silva; Benedetto, Jeaneth dos Santos

    2008-02-11

    The selective removal of zinc(II) over iron(II) by liquid-liquid extraction from spent hydrochloric acid pickling effluents produced by the zinc hot-dip galvanizing industry was studied at room temperature. Two distinct effluents were investigated: effluent 1 containing 70.2g/L of Zn, 92.2g/L of Fe and pH 0.6, and effluent 2 containing 33.9 g/L of Zn, 203.9g/L of Fe and 2M HCl. The following extractants were compared: TBP (tri-n-butyl phosphate), Cyanex 272 [bis(2,4,4-trimethylpentyl)phosphinic acid], Cyanex 301 [bis(2,4,4-trimethylpentyl) dithiophosphinic acid] and Cyanex 302 [bis(2,4,4-trimethylpentyl) monothiophosphinic acid]. The best separation results were obtained for extractants TBP and Cyanex 301. Around 92.5% of zinc and 11.2% of iron were extracted from effluent 1 in one single contact using 100% (v/v) of TBP. With Cyanex 301, around 80-95% of zinc and less than 10% of iron were extracted from effluent 2 at pH 0.3-1.0. For Cyanex 272, the highest extraction yield for zinc (70% of zinc with 20% of iron extraction) was found at pH 2.4. Cyanex 302 presented low metal extraction levels (below 10%) and slow phase disengagement characteristics. Reactions for the extraction of zinc with TBP and Cyanex 301 from hydrochloric acid solution were proposed.

  20. Selective extraction of zinc(II) over iron(II) from spent hydrochloric acid pickling effluents by liquid-liquid extraction.

    PubMed

    Mansur, Marcelo Borges; Rocha, Sônia Denise Ferreira; Magalhães, Fernando Silva; Benedetto, Jeaneth dos Santos

    2008-02-11

    The selective removal of zinc(II) over iron(II) by liquid-liquid extraction from spent hydrochloric acid pickling effluents produced by the zinc hot-dip galvanizing industry was studied at room temperature. Two distinct effluents were investigated: effluent 1 containing 70.2g/L of Zn, 92.2g/L of Fe and pH 0.6, and effluent 2 containing 33.9 g/L of Zn, 203.9g/L of Fe and 2M HCl. The following extractants were compared: TBP (tri-n-butyl phosphate), Cyanex 272 [bis(2,4,4-trimethylpentyl)phosphinic acid], Cyanex 301 [bis(2,4,4-trimethylpentyl) dithiophosphinic acid] and Cyanex 302 [bis(2,4,4-trimethylpentyl) monothiophosphinic acid]. The best separation results were obtained for extractants TBP and Cyanex 301. Around 92.5% of zinc and 11.2% of iron were extracted from effluent 1 in one single contact using 100% (v/v) of TBP. With Cyanex 301, around 80-95% of zinc and less than 10% of iron were extracted from effluent 2 at pH 0.3-1.0. For Cyanex 272, the highest extraction yield for zinc (70% of zinc with 20% of iron extraction) was found at pH 2.4. Cyanex 302 presented low metal extraction levels (below 10%) and slow phase disengagement characteristics. Reactions for the extraction of zinc with TBP and Cyanex 301 from hydrochloric acid solution were proposed. PMID:17570579

  1. Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage.

    PubMed

    Aranda, Suzan; Borrok, David M; Wanty, Richard B; Balistrieri, Laurie S

    2012-03-15

    The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ(66)Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰±0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ(66)Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰±0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters. PMID:22326318

  2. Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage.

    PubMed

    Aranda, Suzan; Borrok, David M; Wanty, Richard B; Balistrieri, Laurie S

    2012-03-15

    The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geochemical tools in the investigation of contaminated waters at the former Waldorf mining site in the Rocky Mountains, Colorado, U.S.A. Geochemical signatures and statistical analysis helped in identifying two primary metal loading pathways at the Waldorf site. The first was characterized by a circumneutral pH, high alkalinity, and high Zn/Cd ratios. The second was characterized by acidic pHs and low Zn/Cd ratios. Zinc isotope signatures in surface water samples collected across the site were remarkably similar (the δ(66)Zn, relative to JMC 3-0749-L, for most samples ranged from 0.20 to 0.30‰±0.09‰ 2σ). This probably suggests that the ultimate source of Zn is consistent across the Waldorf site, regardless of the metal loading pathway. The δ(66)Zn of pore water samples collected within a nearby metal-impacted wetland area, however, were more variable, ranging from 0.20 to 0.80‰±0.09‰ 2σ. Here the Zn isotopes seemed to reflect differences in groundwater flow pathways. However, a host of secondary processes might also have impacted Zn isotopes, including adsorption of Zn onto soil components, complexation of Zn with dissolved organic matter, uptake of Zn into plants, and the precipitation of Zn during the formation of reduced sulfur species. Zinc isotope analysis proved useful in this study; however, the utility of this isotopic tool would improve considerably with the addition of a comprehensive experimental foundation for interpreting the complex isotopic relationships found in soil pore waters.

  3. Cysteine residues in the zinc finger and amino acids adjacent to the finger are necessary for DNA binding by the LAC9 regulatory protein of Kluyveromyces lactis.

    PubMed Central

    Witte, M M; Dickson, R C

    1988-01-01

    LAC9 is a positive regulatory protein that controls transcription of the lactose-galactose regulon in Kluyveromyces lactis. LAC9 is homologous to the GAL4 protein of Saccharomyces cerevisiae. Both proteins have a single "zinc finger" which plays a role in DNA binding. We previously hypothesized (L. V. Wray, M. M. Witte, R. C. Dickson, and M. I. Riley, Mol. Cell. Biol. 7:1111-1121, 1987) that the DNA-binding domain of the LAC9 protein consisted of the zinc finger as well as a region of amino acids on the carboxyl-terminal side of the zinc finger. In this study we used oligonucleotide-directed mutagenesis to introduce 13 single-amino-acid changes into the proposed DNA-binding domain of the LAC9 protein. Variant LAC9 proteins carrying an amino acid substitution in any one of the four highly conserved Cys residues of the zinc finger had reduced DNA-binding activity, suggesting that each Cys is necessary for DNA binding. Three of four variant LAC9 proteins with amino acid substitutions located on the carboxyl-terminal side of the zinc finger had reduced DNA-binding activity. These results support our hypothesis that the DNA-binding domain of the LAC9 protein is composed of the zinc finger and the adjacent region on the carboxyl side of the zinc finger, a region that has the potential to form an alpha-helix. Finally, LAC9 proteins containing His residues substituted for the conserved Cys residues also had reduced DNA-binding activity, indicating that His residues are not equivalent to Cys residues, as had been previously thought. Images PMID:3146691

  4. Effect of sibutramine on 5-hydroxyindole acetic acid levels and selected oxidative biomarkers on brain regions of female rats in the presence of zinc.

    PubMed

    Guzmán, David C; García, Ernestina H; Mejía, Gerardo B; Olguín, Hugo J; Jiménez, Francisca T; Soto, Erick B; Del Angel, Daniel S; Aparicio, Liliana C

    2012-05-01

    A number of drugs, like sibutramine, which are used clinically in weight control, act on serotonergic metabolism. However, their relation with zinc and free radical (FR) production in central nervous system remains unknown. This study aimed to evaluate the effect of sibutramine and zinc on FR production. Female Wistar rats (about 250 g) were used in this study. The animals received 400 μg/kg of zinc and 10 mg/kg of sibutramine intraperitoneally every 36 hr for 15 days. At the end of the study, the rats were killed and their brains used for the measurement of lipid peroxidation thiobarbituric acid-reactive substances (TBARS), reduced glutathione (GSH), hydrogen peroxide (H(2) O(2) ), calcium and 5-hydroxyindole acetic acid (5-HIAA) levels, all by means of validated methods. Corporal weight and food consumption were found to be decreased in the zinc/sibutramine group. TBARS decreased in cortex, hemispheres and medulla oblongata. GSH decreased in cortex, hemispheres and cerebellum in the sibutramine group. Zinc given alone and in combination with sibutramine decreased H(2) O(2) concentration in cortex, hemispheres and cerebellum but increased calcium and 5-HIAA concentration in all brain regions. Our results suggest that sibutramine and zinc are associated with weight loss, an effect that was more pronounced in the group treated with both drugs. Reduction in oxidative stress may be involved in these effects.

  5. Zinc oxide modified with benzylphosphonic acids as transparent electrodes in regular and inverted organic solar cell structures

    SciTech Connect

    Lange, Ilja; Reiter, Sina; Kniepert, Juliane; Piersimoni, Fortunato; Brenner, Thomas; Neher, Dieter; Pätzel, Michael; Hildebrandt, Jana; Hecht, Stefan

    2015-03-16

    An approach is presented to modify the work function of solution-processed sol-gel derived zinc oxide (ZnO) over an exceptionally wide range of more than 2.3 eV. This approach relies on the formation of dense and homogeneous self-assembled monolayers based on phosphonic acids with different dipole moments. This allows us to apply ZnO as charge selective bottom electrodes in either regular or inverted solar cell structures, using poly(3-hexylthiophene):phenyl-C71-butyric acid methyl ester as the active layer. These devices compete with or even surpass the performance of the reference on indium tin oxide/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate. Our findings highlight the potential of properly modified ZnO as electron or hole extracting electrodes in hybrid optoelectronic devices.

  6. Effect of essential fatty acid and zinc supplementation during pregnancy on birth intervals, neonatal piglet brain myelination, stillbirth, and preweaning mortality.

    PubMed

    Vallet, J L; Rempel, L A; Miles, J R; Webel, S K

    2014-06-01

    Omega fatty acids and zinc contribute to physiological pathways that could affect the farrowing process, stillbirth, preweaning mortality, and postweaning return to estrus. To determine effects of omega fatty acids and zinc on these reproductive traits, gilts were mated and fed either a control diet, a diet supplemented with 1.09% Gromega, a diet supplemented with 0.07% zinc sulfate, or a diet supplemented with both Gromega and zinc sulfate from d 80 of gestation until farrowing. Farrowings were video recorded to obtain birth intervals for each piglet, and the number of live and stillborn piglets was recorded. On d 1 after farrowing, piglets were weighed, and the smallest piglet in each litter was sacrificed. A blood sample was collected to measure the immunoglobulin immunocrit ratio, and brain, cerebellum, brain stem, full and empty stomach (to calculate stomach content weight), and heart weights were recorded. Because myelination of specific brain regions may affect preweaning mortality, brain stem, cerebellum, and spinal cord tissues were measured for content of myelin basic proteins and myelin lipids. For remaining piglets, survival to weaning and weaning weights were recorded. Results indicated a weak positive correlation (r = 0.23, P < 0.05) between immunocrit values and brain stem high molecular weight myelin basic protein. There was also a Gromega × zinc supplementation interaction (P < 0.05) on brain stem high molecular weight myelin basic protein in which the combined treatment was greater than the control or each supplement alone. Zinc treatment decreased stillbirth rate during prolonged farrowing and subsequent preweaning survival of low birth weight piglets. Gromega increased overall stillbirth rate and increased the stillbirth rate during prolonged farrowing. There were no relationships between myelin measurements and preweaning survival. In conclusion, combined Gromega and zinc supplementation appeared to improve myelination, but zinc alone improved

  7. Improvement of acetic acid tolerance of Saccharomyces cerevisiae using a zinc-finger-based artificial transcription factor and identification of novel genes involved in acetic acid tolerance.

    PubMed

    Ma, Cui; Wei, Xiaowen; Sun, Cuihuan; Zhang, Fei; Xu, Jianren; Zhao, Xinqing; Bai, Fengwu

    2015-03-01

    Acetic acid is present in cellulosic hydrolysate as a potent inhibitor, and the superior acetic acid tolerance of Saccharomyces cerevisiae ensures good cell viability and efficient ethanol production when cellulosic raw materials are used as substrates. In this study, a mutant strain of S. cerevisiae ATCC4126 (Sc4126-M01) with improved acetic acid tolerance was obtained through screening strains transformed with an artificial zinc finger protein transcription factor (ZFP-TF) library. Further analysis indicated that improved acetic acid tolerance was associated with improved catalase (CAT) activity. The ZFP coding sequence associated with the improved phenotype was identified, and real-time RT-PCR analysis revealed that three of the possible genes involved in the enhanced acetic acid tolerance regulated by this ZFP-TF, namely YFL040W, QDR3, and IKS1, showed decreased transcription levels in Sc4126-M01 in the presence of acetic acid, compared to those in the control strain. Sc4126-M01 mutants having QDR3 and IKS1 deletion (ΔQDR3 and ΔIKS1) exhibited higher acetic acid tolerance than the wild-type strain under acetic acid treatment. Glucose consumption rate and ethanol productivity in the presence of 5 g/L acetic acid were improved in the ΔQDR3 mutant compared to the wild-type strain. Our studies demonstrated that the synthetic ZFP-TF library can be used to improve acetic acid tolerance of S. cerevisiae and that the employment of an artificial transcription factor can facilitate the exploration of novel functional genes involved in stress tolerance of S. cerevisiae.

  8. Improvement of acetic acid tolerance of Saccharomyces cerevisiae using a zinc-finger-based artificial transcription factor and identification of novel genes involved in acetic acid tolerance.

    PubMed

    Ma, Cui; Wei, Xiaowen; Sun, Cuihuan; Zhang, Fei; Xu, Jianren; Zhao, Xinqing; Bai, Fengwu

    2015-03-01

    Acetic acid is present in cellulosic hydrolysate as a potent inhibitor, and the superior acetic acid tolerance of Saccharomyces cerevisiae ensures good cell viability and efficient ethanol production when cellulosic raw materials are used as substrates. In this study, a mutant strain of S. cerevisiae ATCC4126 (Sc4126-M01) with improved acetic acid tolerance was obtained through screening strains transformed with an artificial zinc finger protein transcription factor (ZFP-TF) library. Further analysis indicated that improved acetic acid tolerance was associated with improved catalase (CAT) activity. The ZFP coding sequence associated with the improved phenotype was identified, and real-time RT-PCR analysis revealed that three of the possible genes involved in the enhanced acetic acid tolerance regulated by this ZFP-TF, namely YFL040W, QDR3, and IKS1, showed decreased transcription levels in Sc4126-M01 in the presence of acetic acid, compared to those in the control strain. Sc4126-M01 mutants having QDR3 and IKS1 deletion (ΔQDR3 and ΔIKS1) exhibited higher acetic acid tolerance than the wild-type strain under acetic acid treatment. Glucose consumption rate and ethanol productivity in the presence of 5 g/L acetic acid were improved in the ΔQDR3 mutant compared to the wild-type strain. Our studies demonstrated that the synthetic ZFP-TF library can be used to improve acetic acid tolerance of S. cerevisiae and that the employment of an artificial transcription factor can facilitate the exploration of novel functional genes involved in stress tolerance of S. cerevisiae. PMID:25698512

  9. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  10. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  11. EDTA disodium zinc has superior bioavailability compared to common inorganic or chelated zinc compounds in rats fed a high phytic acid diet.

    PubMed

    Bertinato, Jesse; Sherrard, Lindsey; Plouffe, Louise J

    2012-10-01

    Different zinc (Zn) compounds have unique properties that may influence the amount of Zn absorbed particularly in the presence of phytic acid (PA), a common food component that binds Zn and decreases its bioavailability. In this study, 30-day-old male rats (n=12/diet group) were fed diets supplemented with PA (0.8%) and low levels (8mg Zn/kg diet) of inorganic (Zn oxide, Zn sulphate) or chelated (Zn gluconate, Zn acetate, Zn citrate, EDTA disodium Zn, Zn orotate) Zn compounds for 5 weeks. Two control groups were fed diets supplemented with low or normal (30mg Zn/kg diet) Zn (as Zn oxide) without added PA. Control rats fed the low Zn oxide diet showed depressed Zn status. Addition of PA to this diet exacerbated the Zn deficiency in rats. Growth (body weight gain and femur length) and Zn concentrations in plasma and tissues were similar in rats fed Zn oxide, Zn sulphate, Zn gluconate, Zn acetate, Zn citrate or Zn orotate. Rats fed EDTA disodium Zn showed enhanced growth compared to rats fed Zn oxide or Zn gluconate and had higher Zn concentrations in plasma and femur compared to rats fed all other Zn compounds. Only the haematological profile of rats fed EDTA disodium Zn did not differ from control rats fed normal Zn. These data indicate that in rats fed a high PA diet, bioavailability of commonly used inorganic or chelated Zn compounds does not differ appreciably, but Zn supplied as an EDTA disodium salt has superior bioavailability.

  12. Diel cycling of zinc in a stream impacted by acid rock drainage: Initial results from a new in situ Zn analyzer

    USGS Publications Warehouse

    Chapin, T.P.; Nimick, D.A.; Gammons, C.H.; Wanty, R.B.

    2007-01-01

    Recent work has demonstrated that many trace metals undergo dramatic diel (24-h) cycles in near neutral pH streams with metal concentrations reproducibly changing up to 500% during the diel period (Nimick et al., 2003). To examine diel zinc cycles in streams affected by acid rock drainage, we have developed a novel instrument, the Zn-DigiScan, to continuously monitor in situ zinc concentrations in near real-time. Initial results from a 3-day deployment at Fisher Creek, Montana have demonstrated the ability of the Zn-DigiScan to record diel Zn cycling at levels below 100 ??g/l. Longer deployments of this instrument could be used to examine the effects of episodic events such as rainstorms and snowmelt pulses on zinc loading in streams affected by acid rock drainage. ?? Springer Science+Business Media B.V. 2006.

  13. PM-IRRAS Determination of Molecular Orientation of Phosphonic Acid Self-Assembled Monolayers on Indium Zinc Oxide.

    PubMed

    Sang, Lingzi; Mudalige, Anoma; Sigdel, Ajaya K; Giordano, Anthony J; Marder, Seth R; Berry, Joseph J; Pemberton, Jeanne E

    2015-05-26

    Self-assembled monolayers (SAMs) of phosphonic acids (PAs) on transparent conductive oxide (TCO) surfaces can facilitate improvement in TCO/organic semiconductor interface properties. When ordered PA SAMs are formed on oxide substrates, interface dipole and electronic structure are affected by the functional group properties, orientation, and binding modes of the modifiers. Choosing octylphosphonic acid (OPA), F13-octylphosphonic acid (F13OPA), pentafluorophenyl phosphonic acid (F5PPA), benzyl phosphonic acid (BnPA), and pentafluorobenzyl phosphonic acid (F5BnPA) as a representative group of modifiers, we report polarization modulation-infrared reflection-absorption spectroscopy (PM-IRRAS) of binding and molecular orientation on indium-doped zinc oxide (IZO) substrates. Considerable variability in molecular orientation and binding type is observed with changes in PA functional group. OPA exhibits partially disordered alkyl chains but on average the chain axis is tilted ∼57° from the surface normal. F13OPA tilts 26° with mostly tridentate binding. The F5PPA ring is tilted 23° from the surface normal with a mixture of bidentate and tridentate binding; the BnPA ring tilts 31° from normal with a mixture of bidentate and tridentate binding, and the F5BnPA ring tilts 58° from normal with a majority of bidentate with some tridenate binding. These trends are consistent with what has been observed previously for the effects of fluorination on orientation of phosphonic acid modifiers. These results from PM-IRRAS are correlated with recent results on similar systems from near-edge X-ray absorption fine structure (NEXAFS) and density functional theory (DFT) calculations. Overall, these results indicate that both surface binding geometry and intermolecular interactions play important roles in dictating the orientation of PA modifiers on TCO surfaces. This work also establishes PM-IRRAS as a routine method for SAM orientation determination on complex oxide substrates

  14. Stillbirth rates and folic acid and zinc status in low-socioeconomic pregnant women of Brazilian Amazon.

    PubMed

    Lehti, K K

    1993-01-01

    Twenty-five women in their first trimester and 25 women in their third trimester of pregnancy were randomly chosen from the slum areas of eight towns in the Brazilian Amazon (Manaus, Sao Luis, Boa Vista, Porto Velho, Sao Gabriel, Santarem, Tefe, and Benjamin Constant). Blood samples were removed from the subjects for folic acid and zinc analyses, and the women were asked questions about whether they had suffered from complications during previous pregnancies. It was found that the stillbirth rates reported ranged from 0 to 20/1000 pregnancies. The town that had the highest stillbirth rate (Santarem) also had the highest percentage of women with deficient erythrocyte (red blood cell, RBC) folate status. All of the women in Santarem also had deficient serum folate levels in both trimesters of pregnancy, as well as the lowest average RBC folate value in the third trimester of pregnancy. The same town was also one of two in which the pregnant women had the lowest mean serum zinc levels in the third trimester.

  15. Synthesis of silica coated zinc oxide–poly(ethylene-co-acrylic acid) matrix and its UV shielding evaluation

    SciTech Connect

    Ramasamy, Mohankandhasamy; Kim, Yu Jun; Gao, Haiyan; Yi, Dong Kee; An, Jeong Ho

    2014-03-01

    Graphical abstract: - Highlights: • Well layer thickness controlled silica shell was made on ZnO nanoparticles. • PEAA, an interfacial agent is used to make nanocomposite–polymer matrix by twin-screw extruder. • Si-ZnO/PEAA matrix is highly stable and UV protective as compared to ZnO/PEAA matrix. • Nanoparticle embedded polymer matrix is suggested to make UV shielding fabrics with Nylon4. - Abstract: Silica coated zinc oxide nanoparticles (Si-ZnO NPs) (7 nm thick) were synthesized successfully and melt blended with poly(ethylene-co-acrylic acid) (PEAA resin) to improving ultraviolet (UV) shielding of zinc oxide nanoparticles (ZnO NPs). The photostability of both the ZnO NPs and Si-ZnO NPs were analyzed by the difference in photoluminescence (PL) and by methylene blue (MB) degradation. Photo-degradation studies confirmed that Si-ZnO NPs are highly photostable compared to ZnO NPs. The melt blended matrices were characterized by field emission scanning electron microscopy interfaced with energy dispersive X-ray spectroscopy (FE-SEM-EDX). The UV shielding property was analyzed from the transmittance spectra of UV–visible (UV–vis) spectroscopy. The results confirmed fine dispersion of thick Si-ZnO NPs in the entire resin matrix. Moreover, the Si-ZnO/PEAA showed about 97% UV shielding properties than the ZnO/PEAA.

  16. Photodynamic therapy effect of zinc monoamino phthalocyanine-folic acid conjugate adsorbed on single walled carbon nanotubes on melanoma cells

    NASA Astrophysics Data System (ADS)

    Ogbodu, Racheal O.; Ndhundhuma, Ivy; Karsten, Aletta; Nyokong, Tebello

    2015-02-01

    This work reports on the photodynamic therapy effect of zinc monoamino phthalocyanine linked to folic acid represented as ZnMAPc-FA, which was further immobilized onto single walled carbon nanotube represented as ZnMAPc-FA-SWCNT on melanoma A375 cell line, the effect of SWCNT-FA (without ZnMAPc) was also examined. All the compounds were non-toxic to the melanoma A375 cell line in the absence of light. Upon irradiation of the melanoma A375 cell line with a 676 nm diode laser at a power density of 98 mW/cm2 at 5 J/cm2 about 60% and 63% cell death was observed in the presence of ZnMAPc-FA and ZnMAPc-FA-SWCNT respectively. SWCNT-FA had no significant photodynamic therapy or photothermal effect to the cell, only 23% of cell death was observed after irradiation.

  17. Formation and preliminary in vitro evaluation of a zinc polycarboxylate cement reinforced with neat and acid-treated wollastonite fibers.

    PubMed

    Greish, Yaser E; Hamdan, Najwa M; El Maghraby, Hesham F

    2012-05-01

    Zinc polycarboxylate dental cement is known to form both molecular and mechanical bonds with native tooth materials. However, its relatively weak mechanical properties limit its applications. Wollastonite fibers, with different aspect ratios, were blended with ZnO, prior to its mixing with polyacrylic acid, at weight percentages up to 25%. Setting time, density, compressive strength, and Young's modulus of the formed composites were determined. Composition and morphology of the composites were determined by XRD, IR, and SEM before and after treatment in simulated body fluids. A slight delay in the setting time of the composites was observed. An overall improvement in the compressive strength and modulus of these composites was observed up to 5 wt % of wollastonites, followed by a decrease with increasing the proportion of wollastonite in the composites. Immersion of these composites in SBF solutions resulted in the formation of apatite deposits on the surfaces of the reinforcing fibers.

  18. [Determination of antidangdruff agent salicylic acid, zinc pyrithione, octopirox, climbazole and ketoconazole in shampoo by high performance liquid chromatography].

    PubMed

    Yang, Yan-Wei; Zhu, Ying; Su, Xiao-Qing

    2005-09-01

    A high performance liquid chromatography method was established for determination of antidangdruff agent salicylic acid,zinc pyrithione, octopirox, climbazole and ketoconazole in shampoo on a C18 column using acetonitrile-metholaqueous solution (10 mmol/L KH2 PO4 and 5 mmol/L EDTANa2, pH is adjusted to 4.0 with H3 PO4) (50:10:40) as mobile phase at a flow rate of 1.0 ml/min, with the column temperature 25 degrees C and detection wave 230nm. The precision was less than 3.8% and recovery varied from 92.7% to 104.9%. The experimental results showed that the method was simple, precise and accurate. PMID:16329615

  19. 40 CFR 180.217 - Ammoniates for [ethylenebis-(dithiocarbamato)] zinc and ethyl-enebis [dithiocarbamic acid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Ammoniates for zinc and ethyl-enebis... for zinc and ethyl-enebis bimolecular and trimolecular cyclic anhydrosulfides and disulfides... mixture of 5.2 parts by weight of ammoniates of zinc with 1 part by weight ethylenebis bimolecular...

  20. An acid-stable Zn(II) complex: electrodeposition in sulfuric acid and the effect on the zinc-lead dioxide battery.

    PubMed

    Zhang, Miao Miao; Gong, Yun; Zhang, Pan; Shi, Hui Fang; Lin, Jian Hua

    2014-12-01

    An acid-stable Zn(II) complex formulated as Zn2(HL)2(SO4)·H2O (1) and an acid-unstable complex formulated as Zn2L2·12H2O (2) were hydro(solvo)thermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 features a uninodal 6-connected 2-fold interpenetrating three-dimensional (3D) dense architecture with {4(12)·6(3)}-pcu topology, and complex 2 exhibits a 2-nodal (3, 6)-connected 3D open architecture with (4·6(2))2(4(2)·6(10)·8(3))-rtl topology. The results indicate that the stability of complex 1 in sulfuric acid is probably associated with the coordinated SO4(2-) in the quite dense structure, and complex 1 can also be synthesized via electrodeposition in sulfuric acid; it can improve the discharging characteristics of the zinc-lead dioxide battery at room temperature.

  1. Hydrogen-bubble-propelled zinc-based microrockets in strongly acidic media.

    PubMed

    Gao, Wei; Uygun, Aysegul; Wang, Joseph

    2012-01-18

    Tubular polyaniline (PANI)/Zn microrockets are described that display effective autonomous motion in extreme acidic environments, without any additional chemical fuel. These acid-driven hydrogen-bubble-propelled microrockets have been electrosynthesized using the conical polycarbonate template. The effective propulsion in acidic media reflects the continuous thrust of hydrogen bubbles generated by the spontaneous redox reaction occurring at the inner Zn surface. The propulsion characteristics of PANI/Zn microrockets in different acids and in human serum are described. The observed speed-pH dependence holds promise for sensitive pH measurements in extreme acidic environments. The new microrockets display an ultrafast propulsion (as high as 100 body lengths/s) along with attractive capabilities including guided movement and directed cargo transport. Such acid-driven microtubular rockets offer considerable potential for diverse biomedical and industrial applications. PMID:22188367

  2. Recovering Zinc From Discarded Tires

    NASA Technical Reports Server (NTRS)

    Du Fresne, E. R.

    1984-01-01

    Zinc sulfate monohydrate sold at profit. Shredded tire material steeped in three sulfuric acid baths to extract zinc. Final product removed by evaporating part of solution until product crystallizes out. Recovered as zinc sulfate monohydrate and sold as fertilizer or for general use.

  3. Homochiral frameworks derived from magnesium, zinc and copper salts of L-tartaric acid

    SciTech Connect

    Rood, Jeffrey A.; Noll, Bruce C.; Henderson, Kenneth W.

    2010-01-15

    Five metal-organic frameworks derived from L-tartarate (L-tart=C{sub 4}H{sub 4}O{sub 6}) and the divalent metal ions magnesium, zinc or copper have been prepared and structurally characterized. The frameworks were prepared from the reaction of potassium L-tartrate [KC{sub 4}H{sub 5}O{sub 6}] with the appropriate metal salt in water solutions. The magnesium compound [Mg(L-tart)(H{sub 2}O) contains 1.5H{sub 2}O], 1, crystallizes as a two-dimensional 6{sup 3} sheet structure. The addition of the divergent linker molecules 4,4'-bipyridine (bipy) or trans-1,2-bispyridylethylene (bpe) to systems involving Zn{sup 2+} and Cu{sup 2+} results in the formation of the homochiral three-dimensional structures [Zn{sub 2}(L-tart)2(biyp)(H{sub 2}O) contains 5.25H{sub 2}O], 2, [Cu(L-tart)(bipy) contains 2.33H{sub 2}O], 3, and [Cu(L-tart)(bpe) contains 8H{sub 2}O], 5. Removal of solvent water molecules from 3 resulted in [Cu(L-tart)(bipy) contains 0.2H{sub 2}O], 4. Similar experiments on 2 and 5 resulted in breakdown of the frameworks, illustrating the dependence of the stability of these structures on the guest water molecules. This study reports the structures of two new topological types of binodal nets. - Five metal-organic frameworks derived from L-tartarate and the divalent metal ions magnesium, zinc or copper have been prepared and structurally characterized. Significant structural diversity is displayed within this set of complexes.

  4. Affinity purification and characterisation of zinc chelating peptides from rapeseed protein hydrolysates: possible contribution of characteristic amino acid residues.

    PubMed

    Xie, Ningning; Huang, Jingjing; Li, Bo; Cheng, Jianghua; Wang, Zhuochen; Yin, Junfeng; Yan, Xiaoming

    2015-04-15

    Zinc is an essential trace element for human growth and development. In this work, zinc-chelating peptides from rapeseed protein hydrolysates produced with alcalase were investigated by affinity chromatography with immobilized zinc and Sephadex G-25 gel filtration. Four small peptides, namely, Ala-Arg, Asn-Ser-Met (NSM), Gly-Lys-Arg, and Glu-Pro-Ser-His, were obtained and identified by reversed-phase high-performance liquid chromatography and electrospray ionization mass spectrometry. The zinc-chelating ability of the four peptides was further validated by inductively coupled plasma atomic emission spectrometry (ICP-AES). NSM was found to exhibit the highest zinc-chelating rate, which was better than that of reduced glutathione. We speculated that the Asn residue at the amino-terminus might facilitate this zinc-chelating ability. Therefore, utilizing small peptides from rapeseed protein as novel carriers for zinc supplement was feasible.

  5. Zinc Enzymes.

    ERIC Educational Resources Information Center

    Bertini, I.; And Others

    1985-01-01

    Discusses the role of zinc in various enzymes concerned with hydration, hydrolysis, and redox reactions. The binding of zinc to protein residues, properties of noncatalytic zinc(II) and catalytic zinc, and the reactions catalyzed by zinc are among the topics considered. (JN)

  6. Assessment of zinc loading in an acid rock drainage alpine catchment using a tracer-injection and synoptic-sampling study

    NASA Astrophysics Data System (ADS)

    Crouch, C. M.; McKnight, D. M.; Todd, A.

    2010-12-01

    Seasonal low flow conditions in acid rock drainage (ARD) streams result in increased acidity and metal ion concentrations - changes that have been shown to become more pronounced with longer dry periods. These resulting increases in acidity and metals concentrations may pose an increasing danger to aquatic ecosystems and drinking water supplies. For example, in many ARD-impacted mountain streams, fish populations are not self-sustaining. The study site in the Upper Snake River watershed in Colorado is an alpine catchment impacted by acid rock drainage thought to originate from the natural weathering of pyrite whereas the main stem of the Snake River and its other tributaries are impacted by accelerated ARD resulting from historic mining activities. Because concentrations toxic to aquatic life persist well downstream of the ARD inputs, dissolved zinc is the primary metal of concern in this study. A compilation of historic data from the Snake River Watershed during the low flow months of September and October indicates that zinc concentrations have increased four-fold over the past 30 years. We hypothesize that this increase is due to changes in groundwater flow patterns caused by climate change and associated earlier peak snowmelt (by 2-3 weeks), resulting in lower stream flows and drier soils in late summer. The observed increase in background metals concentrations has implications for mitigation of former mining sites. A synoptic study to identify discrete surface water sources of zinc loading indicated a significant input from a tributary on the north side of the catchment. Zinc concentrations here measured an order of magnitude higher than in the main stem of the stream, and were correlated with increases in sulfate, hardness, and total metals, supporting our contention that increasing zinc concentrations are driven by the acceleration of ARD in the watershed. The current research further investigates sources of metal-rich inflows to the tributary using a tracer

  7. Organic acids induce tolerance to zinc- and copper-exposed fungi under various growth conditions.

    PubMed

    Sazanova, Katerina; Osmolovskaya, Natalia; Schiparev, Sergey; Yakkonen, Kirill; Kuchaeva, Ludmila; Vlasov, Dmitry

    2015-04-01

    Heavy metals, Zn and Cu, in high concentration (2 mM for Zn and 0.5 mM for Cu) have some inhibiting effect on the growth of Aspergillus niger and Penicillium citrinum. Toxic effects of these metals considerably depend on cultivation conditions including nitrogen sources, pH of nutrient media, and its consistency (presence or absence of agar). In general, nitrate media provides less inhibiting effect on fungal growth under heavy metal exposure than ammonium-containing media. Adding of Zn in nitrate media induces oxalic acid production by fungi. Importance of oxalic acid production in detoxification of heavy metals is confirmed by the formation of Zn-containing crystals in fungal cultures. Cu bringing to the cultural media had no stimulating effect on oxalic acid production as well as no copper-containing crystals were observed. But proceeding from essential increase in oxalic acid production during a long-term fungi adaptation to Cu, it may be proposed that oxalic acid plays some functional role in Cu tolerance of fungi as well. It may be concluded that the role of organic acids and oxalate, in particular, in fungi tolerance and adaptation to heavy metals can be determined by the nature of the metal and its ability to form stable complexes with an acid anion. Stimulating effect of metals on acid production is not universal for all species of fungi and largely depends on metal concentration, nitrogen form in a medium, and other cultivation conditions.

  8. Synthesis, structural characterization and DNA interaction of zinc complex from 2,6-diacetylpyridine dihydrazone and {4-[(2E)-2-(hydroxyimino)acetyl]phenoxy} acetic acid.

    PubMed

    Gup, Ramazan; Gökçe, Cansu; Dilek, Nefise

    2015-03-01

    A new water soluble zinc complex has been prepared and structurally characterized. The Zn(II) complex was synthesized by the reaction of 2,6-diacetylpyridine dihydrazone (dph) with {4-[(2E)-2-(hydroxyimino)acetyl]phenoxy} acetic acid (H₂L) in the presence of zinc(II) acetate. Single crystal X-ray diffraction study revealed that the zinc ion is situated in distorted trigonal-bipyramidal environment where the equatorial position is occupied by the nitrogen atom of pyridine ring and the oxygen atoms of acetate groups of two oxime ligands (H₂L) whereas the axial positions of the zinc complex are occupied by the imine nitrogen atoms of dph ligand. Characterization of the complex with FTIR, (1)H and (13)C NMR, UV-vis and elemental analysis also confirmed the proposed structure. Interaction of the Zn(II) complex with calf-thymus DNA (CT-DNA) was investigated through UV-vis spectroscopy and viscosity measurements. The results suggest that the complex preferably bind to DNA through the groove binding mode. The zinc complex cleaves plasmid pBR 322 DNA in the presence and absence of an oxidative agent (H₂O₂), possibly through a hydrolytic pathway which is also supported by DNA cleave experiments in the presence of different radical scavengers. The nuclease activity of the zinc complex significantly depends on concentration of the complex and incubation time both in the presence and absence of H₂O₂. DNA cleave activity is inhibited in the presence of methyl green indicating that the zinc complex seems to bind the major groove of DNA.

  9. Silver nanoparticles in combination with acetic acid and zinc oxide quantum dots for antibacterial activities improvement-A comparative study

    NASA Astrophysics Data System (ADS)

    Sedira, Sofiane; Ayachi, Ahmed Abdelhakim; Lakehal, Sihem; Fateh, Merouane; Achour, Slimane

    2014-08-01

    Due to their remarkable antibacterial/antivirus properties, silver nanoparticles (Ag NPs) and zinc oxide quantum dots (ZnO Qds) have been widely used in the antimicrobial field. The mechanism of action of Ag NPs on bacteria was recently studied and it has been proven that Ag NPs exerts their antibacterial activities mainly by the released Ag+. In this work, Ag NPs and ZnO Qds were synthesized using polyol and hydrothermal method, respectively. It was demonstrated that Ag NPs can be oxidized easily in aqueous solution and the addition of acetic acid can increase the Ag+ release which improves the antibacterial activity of Ag NPs. A comparative study between bactericidal effect of Ag NPs/acetic acid and Ag NPs/ZnO Qds on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus was undertaken using agar diffusion method. The obtained colloids were characterized using UV-vis spectroscopy, Raman spectrometry, X-ray diffraction (XRD), transmission electron microscopy (TEM) and atomic force microscopy (AFM).

  10. Zinc poisoning

    MedlinePlus

    ... other materials to make industrial items such as paint, dyes, and more. These combination substances can be ... Compounds used to make paint, rubber, dyes, wood preservatives, and ... Zinc chloride Zinc oxide (relatively nonharmful) Zinc ...

  11. Relationship between cadmium, zinc, Cd-peptide, and organic acid in tobacco suspension cells

    SciTech Connect

    Krotz, R.M.; Evangelou, B.P.; Wagner, G.J. )

    1989-10-01

    Responses of tobacco (Nicotiana tabacum) suspension cells to Cd and Zn were studied in the presence and absence of ligand of Cd-peptide in order to understand the role of this peptide versus other mechanisms in Cd and Zn accumulation and accommodation in plants. With 45 micromolar Cd and 300 micromolar Zn (non-growth-inhibiting levels), metals appeared rapidly within cells, and intracellular Cd and Zn reached medium concentrations after 6 to 10 hours. Cd-peptide was observed in response to Cd after 2 hours, but this form only accounted for {approximately}30% of soluble Cd after 24 hours. Peptide was not observed in cells exposed to 300 micromolar Zn for up to 7 days. Organic acid-to-metal stoichiometry indicated that endogenous organic acid content of cells was more than sufficient to complex absorbed metals and no evidence was found for stimulation of organic acid biosynthesis by Cd or Zn. Metal-complexing potential of organic acids for Cd and Zn versus endogenous cations is discussed as is vacuolar-extravacuolar distribution of metals. The absence of Cd-peptide does not limit Cd-accumulation in the system studied. Results suggest that tobacco suspension cells accommodte the presence of non-growth-inhibiting and growth-inhibiting levels of Cd and Zn by sequestration in the vacuole as complexes with endogenous organic acids and that this may be a principal means for accommodation of Cd as well as Zn in the presence and absence of Cd-peptide.

  12. Leaching and selective copper recovery from acidic leachates of Três Marias zinc plant (MG, Brazil) metallurgical purification residues.

    PubMed

    Sethurajan, Manivannan; Huguenot, David; Lens, Piet N L; Horn, Heinrich A; Figueiredo, Luiz H A; van Hullebusch, Eric D

    2016-07-15

    Zinc plant purification residue (ZPR), a typical Zn-hydrometallurgical waste, was collected from the Três Marias Zn plant (MG, Brazil). ZPR was characterized for its metal content and fractionation, mineralogy, toxicity and leachability. Toxicity characteristics leaching procedure (TCLP) and European Community Bureau of Reference (BCR) sequential extraction results revealed that this ZPR displays high percentages of metals (Cd, Cu, Zn and Pb) in the highly mobilizable fractions, increasing its hazardous potential. Bulk chemical analysis, pH dependent leaching and acid (H2SO4) leaching studies confirm that the ZPR is polymetallic, rich in Cd, Cu and Zn. The sulfuric acid concentration (1 M), agitation speed (450 rpm), temperature (40 °C) and pulp density (20 g L(-1)) were optimized to leach the maximum amount of heavy metals (Cd, Cu and Zn). Under optimum conditions, more than 50%, 70% and 60% of the total Cd, Cu and Zn present in the ZPR can be leached, respectively. The metals in the acid leachates were investigated for metal sulfide precipitation with an emphasis on selective Cu recovery. Metal sulfide precipitation process parameters such as initial pH and Cu to sulfide ratio were optimized as pH 1.5 and 1:0.5 (Cu:sulfide) mass ratio, respectively. Under optimum conditions, more than 95% of Cu can be selectively recovered from the polymetallic ZPR leachates. The Cu precipitates characterization studies reveal that they are approximately 0.1 μm in diameter and mainly consist of Cu and S. XRD analysis showed covellite (CuS), chalcanthite (CuSO4·5H2O) and natrochalcite (NaCu2(SO4)2(OH)·H2O) as the mineral phases. ZPRs can thus be considered as an alternative resource for copper production. PMID:27074201

  13. Predicting chronic toxicity of sediments spiked with zinc: An evaluation of the acid-volatile sulfide model using a life-cycle test with the midge Chironomus tentans

    SciTech Connect

    Sibley, P.K.; Ankley, G.T.; Cotter, A.M.; Leonard, E.N.

    1996-12-01

    The development of sediment quality criteria for the cationic metals cadmium, copper, lead, nickel, and zinc has focused on the use of acid-volatile sulfide (AVS) as the primary normalization phase for predicting interstitial pore-water concentrations and bioavailability of the metals. To date, most research in support of AVS in this context has utilized short-term laboratory exposures, with a relative paucity of information pertaining to long-term exposures. The purpose of this study, therefore, was to investigate the use of AVS as a predictor of metal toxicity to a benthic organism in a long-term laboratory exposure. Clean sediment was spiked with zinc to obtain nominal treatments ranging from {minus}2.34 to 58.5 {micro} g/g dry weight with respect to the molar difference between simultaneously extracted metal (SEM) and AVS. The test was initiated with newly hatched larvae of the midge Chironomus tentans and carried through one complete generation (56 d) during which survival, growth, emergence, and reproduction were monitored. When the molar difference between SEM and AVS was < 0, the concentration of zinc in the sediment interstitial water was low and no adverse effects were observed for any of the biological endpoints measured. Conversely, when SEM-AVS exceeded 0, a dose-dependent increase in the relative concentration of zinc in the pore water was detected. However, the absolute concentration of pore-water zinc at each treatment declined over the course of the study, corresponding to an increase in sediment AVS and to a loss of zinc due to diffusion into the overlying water, which was renewed twice daily. Only when SEM-AVS exceeded 0 were significant reductions in survival, growth, emergence, and reproduction observed. Together, the chemical and biological data from this study compare favorably with observations made in short-term exposures and thus support the use of AVS as a normalization phase for predicting toxicity in metal-contaminated sediments.

  14. The antidandruff efficacy of a shampoo containing piroctone olamine and salicylic acid in comparison to that of a zinc pyrithione shampoo.

    PubMed

    Lodén, M; Wessman, C

    2000-08-01

    Dandruff (pityriasis capitis) is a chronic scalp condition characterized by scaling and sometimes itching and redness. Shampoos containing antifungal agents are used to control the scaling condition. In the present study, two shampoos with different actives are compared in a double-blind, randomised and bilateral study on 19 subjects. One shampoo contained piroctone olamine (0.75%) combined with salicylic acid (2%) and the other contained zinc pyrithione (1%) as active ingredient. The subjects were treated twice weekly with the shampoos for almost 4 weeks. Before each treatment the degree of dandruff was evaluated. Both shampoos were highly effective in reducing the dandruff. The combination of piroctone olamine and salicylic acid appeared to be slightly more effective than zinc pyrithione in reducing the severity and area affected by the scaling. PMID:18503415

  15. Substitution of DNA-Contacting Amino Acids with Functional Variants in the Gata-1 Zinc Finger: A Structurally and Phylogenetically Guided Mutagenesis

    PubMed Central

    Vonderfecht, Tyson R.; Schroyer, Daniel L.; Schenck, Brandy L.; McDonough, Virginia M.; Pikaart, Michael J.

    2008-01-01

    DNA binding functionality among transcription factor proteins is afforded by a number of structural motifs, such as the helix-turn-helix, helix-loop-helix, and zinc finger domains. The common thread among these diverse structures is their sequence-specific binding to essential promoter or other genetic regulatory sequences with high selectivity and affinity. One such motif, present in a wide range of organisms from bacteria to vertebrates, is the Gata-type zinc finger. This family of DNA-binding proteins is characterized by the presence of one or two (Cys)4 metal binding sites which recognize the protein’s eponymous binding site, GATA. Unlike other conserved DNA binding domains, Gata proteins appear to be restricted to binding consensus GATA sequences, or near variations, in DNA. Since the architecture of the Gata finger seems built around recognizing this particular sequence, we set out to define the allowable range of amino acid substitutions along the DNA-binding surface of a Gata finger that could continue to support sequence specific DNA binding activity. Accordingly, we set up a one-hybrid screen in yeast based on the chicken Gata-1 C-terminal zinc finger. Mutant libraries were generated at five amino acids identified in the Gata-DNA structure as likely to mediate sequence-specific contacts between the Gata finger and DNA. These libraries were designed to give as exhaustive amino acid coverage as possible such that almost all alternative amino acids were screened at each of the five probed positions. Screening and characterization of these libraries revealed several functional amino acid substitutions at two leucines which contact the DNA at the 3’ and 5’ flanks of the GATA binding site, but no functional substituents for amino acids near the core of the binding site. This pattern is consistent with amino acid sequences of known DNA-binding Gata fingers. PMID:18328814

  16. Populus yunnanensis males adopt more efficient protective strategies than females to cope with excess zinc and acid rain.

    PubMed

    Jiang, Hao; Korpelainen, Helena; Li, Chunyang

    2013-05-01

    Dioecious plants show sexually different responses to environmental stresses. However, little is known about the dimorphic morphological and physiological responses to soil pollution. To investigate sex-related adaptive responses of Populus yunnanensis seedlings when exposed to excess zinc (Zn), acid rain (AR) and their combination (Zn+AR), we analyzed growth parameters, Zn accumulation and allocation, photosynthetic capacity and biochemical responses under different treatments. Results revealed that both excess Zn and Zn+AR have a negative effect on plant growth. Males have a greater potential than females to enrich Zn. The photosynthesis limitation could be attributable to a lower stomatal conductance, photosynthetic nitrogen use efficiency and nitrate reductase activity induced by Zn accumulation. Overproduction of reactive oxygen species was detected, and females showed higher levels of H2O2 and O2- than did males under excess Zn and Zn+AR. In addition, indicators related to plant injury showed expected increases and exhibited sexual differences. Males synthesized more biochemical molecules, such as proline and non-protein thiol, showing a stronger defense capacity in responses to either excess Zn or Zn+AR. Taking into account the Zn accumulation and the resulting injuries in plants, we suggest that excess Zn causes sex-related adaptive responses and males possess a more effective self-protection mechanism, Zn-stressed individuals suffering from AR did not show notable aggravation or alleviation when compared to damages induced by excess Zn alone.

  17. TEMPO-functionalized zinc phthalocyanine: synthesis, magnetic properties, and its utility for electrochemical sensing of ascorbic acid.

    PubMed

    Korkut, Sibel Eken; Akyüz, Duygu; Özdoğan, Kemal; Yerli, Yusuf; Koca, Atıf; Şener, M Kasım

    2016-02-21

    Zinc(ii) phthalocyanine (TEMPO-ZnPc), peripherally functionalized with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals is synthesized and its magneto structural and electrochemical behaviors are investigated. TEMPO-ZnPc shows multi-electron ring based reduction reactions and a TEMPO based oxidation reaction. Spectroelectrochemical measurements support these peak assignments. TEMPO-ZnPc is tested as a homogeneous and heterogeneous ascorbic acid (AA) sensor. Disappearance of TEMPO-ZnPc based reduction processes and the observation of new waves at around 0 and 1.20 V with respect to increasing AA concentration indicate the interaction of TEMPO-ZnPc with AA and usability of the complex as an electrochemical AA sensor. For practical usage as heterogeneous electrocatalysts for AA sensing, a glassy carbon electrode (GCE) is coated with TEMPO-ZnPc (GCE/TEMPO-ZnPc) and this modified electrode is tested as a heterogeneous AA sensor. The redox peak of GCE/TEMPO-ZnPc at 0.81 V decreases the peak current while a new wave is observed at 0.65 V during the titration of the electrolyte with AA. GCE/TEMPO-ZnPc sense AA with 1.75 × 10(-6) mol dm(-3) LOD with a sensitivity of 1.89 × 10(3) A cm mol(-1).

  18. Preparing Poly (Lactic-co-Glycolic Acid) (PLGA) Microspheres Containing Lysozyme-Zinc Precipitate Using a Modified Double Emulsion Method

    PubMed Central

    Nafissi Varcheh, Nastaran; Luginbuehl, Vera; Aboofazeli, Reza; Peter Merkle, Hans

    2011-01-01

    Lysozyme, as a model protein, was precipitated through the formation of protein-Zn complex to micronize for subsequent encapsulation within poly (lactic-co-glycolic acid) (PLGA) microspheres. Various parameters, including pH, type and concentration of added salts and protein concentration, were modified to optimize the yield of protein complexation and precipitation. The resulting protein particles (lysozyme-Zn complex as a freshly prepared suspension or a freeze-dried solid) were then loaded into PLGA (Resomer® 503H) microspheres, using a double emulsion technique and microspheres encapsulation efficiency and their sizes were determined. It was observed that salt type could significantly influence the magnitude of protein complexation. At the same conditions, zinc chloride was found to be more successful in producing pelletizable lysozyme. Generally, higher concentrations of protein solution led also to the higher yields of complexation and at the optimum conditions, the percentage of pelletizable lysozyme reached to 80%. Taking advantage of this procedure, a modified technique for preparation of protein-loaded PLGA microspheres was established, although it is also expected that this technique increases the protein drugs stabilization during the encapsulation process. PMID:24250344

  19. Ultra-sensitive detection of zinc oxide nanowires using a quartz crystal microbalance and phosphoric acid DNA

    NASA Astrophysics Data System (ADS)

    Jang, Kuewhan; You, Juneseok; Park, Chanhoo; Park, Hyunjun; Choi, Jaeyeong; Choi, Chang-Hwan; Park, Jinsung; Lee, Howon; Na, Sungsoo

    2016-09-01

    Recent advancements of nanomaterials have inspired numerous scientific and industrial applications. Zinc oxide nanowires (ZnO NWs) is one of the most important nanomaterials due to their extraordinary properties. However, studies performed over the past decade have reported toxicity of ZnO NWs. Therefore, there has been increasing demand for effective detection of ZnO NWs. In this study, we propose a method for the detection of ZnO NW using a quartz crystal microbalance (QCM) and DNA probes. The detection method is based on the covalent interaction between ZnO NWs and the phosphoric acid group of single-stranded DNA (i.e., linker DNA), and DNA hybridization between the linker DNA and the probe DNA strand on the QCM electrode. Rapid, high sensitivity, in situ detection of ZnO NWs was demonstrated for the first time. The limit of detection was 10‑4 μg ml‑1 in deionized water, which represents a sensitivity that is 100000 times higher than the toxic ZnO NW concentration level. Moreover, the selectivity of the ZnO NW detection method was demonstrated by comparison with other types of nanowires and the method was able to detect ZnO NWs in tap water sensitively even after stored for 14 d in a refrigerator. The performance of our proposed method was sufficient to achieve detection of ZnO NW in the ‘real-world’ environment.

  20. Ultra-sensitive detection of zinc oxide nanowires using a quartz crystal microbalance and phosphoric acid DNA

    NASA Astrophysics Data System (ADS)

    Jang, Kuewhan; You, Juneseok; Park, Chanhoo; Park, Hyunjun; Choi, Jaeyeong; Choi, Chang-Hwan; Park, Jinsung; Lee, Howon; Na, Sungsoo

    2016-09-01

    Recent advancements of nanomaterials have inspired numerous scientific and industrial applications. Zinc oxide nanowires (ZnO NWs) is one of the most important nanomaterials due to their extraordinary properties. However, studies performed over the past decade have reported toxicity of ZnO NWs. Therefore, there has been increasing demand for effective detection of ZnO NWs. In this study, we propose a method for the detection of ZnO NW using a quartz crystal microbalance (QCM) and DNA probes. The detection method is based on the covalent interaction between ZnO NWs and the phosphoric acid group of single-stranded DNA (i.e., linker DNA), and DNA hybridization between the linker DNA and the probe DNA strand on the QCM electrode. Rapid, high sensitivity, in situ detection of ZnO NWs was demonstrated for the first time. The limit of detection was 10-4 μg ml-1 in deionized water, which represents a sensitivity that is 100000 times higher than the toxic ZnO NW concentration level. Moreover, the selectivity of the ZnO NW detection method was demonstrated by comparison with other types of nanowires and the method was able to detect ZnO NWs in tap water sensitively even after stored for 14 d in a refrigerator. The performance of our proposed method was sufficient to achieve detection of ZnO NW in the ‘real-world’ environment.

  1. Populus yunnanensis males adopt more efficient protective strategies than females to cope with excess zinc and acid rain.

