Surface Modification of Zinc with an Oxime for Corrosion Protection in Chloride Medium

Directory of Open Access Journals (Sweden)

Ganesha Achary

2013-01-01

Full Text Available The surface treatment of zinc was done with different concentrations of an oxime (2E-2-(hydroxylamino-1,2-diphenylethanol molecule by the immersion method. The electrochemical corrosion studies of surface-treated zinc specimens were performed in aqueous sodium chloride solution (1 M, pH 5.0 at different temperatures in order to study the corrosion mechanism. The recorded electrochemical data indicated a basic modification of the cathodic corrosion behavior of the treated zinc resulting in a decrease of the electron transfer rate. The zinc samples treated by immersion in the inhibiting organic solution presented good corrosion resistance. Using scanning electron microscopy (SEM, it was found that a protective film was formed on the surface of zinc.

Intercalation studies of zinc hydroxide chloride: Ammonia and amino acids

Science.gov (United States)

Arízaga, Gregorio Guadalupe Carbajal

2012-01-01

Zinc hydroxide chloride (ZHC) is a layered hydroxide salt with formula Zn5(OH)8Cl2·2H2O. 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 °C while the exothermic event in ZHN was 366 °C and in the LDH at 276 °C.

Mutual effect of zinc (2) and cadmium (2) during extraction with tributil phosphate from lithium chloride solutions

International Nuclear Information System (INIS)

Prokuev, V.A.; Belousov, E.A.

1980-01-01

Mutual effect of zinc and cadmium chlorides during extraction with tributyl phosphate at 5, 25 and 45 deg C from LiCl solutions is studied. The conclusion about the suppression of zinc and cadmium extraction by extracting macroelement (cadmium and zinc correspondingly) as the result of manifestation of general ion effect (lithium ion) in the extraction systems is made. It is established that the suppression of zink and cadmium extraction increases with the temperature decrease. On the base of the obtained experimental data the different type of extraction element distribution curves at the extraction from the muriatic solutions and lithium chloride solutions with tributyl phosphate is discussed

Interaction of Zinc Chloride with an Aromatase Inhibitor (Letrozole on Anxiety in Adult Male Rats

Directory of Open Access Journals (Sweden)

Sahar Charghan

2016-12-01

Full Text Available Abstract Background: Aromatase is an enzyme converts androstenedione and testosterone to estrone and estradiol, respectively. According to the role of testosterone and zinc in reducing anxiety and the relation between androgenic system function and zinc supplementations, in this research, the effect of zinc chloride injection was analysed in rats which aromatase enzyme was inhibited by aromatase inhibitor (letrozole. Materials and Methods: Adult male Wistar rats (weighing 225±25 g were used. Animals were divided into 12 groups and based on their weight, aromatase inhibitor (letrozole was injected (subcutaneously, and 30 minutes later, ZnCl2 or its solvent (saline was injected intra-peritoneal. Control group was received both solvents (DMSO and saline respectively. Anxiety levels were tested in the elevated plus maze 30 minutes after the last injection, and thereafter, open field was used for measurement of the locomotors activity of animals. Results: The results showed a significant decrease in the percentage of time spent in open arms in letrozole (1.25 mg/kg treated group as compared to that of solvent group. The locomotors activity significantly decreased between letrozole (1.25 mg/kg with the control group. The combined groups received letrozole (2.5 mg/kg and different amounts of zinc chloride (2.5, 5, 10 mg/kg, significantly reduced (p<0.05 the percentage of time spent in the open arm, comparing to the control group. Groups that received the combination of zinc chloride (2.5 mg/kg and different amounts of letrozole (1.25, 5, 10 mg/kg, showed no significant difference in the percentage of entry and time spent in the open arms. Conclusion: Totally, the present study suggests that letrozole alone increased anxiety and decreased locomotors activity and could interfere with anxiolytic effect of ZnCl2 as well.

Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent

International Nuclear Information System (INIS)

McLaughlin, D.F.; Stoltz, R.A.

1988-01-01

In an extractive distillation method for separating hafniuim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which extractive distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a molten salt solvent is circulated into the reflux condenser and through the column to provide a liquid phase, and wherein molten salt solvent containing zirconium tetrachloride is taken from the reboiler and run through a stripper to remove zirconium tetrachloride product from the molten salt solvent and the stripped molten salt solvent is returned to the reflux condenser and hafnium tetrachloride enriched vapor is taken as product from the reflux condenser, the improvement is described comprising: the molten salt having a composition of at least 30 mole percent zinc chloride and at least 10 mole percent of lead chloride

The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

International Nuclear Information System (INIS)

Preston, J.S.; Du Preez, A.C.

1985-01-01

The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

Studies of micromorphology and current efficiency of zinc electrodeposited from flowing chloride electrolytes

Energy Technology Data Exchange (ETDEWEB)

Mc Vay, Laura [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

1986-05-01

Results of a study of the micromorphology and current efficiency of zinc electrodeposited from flowing, acidic chloride solutions are reported. The effects of six variables were examined: flow rate, current density, zinc and hydrogen ion concentration, concentrations of nickel, iron and cadmium impurity ions, and the nature of the substrate. The development of micromorphology was studied in-situ by means of videomicrography and ex-situ by means of scanning electron microscopy. This investigation focused on the formation of grooved deposits, which are found under a wide range of deposition conditions. The major conclusions of this study are: the most important variable determining whether grooved deposits form is the interfacial concentration; large protrusions orient themselves parallel to the flow direction with the orientation starting upstream and progressing downstream; large protrusions become ridges due to growth of the highest current density portions of the electrode under mass transport control. The current efficiency was measured using EDTA titration and weight measurements. The fraction of the current taken by zinc deposition increased with zinc concentration, ranging up to 100%, and decreased with pH. The efficiency of zinc deposition was affected by the flow rate and the substrate employed. Impurities lowered the current efficiency.

Interaction between nanoparticles generated by zinc chloride treatment and oxidative responses in rat liver

Directory of Open Access Journals (Sweden)

Azzouz I

2013-12-01

Full Text Available Inès Azzouz, Hamdi Trabelsi, Amel Hanini, Soumaya Ferchichi, Olfa Tebourbi, Mohsen Sakly, Hafedh AbdelmelekLaboratory of Integrative Physiology, Faculty of Sciences of Bizerte, Carthage University, TunisiaAbstract: The aim of the present study was to investigate the interaction of zinc chloride (3 mg/kg, intraperitoneally [ip] in rat liver in terms of the biosynthesis of nanoparticles. Zinc treatment increased zinc content in rat liver. Analysis of fluorescence revealed the presence of red fluorescence in the liver following zinc treatment. Interestingly, the co-exposure to zinc (3 mg/kg, ip and selenium (0.20 mg/L, per os [by mouth] led to a higher intensity of red fluorescence compared to zinc-treated rats. In addition, X-ray diffraction measurements carried out on liver fractions of zinc-treated rats point to the biosynthesis of zinc sulfide and/or selenide nanocomplexes at nearly 51.60 nm in size. Moreover, co-exposure led to nanocomplexes of about 72.60 nm in size. The interaction of zinc with other mineral elements (S, Se generates several nanocomplexes, such as ZnS and/or ZnSe. The nanocomplex ZnX could interact directly with enzyme activity or indirectly by the disruption of mineral elements' bioavailability in cells. Subacute zinc or selenium treatment decreased malondialdehyde levels, indicating a drop in lipid peroxidation. In addition, antioxidant enzyme assays showed that treatment with zinc or co-treatment with zinc and selenium increased the activities of glutathione peroxidase, catalase, and superoxide dismutase. Consequently, zinc complexation with sulfur and/or selenium at nanoscale level could enhance antioxidative responses, which is correlated to the ratio of number of ZnX nanoparticles (X=sulfur or X=selenium to malondialdehyde level in rat liver.Keywords: nanocomplexes biosynthesis, antioxidative responses, X-ray diffraction, fluorescence microscopy, liver

Indium Doped Zinc Oxide Thin Films Deposited by Ultrasonic Chemical Spray Technique, Starting from Zinc Acetylacetonate and Indium Chloride

Directory of Open Access Journals (Sweden)

Rajesh Biswal

2014-07-01

Full Text Available The physical characteristics of ultrasonically sprayed indium-doped zinc oxide (ZnO:In thin films, with electrical resistivity as low as 3.42 × 10−3 Ω·cm and high optical transmittance, in the visible range, of 50%–70% is presented. Zinc acetylacetonate and indium chloride were used as the organometallic zinc precursor and the doping source, respectively, achieving ZnO:In thin films with growth rate in the order of 100 nm/min. The effects of both indium concentration and the substrate temperature on the structural, morphological, optical, and electrical characteristics were measured. All the films were polycrystalline, fitting well with hexagonal wurtzite type ZnO. A switching in preferential growth, from (002 to (101 planes for indium doped samples were observed. The surface morphology of the films showed a change from hexagonal slices to triangle shaped grains as the indium concentration increases. Potential applications as transparent conductive electrodes based on the resulting low electrical resistance and high optical transparency of the studied samples are considered.

Does the oral zinc tolerance test measure zinc absorption

Energy Technology Data Exchange (ETDEWEB)

Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

1985-01-01

Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi /sup 65/ZnCl/sub 2/ and a non-absorbed marker, /sup 51/CrCl/sub 3/, dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with /sup 65/Zn and /sup 51/Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and /sup 65/Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and /sup 65/Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption.

Does the oral zinc tolerance test measure zinc absorption

International Nuclear Information System (INIS)

Valberg, L.S.; Flanagan, P.R.; Brennan, J.; Chamberlain, M.J.

1985-01-01

Increases in plasma zinc concentration were compared with radiozinc absorption after oral test doses. Ten healthy, fasting subjects were each given 385 mumol zinc chloride (25 mg Zn) labelled with 0.5 muCi 65 ZnCl 2 and a non-absorbed marker, 51 CrCl 3 , dissolved in 100 ml of water; another 10 persons were given 354 mumol zinc chloride and 125 g of minced turkey containing 31 mumol zinc also labelled with 65 Zn and 51 Cr. Measurements were made of plasma zinc concentration at hourly intervals for 5 hours, radiozinc absorption by stool counting of unabsorbed radioactivity 12-36 hours later, and radiozinc retention by whole body counting at 7 days. The mean percentage of radiozinc absorbed and retained in the body from the two test meals was found to be identical (42%). In contrast the increased area under the plasma zinc curve up to 5 hours after the turkey meal, 28 +/- 9 mumol/L (mean +/- SD) was significantly less than that for zinc chloride alone, 47 +/- 15 mumol/L, p less than 0.005. Despite this difference, a good correlation was found between the area under the plasma zinc curve and 65 Zn absorption in individual subjects after each meal. The discrepancy between the results of zinc absorption derived from the plasma zinc curve and 65 Zn absorption for the liquid and solid test meals was most likely explained by binding of zinc to food and delayed gastric emptying of the solid meal. With a test meal of turkey meat at least this dampened the plasma appearance of zinc but did not affect its overall absorption

Lewis acidity dependency of the electrochemical window of zinc chloride-1-ethyl-3-methylimidazolium chloride ionic liquids

International Nuclear Information System (INIS)

Hsiu, S-I; Huang, J.-F.; Sun, I-W.; Yuan, C.-H.; Shiea, Jantaie

2002-01-01

Negative ion fast atom bombardment mass spectra (FAB-MS) recorded for ZnCl 2 -1-ethyl-3-methylimidazolium chloride (ZnCl 2 -EMIC) ionic liquids with various compositions indicate that various Lewis acidic chlorozincate clusters (ZnCl 3 - , Zn 2 Cl 5 - and Zn 3 Cl 7 - ) are present in ZnCl 2 -EMIC ionic liquids depending on the percentage of ZnCl 2 used in preparing the ionic liquids; higher ZnCl 2 percentage favors the larger clusters. Cyclic voltammetry reveals that the potential limits for a basic 1:3 ZnCl 2 -EMIC melt correspond to the cathodic reduction of EMI + and anodic oxidation of Cl - , giving an electrochemical window of approximately 3.0 V which is the same as that observed for basic AlCl 3 -EMIC ionic liquids. For acidic ionic liquids that have a ZnCl 2 /EMIC molar ratio higher than 0.5:1, the negative potential limit is due to the deposition of metallic zinc, and the positive potential limit is due to the oxidation of the chlorozincate complexes. All the acidic ionic liquids exhibit an electrochemical window of approximately 2 V, although the potential limits shifted in the positive direction with increasing ZnCl 2 mole ratio. Underpotential deposition of zinc was observed on Pt and Ni electrodes in the acidic ionic liquids. At proper temperatures and potentials, crystalline zinc electrodeposits were obtained from the acidic ionic liquids

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

Science.gov (United States)

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.

The extraction of zinc from chloride solutions using dibutyl butylphosphonate (DBBP in Exxsol D100

Directory of Open Access Journals (Sweden)

Alguacil, F. J.

1999-08-01

Full Text Available The reaction of zinc chloride with dibutyl butylphosphonate in Exxsol D100 has been studied. The distribution coefficient of zinc is independent of equilibrium pH, thus, suggesting a solvation extraction reaction. Experimental data indicate that this reaction is exothermic (AH°=-28.4 kJ/mol. Slope analysis for the system at various DBBP concentrations reveals the formation in the loaded organic phases of species which probable 1:2 (Zn:DBBP stoichiometries. This was confirmed by results obtained at full DBBP Zn-loading capacity. The stoichiometric factor of water in the extraction reaction is found to be 4, whereas experimental data also indicated that two chloride ions are involved for each metal extracted, resulting in a ZnCl₂∙2L∙4H₂O stoichiometry (L represents the extractant.

Se estudia la extracción de zinc, en medio cloruro, con el dibutil butilfosfonato disuelto en Exxsol D100. El coeficiente de distribución del metal es independiente del pH de equilibrio de la fase acuosa, lo que sugiere un mecanismo de extracción por solvatación. Los resultados experimentales indican que la reacción es exotérmica (AH°=-28,4 kJ/mol. Mediante análisis de la pendiente obtenida cuando se emplean distintas concentraciones de DBBP en la extracción de zinc se deduce la formación de una especie con estequiometría 1:2 (Zn:DBBP en la fase orgánica. Este hecho se confirma con los resultados obtenidos cuando se satura completamente la fase orgánica. En esta fase, el factor estequiométrico para el agua es 4, mientras que para el ion cloruro es 2, por lo que la especie extraída tiene una estequiometría final representada por ZnCl₂∙2L∙4H₂O (L representa al agente de extracción.

Could vitamin C and zinc chloride protect the germ cells against sodium arsenite?

Science.gov (United States)

Altoé, L S; Reis, I B; Gomes, Mlm; Dolder, H; Pirovani, Jc Monteiro

2017-10-01

Arsenic (As) is commonly associated with natural and human processes such as volcanic emissions, mining and herbicides production, being an important pollutant. Several studies have associated As intake with male fertility reduction, thus the aim of the present study was to evaluate whether vitamin C and/or zinc would counteract As side effects within the testicles. Adult male Wistar rats were divided into six experimental groups: control, sodium arsenite (5 mg/kg/day), vitamin C (100 mg/kg/day), zinc chloride (ZnCl 2 ; 20 mg/kg/day), sodium arsenite + vitamin C and sodium arsenite + ZnCl 2 . Testicles and epididymis were harvested and either frozen or routinely processed to be embedded in glycol methacrylate resin. As reduced the seminiferous epithelium and tubules diameter due to germ cell loss. In addition, both the round spermatids population and the daily sperm production were reduced. However, ZnCl 2 and vitamin C showed to be effective against such side effects, mainly regarding to sperm morphology. Long-term As intake increased the proportions of abnormal sperm, whereas the concomitant intake of As with zinc or vitamin C enhanced the proportions of normal sperm, showing that such compounds could be used to protect this cell type against morphological defects.

Effects of iron, tin, and copper on zinc absorption in humans

International Nuclear Information System (INIS)

Valberg, L.S.; Flanagan, P.R.; Chamberlain, M.J.

1984-01-01

Zinc absorption as measured by body retention of [65Zn]zinc chloride or a turkey test meal extrinsically labeled with 65Zn was determined in human subjects by whole body counting after 7 days. Average 65Zn absorption from zinc chloride in persons with a high iron-absorbing capacity was similar to persons with a low capacity to absorb iron. Inorganic iron, 920 mumol (51 mg), or HB iron, 480 mumol (26 mg), inhibited 65Zn absorption from 92 mumol (6 mg) of zinc chloride. When 610 mumol of iron (34 mg) was added to a turkey test meal containing 61 mumol of zinc (4 mg), 65Zn absorption was not inhibited. Tin, 306 mumol (36 mg), given with zinc chloride or turkey test meals (61 mumol, 4 mg, of Zn) significantly reduced 65Zn absorption. Copper, 79 mumol (5 mg), had no significant effect on the 65Zn absorption from 7.9 mumol (0.5 mg) of zinc chloride. In summary, the capacity to absorb iron did not influence 65Zn absorption, but both inorganic iron and heme-iron inhibited 65Zn absorption from zinc chloride. Inorganic iron had no effect, however, on 65Zn absorption from the turkey test meal. Tin in a large dose also inhibited 65Zn absorption from both zinc chloride and the turkey test meal

Textural and chemical properties of zinc chloride activated carbons prepared from pistachio-nut shells

Energy Technology Data Exchange (ETDEWEB)

Ting, Yang [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Lua, Aik Chong [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

2006-12-10

The effects of activation temperature on the textural and chemical properties of the activated carbons prepared from pistachio-nut shells using zinc chloride activation under both inert nitrogen gas atmosphere and vacuum condition were studied. Relatively low temperature of 400 deg. C was beneficial for the development of pore structures. Too high an activation temperature would lead to sintering of volatiles and shrinkage of the carbon structure. The microstructures and microcrystallinity of the activated carbons prepared were examined by scanning electron microscope and powder X-ray diffraction techniques, respectively, while Fourier transform infrared spectra determined the changes in the surface functional groups at the various stages of preparation.

Textural and chemical properties of zinc chloride activated carbons prepared from pistachio-nut shells

International Nuclear Information System (INIS)

Yang Ting; Lua, Aik Chong

2006-01-01

The effects of activation temperature on the textural and chemical properties of the activated carbons prepared from pistachio-nut shells using zinc chloride activation under both inert nitrogen gas atmosphere and vacuum condition were studied. Relatively low temperature of 400 deg. C was beneficial for the development of pore structures. Too high an activation temperature would lead to sintering of volatiles and shrinkage of the carbon structure. The microstructures and microcrystallinity of the activated carbons prepared were examined by scanning electron microscope and powder X-ray diffraction techniques, respectively, while Fourier transform infrared spectra determined the changes in the surface functional groups at the various stages of preparation

Chromate coating of zinc-aluminum plating on mild steel

International Nuclear Information System (INIS)

Haque, I.; Khan, A.; Nadeem, A.

2005-01-01

The chromate coating on zinc-aluminium deposits has been studied. Zinc-aluminium deposition from non-cyanide bath was carried out at current density 3-3.5 A/dm/sup 2/, plating voltage approx. equal to 1.25 V, temperature 18-20 deg. C, for 15 min. The effect of aluminium chloride on the rest potentials of golden, colorless and non-chromated zinc-aluminium alloy deposits was observed. It was found that rest potential was slightly increased with the increase in the concentration of aluminium chloride, only in the case of golden chromating. The rest potential of colorless chromated zinc-aluminium deposits on mild steel were observed to have no correlation with aluminium chloride concentration. The abrasion resistance of colorless chromating was better than golden chromating. (author)

The protective nature of passivation films on zinc: surface charge

International Nuclear Information System (INIS)

Muster, Tim H.; Cole, Ivan S.

2004-01-01

The influence of oxide surface charge on the corrosion performance of zinc metals was investigated. Oxidised zinc species (zinc oxide, zinc hydroxychloride, zinc hydroxysulfate and zinc hydroxycarbonate) with chemical compositions similar to those produced on zinc during atmospheric corrosion were formed as particles from aqueous solution, and as passive films deposited onto zinc powder, and rolled zinc, surfaces. Synthesized oxides were characterised by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and electron probe X-ray microanalysis. The zeta potentials of various oxide particles, as determined by microelectrophoresis, are reported as a function of pH. Particulates containing a majority of zinc hydroxycarbonate and zinc hydroxysulfate crystallites were found to possess a negative surface charge below pH 6, whilst zinc oxide-hydroxide and zinc hydroxychloride crystallites possessed isoelectric points (IEP's) higher than pH 8. The ability of chloride species to pass through a bed of 3 μm diameter zinc powder was found to increase for surfaces possessing carboxy and sulfate surface species, suggesting that negatively charged surfaces can aid in the repulsion of chloride ions. Electrochemical analysis of the open-circuit potential as a function of time at a fixed pH of 6.5 showed that the chemical composition of passive films on zinc plates influenced the ability of chloride ions to access anodic sites for periods of approximately 1 h

Lewis acidic (choline chloride.3ZnCl2) ionic liquid: A green and ...

Indian Academy of Sciences (India)

Choline chloride; zinc chloride; ionic liquid; one-pot; triarylmethane. 1. Introduction ... applications such as zinc electroplating11 and batter- ies.12 It has also been used as ... as indicated by Thin Layer Chromatography (TLC), the catalyst was ...

Laser-induced optical effects in triglycine-zinc chloride single crystals

International Nuclear Information System (INIS)

Wojciechowski, A.; Kityk, I.V.; Lakshminarayana, G.; Fuks-Janczarek, I.; Berdowski, J.; Berdowska, E.; Tylczynski, Z.

2010-01-01

The influence of irradiation by a cw 532 nm laser on the behavior of the absorption and optical second harmonic generation of triglicyne-zinc chloride crystal has been studied. Additional absorption bands correlate well with the time of the cw laser exposure. These lines occur at 260 nm, 305 nm, and, with small intensity, at 355 nm. The remaining part of the spectra shows substantially less changes. According to the performed quantum chemical simulations, one may expect that the observed dependences and the stability of the observed photoinduced changes are caused by formation of polarized electron-phonon states and the principal role should belong here to the electron-phonon anharmonicities, which cause the effects described by the non-polar third rank polar tensor like optical second harmonic generation. The increasing optical SHG signal shows a clear correlation with the behavior of the green laser-532 nm. It is important principal that for the blue laser-405 nm, the SHG effect is substantially less. This may reflect that the additional absorption maxima may be responsible for the non-linear optical effects. The effect demonstrates a slow time decay.

Cathodic protection of steel by electrodeposited zinc-nickel alloy coatings

Energy Technology Data Exchange (ETDEWEB)

Baldwin, K.R.; Smith, C.J.E. [Defence Research Agency, Farnborough (United Kingdom). Structural Materials Centre; Robinson, M.J. [Cranfield Univ. (United Kingdom). School of Industrial and Manufacturing Science

1995-12-01

The ability of electrodeposited zinc-nickel alloy coatings to cathodically protect steel was studied in dilute chloride solutions. The potential distribution along steel strips partly electroplated with zinc-nickel alloys was determined, and the length of exposed steel that was held below the minimum protection potential (E{sub prot}) was taken as a measure of the level of cathodic protection (CP) provided by the alloy coatings. The level of CP afforded by zinc alloy coatings was found to decrease with increasing nickel content. When nickel content was increased to {approx} {ge} 21 wt%, no CP was obtained. Surface analysis of uncoupled zinc-nickel alloys that were immersed in sodium chloride (NaCl) solutions showed the concentration of zinc decreased in the surface layers while the concentration of nickel increased, indicating that the alloys were susceptible to dezincification. The analysis of zinc-nickel alloy coatings on partly electroplated steel strips that were immersed in chloride solution showed a significantly higher level of dezincification than that found for uncoupled alloy coatings. This effect accounted for the rapid loss of CP afforded to steel by some zinc alloy coatings, particularly those with high initial nickel levels.

Effect of zinc supplementation of pregnant rats on short-term and long-term memory of their offspring

International Nuclear Information System (INIS)

Ali, M.A.; Ghotbeddin, Z.; Parham, G.H.

2007-01-01

To see the dose dependent effects of zinc chloride on the short-term and long-term memory in a shuttle box (rats). Six pair adult wistar rats were taken for this experiment. One group of pregnant rats received a daily oral dose of 20 mg/kg Zn as zinc chloride and the remaining groups received a daily oral dose of (30, 50, 70,100 mg/kg) zinc chloride for two weeks by gavage. One month after birth, a shuttle box was used to test short-term and long-term memory. Two criteria were considered to behavioral test, including latency in entering dark chamber and time spent in the dark chamber. This experiment showed that oral administration of ZnCl/sub 2/ with (20, 30, 50 mg/kg/day) doses after 2 weeks at the stage of pregnancy, can improve the working memory of their offspring (p<0.05). Where as ZnCl/sub 2/ with 30 mg/kg/day dose has been more effective than other doses (p<0.001). But rat which received ZnCl/sub 2/ with 100 mg/kg/day at the stage of pregnancy, has shown significant impairment in working (short-term) memory of their offspring (p<0.05) and there was no significant difference in reference (long-term) memory 3 for any of groups. This study has demonstrated that zinc chloride consumption with 30 mg/kg/day dose for two weeks at the stage of pregnancy in rats, has positive effect on short-term memory on their offspring. But consumption of enhanced zinc 100 mg/kg/day in pregnant rats can cause short-term memory impairment. On the other hand, zinc supplementation such as zinc chloride has no effect on long-term memory. (author)

The extraction of zinc and other minor metals from concentrated ammonium chloride solutions with D2EHPA and Cyanex 272

Directory of Open Access Journals (Sweden)

Amer, S.

1995-12-01

Full Text Available A comparative study is made of the extractants D2EHPA and Cyanex 272 for the zinc and minor metal extraction from aqueous concentrated ammonium chloride solutions, as those of the leaching liquors of the CENIM-LNETI process. Extraction equilibrium data for zinc are presented as extraction isotherms at constant pH and at a temperature of 50 °C. Zinc extraction and coextraction of minor metal ions as Cu, Ca, Pb, Mg, Cd, Co, Ni and Hg are studied. Mercury does not extract from concentrated ammonium chloride solutions. Cyanex 272 shows a better selectivity for zinc with regard to the minor metals than D2EHPA, which is especially remarkable for calcium, the most coextracted element by D2EHPA. Nickel and cadmium coextraction is negligible for both extractants. The possible use of the Cyanex 272 as an alternative to D2EHPA is considered.

Se realiza un estudio comparativo del comportamiento del D2EHPA y del Cyanex 272 durante la extracción del cinc y otros metales minoritarios de soluciones acuosas concentradas de cloruro amónico, como las de las soluciones de lixiviación del proceso CENIM-LNETI. Se presentan los datos de equilibrio de extracción del cinc en forma de isotermas de extracción a una temperatura de 50 °C y pH constante y se estudia la coextracción de los metales minoritarios Cu, Ca, Pb, Mg, Cd, Co, Ni y Hg. El mercurio no se extrae de las soluciones concentradas de cloruro amónico. La selectividad del Cyanex 272 para el cinc respecto de esos metales minoritarios es mejor que la del D2EHPA, siendo verdaderamente notable para el calcio, que es la impureza que más se coextrae con el D2EHPA. La coextracción de níquel y de cadmio es muy pequeña para ambos extractantes. Se considera la posibilidad del uso alternativo del Cyanex 272 en lugar del D2EHPA.

Removal of nitrate from water by adsorption onto zinc chloride treated activated carbon

DEFF Research Database (Denmark)

Bhatnagar, A.; Ji, M.; Choi, Y.H.

2008-01-01

Adsorption study with untreated and zinc chloride (ZnCl2) treated coconut granular activated carbon (GAC) for nitrate removal from water has been carried out. Untreated coconut GAC was treated with ZnCl2 and carbonized. The optimal conditions were selected by studying the influence of process...... variables such as chemical ratio and activation temperature. Experimental results reveal that chemical weight ratio of 200% and temperature of 500 degrees C was found to be optimum for the maximum removal of nitrate from water. Both untreated and ZnCl2 treated coconut GACs were characterized by scanning...... capacity of untreated and ZnCl2 treated coconut GACs were found 1.7 and 10.2 mg/g, respectively. The adsorption of nitrate on ZnCl2 treated coconut GAC was studied as a function of contact time, initial concentration of nitrate anion, temperature, and pH by batch mode adsorption experiments. The kinetic...

Habit modification of bis-thiourea zinc chloride (ZTC) semi organic crystals by impurities

Science.gov (United States)

Ruby Nirmala, L.; Thomas Joseph Prakash, J.

2013-06-01

Single crystals of bis-thiourea zinc chloride (ZTC) doped with metal ion (Li+) possess excellent nonlinear optical properties. These crystals were grown by slow evaporation solution growth technique. The effect of Li+ dopant on the growth and properties of ZTC single crystal were investigated and reported. The grown crystals were crystallized in orthorhombic structure with non-centro symmetric space group Pn21a through the parent compound. The amount of dopant incorporated in the parent crystal was revealed by the inductively coupled plasma (ICP-OES) studies. The FT-IR spectroscopy study was done for finding and confirming the functional groups present in the compound. The UV-Visible spectral study was carried out to find the optical behavior and transparency nature of the grown crystal. TG/DTA measurements and Vickers microhardness measurements were traced to find out the thermal and mechanical stability of the grown crystals respectively. Using Nd:YAG laser, the Second harmonic generation (SHG) for the grown crystals were confirmed.

PREPARATION OF ZINC ENRICHED YEAST (SACCHAROMYCES CEREVISIAE BY CULTIVATION WITH DIFFERENT ZINC SALTS

Directory of Open Access Journals (Sweden)

Ľuboš Harangozo

2012-02-01

Full Text Available The yeast Saccharomyces cerevisiae is the best known microorganism and therefore widely used in many branches of industry. This study aims to investigate the accumulation of three inorganic zinc salts. Our research presents the ability of this yeast to absorb zinc from liquid medium and such enriched biomass use as a potential source of microelements in animal and/or human nutrition. It was found that the addition of different zinc forms, i.e. zinc nitrate, zinc sulphate and zinc chloride in fixed concentrations of 0, 25, 50 and 100 mg.100 ml-1 did not affect the amount of dry yeast biomass yielded, i.e. 1.0 – 1.2 g of yeast cells from 100 ml of cultivation medium, while higher presence of zinc solutions caused significantly lower yield of yeast biomass. The highest amount of zinc in yeast cells was achieved when added in the form of zinc nitrate in concentration of 200 mg.100 ml-1 YPD medium. The increment of intracellular zinc was up to 18.5 mg.g-1 of yeast biomass.

Protective effect of ginger and zinc chloride mixture on the liver and kidney alterations induced by malathion toxicity.

Science.gov (United States)

Baiomy, Ahmed A; Attia, Hossam F; Soliman, Mohamed M; Makrum, Omar

2015-03-01

This study was carried out on four groups of male Wistar rats, 10 rats per group. Group I got open access to food intake and water with normal balanced diet. Group II was administered 400 mg ginger per kg body weight (BW) and zinc chloride (ZnCl2) (300 mg/L) diluted in tap water for 4 months. Group III was administered malathion at a dose of 50 mg/kg BW/day in 0.2 mL corn oil via gavages for 4 months. This dose equal to 1/50 of the LD50. Group IV was given a mixture of 400 mg ginger per kg BW and ZnCl2 (300 mg/L) diluted in tap water in addition to 100 mg malathion/kg BW for 4 months. The liver showed histopathological changes include congestion, edema, and leucocytic infiltrations which were ameliorated by the addition of ginger and ZnCl2 mixture. The kidney showed cloudy swelling and hydropic degeneration of the renal tubules. These changes were ameliorated by the addition of ginger and ZnCl2 mixture. Ki67 immunoreactivity was localized in the cytoplasm and nuclear membrane. Its expression was estimated as the percentage of cells positively stained by the antibody in the different groups. In conclusion, malathion was toxic to the liver and kidney and must be avoided and protected by the addition of ginger and zinc mixture. © The Author(s) 2015.

Osmoregulated Chloride Currents in Hemocytes from Mytilus galloprovincialis.

Directory of Open Access Journals (Sweden)

Monica Bregante

Full Text Available We investigated the biophysical properties of the transport mediated by ion channels in hemocytes from the hemolymph of the bivalve Mytilus galloprovincialis. Besides other transporters, mytilus hemocytes possess a specialized channel sensitive to the osmotic pressure with functional properties similar to those of other transport proteins present in vertebrates. As chloride fluxes may play an important role in the regulation of cell volume in case of modifications of the ionic composition of the external medium, we focused our attention on an inwardly-rectifying voltage-dependent, chloride-selective channel activated by negative membrane potentials and potentiated by the low osmolality of the external solution. The chloride channel was slightly inhibited by micromolar concentrations of zinc chloride in the bath solution, while the antifouling agent zinc pyrithione did not affect the channel conductance at all. This is the first direct electrophysiological characterization of a functional ion channel in ancestral immunocytes of mytilus, which may bring a contribution to the understanding of the response of bivalves to salt and contaminant stresses.

Comparative studies on acid leaching of zinc waste materials

Science.gov (United States)

Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

2017-11-01

Three industrial waste materials were characterized in terms of their elemental and phase compositions, leaching behaviour in 10% sulfuric acid solution as well as leaching thermal effects. Slag from melting of mixed metallic scrap contained about 50% Zn and 10% Pb. It consisted mainly of various oxides and oxy-chlorides of metals. Zinc spray metallizing dust contained about 77% Zn in form of zinc and/or zinc-iron oxides, zinc metal and Zn-Fe intermetallic. Zinc ash from hot dip galvanizing was a mixture of zinc oxide, metallic zinc and zinc hydroxide chloride and contained about 80% Zn. Dissolution efficiency of zinc from the first material was 80% (independently on the solid to liquid ratio, 50-150 kg/m3), while decrease of the efficacy from 80% to 60% with increased solid to liquid ratio for the two remaining materials was observed. Both increase in the temperature (20 °C to 35 °C) and agitation rate (300 rpm to 900 rpm) did not improve seriously the leaching results. In all cases, transfer of zinc ions to the leachate was accompanied by different levels of solution contamination, depending on the type of the waste. Leaching of the materials was exothermic with the similar reaction heats for two high oxide-type products (slag, zinc ash) and higher values for the spray metallizing dust.

Benzotriazole as an inhibitor of brass corrosion in chloride solution

International Nuclear Information System (INIS)

Kosec, Tadeja; Milosev, Ingrid; Pihlar, Boris

2007-01-01

The current research explores the formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys in chloride solution containing benzotriazole (BTAH), by use of electrochemical techniques, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Electrochemical reactions and surface products formed at the open circuit potential and as a function of the potential range are discussed. The addition of benzotriazole to aerated, near neutral 0.5 M NaCl solution affects the dissolution of copper, zinc, Cu-10Zn and Cu-40Zn alloys. The research also compares the inhibition efficiency and Gibbs adsorption energies of the investigated process. Benzotriazole, generally known as an inhibitor of copper corrosion is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The surface layer formed on alloys in BTAH-inhibited solution comprised both oxide and polymer components, namely Cu 2 O and ZnO oxides, and Cu(I)-BTA and Zn(II)-BTA polymers. The formation of this mixed copper-zinc oxide polymer surface film provides an effective barrier against corrosion of both metal components in chloride solution

Radio -Protective Role of Zinc Administration Pre-Exposure to Gamma-Irradiation in Male Albino Mice

International Nuclear Information System (INIS)

El-Dawy, H.A.; Aly El-Sayed, S.M.

2004-01-01

This study was performed to evaluate the potency of zinc chloride injected subcutaneously (30 mg/kg b.w.) in male albino mice as a radio-protective agent pre exposure to gamma-irradiation. The investigation of the radio-protective role of zinc chloride was accomplished through measuring the levels of sex hormones, and observation of the chromosomal aberrations and sperm-head abnormalities after exposure to gamma-irradiation. The average of abnormal cells with chromosomal aberration and abnormal sperm % on the 7 th and 21 th days were 32% and 40%, and 14% and 22% respectively in mice exposed to radiation alone compared to 12% and 16%, and 5% and 12% respectively in mice treated with zinc chloride pre-irradiation. Treatment of mice with zinc chloride pre-irradiation induced significant amelioration in FSH and LH hormone levels on the 7 th day only of experimentation period, and showed non-significant amelioration in testosterone level

Influence of soil zinc concentrations on zinc sensitivity and functional diversity of microbial communities

International Nuclear Information System (INIS)

Lock, K.; Janssen, C.R.

2005-01-01

Pollution induced community tolerance (PICT) is based on the phenomenon that toxic effects reduce survival of the most sensitive organisms, thus increasing community tolerance. Community tolerance for a contaminant is thus a strong indicator for the presence of that contaminant at the level of adverse concentrations. Here we assessed PICT in 11 soils contaminated with zinc runoff from galvanised electricity pylons and 11 reference soils sampled at 10 m distance from these pylons. Using PICT, the influence of background concentration and bioavailability of zinc on zinc sensitivity and functional diversity of microbial communities was assessed. Zinc sensitivity of microbial communities decreased significantly with increasing zinc concentrations in pore water and calcium chloride extracted fraction while no significant relationship was found with total zinc concentration in the soil. It was also found that functional diversity of microbial communities decreased with increasing zinc concentrations, indicating that increased tolerance is indeed an undesirable phenomenon when environmental quality is considered. The hypothesis that zinc sensitivity of microbial communities is related to background zinc concentration in pore water could not be confirmed. - Zinc sensitivity of microbial communities and functional diversity decrease with increasing zinc concentration in the pore water

Corrosion mechanism of model zinc-magnesium alloys in atmospheric conditions

International Nuclear Information System (INIS)

Prosek, T.; Nazarov, A.; Bexell, U.; Thierry, D.; Serak, J.

2008-01-01

Recently, superior corrosion properties of zinc coatings alloyed with magnesium have been reported. Corrosion behaviour of model zinc-magnesium alloys was studied to understand better the protective mechanism of magnesium in zinc. Alloys containing from 1 to 32 wt.% magnesium, pure zinc, and pure magnesium were contaminated with sodium chloride and exposed to humid air for 28 days. Composition of corrosion products was analyzed using infrared spectroscopy (FTIR), ion chromatography (IC), and Auger electron spectroscopy (AES). The exposure tests were completed with scanning Kelvin probe (SKP) and electrochemical measurements. Weight loss of ZnMg alloys with 1-16 wt.% magnesium was lower than that of pure zinc. Up to 10-fold drop in weight loss was found for materials with 4-8 wt.% Mg in the structure. The improved corrosion stability of ZnMg alloys was connected to the presence of an Mg-based film adjacent to the metal surface. It ensured stable passivity in chloride environment and limited the efficiency of oxygen reduction

Removal of lead from aqueous solution by activated carbon prepared from Enteromorpha prolifera by zinc chloride activation

Energy Technology Data Exchange (ETDEWEB)

Li Yanhui, E-mail: liyanhui@tsinghua.org.cn [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Du Qiuju [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Wang Xiaodong [College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Zhang Pan [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Wang Dechang [College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Wang Zonghua; Xia Yanzhi [Laboratory of Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China)

2010-11-15

Activated carbon was prepared from Enteromorpha prolifera (EP) by zinc chloride activation. The physico-chemical properties of EP-activated carbon (EPAC) were characterized by thermal stability, zeta potential and Boehm titration methods. The examination showed that EPAC has a porous structure with a high surface area of 1688 m{sup 2}/g. Batch adsorption experiments were carried out to study the effect of various parameters such as initial pH, adsorbent dosage, contact time and temperature on Pb(II) ions adsorption properties by EPAC. The kinetic studies showed that the adsorption data followed a pseudo second-order kinetic model. The isotherm analysis indicated that the adsorption data can be represented by Freundlich isotherm model. Thermodynamic studies indicated that the adsorption reaction was a spontaneous and endothermic process.

Removal of lead from aqueous solution by activated carbon prepared from Enteromorpha prolifera by zinc chloride activation

International Nuclear Information System (INIS)

Li Yanhui; Du Qiuju; Wang Xiaodong; Zhang Pan; Wang Dechang; Wang Zonghua; Xia Yanzhi

2010-01-01

Activated carbon was prepared from Enteromorpha prolifera (EP) by zinc chloride activation. The physico-chemical properties of EP-activated carbon (EPAC) were characterized by thermal stability, zeta potential and Boehm titration methods. The examination showed that EPAC has a porous structure with a high surface area of 1688 m 2 /g. Batch adsorption experiments were carried out to study the effect of various parameters such as initial pH, adsorbent dosage, contact time and temperature on Pb(II) ions adsorption properties by EPAC. The kinetic studies showed that the adsorption data followed a pseudo second-order kinetic model. The isotherm analysis indicated that the adsorption data can be represented by Freundlich isotherm model. Thermodynamic studies indicated that the adsorption reaction was a spontaneous and endothermic process.

Zinc composite anode for batteries with solid electrolyte

Science.gov (United States)

Tedjar, F.; Melki, T.; Zerroual, L.

A new negative composite anode for batteries with a solid electrolyte is studied. Using a complex of zinc ammonium chloride mixed with zinc metal powder, the advantage of the Zn/Zn 2+ electrode ( e = -760 mV) is kept while the energy density and the shelf-life of the battery are increased.

Corrosion behaviour of zinc and aluminium in simulated nuclear accident environments

International Nuclear Information System (INIS)

Piippo, J.; Laitinen, T.; Sirkiae, P.

1997-02-01

The corrosion rates of zinc and aluminium were determined in simulated large pipe break and in severe accident cases. An in situ on fine measurement technique, which is based on the resistance measurement of sample wires, was used. In the large pipe break case the corrosion rates of zinc and aluminium were determined at pH 8 and pH 10 in deaerated and in aerated solutions. Tests were also performed in aerated 0.1 M borate buffer solution at pH 9.2. Temperature range was 130 deg C - 50 deg C. The corrosion of zinc appears to be relatively fast in neutral or mildly alkaline aerated water, while both high pH and deaeration tend to reduce the corrosion rates of zinc. The aeration and pH elevation decrease the corrosion rate of aluminium. The simulation of the severe accident case took place in the pH range 3-11 in chloride containing solutions at 50 deg C temperature. The corrosion rate of aluminium was lower than that of zinc, except for the solution with pH 11, in which the corrosion rate of aluminium was practically identical to that of zinc. Both metals corroded more rapidly in the presence of chlorides in acidic and alkalic conditions than in the absence of chlorides at neutral environment. The solubility of zinc and aluminium and the stability of the corrosion products were estimated using thermodynamical calculations. The experimental results and the thermodynamical calculations were in fair agreement. (8 refs.)

Zinc composite anode for batteries with solid electrolyte

Energy Technology Data Exchange (ETDEWEB)

Tedjar, F.; Melki, T.; Zerroual, L. (Setif Univ. (Algeria). Unite de Recherche Electrochimie)

1992-05-01

A new negative composite anode for batteries with a solid electrolyte is studied. Using a complex of zinc ammonium chloride mixed with zinc metal powder, the advantage of the Zn/Zn[sup 2+] electrode (e = -760 mV) is kept while the energy density and the shelf-life of the battery are increased. (orig.).

The development of a micropatterned electrode for studies of zinc electrodeposition

Energy Technology Data Exchange (ETDEWEB)

Sutija, Dave P. [Univ. of California, Berkeley, CA (United States); Muller, Rolf H. [Univ. of California, Berkeley, CA (United States); Tobias, Charles W. [Univ. of California, Berkeley, CA (United States)

1986-12-01

A micropatterned electrode was prepared for the study of electrocrystallization. Using microphotolithography, in conjunction with evaporation and pulse electrodeposition of thin films, a set of artificially roughened electrodes with hemispherical surface features five microns in diameter was developed. Voltammetric studies were conducted to determine the best electrode material. Gold, platinum, and various carbon surfaces were evaluated for zinc nucleation density and hydrogen overpotential. Surface homogeneity was examined by both light and scanning electron microscopy. Gold was determined to possess the best combination of material properties: chemical inertness, low melting point, and a high work function allowing underpotential deposition of zinc which reduces the rate of hydrogen evolution. Stripping coulometry was employed to determine zinc limiting currents, and evaluate effective diffusion coefficients in concentrated zinc chloride solutions. Although the method worked well for dilute zinc chloride and copper sulfate solutions, it failed at higher current densities; the emergence of surface roughness obscured actual limiting current plateaus.

Process for making rare earth metal chlorides

International Nuclear Information System (INIS)

Kruesi, P.R.

1981-01-01

An uncombined metal or a metal compound such as a sulfide, oxide, carbonate or sulfate is converted in a liquid salt bath to the corresponding metal chloride by reacting it with chlorine gas or a chlorine donor. The process applies to metals of groups 1b, 2a, 2b, 3a, 3b, 4a, 5a and 8 of the periodic table and to the rare earth metals. The chlorine donor may be ferric or sulfur chloride. The liquid fused salt bath is made up of chlorides of alkali metals, alkaline earth metals, ammonia, zinc and ferric iron. Because the formed metal chlorides are soluble in the liquid fused salt bath, they can be recovered by various conventional means

Zinc-chelation contributes to the anti-angiogenic effect of ellagic acid on inhibiting MMP-2 activity, cell migration and tube formation.

Directory of Open Access Journals (Sweden)

Sheng-Teng Huang

Full Text Available BACKGROUND: Ellagic acid (EA, a dietary polyphenolic compound, has been demonstrated to exert anti-angiogenic effect but the detailed mechanism is not yet fully understood. The aim of this study was to investigate whether the zinc chelating activity of EA contributed to its anti-angiogenic effect. METHODS AND PRINCIPAL FINDINGS: The matrix metalloproteinases-2 (MMP-2 activity, a zinc-required reaction, was directly inhibited by EA as examined by gelatin zymography, which was reversed dose-dependently by adding zinc chloride. In addition, EA was demonstrated to inhibit the secretion of MMP-2 from human umbilical vein endothelial cells (HUVECs as analyzed by Western blot method, which was also reversed by the addition of zinc chloride. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK, known to down-regulate the MMP-2 activity, was induced by EA at both the mRNA and protein levels which was correlated well with the inhibition of MMP-2 activity. Interestingly, zinc chloride could also abolish the increase of EA-induced RECK expression. The anti-angiogenic effect of EA was further confirmed to inhibit matrix-induced tube formation of endothelial cells. The migration of endothelial cells as analyzed by transwell filter assay was suppressed markedly by EA dose-dependently as well. Zinc chloride could reverse these two effects of EA also in a dose-dependent manner. Since magnesium chloride or calcium chloride could not reverse the inhibitory effect of EA, zinc was found to be involved in tube formation and migration of vascular endothelial cells. CONCLUSIONS/SIGNIFICANCE: Together these results demonstrated that the zinc chelation of EA is involved in its anti-angiogenic effects by inhibiting MMP-2 activity, tube formation and cell migration of vascular endothelial cells. The role of zinc was confirmed to be important in the process of angiogenesis.

Deposition of zinc on deposits on tubes in combustion systems - a thermodynamic study; Deponering av zink i belaeggningar paa panntuber - en termodynamisk studie

Energy Technology Data Exchange (ETDEWEB)

Nolaeng, Bengt; Sjoeblom, Rolf

2011-02-15

The use of recovered wood based fuels sometimes leads to a substantial increase in the rate of corrosion with outages and increase in maintenance costs as a consequence. Therefore, Vaermeforsk has financed two framework programmes on recovered wood based fuels. All results, except those from thermodynamical calculations, support the conclusion that enhanced levels of zinc and chlorine is one of the most important reasons for the development of harmful deposits. The system zinc chloride - potassium chloride contains several intermediate phases, out of which K{sub 2}ZnCl{sub 4} has a considerably higher melting point compared to pure zinc chloride. This provides ground for the suspicion that there may be synergetic effects between potassium and zinc and that condensation from the gas phase therefore might take place at a temperature which is higher than that which has been reported earlier. The purpose of the present study is to investigate the correctness of this hypothesis by means of thermodynamical calculations. As a first step, the energy of the intermediate phase K{sub 2}ZnCl{sub 4} was modelled utilizing results from electrochemical measurements in salt melt. The thermodynamical calculations were conducted using software which had been developed by BeN Systems including a dedicated database. Thus, all calculations have been carried out independently of those performed previously. In order to ensure full comparability, some calculations were carried out using the same input parameters as used previously and the results were essentially identical. After this, thermodynamical calculations were carried out using a database which included the intermediate phase K{sub 2}ZnCl{sub 4}. The results show that the influence of this phase corresponds to an increase in condensation temperature for zinc chloride with more than 200 deg C. A prerequisite for the formation of this phase is that the amount of available chlorine exceeds that of potassium. Similar effects can be

Zinc Electrodeposition from Chloride Solutions onto Glassy Carbon Electrode

OpenAIRE

Mendoza-Huízar, Luis Humberto; Rios-Reyes, Clara Hilda; Gómez-Villegas, María Guadalupe

2009-01-01

An electrochemical study of zinc deposition was carried out in baths containing 0.5 M ZnCl2 and 0.4 M H3BO3. From the voltammetric study it was found that, in our experimental conditions, zinc electrodeposition is quasi-reversible and occurs under charge transfer control. The average coefficient diffusion calculated was D = 7.14 × 10-6 cm²s-1 while the standard constant at electrode charge was 8.78 × 10-3 cms-1. The nucleation and growth parameters determined from the potentiostatic study sho...

