Flux synthesis of (3,4)-connected zinc phosphites with different framework topologies

International Nuclear Information System (INIS)

Lin Zhien; Dehnen, Stefanie

2009-01-01

Two three-dimensional open-framework zinc phosphites, H 2 aem.Zn 3 (HPO 3 ) 4 .0.5H 2 O (1) and H 2 apm.Zn 3 (HPO 3 ) 4 (2), have been synthesized by a phosphorous acid flux method, where aem=4-(2-aminoethyl)morpholine and apm=4-(3-aminopropyl)morpholine. Compound 1 crystallizes in the monoclinic system, P2 1 /c, a=9.5852(7) A, b=20.3941(8) A, c=10.5339(8) A, β=94.125(9) o , V=2053.8(2) A 3 , Z=4, R 1 =0.0319, wR 2 =0.0628. Compound 2 crystallizes in the monoclinic system, P2 1 /n, a=8.589(2) A, b=14.020(3) A, c=16.606(3) A, β=97.190(8) o , V=1983.9(7) A 3 , Z=4, R 1 =0.0692, wR 2 =0.1479. Both compounds are based on (3,4)-connected networks with 8- and 12-ring channels, which are constructed from Zn 3 (HPO 3 ) 4 clusters as the same secondary building units. These inorganic clusters are spatially organized by different structure-directing agents into different three-dimensional frameworks. - Graphical abstract: Two three-dimensional open-framework zinc phosphites have been synthesized by a phosphorous acid flux method. The two compounds are constructed from Zn 3 (HPO 3 ) 4 clusters and have noz and pcu topologies, respectively.

Specially designed B4C/SnO2 nanocomposite for photocatalysis: traditional ceramic with unique properties

Science.gov (United States)

Singh, Paviter; Kaur, Gurpreet; Singh, Kulwinder; Singh, Bikramjeet; Kaur, Manpreet; Kaur, Manjot; Krishnan, Unni; Kumar, Manjeet; Bala, Rajni; Kumar, Akshay

2018-02-01

Boron carbide: A traditional ceramic material shows unique properties when explored in nano-range. Specially designed boron-based nanocomposite has been synthesized by reflux method. The addition of SnO2 in base matrix increases the defect states in boron carbide and shows unique catalytic properties. The calculated texture coefficient and Nelson-Riley factor show that the synthesized nanocomposite has large number of defect states. Also this composite is explored for the first time for catalysis degradation of industrial used dyes. The degradation analysis of industrial pollutants such as Novacron red Huntsman (NRH) and methylene blue (MB) dye reveals that the composite is an efficient catalyst. Degradation study shows that 1 g/L catalyst concentration of B4C/SnO2 degrades NRH and MB dye up to approximately 97.38 and 79.41%, respectively, in 20 min under sunlight irradiation. This water-insoluble catalyst can be recovered and reused.

Structure of Stenotrophomonas maltophilia FeoA complexed with zinc: a unique prokaryotic SH3-domain protein that possibly acts as a bacterial ferrous iron-transport activating factor

International Nuclear Information System (INIS)

Su, Yi-Che; Chin, Ko-Hsin; Hung, Hui-Chih; Shen, Gwan-Han; Wang, Andrew H.-J.; Chou, Shan-Ho

2010-01-01

The crystal structure of FeoA from Stenotrophomonas maltophilia has been determined to a resolution of 1.7 Å using an Se single-wavelength anomalous dispersion (Se-SAD) approach and revealed a unique dimer cross-linked by two zinc ions and six chloride ions. Iron is vital to the majority of prokaryotes, with ferrous iron believed to be the preferred form for iron uptake owing to its much better solubility. The major route for bacterial ferrous iron uptake is found to be via an Feo (ferrous iron-transport) system comprising the three proteins FeoA, FeoB and FeoC. Although the structure and function of FeoB have received much attention recently, the roles played by FeoA and FeoC have been little investigated to date. Here, the tertiary structure of FeoA from Stenotrophomonas maltophilia (Sm), a vital opportunistic pathogen in immunodepressed hosts, is reported. The crystal structure of SmFeoA has been determined to a resolution of 1.7 Å using an Se single-wavelength anomalous dispersion (Se-SAD) approach. Although SmFeoA bears low sequence identity to eukaryotic proteins, its structure is found to adopt a eukaryotic SH3-domain-like fold. It also bears weak similarity to the C-terminal SH3 domain of bacterial DtxR (diphtheria toxin regulator), with some unique characteristics. Intriguingly, SmFeoA is found to adopt a unique dimer cross-linked by two zinc ions and six anions (chloride ions). Since FeoB has been found to contain a G-protein-like domain with low GTPase activity, FeoA may interact with FeoB through the SH3–G-protein domain interaction to act as a ferrous iron-transport activating factor

Unique photosynthetic phenotypes in Portulaca (Portulacaceae): C3-C4 intermediates and NAD-ME C4 species with Pilosoid-type Kranz anatomy.

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Voznesenskaya, Elena V; Koteyeva, Nuria K; Edwards, Gerald E; Ocampo, Gilberto

2017-01-01

Portulacaceae is a family that has considerable diversity in photosynthetic phenotypes. It is one of 19 families of terrestrial plants where species having C 4 photosynthesis have been found. Most species in Portulaca are in the alternate-leaved (AL) lineage, which includes one clade (Cryptopetala) with taxa lacking C 4 photosynthesis and three clades having C 4 species (Oleracea, Umbraticola and Pilosa). All three species in the Cryptopetala clade lack Kranz anatomy, the leaves have C 3 -like carbon isotope composition and they have low levels of C 4 cycle enzymes. Anatomical, biochemical and physiological analyses show they are all C 3 -C 4 intermediates. They have intermediate CO 2 compensation points, enrichment of organelles in the centripetal position in bundle sheath (BS) cells, with selective localization of glycine decarboxylase in BS mitochondria. In the three C 4 clades there are differences in Kranz anatomy types and form of malic enzyme (ME) reported to function in C 4 (NAD-ME versus NADP-ME): Oleracea (Atriplicoid, NAD-ME), Umbraticola (Atriplicoid, NADP-ME) and Pilosa (Pilosoid, NADP-ME). Structural and biochemical analyses were performed on Pilosa clade representatives having Pilosoid-type leaf anatomy with Kranz tissue enclosing individual peripheral vascular bundles and water storage in the center of the leaf. In this clade, all species except P. elatior are NADP-ME-type C 4 species with grana-deficient BS chloroplasts and grana-enriched M chloroplasts. Surprisingly, P. elatior has BS chloroplasts enriched in grana and NAD-ME-type photosynthesis. The results suggest photosynthetic phenotypes were probably derived from an ancestor with NADP-ME-type C 4 , with two independent switches to NAD-ME type. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

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.

C2H2 type of zinc finger transcription factors in foxtail millet define response to abiotic stresses.

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Muthamilarasan, Mehanathan; Bonthala, Venkata Suresh; Mishra, Awdhesh Kumar; Khandelwal, Rohit; Khan, Yusuf; Roy, Riti; Prasad, Manoj

2014-09-01

C2H2 type of zinc finger transcription factors (TFs) play crucial roles in plant stress response and hormone signal transduction. Hence considering its importance, genome-wide investigation and characterization of C2H2 zinc finger proteins were performed in Arabidopsis, rice and poplar but no such study was conducted in foxtail millet which is a C4 Panicoid model crop well known for its abiotic stress tolerance. The present study identified 124 C2H2-type zinc finger TFs in foxtail millet (SiC2H2) and physically mapped them onto the genome. The gene duplication analysis revealed that SiC2H2s primarily expanded in the genome through tandem duplication. The phylogenetic tree classified these TFs into five groups (I-V). Further, miRNAs targeting SiC2H2 transcripts in foxtail millet were identified. Heat map demonstrated differential and tissue-specific expression patterns of these SiC2H2 genes. Comparative physical mapping between foxtail millet SiC2H2 genes and its orthologs of sorghum, maize and rice revealed the evolutionary relationships of C2H2 type of zinc finger TFs. The duplication and divergence data provided novel insight into the evolutionary aspects of these TFs in foxtail millet and related grass species. Expression profiling of candidate SiC2H2 genes in response to salinity, dehydration and cold stress showed differential expression pattern of these genes at different time points of stresses.

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

Unique bar-like sulfur-doped C3N4/TiO2 nanocomposite: Excellent visible light driven photocatalytic activity and mechanism study

Science.gov (United States)

Zhao, Yu; Xu, Shiping; Sun, Xiang; Xu, Xing; Gao, Baoyu

2018-04-01

In this work, a nanocomposite of TiO2 nanoparticles coupled with sulfur-doped C3N4 (S-C3N4) laminated layer was successfully fabricated using a facile impregnation method and the nanocomposite exhibited superior photocatalytic activity in pollutant removal under visible light irradiation, compared to bare TiO2, g-C3N4 and binary C3N4-TiO2 nanocomposite. The enhanced photocatalytic activity was benefited from the efficient migration and transformation of electron-hole (e--h+) pairs, improved visible light absorption capability, and relatively large specific surface area induce by sulfur doping. Interestingly, the introduction of sulfur changes regulated the morphology of g-C3N4 leading to the formation of ultrathin g-C3N4 layer nanosheet assemblies and unique bar-like g-C3N4/TiO2 nanocomposite, which is beneficial for the outstanding performance of the product. In addition, trapping experiment was carried out to identify the main active species in the photocatalytic reaction over the S-C3N4/TiO2 photocatalyst, and functional mechanism of the composite was proposed. This work may provide new ideas for the fabrication and utilization of highly efficient photocatalyst with excellent visible light response in environmental purification applications.

Reactions of zinc hydride and magnesium hydride with pyridine; synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes

NARCIS (Netherlands)

Koning, A.J. de; Boersma, J.; Kerk, G.J.M. van der

1980-01-01

The synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes are described. Zinc hydride and magnesium hydride dissolve in and react with pyridine, and the reaction has been studied in detail in the case of zinc hydride. Evaporation of the solvent after 1–2 hours at 0°C

Mechanisms of zinc binding to the solute-binding protein AztC and transfer from the metallochaperone AztD.

Science.gov (United States)

Neupane, Durga P; Avalos, Dante; Fullam, Stephanie; Roychowdhury, Hridindu; Yukl, Erik T

2017-10-20

Bacteria can acquire the essential metal zinc from extremely zinc-limited environments by using ATP-binding cassette (ABC) transporters. These transporters are critical virulence factors, relying on specific and high-affinity binding of zinc by a periplasmic solute-binding protein (SBP). As such, the mechanisms of zinc binding and release among bacterial SBPs are of considerable interest as antibacterial drug targets. Zinc SBPs are characterized by a flexible loop near the high-affinity zinc-binding site. The function of this structure is not always clear, and its flexibility has thus far prevented structural characterization by X-ray crystallography. Here, we present intact structures for the zinc-specific SBP AztC from the bacterium Paracoccus denitrificans in the zinc-bound and apo-states. A comparison of these structures revealed that zinc loss prompts significant structural rearrangements, mediated by the formation of a sodium-binding site in the apo-structure. We further show that the AztC flexible loop has no impact on zinc-binding affinity, stoichiometry, or protein structure, yet is essential for zinc transfer from the metallochaperone AztD. We also found that 3 His residues in the loop appear to temporarily coordinate zinc and then convey it to the high-affinity binding site. Thus, mutation of any of these residues to Ala abrogated zinc transfer from AztD. Our structural and mechanistic findings conclusively identify a role for the AztC flexible loop in zinc acquisition from the metallochaperone AztD, yielding critical insights into metal binding by AztC from both solution and AztD. These proteins are highly conserved in human pathogens, making this work potentially useful for the development of novel antibiotics. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Enabling cell-cell communication via nanopore formation: structure, function and localization of the unique cell wall amidase AmiC2 of Nostoc punctiforme.

Science.gov (United States)

Büttner, Felix M; Faulhaber, Katharina; Forchhammer, Karl; Maldener, Iris; Stehle, Thilo

2016-04-01

To orchestrate a complex life style in changing environments, the filamentous cyanobacterium Nostoc punctiforme facilitates communication between neighboring cells through septal junction complexes. This is achieved by nanopores that perforate the peptidoglycan (PGN) layer and traverse the cell septa. The N-acetylmuramoyl-l-alanine amidase AmiC2 (Npun_F1846; EC 3.5.1.28) in N. punctiforme generates arrays of such nanopores in the septal PGN, in contrast to homologous amidases that mediate daughter cell separation after cell division in unicellular bacteria. Nanopore formation is therefore a novel property of AmiC homologs. Immunofluorescence shows that native AmiC2 localizes to the maturing septum. The high-resolution crystal structure (1.12 Å) of its catalytic domain (AmiC2-cat) differs significantly from known structures of cell splitting and PGN recycling amidases. A wide and shallow binding cavity allows easy access of the substrate to the active site, which harbors an essential zinc ion. AmiC2-cat exhibits strong hydrolytic activity in vitro. A single point mutation of a conserved glutamate near the zinc ion results in total loss of activity, whereas zinc removal leads to instability of AmiC2-cat. An inhibitory α-helix, as found in the Escherichia coli AmiC(E. coli) structure, is absent. Taken together, our data provide insight into the cell-biological, biochemical and structural properties of an unusual cell wall lytic enzyme that generates nanopores for cell-cell communication in multicellular cyanobacteria. The novel structural features of the catalytic domain and the unique biological function of AmiC2 hint at mechanisms of action and regulation that are distinct from other amidases. The AmiC2-cat structure has been deposited in the Protein Data Bank under accession number 5EMI. © 2016 Federation of European Biochemical Societies.

PML-RARα stabilized by zinc in human acute promyelocytic leukemia NB4 cells.

Science.gov (United States)

Zhu, Bo; Wang, Jia-Yu; Zhou, Jun-Jie; Zhou, Feng; Cheng, Wei; Liu, Ying-Ting; Wang, Jie; Chen, Xiao; Chen, Dian-Hua; Luo, Lan; Hua, Zi-Chun

2017-10-01

Acute promyelocytic leukemia (APL) is characterized and driven by the promyelocytic leukemia protein-retinoic acid receptor alpha (PML-RARα) fusion gene. Previous studies have highlighted the importance of PML-RARα degradation in the treatment against APL. Considering the presence of two zinc fingers in the PML-RARα fusion protein, we explored the function of zinc homeostasis in maintaining PML-RARα stability. We demonstrated for the first time that zinc depletion by its chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) triggered PML-RARα degradation in NB4 APL cells via the proteasome pathway rather than the autophagy-lysosomal pathway. In contrast, autophagy protected TPEN-mediated PML-RARα degradation in NB4 APL cells. We further demonstrated that crosstalk between zinc homeostasis and nitric oxide pathway played a key role in maintaining PML-RARα stability in NB4 APL cells. These results demonstrate that zinc homeostasis is vital for maintaining PML-RARα stability, and zinc depletion by TPEN may be useful as a potential strategy to trigger PML-RARα degradation in APL cells. We also found that TPEN triggered apoptosis of NB4 APL cells in a time-dependent manner. The relationship between PML-RARα degradation and apoptosis triggered by TPEN deserves further study. Copyright © 2017 Elsevier Inc. All rights reserved.

Uptake and loss of dissolved zinc by the stickleback gasterosteus Aculeatus l. [Zinc 65

Energy Technology Data Exchange (ETDEWEB)

Matthiessen, P.; Brafield, A.E.

1977-01-01

Uptake and loss by sticklebacks of both stable zinc and /sup 65/Zn in hard and soft water were studied for periods up to 400 h. In calcium-free water, the zinc uptake curve is approximately asymptotic over a period of 24 h, while in hard water internal Zn levels dropped at 24 h. Over 5 h, fish in hard tapwater absorb about 3 to 5 times more Zn than those in calcium-free water. There is positive linear correlation between log Zn uptake and log wet weight of fish. Whole-body concentration factors (c.f.) at 16 h reach a maximum of 12.2 (mean = 2.9), highest concentrations of Zn being found in the gills (mean c.f. = 5.1), and lowest concentrations in the gonads (mean c.f. = 0.8). Over longer periods (400 h), internal stable zinc levels of fish exposed to 1 and 4 ppM Zn/sup +2/ remain little higher than controls (max. 28%) /sup 65/Zn efflux in zinc-free water falls to zero after 5 h, more zinc (78%) being lost after uptake in tapwater than in calcium-free water (56%).

Occupancy of a C2-C2 type 'zinc-finger' protein domain by copper. Direct observation by electrospray ionization mass spectrometry.

Science.gov (United States)

Hutchens, T W; Allen, M H; Li, C M; Yip, T T

1992-09-07

The metal ion specificity of most 'zinc-finger' metal binding domains is unknown. The human estrogen receptor protein contains two different C2-C2 type 'zinc-finger' sequences within its DNA-binding domain (ERDBD). Copper inhibits the function of this protein by mechanisms which remain unclear. We have used electrospray ionization mass spectrometry to evaluate directly the 71-residue ERDBD (K180-M250) in the absence and presence of Cu(II) ions. The ERDBD showed a high affinity for Cu and was completely occupied with 4 Cu bound; each Cu ion was evidently bound to only two ligand residues (net loss of only 2 Da per bound Cu). The Cu binding stoichiometry was confirmed by atomic absorption. These results (i) provide the first direct physical evidence for the ability of the estrogen receptor DNA-binding domain to bind Cu and (ii) document a twofold difference in the Zn- and Cu-binding capacity. Differences in the ERDBD domain structure with bound Zn and Cu are predicted. Given the relative intracellular contents of Zn and Cu, our findings demonstrate the need to investigate further the Cu occupancy of this and other zinc-finger domains both in vitro and in vivo.

Delayed plasma clearance and hepatic uptake of lymph chylomicron 14C-cholesterol in marginally zinc-deficient rats

International Nuclear Information System (INIS)

Koo, S.I.; Algilani, K.; Norvell, J.E.; Henderson, D.A.

1986-01-01

Previously, chylomicrons from marginally zinc-deficient rats were shown to be abnormally large, with markedly reduced levels of apoproteins C and E. In the present study, effects of such changes on the plasma clearance and hepatic uptake of chylomicron cholesterol were investigated in rats fed 3 ppm of zinc (ZD), as compared with those fed 30 ppm of zinc (CT). The rate of plasma clearance was determined by plasma 14C-radioactivity at different intervals after intravenous injection of lymph chylomicrons labeled in vivo with 14C-cholesterol. The 14C-clearance curves were nonlinear, consisting of an initial rapid phase followed by a slow phase of clearance. The initial 14C-clearance was significantly (p less than 0.05) delayed whether the labeled chylomicrons from ZD donors were injected into ZD or CT recipients. The hepatic 14C-recovery in extracted lipids was also significantly lower in ZD rats. The present data provide first evidence that a marginal level of zinc deficiency produces a significant delay in the plasma clearance and hepatic uptake of chylomicron cholesterol. This may be attributable in part to the molecular alterations of chylomicrons induced by zinc deficiency

Study of solid state interactions in the systems ZnFe2O4 - CaO, ZnFe2O4 - MgO and zinc cake with CaO and MgO

Directory of Open Access Journals (Sweden)

Peltekov A.B.

2013-01-01

Full Text Available The solid state interactions of CaO and MgO with synthetic and industrial ZnFe2O4 (in zinc cake have been studied using chemical, XRD analysis and Mössbauer spectroscopy. The exchange reactions in the systems ZnFe2O4 - CaO and ZnFe2O4 - MgO have been investigated in the range of 850-1200ºC and duration up to 180 min. It has been established that Ca2+ and Mg2+ ions exchange Zn2+ in ferrite partially and the solubility of zinc in a 7% sulfuric acid solution increases. The possibilities for utilization of the obtained results in zinc hydrometallurgy have been discussed.

Effects of Sodium Citrate on the Ammonium Sulfate Recycled Leaching of Low-Grade Zinc Oxide Ores

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Yang, Kun; Li, Shi-wei; Zhang, Li-bo; Peng, Jin-hui; Ma, Ai-yuan; Wang, Bao-bao

2016-03-01

The effects of sodium citrate on ammonium sulfate recycled leaching of low-grade zinc oxide ores were studied. By applying various kinds of detection and analysis techniques such as chemical composition analysis, chemical phase method, scanning electron microscopy and energy dispersive spectrum (SEM/EDS), X-ray diffraction (XRD) and Fourier-transforming infrared spectrum (FT-IR), zinc raw ore, its leaching slag and the functional mechanism of sodium citrate were investigated. Based on a comprehensive analysis, it can be concluded that in contrast to hemimorphite (Zn4Si2O7(OH)2 · H2O), amorphous smithsonite (ZnCO3) and zinc silicate (Zn2SiO4) prove to be refractory phases under ammonium sulfate leaching, while sodium citrate has a better chelating action with the refractory phases, resulting in a higher zinc leaching rate. Under conditions of [NH3]/[NH3]T molar ratio being 0.5, [NH3]T being 7.5 mol/L, [Na3C6H5O7] being 0.2 mol/L, S/L ratio being 1:5, temperature being 303 K, holding time being 1 h in each of the two stages, and stirring rate being 300 rpm, the leaching rate of zinc reached 93.4%. In this article, sulfate ammonium recycled technology also reveals its unique advantage in processing low-grade zinc oxide ores accompanied by high silicon and high alkaline gangue.

Novel mechanism of aberrant ZIP4 expression with zinc supplementation in oral tumorigenesis

International Nuclear Information System (INIS)

Ishida, Sho; Kasamatsu, Atsushi; Endo-Sakamoto, Yosuke; Nakashima, Dai; Koide, Nao; Takahara, Toshikazu; Shimizu, Toshihiro; Iyoda, Manabu; Shiiba, Masashi; Tanzawa, Hideki; Uzawa, Katsuhiro

2017-01-01

Zrt-Irt-like protein 4 (ZIP4) is critical molecule for proper mammalian development and releasing zinc from vesicular compartments. Recent studies suggested that ZIP4 plays an important role of tumor progression in pancreatic, prostate, and hepatocellular cancers, however, little is known about the detail mechanism of ZIP4 in their cancers. In the present study, we examined the possibility of ZIP4 as a new molecular target for oral squamous cell carcinoma (OSCC). We evaluated ZIP4 expression in OSCC-derived cell lines and primary OSCC samples by quantitative RT-PCR, immunoblotting, and immunohistochemistry (IHC). We also analyzed the clinical correlation between ZIP4 status and clinical behaviors in patients with OSCC. In addition, ZIP4 knockdown cells (shZIP4 cells) and ZnCl 2 treatment were used for functional experiments, including cellular proliferation assay, zinc uptake assay, and cell-cycle analysis. ZIP4 mRNA and protein were up-regulated significantly in OSCCs compared with normal counterparts in vitro and in vivo. IHC showed that ZIP4 expression in the primary OSCC was positively correlated with primary tumoral size. The shZIP4 cells showed decrease accumulation of intercellular zinc and decreased cellular growth by cell-cycle arrest at the G1 phase, resulting from up-regulation of cyclin-dependent kinase inhibitors and down-regulation of cyclins and cyclin-dependent kinases. Since cellular growth of OSCC cells after treatment with zinc was significantly greater than control cells, we speculated that intercellular ZnCl 2 accumulation is an important factor for cellular growth. Consistent with our hypothesis, not only decreased zinc uptake by ZIP4 knockdown but also chelating agent, N,N,N′,N′-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN), showed inhibitory effects of cellular proliferation. Therefore, our data provide evidence for an essential role of ZIP4 and intracellular zinc for tumoral growth in OSCC, suggesting that zinc uptake might be a

[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.

Synthesis, characterization and thermal behavior of antibacterial and antifungal active zinc complexes of bis (3(4-dimethylaminophenyl)-allylidene-1,2-diaminoethane

International Nuclear Information System (INIS)

Montazerozohori, Morteza; Zahedi, Saeedeh; Naghiha, Asghar; Zohour, Mostafa Montazer

2014-01-01

In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV–visible, 1 H and 13 C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX 2 (X = Cl − , Br − , I − , SCN − and N 3 − ) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3–4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E ⁎ ), enthalpy (∆H ⁎ ), entropy (∆S ⁎ ) and Gibbs free energy change (∆G ⁎ ) of the thermal decomposition steps were performed based on the Coats–Redfern relation. - Highlights: • Some novel complexes of Zn(II) with a bidentate Schiff base ligand have been synthesized. • Redox behavior of ligand and zinc complexes was investigated by cyclic voltammetry. • The ligand and its zinc complexes are antibacterial and

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.

Production of zinc and manganese oxide particles by pyrolysis of alkaline and Zn-C battery waste.

Science.gov (United States)

Ebin, Burçak; Petranikova, Martina; Steenari, Britt-Marie; Ekberg, Christian

2016-05-01

Production of zinc and manganese oxide particles from alkaline and zinc-carbon battery black mass was studied by a pyrolysis process at 850-950°C with various residence times under 1L/minN2(g) flow rate conditions without using any additive. The particular and chemical properties of the battery waste were characterized to investigate the possible reactions and effects on the properties of the reaction products. The thermodynamics of the pyrolysis process were studied using the HSC Chemistry 5.11 software. The carbothermic reduction reaction of battery black mass takes place and makes it possible to produce fine zinc particles by a rapid condensation, after the evaporation of zinc from a pyrolysis batch. The amount of zinc that can be separated from the black mass is increased by both pyrolysis temperature and residence time. Zinc recovery of 97% was achieved at 950°C and 1h residence time using the proposed alkaline battery recycling process. The pyrolysis residue is mainly MnO powder with a low amount of zinc, iron and potassium impurities and has an average particle size of 2.9μm. The obtained zinc particles have an average particle size of about 860nm and consist of hexagonal crystals around 110nm in size. The morphology of the zinc particles changes from a hexagonal shape to s spherical morphology by elevating the pyrolysis temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultrasonic synthesis of two new zinc(II) bipyridine coordination polymers: New precursors for preparation of zinc(II) oxide nano-particles.

Science.gov (United States)

Fard, Mohammad Jaafar Soltanian; Hayati, Payam; Firoozadeh, Azita; Janczak, Jan

2017-03-01

Nanoparticles of two zinc(II) coordination polymers (CPs), [Zn(μ-4,4'-bipy)Cl 2 ] n (1) and [Zn(μ-4,4'-bipy)Br 2 ] n (2) L=bpy=4,4'-bipyridine ligand, have been synthesized by use of a sonochemical process and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) spectroscopy and elemental analyses. The single crystal X-ray data of compounds 1 and 2 imply that the Zn +2 ions are four coordinated. Topological analysis shows that 1D coordination networks of 1 and 2 can be classified as underlying nets of topological types 2C1. Nanoparticles of zinc(II) oxide have been prepared by calcination of two different zinc (II) CPs at 450°C that were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and IR spectroscopy. Copyright © 2016 Elsevier B.V. All rights reserved.

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....

Radiation induced traps of zinc phosphate and phosphide

International Nuclear Information System (INIS)

Murali, K.R.; Rao, D.R.

1980-01-01

Thermoluminescence (TL) glow curve (TGC) method has been used to study the traps produced by X-irradiation in Zn 3 (PO 4 ) 2 and Zn 3 P 2 . Prominent TL glow peaks were observed at 100 0 and 360 0 C for zinc phosphate while for zinc phosphide only one glow peak at 245 0 C was observed, and in the latter case the TL output was in general quite low compared to zinc phosphate. The TL spectra for both the glow peaks of zinc phosphate indicated emission band in the region around 560 nm, while for zinc phosphide the emission occurred at 575 nm (in the temperature region 200-270 0 C). The low temperature glow peaks below 270 0 C were less stable compared to those above 300 0 C and were completely destroyed when the irradiated samples were stored in darkness for 24 hr at room temperature. Shining by 470 nm light however produced preferential bleaching of the two TL peaks at 100 and 360 0 C with no effect on the 245 0 C glow peak of zinc phosphide. It is concluded that during heat treatment large numbers of Zn-vacancies are formed due to which complexes like Zn-P are produced by irradiation and the TL traps destroyed in a radiative recombination process are related with these complexes. (author)

Effect of Selenium, Zinc, Vitamin C and E on Boar Ejaculate Quality at Heat Stress

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Pavel Horký

2016-01-01

Full Text Available The aim of experiment was to test effect of selected antioxidants (selenium, zinc, vitamin C and E to reduce the impact of heat stress at boars. In the experiment, boars of Duroc breed were tested. The first control group (n = 10 was not supplemented with antioxidants. The second experimental group (n = 10 was supplemented with antioxidants in the following quantities of 0.5 mg of selenium (seleno-methionine, 100 mg of zinc (zinc-methionine, 70 mg of vitamin E (alpha‑tocopherol and 350 mg of vitamin C (ascorbic acid per kilogram of their feed. The experiment was carried out for 120 days and took place in summer (June to September. During the experiment, average and maximum daily temperatures, where boars were stabled, were monitored. Average daily temperature ranged from 12 to 28 °C. Maximum temperature during the day was from 13 to 32 °C. The evaluation of the semen quality has revealed increased number of abnormal spermatozoa in the control group of boars by 39 % (P < 0.05. There were observed no significant changes at other monitored parameters (ejaculate volume, total count of produced sperm, motility and sperm concentration. The results show that the addition of selenium, zinc, vitamin C and E may reduce the effect of heat stress to some extent at breeding boars.

[Synergistic application of zinc and vitamin C to support memory, attention and the reduction of the risk of the neurological diseases].

Science.gov (United States)

Gromova, O A; Torshin, I Yu; Pronin, A V; Kilchevsky, M A

Zinc and vitamin C supplementation of the body is important for CNS functioning. Zinc ions are involved in the neurotransmission (signal transmission from acetylcholine, catecholamine, serotonin, prostaglandin receptors) and in ubiquitin-related protein degradation. Zinc deficits are associated with Alzheimer's disease and depression. Zinc supplementation (10-30 mg daily) improves neurologic recovery rate in patients with stroke and brain injury, has a positive impact on memory and reduces hyperactivity in children. Vitamin C, a zinc synergist, maintains antioxidant resources of the brain, synaptic activity and detoxification. Vitamin C in dose 130-500 mg daily should be used to prevent dementia and neurodegenerative pathology.

Spectrophotometric Determination of Zinc Using 7-(4-Nitrophenylazo-8-Hydroxyquinoline-5-Sulfonic Acid

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Korn Maria das Graças Andrade

1999-01-01

Full Text Available A sensitive and selective spectrophotometric method is proposed for the rapid determination of zinc(II using an 8-hydroxyquinoline derivative, 7-(4-nitrophenylazo-8-hydroxyquinoline-5-sulfonic acid (p-NIAZOXS, as a new spectrophotometric reagent. The reaction between the p-NIAZOXS and zinc(II is instantaneous at pH 9.2 (borax buffer and the absorbance remains stable for over 24 h. The method allows the determination of zinc over the range of 0.05-1.0 mug mL-1 with a molar absorptivity of 3.75x10(4 L mol-1 cm-1 and features a detection limit of 15 ng mL-1. The proposed method has been successfully applied to the determination of zinc in several pharmaceutical preparations and copper alloys. The precision (R.S.D. < 2% and the accuracy obtained were satisfactory.

Synthesis, characterization and thermal behavior of antibacterial and antifungal active zinc complexes of bis (3(4-dimethylaminophenyl)-allylidene-1,2-diaminoethane

Energy Technology Data Exchange (ETDEWEB)

Montazerozohori, Morteza, E-mail: mmzohori@mail.yu.ac.ir [Department of Chemistry, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Zahedi, Saeedeh [Department of Chemistry, Yasouj University, Yasouj 75918-74831 (Iran, Islamic Republic of); Naghiha, Asghar [Department of Animal Sciences, Faculty of Agriculture, Yasouj University, Yasouj (Iran, Islamic Republic of); Zohour, Mostafa Montazer [Genetics of Non-Communicable Disease Research Center, Zahedan University of Medical Sciences, Zahedan (Iran, Islamic Republic of)

2014-02-01

In this work, synthesis of a new series of zinc halide/pseudohalide complexes of a bidentate Schiff base ligand entitled as bis (3-(4-dimethylaminophenyl)-allylidene)-1,2-diaminoethane(L) is described. The ligand and its zinc complexes were characterized by various techniques such as elemental analysis, FT-IR, UV–visible, {sup 1}H and {sup 13}C NMR spectra, cyclic voltammetry, and conductometry. Accordingly ZnLX{sub 2} (X = Cl{sup −}, Br{sup −}, I{sup −}, SCN{sup −} and N{sub 3}{sup −}) was suggested as molecular formula of the complexes. Redox behaviors of ligand and its zinc complexes were investigated by cyclic voltammetry method. Furthermore, the ligand and its zinc halide/pseudohalide complexes were tested for their in vitro antibacterial activities against two gram positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Also in vitro antifungal activities of them against Candida albicans and Aspergillus niger were investigated. The results indicated that all compounds are antibacterial and antifungal active. Thermal behaviors of ligand and its zinc complexes were studied from room temperature to 1100 °C under argon atmosphere. It was found that the ligand and zinc iodide are decomposed completely via three and four steps respectively while other zinc complexes leave out the metal or organometallic compounds as final residuals after 3–4 decomposition steps at above temperature range. Moreover evaluation of some thermo-kinetic parameters such as activation energy (∆E{sup ⁎}), enthalpy (∆H{sup ⁎}), entropy (∆S{sup ⁎}) and Gibbs free energy change (∆G{sup ⁎}) of the thermal decomposition steps were performed based on the Coats–Redfern relation. - Highlights: • Some novel complexes of Zn(II) with a bidentate Schiff base ligand have been synthesized. • Redox behavior of ligand and zinc complexes was investigated by cyclic voltammetry. • The

Does Zinc Sulfate Prevent Therapy-Induced Taste Alterations in Head and Neck Cancer Patients? Results of Phase III Double-Blind, Placebo-Controlled Trial from the North Central Cancer Treatment Group (N01C4)

International Nuclear Information System (INIS)

Halyard, Michele Y.; Jatoi, Aminah; Sloan, Jeff A.; Bearden, James D.; Vora, Sujay A.; Atherton, Pamela J.; Perez, Edith A.; Soori, Gammi; Zalduendo, Anthony C.; Zhu, Angela; Stella, Philip J.; Loprinzi, Charles L.

2007-01-01

Purpose: Taste alterations (dysgeusia) are well described in head and neck cancer patients who undergo radiotherapy (RT). Anecdotal observations and pilot studies have suggested zinc may mitigate these symptoms. This multi-institutional, double-blind, placebo-controlled trial was conducted to provide definitive evidence of this mineral's palliative efficacy. Methods and Materials: A total of 169 evaluable patients were randomly assigned to zinc sulfate 45 mg orally three times daily vs. placebo. Treatment was to be given throughout RT and for 1 month after. All patients were scheduled to receive ≥2,000 cGy of external beam RT to ≥30% of the oral cavity, were able to take oral medication, and had no oral thrush at study entry. Changes in taste were assessed using the previously validated Wickham questionnaire. Results: At baseline, the groups were comparable in age, gender, and planned radiation dose (<6,000 vs. ≥6,000 cGy). Overall, 61 zinc-treated (73%) and 71 placebo-exposed (84%) patients described taste alterations during the first 2 months (p = 0.16). The median interval to taste alterations was 2.3 vs. 1.6 weeks in the zinc-treated and placebo-exposed patients, respectively (p = 0.09). The reported taste alterations included the absence of any taste (16%), bitter taste (8%), salty taste (5%), sour taste (4%), sweet taste (5%), and the presence of a metallic taste (10%), as well as other descriptions provided by a write in response (81%). Zinc sulfate did not favorably affect the interval to taste recovery. Conclusion: Zinc sulfate, as prescribed in this trial, did not prevent taste alterations in cancer patients who were undergoing RT to the oral pharynx

Hydrothermal synthesis and characterization of a new three-dimensional hybrid zinc phosphate [Zn2(HPO4)2(4,4'-bipy)].3H2O with neutral porous framework

International Nuclear Information System (INIS)

Wang Lei; Yang Ming; Li Guanghua; Shi Zhan; Feng Shouhua

2006-01-01

Employing 4,4'-bipyridine as a bridged ligand, a new three-dimensional (3-D) hybrid zinc phosphate [Zn 2 (HPO 4 ) 2 (4,4'-bipy)].3H 2 O has been prepared under hydrothermal conditions and characterized by single crystal X-ray diffraction. This compound crystallizes in the monoclinic space group C2/c, with cell parameters, a=21.188(4)A, b=10.229(2)A, c=9.0656(18)A, β=90.21(3) o , V=1964.8(7)A 3 and Z=4. The connectivity of the ZnO 3 N and HPO 4 tetrahedra results in a 2-D neutral layer that with interesting 4,8 2 net along the bc plane. Furthermore, the 4,4'-bipyridine molecule links the 4,8 2 net into a 3-D structure. The water molecules sit in the middle of the channels and interact with the framework via hydrogen bonds. The compound exhibits intense photoluminescence at room temperature

Participatory role of zinc in structural and functional characterization of bioremediase: a unique thermostable microbial silica leaching protein.