    PubMed

    Jiang, Hao; Korpelainen, Helena; Li, Chunyang

    2013-05-01

    Dioecious plants show sexually different responses to environmental stresses. However, little is known about the dimorphic morphological and physiological responses to soil pollution. To investigate sex-related adaptive responses of Populus yunnanensis seedlings when exposed to excess zinc (Zn), acid rain (AR) and their combination (Zn+AR), we analyzed growth parameters, Zn accumulation and allocation, photosynthetic capacity and biochemical responses under different treatments. Results revealed that both excess Zn and Zn+AR have a negative effect on plant growth. Males have a greater potential than females to enrich Zn. The photosynthesis limitation could be attributable to a lower stomatal conductance, photosynthetic nitrogen use efficiency and nitrate reductase activity induced by Zn accumulation. Overproduction of reactive oxygen species was detected, and females showed higher levels of H2O2 and O2- than did males under excess Zn and Zn+AR. In addition, indicators related to plant injury showed expected increases and exhibited sexual differences. Males synthesized more biochemical molecules, such as proline and non-protein thiol, showing a stronger defense capacity in responses to either excess Zn or Zn+AR. Taking into account the Zn accumulation and the resulting injuries in plants, we suggest that excess Zn causes sex-related adaptive responses and males possess a more effective self-protection mechanism, Zn-stressed individuals suffering from AR did not show notable aggravation or alleviation when compared to damages induced by excess Zn alone. PMID:23415309

  2. Ultra-sensitive detection of zinc oxide nanowires using a quartz crystal microbalance and phosphoric acid DNA.

    PubMed

    Jang, Kuewhan; You, Juneseok; Park, Chanhoo; Park, Hyunjun; Choi, Jaeyeong; Choi, Chang-Hwan; Park, Jinsung; Lee, Howon; Na, Sungsoo

    2016-09-01

    Recent advancements of nanomaterials have inspired numerous scientific and industrial applications. Zinc oxide nanowires (ZnO NWs) is one of the most important nanomaterials due to their extraordinary properties. However, studies performed over the past decade have reported toxicity of ZnO NWs. Therefore, there has been increasing demand for effective detection of ZnO NWs. In this study, we propose a method for the detection of ZnO NW using a quartz crystal microbalance (QCM) and DNA probes. The detection method is based on the covalent interaction between ZnO NWs and the phosphoric acid group of single-stranded DNA (i.e., linker DNA), and DNA hybridization between the linker DNA and the probe DNA strand on the QCM electrode. Rapid, high sensitivity, in situ detection of ZnO NWs was demonstrated for the first time. The limit of detection was 10(-4) μg ml(-1) in deionized water, which represents a sensitivity that is 100000 times higher than the toxic ZnO NW concentration level. Moreover, the selectivity of the ZnO NW detection method was demonstrated by comparison with other types of nanowires and the method was able to detect ZnO NWs in tap water sensitively even after stored for 14 d in a refrigerator. The performance of our proposed method was sufficient to achieve detection of ZnO NW in the 'real-world' environment.

  3. Ultra-sensitive detection of zinc oxide nanowires using a quartz crystal microbalance and phosphoric acid DNA.

    PubMed

    Jang, Kuewhan; You, Juneseok; Park, Chanhoo; Park, Hyunjun; Choi, Jaeyeong; Choi, Chang-Hwan; Park, Jinsung; Lee, Howon; Na, Sungsoo

    2016-09-01

    Recent advancements of nanomaterials have inspired numerous scientific and industrial applications. Zinc oxide nanowires (ZnO NWs) is one of the most important nanomaterials due to their extraordinary properties. However, studies performed over the past decade have reported toxicity of ZnO NWs. Therefore, there has been increasing demand for effective detection of ZnO NWs. In this study, we propose a method for the detection of ZnO NW using a quartz crystal microbalance (QCM) and DNA probes. The detection method is based on the covalent interaction between ZnO NWs and the phosphoric acid group of single-stranded DNA (i.e., linker DNA), and DNA hybridization between the linker DNA and the probe DNA strand on the QCM electrode. Rapid, high sensitivity, in situ detection of ZnO NWs was demonstrated for the first time. The limit of detection was 10(-4) μg ml(-1) in deionized water, which represents a sensitivity that is 100000 times higher than the toxic ZnO NW concentration level. Moreover, the selectivity of the ZnO NW detection method was demonstrated by comparison with other types of nanowires and the method was able to detect ZnO NWs in tap water sensitively even after stored for 14 d in a refrigerator. The performance of our proposed method was sufficient to achieve detection of ZnO NW in the 'real-world' environment. PMID:27479871

  4. Synthesis of protocatechuic acid-zinc/aluminium-layered double hydroxide nanocomposite as an anticancer nanodelivery system

    NASA Astrophysics Data System (ADS)

    Barahuie, Farahnaz; Hussein, Mohd Zobir; Gani, Shafinaz Abd; Fakurazi, Sharida; Zainal, Zulkarnain

    2015-01-01

    Protocatechuic acid, an active anticancer agent, has been intercalated into Zn/Al-layered double hydroxide at Zn/Al=2) using two different preparation methods, co-precipitation and ion-exchange, which are labelled as PZAE and PZAC, respectively. The release of protocatechuate from the nanocomposites occurred in a controlled manner and was fitted satisfactorily to pseudo-second order kinetics. The basal spacing of the resulting nanocomposites PZAE and PZAC was 10.2 and 11.0 Å, respectively, indicating successful intercalation of protocatechuate anions into the interlayer galleries of Zn/Al-NO3-LDH in a monolayer arrangement with angles of 24 and 33° from the z-axis in PZAE and PZAC, respectively. The formation of nanocomposites was further confirmed by a Fourier transform infrared study. Thermogravimetric and differential thermogravimetric analyses indicated that the thermal stability of the intercalated protocatechuic acid was significantly enhanced compared to its free protocatechuic acid, and the drug content in the nanocomposites was estimated to be approximately 32.6% in PZAE and 29.2% in PZAC. Both PZAE and PZAC nanocomposites inhibit the growth of human cervical, liver and colorectal cancer cell lines and exhibit no toxic effects towards normal fibroblast 3T3 cell after 72 h of treatment.

  5. The Arabidopsis ZINC FINGER PROTEIN3 Interferes with Abscisic Acid and Light Signaling in Seed Germination and Plant Development1[C][W][OPEN

    PubMed Central

    Joseph, Mary Prathiba; Papdi, Csaba; Kozma-Bognár, László; Nagy, István; López-Carbonell, Marta; Rigó, Gábor; Koncz, Csaba; Szabados, László

    2014-01-01

    Seed germination is controlled by environmental signals, including light and endogenous phytohormones. Abscisic acid (ABA) inhibits, whereas gibberellin promotes, germination and early seedling development, respectively. Here, we report that ZFP3, a nuclear C2H2 zinc finger protein, acts as a negative regulator of ABA suppression of seed germination in Arabidopsis (Arabidopsis thaliana). Accordingly, regulated overexpression of ZFP3 and the closely related ZFP1, ZFP4, ZFP6, and ZFP7 zinc finger factors confers ABA insensitivity to seed germination, while the zfp3 zfp4 double mutant displays enhanced ABA susceptibility. Reduced expression of several ABA-induced genes, such as RESPONSIVE TO ABSCISIC ACID18 and transcription factor ABSCISIC ACID-INSENSITIVE4 (ABI4), in ZFP3 overexpression seedlings suggests that ZFP3 negatively regulates ABA signaling. Analysis of ZFP3 overexpression plants revealed multiple phenotypic alterations, such as semidwarf growth habit, defects in fertility, and enhanced sensitivity of hypocotyl elongation to red but not to far-red or blue light. Analysis of genetic interactions with phytochrome and abi mutants indicates that ZFP3 enhances red light signaling by photoreceptors other than phytochrome A and additively increases ABA insensitivity conferred by the abi2, abi4, and abi5 mutations. These data support the conclusion that ZFP3 and the related ZFP subfamily of zinc finger factors regulate light and ABA responses during germination and early seedling development. PMID:24808098

  6. Role of zinc along with ascorbic acid and folic acid during long-term in vitro albumin glycation.

    PubMed

    Tupe, Rashmi Santosh; Agte, Vaishali Vilas

    2010-02-01

    The present study aimed to investigate the role of Zn alone and in the presence of ascorbic acid (AA) and folic acid (FA) in albumin glycation. Glycation was performed by incubations of bovine serum albumin with glucose at 37 degrees C along with Zn, AA or FA separately and Zn + AA or Zn + FA for 150 d. Glycation-mediated modifications were monitored as fluorescence of advanced glycation endproducts, carbonyl formation, beta aggregation (thioflavin T and Congo red dyes), albumin-bound Zn, thiol groups and glycated aggregate's toxicity in HepG2 cells. Zn inhibited glycation and beta aggregation, probably due to observed higher protein-bound Zn. It also protected protein thiols and increased cell survival. AA and FA enhanced glycation, which was lowered in Zn-co-incubated samples. FA increased albumin-bound Zn and showed maximum cell survival. Although these results warrant further in vivo investigation, the present data help in the understanding of the interplay of Zn with micronutrients in albumin glycation.

  7. Enzymatic hydrolysis of cellulose pretreated with zinc chloride and hydrochloric acid

    SciTech Connect

    Chen, L.F.; Gong, C.S.

    1982-01-01

    Microcrystalline cellulose, Avicel, was dissolved in a concentrated solution of ZnCl/sub 2/ and 0.5% hydrochloric acid followed by heating at 145/sup 0/C for 6 min. after cooling, cellulose in its amorphous form was precipitated by the addition of acetone. The resulting cellulose was hydrolyzed by cellulase derived from Trichoderma viride. At concentrations of 20% cellulose and 1% cellulase, cellulose was hydrolyzed completely for form a solution of 19% glucose and 1% cellobiose within 72 h of incubation. 1 figure, 5 tables.

  8. Combined iron and folic acid supplementation with or without zinc reduces time to walking unassisted among Zanzibari infants 5- to 11-mo old.

    PubMed

    Olney, Deanna K; Pollitt, Ernesto; Kariger, Patricia K; Khalfan, Sabra S; Ali, Nadra S; Tielsch, James M; Sazawal, Sunil; Black, Robert; Allen, Lindsay H; Stoltzfus, Rebecca J

    2006-09-01

    Iron and zinc deficiencies have been associated with delayed motor development in nutritionally at-risk children, albeit inconsistently. In this community-based, randomized double-blind trial, iron+folic acid (FeFA) (12.5 mg Fe + 50 mug folic acid), zinc (Zn) (10 mg), and iron+folic acid+zinc (FeFA+Zn) supplements or a placebo were given daily for 1 y to nutritionally at-risk children in Pemba, Zanzibar. The effects of these treatments on attaining unassisted walking were evaluated using survival analysis for 354 children aged 5-11 mo at the start of supplementation. Treatment effects on changes in hemoglobin (Hb) and zinc protoporphyrin (ZPP) and height-for-age (HAZ) and weight-for-age (WAZ) Z scores were evaluated using linear regression. Attained motor milestone was recorded every 2 wk for 1 y. Hb, ZPP, HAZ, and WAZ were measured at baseline and after 6 mo of treatment. FeFA with or without Zn reduced the time it took for children to walk assisted. Children who received any iron walked unassisted sooner than those who received no iron [median difference approximately 15 d, P = 0.035, risk ratio (RR) = 1.28, 95% CI = 1.02, 1.61] and this effect was stronger in those who had iron deficiency anemia (IDA) at baseline (median difference was approximately 30 d; P = 0.002; RR = 1.68; 95% CI = 1.21, 2.32). FeFA alone and Zn alone improved Hb and ZPP compared with placebo. There were no significant treatment effects on changes in HAZ or WAZ. The effects of treatment on time to walking may have been mediated by improvements in iron status or hemoglobin, but were not mediated through improvements in growth.

  9. [Effect of mutations and modifications of amino acid residues on zinc-induced interaction of the metal-binding domain of β-amyloid with DNA].

    PubMed

    Khmeleva, S A; Mezentsev, Y V; Kozin, S A; Mitkevich, V A; Medvedev, A E; Ivanov, A S; Bodoev, N V; Makarov, A A; Radko, S P

    2015-01-01

    Interaction of intranuclear β-amyloid with DNA is considered to be a plausible mechanism of Alzheimer's disease pathogenesis. The interaction of single- and double-stranded DNA with synthetic peptides was analyzed using surface plasmon resonance. The peptides represent the metal-binding domain of β-amyloid (amino acids 1-16) and its variants with chemical modifications and point substitutions of amino acid residues which are associated with enhanced neurotoxicity of β-amyloid in cell tests. It has been shown that the presence of zinc ions is necessary for the interaction of the peptides with DNA in solution. H6R substitution has remarkably reduced the ability of domain 1-16 to bind DNA. This is in accordance with the supposition that the coordination of a zinc ion by amino acid residues His6, Glu11, His13, and His14 of the β-amyloid metal-binding domain results in the occurrence of an anion-binding site responsible for the interaction of the domain with DNA. Zinc-induced dimerization and oligomerization of domain 1-16 associated with phosphorylation of Ser8 and the presence of unblocked amino- and carboxy-terminal groups have resulted in a decrease of peptide concentrations required for detection of the peptide-DNA interaction. The presence of multiple anion-binding sites on the dimers and oligomers is responsible for the enhancement of the peptide-DNA interaction. A substitution of the negatively charged residue Asp7 for the neutral residue Asn in close proximity to the anion-binding site of the domain 1-16 of Aβ facilitates the electrostatic interaction between this site and phosphates of a polynucleotide chain, which enhances zinc-induced binding to DNA.

  10. Syntheses and properties of zinc and calcium complexes of valinate and isovalinate: metal alpha-amino acidates as possible constituents of the early Earth's chemical inventory.

    PubMed

    Strasdeit, H; Büsching, I; Behrends, S; Saak, W; Barklage, W

    2001-03-01

    We have studied the ligand behavior of racemic isovalinate (iva) and valinate (val) towards zinc(II) and calcium(II). The following solid metal amino acidates were obtained from aqueous solutions: Zn3Cl2(iva)4 (1), Zn3Cl2(val)4 (2). Zn(val)2 (3), Zn(iva)2 x 2H2O (4), Zn(iva)2 x 3.25H2O (5), Zn(iva)2 (6), Ca(iva)2x xH2O (7), and Ca(val)2 x H2O (8). Except for complex 3, these were hitherto unknown compounds. The conditions under which they formed, together with current ideas of the conditions on early Earth, support the assumption that alpha-amino acidate complexes of zinc and calcium might have belonged to early Earth's prebiotic chemical inventory. The zinc isovalinates 1, 4, and 5 were characterized by X-ray crystal structure analyses. Complex 1 forms a layer structure containing four- and five-coordinate metal atoms, whereas the zinc atoms in 4 and 5 are five-coordinate. Compound 5 possesses an unprecedented nonpolymeric structure built from cyclic [Zn6(iva)12] complexes, which are separated by water molecules. The thermolyses of solids 1. 3, and 8 at 320 degrees C in an N2 atmosphere yielded numerous organic products, including the cyclic dipeptide of valine from 3 and 8. Condensation, C-C bond breaking and bond formation, aromatization, decarboxylation, and deamination reactions occurred during the thermolyses. Such reactions of metal-bound a-amino acidates that are abiotically formed could already have contributed to an organic-geochemical diversity before life appeared on Earth.

  11. Daily supplementation with iron plus folic acid, zinc, and their combination is not associated with younger age at first walking unassisted in malnourished preschool children from a deficient population in rural Nepal.

    PubMed

    Katz, Joanne; Khatry, Subarna K; Leclerq, Steven C; Mullany, Luke C; Yanik, Elizabeth L; Stoltzfus, Rebecca J; Siegel, Emily H; Tielsch, James M

    2010-07-01

    A community-based, cluster-randomized, placebo-controlled trial of daily zinc and/or iron+folic acid supplementation was conducted in rural southern Nepal to examine motor milestone attainment among 3264 children 1-36 mo of age between 2001 and 2006. Treatment groups included placebo, zinc (10 mg), iron+folic acid (12.5 mg iron + 50 microg folic acid), and zinc+iron+folic acid (10 mg zinc + 12.5 mg iron + 50 microg folic acid). Infants received half of these doses. The iron arms were stopped November 2003 by recommendation of the Data Safety and Monitoring Board; zinc and placebo continued until January 2006. A total of 2457 children had not walked at the time of entry into the trial and 1775 were followed through 36 mo. Mean age at first walking unassisted did not differ among groups and was 444 +/- 81 d (mean +/- SD) in the placebo group, 444 +/- 81 d in the zinc group, 464 +/- 85 d in the iron+folic acid group, and 446 +/- 87 d in the iron+folic acid+zinc group. Results were similar after adjustment for age at enrollment, asset ownership, maternal literacy, and prior child deaths in the household and in children who consumed at least 60 tablets. Compared with placebo, iron+folic acid was associated with an adjusted mean delay of 28.0 d (95% CI: 11.3, 44.7) in time to walking among infants and the delay was more pronounced with mid-upper arm circumference (MUAC) < 9.5 cm [60.6 d, (95% CI: 28.5, 92.6)]. Risks and benefits of universal iron+folic acid supplementation of infants beyond improved hematologic status deserve further consideration.

  12. Daily supplementation with iron plus folic acid, zinc, and their combination is not associated with younger age at first walking unassisted in malnourished preschool children from a deficient population in rural Nepal.

    PubMed

    Katz, Joanne; Khatry, Subarna K; Leclerq, Steven C; Mullany, Luke C; Yanik, Elizabeth L; Stoltzfus, Rebecca J; Siegel, Emily H; Tielsch, James M

    2010-07-01

    A community-based, cluster-randomized, placebo-controlled trial of daily zinc and/or iron+folic acid supplementation was conducted in rural southern Nepal to examine motor milestone attainment among 3264 children 1-36 mo of age between 2001 and 2006. Treatment groups included placebo, zinc (10 mg), iron+folic acid (12.5 mg iron + 50 microg folic acid), and zinc+iron+folic acid (10 mg zinc + 12.5 mg iron + 50 microg folic acid). Infants received half of these doses. The iron arms were stopped November 2003 by recommendation of the Data Safety and Monitoring Board; zinc and placebo continued until January 2006. A total of 2457 children had not walked at the time of entry into the trial and 1775 were followed through 36 mo. Mean age at first walking unassisted did not differ among groups and was 444 +/- 81 d (mean +/- SD) in the placebo group, 444 +/- 81 d in the zinc group, 464 +/- 85 d in the iron+folic acid group, and 446 +/- 87 d in the iron+folic acid+zinc group. Results were similar after adjustment for age at enrollment, asset ownership, maternal literacy, and prior child deaths in the household and in children who consumed at least 60 tablets. Compared with placebo, iron+folic acid was associated with an adjusted mean delay of 28.0 d (95% CI: 11.3, 44.7) in time to walking among infants and the delay was more pronounced with mid-upper arm circumference (MUAC) < 9.5 cm [60.6 d, (95% CI: 28.5, 92.6)]. Risks and benefits of universal iron+folic acid supplementation of infants beyond improved hematologic status deserve further consideration. PMID:20484548

  13. Effects of combinations of simulated acid rain and cadmium or zinc on microbial activity in soil.

    PubMed

    Bewley, R J; Stotzky, G

    1983-08-01

    There was little effect on the rate of CO2 evolution from glucose-supplemented soil, adjusted to pH 3.2 with a 2:1 combination of H2SO4 and fuming HNO3, and concomitant additions of 100 or 1000 ppm Cd or of 1000 or 10,000 ppm Zn (as sulfates) were no more inhibitory than in soil untreated with acid. In soil adjusted to pH 2.8, the lag in CO2 evolution was increased by 1 day, and was extended further by the concomitant addition of 10,000 but not 1000 ppm Zn or of 1000 but not 100 ppm Cd. The growth of Aspergillus niger in soil acidified to pH levels of 3.6 to 4.2 was further reduced by the addition of either 100 or 250 ppm Cd or of 1000 ppm Zn.

  14. Response to zinc deficiency of two rice lines with contrasting tolerance is determined by root growth maintenance and organic acid exudation rates, and not by zinc-transporter activity.

    PubMed

    Widodo, Basuki; Broadley, Martin R; Rose, Terry; Frei, Michael; Pariasca-Tanaka, Juan; Yoshihashi, Tadashi; Thomson, Michael; Hammond, John P; Aprile, Alessio; Close, Timothy J; Ismail, Abdelbagi M; Wissuwa, Matthias

    2010-04-01

    *Zinc (Zn)-deficient soils constrain rice (Oryza sativa) production and cause Zn malnutrition. The identification of Zn-deficiency-tolerant rice lines indicates that breeding might overcome these constraints. Here, we seek to identify processes underlying Zn-deficiency tolerance in rice at the physiological and transcriptional levels. *A Zn-deficiency-tolerant line RIL46 acquires Zn more efficiently and produces more biomass than its nontolerant maternal line (IR74) at low [Zn](ext) under field conditions. We tested if this was the result of increased expression of Zn(2+) transporters; increased root exudation of deoxymugineic acid (DMA) or low-molecular-weight organic acids (LMWOAs); and/or increased root production. Experiments were performed in field and controlled environment conditions. *There was little genotypic variation in transcript abundance of Zn-responsive root Zn(2+)-transporters between the RIL46 and IR74. However, root exudation of DMA and LMWOA was greater in RIL46, coinciding with increased root expression of putative ligand-efflux genes. Adventitious root production was maintained in RIL46 at low [Zn](ext), correlating with altered expression of root-specific auxin-responsive genes. *Zinc-deficiency tolerance in RIL46 is most likely the result of maintenance of root growth, increased efflux of Zn ligands, and increased uptake of Zn-ligand complexes at low [Zn](ext); these traits are potential breeding targets. PMID:20100202

  15. pH- and mol-ratio dependent formation of zinc(II) coordination polymers with iminodiacetic acid: Synthesis, spectroscopic, crystal structure and thermal studies

    SciTech Connect

    Ni Lubin; Zhang Ronghua; Liu Qiongxin; Xia Wensheng; Wang Hongxin; Zhou Zhaohui

    2009-10-15

    Three novel zinc coordination polymers (NH{sub 4}){sub n}[Zn(Hida)Cl{sub 2}]{sub n} (1), [Zn(ida)(H{sub 2}O){sub 2}]{sub n} (2), [Zn(Hida){sub 2}]{sub n}.4nH{sub 2}O (3) (H{sub 2}ida=iminodiacetic acid) and a monomeric complex [Zn(ida)(phen)(H{sub 2}O)].2H{sub 2}O (4) (phen=1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction methods. 1 and 2 form one-dimensional (1-D) chain structures, whereas 3 exhibits a three-dimensional (3-D) diamondoid framework with an open channel. The mononuclear complex 4 is extended into a 3-D supramolecular architecture through hydrogen bonds and pi-pi stacking. Interestingly, cyclic nonplanar tetrameric water clusters are observed that encapsulated in the 3-D lattice of 4. Based on {sup 1}H and {sup 13}C NMR observations, there is obvious coordination of complex 2 in solution, while 1 and 3 decompose into free iminodiacetate ligand. Monomer [Zn(ida)(H{sub 2}O){sub 3}] (5) is considered as a possible discrete species from 2. These coordination polymers can serve as good molecular precursors for zinc oxide. - Text3: Reaction of zinc salt with iminodiacetic acid afforded three new coordination polymers 1-3 and a monomer 4, which is dependent on pH value and molar ratio of the reactants.

  16. Separate recovery of copper and zinc from acid mine drainage using biogenic sulfide.

    PubMed

    Sahinkaya, Erkan; Gungor, Murat; Bayrakdar, Alper; Yucesoy, Zeynep; Uyanik, Sinan

    2009-11-15

    Precipitation of metals from acid mine drainage (AMD) using sulfide gives the possibility of selective recovery due to different solubility product of each metal. Using sulfate reducing bacteria to produce sulfide for that purpose is advantageous due to in situ and on-demand sulfide production. In this study, separate precipitation of Cu and Zn was studied using sulfide produced in anaerobic baffled reactor (ABR). ABR fed with ethanol (1340 mg/L chemical oxygen demand (COD)) and sulfate (2000 mg/L) gave a stable performance with 65% sulfate reduction, 85% COD removal and around 320 mg/L sulfide production. Cu was separately precipitated at low pH (pH<2) using sulfide transported from ABR effluent via N(2) gas. Cu precipitation was complete within 45-60 min and Zn did not precipitate during Cu removal. The Cu precipitation rate increased with initial Cu concentration. After selective Cu precipitation, Zn recovery was studied using ABR effluent containing sulfide and alkalinity. Depending on initial sulfide/Zn ratio, removal efficiency varied between 84 and 98%. The low pH of Zn bearing AMD was also increased to neutral values using alkalinity produced by sulfate reducing bacteria in ABR. The mode of particle size distribution of ZnS and CuS precipitates was around 17 and 46 microm, respectively.

  17. A single amino acid substitution beyond the C2H2-zinc finger in Ros derepresses virulence and T-DNA genes in Agrobacterium tumefaciens.

    PubMed

    Archdeacon, J; Bouhouche, N; O'Connell, F; Kado, C I

    2000-06-15

    Ros is a chromosomally-encoded repressor containing a novel C2H2 zinc finger in Agrobacterium tumefaciens. Ros regulates the expression of six virulence genes and an oncogene on the Ti plasmid. Constitutive expression of these genes occurs in the spontaneous mutant 4011R derived from the octopine strain Ach-5, resulting in T-DNA processing in the absence of induction, and in the biosynthesis of cytokinin. Interestingly, the mutation in 4011R is an Arg to Cys conversion at amino acid residue 125 near the C-terminus well outside the zinc finger of Ros. Yet, Ros bearing this mutation is unable to bind to the Ros-box and is unable to complement other ros mutants. PMID:10856653

  18. The Zinc Finger Transcription Factor SlZFP2 Negatively Regulates Abscisic Acid Biosynthesis and Fruit Ripening in Tomato1

    PubMed Central

    Weng, Lin; Zhao, Fangfang; Li, Rong; Xu, Changjie; Chen, Kunsong

    2015-01-01

    Abscisic acid (ABA) regulates plant development and adaptation to environmental conditions. Although the ABA biosynthesis pathway in plants has been thoroughly elucidated, how ABA biosynthetic genes are regulated at the molecular level during plant development is less well understood. Here, we show that the tomato (Solanum lycopersicum) zinc finger transcription factor SlZFP2 is involved in the regulation of ABA biosynthesis during fruit development. Overexpression of SlZFP2 resulted in multiple phenotypic changes, including more branches, early flowering, delayed fruit ripening, lighter seeds, and faster seed germination, whereas down-regulation of its expression caused problematic fruit set, accelerated ripening, and inhibited seed germination. SlZFP2 represses ABA biosynthesis during fruit development through direct suppression of the ABA biosynthetic genes NOTABILIS, SITIENS, and FLACCA and the aldehyde oxidase SlAO1. We also show that SlZFP2 regulates fruit ripening through transcriptional suppression of the ripening regulator COLORLESS NON-RIPENING. Using bacterial one-hybrid screening and a selected amplification and binding assay, we identified the (A/T)(G/C)TT motif as the core binding sequence of SlZFP2. Furthermore, by RNA sequencing profiling, we found that 193 genes containing the SlZFP2-binding motifs in their promoters were differentially expressed in 2 d post anthesis fruits between the SlZFP2 RNA interference line and its nontransgenic sibling. We propose that SlZFP2 functions as a repressor to fine-tune ABA biosynthesis during fruit development and provides a potentially valuable tool for dissecting the role of ABA in fruit ripening. PMID:25637453

  19. The zinc finger transcription factor SlZFP2 negatively regulates abscisic acid biosynthesis and fruit ripening in tomato.

    PubMed

    Weng, Lin; Zhao, Fangfang; Li, Rong; Xu, Changjie; Chen, Kunsong; Xiao, Han

    2015-03-01

    Abscisic acid (ABA) regulates plant development and adaptation to environmental conditions. Although the ABA biosynthesis pathway in plants has been thoroughly elucidated, how ABA biosynthetic genes are regulated at the molecular level during plant development is less well understood. Here, we show that the tomato (Solanum lycopersicum) zinc finger transcription factor SlZFP2 is involved in the regulation of ABA biosynthesis during fruit development. Overexpression of SlZFP2 resulted in multiple phenotypic changes, including more branches, early flowering, delayed fruit ripening, lighter seeds, and faster seed germination, whereas down-regulation of its expression caused problematic fruit set, accelerated ripening, and inhibited seed germination. SlZFP2 represses ABA biosynthesis during fruit development through direct suppression of the ABA biosynthetic genes NOTABILIS, SITIENS, and FLACCA and the aldehyde oxidase SlAO1. We also show that SlZFP2 regulates fruit ripening through transcriptional suppression of the ripening regulator COLORLESS NON-RIPENING. Using bacterial one-hybrid screening and a selected amplification and binding assay, we identified the (A/T)(G/C)TT motif as the core binding sequence of SlZFP2. Furthermore, by RNA sequencing profiling, we found that 193 genes containing the SlZFP2-binding motifs in their promoters were differentially expressed in 2 d post anthesis fruits between the SlZFP2 RNA interference line and its nontransgenic sibling. We propose that SlZFP2 functions as a repressor to fine-tune ABA biosynthesis during fruit development and provides a potentially valuable tool for dissecting the role of ABA in fruit ripening.

  20. Performance traits and immune response of broiler chicks treated with zinc and ascorbic acid supplementation during cyclic heat stress

    NASA Astrophysics Data System (ADS)

    Chand, Naila; Naz, Shabana; Khan, Ajab; Khan, Sarzamin; Khan, Rifat Ullah

    2014-12-01

    This research was conducted to investigate the effect of supplementation of zinc (Zn) and ascorbic acid (AA) in heat-stressed broilers. A total of 160-day-old broiler chicks of approximately the same weight and appearance were divided into four treatment groups (control, T1, T2, and T3). Control group was fed a standard diet without any supplementation. T1 was supplemented with Zn at the rate of 60 mg/kg of feed, T2 was supplemented with 300 mg/kg of feed AA, and T3 was supplemented with combination of Zn and AA. From week 3 to 5, heat stress environment was provided at the rate of 12 h at 25 °C, 3 h at 25 to 34 °C, 6 h at 34 °C, and 3 h at 34 to 25 °C daily. The results revealed that feed intake, body weight and feed conversion ratio (FCR), and weight of thymus, spleen, and bursa of Fabricius improved significantly ( P < 0.05) in T3 compared to the other treatments. Antibody titer against Newcastle disease (ND), infectious bursal disease (IBD), and infectious bronchitis (IB) increased significantly ( P < 0.05) in T2 and T3 groups. However, total leucocytes count, lymphocytes, and monocytes increased ( P < 0.05) in all treated groups compared to control. The results indicated that the supplementation of Zn or AA alone or in combination improved the performance and immune status of broilers reared under heat stress.

  1. Leaching and efficiency of six organic zinc fertilizers applied to navy bean crop grown in a weakly acidic soil of Spain.

    PubMed

    Gonzalez, D; Novillo, J; Rico, M I; Alvarez, J M

    2008-05-14

    Zinc contamination of groundwater from fertilizers applied to pulse crops is a potential problem, but the use of different types of organic chelates can minimize the contamination potential while still adequately feeding the crops. The objective of this study was to compare the leaching, distribution in fractions and availability, and relative effectiveness of Zn from six organic Zn fertilizers (zinc-ethylenediaminetetraacetate- N-2-hydroxyethylethylenediaminetriacetate (Zn-EDTA-HEDTA), Zn-HEDTA, zinc- S, S'-ethylenediaminedisuccinate (Zn- S, S-EDDS), zinc-polyhydroxyphenylcarboxylate, Zn-EDTA, and zinc-ethylenediaminedi(2-hydroxy-5-sulfophenylacetate) (Zn-EDDHSA)) applied to a navy bean ( Phaseolus vulgaris, L.) crop cultivated by applying different Zn levels, in a weakly acidic soil under greenhouse conditions. Zinc soil behavior was evaluated by diethylenetriaminepentaacetic acid-triethanolamine (DTPA-TEA), DTPA-ammonium bicarbonate (DTPA-AB), Mehlich-3, and BaCl 2 extractions and sequential fractionation. In all the fertilizer treatments, the percentage of labile Zn that remained in the soil was high with respect to the quantity of Zn applied, with values respectively ranging from 42 to 80% for Zn-EDDHSA and Zn-EDTA sources. A positive correlation with a high level of significance existed between the micronutrient concentration in the navy bean crop (total and soluble) and labile Zn fractions, available Zn, and easily leachable Zn ( r ranged from 0.89 to 0.95, P < 0.0001). The relatively high quantity of total Zn leached by applying Zn-EDTA and Zn-S,S-EDDS sources (11.9 and 6.0%, respectively, for the rate 10 mg of Zn kg(-1) of soil) poses a potential pollution risk for neighboring waters. It would seem recommendable to apply Zn-HEDTA or Zn-EDDHSA sources, even applied at the low rate (5 mg of Zn kg(-1) of soil), because they produced available Zn concentrations in the soil that were above the critical concentration and also produced high Zn concentrations in

  2. Zinc- and sequence-dependent binding to nucleic acids by the N-terminal zinc finger of the HIV-1 nucleocapsid protein: NMR structure of the complex with the Psi-site analog, dACGCC.

    PubMed

    South, T L; Summers, M F

    1993-01-01

    The nucleic acid interactive properties of a synthetic peptide with sequence of the N-terminal CCHC zinc finger (CCHC = Cys-X2-Cys-X4-His-X4-Cys; X = variable amino acid) of the human immunodeficiency virus (HIV) nucleocapsid protein, Zn(HIV1-F1), have been studied by 1H NMR spectroscopy. Titration of Zn(HIV1-F1) with oligodeoxyribonucleic acids containing different nucleotide sequences reveals, for the first time, sequence-dependent binding that requires the presence of at least one guanosine residue for tight complex formation. The dynamics of complex formation are sensitive to the nature of the residues adjacent to guanosine, with residues on the 3' side of guanosine having the largest influence. An oligodeoxyribonucleotide with sequence corresponding to a portion of the HIV-1 psi-packaging signal, d(ACGCC), forms a relatively tight complex with Zn(HIV1-F1) (Kd = 5 x 10(-6) M). Two-dimensional nuclear Overhauser effect (NOESY) data indicate that the bound nucleic acid exists predominantly in a single-stranded, A-helical conformation, and the presence of more than a dozen intermolecular NOE cross peaks enabled three-dimensional modeling of the complex. The nucleic acid binds within a hydrophobic cleft on the peptide surface. This hydrophobic cleft is defined by the side chains of residues Val1, Phe4, Ile12, and Ala13. Backbone amide protons of Phe4 and Ala13 and the backbone carbonyl oxygen of Lys2 that lie within this cleft appear to form hydrogen bonds with the guanosine O6 and N1H atoms, respectively. In addition, the positively charged side chain of Arg14 is ideally positioned for electrostatic interactions with the phosphodiester backbone of the nucleic acid. The structural findings provide a rationalization for the general conservation of these hydrophobic and basic residues in CCHC zinc fingers, and are consistent with site-directed mutagenesis results that implicate these residues as direct participants in viral genome recognition.

  3. Zinc, the brain and behavior.

    PubMed

    Pfeiffer, C C; Braverman, E R

    1982-04-01

    The total content of zinc in the adult human body averages almost 2 g. This is approximately half the total iron content and 10 to 15 times the total body copper. In the brain, zinc is with iron, the most concentrated metal. The highest levels of zinc are found in the hippocampus in synaptic vesicles, boutons, and mossy fibers. Zinc is also found in large concentrations in the choroid layer of the retina which is an extension of the brain. Zinc plays an important role in axonal and synaptic transmission and is necessary for nucleic acid metabolism and brain tubulin growth and phosphorylation. Lack of zinc has been implicated in impaired DNA, RNA, and protein synthesis during brain development. For these reasons, deficiency of zinc during pregnancy and lactation has been shown to be related to many congenital abnormalities of the nervous system in offspring. Furthermore, in children insufficient levels of zinc have been associated with lowered learning ability, apathy, lethargy, and mental retardation. Hyperactive children may be deficient in zinc and vitamin B-6 and have an excess of lead and copper. Alcoholism, schizophrenia, Wilson's disease, and Pick's disease are brain disorders dynamically related to zinc levels. Zinc has been employed with success to treat Wilson's disease, achrodermatitis enteropathica, and specific types of schizophrenia.

  4. Synthesis and characterization of zinc-organic frameworks with 1,4-benzenedicarboxylic acid and azobenzene-4,4'-dicarboxylic acid

    NASA Astrophysics Data System (ADS)

    Nguyen, Van Hung; Phuong Thuy Nguyen, Ngoc; Tuyet Nhung Nguyen, Thi; Thanh Thuy Le, Thi; Nghiem Le, Van; Chinh Nguyen, Quoc; Quang Ton, That; Hoang Nguyen, Thai; Phuong Thoa Nguyen, Thi

    2011-06-01

    The solvothermal reactions of 1,4-bezenedicarboxylic acid (H2BDC) or azobenzene-4,4'-dicarboxylic acid (H2ABD) with zinc ions/clusters lead to the formation of four crystalline materials. All of these compounds were characterized by x-ray diffraction, optical microscopy, thermo-gravimetric analysis and nitrogen adsorption. Block-shaped crystals (BZ1) with various shapes and sizes were obtained at H2BDC:Zn mole ratio of 1:1 and H2BDC concentration of 0.1 M. At more dilute H2BDC concentration of 0.01 M and H2BDC:Zn mole ratio of 1 : 4, the reaction product was cubic crystals (BZ2) with a size of 250 μm. In the H2ABD system, flat-plate-like crystals (AZ1) were obtained at H2ABD:Zn mole ratio of 1 : 1 and H2ABD concentration of 0.01 M. Meanwhile, thick-block-like crystals (AZ2) were formed at the same H2ABD:Zn mole ratio but at 0.004 M H2ABD. The Langmuir surface area (SLang) of the materials was remarkable, enhanced by diluting the reaction solution. For the compounds synthesized in N,N'-dimethylformamide (DMF), SLang increased from 304.6 m2 g‑1 for BZ1 to 2631 m2 g‑1 for BZ2 and from 475.8 m2 g‑1 for AZ1 to 3428 m2 g‑1 for AZ2. Meanwhile, BZ2 synthesized in N,N'-diethylformamide (BZ2/DEF) got the highest SLang of 4330 m2 g‑1. Both AZ2 and BZ2 materials were stable up to 400 °C.

  5. Influence of amino acid replacement at position 198 on catalytic properties of zinc-bound water in human carbonic anhydrase III.

    PubMed

    LoGrasso, P V; Tu, C; Chen, X; Taoka, S; Laipis, P J; Silverman, D N

    1993-06-01

    Carbonic anhydrase III, found predominantly in skeletal muscle, is the least efficient of the mammalian carbonic anhydrases in catalyzing the hydration of CO2. Phenylalanine-198 is located on the hydrophobic side of the active-site cavity with its phenyl ring in the proximity of the catalytically active zinc-bound water. We replaced phenylalanine-198 in human carbonic anhydrase III with seven other amino acids (Ala, Asn, Asp, His, Leu, Tyr, Val) using site-directed mutagenesis. The catalytic properties of these enzymes were determined by stopped-flow spectrophotometry, and the exchange of 18O between CO2 and water was measured by mass spectrometry. All of the mutants had maximal values of kcat/Km for the hydration of CO2 enhanced, and five of the mutants had the pKa of the zinc-bound water increased compared with the wild-type enzyme. The largest effects were observed with the replacement Phe-198-->Asp which increased the maximal kcat/Km 140-fold and increased the pKa of the zinc-bound water from near 5 to 9.2. A Brønsted correlation was observed between log(kcat/Km) for hydration of CO2 and the pKa of the zinc-bound water (correlation coefficient r = 0.92); in addition, this pKa was inversely correlated with hydrophobicity of the residue at 198 (correlation coefficient r = -0.83). A direct correlation between the logarithm of the maximal kcat/Km for hydration and the logarithm of the pH-independent value of Ki for inhibition by cyanate (r = 0.95) indicated that the effect of the mutations at residue 198 occurred in large part by enhancement of the rate of dissociation of the enzyme-bicarbonate complex. PMID:8504098

  6. 46 CFR 148.330 - Zinc ashes; zinc dross; zinc residues; zinc skimmings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Zinc ashes; zinc dross; zinc residues; zinc skimmings... Materials § 148.330 Zinc ashes; zinc dross; zinc residues; zinc skimmings. (a) The shipper must inform the cognizant Coast Guard Captain of the Port in advance of any cargo transfer operations involving zinc...

  7. 46 CFR 148.330 - Zinc ashes; zinc dross; zinc residues; zinc skimmings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Zinc ashes; zinc dross; zinc residues; zinc skimmings... Materials § 148.330 Zinc ashes; zinc dross; zinc residues; zinc skimmings. (a) The shipper must inform the cognizant Coast Guard Captain of the Port in advance of any cargo transfer operations involving zinc...

  8. 46 CFR 148.330 - Zinc ashes; zinc dross; zinc residues; zinc skimmings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Zinc ashes; zinc dross; zinc residues; zinc skimmings... Materials § 148.330 Zinc ashes; zinc dross; zinc residues; zinc skimmings. (a) The shipper must inform the cognizant Coast Guard Captain of the Port in advance of any cargo transfer operations involving zinc...

  9. 21 CFR 182.8994 - Zinc stearate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc stearate. 182.8994 Section 182.8994 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from chickedema factor. (b) Conditions of use....

  10. 21 CFR 182.8994 - Zinc stearate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Zinc stearate. 182.8994 Section 182.8994 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from chickedema factor. (b) Conditions of use....

  11. 21 CFR 582.5994 - Zinc stearate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Zinc stearate. 582.5994 Section 582.5994 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from...

  12. 21 CFR 582.5994 - Zinc stearate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Zinc stearate. 582.5994 Section 582.5994 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from...

  13. 21 CFR 182.8994 - Zinc stearate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Zinc stearate. 182.8994 Section 182.8994 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from chickedema factor. (b) Conditions of use....

  14. 21 CFR 582.5994 - Zinc stearate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Zinc stearate. 582.5994 Section 582.5994 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from...

  15. 21 CFR 582.5994 - Zinc stearate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Zinc stearate. 582.5994 Section 582.5994 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from...

  16. 21 CFR 582.5994 - Zinc stearate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Zinc stearate. 582.5994 Section 582.5994 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from...

  17. 21 CFR 182.8994 - Zinc stearate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Zinc stearate. 182.8994 Section 182.8994 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8994 Zinc stearate. (a) Product. Zinc stearate prepared from stearic acid free from chickedema factor. (b) Conditions of use....

  18. Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan

    PubMed Central

    Aoki, Aya; Inoue, Maiko; Nguyen, Elizabeth; Obata, Ryo; Kadonosono, Kazuaki; Shinkai, Shoji; Hashimoto, Hideki; Sasaki, Satoshi; Yanagi, Yasuo

    2016-01-01

    This case-control study reports the association between nutrient intake and neovascular age-related macular degeneration (AMD) in Japan. The nutrient intake of 161 neovascular AMD cases from two university hospitals and 369 population-based control subjects from a cohort study was assessed using a brief-type self-administered questionnaire on diet history, which required respondent recall of the usual intake of 58 foods during the preceding month. Energy-adjusted nutrient intake values were compared between the groups. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs adjusted for smoking history, age, sex, chronic disease history, supplement use, and alcohol consumption. Logistic regression analysis demonstrated that low intakes of n-3 fatty acid, α-tocopherol, zinc, vitamin D, vitamin C, and β-carotene were associated with neovascular AMD (Trend P < 0.0001 for n-3 fatty acid, Trend P < 0.0001 for α-tocopherol, Trend P < 0.0001 for zinc, Trend P = 0.002 for vitamin D, Trend P = 0.04 for vitamin C, Trend P = 0.0004 for β-carotene). There was no association with retinol or cryptoxanthin intake and neovascular AMD (P = 0.67, 0.06). PMID:26846575

  19. Dietary n-3 Fatty Acid, α-Tocopherol, Zinc, vitamin D, vitamin C, and β-carotene are Associated with Age-Related Macular Degeneration in Japan.

    PubMed

    Aoki, Aya; Inoue, Maiko; Nguyen, Elizabeth; Obata, Ryo; Kadonosono, Kazuaki; Shinkai, Shoji; Hashimoto, Hideki; Sasaki, Satoshi; Yanagi, Yasuo

    2016-01-01

    This case-control study reports the association between nutrient intake and neovascular age-related macular degeneration (AMD) in Japan. The nutrient intake of 161 neovascular AMD cases from two university hospitals and 369 population-based control subjects from a cohort study was assessed using a brief-type self-administered questionnaire on diet history, which required respondent recall of the usual intake of 58 foods during the preceding month. Energy-adjusted nutrient intake values were compared between the groups. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% CIs adjusted for smoking history, age, sex, chronic disease history, supplement use, and alcohol consumption. Logistic regression analysis demonstrated that low intakes of n-3 fatty acid, α-tocopherol, zinc, vitamin D, vitamin C, and β-carotene were associated with neovascular AMD (Trend P < 0.0001 for n-3 fatty acid, Trend P < 0.0001 for α-tocopherol, Trend P < 0.0001 for zinc, Trend P = 0.002 for vitamin D, Trend P = 0.04 for vitamin C, Trend P = 0.0004 for β-carotene). There was no association with retinol or cryptoxanthin intake and neovascular AMD (P = 0.67, 0.06). PMID:26846575

  20. Ethylene Diamine Tetraacetic Acid Etched Quantum Dots as a "Turn-On" Fluorescence Probe for Detection of Trace Zinc in Food.

    PubMed

    Liu, Wei; Wei, Fangdi; Xu, Guanhong; Wu, Yanzi; Hu, Chunting; Song, Quan; Yang, Jing; Hu, Qin

    2016-06-01

    In the present paper, a simple and rapid "turn-on" fluorescence sensor for Zn2+ based on ethylene diamine tetraacetic acid (EDTA) etched CdTe quantum dots (QDs) was developed. First, the initial bright fluorescence of mercaptopropionic acid (MPA) capped CdTe QDs was effectively quenched by EDTA, and then the presence of Zn2+ could "turn on" the weak fluorescence of QDs quenched by EDTA due to the formation of ZnS passivation shell. The increase of fluorescence intensity of EDTA etched QDs was found to be linear with the concentration of Zn2+ added. Under the optimum conditions, the calibration curve of this method showed good linearity in the concentration range of 9.1-1 09.1 μM of Zn2+ with the correlation coefficient R2 = 0.998. The limit of detection (3σ/K) was 2 μM. The developed QDs-based sensor was successfully applied to detect trace zinc in zinc fortified table salts and energy drinks with satisfactory results. PMID:27427745

  1. Effect of L-aspartic acid on the growth, structure and spectral studies of Zinc (tris) Thiourea Sulphate (ZTS) single crystals.

    PubMed

    Samuel, Bincy Susan; Krishnamurthy, R; Rajasekaran, R

    2014-11-11

    Single crystals of pure and L-aspartic acid doped Zinc (Tris) Thiourea Sulphate (ZTS) were grown from aqueous solution by solution growth method. The cell parameters and structure of the grown crystals were determined by X-ray diffraction studies. The presence of functional group in the compound has been confirmed by FTIR and FT-Raman analysis. The optical transparency range has been studied through UV-Vis spectroscopy. TGA/DTA studies show thermal stability of the grown crystals. Microhardness study reveals that the hardness number (Hv) increases with load for pure and doped ZTS crystals. Dielectric studies have been carried out and the results are discussed. The second harmonic generation was confirmed for l-aspartic acid doped ZTS which is greater than pure ZTS.

  2. Redox and Lewis acid relay catalysis: a titanocene/zinc catalytic platform in the development of multicomponent coupling reactions.

    PubMed

    Gianino, Joseph B; Campos, Catherine A; Lepore, Antonio J; Pinkerton, David M; Ashfeld, Brandon L

    2014-12-19

    A titanocene-catalyzed multicomponent coupling is described herein. Using catalytic titanocene, phosphine, and zinc dust, zinc acetylides can be generated from the corresponding iodoalkynes to affect sequential nucleophilic additions to aromatic aldehydes. The intermediate propargylic alkoxides are trapped in situ with acetic anhydride, which are susceptible to a second nucleophilic displacement upon treatment with a variety of electron-rich species, including acetylides, allyl silanes, electron-rich aromatics, silyl enol ethers, and silyl ketene acetals. Additionally, employing cyclopropane carboxaldehydes led to ring-opened products resulting from iodine incorporation. Taken together, these results form the basis for a new mode of three-component coupling reactions, which allows for rapid access to value added products in a single synthetic operation.

  3. Evaluation of Controlled-Release Property and Phytotoxicity Effect of Insect Pheromone Zinc-Layered Hydroxide Nanohybrid Intercalated with Hexenoic Acid.

    PubMed

    Ahmad, Rozita; Hussein, Mohd Zobir; Kadir, Wan Rasidah Wan Abdul; Sarijo, Siti Halimah; Hin, Taufiq-Yap Yun

    2015-12-30

    A controlled release formulation for the insect pheromone hexenoic acid (HE) was successfully developed using zinc-layered hydroxide (ZLH) as host material through a simple coprecipitation technique, resulting in the formation of inorganic-organic nanolayered material with sustained release properties. The release of HE from its nanohybrid was found to occur in a controlled manner, governed by a pseudo-second order kinetics model. The maximum amount of HE released from the nanocomposite into solutions at pH 4, 6.5, and 8 was found to be 84, 73, and 83% for 1100 min, respectively. The hexenoate zinc-layered hydroxide nanomaterial (HEN) was found to be nontoxic for plants when green beans and wheat seeds were successfully germinated in all HEN concentrations tested in the experiment, with higher percentage of seed germination and higher radical seed growth as compared to its counter anion, HE. ZLH can be a promising carrier for insect pheromone toward a new generation of environmentally safe pesticide nanomaterial for crop protection. PMID:26501358

  4. A threefold interpenetrated two-dimensional zinc(II) supramolecular architecture based on 3-nitrobenzoic acid and 4,4'-bipyridine.

    PubMed

    Tang, Long; Wang, Ji-Jiang; Fu, Feng; Wang, Sheng-Wen; Liu, Qi-Rui

    2016-02-01

    With regard to crystal engineering, building block or modular assembly methodologies have shown great success in the design and construction of metal-organic coordination polymers. The critical factor for the construction of coordination polymers is the rational choice of the organic building blocks and the metal centre. The reaction of Zn(OAc)2·2H2O (OAc is acetate) with 3-nitrobenzoic acid (HNBA) and 4,4'-bipyridine (4,4'-bipy) under hydrothermal conditions produced a two-dimensional zinc(II) supramolecular architecture, catena-poly[[bis(3-nitrobenzoato-κ(2)O,O')zinc(II)]-μ-4,4'-bipyridine-κ(2)N:N'], [Zn(C7H4NO4)2(C10H8N2)]n or [Zn(NBA)2(4,4'-bipy)]n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction analysis. The Zn(II) ions are connected by the 4,4'-bipy ligands to form a one-dimensional zigzag chain and the chains are decorated with anionic NBA ligands which interact further through aromatic π-π stacking interactions, expanding the structure into a threefold interpenetrated two-dimensional supramolecular architecture. The solid-state fluorescence analysis indicates a slight blue shift compared with pure 4,4'-bipyridine and HNBA. PMID:26846497

  5. Spectral characterization of novel ternary zinc(II) complexes containing 1,10-phenanthroline and Schiff bases derived from amino acids and salicylaldehyde-5-sulfonates

    NASA Astrophysics Data System (ADS)

    Boghaei, Davar M.; Gharagozlou, Mehrnaz

    2007-07-01

    A series of new ternary zinc(II) complexes [Zn(L 1-10)(phen)], where phen is 1,10-phenanthroline and H 2L 1-10 = tridentate Schiff base ligands derived from the condensation of amino acids (glycine, L-phenylalanine, L-valine, L-alanine, and L-leucine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5-sulfonate), have been synthesized. The complexes were characterized by elemental analysis, IR, UV-vis, 1H NMR, and 13C NMR spectra. The IR spectra of the complexes showed large differences between νas(COO) and νs(COO), Δ ν ( νas(COO) - νs(COO)) of 191-225 cm -1, indicating a monodentate coordination of the carboxylate group. Spectral data showed that in these ternary complexes the zinc atom is coordinated with the Schiff base ligand acts as a tridentate ONO moiety, coordinating to the metal through its phenolic oxygen, imine nitrogen, and carboxyl oxygen, and also with the neutral planar chelating ligand, 1,10-phenanthroline, coordinating through nitrogens.

  6. Evaluation of Controlled-Release Property and Phytotoxicity Effect of Insect Pheromone Zinc-Layered Hydroxide Nanohybrid Intercalated with Hexenoic Acid.

    PubMed

    Ahmad, Rozita; Hussein, Mohd Zobir; Kadir, Wan Rasidah Wan Abdul; Sarijo, Siti Halimah; Hin, Taufiq-Yap Yun

    2015-12-30

    A controlled release formulation for the insect pheromone hexenoic acid (HE) was successfully developed using zinc-layered hydroxide (ZLH) as host material through a simple coprecipitation technique, resulting in the formation of inorganic-organic nanolayered material with sustained release properties. The release of HE from its nanohybrid was found to occur in a controlled manner, governed by a pseudo-second order kinetics model. The maximum amount of HE released from the nanocomposite into solutions at pH 4, 6.5, and 8 was found to be 84, 73, and 83% for 1100 min, respectively. The hexenoate zinc-layered hydroxide nanomaterial (HEN) was found to be nontoxic for plants when green beans and wheat seeds were successfully germinated in all HEN concentrations tested in the experiment, with higher percentage of seed germination and higher radical seed growth as compared to its counter anion, HE. ZLH can be a promising carrier for insect pheromone toward a new generation of environmentally safe pesticide nanomaterial for crop protection.

  7. An A20/AN1-type zinc finger protein modulates gibberellins and abscisic acid contents and increases sensitivity to abiotic stress in rice (Oryza sativa).