Anodic solution of alkali earth alloys in potassium chloride-sodium chloride melts

International Nuclear Information System (INIS)

Volkovich, A.V.

1997-01-01

Generalized results of studying the process of anodic dissolution of alkaline-earth metal alloys with zinc, aluminium and copper in the melts of KCl-NaCl equimolar mixture containing alkaline-earth metal chlorides, are presented. It is shown that during dissolution of both pure liquid metals and their alloys there is no electrode polarization in the range of the current densities lower or comparable in their values to corrosion current

High Discharge Rate Electrodeposited Zinc Electrode for Use in Alkaline Microbattery

Directory of Open Access Journals (Sweden)

A. L. Nor Hairin

2012-01-01

Full Text Available High discharge rate zinc electrode is prepared from electrodeposition process. The electrolytic bath consists of zinc chloride as the metal source and ammonium chloride as the supporting electrolyte. The concentration of the supporting electrolyte is varied from zero until 4 M, while the concentration of zinc chloride is fixed at 2 M. The aim is to produce a porous zinc coating with an enhanced and intimate interfacial area per unit volume. These characteristics shall contribute towards reduced ohmic losses, improved active material utilization, and subsequently producing high rate capacity electrochemical cell. Nitrogen physisorption at 77 K is used to measure the BET surface area and pore volume density of the zinc electrodeposits. The electrodeposited zinc electrodes are then fabricated into alkaline zinc-air microbattery measuring 1 cm2 area x ca. 305 µm thick. The use of inorganic MCM-41 membrane separator enables the fabrication of a compact cell design. The quality of the electrodeposited zinc electrodes is gauged directly from the electrochemical performance of zinc-air cell. Zinc electrodeposits prepared from electrolytic bath of 2 M NH4Cl produces the highest discharge capacity.ABSTRAK: Elektrod zink dengan kadar discas tinggi telah dihasilkan dengan proses saduran elektrokimia. Takungan elektrolit terdiri daripada zink klorida sebagai sumber logam dan ammonium klorida sebagai elektrolit sokongan. Kepekatan elektrolit sokongan diubah daripada sifar hingga 4 M, sementara kepekatan zink klorida ditetapkan pada 2 M. Ini bertujuan untuk mendapatkan saduran zink yang poros dengan luas permukaan per unit isipadu dan sentuhan antaramuka yang dipertingkatkan. Ciri-ciri ini akan menyumbang terhadap pengurangan kehilangan disebabkan kerintangan, pertambahan dalam gunapakai bahan aktif dan akhirnya menghasilkan sel elektrokimia berprestasi tinggi. Physisorpsi nitrogen pada 77 K telah digunakan untuk mengukur luas permukaan BET dan isipadu liang

[The morphofunctional state of the bone marrow in lead and zinc intoxication].

Science.gov (United States)

Vladimtseva, T M; Pashkevich, I A; Salmina, A B

2006-01-01

The nucleolus is a compulsory nuclear structure of all cells of eukaryotes. The quantitative and qualitative characteristics of nuclei show the functional activity of a cell, the rate of its synthesis of RNA and portents, and its metabolic state. Heavy metals (zinc chloride and lead acetate) were comparatively investigated for their effects on the nucleolar apparatus of bone marrow cells in in vivo experiments. Zinc chloride and lead acetate were ascertained to damage the nucleolar apparatus of cells, thus decreasing their transcriptional activity or irreversibly damaging them.

Zinc Enolate/Sulfinate Prepared from a Single-Run Reaction Using Zinc Dust with O-Tosylated 4-Hydroxy Coumarin and Pyrone

Energy Technology Data Exchange (ETDEWEB)

Shin, Ueon Sang; Joo, Seong-Ryu; Kim, Seung-Hoi [Dankook University, Cheonan (Korea, Republic of)

2016-07-15

We demonstrated the preparation of new zinc complexes, 2-oxo-2H-chromen-4-yloxy tosylzinc (I), and 6-methyl-2-oxo-2H-pyran-4-yloxy tosylzinc (II), by the oxidative addition of readily available zinc dust into the corresponding 4-tosylated coumarin (A) and pyrone (B), respectively. Of special interest, the thus-obtained zinc complexes showed an electrophile-dependent reactivity. The subsequent coupling reactions of I and II with a variety of acid chlorides provided the O-acylation product in moderate yields. More interestingly, it should be emphasized that the thus-prepared zinc complexes (I and II) functioned both as zinc enolate and zinc sulfinate, providing C(3)-disubstituted product (b) and sulfone (c), respectively, from a single-run reaction when I or II was treated with benzyl halides. Even though somewhat low yields were achieved under the nonoptimized conditions, the novel zinc complexes present another potential application for zinc reagents. Versatile applications of this discovery are currently underway.

Zinc Enolate/Sulfinate Prepared from a Single-Run Reaction Using Zinc Dust with O-Tosylated 4-Hydroxy Coumarin and Pyrone

International Nuclear Information System (INIS)

Shin, Ueon Sang; Joo, Seong-Ryu; Kim, Seung-Hoi

2016-01-01

We demonstrated the preparation of new zinc complexes, 2-oxo-2H-chromen-4-yloxy tosylzinc (I), and 6-methyl-2-oxo-2H-pyran-4-yloxy tosylzinc (II), by the oxidative addition of readily available zinc dust into the corresponding 4-tosylated coumarin (A) and pyrone (B), respectively. Of special interest, the thus-obtained zinc complexes showed an electrophile-dependent reactivity. The subsequent coupling reactions of I and II with a variety of acid chlorides provided the O-acylation product in moderate yields. More interestingly, it should be emphasized that the thus-prepared zinc complexes (I and II) functioned both as zinc enolate and zinc sulfinate, providing C(3)-disubstituted product (b) and sulfone (c), respectively, from a single-run reaction when I or II was treated with benzyl halides. Even though somewhat low yields were achieved under the nonoptimized conditions, the novel zinc complexes present another potential application for zinc reagents. Versatile applications of this discovery are currently underway

Reserve lithium-thionyl chloride battery for missile applications

Science.gov (United States)

Planchat, J. P.; Descroix, J. P.; Sarre, G.

A comparative performance study has been conducted for silver-zinc, thionyl chloride, and thermal batteries designed for such missile applications as ICBM guidance system power supplies. Attention is given to each of the three candidates' conformity to requirements concerning mechanical configuration, electrochemical design, electrolyte reservoir, external case, and gas generator. The silver-zinc and Li-SOCl2 candidates employ similar cell configurations and yield comparable performance. The thermal battery is found to be incapable of meeting battery case temperature-related requirements.

A comprehensive physicochemical, thermal, and spectroscopic characterization of zinc (II) chloride using X-ray diffraction, particle size distribution, differential scanning calorimetry, thermogravimetric analysis/differential thermogravimetric analysis, ultraviolet-visible, and Fourier transform-infrared spectroscopy.

Science.gov (United States)

Trivedi, Mahendra Kumar; Sethi, Kalyan Kumar; Panda, Parthasarathi; Jana, Snehasis

2017-01-01

Zinc chloride is an important inorganic compound used as a source of zinc and has other numerous industrial applications. Unfortunately, it lacks reliable and accurate physicochemical, thermal, and spectral characterization information altogether. Hence, the authors tried to explore in-depth characterization of zinc chloride using the modern analytical technique. The analysis of zinc chloride was performed using powder X-ray diffraction (PXRD), particle size distribution, differential scanning calorimetry (DSC), thermogravimetric analysis/differential thermogravimetric analysis (TGA/DTG), ultraviolet-visible spectroscopy (UV-vis), and Fourier transform-infrared (FT-IR) analytical techniques. The PXRD patterns showed well-defined, narrow, sharp, and the significant peaks. The crystallite size was found in the range of 14.70-55.40 nm and showed average crystallite size of 41.34 nm. The average particle size was found to be of 1.123 ( d 10 ), 3.025 ( d 50 ), and 6.712 ( d 90 ) μm and average surface area of 2.71 m 2 /g. The span and relative span values were 5.849 μm and 1.93, respectively. The DSC thermogram showed a small endothermic inflation at 308.10°C with the latent heat (ΔH) of fusion 28.52 J/g. An exothermic reaction was observed at 449.32°C with the ΔH of decomposition 66.10 J/g. The TGA revealed two steps of the thermal degradation and lost 8.207 and 89.72% of weight in the first and second step of degradation, respectively. Similarly, the DTG analysis disclosed T max at 508.21°C. The UV-vis spectrum showed absorbance maxima at 197.60 nm (λ max ), and FT-IR spectrum showed a peak at 511/cm might be due to the Zn-Cl stretching. These in-depth, comprehensive data would be very much useful in all stages of nutraceuticals/pharmaceuticals formulation research and development and other industrial applications.

Chromium, Nickel and Zinc Induced Histopathological Alterations in ...

African Journals Online (AJOL)

Michael Horsfall

fish, Labeo rohita to chlorides of chromium, nickel and zinc for 30 days. However ... toxicants such as salts of heavy metals, acids, organic matter ... nutritional supply becomes excessive. ... action), petrochemicals, and fertilizers and in steam.

The effect of zinc supplementation of lactating rats on short-term and long-term memory of their male offspring.

Science.gov (United States)

Karami, Mohammad; Ehsanivostacolaee, Simin; Moazedi, Ali Ahmad; Nosrati, Anahita

2013-01-01

In this study the effect of zinc chloride (ZnCl2) administration on the short-term and long-term memory of rats were assessed. We enrolled six groups of adult female and control group of eight Wistar rats in each group. One group was control group with free access to food and water, and five groups drunk zinc chloride in different doses (20, 30, 50, 70 and 100 mg/kg/day) in drinking water for two weeks during lactation .One month after birth, a shuttle box used to short- term and long-term memory and the latency in entering the dark chamber as well. This experiment showed that maternal 70 mg/kg dietary zinc during lactation influenced the working memory of rats' offspring in all groups. Rats received 100 mg/kg/day zinc during lactation so they had significant impairment in working memory (short-term) of their offspring (Plong-term) memory of all groups. Drug consumption below70 mg/kg/day zinc chloride during lactation had no effect. While enhanced 100 mg/ kg/ day zinc in lactating rats could cause short-term memory impairment.

Protection against ionising radiation and synergism with thiols by zinc aspartate

International Nuclear Information System (INIS)

Floersheim, G.L.; Floersheim, P.

1986-01-01

Pre-treatment with zinc aspartate protected mice against the lethal effects of radiation and raised the LD 50 from 8 gy to 12.2 Gy. Zinc chloride and zinc sulphate were clearly less active. The radioprotective effect of zinc aspartate was equivalent to cysteamine and slightly inferior to S,2-aminoethylisothiourea (AET). Zinc aspartate displayed a similar therapeutic index to the thiols but could be applied at an earlier time before irradiation. Synergistic effects occurred with the combined administration of zinc aspartate and thiols. By giving zinc aspartate with cysteamine, the LD 50 was increased to 13.25 Gy and, by combining it in the optimal protocol with AET, to 17.3 Gy. The radioprotection by zinc and its synergism with thiols is explained by the stabilisation of thiols through the formation of zinc complexes. (author)

Zinc-zincate electrochemical behaviour in NaOH medium

International Nuclear Information System (INIS)

Pessine, E.J.

1984-01-01

The reaction mechanism of zinc/NaOH-zincate system was investigated with the rotating disk electrode technique, using both the surfaces of mercury film and zinc in 1M NaOH concentration and 25 0 C temperature. It was found that, at the mercury surface, the zincate ion deposition reaction occurs by two steps with one electron each, with comparable rates, with b sup(-) sub(K1) = (132+ -20)mV/decade and b sup(-) sub(K2) = (74 + - 9)mV/decade cathodic Tafel slopes. At the zinc surface the mechanism of the anodic and cathodic reactions is the same and is by two steps with one electron each. The rate-determining step is the first reaction in the cathodic direction. The exchange current density was found to be between 1.00 and 6.00mA/cm 2 , with b sup(-) sub(K) = (95+ -3)mV/decade cathodic and b sup(-) sub(a) = (61+ -5)mV/decade anodic Tafel slopes. The mechanism of passivation of zinc occurs as a result of the two reactions, the adsorption of the dissolved species of zinc II and the precipitation of the zincate ions over the electrode active sites. It has been verified that of all the chemical species studied namely the zincate, chloride, benzoate, silicate ions and the benzotriazole that affect the zinc anodic reaction the silicate ion is the one that change the reaction rate. However, for all the species studied we have the same anodic reaction mechanism (active dissolution). The deposition reaction mechanism of the zincate ion on zinc electrode is the same with NaOH plus benzoate or chloride. The diffusion coefficient found for the diffusion of the zincate ion in 1M NaOH with the mercury film RDE is D sup(-) = (4,90+ -0,20) x 10 -6 cm 2 s -1 . (Author) [pt

Effect of irrigation water salinity and zinc application on yield, yield components and zinc accumulation of wheat

Directory of Open Access Journals (Sweden)

mohamad ahmadi

2009-06-01

Full Text Available Salinity stress is one of the most important problems of agriculture in crop production in arid and semi arid regions. Under these conditions, in addition to management strategies, proper and adequate nutrition also has an important role in crop improvement. A greenhouse experiment was conducted to study the effect of 4 different irrigation water salinities (blank, 4, 8 and 12 dS m-1, prepared with 1:1 molar ratio of chlorides of calcium and sodium and magnesium sulphate salts. and 5 different zinc applications (0, 10, 20, 30 mg Kg-1 soil and foliar application of salt of zinc sulphate on yield, yield components and zinc concentration of wheat, using a completely randomized design, factorial with three replications. Plant height, spike length, 1000 grain weight, number of grain per spike, grain and straw yield was decreased by Irrigation water salinity. And all of these parameters were improved by zinc application except 1000 grain weight. Zinc absorption and concentration in straw and grain was decreased by Saline water compared to blank. And concentration of zinc significantly was increased in straw and grain by increase zinc application. The results indicated that, zinc application under low to medium salinity conditions improved growth and yield of wheat due to decreasing the impacts salinity.

The Effect of Zinc Supplementation of Lactating Rats on Short-Term and Long-Term Memory of Their Male Offspring

Directory of Open Access Journals (Sweden)

Mohammad Karami

2013-12-01

Full Text Available Background: In this study the effect of zinc chloride (ZnCl2 administration on the short-term and long-term memory of rats were assessed. Methods: We enrolled six groups of adult female and control group of eight Wistar rats in each group. One group was control group with free access to food and water, and five groups drunk zinc chloride in different doses (20, 30, 50, 70 and 100 mg/kg/day in drinking water for two weeks during lactation .One month after birth, a shuttle box used to short- term and long-term memory and the latency in entering the dark chamber as well. Results: This experiment showed that maternal 70 mg/kg dietary zinc during lactation influenced the working memory of rats’ offspring in all groups. Rats received 100 mg/kg/day zinc during lactation so they had significant impairment in working memory (short-term of their offspring (P<0.05. There was no significant difference in reference (long-term memory of all groups. Conclusion: Drug consumption below70 mg/kg/day zinc chloride during lactation had no effect. While enhanced 100 mg/ kg/ day zinc in lactating rats could cause short-term memory impairment.

Electrolytic production of light lanthanides from molten chloride alloys on a large laboratory scale

International Nuclear Information System (INIS)

Szklarski, W.; Bogacz, A.; Strzyzewska, M.

1979-01-01

Literature data relating to electrolytic production of rare earth metals are presented. Conditions and results are given of own investigations into the electrolytic process of light lanthanide chloride solutions (LA-Nd) in molten potassium and sodium chlorides conducted on a large laboratory scale using molybdenic, iron, cobaltic and zinc cathodes. Design schemes of employed electrolysers are enclosed. (author)

Nitrate Removal from Aqueous Solutions Using Almond Charcoal Activated with Zinc Chloride

Directory of Open Access Journals (Sweden)

Mohsen Arbabi

2017-10-01

Full Text Available Background & Aims of the Study: Nitrate is one of the most important contaminants in aquatic environments that can leached to water resources from various sources such as sewage, fertilizers and decomposition of organic waste. Reduction of nitrate to nitrite in infant’s blood stream can cause “blue baby” disease in infants. The aim of this study was to evaluate the nitrate removal from aqueous solutions using modified almond charcoal with zinc chloride. Materials &Methods: This study is an experimental survey. At the first charcoal almond skins were prepared in 5500C and then modified with ZnCl2. Morphologies and characterization of almond shell charcoal were evaluated by using FTIR, EDX, BET and FESEM. Adsorption experiments were conducted with 500 ml sample in Becker. The nitrate concentration removal, contact time, pH and charcoal dosage were investigated. The central composite design method was used to optimizing the nitrate removal process. The results analyzed with ANOVA test. Results: The best condition founded in 48 min, 1250 ppm, 125 mg/l and 3 for retention time, primary nitrate concentration, charcoal dosage and pH respectively. The results showed that the nitrate removal decreases with increasing pH. Modification of skin charcoal is show increasing of nitrate removal from aquatic solution. Conclusion: In this study, the maximum nitrate removal efficiency for raw charcoal and modified charcoal was determined 15.47% and 62.78%, respectively. The results showed that this method can be used as an effective method for removing nitrate from aqueous solutions.

Synthesis of Zinc Diethyldithiocarbamate (ZDEC) and Structure Characterization using Decoupling 1H NMR

International Nuclear Information System (INIS)

Sujarit, Jenjira; Phutdhawong, Weerachai

2003-10-01

A synthesis of zinc diethyldithiocarbamate (ZDEC) has been studied. The optimization mole ratio of the synthetic process was 2: 2: 2: 1 of diethylamine, carbondisulfide, sodium hydroxide, and zinc chloride. Characterization was carried out mainly by analyzing its spectroscopic properties especially decoupling 1 H NMR technique. ZDEC was obtained in 48.5% yield

Effect of condensation product on electrodeposition of zinc on mild ...

Indian Academy of Sciences (India)

WINTEC

Abstract. Electrodeposition of zinc on steel was obtained from acid chloride bath containing condensation products (CP) of 3,4 ..... nucleation number and hence smaller grain size. The ... thesis, Bangalore University, Bangalore. Venkatesha ...

Cloning and occurrence of czrC, a gene conferring cadmium and zinc resistance in MRSA CC398 Isolates

DEFF Research Database (Denmark)

Cavaco, Lina; Hasman, Henrik; Stegger, Marc

2010-01-01

the genetic determinant causing zinc resistance in CC398 and examine its prevalence in isolates of animal and human origin. Based on the sequence of the staphylococcal cassette chromosome mec (SCCmec) element from methicillin-resistant S. aureus (MRSA) CC398 strain SO385, a putative metal resistance gene......-four percent (n = 23) of the animal isolates and 48% (n = 24) of the human MRSA isolates of CC398 were resistant to zinc chloride and positive for czrC. All 48 MSSA strains from both human and pig origins were found to be susceptible to zinc chloride and negative for czrC. Our findings showed that czr......C is encoding zinc and cadmium resistance in CC398 MRSA isolates, and that it is widespread both in humans and animals. Thus, resistance to heavy metals such as zinc and cadmium may play a role in the coselection of methicillin resistance in S. aureus....

Influence of ageing on zinc bioavailability in soils

Energy Technology Data Exchange (ETDEWEB)

Lock, K.; Janssen, C.R

2003-12-01

Currently, soil quality criteria or soil risk assessments of metals are based on laboratory toxicity tests which are carried out in soils freshly spiked with metal salts. With these data, species sensitivity distributions are fitted, from which hazardous concentrations and predicted no effect concentrations are derived. However, due to long-term processes, called ageing, soil metal availability decreases with time. Here we show that pH is the most important parameter determining the effect of ageing on zinc partitioning in soils, with the effect of ageing becoming more important with increasing pH. Furthermore, zinc bioavailability, expressed as the internal zinc concentrations in red clover (Trifolium pratense) is closely related to pore water zinc concentration. In addition, there is a clear dose-response relationship between the survival of the earthworm Eisenia fetida and the calcium chloride-extracted zinc fraction. These results indicate that zinc partitioning can be used to predict zinc bioavailability to terrestrial organisms. However, the use of spiked soils in toxicity assays can result in an over-estimation of the effects of zinc, especially at a high pH. - Zn ageing is affected by pH, while Zn partitioning can be used to predict its bioavailability.

Symptomatic zinc deficiency in experimental zinc deprivation.

OpenAIRE

Taylor, C M; Goode, H F; Aggett, P J; Bremner, I; Walker, B E; Kelleher, J

1992-01-01

An evaluation of indices of poor zinc status was undertaken in five male subjects in whom dietary zinc intake was reduced from 85 mumol d-1 in an initial phase of the study to 14 mumol d-1. One of the subjects developed features consistent with zinc deficiency after receiving the low zinc diet for 12 days. These features included retroauricular acneform macullo-papular lesions on the face, neck, and shoulders and reductions in plasma zinc, red blood cell zinc, neutrophil zinc and plasma alkal...

Negative Effect of Zinc on Testes, Testosterone and Gonadotrophins Levels in Adult Male Wistar Rats

Directory of Open Access Journals (Sweden)

D. Sohrabi

2008-10-01

Full Text Available Background and ObjectivesThe toxic effects of zinc leading to sebaceous gland closure, skin eczema and blister have been previously demonstrated in other studies. The aim of this study is to determine the chronic effects of zinc chloride (ZnCl2 on testicular tissues, testosterone and gonadotrophins in adult male Wistar rats.Methods Twenty four Adult male Wistar rats were divided in to two groups of study and control with each group consisting of 12 rats. Study group rats received 10 mg/kg interaperitoneal Zinc chloride in normal saline (N.S every other day for 30 days. Control group rats received N.S during this time. Blood sample for hormonal evaluation were collected from hearts of these rats. The rats were destroyed and their testes were removed and fixed in a 10% formaldehyde and glutaraldehyde solution.ResultsThe results of this study showed a significant decrease in the level of LH and testosterone hormone among the rats in the study group compared to the control group with p< 0.001 and p< 0.01 respectively. Study of fine structure of testicular cells and tissues in the study group rats revealed swelling of mitochondria, increase in smooth endoplasmic reticulum vacuolization and lysosomic granules (Autophagic vacuoles in cytosol of their germinal cells.ConclusionBased on the results of this study consumption of large amount of compounds which contain zinc should be controlled and limited among men. There is a need for further studies to evaluate and determine the reversibility of most hormonal and physiological changes due to usage of zinc containing compounds.Keywords: Zinc Chloride; Testis; Testosterone; Gonadotrophins

The Practical Realisation of Zinc-Iron CMA Coatings

DEFF Research Database (Denmark)

Jensen, Jens Dahl

1998-01-01

A detailed study of the production opportunities for composition modulated alloy electrodeposits by pulsed current techniques with Zinc-Iron alloys is reported. It is shown that by using a chloride solution, with the additional capability of variable agitation rates, a full range of alloy...... compositions is possible with nanometre layering attainable using single or double bath methods. Furthermore, by the use of a high concentration of ammonium chloride ostensibly as "conductivity" salt, the mechanism of deposition may be modified through control of a thin cathode oxide/hydroxide film....

Reserve lithium-thionyl chloride battery for high rate extended mission applications

Science.gov (United States)

Peabody, Mark; Brown, Robert A.

An effort has been made to develop technology for lithium-thionyl chloride batteries whose emission times will extend beyond 20 min and whose power levels will be in excess of 1800 W, using the requirements for an existing silver-zinc battery's electrical requirements as a baseline. The target design encompasses separate 31- and 76-V sections; the design goal was the reduction of battery weight to 50 percent that of the present silver/zinc cell. A cell has been achieved whose mission can be conducted without container heat losses.

Substituted sodium phenylanthranylates as inhibitors of corrosion in chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, Yu.I.; Fialkov, Yu.A.; Popova, L.I.; Ehndel' man, E.S.; Kuznetsova, I.G. (AN SSSR, Moscow. Inst. Fizicheskoj Khimii)

The efficiency of corrosion protection of armco iron, zinc (Ts-O) aluminium (AB 000) and its alloys (.D16 and AMG6) with sodium phenylanthranylate derivatives in chloride buffer solutions (pH 7.4-8.08) are investigated. It has been ascertained that the introduction of sodium phenylanthranylate into phenyl radical in m- and p-position relative to the amino group of electron-seeking substitutes improves protective properties of an inhibitor. The inhibiting effect of phenylanthranylates and its dependence on electron structure enchances in zinc-aluminium-iron series and decreases in case of transition from pure aluminium to its alloys.

[Remediation Pb, Cd contaminated soil in lead-zinc mining areas by hydroxyapatite and potassium chloride composites].

Science.gov (United States)

Wang, Li; Li, Yong-Hua; Ji, Yan-Fang; Yang, Lin-Sheng; Li, Hai-Rong; Zhang, Xiu-Wu; Yu, Jiang-Ping

2011-07-01

The composite agents containing potassium chloride (KCl) and Hydroxyapatite (HA) were used to remediate the lead and cadmium contaminated soil in Fenghuang lead-zinc mining-smelting areas, Hunan province. The objective of this study was to identify and evaluate the influence of Cl- to the fixing efficiency of Pb and Cd by HA. Two types of contaminated soil (HF-1, HF-2) were chosen and forty treatments were set by five different Hydroxyapatite (HA) dosages and four different Cl- dosages. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the results. It showed that HA could efficiently fix the Pb and Cd from TCLP form. The maximum Pb-fixing efficiency and Cd-fixing efficiency of two types of soil were 83.3%, 97.27% and 35.96%, 57.82% when the HA: Pb: KCl molar ratio was 8: 1: 2. Compared to the fixing efficiency without KCl, KCl at the KCl: Pb molar ratio of 2 improved Pb-fixing efficiency and Cd-fixing efficiency by 6.26%, 0.33% and 7.74%, 0.83% respectively when the HA: Pb molar ratio was 8. Generally, Cl- can improve the Pb/Cd-fixing efficiency in heavy metal contaminated soil by Hydroxyapatite.

Protective Effects of Long Term Administration of Zinc on Bone Metabolism Parameters in Male Wistar Rats Treated with Cadmium

Directory of Open Access Journals (Sweden)

Shiva Najafi

2016-10-01

Full Text Available Background Violent poisoning by cadmium in human is created through drinks or meals which have packed in the metallic tins with cadmium plating. The symptoms of variation in the mineral metabolism of bones are observed and different conditions maybe appeared. The toxic (poisonous effect due to cadmium can be neutralized by intervening zinc. This study has been designed to investigate the protective effects of zinc for reducing the poisonous effects due to cadmium on the metabolism in the parameters related to the bone in rat. Methods In this experimental study, 48 male rats of wistar species were distributed in eight experimental groups and tested in the investigative lab of Falavarjan university. These groups were received 0.5 cc physiological serum, 0.5 mg/kg Zinc, 0.5, 1, 2 mg/kg Cadmium respectively and some groups were included in those were taken all there cadmium and zinc concentrations synchronously. Blood samples were taken in a 60 days period and those factors related to the bone metabolism were measured. The data were analyzed by 2-ANOVA Ways, complementary tests through software SPSS 16. Results The results showed that 0.5, 1, 2 mg/kg doses cadmium chloride caused to increase alkaline Phosphatase, calcium, phosphorus, magnesium and decrease albumin as compared with control group. Also, synchronous usage of all three cadmium chloride concentrations with zinc cause to decrease alkaline phosphatase, calcium, phosphorus, magnesium and increase albumin concentration. In a word, the other bone parameters have been significant in different cadmium and zinc doses (P < 0.05. Conclusions Findings showed that zinc can play a protective role on the metabolism parameters related to bone against to poisoning caused by cadmium.

Cobalt chloride speciation, mechanisms of cytotoxicity on human pulmonary cells, and synergistic toxicity with zinc

International Nuclear Information System (INIS)

Bresson, Carole; Darolles, Carine; Sage, Nicole; Malard, Veronique; Carmona, Asuncion; Roudeau, Stephane; Ortega, Richard; Gautier, Celine; Ansoborlo, Eric

2013-01-01

Cobalt is used in numerous industrial sectors, leading to occupational diseases, particularly by inhalation. Cobalt-associated mechanisms of toxicity are far from being understood and information that could improve knowledge in this area is required. We investigated the impact of a soluble cobalt compound, CoCl 2 .6H 2 O, on the BEAS-2B lung epithelial cell line, as well as its impact on metal homeostasis. Cobalt speciation in different culture media, in particular soluble and precipitated cobalt species, was investigated via theoretical and analytical approaches. The cytotoxic effects of cobalt on the cells were assessed. Upon exposure of BEAS-2B cells to cobalt, intracellular accumulation of cobalt and zinc was demonstrated using direct in situ microchemical analysis based on ion micro-beam techniques and analysis after cell lysis by inductively coupled plasma mass spectrometry (ICP-MS). Microchemical imaging revealed that cobalt was rather homogeneously distributed in the nucleus and in the cytoplasm whereas zinc was more abundant in the nucleus. The modulation of zinc homeostasis led to the evaluation of the effect of combined cobalt and zinc exposure. In this case, a clear synergistic increase in toxicity was observed as well as a substantial increase in zinc content within cells. Western blots performed under the same co-exposure conditions revealed a decrease in ZnT1 expression, suggesting that cobalt could inhibit zinc release through the modulation of ZnT1. Overall, this study highlights the potential hazard to lung function, of combined exposure to cobalt and zinc. (authors)

Cobalt chloride speciation, mechanisms of cytotoxicity on human pulmonary cells, and synergistic toxicity with zinc

International Nuclear Information System (INIS)

Bresson, Carole; Darolles, Carine; Sage, Nicole; Malard, Veronique; Carmona, Asuncion; Roudeau, Stephane; Ortega, Richard; Gautier, Celine; Ansoborlo, Eric

2013-01-01

Complete text of publication follows: Cobalt is used in numerous industrial sectors, leading to occupational diseases, particularly by inhalation. Cobalt-associated mechanisms of toxicity are far from being understood and information that could improve knowledge in this area is required. We investigated the impact of a soluble cobalt compound, CoCl 2 , on the BEAS-2B lung epithelial cell line, as well as its impact on metal homeostasis. Cobalt speciation in different culture media, in particular soluble and precipitated cobalt species, was investigated via theoretical and analytical approaches. The cytotoxic effects of cobalt on the cells were assessed. Upon exposure of BEAS-2B cells to cobalt, intracellular accumulation of cobalt and zinc was demonstrated using direct in situ microchemical analysis based on ion micro-beam techniques and analysis after cell lysis by inductively coupled plasma mass spectrometry (ICP-MS). Microchemical imaging revealed that cobalt was rather homogeneously distributed in the nucleus and in the cytoplasm whereas zinc was more abundant in the nucleus. The modulation of zinc homeostasis led to the evaluation of the effect of combined cobalt and zinc exposure. In this case, a clear synergistic increase in toxicity was observed as well as a substantial increase in zinc content within cells. Western blots performed under the same co-exposure conditions revealed a decrease in ZnT1 expression, suggesting that cobalt could inhibit zinc release through the modulation of ZnT1. Overall, this study highlights the potential hazard to lung function, of combined exposure to cobalt and zinc

Lead and silver extraction from waste cake from hydrometallurgical zinc production

Directory of Open Access Journals (Sweden)

DUSAN D. STANOJEVIC

2008-05-01

Full Text Available This paper presents the experimental results of the extraction of lead and silver from a lead–silver waste cake obtained in the process of hydrometallurgical zinc production. While controlling the pH value, the lead–silver cake was leached at a temperature close to boiling point in different concentrations of aqueous calcium chloride solutions. The experiments were performed applying different ratios between the mass of cake and the volume of the leaching agent under different durations of the process. It was concluded that at the optimal process parameters (pH 2.0–2.5; CaCl2 concentration, 3.6 mol dm-3; temperature, 95 °C; solid/liquid ratio, 1:5, the leaching efficiency of lead and silver could reach the approximate value of 94 %. Applying the same optimal process parameters, the method was applied to the leaching of a lead–silver cake in a magnesium chloride solution, but with significantly lower efficiencies. The results show that leaching of lead and silver in a calcium chloride solution could be a prospective method for increasing the recovery of lead and silver during hydrometallurgical zinc production.

Speciation of Zinc in ash investigated by X-ray absorption spectroscopy; Zinks foerekomstformer i aska studerade med en roentgenabsorptionsspektrometrisk metod

Energy Technology Data Exchange (ETDEWEB)

Steenari, Britt-Marie; Noren, Katarina

2008-06-15

neighbour, but also about the next scattering shell of atoms surrounding the central zinc atom. The EXAFS data and modelling results showed that the most common zinc species in wood fuel ashes from FBC boilers are silicate, aluminate and to a lesser extent hydroxide. It cannot be ruled out that zinc can be bound as ZnO but this form is not dominant. This is the case for both bottom ashes and fly ashes. In one of the FBC boilers (BFB-bio), elementary sulphur is added in order to abate corrosion problems. Both bottom ash and fly ash from that combustor showed indications of the presence of ZnS or ZnCl{sub 2}. It is difficult to distinguish between Zn-S and Zn-Cl distances be EXAFS, but since zinc chloride is not likely to be stable in a combustor bed the conclusion was drawn that some zinc had been bound as sulphide in the bottom ash. The filter ash, however, might contain both sulphide and chloride in small amounts. Kaolin was used as an anti-sintering additive during a test period in the wood fuelled CFB included in this work. The general results from this test period has been published elsewhere but it is interesting for this investigation to note that the kaolin absorbed potassium that otherwise should have formed gaseous KCl and thus, left some more HCl in the flue gas free to react with other metal species in the burning fuel. In addition, it was noted that the kaolin was concentrated in the fly ash as was potassium and zinc. The EXAFS data for this fly ash showed the presence of ZnCl{sub 2} and/or ZnS. Due to the increased presence of HCl in the flue gas zinc chloride is most likely compound. However, it was only present in a small amount and the main part of the Zn was found as silicate. In the fly ash from normal operation of the boiler no zinc chloride was found. Wood ash that had been moistened and aged was shown to contain zinc in silicate, hydroxide and/or aluminate forms. In one sample of an ash the had been aged outdoors for only 0.5 years indication of minor

Improved corrosion behavior of nanocrystalline zinc produced by pulse-current electrodeposition

International Nuclear Information System (INIS)

Youssef, Kh.M.S.; Koch, C.C.; Fedkiw, P.S.

2004-01-01

Pulse electrodeposition was used to produce nanocrystalline (nc) zinc from zinc chloride electrolyte with polyacrylamide and thiourea as additives. Field emission scanning electron microscopy (FESEM) was used to study the grain size and surface morphology of the deposits and X-ray diffraction was used to examine their preferred orientation. Corrosion behavior of the electrodeposited nc zinc in comparison with electrogalvanized (EG) steel in de-aerated 0.5 N NaOH solution was studied using potentiodynamic polarization and impedance measurements. A scanning electron microscope (SEM) was used to characterize the surface morphology of the EG steel before corrosion testing. Surface morphologies of nc zinc deposits and EG steel were also studied after potentiondynamic polarization by SEM. Nanocrystalline zinc (56 nm) with random orientation was produced. The estimated corrosion rate of nc zinc was found to be about 60% lower than that of EG steel, 90 and 229 μA/cm 2 , respectively. The surface morphology of corroded nc zinc was characterized by discrete etch pits, however, uniform corrosion was obtained after potentiodynamic polarization of EG steel. The passive film formed on the nc zinc surface seems to be a dominating factor for the corrosion behavior observed

The effect of residual chlorides on resultant properties of solid and liquid phases after carbonization process

Energy Technology Data Exchange (ETDEWEB)

Plevova Eva; Sugarkova Vera; Kaloc Miroslav [Institute of Geonics ASCR, Ostrava (Czech Republic). Laboratory of Petrology

2004-07-01

The low-concentration condition was employed to model the carbonisation mode for local (Czech Republic) coals with higher concentrations of some metals. After completing the carbonisation, mass balance calculations were performed. Results show that the presence of zinc dichloride, copper dichloride and sodium chloride caused the most pronounced impediment to the formation of tar in contrast to lead dichloride and aluminium chloride that increased tar. The results demonstrated that adding of chloride agents effect both the course of the coking process and the properties of solid and liquid products of coking. Evaluation of the solid phase showed that chloride addition caused a decrease of the caking and swelling value, which corresponds with measurements of plasticity values that are of significant influence on mechanical properties closely related to coking plant processes. Evaluation of the liquid phase pointed towards an increase of aromatic hydrocarbons and their derivatives (especially phenanthrene, fluoranthene, acenaphthylene, pyrene) but a decrease of naphthalene and methylnaphthalene. Chloride addition increased aromaticity and caused a difference in substitution rate at aromatic nucleus. Mesophase estimation indicated extensive mosaic, domain and laminated anisotropic texture occurrence after chloride addition, mainly NaCl and CuCl{sub 2} addition. A more detailed evaluation including detailed screening, TGA, IR and RTG analysis will be subject of further investigation. 4 refs., 2 figs., 5 tabs.

The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

NARCIS (Netherlands)

Veldkamp, T.; Diepen, van J.T.M.; Bikker, P.

2014-01-01

Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR

Metal chloride precursor synthesization of Cu{sub 2}ZnSnS{sub 4} solar cell materials

Energy Technology Data Exchange (ETDEWEB)

Yeh, Min-Yen; Huang, Yu-Fong; Huang, Cheng-Liang; Yang, Chyi-Da [National Kaohsiung Marine University, Kaohsiung, Taiwan (China); Wuu, Dong-Sing [National Chung Hsing University, Taichung, Taiwan (China); Lei, Po-Hsun [National Formosa University, Yunlin, Taiwan (China)

2014-07-15

Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films with kesterite structures were prepared by directly sol-gel synthesizing spin-coated precursors on soda-lime-glass (SLG) substrates. The CZTS precursors were prepared by using solutions of copper (II) chloride, zinc (II) chloride, tin (IV) chloride, and thiourea. The ratio of SnCl{sub 4} in the precursors was found to play a critical role in the synthesization of CZTS. CZTS phases of SnS and SnS{sub 2} were observed in the synthesized films as prepared using precursors with a close to stoichiometric ratio of CuCl{sub 2}:ZnCl{sub 2}:SnCl{sub 4}:CH{sub 4}N{sub 2}S = 4:1:1:8, where SnCl{sub 4} was 1 mol/l. The amounts of the educed SnS and SnS{sub 2} phases observed in the SEM images could be readily reduced by decreasing the volume of SnCl{sub 4} in the mixed solution. With decreasing amount of SnCl{sub 4} from 1 mol/l, the as prepared CZTS reveals a significant improvement in its crystalline properties. In this work, CZTS with an average absorption coefficient and an optical energy gap of over 10{sup 4} cm{sup -1} and ∼1.5 eV, respectively, was obtained using precursors of copper (II) chloride, zinc (II) chloride, tin (IV) chloride, and thiourea mixed in a ratio of 2:1:0.25:8, and it had good crystallinity revealing a Cu-poor composition.

Adsorption properties of cationic rhodamine B dye onto metals chloride-activated castor bean residue carbons.

Science.gov (United States)

Zhi, Lee Lin; Zaini, Muhammad Abbas Ahmad

2017-02-01

This work was aimed to evaluate the feasibility of castor bean residue based activated carbons prepared through metals chloride activation. The activated carbons were characterized for textural properties and surface chemistry, and the adsorption data of rhodamine B were established to investigate the removal performance. Zinc chloride-activated carbon with specific surface area of 395 m 2 /g displayed a higher adsorption capacity of 175 mg/g. Magnesium chloride and iron(III) chloride are less toxic and promising agents for composite chemical activation. The adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetics model. The rate-limiting step in the adsorption of rhodamine B is film diffusion. The positive values of enthalpy and entropy indicate that the adsorption is endothermic and spontaneous at high temperature.

Effect of various parameters on the efficiency of zinc phosphate ...

African Journals Online (AJOL)

... and CMG852 showed enhanced solubilization in presence of 1% sodium chloride. 1% glucose is required for the solubilization of zinc phosphate and no solubilization was appeared in presence of 0.1% glucose. CMG851 (A. lwoffi), CMG 860 (pseudomonas aeruginosa) CMG 857 (Bacillus thuringiensis) were found to be ...

Synthesis and characterization of zinc oxide thin films prepared by ...

African Journals Online (AJOL)

Zinc oxide thin films were prepared with ammonia/ammonium chloride buffer as the reaction moderating agent in the chemical bath deposition technique. An observable color change during the reaction due to variations in the reactants concentration indicated the existence of the cupric (CuO) and cuprous (Cu2O) oxides ...

Deep cleaning of a metallurgical zinc leaching residue and recovery of valuable metals

Science.gov (United States)

Xing, Peng; Ma, Bao-zhong; Zeng, Peng; Wang, Cheng-yan; Wang, Ling; Zhang, Yong-lu; Chen, Yong-qiang; Wang, Shuo; Wang, Qiu-yin

2017-11-01

Huge quantities of zinc leaching residues (ZLRs) generated from zinc production are dumped continuously around the world and pose a potential environmental threat because of their considerable amounts of entrained heavy metals (mainly lead). Most ZLRs have not been properly treated and the valuable metals in them have not yet been effectively recovered. Herein, the deep cleaning of a ZLR and recovery of valuable metals via a hydrometallurgical route were investigated. The cleaning process consists of two essential stages: acid leaching followed by calcium chloride leaching. The optimum conditions for extracting zinc, copper, and indium by acid leaching were a sulfuric acid concentration of 200 g·L-1, a liquid/solid ratio of 4:1 (mL/g), a leaching time of 2 h, and a temperature of 90°C. For lead and silver extractions, the optimum conditions were a calcium chloride concentration of 400 g·L-1, a pH value of 1.0, a leaching time of 1 h, and a temperature of 30°C. After calcium chloride leaching, silver and lead were extracted out and the lead was finally recovered as electrolytic lead by electrowinning. The anglesite phase, which poses the greatest potential environmental hazard, was removed from the ZLR after deep cleaning, thus reducing the cost of environmental management of ZLRs. The treatment of chlorine and spent electrolyte generated in the process was discussed.

Use of Repeated Fluoropolymer Suspensions to Obtain Composite Electrochemical Coating Based on Zinc

Science.gov (United States)

Musikhina, T. A.; Zemtsova, E. A.; Fuks, C. L.

2017-11-01

This article deals with the issues of utilization of the waste products of fluoropolymers, namely, the suspensions of fluoroplasts that have lost their consumer properties. Such waste is recommended to be used as a filler of zinc coatings to provide increased corrosion resistance. Using the method of mathematical planning of the experiment, the authors establish the optimal compositions of galvanizing chloride-ammonium electrolytes to obtain the corrosion-resistant composite electrochemical coatings (CEC) of zinc-fluoropolymer. As a result, coatings with a finely crystalline structure were obtained differing in the distribution pattern on the surface of the samples and depending on the variation in the zinc concentration in the electrolytes. The samples of steel reinforcement with the zinc-fluoropolymer coating were tested on corrosion resistance. The increase of anticorrosive properties in CEC zinc-fluoropolymer and a slight decrease in microhardness were indicated.

Zinc chloride modified electronic transport and relaxation studies in barium-tellurite glasses

Science.gov (United States)

Dhankhar, Sunil; Kundu, R. S.; Rani, Sunita; Sharma, Preeti; Murugavel, S.; Punia, Rajesh; Kishore, N.

2017-09-01

The ac conductivity of halide based tellurium glasses having composition 70 TeO2-(30-x) BaO-x ZnCl2; x = 5, 10, 15, 20 and 25 has been investigated in the frequency range 10-1 Hz to 105Hz and in the temperature range 453 K to 553 K. The frequency and temperature dependent ac conductivity show mixed behaviour with increase in halide content and found to obey Jonscher's universal power law. The values of dc conductivity, crossover frequency and frequency exponent have been estimated from the fitting of experimental data of ac conductivity with Jonscher's universal power law. For determining the conduction mechanism in studied glass system, frequency exponent has been analyzed by various theoretical models. In presently studied glasses, the ac conduction takes place via overlapping large polaron tunneling (OLPT). The values of activation energy for dc conduction (W) and the one associated with relaxation process ( E R) are found to increase with increase in x up to glass sample with x = 15 and thereafter it decrease with increase in zinc chloride content. DC conduction takes place via variable range hopping (VRH) as proposed by Mott with some modification suggested by Punia et al. The value of real part of modulus ( M') is observed to decrease with increase in temperature. The value of stretched exponent (β) obtained from fitting of M'' reveals the presence of non-Debye type of relaxation in presently studied glass samples. Scaling spectra of ac conductivity and values of electric modulus ( M' and M'') collapse into a single master curve for all the compositions and temperatures. The values of relaxation energy ( E R) for all the studied glass compositions are almost equal to W, suggesting that polarons have to overcome same barrier while relaxing and conducting. The conduction and relaxation processes in the studied glass samples are composition and temperature independent. [Figure not available: see fulltext.

Angiotensin-I converting enzyme (ACE): structure, biological roles, and molecular basis for chloride ion dependence.

Science.gov (United States)

Masuyer, Geoffrey; Yates, Christopher J; Sturrock, Edward D; Acharya, K Ravi

2014-10-01

Somatic angiotensin-I converting enzyme (sACE) has an essential role in the regulation of blood pressure and electrolyte fluid homeostasis. It is a zinc protease that cleaves angiotensin-I (AngI), bradykinin, and a broad range of other signalling peptides. The enzyme activity is provided by two homologous domains (N- and C-), which display clear differences in substrate specificities and chloride activation. The presence of chloride ions in sACE and its unusual role in activity was identified early on in the characterisation of the enzyme. The molecular mechanisms of chloride activation have been investigated thoroughly through mutagenesis studies and shown to be substrate-dependent. Recent results from X-ray crystallography structural analysis have provided the basis for the intricate interactions between ACE, its substrate and chloride ions. Here we describe the role of chloride ions in human ACE and its physiological consequences. Insights into the chloride activation of the N- and C-domains could impact the design of improved domain-specific ACE inhibitors.

The bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens

OpenAIRE

Veldkamp, T.; Diepen, van, J.T.M.; Bikker, P.

2014-01-01

Zinc is an essential trace element for all farm animal species. It is commonly included in animal diets as zinc oxide, zinc sulphate or organically bound zinc. Umicore Zinc Chemicals developed zinc oxide products with different mean particle sizes. Umicore Zinc Chemicals requested Wageningen UR Livestock Research to determine the bioavailability of four zinc oxide sources and zinc sulphate in broiler chickens. A precise estimate of the bioavailability of zinc sources is required both for fulf...

Implication of zinc excess on soil health.

Science.gov (United States)

Wyszkowska, Jadwiga; Boros-Lajszner, Edyta; Borowik, Agata; Baćmaga, Małgorzata; Kucharski, Jan; Tomkiel, Monika

2016-01-01

This study was undertaken to evaluate zinc's influence on the resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease. The experiment was conducted in a greenhouse of the University of Warmia and Mazury (UWM) in Olsztyn, Poland. Plastic pots were filled with 3 kg of sandy loam with pHKCl - 7.0 each. The experimental variables were: zinc applied to soil at six doses: 100, 300, 600, 1,200, 2,400 and 4,800 mg of Zn(2+) kg(-1) in the form of ZnCl2 (zinc chloride), and species of plant: oat (Avena sativa L.) cv. Chwat and white mustard (Sinapis alba) cv. Rota. Soil without the addition of zinc served as the control. During the growing season, soil samples were subjected to microbiological analyses on experimental days 25 and 50 to determine the abundance of organotrophic bacteria, actinomyces and fungi, and the activity of dehydrogenases, catalase and urease, which provided a basis for determining the soil resistance index (RS). The physicochemical properties of soil were determined after harvest. The results of this study indicate that excessive concentrations of zinc have an adverse impact on microbial growth and the activity of soil enzymes. The resistance of organotrophic bacteria, actinomyces, fungi, dehydrogenases, catalase and urease decreased with an increase in the degree of soil contamination with zinc. Dehydrogenases were most sensitive and urease was least sensitive to soil contamination with zinc. Zinc also exerted an adverse influence on the physicochemical properties of soil and plant development. The growth of oat and white mustard plants was almost completely inhibited in response to the highest zinc doses of 2,400 and 4,800 mg Zn(2+) kg(-1).