Science.gov (United States)

Chowdhury, Trinath; Sarkar, Manas; Chaudhuri, Biswadeep; Chattopadhyay, Brajadulal; Halder, Umesh Chandra

2015-07-01

A unique protein, bioremediase (UniProt Knowledgebase Accession No.: P86277), isolated from a hot spring bacterium BKH1 (GenBank Accession No.: FJ177512), has shown to exhibit silica leaching activity when incorporated to prepare bio-concrete material. Matrix-assisted laser desorption ionization mass spectrometry analysis suggests that bioremediase is 78% homologous to bovine carbonic anhydrase II though it does not exhibit carbonic anhydrase-like activity. Bioinformatics study is performed for understanding the various physical and chemical parameters of the protein which predicts the involvement of zinc encircled by three histidine residues (His94, His96 and His119) at the active site of the protein. Isothermal titration calorimetric-based thermodynamic study on diethyl pyrocarbonate-modified protein recognizes the presence of Zn(2+) in the enzyme moiety. Exothermic to endothermic transition as observed during titration of the protein with Zn(2+) discloses that there are at least two binding sites for zinc within the protein moiety. Addition of Zn(2+) regains the activity of EDTA chelated bioremediase confirming the presence of extra binding site of Zn(2+) in the protein moiety. Revival of folding pattern of completely unfolded urea-treated protein by Zn(2+) explains the participatory role of zinc in structural stability of the protein. Restoration of the λ max in intrinsic fluorescence emission study of the urea-treated protein by Zn(2+) similarly confirms the involvement of Zn in the refolding of the protein. The utility of bioremediase for silica nanoparticles preparation is observed by field emission scanning electron microscopy.

Zinc(II) and the single-stranded DNA binding protein of bacteriophage T4

International Nuclear Information System (INIS)

Gauss, P.; Krassa, K.B.; McPheeters, D.S.; Nelson, M.A.; Gold, L.

1987-01-01

The DNA binding domain of the gene 32 protein of the bacteriophage T4 contains a single zinc-finger sequence. The gene 32 protein is an extensively studied member of a class of proteins that bind relatively nonspecifically to single-stranded DNA. The authors have sequenced and characterized mutations in gene 32 whose defective proteins are activated by increasing the Zn(II) concentration in the growth medium. The results identify a role for the gene 32 protein in activation of T4 late transcription. Several eukaryotic proteins with zinc fingers participate in activation of transcription, and the gene 32 protein of T4 should provide a simple, well-characterized system in which genetics can be utilized to study the role of a zinc finger in nucleic acid binding and gene expression

Unique temporal and spatial biomolecular emission profile on individual zinc oxide nanorods

Science.gov (United States)

Singh, Manpreet; Song, Sheng; Hahm, Jong-In

2013-12-01

Zinc oxide nanorods (ZnO NRs) have emerged in recent years as extremely useful, optical signal-enhancing platforms in DNA and protein detection. Although the use of ZnO NRs in biodetection has been demonstrated so far in systems involving many ZnO NRs per detection element, their future applications will likely take place in a miniaturized setting while exploiting single ZnO NRs in a low-volume, high-throughput bioanalysis. In this paper, we investigate temporal and spatial characteristics of the biomolecular fluorescence on individual ZnO NR systems. Quantitative and qualitative examinations of the biomolecular intensity and photostability are carried out as a function of two important criteria, the time and position along the long axis (length) of NRs. Photostability profiles are also measured with respect to the position on NRs and compared to those characteristics of biomolecules on polymeric control platforms. Unlike the uniformly distributed signal observed on the control platforms, both the fluorescence intensity and photostability are position-dependent on individual ZnO NRs. We have identified a unique phenomenon of highly localized, fluorescence intensification on the nanorod ends (FINE) of well-characterized, individual ZnO nanostructures. When compared to the polymeric controls, the biomolecular fluorescence intensity and photostability are determined to be higher on individual ZnO NRs regardless of the position on NRs. We have also carried out finite-difference time-domain simulations the results of which are in good agreement with the observed FINE. The outcomes of our investigation will offer a much needed basis for signal interpretation for biodetection devices and platforms consisting of single ZnO NRs and, at the same time, contribute significantly to provide insight in understanding the biomolecular fluorescence observed from ZnO NR ensemble-based systems.Zinc oxide nanorods (ZnO NRs) have emerged in recent years as extremely useful, optical

Synthesis and characterization of [4-(2,4-dichlorophenoxybutyrate)-zinc layered hydroxide] nanohybrid

Science.gov (United States)

Hussein, Mohd Zobir; Hashim, Norhayati; Yahaya, Asmah Hj.; Zainal, Zulkarnain

2010-05-01

A new layered organic-inorganic nanohybrid material in which an agrochemical, 4-(2,4-dichlorophenoxy)butyrate (DPBA) is intercalated into inorganic interlayers of zinc layered hydroxide (ZLH) was synthesized by direct reaction of aqueous DPBA solution with zinc oxide. The resulting nanohybrid is composed of the organic moieties, DPBA sandwiched between ZLH inorganic interlayers. The nanohybrid afforded well ordered crystalline layered structure, a basal spacing of 29.6 Å, 23.5% carbon (w/w) and 47.9% (w/w) loading of DPBA. FTIR study shows that the absorption bands of the resulting nanohybrid composed the FTIR characteristics of both the DPBA and ZLH which further confirmed the intercalation episode. The intercalated organic moiety in the form of nanohybrid is thermally more stable than its sodium salt. Scanning electron micrograph shows the ZnO precursor has very fine granular structure and transformed into a flake-like when the nanohybrid is formed. This work shows that the nanohybrid of DPBA-ZLH can be synthesized using simple, direct reaction of ZnO and DPBA under aqueous environment for the formation of a new generation of agrochemical.

The effect of zinc addition on PWR corrosion product deposition on zircaloy-4

International Nuclear Information System (INIS)

Walters, W.S.; Page, J.D.; Gaffka, A.P.; Kingsbury, A.F.; Foster, J.; Anderson, A.; Wickenden, D.; Henshaw, J.; Zmitko, M.; Masarik, V.; Svarc, V.

2002-01-01

During the period 1995 to 2001 a programme of loop irradiation tests have been performed to confirm the effectiveness of zinc additions on PWR circuit chemistry and corrosion. The programme included two loop irradiation experiments, and subsequent PIE; the experiments were a baseline test (no added zinc) and a test with added zinc (10 ppb). This paper addresses the findings regarding corrosion product deposition and activation on irradiated Zircaloy-4 surfaces. The findings are relevant to overall corrosion of the reactor primary circuit, the use of zinc as a corrosion inhibitor, and activation and transport of corrosion products. The irradiation experience provides information on the equilibration of the loop chemistry, with deliberate injection of zinc. The PIE used novel and innovative techniques (described below) to obtain samples of the oxide from the irradiated Zircaloy. The results of the PIE, under normal chemistry and zinc chemistry, indicate the effect of zinc on the deposition and activation of corrosion products on Zircaloy. It was found that corrosion product deposition on Zircaloy is enhanced by the addition of zinc (but corrosion product deposition on other materials was reduced in the presence of zinc). Chemical analysis and radioisotope gamma counting results are presented, to interpret the findings. A computer model has also been used to simulate the corrosion product deposition and activation, to assist in the interpretation of the results. (authors)

SUPPLEMENTATION OF PATIENTS WITH HOMOZYGOUS SICKLE-CELL DISEASE WITH ZINC, ALPHA-TOCOPHEROL, VITAMIN-C, SOYBEAN OIL, AND FISH OIL

NARCIS (Netherlands)

MUSKIET, FAJ; MUSKIET, FD; MEIBORG, G; SCHERMER, JG

1991-01-01

Thirteen patients (aged 0.7-17.9 y) with homozygous sickle cell disease were supplemented with alpha-tocopherol, vitamin C, zinc, and soybean oil (suppl 1; for 8 mo) and alpha-tocopherol, vitamin C, and fish oil (suppl 2; for 7 mo). Urinary zinc (suppl 1), plasma vitamin C, plasma cholesterol ester

Extreme Population Differences in the Human Zinc Transporter ZIP4 (SLC39A4) Are Explained by Positive Selection in Sub-Saharan Africa

Science.gov (United States)

Pybus, Marc; Andrews, Glen K.; Lalueza-Fox, Carles; Comas, David; Sekler, Israel; de la Rasilla, Marco; Rosas, Antonio; Stoneking, Mark; Valverde, Miguel A.; Vicente, Rubén; Bosch, Elena

2014-01-01

Extreme differences in allele frequency between West Africans and Eurasians were observed for a leucine-to-valine substitution (Leu372Val) in the human intestinal zinc uptake transporter, ZIP4, yet no further evidence was found for a selective sweep around the ZIP4 gene (SLC39A4). By interrogating allele frequencies in more than 100 diverse human populations and resequencing Neanderthal DNA, we confirmed the ancestral state of this locus and found a strong geographical gradient for the derived allele (Val372), with near fixation in West Africa. In extensive coalescent simulations, we show that the extreme differences in allele frequency, yet absence of a classical sweep signature, can be explained by the effect of a local recombination hotspot, together with directional selection favoring the Val372 allele in Sub-Saharan Africans. The possible functional effect of the Leu372Val substitution, together with two pathological mutations at the same codon (Leu372Pro and Leu372Arg) that cause acrodermatitis enteropathica (a disease phenotype characterized by extreme zinc deficiency), was investigated by transient overexpression of human ZIP4 protein in HeLa cells. Both acrodermatitis mutations cause absence of the ZIP4 transporter cell surface expression and nearly absent zinc uptake, while the Val372 variant displayed significantly reduced surface protein expression, reduced basal levels of intracellular zinc, and reduced zinc uptake in comparison with the Leu372 variant. We speculate that reduced zinc uptake by the ZIP4-derived Val372 isoform may act by starving certain pathogens of zinc, and hence may have been advantageous in Sub-Saharan Africa. Moreover, these functional results may indicate differences in zinc homeostasis among modern human populations with possible relevance for disease risk. PMID:24586184

Extreme population differences in the human zinc transporter ZIP4 (SLC39A4 are explained by positive selection in Sub-Saharan Africa.

Directory of Open Access Journals (Sweden)

Johannes Engelken

2014-02-01

Full Text Available Extreme differences in allele frequency between West Africans and Eurasians were observed for a leucine-to-valine substitution (Leu372Val in the human intestinal zinc uptake transporter, ZIP4, yet no further evidence was found for a selective sweep around the ZIP4 gene (SLC39A4. By interrogating allele frequencies in more than 100 diverse human populations and resequencing Neanderthal DNA, we confirmed the ancestral state of this locus and found a strong geographical gradient for the derived allele (Val372, with near fixation in West Africa. In extensive coalescent simulations, we show that the extreme differences in allele frequency, yet absence of a classical sweep signature, can be explained by the effect of a local recombination hotspot, together with directional selection favoring the Val372 allele in Sub-Saharan Africans. The possible functional effect of the Leu372Val substitution, together with two pathological mutations at the same codon (Leu372Pro and Leu372Arg that cause acrodermatitis enteropathica (a disease phenotype characterized by extreme zinc deficiency, was investigated by transient overexpression of human ZIP4 protein in HeLa cells. Both acrodermatitis mutations cause absence of the ZIP4 transporter cell surface expression and nearly absent zinc uptake, while the Val372 variant displayed significantly reduced surface protein expression, reduced basal levels of intracellular zinc, and reduced zinc uptake in comparison with the Leu372 variant. We speculate that reduced zinc uptake by the ZIP4-derived Val372 isoform may act by starving certain pathogens of zinc, and hence may have been advantageous in Sub-Saharan Africa. Moreover, these functional results may indicate differences in zinc homeostasis among modern human populations with possible relevance for disease risk.

Novel β-C3N4/CuO nanoflakes: facile synthesis and unique photocatalytic performance

Science.gov (United States)

Zou, Lan-Rong; Huang, Gui-Fang; Li, Dong-Feng; Tian, Qing-Nan; Yang, Ke; Si, Yuan; Chang, Shengli; Zhang, Xue-Ao; Huang, Wei-Qing

2017-09-01

For the first time, novel β-C3N4/CuO composites with superior photocatalytic activity are successfully fabricated via a facile reflux method followed by a thermal process. The morphologies, particle size and microstructure of the synthesized β-C3N4/CuO composites largely depended upon copper chloride and the volume ratio of V water:V ethanol in the mixed precursors. The fabricated β-C3N4/CuO nanoflakes exhibited obviously enhanced visible light photocatalytic activity for the degradation of methylene blue (MB) with an  ˜3.4 and 1.9 fold increase in efficiency over that of pure g-C3N4 and commercial P25, respectively. The β-C3N4/CuO composite photocatalyst also showed photocatalytic activity for the degradation of methyl orange (MO). Moreover, the β-C3N4/CuO nanoflakes showed almost no loss of photocatalytic activity after three recycles of the degradation of the MB. A multiple synergetic mechanism in β-C3N4/CuO nanoflakes, which is featured by the highly reactive {0 0 2} facets, exposed many active sites of nanoflakes and the efficient charge separation are proposed to account for the distinguished photocatalytic activity. This work provides a facile and cost-effective strategy for designing novel β-C3N4/CuO photocatalysts for application in environmental purification.

Serum zinc level in patients with liver cirrhosis

International Nuclear Information System (INIS)

Soomro, A.A.; Devrajani, B.R.; Shaikh, K.; Shah, S.Z.A.; Devrajani, T.; Bibi, I.

2009-01-01

Objective: To determine the serum zinc level in patients with liver cirrhosis. Methodology: This descriptive cross sectional study was conducted at Liaquat University Hospital Hyderabad Sindh, Pakistan. All patients above 12 years of age, of either gender and known (diagnosed) cases of liver cirrhosis were further evaluated for their serum zinc level. The data was analyzed in statistical software (SPSS) and the p value <0.05 was considered as statistically significant. Result: One hundred twenty seven cirrhotic patients with means age 42.7559 +- 15.8894 were evaluated and assessed. The serum zinc was low in 69% patients. According to Child-Pugh classification 72% zinc deficient cirrhotic subjects were in class C, 16% in class B and 12% in class A. 94% subjects had hepatitis C virus infection, 4% had hepatitis B virus infection and 2% had history of alcoholism. Conclusion: The serum zinc level was low in patients with liver cirrhosis. (author)

Hydrothermal synthesis of zinc oxide nanoparticles using rice as soft biotemplate.

Science.gov (United States)

Ramimoghadam, Donya; Bin Hussein, Mohd Zobir; Taufiq-Yap, Yun Hin

2013-01-01

Rice as a renewable, abundant bio-resource with unique characteristics can be used as a bio-template to synthesize various functional nanomaterials. Therefore, the effect of uncooked rice flour as bio-template on physico-chemical properties, especially the morphology of zinc oxide nanostructures was investigated in this study. The ZnO particles were synthesized through hydrothermal-biotemplate method using zinc acetate-sodium hydroxide and uncooked rice flour at various ratios as precursors at 120°C for 18 hours. The results indicate that rice as a bio-template can be used to modify the shape and size of zinc oxide particles. Different morphologies, namely flake-, flower-, rose-, star- and rod-like structures were obtained with particle size at micro- and nanometer range. Pore size and texture of the resulting zinc oxide particles were found to be template-dependent and the resulting specific surface area enhanced compared to the zinc oxide synthesized without rice under the same conditions. However, optical property particularly the band gap energy is generally quite similar. Pure zinc oxide crystals were successfully synthesized using rice flour as biotemplate at various ratios of zinc salt to rice. The size- and shape-controlled capability of rice to assemble the ZnO particles can be employed for further useful practical applications.

A Nonbactericidal Zinc-Complexing Ligand as a Biofilm Inhibitor: Structure-Guided Contrasting Effects on Staphylococcus aureus Biofilm.

Science.gov (United States)

Kapoor, Vidushi; Rai, Rajanikant; Thiyagarajan, Durairaj; Mukherjee, Sandipan; Das, Gopal; Ramesh, Aiyagari

2017-08-04

Zinc-complexing ligands are prospective anti-biofilm agents because of the pivotal role of zinc in the formation of Staphylococcus aureus biofilm. Accordingly, the potential of a thiosemicarbazone (compound C1) and a benzothiazole-based ligand (compound C4) in the prevention of S. aureus biofilm formation was assessed. Compound C1 displayed a bimodal activity, hindering biofilm formation only at low concentrations and promoting biofilm growth at higher concentrations. In the case of C4, a dose-dependent inhibition of S. aureus biofilm growth was observed. Atomic force microscopy analysis suggested that at higher concentrations C1 formed globular aggregates, which perhaps formed a substratum that favored adhesion of cells and biofilm formation. In the case of C4, zinc supplementation experiments validated zinc complexation as a plausible mechanism of inhibition of S. aureus biofilm. Interestingly, C4 was nontoxic to cultured HeLa cells and thus has promise as a therapeutic anti-biofilm agent. The essential understanding of the structure-driven implications of zinc-complexing ligands acquired in this study might assist future screening regimes for identification of potent anti-biofilm agents. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of Serum Zinc Level in Patients with Diabetes Type 1 and 2 and Its' Relation to HbA1c

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Fatemeh Dorreh

2014-01-01

Full Text Available Background: Diabetes Mellitus (DM is a major health care problem. The relationship between DM and zinc has frequently been reported in various research. The present study aims to investigate serum zinc level in patients with type 1 (IDDM and type 2 (NIDDM. Association between glyaceted hemoglobin and level of zinc is also evaluted. Materials and Methods: This cross-sectional study was conducted on 60 subjects with DM (Type l: N=30; Type 2: N=30 who met inclusion criteria of the study. Patients’ serum zinc level and HbA1c were measured. Data were analyzed using t-test and Mann-Withney U test. Results: Seventy five percent of the subjects were female. The average age of the IDDM was 15.36±5.28 years and that of NIDDM was 48.70±11.45 years. The average HbA1c of subjects was 8.06±1.64%. The average serum level of zinc in IDDM group was 95.82±14.51 μg/dl and that of NIDDM was 97.47±32.36 μg/dl, no significant difference was found between the two groups. Serum zinc difficiency was detected in 20% of the patients with NIDDM and 16.6% of the patients with IDDM. However, no significant correlation between HbA1c and serum level of zinc was detected in this study. Conclusion: Zinc deficiency was detected among a significant percentage of IDDM and NIDDM patients, but no significant correlation between serum zinc level and HbA1c was detected.

Upregulation of Zinc Absorption Matches Increases in Physiologic Requirements for Zinc in Women Consuming High- or Moderate-Phytate Diets during Late Pregnancy and Early Lactation.

Science.gov (United States)

Hambidge, K Michael; Miller, Leland V; Mazariegos, Manolo; Westcott, Jamie; Solomons, Noel W; Raboy, Victor; Kemp, Jennifer F; Das, Abhik; Goco, Norman; Hartwell, Ty; Wright, Linda; Krebs, Nancy F

2017-06-01

Background: Estimated physiologic requirements (PRs) for zinc increase in late pregnancy and early lactation, but the effect on dietary zinc requirements is uncertain. Objective: The aim of this study was to determine changes in daily fractional absorbed zinc and total absorbed zinc (TAZ) from ad libitum diets of differing phytate contents in relation to physiologic zinc requirements during pregnancy and lactation. Methods: This was a prospective observational study of zinc absorption at 8 (phase 1) and 34 (phase 2) wk of gestation and 2 (phase 3) and 6 (phase 4) mo of lactation. Participants were indigenous Guatemalan women of childbearing age whose major food staple was maize and who had been randomly assigned in a larger study to either of 2 ad libitum feeding groups: low-phytate maize (LP; 1.6 mg/g; n = 14) or control maize (C; 7.1 mg/g; n = 8). Total dietary zinc (milligrams per day, TDZ) and phytate (milligrams per day) were determined from duplicate diets and fractional absorption (FAZ) by dual isotope ratio technique (TAZ = TDZ × FAZ). All variables were examined longitudinally and by group and compared with PRs. TAZ values at later phases were compared with phase 1. Measured TAZ was compared with predicted TAZ for nonpregnant, nonlactating (NPNL) women. Results: TAZ was greater in the LP group than in the C group at all phases. All variables increased from phase 1 to phases 2 and 3 and declined at phase 4. TAZ increased by 1.25 mg/d ( P = 0.045) in the C group and by 0.81 mg/d ( P = 0.058) in the LP group at phase 2. At phase 3, the increases were 2.66 mg/d ( P = 0.002) in the C group and 2.28 mg/d ( P = 0.0004) in the LP group, compared with a 1.37-mg/d increase in PR. Measured TAZ was greater than predicted values in phases 2-4. Conclusions: Upregulation of zinc absorption in late pregnancy and early lactation matches increases in PRs of pregnant and lactating women, regardless of dietary phytate, which has implications for dietary zinc requirements of

Zinc oxide tetrapod: a morphology with multifunctional applications

International Nuclear Information System (INIS)

Modi, Gaurav

2015-01-01

Zinc oxide has emerged as a material of great interest due to its unique optical, electrical and magnetic properties. This review comprehensively covers the various aspects of zinc oxide tetrapods. Tetrapod is a one dimensional zinc oxide nano-microstructure and has been found to have very promising applications in diverse fields. The growth model, properties, synthesis methods and variations in the tetrapod morphology by varying the synthesis conditions have been discussed. The promising applications of zinc oxide tetrapod morphology have been also discussed in detail. (review)

Crystal structure of (4,4′-bipyridyl-κNbis[N-(2-hydroxyethyl-N-isopropyldithiocarbamato-κ2S,S′]zinc(II–4,4′-bipyridyl (2/1 and its isostructural cadmium(II analogue

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Yee Seng Tan

2017-11-01

Full Text Available The title structures, [M(C6H12NOS22(C10H8N2]·0.5C10H8N2, for M = Zn, (I, and Cd, (II, feature terminally bound 4,4′-bipyridyl ligands and non-coordinating 4,4′-bipyridyl molecules, with the latter disposed about a centre of inversion. The coordination geometry about the metal atom is defined by two non-symmetrically chelating dithiocarbamate ligands and a pyridyl N atom. The NS4 donor sets are distorted but, approximate to trigonal bipyramidal in each case. In the crystal, hydroxy-O—H...O(hydroxy and hydroxy-O—H...N(pyridyl hydrogen bonds between the zinc-containing molecules lead to a supramolecular layer parallel to (100. The three-dimensional architecture arises as the layers are linked via methine-C—H...S, pyridyl-C—H...O(hydroxy and π–π [inter-centroid distance between coordinated pyridyl rings = 3.6246 (18 Å] interactions. Channels along the c-axis direction are occupied by the non-coordinating 4,4′-bipyridine molecules, which are held in place by C—H...π(chelate ring contacts.

Co3O4/MnO2/Hierarchically Porous Carbon as Superior Bifunctional Electrodes for Liquid and All-Solid-State Rechargeable Zinc-Air Batteries.

Science.gov (United States)

Li, Xuemei; Dong, Fang; Xu, Nengneng; Zhang, Tao; Li, Kaixi; Qiao, Jinli

2018-05-09

The design of efficient, durable, and affordable catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is very indispensable in liquid-type and flexible all-solid-state zinc-air batteries. Herein, we present a high-performance bifunctional catalyst with cobalt and manganese oxides supported on porous carbon (Co 3 O 4 /MnO 2 /PQ-7). The optimized Co 3 O 4 /MnO 2 /PQ-7 exhibited a comparable ORR performance with commercial Pt/C and a more superior OER performance than all of the other prepared catalysts, including commercial Pt/C. When applied to practical aqueous (6.0 M KOH) zinc-air batteries, the Co 3 O 4 /MnO 2 /porous carbon hybrid catalysts exhibited exceptional performance, such as a maximum discharge peak power density as high as 257 mW cm -2 and the most stable charge-discharge durability over 50 h with negligible deactivation to date. More importantly, a series of flexible all-solid-state zinc-air batteries can be fabricated by the Co 3 O 4 /MnO 2 /porous carbon with a layer-by-layer method. The optimal catalyst (Co 3 O 4 /MnO 2 /PQ-7) exhibited an excellent peak power density of 45 mW cm -2 . The discharge potentials almost remained unchanged for 6 h at 5 mA cm -2 and possessed a long cycle life (2.5 h@5 mA cm -2 ). These results make the optimized Co 3 O 4 /MnO 2 /PQ-7 a promising cathode candidate for both liquid-type and flexible all-solid-state zinc-air batteries.

Zinc fingers 1, 2, 5 and 6 of transcriptional regulator, PRDM4, are required for its nuclear localisation

Energy Technology Data Exchange (ETDEWEB)

Tunbak, Hale, E-mail: h.tunbak@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom); Georgiou, Christiana, E-mail: christiana.georgiou.10@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom); Guan, Cui, E-mail: c.guan@qmul.ac.uk [School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Richardson, William David, E-mail: w.richardson@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom); Chittka, Alexandra, E-mail: a.chittka@ucl.ac.uk [The Wolfson Institute for Biomedical Research, University College London, Gower Street, London WC1E 6BT (United Kingdom)

2016-05-27

PRDM4 is a member of the PRDM family of transcriptional regulators which control various aspects of cellular differentiation and proliferation. PRDM proteins exert their biological functions both in the cytosol and the nucleus of cells. All PRDM proteins are characterised by the presence of two distinct structural motifs, the PR/SET domain and the zinc finger (ZF) motifs. We previously observed that deletion of all six zinc fingers found in PRDM4 leads to its accumulation in the cytosol, whereas overexpressed full length PRDM4 is found predominantly in the nucleus. Here, we investigated the requirements for single zinc fingers in the nuclear localisation of PRDM4. We demonstrate that ZF's 1, 2, 5 and 6 contribute to the accumulation of PRDM4 in the nucleus. Their effect is additive as deleting either ZF1-2 or ZF 5–6 redistributes PRDM4 protein from being almost exclusively nuclear to cytosolic and nuclear. We investigated the potential mechanism of nuclear shuttling of PRDM4 via the importin α/β-mediated pathway and find that PRDM4 nuclear targeting is independent of α/β-mediated nuclear import. -- Highlights: •Zinc fingers 1, 2, 5, and 6 are necessary for efficient nuclear localisation of PRDM4. •Zinc fingers 3 and 4 are dispensable for nuclear localisation of PRDM4. •Zinc knuckle is dispensable for nuclear localisation of PRDM4. •PRDM4 nuclear transport is independent of importin α/β-mediated pathway of nuclear import.

Disordered Zinc in Zn4Sb3 with Phonon-Glass and Electron-Crystal Thermoelectric Properties

Science.gov (United States)

Snyder, G. Jeffrey; Christensen, Mogens; Nishibori, Eiji; Caillat, Thierry; Brummerstedt Iversen, Bo

2004-01-01

By converting waste heat into electricity, thermoelectric generators could be an important part of the solution to today's energy challenges. The compound Zn4Sb3 is one of the most efficient thermoelectric materials known. Its high efficiency results from an extraordinarily low thermal conductivity in conjunction with the electronic structure of a heavily doped semiconductor. Previous structural studies have been unable to explain this unusual combination of properties. Here, we show through a comprehensive structural analysis using single-crystal X-ray and powder-synchrotron-radiation diffraction methods, that both the electronic and thermal properties of Zn4Sb3 can be understood in terms of unique structural features that have been previously overlooked. The identification of Sb3- ions and Sb-2(4-) dimers reveals that Zn4Sb3 is a valence semiconductor with the ideal stoichiometry Zn13Sb10. In addition, the structure contains significant disorder, with zinc atoms distributed over multiple positions. The discovery of glass-like interstitial sites uncovers a highly effective mechanism for reducing thermal conductivity. Thus Zn4Sb3 is in many ways an ideal 'phonon glass, electron crystal' thermoelectric material.

Synthesis and optical property of zinc aluminate spinel cryogels

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Lifen Su

2016-06-01

Full Text Available Zinc aluminate spinel cryogels with various molar ratio of Al/Zn are synthesized by sol–gel technology followed by vacuum freeze drying. The structures and optical properties are both found to be affected by the molar ratios of Al/Zn and annealed temperatures. The peaks of zinc oxide (ZnO and zinc dialuminum oxide (ZnAl2O4 are both obtained for the samples with more Zn content annealed at 750 °C or upward. The composites have a large surface area (137 m2/g with mesoporous structure after annealing at 750 °C. The SEM images reveal that the ZnAl2O4 crystals formed a multilayer structure with redundant ZnO particles which deposited on it. Furthermore, the maximum infrared reflectance is about 80% with an improvement of 35% in the infrared region after annealing at 950 °C compared with that of 450 °C, which indicates that these porous cryogels have a potential application as thermal insulating materials at a high temperature.

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.

Atmospheric pressure plasma enhanced chemical vapor deposition of zinc oxide and aluminum zinc oxide

International Nuclear Information System (INIS)

Johnson, Kyle W.; Guruvenket, Srinivasan; Sailer, Robert A.; Ahrenkiel, S. Phillip; Schulz, Douglas L.

2013-01-01

Zinc oxide (ZnO) and aluminum-doped zinc oxide (AZO) thin films were deposited via atmospheric pressure plasma enhanced chemical vapor deposition. A second-generation precursor, bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)(N,N′-diethylethylenediamine) zinc, exhibited significant vapor pressure and good stability at one atmosphere where a vaporization temperature of 110 °C gave flux ∼ 7 μmol/min. Auger electron spectroscopy confirmed that addition of H 2 O to the carrier gas stream mitigated F contamination giving nearly 1:1 metal:oxide stoichiometries for both ZnO and AZO with little precursor-derived C contamination. ZnO and AZO thin film resistivities ranged from 14 to 28 Ω·cm for the former and 1.1 to 2.7 Ω·cm for the latter. - Highlights: • A second generation precursor was utilized for atmospheric pressure film growth. • Addition of water vapor to the carrier gas stream led to a marked reduction of ZnF 2 . • Carbonaceous contamination from the precursor was minimal

Unique negative permittivity of the pseudo conducting radial zinc oxide-poly(vinylidene fluoride) nanocomposite film: Enhanced dielectric and electromagnetic interference shielding properties

Energy Technology Data Exchange (ETDEWEB)

Aepuru, Radhamanohar [Department of Materials Engineering, Defence Institute of Advanced Technology, Girinagar, Pune 411025 (India); Bhaskara Rao, B.V.; Kale, S.N. [Department of Applied Physics, Defence Institute of Advanced Technology, Pune 411025 (India); Panda, H.S., E-mail: himanshusp@diat.ac.in [Department of Materials Engineering, Defence Institute of Advanced Technology, Girinagar, Pune 411025 (India)

2015-11-01

Flower like radial zinc oxide (RZnO) was prepared by using a facile solvothermal method and used to prepare poly(vinylidene fluoride) (PVDF) based nanocomposites. Structural informations of the samples are analyzed by X-ray diffraction and correlated with high resolution transmission electron microscopy along with high annular angular dark field scanning transmission electron microscopy (HAADF-STEM). For the first time, stability studies are carried out by solvent relaxation nuclear magnetic resonance experiments. Dielectric studies of the PVDF and PVDF-RZnO nanocomposites are reported over the wide range of frequency (0.01 Hz–1 MHz) and temperature (25–90 °C). Dielectric property of the PVDF-RZnO nanocomposites was significantly improved wrt filler percentage in PVDF. Unique negative permittivity was observed in the composites having higher filler content (>40 wt%) typically at low frequencies. First time, it is observed that the higher RZnO content in PVDF results the formation of pseudo conducting network and hence improved the electromagnetic shielding efficiency (85%) than PVDF and PVDF-commercial ZnO composites. - Highlights: • Radial ZnO-PVDF nanocomposites were fabricated by using solution casting. • Pseudo conducting network is confirmed through cryo-fracture morphology study. • Stability study of the nano fillers was performed in the polymer matrix. • Unique negative permittivity behavior of the nanocomposites was observed. • EMI shielding property of the radial ZnO-PVDF nanocomposites was performed.

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...

Engineering HIV-resistant human CD4+ T cells with CXCR4-specific zinc-finger nucleases.

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Craig B Wilen

2011-04-01

Full Text Available HIV-1 entry requires the cell surface expression of CD4 and either the CCR5 or CXCR4 coreceptors on host cells. Individuals homozygous for the ccr5Δ32 polymorphism do not express CCR5 and are protected from infection by CCR5-tropic (R5 virus strains. As an approach to inactivating CCR5, we introduced CCR5-specific zinc-finger nucleases into human CD4+ T cells prior to adoptive transfer, but the need to protect cells from virus strains that use CXCR4 (X4 in place of or in addition to CCR5 (R5X4 remains. Here we describe engineering a pair of zinc finger nucleases that, when introduced into human T cells, efficiently disrupt cxcr4 by cleavage and error-prone non-homologous DNA end-joining. The resulting cells proliferated normally and were resistant to infection by X4-tropic HIV-1 strains. CXCR4 could also be inactivated in ccr5Δ32 CD4+ T cells, and we show that such cells were resistant to all strains of HIV-1 tested. Loss of CXCR4 also provided protection from X4 HIV-1 in a humanized mouse model, though this protection was lost over time due to the emergence of R5-tropic viral mutants. These data suggest that CXCR4-specific ZFNs may prove useful in establishing resistance to CXCR4-tropic HIV for autologous transplant in HIV-infected individuals.

Changes in respiration rates and biomass attributes of epilithon due to extended exposure to zinc

International Nuclear Information System (INIS)

Colwell, F.S.

1986-01-01

The purpose of this research was to determine the influence of extended dosing of zinc on the carbon cycling and biomass characteristics of freshwater epilithon. Experiments were conducted in artificial streams continuously dosed with 0.00, 0.05, or 1.00 mg Zn liter -1 for 20 to 30 days during summer and fall, 1984 and 1985. Repeated measurement of epilithon structure and function included estimates of 14 C-glucose respiration, 14 C-glutamate respiration, O 2 and CO 2 flux rates, ash-free dry weight (AFDW), protein, carbohydrate, and algal pigment concentrations, and total and zinc-tolerant colony forming units. An increase in epilithic glucose respiration per unit biomass consistently occurred 5 to 10 days after dosing with 1.0 mg Zn liter -1 was started. At the same time significantly lower epilithon biomass occurred in the high dosed streams relative to controls in 3 out of 4 studies. Although algal pigment concentrations were lowest in the high dose streams at the midpoint of the studies, the chlorophyll a-to-pheophytin a ratio remained high, indicating that the minimal algal population was not senescing in situ. After 30 days, the epilithon dosed with 1.0 mg Zn liter -1 had higher AFDW, protein, and carbohydrate concentrations than the other treatments. The development of unique epilithon communities that are acclimated to prolonged zinc exposure is evident in the eventual recolonization of the artificial surfaces, glucose respiration rates that are comparable to controls, and presence of zinc-tolerant heterotrophs

Ambipolar zinc-polyiodide electrolyte for a high-energy density aqueous redox flow battery.

Science.gov (United States)

Li, Bin; Nie, Zimin; Vijayakumar, M; Li, Guosheng; Liu, Jun; Sprenkle, Vincent; Wang, Wei

2015-02-24

Redox flow batteries are receiving wide attention for electrochemical energy storage due to their unique architecture and advantages, but progress has so far been limited by their low energy density (~25 Wh l(-1)). Here we report a high-energy density aqueous zinc-polyiodide flow battery. Using the highly soluble iodide/triiodide redox couple, a discharge energy density of 167 Wh l(-1) is demonstrated with a near-neutral 5.0 M ZnI2 electrolyte. Nuclear magnetic resonance study and density functional theory-based simulation along with flow test data indicate that the addition of an alcohol (ethanol) induces ligand formation between oxygen on the hydroxyl group and the zinc ions, which expands the stable electrolyte temperature window to from -20 to 50 °C, while ameliorating the zinc dendrite. With the high-energy density and its benign nature free from strong acids and corrosive components, zinc-polyiodide flow battery is a promising candidate for various energy storage applications.

Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

International Nuclear Information System (INIS)

Oliver, S. A.; Harris, V. G.; Hamdeh, H. H.; Ho, J. C.

2000-01-01

The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn 0.55 2+ Fe 0.18 3+ ) tet [Zr 0.45 2+ Fe 1.82 3+ ] oct O 4 through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe 3+ on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics

Subcellular distribution of zinc in the benign and malignant human prostate

International Nuclear Information System (INIS)

Leake, A.; Chrisholm, G.D.; Busuttil, A.; Habib, F.K

1984-01-01

The subcellular distribution of zinc and its interaction with androgens has been examined in the benign and malignant human prostate. Endogenously, most of the zinc was associated with the nuclear fraction but signigicant concentrations were also found in the cytosol. Furthermore, the epithelium contained more zinc than that found in either the stroma or the intact gland. Zinc concentrations were lower in the subcellular fractions of the cancerous tissue when compared to hyperplastic specimens. In vitro uptake of zinc into prostatic homogenates was rapid and at equilibrium the binding was stable for both the 4degC and the 37degC incubations. At low zinc concentrations (<5mM) the uptake was higher in the nucleus, whereas at higher concentraions, the cancerous tissue exhibited a greater capacity for the metal which was predominantly retained by the cytosol. Our data suggest the presence of a saturable zinc retention mechanism in the nucleus. The zinc uptake was found to be independent of any added androgen. In contrast, the total androgen uptake by the prostate was significantly enhanced by the addition of zinc. This effect was not due to increases in the nuclear and cytosolic receptor binding since zinc inhibited the binding of the androgen to these receptors. (author)

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

High-capacity aqueous zinc batteries using sustainable quinone electrodes

Science.gov (United States)

Zhao, Qing; Huang, Weiwei; Luo, Zhiqiang; Liu, Luojia; Lu, Yong; Li, Yixin; Li, Lin; Hu, Jinyan; Ma, Hua; Chen, Jun

2018-01-01

Quinones, which are ubiquitous in nature, can act as sustainable and green electrode materials but face dissolution in organic electrolytes, resulting in fast fading of capacity and short cycle life. We report that quinone electrodes, especially calix[4]quinone (C4Q) in rechargeable metal zinc batteries coupled with a cation-selective membrane using an aqueous electrolyte, exhibit a high capacity of 335 mA h g−1 with an energy efficiency of 93% at 20 mA g−1 and a long life of 1000 cycles with a capacity retention of 87% at 500 mA g−1. The pouch zinc batteries with a respective depth of discharge of 89% (C4Q) and 49% (zinc anode) can deliver an energy density of 220 Wh kg−1 by mass of both a C4Q cathode and a theoretical Zn anode. We also develop an electrostatic potential computing method to demonstrate that carbonyl groups are active centers of electrochemistry. Moreover, the structural evolution and dissolution behavior of active materials during discharge and charge processes are investigated by operando spectral techniques such as IR, Raman, and ultraviolet-visible spectroscopies. Our results show that batteries using quinone cathodes and metal anodes in aqueous electrolyte are reliable approaches for mass energy storage. PMID:29511734

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

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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.