    PubMed

    Zhang, Ye; Lan, Hongxia; Shao, Qiaolin; Wang, Ruqin; Chen, Hui; Tang, Haijuan; Zhang, Hongsheng; Huang, Ji

    2016-01-01

    The plant hormones gibberellins (GA) and abscisic acid (ABA) play important roles in plant development and stress responses. Here we report a novel A20/AN1-type zinc finger protein ZFP185 involved in GA and ABA signaling in the regulation of growth and stress response. ZFP185 was constitutively expressed in various rice tissues. Overexpression of ZFP185 in rice results in a semi-dwarfism phenotype, reduced cell size, and the decrease of endogenous GA3 content. By contrast, higher GA3 content was observed in RNAi plants. The application of exogenous GA3 can fully rescue the semi-dwarfism phenotype of ZFP185 overexpressing plants, suggesting the negative role of ZFP185 in GA biosynthesis. Besides GA, overexpression of ZFP185 decreased ABA content and expression of several ABA biosynthesis-related genes. Moreover, it was found that ZFP185, unlike previously known A20/AN1-type zinc finger genes, increases sensitivity to drought, cold, and salt stresses, implying the negative role of ZFP185 in stress tolerance. ZFP185 was localized in the cytoplasm and lacked transcriptional activation potential. Our study suggests that ZFP185 regulates plant growth and stress responses by affecting GA and ABA biosynthesis in rice.

  8. The effect of calcium salts, ascorbic acid and peptic pH on calcium, zinc and iron bioavailabilities from fortified human milk using an in vitro digestion/Caco-2 cell model.

    PubMed

    Etcheverry, Paz; Wallingford, John Charles; Miller, Dennis Dean; Glahn, Raymond Philip

    2005-05-01

    The calcium, zinc, and iron bioavailabilities of human milk with commercial and noncommercial human milk fortifiers (HMFs) were evaluated under a variety of conditions: peptic digestion at pH 2 and pH 4, supplementation of ascorbic acid, and addition of three calcium salts. The noncommercial HMFs consisted of casein phosphopeptides (CPPs), alpha-lactalbumin, colostrum, and hydrolyzed whey protein concentrate (WPC). They were mixed with human milk (HM) and calcium, zinc, and iron were added. Ascorbic acid (AA) was added in certain studies. The commercial HMFs were Nestlé FM-85, Similac HMF (SHMF), and Enfamil HMF (EHMF). All HMFs were compared to S-26/SMA HMF. Results showed that the peptic pH (2 vs. 4) had no effect on mineral bioavailability. Addition of different calcium salts had no effect on calcium cell uptake and cell ferritin levels (an indicator of iron uptake), however, the addition of calcium glycerophosphate/gluconate increased zinc uptake by Caco-2 cells. Addition of AA significantly increased ferritin levels, with no effect on calcium or zinc uptake. Among the commercial HMFs, FM-85 was significantly lower in zinc uptake than S-26/SMA, and HM+EHMF was significantly higher than HM+S-26/SMA. Cell ferritin levels were significantly higher for HM+S-26/SMA than for all other commercial fortifiers. None of the commercial HMFs were different from HM+S-26/SMA in calcium uptake.

  9. Growth and spectral characterization of ethylene diamine tetra acetic acid (EDTA) doped zinc sulphate hepta hydrate - a semi organic NLO material.

    PubMed

    Ramachandra Raja, C; Ramamurthi, K; Manimekalai, R

    2012-12-01

    Semi-organic non-linear optical single crystals of ethylene diamine tetra acetic acid (EDTA) doped zinc sulphate hepta hydrate crystals were grown by slow evaporation solution growth technique, at room temperature, using de-ionized water as solvent. The modes of vibrations of different molecular groups present in the grown crystal were identified by FT-IR technique. The optical absorbance/transmittance was recorded in the wavelength range of 190-1100 nm. Thermal properties of the grown crystal were studied by thermo gravimetric analysis and differential thermal analysis. The melting point of the grown crystal was estimated by differential scanning calorimetric analysis. The inclusion of the dopant (EDTA) was confirmed by colorimetric estimation method. The second harmonic generation efficiency is about 30% of potassium dihydrogen orthophosphate.

  10. Leaching of cadmium, chromium, copper, lead, and zinc from two slag dumps with different environmental exposure periods under dynamic acidic condition.

    PubMed

    Jin, Zhisheng; Liu, Taoze; Yang, Yuangen; Jackson, Daniel

    2014-06-01

    Over the past few decades, zinc smelting activities in Guizhou, China have produced numerous slag dumps, which are often dispersed on roadsides and hill slopes throughout the region. During periods of acid rain, these exposed slags release heavy metals into surface water bodies. A column leaching study was designed to test the potential release of the heavy metals cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) under simulated acid rain events. Two slags with varying environmental exposure periods were packed in columns and subjected to leaching solutions of pH 3.5, 5.5, or DI H2O at intervals of 1, 7, 14, 28, 56d. Pulse concentrations of Cd in leachate were found above 5μg/L, Cr, Pb, and Zn >10μg/L, whereas, Cu reached 10μg/L. After five leaching events, the leachability (percentage of cumulative heavy metal leached after five leaching events as in its respective total concentration in slags) of Cd was 0.05 percent and 0.035 percent from the old and young slag, respectively. Cr (0.035 percent and 0.05 percent) was greater than Cu (0.002 percent and 0.005 percent) and Zn (0.006 percent and 0.003 percent), while the lowest leachability was observed for Pb (0.0005 percent and 0.0002 percent) from the old and young slags, respectively. Reaction rates (release amount of heavy metals in certain period of leaching) of heavy metals in the leachates demonstrated the sequence of Zn>Cr>Cd, Cu>Pb. Leaching release of heavy metals was jointly affected by the pH of leaching solution and mineral composition of slags (including chemical forms of Cd, Cr, Cu, Pb, and Zn). Environmental exposure period of slags, resulting in the alteration of minerals, could affect the release process of heavy metals in leaching as well. PMID:24632122

  11. Leaching of cadmium, chromium, copper, lead, and zinc from two slag dumps with different environmental exposure periods under dynamic acidic condition.

    PubMed

    Jin, Zhisheng; Liu, Taoze; Yang, Yuangen; Jackson, Daniel

    2014-06-01

    Over the past few decades, zinc smelting activities in Guizhou, China have produced numerous slag dumps, which are often dispersed on roadsides and hill slopes throughout the region. During periods of acid rain, these exposed slags release heavy metals into surface water bodies. A column leaching study was designed to test the potential release of the heavy metals cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), and zinc (Zn) under simulated acid rain events. Two slags with varying environmental exposure periods were packed in columns and subjected to leaching solutions of pH 3.5, 5.5, or DI H2O at intervals of 1, 7, 14, 28, 56d. Pulse concentrations of Cd in leachate were found above 5μg/L, Cr, Pb, and Zn >10μg/L, whereas, Cu reached 10μg/L. After five leaching events, the leachability (percentage of cumulative heavy metal leached after five leaching events as in its respective total concentration in slags) of Cd was 0.05 percent and 0.035 percent from the old and young slag, respectively. Cr (0.035 percent and 0.05 percent) was greater than Cu (0.002 percent and 0.005 percent) and Zn (0.006 percent and 0.003 percent), while the lowest leachability was observed for Pb (0.0005 percent and 0.0002 percent) from the old and young slags, respectively. Reaction rates (release amount of heavy metals in certain period of leaching) of heavy metals in the leachates demonstrated the sequence of Zn>Cr>Cd, Cu>Pb. Leaching release of heavy metals was jointly affected by the pH of leaching solution and mineral composition of slags (including chemical forms of Cd, Cr, Cu, Pb, and Zn). Environmental exposure period of slags, resulting in the alteration of minerals, could affect the release process of heavy metals in leaching as well.

  12. Diosmectite-zinc oxide composite improves intestinal barrier restoration and modulates TGF-β1, ERK1/2, and Akt in piglets after acetic acid challenge.

    PubMed

    Song, Z-H; Ke, Y-L; Xiao, K; Jiao, L-F; Hong, Q-H; Hu, C-H

    2015-04-01

    The present study evaluated the beneficial effect of diosmectite-zinc oxide composite (DS-ZnO) on improving intestinal barrier restoration in piglets after acetic acid challenge and explored the underlying mechanisms. Twenty-four 35-d-old piglets (Duroc × Landrace × Yorkshire), with an average weight of 8.1 kg, were allocated to 4 treatment groups. On d 1 of the trial, colitis was induced via intrarectal injection of acetic acid (10 mL of 10% acetic acid [ACA] solution for ACA, DS-ZnO, and mixture of diosmectite [DS] and ZnO [DS+ZnO] groups) and the control group was infused with saline. Twenty-four hours after challenged, piglets were fed with the following diets: 1) control group (basal diet), 2) ACA group (basal diet), 3) DS-ZnO group (basal diet supplemented with DS-ZnO), and 4) DS+ZnO group (mixture of 1.5 g diosmectite [DS]/kg and 500 mg Zn/kg from ZnO [equal amount of DS and ZnO in the DS-ZnO treatment group]). On d 8 of the trial, piglets were sacrificed. The results showed that DS-ZnO supplementation improved (P < 0.05) ADG, ADFI, and transepithelial electrical resistance and decreased (P < 0.05) fecal scores, crypt depth, and fluorescein isothiocyanate-dextran 4 kDa (FD4) influx as compared with ACA group. Moreover, DS-ZnO increased (P < 0.05) occludin, claudin-1, and zonula occluden-1 expressions; reduced (P < 0.05) caspase-9 and caspase-3 activity and Bax expression; and improved (P < 0.05) Bcl2, XIAP, and PCNA expression. Diosmectite-zinc oxide composite supplementation also increased (P < 0.05) TGF-β1 expression and ERK1/2 and Akt activation. These results suggest that DS-ZnO attenuates the acetic acid-induced colitis by improving mucosa barrier restoration, inhibiting apoptosis, and improving intestinal epithelial cells proliferation and modulation of TGF-β1 and ERK1/2 and Akt signaling pathway.

  13. Sustained release formulation of an anti-tuberculosis drug based on para-amino salicylic acid-zinc layered hydroxide nanocomposite

    PubMed Central

    2013-01-01

    Background Tuberculosis (TB), is caused by the bacteria, Mycobacterium tuberculosis and its a threat to humans since centuries. Depending on the type of TB, its treatment can last for 6–24 months which is a major cause for patients non-compliance and treatment failure. Many adverse effects are associated with the currently available TB medicines, and there has been no new anti-tuberculosis drug on the market for more than 50 year, as the drug development is very lengthy and budget consuming process. Development of the biocompatible nano drug delivery systems with the ability to minimize the side effects of the drugs, protection of the drug from enzymatic degradation. And most importantly the drug delivery systems which can deliver the drug at target site would increase the therapeutic efficacy. Nanovehicles with their tendency to release the drug in a sustained manner would result in the bioavalibilty of the drugs in the body for a longer period of time and this would reduce the dosing frequency in drug administration. The biocompatible nanovehicles with the properties like sustained release of drug of the target site, protection of the drug from physio-chemical degradation, reduction in dosing frequency, and prolong bioavailability of drug in the body would result in the shortening of the treatment duration. All of these factors would improve the patient compliance with chemotherapy of TB. Result An anti-tuberculosis drug, 4-amino salicylic acid (4-ASA) was successfully intercalated into the interlamellae of zinc layered hydroxide (ZLH) via direct reaction with zinc oxide suspension. The X-ray diffraction patterns and FTIR analyses indicate that the molecule was successfully intercalated into the ZLH interlayer space with an average basal spacing of 24 Å. Furthermore, TGA and DTG results show that the drug 4-ASA is stabilized in the interlayers by electrostatic interaction. The release of 4-ASA from the nanocomposite was found to be in a sustained manner. The

  14. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    PubMed

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  15. Effect of arbuscular mycorrhizal fungi on plant biomass and the rhizosphere microbial community structure of mesquite grown in acidic lead/zinc mine tailings.

    PubMed

    Solís-Domínguez, Fernando A; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M

    2011-02-15

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p<0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  16. Effect of Arbuscular Mycorrhizal Fungi on Plant Biomass and the Rhizosphere Microbial Community Structure of Mesquite Grown in Acidic Lead/Zinc Mine Tailings

    PubMed Central

    Solís-Domínguez, Fernando A.; Valentín-Vargas, Alexis; Chorover, Jon; Maier, Raina M.

    2011-01-01

    Mine tailings in arid and semi-arid environments are barren of vegetation and subject to eolian dispersion and water erosion. Revegetation is a cost-effective strategy to reduce erosion processes and has wide public acceptance. A major cost of revegetation is the addition of amendments, such as compost, to allow plant establishment. In this paper we explore whether arbuscular mycorrhizal fungi (AMF) can help support plant growth in tailings at a reduced compost concentration. A greenhouse experiment was performed to determine the effects of three AMF inocula on biomass, shoot accumulation of heavy metals, and changes in the rhizosphere microbial community structure of the native plant Prosopis juliflora (mesquite). Plants were grown in an acidic lead/zinc mine tailings amended with 10% (w/w) compost amendment, which is slightly sub-optimal for plant growth in these tailings. After two months, AMF-inoculated plants showed increased dry biomass and root length (p < 0.05) and effective AMF colonization compared to controls grown in uninoculated compost-amended tailings. Mesquite shoot tissue lead and zinc concentrations did not exceed domestic animal toxicity limits regardless of whether AMF inoculation was used. The rhizosphere microbial community structure was assessed using denaturing gradient gel electrophoresis (DGGE) profiles of the small subunit RNA gene for bacteria and fungi. Canonical correspondence analysis (CCA) of DGGE profiles showed that the rhizosphere fungal community structure at the end of the experiment was significantly different from the community structure in the tailings, compost, and AMF inocula prior to planting. Further, CCA showed that AMF inoculation significantly influenced the development of both the fungal and bacterial rhizosphere community structures after two months. The changes observed in the rhizosphere microbial community structure may be either a direct effect of the AMF inocula, caused by changes in plant physiology induced by

  17. The effect of ascorbic acid on the photophysical properties and photodynamic therapy activities of zinc phthalocyanine-single walled carbon nanotube conjugate on MCF-7 cancer cells.

    PubMed

    Ogbodu, Racheal O; Nyokong, Tebello

    2015-01-01

    Zinc mono carboxy phenoxy phthalocyanine (1) was chemical modified with ascorbic acid via an ester bond to give ZnMCPPc-AA (2). Complexes 2 and 1 were coordinated to single walled carbon nanotubes via π-π interaction to give ZnMCPPc-AA-SWCNT (3) and ZnMCPPc-SWCNT (4) respectively. Complexes 2, 3 and 4 showed better photophysical properties: with improved triplet lifetimes and quantum yields, and singlet oxygen quantum yields when compared to 1 alone. The photodynamic therapy activities of complexes 1, 2, 3 and 4 were tested in vitro on MCF-7 breast cancer cells. Ascorbic acid suppresses the photodynamic therapy effect of 1, due to its ability to reduce oxidative DNA damage as a result of its potent reducing properties. The highest phototoxicity was observed for 4 which resulted in 77% decrease in cell viability, followed by 3 which resulted in 67% decrease in cell viability. This shows the importance of combination therapy, where the phthalocyanines are the photodynamic therapy agents and single walled carbon nanotubes are the photothermal therapy agents.

  18. [Biochemical evaluation of damage due to lead: importance and significance of erythrocyte zinc-protoporhyrin IX and urinary amino acid determination].

    PubMed

    Sanguinetti, F; Dompè, M; Ronca, G

    1977-01-01

    The early detection of lead intoxitation needs practical, simple, reproducible and diagnostically valid screening test. The determination of ALA-D (delta-amino-levulinic acid-dehydratase) in erythrocytes is one of the most reliable test for the evaluation of the occupational exposure to lead. However this test is difficult to standardize, sensible to lead contamination of laboratory glassware and the activity of enzyme decreases rapidly if stored. The determination of erythrocytes ZPP (zinco-protoporphyrin IX) was proposed as useful, alternative test. The protoporphyrin IX is a metabolic intermediate in heme biosynthesis; in erythrocytes is present as free form and zinc-boundend compound. The ZPP give high values only in lead intoxication and sideropenic anemia. The ALA-D and ZPP in erythrocytes were measured and compared in a group of workers exposed to lead. We have shown a good correlation between these two biochemical parameters. Aminoacid excretion in urine from workers exposed to lead was measured and compared with other biochemical parameters of intoxication. All lead workers examined had excessive urinary CP (coproporphyrin) and ALA (delta-amino-levulinic acid) excretion. An abnormal excretion of glycine was present in eight workers (32%), whereas in other four (15%) the glycinuria was at limit of normal values. An abnormal excretion of lysine was present in six workers (21%). The last data appear very interesting because the action of lead in lysine metabolism was not known. PMID:603137

  19. The effect of ascorbic acid on the photophysical properties and photodynamic therapy activities of zinc phthalocyanine-single walled carbon nanotube conjugate on MCF-7 cancer cells.

    PubMed

    Ogbodu, Racheal O; Nyokong, Tebello

    2015-01-01

    Zinc mono carboxy phenoxy phthalocyanine (1) was chemical modified with ascorbic acid via an ester bond to give ZnMCPPc-AA (2). Complexes 2 and 1 were coordinated to single walled carbon nanotubes via π-π interaction to give ZnMCPPc-AA-SWCNT (3) and ZnMCPPc-SWCNT (4) respectively. Complexes 2, 3 and 4 showed better photophysical properties: with improved triplet lifetimes and quantum yields, and singlet oxygen quantum yields when compared to 1 alone. The photodynamic therapy activities of complexes 1, 2, 3 and 4 were tested in vitro on MCF-7 breast cancer cells. Ascorbic acid suppresses the photodynamic therapy effect of 1, due to its ability to reduce oxidative DNA damage as a result of its potent reducing properties. The highest phototoxicity was observed for 4 which resulted in 77% decrease in cell viability, followed by 3 which resulted in 67% decrease in cell viability. This shows the importance of combination therapy, where the phthalocyanines are the photodynamic therapy agents and single walled carbon nanotubes are the photothermal therapy agents. PMID:26135538

  20. Aggregation properties of bis(salicylaldiminato)zinc(II) Schiff-base complexes and their Lewis acidic character.

    PubMed

    Consiglio, Giuseppe; Failla, Salvatore; Finocchiaro, Paolo; Oliveri, Ivan Pietro; Di Bella, Santo

    2012-01-14

    The synthesis, characterization, (1)H NMR, optical absorption and fluorescent properties of a series of amphiphilic Schiff-base bis(salicylaldiminato)zinc(II) complexes are reported. Detailed (1)H NMR, DOSY NMR, optical absorption and fluorescence spectroscopy studies indicate the existence of aggregate species in solutions of non-coordinating solvents. The degree of aggregation is related to the nature of the bridging diamine. Chloroform solutions of complexes where the bridging diamine contains a naphthalene or the pyridine nucleus are always characterized by the presence of defined dimer aggregates, whereas oligomeric aggregates are likely formed by complexes where the bridging diamine contains a benzene ring. In coordinating solvents or in the presence of coordinating species, a complete deaggregation of the complexes occurs, because of the axial coordination to the Zn(II) ion, accompanied by considerable changes in the (1)H NMR and optical absorption spectra. The effect of the alkyl chains length seems to play a minor role in the aggregation properties, as noticed by (1)H NMR data, optical absorption and fluorescence spectra, which remain almost unaltered on changing the chain length. PMID:22005842

  1. Cadmium, lead and zinc leaching from smelter fly ash in simple organic acids--simulators of rhizospheric soil solutions.

    PubMed

    Ettler, Vojtech; Vrtisková, Růzena; Mihaljevic, Martin; Sebek, Ondrej; Grygar, Tomás; Drahota, Petr

    2009-10-30

    Emissions from base-metal smelters are responsible for high contamination of the surrounding soils. Fly ash from a secondary Pb smelter was submitted to a batch leaching procedure (0.5-168 h) in 500 microM solutions of acetic, citric, or oxalic acids to simulate the release of toxic metals (Cd, Pb, Zn) in rhizosphere-like environments. Organic acids increased dissolution of fly ash by a factor of 1.3. Cadmium and Pb formed mobile chloro- and sulphate-complexes, whereas Zn partly present in a citrate (Zn-citrate(-)) complex is expected to be less mobile due to sorption onto the positively charged surfaces of hydrous ferric oxides (HFO) and organic matter (OM) in acidic soil.

  2. Chronic toxicity of zinc-spiked sediments; Evaluation of the acid volatile sulfide (AVS) model using Chironomus tentans

    SciTech Connect

    Sibley, P.K.; Ankley, G.T.; Cotter, A.M.; Leonard, E.N.

    1995-12-31

    Most research supporting AVS as a normalization phase for predicting the bioavailability of cationic metals from sediments is based on short-term laboratory exposures. Evidence supporting the theory with respect to chronic exposures is lacking. The purpose of this study, therefore, was to investigate whether the AVS model could predict toxicity to Chironomus tentans in a life cycle exposure to zinc-spiked sediments. Clean sediment was spiked with Zn to obtain nominal treatments ranging from {minus}2.35 to 58.5 {micro}g/g dw with respect to the molar difference between simultaneously extracted metal and AVS. The test was initiated with newly hatched larvae and carried through one complete generation (56 d) during which survival, growth, emergence, and reproduction were monitored. When SEM-AVS was < 0, the concentration of Zn in the pore water was low and no adverse effects were observed for any of the endpoints. Conversely, when SEM-AVS exceeded 0, a dose-dependent increase in the relative concentration of pore water Zn was observed. However, the absolute concentration of pore water Zn at each treatment declined with time, corresponding to an increase in AVS and to loss of Zn due to diffusion into the overlying water (renewed twice daily). Only when SEM-AVS exceeded approximately 6.5 were significant reductions in survival, growth, emergence, and reproductive output observed. In general, the chemical and biological data of this study agree with observations made in short-term exposures and thus support the use of AVS as a normalization phase for predicting the potential for toxicity in metal-contaminated sediments.

  3. Recovery of zinc and manganese, and other metals (Fe, Cu, Ni, Co, Cd, Cr, Na, K) from Zn-MnO2 and Zn-C waste batteries: Hydroxyl and carbonate co-precipitation from solution after reducing acidic leaching with use of oxalic acid

    NASA Astrophysics Data System (ADS)

    Sobianowska-Turek, A.; Szczepaniak, W.; Maciejewski, P.; Gawlik-Kobylińska, M.

    2016-09-01

    The article discusses the current situation of the spent batteries and portable accumulators management. It reviews recycling technologies of the spent batteries and portable accumulators which are used in the manufacturing installations in the world. Also, it presents the authors' research results on the reductive acidic leaching of waste material of the zinc-carbon batteries (Zn-C) and zinc-manganese batteries (alkaline Zn-MnO2) delivered by a company dealing with mechanical treatment of this type of waste stream. The research data proved that the reductive acidic leaching (H2SO4 + C2H2O4) of the battery's black mass allows to recover 85.0% of zinc and 100% of manganese. Moreover, it was found that after the reductive acidic leaching it is possible to recover nearly 100% of manganese, iron, cadmium, and chromium, 98.0% of cobalt, 95.5% of zinc, and 85.0% of copper and nickel from the solution with carbonate method. On the basis of the results, it is possible to assume that the carbonate method can be used for the preparation of manganese-zinc ferrite.

  4. Highly chemoselective and versatile method for direct conversion of carboxylic acids to ketones utilizing zinc ate complexes.

    PubMed

    Murata, Ryo; Hirano, Keiichi; Uchiyama, Masanobu

    2015-06-01

    Various carboxylic acids were directly transformed into the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to the undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity.

  5. TREATMENT OF ACID MINE DRAINAGE: I. EQUILIBRIUM BIOSORPTION OF ZINC AND COPPER ON NON-VIABLE ACTIVATED SLUDGE

    EPA Science Inventory

    Biosorption is potentially attractive technology for treament of acid mine drainage for separation/recovery of metal ions and mitigation of their toxicity to sulfate reducing bacteria. This study describes the equilibrium biosorptio of Zn(II) and CU(II) by nonviable activated slu...

  6. Zinc phosphide

    Integrated Risk Information System (IRIS)

    Zinc phoshide ; CASRN 1314 - 84 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  7. Zinc cyanide

    Integrated Risk Information System (IRIS)

    Zinc cyanide ; CASRN 557 - 21 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effe

  8. Probing the Efficacy of Peptide-Based Inhibitors against Acid- and Zinc-Promoted Oligomerization of Amyloid-β Peptide via Single-Oligomer Spectroscopy

    PubMed Central

    Powell, Lyndsey R.; Dukes, Kyle D.; Lammi, Robin K.

    2011-01-01

    One avenue for prevention and treatment of Alzheimer's disease involves inhibiting the aggregation of amyloid-β peptide (Aβ). Given the deleterious effects reported for Aβ dimers and trimers, it is important to investigate inhibition of the earliest association steps. We have employed quantized photobleaching of dye-labeled Aβ peptides to characterize four peptide-based inhibitors of fibrillogenesis and/or cytotoxicity, assessing their ability to inhibit association in the smallest oligomers (n = 2–5). Inhibitors were tested at acidic pH and in the presence of zinc, conditions that may promote oligomerization in vivo. Distributions of peptide species were constructed by examining dozens of surface-tethered monomers and oligomers, one at a time. Results show that all four inhibitors shift the distribution of Aβ species toward monomers; however, efficacies vary for each compound and sample environment. Collectively, these studies highlight promising design strategies for future oligomerization inhibitors, affording insight into oligomer structures and inhibition mechanisms in two physiologically significant environments. PMID:21945664

  9. Activation of the Ustilagic Acid Biosynthesis Gene Cluster in Ustilago maydis by the C2H2 Zinc Finger Transcription Factor Rua1▿

    PubMed Central

    Teichmann, Beate; Liu, Lidan; Schink, Kay Oliver; Bölker, Michael

    2010-01-01

    The phytopathogenic basidiomycetous fungus Ustilago maydis secretes, under conditions of nitrogen starvation, large amounts of the biosurfactant ustilagic acid (UA). This secreted cellobiose glycolipid is toxic for many microorganisms and confers biocontrol activity to U. maydis. Recently, a large gene cluster that is responsible for UA biosynthesis was identified. Here, we show that expression of all cluster genes depends on Rua1, a nuclear protein of the C2H2 zinc finger family, whose gene is located within the gene cluster. While deletion of rua1 results in complete loss of UA production, overexpression of rua1 promotes increased UA synthesis even in the presence of a good nitrogen source. Bioinformatic analysis allowed us to identify a conserved sequence element that is present in the promoters of all structural genes involved in UA biosynthesis. Deletion analysis of several promoters within the cluster revealed that this DNA element serves as an upstream activating sequence (UAS) and mediates Rua1-dependent expression. We used the yeast one-hybrid system to demonstrate specific recognition of this DNA element by Rua1. Introduction of nucleotide exchanges into the consensus sequence interfered with Rua1-dependent activation, suggesting that this sequence element acts as a direct binding site for Rua1. PMID:20173069

  10. Activation of the ustilagic acid biosynthesis gene cluster in Ustilago maydis by the C2H2 zinc finger transcription factor Rua1.

    PubMed

    Teichmann, Beate; Liu, Lidan; Schink, Kay Oliver; Bölker, Michael

    2010-04-01

    The phytopathogenic basidiomycetous fungus Ustilago maydis secretes, under conditions of nitrogen starvation, large amounts of the biosurfactant ustilagic acid (UA). This secreted cellobiose glycolipid is toxic for many microorganisms and confers biocontrol activity to U. maydis. Recently, a large gene cluster that is responsible for UA biosynthesis was identified. Here, we show that expression of all cluster genes depends on Rua1, a nuclear protein of the C(2)H(2) zinc finger family, whose gene is located within the gene cluster. While deletion of rua1 results in complete loss of UA production, overexpression of rua1 promotes increased UA synthesis even in the presence of a good nitrogen source. Bioinformatic analysis allowed us to identify a conserved sequence element that is present in the promoters of all structural genes involved in UA biosynthesis. Deletion analysis of several promoters within the cluster revealed that this DNA element serves as an upstream activating sequence (UAS) and mediates Rua1-dependent expression. We used the yeast one-hybrid system to demonstrate specific recognition of this DNA element by Rua1. Introduction of nucleotide exchanges into the consensus sequence interfered with Rua1-dependent activation, suggesting that this sequence element acts as a direct binding site for Rua1. PMID:20173069

  11. Effect of aluminum, zinc, copper, and lead on the acid-base properties of water extracts from soils

    NASA Astrophysics Data System (ADS)

    Motuzova, G. V.; Makarychev, I. P.; Petrov, M. I.

    2013-01-01

    The potentiometric titration of water extracts from the upper horizons of taiga-zone soils by salt solutions of heavy metals (Pb, Cu, and Zn) showed that their addition is an additional source of the extract acidity because of the involvement of the metal ions in complexation with water-soluble organic substances (WSOSs). At the addition of 0.01 M water solutions of Al(NO3)3 to water extracts from soils, Al3+ ions are also involved in complexes with WSOSs, which is accompanied by stronger acidification of the extracts from the upper horizon of soddy soils (with a near-neutral reaction) than from the litter of bog-podzolic soil (with a strongly acid reaction). The effect of the Al3+ hydrolysis on the acidity of the extracts is insignificantly low in both cases. A quantitative relationship was revealed between the release of protons and the ratio of free Cu2+ ions to those complexed with WSOSs at the titration of water extracts from soils by a solution of copper salt.

  12. Zinc protoporphyrin inhibition of lipopolysaccharide-, lipoteichoic acid-, and peptidoglycan-induced nitric oxide production through stimulating iNOS protein ubiquitination

    SciTech Connect

    Chow, J.-M.; Lin, H.-Y.; Shen, S.-C.; Wu, M.-S.; Lin, C.-W.; Chiu, W.-T.; Lin, C.-H. Chen, Y.-C.

    2009-06-15

    In the present study, zinc protoporphyrin (ZnPP), but not ferric protoporphyrin (FePP), tin protoporphyrin (SnPP), or zinc chloride (ZnCl{sub 2}), at the doses of 0.5, 1, and 2 {mu}M, dose-dependently inhibited lipopolysaccharide- (LPS), lipoteichoic acid (LTA), and peptidoglycan (PGN)-induced inducible nitric oxide (iNOS) and nitric oxide (NO) production with an increase in heme oxygenase 1 (HO-1) protein in RAW264.7 macrophages in a serum-free condition. NO inhibition and HO-1 induction by ZnPP were blocked by the separate addition of fetal bovine serum (FBS) and bovine serum albumin (BSA). A decrease in the iNOS/NO ratio and an increase in HO-1 protein by ZnPP were identified in three different conditions including ZnPP pretreatment, ZnPP co-treatment, and ZnPP post-treatment with LPS and LTA. Activation of c-Jun N-terminal kinases (JNKs) and extracellular regulated kinases (ERKs) were detected in LPS-, LTA-, and PGN-treated RAW264.7 cells, and iNOS/NO production was blocked by adding the JNK inhibitor, SP600125, but not the ERK inhibitor, PD98059. However, ZnPP addition potentiated ERK and JNK protein phosphorylation stimulated by LPS, LTA, and PGN. Increases in total protein ubiquitination and ubiquitinated iNOS proteins were detected in ZnPP-treated macrophages elicited by LPS according to Western and immunoprecipitation/Western blotting assays, respectively. The decrease in LPS-induced iNOS protein by ZnPP was reversed by adding the proteasome inhibitors MG132 and lactacystin. The reduction in HO-1 protein induced by ZnPP via transfection of HO-1 small interfering RNA did not affect the inhibitory effect of ZnPP against LPS-induced iNOS/NO production and protein ubiquitination induced by ZnPP in macrophages. Data of the present study provide the first evidence to support ZnPP effectively inhibiting inflammatory iNOS/NO production through activation of protein ubiquitination in a HO-1-independent manner in macrophages.

  13. Comparative analysis of the protective effects of caffeic acid phenethyl ester (CAPE) on pulmonary contusion lung oxidative stress and serum copper and zinc levels in experimental rat model.

    PubMed

    Sırmalı, Mehmet; Solak, Okan; Tezel, Cagatay; Sırmalı, Rana; Ginis, Zeynep; Atik, Dilek; Agackıran, Yetkin; Koylu, Halis; Delibas, Namık

    2013-01-01

    The aim of this study was to investigate the effects of caffeic acid phenethyl ester (CAPE) in the lungs by biochemical and histopathological analyses in an experimental isolated lung contusion model. Eighty-one male Sprague-Dawley rats were used. The animals were divided randomly into four groups: group 1 (n = 9) was defined as without contusion and without CAPE injection. Group 2 (n = 9) was defined as CAPE 10 μmol/kg injection without lung contusion. Group 3 (n = 36) was defined as contusion without CAPE-administrated group which consisted of four subgroups that were created according to analysis between days 0, 1, 2, and 3. Group 4 (n = 27) was defined as CAPE 10 μmol/kg administrated after contusion group divided into three subgroups according to analysis on days 1, 2, and 3. CAPE 10 μmol/kg was injected intraperitoneally 30 min after trauma and on days 1 and 2. Blood samples were obtained to measure catalase (CAT) and superoxide dismutase (SOD) activities and level of malondialdehyde (MDA) and for blood gas analysis. Trace elements such as zinc and copper were measured in serum. The lung tissue was also removed for histopathological examination. Isolated lung contusion increased serum and tissue SOD and CAT activities and MDA levels (p < 0.05). Both serum and tissue SOD, MDA, and CAT levels on day 3 were lower in group 4 compared to group 3 (p < 0.05). Further, the levels of SOD, MDA, and CAT in group 4 were similar compared to group 1 (p > 0.05). CAPE also had a significant beneficial effect on blood gases (p < 0.05). Both serum zinc and copper levels were (p < 0.05) influenced by the administration of CAPE. Histopathological examination revealed lower scores in group 4 compared to group 3 (p < 0.05) and no significant differences compared to group 1 (p > 0.05). CAPE appears to be effective in protecting against severe oxidative stress and tissue damage caused by pulmonary contusion in an

  14. Zinc and its importance for human health: An integrative review

    PubMed Central

    Roohani, Nazanin; Hurrell, Richard; Kelishadi, Roya; Schulin, Rainer

    2013-01-01

    Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers), human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency. PMID:23914218

  15. Zinc and its importance for human health: An integrative review.

    PubMed

    Roohani, Nazanin; Hurrell, Richard; Kelishadi, Roya; Schulin, Rainer

    2013-02-01

    Since its first discovery in an Iranian male in 1961, zinc deficiency in humans is now known to be an important malnutrition problem world-wide. It is more prevalent in areas of high cereal and low animal food consumption. The diet may not necessarily be low in zinc, but its bio-availability plays a major role in its absorption. Phytic acid is the main known inhibitor of zinc. Compared to adults, infants, children, adolescents, pregnant, and lactating women have increased requirements for zinc and thus, are at increased risk of zinc depletion. Zinc deficiency during growth periods results in growth failure. Epidermal, gastrointestinal, central nervous, immune, skeletal, and reproductive systems are the organs most affected clinically by zinc deficiency. Clinical diagnosis of marginal Zn deficiency in humans remains problematic. So far, blood plasma/serum zinc concentration, dietary intake, and stunting prevalence are the best known indicators of zinc deficiency. Four main intervention strategies for combating zinc deficiency include dietary modification/diversification, supplementation, fortification, and bio-fortification. The choice of each method depends on the availability of resources, technical feasibility, target group, and social acceptance. In this paper, we provide a review on zinc biochemical and physiological functions, metabolism including, absorption, excretion, and homeostasis, zinc bio-availability (inhibitors and enhancers), human requirement, groups at high-risk, consequences and causes of zinc deficiency, evaluation of zinc status, and prevention strategies of zinc deficiency.

  16. High performance zinc anode for battery applications

    NASA Technical Reports Server (NTRS)

    Casey, John E., Jr. (Inventor)

    1998-01-01

    An improved zinc anode for use in a high density rechargeable alkaline battery is disclosed. A process for making the zinc electrode comprises electrolytic loading of the zinc active material from a slightly acidic zinc nitrate solution into a substrate of nickel, copper or silver. The substrate comprises a sintered plaque having very fine pores, a high surface area, and 80-85 percent total initial porosity. The residual porosity after zinc loading is approximately 25-30%. The electrode of the present invention exhibits reduced zinc mobility, shape change and distortion, and demonstrates reduced dendrite buildup cycling of the battery. The disclosed battery is useful for applications requiring high energy density and multiple charge capability.

  17. Influence of phytase, EDTA, and polyphenols on zinc absorption in adults from porridges fortified with zinc sulfate or zinc oxide.

    PubMed

    Brnić, Marica; Wegmüller, Rita; Zeder, Christophe; Senti, Gabriela; Hurrell, Richard F

    2014-09-01

    Fortification of cereal staples with zinc is recommended to combat zinc deficiency. To optimize zinc absorption, strategies are needed to overcome the inhibitory effect of phytic acid (PA) and perhaps polyphenols. Five zinc absorption studies were conducted in young adults consuming maize or sorghum porridges fortified with 2 mg zinc as zinc sulfate (ZnSO4) or zinc oxide (ZnO) and containing combinations of PA or polyphenols as potential inhibitors and EDTA and phytase as potential enhancers. Fractional absorption of zinc (FAZ) was measured by using the double isotopic tracer ratio method. Adding phytase to the maize porridge immediately before consumption or using phytase for dephytinization during meal preparation both increased FAZ by >80% (both P < 0.001). Adding Na2EDTA at an EDTA:zinc molar ratio of 1:1 increased FAZ from maize porridge fortified with ZnSO4 by 30% (P = 0.01) but had no influence at higher EDTA ratios or on absorption from ZnO. FAZ was slightly higher from ZnSO4 than from ZnO (P = 0.02). Sorghum polyphenols had no effect on FAZ from dephytinized sorghum porridges but decreased FAZ by 20% from PA-rich sorghum porridges (P < 0.02). The combined inhibitory effect of polyphenols and PA was overcome by EDTA. In conclusion, ZnSO4 was better absorbed than ZnO, phytase used to degrade PA during digestion or during food preparation substantially increased zinc absorption from zinc-fortified cereals, EDTA at a 1:1 molar ratio modestly enhanced zinc absorption from ZnSO4-fortified cereals but not ZnO-fortified cereals, and sorghum polyphenols inhibited zinc absorption in the presence, but not absence, of PA. This trial was registered at clinicaltrials.gov as NCT01210794.

  18. Stabilization of zinc electrodes with a conducting polymer

    NASA Astrophysics Data System (ADS)

    Vatsalarani, J.; Geetha, S.; Trivedi, D. C.; Warrier, P. C.

    The reversibility of zinc anode in alkaline medium was enhanced by electrostatic deposition of a conducting polymer (polypyrrole). Electropolymerization of pyrrole onto zinc in aqueous medium using an organic acid as dopant is feasible and preferred as zinc is less corrosive in this medium. The structure of the polymer film was analyzed by FT-IR spectroscopy and scanning electron microscopy. The effect of the polypyrrole deposit on the zinc electrode was studied by cyclic voltammetry and charge-discharge cycling.

  19. Development of a Simple Adjustable Zinc Acid/Base Hybrid Catalyst for C-C and C-O Bond-Forming and C-C Bond-Cleavage Reactions.

    PubMed

    Yamashita, Yasuhiro; Minami, Kodai; Saito, Yuki; Kobayashi, Shū

    2016-09-01

    A newly designed zinc Lewis acid/base hybrid catalyst was developed. By adjusting the Lewis acidity of the zinc center, aldol-type additions of 2-picolylamine Schiff base to aldehydes proceeded smoothly to afford syn-aldol adduct equivalents, trans-N,O-acetal adducts, in high yields with high selectivities. NMR experiments, including microchanneled cell for synthesis monitoring (MICCS) NMR analysis, revealed that anti-aldol adducts were formed at the initial stage of the reactions under kinetic control, but the final products were the trans-(syn)-N,O-acetal adducts that were produced through a retro-aldol process under thermodynamic control. In the whole reaction process, the zinc catalyst played three important roles: i) promotion of the aldol process (C-C bond formation), ii) cyclization process to the N,O-acetal product (C-O bond formation), and iii) retro-aldol process from the anti-aldol adduct to the syn-aldol adduct (C-C bond cleavage and C-C bond formation).

  20. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    SciTech Connect

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing

    2013-10-15

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H{sub 2}CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn{sub 5}(μ{sub 3}-OH){sub 2}(2,7-CDC){sub 4}(DEF){sub 2}] (1) (DEF=N,N-diethylformamide), [Zn{sub 2}(2,7-CDC){sub 2}(DABCO)(H{sub 2}O)]·5DMF·H{sub 2}O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn{sub 2}(2,7-CDC){sub 2}(bpea)]·3DMA·2 H{sub 2}O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle–wheel [Zn{sub 2}(COO){sub 4}] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle–wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied. - Graphical abstract: A new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid, was used to construct Zn(II) metal-organic frameworks, including a novel self-catenated network with the rare 3D alb-3,6-C2/c net and two pcu-type networks based on an unprecedented pentanuclear clusters and the common paddle–wheel units. The compounds show blue fluorescent properties. Display Omitted - Highlights: • MOFs with a new carbazole-based dicarboxylate ligand. • New pentanuclear [Zn{sub 5}(μ{sub 3}-OH){sub 2}(COO){sub 8}] secondary building unit. • The rare self-catenated 3D alb-3,6-C2/c net.

  1. The isotopic composition of zinc, palladium, silver, cadmium, tin, and tellurium in acid-etched residues of the Allende meteorite

    SciTech Connect

    Loss, R.D.; Rosman, K.J.R.; De Laeter, J.R. )

    1990-12-01

    The isotopic and elemental abundances of Zn, Pd, Ag, Cd, Sn, and Te have been measured in three acid-resistant residues extracted from the Allende meteorite. High-efficiency, low-contamination ion-exchange procedures were developed to separate and purify the nanogram amounts of these elements present. Elemental-abundance determinations performed by Mass Spectrometric Isotope Dilution agree with previously published work for similarly derived residues. No isotope anomalies similar to those found for Xe (Xe-HL) in these samples were detected for any of these elements, which is consistent with the residues not being derived directly from the Xe-HL carriers. The lack of major Te-isotope anomalies does not support earlier reports of {sup 126}Te and {sup 130}Te excesses which were measured by neutron activation in similar samples. Small excesses were detected in the minor isotopes of Sn and Te, but these may be due to measurement problems associated with the small ion currents obtained for these samples. Two of the residue solutions contain Cd with up to several percent excesses for {sup 106}Cd and {sup 108}Cd. Interpretations of these results are limited by the unknown nature of the carrier minerals in the residues but may indicate the presence of a p-process component in Allende residues.

  2. Highly efficient and autocatalytic H2O dissociation for CO2 reduction into formic acid with zinc

    NASA Astrophysics Data System (ADS)

    Jin, Fangming; Zeng, Xu; Liu, Jianke; Jin, Yujia; Wang, Lunying; Zhong, Heng; Yao, Guodong; Huo, Zhibao

    2014-03-01

    Artificial photosynthesis, specifically H2O dissociation for CO2 reduction with solar energy, is regarded as one of the most promising methods for sustainable energy and utilisation of environmental resources. However, a highly efficient conversion still remains extremely challenging. The hydrogenation of CO2 is regarded as the most commercially feasible method, but this method requires either exotic catalysts or high-purity hydrogen and hydrogen storage, which are regarded as an energy-intensive process. Here we report a highly efficient method of H2O dissociation for reducing CO2 into chemicals with Zn powder that produces formic acid with a high yield of approximately 80%, and this reaction is revealed for the first time as an autocatalytic process in which an active intermediate, ZnH- complex, serves as the active hydrogen. The proposed process can assist in developing a new concept for improving artificial photosynthetic efficiency by coupling geochemistry, specifically the metal-based reduction of H2O and CO2, with solar-driven thermochemistry for reducing metal oxide into metal.

  3. Synthesis, structure and properties of zinc(II) coordination polymers with 9H-carbazole-2,7-dicarboxylic acid

    NASA Astrophysics Data System (ADS)

    Yi, Xiu-Chun; Xi, Fu-Gui; Wang, Kun; Su, Zhao; Gao, En-Qing

    2013-10-01

    From a new dicarboxylate ligand, 9H-carbazole-2,7-dicarboxylic acid (2,7-H2CDC), three Zn(II) metal-organic frameworks were synthesized in the absence or presence of ditopic N-donor ligands. They are formulated as [Zn5(μ3-OH)2(2,7-CDC)4(DEF)2] (1) (DEF=N,N-diethylformamide), [Zn2(2,7-CDC)2(DABCO)(H2O)]·5DMF·H2O (2) (DABCO=1-diaza-bicyclo[2.2.2]octane, DMF=N,N-dimethylformamide), and [Zn2(2,7-CDC)2(bpea)]·3DMA·2 H2O (3) (bpea=1,2-bis(4-pyridyl)ethylane, DMA=N,N-dimethylacetamide). Compounds 1 and 3 display the 3D pcu frameworks. In 1 the unusual pentanuclear [Zn5(μ3-OH)2(COO)8] secondary building units (SBUs) are linked by dicarboxylate ligands. Differently, in 3 the well-known paddle-wheel [Zn2(COO)4] SBUs are linked by dicarboxylate and dipyridyl ligands. Compound 2 shows the rare self-catenated 3D alb-3,6-C2/c net topology based on the dinuclear paddle-wheel SBU and a mononuclear unit. The stability and fluorescent properties of the compounds have been studied.

  4. Enhancement of zinc oxide-mediated solar light decoloration of Acid Yellow 99 dye by addition of β-CD

    NASA Astrophysics Data System (ADS)

    Pitchaimuthu, Sakthivel; Rajalakshmi, Subramanian; Kannan, Nagarathinam; Velusamy, Ponnusamy

    2015-06-01

    In the current work, the commercially available ZnO photocatalyst was used to investigate the photodecoloration of Acid yellow 99 (AY99) dye under solar light radiation. Promising enhancement of photodecoloration of AY99 dye was also achieved by the addition of β-cyclodextrin (β-CD) with the ZnO (ZnO-β-CD). The effects of process parameters such as initial concentration, pH, catalyst loading, and illumination time on the extent of decoloration were investigated. The optimum catalyst loading was observed at 2.0 g/L. The higher photoactivity of ZnO-β-CD/solar light system than ZnO/solar light system can be ascribed due to the ligand to metal charge transfer (LMCT) from β-CD to ZnII. The complexation patterns have been confirmed with UV-visible and FT-IR spectroscopy and the interaction between ZnO and β-CD has been characterized by FE-SEM, powder XRD analysis, and UV-visible diffuse reflectance spectroscopy.

  5. Highly efficient and autocatalytic H2O dissociation for CO2 reduction into formic acid with zinc

    PubMed Central

    Jin, Fangming; Zeng, Xu; Liu, Jianke; Jin, Yujia; Wang, Lunying; Zhong, Heng; Yao, Guodong; Huo, Zhibao

    2014-01-01

    Artificial photosynthesis, specifically H2O dissociation for CO2 reduction with solar energy, is regarded as one of the most promising methods for sustainable energy and utilisation of environmental resources. However, a highly efficient conversion still remains extremely challenging. The hydrogenation of CO2 is regarded as the most commercially feasible method, but this method requires either exotic catalysts or high-purity hydrogen and hydrogen storage, which are regarded as an energy-intensive process. Here we report a highly efficient method of H2O dissociation for reducing CO2 into chemicals with Zn powder that produces formic acid with a high yield of approximately 80%, and this reaction is revealed for the first time as an autocatalytic process in which an active intermediate, ZnH− complex, serves as the active hydrogen. The proposed process can assist in developing a new concept for improving artificial photosynthetic efficiency by coupling geochemistry, specifically the metal-based reduction of H2O and CO2, with solar-driven thermochemistry for reducing metal oxide into metal. PMID:24675820

  6. TaCHP: a wheat zinc finger protein gene down-regulated by abscisic acid and salinity stress plays a positive role in stress tolerance.

    PubMed

    Li, Cuiling; Lv, Jian; Zhao, Xin; Ai, Xinghui; Zhu, Xinlei; Wang, Mengcheng; Zhao, Shuangyi; Xia, Guangmin

    2010-09-01

    The plant response to abiotic stresses involves both abscisic acid (ABA)-dependent and ABA-independent signaling pathways. Here we describe TaCHP, a CHP-rich (for cysteine, histidine, and proline rich) zinc finger protein family gene extracted from bread wheat (Triticum aestivum), is differentially expressed during abiotic stress between the salinity-sensitive cultivar Jinan 177 and its tolerant somatic hybrid introgression cultivar Shanrong No.3. TaCHP expressed in the roots of seedlings at the three-leaf stage, and the transcript localized within the cells of the root tip cortex and meristem. TaCHP transcript abundance was higher in Shanrong No.3 than in Jinan 177, but was reduced by the imposition of salinity or drought stress, as well as by the exogenous supply of ABA. When JN17, a salinity hypersensitive wheat cultivar, was engineered to overexpress TaCHP, its performance in the face of salinity stress was improved, and the ectopic expression of TaCHP in Arabidopsis (Arabidopsis thaliana) also improved the ability of salt tolerance. The expression level of a number of stress reporter genes (AtCBF3, AtDREB2A, AtABI2, and AtABI1) was raised in the transgenic lines in the presence of salinity stress, while that of AtMYB15, AtABA2, and AtAAO3 was reduced in its absence. The presence in the upstream region of the TaCHP open reading frame of the cis-elements ABRE, MYBRS, and MYCRS suggests that it is a component of the ABA-dependent and -independent signaling pathways involved in the plant response to abiotic stress. We suggest that TaCHP enhances stress tolerance via the promotion of CBF3 and DREB2A expression.

  7. Uptake of intact zinc-ethylenediaminetetraacetic acid from soil is dependent on plant species and complex concentration.

    PubMed

    Collins, Richard N; Merrington, Graham; McLaughlin, Mike J; Knudsen, Chris

    2002-09-01

    Pot experiments were conducted with barley (Hordeum vulgare L.), potato (Solanum tuberosum L.), Indian mustard (Brassicajuncea L.), and white lupin (Lupinus albus L.) to determine the nature of Zn mobilization, uptake, and root-shoot transport from a Zn-contaminated soil in the presence of increasing concentrations of ethylenediaminetetraacetic acid (EDTA; 0.0-3.4 mmole/kg soil). Increasing EDTA concentrations lead to a greater proportion of soil-solution Zn being detected as the ZnEDTA complex. However, a significant increase in the concentration of soil-solution Zn was only observed after the addition of 3.4 mmole EDTA/ kg soil. At this application rate, regardless of the plant species, 97 +/- 9% (+/- SD) of the increase in soil-solution Zn could be accounted for by chelation/desorption, and 89 +/- 9% of total Zn in solution was measured as ZnEDTA. Although the complex was detected in the xylem exudate of B. juncea after 0.34 mmole EDTA/kg soil had been added, ZnEDTA was only found in the xylem exudate of the other plant species following the highest application rate of EDTA. In this case, the accumulation of Zn and the concentration of ZnEDTA in the xylem sap of B. juncea were significantly greater than those of H. vulgare and S. tuberosum. Measurements of plant transpiration following the addition of EDTA indicated that B. juncea experienced greater physiological stress in the presence of high concentrations of EDTA. It was therefore concluded that two different mechanisms of ZnEDTA uptake existed for these plant species. Based on a review of the literature, it was hypothesized that uptake of ZnEDTA by B. juncea occurred only after physiological damage to its root system, whereas uptake by H. vulgare and S. tuberosum was via an apoplastic pathway (passive extracellular transport into the xylem).

  8. [Improved biological availability of zinc in coarse meal and crisp meal bread].

    PubMed

    Harmuth-Hoene, A E; Meuser, F

    1988-12-01

    A study was undertaken to determine whether the reduction of the molar phytic acid/zinc ratio by enrichment of wholemeal and crispbread with zinc improves zinc availability to the same extent as does the reduction of phytic acid in whole meal cereal products. For three weeks, five diets (three samples of wholemeal bread and two samples of crispbread] were fed to growing rats. Significant increases in bone-zinc deposition and activity of serum alkaline phosphatase were induced by those bread samples in which the phytic acid/zinc ratio had been lowered either by enrichment with zinc or by reduction of phytic acid (enzymatic hydrolysis by adjusting the pH-value of the dough with lactic acid) when compared with untreated bread samples. Weight gain of the animals differed little between the groups. The results suggest that it is possible to improve zinc availability in wholemeal cereal products high in phytate by enrichment with zinc.

  9. Bioavailability of two organic forms of zinc in comparison to zinc sulphate for weaning pigs fed a diet composed mainly of wheat, barley and soybean meal.

    PubMed

    Paulicks, Brigitte R; Ingenkamp, Hanna; Eder, Klaus

    2011-08-01

    This study was performed to compare the bioavailability of two organic zinc compounds, a zinc glycinate complex and a zinc amino acid chelate with that of zinc sulphate in growing pigs fed a basal diet composed mainly of wheat, barley and soybean meal. The experiment included 96 pigs with an average body weight of 8 kg, allotted to ten groups of nine to ten pigs each. The first group received the basal diet, containing 42 mg of native zinc per kg, without zinc supplementation over a period of five weeks. The other nine groups received the basal diet supplemented with 15, 30 or 50 mg of zinc/kg as zinc sulphate, zinc glycinate or the zinc amino acid chelate. Pigs fed the unsupplemented diet had a lower growth performance (body weight gain, feed conversion ratio) than the other nine groups. Supplementation of 15 mg zinc/kg diet (irrespective of zinc form) was sufficient to yield optimum growth performance. Plasma zinc concentration and activity of alkaline phosphatase were rising with increasing zinc supplementation levels up to a maximum reached at a supplementary level of 30 or 50 mg/kg diet for activity of alkaline phosphatase and plasma zinc concentration, respectively. The response of those parameters to zinc supplementation did, however, not differ between the three zinc compounds considered. The apparent digestibility of zinc from the diet was also not different for the three zinc compounds. In conclusion, these findings show that the bioavailability of the two organic zinc compounds did not differ from that of zinc sulphate in growing pigs fed a diet with wheat, barley and soybean meal as major components.