Nonlinear optical and microscopic analysis of Cu2+ doped zinc thiourea chloride (ZTC) monocrystal

Science.gov (United States)

Ramteke, S. P.; Anis, Mohd; Pandian, M. S.; Kalainathan, S.; Baig, M. I.; Ramasamy, P.; Muley, G. G.

2018-02-01

Organometallic crystals offer considerable nonlinear response therefore, present article focuses on bulk growth and investigation of Cu2+ ion doped zinc thiourea chloride (ZTC) crystal to explore its technological impetus for laser assisted nonlinear optical (NLO) device applications. The Cu2+ ion doped ZTC bulk single crystal of dimension 03 × 2.4 × 0.4 cm3 has been grown from pH controlled aqueous solution by employing slow solvent evaporation technique. The structural analysis has been performed by means of single crystal X-ray diffraction technique. The doping of Cu2+ ion in ZTC crystal matrix has been confirmed by means of energy dispersive spectroscopic (EDS) technique. The origin of nonlinear optical properties in Cu2+ ion doped ZTC crystal has been studied by employing the Kurtz-Perry test and Z-scan analysis. The remarkable enhancement in second harmonic generation (SHG) efficiency of Cu2+ ion doped ZTC crystal with reference to ZTC crystal has been determined. The He-Ne laser assisted Z-scan analysis has been performed to determine the third order nonlinear optical (TONLO) nature of grown crystal. The TONLO parameters such as susceptibility, absorption coefficient, refractive index and figure of merit of Cu-ZTC crystal have been evaluated using the Z-scan transmittance data. The laser damage threshold of grown crystal to high intensity of Nd:YAG laser is found to be 706.2 MW/cm2. The hardness number, work hardening index, yield strength and elastic stiffness coefficient of grown crystal has been investigated under microhardness study. The etching study has been carried out to determine the growth likelihood, nature of etch pits and surface quality of grown crystal.

Electrolyte for a lithium/thionyl chloride electric cell, a method of preparing said electrolyte and an electric cell which includes said electrolyte

Energy Technology Data Exchange (ETDEWEB)

Gabano, J.

1983-03-01

An electrolyte for an electric cell whose negative active material is constituted by lithium and whose positive active material is constituted by thionyl chloride. The electrolyte contains at least one solvent and at least one solute, said solvent being thionyl chloride and said solute being chosen from the group which includes lithium tetrachloroaluminate and lithium hexachloroantimonate. According to the invention said electrolyte further includes a complex chosen from the group which includes AlCl/sub 3/,SO/sub 2/ and SbCl/sub 5/,SO/sub 2/. The voltage rise of electric cells which include such an electrolyte takes negligible time.

21 CFR 700.14 - Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products.

Science.gov (United States)

2010-04-01

... propellant of cosmetic aerosol products. 700.14 Section 700.14 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS GENERAL Requirements for Specific Cosmetic Products § 700.14 Use of vinyl chloride as an ingredient, including propellant of cosmetic aerosol products...

Dietary phytate, zinc and hidden zinc deficiency.

Science.gov (United States)

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. Copyright © 2014 Elsevier GmbH. All rights reserved.

Extraction and separation of zinc and cadmium chlorides by TOPO from mixed media

International Nuclear Information System (INIS)

Ben Mousa, S.; Altakrory, A.; Abdel Raouf, M.W.; Alian, A.

1997-01-01

The effect of water-miscible alcohols and acetone on the extraction and separation of Cd and Zn chlorides by TOPO was systematically investigated. The maximum extraction of Zn chloride with 0.1 M TOPO decreases in the order: acetone> methanol> ethanol> 2-propanol> 2-butanol. For alcohols, the sequence of decreasing extractability is thus parallel to the order of their dielectric constants. This can be explained by the increase of HCl extraction by TOPO in the same direction. The presence of additives in the polar phase prevents the formation of a bulky white precipitate encountered during extraction of Zn Cl 2 from pure aqueous solutions. A decrease of Cd chloride extraction was generally noticed in presence of additives; this is more noticeable for the longer chain alcohols. The highest separation factor (E) for Zn Cl 2 and Cd Cl 2 in 0.4 M HCl is obtained from 30% methanol (13.8 compared to about 3.8 in absence of methanol) and from 10-20% acetone where it reaches 30

Study on the effect of x-ray irradiation of seed on zinc uptake in maize (Zea Mays L.) plants

International Nuclear Information System (INIS)

Joshi, Gargi; Singh, K.P.; Joshi, G.C.

2007-01-01

The effects of irradiations by X-rays at the two dose levels (1.1 KR and 2.2 KR) of seeds on uptake of zinc ion in maize (Zea Mays L.) plants were studied. The uptake and internal distribution of zinc ion in the maize plants was carried out by incorporating radioactive zinc as zinc chloride (ZnCl 2 ) in the nutrient solution to the plants. The localization and translocation of radioactive zinc was studied employing phosphor imaging systems (FX). The radioactivity measurement has been carried out using solid scintillation counter. It was observed that zinc ions uptake was higher in plants out of 2.2 KR X-rays irradiated seeds. (author)

Effect of Ammonium Chloride on the Efficiency with Which Copper Sulfate Activates Marmatite: Change in Solution Composition and Regulation of Surface Composition

Directory of Open Access Journals (Sweden)

Shengdong Zhang

2018-06-01

Full Text Available Zinc sulfide minerals are the primary choice for zinc extraction and marmatite is one of the two most common zinc sulphide minerals (sphalerite and marmatite, therefore it is of great significance to study and optimize the flotation of marmatite. To improve the activation of copper sulfate on marmatite, a method involving the addition of ammonium chloride is devised. The method has been proven to be an effective way of improving the activation efficiency of copper sulfate towards marmatite under alkaline conditions. The strengthening mechanism was studied using micro-flotation, adsorption test, X-ray photoelectron spectroscopy, and by analyzing changes in solution composition. Flotation test results show that the activation effect of the copper sulfate towards marmatite is enhanced with the addition of ammonium chloride. According to the results of the adsorption measurements and X-ray photoelectron spectroscopy analysis, when the marmatite surface is activated using copper sulfate with added ammonia chloride, it adsorbs more copper sulfide and less copper hydroxide and zinc hydroxide. These changes in surface composition are believed to occur via the following process: NH3(aq promotes the dissolution of zinc hydroxide and then facilitates the conversion of surface copper hydroxide to copper sulfide. In addition, the occurrence of Cu(NH3n2+ can promote the adsorption of copper ions (Cu2+ can be stored as Cu(NH3n2+ via complexation, and then, when the concentration of copper ions decreases, Cu2+ can be released through the decompositionof Cu(NH3n2+. Hence, the copper ion concentration can be maintained and this can facilitate the adsorption of Cu2+ on marmatite. Based on a comprehensive analysis of all our results, we propose that adding ammonium chloride to the copper sulfate changes the solution components (i.e., the presence of NH3(aq and Cu(NH3n2+ and then regulates the surface composition of marmatite. The change in surface composition

The Influence of Suspended Inert Solid Particles on Zinc Corrosion

DEFF Research Database (Denmark)

Bech-Nielsen, Gregers

1996-01-01

The rate of corrosion of electroplated zinc in near-neutral chloride solutions can be lowered by as much as 75% by adding fine, inert particles of substances such as MnO2, Fe3O4, SiC and TiN to the well-stirred solution. Spreading of local areas of etching is also stopped. Copyright (C) 1996...

Complex sulphide-barite ore leaching in ferric chloride solution

Directory of Open Access Journals (Sweden)

Miroslav Sokić

2016-06-01

Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

Effects of the zinc and zinc-nickel alloys electroplating on the corrodibility of reinforced concrete rebars

Directory of Open Access Journals (Sweden)

F. A. CEDRIM

Full Text Available Abstract This paper shows the analysis performed on the corrosion parameters of three groups of reinforcing steel bars, two of these coated by electroplating process with Zinc (Zn and Zinc-Nickel (Zn-Ni, and the other without any coating. It was used reinforced concrete specimens, which ones were grouped and then subjected to two different corrosion accelerating methods: aging wetting/drying cycles and salt spray exposure. Corrosion potential was measured to qualitative monitoring of the process and, after the end of the tests, corrosion rate was estimated by measuring the mass loss, to quantitative analyses. As it was expected, coated bars presented a better performance than the average bars regarding the corrosion resistance in chloride ions containing environments. It was also observed that the drying/ NaCl solution wetting cycles seems to be more severe than salt spray fog apparatus with respect to the acceleration of corrosion process.

Two mechanisms of oral malodor inhibition by zinc ions.

Science.gov (United States)

Suzuki, Nao; Nakano, Yoshio; Watanabe, Takeshi; Yoneda, Masahiro; Hirofuji, Takao; Hanioka, Takashi

2018-01-18

The aim of this study was to reveal the mechanisms by which zinc ions inhibit oral malodor. The direct binding of zinc ions to gaseous hydrogen sulfide (H2S) was assessed in comparison with other metal ions. Nine metal chlorides and six metal acetates were examined. To understand the strength of H2S volatilization inhibition, the minimum concentration needed to inhibit H2S volatilization was determined using serial dilution methods. Subsequently, the inhibitory activities of zinc ions on the growth of six oral bacterial strains related to volatile sulfur compound (VSC) production and three strains not related to VSC production were evaluated. Aqueous solutions of ZnCl2, CdCl2, CuCl2, (CH3COO)2Zn, (CH3COO)2Cd, (CH3COO)2Cu, and CH3COOAg inhibited H2S volatilization almost entirely. The strengths of H2S volatilization inhibition were in the order Ag+ > Cd2+ > Cu2+ > Zn2+. The effect of zinc ions on the growth of oral bacteria was strain-dependent. Fusobacterium nucleatum ATCC 25586 was the most sensitive, as it was suppressed by medium containing 0.001% zinc ions. Zinc ions have an inhibitory effect on oral malodor involving the two mechanisms of direct binding with gaseous H2S and suppressing the growth of VSC-producing oral bacteria.

Binding of nickel and zinc ions with activated carbon prepared from ...

African Journals Online (AJOL)

Activated carbon was prepared from sugar cane fibre by carbonizing at 500 oC for 30 minutes. This was followed by activation with ammonium chloride. The activated carbon was characterised in terms of pH, bulk density, ash content, surface area and surface charge. Equilibrium sorption of nickel and zinc ions by the ...

ACUTE TOXICITY OF METALS: NICKEL AND ZINC TO PARAMECIUM BURSARIA AND ITS ENDOSYMBIONTS

Directory of Open Access Journals (Sweden)

Patrycja Zagata

2015-02-01

Full Text Available Paramecium bursaria is an unicellular organism, widely distributed in the freshwater environment, where heavy metals are common contaminants. The ciliates, also including Paramecium bursaria, are a very abundant group in aquatic ecosystems, what makes them effective biological indicators of water pollutants. Paramecium bursaria is the only Paramecium which has evolved a mutualistic relationship with algae and it harbors these endosymbionts in its own cytoplasm. The algae are also very effective bioindicators of some pollutants because of their ability to biosorption and bioaccumulation of heavy metals. The aim of this study was to determine the acute toxicity of two metals’ compounds: nickel chloride (NiCl2 and zinc chloride (ZnCl2 to Paramecium bursaria and its endosymbionts. The ciliates were incubated in solutions with 5x10-8 to 5x10-2g/dm3 of NiCl2 and with 5x10-8 to 5x10-2g/dm3 of ZnCl2, at the temperature of 180C, in the light/dark conditions (12L/12D. Microscopic observations of cell divisions rate, cell shape changes as well as the swimming behavior, were conducted after 24, 48, 72 and 120 hours of incubation in the tested solutions and were compared to the control sample. Microscopic observations revealed the lethal doses for both compounds, for nickel chloride 5x10-5g/dm3 and for zinc chloride 5x10-3. These observations also revealed that in lesser concentrations than the lethal one, the slowdown and characteristic movements occur after metal addition. The PEA measurements of Fv/Fm parameter were carried out within 4 days, the first one after 24 hours of incubations. The results of this investigation has given us a view of a fluorescence efficiency by revealing that both compounds solutions can have the stimulating effect on Photosystem II, because the lowest fluorescence efficiency was measured in control samples.

Congenital chloride diarrhea misdiagnosed as pseudo-Bartter syndrome.

Science.gov (United States)

Saneian, Hossein; Bahraminia, Emad

2013-09-01

Congenital chloride diarrhea (CCD) is a rare autosomal recessive disease which is characterized by intractable diarrhea of infancy, failure to thrive, high fecal chloride, hypochloremia, hypokalemia, hyponatremia and metabolic alkalosis. In this case report, we present the first female and the second official case of CCD in Iran. A 15-month-old girl referred to our hospital due to failure to thrive and poor feeding. She had normal kidneys, liver and spleen. Treating her with Shohl's solution, thiazide and zinc sulfate did not result in weight gain. Consequently, pseudo-Bartter syndrome was suspected, she was treated with intravenous (IV) therapy to which she responded dramatically. In addition, hypokalemia resolved quickly. Since this does not usually happen in patients with the pseudo-Bartter syndrome, stool tests were performed. Abnormal level of chloride in stool suggested CCD and she was thus treated with IV fluid replacement, Total parentral nutrition and high dose of oral omeprazole (3 mg/kg/day). She gained 1 kg of weight and is doing fine until present. CCD is a rare hereditary cause of intractable diarrhea of infancy. It should be considered in infants with unknown severe electrolyte disturbances.

Interaction of steel, titanium and zirconium with melted chlorides containing copper and zinc

International Nuclear Information System (INIS)

Ozeryanaya, I.N.; Manukhina, T.I.; Shibanov, B.S.

1976-01-01

Cu and Zn coatings were obtained by contact displacement of their molten chlorides. Cu was deposited on Kh18N10T stainless steel, and Zn was deposited on Ti or Zr at 400-550 0 . Cu was displaced from the electrolyte by all components in the steel. A smooth coating exhibited high adhesion. According to metallography there was a transition layer of a Ni-Cr solid solution between the surface Cu layer and steel. With electronegetiol Ti and Zr, contact deposition of Zn or Cu from chloride melts was possible. The coatings were multilayer and exhibited adequate adhesion. The coating consisted of an intermetallic compound of Ti or Zr with Zn

Synthesis from zinc oxalate, growth mechanism and optical properties of ZnO nano/micro structures

Energy Technology Data Exchange (ETDEWEB)

Raj, C. Justin; Varma, K.B.R. [Materials Research Centre, Indian Institute of Science, Bangalore 560 012 (India); Joshi, R.K. [Special Center for Nano Sciences, Jawaharlal Nehru University, New Delhi 110067 (India)

2011-11-15

We report the synthesis of various morphological micro to nano structured zinc oxide crystals via simple precipitation technique. The growth mechanisms of the zinc oxide nanostructures such as snowflake, rose, platelets, porous pyramid and rectangular shapes were studied in detail under various growth conditions. The precursor powders were prepared using several zinc counter ions such as chloride, nitrate and sulphate along with oxalic acid as a precipitating agent. The precursors were decomposed by heating in air resulting in the formation of different shapes of zinc oxide crystals. Variations in ZnO nanostructural shapes were possibly due to the counter ion effect. Sulphate counter ion led to unusual rose-shape morphology. Strong ultrasonic treatment on ZnO rose shows that it was formed by irregular arrangement of micro to nano size hexagonal zinc oxide platelets. The X-ray diffraction studies confirmed the wurzite structure of all zinc oxide samples synthesized using different zinc counter ions. Functional groups of the zinc oxalate precursor and zinc oxide were identified using micro Raman studies. The blue light emission spectra of the various morphologies were recorded using luminescence spectrometer. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Characterization and Analysis of Ionic Zinc Alloy Running a Potential Dynamic Polarization in Sea Water

International Nuclear Information System (INIS)

Zaifol Samsu; Muhammad Daud; Siti Radiah Mohd Kamarudin

2011-01-01

Zinc is an active metal. The reactive nature of zinc allows it to be used for sacrificial anode in cathodic protection systems by electrically coupled to the protected metal. Zinc is especially well suited for cathodic protection on ships that move between salt water and harbors in brackish rivers or estuaries (1). Zinc anodes also are used to protect ballast tank, heat exchangers, and many mechanical components on ships, coastal power plants, and similar structures. Cathodic protective by zinc is used in sea water, brackish water, fresh water, and in some soil. The relative reactivity of zinc and its ability to attract oxidation to itself makes it an efficient sacrificial anode in cathodic protection (2). For example, cathodic protection of a buried pipeline can be achieved by connecting anodes made from zinc to the pipe. Zinc acts as the anode (negative terminus) by slowly corroding away as it passes electric current to the steel pipeline. When exposed to environment containing halide ions, of which the chloride (Cl-) is the most frequently encountered in service, the oxide film breaks down at specific points leading to the formation of pits on the zinc surface (3). (author)

An introduction to the experimental study of zinc 65 retention by Anguilla anguilla (L)

International Nuclear Information System (INIS)

Foulquier, L.; Delaunay, P.; Lambrechts, A.

1975-01-01

Eels from the Rhone River delta, with a live weight of 15 to 20g representing a total biomass of about 200g, were placed in fresh-water aquaria containing zinc 65 in nitrate or chloride form. The amount of 65 Zn retained by the fish after 20 days was approximately 2% of the activity introduced. 65 Zn fixation was a gradual phenomenon for which equilibrium conditions appeared difficult to achieve. After 21 days the concentration factor for the entire animal was about 14. The branchiae, liver, kidneys and digestive tract showed the greatest specific activity levels. The muscle structure could represent up to 40% of the zinc 65 retained by the eel. Zinc 65 was excreted slowly [fr

Electrodeposition of gallium and zinc onto aluminium. Influence of the electrodeposited metals on the activation process

International Nuclear Information System (INIS)

Flamini, D.O.; Saidman, S.B.; Bessone, J.B.

2007-01-01

The electrodeposition of gallium and/or zinc on aluminium, aluminium-zinc alloy and vitreous carbon electrodes in chloride solutions is analysed. The electrodissolution of the formed interfaces is also described and discussed. For this purpose, potentiodynamic and potentiostatic techniques and open circuit potential measurements were employed and surface characterisation was performed by scanning electron microscopy and energy dispersive X-ray analysis. The presence of zinc, electrodeposited from the solution or as an alloying component, facilitates gallium enrichment at the interface and improves the wetting on the aluminium oxide. These conditions ensure the formation of a surface Ga-Al amalgam. As a result, the dissolution process occurs at potentials which are more active than those observed for aluminium or aluminium-zinc alloy in halide solutions

Electrodeposition of gallium and zinc onto aluminium. Influence of the electrodeposited metals on the activation process

Energy Technology Data Exchange (ETDEWEB)

Flamini, D.O. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Saidman, S.B. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)], E-mail: ssaidman@criba.edu.ar; Bessone, J.B. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

2007-07-31

The electrodeposition of gallium and/or zinc on aluminium, aluminium-zinc alloy and vitreous carbon electrodes in chloride solutions is analysed. The electrodissolution of the formed interfaces is also described and discussed. For this purpose, potentiodynamic and potentiostatic techniques and open circuit potential measurements were employed and surface characterisation was performed by scanning electron microscopy and energy dispersive X-ray analysis. The presence of zinc, electrodeposited from the solution or as an alloying component, facilitates gallium enrichment at the interface and improves the wetting on the aluminium oxide. These conditions ensure the formation of a surface Ga-Al amalgam. As a result, the dissolution process occurs at potentials which are more active than those observed for aluminium or aluminium-zinc alloy in halide solutions.

Zinc resistance of Staphylococcus aureus of animal origin is strongly associated with methicillin resistance

DEFF Research Database (Denmark)

Cavaco, Lina; Hasman, Henrik; Aarestrup, Frank Møller

2011-01-01

This study was conducted to determine the occurrence of zinc and copper resistances in methicillin-resistant Staphylococcus aureus (MRSA) from swine and veal calves in a global strain collection.The test population consisted of 476 porcine MRSA isolates from ten European countries, 18 porcine MRSA...... of the pig MRSA from Europe and the seven Chinese isolates belonged to other CCs and 3 isolates were not classified into a CC.All isolates were tested for susceptibility to zinc chloride and copper sulphate using agar dilution and tested by PCR for the czrC gene encoding zinc resistance.Phenotypic zinc...... resistance (MIC>2mM) was observed in 74% (n=324) and 42% (n=39) of European MRSA CC398 from pigs and veal calves, respectively, and in 44% of the Canadian isolates (n=8), but not among the Chinese isolates. Almost all (99%) zinc-resistant MRSA carried czrC. Of the 37 European non-CC398 MRSA, 62% were...

Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

International Nuclear Information System (INIS)

Lehr, I.L.; Saidman, S.B.

2012-01-01

This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

Science.gov (United States)

Lehr, I. L.; Saidman, S. B.

2012-03-01

This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

Production of zinc pellets

Science.gov (United States)

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.

Effects of Nano-zinc on Biochemical Parameters in Cadmium-Exposed Rats.

Science.gov (United States)

Hejazy, Marzie; Koohi, Mohammad Kazem

2017-12-01

Cadmium (Cd) is a toxic environmental and occupational pollutant with reported toxic effects on the kidneys, liver, lungs, bones, and the immunity system. Based on its physicochemical similarity to cadmium, zinc (Zn) shows protective effects against cadmium toxicity and cadmium accumulation in the body. Nano-zinc and nano-zinc oxide (ZnO), recently used in foods and pharmaceutical products, can release a great amount of Zn 2+ in their environment. This research was carried out to investigate the more potent properties of the metal zinc among sub-acute cadmium intoxicated rats. Seventy-five male Wistar rats were caged in 15 groups. Cadmium chloride (CdCl 2 ) was used in drinking water to induce cadmium toxicity. Different sizes (15, 20, and 30 nm) and doses of nano-zinc particles (3, 10, 100 mg/kg body weight [bw]) were administered solely and simultaneously with CdCl 2 (2-5 mg/kg bw) for 28 days. The experimental animals were decapitated, and the biochemical biomarkers (enzymatic and non-enzymatic) were determined in their serum after oral exposure to nano-zinc and cadmium. Statistical analysis was carried out with a one-way ANOVA and t test. P zinc-treated rats. AST, ALT, triglyceride, total cholesterol, LDL, and free fatty acids increased significantly in the cadmium- and nano-zinc-treated rats compared with the controls. However, albumin, total protein, and HDLc significantly decreased in the cadmium- and nano-zinc-treated rats compared with the controls (P zinc, the smaller sizes with low doses and the larger sizes with high doses are more toxic than metallic zinc. In a few cases, an inverse dose-dependent relationship was seen as well. This research showed that in spite of larger sizes of zinc, smaller sizes of nano-zinc particles are not suitable for protection against cadmium intoxication.

Luminescence properties of copper(I), zinc(II) and cadmium(II) coordination compounds with picoline ligands

Energy Technology Data Exchange (ETDEWEB)

Małecki, Jan Grzegorz, E-mail: gmalecki@us.edu.pl; Maroń, Anna

2017-06-15

Mononuclear coordination compounds of copper(I) – [Cu(PPh{sub 3}){sub 2}(picoline)(NO{sub 3})], zinc(II) – [ZnCl{sub 2}(picoline){sub 2}] (picoline=3– and 4–methylpyridine) and polymeric cadmium(II) – [CdCl{sub 2}(β-picoline){sub 2}]{sub n} were prepared and their luminescence properties in solid state and acetonitrile solutions were determined. Single crystal X-ray crystallography revealed distorted tetrahedral geometry around the central ions of the compounds. The compounds exhibit green photoluminescence in solid state and in acetonitrile solutions. The emission of copper(I) compounds originated from metal-to-ligand charge transfer state combined with nitrato-to-picoline charge transfer state i.e. ({sup 1}(M+X)LCT). The presence of nitrato ligand in the coordination sphere of copper(I) compounds quenches the emission. Luminescence of zinc(II) and cadmium(II) compounds results from chloride-to-picoline charge transfer state and the quantum efficiency in the case of the polymeric Cd(II) compound reaches 39%. The photoluminescence quantum yields of the mononuclear zinc(II) compounds vary from 10 to 16% depending on the conditions (solid state, solution). - Graphical abstract: Coordination compounds of copper(I), zinc(II) and polymeric cadmium(II) with picoline ligands were prepared and their luminescence properties in solid state and acetonitrile solutions were determined. The compounds exhibit green photoluminescence in solid state and in acetonitrile solutions. Emission of copper(I) compounds originated from {sup 1}(M+X)LCT state. Luminescence of zinc(II) and cadmium(II) compounds results from chloride-to-picoline charge transfer state and the quantum efficiency in the case of the polymeric Cd(II) compound reaches 39%. The photoluminescence quantum yields of the mononuclear zinc(II) compounds vary from 10 to 16% depending on the conditions (solid state, solution).

Zinc Signals and Immunity.

Science.gov (United States)

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

An evaluation of the performance and mechanistic action of the costabiliser N-phenyl-3-acetyl pyrrolidine-2,4-dione and its derivatives in poly(vinyl chloride)

International Nuclear Information System (INIS)

Chaudhry, H.I.

1999-10-01

N-phenyl-3-acetyl pyrrolidine-2,4-dione (F6) and its derivatives (F6c and F6d) have been investigated as costabilisers for PVC at processing temperatures, along with the commercial costabilisers: dehydroacetic acid (DHA) and Rhodiostab-83 (R83). Spectroscopic (fluorescence, Fourier-transform infrared and nuclear magnetic resonance) studies on PVC itself, and model compounds of PVC impurities (e.g. 4-chloro-2-hexene) have shown two distinct modes of action: in which a metal complex between the costabiliser and a metal soap stabiliser (zinc stearate and calcium stearate is the active entity, one in which costabiliser action is facilitated by release of zinc chloride. F6 was shown to substitute for allylic chloride by a C-alkylation reaction so inhibiting polyene formation and giving very good initial colour. It was demonstrated that F6 formed a complex with the zinc stearate at room temperature to give a chelate in which the zinc ion is tetracoordinated. Because the costabiliser is able to co-ordinate readily to zinc stearate, this leads to good initial colour, but a more rapid evolution of HCl ('short-term' costabilisation). When the -C=O substituent in the 3-position was replaced by a '-C=N-alkyl' (F6d), or a '-C=N-phenyl' (F6c) group, the behaviour was changed markedly. FTIR and HCl evolution showed that F6d was unstable at 180 deg. C and reacted with HCl evolved from the degraded PVC, decomposing into a basic gas and a structure similar to F6. F6d being more basic formed a complex with the Lewis acid ZnCI 2 instead of zinc stearate. F6c did not interact with the ZnCl 2 or ZnSt 2 , despite the fact that it has an extra nitrogen atom. The reason for this is that the π orbital system of the N-substituted phenyl ring in the 3-position in the pyrrolidine ring is conjugated with the C=N double bond. DHA also interacted with the zinc stearate, but this interaction was significant only at higher temperatures, i.e. after heating to processing temperatures. The

Depolymerization of cellulose into high-value chemicals by using synergy of zinc chloride hydrate and sulfate ion promoted titania catalyst.

Science.gov (United States)

Wei, Weiqi; Wu, Shubin

2017-10-01

Experiments for cellulose depolymerization by synergy of zinc chloride hydrate (ZnCl 2 ·RH 2 O) and sulfated titania catalyst (SO 4 2- /TiO 2 ) were investigated in this study. The results showed the introduction of sulfate into the TiO 2 significantly enhanced the catalyst acid amount, especially for Brønsted acid site, which is beneficial for subsequent cellulose depolymerization. ZnCl 2 ·RH 2 O hydrate, only a narrow composition range of water, specifically 3.0≤R≤4.0, can dissolve cellulose, which finally resulted the cellulose with low crystallinity and weak intrachain and interchain hydrogen bond network. Coupling of ZnCl 2 ·RH 2 O hydrate and SO 4 2- /TiO 2 catalyst as a mixed reaction system promoted cellulose depolymerization, and the products can be adjusted by the control of reaction conditions, the low temperature (80-100°C) seemed beneficial for glucose formation (maximal yield 50.5%), and the high temperature (120-140°C) favored to produce levulinic acid (maximal yield 43.1%). Besides, the addition of organic co-solvent making HMF as the main product (maximal yield 38.3%). Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of Cu-rich sub-layer on the increased corrosion resistance of Cu-xZn alloys in chloride containing borate buffer

International Nuclear Information System (INIS)

Milosev, Ingrid; Mikic, Tadeja Kosec; Gaberscek, Miran

2006-01-01

The electrochemical behaviour of Cu-xZn alloys, as well as their constituent metals, in a borate buffer containing chloride ions in the molar range from 0.01 to 1 M are studied. Characteristics of these materials under anodic polarization are compared and the composition and morphology of the corrosion products formed in the course of polarization experiment are analysed by SEM and EDS. X-ray photoelectron spectroscopy and electrochemical impedance measurements are used for characterization of the surface layers formed on Cu, Zn and Cu-40Zn alloy during 2-h immersion at E oc in a borate buffer containing two different concentrations of chloride ions. New aspects of the behaviour of brass under E oc condition are revealed. The improved corrosion resistance of brass in chloride media, if compared to zinc metal, is attributed to a Cu-rich layer formed by the selective dissolution of zinc. Based on the results, a structural model describing the improved corrosion resistance of Cu-40Zn alloy with respect to Zn metal is proposed

Protective effect of zinc over lead toxicity on testes

International Nuclear Information System (INIS)

Rafique, M.; Shaikh, S.P.; Tahir, F.

2010-01-01

To determine the effects of lead and zinc on testes. Study Design: Randomized control trial. Place and Duration of Study: Basic Medical Sciences Institute, Jinnah Postgraduate Medical Centre, Karachi, from August 2003 to December 2005. Methodology: Sixty adult (90 days old) albino rats were obtained from animal house JPMC for the study and divided into 3 groups. Group A received injection normal saline 1 cc intraperitoneally daily for 8 weeks. Group B received lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily. Group C received zinc chloride in a dose of 1 mg/kg body weight before half an hour of injection of lead chloride in a dose of 10 mg/kg body weight intraperitoneally daily so that to provide pre-treatment. On the day of completion of treatment the animals were sacrificed testes removed and fixed in Bouin's fluid. Testes were dehydrated in the ascending strength of alcohol, 5 mu m thick sections were cut and stained with PAS Iron Hematoxylin. Student's t-test was used for statistical analysis with significance at p < 0.05. Results: The mean diameter of seminiferous tubule was 291.91+-1.18, 198.53 +- 1.67 and 288.77 +- 1.11 mu m in groups A, B and C respectively. Diameter of seminiferous tubules decreased by 31.99% in group B (p < 0.001; CI 89.023 to 97.736) as compared group A and while group B comparing with group C, the diameter of seminiferous tubules was decreased by 31.25% (p-value = 0.076; CI -94.264 to -86.203). Mean thickness of germinal epithelium was 96.19 +- 1.01, 50.69 +- 1.20 and 94.94 +- 0.54 mu m in groups A, B and C respectively. Thickness of germinal epithelium decreased by 47.30 in group B (P < 0.001; CI 42.503 to 48.496) as compared to group A and while comparing group B with group C, the thickness of germinal epithelium was decreased by 46.61% (p=-44.25; CI -46.704 to -41.787). Conclusion: Zinc prevented toxic effects of lead on germinal epithelium in the albino rats. (author)

Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

International Nuclear Information System (INIS)

Zaleta-Alejandre, E.; Camargo-Martinez, J.; Ramirez-Garibo, A.; Pérez-Arrieta, M.L.; Balderas-Xicohténcatl, R.; Rivera-Alvarez, Z.; Aguilar-Frutis, M.; Falcony, C.

2012-01-01

Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10 −3 –10 −2 Ω·cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 °C. The deposition rates obtained were as high as 180 Å·min −1 at a substrate temperature of 450 °C. - Highlights: ► Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). ► USP is of low cost, high growth rates and scalable for industrial applications. ► USP is appropriate for the deposition of metallic oxide films. ► We studied the effect of acetic acid, time deposition and substrate temperature. ► Zinc acetate and indium chloride were used as precursor materials.

Extrinsic labelling of zinc and calcium in bread

International Nuclear Information System (INIS)

Fredlund, Kerstin; Rossander-Hulthen, Lena; Isaksson, Mats; Almgren, Annette; Sandberg, A.-S.

2002-01-01

This study investigated the effect of different means of extrinsic administration of 65 Zn and 47 Ca in white wheat flour bread on the measured absorption. Eight healthy subjects were served 80 g of labelled bread as a standardized breakfast after an overnight fast on three occasions. Extrinsic labelling of the meals with 65 Zn and 47 Ca was done in three ways: (a) by adding the isotopes to the bread 16 h before it was served, (b) by adding the isotopes shortly before serving or (c) by adding the isotopes to the water used in dough making. Zinc and calcium chloride corresponding to 3.2 mg (49 μmol) zinc and 275 mg (6.9 mmol) calcium in one portion were added to the dough. Whole-body retention was measured by whole-body counting. The fractional absorption of zinc was (a) 0.243±0.122, (b) 0.217±0.101 and (c) 0.178±0.063 (mean±SD), and the fractional absorption of calcium (expressed as calcium retention on day 7) was (a) 0.351±0.108, (b) 0.357±0.131 and (c) 0.334±0.117 (mean±SD). No significant difference (p>0.05) was seen between the different ways for either zinc nor calcium

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

International Nuclear Information System (INIS)

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

1991-01-01

The authors 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 ∼3.5 angstrom. In the glucocorticoid receptor, each zinc atom is bound to four cysteine residues; the interatomic zinc-zinc distance is ∼13 angstrom, 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

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

Energy Technology Data Exchange (ETDEWEB)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Tian, Shulei [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering; Wang, Qi [Chinese Research Academy of Environmental Science, Beijing (China); Wu, Ziyu [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Univ. of Science and Technology of China, Hefei (China). National Synchrotron Radiation Lab.; Chinese Academy of Sciences, Beijing (China). Theoretical Physics Center for Science Facilities

2009-07-15

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

International Nuclear Information System (INIS)

Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Chinese Academy of Sciences, Beijing

2009-01-01

The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

Electrochemical Chloride extraction using external electrodes?

DEFF Research Database (Denmark)

Ottosen, Lisbeth M.; Pedersen, Anne Juul

2006-01-01

Electrochemical methods for the removal of chloride from concrete have been developed and the methods are primarily designed for situations where corrosion has started due to an increased chloride concentration in the vicinity of the reinforcement. In these methods the reinforcement is used...... as the cathode. However, some unwanted side effects can occur, including alkali-silica reaction and in some cases hydrogen embrittlement. It is also suggested also to use electrochemical chloride extraction in a preventive way in constructions where chloride induced corrosion is likely to be a problem after...... a period of time, i.e. remove the chlorides before the chloride front reaches the reinforcement. If the chlorides are removed from outer few centimetres from the surface, the chloride will not reach the reinforcement and cause damage. By using the electrochemical chloride removal in this preventive way...

Negative Effect of Zinc on Testes, Testosterone and Gonadotrophins Levels in Adult Male Wistar Rats

Directory of Open Access Journals (Sweden)

D Sohrabi

2012-05-01

Full Text Available

Background and Objectives

The toxic effects of zinc leading to sebaceous gland closure, skin eczema and blister have been previously demonstrated in other studies. The aim of this study is to determine the chronic effects of zinc chloride (ZnCl₂   on testicular tissues, testosterone and gonadotrophins in adult male Wistar rats.

Methods

Twenty four Adult male Wistar rats were divided in to two groups of study and control with each group consisting of 12 rats. Study group rats received 10 mg/kg interaperitoneal Zinc chloride in normal saline (N.S every other day for 30 days. Control group rats received N.S during this time. Blood sample for hormonal evaluation were collected from hearts of these rats. The rats were destroyed and their testes were removed and fixed in a 10% formaldehyde and glutaraldehyde solution.

Results

The results of this study showed a significant decrease in the level of LH and testosterone hormone among the rats in the study group compared to the control group with p< 0.001  and

p< 0.01 respectively. Study of fine structure of testicular cells and tissues in the study group rats  revealed swelling of mitochondria, increase in smooth endoplasmic reticulum vacuolization and lysosomic granules (Autophagic vacuoles in cytosol of their germinal cells.

Conclusion

Based on the results of this study consumption of large amount of compounds which contain zinc should be controlled and limited among men. There is a need for further studies to evaluate and determine the reversibility of most hormonal and physiological changes due to usage of zinc containing compounds.

Zinc at glutamatergic synapses.

Science.gov (United States)

Paoletti, P; Vergnano, A M; Barbour, B; Casado, M

2009-01-12

It has long been known that the mammalian forebrain contains a subset of glutamatergic neurons that sequester zinc in their synaptic vesicles. This zinc may be released into the synaptic cleft upon neuronal activity. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate receptors and transporters. Among these targets, NMDA receptors appear particularly interesting because certain NMDA receptor subtypes (those containing the NR2A subunit) contain allosteric sites exquisitely sensitive to extracellular zinc. The existence of these high-affinity zinc binding sites raises the possibility that zinc may act both in a phasic and tonic mode. Changes in zinc concentration and subcellular zinc distribution have also been described in several pathological conditions linked to glutamatergic transmission dysfunctions. However, despite intense investigation, the functional significance of vesicular zinc remains largely a mystery. In this review, we present the anatomy and the physiology of the glutamatergic zinc-containing synapse. Particular emphasis is put on the molecular and cellular mechanisms underlying the putative roles of zinc as a messenger involved in excitatory synaptic transmission and plasticity. We also highlight the many controversial issues and unanswered questions. Finally, we present and compare two widely used zinc chelators, CaEDTA and tricine, and show why tricine should be preferred to CaEDTA when studying fast transient zinc elevations as may occur during synaptic activity.

Study of belite calcium sulfo-aluminate cement potential for zinc conditioning: From hydration to durability

International Nuclear Information System (INIS)

Berger, St.

2009-12-01

Calcium silicate cements are widely used for low- and intermediate-level radioactive waste conditioning. However, wastes produced by nuclear activities are very diverse and some of their components may chemically react with cement phases. For instance, ashes resulting from the incineration of technological wastes including neoprene and polyvinylchloride may contain substantial amounts of soluble zinc chloride. This compound is known to strongly delay or inhibit Portland cement setting. One approach to limit adverse cement-waste interactions is to select a binder showing a better compatibility with the waste while keeping cement matrix advantages (low cost, simple process, hydration with water provided by the waste...). This work thus investigates the potential of calcium sulfo-aluminate cement for zinc Zn(II) immobilization. Four aspects were considered: hydration (kinetics and products formed), properties of hydrated binders, mechanisms of zinc retention and durability of the cement pastes (based on leaching experiments and modelling). The influence of three main parameters was assessed: the gypsum content of the cement, the concentration of ZnCl 2 and the thermal evolution at early age. It follows that materials based on a calcium sulfo-aluminate cement containing 20% gypsum are interesting candidates for zinc Zn(II) stabilization/solidification: there is no delay in hydration, mineralogy of the hydrated phases is slightly dependent on thermal history, mechanical strength is high, dimensional changes are limited and zinc Zn(II) is well immobilized, even if the cement paste is leached by pure water during a long period (90 d). (author)

The effect of zinc thickness on corrosion film breakdown of Colombian galvanized steel

Science.gov (United States)

Sandoval-Amador, A.; E Torres Ramirez, J.; Cabrales-Villamizar, P. A.; Laverde Cataño, D.; Y Peña-Ballesteros, D.

2017-12-01

This work studies the corrosion behaviour of Colombian galvanized steel in solutions of chloride and sulphate ions. The effect of the thickness and exposure time on the film’s breakdown susceptibility and protectiveness of the corrosion products were studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The corrosion products were analysed using SEM-EDS and XRD. The samples with a higher thickness level in the zinc film (Z180) have the lowest corrosion rate. In this case, one of the products that was formed by the chemical reactions that occurred was Zinc hydroxide, which exhibits a passive behaviour as observed in the Pourbaix curves of the obtained potentials and in how the different Ph levels of the solutions worked. The sheets with the highest thickness (Z180) had the best performance, since at the end of the study they showed the least amount of damage on the surface of the zinc layer. This is because the thickness of the zinc layer favours the formation of simonkolleite, which is the corrosion product that protects the material under the conditions of the study.

UHF-plasma torch emission spectrometry for cadmium, lead and zinc by vaporization introduction

International Nuclear Information System (INIS)

Nakashima, Ryozo

1978-01-01

As the introduction technique of aerosol into the plasma torch, vaporization introduction of metals was studied. An aliquot of metal nitrates was pipetted in a graphite crucible and dried with a vacuum pump. The dried sample was heated in a high-frequency induction furnace under inert gas carrier such as argon or nitrogen (reduction introduction). Chlorination introduction with hydrogen chloride was also studied. High-purity grade of argon, nitrogen and hydrogen chloride was used as carrier. Intensities were based on the peak area of intensity-time curves at 228.8 nm (cadmium), 405.8 nm (lead), and 213.9 nm (zinc). In the reduction introduction, the minimum temperatures to attain a constant peak area, which means a complete vaporization were 700 0 C (cadmium), 1500 0 C (lead), and 1100 0 C (zinc), respectively. In the chlorination, this temperature was 500 0 C (cadmium), 700 0 C (lead), and 300 0 C (zinc) respectively. For two introduction techniques, the latter was more sensitive than the former for cadmium and zinc, while the former was more sensitive for lead. The optimum temperature, detection limits, and the coefficients of variance calculated from the measurements of 1.0 μg of metals were as follows: Cadmium: chlorination at 850 0 C, D.L. 5ng, C.V. 10%. Lead: reduction at 1600 0 C, D.L. 10ng, C.V. 15%. Zinc: chlorination at 850 0 C, D.L. 5ng, C.V. 9%. Linear calibration lines having 45 0 slope at log-log plots, were obtained over the range from 0.05 to 6 μg for cadmium and zinc, 0.06 to 6 μg for lead on the conditions above. These techniques were also applied for analyses of biological materials for three metals without prior separations. Although the sensitivity of the chlorination introduction technique for lead was rather poor compared with that of reduction technique, the chlorination technique was applied to minimize the introduction of coexisting materials such as alkali and alkaline earth metals. The analytical results agreed reasonably with the

Fortification of staple foods with zinc for improving zinc status and other health outcomes in the general population.

Science.gov (United States)

Shah, Dheeraj; Sachdev, Harshpal S; Gera, Tarun; De-Regil, Luz Maria; Peña-Rosas, Juan Pablo

2016-06-09

Zinc deficiency is a global nutritional problem, particularly in children and women residing in settings where diets are cereal based and monotonous. It has several negative health consequences. Fortification of staple foods with zinc may be an effective strategy for preventing zinc deficiency and improving zinc-related health outcomes. To evaluate the beneficial and adverse effects of fortification of staple foods with zinc on health-related outcomes and biomarkers of zinc status in the general population. We searched the following databases in April 2015: Cochrane Central Register of Controlled Trials (CENTRAL, Issue 3 of 12, 2015, the Cochrane Library), MEDLINE & MEDLINE In Process (OVID) (1950 to 8 April 2015), EMBASE (OVID) (1974 to 8 April 2015), CINAHL (1982 to April 2015), Web of Science (1900 to 9 April 2015), BIOSIS (1969 to 9 April 2015), POPLINE (1970 to April 2015), AGRICOLA, OpenGrey, BiblioMap, and Trials Register of Promoting Health Interventions (TRoPHI), besides regional databases (April 2015) and theses. We also searched clinical trial registries (17 March 2015) and contacted relevant organisations (May 2014) in order to identify ongoing and unpublished studies. We included randomised controlled trials, randomised either at the level of the individual or cluster. We also included non-randomised trials at the level of the individual if there was a concurrent comparison group. We included non-randomised cluster trials and controlled before-after studies only if there were at least two intervention sites and two control sites. Interventions included fortification (central/industrial) of staple foods (cereal flours, edible fats, sugar, condiments, seasonings, milk and beverages) with zinc for a minimum period of two weeks. Participants were members of the general population who were over two years of age (including pregnant and lactating women) from any country. Two review authors independently assessed the eligibility of studies for inclusion

Structural, electrical and optical properties of indium chloride doped ZnO films synthesized by Ultrasonic Spray Pyrolysis technique

Energy Technology Data Exchange (ETDEWEB)

Zaleta-Alejandre, E., E-mail: ezaleta@fis.cinvestav.mx [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Camargo-Martinez, J.; Ramirez-Garibo, A. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Perez-Arrieta, M.L. [Universidad Autonoma de Zacatecas, Unidad Academica de Fisica, Calzada Solidaridad esq. Paseo, La Bufa s/n, C.P. 98060, Zacatecas, Mexico (Mexico); Balderas-Xicohtencatl, R.; Rivera-Alvarez, Z. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico); Aguilar-Frutis, M. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada-IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo, Mexico, D.F. (Mexico); Falcony, C. [Centro de Investigacion y de Estudios Avanzados-IPN, Departamento de Fisica, Apdo, Postal 14-470, Del. Gustavo A. Madero, C.P. 07000, Mexico, D.F. (Mexico)

2012-12-01

Indium chloride doped zinc oxide (ZnO:In) thin films were deposited onto glass substrates using zinc acetate by Ultrasonic Spray Pyrolysis technique. The effect of substrate temperature, deposition time and acetic acid added to the spraying solution on the structural, electrical and optical properties of these ZnO:In films is reported. The films were in all cases polycrystalline with a hexagonal (wurtzite) structure, a transparency over 80% and resistivity of the order of 10{sup -3}-10{sup -2} Ohm-Sign {center_dot}cm. The resistivity was dependent on the volume % of acetic acid added to the spraying solution. The minimum resistivity value was obtained with a 5 vol.% acetic acid (pH = 3.71) at substrate temperature of 450 Degree-Sign C. The deposition rates obtained were as high as 180 A{center_dot}min{sup -1} at a substrate temperature of 450 Degree-Sign C. - Highlights: Black-Right-Pointing-Pointer Conductive ZnO:In thin films were deposited by Ultrasonic Spray Pyrolysis (USP). Black-Right-Pointing-Pointer USP is of low cost, high growth rates and scalable for industrial applications. Black-Right-Pointing-Pointer USP is appropriate for the deposition of metallic oxide films. Black-Right-Pointing-Pointer We studied the effect of acetic acid, time deposition and substrate temperature. Black-Right-Pointing-Pointer Zinc acetate and indium chloride were used as precursor materials.

Effect of the Type of Surface Treatment and Cement on the Chloride Induced Corrosion of Galvanized Reinforcements

Science.gov (United States)

Tittarelli, Francesca; Mobili, Alessandra; Vicerè, Anna Maria; Roventi, Gabriella; Bellezze, Tiziano

2017-10-01

The effect of a new passivation treatment, obtained by immersion of the galvanized reinforcements in a trivalent chromium salts based solution, on the chlorides induced corrosion has been investigated. To investigate also the effect of cement alkalinity on corrosion behaviour of reinforcements, concretes manufactured with three different European cements were compared. The obtained results show that the alternative treatment based on hexavalent chromium-free baths forms effective protection layers on the galvanized rebar surfaces. The higher corrosion rates of zinc coating in concrete manufactured with Portland cement compared to those recorded for bars in concrete manufactured with pozzolanic cement depends strongly on the higher chloride content at the steel concrete interface.

Zinc Improves Cognitive and Neuronal Dysfunction During Aluminium-Induced Neurodegeneration.