Textural and morphological studies on zinc-iron alloy electrodeposits

Indian Academy of Sciences (India)

Zinc-iron alloy electrodeposits have industrial significance, since they provide better corrosion resistance and with improved mechanical properties when compared to pure zinc coatings. This is due to the unique phase structure of the alloy formed. But this deposition belongs to anomalous deposition, where the ...

Influence of Dietary Zinc and Vitamin C Supplementation on Some Blood Biochemical Parameters and Egg Production in Free-Range Laying Hens

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Vasko GERZILOV

2015-03-01

Full Text Available The study aimed to follow out the effect of antistress dietary supplements Zinteral 35 and vitamin C on the levels of some blood biochemical parameters (corticosterone, total cholesterol, glucose, total protein and creatinine and egg production in laying hens during cold (7o C, thermoneutral (19o C and hot (31o C periods. The fowls were divided in three groups (26 females and 3 males in each group. They were reared in a free-range management system with elements of organic production. The experimental treatments were as followed: first (control group without dietary supplement, second group with 100 mg Zinteral 35 per kg diet containing 35 mg/kg zinc oxide, third group with the same amount of Zinteral 35 together with 250 mg vitamin C per kg diet. During the three periods with different ambient temperature, the hens supplemented either with zinc alone (second group or co-administered zinc + vitamin C (third group had significantly lower levels of plasma corticosterone (P<0.001, serum cholesterol (P<0.05 and glucose (P<0.05 than those from the first (control group. The differences between the third and the first groups were bigger versus those between the second and the first groups. For the entire period (March 1 and June 21, egg production was higher by 2.22 % and 4.60 % in the second and third groups respectively in comparison to the first group. The combination of 100 mg Zinteral 35 and 250 mg vitamin C per 1 kg diet exhibited a synergistic effect in reducing cold and heat stress in laying hens and increased their egg production.

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 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

Synthesis, thermal, spectral and biological properties of zinc(II) 4-hydroxybenzoate complexes

Czech Academy of Sciences Publication Activity Database

Homzová, K.; Györyová, K.; Bujdošová, Z.; Hudecová, D.; Ganajová, M.; Vargová, Z.; Kovářová, Jana

2014-01-01

Roč. 116, č. 1 (2014), s. 77-91 ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : zinc * 4-hydroxybenzoate * thermal Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.042, year: 2014

Synthesis and crystal structure of a polymeric zinc(II complex derived from 4-nitro- phenylacetic acid and propane-1,3-diamine

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G-H. Sheng

2014-05-01

Full Text Available A new polymeric zinc(II complex, [ZnL2(PDA]n, has been prepared by the reaction of zinc sulfate, 4-nitrophenylacetic acid, and propane-1,3-diamine (PDA in water. Structure of the complex has been characterized by single-crystal X-ray diffraction. The complex crystallizes as orthorhombic space group Pnma, with unit cell dimensions a = 15.732(1 Å, b = 23.912(1 Å, c = 5.5565(3 Å, V = 2090.2(2 Å3, Z = 4, R1 = 0.0427, wR2 = 0.0968, S = 1.048. The Zn atom is coordinated in a tetrahedral geometry. Single crystals of the complex are stabilized by hydrogen bonds and p···p interactions. DOI: http://dx.doi.org/10.4314/bcse.v28i2.17

Zinc can increase the activity of protein kinase C and contributes to its binding to plasma membranes in T lymphocytes

International Nuclear Information System (INIS)

Csermely, P.; Szamel, M.; Resch, K.; Somogyi, J.

1988-01-01

In the primary structure of protein kinase C, the presence of a putative metal-binding site has been suggested. In the present report, the authors demonstrate that the most abundant intracellular heavy metal, zinc, can increase the activity of cytosolic protein kinase C. Zinc reversibly binds the enzyme to plasma membranes,and it may contribute to the calcium-induced binding as well. The intracellular heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine prevents the phorbol ester- and antigen-induced translocation of protein kinase C. This effect can be totally reversed by the concomitant addition of Zn 2+ , while Fe 2+ and Mn 2+ are only partially counteractive. The results suggest that zinc can activate protein kinase C and contributes to its binding to plasma membranes in T lymphocytes induced by Ca 2+ , phorbol ester, or antigen

Intracellular zinc activates KCNQ channels by reducing their dependence on phosphatidylinositol 4,5-bisphosphate.

Science.gov (United States)

Gao, Haixia; Boillat, Aurélien; Huang, Dongyang; Liang, Ce; Peers, Chris; Gamper, Nikita

2017-08-01

M-type (Kv7, KCNQ) potassium channels are proteins that control the excitability of neurons and muscle cells. Many physiological and pathological mechanisms of excitation operate via the suppression of M channel activity or expression. Conversely, pharmacological augmentation of M channel activity is a recognized strategy for the treatment of hyperexcitability disorders such as pain and epilepsy. However, physiological mechanisms resulting in M channel potentiation are rare. Here we report that intracellular free zinc directly and reversibly augments the activity of recombinant and native M channels. This effect is mechanistically distinct from the known redox-dependent KCNQ channel potentiation. Interestingly, the effect of zinc cannot be attributed to a single histidine- or cysteine-containing zinc-binding site within KCNQ channels. Instead, zinc dramatically reduces KCNQ channel dependence on its obligatory physiological activator, phosphatidylinositol 4,5-bisphosphate (PIP 2 ). We hypothesize that zinc facilitates interactions of the lipid-facing interface of a KCNQ protein with the inner leaflet of the plasma membrane in a way similar to that promoted by PIP 2 Because zinc is increasingly recognized as a ubiquitous intracellular second messenger, this discovery might represent a hitherto unknown native pathway of M channel modulation and provide a fresh strategy for the design of M channel activators for therapeutic purposes.

Large zinc cation occupancy of octahedral sites in mechanically activated zinc ferrite powders

Energy Technology Data Exchange (ETDEWEB)

Oliver, S. A. [Center for Electromagnetic Research, Northeastern University, Boston, Massachusetts 02115 (United States); Harris, V. G. [Complex Materials Section, Code 6342, Naval Research Laboratory, Washington, DC 20375 (United States); Hamdeh, H. H. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States); Ho, J. C. [Department of Physics, Wichita State University, Wichita, Kansas 67260 (United States)

2000-05-08

The cation site occupancy of a mechanically activated nanocrystalline zinc ferrite powder was determined as (Zn{sub 0.55}{sup 2+}Fe{sub 0.18}{sup 3+}){sub tet}[Zr{sub 0.45}{sup 2+}Fe{sub 1.82}{sup 3+}]{sub oct}O{sub 4} through analysis of extended x-ray absorption fine structure measurements, showing a large redistribution of cations between sites compared to normal zinc ferrite samples. The overpopulation of cations in the octahedral sites was attributed to the ascendance in importance of the ionic radii over the crystal energy and bonding coordination in determining which interstitial sites are occupied in this structurally disordered powder. Slight changes are observed in the local atomic environment about the zinc cations, but not the iron cations, with respect to the spinel structure. The presence of Fe{sup 3+} on both sites is consistent with the measured room temperature magnetic properties. (c) 2000 American Institute of Physics.

Vacuolar zinc transporter Zrc1 is required for detoxification of excess intracellular zinc in the human fungal pathogen Cryptococcus neoformans.

Science.gov (United States)

Cho, Minsu; Hu, Guanggan; Caza, Mélissa; Horianopoulos, Linda C; Kronstad, James W; Jung, Won Hee

2018-01-01

Zinc is an important transition metal in all living organisms and is required for numerous biological processes. However, excess zinc can also be toxic to cells and cause cellular stress. In the model fungus Saccharomyces cerevisiae, a vacuolar zinc transporter, Zrc1, plays important roles in the storage and detoxification of excess intracellular zinc to protect the cell. In this study, we identified an ortholog of the S. cerevisiae ZRC1 gene in the human fungal pathogen Cryptococcus neoformans. Zrc1 was localized in the vacuolar membrane in C. neoformans, and a mutant lacking ZRC1 showed significant growth defects under high-zinc conditions. These results suggested a role for Zrc1 in zinc detoxification. However, contrary to our expectation, the expression of Zrc1 was induced in cells grown in zinc-limited conditions and decreased upon the addition of zinc. These expression patterns were similar to those of Zip1, the high-affinity zinc transporter in the plasma membrane of C. neoformans. Furthermore, we used the zrc1 mutant in a murine model of cryptococcosis to examine whether a mammalian host could inhibit the survival of C. neoformans using zinc toxicity. We found that the mutant showed no difference in virulence compared with the wildtype strain. This result suggests that Zrc1-mediated zinc detoxification is not required for the virulence of C. neoformans, and imply that zinc toxicity may not be an important aspect of the host immune response to the fungus.

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.)

Proton microprobe analysis of zinc in skeletal tissues

Science.gov (United States)

Doty, S. B.; Jones, K. W.; Kraner, H. W.; Shroy, R. E.; Hanson, A. L.

1981-03-01

A proton microprobe with windowless exit port has been used to study zinc distributions in various types of skeletal tissues. The use of an external beam facilitated positioning of the targets for examination of particular points of interest. The proton microprobe is uniquely suited to this work since it combines high sensitivity for zinc determination in thick samples with good spatial resolution. Our measurements on rat and rabbit Achilles tendon showed a significant increase in zinc concentrations as the beam moved from the unmineralized collagen into the mineralized attachment site. Cartilage gave a similar result, with calcified cartilage having a greater zinc level than the articular surface on unmineralized epiphyseal cartilage.

Proton microprobe analysis of zinc in skeletal tissues

International Nuclear Information System (INIS)

Doty, S.B.; Jones, K.W.; Kraner, H.W.; Shroy, R.E.; Hanson, A.L.

1980-06-01

A proton microprobe with windowless exit port was used to study zinc distributions in various types of skeletal tissues. The use of an external beam facilitated positioning of the targets for examination of particular points of interest. The proton microprobe is uniquely suited to this work since it combines high sensitivity for zinc determinations in thick samples with good spatial resolution. Measurements on rat and rabbit Achilles tendon showed a significant increase in zinc concentrations as the beam moved from the unmineralized collagen into the mineralized attachment site. Cartilage gave a similar result, with calcified cartilage having a greater zinc level than the articular surface on unmineralized epiphyseal cartilage

Supplemental Table S4.xls

Indian Academy of Sciences (India)

143, AT3G05200.1, 8262, I, 0.6, 259312_at, ATL6 (Arabidopsis T?xicos en Levadura 6); protein binding / zinc ion binding. 144, LOC_Os08g37760.1, 8262, D, -1.07, Os.17554.1.S1_at, zinc finger, C3HC4 type family protein, expressed. 145, AT5G27420.1, 8262, D, -0.95, 246777_at, zinc finger (C3HC4-type RING finger) ...

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.

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

Synthesis, structural characterization, and dehydration analysis of uranyl zinc mellitate, (UO{sub 2})Zn(H{sub 2}O){sub 4}(H{sub 2}mel).2H{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Olchowka, Jakub; Volkringer, Christophe; Henry, Natacha; Loiseau, Thierry [Unite de Catalyse et Chimie du Solide (UCCS) - UMR CNRS 8181, Universite de Lille Nord de France, USTL-ENSCL, Villeneuve d' Ascq (France)

2013-04-15

A new heterometallic uranyl zinc carboxylate, (UO{sub 2})Zn(H{sub 2}O){sub 4}(H{sub 2}mel).2H{sub 2}O, has been hydrothermally prepared (150 C, 24 h) by using 1,2,3,4,5,6-benzenehexacarboxylic acid (mellitic acid) as organic linker in order to form a three-dimensional network. Four of the six carboxylate groups of the mellitate ligand interact with mononuclear uranyl or zinc cations, which are eightfold (hexagonal bipyramid, UO{sub 8}) or sixfold [octahedron, ZnO{sub 2}(H{sub 2}O){sub 4}] coordinated, respectively. The remaining free carboxylate arms of the mellitate species preferentially interact through hydrogen bonds with water molecules trapped within the framework. Thermogravimetric and X-ray thermodiffraction (up to 800 C) analyses and in situ infrared spectroscopy (up to 210 C) indicated that both free and bound water species are evacuated from the structure in one step between 80 and 170 C, followed by its transformation into an unknown, anhydrous, poorly crystalline phase [UO{sub 2}Zn(mel)] up to 320 C. After the formation of an amorphous phase, the re-crystallization of oxides α-ZnU{sub 3}O{sub 10} and ZnO was observed from 460 C. The fluorescence spectrum of the as-synthesized uranyl zinc mellitate shows the six bands that are typical for vibronic couplings of the [O=U=O]{sup 2+} moiety. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Negative modulation of presynaptic activity by zinc released from Schaffer collaterals.

Science.gov (United States)

Takeda, Atsushi; Fuke, Sayuri; Tsutsumi, Wataru; Oku, Naoto

2007-12-01

The role of zinc in excitation of Schaffer collateral-CA1 pyramidal cell synapses is poorly understood. Schaffer collaterals stained with ZnAF-2 or ZnAF-2DA, a membrane-impermeable or a membrane-permeable zinc indicator, respectively, were treated by tetanic stimulation (200 Hz, 1 sec). Extracellular and intracellular ZnAF-2 signals were increased in the stratum radiatum of the CA1, in which Schaffer collateral synapses exist. Both the increases were completely blocked in the presence of 1 mM CaEDAT, a membrane-impermeable zinc chelator, suggesting that 1 mM CaEDTA is effective for chelating zinc released from Schaffer collaterals. The role of Schaffer collateral zinc in presynaptic activity was examined by using FM4-64, a fluorescent indicator for vesicular exocytosis. The decrease in FM4-64 signal during tetanic stimulation (10 Hz, 180 sec) was enhanced in Schaffer collaterals in the presence of 1 mM CaEDTA but suppressed in the presence of 5 microM ZnC1(2), suggesting that zinc released from Schaffer collaterals suppresses presynaptic activity during tetanic stimulation. When Schaffer collateral synapses stained with calcium orange AM, a membrane-permeable calcium indicator, were regionally stimulated with 1 mM glutamate, calcium orange signal was increased in the CA1 pyramidal cell layer. This increase was enhanced in the presence of CaEDTA and attenuated in the presence of zinc. These results suggest that zinc attenuates excitation of Schaffer collateral synapses elicited with glutamate via suppression of presynaptic activity. (c) 2007 Wiley-Liss, Inc.

Radioisotopic investigations of zinc uptake into brain slices

International Nuclear Information System (INIS)

Howell, G.A.

1983-01-01

The presence of zinc in the vicinity of the hippocampal mossy fibers has been repeatedly demonstrated, and several lines of evidence suggest that the mossy-fiber zinc is concentrated within the terminals of mossy fibers. In search of insight into the metabolism and function of mossy-fiber zinc, the present study investigated the transport of zinc into tissue slices and the response of the zinc transport to depolarization. Kinetic analysis of zinc accumulation by mouse brain slices in vitro revealed the presence of a high affinity uptake component with an apparent Km of 17.7 μM for hippocampus, 16.6 μM< for cortex and 25 μM for striatum and a V/sub max/ of 9.2 ng/mg/hr for the hippocampus, 10.1 ng/mg/hr for cortex and 9.6 ng/mg/hr for striatum. Cytoarchitectonic differences in zinc transport between the different hippocampal subregions were found with those regions containing granule cells or mossy fiber axons accumulating greater amounts of zinc than the CA 1 region. The present finding that mossy-fiber neuropil selectivity accumulates zinc suggests the presence of a zinc-binding substance unique to mossy-fiber tissue

Zinc can increase the activity of protein kinase C and contributes to its binding to plasma membranes in T lymphocytes

Energy Technology Data Exchange (ETDEWEB)

Csermely, P.; Szamel, M.; Resch, K.; Somogyi, J.

1988-05-15

In the primary structure of protein kinase C, the presence of a putative metal-binding site has been suggested. In the present report, the authors demonstrate that the most abundant intracellular heavy metal, zinc, can increase the activity of cytosolic protein kinase C. Zinc reversibly binds the enzyme to plasma membranes,and it may contribute to the calcium-induced binding as well. The intracellular heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine prevents the phorbol ester- and antigen-induced translocation of protein kinase C. This effect can be totally reversed by the concomitant addition of Zn/sup 2 +/, while Fe/sup 2 +/ and Mn/sup 2 +/ are only partially counteractive. The results suggest that zinc can activate protein kinase C and contributes to its binding to plasma membranes in T lymphocytes induced by Ca/sup 2 +/, phorbol ester, or antigen.

Cloning and characterization of a novel human zinc finger gene, hKid3, from a C2H2-ZNF enriched human embryonic cDNA library

International Nuclear Information System (INIS)

Gao Li; Sun Chong; Qiu Hongling; Liu Hui; Shao Huanjie; Wang Jun; Li Wenxin

2004-01-01

To investigate the zinc finger genes involved in human embryonic development, we constructed a C 2 H 2 -ZNF enriched human embryonic cDNA library, from which a novel human gene named hKid3 was identified. The hKid3 cDNA encodes a 554 amino acid protein with an amino-terminal KRAB domain and 11 carboxyl-terminal C 2 H 2 zinc finger motifs. Northern blot analysis indicates that two hKid3 transcripts of 6 and 8.5 kb express in human fetal brain and kidney. The 6 kb transcript can also be detected in human adult brain, heart, and skeletal muscle while the 8.5 kb transcript appears to be embryo-specific. GFP-fused hKid3 protein is localized to nuclei and the ZF domain is necessary and sufficient for nuclear localization. To explore the DNA-binding specificity of hKid3, an oligonucleotide library was selected by GST fusion protein of hKid3 ZF domain, and the consensus core sequence 5'-CCAC-3' was evaluated by competitive electrophoretic mobility shift assay. Moreover, The KRAB domain of hKid3 exhibits transcription repressor activity when tested in GAL4 fusion protein assay. These results indicate that hKid3 may function as a transcription repressor with regulated expression pattern during human development of brain and kidney

Synthesis, thermal, spectral, and biological properties of zinc(II) 4-aminobenzoate complexes

Czech Academy of Sciences Publication Activity Database

Homzová, K.; Györyová, K.; Hudecová, D.; Koman, M.; Melník, M.; Kovářová, Jana

2017-01-01

Roč. 129, č. 2 (2017), s. 1065-1082 ISSN 1388-6150 Institutional support: RVO:61389013 Keywords : zinc(II) 4-aminobenzoate * thermal * spectral Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 1.953, year: 2016

Crystal structure of an unknown solvate of (piperazine-κN{5,10,15,20-tetrakis[4-(benzoyloxyphenyl]porphyrinato-κ4N}zinc

Directory of Open Access Journals (Sweden)

Soumaya Nasri

2016-07-01

Full Text Available The title compound, [Zn(C72H44N4O8(C4H10N2] or [Zn(TPBP(pipz] (where TPBP and pipz are 5,10,15,20-tetrakis[4-(benzoyloxyphenyl]porphyrinato and piperazine ligands respectively, features a distorted square-pyramidal coordination geometry about the central ZnII atom. This central atom is chelated by the four N atoms of the porphyrinate anion and further coordinated by a nitrogen atom of the piperazine axial ligand, which adopts a chair confirmation. The average Zn—N(pyrrole bond length is 2.078 (7 Å and the Zn— N(pipz bond length is 2.1274 (19 Å. The zinc cation is displaced by 0.4365 (4 Å from the N4C20 mean plane of the porphyrinate anion toward the piperazine axial ligand. This porphyrinate macrocycle exhibits major saddle and moderate ruffling deformations. In the crystal, the supramolecular structure is made by parallel pairs of layers along (100, with an interlayer distance of 4.100 Å while the distance between two pairs of layers is 4.047 Å. A region of electron density was treated with the SQUEEZE [Spek (2015. Acta Cryst. C71, 9–18] procedure in PLATON following unsuccessful attempts to model it as being part of disordered n-hexane solvent and water molecules. The given chemical formula and other crystal data do not take into account these solvent molecules.

Proton microprobe analysis of zinc in skeletal tissues

International Nuclear Information System (INIS)

Doty, S.B.; Jones, K.W.; Kraner, H.W.; Shroy, R.E.; Hanson, A.L.

1981-01-01

A proton microprobe with windowless exit port has been used to study zinc distributions in various types of skeletal tissues. The use of an external beam facilitated positioning of the targets for examination of particular points of interest. The proton micorprobe is uniquely suited to this work since it combines high sensitivity for zinc determinations in thick samples with good spatial resolution. Our measurements on rat and rabbit Achilles tendon showed a significant increase in zinc concentrations as the beam moved from the unmineralized collagen into the mineralized attachment site. Cartilage gave a similar result, with calcified cartilage having a greater zinc level than the articular surface on unmineralized epiphyseal cartilage. (orig.)

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 can increase the activity of protein kinase C and contributes to its binding to plasma membranes in T lymphocytes.

Science.gov (United States)

Csermely, P; Szamel, M; Resch, K; Somogyi, J

1988-05-15

In the primary structure of protein kinase C, the presence of a putative metal-binding site has been suggested (Parker, P.J., Coussens, L., Totty, N., Rhee, L., Young, S., Chen, E., Stabel, S., Waterfield, M.D., and Ullrich, A. (1986) Science 233, 853-859). In the present report, we demonstrate that the most abundant intracellular heavy metal, zinc, can increase the activity of cytosolic protein kinase C. Zinc reversibly binds the enzyme to plasma membranes, and it may contribute to the calcium-induced binding as well. The intracellular heavy metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine prevents the phorbol ester- and antigen-induced translocation of protein kinase C. This effect can be totally reversed by the concomitant addition of Zn2+, while Fe2+ and Mn2+ are only partially counteractive. Our results suggest that zinc can activate protein kinase C and contributes to its binding to plasma membranes in T lymphocytes induced by Ca2+, phorbol ester, or antigen.

Induction of rat hepatic zinc thionein by phorbol ester-mediated protein kinase C pathway

Energy Technology Data Exchange (ETDEWEB)

Garrett, S.H.; Funk, A.E.; Brady, F.O.

1986-05-01

Metallothionein (MT) exists in rat liver mainly as a zinc protein. The levels of this protein fluctuate in response to a variety of internal and external stimuli. Among these inducers of MT are metals, glucocorticoids, catecholamines, and polypeptide hormones. Metals and glucocorticoids are primary inducers of MT, while the others operate either via adenylate cyclase/cAMP/cAMP-dependent protein kinase, or via phospholipase C/inositol 1,4,5-triphosphate, diacylglycerol/Ca/sup 2 +/-dependent protein kinase, protein kinase C. The authors have examined the role of the protein kinase C pathway in the induction of MT by using a phorbol ester, 12-O-tetradecanoyl-phorbol 13-acetate (TPA), to activate it. In vivo TPA is a good inducer of Zn/sub 7/-MT with an ED/sub 0.5/ of 26.5 nmoles/kg b.w. Maximal levels reached were about 7..mu..g Zn in MT/g liver, an induction increase of 8 to 10-fold. An inactive compound, 4..beta..-phorbol, and the vehicle (DMSO) did not stimulate the synthesis of Zn/sub 7/-MT. This induction by TPA requires de novo protein synthesis, as demonstrated by a cycloheximide/(/sup 35/S)-cysteine experiment. TPA stimulated Zn incorporation by 8.6-fold and (/sup 35/S)-cysteine incorporation by 4.8-fold during an 11h induction. These increases were blocked 100% by treatment with cycloheximide at -1 and +5h. These experiments have been repeated in cultured hepatocytes, using (/sup 35/S)-cysteine incorporation, slab SDS-PAGE, and autoradiography to quantitate MT levels.

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

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...

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.)

Preparation of cobalt-zinc ferrite (Co0.8Zn0.2Fe2O4) nanopowder via combustion method and investigation of its magnetic properties

International Nuclear Information System (INIS)

Yousefi, M.H.; Manouchehri, S.; Arab, A.; Mozaffari, M.; Amiri, Gh. R.; Amighian, J.

2010-01-01

Research highlights: → Cobalt-zinc ferrite was prepared by combustion method. → Properties of the sample were characterized by several techniques. → Curie temperature was determined to be 350 o C. -- Abstract: Cobalt-zinc ferrite (Co 0.8 Zn 0.2 Fe 2 O 4 ) was prepared by combustion method, using cobalt, zinc and iron nitrates. The crystallinity of the as-burnt powder was developed by annealing at 700 o C. Crystalline phase was investigated by XRD. Using Williamson-Hall method, the average crystallite sizes for nanoparticles were determined to be about 27 nm before and 37 nm after annealing, and residual stresses for annealed particles were omitted. The morphology of the annealed sample was investigated by TEM and the mean particle size was determined to be about 30 nm. The final stoichiometry of the sample after annealing showed good agreement with the initial stoichiometry using atomic absorption spectrometry. Magnetic properties of the annealed sample such as saturation magnetization, remanence magnetization, and coercivity measured at room temperature were 70 emu/g, 14 emu/g, and 270 Oe, respectively. The Curie temperature of the sample was determined to be 350 o C using AC-susceptibility technique.

Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

Science.gov (United States)

Fermoso, Fernando G.; Collins, Gavin; Bartacek, Jan

2008-01-01

The effect of omitting zinc from the influent of mesophilic (30 °C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of the bioreactor sludge. Limitation of the specific methanogenic activity (SMA) on methanol due to the absence of zinc from the influent developed after 137 days of operation. At that day, the SMA in medium with a complete trace metal solution except Zn was 3.4 g CH4-COD g VSS−1 day−1, compared to 4.2 g CH4-COD g VSS−1 day−1 in a medium with a complete (including zinc) trace metal solution. The methanol removal capacity during these 137 days was 99% and no volatile fatty acids accumulated. Two UASB reactors, inoculated with the zinc-deprived sludge, were operated to study restoration of the zinc limitation by zinc supplementation to the bioreactor influent. In a first reactor, no changes to the operational conditions were made. This resulted in methanol accumulation in the reactor effluent after 12 days of operation, which subsequently induced acetogenic activity 5 days after the methanol accumulation started. Methanogenesis could not be recovered by the continuous addition of 0.5 μM ZnCl2 to the reactor for 13 days. In the second reactor, 0.5 μM ZnCl2 was added from its start-up. Although the reactor stayed 10 days longer methanogenically than the reactor operated without zinc, methanol accumulation was observed in this reactor (up to 1.1 g COD-MeOH L−1) as well. This study shows that zinc limitation can induce failure of methanol fed UASB reactors due to acidification, which cannot be restored by resuming the continuous supply of the deprived metal. PMID:18283507

Chromatically unique 6-bridge graph theta(a,a,a,b,b,c

Directory of Open Access Journals (Sweden)

N.S.A. Karim

2016-04-01

Full Text Available For a graph $G$, let $P(G,\\lambda$ denote the chromatic polynomial of $G$. Two graphs $G$ and $H$ are chromatically equivalent if they share the same chromatic polynomial. A graph $G$ is chromatically unique if for any graph chromatically equivalent to $G$ is isomorphic to $G$. In this paper, the chromatically unique of a new family of 6-bridge graph $\\theta(a,a,a,b,b,c$ where $2\\le a\\le b\\le c$ is investigated.

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%

Plasma zinc in institutionalized elderly individuals: Relation with immune and cardiometabolic biomarkers.

Science.gov (United States)

Sales, Márcia Cristina; de Oliveira, Larissa Praça; de Araújo Cabral, Natalia Louise; de Sousa, Sara Estéfani Soares; das Graças Almeida, Maria; Lemos, Telma Maria Araújo Moura; de Oliveira Lyra, Clélia; de Lima, Kenio Costa; Sena-Evangelista, Karine Cavalcanti Mauricio; de Fatima Campos Pedrosa, Lucia

2018-04-24

Changes in zinc metabolism caused by aging and the institutionalization process may contribute to zinc deficiency in elderly individuals. Hypozincemia results in changes in glycemic, lipid, and inflammatory profiles. The aim of this study was to evaluate plasma zinc concentrations and their relationships with sociodemographic, dietary, inflammatory, and cardiometabolic biomarkers in institutionalized elderly individuals. A cross-sectional study was carried out including 255 elderly adults living in nursing homes. The associations between plasma zinc and dietary zinc intake, sociodemographic indicators, and glycemic, lipid, and inflammatory biomarkers were evaluated. Independent variables were analyzed according to quartiles of plasma zinc concentrations (Q1: 93.7 μg/dL). The relationship between plasma zinc concentrations and predictor variables was also tested. In Q1, higher concentrations of the following variables were observed, compared with those in other quartiles: total cholesterol and low-density lipoprotein cholesterol (LDL-c; Q1 > Q2, Q3, Q4; all p  Q3, Q4; all p  Q3, Q4; p = 0.024 and p = 0.010, respectively); tumor necrosis factor (TNF)-α (Q1 > Q3, p = 0.003). A significant reduction in plasma zinc concentrations was observed with increasing age-adjusted institutionalization time (Δ = - 0.10; 95% confidence interval [CI]: -0.18 to -0.01). The concentrations of total cholesterol (Δ = - 0.19; 95% CI: -0.23 to -0.15), LDL-c (Δ = - 0.19; 95% CI: -0.23 to -0.15), triglycerides (Δ = - 0.11; 95% CI: -0.16 to -0.06), IL-6 (Δ = - 1.41; 95% CI: -2.64 to -0.18), and TNF-α (Δ = - 1.04; 95% CI: -1.71 to -0.36) were also significantly increased. In conclusion, decreased plasma zinc concentrations were associated with longer institutionalization time and worse lipid and inflammatory profiles in elderly institutionalized individuals. Published by Elsevier GmbH.

Introducing zinc cations into zeolite Y via the reduction of HY with zinc metal vapour

Science.gov (United States)

Seidel, A.; Boddenberg, B.

1996-01-01

Zeolites HY and NaY which were contacted with zinc metal vapour at 420°C were investigated by carbon monoxide and xenon adsorption as well as 129Xe NMR spectroscopy. The reaction of zeolite HY results in the incorporation of Zn 2+ cations which are shown to populate the supercage positions S II and S III to an unusually high extent. The supercage zinc cation concentration strongly decreases when the material is saturated with water and subsequently dehydrated at 400°C. The zeolite NaY turns out to be inert towards the reaction with zinc metal vapour.

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

C4 photosynthetic machinery: insights from maize chloroplast proteomics

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Qi eZhao

2013-04-01

Full Text Available C4 plants exhibit much higher CO2 assimilation rates than C3 plants. The specialized differentiation of mesophyll cell (M and bundle sheath cell (BS type chloroplasts is unique to C4 plants and improves photosynthesis efficiency. Maize (Zea mays is an important crop and model with C4 photosynthetic machinery. Current high-throughput quantitative proteomics approaches (e.g., 2DE, iTRAQ, and shotgun proteomics have been employed to investigate maize chloroplast structure and function. These proteomic studies have provided valuable information on C4 chloroplast protein components, photosynthesis, and other metabolic mechanisms underlying chloroplast biogenesis, stromal and membrane differentiation, as well as response to salinity, high/low temperature, and light stress. This review presents an overview of proteomics advances in maize chloroplast biology.

The corrosion inhibition of pure zinc in NH{sub 4}Cl aqueous solutions by N-Alkyl quaternary ammonium bromides

Energy Technology Data Exchange (ETDEWEB)

Branzoi, V.; Pilan, Luisa; Pruna, Alina [University ' Politehnica' of Bucharest, Faculty of Industrial Chemistry, Department of Physical Chemistry and Electrochemistry, Calea Grivitei, 132, Bucharest (Romania); Branzoi, Florina [Institute of Physical Chemistry Bucharest, Splaiul Independentei, 202, Bucharest (Romania)

2004-07-01

The corrosion of zinc in NH{sub 4}Cl solutions of different concentrations has been studied by potentiostatic and potentiodynamic methods and by impedance measurements. The results obtained in a potential region near the zinc corrosion potential showed that the cathodic reaction of hydrogen discharge does not fit a simple exponential law because the Tafel coefficient appears to be electrode potential dependent. At low overvoltages, in the anodic region, the corrosion process is under activation control, while at high overvoltages the process is under diffusion control. N-dodecyl, n-tetra-decyl and n-hexa-decyl ammonium bromides were used as organic inhibitors. The potentiostatic and potentiodynamic polarization studies and EIS measurements showed that each quaternary ammonium salt inhibits the corrosion of pure zinc in 1M NH{sub 4}Cl at 30 deg. C. The inhibition efficiency of the cations was discussed on the basis of Coulomb adsorption behaviour, using molecular coverage areas and polar substituent constant. The inhibition efficiency obtained from the corrosion currents was found to increase linearly with an increase in the molecular coverage area (A) for the series of tetra-alkyl ammonium ions. The efficiency of the cations increased with an increase in the positive charge of the nitrogen atom, which was due to the inductive effect of the electron-attractive groups. This effect on the Coulomb adsorption of the cations was, however, far less than that of the electron donating groups on the chemisorption of un-protonated amines. The steric requirements for the adsorption of the quaternaries with branched alkyl chains were small. Each organic compound exhibits Langmuir behaviour and inhibition increases with increasing alkyl chain length. This is attributed to cohesive Van der Waals forces between the positive head groups co-adsorbed with bromide ions on the positively charged zinc surface. (authors)

1,4-Iron Migration for Expedient Allene Annulations through Iron-Catalyzed C-H/N-H/C-O/C-H Functionalizations.

Science.gov (United States)

Mo, Jiayu; Müller, Thomas; Oliveira, João C A; Ackermann, Lutz

2018-06-25

C-H activation bears great potential for enabling sustainable molecular syntheses in a step- and atom-economical manner, with major advances having been realized with precious 4d and 5d transition metals. In contrast, we employed earth abundant, nontoxic iron catalysts for versatile allene annulations through a unique C-H/N-H/C-O/C-H functionalization sequence. The powerful iron catalysis occurred under external-oxidant-free conditions even at room temperature, while detailed mechanistic studies revealed an unprecedented 1,4-iron migration regime for facile C-H activations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

High temperature dielectric properties of spent adsorbent with zinc sulfate by cavity perturbation technique

Energy Technology Data Exchange (ETDEWEB)

Lin, Guo [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, Yunnan 650093 (China); National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming, Yunnan 650093 (China); Liu, Chenhui [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, Yunnan 650093 (China); National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming, Yunnan 650093 (China); Faculty of Chemistry and Environment, Yunnan Minzu University, Kunming, Yunnan 650093 (China); Zhang, Libo, E-mail: libozhang77@163.com [State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming, Yunnan 650093 (China); National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology, Kunming, Yunnan 650093 (China); and others

2017-05-15

Highlights: • Cavity perturbation technique is employed to measure the dielectric properties. • Microwave absorption capability of ZnO is poor from 20 °C to 850 °C. • Dielectric properties of spent absorbent and zinc sulfate are influenced by temperature especially in high temperature stage. • Penetration depths and heating curve indicate spent adsorbent and ZnO·2ZnSO{sub 4}, ZnSO{sub 4} are excellent microwave absorber. • The pore structures of spent adsorbent are improved significantly by microwave-regeneration directly. - Abstract: Dielectric properties of spent adsorbent with zinc sulfate are investigated by cavity perturbation technique at 2450 MHz from 20 °C to approximately 1000 °C. Two weight loss stages are observed for spent adsorbent by thermogravimetric-differential scanning calorimeter (TG-DSC) analysis, and zinc sulfate is decomposed to ZnO·2ZnSO{sub 4} and ZnO at about 750 °C and 860 °C. Microwave absorption capability of ZnSO{sub 4} increases with increasing temperature and declines after ZnO generation on account of the poor dielectric properties. Dielectric properties of spent adsorbent are dependent on apparent density and noticed an interestingly linearly relationship at room temperature. The three parameters increase gently from 20 °C to 400 °C, but a sharp increase both in real part and imaginary part are found subsequently due to the volatiles release and regeneration of carbon. And material conductivity is improved, which contributes to the π-electron conduction appearance. Relationship between penetration depth and temperature further elaborate spent adsorbent is an excellent microwave absorber and the microwave absorption capability order of zinc compounds is ZnO·2ZnSO{sub 4}, ZnSO{sub 4} and ZnO. Heating characteristics suggest that heating rate is related with dielectric properties of materials. The pore structures of spent adsorbent are improved significantly and the surface is smoother after microwave-regeneration.

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.

The superspin glass transition in zinc ferrite nanoparticles

Czech Academy of Sciences Publication Activity Database

Kaman, Ondřej; Kořínková, T.; Jirák, T.; Maryško, Miroslav; Veverka, Miroslav

2015-01-01

Roč. 117, č. 17 (2015), "17C706-1"-"17C706-4" ISSN 0021-8979 R&D Projects: GA ČR(CZ) GAP108/11/0807; GA ČR GAP204/10/0035 Institutional support: RVO:68378271 Keywords : superspin glass * zinc ferrite * doped magnetite * magnetic nanoparticles * thermal decomposition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.101, year: 2015

Potential ecological risk assessment and predicting zinc accumulation in soils.