  10. Zinc and zinc transporters in prostate carcinogenesis

    PubMed Central

    Kolenko, Vladimir; Teper, Ervin; Kutikov, Alexander; Uzzo, Robert

    2013-01-01

    The healthy human prostate accumulates the highest level of zinc of any soft tissue in the body. This unique property is retained in BPH, but is lost in prostatic malignancy, which implicates changes in zinc and its transporters in carcinogenesis. Indeed, zinc concentrations diminish early in the course of prostate carcinogenesis, preceding histopathological changes, and continue to decline during progression toward castration-resistant disease. Numerous studies suggest that increased zinc intake might protect against progression of prostatic malignancy. Despite increased dietary intake, zinc accumulation might be limited by the diminished expression of zinc uptake transporters, resulting in decreased intratumoural zinc levels. This finding can explain the conflicting results of various epidemiological studies evaluating the role of zinc supplementation on primary and secondary prostate cancer prevention. Overall, more research into the mechanisms of zinc homeostasis are needed to fully understand its impact on prostate carcinogenesis. Only then can the potential of zinc and zinc transport proteins be harnessed in the diagnosis and treatment of men with prostate cancer. PMID:23478540

  11. Production of zinc pellets

    DOEpatents

    Cooper, John F.

    1996-01-01

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries.

  12. Production of zinc pellets

    DOEpatents

    Cooper, J.F.

    1996-11-26

    Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

  13. Effect of humic acids and sunlight on the cytotoxicity of engineered zinc oxide and titanium dioxide nanoparticles to a river bacterial assemblage.

    PubMed

    Dasari, Thabitha P; Hwang, Huey-Min

    2013-09-01

    The effect of a terrestrial humic acid (HA) and Suwannee River HA on the cytotoxicity of engineered zinc oxide nanoparticles (ZnONPs) and titanium dioxide nanoparticles (TiO2NPs) to natural aquatic bacterial assemblages was measured with spread plate counting. The effect of HA (10 and 40 ppm) on the cytotoxicity of ZnONPs and TiO2NPs was tested factorially in the presence and absence of natural sunlight (light irradiation (LI)). The experiment was of full factorial, completely randomized design and the results were analyzed using the General Linear Model in SAS analytical software. The method of least squares means was used to separate the means or combinations of means. We determined the mechanism of toxicity via measurements of oxidative stress and metal ions. The toxicity of ZnONPs and TiO2NPs to natural aquatic bacterial assemblages appears to be concentration dependent. Moreover, the cytotoxicity of ZnONPs and TiO2NPs appeared to be affected by HA concentration, the presence of sunlight irradiation, and the dynamic multiple interactions among these factors. With respect to light versus darkness in the control group, the data indicate that bacterial viability was inhibited more in the light exposure than in the darkness exposure. The same was true in the HA treatment groups. With respect to terrestrial versus Suwanee River HA for a given nanoparticle, in light versus darkness, bacterial viability was more inhibited in the light treatment groups containing the terrestrial HA than in those containing Suwanee River HA. Differences in the extent of reactive oxygen species formation, adsorption/binding of ZnONPs/TiO2NPs by HA, and the levels of free metal ions were speculated to account for the observed cytotoxicity. TEM images indicate the attachment and binding of the tested nanoparticles to natural bacterial assemblages. Besides the individual parameter, significant effects on bacterial viability count were also observed in the following combined treatments: HA

  14. Dietary phytate, zinc and hidden zinc deficiency.

    PubMed

    Sandstead, Harold H; Freeland-Graves, Jeanne H

    2014-10-01

    Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency.

  15. Aluminum colloid formation and its effect on co-precipitation of zinc during acid rock drainage remediation with clinoptilolite in a slurry bubble column

    NASA Astrophysics Data System (ADS)

    Xu, W.; Li, L. Y.; Grace, J. R.

    2012-04-01

    Zinc and other metal ions were adsorbed in a laboratory slurry bubble column (SBC) by natural clinoptilolite sorbent particles. During the remediation process, significant white precipitates were sometimes observed. Both zinc and aluminum were detected in the colloidal mixtures. It is shown that Al leached from clinoptilolite during the agitation, contributing to the precipitate. As a result of the Al leaching and increase of pH during the remediation process, the formation of an Al colloid and zinc adsorption onto it could significantly improve ARD remediation, given the high adsorption capacity of the colloid. Sorption of cations increased with increasing colloid formation. Various conditions were tested to investigate their impact on (a) dealumination of clinoptilolite; (b) Al hydrolysis/colloid formation; and (c) adsorption onto the colloidal mixture. The test results indicate that dealumination contributes to the excess aluminum in the aqueous phase and to precipitates. The excess dealumination varies with pH and agitation time. Al hydrolysis occurs with increasing pH due to the neutralization effect of clinoptilolite. A significant proportion of zinc adsorbed onto the collectible aluminum precipitates.

  16. Zinc recycling through the modified Zincex process

    SciTech Connect

    Diaz, G.; Martin, D.; Lombera, C.

    1995-12-31

    A basic technology coping with a wide range of secondary zinc sources has been developed. The process combines an electrowinning stage, a solvent-extraction unit and a leaching procedure. The acidity generated in zinc electrowinning, transferred by the organic solvent to the aqueous raffinate, is reused to leach the zinc secondary materials. The basic process recovering zinc is described in detail. The route recovering other valuable metals such as copper, cadmium and lead associated with zinc is also described. This nonferrous metals recovery route is advisable for either ecological and/or economical reasons. Main results of an experimental program aiming at the demonstration of the suitability of the process for several feed materials are summarized. Waelz oxides, galvanizing ashes and EAFD coming from different sources were tested in laboratory and continuous pilot plant campaigns. High zinc recovery, low reagents and utilities consumption, and effluents meeting environmental regulation were confirmed. The paper also includes the main results of a feasibility study of an industrial ``base case``. A mixed raw material and Spanish EAFD and 20,000 ta of zinc ingots production were chosen. The SGH zinc recovery from secondary raw material by means of the clean, safe and profitable Modified Zincex Process has been demonstrated. This reliable technology is ready for industrial application.

  17. The role of zinc in liver cirrhosis.

    PubMed

    Grüngreiff, Kurt; Reinhold, Dirk; Wedemeyer, Heiner

    2016-01-01

    Zinc is an essential trace element playing fundamental roles in cellular metabolism. It acts mostly by binding a wide range of proteins, thus affecting a broad spectrum of biological processes, which include cell division, growth and differentiation. Zinc is critical to a large number of structural proteins, enzymatic processes, and transcription factors. Zinc deficiency can result in a spectrum of clinical manifestations, such as poor of appetite, loss of body hair, altered taste and smell, testicular atrophy, cerebral and immune dysfunction, and diminished drug elimination capacity. These are common symptoms in patients with chronic liver diseases, especially liver cirrhosis. The liver is the main organ responsible for the zinc metabolism which can be affected by liver diseases. On the other hand, zinc deficiency may alter hepatocyte functions and also immune responses in inflammatory liver diseases. Liver cirrhosis represents the most advanced stage of chronic liver diseases and is the common outcome of chronic liver injury. It is associated with energy malnutrition, with numerous metabolic disorders, such as hypoalbuminemia, with imbalance between branched-chain amino acids and aromatic amino acids, and with reduced zinc serum concentrations. All these processes can influence the clinical outcome of patients, such ascites, hepatic encephalopathy and hepatocellular carcinoma. In the present review, we summarize the emerging evidence on the pitoval role of zinc in the pathogenesis of liver cirrhosis.

  18. Zinc and vegetarian diets.

    PubMed

    Saunders, Angela V; Craig, Winston J; Baines, Surinder K

    2013-08-19

    Well planned vegetarian diets can provide adequate amounts of zinc from plant sources. Vegetarians appear to adapt to lower zinc intakes by increased absorption and retention of zinc. Good sources of zinc for vegetarians include whole grains, tofu, tempeh, legumes, nuts and seeds, fortified breakfast cereals and dairy products. The inhibitory effects of phytate on absorption of zinc can be minimised by modern food-processing methods such as soaking, heating, sprouting, fermenting and leavening. Absorption of zinc can be improved by using yeast-based breads and sourdough breads, sprouts, and presoaked legumes. Studies show vegetarians have similar serum zinc concentrations to, and no greater risk of zinc deficiency than, non-vegetarians (despite differences in zinc intake).

  19. Evaluating additives and impurities in zinc electrowinning

    NASA Astrophysics Data System (ADS)

    Gonzalez-Dominguez, J. A.; Lew, R. W.

    1995-01-01

    The zinc electrowinning (EW) process is very sensitive to the presence of impurities. There is only one EW plant in the world that we know of that operates at moderate current efficiency and deposition times without using any additives. All the others must use them continuously. Additives allow zinc EW to occur at high current efficiencies while suppressing excessive acid mist formation. The study of the electrochemical effects of additives in zinc EW is not straightforward. This article presents a review of the experimental techniques currently used at Cominco Research: Cyclic voltammetry, Hull cells, laboratory and mini-cell electrowinning techniques are all described and their relationship to the industrial operation is discussed.

  20. Zinc: the neglected nutrient.

    PubMed

    Shambaugh, G E

    1989-03-01

    Zinc was first recognized as essential for animals at the University of Illinois School of Agriculture in 1916, when it was found that zinc-deficient baby pigs were runty, developed dermatitis on their legs, and were sterile. Zinc deficiency was first recognized in man by Dr. Ananda Prasad of Detroit 26 years ago when he measured serum and hair zinc levels in young male Egyptian dwarfs who had failed to mature and were small in stature. By simply adding zinc to their regular diet, they grew in height and became sexually mature. It is now recognized that dwarfism in males is frequent around the Mediterranean, where wheat is the staple of life and has been grown for 4,000 years on the same soil, thereby resulting in the depletion of zinc. Professor Robert Henkin first suggested that zinc deficiency might cause hearing-nerve impairment. Assay of the soft tissues of the cochlea and vestibule revealed a zinc level higher than that of any other part of the body. Previously, the eye was considered to have the highest level of zinc of any organ. To diagnose zinc deficiency clinically, we use serum zinc assays made at the Mayo Clinic Trace Element Laboratory. With zinc supplementation in patients who are marginally zinc deficient, there has been improvement in tinnitus and sensorineural hearing loss in about one-third of elderly adults. We believe zinc deficiency is one causation of presbycusis; by recognizing and correcting it, a progressive hearing loss can be arrested.

  1. Zinc: the neglected nutrient.

    PubMed

    Shambaugh, G E

    1989-03-01

    Zinc was first recognized as essential for animals at the University of Illinois School of Agriculture in 1916, when it was found that zinc-deficient baby pigs were runty, developed dermatitis on their legs, and were sterile. Zinc deficiency was first recognized in man by Dr. Ananda Prasad of Detroit 26 years ago when he measured serum and hair zinc levels in young male Egyptian dwarfs who had failed to mature and were small in stature. By simply adding zinc to their regular diet, they grew in height and became sexually mature. It is now recognized that dwarfism in males is frequent around the Mediterranean, where wheat is the staple of life and has been grown for 4,000 years on the same soil, thereby resulting in the depletion of zinc. Professor Robert Henkin first suggested that zinc deficiency might cause hearing-nerve impairment. Assay of the soft tissues of the cochlea and vestibule revealed a zinc level higher than that of any other part of the body. Previously, the eye was considered to have the highest level of zinc of any organ. To diagnose zinc deficiency clinically, we use serum zinc assays made at the Mayo Clinic Trace Element Laboratory. With zinc supplementation in patients who are marginally zinc deficient, there has been improvement in tinnitus and sensorineural hearing loss in about one-third of elderly adults. We believe zinc deficiency is one causation of presbycusis; by recognizing and correcting it, a progressive hearing loss can be arrested. PMID:2786676

  2. Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

    NASA Astrophysics Data System (ADS)

    Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

    2016-10-01

    With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

  3. Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

    NASA Astrophysics Data System (ADS)

    Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

    2016-08-01

    With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

  4. Measurements of plasma zinc

    PubMed Central

    Davies, I. J. T.; Musa, M.; Dormandy, T. L.

    1968-01-01

    Zinc is an essential trace element. Previous methods of measuring zinc in clinical material have been difficult and reported findings must be treated with caution. Using atomic absorption spectroscopy it has been established that plasma zinc is one of the most uniform biochemical characteristics of normal adult blood. Sex and age differences in adult life are insignificant. Increased metabolic activity, on the other hand, induces a marked, immediate fall in plasma zinc level. The possible implications of this are discussed. Zinc levels in patients with diabetes mellitus, cardiovascular disease, and anaemia due to acute blood loss have been within normal limits. Plasma zinc is low in certain types of liver disease. PMID:5303355

  5. Is zinc a neuromodulator?

    PubMed

    Kay, Alan R; Tóth, Katalin

    2008-01-01

    The vesicles of certain glutamatergic terminals in the mammalian forebrain are replete with ionic zinc. It is believed that during synaptic transmission zinc is released, binds to receptors on the pre- or postsynaptic membranes, and hence acts as a neuromodulator. Although exogenous zinc modulates a wide variety of channels, whether synaptic zinc transits across the synaptic cleft and alters the response of channels has been difficult to establish. We will review the evidence for zinc as a neuromodulator and propose diagnostic criteria for establishing whether it is indeed one. Moreover, we will delineate alternative ways in which zinc might act at synapses.

  6. Preparation of ionic membranes for zinc/bromine storage batteries

    NASA Astrophysics Data System (ADS)

    Assink, R. A.; Arnold, C., Jr.

    Zinc/bromine flow batteries are being developed for vehicular and utility load leveling applications. During charge, an aqueous zinc bromide salt is electrolyzed to zinc metal and molecular bromine. During discharge, the zinc and bromine react to again form the zinc bromide salt. One serious disadvantage of the microporous separators presently used in the zinc/bromine battery is that modest amounts of bromine and negatively charged bromine moieties permeate through these materials and react with the zinc anode. This results in partial self-discharge of the battery and low coulombic efficiencies. Our approach to this problem is to impregnate the microporous separators with a soluble cationic polyelectrolyte. In laboratory screening tests a sulfonated polysulfone resin and fully fluorinated sulfonic acid polymer substantially reduced bromine permeation with only modest increases in the area resistance.

  7. Dietary conditions influencing relative zinc availability from foods to the rat and correlations with in vitro measurements.

    PubMed

    Hunt, J R; Johnson, P E; Swan, P B

    1987-11-01

    Zinc availability from a series of foods was determined using 65Zn-labeled test meals fed to rats. Zinc availability relative to zinc chloride depended on the amount of the zinc source in the test meal. Zinc availability from several foods was similar to that from zinc chloride when tested in smaller amounts, but enhanced when fed in larger amounts. The range of zinc availability was similar for foods of plant and animal origin. Rats retained significantly more zinc from pork, chicken, peanut butter, egg or milk than from rice, beef, soybean flour or navy beans. Foods with intermediate zinc availability were sweet corn, whole wheat bread, cheese and oysters. Several food characteristics were examined for possible relationships with zinc availability, including the solubility or molecular size of zinc compounds after an in vitro enzymatic digestion and the contents of phytic acid, minerals, amino acids, carbohydrate and fatty acids relative to the zinc content of the food. Protein and several amino acids predicted about half of the variance in zinc availability. Following in vitro enzymatic digestion, neither zinc solubility nor the partitioning of zinc between low and high molecular weight substances was a strong predictor of zinc availability.

  8. Zinc oxide overdose

    MedlinePlus

    Zinc oxide is an ingredient in many products. Some of these are certain creams and ointments used ... prevent or treat minor skin burns and irritation. Zinc oxide overdose occurs when someone eats one of ...

  9. Bacitracin zinc overdose

    MedlinePlus

    ... Small amounts of bacitracin zinc are dissolved in petroleum jelly to create antibiotic ointments. Bacitracin zinc overdose ... is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation ...

  10. Zinc and gastrointestinal disease

    PubMed Central

    Skrovanek, Sonja; DiGuilio, Katherine; Bailey, Robert; Huntington, William; Urbas, Ryan; Mayilvaganan, Barani; Mercogliano, Giancarlo; Mullin, James M

    2014-01-01

    This review is a current summary of the role that both zinc deficiency and zinc supplementation can play in the etiology and therapy of a wide range of gastrointestinal diseases. The recent literature describing zinc action on gastrointestinal epithelial tight junctions and epithelial barrier function is described. Zinc enhancement of gastrointestinal epithelial barrier function may figure prominently in its potential therapeutic action in several gastrointestinal diseases. PMID:25400994

  11. Zinc as Allosteric Ion Channel Modulator: Ionotropic Receptors as Metalloproteins

    PubMed Central

    Peralta, Francisco Andrés; Huidobro-Toro, Juan Pablo

    2016-01-01

    Zinc is an essential metal to life. This transition metal is a structural component of many proteins and is actively involved in the catalytic activity of cell enzymes. In either case, these zinc-containing proteins are metalloproteins. However, the amino acid residues that serve as ligands for metal coordination are not necessarily the same in structural proteins compared to enzymes. While crystals of structural proteins that bind zinc reveal a higher preference for cysteine sulfhydryls rather than histidine imidazole rings, catalytic enzymes reveal the opposite, i.e., a greater preference for the histidines over cysteines for catalysis, plus the influence of carboxylic acids. Based on this paradigm, we reviewed the putative ligands of zinc in ionotropic receptors, where zinc has been described as an allosteric modulator of channel receptors. Although these receptors do not strictly qualify as metalloproteins since they do not normally bind zinc in structural domains, they do transitorily bind zinc at allosteric sites, modifying transiently the receptor channel’s ion permeability. The present contribution summarizes current information showing that zinc allosteric modulation of receptor channels occurs by the preferential metal coordination to imidazole rings as well as to the sulfhydryl groups of cysteine in addition to the carboxyl group of acid residues, as with enzymes and catalysis. It is remarkable that most channels, either voltage-sensitive or transmitter-gated receptor channels, are susceptible to zinc modulation either as positive or negative regulators. PMID:27384555

  12. Zinc as Allosteric Ion Channel Modulator: Ionotropic Receptors as Metalloproteins.

    PubMed

    Peralta, Francisco Andrés; Huidobro-Toro, Juan Pablo

    2016-01-01

    Zinc is an essential metal to life. This transition metal is a structural component of many proteins and is actively involved in the catalytic activity of cell enzymes. In either case, these zinc-containing proteins are metalloproteins. However, the amino acid residues that serve as ligands for metal coordination are not necessarily the same in structural proteins compared to enzymes. While crystals of structural proteins that bind zinc reveal a higher preference for cysteine sulfhydryls rather than histidine imidazole rings, catalytic enzymes reveal the opposite, i.e., a greater preference for the histidines over cysteines for catalysis, plus the influence of carboxylic acids. Based on this paradigm, we reviewed the putative ligands of zinc in ionotropic receptors, where zinc has been described as an allosteric modulator of channel receptors. Although these receptors do not strictly qualify as metalloproteins since they do not normally bind zinc in structural domains, they do transitorily bind zinc at allosteric sites, modifying transiently the receptor channel's ion permeability. The present contribution summarizes current information showing that zinc allosteric modulation of receptor channels occurs by the preferential metal coordination to imidazole rings as well as to the sulfhydryl groups of cysteine in addition to the carboxyl group of acid residues, as with enzymes and catalysis. It is remarkable that most channels, either voltage-sensitive or transmitter-gated receptor channels, are susceptible to zinc modulation either as positive or negative regulators. PMID:27384555

  13. Zinc oxyfluoride transparent conductor

    SciTech Connect

    Gordon, R.G.

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400 C to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings. 8 figures.

  14. Zinc oxyfluoride transparent conductor

    DOEpatents

    Gordon, Roy G.

    1991-02-05

    Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

  15. Cysteine-rich intestinal protein binds zinc during transmucosal zinc transport.

    PubMed Central

    Hempe, J M; Cousins, R J

    1991-01-01

    The mechanism of zinc absorption has not been delineated, but kinetic studies show that both passive and carrier-mediated processes are involved. We have identified a low molecular mass zinc-binding protein in the soluble fraction of rat intestinal mucosa that could function as an intracellular zinc carrier. The protein was not detected in liver or pancreas, suggesting a role specific to the intestine. The protein binds zinc during transmucosal zinc transport and shows signs of saturation at higher luminal zinc concentrations, characteristics consistent with a role in carrier-mediated zinc absorption. Microsequence analysis of the protein purified by gel-filtration HPLC and SDS/PAGE showed complete identity within the first 41 N-terminal amino acids with the deduced protein sequence of cysteine-rich intestinal protein [Birkenmeier, E. H. & Gordon, J. I. (1986) Proc. Natl. Acad. Sci. USA 83, 2516-2520]. These investigators showed that the gene for this protein is developmentally regulated in neonates during the suckling period, conserved in many vertebrate species, and predominantly expressed in the small intestine. Cysteine-rich intestinal protein contains a recently identified conserved sequence of histidine and cysteine residues, the LIM motif, which our results suggest confers metal-binding properties that are important for zinc transport and/or functions of this micronutrient. Images PMID:1946385

  16. Bioavailability of zinc in fiber-enriched bread fortified with zinc sulphate.

    PubMed

    Khalil, Mona M

    2002-12-01

    The present study aimed to reduce the caloric value of bread by substituting a part of wheat flour with artichoke bracts at levels of 5%, 10% and 15% without sacrificing taste, texture or acceptability. Moreover, considerable trials had been made to reduce zinc deficiency in wheat bread and fiber-enriched bread and also to study the effect of fiber on zinc bioavailability. Therefore, zinc sulphate was added to bread at levels of 40, 60, 80, 100 and 120 mg/100 g edible portion. The results from this study show that: (i) The addition of artichoke bracts to wheat flour increased the water absorption, arrival time, development time, and weakening of the dough as the level of artichoke bracts increased, while dough stability decreased. (ii) Mixing wheat flour with increasing amount of artichoke bracts increased the content of protein, fiber and total essential amino acids, also all essential amino acids increased in wheat bread and fiber-enriched bread after fortification with zinc sulphate at a level of 100 mg/100 g edible portion except methionine, threonine and tyrosine. (iii) The best level of zinc sulphate to give the best bioavailability for zinc is 100 mg/100 g edible portion. (iv) Evaluation of fortified wheat bread and fiber-enriched bread with zinc sulphate showed no significant difference by test panel.

  17. [Zinc and gastrointestinal disorders].

    PubMed

    Higashimura, Yasuki; Takagi, Tomohisa; Naito, Yuji

    2016-07-01

    Zinc, an essential trace element, affects immune responses, skin metabolism, hormone composition, and some sensory function, so that the deficiency presents various symptoms such as immunodeficiency and taste obstacle. Further, the zinc deficiency also considers as a risk of various diseases. Recent reports demonstrated that -20% of the Japanese population was marginally zinc deficiency, and over 25% of the global population is at high risk of zinc deficiency. In gastrointestinal disorders, zinc plays an important role in the healing of mucosal and epithelial damage. In fact, polaprezinc, a chelate compound of zinc and L-carnosine, has been used for the treatment of gastric ulcer and gastritis. We describe here the therapeutic effect of zinc on gastrointestinal disorders. PMID:27455800

  18. Evaluation of the alkaline electrolysis of zinc

    SciTech Connect

    Meisenhelder, J.H.; Brown, A.P.; Loutfy, R.O.; Yao, N.P.

    1981-05-01

    The alkaline leach and electrolysis process for zinc production is compared to the conventional acid-sulfate process in terms of both energy saving and technical merit. In addition, the potential for industrial application of the alkaline process is discussed on the basis of present market conditions, possible future zinc market scenarios, and the probability of increased secondary zinc recovery. In primary zinc production, the energy-saving potential for the alkaline process was estimated to be greater than 10%, even when significantly larger electrolysis current densities than those required for the sulfate process are used. The principal technical advantages of the alkaline process are that it can handle low-grade, high-iron-content or oxidized ores (like most of those found in the US) in a more cost- and energy-efficient manner than can the sulfate process. Additionally, in the electrowinning operation, the alkaline process should be technically superior because a dendritic or sponge deposit is formed that is amenable to automated collection without interruption of the electrolysis. Also, use of the higher current densities would result in significant capital cost reductions. Alkaline-based electrolytic recovery processes were considered for the recycling of zinc from smelter baghouse dusts and from the potential source of nickel/zinc electric-vehicle batteries. In all comparisons, an alkaline process was shown to be technically superior and, particularly for the baghouse dusts, energetically and economically superior to alternatively proposed recovery methods based on sulfate electrolysis. It is concluded that the alkaline zinc method is an important alternative technology to the conventional acid zinc process. (WHK)

  19. Polyphenol-rich beverages enhance zinc uptake and metallothionein expression in Caco-2 cells.

    PubMed

    Sreenivasulu, Kilari; Raghu, Pullakhandam; Nair, K Madhavan

    2010-05-01

    The effect of red wine (RW), red grape juice (RGJ), green tea (GT), and representative polyphenols on Caco-2 cell (65)Zn uptake was explored. RW, RGJ, and GT enhanced the uptake of zinc from rice matrix. Fractionation of RW revealed that enhancing activity of zinc uptake was exclusively resided in the polyphenol fraction. Among the polyphenols tested, only tannic acid and quercitin stimulated the uptake of zinc while others did not influence the uptake. In tune with these results, only tannic acid and quercitin competed with zinquin (a zinc selective fluorophore) for zinc in vitro. Although all the polyphenols tested appear to enhance the expression of metallothionein (MT), the induction was higher with tannic acid, quercitin, and RW extract. Furthermore, phytic acid abrogated the tannic acid-induced MT expression. These results suggest that polyphenol-rich beverages, tannic acid, and quercitin bind and stimulate the zinc uptake and MT expression in Caco-2 cells.

  20. Hydrothermal syntheses, crystal structures and luminescence properties of zinc(II) and cadmium(II) coordination polymers based on bifunctional 3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid

    SciTech Connect

    Li, Na; Guo, Hui-Lin; Hu, Huai-Ming; Song, Juan; Xu, Bing; Yang, Meng-Lin; Dong, Fa-Xin; Xue, Gang-Lin

    2013-02-15

    Five new coordination polymers, [Zn{sub 2}(ctpy){sub 2}Cl{sub 2}]{sub n} (1), [Zn{sub 2}(ctpy){sub 2}(ox)(H{sub 2}O){sub 2}]{sub n} (2), [Zn{sub 2}(ctpy)(3-btc)(H{sub 2}O)]{sub n}{center_dot}0.5nH{sub 2}O (3), [Cd(ctpy){sub 2}(H{sub 2}O)]{sub n} (4), [Cd{sub 4}(ctpy){sub 2}(2-btc){sub 2}(H{sub 2}O){sub 2}]{sub n}{center_dot}2nH{sub 2}O (5), (Hctpy=3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid, H{sub 2}ox=oxalic acid, H{sub 3}(3-btc)=1,3,5-benzenetricarboxylic acid, H{sub 3}(2-btc)=1,2,4-benzenetricarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Compounds 1-2 are a one-dimensional chain with weak interactions to form 3D supramolecular structures. Compound 3 is a 4-nodal 3D topology framework comprised of binuclear zinc units and (ctpy){sup -} anions. Compound 4 shows two dimensional net. Compound 5 is a (4,5,6)-connected framework with {l_brace}4{sup 4}{center_dot}6{sup 2}{r_brace}{l_brace}4{sup 6}{center_dot}6{sup 4}{r_brace}{sub 2}{l_brace}4{sup 9}{center_dot}6{sup 6}{r_brace} topology. In addition, the thermal stabilities and photoluminescence properties of 1-5 were also studied in the solid state. - Graphical abstract: Five new Zn/Cd compounds with 3,2 Prime :6 Prime ,3 Prime Prime -terpyridine-4 Prime -carboxylic acid were prepared. The photoluminescence and thermal stabilities properties of 1-5 were investigated in the solid state. Highlights: Black-Right-Pointing-Pointer Five new zinc/cadmium metal-organic frameworks have been hydrothermal synthesized. Black-Right-Pointing-Pointer The structural variation is attributed to the diverse metal ions and auxiliary ligand. Black-Right-Pointing-Pointer Compounds 1-5 exhibit 1D ring chain, 2D layer and 3D open-framework, respectively. Black-Right-Pointing-Pointer These compounds exhibit strong solid state luminescence emission at room temperature.

  1. Crystal structure, DNA binding studies, nucleolytic property and topoisomerase I inhibition of zinc complex with 1,10-phenanthroline and 3-methyl-picolinic acid.

    PubMed

    Seng, Hoi-Ling; Von, Sze-Tin; Tan, Kong-Wai; Maah, Mohd Jamil; Ng, Seik-Weng; Rahman, Raja Noor Zaliha Raja Abd; Caracelli, Ignez; Ng, Chew-Hee

    2010-02-01

    Crystal structure analysis of the zinc complex establishes it as a distorted octahedral complex, bis(3-methylpicolinato-kappa(2) N,O)(2)(1,10-phenanthroline-kappa(2) N,N)-zinc(II) pentahydrate, [Zn(3-Me-pic)(2)(phen)]x5H(2)O. The trans-configuration of carbonyl oxygen atoms of the carboxylate moieties and orientation of the two planar picolinate ligands above and before the phen ligand plane seems to confer DNA sequence recognition to the complex. It cannot cleave DNA under hydrolytic condition but can slightly be activated by hydrogen peroxide or sodium ascorbate. Circular Dichroism and Fluorescence spectroscopic analysis of its interaction with various duplex polynucleotides reveals its binding mode as mainly intercalation. It shows distinct DNA sequence binding selectivity and the order of decreasing selectivity is ATAT > AATT > CGCG. Docking studies lead to the same conclusion on this sequence selectivity. It binds strongly with G-quadruplex with human tolemeric sequence 5'-AG(3)(T(2)AG(3))(3)-3', can inhibit topoisomerase I efficiently and is cytotoxic against MCF-7 cell line.

  2. Identification of zinc-binding sites of proteins: zinc binds to the amino-terminal region of tubulin

    SciTech Connect

    Serrano, L.; Dominguez, J.E.; Avila, J.

    1988-07-01

    The discovery that certain proteins may require zinc for their activity, and the fact that several of them cannot be purified in large amounts, has led us to develop a rapid, sensitive method to detect these proteins in samples. This method is based on the fractionation of the proteins by gel electrophoresis, blotting onto nitrocellulose paper, and overlaying with /sup 65/Zn. We have tested the procedure with well-characterized zinc-binding proteins. In the case of tubulin, we have used this method to localize its zinc-binding site. It was found that zinc binds to the first 150 amino acids of both alpha- and beta-tubulin subunits.

  3. Euglena gracilis DNA dependent RNA polymerase II: a zinc metalloenzyme.

    PubMed

    Falchuk, K H; Mazus, B; Ulpino, L; Vallee, B L

    1976-10-01

    Zinc is essential for cellular proliferation. Zinc deficiency of Euglena gracilis results in arrest of cell division and deranges nucleic acid and protein metabolism pointing to a decisive role of zinc in transcription and translation. We have, therefore, investigated the role of zinc in the function of the DNA-dependent RNA polymerases of this organism. Two RNA polymerases from zinc sufficient organisms were purified first by affinity chromatography on a DNA cellulose column and subsequently separated on diethylaminoethyl (DEAE)-Sephadex A-25. The two fractions were characterized as polymerase I and II by their elution pattern from DEAE-Sephadex and sensitivity to alpha-amanitin. RNA polymerase II has a provisional molecular weight of 700 000 and contains an average of 2.2 g=atoms of zinc per mol of enzyme, but not Mn, Cu, or Fe, as measured by microwave emission spectroscopy. Chelating agents, such as 1,10-phenanthroline, 8-hydroxyquinoline, 8-hydroxyquinoline-5-sulfonic acid, and lomofungin, inhibit activity. In contrast, the nonchelating analogues, 1,7-and 4,7-phenanthroline, do not affect activity. Inhibition by 1,10-phenanthroline is instantaneous and fully reversible by dilution. 1,10-Phenanthroline also inhibits RNA polymerase I, suggesting a role of zinc in its function. The demonstration that RNA polymerase II is a zinc enzyme indicates the involvement of zinc in eukaryotic RNA synthesis and serves as a further basis for the definition of the role of this element in eukaryotic cell growth, division, and differentiation.

  4. Improved zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, P.N. Jr.

    1988-06-21

    The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

  5. [Zinc and autophagy].

    PubMed

    Qiaoyun, Liu; Hanming, Shen; Dajing, Xia

    2016-05-25

    Autophagy refers to a catabolic process,in which the damaged organelles or biological macromolecules, such as protein aggregates, are degraded via lysosome. The completion of autophagy depends on a series of autophagy-related genes (Atgs) and many upstream regulatory molecules. Zinc is an essential trace element, and plays an important role in the process of autophagy as a component of enzymes and structural proteins like zinc transporters or zinc finger protein. The regulation of autophagy is closely associated with the zinc ion homeostasis. In addition, many studies suggest that the protective effects of zinc on cells are likely to be done by autophagy. This review aims to summarize the current research progress and discuss the reciprocal regulation mechanism between zinc and autophagy, which may provide insights into the intricate roles of autophagy in diseases and find novel strategies for treatment and prevention of human diseases. PMID:27651198

  6. Zinc recovery and waste sludge minimization from chromium passivation baths.

    PubMed

    Diban, Nazely; Mediavilla, Rosa; Urtiaga, Ane; Ortiz, Inmaculada

    2011-08-30

    This work reports the feasibility of applying emulsion pertraction technology (EPT) aiming at zinc recovery and waste minimization in the zinc electroplating processes that include Cr (III) passivation. The assessment consists of firstly the lifetime extension of the passivation baths by selective removal of the tramp ions zinc and iron, and secondly, the recovery of zinc for further reuse. Spent passivation baths from a local industry were tested, being the major metallic content: Cr(3+) 9000mg L(-1), Zn(2+) 12,000mg L(-1), Fe(3+) 100mg L(-1). Working in a Liqui-Cel hollow fiber membrane contactor and using the extractant bis(2,4,4-trimethylpentyl) phosphinic acid, reduction of zinc and iron concentrations below 60mg L(-1) and 2mg L(-1), respectively were obtained, while trivalent chromium, the active metal that generates the passivation layer, was retained in the baths. Zinc was selectively transferred to an acidic stripping phase that in the experimental time reached a concentration of 157,000mg L(-1). Zinc recovery by electrowinning from the acidic stripping phase without any pretreatment of the electrolyte solution provided a purity of 98.5%, matching the lower commercial zinc grade. As a result of the extension of the life time of the passivation bath, significant environmental advantages are derived such as minimization of the volume of hazardous wastes and savings in the consumption of raw materials. PMID:21704452

  7. Zinc electrode and rechargeable zinc-air battery

    SciTech Connect

    Ross, P.N. Jr.

    1989-06-27

    This patent describes an improved zinc electrode for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed.

  8. Zinc in Entamoeba invadens.

    NASA Technical Reports Server (NTRS)

    Morgan, R. S.; Sattilaro, R. F.

    1972-01-01

    Atomic absorption spectroscopy, electron microprobe analysis, and dithizone staining of trophozoites and cysts of Entamoeba invadens demonstrate that these cells have a high concentration of zinc (approximately one picogram per cell or 1% of their dry weight). In the cysts of this organism, the zinc is confined to the chromatoid bodies, which previous work has shown to contain crystals of ribosomes. The chemical state and function of this zinc are unknown.

  9. Zinc: An Essential Micronutrient

    PubMed Central

    SAPER, ROBERT B.; RASH, REBECCA

    2009-01-01

    Zinc is an essential micronutrient for human metabolism that catalyzes more than 100 enzymes, facilitates protein folding, and helps regulate gene expression. Patients with malnutrition, alcoholism, inflammatory bowel disease, and malabsorption syndromes are at an increased risk of zinc deficiency. Symptoms of zinc deficiency are nonspecific, including growth retardation, diarrhea, alopecia, glossitis, nail dystrophy, decreased immunity, and hypogonadism in males. In developing countries, zinc supplementation may be effective for the prevention of upper respiratory infection and diarrhea, and as an adjunct treatment for diarrhea in malnourished children. Zinc in combination with antioxidants may be modestly effective in slowing the progression of intermediate and advanced age-related macular degeneration. Zinc is an effective treatment for Wilson disease. Current data do not support zinc supplementation as effective for upper respiratory infection, wound healing, or human immunodeficiency virus. Zinc is well tolerated at recommended dosages. Adverse effects of long-term high-dose zinc use include suppressed immunity, decreased high-density lipoprotein cholesterol levels, anemia, copper deficiency, and possible genitourinary complications. PMID:20141096

  10. Zinc and Chlamydia trachomatis

    SciTech Connect

    Sugarman, B.; Epps, L.R.

    1985-07-01

    Zinc was noted to have significant effects upon the infection of McCoy cells by each of two strains of Chlamydia trachomatis. With a high or low Chlamydia inoculant, the number of infected cells increased up to 200% utilizing supplemental zinc (up to 1 x 10/sup -4/ M) in the inoculation media compared with standard Chlamydia cultivation media (8 x 10/sup -6/ M zinc). Ferric chloride and calcium chloride did not effect any such changes. Higher concentrations of zinc, after 2 hr of incubation with Chlamydia, significantly decreased the number of inclusions. This direct effect of zinc on the Chlamydia remained constant after further repassage of the Chlamydia without supplemental zinc, suggesting a lethal effect of the zinc. Supplemental zinc (up to 10/sup -4/ M) may prove to be a useful addition to inoculation media to increase the yield of culturing for Chlamydia trachomatis. Similarly, topical or oral zinc preparations used by people may alter their susceptibility to Chamydia trachomatis infections.

  11. Chelators for investigating zinc metalloneurochemistry.

    PubMed

    Radford, Robert J; Lippard, Stephen J

    2013-04-01

    The physiology and pathology of mobile zinc signaling has become an important topic in metalloneurochemistry. To study the action of mobile zinc effectively, specialized tools are required that probe the temporal and positional changes of zinc ions within live tissue and cells. In the present article we describe the design and implementation of selective zinc chelators as antagonists to interrogate the function of mobile zinc, with an emphasis on the pools of vesicular zinc in the terminals of hippocampal mossy fiber buttons.

  12. Vegetarian diets across the lifecycle: impact on zinc intake and status.

    PubMed

    Foster, Meika; Samman, Samir

    2015-01-01

    Optimal zinc status is an important consideration when evaluating the nutritional adequacy of vegetarian diets. In the absence of animal tissue sources of zinc and with increased intake of inhibitors of zinc absorption, phytic acid in particular, the bioavailability of zinc is thought to be lower from vegetarian as compared to omnivorous diets. The aim of this chapter is to review the research that examines the effects of vegetarian compared to omnivorous diets on zinc intake and zinc status in the elderly, adults, children, pregnancy, and lactation. A narrative review of the published literature was undertaken, focusing on observational studies in humans that reported zinc intake and biomarkers of zinc status at various stages of the life cycle. Compared to their respective nonvegetarian control groups, adult male and female vegetarians have lower dietary zinc intakes and serum zinc concentrations. However in the elderly, children, and in women during pregnancy and lactation, there is insufficient evidence to determine whether zinc intake and status are lower in vegetarians compared to omnivores. Inconsistencies in study findings reflect variations inherent in the definition of vegetarian diets, and in many instances compromised statistical power due to a small sample size. Improved methods for the assessment of zinc status are required to determine whether homeostatic responses are sufficient to maintain an adequate zinc status in vegetarians, particularly during times of increased requirement. Appropriate dietary advice to increase the zinc content and bioavailability of vegetarian diets throughout the life cycle is prudent. PMID:25624036

  13. Vegetarian diets across the lifecycle: impact on zinc intake and status.

    PubMed

    Foster, Meika; Samman, Samir

    2015-01-01

    Optimal zinc status is an important consideration when evaluating the nutritional adequacy of vegetarian diets. In the absence of animal tissue sources of zinc and with increased intake of inhibitors of zinc absorption, phytic acid in particular, the bioavailability of zinc is thought to be lower from vegetarian as compared to omnivorous diets. The aim of this chapter is to review the research that examines the effects of vegetarian compared to omnivorous diets on zinc intake and zinc status in the elderly, adults, children, pregnancy, and lactation. A narrative review of the published literature was undertaken, focusing on observational studies in humans that reported zinc intake and biomarkers of zinc status at various stages of the life cycle. Compared to their respective nonvegetarian control groups, adult male and female vegetarians have lower dietary zinc intakes and serum zinc concentrations. However in the elderly, children, and in women during pregnancy and lactation, there is insufficient evidence to determine whether zinc intake and status are lower in vegetarians compared to omnivores. Inconsistencies in study findings reflect variations inherent in the definition of vegetarian diets, and in many instances compromised statistical power due to a small sample size. Improved methods for the assessment of zinc status are required to determine whether homeostatic responses are sufficient to maintain an adequate zinc status in vegetarians, particularly during times of increased requirement. Appropriate dietary advice to increase the zinc content and bioavailability of vegetarian diets throughout the life cycle is prudent.

  14. Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

    NASA Astrophysics Data System (ADS)

    Acarali, Nil Baran; Bardakci, Melek; Tugrul, Nurcan; Derun, Emek Moroydor; Piskin, Sabriye

    2013-06-01

    The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate (reference ZB) as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time (1-5 h), reactant ratio (H3BO3/ZnO by mass: 2-5), seed ratio (seed crystal/(H3BO3+ZnO) by mass: 0-2wt%), reaction temperature (50-120°C), cooling temperature (10-80°C), and stirring rate (400-700 r/min); the modifying agents involve propylene glycol (PG, 0-6wt%), kerosene (1wt%-6wt%), and oleic acid (OA, 1wt%-6wt%) with solvents (isopropyl alcohol (IPA), ethanol, and methanol). The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.

  15. Characterization of the sporulation-related gamma-D-glutamyl-(L)meso-diaminopimelic-acid-hydrolysing peptidase I of Bacillus sphaericus NCTC 9602 as a member of the metallo(zinc) carboxypeptidase A family. Modular design of the protein.

    PubMed Central

    Hourdou, M L; Guinand, M; Vacheron, M J; Michel, G; Denoroy, L; Duez, C; Englebert, S; Joris, B; Weber, G; Ghuysen, J M

    1993-01-01

    The sporulation-related gamma-D-glutamyl-(L)meso-diaminopimelic-acid-hydrolysing peptidase I of Bacillus sphaericus NCTC 9602 has been analysed by proton-induced X-ray emission. It contains 1 equivalent Zn2+ per mol of protein. As derived from gene cloning and sequencing, the B. sphaericus Zn peptidase I is a two-module protein. A 100-amino-acid-residue N-terminal domain consisting of two tandem segments of similar sequences, is fused to a 296-amino-acid-residue C-terminal catalytic domain. The catalytic domain belongs to the Zn carboxypeptidase A family, the closest match being observed with the Streptomyces griseus carboxypeptidase [Narahashi (1990) J. Biochem. 107, 879-886] and with the family prototype, bovine carboxypeptidase A. The catalytic domain of the B. sphaericus peptidase I possesses, distributed along the amino-acid sequence, peptide segments, a triad His162-Glu165-His307 and a dyad Tyr347-Glu366 that are equivalent to secondary structures, the zinc-binding triad His69-Glu72-His196 and the catalytic dyad Tyr248-Glu270 of bovine carboxypeptidase A respectively. The N-terminal repeats of the B. sphaericus peptidase I have similarity with the C-terminal repeats of the Enterococcus hirae muramidase 2, the Streptococcus (now Enterococcus) faecalis autolysin and the Bacillus phi PZA and phi 29 lysozymes, to which a role in the recognition of a particular moiety of the bacterial cell envelope has been tentatively assigned. Detergents enhance considerably the specific activity of the B. sphaericus peptidase I. Images Figure 1 PMID:8503890

  16. Promyelocytic leukemia zinc finger-retinoic acid receptor α (PLZF-RARα), an oncogenic transcriptional repressor of cyclin-dependent kinase inhibitor 1A (p21WAF/CDKN1A) and tumor protein p53 (TP53) genes.

    PubMed

    Choi, Won-Il; Yoon, Jae-Hyeon; Kim, Min-Young; Koh, Dong-In; Licht, Jonathan D; Kim, Kunhong; Hur, Man-Wook

    2014-07-01

    Promyelocytic leukemia zinc finger-retinoic acid receptor α (PLZF-RARα) is an oncogene transcriptional repressor that is generated by a chromosomal translocation between the PLZF and RARα genes in acute promyelocytic leukemia (APL-type) patients. The molecular interaction between PLZF-RARα and the histone deacetylase corepressor was proposed to be important in leukemogenesis. We found that PLZF-RARα can repress transcription of the p21WAF/CDKN1A gene, which encodes the negative cell cycle regulator p21 by binding to its proximal promoter Sp1-binding GC-boxes 3, 4, 5/6, a retinoic acid response element (RARE), and distal p53-responsive elements (p53REs). PLZF-RARα also acts as a competitive transcriptional repressor of p53, RARα, and Sp1. PLZF-RARα interacts with co-repressors such as mSin3A, NCoR, and SMRT, thereby deacetylating histones Ac-H3 and Ac-H4 at the CDKN1A promoter. PLZF-RARα also interacts with the MBD3-NuRD complex, leading to epigenetic silencing of CDKN1A through DNA methylation. Furthermore, PLZF-RARα represses TP53 and increases p53 protein degradation by ubiquitination, further repressing p21 expression. Resultantly, PLZF-RARα promotes cell proliferation and significantly increases the number of cells in S-phase.

  17. Promyelocytic Leukemia Zinc Finger-Retinoic Acid Receptor α (PLZF-RARα), an Oncogenic Transcriptional Repressor of Cyclin-dependent Kinase Inhibitor 1A (p21WAF/CDKN1A) and Tumor Protein p53 (TP53) Genes*

    PubMed Central

    Choi, Won-Il; Yoon, Jae-Hyeon; Kim, Min-Young; Koh, Dong-In; Licht, Jonathan D.; Kim, Kunhong; Hur, Man-Wook

    2014-01-01

    Promyelocytic leukemia zinc finger-retinoic acid receptor α (PLZF-RARα) is an oncogene transcriptional repressor that is generated by a chromosomal translocation between the PLZF and RARα genes in acute promyelocytic leukemia (APL-type) patients. The molecular interaction between PLZF-RARα and the histone deacetylase corepressor was proposed to be important in leukemogenesis. We found that PLZF-RARα can repress transcription of the p21WAF/CDKN1A gene, which encodes the negative cell cycle regulator p21 by binding to its proximal promoter Sp1-binding GC-boxes 3, 4, 5/6, a retinoic acid response element (RARE), and distal p53-responsive elements (p53REs). PLZF-RARα also acts as a competitive transcriptional repressor of p53, RARα, and Sp1. PLZF-RARα interacts with co-repressors such as mSin3A, NCoR, and SMRT, thereby deacetylating histones Ac-H3 and Ac-H4 at the CDKN1A promoter. PLZF-RARα also interacts with the MBD3-NuRD complex, leading to epigenetic silencing of CDKN1A through DNA methylation. Furthermore, PLZF-RARα represses TP53 and increases p53 protein degradation by ubiquitination, further repressing p21 expression. Resultantly, PLZF-RARα promotes cell proliferation and significantly increases the number of cells in S-phase. PMID:24821728

  18. Zinc Inhibits Hedgehog Autoprocessing

    PubMed Central

    Xie, Jian; Owen, Timothy; Xia, Ke; Singh, Ajay Vikram; Tou, Emiley; Li, Lingyun; Arduini, Brigitte; Li, Hongmin; Wan, Leo Q.; Callahan, Brian; Wang, Chunyu

    2015-01-01

    Zinc is an essential trace element with wide-ranging biological functions, whereas the Hedgehog (Hh) signaling pathway plays crucial roles in both development and disease. Here we show that there is a mechanistic link between zinc and Hh signaling. The upstream activator of Hh signaling, the Hh ligand, originates from Hh autoprocessing, which converts the Hh precursor protein to the Hh ligand. In an in vitro Hh autoprocessing assay we show that zinc inhibits Hh autoprocessing with a Ki of 2 μm. We then demonstrate that zinc inhibits Hh autoprocessing in a cellular environment with experiments in primary rat astrocyte culture. Solution NMR reveals that zinc binds the active site residues of the Hh autoprocessing domain to inhibit autoprocessing, and isothermal titration calorimetry provided the thermodynamics of the binding. In normal physiology, zinc likely acts as a negative regulator of Hh autoprocessing and inhibits the generation of Hh ligand and Hh signaling. In many diseases, zinc deficiency and elevated level of Hh ligand co-exist, including prostate cancer, lung cancer, ovarian cancer, and autism. Our data suggest a causal relationship between zinc deficiency and the overproduction of Hh ligand. PMID:25787080

  19. Preparation of zinc orthotitanate

    NASA Technical Reports Server (NTRS)

    Gates, D. W.; Gilligan, J. E.; Harada, Y.; Logan, W. R.

    1977-01-01

    Use of decomposable precursors to enhance zinc oxide-titanium dioxide reaction and rapid fixing results in rapid preparation of zinc orthotitanate powder pigment. Preparation process allows production under less stringent conditions. Elimination of powder grinding results in purer that is less susceptible to color degradation.

  20. Acceptability of complementary foods and breads prepared from zinc-fortified cereal flours among young children and adults in Senegal.

    PubMed

    Aaron, G J; Lo, N Ba; Hess, S Y; Guiro, A T; Wade, S; Ndiaye, N F; Guinard, J-X; Brown, K H

    2011-01-01

    We completed a series of studies to assess the acceptability of zinc-fortified, cereal-based complementary foods and zinc-fortified wheat breads. Young children and their caregivers completed acceptability tests with complementary foods fortified with iron only (60 mg iron as ferrous fumarate per kilogram cereal flour), or the same level of iron and zinc (240 mg zinc as zinc oxide per kilogram cereal flour), and the caregivers completed triangle taste tests to compare the same products. A separate group of adult participants completed acceptability tests with wheat breads fortified with iron and folic acid (15 mg iron as ferrous fumarate per kilogram flour and 1.5 mg folic acid per kilogram flour) or the same levels of iron-folic acid and 2 levels of zinc (63 mg zinc or 126 mg zinc as zinc oxide per kilogram flour). Finally, a threshold test was administered to another group of adult participants to compare nonfortified wheat bread to breads fortified with zinc in 80 mg increments ranging from 80 to 400 mg zinc as zinc oxide per kilogram flour. All products were acceptable when compared to non-zinc-fortified equivalents, and were well liked by the respective participants. For the triangle tests, caregivers were not able to detect significant differences between products. For threshold tests, adult participants detected differences in breads prepared from fortified wheat flour at 80 mg, 160 mg, and 320 mg zinc per kilogram flour, but not at 240 mg and 400 mg zinc per kilogram flour, respectively, when compared to nonfortified bread equivalents. Zinc fortification of cereal flours in the ranges of fortification that were tested does not adversely affect the acceptability of complementary foods and breads prepared from these flours. Practical Application: Fortification of staple food products is a low-cost approach to deliver additional micronutrients (including zinc) to large segments of a population. Determining the acceptability of products fortified with zinc is

  1. A Lewis basicity scale in dichloromethane for amines and common nonprotogenic solvents using a zinc(II) Schiff-base complex as reference Lewis acid.

    PubMed

    Oliveri, Ivan Pietro; Maccarrone, Giuseppe; Di Bella, Santo

    2011-11-01

    A consistent, reliable scale of Lewis basicity in dichloromethane for 26 bases, involving amines and nonprotogenic solvents, is presented. A Lewis acidic Zn(II) Schiff-base complex, involving formation of stable 1:1 adducts is used as reference acid. Evaluation of binding constants is achieved from spectrophotometric titrations, by the least-squares nonlinear regression of multiwavelength spectrophotometric data. This Lewis basicity scale represents a unique set of data reflecting the actual Lewis basicity with respect this "real world" Lewis acidic species. The comparison of present Lewis basicity scale with data reported in the literature indicates that while for the involved solvents their relative basicity is scarcely affected by the reference Lewis acid, in contrast for sterically encumbered amines the Lewis basicity seems to be dependent from the reference species. Thus, Lewis basicity is governed by the steric hindrance at the donor atom and involves very different relative basicities than those predicted considering typical reference Lewis acids. This is expected to have a major involvement in the organic synthesis and catalysis, given the sterically encumbered nature of commonly involved Lewis acidic organometallic complexes.

  2. Zinc deficiency increases the osmotic fragility of rat erythrocytes.

    PubMed

    O'Dell, B L; Browning, J D; Reeves, P G

    1987-11-01

    Zinc deficiency in rats causes increased osmotic fragility of their erythrocytes. This study was designed to determine the relationship of food intake and dietary sulfur amino acid level to the effect of low zinc status on fragility. Immature rats were fed for a 3-wk period a low zinc diet (less than 1 mg/kg) based on isolated soybean protein or a similar control diet (100 mg Zn/kg diet) supplied either ad libitum or by pair feeding. Fragility was measured by the degree of hemolysis in hypotonic saline solutions. In the first experiment, zinc deficiency resulted in higher fragility than in ad libitum controls; pair-fed controls were intermediate and not different from either. Experiment 2 included two levels of methionine, 0.4 and 0.9%, and two of zinc, 0 and 100 mg Zn/kg diet. At the 0.4%, but not at the 0.9% methionine level, hemolysis of red blood cells from the zinc-deficient rats was significantly greater than those from either pair-fed or ad libitum controls. Repletion for 1 or 2 d completely alleviated the increased fragility, but in vitro addition of zinc had no effect. Restricted intake of the zinc-adequate diet reversed the fragility within 1 d as readily as did ad libitum intake. Thus, the osmotic fragility induced by zinc deficiency was prevented by high sulfur amino acid intake and was readily reversed by dietary zinc. It is postulated that extracellular or membrane-bound zinc protects a component of the membrane that is essential to its function, and that reversal of the defect requires an in vivo metabolic process.