Science.gov (United States)

Singla, Neha; Dhawan, D K

2017-01-01

Metals are considered as important components of a physiologically active cell, and imbalance in their levels can lead to various diseased conditions. Aluminium (Al) is an environmental neurotoxicant, which is etiologically related to several neurodegenerative disorders like Alzheimer's, whereas zinc (Zn) is an essential trace element that regulates a large number of metabolic processes in the brain. The objective of the present study was to understand whether Zn provides any physiological protection during Al-induced neurodegeneration. Male Sprague Dawley rats weighing 140-160 g received either aluminium chloride (AlCl 3 ) orally (100 mg/kg b.wt./day), zinc sulphate (ZnSO 4 ) in drinking water (227 mg/L) or combined treatment of aluminium and zinc for 8 weeks. Al treatment resulted in a significant decline in the cognitive behaviour of rats, whereas zinc supplementation caused an improvement in various neurobehavior parameters. Further, Al exposure decreased (p ≤ 0.001) the levels of neurotransmitters, acetylcholinesterase activity, but increased (p ≤ 0.001) the levels of L-citrulline as well as activities of nitric oxide and monoamine oxidase in the brain. However, zinc administration to Al-treated animals increased the levels of neurotransmitters and regulated the altered activities of brain markers. Western blot of tau, amyloid precursor protein (APP), glial fibrillary acidic protein (GFAP), ubiquitin, α-synuclein and Hsp 70 were also found to be elevated after Al exposure, which however were reversed following Zn treatment. Al treatment also revealed alterations in neurohistoarchitecture in the form of loss of pyramidal and Purkinje cells, which were improved upon zinc co-administration. Therefore, the present study demonstrates that zinc improves cognitive functions by regulating α-synuclein and APP-mediated molecular pathways during aluminium-induced neurodegeneration.

Endogenous zinc excretion in relation to various levels of dietary zinc intake in the mink (Mustela vison)

International Nuclear Information System (INIS)

Mejborn, H.

1990-01-01

Endogenous zinc excretion was studied in adult male mink fed experimental diets for 73 d, including a collection period from d 69 to 73. Dietary zinc levels were 2.8, 26 or 121 mg/kg wet weight. In accordance with the results of a methodological study, also reported here, the animals had an intramuscular injection of 65ZnCl2 12 d before the start of the collection period. Total fecal (endogenous + unabsorbed) zinc excretion for d 69-73 in the three groups was 2.3, 20.4 and 91.0 mg. The endogenous zinc excretion was 1.3, 2.0 and 6.4 mg, corresponding to 80.8, 10.6 and 6.4% of the zinc intake. Thus, the endogenous excretion was mainly important for the zinc homeostasis at low zinc intake, whereas at high intake the homeostasis was regulated via absorption from the digestive tract. The overall conclusion of the experiment was that mink are comparable to other species (including man) in regard to mechanisms controlling zinc homeostasis

Influence of different aggressive media on the protective behaviour of zinc rich paints

International Nuclear Information System (INIS)

Abreu, C. M.; Perez, C.; Sanchez, A.; Izquierdo, M.; Novoa, X. R.

1999-01-01

The aim of the present work is to determine the influence that different atmospheric agents have in steel protection by zinc rich paints based on inorganic silicate binder. The presence of pollutants in the atmosphere has been simulated by periodical deposition of sulphate and/or chloride solutions on the surface of the samples. With the aim of determining the validity of immersion tests, usually used in these types studies, the samples were kept in a controlled atmosphere at 20 degree centigrade and 60% RH. These exposition conditions could represent a relative dry atmosphere allowing the zinc corrosion. Electrochemical impedance spectroscopy was employed to follow the time evolution of the studied paints. The corresponding impedance spectra were modelled using an electrical equivalent circuit approach. This methodology allows establishing that pollutants as well as weathering conditions define the protecting mechanism of these zinc rich paints. The results show a fast evolution towards a barrier-type protecting mechanism

Identification of seven novel mutations including the first two genomic rearrangements in SLC26A3 mutated in congenital chloride diarrhea.

Science.gov (United States)

Höglund, P; Sormaala, M; Haila, S; Socha, J; Rajaram, U; Scheurlen, W; Sinaasappel, M; de Jonge, H; Holmberg, C; Yoshikawa, H; Kere, J

2001-09-01

Congenital chloride diarrhea (CLD) is an autosomal recessive disorder characterized by defective intestinal electrolyte absorption, resulting in voluminous osmotic diarrhea with high chloride content. A variety of mutations in the solute carrier family 26, member 3 gene (SLC26A3, previously known as CLD or DRA) are responsible for the disease. Since the identification of the SLC26A3 gene and the determination of its genomic structure, altogether three founder and 17 private mutations have been characterized within miscellaneous ethnic groups. We screened for mutations in seven unrelated families with CLD. The diagnoses were confirmed by fecal chloride measurements. The combined PCR-SSCP and sequencing analyses revealed altogether seven novel mutations including two missense mutations (S206P, D468V), two splicing defects (IVS12-1G>C, IVS13-2delA), one nonsense mutation (Q436X), one insertion/deletion mutation (2104-2105delGGins29-bp), and an intragenic deletion of SLC26A3 exons 7 and 8. Two previously identified mutations were also found. This is the first report of rearrangement mutations in SLC26A3. Molecular features predisposing SLC26A3 for the two rearrangements may include repetitive elements and palindromic-like sequences. The increasingly wide diversity of SLC26A3 mutations suggests that mutations in the SLC26A3 gene may not be rare events. Copyright 2001 Wiley-Liss, Inc.

Dietary Zinc Intake and Plasma Zinc Concentrations in Children with Short Stature and Failure to Thrive.

Science.gov (United States)

Yazbeck, Nadine; Hanna-Wakim, Rima; El Rafei, Rym; Barhoumi, Abir; Farra, Chantal; Daher, Rose T; Majdalani, Marianne

2016-01-01

The burden of zinc deficiency on children includes an increased incidence of diarrhea, failure to thrive (FTT) and short stature. The aim of this study was to assess whether children with FTT and/or short stature have lower dietary zinc intake and plasma zinc concentrations compared to controls. A case-control study conducted at the American University of Beirut Medical Center included 161 subjects from 1 to 10 years of age. Cases had a statistically significant lower energy intake (960.9 vs. 1,135.2 kcal for controls, p = 0.010), lower level of fat (30.3 vs. 36.5 g/day, p = 0.0043) and iron intake (7.4 vs. 9.1 mg/day, p = 0.034). There was no difference in zinc, copper, carbohydrate and protein intake between the 2 groups. The plasma zinc concentration did not differ between the cases and controls (97.4 vs. 98.2 μg/dl, p = 0.882). More cases had mild-to-moderate zinc deficiency when compared to controls with 10.3 vs. 3.6%, p = 0.095. Our study did not show statistically significant difference in dietary zinc intake and plasma zinc concentrations between children with FTT and/or short stature compared to healthy controls. A prospective study is planned to assess the effect of zinc supplementation on growth parameters in FTT children. © 2016 S. Karger AG, Basel.

Effects of natural organic matter properties on the dissolution kinetics of zinc oxide nanoparticles

Science.gov (United States)

Jiang, Chuanjia; Aiken, George R.; Hsu-Kim, Heileen

2015-01-01

The dissolution of zinc oxide (ZnO) nanoparticles (NPs) is a key step of controlling their environmental fate, bioavailability, and toxicity. Rates of dissolution often depend upon factors such as interactions of NPs with natural organic matter (NOM). We examined the effects of 16 different NOM isolates on the dissolution kinetics of ZnO NPs in buffered potassium chloride solution using anodic stripping voltammetry to directly measure dissolved zinc concentrations. The observed dissolution rate constants (kobs) and dissolved zinc concentrations at equilibrium increased linearly with NOM concentration (from 0 to 40 mg C L–1) for Suwannee River humic and fulvic acids and Pony Lake fulvic acid. When dissolution rates were compared for the 16 NOM isolates, kobs was positively correlated with certain properties of NOM, including specific ultraviolet absorbance (SUVA), aromatic and carbonyl carbon contents, and molecular weight. Dissolution rate constants were negatively correlated to hydrogen/carbon ratio and aliphatic carbon content. The observed correlations indicate that aromatic carbon content is a key factor in determining the rate of NOM-promoted dissolution of ZnO NPs. The findings of this study facilitate a better understanding of the fate of ZnO NPs in organic-rich aquatic environments and highlight SUVA as a facile and useful indicator of NOM interactions with metal-based nanoparticles.

Interaction Between Yeasts and Zinc

Science.gov (United States)

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

Zinc-enriched boutons in rat spinal cord

DEFF Research Database (Denmark)

Schrøder, H D; Danscher, G; Jo, S M

2000-01-01

The rat spinal cord reveals a complex pattern of zinc-enriched (ZEN) boutons. As a result of in vivo exposure to selenide ions, nanosized clusters of zinc selenide are created in places where zinc ions are present, including the zinc-containing synaptic vesicles of ZEN boutons. The clusters can...

Zinc

Science.gov (United States)

... Consumer Datos en español Health Professional Other Resources Zinc Fact Sheet for Consumers Have a question? Ask ... find out more about zinc? Disclaimer What is zinc and what does it do? Zinc is a ...

Renal abnormalities in congenital chloride diarrhea

International Nuclear Information System (INIS)

Al-Hamad, Nadia M.; Al-Eisa, Amal A.

2004-01-01

Congenital chloride diarrhea CLD is a rare autosomal recessive disorder caused by a defect in the chloride/ bicarbonate exchange in the ileum and colon. It is characterized by watery diarrhea, abdominal distension, hypochloremic hypokalemic metabolic alkalosis with high fecal content of chloride >90 mmol/l. We report 3 patients with CLD associated with various renal abnormalities including chronic renal failure secondary to renal hypoplasia, nephrocalcinosis and congenital nephrotic syndrome. (author)

Colorful and transparent poly(vinyl alcohol) composite films filled with layered zinc hydroxide salts, intercalated with anionic orange azo dyes (methyl orange and orange II)

International Nuclear Information System (INIS)

Neves da Silva, Marlon Luiz; Marangoni, Rafael; Cursino, Ana Cristina Trindade; Schreiner, Wido Herwig; Wypych, Fernando

2012-01-01

Highlights: ► Zinc hydroxide salts were successfully intercalated with anionic orange azo dyes. ► The anionic dye was co-intercalated with hydrated chloride anions. ► The orange materials were used as fillers for poly(vinyl alcohol). ► Transparent, homogeneous, colorful PVA films were obtained by wet casting. ► Some composites stored at lower humidity exhibited improved mechanical properties. - Abstract: Layered zinc hydroxide salts (zinc LHS) were intercalated with anionic orange azo dyes, namely methyl orange (MO) and orange II (OII), and co-intercalated with hydrated chloride anions. After characterization by X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), the materials were used as fillers for poly(vinyl alcohol) (PVA). Colorful transparent films were obtained by wet casting, revealing good dispersion of the material into the polymer. In the case of zinc LHS/OII, PVA was intercalated between the zinc LHS layers. Evaluation of the mechanical properties of the PVA composite films revealed that the layered colorful materials were able to increase the mechanical properties of the PVA films only when the films were stored under lower relative humidity. As expected, films with higher water content displayed reduced tensile strength and modulus because of the plasticizing effect of water. As for the films stored at 43% relative humidity, more pronounced improvement of modulus was observed for 1 and 4% zinc LHS/OII, and enhanced tensile strength was achieved for 0.5 and 1% zinc LHS/OII. This effect can be attributed to better dispersion of the layered filler and its better adhesion to the PVA matrix.

46 CFR 151.50-34 - Vinyl chloride (vinyl chloride monomer).

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Vinyl chloride (vinyl chloride monomer). 151.50-34... chloride (vinyl chloride monomer). (a) Copper, aluminum, magnesium, mercury, silver, and their alloys shall... equipment that may come in contact with vinyl chloride liquid or vapor. (b) Valves, flanges, and pipe...

Polyvinyl chloride resin

International Nuclear Information System (INIS)

Kim, Hong Jae

1976-06-01

This book contains polyvinyl chloride resin industry with present condition such as plastic industry and polyvinyl chloride in the world and Japan, manufacture of polyvinyl chloride resin ; suspension polymerization and solution polymerization, extruding, injection process, hollow molding vinyl record, vacuum forming, polymer powders process, vinyl chloride varnish, vinyl chloride latex, safety and construction on vinyl chloride. Each chapter has descriptions on of process and kinds of polyvinyl chloride resin.

Proof-of-Concept of a Zinc-Silver Battery for the Extraction of Energy from a Concentration Difference

Directory of Open Access Journals (Sweden)

Massimo Marino

2014-06-01

Full Text Available The conversion of heat into current can be obtained by a process with two stages. In the first one, the heat is used for distilling a solution and obtaining two flows with different concentrations. In the second stage, the two flows are sent to an electrochemical cell that produces current by consuming the concentration difference. In this paper, we propose such an electrochemical cell, working with water solutions of zinc chloride. The cell contains two electrodes, made respectively of zinc and silver covered by silver chloride. The operation of the cell is analogous to that of the capacitive mixing and of the “mixing entropy battery”: the electrodes are charged while dipped in the concentrated solution and discharged when dipped in the diluted solution. The cyclic operation allows us to extract a surplus of energy, at the expense of the free energy of the concentration difference. We evaluate the feasibility of such a cell for practical applications and find that a power up to 2 W per m2 of the surface of the electrodes can be achieved.

The study and microstructure analysis of zinc and zinc oxide

Directory of Open Access Journals (Sweden)

N. Luptáková

2015-01-01

Full Text Available The given paper is closely connected with the process of the manufacturing of ZnO. The purity of the metal zinc has crucial influence on the quality of ZnO. ZnO can be produced by pyrometallurgical combustion of zinc and hard zinc. But this mentioned method of preparation leads to the creation of the enormous amount of waste including chemical complexes. On the basis of the occurrence of the residual content of other elements, it is possible to make prediction about the material behavior in the metallographic process. The input and finally materials were investigated and this investigation was done from the aspect of structural and chemical composition of the materials.

Bioprotective effect of zinc in macro- and nanoaquachelate form on embryonal development of rats in conditions of lead intoxication

Directory of Open Access Journals (Sweden)

Beletskaya E.M.

2013-06-01

Full Text Available The article presents results of studied influence of low doses of lead and zinc (nanozinc on embryonal development in a la¬boratory experiment on rats. Negative influence of lead on pregnancy of laboratory animals, manifested in violation of the physiological dynamics of the rectal temperature and decrease in body weight gain was revealed. Embryotoxic effect of low doses of lead results in increased fetal mortality by 2.16 times compared to the control group of animals, de¬terioration of the morphometric indices of fetuses, violation of placentogenesis. Simultaneous injections of zinc on back¬ground of lead intoxication causes a protective effect on the body of pregnant rats and embryonal development of the offspring, more pronounced for zinc citrate, received by using aquananotehnology, as compared to zinc chloride. Thus, by morphometry indices, male fetuses were more sensitive to prenatal lead exposure in comparison to female fetuses.

A high power lithium thionyl chloride battery for space applications

Science.gov (United States)

Shah, Pinakin M.

1993-03-01

A high power, 28 V, 330 A h, active lithium thionyl chloride battery has been developed for use as main and payload power sources on an expendable launch vehicle. Nine prismatic cells, along with the required electrical components and a built-in heater system, are efficiently packaged resulting in significant weight savings over presently used silver-zinc batteries. The high rate capability is achieved by designing the cells with a large electrochemical surface area and impregnating an electrocatalyst, polymeric phthalocyanine, into the carbon cathodes. Passivation effects are reduced with the addition of sulfur dioxide into the thionyl chloride electrolyte solution. The results of conducting a detailed thermal analysis are utilized to establish the heater design parameters and the thermal insulation requirements of the battery. An analysis of cell internal pressure and vent characteristics clearly illustrates the margins of safety under different operating conditions. Performance of fresh cells is discussed using polarization scan and discharge data at different rates and temperatures. Self-discharge rate is estimated based upon test results on cells after storage. Results of testing a complete prototype battery are described.

Zinc as a Gatekeeper of Immune Function

Directory of Open Access Journals (Sweden)

Inga Wessels

2017-11-01

Full Text Available After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells. Zinc homeostasis is largely controlled via the expression and action of zinc “importers” (ZIP 1–14, zinc “exporters” (ZnT 1–10, and zinc-binding proteins. Anti-inflammatory and anti-oxidant properties of zinc have long been documented, however, underlying mechanisms are still not entirely clear. Here, we report molecular mechanisms underlying the development of a pro-inflammatory phenotype during zinc deficiency. Furthermore, we describe links between altered zinc homeostasis and disease development. Consequently, the benefits of zinc supplementation for a malfunctioning immune system become clear. This article will focus on underlying mechanisms responsible for the regulation of cellular signaling by alterations in zinc homeostasis. Effects of fast zinc flux, intermediate “zinc waves”, and late homeostatic zinc signals will be discriminated. Description of zinc homeostasis-related effects on the activation of key signaling molecules, as well as on epigenetic modifications, are included to emphasize the role of zinc as a gatekeeper of immune function.

Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

International Nuclear Information System (INIS)

Bahedi, K.; Addou, M.; El Jouad, M.; Sofiani, Z.; Alaoui Lamrani, M.; El Habbani, T.; Fellahi, N.; Bayoud, S.; Dghoughi, L.; Sahraoui, B.; Essaidi, Z.

2009-01-01

Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 deg. C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility χ (3) was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility χ (3) = 20.12 x 10 -12 (esu) of the studied films was found for the 3% doped sample.

The effect of the electrode material on the electrodeposition of zinc from deep eutectic solvents

International Nuclear Information System (INIS)

Vieira, L.; Schennach, R.; Gollas, B.

2016-01-01

Highlights: • Mechanistic insight into zinc electrodeposition from deep eutectic solvents. • Overpotential for hydrogen evolution affects the electrodeposition of zinc. • Electrodeposited zinc forms surface alloys on Cu, Au, and Pt. • In situ PM-IRRAS of a ZnCl_2 containing deep eutectic solvent on glassy carbon. - Abstract: The voltammetric behaviour of the ZnCl_2 containing deep eutectic solvent choline chloride/ethylene glycol 1:2 was investigated on glassy carbon, stainless steel, Au, Pt, Cu, and Zn electrodes. While cyclic voltammetry on glassy carbon and stainless steel showed a cathodic peak for zinc electrodeposition only in the anodic reverse sweep, a cathodic peak was found also in the cathodic forward sweep on Au, Pt, Cu, and Zn. This behaviour is in agreement with the proposed mechanism of zinc deposition from an intermediate species Z, whose formation depends on the cathodic reduction potential of the solvent. The voltammetric reduction of the electrolyte involves hydrogen evolution and as a result the formation of Z and its reduction to zinc depend on the hydrogen overpotential for each electrode material. On Au, Pt, and Cu also the anodic stripping was different from that on glassy carbon and steel due to the formation of surface zinc alloys with the three former metals. The morphology of the zinc layers on Cu has been characterised by scanning electron microscopy and focussed ion beam. X-ray diffraction confirmed the presence of crystalline zinc and a Cu_4Zn phase. Spectroelectrochemistry by means of polarization modulation reflection-absorption spectroscopy (PM-IRRAS) on a glassy carbon electrode in the ZnCl_2 containing deep eutectic solvent showed characteristic potential dependent changes. The variation of band intensities at different applied potentials correlate with the voltammetry and suggest the formation of a compact blocking layer on the electrode surface, which inhibits the electrodeposition of zinc at sufficiently negative

Nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children

Directory of Open Access Journals (Sweden)

Márcia Marília Gomes Dantas Lopes

2015-10-01

Full Text Available Background: Zinc is an essential nutrient that is required for numerous metabolic functions, and zinc deficiency results in growth retardation, cell-mediated immune dysfunction, and cognitive impairment. Objective: This study evaluated nutritional assessment methods for zinc supplementation in prepubertal non-zinc-deficient children. Design: We performed a randomised, controlled, triple-blind study. The children were divided into a control group (10% sorbitol, n=31 and an experimental group (10 mg Zn/day, n=31 for 3 months. Anthropometric and dietary assessments as well as bioelectrical measurements were performed in all children. Results: Our study showed (1 an increased body mass index for age and an increased phase angle in the experimental group; (2 a positive correlation between nutritional assessment parameters in both groups; (3 increased soft tissue, and mainly fat-free mass, in the body composition of the experimental group, as determined using bioelectrical impedance vector analysis; (4 increased consumption of all nutrients, including zinc, in the experimental group; and (5 an increased serum zinc concentration in both groups (p<0.0001. Conclusions: Given that a reference for body composition analysis does not exist for intervention studies, longitudinal studies are needed to investigate vector migration during zinc supplementation. These results reinforce the importance of employing multiple techniques to assess the nutritional status of populations.

Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities

DEFF Research Database (Denmark)

Read, Daniel S.; Matzke, Marianne; Gweon, Hyun S.

2016-01-01

nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied......Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade...... the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc...

Chloride Transport in Undersea Concrete Tunnel

Directory of Open Access Journals (Sweden)

Yuanzhu Zhang

2016-01-01

Full Text Available Based on water penetration in unsaturated concrete of underwater tunnel, a diffusion-advection theoretical model of chloride in undersea concrete tunnel was proposed. The basic parameters including porosity, saturated hydraulic conductivity, chloride diffusion coefficient, initial water saturation, and moisture retention function of concrete specimens with two water-binder ratios were determined through lab-scale experiments. The variation of chloride concentration with pressuring time, location, solution concentration, initial saturation, hydraulic pressure, and water-binder ratio was investigated through chloride transport tests under external water pressure. In addition, the change and distribution of chloride concentration of isothermal horizontal flow were numerically analyzed using TOUGH2 software. The results show that chloride transport in unsaturated concrete under external water pressure is a combined effect of diffusion and advection instead of diffusion. Chloride concentration increased with increasing solution concentration for diffusion and increased with an increase in water pressure and a decrease in initial saturation for advection. The dominant driving force converted with time and saturation. When predicting the service life of undersea concrete tunnel, it is suggested that advection is taken into consideration; otherwise the durability tends to be unsafe.

Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

OpenAIRE

Donangelo, Carmen Marino; King, Janet C.

2012-01-01

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating e...

Zinc and Regulation of Inflammatory Cytokines: Implications for Cardiometabolic Disease

Science.gov (United States)

Foster, Meika; Samman, Samir

2012-01-01

In atherosclerosis and diabetes mellitus, the concomitant presence of low-grade systemic inflammation and mild zinc deficiency highlights a role for zinc nutrition in the management of chronic disease. This review aims to evaluate the literature that reports on the interactions of zinc and cytokines. In humans, inflammatory cytokines have been shown both to up- and down-regulate the expression of specific cellular zinc transporters in response to an increased demand for zinc in inflammatory conditions. The acute phase response includes a rapid decline in the plasma zinc concentration as a result of the redistribution of zinc into cellular compartments. Zinc deficiency influences the generation of cytokines, including IL-1β, IL-2, IL-6, and TNF-α, and in response to zinc supplementation plasma cytokines exhibit a dose-dependent response. The mechanism of action may reflect the ability of zinc to either induce or inhibit the activation of NF-κB. Confounders in understanding the zinc-cytokine relationship on the basis of in vitro experimentation include methodological issues such as the cell type and the means of activating cells in culture. Impaired zinc homeostasis and chronic inflammation feature prominently in a number of cardiometabolic diseases. Given the high prevalence of zinc deficiency and chronic disease globally, the interplay of zinc and inflammation warrants further examination. PMID:22852057

Chloride channels as tools for developing selective insecticides.

Science.gov (United States)

Bloomquist, Jeffrey R

2003-12-01

Ligand-gated chloride channels underlie inhibition in excitable membranes and are proven target sites for insecticides. The gamma-aminobutyric acid (GABA(1)) receptor/chloride ionophore complex is the primary site of action for a number of currently used insecticides, such as lindane, endosulfan, and fipronil. These compounds act as antagonists by stabilizing nonconducting conformations of the chloride channel. Blockage of the GABA-gated chloride channel reduces neuronal inhibition, which leads to hyperexcitation of the central nervous system, convulsions, and death. We recently investigated the mode of action of the silphinenes, plant-derived natural compounds that structurally resemble picrotoxinin. These materials antagonize the action of GABA on insect neurons and block GABA-mediated chloride uptake into mouse brain synaptoneurosomes in a noncompetitive manner. In mammals, avermectins have a blocking action on the GABA-gated chloride channel consistent with a coarse tremor, whereas at longer times and higher concentrations, activation of the channel suppresses neuronal activity. Invertebrates display ataxia, paralysis, and death as the predominant signs of poisoning, with a glutamate-gated chloride channel playing a major role. Additional target sites for the avermectins or other chloride channel-directed compounds might include receptors gated by histamine, serotonin, or acetylcholine.The voltage-sensitive chloride channels form another large gene family of chloride channels. Voltage-dependent chloride channels are involved in a number of physiological processes including: maintenance of electrical excitability, chloride ion secretion and resorption, intravesicular acidification, and cell volume regulation. A subset of these channels is affected by convulsants and insecticides in mammals, although the role they play in acute lethality in insects is unclear. Given the wide range of functions that they mediate, these channels are also potential targets for

Trace elements cadmium and zinc in the pathogenesis of experimental hypertension

International Nuclear Information System (INIS)

Lockett, C.J.R.

1980-01-01

In human kidneys cadmium is bound by a protein, metallothionein, which also contains zinc, and because cadmium apparently competes with zinc on the same binding sites, the cadmium-zinc ratio is particularly important. An increase in this ratio would mean a relative deficiency in zinc which might result in some forms of hypertension in man and animals. Studies were conducted to determine the effect of small amounts of supplementary dietary cadmium on weanling and adult albino rats. Two colonies of rats were examined. The object of this study was to determine if hypertension could be induced and to investigate its effects on renal function and renin levels in these animals. Sodium and potassium levels and balances, renin, angiotensin II, and urea output were therefore estimated in these animals. In order to assess the effect of length of exposure to cadmium in relation to growth and maturation upon blood pressure, experiments were done on a second colony of male weanling rats. Tissue levels of cadmium and zinc, and serum levels of sodium, potassium, chloride, carbon dioxide, urea and urate were measured. All supplemented diets caused hypertension and a significant drop in urinary urea excretion levels. Plasma angiotensin in males, and renal cadmium-zinc ratios were higher than in controls. The results of the studies in adult rats showed slight sodium and water retention. Weanlings showed a more rapid uptake of cadmium and reached higher blood pressure levels. In conclusion, cadmium does seem to be a factor in selected animal hypertension. A possible mechanism is via interference with renal function, and our data regarding urea output support the idea of renal function impairment. The initiation of a renin-angiotensin hypertension is suggested by the raised angiotensin levels which were detected

Crystal structures and DFT calculations of mixed chloride-azide zinc(II) and chloride-isocyanate cadmium(II) complexes with the condensation product of 2-quinolinecarboxaldehyde and Girard's T reagent

Science.gov (United States)

Anđelković, Katarina; Pevec, Andrej; Grubišić, Sonja; Turel, Iztok; Čobeljić, Božidar; Milenković, Milica R.; Keškić, Tanja; Radanović, Dušanka

2018-06-01

The mixed chloride-azide [ZnL(N3)1.65Cl0.35] (1) and chloride-isocyanate [CdL(NCO)1.64Cl0.36] (2) complexes with the condensation product of 2-quinolinecarboxaldehyde and trimethylammonium acetohydrazide chloride (Girard's T reagent) (HLCl) have been prepared and characterized by X-ray crystallography. In complexes 1 and 2, Zn1 and Cd1 ions, respectively, are five-coordinated in a distorted square based pyramidal geometry with NNO set of donor atoms of deprotonated hydrazone ligand and two monodentate ligands N3- and/or N3- and Cl- in the case of 1 and OCN- and/or OCN- and Cl- in the case of 2. The structural parameters of 1 and 2 have been discussed in relation to those of previously reported M(II) complexes with the same hydrazone ligand. Density functional theory calculations have been employed to study the interaction between the Zn2+ and Cd2+ ions and ligands. High affinity of ligands towards the Zn2+ and Cd2+ ions are predicted for both complexes.

The role of nitrergic system in antidepressant effects of acute administration of zinc, magnesium and thiamine on progesterone induced postpartum depression in mice

Directory of Open Access Journals (Sweden)

Nikseresht S

2010-08-01

Full Text Available "nBackground: Postpartum depression is a mood disorder that has harmful effects on mothers, infants, family and relationships. Acute decrease of progesterone after delivery has been proposed as a cause for postpartum depression. This hormone can affect neurotransmitters' function. Zinc (Zn and magnesium (Mg as trace elements exert their antidepressant effects through neurotransmitter pathways. On the other hand, thiamin (Vit B1 deficiency leads to depression in animal models. The aim of this study was to evaluate effects of combination of zinc, magnesium and thiamine on postpartum depression and role of nitrergic system. "n"nMethods: One hundred ten female mice in five groups were used. Postpartum depression was conducted using progesterone injections. Combinations of Zinc chloride, magnesium chloride and thiamine HCL were administered 30 minutes before open field and forced swimming test (FST. In order to investigate role of nitrergic system, L-arginine and LNAME were administered. "n"nResults: All treatment groups spent less immobility time than the control group (p< 0.05. Combined administration of Zn+ Mg+ Vit B1 caused the most reduction in immobility time. Administration of L-NAME in Zn+ Mg+ Vit B1 group caused reduction in immobility time while administration of L-arginine caused increase in immobility time in the same group. "nConclusion: Zinc, magnesium and thiamine can improve depressive symptoms by nitrergic pathway. These elements as supplement compounds could be alternatives for antidepressants in postpartum period.

The effect of zinc on the growth, content of the photosynthetic pigments, and thiol groups of the freshwater alga Pseudokirchneriella subcapitata (Korshikov) Hindak

International Nuclear Information System (INIS)

Filova, A.; Molnarova, M.

2015-01-01

In these experiments were studied the effects of zinc chloride (Zn 2+ ) on the alga Pseudokirchneriella subcapitata (Korshikov) Hindak. The changes in the growth stimulation/inhibition, content of the photosynthetic pigments, and thiol groups were the aim of the article. The zinc concentration 0.036 mg.l -1 supported the algal growth. The first toxic effect of Zn on the growth was observed at the zinc concentration 0.072 mg.l -1 . However, the significant inhibitory effect on the growth was showed in the algal suspensions with 0.360 and 4.320 mg Zn.l -1 . Inhibition of the algal growth was in the range 65 - 70% compared to control (0% inhibition). The content of chlorophyll a was significant inhibited at the zinc concentration 0.0240 mg.l -1 , but at the higher used concentration was inhibited with the extremely significations. With increased zinc content in the algal medium the thiol (-SH) groups content increased and in the highest zinc concentrations (2.160 and 4.320 mg.l -1 ) overreached control three times. (authors)

Development of lithium-thionyl chloride batteries for Centaur

Energy Technology Data Exchange (ETDEWEB)

Halpert, G.; Frank, H.; Lutwack, R.

1988-04-01

Lithium thionyl chloride (LiSOCl2) primary cells and batteries have received considerable attention over the last several years because of their high theoretical specific energy and energy density. The objective was to develop a 300 wh/kg cell capable of safe operation at C/2 rate and active storage life for 5 to 10 years. This technology would replace other primary cell technologies in NASA applications mainly the silver zinc (AgZn) batteries presently in use. The LiSOCl2 system exceeds the capabilities of the AgZn in terms of specific energy of 300 wh/kg (compared with 100 wh/kg for AgZn), active storage life of 10 to 20 times the 3 to 6 months active storage and has a significantly lower projected cost.

[Improvement in zinc nutrition due to zinc transporter-targeting strategy].

Science.gov (United States)

Kambe, Taiho

2016-07-01

Adequate intake of zinc from the daily diet is indispensable to maintain health. However, the dietary zinc content often fails to fulfill the recommended daily intake, leading to zinc deficiency and also increases the risk of developing chronic diseases, particularly in elderly individuals. Therefore, increased attention is required to overcome zinc deficiency and it is important to improve zinc nutrition in daily life. In the small intestine, the zinc transporter, ZIP4, functions as a component that is essential for zinc absorption. In this manuscript, we present a brief overview regarding zinc deficiency. Moreover, we review a novel strategy, called "ZIP4-targeting", which has the potential to enable efficient zinc absorption from the diet. ZIP4-targeting strategy is possibly a major step in preventing zinc deficiency and improving human health.

Zinc content of selected tissues and taste perception in rats fed zinc deficient and zinc adequate rations

International Nuclear Information System (INIS)

Boeckner, L.S.; Kies, C.

1986-01-01

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 -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

Diagnostic study of the roughness surface effect of zirconium on the third-order nonlinear-optical properties of thin films based on zinc oxide nanomaterials

Energy Technology Data Exchange (ETDEWEB)

Bahedi, K., E-mail: bahedikhadija@yahoo.com [Laboratoire Optoelectronique et Physico-chimie des Materiaux Universite Ibn Tofail, Faculte des Sciences BP 133 Kenitra 14000, Maroc (Morocco); Addou, M.; El Jouad, M.; Sofiani, Z.; Alaoui Lamrani, M.; El Habbani, T.; Fellahi, N.; Bayoud, S.; Dghoughi, L. [Laboratoire Optoelectronique et Physico-chimie des Materiaux Universite Ibn Tofail, Faculte des Sciences BP 133 Kenitra 14000, Maroc (Morocco); Sahraoui, B.; Essaidi, Z. [Laboratoire POMA, UMR CNRS 6136, Universite d' Angers 2, Bd Lavoisier, 49045 France (France)

2009-02-01

Zinc oxide (ZnO) and zirconium doped zinc oxide (ZnO:Zr) thin films were deposited by reactive chemical pulverization spray pyrolysis technique on heated glass substrates at 500 deg. C using zinc and zirconium chlorides as precursors. Effects of zirconium doping agent and surface roughness on the nonlinear optical properties were investigated in detail using atomic force microscopy (AFM) and third harmonic generation (THG) technique. The best value of nonlinear optical susceptibility {chi}{sup (3)} was obtained from the doped films with less roughness. A strong third order nonlinear optical susceptibility {chi}{sup (3)} = 20.12 x 10{sup -12} (esu) of the studied films was found for the 3% doped sample.

Cerium(terbium, erbium)chloride-choline chloride aqueous systems

International Nuclear Information System (INIS)

Gajfutdinova, R.K.; Zhuravlev, E.F.; Bikbaeva, G.G.; Domrachev, V.N.; Vanskova, G.I.

1985-01-01

To clarify the effect of rare earth nature on mutual solubility of rare earth salts and amines the solubility of solid phases in the systems, consisting of choline chloride, water and cerium, terbium, erbium chlorides, has been studied. It is established, that solubility isotherms of all the systems, testify to the formation of new solid phases of the composition: Ce(Tb, Er)xCl 3 x2C 5 H 14 ONClx3H 2 O. Individuality of new solid phases is proved by DTA method, the composition is confirmed by chemical analysis and data of PMR spectra, for choline chloride and its complexes with rare earth chlorides of the given composition PMR and IR spectra are studied

Antagonistic effect of nano-ZnO and cetyltrimethyl ammonium chloride on the growth of Chlorella vulgaris: Dissolution and accumulation of nano-ZnO.

Science.gov (United States)

Liu, Na; Wang, Yipeng; Ge, Fei; Liu, Shixiang; Xiao, Huaixian

2018-04-01

The interaction of nanoparticles with coexisting chemicals affects the fate and transport of nanoparticles, as well as their combined effects on aquatic organisms. Here, we evaluated the joint effect of ZnO nanoparticle (nano-ZnO) and cetyltrimethyl ammonium chloride (CTAC) on the growth of Chlorella vulgaris and explored the possible mechanism. Results showed that an antagonistic effect of nano-ZnO and CTAC (0.1, 0.2 and 0.3 mg L -1 ) was found because CTAC stop nano-ZnO being broken down into solution zinc ions (Zn 2+ ). In the presence of CTAC, the zinc (including nano-ZnO and released Zn 2+ ) showed a higher adsorption on bound extracellular polymeric substances (B-EPS) but lower accumulation in the algal cells. Moreover, we directly demonstrated that nano-ZnO was adsorbed on the algal B-EPS and entered into the algal cells by transmission electron microscope coupled with energy dispersive X-ray (TEM-EDX). Hence, these results suggested that the combined system of nano-ZnO and CTAC exhibited an antagonistic effect due to the inhibition of CTAC on dissolution of nano-ZnO and accumulation of the zinc in the algal cells. Copyright © 2017. Published by Elsevier Ltd.

Chitosan–Zinc(II Complexes as a Bio-Sorbent for the Adsorptive Abatement of Phosphate: Mechanism of Complexation and Assessment of Adsorption Performance

Directory of Open Access Journals (Sweden)

Maryam Roza Yazdani

2017-12-01

Full Text Available This study examines zinc(II–chitosan complexes as a bio-sorbent for phosphate removal from aqueous solutions. The bio-sorbent is prepared and is characterized via Fourier Transform Infrared Spectroscopy (FT-IR, Scanning Electron Microscopy (SEM, and Point of Zero Charge (pHPZC–drift method. The adsorption capacity of zinc(II–chitosan bio-sorbent is compared with those of chitosan and ZnO–chitosan and nano-ZnO–chitosan composites. The effect of operational parameters including pH, temperature, and competing ions are explored via adsorption batch mode. A rapid phosphate uptake is observed within the first three hours of contact time. Phosphate removal by zinc(II–chitosan is favored when the surface charge of bio-sorbent is positive/or neutral e.g., within the pH range inferior or around its pHPZC, 7. Phosphate abatement is enhanced with decreasing temperature. The study of background ions indicates a minor effect of chloride, whereas nitrate and sulfate show competing effect with phosphate for the adsorptive sites. The adsorption kinetics is best described with the pseudo-second-order model. Sips (R2 > 0.96 and Freundlich (R2 ≥ 0.95 models suit the adsorption isotherm. The phosphate reaction with zinc(II–chitosan is exothermic, favorable and spontaneous. The complexation of zinc(II and chitosan along with the corresponding mechanisms of phosphate removal are presented. This study indicates the introduction of zinc(II ions into chitosan improves its performance towards phosphate uptake from 1.45 to 6.55 mg/g and provides fundamental information for developing bio-based materials for water remediation.

Zinc(II PVC-based membrane sensor based on 5,6-benzo-4,7,13,16,21,24- hexaoxa-1,10-diazabicyclo[8,8,8]hexacos-5-ene

Directory of Open Access Journals (Sweden)

Zamani Hassan Ali

2006-01-01

Full Text Available The 5,6-benzo-4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8,8,8]hexacos-5-ene (BHDE was used as an excellent ionophore in construction of a Zn(II PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride, 64.5% nitrobenzen (NB, 2.5% BHDE and 3% sodium tetraphenylborate (NaTPB. This sensor shows very good selectivity and sensitivity towards zinc ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor revealed a great enhancement in selectivity coefficients for zinc ions, in comparison to the previously reported zinc sensors. The proposed sensor exhibits a Nernstian behavior (with slope of 29.1 ? 0.4 mV per decade over a wide concentration range (1.0 10-6-1.0 10-1 mol L-1 with a detection limit of 6.3 x10-7 mol L-1 (41.2 ng mL-1. It shows relatively fast response time, in the whole concentration range (< 10s, and can be used for at least 10 weeks in a pH range of 2.8-7.3. The proposed sensor was successfully used in direct determination of zinc ions in wastewater of industrial zinc electroplating companies, and also as an indicator electrode in titration with EDTA.

[Antibacterial actin of vinegar against food-borne pathogenic bacteria including Escherichia coli O157:H7 (Part 2). Effect of sodium chloride and temperature on bactericidal activity].

Science.gov (United States)

Entani, E; Asai, M; Tsujihata, S; Tsukamoto, Y; Ohta, M

1997-05-01

Bactericidal effects of various kinds of AWASEZU (processed vinegar, 2.5% acidity) on food-borne pathogenic bacteria including Escherichia coli O157:H7 and other bacteria were examined. the order of bactericidal activities was NIHAIZU (3.5% NaCl was added) > SANBA-IZU (3.5% NaCl and 10% sucrose were added) > plain vinegar (spirit vinegar) > AMAZU (10% sucrose was added). This indicates that their activities were enhanced by the addition of sodium chloride and suppressed by the addition of sugar. On the other hand, when soy sauce was used instead of sodium chloride, the order of bactericidal activities was plain vinegar > AMAZU > NIHAIZU > SANBAIZU. This is mainly because their activities were suppressed by the increase in the pH value. The effect of sodium chloride (0.01-15%) and temperature (10-50 degrees C) on bactericidal activities against E. coli O157:H7 in spirit vinegar (0.5-2.5% acidity) was further examined. When vinegar was used in combination with sodium chloride, predominant synergism on the bactericidal activity was observed. Their activities were markedly enhanced by the addition of sodium chloride in proportion to the concentration. In addition to this, at higher temperatures spirit vinegar killed bacteria much more rapidly. It should be noted that the bactericidal activity of spirit vinegar was extremely enhanced by the combined use of the addition of sodium chloride and the rise of temperature. For example, in 2.5% acidity vinegar, the time required for 3 log decrease in viable cell numbers at 20 degrees C was shortened to 1/140-fold by the addition of 5% sodium chloride, shortened to 1/51-fold by the rise of the reaction temperature at 40 degrees C, and shortened to 1/830-fold; 0.89 minutes by both the addition of 5% sodium chloride and the rise of temperature at 40 degrees C. In order to propose the methods to prevent food poisoning by bacterial infection, bactericidal activities of vinegar solution containing sodium chloride on cooking tools and

A high power lithium thionyl chloride battery for space applications

Energy Technology Data Exchange (ETDEWEB)

Shah, P.M. (Alliant Techsystems, Inc., Power Sources Center, Horsham, PA (United States))

1993-03-15

A high power, 28 V, 330 A h, active lithium thinoyl chloride battery has been developed for use as main and payload power sources on an expendable launch vehicle. Nine prismatic cells, along with the required electrical components and a built-in heater system, are efficiently packaged resulting in significant weight savings (>40%) over presently used silver-zinc batteries. The high rate capability is achieved by designing the cells with a large electrochemical surface area and impregnating an electrocatalyst, polymeric phthalocyanine, (CoPC)[sub n], into the carbon cathodes. Passivation effects are reduced with the addition of sulfur dioxide into the thionyl chloride electrolyte solution. The results of conducting a detailed thermal analysis are utilized to establish the heater design parameters and the thermal insulation requirements of the battery. An analysis of cell internal pressure and vent characteristics clearly illustrates the margins of safety under different operating conditions. Performance of fresh cells is discussed using polarization scan and discharge data at different rates and temperatures. Self-discharge rate is estimated based upon test results on cells after storage. Finally, the results of testing a complete prototype battery are described in detail. (orig.)

Zinc-mediated Allosteric Inhibition of Caspase-6*

Science.gov (United States)

Velázquez-Delgado, Elih M.; Hardy, Jeanne A.

2012-01-01

Zinc and caspase-6 have independently been implicated in several neurodegenerative disorders. Depletion of zinc intracellularly leads to apoptosis by an unknown mechanism. Zinc inhibits cysteine proteases, including the apoptotic caspases, leading to the hypothesis that zinc-mediated inhibition of caspase-6 might contribute to its regulation in a neurodegenerative context. Using inductively coupled plasma optical emission spectroscopy, we observed that caspase-6 binds one zinc per monomer, under the same conditions where the zinc leads to complete loss of enzymatic activity. To understand the molecular details of zinc binding and inhibition, we performed an anomalous diffraction experiment above the zinc edge. The anomalous difference maps showed strong 5σ peaks, indicating the presence of one zinc/monomer bound at an exosite distal from the active site. Zinc was not observed bound to the active site. The zinc in the exosite was liganded by Lys-36, Glu-244, and His-287 with a water molecule serving as the fourth ligand, forming a distorted tetrahedral ligation sphere. This exosite appears to be unique to caspase-6, as the residues involved in zinc binding were not conserved across the caspase family. Our data suggest that binding of zinc at the exosite is the primary route of inhibition, potentially locking caspase-6 into the inactive helical conformation. PMID:22891250

Zinc-based electrolyte compositions, and related electrochemical processes and articles

Science.gov (United States)

Kniajanski, Sergei; Soloveichik, Grigorii Lev

2018-02-20

An aqueous electrolyte composition is described, including a zinc salt based on zinc acetate or zinc glocolate. The saturation concentration of zinc in the electrolyte composition is in the range of about 2.5M to about 3.5M. The composition also contains at least one salt of a monovalent cation. The molar ratio of zinc to the monovalent cation is about 1:2. An aqueous zinc electroplating bath, containing the aqueous electrolyte composition, is also disclosed, along with a method for the electrochemical deposition of zinc onto a substrate surface, using the electroplating bath. Related flow batteries are also described, including a catholyte, as well as an anolyte based on the aqueous electrolyte composition, with a membrane between the catholyte and the anolyte.

Corrosion of Cu-xZn alloys in slightly alkaline chloride solutions studied by stripping voltammetry and microanalysis.

Science.gov (United States)

Milosev, I; Minović, A

2001-01-01

The mechanism of corrosion of Cu-xZn alloys (x = 10-40 wt %) in slightly alkaline chloride solutions was investigated by analysing solid reaction products by energy dispersive X-ray analysis (EDS) and dissolved reaction products by differential anodic pulse stripping (DAPS) voltammetry. The corrosion process was studied under open circuit and under potentiostatic conditions at selected potentials. Pure metals were studied comparatively so that an interacting effect of particular metal components in the alloy could be determined. All four Cu-xZn alloys show an improved behaviour compared to pure metals. Under open-circuit condition both components dissolve simultaneously in the solution. With increasing immersion time the preferential, dissolution of zinc in the solution becomes pronounced. It is the highest for Cu-10Zn and the lowest for Cu-30Zn alloy. Under potentiostatic control the dissolution mechanism depends on the electrode potential and changes from exclusive dissolution of zinc to simultaneous dissolution of both components with preferential dissolution of zinc. The latter decreases, as the electrode potential becomes more positive.

Multicomponent synthesis of imidazo [1,2-a] pyridines using catalytic zinc chloride

CSIR Research Space (South Africa)

Rousseau, AL

2007-06-01

Full Text Available HN R1 R2 Scheme 1. Tetrahedron Letters 48 (2007) 4079–4082 chloride,12 acetic acid,10a perchloric acid,10e or Montmo- rillonite clay K1013 to catalyze the reaction. The use of solid supports with a range of acid catalysts in the 3CC reaction... tempera- ture (for reactions catalyzed by scandium triflate, acetic acid, toluenesulfonic acid or perchloric acid) or using N X N 1 X=CH 2 X=N N N 3 R1=R2=Cl, R3=R4=C3H7 4 R1=R2=R3=R4=CH3 R1 R2 O N R3 R4 N N SO2Me antagonists.9 Drug...

Synthesis of the semi-organic nonlinear optical crystal l-glutamic acid zinc chloride and investigation of its growth and physiochemical properties

Directory of Open Access Journals (Sweden)

S. Chennakrishnan

2017-11-01

Full Text Available The aim of this study is to synthesize and investigate the growth and physiochemical properties of the nonlinear optical semi-organic crystal l-glutamic acid zinc chloride (LGAZC. An optically transparent and defect-free crystal was grown with the slow evaporation solution growth technique under optimized conditions. The induction periods were measured at various supersaturations, and the interfacial energies were evaluated. Single crystal X-ray diffraction reveals that the crystal has an orthorhombic structure with space group P212121, and the calculated lattice parameters are a = 5.20 Å, b = 6.99 Å, c = 17.58 Å, α = β = γ = 90° and volume = 623.411 Å3. Spectroscopic properties were investigated by recording the Fourier transform infrared and optical transmission spectra. The thermal decomposition of the grown crystal was investigated by Thermo Gravimetric and Differential Thermal Analysis (TG/DTA. The LGAZC crystal exhibits second harmonic generation (SHG efficiency 1.5 times that of inorganic KDP crystal. The presence of the metal ion (Zn+ in a grown crystal was identified by EDAX spectrum analysis. The photoconductivity study demonstrates that LGAZC crystal has a positive photo conducting nature. The dielectric response of the LGAZC crystal was investigated and reported. Keywords: Semi-organic nonlinear optical crystal, X-ray Diffraction, UV-vis-NIR, Thermal study

Influência do zinco na incidência de doenças do cafeeiro Zinc influence on coffee diseases

Directory of Open Access Journals (Sweden)

Vicente Luiz de Carvalho

2008-06-01

Full Text Available Em cafeeiros, poucos estudos foram feitos relacionando aumento ou diminuição da resistência das plantas às doenças, com alteração dos níveis de nutrientes utilizados. Com este trabalho, objetivou-se estudar os efeitos do sulfato de zinco aplicado isoladamente, e associado com fungicidas e cloreto de potássio sobre a ferrugem, cercosporiose e manchas foliares do cafeeiro. O trabalho foi desenvolvido em uma lavoura de café em produção, onde foram testados oxicloreto de cobre, tebuconazole, sulfato de zinco + cloreto de potássio e sulfato de zinco e nas subparcelas foram realizadas diferentes concentrações de sulfato de zinco: ausência, 0,3 %, 0,6 % e 1,2 %. Verificou-se que os tratamentos com oxicloreto de cobre e tebuconazole reduziram a incidência e severidade de ferrugem, a incidência de cercosporiose, de manchas foliares (phoma e ascochyta e a desfolha, independente das concentrações de sulfato de zinco utilizadas. Concentrações de sulfato de zinco na faixa de 0,6 % - 0,75 % apresentaram menor severidade da ferrugem e o aumento nas concentrações de sulfato de zinco aumentou a incidência de cercosporiose, manchas foliares e a desfolha dos cafeeiros.The are few studies have been done related to the increase or decrease of disease resistance in coffee plants, with alteration from plant nutrient levels. The ain of this work was to verify the effect of zinc sulfate, applied either alone or in association with fungicides, and the effect of potassium chloride on coffee leaf rust, brown-eyes and leaf stains in coffee plants. Copper oxichloride, tebuconazole, sulfate of zinc + potassium chloride and sulfate of zinc were applied on plots and concentrations of zinc sulfate (0,0 %, 0,3 %, 0,6 % and 1,2 % were applied on sub plot. Treatments with copper and tebuconazole reduced the incidence and severity of rust, the incidence of brown-eyes and stains leaf (phoma and ascochyta and the defoliate independent of the zinc sulfate

Lithium thionyl chloride battery

Energy Technology Data Exchange (ETDEWEB)

Saathoff, D.J.; Venkatasetty, H.V.