Science.gov (United States)

Baran, Agnieszka; Wieczorek, Jerzy; Mazurek, Ryszard; Urbański, Krzysztof; Klimkowicz-Pawlas, Agnieszka

2018-02-01

The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and intensity of industrial development. The zinc content was affected by soil factors, and the type of land use (arable lands, grasslands, forests, wastelands). A total of 320 soil samples were characterized in terms of physicochemical properties (texture, pH, organic C content, total and available Zn content). Based on the obtained data, assessment of the ecological risk of zinc was conducted using two methods: potential ecological risk index and hazard quotient. Total Zn content in the soils ranged from 8.27 to 7221 mg kg -1 d.m. Based on the surface semivariograms, the highest variability of zinc in the soils was observed from northwest to southeast. The point sources of Zn contamination were located in the northwestern part of the area, near the mining-metallurgical activity involving processing of zinc and lead ores. These findings were confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. The content of bioavailable forms of zinc was between 0.05 and 46.19 mg kg -1 d.m. (0.01 mol dm -3 CaCl 2 ), and between 0.03 and 71.54 mg kg -1 d.m. (1 mol dm -3 NH 4 NO 3 ). Forest soils had the highest zinc solubility, followed by arable land, grassland and wasteland. PCA showed that organic C was the key factor to control bioavailability of zinc in the soils. The extreme, very high and medium zinc accumulation was found in 69% of studied soils. There is no ecological risk of zinc to living organisms in the study area, and in 90

Critical current density in MgB2 bulk samples after co-doping with nano-SiC and poly zinc acrylate complexes

International Nuclear Information System (INIS)

Zhang, Z.; Suo, H.; Ma, L.; Zhang, T.; Liu, M.; Zhou, M.

2011-01-01

SiC and poly zinc acrylate complexes co-doped MgB 2 bulk has been synthesized. Co-doping can cause higher carbon substitutions and the second phase particles. Co-doping can further increase the Jc value of MgB 2 bulk on the base of the SiC doping. The co-doped MgB 2 bulk samples have been synthesized using an in situ reaction processing. The additives is 8 wt.% SiC nano powders and 10 wt.% [(CH 2 CHCOO) 2 Zn] n poly zinc acrylate complexes (PZA). A systematic study was performed on samples doped with SiC or PZA and samples co-doped with both of them. The effects of doping and co-doping on phase formation, microstructure, and the variation of lattice parameters were studied. The amount of substituted carbon, the critical temperature (T c ) and the critical current density (J c ) were determined. The calculated lattice parameters show the decrease of the a-axis, while no obvious change was detected for c-axis parameter in co-doped samples. This indicates that the carbon was substituted by boron in MgB 2 . The amount of substituted carbon for the co-doped sample shows an enhancement compared to that of the both single doped samples. The co-doped samples perform the highest J c values, which reaches 3.3 x 10 4 A/cm 2 at 5 K and 7 T. It is shown that co-doping with SiC and organic compound is an effective way to further improve the superconducting properties of MgB 2 .

Separation of Hepatitis C genotype 4a into IgG-depleted and IgG-enriched fractions reveals a unique quasispecies profile.

LENUS (Irish Health Repository)

Moreau, Isabelle

2012-02-03

BACKGROUND: Hepatitis C virus (HCV) circulates in an infected individual as a heterogeneous mixture of closely related viruses called quasispecies. The E1\\/E2 region of the HCV genome is hypervariable (HVR1) and is targeted by the humoral immune system. Hepatitis C virions are found in two forms: antibody associated or antibody free. The objective of this study was to investigate if separation of Hepatitis C virions into antibody enriched and antibody depleted fractions segregates quasispecies populations into distinctive swarms. RESULTS: A HCV genotype 4a specimen was fractionated into IgG-depleted and IgG-enriched fractions by use of Albumin\\/IgG depletion spin column. Clonal analysis of these two fractions was performed and then compared to an unfractionated sample. Following sequence analysis it was evident that the antibody depleted fraction was significantly more heterogeneous than the antibody enriched fraction, revealing a unique quasispecies profile. An in-frame 3 nt insertion was observed in 26% of clones in the unfractionated population and in 64% of clones in the IgG-depleted fraction. In addition, an in-frame 3 nt indel event was observed in 10% of clones in the unfractionated population and in 9% of clones in the IgG-depleted fraction. Neither of these latter events, which are rare occurrences in genotype 4a, was identified in the IgG-enriched fraction. CONCLUSION: In conclusion, the homogeneity of the IgG-enriched species is postulated to represent a sequence that was strongly recognised by the humoral immune system at the time the sample was obtained. The heterogeneous nature of the IgG-depleted fraction is discussed in the context of humoral escape.

Radical zinc-atom-transfer-based carbozincation of haloalkynes with dialkylzincs

Directory of Open Access Journals (Sweden)

Fabrice Chemla

2013-02-01

Full Text Available The formation of alkylidenezinc carbenoids by 1,4-addition/carbozincation of dialkylzincs or alkyl iodides based on zinc atom radical transfer, in the presence of dimethylzinc with β-(propargyloxyenoates having pendant iodo- and bromoalkynes, is disclosed. Formation of the carbenoid intermediate is fully stereoselective at −30 °C and arises from a formal anti-selective carbozincation reaction. Upon warming, the zinc carbenoid is stereochemically labile and isomerizes to its more stable form.

Relationship between seminal plasma zinc and semen quality in a subfertile population

Directory of Open Access Journals (Sweden)

DMAB Dissanayake

2010-01-01

Full Text Available Rationale : Current knowledge on the relationship between seminal zinc levels and different parameters of human semen is inconsistent. Objectives : To assess the relationship between seminal plasma zinc and semen quality using two markers; zinc concentration (Zn-C and total zinc per ejaculate (Zn-T. Design : The study was carried out as a cross-sectional study. Subjects and Methods : Semen parameters of 152 healthy men undergoing evaluation for subfertility were assessed. Seminal plasma zinc levels were determined using flame atomic absorption spectrometry. Zn-C, expressed as μg/mL, was multiplied by ejaculated volume to calculate Zn-T. Mann Whitney U test and Chi-square test were used to compare the zinc levels between different seminal groups when appropriate. Correlations were observed with Pearson′s correlation of coefficient. Analysis was carried out using SPSS 10.0 for windows software. Results : Zn-C was low in 23 (15% samples, while in 32 (21% of the samples Zn-T was abnormal. The number of subnormal samples was high in the low-zinc groups compared with the normal-zinc groups, 15 vs. 8 (P > 0.05 for Zn-C and 28 vs. 4 (P < 0.001 for Zn-T. Zn-C was significantly high in the asthenozoospermics compared with the normal motile group; 138.11 μg/mL (83.92 vs. 110.69 11 μg/mL (54.59 (P < 0.05. Zn-T was significantly low in samples with hyperviscosity compared with samples with normal viscosity; 220.06 μg (144.09 vs. 336.34 μg (236.33 (P < 0.05. Conversely, Zn-T was high in samples with low viability compared with those with normal viability; 437.67 μg (283.88 vs. 305.15 μg (221.19 (P < 0.05. Weak correlations were found between Zn and some semen parameters. However, the correlation was negative between pH and Zn-C (r = -0.193, P < 0.05 as well as Zn-T (r = -0.280, P < 0.01. On the other hand, correlations were positive between Zn-T and sperm count (r = 0.211, P < 0.05. Conclusion : Count, motility, viability, pH and viscosity are

One-step synthesis of graphitic-C 3 N 4 /ZnS composites for enhanced supercapacitor performance

KAUST Repository

Wei, Binbin

2017-11-24

A series of graphitic-C3N4/ZnS (g-C3N4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C3N4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, g-C3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C3N4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C3N4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C3N4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.

One-step synthesis of graphitic-C 3 N 4 /ZnS composites for enhanced supercapacitor performance

KAUST Repository

Wei, Binbin; Liang, Hanfeng; Wang, Rongrong; Zhang, Dongfang; Qi, Zhengbing; Wang, Zhoucheng

2017-01-01

A series of graphitic-C3N4/ZnS (g-C3N4/ZnS) supercapacitor electrode materials have been prepared via a one-step calcination process of zinc acetate/thiourea with different mass ratios under nitrogen atmosphere. The optimized g-C3N4/ZnS composite shows a highest specific capacitance of 497.7 F/g at 1 A/g and good cycling stability with capacitance retention of 80.4% at 5 A/g after 1000 cycles. Moreover, g-C3N4/ZnS composites display an improved supercapacitor performance in terms of specific capacitance compared to the pure g-C3N4 and ZnS. In addition, our designed symmetric supercapacitor device based on g-C3N4/ZnS composite electrodes can exhibit an energy density of 10.4 Wh/kg at a power density of 187.3 W/kg. As a result, g-C3N4/ZnS composites are expected to be a prospective material for supercapacitors and other energy storage applications.

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.

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.

Histidine protects against zinc and nickel toxicity in Caenorhabditis elegans.

Directory of Open Access Journals (Sweden)

John T Murphy

2011-03-01

Full Text Available Zinc is an essential trace element involved in a wide range of biological processes and human diseases. Zinc excess is deleterious, and animals require mechanisms to protect against zinc toxicity. To identify genes that modulate zinc tolerance, we performed a forward genetic screen for Caenorhabditis elegans mutants that were resistant to zinc toxicity. Here we demonstrate that mutations of the C. elegans histidine ammonia lyase (haly-1 gene promote zinc tolerance. C. elegans haly-1 encodes a protein that is homologous to vertebrate HAL, an enzyme that converts histidine to urocanic acid. haly-1 mutant animals displayed elevated levels of histidine, indicating that C. elegans HALY-1 protein is an enzyme involved in histidine catabolism. These results suggest the model that elevated histidine chelates zinc and thereby reduces zinc toxicity. Supporting this hypothesis, we demonstrated that dietary histidine promotes zinc tolerance. Nickel is another metal that binds histidine with high affinity. We demonstrated that haly-1 mutant animals are resistant to nickel toxicity and dietary histidine promotes nickel tolerance in wild-type animals. These studies identify a novel role for haly-1 and histidine in zinc metabolism and may be relevant for other animals.

Determination of the Optimum Conditions for Leaching of Zinc Cathode Melting Furnace Slag in Ammonium Chloride Media

Science.gov (United States)

Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

2014-04-01

This research is part of a continuing effort to leach zinc from zinc cathode melting furnace slags (ZCMFSs) to produce zinc oxide. The slag with an assay of 68.05 pct Zn was used in ammonium chloride leaching for zinc extraction. In this paper, the effects of influential factors on extraction efficiency of Zn from a ZCMFS were investigated. The Taguchi's method based on orthogonal array (OA) design has been used to arrange the experimental runs in order to maximize zinc extraction from a slag. The softwares named Excel and Design-Expert 7 have been used to design experiments and subsequent analysis. OA L 25 (55) consisting of five parameters, each with five levels, was employed to evaluate the effects of reaction time ( t = 10, 30, 50, 70, 90 minutes), reaction temperature [ T = 313, 323, 333, 343, 353 (40, 50, 60, 70, 80) K (°C)], pulp density ( S/ L = 20, 40, 60, 80, 100 g/L), stirring speed ( R = 300, 400, 500, 600, 700 rpm), and ammonium chloride concentration ( C = 10, 15, 20, 25, 30 pctwt), on zinc extraction percent. Statistical analysis, ANOVA, was also employed to determine the relationship between experimental conditions and yield levels. The results showed that the significant parameters affecting leaching of slag were ammonium chloride concentration and pulp density, and increasing pulp density reduced leaching efficiency of zinc. However, increasing ammonium chloride concentration promoted the extraction of zinc. The optimum conditions for this study were found to be t 4: 70 minutes, T 5: 353 K (80 °C), ( S/ L)2: 40 g/L, R 3: 500 rpm, and C 4: 25 pctwt. Under these conditions, the dissolution percentage of Zn in ammonium chloride media was 94.61 pct.

C3HC4-type RING finger protein NbZFP1 is involved in growth and fruit development in Nicotiana benthamiana.

Directory of Open Access Journals (Sweden)

Wenxian Wu

Full Text Available C3HC4-type RING finger proteins constitute a large family in the plant kingdom and play important roles in various physiological processes of plant life. In this study, a C3HC4-type zinc finger gene was isolated from Nicotiana benthamiana. Sequence analysis indicated that the gene encodes a 24-kDa protein with 191 amino acids containing one typical C3HC4-type zinc finger domain; this gene was named NbZFP1. Transient expression of pGDG-NbZFP1 demonstrated that NbZFP1 was localized to the chloroplast, especially in the chloroplasts of cells surrounding leaf stomata. Virus-induced gene silencing (VIGS analysis indicated that silencing of NbZFP1 hampered fruit development, although the height of the plants was normal. An overexpression construct was then designed and transferred into Nicotiana benthamiana, and PCR and Southern blot showed that the NbZFP1 gene was successfully integrated into the Nicotiana benthamiana genome. The transgenic lines showed typical compactness, with a short internode length and sturdy stems. This is the first report describing the function of a C3HC4-type RING finger protein in tobacco.

Construction and application of a zinc-specific biosensor for assessing the immobilization and bioavailability of zinc in different soils

International Nuclear Information System (INIS)

Liu Pulin; Huang Qiaoyun; Chen Wenli

2012-01-01

The inducibility and specificity of different czcRS operons in Pseudomonas putida X4 were studied by lacZ gene fusions. The data of β-glycosidase activity confirmed that the czcR3 promoter responded quantitatively to zinc. A zinc-specific biosensor, P. putida X4 (pczcR3GFP), was constructed by fusing a promoterless enhanced green fluorescent protein (egfp) gene with the czcR3 promoter in the chromosome of P. putida X4. In water extracts of four different soils amended with zinc, the reporter strain detected about 90% of the zinc content of the samples. Both the bioavailability assessment and the sequential extraction analysis demonstrated that the immobilization of zinc was highly dependent on the physico-chemical properties of soils. The results also showed that the lability of zinc decreased over time. It is concluded that the biosensor constitutes an alternative system for the convenient evaluation of zinc toxicity in the environment. - Highlights: ► A zinc-specific bacterial biosensor was developed. ► Four spiked soils were used to test the application of this biosensor. ► The bioavailable zinc in soil-water extracts decreased due to aging. ► The immobilization and speciation of zinc were highly dependent on the soil type. - The immobilization and bioavailability of zinc in soil were investigated as a function of soil type and aging by a newly constructed zinc-specific biosensor coupled with chemical analysis.

Tetra- and octa-[4-(2-hydroxyethyl)phenoxy bearing novel metal-free and zinc(II) phthalocyanines: Synthesis, characterization and investigation of photophysicochemical properties

Energy Technology Data Exchange (ETDEWEB)

Köksoy, Baybars [Marmara University, Department of Chemistry, 34722 Kadıköy, Istanbul (Turkey); Durmuş, Mahmut [Gebze Technical University, Department of Chemistry, 41400 Gebze, Kocaeli (Turkey); Bulut, Mustafa, E-mail: mbulut@marmara.edu.tr [Marmara University, Department of Chemistry, 34722 Kadıköy, Istanbul (Turkey)

2015-05-15

In this study, four novel phthalonitriles (1–4) and their corresponding metal-free (5–8) and zinc(II) phthalocyanine derivatives (9–12) bearing 4-(hydroxyethyl)phenoxy groups were synthesized. These novel compounds were characterized by IR, elemental analyses, {sup 1}H-NMR, UV–vis, and MALDI-TOF spectral data. Furthermore, photophysical (fluorescence quantum yields and lifetimes) and photochemical properties (singlet oxygen generation and photodegradation quantum yields) of these phthalocyanines were investigated in dimethylsulfoxide. The studied zinc(II) phthalocyanines generated highly singlet oxygen which is very important for the photodynamic therapy (PDT) of cancer. The fluorescence quenching behaviour of the newly synthesized phthalocyanine compounds were also investigated using 1,4-benzoquinone. - Highlights: • Octa and tetra 4-(hydroxyethyl)phenoxy substituted metal-free and zinc(II) phthalocyanines. • Study of photophysicochemical properties of eight new phthalocyanines. • Highly singlet oxygen generation for novel zinc(II) phthalocyanine photosensitizers.

Half-metallicity and ferromagnetism of TcX (X=C, Si and Ge) in zinc blende structure

Energy Technology Data Exchange (ETDEWEB)

Liu, Yong [College of Science, Yanshan University, Qinhuangdao 066004 (China); Physics Department, Brock University, St. Catharines, ON, Canada L2S 3A1 (Canada); Xing, Yue [College of Science, Yanshan University, Qinhuangdao 066004 (China); Bose, S.K., E-mail: sbose@brocku.ca [Physics Department, Brock University, St. Catharines, ON, Canada L2S 3A1 (Canada); Zhao, Yong-Hong [Department of Physics, Sichuan Normal University, Chengdu 610068 (China)

2013-02-15

We report results of a first-principles density-functional study of three binary transition-metal compounds TcX (X=C, Si and Ge) in the hypothetical cubic zinc blende (ZB) structure. Our calculations are based on the full potential linear augmented plane wave (FP-LAPW) plus local orbitals method, together with generalized gradient approximation for the exchange-correlation potential. Half-metallic (HM) ferromagnetism is observed in these binary compounds for their optimized cell volumes. In the HM state, these compounds possess an integer magnetic moment (1.000{mu}{sub B}) per formula unit, which is one of the important characteristics of half-metallic ferromagnets (HMFs). The ferromagnetic (FM) state is found to be stable for ZB TcC, TcSi and TcGe against the nonmagnetic (NM) and antiferromagnetic (AFM) states. Calculations show that half-metallicity can be maintained for a wide range of lattice constants in these binary compounds. Density functional calculations of exchange interactions and the Curie temperatures reveal similar trends for the three compounds with respect to the lattice parameter. These compounds are compatible with the traditional semiconductors, and could be useful in spin-electronics and other applications. The most important aspect of this work is to explore the possibility of not only magnetism, but HM ferromagnetism in compounds involving NM elements and 4d transition element Tc. - Highlights: Black-Right-Pointing-Pointer We study magnetism of the compounds TcSi, TcC, and TcGe. Black-Right-Pointing-Pointer These compounds, with nonmagnetic constituents, are found to be ferromagnetic. Black-Right-Pointing-Pointer They show robust half-metallicity in zinc blende structure. Black-Right-Pointing-Pointer Estimated Curie temperatures suggest that synthesis of these compounds is worth pursuing.

Crystal structures of Er4Ni13C4 and UW4C4

International Nuclear Information System (INIS)

Khalili, M.M.; Bodak, O.I.; Marusin, E.P.; Pecharskaya, A.O.

1990-01-01

Crystal structures of Er 4 Ni 13 C 4 (1) (sp.gr. Cmmm, a=1.1975(4), b=1.1694(3), c=0.3856(1) nm, Z=2) and UW 4 C 4 (2) (sp.gr. P4/m, a=0.8328(8), c=0.31345(9) nm, Z=2), relating to new types are determined. Structural type (1) is a derivative of La 2 Ni 5 C 3 structure, structural type (2) is close to UCr 4 C 4 structure

Zinc Supplementation Does Not Alter Indicators of Insulin Secretion and Sensitivity in Black and White Female Adolescents.

Science.gov (United States)

Lobene, Andrea J; Kindler, Joseph M; Jenkins, Nathan T; Pollock, Norman K; Laing, Emma M; Grider, Arthur; Lewis, Richard D

2017-07-01

Background: Zinc is a micronutrient involved in the production of, and peripheral sensitivity to, pancreatic β cell-derived insulin. To our knowledge, the effect of zinc supplementation on insulin outcomes, and potential risk of diabetes, in otherwise healthy children in the United States has not been investigated. Objective: The objective of this study was to determine the influence of zinc supplementation on insulin outcomes in black and white girls in the early stages of adolescence. A secondary objective was to determine relations between baseline zinc concentrations and insulin outcomes. Methods: Healthy black and white girls aged 9-11 y were randomly assigned to daily supplementation of zinc (9 mg elemental Zn/d; n = 75; blacks: n = 35) or placebo ( n = 72; blacks: n = 32) for 4 wk. Fasting serum insulin, glucose, and C-peptide were assessed at baseline and at 4 wk. C-peptide and glucose values were used to calculate the computer model-derived homeostatic model assessment of insulin resistance (HOMA2-IR). Changes in outcome measures were compared by using repeated-measures, mixed-model ANOVA. Results: Baseline plasma zinc was not correlated with C-peptide ( r = -0.07), insulin ( r = -0.06), or HOMA2-IR ( r = -0.09) (all P > 0.05) after controlling for race and age. Treatment × time interactions for C-peptide and HOMA2-IR were not significant (both P > 0.05). Although the treatment × race × time interactions for C-peptide and HOMA2-IR were not significant (both P = 0.08), black girls who received the placebo experienced slight increases in C-peptide (15.7%) and HOMA2-IR (17.7%) ( P = 0.06). Conclusions: Four weeks of zinc supplementation had no effect on insulin outcomes in healthy black and white early-adolescent girls, although C-peptide and HOMA2-IR tended to increase in black girls who received placebo. Additional trials that are appropriately powered should further explore the effect of zinc on markers of diabetes risk, and whether race affects this

Dynamic transcriptomic profiles of zebrafish gills in response to zinc supplementation

Directory of Open Access Journals (Sweden)

Cunningham Phil

2010-10-01

Full Text Available Abstract Background Dietary zinc supplementation may help to promote growth, boost the immune system, protect against diabetes, and aid recovery from diarrhoea. We exploited the zebrafish (Danio rerio gill as a unique vertebrate ion transporting epithelium model to study the time-dependent regulatory networks of gene-expression leading to homeostatic control during zinc supplementation. This organ forms a conduit for zinc uptake whilst exhibiting conservation of zinc trafficking components. Results Fish were maintained with either zinc supplemented water (4.0 μM and diet (2023 mg zinc kg-1 or water and diet containing Zn2+ at 0.25 μM and 233 mg zinc kg-1, respectively. Gill tissues were harvested at five time points (8 hours to 14 days and transcriptome changes analysed in quintuplicate using a 16 K microarray with results anchored to gill Zn2+ influx and whole body nutrient composition (protein, carbohydrate, lipid, elements. The number of regulated genes increased up to day 7 but declined as the fish acclimated. In total 525 genes were regulated (having a fold-change more than 1.8 fold change and an adjusted P-value less than 0.1 which is controlling a 10% False discovery rate, FDR by zinc supplementation, but little overlap was observed between genes regulated at successive time-points. Many genes displayed cyclic expression, typical for homeostatic control mechanisms. Annotation enrichment analysis revealed strong overrepresentation of "transcription factors", with specific association evident with "steroid hormone receptors". A suite of genes linked to "development" were also statistically overrepresented. More specifically, early regulation of genes was linked to a few key transcription factors (e.g. Mtf1, Jun, Stat1, Ppara, Gata3 and was followed by hedgehog and bone morphogenic protein signalling. Conclusions The results suggest that zinc supplementation reactivated developmental pathways in the gill and stimulated stem cell

Effect of zinc supplementation on E-ADA activity, seric zinc, and cytokines levels of Trypanosoma evansi infected Wistar rats.

Science.gov (United States)

Bottari, Nathieli B; Baldissera, Matheus D; Oliveira, Camila B; Duarte, Thiago; Duarte, Marta M M F; Leal, Marta L R; Thomé, Gustavo R; Zanini, Daniela; Schetinger, Maria Rosa C; Nunes, Matheus A G; Dressler, Valderi L; Monteiro, Silvia G; Tonin, Alexandre A; Da Silva, Aleksandro S

2014-09-01

The aim of this study was to evaluate the effect of zinc supplementation on the ecto-adenosine deaminase activity (E-ADA), zinc seric levels and cytokines (TNF-α, IL-1, IL-6, and IL -10) on rats experimentally infected by Trypanosoma evansi. Four groups with 10 rats each were used as negative controls (groups A and B), while the animals from the groups C and D were infected intraperitoneally with 0.1 mL of cryopreserved blood containing 1.4 × 10(4) of trypanosomes. Animals of groups B and D received two doses of Zinc (Zn) at 5 mg kg(-1), subcutaneously, on the 2nd and 7th day post-infection (PI). Blood samples were collected on days 5 (n = 5) and 15 PI (n = 5). Zn supplementation was able to increase the rat's longevity and to reduce their parasitemia. It was observed that seric Zn levels were increased on infected animals under Zn supplementation. Animals that were infected and supplemented with Zn showed changes in E-ADA activity and in cytokine levels (P ADA activity, as well as reduced the concentration of cytokines. Infected animals from groups C and D showed increased levels of cytokines. Finally, we observed that Zn supplementation led to a modulation on cytokine's level in rats infected by T. evansi, as well as in E-ADA activity. Copyright © 2014 Elsevier Ltd. All rights reserved.

The effect of zinc and phytic acid on the incorporation of 1-14C-acetate into aflatoxin by resting mycelia of Aspergillus parasiticus

International Nuclear Information System (INIS)

Gupta, S.K.; Venkitasubramanian, T.A.

1975-01-01

The effect of zinc and phytic acid on [1- 14 C]-acetate incorporation into aflatoxins by resting mycelium was studied. When different levels of ZnSO 4 were used to study its effect on the incorporation of [1- 14 C]-acetate into aflatoxins, it was found that the specific radioactivity incorporation into aflatoxins was maximum at the level of 10 mM-ZnSO 4 . At this concentration the change in the specific radioactivities of aflatoxins B 1 + B 2 and aflatoxins G 1 + G 2 were +74.61% and +29.66%, respectively. On the other hand, phytic acid had an inhibitory effect on the incorporation of [1- 14 C]-acetate. These observations have been correlated in order to find out why soyabean is unable to produce aflatoxins by Aspergillus parasiticus. (orig.) [de

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.

Uniqueness of a pre-generator for $C_0$-semigroup on a general locally convex vector space

OpenAIRE

Lemle, Ludovic Dan; Wu, Liming

2007-01-01

The main purpose is to generalize a theorem of Arendt about uniqueness of $C_0$-semigroups from Banach space setting to the general locally convex vector spaces, more precisely, we show that cores are the only domains of uniqueness for $C_0$-semigroups on locally convex spaces. As an application, we find a necessary and sufficient condition for that the mass transport equation has one unique $L^1(\\R^d,dx)$ weak solution.

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...

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.

The pro1(+) gene from Sordaria macrospora encodes a C6 zinc finger transcription factor required for fruiting body development.

Science.gov (United States)

Masloff, S; Pöggeler, S; Kück, U

1999-05-01

During sexual morphogenesis, the filamentous ascomycete Sordaria macrospora differentiates into multicellular fruiting bodies called perithecia. Previously it has been shown that this developmental process is under polygenic control. To further understand the molecular mechanisms involved in fruiting body formation, we generated the protoperithecia forming mutant pro1, in which the normal development of protoperithecia into perithecia has been disrupted. We succeeded in isolating a cosmid clone from an indexed cosmid library, which was able to complement the pro1(-) mutation. Deletion analysis, followed by DNA sequencing, subsequently demonstrated that fertility was restored to the pro1 mutant by an open reading frame encoding a 689-amino-acid polypeptide, which we named PRO1. A region from this polypeptide shares significant homology with the DNA-binding domains found in fungal C6 zinc finger transcription factors, such as the GAL4 protein from yeast. However, other typical regions of C6 zinc finger proteins, such as dimerization elements, are absent in PRO1. The involvement of the pro1(+) gene in fruiting body development was further confirmed by trying to complement the mutant phenotype with in vitro mutagenized and truncated versions of the pro1 open reading frame. Southern hybridization experiments also indicated that pro1(+) homologues are present in other sexually propagating filamentous ascomycetes.

Facile Preparation of Hybrid Zinc Porphyrin Dendrimer Using Coordination Complex

Energy Technology Data Exchange (ETDEWEB)

Choi, Go-Eun; Shin, Eun Ju [Sunchon National University, Suncheon (Korea, Republic of)

2016-03-15

Porphyrins and metalloporphyrins have been investigated extensively due to their important role in natural photosynthesis, strong absorption in visible region, good light-harvesting properties, unique photophysical and electrochemical properties, and the development of simple synthetic routes for various derivatives. Dendrimers have globular structure with branches of repeating units and wide diversity of the architecture because their size, shape, and functionalities can be tailored. Numerous dendrimers have been designed and synthesized for various applications ranging from catalyst to drug delivery. Both pyridine dendrons Py-PD and Py-AD were successfully coordinated at axial position on central zinc metal cation in zinc porphyrin dendrimers ZnP-AD, ZnP-AD2, or ZnP-AD4. Therefore, it was proven that the formation of axial coordination complex between metal-centered dendrimer and ligand-containing dendron provides another facile method for the preparation of new hybrid dendrimer.

[Molecular structure and luminescent property of bis(2-(4-methyl-2-hydroxyphenyl)benzothiazolate) zinc].

Science.gov (United States)

Xu, Hui-Xia; Chen, Liu-Qing; Wang, Hua; Hao, Yu-Ying; Xu, Bing-She

2011-02-01

Bis(2-(4-methyl-2-hydroxyphenyl)benzothiazolate) zinc(Zn(4-MeBTZ)2) was synthesized. Its molecular structure was confirmed by single-crystal x-ray diffraction. Single-crystal data are as follows: space group triclinic, P-1; a = 8.989 9(11) angstroms, b =12.161 7 (15) angstroms, c = 12.871 9 (16) angstroms, alpha = 63.492 (2) degrees, beta = 84.825 (2) degrees, gamma =71.187 (2) degrees. The steric hindrance provided by introduction methyl groups on phenoxide ring prohibited effectively the formation of pentacoordinate complex. There is distinct intermolecular pi-pi interaction between molecules. The dihedral angle between the phenol and benzothiazolate rings of Zn(4-MeBTZ)2 is 2.166 degrees. The HOMO energy, LUMO energy and optical gap are -5.84, -3.46 and 2.37 eV, respectively. The maximum wavelength peak of PL spectra located at 470 nm. The double-layer devices were employed using Zn(4-MeBTZ)2 as emitter and NPB as hole-transport material. The EL spectra split into two peaks located at 501 and 544 nm respectively. The broadened EL spectra were demonstrated to be originated from the exciplexes formed at the interface between NPB and Zn(4-MeBTZ)2.

The effect of zinc injection into PWR primary coolant on the reduction of radiation buildup and corrosion control. The solubilities of zinc, nickel and cobalt spinel oxides

International Nuclear Information System (INIS)

Miyajima, Kaori; Hirano, Hideo

1999-01-01

The use of zinc injection into PWR primary coolant to reduce radiation buildup has been widely studied, and te reduction effect has been experimentally confirmed. However, some items, such as the optimal concentration of zinc required to reduce radiation buildup, the corrosion control effect of zinc injection, and the influence of zinc injection on the integrity of fuel cladding, have not been clarified yet. In particular, the corrosion suppression effect of zinc remains unconfirmed. Therefore, it is necessary to measure and calculate the solubilities of zinc and nickel spinel oxides, which are formed on the surface of Ni-based alloys in PWR primary systems. In this study, in order to assess the effectiveness of zinc injection in the reduction of radiation buildup and the corrosion control of Ni-based alloy, the potential-pH diagrams for Zn-Cr-H 2 O, Ni-Cr-H 2 O, and Co-Cr-H 2 O systems at 300degC were constructed and the solubilities of Zn-Cr, Ni-Cr, and Co-Cr spinel oxides were calculated. It is concluded that under pH conditions for which NiCr 2 O 4 is stable, zinc injection is effective in corrosion control as well as in reducing radiation buildup. (author)

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...

Changes in zinc status and zinc transporters expression in whole blood of patients with Systemic Inflammatory Response Syndrome (SIRS).

Science.gov (United States)

Florea, Daniela; Molina-López, Jorge; Hogstrand, Christer; Lengyel, Imre; de la Cruz, Antonio Pérez; Rodríguez-Elvira, Manuel; Planells, Elena

2018-09-01

Critically ill patients develop severe stress, inflammation and a clinical state that may raise the utilization and metabolic replacement of many nutrients and especially zinc, depleting their body reserves. This study was designed to assess the zinc status in critical care patients with systemic inflammatory response syndrome (SIRS), comparing them with a group of healthy people, and studying the association with expression of zinc transporters. This investigation was a prospective, multicentre, comparative, observational and analytic study. Twelve critically ill patients from different hospitals and 12 healthy subjects from Granada, Spain, all with informed consent were recruited. Data on daily nutritional assessment, ICU severity scores, inflammation, clinical and nutritional parameters, plasma and blood cell zinc concentrations, and levels of transcripts for zinc transporters in whole blood were taken at admission and at the seventh day of the ICU stay. Zinc levels on critical ill patient are diminish comparing with the healthy control (HS: 0.94 ± 0.19; CIPF: 0.67 ± 0.16 mg/dL). The 58% of critical ill patients showed zinc plasma deficiency at beginning of study while 50.0% of critical ill after 7 days of ICU stay. ZnT7, ZIP4 and ZIP9 were the zinc transporters with highest expression in whole blood. In general, all zinc transporters were significantly down-regulated (P < 0.05) in the critical ill population at admission in comparison with healthy subjects. Severity scores and inflammation were significantly associated (P < 0.05) with zinc plasma levels, and zinc transporters ZIP3, ZIP4, ZIP8, ZnT6, ZnT7. Expression of 11 out of 24 zinc transporters was analysed, and ZnT1, ZnT4, ZnT5 and ZIP4, which were downregulated by more than 3-fold in whole blood of patients. In summary, in our study an alteration of zinc status was related with the severity-of-illness scores and inflammation in critical ill patients since admission in ICU stay. SIRS

Studies on structural and magnetic properties of ternary cobalt magnesium zinc (CMZ) Co{sub 0.6-x}Mg{sub x}Zn{sub 0.4} Fe{sub 2}O{sub 4} (x = 0.0, 0.2, 0.4, 0.6) ferrite nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Kaur, Manpreet, E-mail: manpreetchem@pau.edu; Jain, Palak; Singh, Mandeep

2015-07-15

In this paper we report the variation in structural and magnetic properties of ternary ferrite nanoparticles (NPs) having stoichiometery Co{sub 0.6-x}Mg{sub x}Zn{sub 0.4} Fe{sub 2}O{sub 4} (x = 0.0, 0.2, 0.4, 0.6) and pure spinel ferrites MFe{sub 2}O{sub 4} (M = Mg, Co). NPs with average particle diameter of 25–45 nm were synthesized employing self-propagating oxalyl dihydrazide - metal nitrate combustion method. The products were characterized using X-ray diffraction (XRD), Vibrating sample magnetometer (VSM), Transmission electron microscopy (TEM) and FT-IR spectroscopy. FT-IR spectral analysis revealed two bands centered at 560 and 440 cm{sup −1} for tetrahedral and octahedral metal–oxygen bond stretching. Zinc doping caused red shift in the frequency band of tetrahedral M−O stretching. XRD powder diffraction patterns confirmed the formation of spinel ferrite nanoparticles, expansion of the lattice on zinc doping and enhancement of spinel phase purity in the doped ferrites. Cobalt ferrite displayed lowering of the magnetic parameters on zinc doping which further decreased in ternary ferrites Co{sub 0.6-x}Mg{sub x}Zn{sub 0.4}Fe{sub 2}O{sub 4} on replacing cobalt ions with non-magnetic magnesium ions up to x = 0.4. At x = 0.6 reverse trend was observed and Ms was enhanced. Magnesium zinc ferrite Mg{sub 0.6}Zn{sub 0.4} Fe{sub 2}O{sub 4} with high value of Ms was obtained. Combustion process employed in the present studies serves as a low temperature facile route for the synthesis and structural analysis of ternary doped ferrite nanoparticles. - Highlights: • Ternary doped cobalt magnesium zinc ferrite nanoparticles are synthesized. • FT-IR displayed red shift in tetrahedral stretching band on Zinc doping. • Expansion of lattice and enhancement of spinel phase purity on zinc doping. • The variation in saturation magnetization (Ms) on doping is explained.

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.

Electronic Structure of C60/Zinc Phthalocyanine/V₂O₅ Interfaces Studied Using Photoemission Spectroscopy for Organic Photovoltaic Applications.

Science.gov (United States)

Lim, Chang Jin; Park, Min Gyu; Kim, Min Su; Han, Jeong Hwa; Cho, Soohaeng; Cho, Mann-Ho; Yi, Yeonjin; Lee, Hyunbok; Cho, Sang Wan

2018-02-18

The interfacial electronic structures of a bilayer of fullerene (C 60 ) and zinc phthalocyanine (ZnPc) grown on vanadium pentoxide (V₂O₅) thin films deposited using radio frequency sputtering under various conditions were studied using X-ray and ultraviolet photoelectron spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO) level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO) level of the C 60 layer was determined and compared with that grown on an indium tin oxide (ITO) substrate. The energy difference of a heterojunction on all V₂O₅ was found to be 1.3~1.4 eV, while that on ITO was 1.1 eV. This difference could be due to the higher binding energy of the HOMO of ZnPc on V₂O₅ than that on ITO regardless of work functions of the substrates. We also determined the complete energy level diagrams of C 60 /ZnPc on V₂O₅ and ITO.

Lower zinc bioavailability may be related to higher risk of subclinical atherosclerosis in Korean adults.