  3. Production of zinc substituted hydroxyapatite using various precipitation routes.

    PubMed

    Shepherd, David; Best, Serena M

    2013-04-01

    Substituted hydroxyapatites have been investigated for use as bone grafts and have been investigated for many years. Zinc is of interest due to its potential to reduce bone resorption and antibacterial properties. However, it has proven problematic to substitute biologically significant levels of zinc into the crystal structure through wet chemical routes, whilst retaining the high temperature phase stability required for processing. The aim of this study is to investigate two different precipitation routes used to synthesize zinc substituted hydroxyapatite and to explore the effects of ammonia used in the reactions on the levels of zinc substituted into the crystal lattice. It was found that considerable amounts of ammonia are required to maintain a pH sufficiently high for the production of stoichiometric hydroxyapatite using a reaction between calcium nitrate, zinc nitrate and ammonium phosphate. X-ray fluorescence analysis showed that a significant proportion of the zinc added did not substitute into the hydroxyapatite lattice. Fourier transform infrared spectroscopy revealed the existence of a zinc-ammonia complex that, it is proposed, inhibits zinc substitution for calcium. It was found that by reacting orthophosphoric acid with calcium nitrate and zinc nitrate, the volume of ammonia required in the reaction was reduced and higher levels of zinc substitution were achieved, with up to 0.58 wt% incorporated into the hydroxyapatite lattice. The resulting products were found to be stoichiometric hydroxyapatite and did not appear to contain any extraneous calcium phosphate phases after heat treatment up to 1100 °C. X-ray diffraction and Rietveld analysis revealed that the effect of substituting zinc into the HA lattice was to decrease the a-lattice parameter whilst increasing the c-lattice. Transmission electron microscopy also showed that the incorporation of zinc reduced both the length and width of the precipitated crystals.

  4. Effects of Zinc Chelators on Aflatoxin Production in Aspergillus parasiticus

    PubMed Central

    Wee, Josephine; Day, Devin M.; Linz, John E.

    2016-01-01

    Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N′,N′-tetrakis (2-pyridylmethyl) ethane-1,2-diamine (TPEN) and 2,3-dimercapto-1-propanesulfonic acid (DMPS) to explore the effect of zinc limitation on aflatoxin synthesis in Aspergillus parasiticus. TPEN but not DMPS decreased aflatoxin biosynthesis up to six-fold depending on whether A. parasiticus was grown on rich or minimal medium. Although we observed significant inhibition of aflatoxin production by TPEN, no detectable changes were observed in expression levels of the aflatoxin pathway gene ver-1 and the zinc binuclear cluster transcription factor, AflR. Treatment of growing A. parasiticus solid culture with a fluorescent zinc probe demonstrated an increase in intracellular zinc levels assessed by increases in fluorescent intensity of cultures treated with TPEN compared to controls. These data suggest that TPEN binds to cytoplasmic zinc therefore limiting fungal access to zinc. To investigate the efficacy of TPEN on food and feed crops, we found that TPEN effectively decreases aflatoxin accumulation on peanut medium but not in a sunflower seeds-derived medium. From an application perspective, these data provide the basis for biological differences that exist in the efficacy of different zinc chelators in various food and feed crops frequently contaminated by aflatoxin. PMID:27271668

  5. Zinc in soybeans. Chemical nature and bioavilability

    SciTech Connect

    Khan, A.

    1987-01-01

    Soybeans were grown hydroponically and intrinsically labeled with /sup 65/Zn through root absorption, stem injection and foliar application. Stem injection resulted in the greatest accumulation of /sup 65/Zn. Regardless of the labeling technique, approximately 40-45% of the seed /sup 65/Zn was associated with the subcellular organelles. The pattern of /sup 65/Zn incorporation into soybeans did not change appreciably as a result of the labelling technique. The major portion of the soluble /sup 65/Zn was either free or associated with very low molecular weight proteins, peptides, or their complexes with phytic acid rather than the major proteins of soybeans. Zinc in soybeans is ionically bound to proteins, peptides and phytic acid. Autoclaving did not affect the chemical association of zinc with soy proteins. Solubility of protein, zinc and phytic acid was studied over the pH range of 3.5-12.0. Bioavailability of zinc to rats from soybeans was lower than from casein and rats adapted to a casein basal diet absorbed more /sup 65/Zn from both casein and soy than rats adapted to a soy basal diet.

  6. Exploring zinc coordination in novel zinc battery electrolytes.

    PubMed

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2014-06-14

    The coordination of zinc ions by tetraglyme has been investigated here to support the development of novel electrolytes for rechargeable zinc batteries. Zn(2+) reduction is electrochemically reversible from tetraglyme. The spectroscopic data, molar conductivity and thermal behavior as a function of zinc composition, between mole ratios [80 : 20] and [50 : 50] [tetraglyme : zinc chloride], all suggest that strong interactions take place between chloro-zinc complexes and tetraglyme. Varying the concentration of zinc chloride produces a range of zinc-chloro species (ZnClx)(2-x) in solution, which hinder full interaction between the zinc ion and tetraglyme. Both the [70 : 30] and [50 : 50] mixtures are promising electrolyte candidates for reversible zinc batteries, such as the zinc-air device.

  7. Exploring zinc coordination in novel zinc battery electrolytes.

    PubMed

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2014-06-14

    The coordination of zinc ions by tetraglyme has been investigated here to support the development of novel electrolytes for rechargeable zinc batteries. Zn(2+) reduction is electrochemically reversible from tetraglyme. The spectroscopic data, molar conductivity and thermal behavior as a function of zinc composition, between mole ratios [80 : 20] and [50 : 50] [tetraglyme : zinc chloride], all suggest that strong interactions take place between chloro-zinc complexes and tetraglyme. Varying the concentration of zinc chloride produces a range of zinc-chloro species (ZnClx)(2-x) in solution, which hinder full interaction between the zinc ion and tetraglyme. Both the [70 : 30] and [50 : 50] mixtures are promising electrolyte candidates for reversible zinc batteries, such as the zinc-air device. PMID:24760367

  8. Spectrophotometric determination of micro quantities of zinc in rocks

    USGS Publications Warehouse

    Huffman, C.; Lipp, H.H.; Rader, L.F.

    1963-01-01

    A chemical method is presented for the determination of microgram amounts of zinc in rocks. Zinc is absorbed on anion-exchange resin from 1.2 M hydrochloric acid and eluted with 0.01 M hydrochloric acid. A diethyldithiocarbamate separation removes traces of interfering elements from the eluate. The zinc-diethyldithiocarbamate complex is extracted into chloroform at pH 8.5 and reextracted from other elements in the chloroform solution with 0.16 M hydrochloric acid and finally determined spectrophotometrically as the zincon complex at 621 m??. The coefficient of variation of the method determined from replicate determinations of zinc on 75 selected samples of basalt, ranging in zinc content from 0.004 to 0.018 per cent, was found to be 6.3 per cent and essentially constant in the range of zinc content studied. This method of analysis has been used extensively for a study of zinc in basalts reported by Rader, Swadley, Huffman and Lipp (companion paper, 1963). ?? 1963.

  9. Zinc bioavailability in rats fed a plant-based diet: a study of fermentation and zinc supplementation

    PubMed Central

    Lazarte, Claudia E.; Vargas, Mirian; Granfeldt, Yvonne

    2015-01-01

    Background Zinc deficiency is a significant problem, in developing countries and in vegetarians, which can be caused by plant-based diets. Thus, dietary strategies, such as fermentation, to improve zinc bioavailability of diets should be investigated. Objective To improve zinc bioavailability in a plant-based diet by the inclusion of fermented food. Design Cassava tubers were fermented and made to replace the unfermented cassava in a basal plant-based diet, and compared with plant-based diets with and without zinc supplement. The zinc bioavailability of the diets was evaluated in Wistar rats that were fed these diets for 28 days. The evaluation was for zinc apparent absorption (ZnAA), serum zinc levels, and zinc deposits in liver and femur; in addition, the feed efficiency ratio (FER) of the diets and femur weight (FW) of the rats were evaluated. Results During the cassava fermentation, lactic acid increased and pH decreased (from 6.8 to 3.9), which is favorable for native phytase activity, resulting in a 90.2% reduction of phytate content in cassava. The diet containing fermented cassava showed significantly higher levels of ZnAA, FER, and FW (p<0.001). Moreover, the zinc levels in serum and femur were significantly higher (p<0.001) compared with the results of the diet with unfermented cassava. The results clearly show a higher zinc bioavailability in the diet containing fermented cassava and are comparable with the results obtained with the plant-based diet with zinc supplement. Conclusions In conclusion, the fermentation of cassava reduces the phytate content. The diet containing the fermented cassava represents a better nutritional alternative than the diet with unfermented cassava and is comparable with the zinc-supplemented diets. PMID:26626410

  10. A metallothionein containing a zinc finger within a four-metal cluster protects a bacterium from zinc toxicity

    PubMed Central

    Blindauer, Claudia A.; Harrison, Mark D.; Parkinson, John A.; Robinson, Andrea K.; Cavet, Jennifer S.; Robinson, Nigel J.; Sadler, Peter J.

    2001-01-01

    Zinc is essential for many cellular processes, including DNA synthesis, transcription, and translation, but excess can be toxic. A zinc-induced gene, smtA, is required for normal zinc-tolerance in the cyanobacterium Synechococcus PCC 7942. Here we report that the protein SmtA contains a cleft lined with Cys-sulfur and His-imidazole ligands that binds four zinc ions in a Zn4Cys9His2 cluster. The thiolate sulfurs of five Cys ligands provide bridges between the two ZnCys4 and two ZnCys3His sites, giving two fused six-membered rings with distorted boat conformations. The inorganic core strongly resembles the Zn4Cys11 cluster of mammalian metallothionein, despite different amino acid sequences, a different linear order of the ligands, and presence of histidine ligands. Also, SmtA contains elements of secondary structure not found in metallothioneins. One of the two Cys4-coordinated zinc ions in SmtA readily exchanges with exogenous metal (111Cd), whereas the other is inert. The thiolate sulfur ligands bound to zinc in this site are buried within the protein. Regions of β-strand and α-helix surround the inert site to form a zinc finger resembling the zinc fingers in GATA and LIM-domain proteins. Eukaryotic zinc fingers interact specifically with other proteins or DNA and an analogous interaction can therefore be anticipated for prokaryotic zinc fingers. SmtA now provides structural proof for the existence of zinc fingers in prokaryotes, and sequences related to the zinc finger motif can be identified in several bacterial genomes. PMID:11493688

  11. Reducing power consumption in zinc electrowinning

    NASA Astrophysics Data System (ADS)

    Parada T, F.; Asselin, E.

    2009-10-01

    Approximately 7 million tons per annum of zinc are produced globally by traditional electrowinning which is a power intensive process. Power consumption is directly proportional to cell voltage which is thermodynamically limited to the potential difference between the oxygen evolution and zinc reduction reactions. This article summarizes several novel approaches which are currently under investigation/or the reduction of power consumption in zinc electrowinning and which focus on alternative anode reactions. In particular, methanol, formic acid, ferrous to ferric and hydrogen oxidation as anodic reactions are examined. There remain several important materials, engineering, and process challenges associated with the new approaches which are reviewed in this article. However, given the current and anticipated future cost of energy, further research is warranted.

  12. Copper and zinc adsorption by softwood and hardwood biochars under elevated sulphate-induced salinity and acidic pH conditions.

    PubMed

    Jiang, Shasha; Huang, Longbin; Nguyen, Tuan A H; Ok, Yong Sik; Rudolph, Victor; Yang, Hong; Zhang, Dongke

    2016-01-01

    Biochar adsorption may lower concentrations of soluble metals in pore water of sulphidic Cu/Pb-Zn mine tailings. Unlike soil, high levels of salinity and soluble cations are present in tailing pore water, which may affect biochar adsorption of metals from solution. In the present study, removal of soluble copper (Cu) and zinc (Zn) ions by soft- (pine) and hard-wood (jarrah) biochars pyrolysed at high temperature (about 700 °C) was evaluated under typical ranges of pH and salinity conditions resembling those in pore water of sulphidic tailings, prior to their direct application into the tailings. Surface alkalinity, cation exchange capacity, and negative surface charge of biochars affected Cu and Zn adsorption capacities. Quantitative comparisons were provided by fitting the adsorption equilibrium data with either the homogeneous or heterogeneous surface adsorption models (i.e. Langmuir and Freundlich, respectively). Accordingly, the jarrah biochar showed higher Cu and Zn adsorption capacity (Qmax=4.39 and 2.31 mg/g, respectively) than the softwood pine biochar (Qmax=1.47 and 1.00 mg/g). Copper and Zn adsorption by the biochars was favoured by high pH conditions under which they carried more negative charges and Cu and Zn ions were predicted undergoing hydrolysis and polymerization. Within the tested range, salinity had relatively weak effects on the adsorption, which perhaps influenced the surface charge and induced competition for negative charged sites between Na(+) and exchangeable Ca(2+) and/or heavy metal ions. Large amounts of waste wood/timber at many mine sites present a cost-effective opportunity to produce biochars for remediation of sulphidic tailings and seepage water. PMID:26206747

  13. Copper and zinc adsorption by softwood and hardwood biochars under elevated sulphate-induced salinity and acidic pH conditions.

    PubMed

    Jiang, Shasha; Huang, Longbin; Nguyen, Tuan A H; Ok, Yong Sik; Rudolph, Victor; Yang, Hong; Zhang, Dongke

    2016-01-01

    Biochar adsorption may lower concentrations of soluble metals in pore water of sulphidic Cu/Pb-Zn mine tailings. Unlike soil, high levels of salinity and soluble cations are present in tailing pore water, which may affect biochar adsorption of metals from solution. In the present study, removal of soluble copper (Cu) and zinc (Zn) ions by soft- (pine) and hard-wood (jarrah) biochars pyrolysed at high temperature (about 700 °C) was evaluated under typical ranges of pH and salinity conditions resembling those in pore water of sulphidic tailings, prior to their direct application into the tailings. Surface alkalinity, cation exchange capacity, and negative surface charge of biochars affected Cu and Zn adsorption capacities. Quantitative comparisons were provided by fitting the adsorption equilibrium data with either the homogeneous or heterogeneous surface adsorption models (i.e. Langmuir and Freundlich, respectively). Accordingly, the jarrah biochar showed higher Cu and Zn adsorption capacity (Qmax=4.39 and 2.31 mg/g, respectively) than the softwood pine biochar (Qmax=1.47 and 1.00 mg/g). Copper and Zn adsorption by the biochars was favoured by high pH conditions under which they carried more negative charges and Cu and Zn ions were predicted undergoing hydrolysis and polymerization. Within the tested range, salinity had relatively weak effects on the adsorption, which perhaps influenced the surface charge and induced competition for negative charged sites between Na(+) and exchangeable Ca(2+) and/or heavy metal ions. Large amounts of waste wood/timber at many mine sites present a cost-effective opportunity to produce biochars for remediation of sulphidic tailings and seepage water.

  14. Interstitial zinc clusters in zinc oxide

    NASA Astrophysics Data System (ADS)

    Gluba, M. A.; Nickel, N. H.; Karpensky, N.

    2013-12-01

    Doped zinc oxide (ZnO) exhibits anomalous Raman modes in the range of 270 to 870 cm-1. Commonly, the resonance at 275 cm-1 is attributed to the local vibration of Zn atoms in the vicinity of extrinsic dopants. We revisit this assignment by investigating the influence of isotopically purified zinc oxide thin films on the frequency of the vibrational mode around 275 cm-1. For this purpose, undoped and nitrogen-doped ZnO thin-films with Zn isotope compositions of natural Zn, 64Zn, 68Zn, and a 1:1 mixture of 64Zn and 68Zn were grown by pulsed laser deposition. The isotopic shift and the line shape of the Raman resonance around 275 cm-1 are analyzed in terms of three different microscopic models, which involve the vibration of (i) interstitial zinc atoms bound to extrinsic defects, (ii) interstitial diatomic Zn molecules, and (iii) interstitial zinc clusters. The energy diagram of interstitial Zn-Zn bonds in a ZnO matrix is derived from density functional theory calculations. The interstitial Zn-Zn bond is stabilized by transferring electrons from the antibonding orbital into the ZnO conduction band. This mechanism facilitates the formation of interstitial Zn clusters and fosters the common n-type doping asymmetry of ZnO.

  15. Designing hydrolytic zinc metalloenzymes.

    PubMed

    Zastrow, Melissa L; Pecoraro, Vincent L

    2014-02-18

    Zinc is an essential element required for the function of more than 300 enzymes spanning all classes. Despite years of dedicated study, questions regarding the connections between primary and secondary metal ligands and protein structure and function remain unanswered, despite numerous mechanistic, structural, biochemical, and synthetic model studies. Protein design is a powerful strategy for reproducing native metal sites that may be applied to answering some of these questions and subsequently generating novel zinc enzymes. From examination of the earliest design studies introducing simple Zn(II)-binding sites into de novo and natural protein scaffolds to current studies involving the preparation of efficient hydrolytic zinc sites, it is increasingly likely that protein design will achieve reaction rates previously thought possible only for native enzymes. This Current Topic will review the design and redesign of Zn(II)-binding sites in de novo-designed proteins and native protein scaffolds toward the preparation of catalytic hydrolytic sites. After discussing the preparation of Zn(II)-binding sites in various scaffolds, we will describe relevant examples for reengineering existing zinc sites to generate new or altered catalytic activities. Then, we will describe our work on the preparation of a de novo-designed hydrolytic zinc site in detail and present comparisons to related designed zinc sites. Collectively, these studies demonstrate the significant progress being made toward building zinc metalloenzymes from the bottom up. PMID:24506795

  16. Designing Hydrolytic Zinc Metalloenzymes

    PubMed Central

    2015-01-01

    Zinc is an essential element required for the function of more than 300 enzymes spanning all classes. Despite years of dedicated study, questions regarding the connections between primary and secondary metal ligands and protein structure and function remain unanswered, despite numerous mechanistic, structural, biochemical, and synthetic model studies. Protein design is a powerful strategy for reproducing native metal sites that may be applied to answering some of these questions and subsequently generating novel zinc enzymes. From examination of the earliest design studies introducing simple Zn(II)-binding sites into de novo and natural protein scaffolds to current studies involving the preparation of efficient hydrolytic zinc sites, it is increasingly likely that protein design will achieve reaction rates previously thought possible only for native enzymes. This Current Topic will review the design and redesign of Zn(II)-binding sites in de novo-designed proteins and native protein scaffolds toward the preparation of catalytic hydrolytic sites. After discussing the preparation of Zn(II)-binding sites in various scaffolds, we will describe relevant examples for reengineering existing zinc sites to generate new or altered catalytic activities. Then, we will describe our work on the preparation of a de novo-designed hydrolytic zinc site in detail and present comparisons to related designed zinc sites. Collectively, these studies demonstrate the significant progress being made toward building zinc metalloenzymes from the bottom up. PMID:24506795

  17. Finger millet (Eleucine coracana) flour as a vehicle for fortification with zinc.

    PubMed

    Tripathi, Bhumika; Platel, Kalpana

    2010-01-01

    Millets, being less expensive compared to cereals and the staple for the poorer sections of population, could be the choice for fortification with micronutrients such as zinc. In view of this, finger millet, widely grown and commonly consumed in southern India, was explored as a vehicle for fortification with zinc in this investigation. Finger millet flour fortified with either zinc oxide or zinc stearate so as to provide 50mg zinc per kg flour, was specifically examined for the bioaccessibility of the fortified mineral, as measured by in vitro simulated gastrointestinal digestion procedure and storage stability. Addition of the zinc salts increased the bioaccessible zinc content by 1.5-3 times that of the unfortified flour. Inclusion of EDTA along with the fortified salt significantly enhanced the bioaccessibility of zinc from the fortified flours, the increase being three-fold. Inclusion of citric acid along with the zinc salt and EDTA during fortification did not have any additional beneficial effect on zinc bioaccessiblity. Moisture and free fatty acid contents of the stored fortified flours indicated the keeping quality of the same, up to 60 days. Both zinc oxide and zinc stearate were equally effective as fortificants, when used in combination with EDTA as a co-fortificant. The preparation of either roti or dumpling from the fortified flours stored up to 60 days did not result in any significant compromise in the bioaccessible zinc content. Thus, the present study has revealed that finger millet flour can effectively be used as a vehicle for zinc fortification to derive additional amounts of bioaccessible zinc, with reasonably good storage stability, to combat zinc deficiency.

  18. Determination of hydroxide and carbonate contents of alkaline electrolytes containing zinc

    NASA Technical Reports Server (NTRS)

    Otterson, D. A.

    1975-01-01

    A method to prevent zinc interference with the titration of OH- and CO3-2 ions in alkaline electrolytes with standard acid is presented. The Ba-EDTA complex was tested and shown to prevent zinc interference with acid-base titrations without introducing other types of interference. Theoretical considerations indicate that this method can be used to prevent interference by other metals.

  19. Zinc fingers, zinc clusters, and zinc twists in DNA-binding protein domains.

    PubMed Central

    Vallee, B L; Coleman, J E; Auld, D S

    1991-01-01

    We now recognize three distinct motifs of DNA-binding zinc proteins: (i) zinc fingers, (ii) zinc clusters, and (iii) zinc twists. Until very recently, x-ray crystallographic or NMR three-dimensional structure analyses of DNA-binding zinc proteins have not been available to serve as standards of reference for the zinc binding sites of these families of proteins. Those of the DNA-binding domains of the fungal transcription factor GAL4 and the rat glucocorticoid receptor are the first to have been determined. Both proteins contain two zinc binding sites, and in both, cysteine residues are the sole zinc ligands. In GAL4, two zinc atoms are bound to six cysteine residues which form a "zinc cluster" akin to that of metallothionein; the distance between the two zinc atoms of GAL4 is approximately 3.5 A. In the glucocorticoid receptor, each zinc atom is bound to four cysteine residues; the interatomic zinc-zinc distance is approximately 13 A, and in this instance, a "zinc twist" is represented by a helical DNA recognition site located between the two zinc atoms. Zinc clusters and zinc twists are here recognized as two distinctive motifs in DNA-binding proteins containing multiple zinc atoms. For native "zinc fingers," structural data do not exist as yet; consequently, the interatomic distances between zinc atoms are not known. As further structural data become available, the structural and functional significance of these different motifs in their binding to DNA and other proteins participating in the transmission of the genetic message will become apparent. Images PMID:1846973

  20. Control of zinc transfer between thionein, metallothionein, and zinc proteins

    PubMed Central

    Jacob, Claus; Maret, Wolfgang; Vallee, Bert L.

    1998-01-01

    Metallothionein (MT), despite its high metal binding constant (KZn = 3.2 × 1013 M−1 at pH 7.4), can transfer zinc to the apoforms of zinc enzymes that have inherently lower stability constants. To gain insight into this paradox, we have studied zinc transfer between zinc enzymes and MT. Zinc can be transferred in both directions—i.e., from the enzymes to thionein (the apoform of MT) and from MT to the apoenzymes. Agents that mediate or enhance zinc transfer have been identified that provide kinetic pathways in either direction. MT does not transfer all of its seven zinc atoms to an apoenzyme, but apparently contains at least one that is more prone to transfer than the others. Modification of thiol ligands in MT zinc clusters increases the total number of zinc ions released and, hence, the extent of transfer. Aside from disulfide reagents, we show that selenium compounds are potential cellular enhancers of zinc transfer from MT to apoenzymes. Zinc transfer from zinc enzymes to thionein, on the other hand, is mediated by zinc-chelating agents such as Tris buffer, citrate, or glutathione. Redox agents are asymmetrically involved in both directions of zinc transfer. For example, reduced glutathione mediates zinc transfer from enzymes to thionein, whereas glutathione disulfide oxidizes MT with enhanced release of zinc and transfer of zinc to apoenzymes. Therefore, the cellular redox state as well as the concentration of other biological chelating agents might well determine the direction of zinc transfer and ultimately affect zinc distribution. PMID:9520393

  1. Folic acid and protein content in maternal diet and postnatal high-fat feeding affect the tissue levels of iron, zinc, and copper in the rat.

    PubMed

    Król, Ewelina; Krejpcio, Zbigniew; Chmurzynska, Agata

    2011-12-01

    Although maternal, fetal, and placental mechanisms compensate for disturbances in the fetal environment, any nutritional inadequacies present during pregnancy may affect fetal metabolism, and their consequences may appear in later life. The aim of the present study is to investigate the influence of maternal diet during gestation on Fe, Zn, and Cu levels in the livers and kidneys of adult rats. The study was carried out on the offspring (n = 48) of mothers fed either a protein-balanced or a protein-restricted diet (18% vs. 9% casein) during pregnancy, with or without folic acid supplementation (0.005- vs. 0.002-g folic acid/kg diet). At 10 weeks of age, the offspring of each maternal group were randomly assigned to groups fed either the AIN-93G diet or a high-fat diet for 6 weeks, until the end of the experiment. The levels of Fe, Zn, and Cu in the livers and kidneys were determined by the F-AAS method. It was found that postnatal exposure to the high-fat diet was associated with increased hepatic Fe levels (p < 0.001), and with decreased liver Zn and Cu contents (p < 0.01 and p < 0.05, respectively), as well as with decreased renal Cu contents (p < 0.001). Moreover, the offspring's tissue mineral levels were also affected by protein and folic acid content in the maternal diet. Both prenatal protein restriction and folic acid supplementation increased the liver Zn content (p < 0.05) and the kidney Zn content (p < 0.001; p < 0.05, respectively), while folic acid supplementation resulted in a reduction in renal Cu level (p < 0.05). Summarizing, the results of this study show that maternal dietary folic acid and protein intake during pregnancy, as well as the type of postweaning diet, affect Fe, Zn, and Cu levels in the offspring of the rat. However, the mechanisms responsible for this phenomenon are unclear, and warrant further investigation.

  2. Role of Cyt-C/caspases-9,3, Bax/Bcl-2 and the FAS death receptor pathway in apoptosis induced by zinc oxide nanoparticles in human aortic endothelial cells and the protective effect by alpha-lipoic acid.

    PubMed

    Liang, Shuhang; Sun, Kuo; Wang, Yue; Dong, Shuying; Wang, Cheng; Liu, LianXin; Wu, YongHui

    2016-10-25

    Zinc oxide nanoparticles (ZnO NPs) are widely used in a variety of products used in daily life. However, their impact on human health has not been completely elucidated. This study was designed to investigate the cytotoxicity associated with ZnO NPs, the role of dissolution in the toxicity of ZnO NPs, the molecular mechanisms and mode of cell death induced by ZnO NPs in human aortic endothelial cells (HAECs), and the protective effects of the antioxidant alpha-lipoic acid (LA). ZnO NPs significantly reduced cell viability in a dose- and time-dependent manner, resulted in intracellular oxidative stress and cell membrane leakage when treated with doses of 8-50 μg/mL for 12 and 24 h in HAECs. The toxicity was produced by undissolved ZnO NPs but not dissolved Zn(2+) and metal impurities. Exposure to ZnO NPs was found to induce apoptosis at 12 h and necrosis after 24 h. Apoptosis was confirmed using reactive oxygen species that triggered a decrease in mitochondria membrane potential, increase in Cyt-C release, activation of caspases 3 and caspases9 and increase in the ratio of Bax/Bcl-2. Futhermore, ZnO NPs could activate the Fas death receptor pathway. In addition, the antioxidant LA was able to protect HAECs from apoptosis induced by ZnO NPs. PMID:27544635

  3. Role of Cyt-C/caspases-9,3, Bax/Bcl-2 and the FAS death receptor pathway in apoptosis induced by zinc oxide nanoparticles in human aortic endothelial cells and the protective effect by alpha-lipoic acid.

    PubMed

    Liang, Shuhang; Sun, Kuo; Wang, Yue; Dong, Shuying; Wang, Cheng; Liu, LianXin; Wu, YongHui

    2016-10-25

    Zinc oxide nanoparticles (ZnO NPs) are widely used in a variety of products used in daily life. However, their impact on human health has not been completely elucidated. This study was designed to investigate the cytotoxicity associated with ZnO NPs, the role of dissolution in the toxicity of ZnO NPs, the molecular mechanisms and mode of cell death induced by ZnO NPs in human aortic endothelial cells (HAECs), and the protective effects of the antioxidant alpha-lipoic acid (LA). ZnO NPs significantly reduced cell viability in a dose- and time-dependent manner, resulted in intracellular oxidative stress and cell membrane leakage when treated with doses of 8-50 μg/mL for 12 and 24 h in HAECs. The toxicity was produced by undissolved ZnO NPs but not dissolved Zn(2+) and metal impurities. Exposure to ZnO NPs was found to induce apoptosis at 12 h and necrosis after 24 h. Apoptosis was confirmed using reactive oxygen species that triggered a decrease in mitochondria membrane potential, increase in Cyt-C release, activation of caspases 3 and caspases9 and increase in the ratio of Bax/Bcl-2. Futhermore, ZnO NPs could activate the Fas death receptor pathway. In addition, the antioxidant LA was able to protect HAECs from apoptosis induced by ZnO NPs.

  4. Inhibitory zinc sites in enzymes.

    PubMed

    Maret, Wolfgang

    2013-04-01

    Several pathways increase the concentrations of cellular free zinc(II) ions. Such fluctuations suggest that zinc(II) ions are signalling ions used for the regulation of proteins. One function is the inhibition of enzymes. It is quite common that enzymes bind zinc(II) ions with micro- or nanomolar affinities in their active sites that contain catalytic dyads or triads with a combination of glutamate (aspartate), histidine and cysteine residues, which are all typical zinc-binding ligands. However, for such binding to be physiologically significant, the binding constants must be compatible with the cellular availability of zinc(II) ions. The affinity of inhibitory zinc(II) ions for receptor protein tyrosine phosphatase β is particularly high (K i = 21 pM, pH 7.4), indicating that some enzymes bind zinc almost as strongly as zinc metalloenzymes. The competitive pattern of zinc inhibition for this phosphatase implicates its active site cysteine and nearby residues in the coordination of zinc. Quantitative biophysical data on both affinities of proteins for zinc and cellular zinc(II) ion concentrations provide the basis for examining the physiological significance of inhibitory zinc-binding sites in proteins and the role of zinc(II) ions in cellular signalling. Regulatory functions of zinc(II) ions add a significant level of complexity to biological control of metabolism and signal transduction and embody a new paradigm for the role of transition metal ions in cell biology.

  5. Zinc in diet

    MedlinePlus

    ... Zinc is also needed for the senses of smell and taste. During pregnancy, infancy, and childhood the ... sense of taste Problems with the sense of smell Skin sores Slow growth Trouble seeing in the ...

  6. Zinc electrode and rechargeable zinc-air battery

    DOEpatents

    Ross, Jr., Philip N.

    1989-01-01

    An improved zinc electrode is disclosed for a rechargeable zinc-air battery comprising an outer frame and a porous foam electrode support within the frame which is treated prior to the deposition of zinc thereon to inhibit the formation of zinc dendrites on the external surface thereof. The outer frame is provided with passageways for circulating an alkaline electrolyte through the treated zinc-coated porous foam. A novel rechargeable zinc-air battery system is also disclosed which utilizes the improved zinc electrode and further includes an alkaline electrolyte within said battery circulating through the passageways in the zinc electrode and an external electrolyte circulation means which has an electrolyte reservoir external to the battery case including filter means to filter solids out of the electrolyte as it circulates to the external reservoir and pump means for recirculating electrolyte from the external reservoir to the zinc electrode.

  7. Improved synthesis of fine zinc borate particles using seed crystals

    NASA Astrophysics Data System (ADS)

    Gürhan, Deniz; Çakal, Gaye Ö.; Eroğlu, İnci; Özkar, Saim

    2009-03-01

    Zinc borate is a flame retardant additive used in polymers, wood applications and textile products. There are different types of zinc borate having different chemical compositions and structures. In this study, the production of zinc borate having the molecular formula of 2ZnO·3B 2O 3·3.5H 2O was reexamined by studying the effects of reaction parameters on the properties of product as well as the reaction kinetics. Production of zinc borate from the reaction of boric acid and zinc oxide in the presence of seed crystals was performed in a continuously stirred, temperature-controlled batch reactor having a volume of 1.5 L. Samples taken in regular time intervals during the experiments were analyzed for the concentration of zinc oxide and boron oxide in the solid as well as for the conversion of zinc oxide to zinc borate versus time. The zinc borate production reaction was fit to the logistic model. The reaction rate, reaction completion time, composition and particle size distribution of zinc borate product were determined by varying the following parameters: the boric acid to zinc oxide ratio (H 3BO 3:ZnO=3:1, 3.5:1, 5:1 and 7:1), the particle size of zinc oxide (10 and 25 μm), stirring rate (275, 400, 800 and 1600 rpm), temperature (75, 85 and 95 °C) and the size of seed crystals (10 and 2 μm). The products were also analyzed for particle size distribution. The experimental results showed that the reaction rate increases with the increase in H 3BO 3:ZnO ratio, particle size of zinc oxide, stirring rate and temperature. Concomitantly, the reaction completion time is decreased by increasing the H 3BO 3:ZnO ratio, stirring rate and temperature. The average particle sizes of the zinc borate products are in the range 4.3-16.6 μm (wet dispersion analysis).

  8. Modulation of brain opioid receptors by zinc and histidine

    SciTech Connect

    Hanissian, S.H.

    1988-01-01

    The effect of zinc and several trace elements was studied on the binding of the opioid receptor antagonist ({sup 3}H)-naloxone and the agonists ({sup 3}H)-DAGO, ({sup 3}H)-DSTLE, and ({sup 3}H)-EKC, specific for the mu, delta and kappa receptors, respectively, in several areas of the rat brain. Physiological concentrations of zinc were inhibitory to the binding of naloxone, DAGO, and EKC, whereas delta receptors were insensitive to this inhibition. Copper, cadmium, and mercury also inhibited the binding of all the ligands studied to their receptors. Histidine was most effective in preventing the inhibitory effects of zinc and copper, whereas it was less effective on cadmium, and without any effect on the inhibit was less effective on cadmium, and without any effect on the inhibition caused by mercury. Its metabolites histamine and imidazoleacetic acid, and also citrate were ineffective. Magnesium and manganese were stimulatory to opioid receptor binding, whereas cobalt and nickel had dual effects. Concentrations of zinc less that its IC{sub 50} totally prevented the stimulatory effects of magnesium and manganese on the mu and delta receptors on which zinc alone had no effects. The reducing reagents dithiothreitol and B-mercaptoethanol partially protected against zinc inhibition, and the oxidizing reagent dithiobisnitrobenzoic acid even potentiated the inhibitory effects of zinc on DSTLE and DAGO binding, although to different extents.

  9. Zinc deficiency in elderly patients.

    PubMed

    Prasad, A S; Fitzgerald, J T; Hess, J W; Kaplan, J; Pelen, F; Dardenne, M

    1993-01-01

    Zinc is needed for growth and development, DNA synthesis, neurosensory functions, and cell-mediated immunity. Although zinc intake is reduced in elderly people, its deficiency and effects on cell-mediated immunity of the elderly have not been established. Subjects enrolled in "A Model Health Promotion and Intervention Program for Urban Middle Aged and Elderly Americans" were assessed for nutrition and zinc status. One hundred eighty healthy subjects were randomly selected for the study. Their mean dietary zinc intake was 9.06 mg/day, whereas the recommended dietary allowance is 15 mg/day. Plasma zinc was normal, but zinc in granulocytes and lymphocytes were decreased compared with younger control subjects. Of 118 elderly subjects in whom zinc levels in both granulocytes and lymphocytes were available, 36 had deficient levels. Plasma copper was increased, and interleukin 1 (IL-1) production was significantly decreased. Reduced response to the skin-test antigen panel and decreased taste acuity were observed. Thirteen elderly zinc-deficient subjects were supplemented with zinc, and various variables were assessed before and after zinc supplementation. Zinc supplementation corrected zinc deficiency and normalized plasma copper levels. Serum thymulin activity, IL-1 production, and lymphocyte ecto-5'-nucleotidase increased significantly after supplementation. Improvement in response to skin-test antigens and taste acuity was observed after zinc supplementation. A mild zinc deficiency appears to be a significant clinical problem in free-living elderly people. PMID:8353362

  10. Treatment of zinc deficiency without zinc fortification

    PubMed Central

    Oberleas, Donald; Harland, Barbara F.

    2008-01-01

    Zinc (Zn) deficiency in animals became of interest until the 1950s. In this paper, progresses in researches on physiology of Zn deficiency in animals, phytate effect on bioavailability of Zn, and role of phytase in healing Zn deficiency of animals were reviewed. Several studies demonstrated that Zn is recycled via the pancreas; the problem of Zn deficiency was controlled by Zn homeostasis. The endogenous secretion of Zn is considered as an important factor influencing Zn deficiency, and the critical molar ratio is 10. Phytate (inositol hexaphosphate) constituted up to 90% of the organically bound phosphorus in seeds. Great improvement has been made in recent years on isolating and measuring phytate, and its structure is clear. Phytate is considered to reduce Zn bioavailability in animal. Phytase is the enzyme that hydrolyzes phytate and is present in yeast, rye bran, wheat bran, barley, triticale, and many bacteria and fungi. Zinc nutrition and bioavailability can be enhanced by addition of phytase to animal feeds. Therefore, using phytase as supplements, the most prevalent Zn deficiency in animals may be effectively corrected without the mining and smelting of several tons of zinc daily needed to correct this deficiency by fortification worldwide. PMID:18357621

  11. Dietary taurine reduces zinc-induced toxicity in male Wistar rats.

    PubMed

    Yeh, Yen-Hung; Lee, Ya-Ting; Hsieh, You-Liang; Hwang, Deng-Fwu

    2011-05-01

    Taurine is an agent for treating the heavy metal intoxication and presence of metals such as zinc, copper, and iron may have a role in heavy metal toxicity, a study was undertaken to investigate the effect of taurine on the toxicity of zinc in male Wistar rats. The rats were divided into 8 groups and fed different diets with or without supplement of 5% taurine and 150 to 600 ppm zinc for 2 mo. It was found that the body weight of rats, the ratios of liver and kidney weight to body weight, and the level of glutathione in the liver were decreased with increasing the dose of zinc. The levels of zinc in the liver, kidney, and plasma, the levels of malondialdehyde in the plasma, the levels of thiobarbiture acid-reactive substances in the liver, the activities of aspartate transaminase, alanine transaminase in the plasma, the levels of blood urea nitrogen and creatinine in the plasma of rats were increased with the increasing dose of zinc. Hence, symptoms of zinc toxicity in rats included loss of body weight, hepatotoxicity, and nephrotoxicity. However, these toxic effects of zinc were significantly reduced when the rats fed diet with supplement of taurine. Furthermore, the level of zinc in the feces of rats treated with taurine and zinc was higher than that of rats treated with zinc alone. It indicated that taurine thereby leading to a decreased absorption of dietary zinc and promoted excretion. PMID:22417375

  12. Zinc Salts Inactivate Clinical Isolates of Herpes Simplex Virus In Vitro

    PubMed Central

    Arens, Max; Travis, Sharon

    2000-01-01

    Using a standard plaque assay and clinical isolates of herpes simplex virus (HSV), we have tested the ability of zinc salts to inactivate HSV. Virus was treated by incubation at 37°C with zinc salts in morpholinepropanesulfonic acid-buffered culture medium and was then diluted and plated onto CV-1 cells for detection and quantitation of remaining infectious virus. Of 10 randomly chosen clinical isolates (five HSV type 1 [HSV-1] isolates and five HSV-2 isolates), seven were inactivated >98% by treatment in vitro with 50 mM zinc gluconate for 2 h and nine were inactivated >97% by treatment with zinc lactate. The effect was concentration dependent. With an HSV-1 isolate, 50 mM zinc gluconate or zinc lactate caused 100% inactivation, 15 mM caused 98 to 99% inactivation, and 5 mM caused 63 to 86% inactivation. With an HSV-2 isolate, 50 and 15 mM zinc gluconate caused 30% inactivation and 5 and 1 mM caused less than 9% inactivation, whereas 50 and 15 mM zinc lactate caused greater than 92% inactivation and 5 and 1 mM caused 37 and 26% inactivation, respectively. The ability of the zinc salts to inactivate HSV was not related to pH in the pH range of 6.1 to 7.6 since inactivation by zinc gluconate or zinc lactate in that pH range was 99.7 to 100% with a 2-h treatment with 50 mM zinc salt. Short (5-min) treatments of selected isolates with zinc gluconate, zinc lactate, zinc acetate, or zinc sulfate yielded inactivation rates of 0 to 55%. PMID:10790094

  13. Endogenous zinc in neurological diseases.

    PubMed

    Koh, Jae-Yong

    2005-10-01

    The use of zinc in medicinal skin cream was mentioned in Egyptian papyri from 2000 BC (for example, the Smith Papyrus), and zinc has apparently been used fairly steadily throughout Roman and modern times (for example, as the American lotion named for its zinc ore, 'Calamine'). It is, therefore, somewhat ironic that zinc is a relatively late addition to the pantheon of signal ions in biology and medicine. However, the number of biological functions, health implications and pharmacological targets that are emerging for zinc indicate that it might turn out to be 'the calcium of the twenty-first century'. Here neurobiological roles of endogenous zinc is summarized.

  14. Endogenous Zinc in Neurological Diseases

    PubMed Central

    2005-01-01

    The use of zinc in medicinal skin cream was mentioned in Egyptian papyri from 2000 BC (for example, the Smith Papyrus), and zinc has apparently been used fairly steadily throughout Roman and modern times (for example, as the American lotion named for its zinc ore, 'Calamine'). It is, therefore, somewhat ironic that zinc is a relatively late addition to the pantheon of signal ions in biology and medicine. However, the number of biological functions, health implications and pharmacological targets that are emerging for zinc indicate that it might turn out to be 'the calcium of the twenty-first century'. Here neurobiological roles of endogenous zinc is summarized. PMID:20396459

  15. Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

    PubMed Central

    Messaoud, Mohamed Yacine Ameur; Hedidi, Madani; Derdour, Aïcha; Chevallier, Floris; Ivashkevich, Oleg A; Matulis, Vadim E; Roisnel, Thierry; Dorcet, Vincent

    2015-01-01

    Summary The synthesis of N-arylated pyrroles and indoles is documented, as well as their functionalization by deprotonative metallation using the base in situ prepared from LiTMP and ZnCl2·TMEDA (1/3 equiv). With N-phenylpyrrole and -indole, the reactions were carried out in hexane containing TMEDA which regioselectively afforded the 2-iodo derivatives after subsequent iodolysis. With pyrroles and indoles bearing N-substituents such as 2-thienyl, 3-pyridyl, 4-methoxyphenyl and 4-bromophenyl, the reactions all took place on the substituent, at the position either adjacent to the heteroatom (S, N) or ortho to the heteroatom-containing substituent (OMe, Br). The CH acidities of the substrates were determined in THF solution using the DFT B3LYP method in order to rationalize the experimental results. PMID:26425204

  16. Recovery of manganese and zinc from spent Zn-C cell powder: Experimental design of leaching by sulfuric acid solution containing glucose.

    PubMed

    Biswas, Ranjit K; Karmakar, Aneek K; Kumar, Sree L

    2016-05-01

    The spent Zn-C cell powder, containing ZnMn2O4, ZnO, MnO(OH) and possibly Mn2O3 and Mn3O4, can be leached by a sulfuric acid solution mixed with some glucose. The leaching is found to be dependent on solid to liquid (S/L) ratio, amount of glucose, concentration of sulfuric acid solution, time and pulp agitation speed. For 5g powder (S), 1h leaching time and 300rpm pulp agitation speed, two-level four-factor (2(4)) experimental designs have been carried out to derive models for extraction of both Mn(II) and Zn(II). Amount of glucose (G, g), concentration of H2SO4 solution (C, mol/L), volume of H2SO4 solution as leachant (L, mL) and leaching temperature (T, °C) are considered as factors (variables). The model in both cases consists of mean, factor effects and interaction effects. The four-factor interaction effect is observed in neither of the cases. Some two-factor and three-factor effects are found to have produced positive or negative contributions to dissolution percentage in both cases. The models are examined for comparison with experimental results with good fits and also used for optimization of factors. At optimized condition (G=0.50g, C=2mol/L, L=250mL and T=100°C), an aliquot of 5g powder in 1h and at 300rpm produces a solution containing (7.08±0.10)g/L Mn(II) and (2.20±0.06)g/L Zn(II) corresponding to almost 100% extraction of both metal ions. PMID:26564257

  17. ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, ...

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

    ZINC ROUGHER CELLS ON LEFT, ZINC CLEANER CELLS ON RIGHT, LOOKING NORTH. NOTE ONE STYLE OF DENVER AGITATOR IN LOWER RIGHT CELL. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  18. Suppression of zinc dendrites in zinc electrode power cells

    NASA Technical Reports Server (NTRS)

    Damjanovic, A.; Diggle, J. W.

    1970-01-01

    Addition of various tetraalkyl quarternary ammonium salts, to alkaline zincate electrolyte of cell, prevents formation of zinc dendrites during charging of zinc electrode. Electrode capacity is not impaired and elimination of dendrites prolongs cell life.

  19. Protective Coats For Zinc-Rich Primers

    NASA Technical Reports Server (NTRS)

    Macdowell, Louis G, III

    1993-01-01

    Report describes tests of topcoats for inorganic zinc-rich primers on carbon steel. Topcoats intended to provide additional protection against corrosion in acidic, salty seacoast-air/rocket-engine-exhaust environment of Space Shuttle launch site. Tests focused on polyurethane topcoats on epoxy tie coats on primers. Part of study involved comparison between "high-build" coating materials and thin-film coating materials.

  20. Vitellogenin and lipovitellin: zinc proteins of Xenopus laevis oocytes.

    PubMed

    Montorzi, M; Falchuk, K H; Vallee, B L

    1995-08-29

    Xenopus laevis vitellogenin is a plasma protein that contains a total of 5 mol of metal/440 kDa dimer, 2 mol of zinc, and 3 mol of calcium (Montorzi et al. (1994) Biochem. Biophys. Res. Commun. 200, 1407-1413]. There are no other group IIB or transition metals in the molecule. The zinc atoms are removed instantaneously by 1,10-phenanthroline (OP) (pK 4.8). Once internalized by receptor-mediated endocytosis, vitellogenin is cleaved into multiple polypeptides, i.e., the two lipovitellin subunits (1 and 2) plus phosvitin; these are then stored as microcrystals within yolk platelets. We here show by metal analysis of the individual proteins generated by vitellogenin processing that zinc and calcium occur in different domains of the vitellogenin polypeptide chain. All of the vitellogenin zinc is present in lipovitellin, in amounts equal to 1 mol of zinc/141 kDa. Calcium, in contrast, is detected exclusively in phosvitin which, in addition, contains 3 mol of magnesium/35 kDa, apparently acquired following vitellogenin entry into the oocyte. The zinc in lipovitellin is removed by OP in a concentration-dependent manner with a pK of 4.8, identical to that obtained for vitellogenin, and by exposure to acidic conditions (below pH 5). Following removal of zinc, the two lipovitellin subunits remain associated, suggesting that zinc is not involved in their interaction. On exposure to 1% SDS, lipovitellin does dissociate into 106 and 33 kDa subunits. The presence of stoichiometric quantities of zinc in both vitellogenin and lipovitellin calls for the study of the hitherto unrecognized biochemistry and functions of these proteins in zinc metabolism and development of the frog oocyte and embryo.

  1. Trace elements in human physiology and pathology: zinc and metallothioneins.

    PubMed

    Tapiero, Haim; Tew, Kenneth D

    2003-11-01

    Zinc is one of the most abundant nutritionally essential elements in the human body. It is found in all body tissues with 85% of the whole body zinc in muscle and bone, 11% in the skin and the liver and the remaining in all the other tissues. In multicellular organisms, virtually all zinc is intracellular, 30-40% is located in the nucleus, 50% in the cytoplasm, organelles and specialized vesicles (for digestive enzymes or hormone storage) and the remainder in the cell membrane. Zinc intake ranges from 107 to 231 micromol/d depending on the source, and human zinc requirement is estimated at 15 mg/d. Zinc has been shown to be essential to the structure and function of a large number of macromolecules and for over 300 enzymic reactions. It has both catalytic and structural roles in enzymes, while in zinc finger motifs, it provides a scaffold that organizes protein sub-domains for the interaction with either DNA or other proteins. It is critical for the function of a number of metalloproteins, inducing members of oxido-reductase, hydrolase ligase, lyase family and has co-activating functions with copper in superoxide dismutase or phospholipase C. The zinc ion (Zn(++)) does not participate in redox reactions, which makes it a stable ion in a biological medium whose potential is in constant flux. Zinc ions are hydrophilic and do not cross cell membranes by passive diffusion. In general, transport has been described as having both saturable and non-saturable components, depending on the Zn(II) concentrations involved. Zinc ions exist primarily in the form of complexes with proteins and nucleic acids and participate in all aspects of intermediary metabolism, transmission and regulation of the expression of genetic information, storage, synthesis and action of peptide hormones and structural maintenance of chromatin and biomembranes. PMID:14652165

  2. Effects of spatial and temporal variation of acid-volatile sulfide on the bioavailability of copper and zinc in freshwater sediments

    SciTech Connect

    Besser, J.M.; Ingersoll, C.G.; Giesy, J.P.

    1996-03-01

    Variation in concentrations of acid-volatile sulfide (AVS) in sediments from the upper Clark Fork River of Montana, USA, was associated with differences in bioaccumulation of Cu and Zn and growth of larvae of the midge, Chironomus tentans. Growth of midge larvae was significantly greater and bioaccumulation of Cu was significantly less in surface sections (0--3 cm depth) of sediment cores, which had greater concentrations of AVS and lesser ratios of simultaneously extracted metals to AVS (SEM:AVS ratios) than in subsurface sediments (6--9 cm). Concentrations of AVS were significantly less in sediments incubated with oxic overlying water for 9 weeks than in the same sediments incubated under anoxic conditions. Bioaccumulation of Cu differed significantly between incubation treatments, corresponding to differences in concentrations of AVS and SEM:AVS ratios, although midge growth did not. Bioaccumulation of Zn did not differ significantly between depth strata of sediment cores or between incubation treatments. When results from the two sets of bioassays were combined, bioaccumulation of Cu and Zn, but not growth, was significantly correlated with SEM:AVS ratios and other estimates of bioavailable metal fractions in sediments. Growth of midge larvae was significantly correlated with bioaccumulation of Zn, but not Cu, suggesting that Zn was the greater contributor to the toxicity of these sediments. Assessments of the toxicity of metal-contaminated freshwater sediments should consider the effects of spatial and temporal variation in AVS concentrations on metal bioavailability.

  3. Cadmium and zinc chain and cluster-based layered coordination polymers prepared from flexible-arm aromatic ortho-dicarboxylic acids and 4-pyridylnicotinamide

    NASA Astrophysics Data System (ADS)

    Kraft, Peter E.; Uebler, Jacob W.; LaDuca, Robert L.

    2013-04-01

    Hydrothermal reaction of a d10-metal nitrate salt, a flexible-arm aromatic ortho-dicarboxylic acid, and 4-pyridylnicotinamide (4-pna) afforded four new crystalline coordination polymers, which were characterized by single-crystal X-ray diffraction. [Cd(Hhmph)(nic)(H2O)2]n (1, hmph = homophthalate, nic = nicotinate) is a 1-D coordination polymer chain compound whose nic ligands were generated in situ via 4-pna hydrolysis. Addition of base and a shorter reaction duration afforded [Cd(hmph)(4-pna)]n (2), which has dinuclear [Cd2(hmph)2] dimers linked into a 1-D ladder polymer via 4-pna ligands. A similar chain structure, albeit with a different hmph binding mode, is seen in [Zn(hmph)(4-pna)]n (3). {[Zn2(phda)2(4-pna)2(H2O)]ṡH2O}n (4, phda = 1,2-phenylenediacetate) has both anti-syn bridged [Zn2(OCO)2] ring dimers and [Zn2(OCO)4] paddlewheel dimers, linked into a layered coordination polymer by dipodal 4-pna ligands. Luminescent properties of these new materials are also presented.

  4. Effect of zinc source and picolinic acid on /sup 65/Zn uptake in an in vitro continuous-flow perfusion system for pig and poultry intestinal segments

    SciTech Connect

    Hill, D.A.; Peo, E.R. Jr.; Lewis, A.J.

    1987-10-01

    Twenty weanling pigs and fourteen 9-wk-old broiler chickens were used in three continuous-flow in vitro perfusion experiments using noneverted intestinal sacs to 1) determine differences in /sup 65/Zn absorption due to location within the intestinal tract, 2) evaluate /sup 65/Zn uptake from ZnCl/sub 2/ and Zn-methionine (ZnMet) with or without added picolinic acid (PA) in pig intestinal sacs and 3) evaluate /sup 65/Zn uptake from ZnCl/sub 2/ and ZnMet in chicken intestinal sacs. No differences in /sup 65/Zn uptake due to gut segment position were observed in the pigs. A Zn source x PA interaction was observed for /sup 65/Zn uptake into the pig gut tissue and for /sup 65/Zn uptake to the serosal side of the gut sacs. Total /sup 65/Zn absorption in the pig gut sacs from the two Zn sources was not different, but the addition of a 5 M ratio of PA to Zn depressed /sup 65/Zn absorption. No differences were observed in total /sup 65/Zn absorption or /sup 65/Zn uptake in poultry gut sac tissue. There was, however, greater uptake of /sup 65/Zn from ZnCl/sub 2/ to the serosal side of the sacs than from ZnMet. The data indicate that /sup 65/Zn from ZnCl/sub 2/ and ZnMet is similar in total absorption and that the addition of PA depresses Zn uptake.

  5. Electroplating and corrosion behavior of tin-zinc alloy

    NASA Astrophysics Data System (ADS)

    Wang, Kai

    measured by the electrochemical impedance spectroscopy (EIS). They are in accordance with the IR drop mechanism. Chromate treatment shifts the OCP to more noble values and decreases the anodic current density. In acid solution, the chromate layer itself dissolves gradually so that the electrochemical quartz crystal microbalance (EQCM) is not suitable to estimate the zinc dissolution rate. Measurement of the polarization resistance Rp shows that, chromate treatment increases the corrosion resistance of both tin-zinc alloys and pure zinc coatings. (Abstract shortened by UMI.)