1982-10-19

The discharge rate and internal conductivity of electrochemical cell including a lithium anode, and a cathode and an electrolyte including LiAlCl4 and SOC2 is improved by the addition of an amount of a mixture containing AlCl3 and butyl pyridinium chloride.

Viscosity and density tables of sodium chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Fair, J.A.; Ozbek, H. (comps.)

1977-04-01

A file is presented containing tabulated data extracted from the scientific literature on the density and viscosity of aqueous sodium chloride solutions. Also included is a bibliography of the properties of aqueous sodium chloride solutions. (MHR)

Zinc status in South Asian populations--an update.

Science.gov (United States)

Akhtar, Saeed

2013-06-01

This article attempts to highlight the prevalence of zinc deficiency and its health and economic consequences in South Asian developing countries and to shed light on possible approaches to combating zinc deficiency. A computer-based search was performed on PubMed, Google, and ScienceDirect.com to retrieve relevant scientific literature published between 2000 and 2012. The search yielded 194 articles, of which 71 were culled. Studies were further screened on the basis of population groups, age and sex, pregnancy, and lactation. The most relevant articles were included in the review. Cutoffs for serum zinc concentration defined for zinc deficiency were 65 microg/dL for males and females aged or = 10 years. Population segments from rural and urban areas of South Asian developing countries were included in the analysis. They comprised pregnant and lactating women, preschool and school children. The analysis reveals that zinc deficiency is high among children, pregnant and lactating women in India, Pakistan, Bangladesh, Sri Lanka, and Nepal. Diarrhoea has been established as a leading cause to intensify zinc deficiency in Bangladesh. Little has been done in Sri Lanka and Nepal to estimate the prevalence of zinc deficiency precisely. A substantial population segment of the South Asian developing countries is predisposed to zinc deficiency which is further provoked by increased requirements for zinc under certain physiological conditions. Supplementation, fortification, and dietary diversification are the most viable strategies to enhancing zinc status among various population groups.

Influence of DNA-methylation on zinc homeostasis in myeloid cells: Regulation of zinc transporters and zinc binding proteins.

Science.gov (United States)

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. Copyright © 2016 Elsevier GmbH. All rights reserved.

[Forensic Analysis for 54 Cases of Suxamethonium Chloride Poisoning].

Science.gov (United States)

Zhao, Y F; Zhao, B Q; Ma, K J; Zhang, J; Chen, F Y

2017-08-01

To observe and analyze the performance of forensic science in the cases of suxa- methonium chloride poisoning, and to improve the identification of suxamethonium chloride poisoning. Fifty-four cases of suxamethonium chloride poisoning were collected. The rules of determination of suxamethonium chloride poisoning were observed by the retrospective analysis of pathological and toxicological changes as well as case features. The pathological features of suxamethonium chloride poisoning were similar to the general changes of sudden death, which mainly included acute pulmonary congestion and edema, and partly showed myocardial disarray and fracture. Suxamethonium chloride could be detected in the heart blood of all cases and in skin tissue of part cases. Suxa-methonium chloride poisoning has the characteristics with fast death and covert means, which are difficult to rescue and easily miss inspection. For the cases of sudden death or suspicious death, determination of suxamethonium chloride should be taken as a routine detection index to prevent missing inspection. Copyright© by the Editorial Department of Journal of Forensic Medicine

Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

Science.gov (United States)

Donangelo, Carmen Marino; King, Janet C.

2012-01-01

Zinc plays critical roles during embryogenesis, fetal growth, and milk secretion, which increase the zinc need for pregnancy and lactation. Increased needs can be met by increasing the dietary zinc intake, along with making homeostatic adjustments in zinc utilization. Potential homeostatic adjustments include changes in circulating zinc, increased zinc absorption, decreased zinc losses, and changes in whole body zinc kinetics. Although severe zinc deficiency during pregnancy has devastating effects, systematic reviews and meta-analysis of the effect of maternal zinc supplementation on pregnancy outcomes have consistently shown a limited benefit. We hypothesize, therefore, that zinc homeostatic adjustments during pregnancy and lactation improve zinc utilization sufficiently to provide the increased zinc needs in these stages and, therefore, mitigate immediate detrimental effects due to a low zinc intake. The specific questions addressed are the following: How is zinc utilization altered during pregnancy and lactation? Are those homeostatic adjustments influenced by maternal zinc status, dietary zinc, or zinc supplementation? These questions are addressed by critically reviewing results from published human studies on zinc homeostasis during pregnancy and lactation carried out in different populations worldwide. PMID:22852063

Method of capturing or trapping zinc using zinc getter materials

Science.gov (United States)

Hunyadi Murph, Simona E.; Korinko, Paul S.

2017-07-11

A method of trapping or capturing zinc is disclosed. In particular, the method comprises a step of contacting a zinc vapor with a zinc getter material. The zinc getter material comprises nanoparticles and a metal substrate.

The Relevance of the Colon to Zinc Nutrition

Directory of Open Access Journals (Sweden)

Geetha Lavaniya Gopalsamy

2015-01-01

Full Text Available Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income countries. Apart from inadequate dietary intake of bioavailable zinc, other significant contributors to zinc deficiency include the excessive intestinal loss of endogenously secreted zinc and impairment in small intestinal absorptive function. Such changes are likely to occur in children suffering from environmental (or tropical enteropathy (EE—an almost universal condition among inhabitants of developing countries characterized by morphologic and functional changes in the small intestine. Changes to the proximal gut in environmental enteropathy will likely influence the nature and amount of zinc delivered into the large intestine. Consequently, we reviewed the current literature to determine if colonic absorption of endogenous or exogenous (dietary zinc could contribute to overall zinc nutriture. Whilst we found evidence that significant zinc absorption occurs in the rodent colon, and is favoured when microbially-fermentable carbohydrates (specifically resistant starch are consumed, it is unclear whether this process occur in humans and/or to what degree. Constraints in study design in the few available studies may well have masked a possible colonic contribution to zinc nutrition. Furthermore these few available human studies have failed to include the actual target population that would benefit, namely infants affected by EE where zinc delivery to the colon may be increased and who are also at risk of zinc deficiency. In conducting this review we have not been able to confirm a colonic contribution to zinc absorption in humans. However, given the observations in rodents and that feeding resistant starch to children is feasible, definitive studies utilising the dual stable isotope method in children with EE should be undertaken.

Chloride ingress prediction

DEFF Research Database (Denmark)

Frederiksen, Jens Mejer; Geiker, Mette Rica

2008-01-01

Prediction of chloride ingress into concrete is an important part of durability design of reinforced concrete structures exposed to chloride containing environment. This paper presents experimentally based design parameters for Portland cement concretes with and without silica fume and fly ash...... in marine atmospheric and submersed South Scandinavian environment. The design parameters are based on sequential measurements of 86 chloride profiles taken over ten years from 13 different types of concrete. The design parameters provide the input for an analytical model for chloride profiles as function...... of depth and time, when both the surface chloride concentration and the diffusion coefficient are allowed to vary in time. The model is presented in a companion paper....

Zinc electrode - its behaviour in the nickel oxide-zinc accumulator

Energy Technology Data Exchange (ETDEWEB)

1984-01-01

Certain aspects of zinc electrode reaction and behavior are investigated in view of their application to batteries. The properties of the zinc electrode in a battery system are discussed, emphasizing porous structure. Shape change is emphasized as the most important factor leading to limited battery cycle life. It is shown that two existing models of shape change based on electroosmosis and current distribution are unable to consistently describe observed phenomena. The first stages of electrocrystallization are studied and the surface reactions between the silver substrate and the deposited zinc layer are investigated. The reaction mechanism of zinc and amalgamated zinc in an alkaline electrolyte is addressed, and the batter system is studied to obtain information on cycling behavior and on the shape change phenomenon. The effect on cycle behavior of diferent amalgamation techniques of the zinc electrode and several additives is addressed. Impedance measurements on zinc electrodes are considered, and battery behavior is correlated with changes in the zinc electrode during cycling. 193 references.

Nitrogen implantation into steel wire coated with zinc used as reinforcement in power transmission conductors

Science.gov (United States)

Castro-Maldonado, J. J.; Dulcé-Moreno, H. J.; V-Niño, E. D.

2013-11-01

In tropical environments, diversity of climatic factors such as temperature, relative humidity, deposition of environmental contaminants (such as sulfates and chlorides) affect a large proportion of materials exposed to the weather, and electrochemical corrosion is one of the phenomena that occur in the case of metals and alloys [1, 2]. It is therefore particularly important to study this behavior in the Zinc-coated steel, since this material is used for its economy in the industry specifically in the area of transport of electricity.

Zinc Levels Modulate Lifespan through Multiple Longevity Pathways in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

Jitendra Kumar

Full Text Available Zinc is an essential trace metal that has integral roles in numerous biological processes, including enzymatic function, protein structure, and cell signaling pathways. Both excess and deficiency of zinc can lead to detrimental effects on development and metabolism, resulting in abnormalities and disease. We altered the zinc balance within Caenorhabditis elegans to examine how changes in zinc burden affect longevity and healthspan in an invertebrate animal model. We found that increasing zinc levels in vivo with excess dietary zinc supplementation decreased the mean and maximum lifespan, whereas reducing zinc levels in vivo with a zinc-selective chelator increased the mean and maximum lifespan in C. elegans. We determined that the lifespan shortening effects of excess zinc required expression of DAF-16, HSF-1 and SKN-1 proteins, whereas the lifespan lengthening effects of the reduced zinc may be partially dependent upon this set of proteins. Furthermore, reducing zinc levels led to greater nuclear localization of DAF-16 and enhanced dauer formation compared to controls, suggesting that the lifespan effects of zinc are mediated in part by the insulin/IGF-1 pathway. Additionally, zinc status correlated with several markers of healthspan in worms, including proteostasis, locomotion and thermotolerance, with reduced zinc levels always associated with improvements in function. Taken together, these data support a role for zinc in regulating both development and lifespan in C. elegans, and that suggest that regulation of zinc homeostasis in the worm may be an example of antagonistic pleiotropy.

Zinc Levels Modulate Lifespan through Multiple Longevity Pathways in Caenorhabditis elegans

Science.gov (United States)

Kumar, Jitendra; Barhydt, Tracy; Awasthi, Anjali; Lithgow, Gordon J.; Killilea, David W.; Kapahi, Pankaj

2016-01-01

Zinc is an essential trace metal that has integral roles in numerous biological processes, including enzymatic function, protein structure, and cell signaling pathways. Both excess and deficiency of zinc can lead to detrimental effects on development and metabolism, resulting in abnormalities and disease. We altered the zinc balance within Caenorhabditis elegans to examine how changes in zinc burden affect longevity and healthspan in an invertebrate animal model. We found that increasing zinc levels in vivo with excess dietary zinc supplementation decreased the mean and maximum lifespan, whereas reducing zinc levels in vivo with a zinc-selective chelator increased the mean and maximum lifespan in C. elegans. We determined that the lifespan shortening effects of excess zinc required expression of DAF-16, HSF-1 and SKN-1 proteins, whereas the lifespan lengthening effects of the reduced zinc may be partially dependent upon this set of proteins. Furthermore, reducing zinc levels led to greater nuclear localization of DAF-16 and enhanced dauer formation compared to controls, suggesting that the lifespan effects of zinc are mediated in part by the insulin/IGF-1 pathway. Additionally, zinc status correlated with several markers of healthspan in worms, including proteostasis, locomotion and thermotolerance, with reduced zinc levels always associated with improvements in function. Taken together, these data support a role for zinc in regulating both development and lifespan in C. elegans, and that suggest that regulation of zinc homeostasis in the worm may be an example of antagonistic pleiotropy. PMID:27078872

Zinc promotes the death of hypoxic astrocytes by upregulating hypoxia-induced hypoxia-inducible factor-1alpha expression via poly(ADP-ribose) polymerase-1.

Science.gov (United States)

Pan, Rong; Chen, Chen; Liu, Wen-Lan; Liu, Ke-Jian

2013-07-01

Pathological release of excess zinc ions has been implicated in ischemic brain cell death. However, the underlying mechanisms remain to be elucidated. In stroke, ischemia-induced zinc release and hypoxia-inducible factor-1 (HIF-1) accumulation concurrently occur in the ischemic tissue. The present study tests the hypothesis that the presence of high intracellular zinc concentration is a major cause of modifications to PARP-1 and HIF-1α during hypoxia, which significantly contributes to cell death during ischemia. Primary cortical astrocytes and C8-D1A cells were exposed to different concentrations of zinc chloride. Cell death rate and protein expression of HIF-1 and Poly(ADP-ribose) polymerase (PARP)-1 were examined after 3-h hypoxic treatment. Although 3-h hypoxia or 100 μM of zinc alone did not induce noticeable cytotoxicity, their combination led to a dramatic increase in astrocytic cell death in a zinc-concentration-dependent manner. Exposure of astrocytes to hypoxia for 3 h remarkably increased the levels of intracellular zinc and HIF-1α protein, which was further augmented by added exogenous zinc. Notably, HIF-1α knockdown blocked zinc-induced astrocyte death. Moreover, knockdown of PARP-1, another important protein in the response of hypoxia, attenuated the overexpression of HIF-1α and reduced the cell death rate. Our studies show that zinc promotes hypoxic cell death through overexpression of the hypoxia response factor HIF-1α via the cell fate determine factor PARP-1 modification, which provides a novel mechanism for zinc-mediated ischemic brain injury. © 2013 John Wiley & Sons Ltd.

Zinc and the modulation of redox homeostasis

Science.gov (United States)

Oteiza, Patricia I.

2012-01-01

Zinc, a redox inactive metal, has been long viewed as a component of the antioxidant network, and growing evidence points to its involvement in redox-regulated signaling. These actions are exerted through several mechanisms based on the unique chemical and functional properties of zinc. Overall, zinc contributes to maintain the cell redox balance through different mechanisms including: i) the regulation of oxidant production and metal-induced oxidative damage; ii) the dynamic association of zinc with sulfur in protein cysteine clusters, from which the metal can be released by nitric oxide, peroxides, oxidized glutathione and other thiol oxidant species; iii) zinc-mediated induction of the zinc-binding protein metallothionein, which releases the metal under oxidative conditions and act per se scavenging oxidants; iv) the involvement of zinc in the regulation of glutathione metabolism and of the overall protein thiol redox status; and v) a direct or indirect regulation of redox signaling. Findings of oxidative stress, altered redox signaling, and associated cell/tissue disfunction in cell and animal models of zinc deficiency, stress the relevant role of zinc in the preservation of cell redox homeostasis. However, while the participation of zinc in antioxidant protection, redox sensing, and redox-regulated signaling is accepted, the involved molecules, targets and mechanisms are still partially known and the subject of active research. PMID:22960578

Zinc Finger Takes on a Whole New Meaning: Reducing and Monitoring Zinc Blanks in the Isotope Lab

Science.gov (United States)

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 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 delta = 0 that is strongly enriched in light isotopes relative to both brands of gloves. We caution others who measure

Chloride Test

Science.gov (United States)

... metabolic acidosis ) or when a person hyperventilates (causing respiratory alkalosis ). A decreased level of blood chloride (called hypochloremia) ... disease , emphysema or other chronic lung diseases (causing respiratory ... metabolic alkalosis). An increased level of urine chloride can indicate ...

Zinc in diet

Science.gov (United States)

... Effects Symptoms of zinc deficiency include: Frequent infections Hypogonadism in males Loss of hair Poor appetite Problems with the ... any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should ...

Effect of consuming zinc-fortified bread on serum zinc and iron status of zinc-deficient women: A double blind, randomized clinical trial

Directory of Open Access Journals (Sweden)

Akbar Badii

2012-01-01

Full Text Available After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1 a non-fortified bread, (2 a high-zinc bread, and (3 a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05. Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p < 0.01. It was concluded that fortification of flour with 50-100 ppm zinc was an effective way to achieve adequate zinc intake and absorption in zinc-deficient people. It also appeared that consuming zinc-fortified bread improved iron absorption.

Method for synthesizing pollucite from chabazite and cesium chloride

International Nuclear Information System (INIS)

Pereira, C.

1999-01-01

A method is described for immobilizing waste chlorides salts containing radionuclides and hazardous nuclear material for permanent disposal, and in particular, a method is described for immobilizing waste chloride salts containing cesium, in a synthetic form of pollucite. The method for synthesizing pollucite from chabazite and cesium chloride includes mixing dry, non-aqueous cesium chloride with chabazite and heating the mixture to a temperature greater than the melting temperature of the cesium chloride, or above about 700 C. The method further comprises significantly improving the rate of retention of cesium in ceramic products comprised of a salt-loaded zeolite by adding about 10% chabazite by weight to the salt-loaded zeolite prior to conversion at elevated temperatures and pressures to the ceramic composite. 3 figs

Oral zinc for treating diarrhoea in children

Science.gov (United States)

Lazzerini, Marzia; Wanzira, Humphrey

2016-01-01

Background In developing countries, diarrhoea causes around 500,000 child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF). Objectives To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library 2016, Issue 5), MEDLINE, Embase, LILACS, CINAHL, mRCT, and reference lists up to 30 September 2016. We also contacted researchers. Selection criteria Randomized controlled trials (RCTs) that compared oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery. Data collection and analysis Both review authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. The primary outcomes were diarrhoea duration and severity. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using either a fixed-effect or random-effects model) and assessed heterogeneity. We assessed the certainty of the evidence using the GRADE approach. Main results Thirty-three trials that included 10,841 children met our inclusion criteria. Most included trials were conducted in Asian countries that were at high risk of zinc deficiency. Acute diarrhoea There is currently not enough evidence from well-conducted RCTs to be able to say whether zinc supplementation during acute diarrhoea reduces death or number of children hospitalized (very low certainty evidence). In children older than six months of age, zinc supplementation may shorten the average duration of diarrhoea by around half a day (MD −11.46 hours, 95% CI −19.72 to −3.19; 2581 children, 9 trials, low

Mapping the spatial distribution of chloride deposition across Australia

Science.gov (United States)

Davies, P. J.; Crosbie, R. S.

2018-06-01

The high solubility and conservative behaviour of chloride make it ideal for use as an environmental tracer of water and salt movement through the hydrologic cycle. For such use the spatial distribution of chloride deposition in rainfall at a suitable scale must be known. A number of authors have used point data acquired from field studies of chloride deposition around Australia to construct relationships to characterise chloride deposition as a function of distance from the coast; these relationships have allowed chloride deposition to be interpolated in different regions around Australia. In this paper we took this a step further and developed a chloride deposition map for all of Australia which includes a quantification of uncertainty. A previously developed four parameter model of chloride deposition as a function of distance from the coast for Australia was used as the basis for producing a continental scale chloride deposition map. Each of the four model parameters were made spatially variable by creating parameter surfaces that were interpolated using a pilot point regularisation approach within a parameter estimation software. The observations of chloride deposition were drawn from a literature review that identified 291 point measurements of chloride deposition over a period of 80 years spread unevenly across all Australian States and Territories. A best estimate chloride deposition map was developed from the resulting surfaces on a 0.05 degree grid. The uncertainty in the chloride deposition map was quantified as the 5th and 95th percentile of 1000 calibrated models produced via Null Space Monte Carlo analysis and the spatial variability of chloride deposition across the continent was consistent with landscape morphology. The temporal variability in chloride deposition on a decadal scale was investigated in the Murray-Darling Basin, this highlighted the need for long-term monitoring of chloride deposition if the uncertainty of the continental scale map is

A cyclic GMP-dependent calcium-activated chloride current in smooth-muscle cells from rat mesenteric resistance arteries

DEFF Research Database (Denmark)

Matchkov, Vladimir; Aalkjær, Christian; Nilsson, Holger

2004-01-01

We have previously demonstrated the presence of a cyclic GMP (cGMP)-dependent calcium-activated inward current in vascular smooth-muscle cells, and suggested this to be of importance in synchronizing smooth-muscle contraction. Here we demonstrate the characteristics of this current. Using......M) in the pipette solution. The current was found to be a calcium-activated chloride current with an absolute requirement for cyclic GMP (EC50 6.4 microM). The current could be activated by the constitutively active subunit of PKG. Current activation was blocked by the protein kinase G antagonist Rp-8-Br-PET-cGMP...... differed from those of the calcium-activated chloride current in pulmonary myocytes, which was cGMP-independent, exhibited a high sensitivity to inhibition by niflumic acid, was unaffected by zinc ions, and showed outward current rectification as has previously been reported for this current. Under...

40 CFR 61.65 - Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants.

Science.gov (United States)

2010-07-01

... dichloride, vinyl chloride and polyvinyl chloride plants. 61.65 Section 61.65 Protection of Environment... AIR POLLUTANTS National Emission Standard for Vinyl Chloride § 61.65 Emission standard for ethylene dichloride, vinyl chloride and polyvinyl chloride plants. An owner or operator of an ethylene dichloride...

Natural Attenuation of Arsenic, Cadmium, Lead, and Zinc Using Hydrograph Separation

Science.gov (United States)

Burrows, J. E.; Peters, S. C.

2009-12-01

Strategies for remediating contaminated sites range from complete removal of the contaminated soil to in-situ monitored natural attenuation. The decision to let a property naturally attenuate is partially based on the estimated time it will take to return to ambient conditions. The Lehigh Gap Wildlife Refuge at Palmerton, PA was historically contaminated with arsenic, cadmium, lead, and zinc from a zinc smelting operation that ceased emissions twenty-nine years ago. This property provides an opportunity to assess whether the length of time required for the natural attenuation of metals in soil has been achieved using a watershed mass balance approach, focusing particularly on perturbations observed in the concentration-discharge relationships of contaminants compared to the conservative tracers sodium and chloride, and silicon as an indicator of rock-water interactions. Water samples were collected from 3 springs in the Wildlife Refuge for approximately 4 days following the onset of storm events and analyzed for cation and anion concentrations. Preliminary results show that while the concentrations of arsenic and lead were below detection limits, the fluxes of zinc and cadmium increase corresponding with the peak in the hydrograph relative to the fluxes of the tracers, indicating the solutes are being released from adsorption sites located in an unsaturated zone that is temporarily inundated during storm events. In comparison, the flux of the tracers remains constant, indicative of a steady-state leakage of the solutes from their respective reservoirs in the soil. Along with flux, the concentrations of zinc and cadmium also increase following the rise in discharge after storm events, further suggesting that these contaminants are being mobilized out of the soil profile.

The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor

International Nuclear Information System (INIS)

Ren Xiulian; Wei Qifeng; Hu Surong; Wei Sijie

2010-01-01

This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with ω 1/2 (ω: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH 4 Cl concentration was 53.46 g L -1 and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min -1 . Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor.

Cysteine-rich intestinal protein binds zinc during transmucosal zinc transport

International Nuclear Information System (INIS)

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. The authors 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 HPCL and SDS/PAGE showed complete identity within the first 41 N-terminal amino acids with the deduced protein sequence of cysteine-rich intestinal protein. 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

Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

Science.gov (United States)

Maret, Wolfgang

2017-10-31

In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

Effect of Consuming Zinc-fortified Bread on Serum Zinc and Iron Status of Zinc-deficient Women: A Double Blind, Randomized Clinical Trial.

Science.gov (United States)

Badii, Akbar; Nekouei, Niloufar; Fazilati, Mohammad; Shahedi, Mohammad; Badiei, Sajad

2012-03-01

After iron deficiency, zinc deficiency is the major micronutrient deficiency in developing countries, and staple food fortification is an effective strategy to prevent and improve it among at-risk-populations. No action has been taken to reduce zinc deficiency via flour fortification so far in Iran, and little is known about the influence of zinc fortification of flour on serum zinc and the iron status, and also about the optimum and effective amount of zinc compound that is used in food fortification. The objective of this study is to evaluate the influence of consuming zinc-fortified breads on the zinc and iron status in the blood serum. In this study, three types of bread were prepared from non-fortified and fortified flours, with 50 and 100 ppm elemental zinc in the form of sulfate. Eighty zinc-deficient women aged 19 to 49 years were randomly assigned to three groups; The volunteers received, daily, (1) a non-fortified bread, (2) a high-zinc bread, and (3) a low-zinc bread for one month. Serum zinc and iron were measured by Atomic Absorption before and after the study. Results showed a significant increase in serum zinc and iron levels in all groups (p 0.05). Absorption of zinc and iron in the group that consumed high-zinc bread was significantly greater than that in the group that received low-zinc bread (p bread improved iron absorption.

Estimating Anthropogenic Emissions of Hydrogen Chloride and Fine Particulate Chloride in China

Science.gov (United States)

Fu, X.; Wang, T.; Wang, S.; Zhang, L.

2017-12-01

Nitryl chloride (ClNO2) can significantly impact the atmospheric photochemistry via photolysis and subsequent reactions of chlorine radical with other gases. The formation of ClNO2 in the atmosphere is sensitive to the emissions of chlorine-containing particulates from oceanic and anthropogenic sources. For China, the only available anthropogenic chlorine emission inventory was compiled for the year 1990 with a coarse resolution of 1 degree. In this study, we developed an up-to-date anthropogenic inventory of hydrogen chloride (HCl) and fine particulate chloride (Cl-) emissions in China for the year 2014, including coal burning, industrial processes, biomass burning and waste burning. Bottom-up and top-down methodologies were combined. Detailed local data (e.g. Cl content in coal, control technologies, etc.) were collected and applied. In order to improve the spatial resolution of emissions, detailed point source information were collected for coal-fired power plants, cement factories, iron & steel factories and waste incineration factories. Uncertainties of this emission inventory and their major causes were analyzed using the Monte Carlo method. This work enables better quantification of the ClNO2 production and impact over China.

Zinc

Science.gov (United States)

... Some early research suggests that zinc supplementation increases sperm count, testosterone levels, and pregnancy rates in infertile men with low testosterone levels. Other research suggests that taking zinc can improve sperm shape in men with moderate enlargement of a ...

High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

Energy Technology Data Exchange (ETDEWEB)

Lengyel,I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

2007-01-01

One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD.

High Concentration of Zinc in Sub-retinal Pigment Epithelial Deposits

International Nuclear Information System (INIS)

Lengyel, I.; Flinn, J.; Peto, T.; Linkous, D.; Cano, K.; Bird, A.; Lanzirotti, A.; Frederickson, C.; van Kuijk, F.

2007-01-01

One of the hallmarks of age-related macular degeneration (AMD), the leading cause of blindness in the elderly in Western societies, is the accumulation of sub-retinal pigment epithelial deposits (sub-RPE deposits), including drusen and basal laminar deposits, in Bruch's membrane (BM). The nature and the underlying mechanisms of this deposit formation are not fully understood. Because we know that zinc contributes to deposit formation in neurodegenerative diseases, we tested the hypothesis that zinc might be involved in deposit formation in AMD. Using zinc specific fluorescent probes and microprobe synchrotron X-ray fluorescence we showed that sub-RPE deposits in post-mortem human tissues contain unexpectedly high concentrations of zinc, including abundant bio-available (ionic and/or loosely protein bound) ions. Zinc accumulation was especially high in the maculae of eyes with AMD. Internal deposit structures are especially enriched in bio-available zinc. Based on the evidence provided here we suggest that zinc plays a role in sub-RPE deposit formation in the aging human eye and possibly also in the development and/or progression of AMD

Relationship between maternal serum zinc, cord blood zinc and ...

African Journals Online (AJOL)

Background: Adequate in utero supply of zinc is essential for optimal fetal growth because of the role of zinc in cellular division, growth and differentiation. Low maternal serum zinc has been reported to be associated with low birth weight and the later is associated with increased morbidity and mortality in newborns.

Effects of serum zinc level on tinnitus.

Science.gov (United States)

Berkiten, Güler; Kumral, Tolgar Lütfi; Yıldırım, Güven; Salturk, Ziya; Uyar, Yavuz; Atar, Yavuz

2015-01-01

The aim of this study was to assess zinc levels in tinnitus patients, and to evaluate the effects of zinc deficiency on tinnitus and hearing loss. One-hundred patients, who presented to an outpatient clinic with tinnitus between June 2009 and 2014, were included in the study. Patients were divided into three groups according to age: Group I (patients between 18 and 30years of age); Group II (patients between 31 and 60years of age); and Group III (patients between 61 and 78years of age). Following a complete ear, nose and throat examination, serum zinc levels were measured and the severity of tinnitus was quantified using the Tinnitus Severity Index Questionnaire (TSIQ). Patients were subsequently asked to provide a subjective judgment regarding the loudness of their tinnitus. The hearing status of patients was evaluated by audiometry and high-frequency audiometry. An average hearing sensitivity was calculated as the mean value of hearing thresholds between 250 and 20,000Hz. Serum zinc levels between 70 and 120μg/dl were considered normal. The severity and loudness of tinnitus, and the hearing thresholds of the normal zinc level and zinc-deficient groups, were compared. Twelve of 100 (12%) patients exhibited low zinc levels. The mean age of the zinc-deficient group was 65.41±12.77years. Serum zinc levels were significantly lower in group III (p<0.01). The severity and loudness of tinnitus were greater in zinc-deficient patients (p=0.011 and p=0.015, respectively). Moreover, the mean thresholds of air conduction were significantly higher in zinc-deficient patients (p=0.000). We observed that zinc levels decrease as age increases. In addition, there was a significant correlation between zinc level and the severity and loudness of tinnitus. Zinc deficiency was also associated with impairments in hearing thresholds. Copyright © 2015 Elsevier Inc. All rights reserved.

Study of Brasgel clay looking at its use in the removal of heavy metal zinc in analytical effluents

International Nuclear Information System (INIS)

Patricio, A.C.L.; Silva, M.M. da; Lima, W.S.; Cartaxo, J. de M.; Rodrigues, M.G.F.

2011-01-01

This work aims to characterize the clay Brasgel in its natural form and after its organophilization through salt distearyl dimethyl chloride (Praepagen) and then evaluate the potential of clay in the process of treating wastewater contaminated by heavy metal zinc. After the treatment technique, specimens in natural form and organoclay were characterized by techniques of X-ray diffraction (XRD), infrared spectroscopy (IR), moreover, was the analysis of the behavior of organoclay in certain organic solvents through the swelling of Foster. In this work we adopted the procedure for removal of Zn"+"2 present in aqueous solutions, based on a factorial design, 2"2 + 3 repetitions at the central point, with the analysis parameters as the solution pH (3.0 to 5.0) and initial concentration of zinc ranging from 10 to 50 ppm. (author)

BWR zinc addition Sourcebook

International Nuclear Information System (INIS)

Garcia, Susan E.; Giannelli, Joseph F.; Jarvis, Alfred J.

2014-01-01

Boiling Water Reactors (BWRs) have been injecting zinc into the primary coolant via the reactor feedwater system for over 25 years for the purpose of controlling primary system radiation fields. The BWR zinc injection process has evolved since the initial application at the Hope Creek Nuclear Station in 1986. Key transitions were from the original natural zinc oxide (NZO) to depleted zinc oxide (DZO), and from active zinc injection of a powdered zinc oxide slurry (pumped systems) to passive injection systems (zinc pellet beds). Zinc addition has continued through various chemistry regimes changes, from normal water chemistry (NWC) to hydrogen water chemistry (HWC) and HWC with noble metals (NobleChem™) for mitigation of intergranular stress corrosion cracking (IGSCC) of reactor internals and primary system piping. While past reports published by the Electric Power Research Institute (EPRI) document specific industry experience related to these topics, the Zinc Sourcebook was prepared to consolidate all of the experience gained over the past 25 years. The Zinc Sourcebook will benefit experienced BWR Chemistry, Operations, Radiation Protection and Engineering personnel as well as new people entering the nuclear power industry. While all North American BWRs implement feedwater zinc injection, a number of other BWRs do not inject zinc. This Sourcebook will also be a valuable resource to plants considering the benefits of zinc addition process implementation, and to gain insights on industry experience related to zinc process control and best practices. This paper presents some of the highlights from the Sourcebook. (author)

Chloride flux in phagocytes.

Science.gov (United States)

Wang, Guoshun

2016-09-01

Phagocytes, such as neutrophils and macrophages, engulf microbes into phagosomes and launch chemical attacks to kill and degrade them. Such a critical innate immune function necessitates ion participation. Chloride, the most abundant anion in the human body, is an indispensable constituent of the myeloperoxidase (MPO)-H2 O2 -halide system that produces the potent microbicide hypochlorous acid (HOCl). It also serves as a balancing ion to set membrane potentials, optimize cytosolic and phagosomal pH, and regulate phagosomal enzymatic activities. Deficient supply of this anion to or defective attainment of this anion by phagocytes is linked to innate immune defects. However, how phagocytes acquire chloride from their residing environment especially when they are deployed to epithelium-lined lumens, and how chloride is intracellularly transported to phagosomes remain largely unknown. This review article will provide an overview of chloride protein carriers, potential mechanisms for phagocytic chloride preservation and acquisition, intracellular chloride supply to phagosomes for oxidant production, and methods to measure chloride levels in phagocytes and their phagosomes. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Chlorides behavior in raw fly ash washing experiments

International Nuclear Information System (INIS)

Zhu Fenfen; Takaoka, Masaki; Oshita, Kazuyuki; Kitajima, Yoshinori; Inada, Yasuhiro; Morisawa, Shinsuke; Tsuno, Hiroshi

2010-01-01

Chloride in fly ash from municipal solid waste incinerators (MSWIs) is one of the obstructive substances in recycling fly ash as building materials. As a result, we have to understand the behavior of chlorides in recycling process, such as washing. In this study, we used X-ray absorption near edge structure (XANES) and X-ray diffraction (XRD) to study the chloride behavior in washed residue of raw fly ash (RFA). We found that a combination of XRD and XANES, which is to use XRD to identify the situation of some compounds first and then process XANES data, was an effective way to explain the chlorides behavior in washing process. Approximately 15% of the chlorine in RFA was in the form of NaCl, 10% was in the form of KCl, 51% was CaCl 2 , and the remainder was in the form of Friedel's salt. In washing experiments not only the mole percentage but also the amount of soluble chlorides including NaCl, KCl and CaCl 2 decreases quickly with the increase of liquid to solid (L/S) ratio or washing frequency. However, those of insoluble chlorides decrease slower. Moreover, Friedel's salt and its related compound (11CaO.7Al 2 O 3 .CaCl 2 ) were reliable standards for the insoluble chlorides in RFA, which are strongly related to CaCl 2 . Washing of RFA promoted the release of insoluble chlorides, most of which were in the form of CaCl 2 .

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

Science.gov (United States)

Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

2017-06-01

The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

Directory of Open Access Journals (Sweden)

Gai-Fei Peng

2014-04-01

Full Text Available The influence of a chloride-ion adsorption agent (Cl agent in short, composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms.

Association of Mood Disorders with Serum Zinc Concentrations in Adolescent Female Students.

Science.gov (United States)

Tahmasebi, Kobra; Amani, Reza; Nazari, Zahra; Ahmadi, Kambiz; Moazzen, Sara; Mostafavi, Seyed-Ali

2017-08-01

Among various factors influencing mood disorders, the impact of micronutrient deficiencies has attracted a great attention. Zinc deficiency is considered to play a crucial role in the onset and progression of mood disorders in different stages of life. The main objective of this study was to assess the correlation between serum zinc levels and mood disorders in high school female students. This cross-sectional study was conducted on a random sample of 100 representative high school female students. The participants completed 24-h food recall questionnaires to assess the daily zinc intakes. Serum zinc status was assessed using flame atomic absorption spectrometry, and zinc deficiency was defined accordingly. Mood disorders were estimated by calculating the sum of two test scores including Beck's depression inventory (BDI) and hospital anxiety depression scale (HADS) tests. General linear model (GLM) and Pearson's regression test were applied to show the correlation of serum zinc levels and mood disorder scores and the correlation between zinc serum levels and BDI scores, respectively. Dietary zinc intake was higher in subjects with normal zinc concentrations than that of zinc-deficient group (p = 0.001). Serum zinc levels were inversely correlated with BDI and HADS scores (p zinc levels led to 0.3 and 0.01 decrease in depression and anxiety scores, respectively (p zinc levels were inversely correlated with mood disorders including depression and anxiety in adolescent female students. Increasing serum levels of zinc in female students could improve their mood disorders.

Removal of uranium from simulated fly ash by chloride volatilization method

International Nuclear Information System (INIS)

Nobuaki, Sato; Yoshikatsu, Tochigi; Toshiki, Fukui; Takeo, Fujino

2003-01-01

Fly ash is generated from LWR nuclear power plant as a low-level waste, which is contaminated with a small amount of radioactive materials, composed mainly of uranium oxide. The constituents of the fly ash are similar to those of the ore; the major components of the ash are oxides of silicon, aluminum, sodium, magnesium, zinc, iron sodium and uranium. In this study, removal of uranium from the simulated fly ash, of which composition was U 3 O 8 : 10, CaO:25, SiO 2 : 25, Al 2 O 3 : 20, MgO: 10, ZnO:5, Fe 2 O 3 : 3 and Na 2 CO 3 : 2 wt%, by chloride volatilization method was examined. The simulated fly ash was chlorinated by the same manner as the dry way processing for the ore; namely, the ash was heated in a flow of chlorine in the presence of carbon at high temperatures. In the case of volatilization of uranium from U 3 O 8 and a simulated fly ash by chlorination using chlorine and carbon, it was seen that uranium of both samples showed similar volatilization behaviour: The volatilization ratio of uranium (VU) increased with increasing temperature from 800 to 1100 C. The VU value attained 99.9% at 1100 C. Iron, silicon and zinc showed similar behaviour to uranium, namely, they vaporized completely. The volatilization ratio of aluminum, magnesium and sodium were still high in a range 80-90%. The volatilization ratio of calcium was ∼40% under the same chlorination condition, though it changed to chloride. For recovery of uranium from fly ash by chlorination using chlorine in the presence of carbon, high volatilization ratio of uranium can be achieved at high temperatures. Volatilization ratio of other components also increases, which decreases the amount of decontaminated residue resulting in the reducing of decontamination effect. Selection of heating condition is important. (author)

Sorption of zinc on human teeth

International Nuclear Information System (INIS)

Helal, A.; Amin, H.; Alian, G.

1997-01-01

Zinc containing dental amalgams are sometimes used as fillings by dentists. The freshly mixed mass of the amalgam alloy and liquid mercury packed or condensed into a prepared tooth cavity. Zinc has been included in amalgams alloys up to 2% as an aid in manufacturing by helping to produce clean sound castings of the ingots. Although such restorations have a relatively long service life, they are subject to corrosion and galvanic action, thus releasing metallic products into the oral environment. The aim of this paper is to investigate the uptake (sorption) of Zinc ionic species on human teeth using the radioactive tracer technique. For this purpose the isotope Zn-65 produced from pile-irradiation of zinc metal was used. The various liquids studied were drinking water (tap water), tea, coffee, red tea and chicken soup. Sorption was studied through immersion of a single human tooth (extracted) in each of these liquids

Chloride test - blood

Science.gov (United States)

Serum chloride test ... A greater-than-normal level of chloride is called hyperchloremia. It may be due to: Carbonic anhydrase inhibitors (used to treat glaucoma) Diarrhea Metabolic acidosis Respiratory alkalosis (compensated) Renal ...

Chloride in diet

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/002417.htm Chloride in diet To use the sharing features on this page, please enable JavaScript. Chloride is found in many chemicals and other substances ...

Mercuric chloride poisoning

Science.gov (United States)

... page: //medlineplus.gov/ency/article/002474.htm Mercuric chloride poisoning To use the sharing features on this page, please enable JavaScript. Mercuric chloride is a very poisonous form of mercury. It ...

The study and microstructure analysis of zinc and zinc oxide

Czech Academy of Sciences Publication Activity Database

Luptáková, Natália; Pešlová, F.; Kliber, J.

2015-01-01

Roč. 54, č. 1 (2015), s. 43-46 ISSN 0543-5846 Grant - others:KEGA(SK) KEGA 007 TnUAD-4/2013 Institutional support: RVO:68081723 Keywords : zinc * production of zinc oxide * microstructure * chemical composition * zinc slag Subject RIV: JG - Metal lurgy Impact factor: 0.959, year: 2014

Zinc Biochemistry: From a Single Zinc Enzyme to a Key Element of Life12

Science.gov (United States)

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

HUBUNGAN ANTARA ZINC SERUM DENGAN STATUS GIZI LANSIA

Directory of Open Access Journals (Sweden)

Fitrah Emawati

2012-11-01

Full Text Available RELATIONSHIP BETWEEN ZINC SERUM AND NUTRITIONAL STATUS OF ELDERLY PEOPLE.Background: The findings of study that 30% in Bogor and 27% in Jakarta of elderly people were undernourished. Malnutrition may occur due to infection and low food intake. Among elderly people, one of the factors that causes low food intake is affected by impairment of taste sensory and teeth function. The impairment of taste sensory is influenced by zinc status in the body.Objective: To collect food consumption pattem data of zinc rich foods, zinc concentration in serum and to analyze association of zinc concentration and nutritional status.Methods: Research design was cross sectional, and conducted in two sub districts in Bogor city. The respondents were women in 60-75 years of age, no suffering from illnesses and chronically disease. The total respondent was 90 people, and divided into three groups of 30 peoples. Data gathered included respondent identity, physical examination, anthropometry, blood biochemical and zinc dietary consumption.Results: Zinc dietary consumption adequacy of underweight group was only 30% of recommended dietary allowance, while for normal and overweight groups were 40% of dietary allowance. Zinc serum concentration of underweight group (82 ug/dl was not significantly different with normal group (85 ug/dl, however differed significantly (p<0.05 with overweight group (95 ug/dl. Underweight group suffered 40% zinc deficiency, 27% for normal and only 7% for overweight group.Conclusions: Zinc deficiency was more prevalent in underweight group than that of normal and overweight group. [Panel Gizi Makan 2002,25: 26-33.Keywords: zinc serum concentration, zinc dietary consumption, underweight

An experimental study of the retention of zinc, zinc-cadmium mixture and zinc-65 in the presence of cadmium in Anguilla anguilla (L.)

International Nuclear Information System (INIS)

Pally, Monique; Foulquier, Luc

1976-07-01

Zinc uptake was studied in eels in fresh water, using stable zinc, a zinc-cadmium mixture, and zinc 65 in the presence of small amounts of cadmium. The zinc content in the eel began to increase after 45 days only, and reached approximately 85 ppm after 76 days in water initially containing 5ppm of zinc. At the conclusion of the experiment (76 days), the body organs could be classified in decreasing order in zinc content (in ppm): kidneys (152), skeleton (133), skin (129), muscles (89), head (80), gills (78), digestive tract (77), liver (63) spleen-heart-air bladder (32), and mucus (15). A comparison of experimental results obtained with the zinc-cadmium mixture and cadmium alone showed that zinc decreased the cadmium content of all organs except the gills. The presence of cadmium in water did not inhibit zinc uptake. As cadmium content in water increased, then zinc content in the digestive tract and the kidneys decreased and in all cases remained lower than when zinc alone was present. In the presence of cadmium the percentage of zinc in the kidneys was always lower than the value obtained for zinc alone, and that of the digestive tract did not increase. Contamination of eels treated with 18 and 50ppb of cadmium for 29 days, then contaminated by zinc-65 (5μCi/l) while maintaining the same low cadmium content, showed no significant difference in zinc 65 uptake in the two groups. The same applied to the body organs, and particularly the digestive tract and kidneys, where the highest activity levels were observed. By weight, muscles represented approximately 30% of the total contamination after 45 days [fr

Effect of zinc sources on yield and utilization of zinc in rice-wheat sequence

International Nuclear Information System (INIS)

Deb, D.L.

1990-01-01

A field experiment was conducted on an inceptisol of Delhi to evaluate three sources of zinc, namely, zinc sulphate, zincated urea and zinc oxide on yield and utilization of zinc in rice-wheat sequence. Results indicated that, amongst the three zinc sources, zinc sulphate and zincated urea gave the best performance in increasing the grain yield of rice whereas zinc oxide depressed the grain yield of wheat significantly when compared to other treatments. The highest Zn derived from fertilizer and its utilization was obtained with zinc sulphate for both rice and wheat crops. (author). 9 refs., 4 tabs

Zinc blotting assay for detection of zinc binding prolamin in barley (Hordeum vulgare) grain

DEFF Research Database (Denmark)

Uddin, Mohammad Nasir; Nielsen, Ane Langkilde-Lauesen; Vincze, Eva

2014-01-01

In plants, zinc is commonly found bound to proteins. In barley (Hordeum vulgare), major storage proteins are alcohol-soluble prolamins known as hordeins, and some of them have the potential to bind or store zinc. 65Zn overlay and blotting techniques have been widely used for detecting zinc......-binding protein. However, to our knowledge so far this zinc blotting assay has never been applied to detect a prolamin fraction in barley grains. A radioactive zinc (65ZnCl2) blotting technique was optimized to detect zinc-binding prolamins, followed by development of an easy-to-follow nonradioactive colorimetric...... zinc blotting method with a zinc-sensing dye, dithizone. Hordeins were extracted from mature barley grain, separated by SDS-PAGE, blotted on a membrane, renatured, overlaid, and probed with zinc; subsequently, zinc-binding specificity of certain proteins was detected either by autoradiography or color...

Chloride removal from vitrification offgas

Energy Technology Data Exchange (ETDEWEB)

Slaathaug, E.J. [Westinghouse Hanford Co., Richland, WA (United States)

1995-06-01

This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations.

Chloride removal from vitrification offgas

International Nuclear Information System (INIS)

Slaathaug, E.J.

1995-01-01

This study identified and investigated techniques of selectively purging chlorides from the low-level waste (LLW) vitrification process with the purge stream acceptable for burial on the Hanford Site. Chlorides will be present in high concentration in several individual feeds to the LLW Vitrification Plant. The chlorides are highly volatile in combustion type melters and are readily absorbed by wet scrubbing of the melter offgas. The Tank Waste Remediation System (TWRS) process flow sheets show that the resulting chloride rich scrub solution is recycled back to the melter. The chlorides must be purged from the recycle loop to prevent the buildup of excessively high chloride concentrations

The immune system and the impact of zinc during aging

Directory of Open Access Journals (Sweden)

Haase Hajo

2009-06-01

Full Text Available Abstract The trace element zinc is essential for the immune system, and zinc deficiency affects multiple aspects of innate and adaptive immunity. There are remarkable parallels in the immunological changes during aging and zinc deficiency, including a reduction in the activity of the thymus and thymic hormones, a shift of the T helper cell balance toward T helper type 2 cells, decreased response to vaccination, and impaired functions of innate immune cells. Many studies confirm a decline of zinc levels with age. Most of these studies do not classify the majority of elderly as zinc deficient, but even marginal zinc deprivation can affect immune function. Consequently, oral zinc supplementation demonstrates the potential to improve immunity and efficiently downregulates chronic inflammatory responses in the elderly. These data indicate that a wide prevalence of marginal zinc deficiency in elderly people may contribute to immunosenescence.