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Su Kyoung Jung

Full Text Available BACKGROUND: There is a proposed link between dietary zinc intake and atherosclerosis, but this relationship remains unclear. Phytate may contribute to this relationship by influencing zinc bioavailability. OBJECTIVE: The aim of this study is to examine the relationship between zinc bioavailability and subclinical atherosclerosis in healthy Korean adults. MATERIALS AND METHODS: The present cross-sectional analysis used baseline data from the Korean multi-Rural Communities Cohort Study (MRCohort, which is a part of The Korean Genome Epidemiology Study (KoGES. A total of 5,532 subjects (2,116 men and 3,416 women aged 40 years and older were recruited from rural communities in South Korea between 2005 and 2010. Phytate:zinc molar ratio, estimated from a food-based food frequency questionnaire (FFQ of 106 food items, was used to determine zinc bioavailability, and carotid intima media thickness (cIMT and pulse wave velocity (PWV were measured to calculate the subclinical atherosclerotic index. RESULTS: We found that phytate:zinc molar ratio is positively related to cIMT in men. A higher phytate:zinc molar ratio was significantly related to an increased risk of atherosclerosis in men, defined as the 80(th percentile value of cIMT (5(th vs. 1(st quintile, OR = 2.11, 95% CI 1.42-3.15, P for trend = 0.0009, and especially in elderly men (5(th vs. 1(st quintile, OR = 2.58, 95% CI 1.52-4.37, P for trend = 0.0021. We found a positive relationship between phytate:zinc molar ratio and atherosclerosis risk among women aged 65 years or younger. Phytate:zinc molar ratio was not found to be related to PWV. CONCLUSIONS: Lower zinc bioavailability may be related to higher atherosclerosis risk.

Improved colorimetric determination of serum zinc.

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Johnson, D J; Djuh, Y Y; Bruton, J; Williams, H L

1977-07-01

We show how zinc may easily be quantified in serum by first using an optimum concentration of guanidine hydrochloride to cause release of zinc from proteins, followed by complexation of released metals with cyanide. The cyanide complex of zinc is preferentially demasked with chloral hydrate, followed by a colorimetric reaction between zinc and 4-(2-pyridylazo)resorcinol. This is a sensitive water-soluble ligand; its complex with zinc has an absorption maximum at 497 nm. Values found by this technique compare favorably with those obtained by atomic absorption spectroscopy.

ZNF322, a novel human C2H2 Krueppel-like zinc-finger protein, regulates transcriptional activation in MAPK signaling pathways

International Nuclear Information System (INIS)

Li Yongqing; Wang Yuequn; Zhang Caibo; Yuan Wuzhou; Wang Jun; Zhu Chuanbing; Chen Lei; Huang Wen; Zeng Weiqi; Wu Xiushan; Liu Mingyao

2004-01-01

Cardiac differentiation involves a cascade of coordinated gene expression that regulates cell proliferation and matrix protein formation in a defined temporal-spatial manner. The C 2 H 2 zinc finger-containing transcription factors have been implicated as critical regulators of multiple cardiac-expressed genes and are important for human heart development and diseases. Here we have identified and characterized a novel zinc-finger gene named ZNF322 using degenerated primers from a human embryo heart cDNA library. The gene contains four exons and spans 23.2 kb in chromosome 6p22.1 region, and transcribes a 2.7 kb mRNA that encodes a protein with 402 amino acid residues. The predicted protein contains 9 tandem C 2 H 2 -type zinc-finger motifs. Northern blot analysis shows that ZNF322 is expressed in every human tissue examined at adult stage and during embryonic developmental stages from 80 days to 24 weeks. When overexpressed in COS-7 cells, ZNF322-EGFP fusion protein is detected in the nucleus and cytoplasm. Reporter gene assays show that ZNF322 is a transcriptional activator. Furthermore, overexpression of ZNF322 in COS-7 cells activates the transcriptional activity of SRE and AP-1. Together, these results suggest that ZNF322 is a member of the zinc-finger transcription factor family and may act as a positive regulator in gene transcription mediated by the MAPK signaling pathways

Comparative studies on acid leaching of zinc waste materials

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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.

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

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

2011-06-01

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

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

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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.

Zinc

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... 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 ...

Zinc Deficiency‐Like Syndrome in Fleckvieh Calves: Clinical and Pathological Findings and Differentiation from Bovine Hereditary Zinc Deficiency

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Jung, S.; Majzoub‐Altweck, M.; Trefz, F.M.; Seifert, C.; Knubben‐Schweizer, G.; Fries, R.; Hermanns, W.; Gollnick, N.S.

2018-01-01

Background Zinc deficiency‐like (ZDL) syndrome is an inherited defect of Fleckvieh calves, with striking similarity to bovine hereditary zinc deficiency (BHZD). However, the causative mutation in a phospholipase D4 encoding gene (PLD4) shows no connection to zinc metabolism. Objectives To describe clinical signs, laboratory variables, and pathological findings of ZDL syndrome and their utility to differentiate ZDL from BHZD and infectious diseases with similar phenotype. Animals Nine hospitalized calves with crusting dermatitis and confirmed mutation in PLD4 and medical records from 25 calves with crusting dermatitis or suspected zinc deficiency. Methods Prospective and retrospective case series. Results The 9 calves (age: 5–53 weeks) displayed a moderate to severe crusting dermatitis mainly on the head, ventrum, and joints. Respiratory and digestive tract inflammations were frequently observed. Zinc supplementation did not lead to remission of clinical signs in 4 calves. Laboratory variables revealed slight anemia in 8 calves, hypoalbuminemia in 6 calves, but reduced serum zinc concentrations in only 3 calves. Mucosal erosions/ulcerations were present in 7 calves and thymus atrophy or reduced thymic weights in 8 calves. Histologically, skin lesions were indistinguishable from BHZD. Retrospective analysis of medical records revealed the presence of this phenotype since 1988 and pedigree analysis revealed a common ancestor of several affected calves. Conclusions and Clinical Importance ZDL syndrome should be suspected in Fleckvieh calves with crusting dermatitis together with diarrhea or respiratory tract inflammations without response to oral zinc supplementation. Definite diagnosis requires molecular genetic confirmation of the PLD4 mutation. PMID:29424482

Expression of zinc transporter genes in rice as influenced by zinc-solubilizing Enterobacter cloacae strain ZSB14

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Selvaraj eKrithika

2016-04-01

Full Text Available Zinc (Zn deficiency in major food crops has been considered as an important factor affecting the crop production and subsequently the human health. Rice (Oryza sativa is sensitive to Zn deficiency and thereby causes malnutrition to most of the rice-eating Asian populations. Application of zinc solubilizing bacteria (ZSB could be a sustainable agronomic approach to increase the soil available Zn which can mitigate the yield loss and consequently the nutritional quality of rice. Understanding the molecular interactions between rice and unexplored ZSB is useful for overcoming Zn deficiency problems. In the present study, the role of zinc solubilizing bacterial strain Enterobacter cloacae strain ZSB14 on regulation of Zn-regulated transporters and iron (Fe-regulated transporter-like protein (ZIP genes in rice under iron sufficient and deficient conditions was assessed by quantitative real-time reverse transcription PCR. The expression patterns of OsZIP1, OsZIP4 and OsZIP5 in root and shoot of rice were altered due to the Zn availability as dictated by Zn sources and ZSB inoculation. Fe sufficiency significantly reduced the root and shoot OsZIP1 expression, but not the OsZIP4 and OsZIP5 levels. Zinc oxide in the growth medium up-regulated all the assessed ZIP genes in root and shoot of rice seedlings. When ZSB was inoculated to rice seedlings grown with insoluble zinc oxide in the growth medium, the expression of root and shoot OsZIP1, OsZIP4 and OsZIP5 was reduced. In the absence of zinc oxide, ZSB inoculation up-regulated OsZIP1 and OsZIP5 expressions. Zinc nutrition provided to the rice seedling through ZSB-bound zinc oxide solubilization was comparable to the soluble zinc sulphate application which was evident through the ZIP genes’ expression and the Zn accumulation in root and shoot of rice seedlings. These results demonstrate that zinc solubilizing bacteria could play a crucial role in zinc fertilization and fortification of rice.

Iron, zinc, copper and magnesium nutritional status in Mexican children aged 1 to 11 years.

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Morales-Ruán, Ma del Carmen; Villalpando, Salvador; García-Guerra, Armando; Shamah-Levy, Teresa; Robledo-Pérez, Ricardo; Avila-Arcos, Marco Antonio; Rivera, Juan A

2012-01-01

To describe the micronutrient nutritional status of a national sample of 1-11 year old Mexican children surveyed in 2006 in National Health and Nutrition Survey (ENSANUT 2006) and their association with dietary and sociodemographic factors. Serum samples were used (n=5 060) to measure the concentrations of ferritin, transferrin receptor, zinc, copper and magnesium. Prevalence of deficiencies in 1-4 and 5-11y old children were for iron (using low ferritin) 26.0 and 13.0%; zinc, 28.1 and 25.8%, respectively; and copper, ≈30% in both age groups. Magnesium low serum concentrations (MLSC), were found in 12.0% and 28.4% of the children, respectively. Being beneficiary of Liconsa (OR=0.32; C.I.95%, 0.17-0.61) or belonging to higher socioeconomic status (OR=0.63; C.I.95%, 0.41-0.97) were protective against iron deficiency. Increasing age (OR=0.59; C.I.95%, 1.19-1.32) and living in the Central Region (OR=0.59; C.I.95%, 0.36-0.97) were protective against MLSC. Deficiencies of iron and zinc are serious public health problems in Mexican children.

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

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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.

Studies of zinc(II in pharmaceutical and biological samples by extractive spectrophotometry: using pyridoxal-4-phenyl-3-thiosemicarbazone as chelating reagent

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Sarma L. Subramanyam

2006-01-01

Full Text Available Pyridoxal-4-phenyl-3-thiosemicarbazone (PPT is proposed as a new sensitive reagent for the sensitive extractive spectrophotometric determination of zinc(II. PPT reacts with zinc(II in the pH range 5.0-6.0 to form a yellow colored complex, which was well extracted into n-butanol. The absorbance value of Zn(II-PPT complex was measured at different intervals of time at 430 nm, to ascertain the stability of the complex. It was observed that the color development was instantaneous and stable for more than 48 h. The system obeyed Beer's law up to 6.0 µg mL-1 of zinc(II, with an excellent linearity in terms of correlation coefficient value of 0.999. The molar absorptivity and Sandell's sensitivity of the extracted species is 1.6 X 10(4 L mol-1 cm-1 and 4.085 X 10-3 µg cm-2 at 430 nm. The detection limit of the method is 0.04 µg mL-1. To assess precision of the method, determinations were carried out at different concentrations; the relative standard deviation does not exceed 3.1%. The composition of the zinc(II complex with PPT was studied by the method of Job's continuous variation, molar ratio method, Asmus' method and slope ratio method. It has been satisfactorily applied for the determination of zinc(II, when present alone or in presence of diverse ions, which are usually associated with zinc(II in pharmaceutical and biological samples. Various certified reference materials (NIST 1573, NBS 1572 and NIST SRM 8435 have been tested for the determination of zinc for evaluating the accuracy of the developed method. The results of the proposed method are in agreement with flame atomic absorption spectometry.

Zinc uptake in vitro by human retinal pigment epithelium

International Nuclear Information System (INIS)

Newsome, D.A.; Rothman, R.J.

1987-01-01

Zinc, an essential trace element, is present in unusually high concentrations in the chorioretinal complex relative to most other tissues. Because little has been known about the interactions between the retinal pigment epithelium and free or protein-associated zinc, we studied 65 Zn uptake by human retinal pigment epithelium in vitro. When monolayers were exposed to differing concentrations from 0 to 30 microM 65 Zn in Dulbecco's modified Eagle's medium with 5.4 gm/l glucose at 37 degrees C and 4 degrees C, we observed a temperature-dependent saturable accumulation of the radiolabel. With 15 microM 65 Zn, we saw a biphasic pattern of uptake with a rapid first phase and a slower second phase over 120 min. Uptake of 65 Zn was inhibited by iodacetate and cold, and reduced approximately 50% by the addition of 2% albumin to the labelling medium. Neither ouabain nor 2-deoxyglucose inhibited uptake. Cells previously exposed to 65 Zn retained approximately 70% of accumulated 65 Zn 60 min after being changed to radiolabel-free medium. Following removal of cells from the extracellular matrix adherent to the dish bottom, a variable amount of nonspecific binding of 65 Zn to the residual matrix was demonstrated. These observations are consistent with a facilitated type of transport and demonstrate the ability of human retinal pigment epithelium in vitro to accumulate and retain zinc

Metal-Organic Framework-Derived Reduced Graphene Oxide-Supported ZnO/ZnCo2O4/C Hollow Nanocages as Cathode Catalysts for Aluminum-O2 Batteries.

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Liu, Yisi; Jiang, Hao; Hao, Jiayu; Liu, Yulong; Shen, Haibo; Li, Wenzhang; Li, Jie

2017-09-20

Aluminum-air battery is a promising candidate for large-scale energy applications because of its low cost and high energy density. Remarkably, tremendous efforts have been concentrated on developing efficient and stable cathode electrocatalysts toward the oxygen reduction reaction. In this work, a hydrothermal-calcination approach was utilized to prepare novel reduced graphene oxide (rGO)-supported hollow ZnO/ZnCo 2 O 4 nanoparticle-embedded carbon nanocages (ZnO/ZnCo 2 O 4 /C@rGO) using a zeolitic imidazolate framework (ZIF-67)/graphene oxide/zinc nitrate composite as the precursor. The ZnO/ZnCo 2 O 4 /C@rGO hybrid exhibits remarkable electrocatalytic performance for oxygen reduction reaction under alkaline conditions and superior stability and methanol tolerance to those of the commercial Pt/C catalyst. Furthermore, novel and simple Al-air coin cells were first fabricated using the hybrid materials as cathode catalysts under ambient air conditions to further investigate their catalytic performance. The coin cell with the ZnO/ZnCo 2 O 4 /C@rGO cathode catalyst displays a higher open circuit voltage and discharge voltage and more sluggish potential drop than those of the cell with the ZnO/ZnCo 2 O 4 /C cathode catalyst, which confirms that rGO can enhance the electrocatalytic activity and stability of the catalyst system. The excellent electrocatalytic performance of the ZnO/ZnCo 2 O 4 /C@rGO hybrid is attributed to the prominent conductivity and high specific surface area resulting from rGO, the more accessible catalytic active sites induced by the unique porous hollow nanocage structure, and synergic covalent coupling between rGO sheets and ZnO/ZnCo 2 O 4 /C nanocages.

Comparison of the serumic levels of vitamin A, vitamin C and zinc between apparently healthy and those affected by febrile pneumonia in Ghezel sheep

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M Mashayekhi

2010-11-01

Full Text Available The aim of this study was to determine the correlation between subclinical deficiency of Vit A, Vit C and zinc and ovine pneumonia. This study was conducted on 400 sheep affected by pneumonia and 100 apparently healthy sheep. All animals were from the Ghezel breed with the age of 0.5-2 years and body weight of 35-60 kg. Sampling was done during the summer and autumn in Miandoab province. Patients showing signs of rapid and shallow breathing, dyspnea, coughing, nasal discharge and abnormal lung sound were selected as having pneumonia. Animals without any sign of particular disease were selected as apparently healthy after general examination. Blood samples were collected from the jugular vein. The results indicated that serum levels of vitamin A, vitamin C and zinc were 46.94±0.26 (μg/dl, 1.83±0.05 (mg/dl and 183.25±1.86 (μg/dl in healthy sheep respectively and serum levels of vitamin A, vitamin C and zinc were 42.45±0.19 (μg/dl, 1.47±0.02 (mg/dl and 134.59±1.77 (μg/dl in pneumonic sheep (p=0.000 respectively. It can be concluded that there is a significant correlation between subclinical deficiency of vitamin A, vitamin C and zinc serum and ovine pneumonia

Patterned transparent zinc oxide films produced by sol-gel embossing

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Rao, J.; Koh, L.H.K.; Crean, G.M. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Department of Microelectronic Engineering, University College Cork, Cork (Ireland); O' Brien, S. [Tyndall National Institute, Lee Maltings, Prospect Row, Cork (Ireland); Winfield, R.J.

2008-08-15

A low cost zinc oxide embossing technique is reported as a method of fabricating structures relevant to a variety of applications. A zinc based sol-gel material was prepared from zinc acetate[Zn(C{sub 2}H{sub 3}O{sub 2}){sub 2}], monoethanolamine[H{sub 2}NC{sub 2}H{sub 4}OH] and isopropanol. The sol-gel was cast into a polydimethylsiloxane (PDMS) mould a track design, placed in contact with the substrate and dried under vacuum at 70 C for 3 hours. The formed track pattern was further densified to provide a stable conductor film that retained the embossed shape. An optimum Zn sol-gel content of 0.6 M was identified. The embossed films had a transparency of greater than 83% in the visible region. The optical bandgap energy was evaluated to be 3.306 eV. The influence of ZnO sol-gel film synthesis and embossing parameters on the microstructure, morphology and optical transparency of fabricated structures is described. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Molecular basis for the effects of zinc deficiency on spermatogenesis: An experimental study in the Sprague-dawley rat model

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Alexander E Omu

2015-01-01

Full Text Available Introduction: The objective of this study is to investigate the molecular mechanisms underlying the effects of zinc deficiency on spermatogenesis in the Sprague-Dawley (SD rat. Materials and Methods: Three groups of eight adult male SD rats were maintained for 4 weeks on a normal diet as control, zinc deficient diet and zinc deficient diet with zinc supplementation of 28 mg zinc/kg body weight respectively. Using standard techniques, the following parameters were compared between the three groups of experimental animals at the end of 4 weeks: (a Serum zinc, magnesium (Mg, copper (Cu, selenium (Se and cadmium (Cd, (b serum sex hormones, malondialdehyde (MDA, superoxide dismutase (SOD and glutathione peroxidase (GPX, (c interleukin-4 (IL-4, tumor necrosis factor-alpha (TNF-α, Bcl-2, Bax and caspase-3 expression in the testes, (d assessment of apoptosis of testicular cells using electron microscopy and (e testicular volume and histology using the orchidometer and Johnsen score, respectively. Results: The zinc deficient group showed a reduction of testicular volume, serum concentrations of Zn, Cu, Se, Mg, SOD, GPX, IL-4, Bcl-2 and testosterone (P < 0.05, as well as increased levels of serum Cd, MDA and tissue TNF-α, Bax, caspase-3 and apoptosis of the germ cells (P < 0.05 compared with control and zinc supplementation groups. Conclusion: Zinc deficiency is associated with impaired spermatogenesis because of reduced testosterone production, increased oxidative stress and apoptosis. These findings suggest that zinc has a role in male reproduction.

20-hydroxyecdysone enhances the expression of the chitinase 5 via Broad-Complex Zinc-Finger 4 during metamorphosis in silkworm, Bombyx mori.

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Zhang, X; Zheng, S

2017-04-01

Insect chitinases are hydrolytic enzymes required for the degradation of chitin. They are essential for insect moulting and metamorphosis. In this study, the regulation mechanism of a chitinase gene, Bombyx mori chitinase 5 (BmCHT5), was studied. Quantitative reverse transcription PCR (qRT-PCR) analysis showed that BmCHT5 was up-regulated during the larval-larval and larval-pupa transitions and notably induced by 20-hydroxyecdysone (20E). Analysis of the BmCHT5 promoter revealed the presence of one Bombyx mori Broad-Complex Zinc-Finger Isoform 4 (BR-C Z4), two BR-C Z2 and two ecdysone-induced protein 74A (E74A) cis-regulatory elements (CREs) that are related to 20E. qRT-PCR showed that the expression of both BmBR-C Z4 and BmBR-C Z2 during metamorphosis, and when induced by 20E, was anastomotic with the variations in BmCHT5 mRNA level. In contrast, BmE74A did not follow this trend. An electrophoretic mobility shift assay did not retrieve a binding partner for the two BR-C Z2 CREs in the BmN cell line nuclear extract, whereas BR-C Z4 CRE specifically bound to BmBR-C Z4. Besides, luciferase activity analysis confirmed that BmBR-C Z4 could enhance the activity of the BmCHT5 promoter with BR-C Z4 CRE and could not enhance the promoter activity by mutating BR-C Z4 CRE. Taken together, these data suggest that the transcription factor BmBR-C Z4 enhances the expression of BmCHT5 during metamorphosis. © 2016 The Royal Entomological Society.

Fabrication of Poly(o/m-Toluidine–SiC/Zinc Bilayer Coatings and Evaluation of Their Corrosion Resistances

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Chuanbo Hu

2018-05-01

Full Text Available The purpose of this research was to study the structure and corrosion resistance of poly(o/m-toluidine-SiC/zinc (Zn bilayer coatings. Poly(o/m-toluidine films, such as poly(o-toluidine (POT and poly(m-toluidine (PMT, were chemically deposited on the surface of composite SiC/Zn coating using the solution evaporation method. The structures of poly(o/m-toluidine were characterized by various optic techniques and the electrochemical behavior was studied by cyclic voltammetry (CV. The structures and morphologies of the SiC/Zn coating were detected by Fourier transformation infrared spectroscopy (FTIR, X-ray diffraction (XRD, energy dispersive spectrometer (EDS, and scanning electron microscopy (SEM. Thereafter, the corrosion resistances of electrodeposited and bilayer coatings were investigated in 3.5% NaCl solution by electrochemical corrosion techniques and an accelerated immersion test. The results showed that the outer POT film exhibits a lower corrosion behavior with respect to PMT, which significantly reduces the corrosion rate of SiC/Zn coating and prolongs the service life of the zinc matrix. The conclusion demontrates that the stronger adsorptive POT film ensures the formed POT–SiC/Zn bilayer coatings possess a compact and low-defect surface, which facilitates POT film to develop its excellent barrier and passivation properties against corrosion.

Zinc incorporation improves biological activity of beta-tricalcium silicate resin-based cement.

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Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Tim F; Toledano, Manuel

2014-11-01

Matrix metalloproteinase (MMP) inhibition may improve endodontic treatment prognosis. The purpose of this study was to determine if zinc incorporation into experimental resin cements containing bioactive fillers may modulate MMP-mediated collagen degradation of dentin. Human dentin samples untreated and demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (OSspray, London, UK), (3) resin with beta-tricalcium silicate particles (βTCS), (4) resin with zinc-doped Bioglass 45S5, and (5) resin with zinc-doped βTCS particles. The specimens were stored in artificial saliva (for 24 hours, 1 week, and 4 weeks) and submitted to radioimmunoassay to quantify C-terminal telopeptide. Scanning electron microscopy analysis was also undertaken on dentin samples after 4 weeks of storage. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced MMP activity in demineralized dentin. Resin containing Bioglass 45S5 particles exerted higher and stable protection of collagen. The presence of zinc in βTCS particles increases MMP inhibition. Different mineral precipitation was attained in dentin infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced after resin infiltration of dentin. Zinc incorporation in βTCS particles exerted an additional protection against MMP-mediated collagen degradation. However, it did not occur in resin containing Bioglass 45S5 particles, probably because of the formation of phosphate-zinc compounds. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Zinc Deficiency-Like Syndrome in Fleckvieh Calves: Clinical and Pathological Findings and Differentiation from Bovine Hereditary Zinc Deficiency.

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Langenmayer, M C; Jung, S; Majzoub-Altweck, M; Trefz, F M; Seifert, C; Knubben-Schweizer, G; Fries, R; Hermanns, W; Gollnick, N S

2018-03-01

Zinc deficiency-like (ZDL) syndrome is an inherited defect of Fleckvieh calves, with striking similarity to bovine hereditary zinc deficiency (BHZD). However, the causative mutation in a phospholipase D4 encoding gene (PLD4) shows no connection to zinc metabolism. To describe clinical signs, laboratory variables, and pathological findings of ZDL syndrome and their utility to differentiate ZDL from BHZD and infectious diseases with similar phenotype. Nine hospitalized calves with crusting dermatitis and confirmed mutation in PLD4 and medical records from 25 calves with crusting dermatitis or suspected zinc deficiency. Prospective and retrospective case series. The 9 calves (age: 5-53 weeks) displayed a moderate to severe crusting dermatitis mainly on the head, ventrum, and joints. Respiratory and digestive tract inflammations were frequently observed. Zinc supplementation did not lead to remission of clinical signs in 4 calves. Laboratory variables revealed slight anemia in 8 calves, hypoalbuminemia in 6 calves, but reduced serum zinc concentrations in only 3 calves. Mucosal erosions/ulcerations were present in 7 calves and thymus atrophy or reduced thymic weights in 8 calves. Histologically, skin lesions were indistinguishable from BHZD. Retrospective analysis of medical records revealed the presence of this phenotype since 1988 and pedigree analysis revealed a common ancestor of several affected calves. ZDL syndrome should be suspected in Fleckvieh calves with crusting dermatitis together with diarrhea or respiratory tract inflammations without response to oral zinc supplementation. Definite diagnosis requires molecular genetic confirmation of the PLD4 mutation. Copyright © 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

A moonlighting function of Mycobacterium smegmatis Ku in zinc homeostasis?

Science.gov (United States)

Kushwaha, Ambuj K; Deochand, Dinesh K; Grove, Anne

2015-02-01

Ku protein participates in DNA double-strand break repair via the nonhomologous end-joining pathway. The three-dimensional structure of eukaryotic Ku reveals a central core consisting of a β-barrel domain and pillar and bridge regions that combine to form a ring-like structure that encircles DNA. Homologs of Ku are encoded by a subset of bacterial species, and they are predicted to conserve this core domain. In addition, the bridge region of Ku from some bacteria is predicted from homology modeling and sequence analyses to contain a conventional HxxC and CxxC (where x is any residue) zinc-binding motif. These potential zinc-binding sites have either deteriorated or been entirely lost in Ku from other organisms. Using an in vitro metal binding assay, we show that Mycobacterium smegmatis Ku binds two zinc ions. Zinc binding modestly stabilizes the Ku protein (by ∼3°C) and prevents cysteine oxidation, but it has little effect on DNA binding. In vivo, zinc induces significant upregulation of the gene encoding Ku (∼sixfold) as well as a divergently oriented gene encoding a predicted zinc-dependent MarR family transcription factor. Notably, overexpression of Ku confers zinc tolerance on Escherichia coli. We speculate that zinc-binding sites in Ku proteins from M. smegmatis and other mycobacterial species have been evolutionarily retained to provide protection against zinc toxicity without compromising the function of Ku in DNA double-strand break repair. © 2014 The Protein Society.

Prevalence of zinc deficiency among primary school children in a ...

African Journals Online (AJOL)

Few zinc-rich sources appeared in the diet that was predominantly plant-based. Mean dietary zinc intake was 4.6±2.2 mg/day. The mean value of serum zinc was 66.4±21.5 μg/dL, with 46% of the children having values less than the 70 μg/dL cutoff. The findings indicate a high risk of zinc deficiency and suboptimal zinc ...

Intercalation studies of zinc hydroxide chloride: Ammonia and amino acids

International Nuclear Information System (INIS)

Arízaga, Gregorio Guadalupe Carbajal

2012-01-01

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

Hydrothermal synthesis and characterization of a two-dimensional piperazinium cobalt–zinc phosphate via a metastable one-dimensional phase

International Nuclear Information System (INIS)

Torre-Fernández, Laura; Khainakova, Olena A.; Espina, Aránzazu; Amghouz, Zakariae; Khainakov, Sergei A.; Alfonso, Belén F.; Blanco, Jesús A.; García, José R.; García-Granda, Santiago

2015-01-01

A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C 4 N 2 H 12 ) 1.5 (Co 0.6 Zn 0.4 ) 2 (HPO 4 ) 2 (PO 4 )·H 2 O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P2 1 /c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C 4 N 2 H 12 )Co 0.3 Zn 0.7 (HPO 4 ) 2 ·H 2 O (1D), was also isolated and the crystal structure was determined (monoclinic P2 1 /c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N) analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Graphical abstract: Hydrothermal synthesis and structural characterization of a two-dimensional piperazinium cobalt–zinc phosphate, (C 4 N 2 H 12 ) 1.5 (Co 0.6 Zn 0.4 ) 2 (HPO 4 ) 2 (PO 4 )·H 2 O (2D), have been reported. The crystal structure of a one-dimensional piperazinium cobalt–zinc phosphate, (C 4 N 2 H 12 )Co 0.3 Zn 0.7 (HPO 4 ) 2 ·H 2 O (1D) a metastable phase during the hydrothermal synthesis, was also determined. The thermal behavior of 2D compound is strongly dependent on the selected heating rate and the magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Highlights: • A 2D piperazinium cobalt–zinc phosphate has been synthesized and characterized. • Crystal structure of 1D metastable phase was also determined. • Thermal behavior of 2D compound is strongly dependent on the selected heating rate. • Magnetic

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.

Hexagonal ZnO porous plates prepared from microwave synthesized layered zinc hydroxide sulphate via thermal decomposition

Energy Technology Data Exchange (ETDEWEB)

Machovsky, Michal, E-mail: machovsky@ft.utb.cz [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, Nam. T.G. Masaryka 275, 762 72 Zlin (Czech Republic); Kuritka, Ivo, E-mail: ivo@kuritka.net [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, Nam. T.G. Masaryka 275, 762 72 Zlin (Czech Republic); Sedlak, Jakub, E-mail: j1sedlak@ft.utb.cz [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Polymer Centre, Faculty of Technology, Tomas Bata University in Zlin, Nam. T.G. Masaryka 275, 762 72 Zlin (Czech Republic); Pastorek, Miroslav, E-mail: pastorek@ft.utb.cz [Centre of Polymer Systems, University Institute, Tomas Bata University in Zlin, Nad Ovcirnou 3685, 760 01 Zlin (Czech Republic); Department of Polymer Engineering, Faculty of Technology, Tomas Bata University in Zlin, Nam. T.G. Masaryka 275, 762 72 Zlin (Czech Republic)

2013-10-15

Graphical abstract: - Highlights: • Zinc hydroxy sulphate was synthesized in 3 min via microwave hydrothermal route. • Zinc hydroxy sulphate was converted into mesh like porous ZnO by calcining at 900°. • The process of transformation is topotactic. - Abstract: Layered zinc hydroxide sulphate (ZHS) was prepared by microwave-assisted hydrothermal precipitation of zinc sulphate monohydrate with hexamethylenetetramine. Under ambient conditions, the structure of ZHS determined by X-ray diffraction (XRD) was found to be a mixture of zinc hydroxide sulphate pentahydrate Zn{sub 4}SO{sub 4}(OH){sub 6}·5H{sub 2}O and tetrahydrate Zn{sub 4}SO{sub 4}(OH){sub 6}·4H{sub 2}O. Fourier transform infrared (FTIR) spectroscopy was used for characterization of the prepared materials. Based on the interpretation of ZHS's thermal decomposition profile obtained by thermogravimetric analysis, ZnO of high purity was prepared by calcination at 900 °C for 2 h. The structure of the resulting ZnO was confirmed by the XRD. The morphology examination by scanning electron microscopy revealed a porous mesh-like ZnO structure developed from the ZHS precursor at the expense of mass removal due to the release of water and sulphate during the calcination.

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

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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

Enhanced microwave absorption properties in cobalt–zinc ferrite based nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Poorbafrani, A., E-mail: a.poorbafrani@gmail.com; Kiani, E.

2016-10-15

In an attempt to find a solution to the problem of the traditional spinel ferrite used as the microwave absorber, the Co{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4}–Paraffin nanocomposites were investigated. Cobalt–zinc ferrite powders, synthesized through PVA sol–gel method, were combined with differing concentrations of Paraffin wax. The nanocomposite samples were characterized employing various experimental techniques including X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Alternating Gradient Force Magnetometer (AGFM), and Vector Network Analyzer (VNA). The saturation magnetization and coercivity were enhanced utilizing appropriate stoichiometry, coordinate agent, and sintering temperature required for the preparation of cobalt–zinc ferrite. The complex permittivity and permeability spectra, and Reflection Loss (RL) of Co{sub 0.6}Zn{sub 0.4}Fe{sub 2}O{sub 4}–Paraffin nanocomposites were measured in the frequency range of 1–18 GHz. The microwave absorption properties of nanocomposites indicated that the absorbing composite containing 20 wt% of paraffin manifests the strongest microwave attenuation ability. The composite exhibited the reflection loss less than –10 dB in the whole C-band and 30% of the X-band frequencies. - Highlights: • We enhanced the magnetic properties of cobalt–zinc Ferrite nanocomposites. • The samples showed absorption in the whole C-band and 30% of the X-band frequencies. • We tried to solve the problem of the spinel ferrite utilized as efficient absorber. • We enhanced the microwave reflection loss over extended frequency ranges.

ynthesis, theoretical study on Zinc (II and Ni(II complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl thiosemicarbazone

Directory of Open Access Journals (Sweden)

Fatma Kandemirli

2012-03-01

Full Text Available Zinc(II and nickel(II-complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl thiosemicarbazone] (H2MICP were synthesized and characterized by infrared, ultraviolet and 1H-NMR spectroscopies as well as elemental analysis. Model of H2MICP and its zinc(II and nickel(II-complexes were optimized with B3LYP method using 6-31G(d,p, 6-311G(d,p, 6-311++G(d,p, 6-311++G(2d,2p basis sets. The calculated 1H-NMR, UV and IR spectra data were compared with experimental results. In addition to the Natural Bond Orbital (NBO analysis of H2MICP and its Zinc(II and Nickel(II complexes, Fukui functions of H2MICP were also reported.

Proton microprobe analysis of zinc in skeletal tissues. [Proton induced x-ray emission analysis

Energy Technology Data Exchange (ETDEWEB)

Doty, S B; Jones, K W; Kraner, H W; Shroy, R E; Hanson, A L

1980-06-01

A proton microprobe with windowless exit port was used to study zinc distributions in various types of skeletal tissues. The use of an external beam facilitated positioning of the targets for examination of particular points of interest. The proton microprobe is uniquely suited to this work since it combines high sensitivity for zinc determinations in thick samples with good spatial resolution. Measurements on rat and rabbit Achilles tendon showed a significant increase in zinc concentrations as the beam moved from the unmineralized collagen into the mineralized attachment site. Cartilage gave a similar result, with calcified cartilage having a greater zinc level than the articular surface on unmineralized epiphyseal cartilage.

Anglesite and silver recovery from jarosite residues through roasting and sulfidization-flotation in zinc hydrometallurgy

International Nuclear Information System (INIS)

Han, Haisheng; Sun, Wei; Hu, Yuehua; Jia, Baoliang; Tang, Honghu

2014-01-01

Highlights: • Jarosite precipitate hindered the recovery of valuable minerals. • Under 600–700 °C, jarosite decomposed and released the encapsulated valuable minerals. • The bared valuable minerals were easily collected by flotation process. • The new process was promising for dealing with jarosite residues. - Abstract: Hazardous jarosite residues contain abundant valuable minerals that are difficult to be recovered by traditional flotation process. This study presents a new route, roasting combined with sulfidization-flotation, for the recovery of anglesite and silver from jarosite residues of zinc hydrometallurgy. Surface appearance and elemental distribution of jarosite residues was examined by scanning electron microscopy and energy dispersive X-ray spectrometry analysis, respectively. Decomposition and transformation mechanisms of jarosite residues were illustrated by differential thermal analysis. Results showed that after roasting combined with flotation, the grade and recovery of lead were 43.89% and 66.86%, respectively, and those of silver were 1.3 kg/t and 81.60%, respectively. At 600–700 °C, jarosite was decomposed to release encapsulated valuable minerals such as anglesite (PbSO 4 ) and silver mineral; silver jarosite decomposed into silver sulfate (Ag 2 SO 4 ); and zinc ferrite (ZnO·Fe 2 O 3 ) decomposed into zinc sulfate (ZnSO 4 ) and hematite (Fe 2 O 3 ). Bared anglesite and silver minerals were modified by sodium sulfide and easily collected by flotation collectors. This study demonstrates that the combination of roasting and sulfidization-flotation provides a promising process for the recovery of zinc, lead, and silver from jarosite residues of zinc hydrometallurgy

Zinc Binding by Lactic Acid Bacteria

Directory of Open Access Journals (Sweden)

Jasna Mrvčić

2009-01-01

Full Text Available Zinc is an essential trace element in all organisms. A common method for the prevention of zinc deficiency is pharmacological supplementation, especially in a highly available form of a metalloprotein complex. The potential of different microbes to bind essential and toxic heavy metals has recently been recognized. In this work, biosorption of zinc by lactic acid bacteria (LAB has been investigated. Specific LAB were assessed for their ability to bind zinc from a water solution. Significant amount of zinc ions was bound, and this binding was found to be LAB species-specific. Differences among the species in binding performance at a concentration range between 10–90 mg/L were evaluated with Langmuir model for biosorption. Binding of zinc was a fast process, strongly influenced by ionic strength, pH, biomass concentration, and temperature. The most effective metal-binding LAB species was Leuconostoc mesenteroides (27.10 mg of Zn2+ per gram of dry mass bound at pH=5 and 32 °C, during 24 h. FT-IR spectroscopy analysis and electron microscopy demonstrated that passive adsorption and active uptake of the zinc ions were involved.

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.

Zinc-aluminates for an in situ sulfur reduction in cracked gasoline

Energy Technology Data Exchange (ETDEWEB)

Quintana-Solorzano, R.; Valente, J.S.; Hernandez-Beltran, F.J.; Castillo-Araiza, C.O. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas Norte 152 C.P., 07730 Mexico, D.F. (Mexico)

2008-05-30

Using additives remains as an attractive alternative for an in situ sulfur reduction in cracked gasoline since it is a practical, flexible and economical option. Zinc-aluminates prepared by the sol-gel method are used as additives for reducing sulfur in gasoline from the cracking of a high-sulfur feed in a fixed-bed bench reactor. Products distribution and feed conversion are not dramatically altered after incorporating the additive to the base catalyst with some effect on gasoline and its octane number and coke. A decrease in the gasoline sulfur content of up to 35 wt% including benzothiophene, and up to 50% excluding benzothiophene, is observed when blending the zinc-aluminates to the base catalyst, which is caused by lowering the C{sub 1} to C{sub 4} alkyl-thiophenes content. The zinc content of the zinc-aluminates has a positive effect on the gasoline sulfur reduction. It is suggested that together with the direct cracking of adsorbed thiophenic species on the additive, a further gasoline sulfur decrease is possible through cracking of saturated thiophenic species formed by hydrogenation of adsorbed thiophenic species with hydrogen produced in situ in the additive. The obtained results also demonstrate that solids with higher Lewis acidity are not unfailingly the most effective for gasoline sulfur reduction. (author)

High-pressure Gas Activation for Amorphous Indium-Gallium-Zinc-Oxide Thin-Film Transistors at 100 °C.