  6. International Lead Zinc Research Organization-sponsored field-data collection and analysis to determine relationships between service conditions and reliability of valve-regulated lead-acid batteries in stationary applications

    NASA Astrophysics Data System (ADS)

    Taylor, P. A.; Moseley, P. T.; Butler, P. C.

    The International Lead Zinc Research Organization (ILZRO), in cooperation with Sandia National Laboratories, has initiated a multi-phase project with the following aims: to characterize relationships between valve-regulated lead-acid (VRLA) batteries, service conditions, and failure modes; to establish the degree of correlation between specific operating procedures and PCL; to identify operating procedures that mitigate PCL; to identify best-fits between the operating requirements of specific applications and the capabilities of specific VRLA technologies; to recommend combinations of battery design, manufacturing processes, and operating conditions that enhance VRLA performance and reliability. In the first phase of this project, ILZRO has contracted with Energetics to identify and survey manufacturers and users of VRLA batteries for stationary applications (including electric utilities, telecommunications companies, and government facilities). The confidential survey is collecting the service conditions of specific applications and performance records for specific VRLA technologies. From the data collected, Energetics is constructing a database of the service histories and analyzing the data to determine trends in performance for particular technologies in specific service conditions. ILZRO plans to make the final report of the analysis and a version of the database (that contains no proprietary information) available to ILZRO members, participants in the survey, and participants in a follow-on workshop for stakeholders in VRLA reliability. This paper presents the surveys distributed to manufacturers and end-users, discusses the analytic approach, presents an overview of the responses to the surveys and trends that have emerged in the early analysis of the data, and previews the functionality of the database being constructed.

  7. A novel rice C2H2-type zinc finger protein, ZFP36, is a key player involved in abscisic acid-induced antioxidant defence and oxidative stress tolerance in rice

    PubMed Central

    Zhang, Hong; Liu, Yanpei; Wen, Feng; Yao, Dongmei; Wang, Lu; Guo, Jin; Ni, Lan; Zhang, Aying; Tan, Mingpu; Jiang, Mingyi

    2014-01-01

    C2H2-type zinc finger proteins (ZFPs) have been shown to play important roles in the responses of plants to oxidative and abiotic stresses, and different members of this family might have different roles during stresses. Here a novel abscisic acid (ABA)- and hydrogen peroxide (H2O2)-responsive C2H2-type ZFP gene, ZFP36, is identified in rice. The analyses of ZFP36-overexpressing and silenced transgenic rice plants showed that ZFP36 is involved in ABA-induced up-regulation of the expression and the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). Overexpression of ZFP36 in rice plants was found to elevate the activities of antioxidant enzymes and to enhance the tolerance of rice plants to water stress and oxidative stress. In contrast, an RNA interference (RNAi) mutant of ZFP36 had lower activities of antioxidant enzymes and was more sensitive to water stress and oxidative stress. ABA-induced H2O2 production and ABA-activated mitogen-activated protein kinases (MAPKs) were shown to regulate the expression of ZFP36 in ABA signalling. On the other hand, ZFP36 also regulated the expression of NADPH oxidase genes, the production of H2O2, and the expression of OsMPK genes in ABA signalling. These results indicate that ZFP36 is required for ABA-induced antioxidant defence, for the tolerance of rice plants to water stress and oxidative stress, and for the regulation of the cross-talk between NADPH oxidase, H2O2, and MAPK in ABA signalling. PMID:25071223

  8. Clinical manifestations of zinc deficiency.

    PubMed

    Prasad, A S

    1985-01-01

    The essentiality of zinc for humans was recognized in the early 1960s. The causes of zinc deficiency include malnutrition, alcoholism, malabsorption, extensive burns, chronic debilitating disorders, chronic renal diseases, following uses of certain drugs such as penicillamine for Wilson's disease and diuretics in some cases, and genetic disorders such as acrodermatitis enteropathica and sickle cell disease. In pregnancy and during periods of growth the requirement of zinc is increased. The clinical manifestations in severe cases of zinc deficiency include bullous-pustular dermatitis, alopecia, diarrhea, emotional disorder, weight loss, intercurrent infections, hypogonadism in males; it is fatal if unrecognized and untreated. A moderate deficiency of zinc is characterized by growth retardation and delayed puberty in adolescents, hypogonadism in males, rough skin, poor appetite, mental lethargy, delayed wound healing, taste abnormalities, and abnormal dark adaptation. In mild cases of zinc deficiency in human subjects, we have observed oligospermia, slight weight loss, and hyperammonemia. Zinc is a growth factor. Its deficiency adversely affects growth in many animal species and humans. Inasmuch as zinc is needed for protein and DNA synthesis and for cell division, it is believed that the growth effect of zinc is related to its effect on protein synthesis. Whether or not zinc is required for the metabolism of somatomedin needs to be investigated in the future. Testicular functions are affected adversely as a result of zinc deficiency in both humans and experimental animals. This effect of zinc is at the end organ level; the hypothalamic-pituitary axis is intact in zinc-deficient subjects. Inasmuch as zinc is intimately involved in cell division, its deficiency may adversely affect testicular size and thus affect its functions. Zinc is required for the functions of several enzymes and whether or not it has an enzymatic role in steroidogenesis is not known at present

  9. Characterization of Zinc Influx Transporters (ZIPs) in Pancreatic β Cells: ROLES IN REGULATING CYTOSOLIC ZINC HOMEOSTASIS AND INSULIN SECRETION.

    PubMed

    Liu, Ying; Batchuluun, Battsetseg; Ho, Louisa; Zhu, Dan; Prentice, Kacey J; Bhattacharjee, Alpana; Zhang, Ming; Pourasgari, Farzaneh; Hardy, Alexandre B; Taylor, Kathryn M; Gaisano, Herbert; Dai, Feihan F; Wheeler, Michael B

    2015-07-24

    Zinc plays an essential role in the regulation of pancreatic β cell function, affecting important processes including insulin biosynthesis, glucose-stimulated insulin secretion, and cell viability. Mutations in the zinc efflux transport protein ZnT8 have been linked with both type 1 and type 2 diabetes, further supporting an important role for zinc in glucose homeostasis. However, very little is known about how cytosolic zinc is controlled by zinc influx transporters (ZIPs). In this study, we examined the β cell and islet ZIP transcriptome and show consistent high expression of ZIP6 (Slc39a6) and ZIP7 (Slc39a7) genes across human and mouse islets and MIN6 β cells. Modulation of ZIP6 and ZIP7 expression significantly altered cytosolic zinc influx in pancreatic β cells, indicating an important role for ZIP6 and ZIP7 in regulating cellular zinc homeostasis. Functionally, this dysregulated cytosolic zinc homeostasis led to impaired insulin secretion. In parallel studies, we identified both ZIP6 and ZIP7 as potential interacting proteins with GLP-1R by a membrane yeast two-hybrid assay. Knock-down of ZIP6 but not ZIP7 in MIN6 β cells impaired the protective effects of GLP-1 on fatty acid-induced cell apoptosis, possibly via reduced activation of the p-ERK pathway. Therefore, our data suggest that ZIP6 and ZIP7 function as two important zinc influx transporters to regulate cytosolic zinc concentrations and insulin secretion in β cells. In particular, ZIP6 is also capable of directly interacting with GLP-1R to facilitate the protective effect of GLP-1 on β cell survival.

  10. Zinc titanate sorbents

    DOEpatents

    Gupta, Raghubir P.; Gangwal, Santosh K.; Jain, Suresh C.

    1998-01-01

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750.degree. C. to about 950.degree. C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 .mu., and about 1 part titanium dioxide having a median particle size of less than about 1 .mu.. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  11. Zinc titanate sorbents

    DOEpatents

    Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

    1998-02-03

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750 to about 950 C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 microns, and about 1 part titanium dioxide having a median particle size of less than about 1 micron. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  12. Observations of interstellar zinc

    NASA Technical Reports Server (NTRS)

    Jura, M.; York, D.

    1981-01-01

    The International Ultraviolet Explorer observations of interstellar zinc toward 10 stars are examined. It is found that zinc is at most only slightly depleted in the interstellar medium; its abundance may serve as a tracer of the true metallicity in the gas. The local interstellar medium has abundances that apparently are homogeneous to within a factor of two, when integrated over paths of about 500 pc, and this result is important for understanding the history of nucleosynthesis in the solar neighborhood. The intrinsic errors in detecting weak interstellar lines are analyzed and suggestions are made as to how this error limit may be lowered to 5 mA per target observation.

  13. Photovoltaic cells employing zinc phosphide

    DOEpatents

    Barnett, Allen M.; Catalano, Anthony W.; Dalal, Vikram L.; Masi, James V.; Meakin, John D.; Hall, Robert B.

    1984-01-01

    A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

  14. Photovoltaic cells employing zinc phosphide

    SciTech Connect

    Barnett, A.M.; Catalano, A.W.; Dalal, V.L.; Hall, R.B.; Masi, J.V.; Meakin, J.D.

    1984-10-16

    A photovoltaic cell having a zinc phosphide absorber. The zinc phosphide can be a single or multiple crystal slice or a thin polycrystalline film. The cell can be a Schottky barrier, heterojunction or homojunction device. Methods for synthesizing and crystallizing zinc phosphide are disclosed as well as a method for forming thin films.

  15. Inhibition of copper absorption by zinc. Effect of histidine.

    PubMed

    Wapnir, R A; Balkman, C

    1991-06-01

    Copper and zinc interact at the intestinal mucosal level, affecting copper absorption. Amino acids, such as histidine, may affect the absorption of these two elements by chelating these cations. The two mechanisms could have additive potential. This possibility was investigated using a duodenal-jejunal single-pass perfusion procedure in anesthetized rats. Copper absorption and tissue retention from solutions containing 0.1 mM copper were determined in the presence of either no zinc or equimolar zinc, or at a zinc/copper ratio of 10/1, either without histidine or with histidine at a 10/1 or 20/1 ratio to copper. Copper removal from the intestinal lumen was decreased by zinc, and further reduced by increasing concentrations of histidine. There was a greater accumulation of copper in the small intestine, reaching a maximum with a 10-fold excess of histidine. With zinc at a 10/1 ratio to copper, the addition of a 10- or 20-fold molar excess of histidine further decreased the net uptake of copper from the perfusate while greater copper accumulation in the tissue occurred. Histidine thus enhances the inhibitory effects of zinc on copper absorption, suggesting the application of convergent mechanisms for diminishing copper uptake. This could be relevant for the treatment of Wilson's disease.

  16. Effects of zinc on SN56 cholinergic neuroblastoma cells.

    PubMed

    Ronowska, Anna; Gul-Hinc, Sylwia; Bielarczyk, Hanna; Pawełczyk, Tadeusz; Szutowicz, Andrzej

    2007-11-01

    Zinc is a trace element necessary for proper development and function of brain cells. However, excessive accumulation of zinc exerts several cytotoxic effects in the brain. The aim of this work was to see whether cytotoxic effects of zinc are quantitatively correlated with changes in acetyl-CoA metabolism. The zinc levels up to 0.20 mmol/L caused concentration-dependent inhibition of pyruvate dehydrogenase (PDH) activity that correlated with the increase in trypan blue-positive fraction and the decrease in cultured cell number (r = 0.96, p = 0.0001). Chronic exposure of cells to 0.15 mmol/L zinc decreased choline acetyltransferase and aconitase activities, cytoplasmic acetyl-CoA and whole cell ATP level by 38%, 57%, 35%, and 62%, respectively but caused no change in mitochondrial acetyl-CoA level and activities of other enzymes of glycolytic and tricarboxylic acid cycle. dl-alpha-lipoamide when added simultaneously with zinc to cultured cells or their homogenates attenuated its chronic or acute suppressive effects. In homogenates of chronically Zn-treated cells, lipoamide overcame PDH but not aconitase inhibition. Presented data indicate that acute-transient elevation of zinc caused reversible inhibition of PDH, aconitase activities and acetyl-CoA metabolism, which when prolonged could lead to irreversible enzyme inactivation yielding decrease in cell viability and secondary suppression of their cholinergic phenotype. PMID:17662047

  17. Zinc requirements and zinc intakes of breast-fed infants.

    PubMed

    Krebs, N F; Hambidge, K M

    1986-02-01

    Longitudinal changes in dietary zinc requirements for infants at different levels of net absorption were estimated using a factorial approach. Apart from variations in net absorption, the zinc needed for new lean body mass is the major determinant of requirements. As growth velocity declines progressively, estimated zinc requirements for growth and for replacement of urine and sweat losses decrease from a high for male infants of 780 micrograms/day at 1 mo to 480 micrograms/day in the 5th mo and then remain quite constant through the 1st yr. Calculated percentage absorption of zinc from human milk necessary to meet estimated requirements increases with duration of lactation. For infants of mothers whose zinc intake approximated 25 mg/day the calculated percentage absorption remained within plausible limits. It is suggested that the progressive decrease in milk zinc concentrations provides a mechanism for conserving maternal zinc while meeting infant needs. PMID:3946293

  18. Involvement of zinc in cell-free protein synthesizing systems from rat liver

    SciTech Connect

    Hicks, S.E.; Wallwork, J.C.

    1986-03-05

    There are conflicting reports in the literature concerning the role of zinc in protein synthesis. This study presents evidence for the direct involvement of zinc in the translation of polypeptide chains in rats. Cell-free systems for incorporation of amino acids into acid-insoluble proteins were prepared from livers of three populations of rats: (1) rats fed ad libitum a diet containing 25 ppm zinc; (2) rats fed a diet containing less than 1 ppm zinc and (3) rats pair-fed a diet containing 25 ppm zinc. The diets contained 20% egg white and were enriched with biotin. Distilled deionized drinking water was given. The animals were maintained on the regimen for 45 days with precautions to limit zinc contamination. Group 2 showed typical signs of zinc deficiency, including decreased bone zinc. In vitro systems containing liver polysomes and a pH5 precipitate enzyme fraction indicated that the synthetic ability of systems isolated from zinc-deficient rats was considerably depressed, resulting in incorporation of amino acids 15 to 30% less than systems from pair-fed rats and 30 to 50% less than ad libitum-fed control animals. The results of crossover experiments performed by mixing polysome and enzyme fractions from the different groups indicated that the defect is due primarily to the pH precipitate enzyme fraction and not the polysomes.

  19. A Comparison of Diets Supplemented with a Feed Additive Containing Organic Acids, Cinnamaldehyde and a Permeabilizing Complex, or Zinc Oxide, on Post-Weaning Diarrhoea, Selected Bacterial Populations, Blood Measures and Performance in Weaned Pigs Experimentally Infected with Enterotoxigenic E. coli †

    PubMed Central

    Stensland, Ingunn; Kim, Jae Cheol; Bowring, Bethany; Collins, Alison M.; Mansfield, Josephine P.; Pluske, John R.

    2015-01-01

    Simple Summary This experiment was conducted to assess the effects of three diets on diarrhoea, performance (weight change, feed intake and feed conversion ratio), selected bacterial populations and blood measures of weaner pigs infected with enterotoxigenic E. coli. The three diets were: base diet (no antimicrobial compounds), base diet containing zinc oxide, and base diet containing a feed additive (blend of organic acids, cinnamaldehyde and permeabilizing complex). Only feeding zinc oxide decreased diarrhoea, with zinc oxide-fed pigs performing better than base diet-fed pigs. Zinc oxide-fed pigs performed similarly to pigs fed the organic acids, cinnamaldehyde and permeabilizing complex. Significant interactions between treatment and day after weaning were found for some bacterial populations, although the implications of such findings require further examination. Abstract The effects of feeding a diet supplemented with zinc oxide (ZnO) or a blend of organic acids, cinnamaldehyde and a permeabilizing complex (OACP) on post-weaning diarrhoea (PWD) and performance in pigs infected with enterotoxigenic E. coli (ETEC) were examined. Additionally, changes in selected bacterial populations and blood measures were assessed. A total of 72 pigs weaned at 22 d of age and weighing 7.2 ± 1.02 kg (mean ± SEM) was used. Treatments were: base diet (no antimicrobial compounds); base diet + 3 g ZnO/kg; base diet + 1.5 g OACP/kg. Dietary treatments started on the day of weaning and were fed ad libitum for 3 weeks. All pigs were infected with an F4 ETEC on d 4, 5 and 6 after weaning. The incidence of PWD was lower in pigs fed ZnO (p = 0.026). Overall, pigs fed ZnO grew faster (p = 0.013) and ate more (p = 0.004) than the base diet-fed pigs, with OACP-fed pigs performing the same (p > 0.05) as both the ZnO- and base diet-fed pigs. Feed conversion ratio was similar for all diets (p > 0.05). The percentage of E. coli with F4 fimbriae was affected a day by treatment interaction (p

  20. Solution NMR characterization of Sgf73(1-104) indicates that Zn ion is required to stabilize zinc finger motif

    SciTech Connect

    Lai, Chaohua; Wu, Minhao; Li, Pan; Shi, Chaowei; Tian, Changlin; Zang, Jianye

    2010-07-02

    Zinc finger motif contains a zinc ion coordinated by several conserved amino acid residues. Yeast Sgf73 protein was identified as a component of SAGA (Spt/Ada/Gcn5 acetyltransferase) multi-subunit complex and Sgf73 protein was known to contain two zinc finger motifs. Sgf73(1-104), containing the first zinc finger motif, was necessary to modulate the deubiquitinase activity of SAGA complex. Here, Sgf73(1-104) was over-expressed using bacterial expression system and purified for solution NMR (nuclear magnetic resonance) structural studies. Secondary structure and site-specific relaxation analysis of Sgf73(1-104) were achieved after solution NMR backbone assignment. Solution NMR and circular dichroism analysis of Sgf73(1-104) after zinc ion removal using chelation reagent EDTA (ethylene-diamine-tetraacetic acid) demonstrated that zinc ion was required to maintain stable conformation of the zinc finger motif.

  1. The mineralogical deportment of germanium in the Clarksville Electrolytic Zinc Plant of Savage Zinc Inc.

    SciTech Connect

    Dutrizac, J.E.; Chen, T.T.; Longton, R.J.

    1996-08-01

    Germanium is a strategic element which is widely used for infrared night vision systems, fiber optics, gamma-ray detectors, semiconductors, catalysts, and phosphors. Germanium is recovered from the dusts and residues generated during the processing of certain complex Zn-Cu-Pb sulfide ores or low-temperature sphalerite ores. A mineralogical study was carried out on the neutral leach residue and weak acid leach residue generated from Gordonsville zinc concentrate at the Clarksville Electrolytic Zinc Plant of Savage Zinc Inc. The intent was to characterize the mineral forms and associations of germanium. The Gordonsville zinc concentrate consists mostly of sphalerite which has a solid solution Ge content of {approximately} 400 ppm; the sphalerite is the dominant, if not only, Ge carrier in the concentrate. The major Ge carrier in the neutral residue is the iron gel-silica gel phase, but modest amounts of Ge are present in the ZnO, ZnFe{sub 2}O{sub 4}, sphalerite, and Zn-Fe-Pb silicate phases. The major Ge carrier in the acid residue is the iron gel-silica gel phase which contains up to 1.7% Ge and accounts for {approximately} 70% of the total Ge content of this residue. The remaining Ge is carried by the Zn-Fe-Pb silicate, ZnFe{sub 2}O{sub 4}, and some of the rare Mn-Pb-Fe oxide phases.

  2. Imaging Mobile Zinc in Biology

    PubMed Central

    Tomat, Elisa; Lippard, Stephen J.

    2009-01-01

    Summary Trafficking and regulation of mobile zinc pools influence cellular functions and pathological conditions in multiple organs, including brain, pancreas, and prostate. The quest for a dynamic description of zinc distribution and mobilization in live cells fuels the development of increasingly sophisticated probes. Detection systems that respond to zinc binding with changes of their fluorescence emission properties have provided sensitive tools for mobile zinc imaging, and fluorescence microscopy experiments have afforded depictions of zinc distribution within live cells and tissues. Both small-molecule and protein-based fluorescent probes can address complex imaging challenges, such as analyte quantification, site-specific sensor localization, and real-time detection. PMID:20097117

  3. Zinc and Compounds

    Integrated Risk Information System (IRIS)

    Zinc and Compounds ; CASRN 7440 - 66 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  4. Creep Resistant Zinc Alloy

    SciTech Connect

    Frank E. Goodwin

    2002-12-31

    This report covers the development of Hot Chamber Die Castable Zinc Alloys with High Creep Strengths. This project commenced in 2000, with the primary objective of developing a hot chamber zinc die-casting alloy, capable of satisfactory service at 140 C. The core objectives of the development program were to: (1) fill in missing alloy data areas and develop a more complete empirical model of the influence of alloy composition on creep strength and other selected properties, and (2) based on the results from this model, examine promising alloy composition areas, for further development and for meeting the property combination targets, with the view to designing an optimized alloy composition. The target properties identified by ILZRO for an improved creep resistant zinc die-casting alloy were identified as follows: (1) temperature capability of 1470 C; (2) creep stress of 31 MPa (4500 psi); (3) exposure time of 1000 hours; and (4) maximum creep elongation under these conditions of 1%. The project was broadly divided into three tasks: (1) Task 1--General and Modeling, covering Experimental design of a first batch of alloys, alloy preparation and characterization. (2) Task 2--Refinement and Optimization, covering Experimental design of a second batch of alloys. (3) Task 3--Creep Testing and Technology transfer, covering the finalization of testing and the transfer of technology to the Zinc industry should have at least one improved alloy result from this work.

  5. Doped zinc oxide microspheres

    DOEpatents

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel.

  6. Doped zinc oxide microspheres

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-12-14

    A new composition and method of making same for a doped zinc oxide microsphere and articles made therefrom for use in an electrical surge arrestor which has increased solid content, uniform grain size and is in the form of a gel. 4 figures.

  7. Zinc sulfide liquefaction catalyst

    DOEpatents

    Garg, Diwakar

    1984-01-01

    A process for the liquefaction of carbonaceous material, such as coal, is set forth wherein coal is liquefied in a catalytic solvent refining reaction wherein an activated zinc sulfide catalyst is utilized which is activated by hydrogenation in a coal derived process solvent in the absence of coal.

  8. Additive agent for zinc alloy electrolyte and process

    SciTech Connect

    Bammel, B.D.

    1986-07-01

    An aqueous acidic electrolyte is described suitable for electrodepositing zinc alloys on a substrate comprising zinc ions and at least one additional metal ion selected from the group consisting nickel, cobalt, iron and mixtures thereof present in an amount sufficient to electrodeposit a zinc alloy, and, for providing improved grain-refinement and enhancing the codeposition of the alloying metals in the zinc alloy deposit. An effective amount of an additive agent consists of a bath-soluble anionic carboxylated polyoxyalkylene compound derived from the carboxylation of: (a) the polymerization of alkylene oxides selected from the group consisting of ethylene oxide, propylene oxide, glycidol, butylene oxide and mixtures thereof; and (b) the alkoxylation of mono and polyhydroxy compounds selected from the group consisting of hydroxyl containing alkyl, alkenyl, alkynyl, aryl, as well as mixtures thereof.

  9. [Significance of zinc and sarcopenia in patients undergoing surgery].

    PubMed

    Kaido, Toshimi; Tamai, Yumiko; Uemoto, Shinji

    2016-07-01

    Sarcopenia is characterized by muscle mass depletion and decrease in muscle power or physical activity. We evaluated significance of sarcopenia in patients undergoing living donor liver transplantation (LDLT). Patients with low skeletal muscle mass (SMM) had significantly worse survival compared with patients with normal/high SMM (p < 0.001). Correlations of preoperative zinc with prealbumin and branched-chain amino acids were significantly positive. While, correlations of zinc with tyrosine and ammonia levels were significantly negative. The low pre-transplant zinc level steeply dropped for 2/3 days after LDLT and subsequently increased back to reach the pre-transplant level around the postoperative day 5, and continued to increase until normalized during 2 weeks. Perioperative nutritional therapy including zinc supplement significantly increased survival in patients with low SMM (p = 0.009). PMID:27455815

  10. Bacterial extracellular zinc-containing metalloproteases.

    PubMed Central

    Häse, C C; Finkelstein, R A

    1993-01-01

    Extracellular zinc-containing metalloproteases are widely distributed in the bacterial world. The most extensively studied are those which are associated with pathogenic bacteria or bacteria which have industrial significance. They are found practically wherever they are sought in both gram-negative and gram-positive microorganisms, be they aerobic or anaerobic. This ubiquity in itself implies that these enzymes serve important functions for the organisms which produce them. Because of the importance of zinc to enzymatic activity, it is not surprising that there is a pervasive amino acid sequence homology in the primary structure of this family of enzymes regardless of their source. The evidence suggests that both convergent and divergent evolutionary forces are at work. Within the large family of bacterial zinc-containing metalloendopeptidases, smaller family units are observed, such as thermolysin-like, elastase-like, and Serratia protease-like metalloproteases from various bacterial species. While this review was in the process of construction, a new function for zinc-containing metalloproteases was discovered: the neurotoxins of Clostridium tetani and Clostridium botulinum type B have been shown to be zinc metalloproteases with specificity for synaptobrevin, an integral membrane protein of small synaptic vesicles which is involved in neurotransmission. Additional understanding of the mode of action of proteases which contribute to pathogenicity could lead to the development of inhibitors, such as chelators, surrogate substrates, or antibodies, which could prevent or interrupt the disease process. Further studies of this broad family of metalloproteases will provide important additional insights into the pathogenesis and structure-function relationships of enzymes and will lead to the development of products, including "designer proteins," which might be industrially and/or therapeutically useful. PMID:8302217

  11. Vegetation establishment on a deposit of zinc mine wastes.

    PubMed

    Bergholm, J; Steen, E

    1989-01-01

    Field trials concerning the establishment of plant cover on a deposit of wastes from the Ammeberg zinc mine in central Sweden were carried out during 1976-1985. Different soil conditioners and manures were applied and plant species cultivars were evaluated with regard to plant biomass, vigour, durability and content of zinc, lead and cadmium. Sewage sludge and topsoil led to better establishment of grasses than did municipal waste, straw and hydraulic seeding. After 2 years, Festuca rubra and Poa pratensis dominated the swards. Other species (Dactylis glomerata, Bromus inermis, Lolium perenne, Phleum nodosum, Festuca pratensis and F. arundinacea) constituted only a minor part of the stand. After 10 years, F. rubra was the most dominant species, while native Agrostis tenuis had invaded 20-50% of the area within the plots. Merlin was the clearly dominant red fescue cultivar. The concentration of zinc in shoots (616 mg kg(-1) dw) was about 10% of that in the soil. Zinc concentration decreased with increasing biomass above ground. It increased with age in Scots pine needles and was very high in birch leaves. Grasses survived longer than legumes in the zinc sand waste. Among the surviving grasses was a group with high (3800 mg kg(-1) dw) and a group with low (320 mg kg(-1) dw) zinc concentrations. The low group included Merlin red fescue and Sobel creeping bent. The cultivar Merlin contained a much lower zinc concentration than the other cultivars of red fescue (375 and 624 mg kg(-1) dw, respectively). A large amount of root biomass was present in plots with dominating Merlin red fescue (1715 g m(-2)), 97% of which was concentrated in the top 10 cm of the soil. The concentration of zinc in the roots was very high (13 000-25 000 mg kg(-1) dw). Nitrate fertilizer, especially ammonium nitrate, and acidic water (pH 4.3) increased zinc leaching.

  12. Zinc modulation of water permeability reveals that aquaporin 0 functions as a cooperative tetramer.

    PubMed

    Németh-Cahalan, Karin L; Kalman, Katalin; Froger, Alexandrine; Hall, James E

    2007-11-01

    We previously showed that the water permeability of AQP0, the water channel of the lens, increases with acid pH and that His40 is required (Németh-Cahalan, K.L., and J.E. Hall. 2000. J. Biol. Chem. 275:6777-6782; Németh-Cahalan, K.L., K. Kalman, and J.E. Hall. 2004. J. Gen. Physiol. 123:573-580). We have now investigated the effect of zinc (and other transition metals) on the water permeability of AQP0 expressed in Xenopus oocytes and determined the amino acid residues that facilitate zinc modulation. Zinc (1 mM) increased AQP0 water permeability by a factor of two and prevented any additional increase induced by acid pH. Zinc had no effect on water permeability of AQP1, AQP4 or MIPfun (AQP0 from killifish), or on mutants of AQP1 and MIPfun with added external histidines. Nickel, but not copper, had the same effect on AQP0 water permeability as zinc. A fit of the concentration dependence of the zinc effect to the Hill equation gives a coefficient greater than three, suggesting that binding of more than one zinc ion is necessary to enhance water permeability. His40 and His122 are necessary for zinc modulation of AQP0 water permeability, implying structural constraints for zinc binding and functional modulation. The change in water permeability was highly sensitive to a coinjected zinc-insensitive mutant and a single insensitive monomer completely abolished zinc modulation. Our results suggest a model in which positive cooperativity among subunits of the AQP0 tetramer is required for zinc modulation, implying that the tetramer is the functional unit. The results also offer the possibility of a pharmacological approach to manipulate the water permeability and transparency of the lens. PMID:17938229

  13. Uniqueness of Zinc as a Bioelement: Principles and Applications in Bioinorganic Chemistry--III.

    ERIC Educational Resources Information Center

    Ochiai, Ei-Ichiro

    1988-01-01

    Attempts to delineate certain basic principles and applications of bioinorganic chemistry to oxidation-reduction reactions. Examines why zinc(II) is so uniquely suited to enzymated reactions of the acid-base type. Suggests the answer may be in the natural abundance and the basic physicochemical properties of zinc(II). (MVL)

  14. Comparative toxicity of a zinc salt, zinc powder and zinc oxide to Eisenia fetida, Enchytraeus albidus and Folsomia candida.

    PubMed

    Lock, Koen; Janssen, Colin R

    2003-12-01

    The pore water zinc concentration and the calcium chloride extracted zinc fraction are higher in the soils spiked with a zinc salt (ZnCl2) compared to soils spiked with zinc oxide or zinc powder. Based on total zinc concentrations in the soil, the acute toxicity of zinc salt to the compost worm Eisenia fetida, the potworm Enchytraeus albidus and the springtail Folsomia candida was lower compared to zinc oxide and zinc powder. However, when expressed on the basis of pore water concentrations or calcium chloride extracted fractions, acute toxicity was higher for zinc salt, which indicated that dermal uptake via the pore water is not the only route of uptake. Chronic toxicity of zinc salt, zinc oxide and zinc powder was similar when based on total concentrations in the soil which again indicates that the pore water route of uptake is not the only route of exposure but that oral uptake is also important.

  15. Simultaneous determination of arsenic, cadmium, calcium, chromium, cobalt, copper, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in fertilizers by microwave acid digestion and inductively coupled plasma-optical emission spectrometry detection: single-laboratory validation of a modification and extension of AOAC 2006.03.

    PubMed

    Webb, Sharon; Bartos, James; Boles, Rhonda; Hasty, Elaine; Thuotte, Ethel; Thiex, Nancy J

    2014-01-01

    A single-laboratory validation study was conducted for the simultaneous determination of arsenic, cadmium, calcium, cobalt, copper, chromium, iron, lead, magnesium, manganese, molybdenum, nickel, selenium, and zinc in all major types of commercial fertilizer products by microwave digestion and inductively coupled plasma-optical emission spectroscopy analysis. This validation study proposes an extension and modification of AOAC 2006.03. The extension is the inclusion of calcium, copper, iron, magnesium, manganese, and zinc, and the modification is incorporation of hydrochloric acid in the digestion system. This dual acid digestion utilizes both hydrochloric and nitric acids in a 3 to 9 mL volume ratio/100 mL. In addition to 15 of the 30 original validation materials used in the 2006.03 collaborative study, National Institute of Standards and Technology Standard Reference Material 695 and Magruder 2009-06 were incorporated as accuracy materials. The main benefits of this proposed method are a significant increase in laboratory efficiency when compared to the use of both AOAC Methods 965.09 and 2006.03 to achieve the same objective and an enhanced recovery of several metals.

  16. Acute changes in cellular zinc alters zinc uptake rates prior to zinc transporter gene expression in Jurkat cells.

    PubMed

    Holland, Tai C; Killilea, David W; Shenvi, Swapna V; King, Janet C

    2015-12-01

    A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells.

  17. Isolation and characterization of a new zinc-binding protein from albacore tuna plasma

    SciTech Connect

    Dyke, B.; Hegenauer, J.; Saltman, P.; Laurs, R.M.

    1987-06-02

    The protein responsible for sequestering high levels of zinc in the plasma of the albacore tuna (Thunnus alalunga) has been isolated by sequential chromatography. The glycoprotein has a molecular weight of 66,000. Approximately 8.2% of its amino acid residues are histidines. Equilibrium dialysis experiments show it to bind 3 mol of zinc/mol of protein. The stoichiometric constant for the association of zinc with a binding site containing three histidines was determined to be 10/sup 9.4/. This protein is different from albumin and represents a previously uncharacterized zinc transport protein.

  18. Novel electrochemical behavior of zinc anodes in zinc/air batteries in the presence of additives

    NASA Astrophysics Data System (ADS)

    Lee, Chang Woo; Sathiyanarayanan, K.; Eom, Seung Wook; Kim, Hyun Soo; Yun, Mun Soo

    In our continued efforts to find an electrically rechargeable zn/air secondary battery, we report the unique behavior of a zinc oxide anode in the presence of additives such as phosphoric acid, tartaric acid, succinic acid and citric acid. These additives were added to the electrolyte, which is an 8.5 M KOH solution containing 25 g of ZnO and 3000 ppm of polyethylene glycol in 1 l of water. In zn/air systems there are two main problems namely the hydrogen overpotential and dendrite formation during recharging. Investigations have studied in detail both of the problems in order to overcome them. The results obtained in presence of additives are compared with the behavior of the electrolyte 8.5 M KOH in the absence of additives. It has been concluded that the hydrogen overpotential is raised enormously while dendrite formation is reduced to some extent. Out of the four acids studied, the order of increase in hydrogen overpotential is: tartaric acid > succinic acid > phosphoric acid > citric acid. The prevention of dendrite formation follows the order: citric acid > succinic acid > tartaric acid > phosphoric acid.

  19. Rhodiola rosea, folic acid, zinc and biotin (EndEP®) is able to improve ejaculatory control in patients affected by lifelong premature ejaculation: Results from a phase I-II study

    PubMed Central

    Cai, Tommaso; Verze, Paolo; Massenio, Paolo; Tiscione, Daniele; Malossini, Gianni; Cormio, Luigi; Carrieri, Giuseppe; Mirone, Vincenzo

    2016-01-01

    The therapeutic armamentarium currently available for the treatment of premature ejaculation (PE) is not highly satisfactory. However, phytotherapeutics appear to be an interesting option for PE management. The present study aimed to evaluate the tolerability and efficacy of a phytotherapeutic combination of Rhodiola rosea, folic acid, biotin and zinc (EndEP®) in the treatment of patients affected by lifelong PE. All patients affected by lifelong PE who were attending three Urological Institutions from July to December 2014 were enrolled in this prospective, multicentre, phase I–II study. All patients were assigned to receive oral tablets of EndEP® (one tablet per day) for 90 days. Clinical and instrumental analyses were carried out at enrolment and at the end of the study. International Prostatic Symptom Score (IPSS), International Index of Erectile Function (IIEF)-15, Premature Ejaculation Diagnostic Tool (PEDT) and Short Form (SF)-36 questionnaires were used. The intravaginal ejaculation latency time (IELT) for each event was also evaluated using the stop-watch technique. The main outcome measure was the difference from baseline in PEDT questionnaire and mean IELT at the end of the follow-up period. In total, 91 patients (mean age, 32.3±5.6 years) were analysed. The baseline questionnaires mean scores were 1.1±1.6, 26.1±2.9, 15.3±3.4 and 98.2±0.5, for IPSS, IIEF-15, PEDT and SF-36, respectively. The mean IELT at baseline was 73.6±46.9s. At the follow-up examination (90 days after the start of treatment), no statistically significant differences were identified in terms of IPSS (1.4±1.5) or IIEF-15 (26.3±3.1) compared with the pre-treatment values (P=0.19 and P=0.64, respectively). A statistically significant difference was detected between the mean IELT at enrolment and after treatment (73.6±46.9 vs. 102.3±60.0; P<0.001) and SF-36 questionnaire (98.2±0.5 vs. 99.4±0.1; P<0.001). Fifty-five patients reported improvement in the control of

  20. Rhodiola rosea, folic acid, zinc and biotin (EndEP®) is able to improve ejaculatory control in patients affected by lifelong premature ejaculation: Results from a phase I-II study

    PubMed Central

    Cai, Tommaso; Verze, Paolo; Massenio, Paolo; Tiscione, Daniele; Malossini, Gianni; Cormio, Luigi; Carrieri, Giuseppe; Mirone, Vincenzo

    2016-01-01

    The therapeutic armamentarium currently available for the treatment of premature ejaculation (PE) is not highly satisfactory. However, phytotherapeutics appear to be an interesting option for PE management. The present study aimed to evaluate the tolerability and efficacy of a phytotherapeutic combination of Rhodiola rosea, folic acid, biotin and zinc (EndEP®) in the treatment of patients affected by lifelong PE. All patients affected by lifelong PE who were attending three Urological Institutions from July to December 2014 were enrolled in this prospective, multicentre, phase I–II study. All patients were assigned to receive oral tablets of EndEP® (one tablet per day) for 90 days. Clinical and instrumental analyses were carried out at enrolment and at the end of the study. International Prostatic Symptom Score (IPSS), International Index of Erectile Function (IIEF)-15, Premature Ejaculation Diagnostic Tool (PEDT) and Short Form (SF)-36 questionnaires were used. The intravaginal ejaculation latency time (IELT) for each event was also evaluated using the stop-watch technique. The main outcome measure was the difference from baseline in PEDT questionnaire and mean IELT at the end of the follow-up period. In total, 91 patients (mean age, 32.3±5.6 years) were analysed. The baseline questionnaires mean scores were 1.1±1.6, 26.1±2.9, 15.3±3.4 and 98.2±0.5, for IPSS, IIEF-15, PEDT and SF-36, respectively. The mean IELT at baseline was 73.6±46.9s. At the follow-up examination (90 days after the start of treatment), no statistically significant differences were identified in terms of IPSS (1.4±1.5) or IIEF-15 (26.3±3.1) compared with the pre-treatment values (P=0.19 and P=0.64, respectively). A statistically significant difference was detected between the mean IELT at enrolment and after treatment (73.6±46.9 vs. 102.3±60.0; P<0.001) and SF-36 questionnaire (98.2±0.5 vs. 99.4±0.1; P<0.001). Fifty-five patients reported improvement in the control of

  1. Interaction Between Yeasts and Zinc

    NASA Astrophysics Data System (ADS)

    Nicola, Raffaele De; Walker, Graeme

    Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

  2. Zinc hydroxide sulphate and its transformation to crystalline zinc oxide.

    PubMed

    Moezzi, Amir; Cortie, Michael B; McDonagh, Andrew M

    2013-10-28

    The thermal transformation of zinc hydroxide sulphate hydrate to zinc oxide has been examined using synchrotron X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and surface area measurements. By collecting X-ray diffraction data in situ, we found that the dehydration of zinc hydroxide sulphate pentahydrate proceeded in discrete steps to form anhydrous zinc hydroxide sulphate. This compound then decomposed to a mixture of zinc oxide and a compound tentatively identified as Zn3(OH)2(SO4)2 at ~235 °C. At ~360 °C, the final dehydroxylation occurred with the formation of zinc oxy-sulphate, Zn3O(SO4)2, which then decomposed to ZnO at about ~800 °C. Interruption of the dehydration process can be used to synthesize the intermediate compounds.

  3. Experimental phasing using zinc anomalous scattering

    SciTech Connect

    Cha, Sun-Shin; An, Young Jun; Jeong, Chang-Sook; Kim, Min-Kyu; Lee, Sung-Gyu; Lee, Kwang-Hoon; Oh, Byung-Ha

    2012-09-01

    The surface of proteins can be charged with zinc ions and the anomalous signals from these zinc ions can be used for structure determination of proteins. Zinc is a suitable metal for anomalous dispersion phasing methods in protein crystallography. Structure determination using zinc anomalous scattering has been almost exclusively limited to proteins with intrinsically bound zinc(s). Here, it is reported that multiple zinc ions can easily be charged onto the surface of proteins with no intrinsic zinc-binding site by using zinc-containing solutions. Zn derivatization of protein surfaces appears to be a largely unnoticed but promising method of protein structure determination.

  4. Zinc in the prevention of Fe2+-initiated lipid and protein oxidation.

    PubMed

    Zago, M P; Verstraeten, S V; Oteiza, P I

    2000-01-01

    In the present study we characterized the capacity of zinc to protect lipids and proteins from Fe2+-initiated oxidative damage. The effects of zinc on lipid oxidation were investigated in liposomes composed of brain phosphatidylcholine (PC) and phosphatidylserine (PS) at a molar relationship of 60:40 (PC:PS, 60:40). Lipid oxidation was evaluated as the oxidation of cis-parinaric acid or as the formation of 2-thiobarbituric acid-reactive substances (TBARS). Zinc protected liposomes from Fe2+ (2.5-50 microM)-supported lipid oxidation. However, zinc (50 microM) did not prevent the oxidative inactivation of glutamine synthetase and glucose 6-phosphate dehydrogenase when rat brain supernatants were oxidized in the presence of 5 microM Fe2+ and 0.5 mM H2O2. We also studied the interactions of zinc with epicatechin in the prevention of lipid oxidation in liposomes. The simultaneous addition of 0.5 microM epicatechin (EC) and 50 microM zinc increased the protection of liposomes from oxidation compared to that observed in the presence of zinc or EC separately. Zinc (50 microM) also protected liposomes from the stimulatory effect of aluminum on Fe2+-initiated lipid oxidation. Zinc could play an important role as an antioxidant in biological systems, replacing iron and other metals with pro-oxidant activity from binding sites and interacting with other components of the oxidant defense system. PMID:15693281

  5. 21 CFR 73.1991 - Zinc oxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc... indirect process whereby zinc metal isolated from the zinc-containing ore is vaporized and then...

  6. 21 CFR 73.1991 - Zinc oxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc... indirect process whereby zinc metal isolated from the zinc-containing ore is vaporized and then...

  7. 21 CFR 73.1991 - Zinc oxide.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc... indirect process whereby zinc metal isolated from the zinc-containing ore is vaporized and then...

  8. 21 CFR 73.1991 - Zinc oxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc... indirect process whereby zinc metal isolated from the zinc-containing ore is vaporized and then...

  9. 21 CFR 73.1991 - Zinc oxide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Zinc oxide. 73.1991 Section 73.1991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1991 Zinc oxide. (a) Identity. (1) The color additive zinc... indirect process whereby zinc metal isolated from the zinc-containing ore is vaporized and then...

  10. Degradation and antioxidant activities of peptides and zinc-peptide complexes during in vitro gastrointestinal digestion.

    PubMed

    Wang, Chan; Li, Bo; Wang, Bo; Xie, Ningning

    2015-04-15

    The degradation characteristics of three peptides (Ser-Met, Asn-Cys-Ser, and glutathione) and their zinc-peptide complexes were studied using a two-stage in vitro digestion model. Enzyme-resistant peptides and zinc-peptide complexes, antioxidant activities, and free amino acids released by digestive enzymes, were measured in this study. The results revealed that the three peptides and their zinc-peptide complexes were resistant to pepsin but not to pancreatin. Pancreatin can partly hydrolyse both peptides and zinc-peptide complexes, but more than half of them remaining in their original form after gastrointestinal digestion. The coordination of zinc improved the enzymatic resistance of the peptide due to lower solubility of complexes and affected the hydrolytic site of pepsin and pancreatin. Zinc-Asn-Cys-Ser, which is highly resistant to enzymatic hydrolysis and maintains Zn in a soluble form, may have potential to improve Zn bioavailability.

  11. Spectrophotometric studies and applications for the determination of Ni2+ in zinc-nickel alloy electrolyte

    NASA Astrophysics Data System (ADS)

    Qiao, Xiaoping; Li, Helin; Zhao, Wenzhen; Li, Dejun

    The absorption properties of zinc-nickel alloy electrolyte were studied by visible spectrophotometer. The results show that the relationship between the absorbance of the zinc-nickel alloy electrolyte and Ni2+ concentration in the electrolyte obeys Beer's law at 660 nm. In addition, other components except Ni2+ in the zinc-nickel alloy electrolyte such as zinc chloride, ammonium chloride, potassium chloride and boric acid have no obvious effect on the absorbance of zinc-nickel alloy electrolyte. Based on these properties, a new method is developed to determine Ni2+ concentration in zinc-nickel alloy electrolyte. Comparing with other methods, this method is simple, direct and accurate. Moreover, the whole testing process does not consume any reagent and dilution, and after testing, the electrolyte samples can be reused without any pollution to the environment.

  12. Polymerization of UDMA using zinc particles and 4-META with and without BPO.

    PubMed

    Wanichacheva, N; Miyagawa, Y; Ogura, H

    2000-06-01

    The polymerization phenomena of zinc particles moistened with a small amount of water, 4-META, and UDMA without amine in the presence and absence of BPO were investigated. The effects of 4-META and BPO on the setting time and the degree of conversion (DC) were studied. Moreover, the effect of zinc ion amount on the setting time was investigated. As-received zinc particles could induce the polymerization either with or without BPO. A higher concentration of 4-META shortened the setting time and increased DC when BPO was absent. However, the presence of BPO generally retarded the setting time and decreased DC, although its effect was dependent on the 4-META concentration. A higher amount of zinc ion retarded the setting reaction in the presence of 4-META. The zinc particles mixed with 10% zinc sulfate and acetic acid solutions could induce the polymerization of UDMA containing BPO when the amine and 4-META were absent.

  13. Diphosphonate thin films on zinc: Preparation, structure characterization and corrosion protection effects

    NASA Astrophysics Data System (ADS)

    Pilbáth, A.; Bertóti, I.; Sajó, I.; Nyikos, L.; Kálmán, E.

    2008-12-01

    The reaction of water-based solution of 1,5-diphosphono-pentane (DPP) and 1,7-diphosphono-heptane (DPH) with high purity polycrystalline zinc surface was investigated at room temperature. XRD and XPS studies evidenced the formation of crystalline zinc-phosphonate film on the metal surface. The formed layers give hydrophilic properties to the surface. A conversion-type interaction of diphosphonic acid compounds with the oxidized zinc surface was unambiguously shown by XPS analysis. Conclusive results were obtained by synthesized zinc-diphosphonate model compounds imitating the ones developed on the zinc surface, revealing a simple, closely 1:1 ratio of the phosphonate groups with zinc. Reactions with both diphosphonates resulted in significant protective effect of zinc against corrosion, although the structure and quality of the formed layers exhibit marked differences. The in-depth distribution of the composition and dissimilarity of the layer thickness were determined by glow discharge optical emission spectrometry (GD-OES). The corrosion inhibition was explained by the formation of insoluble zinc-phosphonate salt on the zinc surface, blocking the zinc dissolution process.

  14. Observations of interstellar zinc

    NASA Technical Reports Server (NTRS)

    York, D. G.; Jura, M.

    1982-01-01

    IUE observations toward 10 stars have shown that zinc is not depleted in the interstellar medium by more than a factor of two, suggesting that its abundance may serve as a tracer of the true metallicity in the gas. A result pertinent to the history of nucleosynthesis in the solar neighborhood is that the local interstellar medium has abundances that appear to be homogeneous to within a factor of two, when integrated over paths of about 500 pc.

  15. Surface energy of zinc

    SciTech Connect

    Bilello, J.C.; Dew-Hughes, D.; Pucino, A.T.

    1983-04-01

    The influence of temperature and associated dislocation microstructure on the energetics of basal plane cleavage in zinc crystals has been investigated using the method of Hull, Beardmore, and Valentine (HBV). A marked temperature dependence was observed in the zinc surface energy, over the range 77--298 /sup 0/K, contrary to previous expectations. Plastic relaxation was associated with crack initiation at 77 /sup 0/K, but not propagation; while at room temperature a plastic zone of 1200--1500 ..mu..m in depth was produced by crack extension. The surface energy could be estimated, independent of the usual Griffith analysis, by measuring the energy dissipation in a fully relaxed deformed zone associated with an explosively formed precursor crack. This method yielded surface energies of 0.066 to 0.079 J m/sup -2/ which was in good agreement with previous work. It is demonstrated that the cleavage surface energy of zinc is well below the thermodynamic surface energy and that this discrepancy is not related to plastic deformation.

  16. Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies.

    PubMed

    Wang, S X; Song, J X; Li, G H; Wu, Y; Zhang, L; Wan, Q; Streets, D G; Chin, Conrad K; Hao, J M

    2010-10-01

    Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t(-1) of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting.

  17. Dissolution and corrosion inhibition of copper, zinc, and their alloys

    SciTech Connect

    Jinturkar, P.; Guan, Y.C.; Han, K.N.

    1998-02-01

    The corrosion behavior of copper, zinc, and their alloys in sulfuric acid (H{sub 2}SO{sub 4}) solutions with oxygen and ferric ions (Fe{sup 3+}) was studied using a potentiostat. Oxygen and Fe{sup 3+} ions were shown to play an important role in corrosion of copper and copper-zinc alloys. Cathodic reduction of oxygen mainly was controlled by chemical reaction, and that of Fe{sup 3+} ions was controlled by diffusion. The overall cathodic process was the summation of the reduction of oxygen and Fe{sup 3+} ions. Corrosion of zinc was controlled mainly by reduction of water. Corrosion inhibition using benzotriazole (BTAH) also was investigated in aerated and deaerated solutions. BTAH was found to be a useful inhibitor, and the inhibition layer was shown to be stable and persistent. Morphology of the surface of copper, zinc, and brasses after corrosion in the presence and absence of BTAH was examined by scanning electron microscopy. BTAH formed a protective layer on the surface, thereby inhibiting corrosion. Solution analysis of the dissolution of brasses showed that zinc dissolved preferentially in the initial stages, followed by simultaneous dissolution of copper and zinc.

  18. 21 CFR 175.390 - Zinc-silicon dioxide matrix coatings.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... removed by water washing. Iron oxide Lithium hydroxide Removed by water washing. Methyl orange As an acid-base indicator. Potassium dichromate Removed by water washing. Silica gel Sodium silicate Zinc,...

  19. Natural zinc ribbon HNH endonucleases and engineered zinc finger nicking endonuclease

    PubMed Central

    Xu, Shuang-yong; Gupta, Yogesh K.

    2013-01-01

    Many bacteriophage and prophage genomes encode an HNH endonuclease (HNHE) next to their cohesive end site and terminase genes. The HNH catalytic domain contains the conserved catalytic residues His-Asn-His and a zinc-binding site [CxxC]2. An additional zinc ribbon (ZR) domain with one to two zinc-binding sites ([CxxxxC], [CxxxxH], [CxxxC], [HxxxH], [CxxC] or [CxxH]) is frequently found at the N-terminus or C-terminus of the HNHE or a ZR domain protein (ZRP) located adjacent to the HNHE. We expressed and purified 10 such HNHEs and characterized their cleavage sites. These HNHEs are site-specific and strand-specific nicking endonucleases (NEase or nickase) with 3- to 7-bp specificities. A minimal HNH nicking domain of 76 amino acid residues was identified from Bacillus phage γ HNHE and subsequently fused to a zinc finger protein to generate a chimeric NEase with a new specificity (12–13 bp). The identification of a large pool of previously unknown natural NEases and engineered NEases provides more ‘tools’ for DNA manipulation and molecular diagnostics. The small modular HNH nicking domain can be used to generate rare NEases applicable to targeted genome editing. In addition, the engineered ZF nickase is useful for evaluation of off-target sites in vitro before performing cell-based gene modification. PMID:23125367

  20. Depleted zinc: Properties, application, production.

    PubMed

    Borisevich, V D; Pavlov, A V; Okhotina, I A

    2009-01-01

    The addition of ZnO, depleted in the Zn-64 isotope, to the water of boiling water nuclear reactors lessens the accumulation of Co-60 on the reactor interior surfaces, reduces radioactive wastes and increases the reactor service-life because of the inhibitory action of zinc on inter-granular stress corrosion cracking. To the same effect depleted zinc in the form of acetate dihydrate is used in pressurized water reactors. Gas centrifuge isotope separation method is applied for production of depleted zinc on the industrial scale. More than 20 years of depleted zinc application history demonstrates its benefits for reduction of NPP personnel radiation exposure and combating construction materials corrosion.

  1. Innovative uses for zinc in dermatology.

    PubMed

    Bae, Yoon Soo; Hill, Nikki D; Bibi, Yuval; Dreiher, Jacob; Cohen, Arnon D

    2010-07-01

    Severe zinc deficiency states, such as acrodermatitis enteropathica, are associated with a variety of skin manifestations, such as perioral, acral, and perineal dermatitis. These syndromes can be reversed with systemic zinc repletion. In addition to skin pathologies that are clearly zinc-dependent, many dermatologic conditions (eg, dandruff, acne, and diaper rash) have been associated and treated with zinc. Success rates for treatment with zinc vary greatly depending on the disease, mode of administration, and precise zinc preparation used. With the exception of systemic zinc deficiency states, there is little evidence that convincingly demonstrates the efficacy of zinc as a reliable first-line treatment for most dermatologic conditions. However, zinc may be considered as an adjunctive treatment modality. Further research is needed to establish the indications for zinc treatment in dermatology, optimal mode of zinc delivery, and best type of zinc compound to be used. PMID:20510767

  2. Application of zinc oxide quantum dots in food safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Zinc oxide quantum dots (ZnO QDs) are nanoparticles of purified powdered ZnO. The ZnO QDs were directly added into liquid foods or coated on the surface of glass jars using polylactic acid (PLA) as a carrier. The antimicrobial activities of ZnO QDs against Listeria monocytogenes, Salmonella Enteriti...