The zinc dyshomeostasis hypothesis of Alzheimer's disease.

Directory of Open Access Journals (Sweden)

Travis J A Craddock

Full Text Available Alzheimer's disease (AD is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ, intracellular neurofibrillary tangles (NFTs composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau, and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1 used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2 performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3 used metallomic imaging mass spectrometry (MIMS to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of

The zinc dyshomeostasis hypothesis of Alzheimer's disease.

Science.gov (United States)

Craddock, Travis J A; Tuszynski, Jack A; Chopra, Deepak; Casey, Noel; Goldstein, Lee E; Hameroff, Stuart R; Tanzi, Rudolph E

2012-01-01

Alzheimer's disease (AD) is the most common form of dementia in the elderly. Hallmark AD neuropathology includes extracellular amyloid plaques composed largely of the amyloid-β protein (Aβ), intracellular neurofibrillary tangles (NFTs) composed of hyper-phosphorylated microtubule-associated protein tau (MAP-tau), and microtubule destabilization. Early-onset autosomal dominant AD genes are associated with excessive Aβ accumulation, however cognitive impairment best correlates with NFTs and disrupted microtubules. The mechanisms linking Aβ and NFT pathologies in AD are unknown. Here, we propose that sequestration of zinc by Aβ-amyloid deposits (Aβ oligomers and plaques) not only drives Aβ aggregation, but also disrupts zinc homeostasis in zinc-enriched brain regions important for memory and vulnerable to AD pathology, resulting in intra-neuronal zinc levels, which are either too low, or excessively high. To evaluate this hypothesis, we 1) used molecular modeling of zinc binding to the microtubule component protein tubulin, identifying specific, high-affinity zinc binding sites that influence side-to-side tubulin interaction, the sensitive link in microtubule polymerization and stability. We also 2) performed kinetic modeling showing zinc distribution in extra-neuronal Aβ deposits can reduce intra-neuronal zinc binding to microtubules, destabilizing microtubules. Finally, we 3) used metallomic imaging mass spectrometry (MIMS) to show anatomically-localized and age-dependent zinc dyshomeostasis in specific brain regions of Tg2576 transgenic, mice, a model for AD. We found excess zinc in brain regions associated with memory processing and NFT pathology. Overall, we present a theoretical framework and support for a new theory of AD linking extra-neuronal Aβ amyloid to intra-neuronal NFTs and cognitive dysfunction. The connection, we propose, is based on β-amyloid-induced alterations in zinc ion concentration inside neurons affecting stability of polymerized

Resistance of Alkali-Activated Slag Concrete to Chloride-Induced Corrosion

Directory of Open Access Journals (Sweden)

Joon Woo Park

2015-01-01

Full Text Available The corrosion resistance of steel in alkali-activated slag (AAS mortar was evaluated by a monitoring of the galvanic current and half-cell potential with time against a chloride-contaminated environment. For chloride transport, rapid chloride penetration test was performed, and chloride binding capacity of AAS was evaluated at a given chloride. The mortar/paste specimens were manufactured with ground granulated blast-furnace slag, instead of Portland cement, and alkali activators were added in mixing water, including Ca(OH2, KOH and NaOH, to activate hydration process. As a result, it was found that the corrosion behavior was strongly dependent on the type of alkali activator: the AAS containing the Ca(OH2 activator was the most passive in monitoring of the galvanic corrosion and half-cell potential, while KOH, and NaOH activators indicated a similar level of corrosion to Portland cement mortar (control. Despite a lower binding of chloride ions in the paste, the AAS had quite a higher resistance to chloride transport in rapid chloride penetration, presumably due to the lower level of capillary pores, which was ensured by the pore distribution of AAS mortar in mercury intrusion porosimetry.

Determination of silver, bismuth, cadmium, copper, lead, and zinc in geologic materials by atomic absorption spectrometry with tricaprylylmethylammonium chloride

Science.gov (United States)

Viets, J.G.

1978-01-01

Interferences commonly encountered in the determination of silver, bismuth, cadmium, copper, lead, and zinc at crustal abundance levels are effectively eliminated using a rapid, sensitive, organic extraction technique. A potassium chlorate-hydrochloric acid digestion solubilizes the metals not tightly bound in the silicate lattice of rocks, soils, and stream sediments. The six metals are selectively extracted into a 10% Aliquat 336-MIBK organic phase in the presence of ascorbic acid and potassium iodide. Metals in the organic extract are determined by flame atomic absorption spectrometry to the 0.02-ppm level for silver, cadmium, copper, and zinc and to the 0.2-ppm level for bismuth and lead with a maximum relative standard deviation of 18.8% for known reference samples. An additional hydrofluoric acid digestion may be used to determine metals substituted in the silicate lattice.

Chlorides behavior in raw fly ash washing experiments.

Science.gov (United States)

Zhu, Fenfen; Takaoka, Masaki; Oshita, Kazuyuki; Kitajima, Yoshinori; Inada, Yasuhiro; Morisawa, Shinsuke; Tsuno, Hiroshi

2010-06-15

Chloride in fly ash from municipal solid waste incinerators (MSWIs) is one of the obstructive substances in recycling fly ash as building materials. As a result, we have to understand the behavior of chlorides in recycling process, such as washing. In this study, we used X-ray absorption near edge structure (XANES) and X-ray diffraction (XRD) to study the chloride behavior in washed residue of raw fly ash (RFA). We found that a combination of XRD and XANES, which is to use XRD to identify the situation of some compounds first and then process XANES data, was an effective way to explain the chlorides behavior in washing process. Approximately 15% of the chlorine in RFA was in the form of NaCl, 10% was in the form of KCl, 51% was CaCl(2), and the remainder was in the form of Friedel's salt. In washing experiments not only the mole percentage but also the amount of soluble chlorides including NaCl, KCl and CaCl(2) decreases quickly with the increase of liquid to solid (L/S) ratio or washing frequency. However, those of insoluble chlorides decrease slower. Moreover, Friedel's salt and its related compound (11CaO.7Al(2)O(3).CaCl(2)) were reliable standards for the insoluble chlorides in RFA, which are strongly related to CaCl(2). Washing of RFA promoted the release of insoluble chlorides, most of which were in the form of CaCl(2). Copyright 2010 Elsevier B.V. All rights reserved.

Recent advances in knowledge of zinc nutrition and human health.

Science.gov (United States)

Hess, Sonja Y; Lönnerdal, Bo; Hotz, Christine; Rivera, Juan A; Brown, Kenneth H

2009-03-01

Zinc deficiency increases the risk and severity of a variety of infections, restricts physical growth, and affects specific outcomes of pregnancy. Global recognition of the importance of zinc nutrition in public health has expanded dramatically in recent years, and more experience has accumulated on the design and implementation of zinc intervention programs. Therefore, the Steering Committee of the International Zinc Nutrition Consultative Group (IZiNCG) completed a second IZiNCG technical document that reexamines the latest information on the intervention strategies that have been developed to enhance zinc nutrition and control zinc deficiency. In particular, the document reviews the current evidence regarding preventive zinc supplementation and the role of zinc as adjunctive therapy for selected infections, zinc fortification, and dietary diversification or modification strategies, including the promotion and protection of breastfeeding and biofortification. The purposes of this introductory paper are to summarize new guidelines on the assessment of population zinc status, as recommended by the World Health Organization (WHO), the United Nations Children's Fund (UNICEF), the International Atomic Energy Agency (IAEA), and IZiNCG, and to provide an overview on several new advances in zinc metabolism. The following papers will then review the intervention strategies individually.

Neodymium conversion layers formed on zinc powder for improving electrochemical properties of zinc electrodes

International Nuclear Information System (INIS)

Zhu Liqun; Zhang Hui; Li Weiping; Liu Huicong

2008-01-01

Zinc powder, as active material of secondary alkaline zinc electrode, can greatly limit the performance of zinc electrode due to corrosion and dendritic growth of zinc resulting in great capacity-loss and short cycle life of the electrode. This work is devoted to modification study of zinc powder with neodymium conversion films coated directly onto it using ultrasonic immersion method for properties improvement of zinc electrodes. Scanning electron microscopy and other characterization techniques are applied to prove that neodymium conversion layers are distributing on the surface of modified zinc powder. The electrochemical performance of zinc electrodes made of such modified zinc powder is investigated through potentiodynamic polarization, potentiostatic polarization and cyclic voltammetry. The neodymium conversion films are found to have a significant effect on inhibition corrosion capability of zinc electrode in a beneficial way. It is also confirmed that the neodymium conversion coatings can obviously suppress dendritic growth of zinc electrode, which is attributed to the amelioration of deposition state of zinc. Moreover, the results of cyclic voltammetry reveal that surface modification of zinc powder enhances the cycle performance of the electrode mainly because the neodymium conversion films decrease the amounts of ZnO or Zn(OH) 2 dissolved in the electrolyte

Amine and Titanium (IV Chloride, Boron (III Chloride or Zirconium (IV Chloride-Promoted Baylis-Hillman Reactions

Directory of Open Access Journals (Sweden)

Shi-Cong Cui

2001-10-01

Full Text Available The Baylis-Hillman reactions of various aryl aldehydes with methyl vinyl ketone at temperatures below -20oC using Lewis acids such as titanium (IV chloride, boron (III chloride or zirconium (IV chloride in the presence of a catalytic amount of selected amines used as a Lewis bases afford the chlorinated compounds 1 as the major product in very high yields. Acrylonitrile can also undergo the same reaction to give the corresponding chlorinated product in moderate yield. A plausible reaction mechanism is proposed. However, if the reaction was carried out at room temperature (ca. 20oC, then the Z-configuration of the elimination product 3, derived from 1, was formed as the major product.

Zinc in human serum

International Nuclear Information System (INIS)

Kiilerich, S.

1987-01-01

The zinc ion is essential for the living organism. Many pathological conditions have been described as a consequence of zinc deficiency. As zinc constitutes less than 0.01 per cent of the body weight, it conventionally belongs to the group of trace elements. The method of atomic absorption spectrophotometry is used to measure the concentration of zinc in serum and urine from healthy persons. The assumptions of the method is discussed. The importance of proteinbinding, diet and the diurnal variation of serum zinc concentration is presented. Serum versus plasma zinc concentration is discussed. Reference serum zinc values from 104 normal subjects are given. Zinc in serum is almost entirely bound to proteins. A preliminary model for the estimation of the distribution of zinc between serum albumin and α 2 -macroglobulin is set up. This estimate has been examined by an ultracentrufugation method. The binding of zinc to a α 2 -macroglobulin in normal persons is appoximately 7 per cent, in patients with cirrhosis of the liver of alcoholic origin approximately 6 per cent, in patients with insulin dependent diabetes mellitus approximately 5 per cent, and in patients with chronic renal failure approximately 2 per cent. It is concluded, therefore, that for clinical purposes it is sufficient to use the concentration of total serum zinc corrected for the concentration of serum albumin. (author)

Iron and Zinc Nutrition in the Economically-Developed World: A Review

Directory of Open Access Journals (Sweden)

Alison O. Booth

2013-08-01

Full Text Available This review compares iron and zinc food sources, dietary intakes, dietary recommendations, nutritional status, bioavailability and interactions, with a focus on adults in economically-developed countries. The main sources of iron and zinc are cereals and meat, with fortificant iron and zinc potentially making an important contribution. Current fortification practices are concerning as there is little regulation or monitoring of intakes. In the countries included in this review, the proportion of individuals with iron intakes below recommendations was similar to the proportion of individuals with suboptimal iron status. Due to a lack of population zinc status information, similar comparisons cannot be made for zinc intakes and status. Significant data indicate that inhibitors of iron absorption include phytate, polyphenols, soy protein and calcium, and enhancers include animal tissue and ascorbic acid. It appears that of these, only phytate and soy protein also inhibit zinc absorption. Most data are derived from single-meal studies, which tend to amplify impacts on iron absorption in contrast to studies that utilize a realistic food matrix. These interactions need to be substantiated by studies that account for whole diets, however in the interim, it may be prudent for those at risk of iron deficiency to maximize absorption by reducing consumption of inhibitors and including enhancers at mealtimes.

Impact of residual elements on zinc quality in the production of zinc oxide

Czech Academy of Sciences Publication Activity Database

Luptáková, Natália; Dymáček, Petr; Pešlová, F.; Jurkovič, Z.; Barborák, O.; Stodola, J.

2016-01-01

Roč. 55, č. 3 (2016), s. 407-410 ISSN 0543-5846 Institutional support: RVO:68081723 Keywords : zinc * metallography * microstructure of zinc * zinc oxide * production of zinc oxide Subject RIV: JG - Metallurgy Impact factor: 0.959, year: 2014

Cyclic AMP Pathway Activation and Extracellular Zinc Induce Rapid Intracellular Zinc Mobilization in Candida albicans

Science.gov (United States)

Kjellerup, Lasse; Winther, Anne-Marie L.; Wilson, Duncan; Fuglsang, Anja T.

2018-01-01

Zinc is an essential micronutrient, required for a range of zinc-dependent enzymes and transcription factors. In mammalian cells, zinc serves as a second messenger molecule. However, a role for zinc in signaling has not yet been established in the fungal kingdom. Here, we used the intracellular zinc reporter, zinbo-5, which allowed visualization of zinc in the endoplasmic reticulum and other components of the internal membrane system in Candida albicans. We provide evidence for a link between cyclic AMP/PKA- and zinc-signaling in this major human fungal pathogen. Glucose stimulation, which triggers a cyclic AMP spike in this fungus resulted in rapid intracellular zinc mobilization and this “zinc flux” could be stimulated with phosphodiesterase inhibitors and blocked via inhibition of adenylate cyclase or PKA. A similar mobilization of intracellular zinc was generated by stimulation of cells with extracellular zinc and this effect could be reversed with the chelator EDTA. However, zinc-induced zinc flux was found to be cyclic AMP independent. In summary, we show that activation of the cyclic AMP/PKA pathway triggers intracellular zinc mobilization in a fungus. To our knowledge, this is the first described link between cyclic AMP signaling and zinc homeostasis in a human fungal pathogen. PMID:29619016

Reactivation in vitro of zinc-requiring apo-enzymes by rat liver zinc-thionein

OpenAIRE

Udom, Albert O.; Brady, Frank O.

1980-01-01

The ability of rat liver zinc-thionein to donate its metal to the apo-enzymes of the zinc enzymes horse liver alcohol dehydrogenase, yeast aldolase, thermolysin, Escherichia coli alkaline phosphatase and bovine erythrocyte carbonic anhydrase was investigated. Zinc-thionein was as good as, or better than, ZnSO4, Zn(CH3CO2)2 or Zn(NO3)2 in donating its zinc to these apo-enzymes. Apo-(alcohol dehydrogenase) could not be reactivated by zinc salts or by zinc-thionein. Incubation of the other apo-e...

Chloride Transport in Heterogeneous Formation

Science.gov (United States)

Mukherjee, A.; Holt, R. M.

2017-12-01

The chloride mass balance (CMB) is a commonly-used method for estimating groundwater recharge. Observations of the vertical distribution of pore-water chloride are related to the groundwater infiltration rates (i.e. recharge rates). In CMB method, the chloride distribution is attributed mainly to the assumption of one dimensional piston flow. In many places, however, the vertical distribution of chloride will be influenced by heterogeneity, leading to horizontal movement of infiltrating waters. The impact of heterogeneity will be particularly important when recharge is locally focused. When recharge is focused in an area, horizontal movement of chloride-bearing waters, coupled with upward movement driven by evapotranspiration, may lead to chloride bulges that could be misinterpreted if the CMB method is used to estimate recharge. We numerically simulate chloride transport and evaluate the validity of the CMB method in highly heterogeneous systems. This simulation is conducted for the unsaturated zone of Ogallala, Antlers, and Gatuna (OAG) formations in Andrews County, Texas. A two dimensional finite element model will show the movement of chloride through heterogeneous systems. We expect to see chloride bulges not only close to the surface but also at depths characterized by horizontal or upward movement. A comparative study of focused recharge estimates in this study with available recharge data will be presented.

Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

International Nuclear Information System (INIS)

Simescu, Florica; Idrissi, Hassane

2008-01-01

We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 . After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

Effect of zinc phosphate chemical conversion coating on corrosion behaviour of mild steel in alkaline medium: protection of rebars in reinforced concrete

Directory of Open Access Journals (Sweden)

Florica Simescu and Hassane Idrissi

2008-01-01

Full Text Available We outline the ability of zinc phosphate coatings, obtained by chemical conversion, to protect mild steel rebars against localized corrosion, generated by chloride ions in alkaline media. The corrosion resistance of coated steel, in comparison with uncoated rebars and coated and uncoated steel rebars embedded in mortar, were evaluated by open-circuit potential, potentiodynamic polarization, cronoamperometry and electrochemical impedance spectroscopy. The coated surfaces were characterized by x-ray diffraction and scanning electron microscopy. First, coated mild steel rebars were studied in an alkaline solution with and without chloride simulating a concrete pore solution. The results showed that the slow dissolution of the coating generates hydroxyapatite Ca10(PO46(OH2. After a long immersion, the coating became dense and provided an effective corrosion resistance compared with the mild steel rebar. Secondly, the coated and uncoated steel rebars embedded in mortar and immersed in chloride solution showed no corrosion or deterioration of the coated steel. Corrosion rate is considerably lowered by this phosphate coating.

The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor

Energy Technology Data Exchange (ETDEWEB)

Ren Xiulian [College of Ocean, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Wei Qifeng, E-mail: weiqifeng163@163.com [College of Ocean, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Hu Surong; Wei Sijie [College of Ocean, Harbin Institute of Technology at Weihai, Weihai 264209 (China)

2010-09-15

This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with {omega}{sup 1/2} ({omega}: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH{sub 4}Cl concentration was 53.46 g L{sup -1} and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min{sup -1}. Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor.

The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor.

Science.gov (United States)

Ren, Xiulian; Wei, Qifeng; Hu, Surong; Wei, Sijie

2010-09-15

This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with omega(1/2) (omega: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH(4)Cl concentration was 53.46 g L(-1) and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min(-1). Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor. Copyright 2010 Elsevier B.V. All rights reserved.

mRNA Levels of Placental Iron and Zinc Transporter Genes Are Upregulated in Gambian Women with Low Iron and Zinc Status.

Science.gov (United States)

Jobarteh, Modou Lamin; McArdle, Harry J; Holtrop, Grietje; Sise, Ebrima A; Prentice, Andrew M; Moore, Sophie E

2017-07-01

Background: The role of the placenta in regulating micronutrient transport in response to maternal status is poorly understood. Objective: We investigated the effect of prenatal nutritional supplementation on the regulation of placental iron and zinc transport. Methods: In a randomized trial in rural Gambia [ENID (Early Nutrition and Immune Development)], pregnant women were allocated to 1 of 4 nutritional intervention arms: 1 ) iron and folic acid (FeFol) tablets (FeFol group); 2 ) multiple micronutrient (MMN) tablets (MMN group); 3 ) protein energy (PE) as a lipid-based nutrient supplement (LNS; PE group); and 4 ) PE and MMN (PE+MMN group) as LNS. All arms included iron (60 mg/d) and folic acid (400 μg/d). The MMN and PE+MMN arms included 30 mg supplemental Zn/d. In a subgroup of ∼300 mother-infant pairs, we measured maternal iron status, mRNA levels of genes encoding for placental iron and zinc transport proteins, and cord blood iron levels. Results: Maternal plasma iron concentration in late pregnancy was 45% and 78% lower in the PE and PE+MMN groups compared to the FeFol and MMN groups, respectively ( P Zinc supplementation in the MMN arm was associated with higher maternal plasma zinc concentrations (10% increase; P zinc-uptake proteins, in this case zrt, irt-like protein (ZIP) 4 and ZIP8, were 96-205% lower in the PE+MMN arm than in the intervention arms without added zinc ( P zinc, the placenta upregulates the gene expression of iron and zinc uptake proteins, presumably in order to meet fetal demands in the face of low maternal supply. The ENID trial was registered at www.controlled-trials.com as ISRCTN49285450.

Galvanostatic polarization of zinc microanodes in KOH electrolytes

Energy Technology Data Exchange (ETDEWEB)

Liu, M.B.; Cook, G.M.; Yao, N.P.

1980-05-01

This report includes a critical review of the current literature on the anodic passivation of zinc electrodes, a description of supplementary experimental studies to extend the data to a low-current-density region and to provide a basis for evaluating conflicting results of published work, and a new interpretation of the anodic passivation mechanism. This work provides a starting point for understanding passivation phenomena in battery electrodes. The utilization of a zinc electrode in alkaline batteries depends on the ability of the electrode to remain active during the anodic dissolution process. This dissolution period is often terminated by the onset of passivation. Experiments were conducted on the effects of current density on passivation time of a small zinc anode (6.6 x 10/sup -3/ cm/sup 2/) in KOH at concentrations of 0.784, 2.92, 4.98 and 7.24M KOH as well as 7.24M KOH saturated with zinc oxide. It was concluded that there are two mechanisms for anodic passivation, one occurring at current densities below about 150 mA/cm/sup 2/ and another at higher current densities. Accordingly, in the overall mechanism, the total time to passivation includes the times to achieve the maximum zincate concentration as well as to form porous type I ZnO and compact type II ZnO. In Ni/Zn batteries under development for vehicle propulsion, the electrolyte is usually 30% KOH (7M) saturated with zinc oxide; and the zinc electrode is formed in-situ by electrodeposition of zinc onto the grid. For a current density of 20 mA/cm/sup 2/ in a Ni/Zn battery cycled at a 2-h rate and a zinc electrode with a porosity of 0.6 at the fully charged state, a current density of 338 mA/cm/sup 2/ was calculated to be that above which the passivation limits the utilization of the zinc electrode. 7 figures, 4 tables.

Electrochemical synthesis and characterization of zinc carbonate and zinc oxide nanoparticles

Science.gov (United States)

Pourmortazavi, Seied Mahdi; Marashianpour, Zahra; Karimi, Meisam Sadeghpour; Mohammad-Zadeh, Mohammad

2015-11-01

Zinc oxide and its precursor i.e., zinc carbonate is widely utilized in various fields of industry, especially in solar energy conversion, optical, and inorganic pigments. In this work, a facile and clean electrodeposition method was utilized for the synthesis of zinc carbonate nanoparticles. Also, zinc oxide nanoparticles were produced by calcination of the prepared zinc carbonate powder. Zinc carbonate nanoparticles with different sizes were electrodeposited by electrolysis of a zinc plate as anode in the solution of sodium carbonate. It was found that the particle size of zinc carbonate might be tuned by process parameters, i.e., electrolysis voltage, carbonate ion concentration, solvent composition and stirring rate of the electrolyte solution. An orthogonal array design was utilized to identify the optimum experimental conditions. The experimental results showed that the minimum size of the electrodeposited ZnCO3 particles is about 24 nm whereas the maximum particle size is around 40 nm. The TG-DSC studies of the nanoparticles indicated that the main thermal degradation of ZnCO3 occurs in two steps over the temperature ranges of 150-250 and 350-400 °C. The electrosynthesized ZnCO3 nanoparticles were calcined at the temperature of 600 °C to prepare ZnO nanoparticles. The prepared ZnCO3 and ZnO nanoparticles were characterized by SEM, X-ray diffraction (XRD), and FT-IR techniques.

An overview of zinc addition for BWR dose rate control

Energy Technology Data Exchange (ETDEWEB)

Marble, W.J. [GE Nuclear Energy, San Jose, CA (United States)

1995-03-01

This paper presents an overview of the BWRs employing feedwater zinc addition to reduce primary system dose rates. It identifies which BWRs are using zinc addition and reviews the mechanical injection and passive addition hardware currently being employed. The impact that zinc has on plant chemistry, including the factor of two to four reduction in reactor water Co-60 concentrations, is discussed. Dose rate results, showing the benefits of implementing zinc on either fresh piping surfaces or on pipes with existing films are reviewed. The advantages of using zinc that is isotopically enhanced by the depletion of the Zn-64 precursor to Zn-65 are identified.

Factors influencing chloride deposition in a coastal hilly area and application to chloride deposition mapping

Directory of Open Access Journals (Sweden)

H. Guan

2010-05-01

Full Text Available Chloride is commonly used as an environmental tracer for studying water flow and solute transport in the environment. It is especially useful for estimating groundwater recharge based on the commonly used chloride mass balance (CMB method. Strong spatial variability in chloride deposition in coastal areas is one difficulty encountered in appropriately applying the method. A high-resolution bulk chloride deposition map in the coastal region is thus needed. The aim of this study is to construct a chloride deposition map in the Mount Lofty Ranges (MLR, a coastal hilly area of approximately 9000 km² spatial extent in South Australia. We examined geographic (related to coastal distance, orographic, and atmospheric factors that may influence chloride deposition, using partial correlation and regression analyses. The results indicate that coastal distance, elevation, as well as terrain aspect and slope, appear to be significant factors controlling chloride deposition in the study area. Coastal distance accounts for 70% of spatial variability in bulk chloride deposition, with elevation, terrain aspect and slope an additional 15%. The results are incorporated into a de-trended residual kriging model (ASOADeK to produce a 1 km×1 km resolution bulk chloride deposition and concentration maps. The average uncertainty of the deposition map is about 20–30% in the western MLR, and 40–50% in the eastern MLR. The maps will form a useful basis for examining catchment chloride balance for the CMB application in the study area.

Effects of Foliar Application of Nano Zinc Chelate and Zinc Sulfate on Zinc Content, Pigments and Photosynthetic Indices of Holy Basil (Ocimum sanctum(

Directory of Open Access Journals (Sweden)

Zohreh Moghimi pour

2017-02-01

Full Text Available Introduction: Holy basil is a perennial plant belongs to Lamiaceae family. The plant is a perennial and thrives well in the hot and humid climate. Its aerial parts have been in use for food, pharmaceuticals, cosmetics and perfumery industries. Leaves contain 0.5-1.5% essential oil and main oil components are eugenol, methyl eugenol, carvacrol, methyl chavicol and1,8-cineole. A balanced fertilization program with macro and micronutrients is very important in producing high quality yield. Zinc is involved in IAA production, chlorophyll biosynthesis, carbon assimilation, saccharids accumulation, reactive oxygen radicals scavenging and finally carbon utilization in volatile oil biosynthesis. Material and methods: In order to evaluate the effect on zinc foliar application on zinc content of leaves, photosynthetic indices and pigments of holy basil, an experiment was carried out in 2013 at a research farm of Horticultural Science, Shahid Chamran University (31°20'N latitude and 48°40'E longitude and 22.5 m mean sea level, Ahvaz (Iran, a region characterized by semi-dry climate. The experiment was arranged based on Randomized Complete Block Design (RCBD with six treatments and three replications. The treatments were nano zinc chelate (0, 0.5, 1 and 1.5 g.l-1 and zinc sulfate (1 and 1.5 g.l-1 fertilizers. Land preparation includes disking and the formation of raising beds (15cm high and 45cm wide across the top using a press-pan-type bed shaper. Holy basil seeds were sown on two rows on each bed, with 15 cm in-row and 40 cm between-row spacing. The plants were irrigated weekly as needed. Foliar application of zinc fertilizers was done at six-eight leaf stage and were repeated with interval 15 days until full bloom stage. Zinc content, stomata conductance (gs, CO2 under stomata (Ci, transpiration rate (E, net photosynthesis (Pn, light use efficiency (LUE, water use efficiency (WUE and also chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoid

Zinc supplements for preventing otitis media.

Science.gov (United States)

Gulani, Anjana; Sachdev, Harshpal S

2014-06-29

Otitis media is inflammation of the middle ear and is usually caused by infection. It affects people of all ages but is particularly common in young children. Around 164 million people worldwide have long-term hearing loss caused by this condition, 90% of them in low-income countries. As zinc supplements prevent pneumonia in disadvantaged children, we wanted to investigate whether zinc supplements could also prevent otitis media. To evaluate whether zinc supplements prevent otitis media in adults and children of different ages. We searched CENTRAL (2014, Issue 1), MEDLINE (1950 to February week 4, 2014) and EMBASE (1974 to March 2014). Randomised, placebo-controlled trials of zinc supplements given at least once a week for at least a month for preventing otitis media. Two review authors independently assessed the eligibility and methodological quality of the included trials and extracted and analysed data. We summarised results using risk ratios (RRs) or rate ratios for dichotomous data and mean differences (MDs) for continuous data. We combined trial results where appropriate. No new trials were identified for inclusion in this update. We identified 12 trials for inclusion, 10 of which contributed outcomes data. There were a total of 6820 participants. In trials of healthy children living in low-income communities, two trials did not demonstrate a significant difference between the zinc-supplemented and placebo groups in the numbers of participants experiencing an episode of definite otitis media during follow-up (3191 participants); another trial showed a significantly lower incidence rate of otitis media in the zinc group (rate ratio 0.69, 95% confidence interval (CI) 0.61 to 0.79, n = 1621). A small trial of 39 infants undergoing treatment for severe malnutrition suggested a benefit of zinc for the mean number of episodes of otitis media (mean difference (MD) -1.12 episodes, 95% CI -2.21 to -0.03). Zinc supplements did not seem to cause any serious adverse

The relative efficiency of zinc carriers on growth and zinc nutrition of corn

International Nuclear Information System (INIS)

Prasad, B.; Sinha, K.

1981-01-01

A comparison of different zinc carriers showed that application of Zn-DTPA, Zn-EDTA, Zn-fulvate and ZnSO 4 significantly increased the dry matter yield and zinc uptake by corn over the control treatment where no zinc was applied. The chelates in particular enhanced to a greater extent the uptake of both native and applied sources than that observed with ZnSO 4 as the zinc carrier. Both the dry matter yield and zinc uptake by corn showed a positive and significant relationship with self-diffusion coefficient of zinc showing thereby that diffusion contributed mainly the supply of Zn from the ambient soil matrix to plant roots. The effectiveness of the chelates varied depending on their capacity to retain Zn in a soluble form in the soil solution. It is evident that zinc nutrition of plants in alkaline and calcareous soils can be more effectively regulated by both synthetic and natural chelates or organic manures which contain substantial amount of complexed zinc. (orig.)

Optimization of the lithium/thionyl chloride battery

Science.gov (United States)

White, Ralph E.

1989-01-01

A 1-D math model for the lithium/thionyl chloride primary cell is used in conjunction with a parameter estimation technique in order to estimate the electro-kinetic parameters of this electrochemical system. The electro-kinetic parameters include the anodic transfer coefficient and exchange current density of the lithium oxidation, alpha sub a,1 and i sub o,i,ref, the cathodic transfer coefficient and the effective exchange current density of the thionyl chloride reduction, alpha sub c,2 and a sup o i sub o,2,ref, and a morphology parameter, Xi. The parameter estimation is performed on simulated data first in order to gain confidence in the method. Data, reported in the literature, for a high rate discharge of an experimental lithium/thionyl chloride cell is used for an analysis.

21 CFR 184.1297 - Ferric chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferric chloride. 184.1297 Section 184.1297 Food and... Substances Affirmed as GRAS § 184.1297 Ferric chloride. (a) Ferric chloride (iron (III) chloride, FeC13, CAS Reg. No. 7705-08-0) may be prepared from iron and chlorine or from ferric oxide and hydrogen chloride...

Zinc triggers microglial activation.

Science.gov (United States)

Kauppinen, Tiina M; Higashi, Youichirou; Suh, Sang Won; Escartin, Carole; Nagasawa, Kazuki; Swanson, Raymond A

2008-05-28

Microglia are resident immune cells of the CNS. When stimulated by infection, tissue injury, or other signals, microglia assume an activated, "ameboid" morphology and release matrix metalloproteinases, reactive oxygen species, and other proinflammatory factors. This innate immune response augments host defenses, but it can also contribute to neuronal death. Zinc is released by neurons under several conditions in which microglial activation occurs, and zinc chelators can reduce neuronal death in animal models of cerebral ischemia and neurodegenerative disorders. Here, we show that zinc directly triggers microglial activation. Microglia transfected with a nuclear factor-kappaB (NF-kappaB) reporter gene showed a severalfold increase in NF-kappaB activity in response to 30 microm zinc. Cultured mouse microglia exposed to 15-30 microm zinc increased nitric oxide production, increased F4/80 expression, altered cytokine expression, and assumed the activated morphology. Zinc-induced microglial activation was blocked by inhibiting NADPH oxidase, poly(ADP-ribose) polymerase-1 (PARP-1), or NF-kappaB activation. Zinc injected directly into mouse brain induced microglial activation in wild-type mice, but not in mice genetically lacking PARP-1 or NADPH oxidase activity. Endogenous zinc release, induced by cerebral ischemia-reperfusion, likewise induced a robust microglial reaction, and this reaction was suppressed by the zinc chelator CaEDTA. Together, these results suggest that extracellular zinc triggers microglial activation through the sequential activation of NADPH oxidase, PARP-1, and NF-kappaB. These findings identify a novel trigger for microglial activation and a previously unrecognized mechanism by which zinc may contribute to neurological disorders.

Effects of dietary supplementation with tribasic zinc sulfate or zinc sulfate on growth performance, zinc content and expression of zinc transporters in young pigs.

Science.gov (United States)

Deng, Bo; Zhou, Xihong; Wu, Jie; Long, Ciming; Yao, Yajun; Peng, Hongxing; Wan, Dan; Wu, Xin

2017-10-01

An experiment was conducted to compare the effects of zinc sulfate (ZS) and tribasic zinc sulfate (TBZ) as sources of supplemental zinc on growth performance, serum zinc (Zn) content and messenger RNA (mRNA) expression of Zn transporters (ZnT1/ZnT2/ZnT5/ZIP4/DMT1) of young growing pigs. A total of 96 Duroc × Landrace × Yorkshire pigs were randomly allotted to two treatments and were fed a basal diet supplemented with 100 mg/kg Zn from either ZS or TBZ for 28 days. Feed : gain ratio in pigs fed TBZ were lower (P zinc transporter in either duodenum or jejunum of pigs fed TBZ were higher (P < 0.05) than pigs fed ZS. These results indicate that TBZ is more effective in serum Zn accumulation and intestinal Zn absorption, and might be a potential substitute for ZS in young growing pigs. © 2017 Japanese Society of Animal Science.

Availability of native and fertilizer zinc in some Indian soils: studies with 65Zinc

International Nuclear Information System (INIS)

Chaudhury, J.; Deb, D.L.

1979-01-01

Isotopically exchangeable zinc (Et values) was determined by different methods in some soils having pH(H 2 O) varying from 3.05 to 8.40 using 65 Zn. The Et values obtained using different extractants showed significant correlation with available zinc, organic carbon and soil pH. The recovery of applied zinc in the aqueous phase was less than one percent in most of the soils having pH higher than 7.0. Application of zinc with complexing agents like DTPA and EDTA increased the recovery of applied zinc in the solution to about 95 percent. Soil pH, organic C and DTPA extractable zinc showed significant relationship with the recovery of applied zinc under different treatments. Use of EDTA and DTPA extractants reduced the zinc buffering capacity of soil to a value less than one, irrespective of the initial pH of the soil, whereas the values were comparatively higher in presence of different levels of zinc carrier. (auth.)

65Zinc and endogenous zinc content and distribution in islets in relationship to insulin content

International Nuclear Information System (INIS)

Figlewicz, D.P.; Forhan, S.E.; Hodgson, A.T.; Grodsky, G.M.

1984-01-01

Uptake of 65 Zn and distribution of 65 Zn, total zinc, and insulin were measured in rat islets and islet granules under different conditions of islet culture. Specific activity of islet zinc ( 65 Zn/zinc) was less than 15% that of extracellular zinc even after 48 h. In contrast, once in the islet, 65 Zn approached 70% of equilibrium with granular zinc in 24 h and apparent equilibrium by 48 h. During a 24-h culture, at either high or low glucose, reduction of both islet zinc and insulin occurred. However, zinc depletion was greater than that predicted if zinc loss was proportional to insulin depletion and occurred only from the granular compartment, which represents only one third of the total islet zinc. Extension of culture to 48 h caused additional insulin depletion, but islet zinc was unchanged. Omission of calcium during the 48-h culture caused a predicted increase in insulin retention, presumably by inhibiting secretion; however, zinc retention was not increased proportionately. Pretreatment of rats with tolbutamide caused a massive depletion of insulin stored in isolated islets, with little change in total islet zinc; subsequent culture of these islets resulted in a greater loss of granular zinc than predicted from the small loss of granular insulin. None of the conditions tested affected the percentage of either 65 Zn or total zinc that was distributed in the islet granules. Results show that zinc exists in a metabolically labile islet compartment(s) as well as in secretory granules; and extra-granular zinc, although not directly associated with insulin storage, may act as a reservoir for granular zinc and may regulate insulin synthesis, storage, and secretion in ways as yet unknown

The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

Directory of Open Access Journals (Sweden)

Cuong D. Tran

2015-05-01

Full Text Available It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

The Potential for Zinc Stable Isotope Techniques and Modelling to Determine Optimal Zinc Supplementation

Science.gov (United States)

Tran, Cuong D.; Gopalsamy, Geetha L.; Mortimer, Elissa K.; Young, Graeme P.

2015-01-01

It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease. PMID:26035248

Effect of zinc from zinc sulfate on trace mineral concentrations of milk ...

African Journals Online (AJOL)

PRECIOUS

2009-11-16

Nov 16, 2009 ... It suggests that supplementation of ewes diet with zinc sulfate could be an effective way to increase zinc ... alkaline phosphates activity. Zinc supplements were .... Similar results have been reported previously when dairy cows.

Evolution of the zinc compound nanostructures in zinc acetate single-source solution

International Nuclear Information System (INIS)

Wang Ying; Li Yinhua; Zhou Zhengzhi; Zu Xihong; Deng Yulin

2011-01-01

A series of nanostructured zinc compounds with different nanostructures such as nanobelts, flake-like, flower-like, and twinning crystals was synthesized using zinc acetate (Zn(Ac) 2 ) as a single-source. The evolution of the zinc compounds from layered basic zinc acetate (LBZA) to bilayered basic zinc acetate (BLBZA) and twinned ZnO nano/microcrystal was studied. The low-angle X-ray diffraction spectra indicate the layered spacing is 1.34 and 2.1 nm for LBZA and BLBZA, respectively. The Fourier transform infrared (FTIR) spectra results confirmed that the bonding force of acetate anion with zinc cations decreases with the phase transformation from Zn(Ac) 2 to BLBZA, and finally to LBZA. The OH − groups gradually replaced the acetate groups coordinated to the matrix zinc cation, and the acetate groups were released completely. Finally, the Zn(OH) 2 and ZnO were formed at high temperature. The conversion process from Zn(Ac) 2 to ZnO with release of acetate anions can be described as Zn(Ac) 2 → BLBZA → LBZA → Zn(OH) 2 → ZnO.

Effects of dietary zinc status on seizure susceptibility and hippocampal zinc content in the El (epilepsy) mouse.

Science.gov (United States)

Fukahori, M; Itoh, M

1990-10-08

The effects of dietary zinc status on the development of convulsive seizures, and zinc concentrations in discrete hippocampal areas and other parts of the limbic system were studied in the El mouse model receiving zinc-adequate, zinc-deficient or zinc-loaded diets. Seizure susceptibility of the El mouse was increased by zinc deficiency, and decreased by zinc loading, while an adequate diet had no effect. Zinc loading was accompanied by a marked increase in hippocampal zinc content in the El mouse. Conversely, hippocampal zinc content declined in the El mouse fed a zinc-deficient diet. These results suggest that zinc may have a preventive effect on the development of seizures in the El mouse, and hippocampal zinc may play an important role in the pathophysiology of convulsive seizures of epilepsy.

Adhesion of Zinc Hot-dip Coatings

Directory of Open Access Journals (Sweden)

Michal Černý

2014-01-01

Full Text Available The work is focused on verification of quality adhesion of zinc coating. It describes elements which affect quality and adhesive solidity within the coating. For assessment itself it will be neccessary to get know the basic elements which can affect adhesion of hot-dip coating which will be essential for choosing suitable samples for verification itself. These elements characterise acoustic responses during delamination coating. They affect elements influencing progress of signal. In research there is also a summary of existing methods for testing adhesion of coatings. As a result a new proposal of a new method comes out for purpose of quality testing of adhesion zinc hot-dip coating. The results of verification of this method are put to scientific analysis and findings lead to assessment of proposed method and its application in technical practise.The goal of this contribution is also include to proposed methodology testing adhesion zinc coating by nondestructive diagnostic method of acoustic emission (AE, which would monitor characterise progress of coating delamination of hot-dip zinc from basic material in way to adhesion tests would be practicable in situ. It can be enabled by analysis and assessment of results acquired by method AE and its application within verification of new method of adhesion anti-corrosive zinc coating.

Index of refraction enhancement of calcite particles coated with zinc carbonate

Science.gov (United States)

Lattaud, Kathleen; Vilminot, Serge; Hirlimann, Charles; Parant, Hubert; Schoelkopf, Joachim; Gane, Patrick

2006-10-01

ZnCO 3 coating on calcite particles has been developed in order to enhance the index of refraction of this mineral that is used as a charge in paper, paint and polymer industries. Chemical reaction between calcite particles in an aqueous suspension with zinc chloride promotes the formation of a ZnCO 3 coating consisting of two layers with different interactions with the calcite particle. The refraction index of the resulting composite particles increases with the Zn/Ca ratio. A model allows to evaluate the coating thickness. The value of the scattering S and diffusion K coefficients of sheets coated with the ZnCO 3 coated particles reveal a dependence on the preparation conditions with a 15% increase for the best samples.

Dynamic electrochemical measurement of chloride ions

NARCIS (Netherlands)

Abbas, Yawar; de Graaf, Derk B.; Olthuis, Wouter; van den Berg, Albert

2016-01-01

This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver chloride electrode is used extensively for potentiometric measurement of chloride ions concentration in electrolyte. In this measurement,

Reaction of calcium chloride with alkali metal chlorides in melts

International Nuclear Information System (INIS)

Savin, V.D.; Mikhajlova, N.P.

1984-01-01

Thermochemical characteristics of CaCl 2 reaction with sodium, potassium, rubidium and cesium chlorides in melts at 890 deg C are determined. The values of formation enthalpies of infinitely diluted by CaCl 2 solutions (ΔH) in the chloride row increase from -22 in NaCl to -47 kJ/mol of CaCl 2 in CsCl. With increasing the concentration of calcium chloride in the solution the ΔH values decrease. The regularities of separation from the solution of the CaCl 2 -CsCl system at 890 deg C of the CaCl 2 x CsCl in solid are studied. Formation enthalpies under the given conditions constitutes -70+-3 kJ/mol

Intestinal absorption and excretion of zinc in streptozotocin-diabetic rats as affected by dietary zinc and protein

International Nuclear Information System (INIS)

Johnson, W.T.; Canfield, W.K.

1985-01-01

65 Zn was used to examine the effects of dietary zinc and protein on true zinc absorption and intestinal excretion of endogenous zinc by an isotope dilution technique in streptozotocin-diabetic and control rats. Four groups each of diabetic and control rats were fed diets containing 20 ppm Zn, 20% egg white protein (HMHP); 20 ppm Zn, 10% egg white protein (HMLP); 10 ppm Zn, 20% egg white protein (LMHP); and 10 ppm Zn, 10% egg white protein (LMLP). Measurement of zinc balance was begun 9 d after an i.m. injection of 65 Zn. True zinc absorption and the contribution of endogenous zinc to fecal zinc excretion were calculated from the isotopically labeled and unlabeled zinc in the feces, duodenum and kidney. Results from the isotope dilution study indicated that diabetic rats, but not control rats, absorbed more zinc from 20 ppm zinc diets than from 10ppm zinc diets and that all rats absorbed more zinc from 20% protein diets than from 10% protein diets. Furthermore, all rats excreted more endogenous zinc from their intestines when dietary zinc and protein levels resulted in greater zinc absorption. In diabetic and control rats, consuming equivalent amounts of zinc, the amount of zinc absorbed was not significantly different, but the amount of zinc excreted by the intestine was less in the diabetic rats. Decreased intestinal excretion of endogenous zinc may be a homeostatic response to the increased urinary excretion of endogenous zinc in the diabetic rats and may also lead to the elevated zinc concentrations observed in some organs of the diabetic rats

Synthesis and characterization of two new zinc(II) coordination polymers with bidentate flexible ligands: Formation of a 2D structure with (44.62)-sql topology

Science.gov (United States)

Lalegani, Arash; Khaledi Sardashti, Mohammad; Gajda, Roman; Woźniak, Krzysztof

2017-12-01

Zinc(II) coordination polymers [Zn(bip)2(NCS)2]n (1) and [Zn(μ-bbd)(N3)2]n (2) were synthesized by using the neutral flexible bidentate N-donor ligands 1,4-bis(3,5-dimethylpyrazolyl)butane (bbd) and 1,3-bis(imidazolyl)propane (bip), mono-anionic NCS- or N3-ligand and zinc(II) chloride salts. The results of the X-ray analyses demonstrate that in the structure of 1, the zinc(II) ion is located on an inversion center and exhibits an ZnN6 octahedral arrangement while, in the structure of 2, the zinc(II) ion adopts an ZnN4 tetrahedral geometry. In the polymer 1, the NCS groups are terminally N-bonded to the metal center and the each bip with anti-gauche conformation acts as bridging connecting four zinc(II) ions to form a two-dimensional network with a sql [point symbol (44.62)] topology while, in the polymer 1, the N3 groups are terminally bonded to the metal center and each bbd with anti-anti-anti conformation acts as bridging ligand connecting two zinc(II) ions to form a one-dimensional zig-zag chain. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. Thermal analyses of polymers were also presented.

Hair Zinc: an Index for Zinc Status in Under-Five Children from Low-Income Communities in Kanam Area of North-Central Nigeria.

Science.gov (United States)

Jaryum, Kiri H; Okoye, Zebulon Sunday C; Stoecker, Barbara

2018-06-01

Nutritional deficiencies of trace elements are among the top ten causes of death in Sub Saharan Africa. In Kanam Local Government Area of Nigeria, the problem is compounded by high levels of poverty and illiteracy. Abnormally low hair zinc levels are important, sensitive diagnostic biochemical indices of Zinc deficiency. The purpose of this study is to assess the zinc status of children less than 5 years in Kanam local government area, north-central Nigeria, by measuring the zinc level in hair samples collected from 44 under-5 children across the area. A household survey was made to assess the pattern and frequency of consumption of zinc-rich foods which was done by means of questionnaire. Hair samples were analysed for zinc content by the inductively coupled plasma-mass spectrophotometry (ICP-MS). The data were analysed statistically using the Student's t test, z test, and Pearson correlation, while questionnaire-captured data were analysed by simple arithmetic. The results of the analyses showed that the average hair zinc level was 74.35 ± 48.05 μg/g. This was below the normal range of 130-140 μg/g, for children less than 5 years. Based on the results, 86.36% have hair zinc level below the lower limit of the normal range of 130 μg/g. Between the gender, boys have higher hair zinc content than girls. Data from the questionnaire showed that 53.45% of the population studied have poor/inadequate intake of zinc-rich foods of animal origin, a dietary behaviour reported to predispose to micronutrient deficiency, including zinc.

Facile Preparation of Chloride-Conducting Membranes : First Step towards a Room-Temperature Solid-State Chloride-Ion Battery

NARCIS (Netherlands)

Gschwind, Fabienne; Steinle, Dominik; Sandbeck, Daniel; Schmidt, Celine; von Hauff, Elizabeth

2016-01-01

Three types of chloride-conducting membranes based on polyvinyl chloride, commercial gelatin, and polyvinyldifluoride-hexafluoropolymer are introduced in this report. The polymers are mixed with chloride-containing salts, such as tetrabutylammonium chloride, and cast to form membranes. We studied

The speciation of aqueous zinc(II) bromide solutions to 500 °C and 900 MPa determined using Raman spectroscopy

Science.gov (United States)

Mibe, Kenji; Chou, I-Ming; Anderson, Alan J.; Mayanovic, Robert A.; Bassett, William A.