Science.gov (United States)

Kim, Won-Gi; Tak, Young Jun; Du Ahn, Byung; Jung, Tae Soo; Chung, Kwun-Bum; Kim, Hyun Jae

2016-03-14

We investigated the use of high-pressure gases as an activation energy source for amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs). High-pressure annealing (HPA) in nitrogen (N2) and oxygen (O2) gases was applied to activate a-IGZO TFTs at 100 °C at pressures in the range from 0.5 to 4 MPa. Activation of the a-IGZO TFTs during HPA is attributed to the effect of the high-pressure environment, so that the activation energy is supplied from the kinetic energy of the gas molecules. We reduced the activation temperature from 300 °C to 100 °C via the use of HPA. The electrical characteristics of a-IGZO TFTs annealed in O2 at 2 MPa were superior to those annealed in N2 at 4 MPa, despite the lower pressure. For O2 HPA under 2 MPa at 100 °C, the field effect mobility and the threshold voltage shift under positive bias stress were improved by 9.00 to 10.58 cm(2)/V.s and 3.89 to 2.64 V, respectively. This is attributed to not only the effects of the pressurizing effect but also the metal-oxide construction effect which assists to facilitate the formation of channel layer and reduces oxygen vacancies, served as electron trap sites.

A zinc enolate of amide: Preparation and application in reformasky-like reaction leading to β-hydroxy amides

Energy Technology Data Exchange (ETDEWEB)

Cho, Hyun Hee; Kim, Seung Hoi [Dept. of Chemistry, Dankook University, Cheonan (Korea, Republic of)

2015-04-15

One of the best known functionalized organic complexes is the β-hydroxy carbonyl compound. This unique functionality has been frequently found in naturally occurring bioactive derivatives. The cross-coupling reaction of A with aldehydes were carried out in the absence of any catalyst and completed in most cases within 1.0 h at room temperature. We have developed an efficient synthetic route for the preparation of β-hydroxy amides. The method involved the preparation of room-temperature-stable organo zinc reagents (A, B, and C) in THF and their subsequent coupling reactions with various carbonyl derivatives under mild conditions. Significantly, this approach using zinc enolate of amides could expand the scope of Reformatsky-like reactions. Further studies to elucidate this synthetic protocol are currently under way in our laboratory.

Functional analysis of a novel KRAB/C2H2 zinc finger protein Mipu1

International Nuclear Information System (INIS)

Jiang, Lei; Tang, Daolin; Wang, Kangkai; Zhang, Huali; Yuan, Can; Duan, Dayue; Xiao, Xianzhong

2007-01-01

A novel rat gene, Mipu1, encodes a 608 amino acid protein with an amino-terminal KRAB domain and 14 carboxyl-terminal C 2 H 2 zinc finger motifs. Mipu1 is localized to the nucleus through its KRAB domain or the linker adjacent to its zinc finger region. Using the GST-Mipu1 bound to glutathione-Sepharose beads, a consensus putative DNA binding site (5'-TGTCTTATCGAA-3') was extracted from a random oligonucleotide library. EMSA and target detection assay showed that the probe containing the putative site can bind to purified GST-Mipu1 fusion protein. The oligonucleotide containing the putative site was inserted into the pGL3-promotor vector to produce a reporter construct. The expression of reporter gene was repressed by overexpression of Mipu1 in a dose-dependent manner. Mutation analysis of the consensus sequence indicated that the repression mediated by Mipu1 is sequence-dependent. These results suggest that Mipu1 is a nuclear protein, which functions as a transcriptional repressor

Zinc isotope separation in acetone by displacement chromatography using benzo-15-crown-5 resin

International Nuclear Information System (INIS)

Ding Xingcheng; Tatsuya Suzuki; Masao Nomura; Yashuhiko Fujii

2005-01-01

Zinc is considered as a useful material for cooling water treatment in light water plants. Injection of 64 Zn depleted Zinc is expected to further reduce the radiation in the reactor water system. For such a purpose of Zinc isotope separation, chemical exchange method has been studied. Breakthrough methods of chromatography experiments were performed. 0.5 mol/dm 3 ZnCl 2 dissolved in acetone solution was fed to glass columns packed with benzo-15-crown-5 resin at 35 degree C. The effluent was collected in fractions of which zinc concentration was determined by atomic adsorption spectrometer and isotope ratio was measured by ICP-MS. Observed enrichment ratios defined as, ( i Zn/ 64 Zn) sample / ( i Zn/ 64 Zn) original , where i=66,68, are plotted in Figure. From the results of experiment, it was confirmed that heavier zinc is preferentially enriched in the eluted samples of front band regions. The separation coefficient (ε) for 66 Zn/ 64 Zn and 68 Zn/ 64 Zn of five meters migration was obtained as 5.2 x 10 -4 and 8.1 x 10 -4 , respectively. The error is estimated to be 20% of the values.

Nest-like LiFePO4/C architectures for high performance lithium ion batteries

International Nuclear Information System (INIS)

Deng Honggui; Jin Shuangling; Zhan Liang; Qiao Wenming; Ling Licheng

2012-01-01

Highlights: ► Nest-like LiFePO 4 /C architectures (nest-like LPCs) were synthesized by solvothermal method. ► The microstructures of nest-like LPCs are very stable constructed by many nanosheets. ► The unique structures offer nest-like LPC electrode with high rate performance. ► The reversible capacity of nest-like LPCs electrode is as high as 120 mAh g −1 at 10 C. - Abstract: A novel kind of microsized nest-like LiFePO 4 /C architectures was synthesized by solvothermal method using inexpensive and stable Fe 3+ salt as iron source and ethylene glycol as mediate. A layer of carbon could be coated directly on the surface of LiFePO 4 crystals and the nest-like unique structures offer the cathode materials with high reversible capacity, excellent cycling stability and high rate performance. The reversible capacity can maintain 159 mAh g −1 at 0.1 C and 120 mAh g −1 at 10 C.

Unique edge-sharing sulfate-transition metal coordination in Na2M(SO4)2 (M=Ni and Co)

International Nuclear Information System (INIS)

Fry, Allyson M.; Sweeney, Owen T.; Adam Phelan, W.; Drichko, Natalia; Siegler, Maxime A.; McQueen, Tyrel M.

2015-01-01

Two compounds, Na 2 Ni(SO 4 ) 2 and Na 2 Co(SO 4 ) 2 , were synthesized and their structure and properties were characterized. They adopt a structure that contains a bidentate coordination of sulfate to the transition metal center, which was determined via single crystal X-ray diffraction combined with model refinements to both laboratory X-ray and time-of-flight neutron powder diffraction data. The compounds were both found to crystallize in the C2/c space group with Z=24 and a unit cell of a=23.3461(3) Å, b=10.3004(1) Å, c=17.4115(2) Å, β=98.8659(9)°, and V=4136.99(8) Å 3 for the cobalt analog and a=23.2253(1) Å, b=10.26155(6) Å, c=17.3353(1) Å, β=99.0376(5)°, and V=4080.20(5) Å 3 for the nickel analog. Magnetization measurements show that the transition metal centers have negligible interactions with neighboring sites. Infrared and Raman spectroscopies were used to further probe the unique sulfate-transition metal coordination, and confirm the bidentate binding motif. The resulting pseudo-trigonal bipyramidal coordination produces vivid violet, Na 2 Co(SO 4 ) 2 , and yellow, Na 2 Ni(SO 4 ) 2 , colors that were probed by diffuse reflectance. - Graphical abstract: Two blue distorted transition metal octahedra (oxygen in red) bridged by two sulfate tetrahedra are shown here. Each bridging sulfate tetrahedra shares an edge with one octahedron and a corner with the other. All of the remaining corners of the octahedra are corner sharing with four tetrahedra forming a polyhedral network. - Highlights: • Structure of Na2Ni(SO4)2 and Na2Co(SO4)2 is determined. • Unique sulfate-transition metal binding observed in the new structure. • Combined diffraction and spectroscopic techniques were used. • Magnetization measurements show negligible interactions between sites

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

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

Single-crystal structure, photophysical characteristics and electroluminescent properties of bis(2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate)zinc

International Nuclear Information System (INIS)

Xu Huixia; Yue, Yan; Wang Hua; Chen Liuqing; Hao Yuying; Xu Bingshe

2012-01-01

In this paper, a zinc (II) complex of Zn 2 (4-tfmBTZ) 4 (4-tfmBTZ=2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate) was reported. Via combination of experimental and theoretical approaches, its molecular structure, photophysical characteristics, electronic structure and electroluminescent properties were investigated. The results indicate that Zn 2 (4-tfmBTZ) 4 exists as five-coordinate geometric structure and two zinc atoms are bridged by oxygen atoms. The intense absorption band was located at 404 nm, which mainly originate from the transition HOMO−1 to LUMO+2. The blue-light emission was observed in tetrahydrofuran solution and thin film. White-light emission with four emission peaks was observed with CIE coordinate of (0.29, 0.33) and a higher CRI of 85.1 by fabricating bilayer device using Zn 2 (4-tfmBTZ) 4 as electron-transport and NPB as hole-transport material. - Highlights: ► The single-crystal and electronic structures of Zn 2 (4-tfmBTZ) 4 . ► The multicolor emission of Zn 2 (4-tfmBTZ) 4 were realized by the simple devices. ► White OLED is achieved with particularly high color rending index (CRI) by the emission of Zn 2 (4-tfmBTZ) 4 .

CO and C3H8 Sensitivity Behavior of Zinc Antimonate Prepared by a Microwave-Assisted Solution Method

Directory of Open Access Journals (Sweden)

Héctor Guillen-Bonilla

2015-01-01

Full Text Available ZnSb2O6 has been synthesized by a microwave-assisted solution method in order to test its possible application as a gas sensor. Zinc nitrate, antimony trichloride, and ethylenediamine were used as precursors and deionized water as solvent. Microwave radiation, with a power of ~350 W, was applied for solvent evaporation. The thermal decomposition of the precursors leads to the formation of ZnSb2O6 at 600°C. This oxide crystallized in a tetragonal structure with cell parameters a=4.66 Å, c=9.26 Å and space group P42/mnm. Microwires and microrods formed by nanocrystals were observed by means of scanning and transmission electron microscopies (SEM and TEM, resp.. Pellets of the oxide were tested as gas sensors in flowing atmospheres of carbon monoxide (CO and propane (C3H8. Sensitivity increased with the gas concentration (0–300 ppm and working temperatures (ambient, 150 and 250°C increase. The results indicate high sensitivity of ZnSb2O6 in both gases at different concentrations and operating temperatures.

Synthesis and controlled release properties of 2,4-dichlorophenoxy acetate–zinc layered hydroxide nanohybrid

International Nuclear Information System (INIS)

Bashi, Abbas M.; Hussein, Mohd Zobir; Zainal, Zulkarnain; Tichit, Didier

2013-01-01

Direct reaction of ZnO with 2,4-dichlorophenoxyacetic acid (24D) solutions of different concentrations allows obtaining new organic–inorganic nanohybrid materials formed by intercalation of 24D into interlayers of zinc layered hydroxide (ZLH). XRD patterns show a progressive evolution of the structure as 24D concentration increases. The nanohybrid obtained at higher 24D concentration (24D–ZLH(0.4)) reveals a well ordered layered structure with two different basal spacings at 25.2 Å and 24 Å. The FTIR spectrum showing the vibrations bands of the functional groups of 24D and of the ZLH confirms the intercalation. SEM images are in agreement with the structural evolution observed by XRD and reveal the ribbon morphology of the nanohybrids. The release studies of 24D showed a rapid release of 94% for the first 100 min governed by the pseudo-second order kinetic model. - Graphical abstract: The phenomenon indicates that the optical energy gap is enlarged with the increase of molar concentrations in 2,4-dichlorophenoxy acetate anion content into ZnO to create a ZLH–24D nanohybrid. - Highlights: • Nanohybrid was synthesized from 2,4-dichlorophenoxy acetate with-Zinc LHD, using wet chemistry. • Characterized using SEM, TEM, EDX, FTIR, XRD and TGA. • Ribbon-shaped 24D–Zn-layered hydroxide nanoparticles with (003) diffractions of 2.5 nm phase were synthesized

Study of iron-zinc catalysts by Moessbauer spectroscopy

International Nuclear Information System (INIS)

Arriola, S.H.

1990-01-01

The Moessbauer parameters were determined on a series of catalyst mixtures of iron and zinc oxides with variable quantities of zinc. A change in the crystal structure of the iron oxide when introducing zinc into the samples was observed. The corundum structure of the α-Fe 2 O 3 phase was transformed into the spinel type of zinc ferrite when zinc oxide was present in any quantity. A strong electronic interaction between the zinc ferrite and the zinc oxide present in excess was evident. The catalysts were analyzed using x-ray fluorescence and x-ray diffraction methods. (author) 10 refs.; 4 figs.; 2 tabs

Development of a Unique Small Molecule Modulator of CXCR4

Science.gov (United States)

Yoon, Younghyoun; Lin, Songbai; Sasaki, Maiko; Klapproth, Jan-Michael A.; Yang, Hua; Grossniklaus, Hans E.; Xu, Jianguo; Rojas, Mauricio; Voll, Ronald J.; Goodman, Mark M.; Arrendale, Richard F.; Liu, Jin; Yun, C. Chris; Snyder, James P.; Liotta, Dennis C.; Shim, Hyunsuk

2012-01-01

Background Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4) and its ligand stromal cell-derived factor-1 (CXCL12) interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites. Methodology/Principal Findings We describe the actions of N,N′-(1,4-phenylenebis(methylene))dipyrimidin-2-amine (designated MSX-122), a novel small molecule and partial CXCR4 antagonist with properties quite unlike that of any other reported CXCR4 antagonists, which was prepared in a single chemical step using a reductive amination reaction. Its specificity toward CXCR4 was tested in a binding affinity assay and a ligand competition assay using 18F-labeled MSX-122. The potency of the compound was determined in two functional assays, Matrigel invasion assay and cAMP modulation. The therapeutic potential of MSX-122 was evaluated in three different murine models for inflammation including an experimental colitis, carrageenan induced paw edema, and bleomycin induced lung fibrosis and three different animal models for metastasis including breast cancer micrometastasis in lung, head and neck cancer metastasis in lung, and uveal melanoma micrometastasis in liver in which CXCR4 was reported to play crucial roles. Conclusions/Significance We developed a novel small molecule, MSX-122, that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for

Development of a unique small molecule modulator of CXCR4.

Directory of Open Access Journals (Sweden)

Zhongxing Liang

Full Text Available Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4 and its ligand stromal cell-derived factor-1 (CXCL12 interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites.We describe the actions of N,N'-(1,4-phenylenebis(methylenedipyrimidin-2-amine (designated MSX-122, a novel small molecule and partial CXCR4 antagonist with properties quite unlike that of any other reported CXCR4 antagonists, which was prepared in a single chemical step using a reductive amination reaction. Its specificity toward CXCR4 was tested in a binding affinity assay and a ligand competition assay using (18F-labeled MSX-122. The potency of the compound was determined in two functional assays, Matrigel invasion assay and cAMP modulation. The therapeutic potential of MSX-122 was evaluated in three different murine models for inflammation including an experimental colitis, carrageenan induced paw edema, and bleomycin induced lung fibrosis and three different animal models for metastasis including breast cancer micrometastasis in lung, head and neck cancer metastasis in lung, and uveal melanoma micrometastasis in liver in which CXCR4 was reported to play crucial roles.We developed a novel small molecule, MSX-122, that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for long-term blockade of metastasis than other reported CXCR4

CO and C_3H_8 Sensitivity Behavior of Zinc Antimonate Prepared by a Microwave-Assisted Solution Method

International Nuclear Information System (INIS)

Guillen-Bonilla, H.; Rodiguez Betancourtt, V. M.; Flores-Martinez, M.; Guillen-Bonilla, J. T.; Reyes-Gomez, J.; Gildo-Ortiz, L.; Olvera-Amador, M. L.; Santoyo-Salazar, J.

2015-01-01

ZnSb_2O_6 has been synthesized by a microwave-assisted solution method in order to test its possible application as a gas sensor. Zinc nitrate, antimony trichloride, and ethylenediamine were used as precursors and deionized water as solvent. Microwave radiation, with a power of "approx"350 W, was applied for solvent evaporation. The thermal decomposition of the precursors leads to the formation of ZnSb_2O_6 at 600 degree. This oxide crystallized in a tetragonal structure with cell parameters a=4.66 angstrom sign, c=9.26 angstrom sign and space group P4_2/ mnm. Micro wires and micro rods formed by nano crystals were observed by means of scanning and transmission electron micros copies (SEM and TEM, resp.). Pellets of the oxide were tested as gas sensors in flowing atmospheres of carbon monoxide (CO) and propane (C_3H_8). Sensitivity increased with the gas concentration (0-300 ppm) and working temperatures (ambient, 150 and 250 degree) increase. The results indicate high sensitivity of ZnSb_2O_6 in both gases at different concentrations and operating temperatures.

Low-temperature solution-processed zinc oxide field effect transistor by blending zinc hydroxide and zinc oxide nanoparticle in aqueous solutions

Science.gov (United States)

Shin, Hyeonwoo; Kang, Chan-mo; Baek, Kyu-Ha; Kim, Jun Young; Do, Lee-Mi; Lee, Changhee

2018-05-01

We present a novel methods of fabricating low-temperature (180 °C), solution-processed zinc oxide (ZnO) transistors using a ZnO precursor that is blended with zinc hydroxide [Zn(OH)2] and zinc oxide hydrate (ZnO • H2O) in an ammonium solution. By using the proposed method, we successfully improved the electrical performance of the transistor in terms of the mobility (μ), on/off current ratio (I on/I off), sub-threshold swing (SS), and operational stability. Our new approach to forming a ZnO film was systematically compared with previously proposed methods. An atomic forced microscopic (AFM) image and an X-ray photoelectron spectroscopy (XPS) analysis showed that our method increases the ZnO crystallite size with less OH‑ impurities. Thus, we attribute the improved electrical performance to the better ZnO film formation using the blending methods.

Heteroepitaxy of zinc-blende SiC nano-dots on Si substrate by organometallic ion beam

International Nuclear Information System (INIS)

Matsumoto, T.; Kiuchi, M.; Sugimoto, S.; Goto, S.

2006-01-01

The self-assembled SiC nano-dots were fabricated on Si(111) substrate at low-temperatures using the organometallic ion beam deposition technique. The single precursor of methylsilicenium ions (SiCH 3 + ) with the energy of 100 eV was deposited on Si(111) substrate at 500, 550 and 600 deg. C. The characteristics of the self-assembled SiC nano-dots were analyzed by reflection high-energy electron diffraction (RHEED), Raman spectroscopy and atomic force microscope (AFM). The RHEED patterns showed that the crystal structure of the SiC nano-dots formed on Si(111) substrate was zinc-blende SiC (3C-SiC) and it was heteroepitaxy. The self-assembled SiC nano-dots were like a dome in shape, and their sizes were the length of 200-300 nm and the height of 10-15 nm. Despite the low-temperature of 500 deg. C as SiC crystallization the heteroepitaxial SiC nano-dots were fabricated on Si(111) substrate using the organometallic ion beam

What is IgG4? A review of the biology of a unique immunoglobulin subtype.

Science.gov (United States)

Nirula, Ajay; Glaser, Scott M; Kalled, Susan L; Taylor, Frederick R; Taylora, Frederick R

2011-01-01

Recent descriptions of the group of clinical disorders collectively defined as IgG4-related systemic disease (IgG4-RSD) have prompted this review of the unique biology of the IgG4 antibody. This article will discuss IgG4 structure and function, the unique phenomenon of half-antibody exchange, and the implications of IgG4 biology for its proposed role in immunologic diseases. IgG4 antibodies have unique structural and functional properties and undergo 'half-antibody exchange' in vivo, resulting in recombined antibodies composed of two different binding specificities. The production of IgG4 antibodies appears to be driven in part by T helper 2 (Th2) cytokines that mediate allergic responses and IgE production. Although serum IgG4 levels in healthy individuals vary significantly, data from multiple sclerosis (MS) patients suggest tight regulation of individual IgG4 levels over time. IgG4-RSD represents a diverse group of clinical disorders unified by elevated IgG4 levels and specific histopathologic findings. A key unanswered question is whether IgG4, a relatively weak activator of effector cells, is pathogenic in these disorders. IgG4 is a unique antibody biologically and structurally. Increased understanding of its precise role in the clinical syndromes that comprise IgG4-RSD may ultimately elucidate the underlying pathogenesis.

Copper Doping of Zinc Oxide by Nuclear Transmutation

Science.gov (United States)

2014-03-27

Copper Doping of Zinc Oxide by Nuclear Transmutation THESIS Matthew C. Recker, Captain, USAF AFIT-ENP-14-M-30 DEPARTMENT OF THE AIR FORCE AIR...NUCLEAR TRANSMUTATION THESIS Presented to the Faculty Department of Engineering Physics Graduate School of Engineering and Management Air Force...COPPER DOPING OF ZINC OXIDE BY NUCLEAR TRANSMUTATION Matthew C. Recker, BS Captain, USAF Approved: //signed// 27 February 2014 John W. McClory, PhD

Hydrothermal synthesis and characterization of a two-dimensional piperazinium cobalt–zinc phosphate via a metastable one-dimensional phase

Energy Technology Data Exchange (ETDEWEB)

Torre-Fernández, Laura; Khainakova, Olena A. [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, 33006 Oviedo (Spain); Espina, Aránzazu [Servicios Científico Técnicos, Universidad de Oviedo, 33006 Oviedo (Spain); Amghouz, Zakariae, E-mail: amghouz.uo@uniovi.es [Servicios Científico Técnicos, Universidad de Oviedo, 33006 Oviedo (Spain); Khainakov, Sergei A. [Servicios Científico Técnicos, Universidad de Oviedo, 33006 Oviedo (Spain); Alfonso, Belén F.; Blanco, Jesús A. [Departamento de Física, Universidad de Oviedo, 33007 Oviedo (Spain); García, José R.; García-Granda, Santiago [Departamentos de Química Física y Analítica y Química Orgánica e Inorgánica, Universidad de Oviedo-CINN, 33006 Oviedo (Spain)

2015-05-15

A two-dimensional piperazinium cobalt–zinc phosphate, formulated as (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), was synthesized under hydrothermal conditions. The crystal structure was determined using single-crystal X-ray diffraction data (monoclinic P2{sub 1}/c, a=8.1165(3) Å, b=26.2301(10) Å, c=8.3595(4) Å, and β=110.930(5)°) and the hydrogen atom positions were optimized by DFT calculations. A single-crystal corresponding to one-dimensional metastable phase, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D), was also isolated and the crystal structure was determined (monoclinic P2{sub 1}/c, a=8.9120(6) Å, b=14.0290(1) Å, c=12.2494(5) Å, and β=130.884(6)°). The bulk was characterized by chemical (C–H–N) analysis, powder X-ray diffraction (PXRD), powder X-ray thermodiffractometry (HT-XRD), transmission electron microscopy (STEM(DF)-EDX and EFTEM), and thermal analysis (TG/SDTA-MS), including activation energy data of its thermal decomposition. The magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Graphical abstract: Hydrothermal synthesis and structural characterization of a two-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12}){sub 1.5}(Co{sub 0.6}Zn{sub 0.4}){sub 2}(HPO{sub 4}){sub 2}(PO{sub 4})·H{sub 2}O (2D), have been reported. The crystal structure of a one-dimensional piperazinium cobalt–zinc phosphate, (C{sub 4}N{sub 2}H{sub 12})Co{sub 0.3}Zn{sub 0.7}(HPO{sub 4}){sub 2}·H{sub 2}O (1D) a metastable phase during the hydrothermal synthesis, was also determined. The thermal behavior of 2D compound is strongly dependent on the selected heating rate and the magnetic susceptibility and magnetization measurements show no magnetic ordering down to 4 K. - Highlights: • A 2D piperazinium cobalt–zinc phosphate has been synthesized and characterized. • Crystal

Parameters Influencing Zinc in Experimental Systems in Vivo and in Vitro

OpenAIRE

Johanna Ollig; Veronika Kloubert; Inga Weßels; Hajo Haase; Lothar Rink

2016-01-01

In recent years, the role of zinc in biological systems has been a subject of intense research. Despite wide increase in our knowledge and understanding of zinc homeostasis, numerous questions remain to be answered, encouraging further research. In particular, the quantification of intracellular zinc ions and fluctuation, as well as the function of zinc in signaling processes are being intensely investigated. The determination of free intracellular zinc ions is difficult and error-prone, as c...

Incorporation of zinc into the coccoliths of the microalga Emiliania huxleyi.

Science.gov (United States)

Santomauro, Giulia; Sun, Wei-Lin; Brümmer, Franz; Bill, Joachim

2016-04-01

The coccolithophore Emiliania huxleyi is covered with elaborated calcite plates, the so-called coccoliths, which are produced inside the cells. We investigated the incorporation of zinc into the coccoliths of E. huxleyi by applying different zinc and calcium amounts via the culture media and subsequently analyzing the zinc content in the cells and the Zn/Ca ratio of the coccoliths. To investigate the Zn/Ca ratio of coccoliths built in the manipulated media, the algae have first to be decalcified, i.e. coccolith free. We used a newly developed decalcification method to obtain 'naked' cells for cultivation. E. huxleyi proliferated and produced new coccoliths in all media with manipulated Zn/Ca ratios. The cells and the newly built coccoliths were investigated regarding their zinc content and their Zn/Ca ratio, respectively. High zinc amounts were taken up by the algae. The Zn/Ca ratio of the coccoliths was positively correlated to the Zn/Ca ratio of the applied media. The unique feature of the coccoliths was maintained also at high Zn/Ca ratios. We suggest the following pathway of the zinc ions into the coccoliths: first, the zinc ions are bound to the cell surface, followed by their transportation into the cytoplasm. Obviously, the zinc ions are removed afterwards into the coccolith vesicle, where the zinc is incorporated into the calcite coccoliths which are then extruded. The incorporation of toxic zinc ions into the coccoliths possibly due to a new function of the coccoliths as detoxification sites is discussed.

Electroluminescence of Zn{sub 2}GeO{sub 4}:Mn through SiC whisker electric field enhancement

Energy Technology Data Exchange (ETDEWEB)

Wagstaff, Brandon, E-mail: wagstabj@mcmaster.ca [McMaster University, Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada); Kitai, Adrian, E-mail: kitaia@mcmaster.ca [McMaster University, Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada); McMaster University, Department of Materials Science and Engineering, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8 (Canada)

2015-11-15

Alternating current (AC) electroluminescence of thin film oxide phosphors is well known. However in this work electroluminescence of bulk oxide powder phosphors is achieved. A new type of AC Electroluminescent (ACEL) device has been created and developed by integrating SiC whiskers into a phosphor matrix composed of manganese-activated zinc germanate (Zn{sub 2}GeO{sub 4}:Mn{sup 2+}). The conductive SiC whiskers enhance the average electric field in specific regions of the phosphor such that localized breakdown of the phosphor occurs, thus emitting green light. This field enhancement allows light emission to occur in thick film oxide powder phosphors and is notably the first time that bright and reasonably efficient electroluminescence of zinc germanate has been observed without using expensive thin film deposition techniques. Light emission has been achieved in thick pressed pellets using surface-deposited electrodes and the brightness-voltage characteristics of light emission are shown to be consistent with field emission of carriers from the embedded whiskers. - Highlights: • A new electroluminescent phosphor, Zn{sub 2}GeO{sub 4}Mn{sup 2+}+SiC whiskers, is proposed. • A procedure is described to fabricate a solid sample of this composite material. • Under an AC voltage, green light is emitted only in samples containing the SiC whiskers. • A brightness of 25 Cd/m{sup 2} and efficiency of 0.25 Lm/W is observed 9.6×10{sup 6} V/m. • This is notably the first time that ACEL has been observed in bulk Zn{sub 2}GeO{sub 4}Mn{sup 2+}.

Anglesite and silver recovery from jarosite residues through roasting and sulfidization-flotation in zinc hydrometallurgy

Energy Technology Data Exchange (ETDEWEB)

Han, Haisheng; Sun, Wei, E-mail: hanhaishengjingji@126.com; Hu, Yuehua; Jia, Baoliang; Tang, Honghu

2014-08-15

Highlights: • Jarosite precipitate hindered the recovery of valuable minerals. • Under 600–700 °C, jarosite decomposed and released the encapsulated valuable minerals. • The bared valuable minerals were easily collected by flotation process. • The new process was promising for dealing with jarosite residues. - Abstract: Hazardous jarosite residues contain abundant valuable minerals that are difficult to be recovered by traditional flotation process. This study presents a new route, roasting combined with sulfidization-flotation, for the recovery of anglesite and silver from jarosite residues of zinc hydrometallurgy. Surface appearance and elemental distribution of jarosite residues was examined by scanning electron microscopy and energy dispersive X-ray spectrometry analysis, respectively. Decomposition and transformation mechanisms of jarosite residues were illustrated by differential thermal analysis. Results showed that after roasting combined with flotation, the grade and recovery of lead were 43.89% and 66.86%, respectively, and those of silver were 1.3 kg/t and 81.60%, respectively. At 600–700 °C, jarosite was decomposed to release encapsulated valuable minerals such as anglesite (PbSO{sub 4}) and silver mineral; silver jarosite decomposed into silver sulfate (Ag{sub 2}SO{sub 4}); and zinc ferrite (ZnO·Fe{sub 2}O{sub 3}) decomposed into zinc sulfate (ZnSO{sub 4}) and hematite (Fe{sub 2}O{sub 3}). Bared anglesite and silver minerals were modified by sodium sulfide and easily collected by flotation collectors. This study demonstrates that the combination of roasting and sulfidization-flotation provides a promising process for the recovery of zinc, lead, and silver from jarosite residues of zinc hydrometallurgy.

Medicago truncatula Zinc-Iron Permease6 provides zinc to rhizobia-infected nodule cells.

Science.gov (United States)

Abreu, Isidro; Saéz, Ángela; Castro-Rodríguez, Rosario; Escudero, Viviana; Rodríguez-Haas, Benjamín; Senovilla, Marta; Larue, Camille; Grolimund, Daniel; Tejada-Jiménez, Manuel; Imperial, Juan; González-Guerrero, Manuel

2017-11-01

Zinc is a micronutrient required for symbiotic nitrogen fixation. It has been proposed that in model legume Medicago truncatula, zinc is delivered by the root vasculature into the nodule and released in the infection/differentiation zone. There, transporters must introduce this element into rhizobia-infected cells to metallate the apoproteins that use zinc as a cofactor. MtZIP6 (Medtr4g083570) is an M. truncatula Zinc-Iron Permease (ZIP) that is expressed only in roots and nodules, with the highest expression levels in the infection/differentiation zone. Immunolocalization studies indicate that it is located in the plasma membrane of nodule rhizobia-infected cells. Down-regulating MtZIP6 expression levels with RNAi does not result in any strong phenotype when plants are fed mineral nitrogen. However, these plants displayed severe growth defects when they depended on nitrogen fixed by their nodules, losing of 80% of their nitrogenase activity. The reduction of this activity was likely an indirect effect of zinc being retained in the infection/differentiation zone and not reaching the cytosol of rhizobia-infected cells. These data are consistent with a model in which MtZIP6 would be responsible for zinc uptake by rhizobia-infected nodule cells in the infection/differentiation zone. © 2017 John Wiley & Sons Ltd.

Extraction of Zinc and Manganese from Alkaline and Zinc-Carbon Spent Batteries by Citric-Sulphuric Acid Solution

Directory of Open Access Journals (Sweden)

Francesco Ferella

2010-01-01

Full Text Available The paper is focused on the recovery of zinc and manganese from alkaline and zinc-carbon spent batteries. Metals are extracted by sulphuric acid leaching in the presence of citric acid as reducing agent. Leaching tests are carried out according to a 24 full factorial design, and empirical equations for Mn and Zn extraction yields are determined from experimental data as a function of pulp density, sulphuric acid concentration, temperature, and citric acid concentration. The highest values experimentally observed for extraction yields were 97% of manganese and 100% of zinc, under the following operating conditions: temperature 40∘C, pulp density 20%, sulphuric acid concentration 1.8 M, and citric acid 40 g L-1. A second series of leaching tests is also performed to derive other empirical models to predict zinc and manganese extraction. Precipitation tests, aimed both at investigating precipitation of zinc during leaching and at evaluating recovery options of zinc and manganese, show that a quantitative precipitation of zinc can be reached but a coprecipitation of nearly 30% of manganese also takes place. The achieved results allow to propose a battery recycling process based on a countercurrent reducing leaching by citric acid in sulphuric solution.

Daya antibakteri penambahan Propolis pada zinc oxide eugenol dan zinc oxide terhadap kuman campur gigi molar sulung non vital (The antibacterial effect of propolis additional to zinc oxide eugenol and zinc oxide on polybacteria of necrotic primary molar

Directory of Open Access Journals (Sweden)

Yemy Ameliana

2014-12-01

Full Text Available Background: Materials commonly used for root canal filling of primary teeth is zinc oxide eugenol. Eugenol has some disadvantages that can irritate the periapical tissues, has the risk of disturbing the growth and development of permanent tooth buds, and has a narrow antibacterial spectrum. Studies showed that propolis at concentration of 20 % has antibacterial activity against Staphylococcus aureus. Purpose: The purpose of this study was to examine the antimicrobial activity of root canal pastes with the additional of propolis additional to zinc oxide eugenol (ZOEP and to zinc oxide (ZOP. Methods: Polybacteria cultures collected from root canals of necrotic primary molar from 5 children patients who received root canal treatment. The bacteria were grown in BHI Broth, and inoculated into Muller Hinton Agar media. The agar plates was divided into 3 areas, and one well was made at each area. The first well filled with ZOE as a control, second well filled with ZOEP and the third well filled with ZOP, then incubated for 24 hour at 370 C. Antimicrobial activity was determined by measuring the diameters of inhibition zones of polybacteria growth. The data were statistically analyzed by independent T-test. Results: The pasta mixture of zinc oxide propolis had the strongest antibacterial activity against polybacteria of necrotic primary molar, followed by zinc oxide eugenol propolis paste, and zinc oxide eugenol paste. There were significant differences of inhibition zones between ZOE, ZOEP and ZOP (p<0,05. Conclusion: The study suggested that the additional of propolis to zinc oxide paste could increase the antimicrobial effect against root canal polybacteria of necrotic primary molar.Latar belakang: Bahan yang sering digunakan untuk pengisian saluran akar gigi sulung adalah zinc oxide eugenol. Eugenol memiliki beberapa kekurangan yaitu dapat mengiritasi jaringan periapikal, beresiko mengganggu pertumbuhan dan perkembangan benih gigi permanen pengganti

Welding zinc coated steel with a CO/sub 2/ laser

International Nuclear Information System (INIS)

Akhter, R.; Steen, W.M.

1993-01-01

Welding of zinc coated steel has been studied using a high power CO/sub 2/ laser. This process is of great interest to the manufactures of car, washing machines and other components made from sheet steel and subject to corrosion. The problem associated with the welding of zinc coated steel is the low boiling point of zinc (906C) relative to the high melting point of steel (1500C). The problem is particularly important in lap welding where the zinc layer is between the lapped sheets. Under these conditions the laser 'keyhole' will generate very high vapour pressure in the zinc layer with a consequent severe risk of vapour eruption destroying the continuity of the weld bead. Several techniques are presented for the removal of zinc vapours from the interface between the two sheets. It is shown that this problem solved by suitable gap between the sheets during lap welding. Hence full penetration welds without deterioration of the weld bead can be obtained. A theory has been presented which predicted an exact gap size needed to exhaust the zinc vapour. The gap depends upon the welding speed, zinc coating thickness and thickness of the sheet. The theory predicts the weld quality satisfactorily. (author)

The recovery of Zn and Pb and the manufacture of lightweight bricks from zinc smelting slag and clay.

Science.gov (United States)

Hu, Huiping; Deng, Qiufeng; Li, Chao; Xie, Yue; Dong, Zeqin; Zhang, Wei

2014-04-30

Novel lightweight bricks have been produced by sintering mixes of zinc smelting slag and clay. A two-stage sintered process has been proposed to recovery of Zn and Pb and reutilization of the zinc smelting slag. In the first stage of the process, called reduction and volatilization procedure, zinc and lead were reduced by the carbon contained in the zinc smelting slag and volatilized into the dust, and the dust can be used as a secondary zinc resource. In the second stage of the process, called oxidation sintering procedure, a lightweight brick was produced. Samples containing up to 60 wt.% zinc smelting slag and 40 wt.% kaolin clay were reduced at 1050°C for 6h, and then sintered at 1050°C for 4h. The recoveries of Zn and Pb from the brick are 94.5 ± 0.6% and 97.6 ± 0.2%, respectively. Low bulk density (1.42 g cm(-3)) and relatively high compressive strength (2 2MPa) sintered bricks were produced, and the leaching toxicity of the sintered bricks was below the regulatory thresholds of Chinese National Standards. Copyright © 2014 Elsevier B.V. All rights reserved.