  3. In vitro bioavailability of iron from spinach (Spinacea oleracea) cultivated in soil fortified with graded levels of iron and zinc.

    PubMed

    Reddy, N S; Sondge, C V; Khan, T N

    1993-11-01

    A pot-culture experiment was conducted to assess the bioavailability of iron from spinach cultivated in soil fortified with graded levels of iron and zinc (FeSO4 x 7H2(0) and ZnSO4 x 7H2(0), respectively). Applications of varying levels of iron to soil increased the total iron and phosphorus contents and decreased the zinc content (P < 0.05). The effect of applying varying levels of zinc was the opposite of on the minerals in spinach. The ascorbic acid content was remarkably reduced with varying levels of iron and zinc. Higher levels of zinc and lower levels of iron in the soil increased the bioavailability of iron from spinach (P < 0.05). In conclusion, the interactions of 15 ppm zinc with 30 ppm iron significantly enhanced the bioavailability of iron, total iron and zinc contents.

  4. Comparative effects of zinc-nano complexes, zinc-sulphate and zinc-methionine on performance in broiler chickens.

    PubMed

    Mohammadi, V; Ghazanfari, S; Mohammadi-Sangcheshmeh, A; Nazaran, M H

    2015-01-01

    Micronutrients, especially zinc, have an important role in normal metabolism and growth of broilers. Using novel technologies helps to synthesise novel zinc complexes to deliver this micronutrient more efficiently. In the present study, the effects of different zinc complexes and nano complexes on broiler performance were compared. Broilers in 6 groups were given basal diet (without zinc) and basal diet supplemented with zinc-sulphate, zinc-methionine, zinc-nano-sulphate, zinc-nano-methionine and zinc-nano-max (that was synthesised based on nanochelating technology) at a concentration of 80 mg/kg of diet. At 1-42 d of age, dietary zinc-nano-sulphate supplementation decreased weight gain and feed intake. However, feed conversion ratio was not influenced by treatments. Carcass yield (%) of birds in the zinc-nano-sulphate and control groups were dramatically reduced at 42 d of age and abdominal fat (%) increased in these groups. Relative to the control group, the antibody titre, spleen and bursa of Fabricius (%) were significantly higher in groups supplemented with zinc. Heterophil (%) was also significantly higher in the zinc-nano-methionine group in blood on d 42 compared to the control, zinc-sulphate and zinc-nano-sulphate. Compared to the controls, the mean malondialdehyde content in thigh tissue was significantly reduced in groups supplemented with zinc at the time 0, 50, 100 and 150 min after oxidation. Tibia zinc concentration in nanoparticle zinc samples was significantly higher relative to the control and zinc-sulphate groups. Taken together, our data indicate that delivery of zinc in the structure of zinc-nano-methionine and zinc-nano-max at concentrations of 80 mg/kg of diet improves growth performance. However, dietary zinc-nano-sulphate decreased growth performance in broilers.

  5. Uptake and partitioning of zinc in Lemnaceae.

    PubMed

    Lahive, Elma; O'Callaghan, Michael J A; Jansen, Marcel A K; O'Halloran, John

    2011-11-01

    Macrophytes provide food and shelter for aquatic invertebrates and fish, while also acting as reservoirs for nutrients and trace elements. Zinc accumulation has been reported for various Lemnaceae species. However, comparative accumulation across species and the link between zinc accumulation and toxicity are poorly understood. Morphological distribution and cellular storage, in either bound or soluble form, are important for zinc tolerance. This study shows differences in the uptake and accumulation of zinc by three duckweed species. Landoltia punctata and Lemna minor generally accumulated more zinc than Lemna gibba. L. minor, but not L. gibba or L. punctata, accumulated greater concentrations of zinc in roots compared to fronds when exposed to high levels of zinc. The proportion of zinc stored in the bound form relative to the soluble-form was higher in L. minor. L. punctata accumulated greater concentrations of zinc in fronds compared to roots and increased the proportion of zinc it stored in the soluble form, when exposed to high zinc levels. L. gibba is the only species that significantly accumulated zinc at low concentrations, and was zinc-sensitive. Overall, internal zinc concentrations showed no consistent correlation with toxic effect. We conclude that relationships between zinc toxicity and uptake and accumulation are species specific reflecting, among others, zinc distribution and storage. Differences in zinc distribution and storage are also likely to have implications for zinc bioavailability and trophic mobility. PMID:21755349

  6. Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

    PubMed

    Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

    2016-04-25

    Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process. PMID:27030646

  7. Zinc(II) in saliva: determination of concentrations produced by different formulations of zinc gluconate lozenges containing common excipients.

    PubMed

    Zarembo, J E; Godfrey, J C; Godfrey, N J

    1992-02-01

    A study of the pH of saliva produced by humans sucking hard candy lozenges containing zinc gluconate and citric acid demonstrated the probability that the formulation delivered an insignificant amount of the contained zinc as Zn2+. This could account for the negative results of several clinical studies of this lozenge and similar formulations as treatment for the common cold. Direct measurement of unbound Zn2+ in saliva from this and other zinc gluconate formulations was required to substantiate the inference from the pH study. A specific-ion-electrode assay method was developed. Using this method, it was found that saliva completely suppresses the ionization of zinc to free Zn2+ in the presence of citric acid or a 30-fold molar excess of mannitol plus sorbitol. Under the same conditions, however, the presence of an excess of glycine does not interfere with ionization to produce Zn2+. This finding supports the hypothesis that the positive clinical results of three studies were due to the use of formulations which release ionic zinc.

  8. Dietary zinc deficiency effects dorso-lateral and ventral prostate of Wistar rats: histological, biochemical and trace element study.

    PubMed

    Joshi, Sangeeta; Nair, Neena; Bedwal, R S

    2014-10-01

    Zinc deficiency has become a global problem affecting the developed and developing countries due to inhibitors in the diet which prevents its absorption or due to a very low concentration of bioavailable zinc in the diet. Being present in high concentration in the prostate and having diverse biological function, we investigated the effects of dietary zinc deficiency for 2 and 4 weeks on dorso-lateral and ventral prostate. Sixty prepubertal rats were divided into three groups: zinc control (ZC), pair fed (PF) and zinc deficient (ZD) and fed on 100 μg/g (zinc control and pair fed groups) and 1 μg/g (zinc deficient) diet. Zinc deficiency was associated with degenerative changes in dorso-lateral and ventral prostate as made evident by karyolysis, karyorhexis, cytoplasmolysis, loss of cellularisation, decreased intraluminar secretion and degeneration of fibromuscular stroma. In response, protein carbonyl, nitric oxide, acid phosphatase, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase increased, exhibiting variable level of significance. Total protein and total zinc concentration in dorso-lateral and ventral prostate as well as in serum decreased (P < 0.001). Decrease (P < 0.001) was recorded in serum FSH and testosterone after 2 and 4 weeks of zinc deficiency. The changes were more prominent after 4 weeks of synthetic zinc deficient diet. The results indicate that zinc deficiency during prepubertal period affects the prostate structure, total protein concentration, enhanced protein carbonyl concentration, nitric oxide as well as acid phosphatase activities and impaired hydroxysteroid dehydrogenase activities. Evidently these changes could be attributed to dysfunction of dorso-lateral and ventral prostate after dietary zinc deficiency as well as impairment of metabolic and secretory activity, reduced gonadotropin levels by hypothalamus -hypophysial system which is indicative of a critical role of zinc in maintaining the prostate integrity. PMID

  9. [The role of zinc in the treatment of hyperactivity disorder in children].

    PubMed

    Dodig-Curković, Katarina; Dovhanj, Jasna; Curković, Mario; Dodig-Radić, Josipa; Degmecić, Dunja

    2009-10-01

    Zinc is an essential cofactor of more than 100 enzymes, including metalloenzymes and metalloenzyme complexes, which are necessary in the metabolism of carbohydrates, fatty acids, proteins and nucleic acids. It is an important factor in the metabolism of neurotransmitters, prostaglandins, and for maintaining brain structure and function. Dopamine is one of the most important factors in the pathophysiology of hyperactivity disorder, and the hormone melatonin has an important role in the regulation of dopamine. Because zinc is necessary in the metabolism of melatonin, it can be assumed that zinc is a very important factor in the treatment of attention deficit and hyperactivity disorder (ADHD). It is known that deficit of some minerals and vitamins is connected with hyperkinetic disorder. Preliminary investigations in humans show that many children with ADHD have lower zinc concentration in relation to healthy children. Zinc sulfate as an adjunct to methylphenidate has favorable effects in the treatment of ADHD children, pointing to the possible association of zinc deficit and ADHD pathophysiology. Zinc concentration can only point to some other factors (malnutrition) that can lead to ADHD, but is not a factor that has a causative role in ADHD. Therefore, zinc supplementation to nutrition or to ADHD therapy may be of great benefit in ADHD children with zinc deficit or low plasma zinc concentration. ADHD occurs in different cultures, mostly before seven years of age. In children younger than five years it is difficult to make an accurate diagnosis because their behavior is more variable than in older children. Hyperactive disorder is mostly observed in younger age, i.e. in childhood and adolescence. The majority of the main characteristics are less pronounced or completely lost in adult age. In the 1960s, the disorder was named "minimal cerebral dysfunction" and was most often the consequence of head trauma or low birth weight. Later, the term was changed as hyperactive

  10. [The role of zinc in the treatment of hyperactivity disorder in children].

    PubMed

    Dodig-Curković, Katarina; Dovhanj, Jasna; Curković, Mario; Dodig-Radić, Josipa; Degmecić, Dunja

    2009-10-01

    Zinc is an essential cofactor of more than 100 enzymes, including metalloenzymes and metalloenzyme complexes, which are necessary in the metabolism of carbohydrates, fatty acids, proteins and nucleic acids. It is an important factor in the metabolism of neurotransmitters, prostaglandins, and for maintaining brain structure and function. Dopamine is one of the most important factors in the pathophysiology of hyperactivity disorder, and the hormone melatonin has an important role in the regulation of dopamine. Because zinc is necessary in the metabolism of melatonin, it can be assumed that zinc is a very important factor in the treatment of attention deficit and hyperactivity disorder (ADHD). It is known that deficit of some minerals and vitamins is connected with hyperkinetic disorder. Preliminary investigations in humans show that many children with ADHD have lower zinc concentration in relation to healthy children. Zinc sulfate as an adjunct to methylphenidate has favorable effects in the treatment of ADHD children, pointing to the possible association of zinc deficit and ADHD pathophysiology. Zinc concentration can only point to some other factors (malnutrition) that can lead to ADHD, but is not a factor that has a causative role in ADHD. Therefore, zinc supplementation to nutrition or to ADHD therapy may be of great benefit in ADHD children with zinc deficit or low plasma zinc concentration. ADHD occurs in different cultures, mostly before seven years of age. In children younger than five years it is difficult to make an accurate diagnosis because their behavior is more variable than in older children. Hyperactive disorder is mostly observed in younger age, i.e. in childhood and adolescence. The majority of the main characteristics are less pronounced or completely lost in adult age. In the 1960s, the disorder was named "minimal cerebral dysfunction" and was most often the consequence of head trauma or low birth weight. Later, the term was changed as hyperactive

  11. 40 CFR 721.10326 - 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2... 2-Propenoic acid, 2-methyl-, methyl ester, polymer with butyl 2-propenoate, ethyl 2-propenoate, zinc 2-methyl-2-propenoate (1:2) and zinc 2-propenoate (1:2), 2,2'-(1,2-diazenediyl)bis - and...

  12. Arsenic doped zinc oxide

    SciTech Connect

    Volbers, N.; Lautenschlaeger, S.; Leichtweiss, T.; Laufer, A.; Graubner, S.; Meyer, B. K.; Potzger, K.; Zhou Shengqiang

    2008-06-15

    As-doping of zinc oxide has been approached by ion implantation and chemical vapor deposition. The effect of thermal annealing on the implanted samples has been investigated by using secondary ion mass spectrometry and Rutherford backscattering/channeling geometry. The crystal damage, the distribution of the arsenic, the diffusion of impurities, and the formation of secondary phases is discussed. For the thin films grown by vapor deposition, the composition has been determined with regard to the growth parameters. The bonding state of arsenic was investigated for both series of samples using x-ray photoelectron spectroscopy.

  13. Zinc Oxide Nanophotonics

    NASA Astrophysics Data System (ADS)

    Choi, Sumin; Aharonovich, Igor

    2015-12-01

    The emerging field of nanophotonics initiated a dedicated study of single photon sources and optical resonators in new class of materials. One such material is zinc oxide (ZnO) that has been long considered only for classical light-emitting applications. However, it recently showed promise for quantum photonics technologies. In this review, we highlight the recent advances in studying single emitters in ZnO, engineering of optical cavities and practical nanophotonics devices including nanolasers and electrically triggered devices. We finalize with an outlook at this promising area, as well as provide perspectives and open questions in solid state nanophotonics employing ZnO.

  14. Associations among dietary zinc intakes and biomarkers of zinc status before and after a zinc supplementation program in Guatemalan schoolchildren

    PubMed Central

    Bui, Vinh Q.; Marcinkevage, Jessica; Ramakrishnan, Usha; Flores-Ayala, Rafael C.; Ramirez-Zea, Manuel; Villalpando, Salvador; Martorell, Reynaldo; DiGirolamo, Ann M.; Stein, Aryeh D.

    2015-01-01

    Background The associations among dietary zinc intakes and biomarkers of zinc status are unknown in apparently healthy children at high risk for zinc deficiency. Objective To assess associations among zinc-related parameters in a sample of Guatemalan school-aged children. Methods We assessed total dietary intakes and biomarkers of zinc status before and after receiving 6 months of zinc supplementation or placebo in 691 Guatemalan schoolchildren aged 6 to 11 years. Most of the children also received zinc-fortified milk from a government program that started shortly after the trial began. We assessed associations between zinc intakes and serum zinc, alkaline phosphatase (ALP), and albumin. Results At baseline, the prevalence of serum zinc < 65 μg/dL and dietary zinc intake below Estimated Average Requirements (EAR) (< 4 and < 7 mg/day for children < 9 and ≥ 9 years, respectively) were 21.6% and 39.4%, respectively. Pearson correlations between serum zinc concentration and dietary zinc intake, serum ALP, and serum albumin were r = 0.07, 0.15, and 0.07, respectively. At the 6-month follow-up, low serum zinc and low total (diet plus fortified milk) zinc intakes were observed in 1.2% and 0.0% of children in the zinc-supplemented group and 4.0% and 34.1% in the placebo group, respectively. Pearson correlations between serum zinc concentration and total zinc intake, serum ALP, and serum albumin were 0.10, 0.06, and −0.11 in the zinc-supplemented group and −0.04, 0.05, and 0.01 in the placebo group, respectively. Conclusions Zinc intake was inconsistently associated with markers of serum zinc concentration. Zinc fortification or supplementation attenuated the associations. PMID:23964387

  15. Health risks following ingestion of mercury and zinc air batteries.

    PubMed

    Nolan, M; Tucker, I

    1981-01-01

    This paper reports on a study set up to assess the corrosive behaviour of mercury and zinc air batteries in the gastric juice environment of the stomach. The results show a relatively rapid rate of corrosion for charged mercury batteries. In contrast, the zinc air battery showed no visible corrosion under the same conditions. In view of the toxic dangers from leakage of mercury batteries, it is recommended that steps be taken to ensure that such batteries do not remain in the acidic environment of the stomach, should ingestion occur. PMID:7302525

  16. Spouted bed electrowinning of zinc: Part I. Laboratory-scale electrowinning experiments

    NASA Astrophysics Data System (ADS)

    Salas-Morales, Juan Carlos; Evans, J. W.; Newman, O. M. G.; Adcock, P. A.

    1997-02-01

    Two types of laboratory cells have been constructed to electrowin zinc from sulfate electrolytes: one cell was cylindrical while the other had a rectangular (flat) geometry. Cells were operated on industrial or synthetic electrolytes to electrodeposit zinc onto a spouted bed of zinc particles in the range of 0.75 to 1.45 mm. Current efficiencies and cell voltages have been measured during the course of batch experiments, enabling the calculation of the energy consumption per kilogram of zinc deposited. Electrolyte samples have been analyzed. Current densities (current per unit of cell cross-sectional area) were in the range of 1380 to 6200 A/m2. Most catholytes were initially neutral and contained on the order of 150 g/L of zinc. Final acid contents were in the range of 39 to 114 g/L of sulfuric acid. The performance of the cells (particularly with respect to current efficiency) was superior to prior work on fluidized bed electrowinning from similar electrolytes. The flat cell was superior to the cylindrical cell and showed energy consumptions of less than 3 kWh/kg zinc at current densities up to 3500 A/m2 when used to take the zinc content from 150 to 100 g/L zinc. Current efficiencies in this application ranged from 91 to 92 pct.

  17. Zinc gluconate and the common cold. Review of randomized controlled trials.

    PubMed Central

    Marshall, S.

    1998-01-01

    OBJECTIVE: To examine the evidence of seven randomized controlled trials (RCT) on the therapeutic effectiveness of zinc gluconate lozenges for treating the common cold. DATA SOURCES: Using the MeSH headings common cold and zinc gluconate, MEDLINE was searched from 1966 on for all published RCTs evaluating use of zinc gluconate for treating the common cold. STUDY SELECTION: For this study, only double-blind RCTs were included. SYNTHESIS: Fair evidence suggests that zinc gluconate lozenges have a therapeutic effect in treating the common cold. Starting therapy with zinc gluconate lozenges within 24 to 48 hours of onset of cold symptoms reduces the duration and severity of the cold. Patients must suck lozenges every 2 hours while awake during the cold. Minimum effective dose appears to be 13.3 mg of elemental zinc per lozenge. Evidence suggests that compounds such as citric acid, sorbitol, and mannitol bind the free zinc ion in the mouth, and this could account for variations in therapeutic benefit. Bad taste and nausea are important side effects of zinc lozenges. CONCLUSION: Evidence supports use of zinc gluconate lozenges for reducing the symptoms and duration of the common cold, but the side effects, bad taste, and therapeutic protocol might limit patient compliance. PMID:9612589

  18. Quantitative separation of zinc traces from cadmium matrices by solid-phase extraction with polyurethane foam.

    PubMed

    Santiago de Jesus, D; Souza de Carvalho, M; Spínola Costa, A C; Costa Ferreira, S L

    1998-08-01

    A system for separation of zinc traces from large amounts of cadmium is proposed in this paper. It is based on the solid-phase extraction of the zinc in the form of thiocyanate complexes by the polyurethane foam. The following parameters were studied: effect of pH and of the thiocyanate concentration on the zinc extraction, shaking time required for quantitative extraction, amount of PU foam necessary for complete extraction, conditions for the separation of zinc from cadmium, influence of other cations and anions on the zinc sorption by PU foam, and required conditions for back extraction of zinc from the PU foam. The results show that zinc traces can be separated from large amounts of cadmium at pH 3.0+/-0.50, with the range of thiocyanate concentration from 0.15 to 0.20 mol l(-1), and the shaking time of 5 min. The back extraction of zinc can be done by shaking it with water for 10 min. Calcium, barium, strontium, magnesium, aluminum, nickel and iron(II) are efficiently separated. Iron(III), copper(II) and cobalt(II) are extracted simultaneously with zinc, but the iron reduction with ascorbic acid and the use of citrate to mask copper(II) and cobalt(II) increase the selectivity of the zinc extraction. The anions nitrate, chloride, sulfate, acetate, thiosulphate, tartarate, oxalate, fluoride, citrate, and carbonate do not affect the zinc extraction. Phosphate and EDTA must be absent. The method proposed was applied to determine zinc in cadmium salts using 4-(2-pyridylazo)-resorcinol (PAR) as a spectrophotometric reagent. The result achieved did not show significant difference in the accuracy and precision (95% confidence level) with those obtained by ICP-AES analysis. PMID:18967283

  19. The effect of zinc supplementation on the effects of lead on the rat testis.

    PubMed

    Batra, N; Nehru, B; Bansal, M P

    1998-01-01

    With increasing concerns about environmental pollution, the interaction of micronutrients with toxic metals is of great interest. The present study was designed to investigate testicular effects of lead following concomitant administration of zinc. Lead was administered orally as lead acetate (50 mg/kg b.w.) daily for 3 months to male Portan rats with or without zinc (1 mg/kg b.w. as zinc sulphate). The control group was given the same volume of distilled water. Endpoints included lead concentration in various body organs as well as in the reproductive system, including testicular subfractions; the testicular enzymes superoxide dismutase (SOD) and catalase; the marker enzyme delta-aminolevulinic acid dehydratase (delta-ALAD); and testicular histoarchitecture. The concentrations of lead in bone, kidney, prostate, testis, liver, epididymis, spleen, seminal vesicles, and blood were significantly higher in lead-treated rats. Lead deposition was reduced in animals that received supplemental zinc. There was a 30% reduction in lead deposition in the testis when zinc was coadministered. At the subcellular level, there was differential accumulation of lead; the nucleus preferentially took up the metal after lead treatment alone, while zinc coadministration shifted lead accumulation to the mitochondria. A significant decrease in delta-ALAD and in SOD activity was seen in the testis with lead treatment. Coadministration of zinc prevented these decreases, at least partially. Zinc coadministration did not prevent the inhibition of catalase observed with lead treatment. Histologically, the alterations in the testis with lead treatment alone were more pronounced compared to animals in which zinc was supplemented. Improvement in the inhibition of delta-ALAD and in the ubiquitous cellular enzyme SOD suggests less testicular tissue damage due to detoxification of free radicals. In conclusion, zinc supplementation ameliorates lead-induced testicular damage both at the cellular and

  20. The effect of zinc supplementation on the effects of lead on the rat testis.

    PubMed

    Batra, N; Nehru, B; Bansal, M P

    1998-01-01

    With increasing concerns about environmental pollution, the interaction of micronutrients with toxic metals is of great interest. The present study was designed to investigate testicular effects of lead following concomitant administration of zinc. Lead was administered orally as lead acetate (50 mg/kg b.w.) daily for 3 months to male Portan rats with or without zinc (1 mg/kg b.w. as zinc sulphate). The control group was given the same volume of distilled water. Endpoints included lead concentration in various body organs as well as in the reproductive system, including testicular subfractions; the testicular enzymes superoxide dismutase (SOD) and catalase; the marker enzyme delta-aminolevulinic acid dehydratase (delta-ALAD); and testicular histoarchitecture. The concentrations of lead in bone, kidney, prostate, testis, liver, epididymis, spleen, seminal vesicles, and blood were significantly higher in lead-treated rats. Lead deposition was reduced in animals that received supplemental zinc. There was a 30% reduction in lead deposition in the testis when zinc was coadministered. At the subcellular level, there was differential accumulation of lead; the nucleus preferentially took up the metal after lead treatment alone, while zinc coadministration shifted lead accumulation to the mitochondria. A significant decrease in delta-ALAD and in SOD activity was seen in the testis with lead treatment. Coadministration of zinc prevented these decreases, at least partially. Zinc coadministration did not prevent the inhibition of catalase observed with lead treatment. Histologically, the alterations in the testis with lead treatment alone were more pronounced compared to animals in which zinc was supplemented. Improvement in the inhibition of delta-ALAD and in the ubiquitous cellular enzyme SOD suggests less testicular tissue damage due to detoxification of free radicals. In conclusion, zinc supplementation ameliorates lead-induced testicular damage both at the cellular and

  1. Zinc flexes its muscle: Correcting a novel analysis of calcium for zinc interference uncovers a method to measure zinc.

    PubMed

    Qian, Cheng; Colvin, Robert A

    2016-01-01

    The divalent cation chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), often used to buffer physiological changes in cytosolic Ca(2+), also binds Zn(2+) with high affinity. In a recently published method (Lamboley et al. 2015. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201411250), the absorbance shift of BAPTA at 292 nm was successfully used to determine the total calcium concentrations of various skeletal muscle tissues. In the present study, we show that endogenous Zn(2+) in rat skeletal muscle tissue can be unknowingly measured as "Ca(2+)," unless appropriate measures are taken to eliminate Zn(2+) interference. We analyzed two rat skeletal muscle tissues, soleus and plantaris, for total calcium and zinc using either inductively coupled plasma mass spectrometry (ICP-MS) or the BAPTA method described above. ICP-MS analysis showed that total zinc contents in soleus and plantaris were large enough to affect the determination of total calcium by the BAPTA method (calcium = 1.72 ± 0.31 and 1.96 ± 0.14, and zinc = 0.528 ± 0.04 and 0.192 ± 0.01; mean ± standard error of the mean [SEM]; n = 5; mmole/kg, respectively). We next analyzed total calcium using BAPTA but included the Zn(2+)-specific chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) that buffers Zn(2+) without affecting Ca(2+)/BAPTA binding. We found that estimated concentrations of total calcium ([CaT]WM) in soleus and plantaris were reduced after TPEN addition ([CaT]WM = 3.71 ± 0.62 and 3.57 ± 0.64 without TPEN and 3.39 ± 0.64 and 3.42 ± 0.62 with TPEN; mean ± SEM; n = 3; mmole/kg, respectively). Thus, we show that a straightforward correction can be applied to the BAPTA method to improve the accuracy of the determination of total calcium that should be applicable to most any tissue studied. In addition, we show that using TPEN in combination with the BAPTA method allows one to make reasonable estimates of total zinc concentration that are in agreement

  2. Zinc flexes its muscle: Correcting a novel analysis of calcium for zinc interference uncovers a method to measure zinc.

    PubMed

    Qian, Cheng; Colvin, Robert A

    2016-01-01

    The divalent cation chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), often used to buffer physiological changes in cytosolic Ca(2+), also binds Zn(2+) with high affinity. In a recently published method (Lamboley et al. 2015. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201411250), the absorbance shift of BAPTA at 292 nm was successfully used to determine the total calcium concentrations of various skeletal muscle tissues. In the present study, we show that endogenous Zn(2+) in rat skeletal muscle tissue can be unknowingly measured as "Ca(2+)," unless appropriate measures are taken to eliminate Zn(2+) interference. We analyzed two rat skeletal muscle tissues, soleus and plantaris, for total calcium and zinc using either inductively coupled plasma mass spectrometry (ICP-MS) or the BAPTA method described above. ICP-MS analysis showed that total zinc contents in soleus and plantaris were large enough to affect the determination of total calcium by the BAPTA method (calcium = 1.72 ± 0.31 and 1.96 ± 0.14, and zinc = 0.528 ± 0.04 and 0.192 ± 0.01; mean ± standard error of the mean [SEM]; n = 5; mmole/kg, respectively). We next analyzed total calcium using BAPTA but included the Zn(2+)-specific chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) that buffers Zn(2+) without affecting Ca(2+)/BAPTA binding. We found that estimated concentrations of total calcium ([CaT]WM) in soleus and plantaris were reduced after TPEN addition ([CaT]WM = 3.71 ± 0.62 and 3.57 ± 0.64 without TPEN and 3.39 ± 0.64 and 3.42 ± 0.62 with TPEN; mean ± SEM; n = 3; mmole/kg, respectively). Thus, we show that a straightforward correction can be applied to the BAPTA method to improve the accuracy of the determination of total calcium that should be applicable to most any tissue studied. In addition, we show that using TPEN in combination with the BAPTA method allows one to make reasonable estimates of total zinc concentration that are in agreement

  3. Zinc flexes its muscle: Correcting a novel analysis of calcium for zinc interference uncovers a method to measure zinc

    PubMed Central

    Qian, Cheng

    2016-01-01

    The divalent cation chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), often used to buffer physiological changes in cytosolic Ca2+, also binds Zn2+ with high affinity. In a recently published method (Lamboley et al. 2015. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201411250), the absorbance shift of BAPTA at 292 nm was successfully used to determine the total calcium concentrations of various skeletal muscle tissues. In the present study, we show that endogenous Zn2+ in rat skeletal muscle tissue can be unknowingly measured as “Ca2+,” unless appropriate measures are taken to eliminate Zn2+ interference. We analyzed two rat skeletal muscle tissues, soleus and plantaris, for total calcium and zinc using either inductively coupled plasma mass spectrometry (ICP-MS) or the BAPTA method described above. ICP-MS analysis showed that total zinc contents in soleus and plantaris were large enough to affect the determination of total calcium by the BAPTA method (calcium = 1.72 ± 0.31 and 1.96 ± 0.14, and zinc = 0.528 ± 0.04 and 0.192 ± 0.01; mean ± standard error of the mean [SEM]; n = 5; mmole/kg, respectively). We next analyzed total calcium using BAPTA but included the Zn2+-specific chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) that buffers Zn2+ without affecting Ca2+/BAPTA binding. We found that estimated concentrations of total calcium ([CaT]WM) in soleus and plantaris were reduced after TPEN addition ([CaT]WM = 3.71 ± 0.62 and 3.57 ± 0.64 without TPEN and 3.39 ± 0.64 and 3.42 ± 0.62 with TPEN; mean ± SEM; n = 3; mmole/kg, respectively). Thus, we show that a straightforward correction can be applied to the BAPTA method to improve the accuracy of the determination of total calcium that should be applicable to most any tissue studied. In addition, we show that using TPEN in combination with the BAPTA method allows one to make reasonable estimates of total zinc concentration that are in agreement with

  4. The behavior of thiourea and flotation reagents in zinc electrowinning circuits

    NASA Astrophysics Data System (ADS)

    MacKinnon, D. J.; Dutrizac, J. E.; Brannen, J. M.; Hardy, D. J.

    1988-04-01

    The effect of thiourea and flotation reagents on the electrowinning of zinc from industrial electrolytes was studied, and all the compounds were found to reduce the zinc deposition current efficiency and to change the properties of the zinc deposits. The effectiveness of activated carbon, two-stage cementation, and hot acid leaching on the destruction/removal of the organic compounds also was addressed. Activated carbon pretreatment of thiourea-containing electrolytes restored the current efficiency for 1-hour zinc deposits to values comparable to those obtained for thiourea-free electrolytes. The activated carbon pretreatment, however, altered the deposit morphology and orientation, but produced a cyclic voltammogram similar to that of the thiourea-free solution. Two-stage cementation did not counteract the harmful effects of thiourea. Hot acid leaching destroyed the thiourea but generated large concentrations of ferrous ion that reduced the current efficiency. The ferrous concentrations, however, were readily controlled by KMnO4 or MnO2 oxidation. None of the treatment options (activated carbon, two-stage cementation, or hot acid leaching) was effective in controlling the flotation reagents, and their moderately harmful effect on zinc electrowinning persisted. Even low concentrations of these reagents polarized zinc deposition, and this resulted in a “glue-type” zinc deposit.

  5. The effects of zinc sulphate on hypercholesterolaemia induced by cholesterol-choleate in rats.

    PubMed

    Cho, C H; Chen, S M; Ogle, C W

    1985-05-01

    The effects of zinc sulphate on cholesterol-choleate-induced hypercholesterolaemia were studied in rats. Zinc sulphate (20 or 40 mg/kg, p.o. once daily for 5 days) administration, which raised serum zinc levels, significantly increased bile acid secretion and lowered high-density lipoprotein-cholesterol (HDL-C) levels in the serum. Cholesterol-choleate, given by the same route and schedule, markedly elevated serum total cholesterol level, but decreased serum HDL-C concentration. Bile acid in serum and in bile was also increased, but these changes were inhibited by zinc sulphate pretreatment. Zinc sulphate also worsened the decrease in HDL-C and slightly prolonged the elevation in total cholesterol produced by cholesterol-choleate administration. It is concluded that the moderate increase in serum total cholesterol level by zinc sulphate could be due to inhibition of hepatic metabolism of cholesterol to bile acid. The specific action of zinc ions on HDL-C metabolism is discussed.

  6. 76 FR 51992 - Determination That PENTETATE ZINC TRISODIUM (Zinc Trisodium Diethylenetriaminepentaacetate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-19

    ... HUMAN SERVICES Food and Drug Administration Determination That PENTETATE ZINC TRISODIUM (Zinc Trisodium... Administration (FDA) has determined that PENTETATE ZINC TRISODIUM (zinc trisodium diethylenetriaminepentaacetate... PENTETATE ZINC TRISODIUM (Zn-DTPA) solution for intravenous or inhalation administration (EQ 1 g base/5...

  7. 21 CFR 522.2690 - Zinc gluconate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Zinc gluconate. 522.2690 Section 522.2690 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.2690 Zinc gluconate. (a) Specifications. Each milliliter of solution contains 13.1 milligrams zinc as zinc...

  8. 21 CFR 522.2690 - Zinc gluconate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Zinc gluconate. 522.2690 Section 522.2690 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.2690 Zinc gluconate. (a) Specifications. Each milliliter of solution contains 13.1 milligrams zinc as zinc...

  9. 21 CFR 522.2690 - Zinc gluconate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Zinc gluconate. 522.2690 Section 522.2690 Food and..., FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.2690 Zinc gluconate. (a) Specifications. Each milliliter of solution contains 13.1 milligrams zinc as zinc...

  10. Regeneration of zinc chloride hydrocracking catalyst

    DOEpatents

    Zielke, Clyde W.

    1979-01-01

    Improved rate of recovery of zinc values from the solids which are carried over by the effluent vapors from the oxidative vapor phase regeneration of spent zinc chloride catalyst is achieved by treatment of the solids with both hydrogen chloride and calcium chloride to selectively and rapidly recover the zinc values as zinc chloride.

  11. Zinc Bells Rang in Jerusalem!

    PubMed Central

    Hershfinkel, Michal; Aizenman, Elias; Andrews, Glen; Sekler, Israel

    2010-01-01

    “Oh, Jerusalem of gold, and of light, and of bronze…” goes the popular song. But it was another metal that towered above the Jerusalem landscape during the meeting of the International Society for Zinc Biology (ISZB; http://www.iszb.org/), held at Mishkenot Sha’ananim, a whisper away from the Old City walls. More than 100 scientists gathered on 1 to 5 December 2009 to discuss their research on the biology of this metal. Zinc is a double-edged sword. Zinc supplementation accelerates wound healing and growth and promotes an effective immune response. On the other hand, zinc deficiency leads to growth retardation and impaired learning and memory function, and has been linked to mood disorders. At the cellular level, however, uncontrolled increases in zinc concentrations can lead to neuronal cell death and may be involved in neurodegenerative disorders. Through regulation of various intracellular signaling pathways, zinc can accelerate cell growth and possibly contribute to cancer. However, despite the physiological and clinical importance of this metal, research on the molecular basis of these effects is still in its infancy. The 2009 ISZB meeting provided a venue for investigators working on various zinc-related issues to share their thoughts and ideas and to promote the growth of this field. PMID:20606213

  12. Full size zinc-air battery

    SciTech Connect

    Goldstein, J.R.; Koretz, B.

    1993-11-01

    The Electric Fuel zinc-air battery yielded energy densities from 6.8 to 10.2 times higher than those of the lead-acid batteries. The higher the power and the more difficult the driving cycle, the higher this ratio of energy densities grew. Not only was the Electric Fuel battery capable of extended high-power discharge, the impact of such discharge conditions on energy and driving range was show to be quite small, and was much smaller than the comparable impact on lead-acid traction batteries. At the time of writing this paper, tests are scheduled to continue with the 110-kWh battery in the Mercedes van, and preliminary plans have been made for testing of additional batteries on other vehicle types.

  13. Zinc transporter 7 deficiency affects lipid synthesis in adipocytes by inhibiting insulin-dependent Akt activity and glucose uptake

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mice deficient for zinc transporter 7 (Znt7) are mildly zinc deficient, accompanied with low body weight gain and body fat accumulation. To investigate the underlying mechanism of Znt7 deficiency in body adiposity, we investigated fatty acid composition and insulin sensitivity in visceral (epididyma...

  14. Zinc Finger Takes on a Whole New Meaning: Reducing and Monitoring Zinc Blanks in the Isotope Lab

    NASA Astrophysics Data System (ADS)

    Wilkes, E. B.; Wasylenki, L. E.; Anbar, A. D.

    2010-12-01

    In terms of avoiding contamination, zinc is one of the most difficult elements to study isotopically. The reason for this is that zinc stearate is a very common mold release agent in the production of plastics, including those most often used in isotope geochemistry clean labs. While polyethylene bottles, polypropylene centrifuge tubes, pipette tips, and Kimwipes are all potential sources of contaminant zinc, by far the largest amount of zinc is introduced to the laboratory by gloves. Most items can be effectively rid of zinc by soaking in dilute hydrochloric acid, but gloves cannot be cleaned easily, and use of gloves can quickly lead to contamination on many surfaces throughout the lab. We recently conducted several experiments in which dissolved zinc was partly adsorbed onto synthetic Mn oxyhydroxide particles. The dissolved and adsorbed pools were separated by filtration, purified with ion exchange chemistry, and analyzed for isotope composition by MC-ICP-MS. We used a commercially purchased ICP standard solution both as our standard (delta66/64Zn = 0) and as the source of the zinc in the experiments. Whenever gloves were worn during purification, process blanks contained as much as 150 ng Zn, and both the dissolved and adsorbed pools of zinc came out enriched in heavy isotopes relative to the starting pool, contrary to our expectation of mass balance. When gloves were not worn, blanks were <10 ng, and, as expected, one pool of Zn was lighter and one heavier than the standard. Zinc leached from two different brands of vinyl gloves, including one brand recommended to us for being “low” in zinc, measured +10‰ relative to our standard. We therefore concluded that glove zinc contaminated most of our experimental samples. We were only able to see such clear evidence of contamination because (1) we were doing an experiment in which we expected one light and one heavy pool of zinc compared to our standard, and (2) we happened to use an ICP standard solution for

  15. Zinc - an indispensable micronutrient.

    PubMed

    Sharma, Ashish; Patni, Babita; Shankhdhar, Deepti; Shankhdhar, S C

    2013-01-01

    Availability of Zn to plant is hampered by its immobile nature and adverse soil conditions. Thus, Zn deficiency is observed even though high amount is available in soil. Root-shoot barrier, a major controller of zinc transport in plant is highly affected by changes in the anatomical structure of conducting tissue and adverse soil conditions like pH, clay content, calcium carbonate content, etc. Zn deficiency results in severe yield losses and in acute cases plant death. Zn deficiency in edible plant parts results in micronutrient malnutrition leading to stunted growth and improper sexual development in humans. To overcome this problem several strategies have been used to enrich Zn availability in edible plant parts, including nutrient management, biotechnological tools, and classical and molecular breeding approaches. PMID:24381434

  16. Mineral resource of the month: zinc

    USGS Publications Warehouse

    Tolcin, Amy C.

    2009-01-01

    The article provides information on zinc, the fourth most-widely consumed metal. It traces the first use of zinc with the Romans' production of brass. It describes the presence of zinc in Earth's crust and the importance of sphalerite as a source of zinc and other some minor metal production. The production and consumption of zinc as well as the commercial and industrial uses of this metal are also discussed.

  17. The Endophytic Bacterium, Sphingomonas SaMR12, Improves the Potential for Zinc Phytoremediation by Its Host, Sedum alfredii

    PubMed Central

    Zhang, Xincheng; Pan, Fengshan; Yang, Xiaoe; Feng, Ying

    2014-01-01

    The endophytic bacterium, Sphingomonas SaMR12, isolated from Sedum alfredii Hance, appears to increase plant biomass and zinc-extraction from contaminated soil; however, the mechanism by which this occurs is not clear. Here, the ability of SaMR12 to promote zinc extraction and its effects on root morphology and exudation were examined in hydroponics. Zinc treatment increased shoot biomass by 30 to 45%, and by a further 10 to 19% when combined with SaMR12 inoculation. Zinc treatment also increased zinc accumulation modestly and this too was enhanced with SaMR12. Both biomass and zinc levels increased in a dose-dependent manner with significant effects seen at 50 µM zinc and apparent saturation at 500 µM. Zinc and the endophyte also increased levels of auxin but not at 50 µM and zinc increased levels of superoxide and hydrogen peroxide but mainly at 500 µM. As for root morphology, SaMR12 increased root branching, the number of root tips, and surface area. Zinc and SaMR12 also increased the exudation of oxalic acid. For most assays the effects of the endophyte and zinc were additive, with the notable exception of SaMR12 strongly reducing the production of reactive oxygen species at 500 µM zinc. Taken together, these results suggest that the promotion of growth and zinc uptake by exposure to zinc and to SaMR12 are independent of reactive oxygen and do not involve increases in auxin. PMID:25198772

  18. Studies of the Electronic Effects of Zinc Cluster Catalysts and Their Application to the Transesterification of β-Keto Esters.

    PubMed

    Agura, Kazushi; Hayashi, Yukiko; Wada, Mari; Nakatake, Daiki; Mashima, Kazushi; Ohshima, Takashi

    2016-05-20

    The electronic effects of tetranuclear zinc cluster catalysts on transesterification were investigated by changing the carboxylate ligands in the clusters. High catalyst activity crucially depended on the balance between Lewis acidity and Brønsted basicity of the catalyst; this was consistent with the dual activation of both the electrophile and nucleophile by the cooperative zinc centers. In addition, tetranuclear zinc cluster catalysts achieved the transesterification of β-keto esters with unprecedented levels of broad substrate generality, in which a newly developed pentafluoropropionate-bridged zinc cluster and 4-dimethylaminopyridine additive greatly improved the reactivity of sterically congested α- and α,α-disubstituted β-keto esters.

  19. Zinc tolerance and zinc removal ability of living and dried biomass of Desmodesmus communis.

    PubMed

    Novák, Zoltán; Jánószky, Mihály; B-Béres, Viktória; Nagy, Sándor Alex; Bácsi, István

    2014-12-01

    Effects of zinc on growth, cell morphology, oxidative stress, and zinc removal ability of the common phytoplankton species Desmodesmus communis were investigated at a concentration range of 0.25-160 mg L(-1) zinc. Cell densities and chlorophyll content decreased in treated cultures, changes in coenobia morphology and elevated lipid peroxidation levels appeared above 2.5 mg L(-1) zinc. The most effective zinc removal was observed at 5 mg L(-1) zinc concentration, while maximal amount of removed zinc appeared in 15 mg L(-1) zinc treated culture. Removed zinc is mainly bound on the cell surface. Dead biomass adsorbed more zinc than living biomass relative to unit of dry mass, but living biomass was more effective, relative to initial zinc content. This study comprehensively examines the zinc tolerance and removal ability of D. communis and demonstrates, in comparison with published literature, that these characteristics of different isolates of the same species can vary within a wide range. PMID:25193446

  20. Comparison of proteome response to saline and zinc stress in lettuce.

    PubMed

    Lucini, Luigi; Bernardo, Letizia

    2015-01-01

    Zinc salts occurring in soils can exert an osmotic stress toward plants. However, being zinc a heavy metal, some more specific effects on plant metabolisms can be forecast. In this work, lettuce has been used as a model to investigate salt and zinc stresses at proteome level through a shotgun tandem MS proteomic approach. The effect of zinc stress in lettuce, in comparison with NaCl stress, was evaluated to dissect between osmotic/oxidative stress related effects, from those changes specifically related to zinc. The analysis of proteins exhibiting a fold change of 3 as minimum (on log 2 normalized abundances), revealed the involvement of photosynthesis (via stimulation of chlorophyll synthesis and enhanced role of photosystem I) as well as stimulation of photophosphorylation. Increased glycolytic supply of energy substrates and ammonium assimilation [through formation of glutamine synthetase (GS)] were also induced by zinc in soil. Similarly, protein metabolism (at both transcriptional and ribosomal level), heat shock proteins, and proteolysis were affected. According to their biosynthetic enzymes, hormones appear to be altered by both the treatment and the time point considered: ethylene biosynthesis was enhanced, while production of abscisic acid was up-regulated at the earlier time point to decrease markedly and gibberellins were decreased at the later one. Besides aquaporin PIP2 synthesis, other osmotic/oxidative stress related compounds were enhanced under zinc stress, i.e., proline, hydroxycinnamic acids, ascorbate, sesquiterpene lactones, and terpenoids biosynthesis. Although the proteins involved in the response to zinc stress and to salinity were substantially the same, their abundance changed between the two treatments. Lettuce response to zinc was more prominent at the first sampling point, yet showing a faster adaptation than under NaCl stress. Indeed, lettuce plants showed an adaptation after 30 days of stress, in a more pronounced way in the case of

  1. Comparison of proteome response to saline and zinc stress in lettuce

    PubMed Central

    Lucini, Luigi; Bernardo, Letizia

    2015-01-01

    Zinc salts occurring in soils can exert an osmotic stress toward plants. However, being zinc a heavy metal, some more specific effects on plant metabolisms can be forecast. In this work, lettuce has been used as a model to investigate salt and zinc stresses at proteome level through a shotgun tandem MS proteomic approach. The effect of zinc stress in lettuce, in comparison with NaCl stress, was evaluated to dissect between osmotic/oxidative stress related effects, from those changes specifically related to zinc. The analysis of proteins exhibiting a fold change of 3 as minimum (on log 2 normalized abundances), revealed the involvement of photosynthesis (via stimulation of chlorophyll synthesis and enhanced role of photosystem I) as well as stimulation of photophosphorylation. Increased glycolytic supply of energy substrates and ammonium assimilation [through formation of glutamine synthetase (GS)] were also induced by zinc in soil. Similarly, protein metabolism (at both transcriptional and ribosomal level), heat shock proteins, and proteolysis were affected. According to their biosynthetic enzymes, hormones appear to be altered by both the treatment and the time point considered: ethylene biosynthesis was enhanced, while production of abscisic acid was up-regulated at the earlier time point to decrease markedly and gibberellins were decreased at the later one. Besides aquaporin PIP2 synthesis, other osmotic/oxidative stress related compounds were enhanced under zinc stress, i.e., proline, hydroxycinnamic acids, ascorbate, sesquiterpene lactones, and terpenoids biosynthesis. Although the proteins involved in the response to zinc stress and to salinity were substantially the same, their abundance changed between the two treatments. Lettuce response to zinc was more prominent at the first sampling point, yet showing a faster adaptation than under NaCl stress. Indeed, lettuce plants showed an adaptation after 30 days of stress, in a more pronounced way in the case of

  2. Comparison of proteome response to saline and zinc stress in lettuce.

    PubMed

    Lucini, Luigi; Bernardo, Letizia

    2015-01-01

    Zinc salts occurring in soils can exert an osmotic stress toward plants. However, being zinc a heavy metal, some more specific effects on plant metabolisms can be forecast. In this work, lettuce has been used as a model to investigate salt and zinc stresses at proteome level through a shotgun tandem MS proteomic approach. The effect of zinc stress in lettuce, in comparison with NaCl stress, was evaluated to dissect between osmotic/oxidative stress related effects, from those changes specifically related to zinc. The analysis of proteins exhibiting a fold change of 3 as minimum (on log 2 normalized abundances), revealed the involvement of photosynthesis (via stimulation of chlorophyll synthesis and enhanced role of photosystem I) as well as stimulation of photophosphorylation. Increased glycolytic supply of energy substrates and ammonium assimilation [through formation of glutamine synthetase (GS)] were also induced by zinc in soil. Similarly, protein metabolism (at both transcriptional and ribosomal level), heat shock proteins, and proteolysis were affected. According to their biosynthetic enzymes, hormones appear to be altered by both the treatment and the time point considered: ethylene biosynthesis was enhanced, while production of abscisic acid was up-regulated at the earlier time point to decrease markedly and gibberellins were decreased at the later one. Besides aquaporin PIP2 synthesis, other osmotic/oxidative stress related compounds were enhanced under zinc stress, i.e., proline, hydroxycinnamic acids, ascorbate, sesquiterpene lactones, and terpenoids biosynthesis. Although the proteins involved in the response to zinc stress and to salinity were substantially the same, their abundance changed between the two treatments. Lettuce response to zinc was more prominent at the first sampling point, yet showing a faster adaptation than under NaCl stress. Indeed, lettuce plants showed an adaptation after 30 days of stress, in a more pronounced way in the case of

  3. Synthesis of hydrophobic zinc borate nanoflakes and its effect on flame retardant properties of polyethylene

    SciTech Connect

    Li Shengli; Long Beihong; Wang Zichen; Tian Yumei; Zheng Yunhui; Zhang Qian

    2010-04-15

    Zinc borate (2ZnO.3B{sub 2}O{sub 3}.3.5H{sub 2}O) has relatively high dehydration on-set temperature which property permits processing in a wide range of polymer system. But zinc borate particles are hardly dispersed in a polymer matrix so that they prevent their using in industry. To address this problem, we synthesized hydrophobic zinc borate (2ZnO.3B{sub 2}O{sub 3}.3.5H{sub 2}O) nanoflakes by employing solid-liquid reaction of zinc oxide (ZnO) and boric acid (H{sub 3}BO{sub 3}) in the presence of oleic acid. This method does not bring pollution. By conducting morphological and microscopic analyses, we found that this compound displayed nanoflake morphology with particle size of around 100-200 nm, thickness less than 100 nm and there were uniform mesopores with the diameter about 10 nm within the particles. Furthermore, our products had an effect on flame retardant of polyethylene, especially when the zinc borate was modified by oleic acid. - Graphical abstract: The contact angle of hydrophobic zinc borate nanoflakes is 129.02 deg. with added 2.0 wt% of oleic acid.

  4. Nutrition intervention strategies to combat zinc deficiency in developing countries.

    PubMed

    Gibson, R S; Ferguson, E L

    1998-06-01

    . In the future, dietary modification/diversification, although long term, may be the preferred strategy because it is more sustainable, economically feasible, culturally acceptable, and equitable, and can be used to alleviate several micronutrient deficiencies simultaneously, without danger of inducing antagonistic micronutrient interactions. Appropriate dietary strategies include consumption of zinc-dense foods and those known to enhance zinc absorption, reducing the phytic acid content of plant based staples via enzymic hydrolysis induced by germination/fermentation or nonenzymic hydrolysis by soaking or thermal processing. All the strategies outlined above should be integrated with ongoing national food, nutrition and health education programmes, to enhance their effectiveness and sustainability, and implemented using nutrition education and social marketing techniques. Ultimately the success of any approach for combating zinc deficiency depends on strong advocacy, top level commitment, a stable infrastructure, long term financial support and the capacity to control quality and monitor and enforce compliance at the national or regional level. To be cost effective, costs for these strategies must be shared by industry, government, donors and consumers. PMID:19087462

  5. Zinc toxicology following particulate inhalation.

    PubMed

    Cooper, Ross G

    2008-04-01

    The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl(2) inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection.

  6. Zinc toxicology following particulate inhalation

    PubMed Central

    Cooper, Ross G.

    2008-01-01

    The current mini-review describes the toxic effects of zinc inhalation principally in the workplace and associated complications with breathing and respiration. The International Classification of Functioning, Disability and Health Criteria were used to specifically select articles. Most of the commercial production of zinc involves the galvanizing of iron and the manufacture of brass. The recommended daily allowance for adults is 15 mg zinc/day. Metal fume fever associated with inhalation of fumes of ZnO is characterized by fatigue, chills, fever, myalgias, cough, dyspnea, leukocytosis, thirst, metallic taste and salivation. ZnCl2 inhalation results in edema in the alveolar surface and the protein therein the lavage fluid is elevated. Particular pathological changes associated with zinc intoxication include: pale mucous membranes; jaundice; numerous Heinz bodies; and marked anemia. Adequate ambient air monitors for permissible exposure limits, excellent ventilation and extraction systems, and approved respirators are all important in providing adequate protection. PMID:20040991

  7. Zinc Binding Modulates the Entire Folding Free Energy Surface of Human Cu,Zn Superoxide Dismutase

    PubMed Central

    Kayatekin, Can; Zitzewitz, Jill A.; Matthews, C. Robert

    2009-01-01

    Over 100 amino acid replacements in human Cu, Zn superoxide dismutase (SOD) are known to cause amyotrophic lateral sclerosis, a gain-of-function neurodegenerative disease that destroys motor neurons. Supposing that aggregates of partially-folded states are primarily responsible for toxicity, the role of the structurally-important zinc ion in defining the folding free energy surface of dimeric SOD was determined by comparing the thermodynamic and kinetic folding properties of the zinc-free and zinc-bound forms of the protein. The presence of zinc was found to decrease the free energies of a peptide model of the unfolded monomer, a stable variant of the folded monomeric intermediate and the folded dimeric species. The unfolded state binds zinc weakly with a micromolar dissociation constant, and the folded monomeric intermediate and the native dimeric form both bind zinc tightly, with sub-nanomolar dissociation constants. Coupled with the strong driving force for the subunit association reaction, the shift in the populations towards more well-folded states in the presence of zinc decreases the steady-state populations of higher-energy states in SOD under expected in vivo zinc concentrations (∼nanomolar). The significant decrease in the population of partially-folded states is expected to diminish their potential for aggregation and account for the known protective effect of zinc. The ∼100-fold increase in the rate of folding of SOD in the presence of micromolar concentrations of zinc demonstrates a significant role for a pre-organized zinc-binding loop in the transition state ensemble for the rate-limiting monomer folding reaction in this β-barrel protein. PMID:18840448

  8. The Role of Particulate Matter-Associated Zinc in Cardiac Injury in Rats

    PubMed Central

    Kodavanti, Urmila P.; Schladweiler, Mette C.; Gilmour, Peter S.; Wallenborn, J. Grace; Mandavilli, Bhaskar S.; Ledbetter, Allen D.; Christiani, David C.; Runge, Marschall S.; Karoly, Edward D.; Costa, Daniel L.; Peddada, Shyamal; Jaskot, Richard; Richards, Judy H.; Thomas, Ronald; Madamanchi, Nageswara R.; Nyska, Abraham

    2008-01-01

    Background Exposure to particulate matter (PM) has been associated with increased cardiovascular morbidity; however, causative components are unknown. Zinc is a major element detected at high levels in urban air. Objective We investigated the role of PM-associated zinc in cardiac injury. Methods We repeatedly exposed 12- to 14-week-old male Wistar Kyoto rats intratracheally (1×/week for 8 or16 weeks) to a) saline (control); b) PM having no soluble zinc (Mount St. Helens ash, MSH); or c) whole-combustion PM suspension containing 14.5 μg/mg of water-soluble zinc at high dose (PM-HD) and d ) low dose (PM-LD), e) the aqueous fraction of this suspension (14.5 μg/mg of soluble zinc) (PM-L), or f ) zinc sulfate (rats exposed for 8 weeks received double the concentration of all PM components of rats exposed for 16 weeks). Results Pulmonary inflammation was apparent in all exposure groups when compared with saline (8 weeks > 16 weeks). PM with or without zinc, or with zinc alone caused small increases in focal subepicardial inflammation, degeneration, and fibrosis. Lesions were not detected in controls at 8 weeks but were noted at 16 weeks. We analyzed mitochondrial DNA damage using quantitative polymerase chain reaction and found that all groups except MSH caused varying degrees of damage relative to control. Total cardiac aconitase activity was inhibited in rats receiving soluble zinc. Expression array analysis of heart tissue revealed modest changes in mRNA for genes involved in signaling, ion channels function, oxidative stress, mitochondrial fatty acid metabolism, and cell cycle regulation in zinc but not in MSH-exposed rats. Conclusion These results suggest that water-soluble PM-associated zinc may be one of the causal components involved in PM cardiac effects. PMID:18197293

  9. An investigation of zinc electrodes relevant to zinc-air batteries

    SciTech Connect

    Choi, H.S.