2009-01-01

A Raman spectral study was carried out on 3 solutions of varying concentration and bromide/zinc ratios. Spectra were collected at 11 different temperature-pressure conditions ranging from ambient to 500????C-0.9??GPa. Raman band assignments for zinc(II) bromide species reported in previous studies were used to determine the relative concentrations of ZnBr42-, ZnBr3-, ZnBr2, and ZnBr+ species at various temperatures and pressures. Our results are in close agreement with X-ray absorption spectroscopic (XAS) data, and confirm that the tetrabromo zinc(II) complex, ZnBr42-, is the predominant species up to 500????C in solutions having high Zn concentrations (1??m) and high bromide/zinc molar ratios ([Br]/[Zn] = 8). In agreement with previous solubility and Raman spectroscopic experiments, our measurements indicate that species with a lower number of halide ligands and charge are favored with increasing temperature in dilute solutions, and solutions with low bromide/zinc ratios ([Br]/[Zn] Raman technique provides an independent experimental means of evaluating the quality of XAS analyses of data obtained from high temperature disordered systems. The combination of these two techniques provides complementary data on speciation and the structure of zinc(II) bromide complexes. The preponderance of the ZnBr42- species in highly saline brines at high temperature is consistent with the predominance of ZnCl42- in chloride-rich brines reported in previous XAS studies. Knowledge of Zn complexing in metal-rich highly saline brines is important for numerical models of ore deposition in high temperature systems such as skarns and porphyry-type deposits. ?? 2008 Elsevier B.V.

Chelators for investigating zinc metalloneurochemistry

OpenAIRE

Radford, Robert John; Lippard, Stephen J.

2013-01-01

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 o...

Fine structure study on low concentration zinc substituted hydroxyapatite nanoparticles

International Nuclear Information System (INIS)

Hu, Wei; Ma, Jun; Wang, Jianglin; Zhang, Shengmin

2012-01-01

The fine structure of zinc substituted hydroxyapatite was studied using experimental analysis and first-principles calculations. The synthetic hydroxyapatite nanoparticles containing low Zn concentration show rod-like morphology. The crystallite sizes and unit-cell volumes tended to decrease with the increased Zn concentration according to X-ray diffraction patterns. The Zn K-edge X-ray absorption spectra and fitting results suggest that the hydroxyapatite doped with 0.1 mole% zinc is different in the zinc coordination environments compared with that containing more zinc. The density function theory calculations were performed on zinc substituted hydroxyapatite. Two mechanisms included replacing calcium by zinc and inserting zinc along the hydroxyl column and were investigated, and the related substitution energies were calculated separately. It is found that the substitution energies are negative and lowest for inserting zinc between the two oxygen atoms along the hydroxyl column (c-axis). Combined with the spectral analysis, it is suggested that the inserting mechanism is favored for low concentration zinc substituted hydroxyapatite. Highlights: ► We investigate the fine structure of hydroxyapatite with low content of Zn. ► XANES spectra are similar but a little different at low zinc content. ► Zinc ions influence hydroxyapatite crystal formation and lattice parameters. ► Formation energies are calculated according to plane-wave density function theory. ► Low content of zinc prefers to locate at hydroxyl column in hydroxyapatite lattice.

Zinc and gastrointestinal disease

Institute of Scientific and Technical Information of China (English)

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

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.

Zinc species distribution in EDTA-extract residues of zinc-contaminated soil

International Nuclear Information System (INIS)

Chang, S.-H.; Wei, Y.-L.; Wang, H. Paul

2007-01-01

Soil sample from a site heavily contaminated with >10 wt.% zinc is sampled and extracted with aqueous solutions of ethylene diamine tetra-acetic acid (EDTA) that is a reagent frequently used to extract heavy metals in soil remediation. Three liquid/soil ratios (5/1, 20/1, and 100/1) were used in the extracting experiment. The molecular environment of the residual Zn in the EDTA-extract residues of zinc-contaminated soil is investigated with XANES technique. The results indicate that EDTA does not show considerable preference of chelating for any particular Zn species during the extraction. Zn species distribution in the sampled soil is found to resemble that in all EDTA-extract residues; Zn(OH) 2 is determined as the major zinc species (60-70%), seconded by organic zinc (21-26%) and zinc oxide (9-14%)

Innovative uses for zinc in dermatology.

Science.gov (United States)

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. Copyright 2010 Elsevier Inc. All rights reserved.

Combinatorial effects of zinc deficiency and arsenic exposure on zebrafish (Danio rerio development.

Directory of Open Access Journals (Sweden)

Laura M Beaver

Full Text Available Zinc deficiency and chronic low level exposures to inorganic arsenic in drinking water are both significant public health concerns that affect millions of people including pregnant women. These two conditions can co-exist in the human population but little is known about their interaction, and in particular, whether zinc deficiency sensitizes individuals to arsenic exposure and toxicity, especially during critical windows of development. To address this, we utilized the Danio rerio (zebrafish model to test the hypothesis that parental zinc deficiency sensitizes the developing embryo to low-concentration arsenic toxicity, leading to altered developmental outcomes. Adult zebrafish were fed defined zinc deficient and zinc adequate diets and were spawned resulting in zinc adequate and zinc deficient embryos. The embryos were treated with environmentally relevant concentrations of 0, 50, and 500 ppb arsenic. Arsenic exposure significantly reduced the amount of zinc in the developing embryo by ~7%. The combination of zinc deficiency and low-level arsenic exposures did not sensitize the developing embryo to increased developmental malformations or mortality. The combination did cause a 40% decline in physical activity of the embryos, and this decline was significantly greater than what was observed with zinc deficiency or arsenic exposure alone. Significant changes in RNA expression of genes that regulate zinc homeostasis, response to oxidative stress and insulin production (including zip1, znt7, nrf2, ogg1, pax4, and insa were found in zinc deficient, or zinc deficiency and arsenic exposed embryos. Overall, the data suggests that the combination of zinc deficiency and arsenic exposure has harmful effects on the developing embryo and may increase the risk for developing chronic diseases like diabetes.

Electrochemical chloride extraction of a beam polluted by chlorides after 40 years in the sea

OpenAIRE

BOUTEILLER, Véronique; LAPLAUD, André; MALOULA, Aurélie; MORELLE, René Stéphane; DUCHESNE, Béatrice; MORIN, Mathieu

2006-01-01

A beam element, naturally polluted by chlorides after 40 years of a marine tidal exposure, has been treated by electrochemical chloride extraction. The chloride profiles, before and after treatment, show that free chlorides are extrated with an efficiency of 70 % close to the steel, 50 % in the intermediate cover and only 5 % at the concrete surface. From the electrochemical characterizations (before, after, 1, 2 and 17 months after treatment), the steel potential values can, semehow, indicat...

Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

Science.gov (United States)

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

Sorption of sulphur dioxide in calcium chloride and nitrate chloride liquids

International Nuclear Information System (INIS)

Trzepierczynska, I.; Gostomczyk, M.A.

1989-01-01

Flue gas desulphurization via application of suspensions has one inherent disadvantage: fixation of sulphur dioxide is very poor. This should be attributed to the low content of calcium ions which results from the solubility of the sorbing species. The solubility of sparingly soluble salts (CaO, CaCO 3 ) may be increased by decreasing the pH of the solution; yet, there is a serious limitation in this method: the corrosivity of the scrubber. The objective of this paper was to assess the sorbing capacity of two soluble calcium salts, calcium chloride and calcium nitrate, as a function of calcium ion concentration in the range of 20 to 82 kg/m 3 . It has been found that sorbing capacity increases with the increasing calcium ion concentration until the calcium concentration in the calcium chloride solution reaches the level of 60 kg/m 3 which is equivalent to the chloride ion content of ∼ 110 kg/m 3 . Addition of calcium hydroxide to the solutions brings about an increase in the sorbing capacity up to 1.6 kg/m 3 and 2.2 kg/m 3 for calcium chloride and calcium nitrate, respectively, as a result of the increased sorbent alkalinity. The sorption capacity of the solutions is considerably enhanced by supplementing them by acetate ions (2.8 to 13.9 kg/m 3 ). Increase in the sorption capacity of calcium nitrate solutions enriched with calcium acetate was approximately 30% as high as that of the chloride solutions enriched with calcium acetate was approximately 30% as high as that of the chloride solutions supplemented in the same way. (author). 12 refs, 7 refs, 4 tabs

Sulfidation of zinc plating sludge with Na2S for zinc resource recovery

International Nuclear Information System (INIS)

Kuchar, D.; Fukuta, T.; Onyango, M.S.; Matsuda, H.

2006-01-01

A high amount of zinc disposed in the landfill sites as a mixed-metal plating sludge represents a valuable zinc source. To recover zinc from the plating sludge, a sulfidation treatment is proposed in this study, while it is assumed that ZnS formed could be separated by flotation. The sulfidation treatment was conducted by contacting simulated zinc plating sludge with Na 2 S solution at S 2- to Zn 2+ molar ratio of 1.5 for a period of 1-48 h, while changing the solid to liquid (S:L) ratio from 0.25:50 to 1.00:50. The conversion of zinc compounds to ZnS was determined based on the consumption of sulfide ions. The reaction products formed by the sulfidation of zinc were identified by X-ray diffraction (XRD). As a result, it was found that the conversion of zinc compounds to ZnS increased with an increase in S:L ratio. A maximum conversion of 0.809 was obtained at an S:L ratio of 1.00:50 after 48 h. However, when the zinc sludge treated at S:L ratio of 1.00:50 for 48 h was subjected to XRD analyses, only ZnS was identified in the treated zinc sludge. The result suggested that the rest of zinc sludge remained unreacted inside the agglomerates of ZnS. The formation behavior of ZnS was predicted by Elovich equation, which was found to describe the system satisfactorily indicating the heterogeneous nature of the sludge

Zinc, nickel, and cobalt ions removal from aqueous solution and plating plant wastewater by modified Aspergillus flavus biomass: A dataset

Directory of Open Access Journals (Sweden)

Rauf Foroutan

2017-06-01

Full Text Available The biomass of Aspergillus flavus was modified by calcium chloride to achieve a bioadsorbent for treating nickel, cobalt, and zinc ions from aqueous solutions. The information of pH, bioadsorbent dose, contact time, and temperature effect on the removal efficiency are presented. The data of Freundlich and Langmuir isotherm and pseudo-first-order and pseudo-second-order kinetic models are also depicted. The data showed that the maximum bioadsorption capacity of nickel, cobalt, and zinc ions is 32.26, 31.06 and 27.86 mg/g, respectively. The suitability of the bioadsorbent in heavy metals removal at field condition was tested with a real wastewater sample collected from a plating plant in the final part of this dataset. Based on the findings, the bioadsorbent was shown to be an affordable alternative for the removal of metals in the wastewater.

Zinc Is Indispensable in Exercise-Induced Cardioprotection against Intermittent Hypoxia-Induced Left Ventricular Function Impairment in Rats.

Directory of Open Access Journals (Sweden)

Tsung-I Chen

Full Text Available In obstructive sleep apnea (OSA, recurrent obstruction of the upper airway leads to intermittent hypoxia (IH during sleep, which can result in impairment of cardiac function. Although exercise can have beneficial effects against IH-induced cardiac dysfunction, the mechanism remains unclear. This study aimed to investigate the interactions of zinc and exercise on IH-triggered left ventricular dysfunction in a rat model that mimics IH in OSA patients. Nine-week-old male Sprague-Dawley rats were randomly assigned to either a control group (CON or to a group receiving 10 weeks of exercise training (EXE. During weeks 9 and 10, half the rats in each group were subjected to IH for 8 h per day for 14 days (IHCON, IHEXE, whereas the remainder continued to breathe room air. Rats within each of the CON, IHCON, EXE, and IHEXE groups were further randomly assigned to receive intraperitoneal injections of either zinc chloride, the zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl ethylenediamine (TPEN, or injection vehicle only. IH induced a lower left ventricular fractional shortening, reduced ejection fraction, higher myocardial levels of inflammatory factors, increased levels oxidative stress, and lower levels of antioxidative capacity, all of which were abolished by zinc treatment. IHEXE rats exhibited higher levels of cardiac function and antioxidant capacity and lower levels of inflammatory factors and oxidative stress than IHCON rats; however, IHEXE rats receiving TPEN did not exhibit these better outcomes. In conclusion, zinc is required for protecting against IH-induced LV functional impairment and likely plays a critical role in exercise-induced cardioprotection by exerting a dual antioxidant and anti-inflammatory effect.

Zinc Is Indispensable in Exercise-Induced Cardioprotection against Intermittent Hypoxia-Induced Left Ventricular Function Impairment in Rats

Science.gov (United States)

Chen, Michael Yu-Chih

2016-01-01

In obstructive sleep apnea (OSA), recurrent obstruction of the upper airway leads to intermittent hypoxia (IH) during sleep, which can result in impairment of cardiac function. Although exercise can have beneficial effects against IH-induced cardiac dysfunction, the mechanism remains unclear. This study aimed to investigate the interactions of zinc and exercise on IH-triggered left ventricular dysfunction in a rat model that mimics IH in OSA patients. Nine-week-old male Sprague-Dawley rats were randomly assigned to either a control group (CON) or to a group receiving 10 weeks of exercise training (EXE). During weeks 9 and 10, half the rats in each group were subjected to IH for 8 h per day for 14 days (IHCON, IHEXE), whereas the remainder continued to breathe room air. Rats within each of the CON, IHCON, EXE, and IHEXE groups were further randomly assigned to receive intraperitoneal injections of either zinc chloride, the zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), or injection vehicle only. IH induced a lower left ventricular fractional shortening, reduced ejection fraction, higher myocardial levels of inflammatory factors, increased levels oxidative stress, and lower levels of antioxidative capacity, all of which were abolished by zinc treatment. IHEXE rats exhibited higher levels of cardiac function and antioxidant capacity and lower levels of inflammatory factors and oxidative stress than IHCON rats; however, IHEXE rats receiving TPEN did not exhibit these better outcomes. In conclusion, zinc is required for protecting against IH-induced LV functional impairment and likely plays a critical role in exercise-induced cardioprotection by exerting a dual antioxidant and anti-inflammatory effect. PMID:27977796

21 CFR 173.375 - Cetylpyridinium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cetylpyridinium chloride. 173.375 Section 173.375... CONSUMPTION Specific Usage Additives § 173.375 Cetylpyridinium chloride. Cetylpyridinium chloride (CAS Reg. No....1666 of this chapter, at a concentration of 1.5 times that of cetylpyridinium chloride. (c) The...

21 CFR 184.1622 - Potassium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium chloride. 184.1622 Section 184.1622 Food... Specific Substances Affirmed as GRAS § 184.1622 Potassium chloride. (a) Potassium chloride (KCl, CAS Reg... levels not to exceed current good manufacturing practice. Potassium chloride may be used in infant...

Temperature dependence of diffusion coefficients of trivalent uranium ions in chloride and chloride-fluoride melts

International Nuclear Information System (INIS)

Komarov, V.E.; Borodina, N.P.

1981-01-01

Diffusion coefficients of U 3+ ions are measured by chronopotentiometric method in chloride 3LiCl-2KCl and in mixed chloride fluoride 3LiCl(LiF)-2KCl melts in the temperature range 633-1235 K. It is shown It is shown that experimental values of diffusion-coefficients are approximated in a direct line in lg D-1/T coordinate in chloride melt in the whole temperature range and in chloride-fluoride melt in the range of 644-1040 K. Experimental values of diffusion coefficients diviate from Arrhenius equation in the direction of large values in chloride-fluoride melt at further increase of temperature up to 1235 K. Possible causes of such a diviation are considered [ru

Zinc: a multipurpose trace element

Energy Technology Data Exchange (ETDEWEB)

Stefanidou, M.; Maravelias, C.; Dona, A.; Spiliopoulou, C. [University of Athens, Department of Forensic Medicine and Toxicology, Athens (Greece)

2006-01-01

Zinc (Zn) is one of the most important trace elements in the body and it is essential as a catalytic, structural and regulatory ion. It is involved in homeostasis, in immune responses, in oxidative stress, in apoptosis and in ageing. Zinc-binding proteins (metallothioneins, MTs), are protective in situations of stress and in situations of exposure to toxic metals, infections and low Zn nutrition. Metallothioneins play a key role in Zn-related cell homeostasis due to their high affinity for Zn, which is in turn relevant against oxidative stress and immune responses, including natural killer (NK) cell activity and ageing, since NK activity and Zn ion bioavailability decrease in ageing. Physiological supplementation of Zn in ageing and in age-related degenerative diseases corrects immune defects, reduces infection relapse and prevents ageing. Zinc is not stored in the body and excess intakes result in reduced absorption and increased excretion. Nevertheless, there are cases of acute and chronic Zn poisoning. (orig.)

Silver-zinc: status of technology and applications

Energy Technology Data Exchange (ETDEWEB)

Karpinski, A.P.; Makovetski, B.; Russell, S.J.; Serenyi, J.R.; Williams, D.C. [Yardney Technical Products, Pawcatuck, CT (United States)

1999-07-01

Michel Yardney and Professor Henri Andre 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

Range-extending Zinc-air battery for electric vehicle

Directory of Open Access Journals (Sweden)

Steven B. Sherman

2018-01-01

Full Text Available A vehicle model is used to evaluate a novel powertrain that is comprised of a dual energy storage system (Dual ESS. The system includes two battery packs with different chemistries and the necessary electronic controls to facilitate their coordination and optimization. Here, a lithium-ion battery pack is used as the primary pack and a Zinc-air battery as the secondary or range-extending pack. Zinc-air batteries are usually considered unsuitable for use in vehicles due to their poor cycle life, but the model demonstrates the feasibility of this technology with an appropriate control strategy, with limited cycling of the range extender pack. The battery pack sizes and the battery control strategy are configured to optimize range, cost and longevity. In simulation the vehicle performance compares favourably to a similar vehicle with a single energy storage system (Single ESS powertrain, travelling up to 75 km further under test conditions. The simulation demonstrates that the Zinc-air battery pack need only cycle 100 times to enjoy a ten-year lifespan. The Zinc-air battery model is based on leading Zinc-air battery research from literature, with some assumptions regarding achievable improvements. Having such a model clarifies the performance requirements of Zinc-air cells and improves the research community's ability to set performance targets for Zinc-air cells.

Iron and zinc concentrations and 59Fe retention in developing fetuses of zinc-deficient rats

International Nuclear Information System (INIS)

Rogers, J.M.; Loennerdal, B.H.; Hurley, L.S.; Keen, C.L.

1987-01-01

Because disturbances in iron metabolism might contribute to the teratogenicity of zinc deficiency, we examined the effect of zinc deficiency on fetal iron accumulation and maternal and fetal retention of 59 Fe. Pregnant rats were fed from mating a purified diet containing 0.5, 4.5 or 100 micrograms Zn/g. Laparotomies were performed on d 12, 16, 19 and 21 of gestation. Maternal blood and concepti were analyzed for zinc and iron. Additional groups of dams fed 0.5 or 100 micrograms Zn/g diet were gavaged on d 19 with a diet containing 59 Fe. Six hours later maternal blood and tissues, fetuses and placentas were counted for 59 Fe. Maternal plasma zinc, but not iron, concentration was affected by zinc deficiency on d 12. Embryo zinc concentration on d 12 increased with increasing maternal dietary zinc, whereas iron concentration was not different among groups. On d 16-21 plasma iron was higher in dams fed 0.5 micrograms Zn/g diet than in those fed 4.5 or 100 micrograms/g, whereas plasma zinc was lower in dams fed 0.5 or 4.5 micrograms Zn/g than in those fed 100 micrograms Zn/g diet. On d 19 zinc concentration in fetuses from dams fed 0.5 micrograms/g zinc was not different from that of those fed 4.5 micrograms/g zinc, and iron concentration was higher in the 0.5 microgram Zn/g diet group. The increase in iron concentration in zinc-deficient fetuses thus occurs too late to be involved in major structural teratogenesis. Although whole blood concentration of 59 Fe was not different in zinc-deficient and control dams, zinc-deficient dams had more 59 Fe in the plasma fraction

Elicitation threshold of cobalt chloride

DEFF Research Database (Denmark)

Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage

2016-01-01

: On the basis of five included studies, the ED10 values of aqueous cobalt chloride ranged between 0.0663 and 1.95 µg cobalt/cm(2), corresponding to 30.8-259 ppm. CONCLUSIONS: Our analysis provides an overview of the doses of cobalt that are required to elicit allergic cobalt contactdermatitis in sensitized...

Chloroquine is a zinc ionophore.

Directory of Open Access Journals (Sweden)

Jing Xue

Full Text Available Chloroquine is an established antimalarial agent that has been recently tested in clinical trials for its anticancer activity. The favorable effect of chloroquine appears to be due to its ability to sensitize cancerous cells to chemotherapy, radiation therapy, and induce apoptosis. The present study investigated the interaction of zinc ions with chloroquine in a human ovarian cancer cell line (A2780. Chloroquine enhanced zinc uptake by A2780 cells in a concentration-dependent manner, as assayed using a fluorescent zinc probe. This enhancement was attenuated by TPEN, a high affinity metal-binding compound, indicating the specificity of the zinc uptake. Furthermore, addition of copper or iron ions had no effect on chloroquine-induced zinc uptake. Fluorescent microscopic examination of intracellular zinc distribution demonstrated that free zinc ions are more concentrated in the lysosomes after addition of chloroquine, which is consistent with previous reports showing that chloroquine inhibits lysosome function. The combination of chloroquine with zinc enhanced chloroquine's cytotoxicity and induced apoptosis in A2780 cells. Thus chloroquine is a zinc ionophore, a property that may contribute to chloroquine's anticancer activity.

[Advances in the research of zinc deficiency and zinc supplementation treatment in patients with severe burns].

Science.gov (United States)

Wang, X X; Zhang, M J; Li, X B

2018-01-20

Zinc is one of the essential trace elements in human body, which plays an important role in regulating acute inflammatory response, glucose metabolism, anti-oxidation, immune and gastrointestinal function of patients with severe burns. Patients with severe burns may suffer from zinc deficiency because of insufficient amount of zinc intake from the diet and a large amount of zinc lose through wounds and urine. Zinc deficiency may affect their wound healing process and prognosis. This article reviews the characteristics of zinc metabolism in patients with severe burns through dynamic monitoring the plasma and urinary concentration of zinc. An adequate dosage of zinc supplemented to patients with severe burns by an appropriate method can increase the level of zinc in plasma and skin tissue and improve wound healing, as well as reduce the infection rates and mortality. At the same time, it is important to observe the symptoms and signs of nausea, dizziness, leukopenia and arrhythmia in patients with severe burns after supplementing excessive zinc.

Systematic review of zinc biochemical indicators and risk of coronary heart ‎disease

Directory of Open Access Journals (Sweden)

Maryam Hashemian

2015-11-01

Full Text Available BACKGROUND: Poor zinc nutritional status is suspected as a risk factor for coronary heart disease (CHD. Since zinc absorption may be influenced by some nutritional and physiologic factors, it would be better to investigate zinc status through biochemical measurements. The objective of the present study was to review recent studies investigating the association of zinc biomarkers with CHD, systematically. METHODS: The MEDLINE database was used for relevant studies published from January 2009 to December 2013 with appropriate keywords. Articles were included in this study if they were human studies, original articles, and published in English. RESULTS: Six case-control studies and two prospective cohort studies that measured zinc biomarkers were included in the study. Almost all case-control studies suggest that decreased plasma zinc was associated with increased CHD risk. Cohort studies did not support this relationship. CONCLUSION: The majority of the evidence for this theory is extracted from case-control studies, which might have bias. Prospective studies and randomized clinical trials are needed to investigate whether poor zinc status is associated with increased CHD risk. Consequently, a protective role of zinc in CHD could not be still established. 

21 CFR 184.1138 - Ammonium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ammonium chloride. 184.1138 Section 184.1138 Food... Specific Substances Affirmed as GRAS § 184.1138 Ammonium chloride. (a) Ammonium chloride (NH4Cl, CAS Reg. No. 12125-02-9) is produced by the reaction of sodium chloride and an ammonium salt in solution. The...

21 CFR 184.1426 - Magnesium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium chloride. 184.1426 Section 184.1426 Food... Specific Substances Affirmed as GRAS § 184.1426 Magnesium chloride. (a) Magnesium chloride (MgC12·6H2O, CAS... hydrochloric acid solution and crystallizing out magnesium chloride hexahydrate. (b) The ingredient meets the...

A multi-platform metabolomics approach demonstrates changes in energy metabolism and the transsulfuration pathway in Chironomus tepperi following exposure to zinc

International Nuclear Information System (INIS)

Long, Sara M.; Tull, Dedreia L.; Jeppe, Katherine J.; De Souza, David P.; Dayalan, Saravanan; Pettigrove, Vincent J.; McConville, Malcolm J.; Hoffmann, Ary A.

2015-01-01

Highlights: • An integrated metabolomics approach was applied to examine zinc exposure in midges. • Changes in carbohydrate and energy metabolism were observed using GC–MS. • Transsulfuration pathway is affected by zinc exposure. • Heavy metals other than zinc affect the transsulfuration pathways differently. - Abstract: Measuring biological responses in resident biota is a commonly used approach to monitoring polluted habitats. The challenge is to choose sensitive and, ideally, stressor-specific endpoints that reflect the responses of the ecosystem. Metabolomics is a potentially useful approach for identifying sensitive and consistent responses since it provides a holistic view to understanding the effects of exposure to chemicals upon the physiological functioning of organisms. In this study, we exposed the aquatic non-biting midge, Chironomus tepperi, to two concentrations of zinc chloride and measured global changes in polar metabolite levels using an untargeted gas chromatography–mass spectrometry (GC–MS) analysis and a targeted liquid chromatography–mass spectrometry (LC–MS) analysis of amine-containing metabolites. These data were correlated with changes in the expression of a number of target genes. Zinc exposure resulted in a reduction in levels of intermediates in carbohydrate metabolism (i.e., glucose 6-phosphate, fructose 6-phosphate and disaccharides) and an increase in a number of TCA cycle intermediates. Zinc exposure also resulted in decreases in concentrations of the amine containing metabolites, lanthionine, methionine and cystathionine, and an increase in metallothionein gene expression. Methionine and cystathionine are intermediates in the transsulfuration pathway which is involved in the conversion of methionine to cysteine. These responses provide an understanding of the pathways affected by zinc toxicity, and how these effects are different to other heavy metals such as cadmium and copper. The use of complementary

A multi-platform metabolomics approach demonstrates changes in energy metabolism and the transsulfuration pathway in Chironomus tepperi following exposure to zinc

Energy Technology Data Exchange (ETDEWEB)

Long, Sara M., E-mail: hoskins@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Tull, Dedreia L., E-mail: dedreia@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Jeppe, Katherine J., E-mail: k.jeppe@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); De Souza, David P., E-mail: desouzad@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Dayalan, Saravanan, E-mail: sdayalan@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Pettigrove, Vincent J., E-mail: vpet@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, The University of Melbourne, 3010 (Australia); McConville, Malcolm J., E-mail: malcolmm@unimelb.edu.au [Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, 30 Flemington Road, Parkville, 3052 (Australia); Hoffmann, Ary A., E-mail: ary@unimelb.edu.au [Centre for Aquatic Pollution, Identification and Management (CAPIM), School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia); School of BioSciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 30 Flemington Road, Parkville, 3052 (Australia)

2015-05-15

Highlights: • An integrated metabolomics approach was applied to examine zinc exposure in midges. • Changes in carbohydrate and energy metabolism were observed using GC–MS. • Transsulfuration pathway is affected by zinc exposure. • Heavy metals other than zinc affect the transsulfuration pathways differently. - Abstract: Measuring biological responses in resident biota is a commonly used approach to monitoring polluted habitats. The challenge is to choose sensitive and, ideally, stressor-specific endpoints that reflect the responses of the ecosystem. Metabolomics is a potentially useful approach for identifying sensitive and consistent responses since it provides a holistic view to understanding the effects of exposure to chemicals upon the physiological functioning of organisms. In this study, we exposed the aquatic non-biting midge, Chironomus tepperi, to two concentrations of zinc chloride and measured global changes in polar metabolite levels using an untargeted gas chromatography–mass spectrometry (GC–MS) analysis and a targeted liquid chromatography–mass spectrometry (LC–MS) analysis of amine-containing metabolites. These data were correlated with changes in the expression of a number of target genes. Zinc exposure resulted in a reduction in levels of intermediates in carbohydrate metabolism (i.e., glucose 6-phosphate, fructose 6-phosphate and disaccharides) and an increase in a number of TCA cycle intermediates. Zinc exposure also resulted in decreases in concentrations of the amine containing metabolites, lanthionine, methionine and cystathionine, and an increase in metallothionein gene expression. Methionine and cystathionine are intermediates in the transsulfuration pathway which is involved in the conversion of methionine to cysteine. These responses provide an understanding of the pathways affected by zinc toxicity, and how these effects are different to other heavy metals such as cadmium and copper. The use of complementary

Zinc hexacyanoferrate film as an effective protecting layer in two-step and one-step electropolymerization of pyrrole on zinc substrate

Energy Technology Data Exchange (ETDEWEB)

Pournaghi-Azar, M.H. [Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)]. E-mail: pournaghiazar@tabrizu.ac.ir; Nahalparvari, H. [Electroanalytical Chemistry Laboratory, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

2005-03-15

The two-step and one-step electrosynthesis processes of polypyrrole (PPy) films on the zinc substrate are described. The two-step process includes (i) the zinc surface pretreatment with hexacyanoferrate ion in the aqueous medium in order to form a zinc hexacyanoferrate (ZnHCF) film non-blocking passive layer on the surface and with the view to prevent its reactivity and (ii) electropolymerization of pyrrole on the ZnHCF vertical bar Zn-modified electrode in aqueous pyrrole solution. In this context, both the non-electrolytic and electrolytic procedures were adapted, and the effect of some experimental conditions such as supporting electrolyte, pH and temperature of the solution at the zinc surface pretreatment step as well as pyrrole concentration and electrochemical techniques at the polymerization step was investigated. By optimizing the experimental conditions in both steps, we have obtained a homogeneous and strongly adherent PPy films on the zinc substrate. The one-step process is based on the use of an aqueous medium containing Fe(CN){sub 6}{sup 4-} and pyrrole. The ferrocyanide ion passivates the substrate by formation of ZnHCF film during the electropolymerization process of pyrrole and therefore makes it possible to obtain strongly adherent PPy films, with controlled thickness, either by cyclic voltammetry or by electrolysis at constant current or constant potential without any previously treatment of the zinc electrode surface. The polypyrrole films deposited on the zinc electrode were characterized by cyclic voltammetry and scanning electron microscopic (SEM) measurement.

Zinc hexacyanoferrate film as an effective protecting layer in two-step and one-step electropolymerization of pyrrole on zinc substrate

International Nuclear Information System (INIS)

Pournaghi-Azar, M.H.; Nahalparvari, H.

2005-01-01

The two-step and one-step electrosynthesis processes of polypyrrole (PPy) films on the zinc substrate are described. The two-step process includes (i) the zinc surface pretreatment with hexacyanoferrate ion in the aqueous medium in order to form a zinc hexacyanoferrate (ZnHCF) film non-blocking passive layer on the surface and with the view to prevent its reactivity and (ii) electropolymerization of pyrrole on the ZnHCF vertical bar Zn-modified electrode in aqueous pyrrole solution. In this context, both the non-electrolytic and electrolytic procedures were adapted, and the effect of some experimental conditions such as supporting electrolyte, pH and temperature of the solution at the zinc surface pretreatment step as well as pyrrole concentration and electrochemical techniques at the polymerization step was investigated. By optimizing the experimental conditions in both steps, we have obtained a homogeneous and strongly adherent PPy films on the zinc substrate. The one-step process is based on the use of an aqueous medium containing Fe(CN) 6 4- and pyrrole. The ferrocyanide ion passivates the substrate by formation of ZnHCF film during the electropolymerization process of pyrrole and therefore makes it possible to obtain strongly adherent PPy films, with controlled thickness, either by cyclic voltammetry or by electrolysis at constant current or constant potential without any previously treatment of the zinc electrode surface. The polypyrrole films deposited on the zinc electrode were characterized by cyclic voltammetry and scanning electron microscopic (SEM) measurement

Removal of chloride from MSWI fly ash.

Science.gov (United States)

Chen, Wei-Sheng; Chang, Fang-Chih; Shen, Yun-Hwei; Tsai, Min-Shing; Ko, Chun-Han

2012-10-30

The high levels of alkali chloride and soluble metal salts present in MSWI fly ash is worth noting for their impact on the environment. In addition, the recycling or reuse of fly ash has become an issue because of limited landfill space. The chloride content in fly ash limits its application as basis for construction materials. Water-soluble chlorides such as potassium chloride (KCl), sodium chloride (NaCl), and calcium chloride hydrate (CaCl(2) · 2H(2)O) in fly ash are easily washed away. However, calcium chloride hydroxide (Ca(OH)Cl) might not be easy to leach away at room temperature. The roasting and washing-flushing processes were applied to remove chloride content in this study. Additionally, air and CO(2) were introduced into the washing process to neutralize the hazardous nature of chlorides. In comparison with the water flushing process, the roasting process is more efficient in reducing the process of solid-liquid separation and drying for the reuse of Cl-removed fly ash particles. In several roasting experiments, the removal of chloride content from fly ash at 1050°C for 3h showed the best results (83% chloride removal efficiency). At a solid to liquid ratio of 1:10 the water-flushing process can almost totally remove water-soluble chloride (97% chloride removal efficiency). Analyses of mineralogical change also prove the efficiency of the fly ash roasting and washing mechanisms for chloride removal. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of chloride, sulfate and natural organic matter (NOM) on the accumulation and release of trace-level inorganic contaminants from corroding iron.

Science.gov (United States)

Peng, Ching-Yu; Ferguson, John F; Korshin, Gregory V

2013-09-15

This study examined effects of varying levels of anions (chloride and sulfate) and natural organic matter (NOM) on iron release from and accumulation of inorganic contaminants in corrosion scales formed on iron coupons exposed to drinking water. Changes of concentrations of sulfate and chloride were observed to affect iron release and, in lesser extent, the retention of representative inorganic contaminants (vanadium, chromium, nickel, copper, zinc, arsenic, cadmium, lead and uranium); but, effects of NOM were more pronounced. DOC concentration of 1 mg/L caused iron release to increase, with average soluble and total iron concentrations being four and two times, respectively, higher than those in the absence of NOM. In the presence of NOM, the retention of inorganic contaminants by corrosion scales was reduced. This was especially prominent for lead, vanadium, chromium and copper whose retention by the scales decreased from >80% in the absence of NOM to chloride levels. Modeling indicated that the observed effects were associated with the formation of metal-NOM complexes and effects of NOM on the sorption of the inorganic contaminants on solid phases that are typical for iron corrosion in drinking water. Copyright © 2013 Elsevier Ltd. All rights reserved.

Antibacterial activity of zinc oxide-coated nanoporous alumina

Energy Technology Data Exchange (ETDEWEB)

Skoog, S.A. [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Bayati, M.R. [Department of Materials Science and Engineering, North Carolina State University, Box 7907, Raleigh, NC 27695-7907 (United States); Petrochenko, P.E. [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Division of Biology, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993 (United States); Stafslien, S.; Daniels, J.; Cilz, N. [Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102 (United States); Comstock, D.J.; Elam, J.W. [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Narayan, R.J., E-mail: roger_narayan@msn.com [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Department of Materials Science and Engineering, North Carolina State University, Box 7907, Raleigh, NC 27695-7907 (United States)

2012-07-25

Highlights: Black-Right-Pointing-Pointer Atomic layer deposition was used to deposit ZnO on nanoporous alumina membranes. Black-Right-Pointing-Pointer Scanning electron microscopy showed continuous coatings of zinc oxide nanocrystals. Black-Right-Pointing-Pointer Activity against B. subtilis, E. coli, S. aureus, and S. epidermidis was shown. - Abstract: Nanoporous alumina membranes, also known as anodized aluminum oxide membranes, are being investigated for use in treatment of burn injuries and other skin wounds. In this study, atomic layer deposition was used for coating the surfaces of nanoporous alumina membranes with zinc oxide. Agar diffusion assays were used to show activity of zinc oxide-coated nanoporous alumina membranes against several bacteria found on the skin surface, including Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis. On the other hand, zinc oxide-coated nanoporous alumina membranes did not show activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Candida albicans. These results suggest that zinc oxide-coated nanoporous alumina membranes have activity against some Gram-positive and Gram-negative bacteria that are associated with skin colonization and skin infection.

21 CFR 184.1193 - Calcium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium chloride. 184.1193 Section 184.1193 Food... Specific Substances Affirmed as GRAS § 184.1193 Calcium chloride. (a) Calcium chloride (CaCl2·2H2O, CAS Reg. No. 10035-04-8) or anhydrous calcium chloride (CaCl2, CAS Reg. No. 10043-52-4) may be commercially...

Zinc bioavailability in the chick

International Nuclear Information System (INIS)

Hempe, J.M.

1987-01-01

Methods for assessing zinc bioavailability were evaluated in the chick. A low-zinc chick diet was developed using rehydrated, spray-dried egg white autoclaved at 121 C for 30 min as the primary protein source. The relative bioavailability of zinc from soy flour and beef was determined by whole-body retention of extrinsic 65 Zn, and in slope ratio assays for growth rate and tissue zinc. Compared to zinc carbonate added to an egg white-based diet, all methods gave similar estimates of approximately 100% zinc bioavailability for beef but estimates for soy flour varied widely. The slope ratio assay for growth rate gave the best estimate of zinc bioavailability for soy flour. True absorption, as measured by percent isotope retention from extrinsically labeled soy flour, was 47%

Determination of chloride in MOX samples using chloride ion selective electrode

Energy Technology Data Exchange (ETDEWEB)

Govindan, R; Das, D K; Mallik, G K; Sumathi, A; Patil, Sangeeta; Raul, Seema; Bhargava, V K; Kamath, H S [Bhabha Atomic Research Centre, Tarapur (India). Advanced Fuel Fabrication Facility

1997-09-01

The chloride present in the MOX fuel is separated from the matrix by pyrohydrolysis at a temperature of 950 {+-} 50 degC and is then analyzed by chloride ion selective electrode (Cl-ISE). The range covered is 0.4-4 ppm with a precision of better than {+-}5% R.S.D. (author). 4 refs., 1 tab.

Zinc and zinc transporters in macrophages and their roles in efferocytosis in COPD.

Directory of Open Access Journals (Sweden)

Rhys Hamon

Full Text Available Our previous studies have shown that nutritional zinc restriction exacerbates airway inflammation accompanied by an increase in caspase-3 activation and an accumulation of apoptotic epithelial cells in the bronchioles of the mice. Normally, apoptotic cells are rapidly cleared by macrophage efferocytosis, limiting any secondary necrosis and inflammation. We therefore hypothesized that zinc deficiency is not only pro-apoptotic but also impairs macrophage efferocytosis. Impaired efferocytic clearance of apoptotic epithelial cells by alveolar macrophages occurs in chronic obstructive pulmonary disease (COPD, cigarette-smoking and other lung inflammatory diseases. We now show that zinc is a factor in impaired macrophage efferocytosis in COPD. Concentrations of zinc were significantly reduced in the supernatant of bronchoalveolar lavage fluid of patients with COPD who were current smokers, compared to healthy controls, smokers or COPD patients not actively smoking. Lavage zinc was positively correlated with AM efferocytosis and there was decreased efferocytosis in macrophages depleted of Zn in vitro by treatment with the membrane-permeable zinc chelator TPEN. Organ and cell Zn homeostasis are mediated by two families of membrane ZIP and ZnT proteins. Macrophages of mice null for ZIP1 had significantly lower intracellular zinc and efferocytosis capability, suggesting ZIP1 may play an important role. We investigated further using the human THP-1 derived macrophage cell line, with and without zinc chelation by TPEN to mimic zinc deficiency. There was no change in ZIP1 mRNA levels by TPEN but a significant 3-fold increase in expression of another influx transporter ZIP2, consistent with a role for ZIP2 in maintaining macrophage Zn levels. Both ZIP1 and ZIP2 proteins were localized to the plasma membrane and cytoplasm in normal human lung alveolar macrophages. We propose that zinc homeostasis in macrophages involves the coordinated action of ZIP1 and ZIP2

Effects of zinc supplementation on catch-up growth in children with failure to thrive.

Science.gov (United States)

Park, Seul-Gi; Choi, Ha-Neul; Yang, Hye-Ran; Yim, Jung-Eun

2017-12-01

Although globally the numbers of children diagnosed with failure to thrive (FTT) have decreased, FTT is still a serious pediatric problem. We aimed to investigate the effects of zinc supplementation for 6 months on growth parameters of infants and children with FTT. In this retrospective study, of the 114 participants aged between 4 months and 6 years, 89 were included in the zinc supplementation group and were provided with nutrition counseling plus an oral zinc supplement for 6 months. The caregivers of the 25 participants in the control group received nutrition counseling alone. Medical data of these children, including sex, age, height, weight, serum zinc level, and serum insulin-like growth factor 1 (IGF1) level were analyzed. Zinc supplementation for 6 months increased weight-for-age Z-score and serum zinc levels (5.5%) in the zinc supplementation group of underweight category children. As for stunting category, height-for-age Z-score of the participants in the zinc supplementation group increased when compared with the baseline, and serum zinc levels increased in the normal or mild stunting group. Serum IGF1 levels did not change significantly in any group. Thus, zinc supplementation was more effective in children in the underweight category than those in the stunted category; this effect differed according to the degree of the FTT. These findings suggest that zinc supplementation may have beneficial effects for growth of infants and children with FTT, and zinc supplementation would be required according to degree of FTT.

Essential role for zinc-triggered p75NTR activation in preconditioning neuroprotection.

Science.gov (United States)

Lee, Jin-Yeon; Kim, Yu-Jin; Kim, Tae-Youn; Koh, Jae-Young; Kim, Yang-Hee

2008-10-22

Ischemic preconditioning (PC) of the brain is a phenomenon by which mild ischemic insults render neurons resistant to subsequent strong insults. Key steps in ischemic PC of the brain include caspase-3 activation and poly(ADP-ribose) polymerase-1 (PARP-1) cleavage, but upstream events have not been clearly elucidated. We have tested whether endogenous zinc is required for ischemic PC of the brain in rats. Mild, transient zinc accumulation was observed in certain neurons after ischemic PC. Moreover, intraventricular administration of CaEDTA during ischemic PC abrogated both zinc accumulation and the protective effect against subsequent full ischemia. To elucidate the mechanism of the zinc-triggered PC (Zn PC) effect, cortical cultures were exposed to sublethal levels of zinc, and 18 h later to lethal levels of zinc or NMDA. Zn PC exhibited the characteristic features of ischemic PC, including caspase-3 activation, PARP-1 cleavage, and HSP70 induction, all of which are crucial for subsequent neuroprotection against NMDA or zinc toxicity. HSP70 induction was necessary for protection, as it halted caspase-3 activation before apoptosis. Interestingly, in both Zn PC in vitro and ischemic PC in vivo, p75(NTR) was necessary for neuroprotection. These results suggest that caspase-3 activation during ischemic PC, a necessary event for subsequent neuroprotection, may result from mild zinc accumulation and the consequent p75(NTR) activation in neurons.

Pharmacokinetics of vinyl chloride in the rat

International Nuclear Information System (INIS)

Bolt, H.M.; Laib, R.J.; Kappus, H.; Buchter, A.

1977-01-01

When rats are exposed to [ 14 C]vinyl chloride in a closed system, the vinyl chloride present in the atmosphere equilibrates with the animals' organism within 15 min. The course of equilibration could be determined using rats which had been given 6-nitro-1,2,3-benzothiadiazole. This compound completely blocks metabolism of vinyl chloride. The enzymes responsible for metabolism of vinyl chloride are saturated at an atmospheric concentration of vinyl chloride of 250 ppm. Pharmacokinetic analysis shows that no significant cumulation of vinyl chloride or its major metabolites is to be expected on repeated administration of vinyl chlorides. This may be consistent with the theory that a reactive, shortly living metabolite which occurs in low concentration only, may be responsible for the toxic effects of vinyl chloride

Laboratory investigation of electro-chemical chloride extraction from concrete with penetrated chloride

NARCIS (Netherlands)

Polder, R.B.; Hondel, A.W.M. van den

2002-01-01

Chloride extraction of concrete is a short-term electrochemical treatment against corrosion of reinforcing steel. The aim is to remove chloride ions from the concrete cover in order to reinstate passive behaviour. Physically sound concrete is left in place. To make this method more predictable and

Bioavailability of Zinc in Wistar Rats Fed with Rice Fortified with Zinc Oxide

Science.gov (United States)

Della Lucia, Ceres Mattos; Santos, Laura Luiza Menezes; Rodrigues, Kellen Cristina da Cruz; Rodrigues, Vivian Cristina da Cruz; Martino, Hércia Stampini Duarte; Pinheiro Sant’Ana, Helena Maria

2014-01-01

The study of zinc bioavailability in foods is important because this mineral intake does not meet the recommended doses for some population groups. Also, the presence of dietary factors that reduce zinc absorption contributes to its deficiency. Rice fortified with micronutrients (Ultra Rice®) is a viable alternative for fortification since this cereal is already inserted into the population habit. The aim of this study was to evaluate the bioavailability of zinc (Zn) in rice fortified with zinc oxide. During 42 days, rats were divided into four groups and fed with diets containing two different sources of Zn (test diet: UR® fortified with zinc oxide, or control diet: zinc carbonate (ZnCO3)), supplying 50% or 100%, respectively, of the recommendations of this mineral for animals. Weight gain, food intake, feed efficiency ratio, weight, thickness and length of femur; retention of zinc, calcium (Ca) and magnesium (Mg) in the femur and the concentrations of Zn in femur, plasma and erythrocytes were evaluated. Control diet showed higher weight gain, feed efficiency ratio, retention of Zn and Zn concentration in the femur (p 0.05) for dietary intake, length and thickness of the femur, erythrocyte and plasmatic Zn between groups. Although rice fortified with zinc oxide showed a lower bioavailability compared to ZnCO3, this food can be a viable alternative to be used as a vehicle for fortification. PMID:24932657

Associations between Dietary Iron and Zinc Intakes, and between Biochemical Iron and Zinc Status in Women

Directory of Open Access Journals (Sweden)

Karen Lim

2015-04-01

Full Text Available Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1 describe dietary intakes and biochemical status of iron and zinc; (2 investigate associations between dietary iron and zinc intakes; and (3 investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18–50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379. Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection, and presence of infection/inflammation using C-reactive protein (n = 326. Associations were explored using multiple regression and logistic regression. Mean (SD iron and zinc intakes were 10.5 (3.5 mg/day and 9.3 (3.8 mg/day, respectively. Median (interquartile range serum ferritin was 22 (12–38 μg/L and mean serum zinc concentrations (SD were 12.6 (1.7 μmol/L in fasting samples and 11.8 (2.0 μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340. Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.

Corrosive gas generation potential from chloride salt radiolysis in plutonium environments

International Nuclear Information System (INIS)

Tandon, L.; Allen, T.H.; Mason, R.E.; Penneman, R.A.

1999-01-01

The specific goal of this project was to evaluate the magnitude and practical significance of radiation effects involving mixtures of chloride salts and plutonium dioxide (PuO 2 ) sealed in stainless steel containers and stored for up to 50 yr, after stabilization at 950 C and packaging according to US Department of Energy (DOE) standards. The potential for generating chemically aggressive molecular chlorine (and hydrogen chloride by interaction with adsorbed water or hydrogen gas) by radiolysis of chloride ions was studied. To evaluate the risks, an annotated bibliography on chloride salt radiolysis was created with emphasis on effects of plutonium alpha radiation. The authors present data from the material identification and surveillance (MIS) project obtained from examination and analysis of representative PuO 2 items from various DOE sites, including the headspace gas analysis data of sealed mixtures of PuO 2 and chloride salts following long-term storage

Characterisation of the steel concrete interface submitted to chloride-induced corrosion

International Nuclear Information System (INIS)

L'Hostis, V.; Amblard, E.; Guillot, W.; Paris, C.; Bellot-Gurlet, L.