Photocatalysis application of zinc oxide fibers obtained by electrospinning

International Nuclear Information System (INIS)

Gerchman, D.; Alves, A.K.; Berutti, F.A.; Bergmann, C.P.

2010-01-01

Using the electrospinning technique, composite fibers of polyvinylbutyral and zinc nitrate were obtained. After a heat treatment at 600 deg C, nanostructured zinc oxide fibers were obtained. The fibers were characterized using X ray diffraction. The photocatalytic activity of the nanostructured fibers was determined using the photodegradation of a methyl orange solution. The increase in the heat treatment temperature decreases the photoactivity of the zinc oxide. The heat treatment, the phases and the surface area, affect the physical, chemical and photocatalytic activity of the zinc oxide. (author)

Despite phylogenetic effects, C3-C4 lineages bridge the ecological gap to C4 photosynthesis.

Science.gov (United States)

Lundgren, Marjorie R; Christin, Pascal-Antoine

2017-01-01

C 4 photosynthesis is a physiological innovation involving several anatomical and biochemical components that emerged recurrently in flowering plants. This complex trait evolved via a series of physiological intermediates, broadly termed 'C 3 -C 4 ', which have been widely studied to understand C 4 origins. While this research program has focused on biochemistry, physiology, and anatomy, the ecology of these intermediates remains largely unexplored. Here, we use global occurrence data and local habitat descriptions to characterize the niches of multiple C 3 -C 4 lineages, as well as their close C 3 and C 4 relatives. While C 3 -C 4 taxa tend to occur in warm climates, their abiotic niches are spread along other dimensions, making it impossible to define a universal C 3 -C 4 niche. Phylogeny-based comparisons suggest that, despite shifts associated with photosynthetic types, the precipitation component of the C 3 -C 4 niche is particularly lineage specific, being highly correlated with that of closely related C 3 and C 4 taxa. Our large-scale analyses suggest that C 3 -C 4 lineages converged toward warm habitats, which may have facilitated the transition to C 4 photosynthesis, effectively bridging the ecological gap between C 3 and C 4 plants. The intermediates retained some precipitation aspects of their C 3 ancestors' habitat, and likely transmitted them to their C 4 descendants, contributing to the diversity among C 4 lineages seen today. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

PYROLYSIS OF ZINC CONTAMINATED BIOMASS FROM PHYTOREMEDIATION

OpenAIRE

Özkan, Aysun; Günkaya, Zerrin; Banar, Müfide; Kulaç, Alev; Yalçın, Gülser; Taşpınar, Kadriye; Altay, Abdullah

2015-01-01

The objective of this study was to stabilize of zinc (Zn) from soil to pyrolysis solid product. For this aim, phytoremediation and pyrolysis were sequentially applied. In the first stage of the study, phytoremediation was first applied to zinc contaminated soil via  sunflower (Helianthus annuus), corn (Zea mays) and rape (Brassica napus), After harvesting, the plants were pyrolyzed at 500°C with the heating rate of 35 °C/min in a fixed bed stainless steel (380 S) 240 cm3 reactor. The phytorem...

The Uses of Copper and Zinc Aluminates to Capture and Convert Carbon dioxide to Syn-gas at Higher Temperature

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R.Y. Raskar

2014-03-01

Full Text Available The uses of copper and zinc aluminates to capture and convert the CO2 to syn-gas were studied at higher temperatures. The samples of copper and zinc aluminates were prepared by solid-solid fusion method by calcining in air at 900 oC for 3 h. Those samples were characterized by acidity/alkalinity, surface area, XRD pattern, IR, SEM images and screening to capture CO2 at the different temperatures. The phases Cu2O, CuO, ZnO, CuAl2O4 and ZnAl2O4 were found to be in the samples of zinc and copper aluminates. Acidity and surface area of the samples of copper and zinc aluminates were found to be in the ranges from 0.063 to 9.37 mmol g-1 and 3.04 to 11.8 m2 g-1, respectively. The captured CO2 by the samples of copper and zinc aluminates was found to be 19.92 to 31.52 wt% for the temperature range 40 to 850 oC. The captured CO2 at 550 oC by variable Zn/Al and Cu/Al mol ratio from 0.5 to 6 of the samples of copper and zinc aluminates was found to be 12.81 to 18.04 wt%. The reduction of carbon dioxide by zinc and copper aluminates was observed. The conversion of CO2 by methane over variable mol ratio of Cu/Al and Zn/Al in copper and zinc aluminates, respectively, at 500 oC showed the production of syn-gas by using the gas hourly space velocities (GHSV 12000, 12000 and 6000 ml. h-1. g-1 of helium, CO2 and methane. The conversions of CO2 by methane over the samples of zinc and copper aluminates were studied at different mol ratios of CO2 to methane.  © 2014 BCREC UNDIP. All rights reservedReceived: 13rd May 2013; Revised: 8th November 2013; Accepted: 8th November 2013[How to Cite: Raskar, R.Y., Gaikwad, A.G. (2014. The Uses of Copper and Zinc Aluminates to Cap-ture and Convert Carbon Dioxide to Syn-gas at Higher Temperature. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (1: 1-15. (doi:10.9767/bcrec.9.1.4899.1-15[Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.1.4899.1-15

Zinc ions bind to and inhibit activated protein C

DEFF Research Database (Denmark)

Zhu, Tianqing; Ubhayasekera, Wimal; Nickolaus, Noëlle

2010-01-01

fold enhanced, presumably due to the Ca2+-induced conformational change affecting the conformation of the Zn2+-binding site. The inhibition mechanism was non-competitive both in the absence and presence of Ca2+. Comparisons of sequences and structures suggested several possible sites for zinc binding...

Erythrocyte zinc levels in children with bronchial asthma.

Science.gov (United States)

Arik Yilmaz, E; Ozmen, S; Bostanci, I; Misirlioglu, E Dibek; Ertan, U

2011-12-01

Zinc deficiency may be suspected to play a role in the pathogenesis, control, and severity of asthma because of its antioxidant, antiapoptotic, and anti-inflammatory effects. We aimed to investigate whether there was any relationship between erythrocyte zinc levels and childhood asthma. The erythrocyte zinc levels of 67 asthmatic and 45 healthy children were analyzed in this case-control study. The mean concentrations of erythrocyte zinc were 1215.8 ± 145.1 µg/dl in asthma patients and 1206.9 ± 119.5 µg/dl in controls with no significant difference (P = 0.472). The erythrocyte zinc level was below 1,000 µg/dl in 6 asthmatic patients (8.9%) and 2 control group patients (4.4%). There was no relationship between erythrocyte zinc levels and duration of follow-up, severity, and control of the asthma (P > 0.05). On the other hand, patients hospitalized for an asthma attack had significantly lower erythrocyte zinc levels compared with nonhospitalized patients and the control group (P = 0.000 and P = 0.004 respectively). This study's findings indicate that asthmatic children are not a risk group for zinc deficiency. We emphasize that checking zinc levels in children who are hospitalized for an asthma attack may be useful. Copyright © 2011 Wiley Periodicals, Inc.

Single-crystal structure, photophysical characteristics and electroluminescent properties of bis(2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate)zinc

Energy Technology Data Exchange (ETDEWEB)

Xu Huixia, E-mail: xuhuixia0824@163.com [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Yue, Yan [Department of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Wang Hua [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Chen Liuqing [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Hao Yuying [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Xu Bingshe [Key Laboratory of Interface Science and Engineering in Advanced Materials, Taiyuan University of Technology, Taiyuan 030024 (China); College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

2012-04-15

In this paper, a zinc (II) complex of Zn{sub 2}(4-tfmBTZ){sub 4} (4-tfmBTZ=2-(4-trifluoromethyl-2-hydroxyphenyl)benzothiazolate) was reported. Via combination of experimental and theoretical approaches, its molecular structure, photophysical characteristics, electronic structure and electroluminescent properties were investigated. The results indicate that Zn{sub 2}(4-tfmBTZ){sub 4} exists as five-coordinate geometric structure and two zinc atoms are bridged by oxygen atoms. The intense absorption band was located at 404 nm, which mainly originate from the transition HOMO-1 to LUMO+2. The blue-light emission was observed in tetrahydrofuran solution and thin film. White-light emission with four emission peaks was observed with CIE coordinate of (0.29, 0.33) and a higher CRI of 85.1 by fabricating bilayer device using Zn{sub 2}(4-tfmBTZ){sub 4} as electron-transport and NPB as hole-transport material. - Highlights: Black-Right-Pointing-Pointer The single-crystal and electronic structures of Zn{sub 2}(4-tfmBTZ){sub 4}. Black-Right-Pointing-Pointer The multicolor emission of Zn{sub 2}(4-tfmBTZ){sub 4} were realized by the simple devices. Black-Right-Pointing-Pointer White OLED is achieved with particularly high color rending index (CRI) by the emission of Zn{sub 2}(4-tfmBTZ){sub 4}.

First C/sub 4/-functionalisation of condensed tannins. Phlobatannins as prototype of a new class of C-ring isomerised oligomers. Die eerste C/sub 4/-funksionalisering van gekondenseerde tanniene. Flobatanniene as prototipe van 'n nuwe klas van C-ring geisomeriseerde oligomere

Energy Technology Data Exchange (ETDEWEB)

Steenkamp, J A

1986-06-01

This thesis comprises besides the characterisation of new oligomeric flavenoids from the core wood of the indigeneous Colophosphermum mopane, an investigation into the C/sub 4/-functionalisation of flavan-3-ol analogues. The first peltogynoid biflavenoid and prototypes of a new series C-ring isomerised condensed tannins, namely the phlobatannins, were isolated. Besides /sup 1/H- nmr-parameters for structure analysis, the natural phlobatannins were characterised and the unique ring isomerisation was investigated.

Zinc (II) [tetra(4-methylphenyl)] Porphyrin: a Novel and Reusable Catalyst for Efficient Synthesis of 2,4,5-trisubstituted Imidazoles Under Ultrasound Irradiation

Energy Technology Data Exchange (ETDEWEB)

Safari, Javad; Khalili, Shiva Dehghan; Banitaba, Sayed Hossein; Dehghani, Hossein [Univ. of Kashan, Kashan (Iran, Islamic Republic of)

2011-10-15

An efficient three-component one-step synthesis of 2,4,5-trisubstituted imidazoles by condensation reaction of 1,2-diketones or α-hydroxyketones with aromatic aldehydes and ammonium acetate using Zinc (II) [tetra (4-methylphenyl)] porphyrin as a novel and reusable catalyst under ultrasound irradiation at ambient temperature is described. In this method, α-hydroxyketones as well as 1,2-diketones were converted to their corresponding 2,4,5-trisubstituted imidazoles in excellent yields.

Retention of zinc and calcium from the human colon

International Nuclear Information System (INIS)

Sandstroem, B.C.; Cederblad, A.; Kivistoe, B.S.; Stenquist, B.; Andersson, H.

1986-01-01

Colonic retention of zinc and calcium was studied after installation during colonoscopy of 30 mumol of zinc and 6.4 mmol of calcium labeled with 65 Zn and 47 Ca, and measurement of the whole-body retention of the radionuclides. After cecal installation in nine patients, retention (day 13) of zinc was 3.5 +/- 2.1% (mean +/- SD) and of calcium 3.5 +/- 2.7%. The calculated mean absorption was 4.1% for zinc and 14.1% for calcium. Application at the hepatic flexure in four patients resulted in a mean retention (day 13) of 1.2% for zinc and 0.6% for calcium. Under prevailing conditions, colonic absorption of zinc is relatively small, compared to the uptake after oral administration. Colonic absorption of calcium could, however, account for a substantial part of the total calcium uptake

Zinc stannate nanostructures: hydrothermal synthesis

International Nuclear Information System (INIS)

Baruah, Sunandan; Dutta, Joydeep

2011-01-01

Nanostructured binary semiconducting metal oxides have received much attention in the last decade owing to their unique properties rendering them suitable for a wide range of applications. In the quest to further improve the physical and chemical properties, an interest in ternary complex oxides has become noticeable in recent times. Zinc stannate or zinc tin oxide (ZTO) is a class of ternary oxides that are known for their stable properties under extreme conditions, higher electron mobility compared to its binary counterparts and other interesting optical properties. The material is thus ideal for applications from solar cells and sensors to photocatalysts. Among the different methods of synthesizing ZTO nanostructures, the hydrothermal method is an attractive green process that is carried out at low temperatures. In this review, we summarize the conditions leading to the growth of different ZTO nanostructures using the hydrothermal method and delve into a few of its applications reported in the literature. (topical review)

Zinc deficiency-induced iron accumulation, a consequence of alterations in iron regulatory protein-binding activity, iron transporters, and iron storage proteins.

Science.gov (United States)

Niles, Brad J; Clegg, Michael S; Hanna, Lynn A; Chou, Susan S; Momma, Tony Y; Hong, Heeok; Keen, Carl L

2008-02-22

One consequence of zinc deficiency is an elevation in cell and tissue iron concentrations. To examine the mechanism(s) underlying this phenomenon, Swiss 3T3 cells were cultured in zinc-deficient (D, 0.5 microM zinc), zinc-supplemented (S, 50 microM zinc), or control (C, 4 microM zinc) media. After 24 h of culture, cells in the D group were characterized by a 50% decrease in intracellular zinc and a 35% increase in intracellular iron relative to cells in the S and C groups. The increase in cellular iron was associated with increased transferrin receptor 1 protein and mRNA levels and increased ferritin light chain expression. The divalent metal transporter 1(+)iron-responsive element isoform mRNA was decreased during zinc deficiency-induced iron accumulation. Examination of zinc-deficient cells revealed increased binding of iron regulatory protein 2 (IRP2) and decreased binding of IRP1 to a consensus iron-responsive element. The increased IRP2-binding activity in zinc-deficient cells coincided with an increased level of IRP2 protein. The accumulation of IRP2 protein was independent of zinc deficiency-induced intracellular nitric oxide production but was attenuated by the addition of the antioxidant N-acetylcysteine or ascorbate to the D medium. These data support the concept that zinc deficiency can result in alterations in iron transporter, storage, and regulatory proteins, which facilitate iron accumulation.

Reduction kinetics of zinc and cadmium sulfides with hydrogen

International Nuclear Information System (INIS)

Turgenev, I.S.; Kabisov, I.Kh.; Zviadadze, G.N.; Vasil'eva, O.Yu.

1985-01-01

Kinetics of reduction processes of zinc sulfide in the temperature range 800-1100 deg C and of cadmium sulfide 600-900 deg C has been stodied. Activation energies and reaction order in terms of hydrogen are calculated. Thermodynamic processes of reduction depend on aggregate state of the metal formed. For vaporous zinc in the temperature range 1050-950 deq C activation energy constitutes 174 kJ/mol, for liquid in the range 900-850 deg - 151 kJ/mol and reaction order in terms of hydrogen is 1.0. For vaporous cadmium in the temperature range 900-700 deg C activation energy constitutes 144 kJ/mol and reaction order in terms of hydrogen is 0.86, for liquid in the range 675-600 deg C 127 kJ/mol and 0.8 respectively. The processes of zinc and cadmium sulfide reduction proceed in kinetic regime and are limited by the rate of chemical reaction

A novel layered bimetallic phosphite intercalating with organic amines: Synthesis and characterization of Co(H2O)4Zn4(HPO3)6.C2N2H1

International Nuclear Information System (INIS)

Lin Zhien; Fan Wei; Gao Feifei; Chino, Naotaka; Yokoi, Toshiyuki; Okubo, Tatsuya

2006-01-01

A new layered cobalt-zinc phosphite, Co(H 2 O) 4 Zn 4 (HPO 3 ) 6 .C 2 N 2 H 1 has been synthesized in the presence of ethylenediamine as the structure-directing agent. The compound crystallizes in the monoclinic system, space group Cc (No. 9), a=18.2090(8), b=9.9264(7), c=15.4080(7) A, β=114.098(4) o , V=2542.3(2) A 3 , Z=4, R=0.0323, wR=0.0846. The structure consists of ZnO 4 tetrahedra, CoO 6 octahedra and HPO 3 pseudopyramids through their vertices forming bimetallic phosphite layers parallel to the ab plane. Organic cations, which reside between the inorganic layers, are mobile and can be exchanged by NH 4 + cations without the collapse of the framework

Foliar uptake of zinc by vascular plants. Radiometric study

International Nuclear Information System (INIS)

Maresova, J.; Remenarova, L.; Hornik, M.; Pipiska, M.; Augustin, J.; Lesny, J.

2012-01-01

The aim of this paper was to obtain quantitative data of foliar uptake kinetics and long distance transport of zinc in tobacco (Nicotiana tabacum L.) and hop (Humulus lupulus L.) plants. Zinc was used as a model of microelement and toxic metal, tobacco and hop as a representatives of agriculturally important plants. A tip of leaf blade was immersed in the solution spiked with 65 ZnCl 2 and foliar uptake and translocation to other parts of the plant grown in nutrient solution was measured by gamma-spectrometry and autoradiography. We found that foliar zinc uptake by both plants is dependent on the initial metal concentration within the range C 0 = 10-100 μmol dm -3 ZnCl 2 . Zinc is immobilized mainly in immersed part of the contact leaf and only 0 = 0.1 mmol dm -3 ZnCl 2 concentrations >2.5 mg/g Zn and 4.8 mg/g Zn (dry wt.) in immersed part of tobacco and hop leaf plant, respectively were found after 5 days of exposure. Low mobility of zinc entering the plant via the leaf surface can be attributed to the immobilization of zinc into Zn-ligand complexes with high stability constants log K at pH 6.0-8.0, such as the reaction products of Zn 2+ ions with citric acid, histidine or phosphates. Zinc can be extracted from dried leaves by the solutions of inorganic salts, carboxylic acids, amino acids and synthetic complexing ligands such as EDTA. Anionic (SDS) and non-ionic (Tween 40) surfactants causes the decrease of the Zn foliar uptake, but not translocation of Zn from the contact leaf area. Obtained data are discussed from the point of view of possible limited efficiency of liquid formulations designed for practical applications as Zn foliar fertilizers. (author)

Transition metal complexes with pyrazole-based ligands.Part 29. Reactions of zinc(II and mercury(II thiocyanate with 4-acetyl-3-amino-5-methylpyrazole

Directory of Open Access Journals (Sweden)

KATALIN MÉSZÁROS SZÉCSÉNYI

2009-11-01

Full Text Available The work is concerned with the crystal and molecular structures of zinc(II and mercury(II complexes with 4-acetyl-3-amino-5-methyl-pyrazole (aamp of the coordination formulae [Zn(NCS2(aamp2] and (Haamp2[Hg(SCN4]. The zinc(II complex was obtained by the reaction of a warm methanolic solution of aamp with a mixture of zinc(II nitrate and ammonium thiocyanate, whereas the mercury(II complex was prepared by the reaction of a warm ethanolic solution of aamp and a warm, slightly acidified aqueous solution of [Hg(SCN4]2-. Both complexes have a tetrahedral geometry, which in the case of zinc complex is formed by monodentate coordination of two aamp molecules and two isothiocyanate groups. The Zn(II and Hg(II atoms have significantly deformed coordination geometry. In both crystal structures the pyrazole derivative has a planar form, probably stabilized by an intramolecular N–H···O hydrogen bond. Apart from the X-ray structural analysis, the isolated complexes were characterized by elemental analysis, IR spectroscopy, conductometric measurements and thermal analysis.

Repletion of zinc in zinc-deficient cells strongly up-regulates IL-1β-induced IL-2 production in T-cells.

Science.gov (United States)

Daaboul, Doha; Rosenkranz, Eva; Uciechowski, Peter; Rink, Lothar

2012-10-01

Mild zinc deficiency in humans negatively affects IL-2 production resulting in declined percentages of cytolytic T cells and decreased NK cell lytic activity, which enhances the susceptibility to infections and malignancies. T-cell activation is critically regulated by zinc and the normal physiological zinc level in T-cells slightly lies below the optimal concentration for T-cell functions. A further reduction in zinc level leads to T-cell dysfunction and autoreactivity, whereas high zinc concentrations (100 μM) were shown to inhibit interleukin-1 (IL-1)-induced IL-1 receptor kinase (IRAK) activation. In this study, we investigated the molecular mechanism by which zinc regulates the IL-1β-induced IL-2 expression in T-cells. Zinc supplementation to zinc-deficient T-cells increased intracellular zinc levels by altering the expression of zinc transporters, particularly Zip10 and Zip12. A zinc signal was observed in the murine T-cell line EL-4 6.1 after 1 h of stimulation with IL-1β, measured by specific zinc sensors FluoZin-3 and ZinPyr-1. This signal is required for the phosphorylation of MAPK p38 and NF-κB subunit p65, which triggers the transcription of IL-2 and strongly increases its production. These results indicate that short-term zinc supplementation to zinc-deficient T-cells leads to a fast rise in zinc levels which subsequently enhance cytokine production. In conclusion, low and excessive zinc levels might be equally problematic for zinc-deficient subjects, and stabilized zinc levels seem to be essential to avoid negative concentration-dependent zinc effects on T-cell activation.

Two new three-dimensional zinc phosphites templated by piperazine: [H2pip][Zn3(HPO3)4(H2O)2] and K[H2pip]0.5[Zn3(HPO3)4

Science.gov (United States)

Zhang, Xiao; Wang, Guo-Ming; Wang, Zong-Hua; Wang, Ying-Xia; Lin, Jian-Hua

2014-01-01

Two three-dimensional open-framework zinc phosphites with the same organically templated, [H2pip][Zn3(HPO3)4(H2O)2] (1) and K[H2pip]0.5[Zn3(HPO3)4] (2) (pip = piperazine), have been solvothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. Compound 1 consists of ZnO4 tetrahedra, [HPO3] pseudopyramids and [ZnO4(H2O)2] octahedra, which are linked through their vertexes to generate three-dimensional architecture with intersecting 8-membered channels along the [1 0 0], [0 0 1] and [1 0 1] directions. Compound 2 is constructed from strictly alternating ZnO4 tetrahedra and [HPO3] pseudopyramids, and exhibits (3,4)-connected inorganic framework with 8-, and 12-membered channels, in which the K+ and diprotonated H2pip2+ extra-framework cations reside, respectively. The coexistence of inorganic K+ and organic piperazine mixed templates in the structure is unique and, to the best of our knowledge, firstly observed in metal-phosphite materials. In addition, the participation of left-handed and right-handed helical chains in construction of the puckered 4.82 sheet structure in 2 is also noteworthy.

Anglesite and silver recovery from jarosite residues through roasting and sulfidization-flotation in zinc hydrometallurgy.

Science.gov (United States)

Han, Haisheng; Sun, Wei; Hu, Yuehua; Jia, Baoliang; Tang, Honghu

2014-08-15

Hazardous jarosite residues contain abundant valuable minerals that are difficult to be recovered by traditional flotation process. This study presents a new route, roasting combined with sulfidization-flotation, for the recovery of anglesite and silver from jarosite residues of zinc hydrometallurgy. Surface appearance and elemental distribution of jarosite residues was examined by scanning electron microscopy and energy dispersive X-ray spectrometry analysis, respectively. Decomposition and transformation mechanisms of jarosite residues were illustrated by differential thermal analysis. Results showed that after roasting combined with flotation, the grade and recovery of lead were 43.89% and 66.86%, respectively, and those of silver were 1.3 kg/t and 81.60%, respectively. At 600-700 °C, jarosite was decomposed to release encapsulated valuable minerals such as anglesite (PbSO4) and silver mineral; silver jarosite decomposed into silver sulfate (Ag2SO4); and zinc ferrite (ZnO · Fe2O3) decomposed into zinc sulfate (ZnSO4) and hematite (Fe2O3). Bared anglesite and silver minerals were modified by sodium sulfide and easily collected by flotation collectors. This study demonstrates that the combination of roasting and sulfidization-flotation provides a promising process for the recovery of zinc, lead, and silver from jarosite residues of zinc hydrometallurgy. Copyright © 2014 Elsevier B.V. All rights reserved.

C1 Polymerization: a unique tool towards polyethylene-based complex macromolecular architectures

KAUST Repository

Wang, De

2017-05-09

The recent developments in organoborane initiated C1 polymerization (chain grows by one atom at a time) of ylides opens unique horizons towards well-defined/perfectly linear polymethylenes (equivalent to polyethylenes, PE) and PE-based complex macromolecular architectures. The general mechanism of C1 polymerization (polyhomologation) involves the formation of a Lewis complex between a methylide (monomer) and a borane (initiator), followed by migration/insertion of a methylene into the initiator and after oxidation/hydrolysis to afford OH-terminated polyethylenes. This review summarizes efforts towards conventional and newly discovered borane-initiators and ylides (monomers), as well as a combination of polyhomologation with other polymerization methods. Initial efforts dealing with C3 polymerization and the synthesis of the first C1/C3 copolymers are also given. Finally, some thoughts for the future of these polymerizations are presented.

C1 Polymerization: a unique tool towards polyethylene-based complex macromolecular architectures

KAUST Repository

Wang, De; Zhang, Zhen; Hadjichristidis, Nikolaos

2017-01-01

The recent developments in organoborane initiated C1 polymerization (chain grows by one atom at a time) of ylides opens unique horizons towards well-defined/perfectly linear polymethylenes (equivalent to polyethylenes, PE) and PE-based complex macromolecular architectures. The general mechanism of C1 polymerization (polyhomologation) involves the formation of a Lewis complex between a methylide (monomer) and a borane (initiator), followed by migration/insertion of a methylene into the initiator and after oxidation/hydrolysis to afford OH-terminated polyethylenes. This review summarizes efforts towards conventional and newly discovered borane-initiators and ylides (monomers), as well as a combination of polyhomologation with other polymerization methods. Initial efforts dealing with C3 polymerization and the synthesis of the first C1/C3 copolymers are also given. Finally, some thoughts for the future of these polymerizations are presented.

REMOVING ZINC FROM GALVANIZED STEEL SCRAP TO FEASIBLE THE BOF SLUDGE RECYCLING

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Mônica Marques Caetano de Lima

2013-06-01

Full Text Available Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contains high iron content, it could be recycled to the process, but due to its zinc content, it is disposed in landfills. For this reason, this study aimed to treat these scraps to remove zinc layer using a thermal treatment process. The samples were fed to a rotative furnace in an inert ambient. It was tested the hot dip galvanized and eletrogalvanized scraps, varying the zinc coating weight between 20g/m2 and 150g/m2, temperature between 700°C and 900°C and time between 3 minutes and 10 minutes. Considering these conditions, it is verified that more than 70% of the zinc layer is removed at 700°C, in 10 minutes. Dust captured is about 60% of metallic zinc and 40% as zinc oxide. Based on these results, the recycling of BOF sludge can be feasible to the ironmaking process.

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

Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4 and Zinc Ferrite (ZnFe2O4 Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

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Samikannu Kanagesan

2016-08-01

Full Text Available Spinel copper ferrite (CuFe2O4 and zinc ferrite (ZnFe2O4 nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, Transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

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.

Iron Bioavailability from Ferric Pyrophosphate in Extruded Rice Cofortified with Zinc Sulfate Is Greater than When Cofortified with Zinc Oxide in a Human Stable Isotope Study.

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Hackl, Laura; Zimmermann, Michael B; Zeder, Christophe; Parker, Megan; Johns, Paul W; Hurrell, Richard F; Moretti, Diego

2017-03-01

Background: Extruded rice grains are often cofortified with iron and zinc. However, it is uncertain if the addition of zinc to iron-fortified rice affects iron absorption and whether this is zinc-compound specific. Objective: We investigated whether zinc, added as zinc oxide (ZnO) or zinc sulfate (ZnSO 4 ), affects human iron absorption from extruded rice fortified with ferric pyrophosphate (FePP). Methods: In 19 iron-depleted Swiss women (plasma ferritin ≤16.5 μ/L) aged between 20 and 39 y with a normal body mass index (in kg/m 2 ; 18.7-24.8), we compared iron absorption from 4 meals containing fortified extruded rice with 4 mg Fe and 3 mg Zn. Three of the meals contained extruded rice labeled with FePP ( 57 FePP): 1 ) 1 meal without added zinc ( 57 FePP-Zn), 2 ) 1 cofortified with ZnO ( 57 FePP+ZnO), and 3 ) 1 cofortified with ZnSO 4 ( 57 FePP+ZnSO 4 ). The fourth meal contained extruded rice without iron or zinc, extrinsically labeled with ferrous sulfate ( 58 FeSO 4 ) added as a solution after cooking. All 4 meals contained citric acid. Iron bioavailability was measured by isotopic iron ratios in red blood cells. We also measured relative in vitro iron solubility from 57 FePP-Zn, 57 FePP+ZnO, and 57 FePP+ZnSO 4 expressed as a fraction of FeSO 4 solubility. Results: Geometric mean fractional iron absorption (95% CI) from 57 FePP+ZnSO 4 was 4.5% (3.4%, 5.8%) and differed from 57 FePP+ZnO (2.7%; 1.8%, 4.1%) ( P iron bioavailabilities compared with 58 FeSO 4 were 62%, 57%, and 38% from 57 FePP+ZnSO 4 , 57 FePP-Zn, and 57 FePP+ZnO, respectively. In vitro solubility from 57 FePP+ZnSO 4 differed from that of 57 FePP-Zn (14.3%; P iron-depleted women, iron absorption from FePP-fortified extruded rice cofortified with ZnSO 4 was 1.6-fold (95% CI: 1.4-, 1.9-fold) that of rice cofortified with ZnO. These findings suggest that ZnSO 4 may be the preferable zinc cofortificant for optimal iron bioavailability of iron-fortified extruded rice. This trial was registered at

Investigation into interaction of mixture of zinc and neodymium nitrates with sodium tungstates in aqueous solutions

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Rozantsev, G M; Krivobok, V I [Donetskij Gosudarstvennyj Univ. (Ukrainian SSR)

1978-09-01

The methods of residual concentrations, pH-potentiometry, and conductometry have been used for studying interaction between the mixture of zinc and neodymium nitrates with sodium tungstate in aqueous solutions. It has been established that independent of the ratio between the components the reaction product is a mixture of simultaneously precipitated zinc and neodymium orthotungstates. Thermal treatment of such mixtures at 650-700 deg C for 40 h and subsequent hardening yields solid solution of the structure ..cap alpha..-Eu/sub 2/(WO/sub 4/)/sub 3/ within the concentration range 85-100 mol % of Nd/sub 2/(WO/sub 4/)/sub 3/.

Solution structure of an archaeal DNA binding protein with an eukaryotic zinc finger fold.

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Florence Guillière

Full Text Available While the basal transcription machinery in archaea is eukaryal-like, transcription factors in archaea and their viruses are usually related to bacterial transcription factors. Nevertheless, some of these organisms show predicted classical zinc fingers motifs of the C2H2 type, which are almost exclusively found in proteins of eukaryotes and most often associated with transcription regulators. In this work, we focused on the protein AFV1p06 from the hyperthermophilic archaeal virus AFV1. The sequence of the protein consists of the classical eukaryotic C2H2 motif with the fourth histidine coordinating zinc missing, as well as of N- and C-terminal extensions. We showed that the protein AFV1p06 binds zinc and solved its solution structure by NMR. AFV1p06 displays a zinc finger fold with a novel structure extension and disordered N- and C-termini. Structure calculations show that a glutamic acid residue that coordinates zinc replaces the fourth histidine of the C2H2 motif. Electromobility gel shift assays indicate that the protein binds to DNA with different affinities depending on the DNA sequence. AFV1p06 is the first experimentally characterised archaeal zinc finger protein with a DNA binding activity. The AFV1p06 protein family has homologues in diverse viruses of hyperthermophilic archaea. A phylogenetic analysis points out a common origin of archaeal and eukaryotic C2H2 zinc fingers.

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.

Bioavailability of Trace Elements in Beans and Zinc-Biofortified Wheat in Pigs

DEFF Research Database (Denmark)

Carlson, Dorthe; Nørgaard, Jan Værum; Torun, B

2012-01-01

The objectives of this experiment were to study bioavailability of trace elements in beans and wheat containing different levels of zinc and to study how the water solubility of trace elements was related to the bioavailability in pigs. Three wheat and two bean types were used: wheat of Danish...... origin as a control (CtrlW), two Turkish wheat types low (LZnW) and high (HZnW) in zinc, a common bean (Com), and a faba bean (Faba). Two diets were composed by combining 81 % CtrlW and 19 % Com or Faba beans. Solubility was measured as the trace element concentration in the supernatant of feedstuffs......, and diets incubated in distilled water at pH 4 and 38°C for 3 h. The bioavailability of zinc and copper of the three wheat types and the two bean-containing diets were evaluated in the pigs by collection of urine and feces for 7 days. The solubility of zinc was 34–63 %, copper 18–42 %, and iron 3...

Zinc deprivation of methanol fed anaerobic granular sludge bioreactors

NARCIS (Netherlands)

Fermoso, F.G.; Collins, G.; Bartacek, J.; Lens, P.N.L.

2008-01-01

The effect of omitting zinc from the influent of mesophilic (30 degrees C) methanol fed upflow anaerobic sludge bed (UASB) reactors, and latter zinc supplementation to the influent to counteract the deprivation, was investigated by coupling the UASB reactor performance to the microbial ecology of

Sulfur dioxide leaching of spent zinc-carbon-battery scrap

Energy Technology Data Exchange (ETDEWEB)

Avraamides, J.; Senanayake, G.; Clegg, R. [A.J. Parker Cooperative Research Centre for Hydrometallurgy, Murdoch University, Perth, WA 6150 (Australia)

2006-09-22

Zinc-carbon batteries, which contain around 20% zinc, 35% manganese oxides and 10% steel, are currently disposed after use as land fill or reprocessed to recover metals or oxides. Crushed material is subjected to magnetic separation followed by hydrometallurgical treatment of the non-magnetic material to recover zinc metal and manganese oxides. The leaching with 2M sulfuric acid in the presence of hydrogen peroxide recovers 93% Zn and 82% Mn at 25{sup o}C. Alkaline leaching with 6M NaOH recovers 80% zinc. The present study shows that over 90% zinc and manganese can be leached in 20-30min at 30{sup o}C using 0.1-1.0M sulfuric acid in the presence of sulfur dioxide. The iron extraction is sensitive to both acid concentration and sulfur dioxide flow rate. The effect of reagent concentration and particle size on the extraction of zinc, manganese and iron are reported. It is shown that the iron and manganese leaching follow a shrinking core kinetic model due to the formation of insoluble metal salts/oxides on the solid surface. This is supported by (i) the decrease in iron and manganese extraction from synthetic Fe(III)-Mn(IV)-Zn(II) oxide mixtures with increase in acid concentration from 1M to 2M, and (ii) the low iron dissolution and re-precipitation of dissolved manganese and zinc during prolonged leaching of battery scrap with low sulfur dioxide. (author)

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).

Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

Energy Technology Data Exchange (ETDEWEB)

Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Wada, Eiji, E-mail: gacchu1@yahoo.co.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Zammit, Peter S., E-mail: peter.zammit@kcl.ac.uk [Randall Division of Cell and Molecular Biophysics, King' s College London, London SE1 1UL (United Kingdom); Shiozuka, Masataka, E-mail: cmuscle@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan); Matsuda, Ryoichi, E-mail: cmatsuda@mail.ecc.u-tokyo.ac.jp [Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo (Japan)

2015-05-01

Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc on differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.

Influence of synthesis procedure on the formation and properties of zinc oxide

International Nuclear Information System (INIS)

Music, S.; Popovic, S.; Maljkovic, M.; Dragcevic, D.