    1986-12-01

    The particulate electrode (fluidized bed electrode or moving bed electrode) has been studied to evaluate its possible application to energy storage. The first part of this study is concerned with the effect of current fluctuation on the morphology of zinc electrodeposited on the rotating disc electrode from alkaline zincate electrolyte. The effect of the fluctuation on the morphology was examined by scanning electron microscopy. The deposits under the condition of fluctuating current density were smoother than those formed under constant current density. The second part is concerned with the electrodeposition of zinc from alkaline electrolyte with the cell employing a fluidized bed electrode which simulates the recharge process of the secondary battery employing a particulate electrode. Except at high current density, energy consumption per unit production was less than 3 to 4 kWh/kg which is the characteristic value of conventional electrowinning from acidic solution. A laboratory cell with a particulate zinc electrode and an air counter electrode was constructed and discharge characteristics were studied to evaluate the cell. Energy efficiencies during discharge at 5 and 2.5A were about 20 and 30% respectively.

  10. Powering future vehicles with the refuelable zinc/air battery

    SciTech Connect

    1995-10-01

    A recent road test at LLNL underscored the zinc/air battery`s capacity to give electric vehicles some of the attractive features of gas-driven cars: a 400-km range between refueling, 10-minute refueling, and highway-safe acceleration. Developed at Lawrence Livermore National Laboratory, the battery weights only one-sixth as much as standard lead/acid batteries and occupies one-third the space, yet costs less per mile to operate. What`s more, because the battery is easily refuelable, it promises trouble-free, nearly 24-hour-a-day operation for numerous kinds of electric vehicles, from forklifts to delivery vans and possibly, one day, personal automobiles. The test of a Santa Barbara Municipal Transit bus with a hybrid of zinc/air and lead/acid batteries capped a short development period for the zinc/air battery. The test run indicated the zinc/air battery`s potential savings in vehicle weight from 5.7 to 4.0 metric tons, in battery weight from 2.0 to 0.3 metric tons, in battery volume from 0.79 to 0.25 m{sup 3}, and in electricity cost from 5.6 cents per mile to 4.7 cents per mile. The power, however, remains the same.

  11. Heat-sterilized silver oxide-zinc cells: Cycle life studies

    NASA Technical Reports Server (NTRS)

    Arms, J. T.

    1973-01-01

    A JPL study was conducted to evaluate the cell design parameters that contribute to the cycle life of sealed, heat-sterilized silver oxide-zinc cells. Test cells having a rated capacity of 4.2 A-h were fabricated using zinc oxide electrodes prepared by the sintered Teflon process. Two separator variations were evaluated, one having acrylic acid and the other methacrylic acid grafted to irradiated polyethylene film. Significant results of this study include the following: (1) cycle life in excess of 300 cycles was attained; (2) a zinc oxide/silver stoichiometric ratio of 1.5 resulted in greater cycle life than a ratio of 1.1, and similar cycle life to cells having a ratio of 2; (3) cells having methacrylic acid grafted separators suffered somewhat less in capacity loss due to zinc electrode shape change than cells having acrylic acid type; (4) use of acrylic acid grafted separators was slightly superior to the methacrylic acid type in respect to silver penetration; and (5) the inclusion of a layer of potassium titanate paper adjacent to the zinc electrodes resulted in cells that achieved higher cycle life before any of the group failed than that reached by cells of any other construction.

  12. Behavior in the forced swim test and neurochemical changes in the hippocampus in young rats after 2-week zinc deprivation.

    PubMed

    Tamano, Haruna; Kan, Fumika; Kawamura, Mika; Oku, Naoto; Takeda, Atsushi

    2009-12-01

    Abnormal behavior in zinc deficiency and its cause are poorly understood. In the present paper, behavior in the forced swim test and neurochemical changes in the brain associated with its behavior were studied focused on abnormal corticosterone secretion in zinc deficiency. The effect of chronic corticosterone treatment was also studied. Immobility time in the forced swim test was increased in young rats fed a zinc-deficient diet for 2 weeks, as well as corticosterone (40mg/kg/dayx14 days)-treated control rats. The basal Ca(2+) levels in the hippocampus, which were determined by fluo-4FF, AM, were increased in both brain slices from zinc-deficient and corticosterone-treated rats. Serum glucose level was decreased in zinc deficiency and hippocampal glucose metabolism, which is determined by [(14)C]2-deoxyglucose uptake, was elevated. Hippocampal ATP level was not decreased, whereas, the concentrations of glutamate, GABA and glutamine in the hippocampus, unlike the whole brain, were decreased in zinc deficiency. However, the decrease in these amino acids was restored by adrenalectomy prior to zinc deficiency. These results suggest that glucose is insufficient for the synthesis of amino acids in the hippocampus of zinc-deficient rats. It is likely that the neurochemical and metabolic changes in the hippocampus, which may be associated with abnormal corticosterone secretion, is the base of abnormal behavior associated with neuropsychological symptoms in zinc deficiency. PMID:19463882

  13. Alterations in zinc binding capacity, free zinc levels and total serum zinc in a porcine model of sepsis.

    PubMed

    Hoeger, Janine; Simon, Tim-Philipp; Doemming, Sabine; Thiele, Christoph; Marx, Gernot; Schuerholz, Tobias; Haase, Hajo

    2015-08-01

    Zinc is crucial for immune function. In addition, the redistribution of zinc and other nutrients due to infection is an integral part of the host immune response to limit availability to pathogens. However, the major zinc binding protein albumin is down regulated during the acute phase response, implicating a decrease in zinc binding capacity. A prospective animal study with eight female German landrace pigs was conducted to investigate alterations in zinc binding capacity, total serum zinc and free zinc levels in the initial phase of sepsis. Sepsis was induced by instillation of autologous feces via midline laparotomy. Total serum zinc declined significantly after 1 h (10.89 ± 0.42 µM vs. 7.67 ± 0.41 µM, p < 0.001), total serum copper and iron reached a significant reduction at 4 h. Urinary excretion of zinc declined in line with total serum zinc. In comparison to total serum zinc, free zinc levels declined to a lesser, though significant, extent. Zinc binding capacity of serum decreased over time, whereby free zinc levels after addition of zinc correlated negatively with total serum protein and albumin levels. In addition IL-6 and TNF-α concentrations were measured and increased significantly 2 h after induction of sepsis. Hence, total serum zinc was the first marker of inflammation in our experiment, and might therefore be a promising biomarker for the early diagnosis of sepsis. Furthermore the observation of a substantially different serum free zinc homeostasis during sepsis provides valuable information for a potential therapeutic zinc supplementation, which has to take buffering capacity by serum proteins into account.

  14. Nutritional zinc increases platelet reactivity.

    PubMed

    Marx, G; Krugliak, J; Shaklai, M

    1991-11-01

    After ingestion of 220 mg zinc sulfate, platelet aggregation was evaluated at various time intervals (i.e., T = 0, 1, and 3 hr) and the autologous plasma analyzed by atomic absorption analysis. The zinc levels increased maximally some 0.4 +/- 0.2 microgram/ml within 3 hr after ingestion, which for the entire blood pool corresponds to only 5% of the ingested zinc. Aggregation responses of platelet rich plasma (PRP), instigated with suboptimal levels of thrombin (less than 0.2 U/ml), ADP (less than 2 microM), epinephrine (less than 2 microM), collagen (less than 2 micrograms/ml), or PAF (less than 50 ng/ml), show significant improvement to at least one aggregant. Mean +/- SEM values for delta % aggregation increase are as follows: thrombin, 51 +/- 10%; epinephrine, 21 +/- 6%; ADP, 31 +/- 6%; collagen 23 +/- 6%; and platelet aggregating factor (PAF), 56 +/- 6%. For controls, the platelets from one individual with Glanzmann thrombasthenia as well as four undosed volunteers exhibited no significant changes in platelet responsiveness. Increased platelet responsiveness to agonists after zinc sulfate ingestion was observed in PRP from blood collected in either citrate or heparin. We demonstrate that within a relatively short time period, single bolus of nutritional zinc intake can significantly increase platelet reactivity. These findings show that nutritional zinc availability is relevant to hemostasis and may pertain to the viability of platelet concentrates in blood banks.

  15. Extreme zinc tolerance in acidophilic microorganisms from the bacterial and archaeal domains.

    PubMed

    Mangold, Stefanie; Potrykus, Joanna; Björn, Erik; Lövgren, Lars; Dopson, Mark

    2013-01-01

    Zinc can occur in extremely high concentrations in acidic, heavy metal polluted environments inhabited by acidophilic prokaryotes. Although these organisms are able to thrive in such severely contaminated ecosystems their resistance mechanisms have not been well studied. Bioinformatic analysis of a range of acidophilic bacterial and archaeal genomes identified homologues of several known zinc homeostasis systems. These included primary and secondary transporters, such as the primary heavy metal exporter ZntA and Nramp super-family secondary importer MntH. Three acidophilic model microorganisms, the archaeon 'Ferroplasma acidarmanus', the Gram negative bacterium Acidithiobacillus caldus, and the Gram positive bacterium Acidimicrobium ferrooxidans, were selected for detailed analyses. Zinc speciation modeling of the growth media demonstrated that a large fraction of the free metal ion is complexed, potentially affecting its toxicity. Indeed, many of the putative zinc homeostasis genes were constitutively expressed and with the exception of 'F. acidarmanus' ZntA, they were not up-regulated in the presence of excess zinc. Proteomic analysis revealed that zinc played a role in oxidative stress in At. caldus and Am. ferrooxidans. Furthermore, 'F. acidarmanus' kept a constant level of intracellular zinc over all conditions tested whereas the intracellular levels increased with increasing zinc exposure in the remaining organisms.

  16. Thermodynamic and Kinetic Studies for Intensifying Selective Decomposition of Zinc Ferrite

    NASA Astrophysics Data System (ADS)

    Han, Junwei; Liu, Wei; Qin, Wenqing; Jiao, Fen; Wang, Dawei; Liang, Chao

    2016-01-01

    A novel method to intensify the selective decomposition of zinc ferrite by a roasting process including reduction and magnetization stages was proposed. The relevant thermodynamic analysis with HSC [enthalpy (H), entropy (S) and heat capacity (C)] Chemistry 5.0 and experimental research on a laboratory scale were investigated. The thermodynamic calculations show that increasing the temperature and the CO amount promote not only the decomposition of zinc ferrite but also the formation of wustite, which can be converted to magnetite using sufficient CO2 at 823 K. The experimental results indicate that the zinc ferrite was decomposed into zinc oxide and wustite by reduction roasting under a gas mixture of 20% CO, 20% CO2 and 60% N2 at 1023 K for 90 min, and the decomposition degree of zinc ferrite reached 94%. Then, the generated wustite was transformed into magnetite by magnetization roasting under CO2 atmosphere at 823 K for 75 min, after which the selective extraction of zinc from zinc ferrite could be well achieved by low acid leaching. Increasing temperature and time were conducive to the magnetization within low temperature range, but when the temperature was above 823 K the zinc ferrite could be regenerated.

  17. Analysis of the structural consensus of the zinc coordination centers of metalloprotein structures.

    PubMed

    Patel, Kirti; Kumar, Anil; Durani, Susheel

    2007-10-01

    In a recent sequence-analysis study it was concluded that up to 10% of the human proteome could be comprised of zinc proteins, quite varied in the functional spread. The native structures of only few of the proteins are actually established. The elucidation of rest of the sequences of not just human but even other actively investigated genomes may benefit from knowledge of the structural consensus of the zinc-binding centers of the currently known zinc proteins. Nearly four hundred X-ray and NMR structures in the database of zinc-protein structures available as of April 2007 were investigated for geometry and conformation in the zinc-binding centers; separately for the structural and catalytic proteins and individually in the zinc centers coordinated to three and four amino-acid ligands. Enhanced cysteine involvement in agreement with the observation in human proteome has been detected in contrast with previous reports. Deviations from ideal coordination geometries are detected, possible underlying reasons are investigated, and correlations of geometry and conformation in zinc-coordination centers with protein function are established, providing possible benchmarks for putative zinc-binding patterns of the burgeoning genome data.

  18. Thermodynamic and Kinetic Studies for Intensifying Selective Decomposition of Zinc Ferrite

    NASA Astrophysics Data System (ADS)

    Han, Junwei; Liu, Wei; Qin, Wenqing; Jiao, Fen; Wang, Dawei; Liang, Chao

    2016-09-01

    A novel method to intensify the selective decomposition of zinc ferrite by a roasting process including reduction and magnetization stages was proposed. The relevant thermodynamic analysis with HSC [enthalpy (H), entropy (S) and heat capacity (C)] Chemistry 5.0 and experimental research on a laboratory scale were investigated. The thermodynamic calculations show that increasing the temperature and the CO amount promote not only the decomposition of zinc ferrite but also the formation of wustite, which can be converted to magnetite using sufficient CO2 at 823 K. The experimental results indicate that the zinc ferrite was decomposed into zinc oxide and wustite by reduction roasting under a gas mixture of 20% CO, 20% CO2 and 60% N2 at 1023 K for 90 min, and the decomposition degree of zinc ferrite reached 94%. Then, the generated wustite was transformed into magnetite by magnetization roasting under CO2 atmosphere at 823 K for 75 min, after which the selective extraction of zinc from zinc ferrite could be well achieved by low acid leaching. Increasing temperature and time were conducive to the magnetization within low temperature range, but when the temperature was above 823 K the zinc ferrite could be regenerated.

  19. Biofortification and Bioavailability of Rice Grain Zinc as Affected by Different Forms of Foliar Zinc Fertilization

    PubMed Central

    Yang, Xiaoe

    2012-01-01

    Background Zinc (Zn) biofortification through foliar Zn application is an attractive strategy to reduce human Zn deficiency. However, little is known about the biofortification efficiency and bioavailability of rice grain from different forms of foliar Zn fertilizers. Methodology/Principal Findings Four different Zn forms were applied as a foliar treatment among three rice cultivars under field trial. Zinc bioavailability was assessed by in vitro digestion/Caco-2 cell model. Foliar Zn fertilization was an effective agronomic practice to promote grain Zn concentration and Zn bioavailability among three rice cultivars, especially, in case of Zn-amino acid and ZnSO4. On average, Zn-amino acid and ZnSO4 increased Zn concentration in polished rice up to 24.04% and 22.47%, respectively. On average, Zn-amino acid and ZnSO4 increased Zn bioavailability in polished rice up to 68.37% and 64.43%, respectively. The effectiveness of foliar applied Zn-amino acid and ZnSO4 were higher than Zn-EDTA and Zn-Citrate on improvement of Zn concentration, and reduction of phytic acid, as a results higher accumulation of bioavailable Zn in polished rice. Moreover, foliar Zn application could maintain grain yield, the protein and minerals (Fe and Ca) quality of the polished rice. Conclusions Foliar application of Zn in rice offers a practical and useful approach to improve bioavailable Zn in polished rice. According to current study, Zn-amino acid and ZnSO4 are recommended as excellent foliar Zn forms to ongoing agronomic biofortification. PMID:23029003

  20. Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

    PubMed Central

    Fermoso, Fernando G.; Collins, Gavin; Bartacek, Jan

    2008-01-01

    The effect of omitting zinc from the influent of mesophilic (30 °C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of the bioreactor sludge. Limitation of the specific methanogenic activity (SMA) on methanol due to the absence of zinc from the influent developed after 137 days of operation. At that day, the SMA in medium with a complete trace metal solution except Zn was 3.4 g CH4-COD g VSS−1 day−1, compared to 4.2 g CH4-COD g VSS−1 day−1 in a medium with a complete (including zinc) trace metal solution. The methanol removal capacity during these 137 days was 99% and no volatile fatty acids accumulated. Two UASB reactors, inoculated with the zinc-deprived sludge, were operated to study restoration of the zinc limitation by zinc supplementation to the bioreactor influent. In a first reactor, no changes to the operational conditions were made. This resulted in methanol accumulation in the reactor effluent after 12 days of operation, which subsequently induced acetogenic activity 5 days after the methanol accumulation started. Methanogenesis could not be recovered by the continuous addition of 0.5 μM ZnCl2 to the reactor for 13 days. In the second reactor, 0.5 μM ZnCl2 was added from its start-up. Although the reactor stayed 10 days longer methanogenically than the reactor operated without zinc, methanol accumulation was observed in this reactor (up to 1.1 g COD-MeOH L−1) as well. This study shows that zinc limitation can induce failure of methanol fed UASB reactors due to acidification, which cannot be restored by resuming the continuous supply of the deprived metal. PMID:18283507

  1. Absorption of zinc and iron by rats fed meals containing sorghum food products

    SciTech Connect

    Stuart, S.M.A.; Johnson, P.E.; Hamaker, B.; Kirleis, A.

    1986-03-05

    Zinc and iron absorption from freeze-dried traditionally-prepared sorghum food products was studied in rats. After a period of marginal zinc or iron depletion, rats were fed test meals containing 1 of 4 sorghum foods cooked maize gruel or an inorganic mineral each of which was extrinsically labeled with either /sup 65/Zn or /sup 59/Fe before being added to the diets. Absorption was determined by whole body percent retention of the initial radioisotope dose over a period of 19 days. Iron was highly available from all products tested (75-83%) with no significant differences in absorption among groups (p>0.05). Zinc from fermented Aceta (97%) was more available than that from the other sorghum products (69-78%) or maize gruel (76%). Zinc from acid To (78%) and Aceta (97%) was as available as that from zinc oxide in the control diet (93%) (p>0.05). There were no significant differences in zinc absorption among groups fed Acid To (78%), neutral To (76), alkali To (69%) or maize gruel (76%) (p<0.05). Phytate in the fermented Aceta was 33% lower than in the other sorghum foods. Iron and zinc were highly available from all sorghum foods. Reduction phytate by fermentation increased Zn availability.

  2. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD). Part II: Downstream processing and zinc recovery by electrowinning.

    PubMed

    Tsakiridis, P E; Oustadakis, P; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The characterization and the agitation leaching of electric arc furnace dust (EAFD) by diluted sulphuric acid have been studied in Part I, as a separate article. The aim of the present research work (Part II) is the development of a purification process of the leach liquor for the recovery of high-purity zinc by electrowinning. The proposed hydrometallurgical process consists of the following four (4) unit operations: (1) Removal of iron as easily filterable crystalline basic sulphate salt of the jarosite type, at atmospheric pressure, by chemical precipitation at pH: 3.5 and 95 degrees C. (2) Zinc solvent extraction by Cyanex 272 at pH: 3.5, T: 40 degrees C, with 25% extractant concentration. (3) Stripping of the loaded organic phase by zinc spent electrolyte (62.5 g/L Zn(2+)) at T: 40 degrees C with diluted H(2)SO(4) (3 mol/L). (4) Zinc electrowinning from sulphate solutions (at 38 degrees C) using Al as cathode and Pb as anode. The acidity of the electrolyte was fixed at 180 g/L H(2)SO(4), while the current density was kept constant at 500 A/m(2). PMID:20434263

  3. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD). Part II: Downstream processing and zinc recovery by electrowinning.

    PubMed

    Tsakiridis, P E; Oustadakis, P; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The characterization and the agitation leaching of electric arc furnace dust (EAFD) by diluted sulphuric acid have been studied in Part I, as a separate article. The aim of the present research work (Part II) is the development of a purification process of the leach liquor for the recovery of high-purity zinc by electrowinning. The proposed hydrometallurgical process consists of the following four (4) unit operations: (1) Removal of iron as easily filterable crystalline basic sulphate salt of the jarosite type, at atmospheric pressure, by chemical precipitation at pH: 3.5 and 95 degrees C. (2) Zinc solvent extraction by Cyanex 272 at pH: 3.5, T: 40 degrees C, with 25% extractant concentration. (3) Stripping of the loaded organic phase by zinc spent electrolyte (62.5 g/L Zn(2+)) at T: 40 degrees C with diluted H(2)SO(4) (3 mol/L). (4) Zinc electrowinning from sulphate solutions (at 38 degrees C) using Al as cathode and Pb as anode. The acidity of the electrolyte was fixed at 180 g/L H(2)SO(4), while the current density was kept constant at 500 A/m(2).

  4. Zinc and copper: proposed fortification levels and recommended zinc compounds.

    PubMed

    Rosado, Jorge L

    2003-09-01

    Micronutrient fortification of foods is now a highly relevant tool worldwide for overcoming micronutrient deficiency. Recent data show that subclinical zinc deficiency is widespread; in Mexico a national survey showed that 25% of children less than age 11 y had plasma zinc concentrations below 10.0 micromol/L (65 microg/dL). Copper deficiency in populations is unknown but copper supplementation is recommended to accompany zinc supplementation. Of the foods available for fortification, staple cereals are very good candidates for reducing micronutrient deficiencies. Because of its higher stability and lower cost, we recommend fortification of cereal flours with zinc oxide, which is absorbed as well as the less stable and more expensive forms of zinc. Depending on the amount of the food that is expected to be eaten, zinc fortification of staple foods could be 20-50 mg/kg of flour. For copper fortification the safer compound is copper gluconate. Copper sulfate is significantly less expensive, but an evaluation of potential physicochemical reactions that affect the final food product is recommended. The suggested amount of copper added to staple foods is 1.2-3.0 mg/kg of flour. For food supplements designed as part of supplementation programs to reduce micronutrient deficiency in children less than age 3 y, a dose of the final product (usually approximately 40-50 g) should contain approximately 4-5 mg of zinc and approximately 0.2-0.4 mg of copper depending on the habitual diet, magnitude of deficiencies and period of supplementation. PMID:12949397

  5. Zinc Absorption by Young Adults from Supplemental Zinc Citrate Is Comparable with That from Zinc Gluconate and Higher than from Zinc Oxide123

    PubMed Central

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnić, Marica; Hurrell, Richard F.

    2014-01-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with 67Zn and 70Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6–71.0) and was not different from that from zinc gluconate with 60.9% (50.6–71.7). Absorption from zinc oxide at 49.9% (40.9–57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

  6. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide.

    PubMed

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnic, Marica; Hurrell, Richard F

    2014-02-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with (67)Zn and (70)Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6-71.0) and was not different from that from zinc gluconate with 60.9% (50.6-71.7). Absorption from zinc oxide at 49.9% (40.9-57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627.

  7. Zinc absorption by young adults from supplemental zinc citrate is comparable with that from zinc gluconate and higher than from zinc oxide.

    PubMed

    Wegmüller, Rita; Tay, Fabian; Zeder, Christophe; Brnic, Marica; Hurrell, Richard F

    2014-02-01

    The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with (67)Zn and (70)Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6-71.0) and was not different from that from zinc gluconate with 60.9% (50.6-71.7). Absorption from zinc oxide at 49.9% (40.9-57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627. PMID:24259556

  8. Zinc absorption in humans from meals based on rye, barley, oatmeal, triticale and whole wheat

    SciTech Connect

    Sandstroem, B.A.; Almgren, A.; Kivistoe, B.C.; Cederblad, A.

    1987-11-01

    The absorption of zinc from meals based on 60 g of rye, barley, oatmeal, triticale or whole wheat was studied by use of extrinsic labelling with /sup 65/Zn and measurement of the whole-body retention of the radionuclide. The cereals were prepared in the form of bread or porridge and were served with 200 mL of milk. The oatmeal flakes were also served without further preparation. The absorption of zinc was negatively correlated to the phytic acid content of the meal with the highest absorption, 26.8 +/- 7.4%, from the rye bread meal containing 100 mumol of phytic acid and the lowest, 8.4 +/- 1.0%, from oatmeal porridge with a phytic acid content of 600 mumol. It is concluded that food preparation that decreases the phytic acid content improves zinc absorption.

  9. Zinc absorption in humans from meals based on rye, barley, oatmeal, triticale and whole wheat.

    PubMed

    Sandström, B; Almgren, A; Kivistö, B; Cederblad, A

    1987-11-01

    The absorption of zinc from meals based on 60 g of rye, barley, oatmeal, triticale or whole wheat was studied by use of extrinsic labelling with 65Zn and measurement of the whole-body retention of the radionuclide. The cereals were prepared in the form of bread or porridge and were served with 200 mL of milk. The oatmeal flakes were also served without further preparation. The absorption of zinc was negatively correlated to the phytic acid content of the meal with the highest absorption, 26.8 +/- 7.4%, from the rye bread meal containing 100 mumol of phytic acid and the lowest, 8.4 +/- 1.0%, from oatmeal porridge with a phytic acid content of 600 mumol. It is concluded that food preparation that decreases the phytic acid content improves zinc absorption.

  10. Silver-zinc: status of technology and applications

    NASA Astrophysics Data System (ADS)

    Karpinski, A. P.; Makovetski, B.; Russell, S. J.; Serenyi, J. R.; Williams, D. C.

    Michel Yardney and Professor Henri André developed the first practical silver-zinc battery more than 55 years ago. Since then, primary and rechargeable silver-zinc batteries have attracted a variety of applications due to their high specific energy/energy density, proven reliability and safety, and the highest power output per unit weight and volume of all commercially available batteries. Although significant improvements have been achieved on traditional systems such as lead-acid and nickel/cadmium, and in spite of the advent of new electrochemistries such as lithium-ion and nickel/metal hydride, many users still rely on silver-zinc to satisfy their most demanding and critical requirements. Over the past few years, several of the internal components have been subject to many studies which resulted in significant improvements in the battery wet life and cycle life. Specifically, these include new separator materials which offer an alternative to the cellulosic membranes, improvements to the zinc electrode that include additives that help reduce shape-change and dendritic growth, and to a lesser extent, process changes to the silver electrode and additives to the electrolyte. In comparison, the commonly used secondary systems are lead-acid, nickel/cadmium, nickel/metal hydride, and lithium-ion. Each has attributes which make them desirable for certain applications. Where low cost, high voltage, and high rate capability is required, the lead-acid battery is an obvious choice whenever size and weight are not critical. For applications requiring longer wet life, moderate rate capability, and high cycle life, nickel/cadmium or nickel/metal hydride can be used in spite of their poor charge retention and higher costs. Relatively newer systems are also available such as lithium-ion or lithium polymer technology which are preferred for their high voltage and excellent cycle life. Among the disadvantages of these systems are higher costs, limited configurations (usually

  11. Zinc and Diabetic Retinopathy

    PubMed Central

    Miao, Xiao; Sun, Weixia; Miao, Lining; Fu, Yaowen; Wang, Yonggang; Su, Guanfang; Liu, Quan

    2013-01-01

    Zinc (Zn) is an important nutrient that is involved in various physiological metabolisms. Zn dyshomeostasis is often associated with various pathogeneses of chronic diseases, such as metabolic syndrome, diabetes, and related complications. Zn is present in ocular tissue in high concentrations, particularly in the retina and choroid. Zn deficiencies have been shown to affect ocular development, cataracts, age-related macular degeneration, and even diabetic retinopathy. However, the mechanism by which Zn deficiency increases the prevalence of diabetic retinopathy remains unclear. In addition, due to the negative effect of Zn deficiency on the eye, Zn supplementation should prevent diabetic retinopathy; however, limited available data do not always support this notion. Therefore, the goal of this paper was to summarize these pieces of available information regarding Zn prevention of diabetic retinopathy. Current theories and possible mechanisms underlying the role of Zn in the eye-related diseases are discussed. The possible factors that affect the preventive effect of Zn supplementation on diabetic retinopathy were also discussed. PMID:23671870

  12. Zinc content of selected tissues and taste perception in rats fed zinc deficient and zinc adequate rations

    SciTech Connect

    Boeckner, L.S.; Kies, C.

    1986-03-05

    The objective of the study was to determine the effects of feeding zinc sufficient and zinc deficient rations on taste sensitivity and zinc contents of selected organs in rats. The 36 Sprague-Dawley male weanling rats were divided into 2 groups and fed zinc deficient or zinc adequate rations. The animals were subjected to 4 trial periods in which a choice of deionized distilled water or a solution of quinine sulfate at 1.28 x 10/sup -6/ was given. A randomized schedule for rat sacrifice was used. No differences were found between zinc deficient and zinc adequate rats in taste preference aversion scores for quinine sulfate in the first three trial periods; however, in the last trial period rats in the zinc sufficient group drank somewhat less water containing quinine sulfate as a percentage of total water consumption than did rats fed the zinc deficient ration. Significantly higher zinc contents of kidney, brain and parotid salivary glands were seen in zinc adequate rats compared to zinc deficient rats at the end of the study. However, liver and tongue zinc levels were lower for both groups at the close of the study than were those of rats sacrificed at the beginning of the study.

  13. Sorbitol dehydrogenase is a zinc enzyme.

    PubMed Central

    Jeffery, J; Chesters, J; Mills, C; Sadler, P J; Jörnvall, H

    1984-01-01

    Evidence is given that tetrameric sorbitol dehydrogenase from sheep liver contains one zinc atom per subunit, most probably located at the active site, and no other specifically bound zinc or iron atom. In alcohol dehydrogenases that are structurally related to sorbitol dehydrogenase, more than one zinc atom per subunit can complicate investigations of zinc atom function. Therefore, sorbitol dehydrogenase will be particularly valuable for defining the precise roles of zinc in alcohol and polyol dehydrogenases, and for establishing correlations of structure and function with other important zinc-containing proteins. PMID:6370679

  14. Characterization of a zinc-cerium flow battery

    NASA Astrophysics Data System (ADS)

    Leung, P. K.; Ponce-de-León, C.; Low, C. T. J.; Shah, A. A.; Walsh, F. C.

    The performance of a divided, parallel-plate zinc-cerium redox flow battery using methanesulfonic acid electrolytes was studied. Eight two and three-dimensional electrodes were tested under both constant current density and constant cell voltage discharge. Carbon felt and the three-dimensional platinised titanium mesh electrodes exhibited superior performance over the 2-dimensional electrodes. The charge and discharge characteristics of the redox flow battery were studied under different operating conditions and Zn/Ce reactant, as well as methansulfonic acid concentration. The cell performance improved at higher operating temperatures and faster electrolyte flow velocities. The number of possible cycles increased at reduced states of charge. During 15 min charge/discharge per cycle experiment, 57 cycles were obtained and the zinc reaction was found to be the limiting process during long term operation.

  15. History of Zinc in Agriculture12

    PubMed Central

    Nielsen, Forrest H.

    2012-01-01

    Zinc was established as essential for green plants in 1926 and for mammals in 1934. However, >20 y would pass before the first descriptions of zinc deficiencies in farm animals appeared. In 1955, it was reported that zinc supplementation would cure parakeratosis in swine. In 1958, it was reported that zinc deficiency induced poor growth, leg abnormalities, poor feathering, and parakeratosis in chicks. In the 1960s, zinc supplementation was found to alleviate parakeratosis in grazing cattle and sheep. Within 35 y, it was established that nearly one half of the soils in the world may be zinc deficient, causing decreased plant zinc content and production that can be prevented by zinc fertilization. In many of these areas, zinc deficiency is prevented in grazing livestock by zinc fertilization of pastures or by providing salt licks. For livestock under more defined conditions, such as poultry, swine, and dairy and finishing cattle, feeds are easily supplemented with zinc salts to prevent deficiency. Today, the causes and consequences of zinc deficiency and methods and effects of overcoming the deficiency are well established for agriculture. The history of zinc in agriculture is an outstanding demonstration of the translation of research into practical application. PMID:23153732

  16. Zinc improves antioxidative enzymes in red blood cells and hematology in lithium-treated rats.

    PubMed

    Malhotra, Anshoo; Dhawan, Devinder K

    2008-01-01

    The present study was designed to evaluate the protective role of zinc in attenuating the adverse effects induced by lithium in blood of female Wistar rats. Female Wistar rats received lithium in the form of lithium carbonate in diet at a dose level of 1.1 g/kg diet, zinc alone in the form of zinc sulfate in drinking water at a dose level of 227 mg/L drinking water, or lithium plus zinc treatments in the combined group for a total duration of 2 months. Effects of the treatments were studied on antioxidant defense system, various hematologic parameters, and percentage of (65)Zn-specific activity. Lithium treatment resulted in a significant increase in lipid peroxidation levels but caused a significant decrease in reduced glutathione levels and the activities of catalase, glutathione S-transferase, and superoxide dismutase. Lithium treatment also caused a significant decrease in the activities of aminolevulinic acid dehydratase and Na(+) K(+) adenosine triphosphatase. However, it resulted in a significant increase in total leukocyte counts, neutrophils, and lymphocyte counts as well as zinc protoporphyrin levels, whereas a significant decrease in counts of monocytes, eosinophils, and percentage specific activity of (65)Zn in blood and its various fractions was noticed. Furthermore, lithium treatment caused a significant decrease in serum zinc levels. However, zinc supplementation to lithium-treated rats effectively raised the reduced glutathione levels and also normalized lipid peroxidation and the activities of antioxidative enzymes, which included catalase, glutathione S-transferase, and superoxide dismutase. Moreover, zinc supplementation could raise the activities of the enzymes aminolevulinic acid dehydratase and Na(+) K(+) adenosine triphosphatase as well as the percentage uptake values of (65)Zn in blood and its fractions. The study suggests that zinc, as a nutritional supplement, has the potential in attenuating most of the adverse effects induced by lithium

  17. Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

    PubMed

    Kessels, Jana Elena; Wessels, Inga; Haase, Hajo; Rink, Lothar; Uciechowski, Peter

    2016-09-01

    The distribution of intracellular zinc, predominantly regulated through zinc transporters and zinc binding proteins, is required to support an efficient immune response. Epigenetic mechanisms such as DNA methylation are involved in the expression of these genes. In demethylation experiments using 5-Aza-2'-deoxycytidine (AZA) increased intracellular (after 24 and 48h) and total cellular zinc levels (after 48h) were observed in the myeloid cell line HL-60. To uncover the mechanisms that cause the disturbed zinc homeostasis after DNA demethylation, the expression of human zinc transporters and zinc binding proteins were investigated. Real time PCR analyses of 14 ZIP (solute-linked carrier (SLC) SLC39A; Zrt/IRT-like protein), and 9 ZnT (SLC30A) zinc transporters revealed significantly enhanced mRNA expression of the zinc importer ZIP1 after AZA treatment. Because ZIP1 protein was also enhanced after AZA treatment, ZIP1 up-regulation might be the mediator of enhanced intracellular zinc levels. The mRNA expression of ZIP14 was decreased, whereas zinc exporter ZnT3 mRNA was also significantly increased; which might be a cellular reaction to compensate elevated zinc levels. An enhanced but not significant chromatin accessibility of ZIP1 promoter region I was detected by chromatin accessibility by real-time PCR (CHART) assays after demethylation. Additionally, DNA demethylation resulted in increased mRNA accumulation of zinc binding proteins metallothionein (MT) and S100A8/S100A9 after 48h. MT mRNA was significantly enhanced after 24h of AZA treatment also suggesting a reaction of the cell to restore zinc homeostasis. These data indicate that DNA methylation is an important epigenetic mechanism affecting zinc binding proteins and transporters, and, therefore, regulating zinc homeostasis in myeloid cells.

  18. Alterations of Bio-elements, Oxidative, and Inflammatory Status in the Zinc Deficiency Model in Rats.

    PubMed

    Doboszewska, Urszula; Szewczyk, Bernadeta; Sowa-Kućma, Magdalena; Noworyta-Sokołowska, Karolina; Misztak, Paulina; Gołębiowska, Joanna; Młyniec, Katarzyna; Ostachowicz, Beata; Krośniak, Mirosław; Wojtanowska-Krośniak, Agnieszka; Gołembiowska, Krystyna; Lankosz, Marek; Piekoszewski, Wojciech; Nowak, Gabriel

    2016-01-01

    Our previous study showed that dietary zinc restriction induces depression-like behavior with concomitant up-regulation of the N-methyl-D-aspartate receptor (NMDAR). Because metal ions, oxidative stress, and inflammation are involved in depression/NMDAR function, in the present study, bio-elements (zinc, copper, iron, magnesium, and calcium), oxidative (thiobarbituric acid-reactive substances; protein carbonyl content), and inflammatory (IL-1α, IL-1β) factors were measured in serum, hippocampus (Hp), and prefrontal cortex (PFC) of male Sprague-Dawley rats subjected to a zinc-adequate (ZnA) (50 mg Zn/kg) or a zinc-deficient (ZnD) (3 mg Zn/kg) diet for 4 or 6 weeks. Both periods of dietary zinc restriction reduced serum zinc and increased serum iron levels. At 4 weeks, lowered zinc level in the PFC and Hp as well as lowered iron level in the PFC of the ZnD rats was observed. At 6 weeks, however, iron level was increased in the PFC of these rats. Although at 6 weeks zinc level in the PFC did not differ between the ZnA and ZnD rats, extracellular zinc concentration after 100 mM KCl stimulation was reduced in the PFC of the ZnD rats and was accompanied by increased extracellular iron and glutamate levels (as measured by the in vivo microdialysis). The examined oxidative and inflammatory parameters were generally enhanced in the tissue of the ZnD animals. The obtained data suggest dynamic redistribution of bio-elements and enhancement of oxidative/inflammatory parameters after dietary zinc restriction, which may have a link with depression-like behavior/NMDAR function/neurodegeneration.

  19. Zinc in Multiple Sclerosis

    PubMed Central

    Frederiksen, Jette Lautrup

    2016-01-01

    In the last 35 years, zinc (Zn) has been examined for its potential role in the disease multiple sclerosis (MS). This review gives an overview of the possible role of Zn in the pathogenesis of MS as well as a meta-analysis of studies having measured Zn in serum or plasma in patients with MS. Searching the databases PubMed and EMBASE as well as going through reference lists in included articles 24 studies were found measuring Zn in patients with MS. Of these, 13 met inclusion criteria and were included in the meta-analysis. The result of the meta-analysis shows a reduction in serum or plasma Zn levels in patients with MS with a 95% CI of [−3.66, −0.93] and a p value of .001 for the difference in Zn concentration in μM. One of six studies measuring cerebrospinal fluid, Zn levels found a significant increase in patients with MS with controls. The studies measuring whole blood and erythrocyte Zn levels found up to several times higher levels of Zn in patients with MS compared with healthy controls with decreasing levels during attacks in relapsing-remitting MS patients. Future studies measuring serum or plasma Zn are encouraged to analyze their data through homogenous MS patient subgroups on especially age, sex, and disease subtype since the difference in serum or plasma Zn in these subgroups have been found to be significantly different. It is hypothesized that local alterations of Zn may be actively involved in the pathogenesis of MS. PMID:27282383

  20. Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

    PubMed Central

    Maret, Wolfgang

    2013-01-01

    The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

  1. Successful management of zinc phosphide poisoning

    PubMed Central

    Shakoori, Vahid; Agahi, Mahsa; Vasheghani-Farahani, Maryam; Marashi, Sayed Mahdi

    2016-01-01

    Zinc phosphide (Zn2P3) rodenticide, is generally misused intentionally for suicidal purpose in Iran. For many years, scientists believe that liberation of phosphine (PH3) on contact with acidic content of the stomach is responsible for clinical presentations. However, relatively long time interval between ingestion of Zn2P3 and presentation of its systemic toxicity, and progression of acute liver failure could not be explained by the current opinion. Hence, an innovative theory intended that phosphonium, as an intermediate product will create and pass through the stomach, which then will reduce to produce PH3in the luminal tract. Here, we present a case of massive Zn2P3 poisoning. In our case, we used repeated doses of castor oil to induce bowel movement with an aim of removing unabsorbed toxin, which was proved by radiography. Interestingly, the patient presents only mild symptoms of toxicity such as transient metabolic acidosis and hepatic dysfunction. PMID:27390464

  2. Successful management of zinc phosphide poisoning.

    PubMed

    Shakoori, Vahid; Agahi, Mahsa; Vasheghani-Farahani, Maryam; Marashi, Sayed Mahdi

    2016-06-01

    Zinc phosphide (Zn2P3) rodenticide, is generally misused intentionally for suicidal purpose in Iran. For many years, scientists believe that liberation of phosphine (PH3) on contact with acidic content of the stomach is responsible for clinical presentations. However, relatively long time interval between ingestion of Zn2P3 and presentation of its systemic toxicity, and progression of acute liver failure could not be explained by the current opinion. Hence, an innovative theory intended that phosphonium, as an intermediate product will create and pass through the stomach, which then will reduce to produce PH3in the luminal tract. Here, we present a case of massive Zn2P3 poisoning. In our case, we used repeated doses of castor oil to induce bowel movement with an aim of removing unabsorbed toxin, which was proved by radiography. Interestingly, the patient presents only mild symptoms of toxicity such as transient metabolic acidosis and hepatic dysfunction. PMID:27390464

  3. Direct in situ measurement of dissolved zinc in the presence of zinc oxide nanoparticles using anodic stripping voltammetry.

    PubMed

    Jiang, Chuanjia; Hsu-Kim, Heileen

    2014-11-01

    The wide use of metal-based nanomaterials such as zinc oxide (ZnO) nanoparticles (NPs) has generated concerns regarding their environmental and health risks. For ZnO NPs, their toxicity in aquatic systems often depends on the release of dissolved zinc species, and the rate of dissolution is influenced by water chemistry, including the presence of zinc-chelating ligands. A challenge, however, remains in quantifying the dissolution of ZnO NPs, particularly for time scales that are short enough to determine rates. This paper reports the application of anodic stripping voltammetry (ASV) with a hanging mercury drop electrode to directly measure the concentration of dissolved zinc in ZnO NP suspensions, without separation of the ZnO NPs from the aqueous phase. The effects of the deposition time and the electrochemical potential scan rate on the ASV measurement were consistent with expectations for dissolved phase measurements. The dissolved zinc concentration measured by ASV ([Zn]ASV) was compared with that measured by inductively coupled plasma mass spectrometry (ICP-MS) after ultracentrifugation ([Zn]ICP-MS), for four types of ZnO NPs with different coatings and primary particle diameters. For small ZnO NPs (4-5 nm), [Zn]ASV was 20% higher than [Zn]ICP-MS, suggesting that these small NPs contributed to the voltammetric measurement. For larger ZnO NPs (approximately 20 nm), [Zn]ASV was (79 ± 19)% of [Zn]ICP-MS, despite the high concentrations of ZnO NPs in suspension. Using ASV, the dissolution of ZnO NPs was studied, with or without Suwannee River Fulvic Acid (SRFA). Although SRFA diminished the ASV stripping current, dissolution of 20 nm ZnO NPs was significantly promoted at high fulvic acid to ZnO NP ratios. The ASV method described in this paper provides a useful tool for studying the dissolution kinetics of ZnO NPs in complex environmental matrices.

  4. Chronic toxicity of mixtures of copper, cadmium and zinc to Daphnia pulex

    SciTech Connect

    Flickinger, A.L.

    1984-01-01

    Daphnia pulex (de Greer) were exposed to single and bimetal mixtures of copper, cadmium and zinc in reconstituted waters of different hardness/alkalinity and humic acid concentrations. The effect of single and bimetal exposure to these metals was evaluated by survivorship and reproductive indices of brood size, percent aborted eggs/brood, age at reproductive maturity, age at first reproduction and the instantaneous rate of population growth. Accumulation by 7-day-old Daphnia magna of metals in these mixtures was also assessed in medium water containing 0.0 and 0.75 mg humic acid/L. The addition of 0.75 mg humic acid/L decreased the acute toxicity of copper and zinc but increased the acute toxicity of cadmium. Survival was the best index of a single or bimetal chronic stress since it was equally or more sensitive than any reproductive index. The interaction between copper and zinc was variable in soft water which contained 0.15 mg humic acid/L, but largely independent in medium water which contained 0.0 and 0.75 mg humic acid/L. Zinc and humic acid had no effect on the accumulation of copper in medium water. Copper and cadmium were synergistic in their interaction on daphniid survival in medium water which contained 0.0 and 0.75 mg humic acid/L.

  5. Zinc, aging, and immunosenescence: an overview

    PubMed Central

    Cabrera, Ángel Julio Romero

    2015-01-01

    Zinc plays an essential role in many biochemical pathways and participates in several cell functions, including the immune response. This review describes the role of zinc in human health, aging, and immunosenescence. Zinc deficiency is frequent in the elderly and leads to changes similar to those that occur in oxidative inflammatory aging (oxi-inflamm-aging) and immunosenescence. The possible benefits of zinc supplementation to enhance immune function are discussed. PMID:25661703

  6. Low-Resistivity Zinc Selenide for Heterojunctions

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.

    1986-01-01

    Magnetron reactive sputtering enables doping of this semiconductor. Proposed method of reactive sputtering combined with doping shows potential for yielding low-resistivity zinc selenide films. Zinc selenide attractive material for forming heterojunctions with other semiconductor compounds as zinc phosphide, cadmium telluride, and gallium arsenide. Semiconductor junctions promising for future optoelectronic devices, including solar cells and electroluminescent displays. Resistivities of zinc selenide layers deposited by evaporation or chemical vapor deposition too high to form practical heterojunctions.

  7. Zinc oxide varistors and/or resistors

    DOEpatents

    Arnold, Jr., Wesley D.; Bond, Walter D.; Lauf, Robert J.

    1993-01-01

    Varistors and/or resistors that includes doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

  8. Zinc oxide varistors and/or resistors

    DOEpatents

    Arnold, W.D. Jr.; Bond, W.D.; Lauf, R.J.

    1993-07-27

    Varistors and/or resistors are described that include doped zinc oxide gel microspheres. The doped zinc oxide gel microspheres preferably have from about 60 to about 95% by weight zinc oxide and from about 5 to about 40% by weight dopants based on the weight of the zinc oxide. The dopants are a plurality of dopants selected from silver salts, boron oxide, silicon oxide and hydrons oxides of aluminum, bismuth, cobalt, chromium, manganese, nickel, and antimony.

  9. Zinc, aging, and immunosenescence: an overview.

    PubMed

    Cabrera, Ángel Julio Romero

    2015-01-01

    Zinc plays an essential role in many biochemical pathways and participates in several cell functions, including the immune response. This review describes the role of zinc in human health, aging, and immunosenescence. Zinc deficiency is frequent in the elderly and leads to changes similar to those that occur in oxidative inflammatory aging (oxi-inflamm-aging) and immunosenescence. The possible benefits of zinc supplementation to enhance immune function are discussed.

  10. Nucleation and growth of zinc from chloride concentrated solutions

    SciTech Connect

    Trejo, G.; Ortega B, R.; Meas V, Y.; Ozil, P.; Chainet, E.; Nguyen, B.

    1998-12-01

    The electrodeposition of metals is a complex phenomenon influenced by a number of factors that modify the rates of nucleation and growth and determine the properties of the deposits. In this work the authors study the influence of the zinc chloride (ZnCl{sub 2}) concentration on the zinc nucleation process on glassy carbon, in a KCl electrolyte under conditions close to those employed in commercial acid deposition baths for zinc. The electrochemical study was performed using cyclic voltammetry and potentiostatic current-time transients. The charge-transfer coefficient and the formal potential for ZnCl{sub 2} reduction were evaluated from cyclic voltammetry experiments. The nucleation process was analyzed by comparing the transients obtained with the known dimensionless (i/i{sub m}){sup 2} vs. t/t{sub m} response for instantaneous or progressive nucleation. The results show that the nucleation process and the number density of sites are dependent on ZnCl{sub 2} concentration. Scanning electron microscopy analysis of the deposits shows that the deposits are homogeneous and compact although a change in the morphology is observed as a function of ZnCl{sub 2} concentration. Evaluation of the corrosion resistance reveals the influence of the nucleation process on the subsequent corrosion resistance of the zinc deposits.

  11. Zinc metalloproteins as medicinal targets.

    PubMed

    Anzellotti, A I; Farrell, N P

    2008-08-01

    Zinc bioinorganic chemistry has emphasized the role of the metal ion on the structure and function of the protein. There is, more recently, an increasing appreciation of the role of zinc proteins in a variety of human diseases. This critical review, aimed at both bioinorganic and medicinal chemists, shows how apparently widely-diverging diseases share the common mechanistic approaches of targeting the essential function of the metal ion to inhibit activity. Protein structure and function is briefly summarized in the context of its clinical relevance. The status of current and potential inhibitors is discussed along with the prospects for future developments (162 references).

  12. Mutational analysis of the two zinc-binding sites of the Bacillus cereus 569/H/9 metallo-beta-lactamase.

    PubMed Central

    de Seny, Dominique; Prosperi-Meys, Christelle; Bebrone, Carine; Rossolini, Gian Maria; Page, Michael I; Noel, Philippe; Frère, Jean-Marie; Galleni, Moreno

    2002-01-01

    The metallo-beta-lactamase BcII from Bacillus cereus 569/H/9 possesses a binuclear zinc centre. The mono-zinc form of the enzyme displays an appreciably high activity, although full efficiency is observed for the di-zinc enzyme. In an attempt to assign the involvement of the different zinc ligands in the catalytic properties of BcII, individual substitutions of selected amino acids were generated. With the exception of His(116)-->Ser (H116S), C221A and C221S, the mono- and di-zinc forms of all the other mutants were poorly active. The activity of H116S decreases by a factor of 10 when compared with the wild type. The catalytic efficiency of C221A and C221S was zinc-dependent. The mono-zinc forms of these mutants exhibited a low activity, whereas the catalytic efficiency of their respective di-zinc forms was comparable with that of the wild type. Surprisingly, the zinc contents of the mutants and the wild-type BcII were similar. These data suggest that the affinity of the beta-lactamase for the metal was not affected by the substitution of the ligand. The pH-dependence of the H196S catalytic efficiency indicates that the zinc ions participate in the hydrolysis of the beta-lactam ring by acting as a Lewis acid. The zinc ions activate the catalytic water molecule, but also polarize the carbonyl bond of the beta-lactam ring and stabilize the development of a negative charge on the carbonyl oxygen of the tetrahedral reaction intermediate. Our studies also demonstrate that Asn(233) is not directly involved in the interaction with the substrates. PMID:11964169

  13. DNA Recognition by the DNA Primase of Bacteriophage T7: A Structure Function Study of the Zinc-Binding Domain

    SciTech Connect

    Akabayov, B.; Lee, S; Akabayov, S; Rekhi, S; Zhu, B; Richardson, C

    2009-01-01

    Synthesis of oligoribonucleotide primers for lagging-strand DNA synthesis in the DNA replication system of bacteriophage T7 is catalyzed by the primase domain of the gene 4 helicase-primase. The primase consists of a zinc-binding domain (ZBD) and an RNA polymerase (RPD) domain. The ZBD is responsible for recognition of a specific sequence in the ssDNA template whereas catalytic activity resides in the RPD. The ZBD contains a zinc ion coordinated with four cysteine residues. We have examined the ligation state of the zinc ion by X-ray absorption spectroscopy and biochemical analysis of genetically altered primases. The ZBD of primase engaged in catalysis exhibits considerable asymmetry in coordination to zinc, as evidenced by a gradual increase in electron density of the zinc together with elongation of the zinc-sulfur bonds. Both wild-type primase and primase reconstituted from purified ZBD and RPD have a similar electronic change in the level of the zinc ion as well as the configuration of the ZBD. Single amino acid replacements in the ZBD (H33A and C36S) result in the loss of both zinc binding and its structural integrity. Thus the zinc in the ZBD may act as a charge modulation indicator for the surrounding sulfur atoms necessary for recognition of specific DNA sequences.

  14. 21 CFR 582.5985 - Zinc chloride.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Zinc chloride. 582.5985 Section 582.5985 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5985 Zinc chloride. (a) Product. Zinc chloride. (b) Conditions of use. This substance...

  15. 21 CFR 182.8988 - Zinc gluconate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Zinc gluconate. 182.8988 Section 182.8988 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8988 Zinc gluconate. (a) Product. Zinc gluconate. (b) Conditions of use. This substance is generally recognized as safe when...

  16. 21 CFR 73.2991 - Zinc oxide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Zinc oxide. 73.2991 Section 73.2991 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2991 Zinc oxide. (a) Identity and specifications. The color additive zinc oxide shall conform in identity and specifications to the requirements of §...

  17. 21 CFR 582.5991 - Zinc oxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Zinc oxide. 582.5991 Section 582.5991 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is...

  18. 21 CFR 182.8991 - Zinc oxide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Zinc oxide. 182.8991 Section 182.8991 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally recognized as safe when used...

  19. 21 CFR 182.8988 - Zinc gluconate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Zinc gluconate. 182.8988 Section 182.8988 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8988 Zinc gluconate. (a) Product. Zinc gluconate....

  20. 21 CFR 182.8991 - Zinc oxide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Zinc oxide. 182.8991 Section 182.8991 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8991 Zinc oxide. (a) Product. Zinc oxide. (b) Conditions of use. This substance is generally recognized as safe when used...