2013-01-01

This paper deals with the characterisation by means of electrochemical, gravimetric and analytical methods of chloride-induced-corrosion behaviour of steel coupons embedded in chloride-containing-cement pastes. Corrosion rates were estimated from electrochemical measurements as well as gravimetric ones. They vary from 2.6 to 5.7μm/year for 5 and 10 g/L chloride-containing cement pastes. Analytical characterisations (including optical and electron microscopy and Raman micro-spectroscopy) showed that corrosion patterns are not depending on the chloride content of the cement paste (5 and 10 g/L chloride in the interstitial solution). A localised corrosion pattern composed of pits growing inside the metallic substratum, a corrosion products layer (CPL) and a transformed medium (TM) was pointed out. CPL can be divided into two sub-layers (CPL1 and CPL2), characterised by the presence or absence of calcium coming from the cement matrix. (authors)

Effects of zinc supplementation and zinc chelation on in vitro β-cell function in INS-1E cells

DEFF Research Database (Denmark)

Nygaard, Sanne Bjørn; Larsen, Agnete; Knuhtsen, Astrid

2014-01-01

BACKGROUND: Zinc is essential for the activities of pancreatic β-cells, especially insulin storage and secretion. Insulin secretion leads to co-release of zinc which contributes to the paracrine communication in the pancreatic islets. Zinc-transporting proteins (zinc-regulated transporter, iron......-regulated transporter-like proteins [ZIPs] and zinc transporters [ZnTs]) and metal-buffering proteins (metallothioneins, MTs) tightly regulate intracellular zinc homeostasis. The present study investigated how modulation of cellular zinc availability affects β-cell function using INS-1E cells. RESULTS: Using INS-1E...... cells, we found that zinc supplementation and zinc chelation had significant effects on insulin content and insulin secretion. Supplemental zinc within the physiological concentration range induced insulin secretion. Insulin content was reduced by zinc chelation with N,N,N',N-tektrakis(2-pyridylmethyl...

Leptin, NPY, Melatonin and Zinc Levels in Experimental Hypothyroidism and Hyperthyroidism: The Relation to Zinc.

Science.gov (United States)

Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

2017-06-01

Since zinc mediates the effects of many hormones or is found in the structure of numerous hormone receptors, zinc deficiency leads to various functional impairments in the hormone balance. And also thyroid hormones have important activity on metabolism and feeding. NPY and leptin are affective on food intake and regulation of appetite. The present study is conducted to determine how zinc supplementation and deficiency affect thyroid hormones (free and total T3 and T4), melatonin, leptin, and NPY levels in thyroid dysfunction in rats. The experiment groups in the study were formed as follows: Control (C); Hypothyroidism (PTU); Hypothyroidism+Zinc (PTU+Zn); Hypothyroidism+Zinc deficient; Hyperthyroidism (H); Hyperthyroidism+Zinc (H+Zn); and Hyperthyroidism+Zinc deficient. Thyroid hormone parameters (FT 3 , FT 4 , TT 3 , and TT 4 ) were found to be reduced in hypothyroidism groups and elevated in the hyperthyroidism groups. Melatonin values increased in hyperthyroidism and decreased in hypothyroidism. Leptin and NPY levels both increased in hypo- and hyperthyroidism. Zinc levels, on the other hand, decreased in hypothyroidism and increased in hyperthyroidism. Zinc supplementation, particularly when thyroid function is impaired, has been demonstrated to markedly prevent these changes.

Zinc deficiency in the pediatric age group is common but underevaluated.

Science.gov (United States)

Vuralli, Dogus; Tumer, Leyla; Hasanoglu, Alev

2017-08-01

Subclinical micronutrient deficiencies have been gradually becoming more important as a public health problem and drawing attention of the health authorities. Today it has been known that detecting and treating people having deficiency symptoms alone is no longer sufficient. It is important to detect and prevent any deficiency before it displays clinical manifestations. Zinc deficiency is one of the most widespread micronutrient deficiencies. In this study, we aimed to evaluate the zinc status and the associated factors in healthy school-age children. The study was carried out in schools in Altindag, the district of Ankara. A total of 1063 healthy children, 585 girls and 478 boys, aged 5-16 years were included in the study. Serum zinc, high-sensitivity C-reactive protein levels and white blood cell count were measured. A serum zinc level zinc deficiency for children zinc concentration were set at 66 μg/dL for females and 70 μg/dL for males. A questionnaire was developed to collect socioeconomic and demographic information of the participants. The prevalence of subclinical zinc deficiency in children attending the study was detected to be 27.8%. This high ratio showed zinc deficiency was an important health problem in the Altindag district of Ankara, Turkey. Evaluating the indicators of zinc deficiency such as serum zinc concentration, dietary zinc intake and stunting prevalence, this study is the most comprehensive epidemiological study performed in children in Turkey. This study reveals the high prevalence of subclinical zinc deficiency and indicates that zinc deficiency is a public health concern for the study population.

Molecular determinants of ivermectin sensitivity at the glycine receptor chloride channel

DEFF Research Database (Denmark)

Lynagh, Timothy; Webb, Timothy I.; Dixon, Christine L.

2011-01-01

Ivermectin is an anthelmintic drug that works by activating glutamate-gated chloride channel receptors (GluClRs) in nematode parasites. GluClRs belong to the Cys-loop receptor family that also includes glycine receptor (GlyR) chloride channels. GluClRs and A288G mutant GlyRs are both activated...

Uptake and partitioning of zinc in Lemnaceae.

Science.gov (United States)

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.

Many rivers to cross: the journey of zinc from soil to seed

Directory of Open Access Journals (Sweden)

Lene Irene Olsen

2014-02-01

Full Text Available An important goal of micronutrient biofortification is to enhance the amount of bioavailable zinc in the edible seed of cereals and more specifically in the endosperm. The picture is starting to emerge for how zinc is translocated from the soil through the mother plant to the developing seed. On this journey, zinc is transported from symplast to symplast via multiple apoplastic spaces. During each step, zinc is imported into a symplast before it is exported again. Cellular import and export of zinc requires passage through biological membranes, which makes membrane-bound transporters of zinc especially interesting as potential transport bottlenecks. Inside the cell, zinc can be imported into or exported out of organelles by other transporters. The function of several membrane proteins involved in the transport of zinc across the tonoplast, chloroplast or plasma membranes are currently known. These include members of the ZIP (ZRT-IRT-like Protein, and MTP (Metal Tolerance Protein and Heavy Metal ATPase (HMA families. An important player in the transport process is the ligand nicotianamine that binds zinc to increase its solubility in living cells and in this way buffers the intracellular zinc concentration.

Iron chloride catalysed PCDD/F-formation: Experiments and PCDD/F-signatures.

Science.gov (United States)

Zhang, Mengmei; Buekens, Alfons; Ma, Siyuan; Li, Xiaodong

2018-01-01

Iron chloride is often cited as catalyst of PCDD/F-formation, together with copper chloride. Conversely, iron chloride catalysis has been less studied during de novo tests. This paper presents such de novo test data, derived from model fly ash incorporating iron (III) chloride and established over a vast range of temperature and oxygen concentration in the gas phase. Both PCDD/F-output and its signature are extensively characterised, including homologue and congener profiles. For the first time, a complete isomer-specific analysis is systematically established, for all samples. Special attention is paid to the chlorophenols route PCDD/F, to the 2,3,7,8-substituted congeners, and to their relationship and antagonism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chloride Ingress in Concrete with Different Age at Time of First Chloride Exposure

DEFF Research Database (Denmark)

Hansen, Esben Østergaard; Iskau, Martin Riis; Hasholt, Marianne Tange

2016-01-01

Concrete structures cast in spring have longer time to hydrate and are therefore denser and more resistant to chloride ingress when first subjected to deicing salts in winter than structures cast in autumn. Consequently, it is expected that a spring casting will have a longer service life....... This hypothesis is investigated in the present study by testing drilled cores from concrete cast in 2012 and 2013 on the Svendborgsund Bridge. The cores are subject to petrographic examination and mapping of chloride profiles. Moreover, chloride migration coefficients have been measured. The study shows...

Zinc oxide overdose

Science.gov (United States)

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 ...

Producing ammonium chloride from coal or shale

Energy Technology Data Exchange (ETDEWEB)

Christenson, O L

1921-02-25

Process of producing ammonium chloride consists of mixing the substance to be treated with a chloride of an alkali or alkaline earth metal, free silica, water and free hydrochloric acid, heating the mixture until ammonium chloride distills off and collecting the ammonium chloride.

Ion Channels and Zinc: Mechanisms of Neurotoxicity and Neurodegeneration

Directory of Open Access Journals (Sweden)

Deborah R. Morris

2012-01-01

Full Text Available Ionotropic glutamate receptors, such as NMDA, AMPA and kainate receptors, are ligand-gated ion channels that mediate much of the excitatory neurotransmission in the brain. Not only do these receptors bind glutamate, but they are also regulated by and facilitate the postsynaptic uptake of the trace metal zinc. This paper discusses the role of the excitotoxic influx and accumulation of zinc, the mechanisms responsible for its cytotoxicity, and a number of disorders of the central nervous system that have been linked to these neuronal ion channels and zinc toxicity including ischemic brain injury, traumatic brain injury, and epilepsy.

Zinc injection during Hot Functional Test (HFT) in Tomari Unit 3

International Nuclear Information System (INIS)

Hayakawa, H.; Mino, Y.; Nakahama, S.; Aizawa, Y.; Nishimura, T.; Umehara, R.; Shimuz, Y.; Kogawa, N.; Ojima, Z.

2010-01-01

Zinc injection is performed to reduce radiation exposure around the world, and its effect is confirmed. In Japanese PWRs, the actual effect is also confirmed. Therefore, number of Japanese PWR plans, where zinc is injected, increase. We conclude that zinc injection from Hot Function Test (HFT), when RCS temperature and corrosion rate of material of primary components are increased firstly, is more effective for reducing radiation exposure, because oxide layer with zinc is more stable than with other metals such as cobalt and it is confirmed that zinc injection reduces corrosion amount of alloy 690TT in laboratory test. Therefore in Tomari Unit 3 (PWR, commercial operation from December 2009) of HOKKAIDO ELECTRIC POWER CO., INC, zinc injection was started from first Heat-up during trial operation. During HFT, zinc consumption coincides with assumed plan and Ni concentration is lower than in reference plant. Therefore we conclude that stable and fine oxide layer including zinc is formed. We hope that radiation exposure reduces because of these results. (We published at Asia Water Chemistry Symposium 2009 in NAGOYA.) Results of analysis of oxide layer on SG insert plate, removed after HFT, will be reported. Also Actual results of water chemistry and zinc injection after HFT will be reported. (author)

Synthesis and characterization of nanometric zinc oxide for a stationary phase in liquid chromatography

International Nuclear Information System (INIS)

Gordillo-Delgado, F; Soto-Barrera, C C; Plazas-Saldaña, J

2017-01-01

The increasing demand for equipment to remove organic compounds in industry and research activity has led to evaluate nanometric zinc oxide (ZnO). In this work, we present the ZnO nanoparticles synthesis for reusing of discarded columns, as a low-cost alternative. The compound was obtained by sol-gel technique using zinc chloride and sodium hydroxide as precursors and a drying temperature of 169°C. An X-ray diffractometer was used to estimate the average particle size at 20.3±0.2nm; the adsorption capacity was 0.0144L/g and the chemical resistance was tested with HCl and NaOH. The ZnO nanopowder was packed with 100psi pressure in an empty C-18 column cavity. The column packing resolution was evaluated using a high performance liquid chromatographer (HPLC-Thermo Scientific Dionex UltiMate 3000); using a caffeine standard, the following parameters were established: solvent flow: 1.2mL/min, average column temperature: 40°C, running time: 10 minutes, mobile phase acetonitrile-water composition (9:1). These results validate the potential of ZnO nanopowder as a column packing material in HPLC technique. (paper)

Synthesis and characterization of nanometric zinc oxide for a stationary phase in liquid chromatography

Science.gov (United States)

Gordillo-Delgado, F.; Soto-Barrera, C. C.; Plazas-Saldaña, J.

2017-01-01

The increasing demand for equipment to remove organic compounds in industry and research activity has led to evaluate nanometric zinc oxide (ZnO). In this work, we present the ZnO nanoparticles synthesis for reusing of discarded columns, as a low-cost alternative. The compound was obtained by sol-gel technique using zinc chloride and sodium hydroxide as precursors and a drying temperature of 169°C. An X-ray diffractometer was used to estimate the average particle size at 20.3±0.2nm the adsorption capacity was 0.0144L/g and the chemical resistance was tested with HCl and NaOH. The ZnO nanopowder was packed with 100psi pressure in an empty C-18 column cavity. The column packing resolution was evaluated using a high performance liquid chromatographer (HPLC-Thermo Scientific Dionex UltiMate 3000); using a caffeine standard, the following parameters were established: solvent flow: 1.2mL/min, average column temperature: 40°C, running time: 10 minutes, mobile phase acetonitrile-water composition (9:1). These results validate the potential of ZnO nanopowder as a column packing material in HPLC technique.

21 CFR 173.400 - Dimethyldialkylammonium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dimethyldialkylammonium chloride. 173.400 Section... HUMAN CONSUMPTION Specific Usage Additives § 173.400 Dimethyldialkylammonium chloride. Dimethyldialkylammonium chloride may be safely used in food in accordance with the following prescribed conditions: (a...

Isotope aided micronutrient studies in rice production with special reference to zinc deficiency pt. 1

International Nuclear Information System (INIS)

Kim, T.S.; Song, K.J.; Han, K.W.; U, Z.K.

1978-01-01

Using tracer technique of 65 Zn, a field experiment has been carried out to evaluate the efficiency of zinc fertilzer by rice plant grown under flooded conditions. The treatments include zinc sulfate mixed throughout the soil with and without organic matter, combined urea-zinc fertilizer (N: 37.7%. Zn: 3.1%), and surface application at transplanting and two weeks after transplanting at the rate of 5 kg Zn/ha respectively. Other treatments were zinc sulfate mixed throughout the soil at the rate of 10 kg and 20 kg Zn/ha respectively. Root dipping in 2% ZnO suspension, only organic matter added, and control were also included. There was not much difference in rough grain yield between zinc levels and different application methods, but the highest yield was obtained from the treatment of the root dipping in 2% ZnO suspension. Among the 5 kg Zn/ha treatments, the highest total zinc yield was observed from the zinc mixed throughout the soil. The organic matter treatment seemed to reduce the zinc fertilizer efficiency. In case of the zinc fertilizer levels, 5 kg Zn/ha mixed throughout the soil showed the highest zinc fertilizer efficiency as compared with 10 kg and 20 kg Zn/ha treatments. (author)

Microbial reductive dehalogenation of vinyl chloride

Science.gov (United States)

Spormann, Alfred M [Stanford, CA; Muller, Jochen A [Baltimore, MD; Rosner, Bettina M [Berlin, DE; Von Abendroth, Gregory [Nannhein, DE; Meshulam-Simon, Galit [Los Altos, CA; McCarty, Perry L [Stanford, CA

2011-11-22

Compositions and methods are provided that relate to the bioremediation of chlorinated ethenes, particularly the bioremediation of vinyl chloride by Dehalococcoides-like organisms. An isolated strain of bacteria, Dehalococcoides sp. strain VS, that metabolizes vinyl chloride is provided; the genetic sequence of the enzyme responsible for vinyl chloride dehalogenation; methods of assessing the capability of endogenous organisms at an environmental site to metabolize vinyl chloride; and a method of using the strains of the invention for bioremediation.

Effect of zinc gluconate, sage oil on inflammatory patterns and hyperglycemia in zinc deficient diabetic rats.

Science.gov (United States)

Elseweidy, Mohamed M; Ali, Abdel-Moniem A; Elabidine, Nabila Zein; Mursey, Nada M

2017-11-01

The relationship between zinc homeostasis and pancreatic function had been established. In this study we aimed firstly to configure the inflammatory pattern and hyperglycemia in zinc deficient diabetic rats. Secondly to illustrate the effect of two selected agents namely Zinc gluconate and sage oil (Salvia Officinalis, family Lamiaceae). Rats were fed on Zinc deficient diet, deionized water for 28days along with Zinc level check up at intervals to achieve zinc deficient state then rats were rendered diabetic through receiving one dose of alloxan monohydrate (120mg/kg) body weight, classified later into 5 subgroups. Treatment with sage oil (0.042mg/kg IP) and Zinc gluconate orally (150mg/kg) body weight daily for 8 weeks significantly reduced serum glucose, C-reactive protein (CRP), Tumor necrosis factor alpha (TNF- α), interleukins-6 1 β, inflammatory8 (IFN ȣ), pancreatic 1L1-β along with an increase in serum Zinc and pancreatic Zinc transporter 8 (ZNT8). Histopathological results of pancreatic tissues showed a good correlation with the biochemical findings. Both sage oil and zinc gluconate induced an improvement in the glycemic and inflammatory states. This may be of value like the therapeutic agent for diabetes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Nutrition intervention strategies to combat zinc deficiency in developing countries.

Science.gov (United States)

Gibson, R S; Ferguson, E L

1998-06-01

Widespread zinc deficiency is likely to exist in developing countries where staple diets are predominantly plant based and intakes of animal tissues are low. The severe negative consequences of zinc deficiency on human health in developing countries, however, have only recently been recognized. An integrated approach employing targeted supplementation, fortification and dietary strategies must be used to maximize the likelihood of eliminating zinc deficiency at a national level in developing countries. Supplementation is appropriate only for populations whose zinc status must be improved over a relatively short time period, and when requirements cannot be met from habitual dietary sources. As well, the health system must be capable of providing consistent supply, distribution, delivery and consumption of the zinc supplement to the targeted groups. Uncertainties still exist about the type, frequency, and level of supplemental zinc required for prevention and treatment of zinc deficiency. Salts that are readily absorbed and at levels that will not induce antagonistic nutrient interactions must be used. At a national level, fortification with multiple micronutrients could be a cost effective method for improving micronutrient status, including zinc, provided that a suitable food vehicle which is centrally processed is available. Alternatively, fortification could be targeted for certain high risk groups (e.g. complementary foods for infants). Efforts should be made to develop protected fortificants for zinc, so that potent inhibitors of zinc absorption (e.g. phytate) present either in the food vehicle and/or indigenous meals do not compromise zinc absorption. Fortification does not require any changes in the existing food beliefs and practices for the consumer and, unlike supplementation, does not impose a burden on the health sector. A quality assurance programme is required, however, to ensure the quality of the fortified food product from production to consumption

Bioleaching combined brine leaching of heavy metals from lead-zinc mine tailings: Transformations during the leaching process.

Science.gov (United States)

Ye, Maoyou; Yan, Pingfang; Sun, Shuiyu; Han, Dajian; Xiao, Xiao; Zheng, Li; Huang, Shaosong; Chen, Yun; Zhuang, Shengwei

2017-02-01

During the process of bioleaching, lead (Pb) recovery is low. This low recovery is caused by a problem with the bioleaching technique. This research investigated the bioleaching combination of bioleaching with brine leaching to remove heavy metals from lead-zinc mine tailings. The impact of different parameters were studied, including the effects of initial pH (1.5-3.0) and solid concentration (5-20%) for bioleaching, and the effects of sodium chloride (NaCl) concentration (10-200 g/L) and temperature (25 and 50 °C) for brine leaching. Complementary characterization experiments (Sequential extraction, X-ray diffractometer (XRD), scanning electronic microscope (SEM)) were also conducted to explore the transformation of tailings during the leaching process. The results showed that bioleaching efficiency was significantly influenced by initial pH and solid concentration. Approximately 85.45% of iron (Fe), 4.12% of Pb, and 97.85% of zinc (Zn) were recovered through bioleaching in optimum conditions. Increasing the brine concentration and temperature promoted lead recovery. Lead was recovered from the bioleaching residues at a rate of 94.70% at 25 °C and at a rate of 99.46% at 50 °C when the NaCl concentration was 150 g/L. The study showed that bioleaching significantly changed the speciation of heavy metals and the formation and surface morphology of tailings. The metals were mainly bound in stable fractions after bioleaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

21 CFR 522.1862 - Sterile pralidoxime chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sterile pralidoxime chloride. 522.1862 Section 522....1862 Sterile pralidoxime chloride. (a) Chemical name. 2-Formyl-1-methylpyridinium chloride oxime. (b) Specifications. Sterile pralidoxime chloride is packaged in vials. Each vial contains 1 gram of sterile...

49 CFR 173.322 - Ethyl chloride.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Ethyl chloride. 173.322 Section 173.322 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.322 Ethyl chloride. Ethyl chloride must be...

Preparation of pure anhydrous rare earth chlorides

International Nuclear Information System (INIS)

Bel'kova, N.L.; Slastenova, N.M.; Batyaev, I.M.; Solov'ev, M.A.

1979-01-01

A method has been suggested for obtaining extra-pure anhydrous REE chlorides by chloridizing corresponding oxalates by chlorine in a fluid bed, the chloridizing agents being diluted by an inert gas in a ratio of 2-to-1. The method is applicable to the manufacture of quality chlorides not only of light, but also of heavy REE. Neodymium chloride has an excited life of tau=30 μs, this evidencing the absence of the damping impurities

Impact of anode substrates on electrodeposited zinc over cycling in zinc-anode rechargeable alkaline batteries

International Nuclear Information System (INIS)

Wei, Xia; Desai, Divyaraj; Yadav, Gautam G.; Turney, Damon E.; Couzis, Alexander; Banerjee, Sanjoy

2016-01-01

Electrochemical behavior of Ag, Bi, Cu, Fe, Ni and Sn substrates on zinc deposition was evaluated over battery cycling by cyclic voltammetry and electrochemical impedance spectroscopy. The effect of Bi, Cu, Ni, and Sn substrates on zinc electrodeposition during battery cycling was investigated using scanning electron microscopy and X-ray diffraction. The corrosion behavior of each metal in 9 M KOH and the corrosion rates of zinc plated on each substrate were analyzed by Tafel extrapolation method from the potentiodynamic polarization curves and electrochemical impedance spectroscopy. Although the charge-transfer resistance (R_c_t) of zinc electrodeposition is lowest on Sn, Sn eventually corrodes on cycling in alkaline media. Use of Ni as a substrate causes zinc to deteriorate on account of rapid hydrogen evolution. Bi and Cu substrates are more suitable for use as current collectors in zinc-anode alkaline rechargeable batteries because of their low corrosion rate and compact zinc deposition over battery cycling.

Immersion autometallography: histochemical in situ capturing of zinc ions in catalytic zinc-sulfur nanocrystals.

Science.gov (United States)

Danscher, Gorm; Stoltenberg, Meredin; Bruhn, Mikkel; Søndergaard, Chris; Jensen, Dorete

2004-12-01

In the mid-1980s, two versions of Timm's original immersion sulfide silver method were published. The authors used immersion of tissue in a sulfide solution as opposed to Timm, who used immersion of tissue blocks in hydrogen sulfide-bubbled alcohol. The autometallography staining resulting from the "sulfide only immersion" was not particularly impressive, but the significance of this return to an old approach became obvious when Wenzel and co-workers presented their approach in connection with introduction by the Palmiter group of zinc transporter 3 (ZnT3). The Wenzel/Palmiter pictures are the first high-resolution, high-quality pictures taken from tissues in which free and loosely bound zinc ions have been captured in zinc-sulfur nanocrystals by immersion. The trick was to place formalin-fixed blocks of mouse brains in a solution containing 3% glutaraldehyde and 0.1% sodium sulfide, ingredients used for transcardial perfusion in the zinc-specific NeoTimm method. That the NeoTimm technique results in silver enhancement of zinc-sulfur nanocrystals has been proved by proton-induced X-ray multielement analyses (PIXE) and in vivo chelation with diethyldithiocarbamate (DEDTC). The aims of the present study were (a) to make the immersion-based capturing of zinc ions in zinc-sulfur nanocrystals work directly on sections and slices of fixed brain tissue, (b) to work out protocols that ensure zinc specificity and optimal quality of the staining, (c) to apply "immersion autometallography" (iZnSAMG) to other tissues that contain zinc-enriched (ZEN) cells, and (d) to make the immersion approach work on unfixed fresh tissue.

Crystal field influence on vibration spectra: anhydrous uranyl chloride and dihydroxodiuranyl chloride tetrahydrate

International Nuclear Information System (INIS)

Perrin, Andre; Caillet, Paul

1976-01-01

Vibrational spectra of anhydrous uranyl chloride UO 2 Cl 2 and so called basic uranyl chloride: dihydroxodiuranyl chloride tetrahydrate /UO 2 (OH) 2 UO 2 /Cl 2 (H 2 O) 4 are reported. Factor group method analysis leads for the first time to complete and comprehensive interpretation of their spectra. Two extreme examples of crystal field influence on vibrational spectra are pointed out: for UO 2 Cl 2 , one is unable to explain spectra without taking into account all the elements of primitive crystalline cell, whilst for dihydroxodiuranyl dichloride tetrahydrate the crystal packing has very little effect on vibrational spectra [fr

Galvanizing action: conclusions and next steps for mainstreaming zinc interventions in public health programs.

Science.gov (United States)

Brown, Kenneth H; Baker, Shawn K

2009-03-01

This paper summarizes the results of the foregoing reviews of the impact of different intervention strategies designed to enhance zinc nutrition, including supplementation, fortification, and dietary diversification or modification. Current evidence indicates a beneficial impact of such interventions on zinc status and zinc-related functional outcomes. Preventive zinc supplementation reduces the incidence of diarrhea and acute lower respiratory tract infection among young children, decreases mortality of children over 12 months of age, and increases growth velocity. Therapeutic zinc supplementation during episodes of diarrhea reduces the duration and severity of illness. Zinc fortification increases zinc intake and total absorbed zinc, and recent studies are beginning to confirm a positive impact of zinc fortification on indicators of population zinc status. To assist with the development of zinc intervention programs, more information is needed on the prevalence of zinc deficiency in different countries, and rigorous evaluations of the effectiveness of large-scale zinc intervention programs should be planned. Recommended steps for scaling up zinc intervention programs, with or without other micronutrients, are described. In summary, there is now clear evidence of the benefit of selected interventions to reduce the risk of zinc deficiency, and a global commitment is urgently needed to conduct systematic assessments of population zinc status and to develop interventions to control zinc deficiency in the context of existing public health and nutrition programs.

The relationship between seminal plasma zinc levels and high molecular weight zinc binding protein and sperm motility in Iraqi infertile men

International Nuclear Information System (INIS)

AbdulRasheed, Omar F

2009-01-01

To evaluate the relationship between sperm motility and total seminal plasma zinc concentration and high molecular weight zinc bound protein values in infertile Iraqi men. A case-control study was conducted at the Chemistry and Biochemistry Department, College of Medicine, Al-Nahrain University, Baghdad, Iraq between March 2005 to February 2006. The subjects for the study included 60 infertile male patients who were recruited Al-Kadhimiya Teaching Hospital, and Institute of Embryo Research and Infertility Treatment, Baghdad, Iraq. They were categorized according to their seminal parameters to oligozoospermia (n=32), azoospermia (n=22), and asthenozoospermia (n=6). Thirty nine fertile men (age range 31.87 +/- 3.76 years) were selected as controls, whose partners had conceived within the last year before participation with this study, and having normal spermiogram parameters. Seminal plasma zinc concentration and high molecular weight zinc binding proteins (HMW-Zn) were assayed in the ejaculates of fertile and infertile men. The seminal plasma zinc levels were 181.92 +/- 23.40 ug/mL in the oligozoospermia group, 178.50 +/- 18.61 ug/mL in the azoospermia group, 195.33 +/- 13.00 ug/mL in the asthenozoospermia group, and 184.66 +/- 21.31 ug/mL in the control group. The HMW-Zn% is a good index of sperm function rather than the total seminal plasma zinc levels. (author)

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

Energy Technology Data Exchange (ETDEWEB)

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; Kong, Betty Y.; Gleber, Sophie C.; Vogt, Stefan; Chen, Si; Garwin, Seth A.; Bayer, Amanda R.; Dravid, Vinayak P.; Woodruff, Teresa K.; O' Halloran, Thomas V.

2014-12-15

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes

Modelling chloride penetration in concrete using electrical voltage and current approaches

Directory of Open Access Journals (Sweden)

Juan Lizarazo-Marriaga

2011-03-01

Full Text Available This paper reports a research programme aimed at giving a better understanding of the phenomena involved in the chloride penetration in cement-based materials. The general approach used was to solve the Nernst-Planck equation numerically for two physical ideal states that define the possible conditions under which chlorides will move through concrete. These conditions are named in this paper as voltage control and current control. For each condition, experiments and simulations were carried out in order to establish the importance of electrical variables such as voltage and current in modelling chloride transport in concrete. The results of experiments and simulations showed that if those electrical variables are included as key parameters in the modelling of chloride penetration through concrete, a better understanding of this complex phenomenon can be obtained.

21 CFR 582.3845 - Stannous chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Stannous chloride. 582.3845 Section 582.3845 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3845 Stannous chloride. (a) Product. Stannous chloride. (b) Tolerance. This substance is generally...

7 CFR 58.434 - Calcium chloride.

Science.gov (United States)

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the Food...

Effects of pyrithiones and surfactants on zinc and enzyme levels in rabbits.

Science.gov (United States)

Spiker, R C; Ciuchta, H P

1980-04-01

The effects of zinc pyrithione (ZnPT) and sodium pyrithione (NaPT), including the influence of various vehicles, upon whole blood and plasma zinc levels and serum alkaline phosphatase (SAP) have been investigated in rabbits following dermal and/or iv administration. Two such vehicles, ammonium lauryl sulfate (ALS) and triethanolamine lauryl sulfate, affected zinc homeostasis differently than the pyrithiones, in that, unlike the pyrithiones, no whole blood changes were observed, although there were delayed and sustained declines in plasma zinc and SAP values. These changes were most likely related to the skin irritation caused by the surfactants. In contrast, NaPT-dimethyl sulfoxide (DMSO) dermal and iv exposures produced rapid decreases in plasma zinc followed by quick recovery, coupled with smaller and unsustained declines in SAP. Large increases in whole blood zinc were also observed in both cases, as well as in a ZnPT-DMSO iv exposure. DMSO itself had no effects on the measured parameters. Experiments involving combinations of the pyrithiones and ALS demonstrated effects on zinc homeostasis that were attributable to both substances, i.e. large increases in whole blood zinc (PT effect), quick drops in plasma zinc (PT effect) and slowly recovering plasma zinc and SAP values (surfactant effect). The chelating nature of the PT molecule may have been responsible for some of the observed changes in zinc distribution.

Clinical Aspects of Trace Elements: Zinc in Human Nutrition – Zinc Deficiency and Toxicity

Directory of Open Access Journals (Sweden)

Michelle M Pluhator

1996-01-01

Full Text Available Available evidence suggests that trace elements, such as zinc, once thought to have no nutritional relevance, are possibly deficient in large sections of the human population. Conditioned deficiencies have been reported to result from malabsorption syndromes, acrodermatitis enteropathica, alcoholism, gastrointestinal disease, thermal injury, chronic diseases (eg, diabetes, sickle cell anemia, and in total parenteral nutrition therapy. Awareness that patients with these problems are at risk has led health professionals to focus increasingly on the importance of zinc therapy in the prevention and treatment of deficiency. More recently zinc toxicity and its role in human nutrition and well-being have come under investigation. Reports have focused on the role of zinc toxicity in causes of copper deficiency, changes in the immune system and alterations in blood lipids. As the numerous challenges presented by the study of zinc in human nutrition are met, more appropriate recommendations for dietary and therapeutic zinc intake are being made.

21 CFR 582.6193 - Calcium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is generally...

Zinc in Infection and Inflammation.

Science.gov (United States)

Gammoh, Nour Zahi; Rink, Lothar

2017-06-17

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

Oxidative addition of aryl chlorides to monoligated palladium(0): A DFT-SCRF study

DEFF Research Database (Denmark)

Ahlquist, Mårten Sten Gösta; Norrby, Per-Ola

2007-01-01

Oxidative addition of aryl chlorides to palladium has been investigated by hybrid density functional theory methods (B3LYP), including a continuum model describing the solvent implicitly. A series of para-substituted aryl chlorides were studied to see the influence of electronic effects...

Lead, zinc and copper fine powder with controlled size and shape

Directory of Open Access Journals (Sweden)

Mahmoud A Rabah

2017-12-01

Full Text Available This study describes the preparation of lead, zinc and copper powders by hydrometallurgy from secondary resources. Chloride, sulphate and acetate salts of zinc, copper and lead were prepared. The powders were prepared by reducing the ionic species of these metals by hydrazine hydrate or ascorbic acid. The effect of addition of some water soluble polar organic solvents to the aqueous salt solutions on the morphology and particle size of the prepared powder was studied. Findings were explained on the basis of the transition state theory and according to the Hughes and Ingold’s rule. Aqueous solutions alone produce metal powder having different size and irregular shape. The presence of polar organic solvents with high molecular weight and polarity produce powders having controlled size and regular morphology. The reason was because solvent polarity enhances the rate of red-ox reactions between metal ions and the reducing agent. The mean particle size of the powder was 60 um with zinc, 80 um with copper, and 90 um with lead. The extent of productivity was ≥98%. Results highlighted that the chemical reduction of the ionic species took place in a sequence steps. The first is a diffusion of the reactants across a boundary layer established at the polar site of the organic solvent molecules. The next step is the direct contact of the reactants. The third step involved reduction to yield powder. The last is the backward diffusion of the powder outside the boundary layer. Results showed that addition of water-miscible solvents having high dielectric constant increased the polarity of the medium. This energizes and enhances the one or more t step of the model to be more rapid to yield particles with small size and symmetrical shape.

Chloride removal from plutonium alloy

International Nuclear Information System (INIS)

Holcomb, H.P.

1983-01-01

SRP is evaluating a program to recover plutonium from a metallic alloy that will contain chloride salt impurities. Removal of chloride to sufficiently low levels to prevent damaging corrosion to canyon equipment is feasible as a head-end step following dissolution. Silver nitrate and mercurous nitrate were each successfully used in laboratory tests to remove chloride from simulated alloy dissolver solution containing plutonium. Levels less than 10 ppM chloride were achieved in the supernates over the precipitated and centrifuged insoluble salts. Also, less than 0.05% loss of plutonium in the +3, +4, or +6 oxidation states was incurred via precipitate carrying. These results provide impetus for further study and development of a plant-scale process to recover plutonium from metal alloy at SRP

Influence of usual zinc intake and zinc in a meal on 65Zn retention and turnover in the rat

International Nuclear Information System (INIS)

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

1987-01-01

The influences of zinc in a meal and usual zinc intake on zinc retention and turnover were investigated in 7-wk-old male rats fed diets containing 12-151 mg Zn/kg for 3 wk before and after consuming a 65 Zn-labeled meal containing ZnCl 2 . Retention corrected to zero time and turnover rate were determined by whole-body counting. Percent zinc retention was inversely proportional to the natural logarithm of the meal zinc, between 0.09 and 26 mumol. In comparison to lower doses, higher doses resulted in lower percent retention but greater amounts of zinc retained. Although the latter relationship was slightly curvilinear, there was no indication of a limited capacity for zinc retention with high doses. However, doses above 4 mumol resulted in higher turnover rates in rats accustomed to lower zinc intakes. Percent retention and the reciprocal of the turnover rate were proportional to the reciprocal of the dietary zinc concentration. The greatest differences in retention and turnover occurred between 12 and 26 mg Zn/kg diet. The zinc dose in a meal and the usual dietary zinc separately influenced percent zinc retention. These factors also interacted, such that greater dose effects were observed at lower zinc intakes and greater dietary zinc effects were observed at lower doses

Effect of annealing temperature on optical properties of binary zinc tin oxide nano-composite prepared by sol-gel route using simple precursors: structural and optical studies by DRS, FT-IR, XRD, FESEM investigations.

Science.gov (United States)

Habibi, Mohammad Hossein; Mardani, Maryam

2015-02-25

Binary zinc tin oxide nano-composite was synthesized by a facile sol-gel method using simple precursors from the solutions consisting of zinc acetate, tin(IV) chloride and ethanol. Effect of annealing temperature on optical and structural properties was investigated using X-ray diffraction (XRD), diffuse reflectance spectra (DRS), field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). XRD results revealed the existence of the ZnO and SnO2 phases. FESEM results showed that binary zinc tin oxide nano-composites ranges from 56 to 60 nm in diameter at 400°C and 500°C annealing temperatures respectively. The optical band gap was increased from 2.72 eV to 3.11 eV with the increasing of the annealing temperature. FTIR results confirmed the presence of zinc oxide and tin oxide and the broad absorption peaks at 3426 and 1602 cm(-1) can be ascribed to the vibration of absorptive water, and the absorption peaks at 546, 1038 and 1410 cm(-1) are due to the vibration of Zn-O or Sn-O groups in binary zinc tin oxide. Copyright © 2014 Elsevier B.V. All rights reserved.

Interdependence of free zinc changes and protein complex assembly - insights into zinc signal regulation.

Science.gov (United States)

Kocyła, Anna; Adamczyk, Justyna; Krężel, Artur

2018-01-24

Cellular zinc (Zn(ii)) is bound with proteins that are part of the proteomes of all domains of life. It is mostly utilized as a catalytic or structural protein cofactor, which results in a vast number of binding architectures. The Zn(ii) ion is also important for the formation of transient protein complexes with a Zn(ii)-dependent quaternary structure that is formed upon cellular zinc signals. The mechanisms by which proteins associate with and dissociate from Zn(ii) and the connection with cellular Zn(ii) changes remain incompletely understood. In this study, we aimed to examine how zinc protein domains with various Zn(ii)-binding architectures are formed under free Zn(ii) concentration changes and how formation of the Zn(ii)-dependent assemblies is related to the protein concentration and reactivity. To accomplish these goals we chose four zinc domains with different Zn(ii)-to-protein binding stoichiometries: classical zinc finger (ZnP), LIM domain (Zn 2 P), zinc hook (ZnP 2 ) and zinc clasp (ZnP 1 P 2 ) folds. Our research demonstrated a lack of changes in the saturation level of intraprotein zinc binding sites, despite various peptide concentrations, while homo- and heterodimers indicated a concentration-dependent tendency. In other words, at a certain free Zn(ii) concentration, the fraction of a formed dimeric complex increases or decreases with subunit concentration changes. Secondly, even small or local changes in free Zn(ii) may significantly affect protein saturation depending on its architecture, function and subcellular concentration. In our paper, we indicate the importance of interdependence of free Zn(ii) availability and protein subunit concentrations for cellular zinc signal regulation.

21 CFR 173.255 - Methylene chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Methylene chloride. 173.255 Section 173.255 Food... Solvents, Lubricants, Release Agents and Related Substances § 173.255 Methylene chloride. Methylene chloride may be present in food under the following conditions: (a) In spice oleoresins as a residue from...

21 CFR 182.8252 - Choline chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Choline chloride. 182.8252 Section 182.8252 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... chloride. (a) Product. Choline chloride. (b) Conditions of use. This substance is generally recognized as...

21 CFR 582.5446 - Manganese chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese chloride. 582.5446 Section 582.5446 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5446 Manganese chloride. (a) Product. Manganese chloride. (b) Conditions of use. This...

21 CFR 582.5252 - Choline chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Choline chloride. 582.5252 Section 582.5252 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5252 Choline chloride. (a) Product. Choline chloride. (b) Conditions of use. This...

21 CFR 582.5622 - Potassium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium chloride. 582.5622 Section 582.5622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5622 Potassium chloride. (a) Product. Potassium chloride. (b) Conditions of use. This...

21 CFR 582.1193 - Calcium chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance...

Formation of zeolite-like zinc 1,3,5-benzenetriphosphonate open-frameworks by topotactic pillaring of anionic layers.

Science.gov (United States)

Maeda, Kazuyuki; Takamatsu, Ryohei; Mochizuki, Miki; Kawawa, Kanako; Kondo, Atsushi

2013-08-07

An ab initio powder X-ray crystal structure analysis revealed that layered zinc 1,3,5-benzenetriphosphonates containing interlayer tetramethylammonium (ZBP-TMA) or 4,4'-bipyridinium cations (ZBP-bpy) are transformed to novel isomorphous 3D open-framework compounds ZBP-M (M: K, Rb, and Cs) by treatment in aqueous alkali metal chloride solutions. ZBP-Ms have a pillared layer-type of anionic framework containing 2D zigzag channels connected with cage-like spaces. The potassium atoms in ZBP-K are located near 8MR windows in the 2D zigzag channels, and the potassium cations are successfully exchanged with ammonium cations retaining the open-framework structure. The ammonium form (ZBP-NH4) showed remarkable cation exchange selectivity for Rb(+) and Cs(+) in a mixture of alkali metal cations. It is assumed that zinc ions partially dissolved from the starting layered ZBP precursors are intercalated in ZBP layers to form pillared layered 3D open-frameworks. These results clearly show that topotactic pillared layer approaches are applicable not only to zeolite-related materials but also to novel open-framework metal organophosphonates.

Zinc in Early Life: A Key Element in the Fetus and Preterm Neonate

Science.gov (United States)

Terrin, Gianluca; Berni Canani, Roberto; Di Chiara, Maria; Pietravalle, Andrea; Aleandri, Vincenzo; Conte, Francesca; De Curtis, Mario

2015-01-01

Zinc is a key element for growth and development. In this narrative review, we focus on the role of dietary zinc in early life (including embryo, fetus and preterm neonate), analyzing consequences of zinc deficiency and adequacy of current recommendations on dietary zinc. We performed a systematic search of articles on the role of zinc in early life. We selected and analyzed 81 studies. Results of this analysis showed that preservation of zinc balance is of critical importance for the avoidance of possible consequences of low zinc levels on pre- and post-natal life. Insufficient quantities of zinc during embryogenesis may influence the final phenotype of all organs. Maternal zinc restriction during pregnancy influences fetal growth, while adequate zinc supplementation during pregnancy may result in a reduction of the risk of preterm birth. Preterm neonates are at particular risk to develop zinc deficiency due to a combination of different factors: (i) low body stores due to reduced time for placental transfer of zinc; (ii) increased endogenous losses; and (iii) marginal intake. Early diagnosis of zinc deficiency, through the measurement of serum zinc concentrations, may be essential to avoid severe prenatal and postnatal consequences in these patients. Typical clinical manifestations of zinc deficiency are growth impairment and dermatitis. Increasing data suggest that moderate zinc deficiency may have significant subclinical effects, increasing the risk of several complications typical of preterm neonates (i.e., necrotizing enterocolitis, chronic lung disease, and retinopathy), and that current recommended intakes should be revised to meet zinc requirements of extremely preterm neonates. Future studies evaluating the adequacy of current recommendations are advocated. PMID:26690476

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

International Nuclear Information System (INIS)

Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

2017-01-01

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn 2+ cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn 2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

Energy Technology Data Exchange (ETDEWEB)

Salehi, E.; Naderi, Reza [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Ramezanzadeh, B., E-mail: ramezanzadeh@aut.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of)

2017-02-28

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn{sup 2+} cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn{sup 2+} and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

21 CFR 172.180 - Stannous chloride.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Stannous chloride. 172.180 Section 172.180 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Preservatives § 172.180 Stannous chloride. The food additive stannous chloride may be safely used for color...

STABILISATION OF SILTY CLAY SOIL USING CHLORIDE

Directory of Open Access Journals (Sweden)

TAMADHER T. ABOOD

2007-04-01

Full Text Available The object of this paper is to investigate the effect of adding different chloride compounds including (NaCl, MgCl2, CaCl2 on the engineering properties of silty clay soil. Various amounts of salts (2%, 4%, and 8% were added to the soil to study the effect of salts on the compaction characteristics, consistency limits and compressive strength. The main findings of this study were that the increase in the percentage of each of the chloride compounds increased the maximum dry density and decrease the optimum moisture content. The liquid limit, plastic limit and plasticity index decreased with the increase in salt content. The unconfinedcompressive strength increased as the salt content increased.

The degradation of lining of rotary furnaces in the production of zinc oxide

OpenAIRE

Natália Luptáková; Evgeniy Anisimov; Františka Pešlová

2014-01-01

This paper is closely connected with the complex problem of degradation relating to the refractories of rotary furnace linings in the production of zinc oxide. Zinc oxide can be produced by variety of ways, but the most common method of production which is used in Europe is indirect, i.e. pyrolytic combustion of zinc. This method is also called "French process" of manufacturing ZnO. But this mentioned method of preparation leads to the creation of the enormous amount of zinc slag including ch...

Recent development in PWR zinc injection

International Nuclear Information System (INIS)

Ocken, H.; Fruzzetti, K.; Frattini, P.; Wood, C.J.

2002-01-01

Zinc injection to the reactor coolant system (RCS) of PWRs holds the promise to alleviate two key challenges facing PWR plant operators: (1) reducing degradation of coolant system materials, including nickel-base alloy tubing and lower alloy penetrations due to stress corrosion cracking, and (2) lowering shutdown dose rates. Primary water stress corrosion cracking (PWSCC) is a dominant tube failure mode at many plants. This paper summarizes recent observations from U. S. and international PWRs that have implemented zinc injection, focusing primarily on coolant chemistry and dose rate issues. It also provides a look at the future direction of EPRI-sponsored projects on this topic. (authors)

Chitosan/zinc oxide-polyvinylpyrrolidone (CS/ZnO-PVP) nanocomposite for better thermal and antibacterial activity.

Science.gov (United States)

Karpuraranjith, M; Thambidurai, S

2017-11-01

A new biopolymer based ZnO-PVP nanocomposite was successfully synthesized by single step in situ precipitation method using chitosan as biosurfactant, zinc chloride as a source material, PVP as stabilizing agent and sodium hydroxide as precipitating agent. The chemical bonding and crystalline behaviors of chitosan, zinc oxide and PVP were confirmed by FT-IR and XRD analysis. The biopolymer connected ZnO particles intercalated PVP matrix was layer and rod like structure appeared in nanometer range confirmed by HR-SEM and TEM analysis. The surface topography image of CS/ZnO-PVP nanocomposite was obtained in the average thickness of 12nm was confirmed by AFM analysis. Thermal stability of cationic biopolymer based ZnO intercalated PVP has higher stability than CS-PVP and chitosan. Consequently, antimicrobial activity of chitosan/ZnO-PVP matrix acts as a better microbial inhibition activity than PVP-ZnO nanocomposite. The obtained above results demonstrate that CS and ZnO intercalated PVP matrix has better reinforced effect than other components. Therefore, Chitosan/ZnO-PVP nanocomposite may be a promising material for the biomedical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Deficiencia de zinc y sus implicaciones funcionales Zinc deficiency and its functional implications

Directory of Open Access Journals (Sweden)

JORGE L ROSADO

1998-03-01

Full Text Available El presente trabajo tiene por objeto revisar los aspectos teóricos y los estudios realizados en México que sugieren la existencia de la deficiencia moderada de zinc en niños de población rural, así como algunas de las consecuencias de dicha deficiencia en la salud. El zinc es un nutrimento indispensable para el organismo de los humanos y juega un papel importante en una serie de procesos metabólicos: participa en el sitio catalítico de varios sistemas enzimáticos; participa como ion estructural en membranas biológicas, y guarda una estrecha relación con la síntesis de proteínas, entre otras cosas. Es por esto que la deficiencia de zinc está asociada con consecuencias importantes en la salud y la funcionalidad de los individuos, especialmente durante las primeras etapas de la vida. De relevancia para México es la existencia de una deficiencia moderada de zinc en los niños y las consecuencias que ésta pueda tener en la salud de los mismos. Los estudios realizados sugieren que la deficiencia moderada de zinc se presenta asociada con la ingestión de dietas basadas en alimentos de origen vegetal, las cuales contienen cantidades importantes de inhibidores de la absorción de zinc. Este tipo de dietas se consume habitualmente en las zonas rurales y en la población marginal de las ciudades en el país. Entre las consecuencias más importantes de esta deficiencia se encontró un aumento en la presencia de enfermedades infecciosas, especialmente de diarrea, y posibles alteraciones en el desarrollo de la capacidad cognoscitiva.The purpose of this article is to review theoretical aspects and research performed in Mexico suggesting the existence of marginal zinc deficiency in rural children and its consequences on health. Zinc is an indispensable nutrient for humans since it plays an important role in several metabolic pathways: it participates in the catalytic site of several enzymes, as a structural ion of biological membranes and is

Salt, chloride, bleach, and innate host defense

Science.gov (United States)

Wang, Guoshun; Nauseef, William M.

2015-01-01

Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense. PMID:26048979

Salt, chloride, bleach, and innate host defense.

Science.gov (United States)

Wang, Guoshun; Nauseef, William M

2015-08-01

Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense. © Society for Leukocyte Biology.

Zinc in Infection and Inflammation

Directory of Open Access Journals (Sweden)

Nour Zahi Gammoh

2017-06-01

Full Text Available Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB, a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.