2002-01-01

Formation and properties of zinc oxide were investigated in dependence on the synthesis procedure. Zinc oxide did not crystallize upon hydrothermal treatment of Zn(NO 3 ) 2 aqueous solutions containing urea, up to 160 deg. C. Hydrozincite was formed instead. Changes in the X-ray diffraction patterns and Fourier transform infrared (FT-IR) spectra were interpreted in terms of stacking disorder in hydrozincite crystals. Zinc oxide powder was obtained by thermal treatment in air of precipitated hydrozincite. The conditions for instantaneous synthesis of very fine zinc oxide particles were found. This procedure is based on addition of TMAH (tetramethylammonium hydroxide) solution to an ethanolic solution of zinc acetate dihydrate, up to pH∼14. On the other hand, addition of an equivalent volume of water to the ethanolic solution of zinc acetate dihydrate, prior to the addition of TMAH solution up to pH∼14, yielded ZnO flakes without any specific shape. All zinc oxide particles produced upon heating at 600 deg. C in air showed similar morphology and tendency to aggregation due to the sintering effect. The features of the FT-IR spectra of zinc oxide particles were related to their shapes

Iron, zinc, copper and magnesium nutritional status in Mexican children aged 1 to 11 years Estado nutricio de hierro, zinc, cobre y magnesio en niños mexicanos de 1 a 11 años de edad

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Ma. del Carmen Morales-Ruán

2012-04-01

Full Text Available OBJECTIVE: To describe the micronutrient nutritional status of a national sample of 1-11 year old Mexican children surveyed in 2006 in National Health and Nutrition Survey (ENSANUT 2006 and their association with dietary and sociodemographic factors. MATERIALS AND METHODS: Serum samples were used (n=5 060 to measure the concentrations of ferritin, transferrin receptor, zinc, copper and magnesium. RESULTS: Prevalence of deficiencies in 1-4 and 5-11y old children were for iron (using low ferritin 26.0 and 13.0%; zinc, 28.1 and 25.8%, respectively; and copper, ≈30% in both age groups. Magnesium low serum concentrations (MLSC, were found in 12.0% and 28.4% of the children, respectively. Being beneficiary of Liconsa (OR=0.32; C.I.95%, 0.17-0.61 or belonging to higher socioeconomic status (OR=0.63; C.I.95%, 0.41-0.97 were protective against iron deficiency. Increasing age (OR=0.59; C.I.95%, 1.19-1.32 and living in the Central Region (OR=0.59; C.I.95%, 0.36-0.97 were protective against MLSC. CONCLUSIONS: Deficiencies of iron and zinc are serious public health problems in Mexican children.OBJETIVO: Describir el estado nutricio de micronutrimentos en niños de 1-11 años de edad de la Encuesta Nacional de Salud y Nutrición 2006 y su asociación con factores dietéticos y sociodemográficos. MATERIAL Y MÉTODOS: Se usaron muestras séricas (n=5060 para medir las concentraciones de ferritina, receptor de transferrina, zinc, cobre y magnesio. RESULTADOS: La prevalencias de deficiencias en niños de 1-4 y de 5 a 11 años fueron para ferritina, 26.0 y 13%; zinc, 28.1 y 25.8% respectivamente y cobre ≈30% en ambos grupos. Las concentraciones bajas de magnesio (CBM fueron 12.0 y 28.4%, respectivamente. Ser beneficiario de Liconsa (RM=0.32; IC 95%: 0.17-0.61 y pertenecer al nivel socioeconómico alto (RM=0.63; IC, 95%: 0.41-0.97 fueron protectores para deficiencia de hierro. La edad (RM=1.26; IC, 95%: 1.19-1.32 y vivir en la región Centro (RM=0.59; IC, 95

A novel zinc finger protein Zfp277 mediates transcriptional repression of the Ink4a/arf locus through polycomb repressive complex 1

DEFF Research Database (Denmark)

Negishi, Masamitsu; Saraya, Atsunori; Mochizuki, Shinobu

2010-01-01

. METHODOLOGY/PRINCIPAL FINDINGS: We examined the function of Zinc finger domain-containing protein 277 (Zfp277), a novel zinc finger protein that interacts with the PcG protein Bmi1. Zfp277 binds to the Ink4a/Arf locus in a Bmi1-independent manner and interacts with polycomb repressor complex (PRC) 1 through...... is essential for the recruitment of PRC1 to the Ink4a/Arf locus. Our findings also highlight dynamic regulation of both Zfp277 and PcG proteins by the oxidative stress pathways....

Myocardial ischemic preconditioning upregulated protein 1(Mipu1):zinc finger protein 667 - a multifunctional KRAB/C{sub 2}H{sub 2} zinc finger protein

Energy Technology Data Exchange (ETDEWEB)

Han, D.; Zhang, C. [Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, Post-doctoral Mobile Stations for Basic Medicine, University of South China, Hengyang City, Hunan Province (China); Fan, W.J. [Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, Post-doctoral Mobile Stations for Basic Medicine, University of South China, Hengyang City, Hunan Province (China); The Second Affiliated Hospital, University of South China, Hengyang City, Hunan Province (China); Pan, W.J.; Feng, D.M.; Qu, S.L.; Jiang, Z.S. [Institute of Cardiovascular Disease, Key Lab for Arteriosclerology of Hunan Province, Post-doctoral Mobile Stations for Basic Medicine, University of South China, Hengyang City, Hunan Province (China)

2014-10-31

Myocardial ischemic preconditioning upregulated protein 1 (Mipu1) is a newly discovered upregulated gene produced in rats during the myocardial ischemic preconditioning process. Mipu1 cDNA contains a 1824-base pair open reading frame and encodes a 608 amino acid protein with an N-terminal Krüppel-associated box (KRAB) domain and classical zinc finger C{sub 2}H{sub 2} motifs in the C-terminus. Mipu1 protein is located in the cell nucleus. Recent studies found that Mipu1 has a protective effect on the ischemia-reperfusion injury of heart, brain, and other organs. As a nuclear factor, Mipu1 may perform its protective function through directly transcribing and repressing the expression of proapoptotic genes to repress cell apoptosis. In addition, Mipu1 also plays an important role in regulating the gene expression of downstream inflammatory mediators by inhibiting the activation of activator protein-1 and serum response element.

Electronic Structure of C60/Zinc Phthalocyanine/V2O5 Interfaces Studied Using Photoemission Spectroscopy for Organic Photovoltaic Applications

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Chang Jin Lim

2018-02-01

Full Text Available The interfacial electronic structures of a bilayer of fullerene (C60 and zinc phthalocyanine (ZnPc grown on vanadium pentoxide (V2O5 thin films deposited using radio frequency sputtering under various conditions were studied using X-ray and ultraviolet photoelectron spectroscopy. The energy difference between the highest occupied molecular orbital (HOMO level of the ZnPc layer and the lowest unoccupied molecular orbital (LUMO level of the C60 layer was determined and compared with that grown on an indium tin oxide (ITO substrate. The energy difference of a heterojunction on all V2O5 was found to be 1.3~1.4 eV, while that on ITO was 1.1 eV. This difference could be due to the higher binding energy of the HOMO of ZnPc on V2O5 than that on ITO regardless of work functions of the substrates. We also determined the complete energy level diagrams of C60/ZnPc on V2O5 and ITO.

A multiscale approach to simulating the conformational properties of unbound multi-C₂H₂ zinc finger proteins.

Science.gov (United States)

Liu, Lei; Wade, Rebecca C; Heermann, Dieter W

2015-09-01

The conformational properties of unbound multi-Cys2 His2 (mC2H2) zinc finger proteins, in which zinc finger domains are connected by flexible linkers, are studied by a multiscale approach. Three methods on different length scales are utilized. First, atomic detail molecular dynamics simulations of one zinc finger and its adjacent flexible linker confirmed that the zinc finger is more rigid than the flexible linker. Second, the end-to-end distance distributions of mC2H2 zinc finger proteins are computed using an efficient atomistic pivoting algorithm, which only takes excluded volume interactions into consideration. The end-to-end distance distribution gradually changes its profile, from left-tailed to right-tailed, as the number of zinc fingers increases. This is explained by using a worm-like chain model. For proteins of a few zinc fingers, an effective bending constraint favors an extended conformation. Only for proteins containing more than nine zinc fingers, is a somewhat compacted conformation preferred. Third, a mesoscale model is modified to study both the local and the global conformational properties of multi-C2H2 zinc finger proteins. Simulations of the CCCTC-binding factor (CTCF), an important mC2H2 zinc finger protein for genome spatial organization, are presented. © 2015 Wiley Periodicals, Inc.

From zinc selenate to zinc selenide nano structures synthesized by reduction process

International Nuclear Information System (INIS)

Hutagalung, S.D.; Eng, S.T.; Ahmad, Z.A.; Ishak Mat; Yussof Wahab

2009-01-01

One-dimensional nano structure materials are very attractive because of their electronic and optical properties depending on their size. It is well known that properties of material can be tuned by reducing size to nano scale because at the small sizes, that they behave differently with its bulk materials and the band gap will control by the size. The tunability of the band gap makes nano structured materials useful for many applications. As one of the wide band gaps semiconductor compounds, zinc selenide (ZnSe) nano structures (nanoparticles, nano wires, nano rods) have received much attention for the application in optoelectronic devices, such as blue laser diode, light emitting diodes, solar cells and IR optical windows. In this study, ZnSe nano structures have been synthesized by reduction process of zinc selenate using hydrazine hydrate (N 2 H 4 .2H 2 O). The reductive agent of hydrazine hydrate was added to the starting materials of zinc selenate were heat treated at 500 degree Celsius for 1 hour under argon flow to form one-dimensional nano structures. The SEM and TEM images show the formation of nano composite-like structure, which some small nano bar and nano pellets stick to the rod. The x-ray diffraction and elemental composition analysis confirm the formation of mixture zinc oxide and zinc selenide phases. (author)

New template for metal decoration and hydrogen adsorption on graphene-like C3N4

International Nuclear Information System (INIS)

Zhang Yi; Sun Hong; Chen Changfeng

2009-01-01

From density functional theory calculations we identify a graphene-like C 3 N 4 (g-C 3 N 4 ) as an excellent template for stable and well dispersed decoration of alkali (Li) and 3d transition metal (TM) atoms. The porous sites of g-C 3 N 4 accommodate excessive N lone-pair electrons and promote hybridization between the orbitals of N and the metal atoms. The most stable TM decorations (Ti and Sc) on g-C 3 N 4 exhibit high capacities of hydrogen adsorption with binding energies suitable for mobile applications. These metal decorated g-C 3 N 4 may also prove useful in catalytic and sensing applications for their unique nanoscale structural features unavailable in conventional nano-clusters.

A novel thiolated human-like collage zinc complex as a promising zinc supplement: physicochemical characteristics and biocompatibility.

Science.gov (United States)

Zhu, Chenhui; Ma, Xiaoxuan; Wang, Yonghui; Mi, Yu; Fan, Daidi; Deng, Jianjun; Xue, Wenjiao

2014-11-01

To improve zinc binding ability to human-like collagen (HLC) and stability of metal complex, HLC was thiolated by mercaptosuccinylation reaction with S-acetylmercaptosuccinic anhydride (S-AMSA) at pH8.0. One mole of thiolated HLC-Zn (SHLC-Zn) complex possessed 24.3mol zinc ions when pH was 8.0 and zinc concentration was 15 mM. The physicochemical properties and biocompatibility of thiolated HLC-Zn (SHLC-Zn) complex were investigated by UV-vis, CD, electrophoresis analysis, differential scanning calorimetry (DSC) and cell viability assay, respectively. The results showed that SHLC-Zn complex(1) exhibited higher zinc ions than that of native HLC and still maintained the secondary structure of HLC though interaction occurred between SHLC and zinc ions, (2) increased the apparent molecular weight when compared with native HLC, (3) exhibited greater thermal stability than native HLC, and (4) presented toxicity free for BHK cells. This study suggests that the SHLC-Zn complex is a potential nutrition as well as zinc supplement in the medical application. Copyright © 2014 Elsevier B.V. All rights reserved.

X-ray absorption near edge structure study on Acutolysin-C, a zinc-metalloproteinase from Agkistrodon acutus venom: Insight into the acid-inactive mechanism

International Nuclear Information System (INIS)

Zhao Wei; Chu Wangsheng; Li Shujun; Liu Yiwei; Gao Bin; Niu Liwen; Teng Maikun; Benfatto, Maurizio; Hu Tiandou; Wu Ziyu

2007-01-01

Acutolysin-C, a snake-venom zinc metalloproteinase, displays a distinct pH-dependent proteolytic activity, which has been tentatively assigned to a structural change of the zinc-containing catalytic center. In this work we compare X-ray absorption near-edge structure (XANES) experimental spectra at the Zn K-edge and theoretical calculations of solutions at different pH values. The experimental data show clear differences confirmed by a best fit using the MXAN procedure. The results show that, when pH decreases from pH 8.0 to pH 3.0, the zinc-coordinating catalytic water molecule moves far from the Glu143 residue that is considered to play an essential role in the proteolytic process. Data suggests that this is the possible mechanism that deactivates the metalloproteinase

INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl) ACID ...

African Journals Online (AJOL)

2015-05-01

May 1, 2015 ... corrosion inhibitor for zinc in phosphoric acid. Vashi et al.[8-9] studied the corrosion inhibition of zinc in (HNO3 + H2SO4) and (HNO3 + H3PO4) binary acid mixture by aniline. In the present work, the role of aniline as inhibitor for corrosion of zinc in (HNO3 + HCl) binary acid mixture has been reported. 2.

Removal of zinc from aqueous solutions by natural bentonite

International Nuclear Information System (INIS)

Mellah, A.; Chegrouche, S.

1994-01-01

The equilibrium isotherms of zinc adsorption onto natural bentonite show that the data correlate well with freundlich and Langmuir's models and that the adsorption is physical in nature. The operating parameters (agitation speed, solid/liquid ratio temperature, particle size and initial zinc concentration) influenced the rate of adsorption. The maximum monomolecular capacity (Q 0 ) according to the Langmuir model is 52.91 mg. g-1 for an initial zinc concentration of 300 mg. litre-1, At 20 0 C

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...

Renal AA amyloidosis in a patient with hereditary complete complement C4 deficiency

Directory of Open Access Journals (Sweden)

Imed Helal

2011-01-01

Full Text Available Hereditary complete C4 deficiency has until now been reported in 30 cases only. A disturbed clearance of immune- complexes probably predisposes these individuals to systemic lupus erythematosus, other immune- complex diseases and recurrent microbial infections. We present here a 20- year- old female with hereditary complete C4 deficiency. Renal biopsy demonstrated renal AA amyloidosis. This unique case further substantiates that deficiency of classical pathway components predisposes to the development of recurrent microbial infections and that the patients may develop AA amyloidosis. Furthermore, in clinical practice, the nephrotic syndrome occurring in a patient with hereditary complete complement C4 deficiency should lead to the suspicion of renal AA amyloidosis.

Enhancement of hippocampal mossy fiber activity in zinc deficiency and its influence on behavior.

Science.gov (United States)

Takeda, Atsushi; Itoh, Hiromasa; Yamada, Kohei; Tamano, Haruna; Oku, Naoto

2008-10-01

The extracellular concentration of glutamate in the hippocampus is increased by hippocampal perfusion with CaEDTA, a membrane-impermeable zinc chelator, suggesting that the activity of glutamatergic neurons in the hippocampus are influenced by the extracellular concentrations of zinc. In the present study, the relationship between the extracellular concentrations of zinc and mossy fiber activity in the hippocampus was examined in mice and rats fed a zinc-deficient diet for 4 weeks. Timm's stain, by which histochemically reactive zinc in the presynaptic vesicles is detected, was attenuated in the hippocampus in zinc deficiency. The extracellular signal of ZnAF-2, a membrane-impermeable zinc indicator, was also lower in the hippocampal CA3, suggesting that the basal extracellular concentrations of zinc are lower maintained in zinc deficiency. To check mossy fiber activity after 4-week zinc deprivation, the decrease in the signal of FM4-64, an indicator of presynaptic activity (exocytosis), at mossy fiber synapses was measured under the condition of spontaneous depolarization. The decrease was significantly facilitated by zinc deficiency, suggesting that the basal exocytosis at mossy fiber synapses is enhanced by zinc deficiency. On the other hand, the increase in anxiety-like behavior was observed in the open-field test after 4-week zinc deprivation. The present study demonstrates that the decrease in the basal extracellular concentrations of zinc may be linked to the enhancement of the basal mossy fiber activity in zinc deficiency. This decrease seems to be also involved in neuropsychological behavior in zinc deficiency.

Incorporation of zinc for fabrication of low-cost spinel-based composite ceramic membrane support to achieve its stabilization.

Science.gov (United States)

Li, Lingling; Dong, Xinfa; Dong, Yingchao; Zhu, Li; You, Sheng-Jie; Wang, Ya-Fen

2015-04-28

In order to reduce environment risk of zinc, a spinel-based porous membrane support was prepared by the high-temperature reaction of zinc and bauxite mineral. The phase evolution process, shrinkage, porosity, mechanical property, pore size distribution, gas permeation flux and microstructure were systematically studied. The XRD results, based on a Zn/Al stoichiometric composition of 1/2, show a formation of ZnAl2O4 structure starting from 1000°C and then accomplished at 1300°C. For spinel-based composite membrane, shrinkage and porosity are mainly influenced by a combination of an expansion induced by ZnAl2O4 formation and a general densification due to amorphous liquid SiO2. The highest porosity, as high as 44%, is observed in ZnAl4 membrane support among all the investigated compositions. Compared with pure bauxite (Al), ZnAl4 composite membrane support is reinforced by ZnAl2O4 phase and inter-locked mullite crystals, which is proved by the empirical strength-porosity relationships. Also, an increase in average pore diameter and gas flux can be observed in ZnAl4. A prolonged leaching experiment reveals the zinc can be successfully incorporated into ceramic membrane support via formation of ZnAl2O4, which has substantially better resistance toward acidic attack. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

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

Properties of ice-cream fortified with zinc and Lactobacillus casei.

Science.gov (United States)

Gheisari, Hamid R; Ahadi, Leila; Khezli, Sanaz; Dehnavi, Tayebeh

2016-01-01

In this study, the possible effects of zinc on physicochemical properties of ice cream and the survival of Lactobacillus casei during a 90 days storage at -18°C was investigated. Samples were divided into four experimental groups as follows: control, zinc fortified ice cream, probiotic ice cream, zinc fortified and probiotic ice cream. The physicochemical, texture, organoleptic properties and the survival of probiotics, were investigated. Results showed that the addition of zinc did not affect the textural properties of ice creams. Viscosity and pH were independently decreased in all groups in the presence of zinc. A significant increase in the lipid oxidation rate especially in the zinc fortified group was also observed. The probiotic counts were maintained above the least advised quantities (106 cfu/g) which were subsequently reduced following the three months of storage. In the zinc fortified samples, the counts were higher compared to the other groups with no zinc addition. The addition of probiotics and zinc had no significant effect on the sensory properties of ice cream. As a final conclusion, the commercial production of zinc fortified ice cream is recommended.

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF4/Ar plasma

International Nuclear Information System (INIS)

Joo, Young-Hee; Kim, Chang-Il

2015-01-01

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF 4 /Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF 4 /Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF 4 /Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF 4 /Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar + sputtering and then reacted with the C-F x radicals. • The physical sputtering is dominant in etch control compared with chemical etching

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.

The first C4-functionalisation of condensed tannins. Phlobatannins as prototype of a new class of C-ring isomerised oligomers

International Nuclear Information System (INIS)

Steenkamp, J.A.

1986-06-01

This thesis comprises besides the characterisation of new oligomeric flavenoids from the core wood of the indigeneous Colophosphermum mopane, an investigation into the C 4 -functionalisation of flavan-3-ol analogues. The first peltogynoid biflavenoid and prototypes of a new series C-ring isomerised condensed tannins, namely the phlobatannins, were isolated. Besides 1 H- nmr-parameters for structure analysis, the natural phlobatannins were characterised and the unique ring isomerisation was investigated

Byproduct-free mass production of compound semiconductor nanowires: zinc phosphide

Science.gov (United States)

Chen, Yixi; Polinnaya, Rakesh; Vaddiraju, Sreeram

2018-05-01

A method for the mass production of compound semiconductor nanowires that involves the direct reaction of component elements in a chemical vapor deposition chamber (CVD) is presented. This method results in nanowires, without the associated production of any other byproducts such as nanoparticles or three-dimensional (3D) bulk crystals. Furthermore, no unreacted reactants remain mixed with the nanowire product in this method. This byproduct-free nanowire production thus circumvents the need to tediously purify and collect nanowires from a mixture of products/reactants after their synthesis. Demonstration made using zinc phosphide (Zn3P2) material system as an example indicated that the direct reaction of zinc microparticles with phosphorus supplied via the vapor phase results in the production of gram quantities of nanowires. To enhance thermal transport and achieve the complete reaction of zinc microparticles, while simultaneously ensuring that the microparticles do not agglomerate into macroscale zinc particles and partly remain unreacted (owing to diffusion limitations), pellets composed of mixtures of zinc and a sacrificial salt, NH4Cl, were employed as the starting material. The sublimation by decomposition of NH4Cl in the early stages of the reaction leaves a highly porous pellet of zinc composed of only zinc microparticles, which allows for inward diffusion of phosphorus/outward diffusion of zinc and the complete conversion of zinc into Zn3P2 nanowires. NH4Cl also aids in removal of any native oxide layer present on the zinc microparticles that may prevent their reaction with phosphorus. This method may be used to mass produce many other nanowires in a byproduct-free manner, besides Zn3P2.

A review on g-C3N4-based photocatalysts

International Nuclear Information System (INIS)

Wen, Jiuqing; Xie, Jun; Chen, Xiaobo; Li, Xin

2017-01-01

Graphical abstract: The photocatalytic fundamentals, versatile properties, design strategies and potential applications of g-C 3 N 4 -based photocatalysts were systematically summarized and addressed. - Highlights: • The photocatalytic fundamentals of g-C 3 N 4 were systematically summarized. • The versatile properties of g-C 3 N 4 photocatalysts were highlighted. • The different design strategies of g-C 3 N 4 photocatalysts were reviewed. • The important photocatalytic applications of g-C 3 N 4 were also addressed. - Abstract: As one of the most appealing and attractive technologies, heterogeneous photocatalysis has been utilized to directly harvest, convert and store renewable solar energy for producing sustainable and green solar fuels and a broad range of environmental applications. Due to their unique physicochemical, optical and electrical properties, a wide variety of g-C 3 N 4 -based photocatalysts have been designed to drive various reduction and oxidation reactions under light irradiation with suitable wavelengths. In this review, we have systematically summarized the photocatalytic fundamentals of g-C 3 N 4 -based photocatalysts, including fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C 3 N 4 -based photocatalysts. The versatile properties of g-C 3 N 4 -based photocatalysts are highlighted, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties. Various design strategies are also thoroughly reviewed, including band-gap engineering, defect control, dimensionality tuning, pore texture tailoring, surface sensitization, heterojunction construction, co-catalyst and nanocarbon loading. Many important applications are also addressed, such as photocatalytic water splitting (H 2 evolution and overall water splitting), degradation of pollutants, carbon dioxide reduction, selective organic

Effects of peroral supplementation of different forms of zinc on the ruminal mucosa of goat kids – a morphometric study

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Julius Černík

2013-01-01

Full Text Available The aim of the study was to identify the effect of supplementation of various forms of zinc on the ruminal mucosa and dimensions of ruminal papillae in 6-month-old goat kids. The experimental period lasted from weaning to slaughter (4 months. All 20 kids divided into four groups of five animals, were fed with the same feeding dose, which was different only in the quantity and form of zinc. Control group was without additional zinc supplementation (group A, the other groups were supplemented with zinc in the form of ZnO (group B, zinc in the form of chelate (group C and zinc in the form of lactate (group D. Samples for histopathological and morphometric examination were collected after the slaughter of all animals from the bottom of saccus ruminis ventralis everytime from the same place. Significant differences were reported within the comparison of the length of ruminal papillae between groups B and C (P = 0.026 and B and D (P = 0.040, within the comparison of the width of ruminal papillae between groups A and D (P = 0.020 and within the comparison of the intensity of keratinisation of the mucosa of ruminal papillae between groups A and B (P = 0.034, A and C (P = 0.038 and A and D (P = 0.001. Histopathological and morphometric examination of ruminal mucosa indicated that the ruminal papillae of kids supplemented with zinc in the form of ZnO (group B were better developed compared to the other groups. This result indicates better utilisation of the supplemented zinc in the form of ZnO.

De novo Transcriptome Assembly and Comparison of C3, C3-C4, and C4 Species of Tribe Salsoleae (Chenopodiaceae

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Maximilian Lauterbach

2017-11-01

Full Text Available C4 photosynthesis is a carbon-concentrating mechanism that evolved independently more than 60 times in a wide range of angiosperm lineages. Among other alterations, the evolution of C4 from ancestral C3 photosynthesis requires changes in the expression of a vast number of genes. Differential gene expression analyses between closely related C3 and C4 species have significantly increased our understanding of C4 functioning and evolution. In Chenopodiaceae, a family that is rich in C4 origins and photosynthetic types, the anatomy, physiology and phylogeny of C4, C2, and C3 species of Salsoleae has been studied in great detail, which facilitated the choice of six samples of five representative species with different photosynthetic types for transcriptome comparisons. mRNA from assimilating organs of each species was sequenced in triplicates, and sequence reads were de novo assembled. These novel genetic resources were then analyzed to provide a better understanding of differential gene expression between C3, C2 and C4 species. All three analyzed C4 species belong to the NADP-ME type as most genes encoding core enzymes of this C4 cycle are highly expressed. The abundance of photorespiratory transcripts is decreased compared to the C3 and C2 species. Like in other C4 lineages of Caryophyllales, our results suggest that PEPC1 is the C4-specific isoform in Salsoleae. Two recently identified transporters from the PHT4 protein family may not only be related to the C4 syndrome, but also active in C2 photosynthesis in Salsoleae. In the two populations of the C2 species S. divaricata transcript abundance of several C4 genes are slightly increased, however, a C4 cycle is not detectable in the carbon isotope values. Most of the core enzymes of photorespiration are highly increased in the C2 species compared to both C3 and C4 species, confirming a successful establishment of the C2 photosynthetic pathway. Furthermore, a function of PEP-CK in C2 photosynthesis

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

contents were measured at beginning of flowering stage. Photosynthetic parameters were measured by Infra-red gas analyzer (LCA4, ADC Co. Ltd., Hoddesdon, UK. Instantaneous water use efficiency (WUEinst was calculated as Pn/E ratio. Light use efficiency was calculated as Pn/PPFD ratio. Result and discussion: The results showed that the effect of foliar application of zinc fertilizers on all measured traits except Ci and WUE was significant (p≥0.01. The highest values of zinc content (110.53 mg.kg-1, chlorophyll a (0.99 mg.kg-1 fresh weight, chlorophyll b (0.30 mg.kg-1 fresh weight, chlorophyll a+b (1.29 mg.kg-1 fresh weight and carotenoid (0.18 mg.kg-1 fresh weight traits were obtained in plants sprayed with 1.5 g.l-1 nano zinc chelate. The lowest amount of zinc content (21.37 mg.kg-1, chlorophyll a (0.58 mg.kg-1 fresh weight, chlorophyll b (0.14 mg.kg-1 fresh weight, chlorophyll a+b (0.72 mg.kg-1 fresh weight and carotenoid (0.13 mg.kg-1 fresh weight traits were obtained in control plants. Foliar application of holy basil with 1.5 g.l-1 nano zinc chelate led to increase in stomata conductance (322.22 mm H2O.m-2.s-1, transpiration rate (2.86 mm H2O.m-2.s-1, net photosynthesis (11.75 μm CO2.m-2.s-1 and light use efficiency (6.10 μm CO2. μm photon-1. The minimum amount of stomata conductance (172.00 mm H2O.m-2.s-1, transpiration rate (2.16 mm H2O.m-2.s-1, net photosynthesis (8.23 μm CO2.m-2.s-1 and light use efficiency (4.46 μm CO2. μm photon-1 were observed in control plants. There were positive correlation (p≥0.01 between zinc content and chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoid. Zinc content also had positive and significant correlation (p≥0.01 with stomata conductance, CO2 under stomata, transpiration rate, net photosynthesis and light use efficiency. So, providing zinc by foliar application with 1 and 1.5 g.l-1 nano zinc chelate and 1.5 g.l-1 zinc sulfate can lead to increase in chlorophyll and carotenoid contents. Increase in net

Effect of synthesized zinc stearate on the properties of natural rubber vulcanizates in the absence and presence of some fillers

International Nuclear Information System (INIS)

Helaly, F.M.; El Sabbagh, S.H.; El Kinawy, O.S.; El Sawy, S.M.

2011-01-01

Research highlights: → The mechanical properties of NR were enhanced through partial and complete replacement of zinc stearate. → The effect of adding different concentrations of zinc stearate on the physic-mechanical and SEM properties has been investigated. → Zinc stearate was found to play dual role, it reinforces the matrix blow its melting point and higher temperature it plasticizers the system. → Zinc stearate can be used as activator for sulfur vulcanization process of rubber instead of ZnO and stearic acid; in absence and presence of fillers. -- Abstract: Zinc stearate was synthesized by precipitation method through two steps; neutralization of stearic acid by sodium hydroxide then double decomposition using zinc sulphate to precipitate zinc stearate. Mass balances of the two steps were calculated and the physical properties of the prepared zinc stearate were measured and compared to standard. It was characterized and incorporated it into natural rubber in the absence and presence of some filler through mixing process of rubber. The vulcanization process was carried out at 142 o C. The rheological properties of natural rubber mixes were measured using oscillating disc rheometer. The plysico-mechanical properties of the vulcanizates were determined using tensile testing machine. It was found that, partial and complete replacement of synthesized zinc stearate instead of the conventional zinc oxide and stearic acid; enhanced the physico-mechanical properties of natural rubber. The measured reinforcing parameter value α f can be arranged according to the type of filler as follows: HAF>Hisil>CaCO 3 >Ca 3 (PO 4 ) 2 >BaSO 4 >Talc The highest value of α f represents the strength of filler and consequently the reinforcing effect of carbon black (HAF) filler while the lowest value of α f was observed for Talc which show moderate reinforcing effect of Talc. The scanning electron microscope study showed high surface homogenity and good dispersion of zinc

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.)

on the magnetic properties of ultra-fine zinc ferrites

NARCIS (Netherlands)

Anantharaman, M.R.; Jagatheesan, S.; Malini, K.A.; Sindhu, S.; Narayanasamy, A.; Chinnasamy, C.N.; Jacobs, J.P.; Reijne, S.; Seshan, Kulathuiyer; Smits, R.H.H.; Smits, R.H.H.; Brongersma, H.H.

1998-01-01

Zinc ferrite belongs to the class of normal spinels where it is assumed to have a cation distribution of Zn2+(Fe3+)2(O2−)4, and it is purported to be showing zero net magnetisation. However, there have been recent reports suggesting that zinc ferrite exhibits anomaly in its magnetisation. Zinc

Zinc mediated activation of terminal alkynes: stereoselective synthesis of alkynyl glycosides.

Science.gov (United States)

Tatina, Madhu Babu; Kusunuru, Anil Kumar; Yousuf, Syed Khalid; Mukherjee, Debaraj

2014-10-28

Zinc mediated alkynylation reaction was studied for the preparation of C-glycosides from unactivated alkynes. Different glycosyl donors such as glycals and anomeric acetates were tested towards an alkynyl zinc reagent obtained from alkynes using zinc dust and ethyl bromoacetate as an additive. The method provides simple, mild and stereoselective access to alkynyl glycosides both from aromatic and aliphatic acetylenes.

Ameliorative effects of selenium and zinc

African Journals Online (AJOL)

Methidathion-induced hematological, biochemical and hepatohistological alterations in rat: Ameliorative effects of selenium and zinc. L Barkat, A Boumendjel, C Abdennour, MS Boulakoud, A El Feki, M Messarah ...

Absorbed zinc and exchangeable zinc pool size are significantly greater in Pakistani infants receiving traditional complementary foods with zinc fortified micronutrient powder

International Nuclear Information System (INIS)

Ariff, Shabina; Soofi, Sajid; Bhutta, Zulfiqar; Krebs, Nancy; Westcott, Jamie

2014-01-01

Full text: Adequacy of zinc intake from breast milk alone becomes marginal in relation to infant requirements by around six months of age. Simple and cost effective strategies are needed at population level to ensure adequate intakes of zinc in infants and toddlers in populations at risk of zinc deficiency. We determined the amount of absorbed zinc (AZ) from a micronutrient powder (MNP) without and with 10 mg of zinc (MNP, MNP+Zn, respectively) added to local complementary foods used in Pakistan, and the impact on the exchangeable zinc pool (EZP) size. As a nested study within a large prospective cluster randomized trial, 6 month old infants were randomized to receive MNP or MNP+Zn. Stable isotope methodology was applied after ~ 3 and 9 months of use to measure AZ from MNP-fortified test meals of rice-lentils (khitchri) and EZP. Nineteen infants per group completed the first metabolic studies; 14 and 17 infants in MNP and MNP+Zn groups, completed the follow-up studies. Mean (±SD) AZs were 0.1± 0.1 and 1.2±0.5 mg at the first point for the MNP and MNP+Zn groups, respectively (p <0.001); results were nearly identical at the follow-up measurement. EZP did not differ between groups at the first measurement but was less in the MNP group (3.7±0.6 mg/kg) than in the MNP+Zn group (4.5±1.0 mg/kg) at the second measurement (P = 0.01). These data confirm that the MNP+Zn in khitchri were well absorbed, and after a year of home fortification, zinc status assessed by EZP was significantly better for the MNP+Zn group. Additional field studies may be necessary to ascertain the adequacy of this dose for infants at high risk of deficiency. (author)

Synthesis and characterization of tricalcium phosphate ceramics doped with zinc

International Nuclear Information System (INIS)

Kai, K.C.; Marchi, J.; Ussui, V.; Bressiani, A.H.A.

2011-01-01

Due to its biocompatibility, the tricalcium phosphate (TCP) is used as a biomaterial for bone replacement and reconstruction. Zinc (Zn) can replace calcium in the crystal structure of TCP to be added in small quantities, can result in stimulatory effects on bone formation in vitro and in vivo. In this work, pure TCP and Zn-TCP, with general formula (Ca_1_-_xZn_x)_3 (PO_4)_2 and 0 ≤ x ≤ 0.0225, were prepared by wet synthesis, from precursors Ca(OH)_2, H_3PO_4 and ZnO, after calcinated at 800 deg C and characterized by X-ray diffraction, specific surface area, agglomerate size distribution, differential thermal analysis and scanning electron microscopy. The results showed that the addition of small amounts of Zn resulted in TCP with suitable densification and higher specific surface area, may be promising as biomaterial due to the stimulatory effects of zinc associated with suitable mechanical properties of the final material. (author)

Zinc transporter ZIP14 functions in hepatic zinc, iron and glucose homeostasis during the innate immune response (endotoxemia.

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Tolunay Beker Aydemir

Full Text Available ZIP14 (slc39A14 is a zinc transporter induced in response to pro-inflammatory stimuli. ZIP14 induction accompanies the reduction in serum zinc (hypozincemia of acute inflammation. ZIP14 can transport Zn(2+ and non-transferrin-bound Fe(2+ in vitro. Using a Zip14(-/- mouse model we demonstrated that ZIP14 was essential for control of phosphatase PTP1B activity and phosphorylation of c-Met during liver regeneration. In the current studies, a global screening of ZIP transporter gene expression in response to LPS-induced endotoxemia was conducted. Following LPS, Zip14 was the most highly up-regulated Zip transcript in liver, but also in white adipose tissue and muscle. Using ZIP14(-/- mice we show that ZIP14 contributes to zinc absorption from the gastrointestinal tract directly or indirectly as zinc absorption was decreased in the KOs. In contrast, Zip14(-/- mice absorbed more iron. The Zip14 KO mice did not exhibit hypozincemia following LPS, but do have hypoferremia. Livers of Zip14-/- mice had increased transcript abundance for hepcidin, divalent metal transporter-1, ferritin and transferrin receptor-1 and greater accumulation of iron. The Zip14(-/- phenotype included greater body fat, hypoglycemia and higher insulin levels, as well as increased liver glucose and greater phosphorylation of the insulin receptor and increased GLUT2, SREBP-1c and FASN expression. The Zip14 KO mice exhibited decreased circulating IL-6 with increased hepatic SOCS-3 following LPS, suggesting SOCS-3 inhibited insulin signaling which produced the hypoglycemia in this genotype. The results are consistent with ZIP14 ablation yielding abnormal labile zinc pools which lead to increased SOCS-3 production through G-coupled receptor activation and increased cAMP production as well as signaled by increased pSTAT3 via the IL-6 receptor, which inhibits IRS 1/2 phosphorylation. Our data show the role of ZIP14 in the hepatocyte is multi-functional since zinc and iron trafficking are

Zinc dosing and glucose tolerance in humans

International Nuclear Information System (INIS)

Greenley, S.; Taylor, M.

1986-01-01

Animal data suggest the existence of a physiologic relationship between glucoregulatory hormones and zinc metabolism. In order to investigate this proposed relationship in humans, they examined the effect of moderately elevated plasma zinc levels on blood glucose clearance. Eight women (24-37 yrs) served as subjects for the study. Fasted volunteers were tested under two experimental conditions (a) ingestion of 50 g D-glucose (b) ingestion of 25 mg zinc followed 60 min later by ingestion of 50 g D-glucose. Five ml venous blood was drawn into trace-metal-free, fluoride-containing vacutainer tubes prior to and 15, 30, 45, 60, 90, and 120 min after glucose ingestion. Plasma was analyzed for glucose and zinc; glycemic responses were quantified by computing areas under the curves and times to peak concentration. Their human data indicate varied glycemic responses to the acute elevation of plasma zinc: 4 subjects showed little apparent effect; 3 subjects marginally increased either the area under the curve or time to peak and 1 subject (classified as suspect diabetic in the non-zinc condition) showed marked improvement in glycemic response following zinc ingestion. Their preliminary results suggest that blood glucose clearance may be affected in some individuals by the acute elevation of plasma zinc

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

Evaluation of the serum zinc level in adult patients with melasma: Is there a relationship with serum zinc deficiency and melasma?

Science.gov (United States)

Rostami Mogaddam, Majid; Safavi Ardabili, Nastaran; Iranparvar Alamdari, Manouchehr; Maleki, Nasrollah; Aghabalaei Danesh, Maryam

2017-11-12

Melasma is a common acquired hypermelanosis of sun-exposed skin, particularly on the face, which presents as symmetric, light- to gray-brown-colored macules and patches. There are several studies of serum zinc levels in cutaneous disorders. So far, no studies have been carried out to assess the serum zinc level in patients with melasma. The aim of this study is to determine the serum zinc level in patients with melasma compared to healthy subjects. A total of 118 patients with melasma and 118 healthy controls were enrolled in this prospective cross-sectional study. The two groups were matched for age and sex. Atomic absorption spectrophotometry was used to measure serum zinc levels. The statistical analysis was performed using SPSS software. The mean serum level of zinc in melasma patients and controls was 77.4±23.2 μg/dL and 82.2±23.9 μg/dL, respectively (P-value=.0001). Serum zinc deficiency was found in 45.8% and 23.7% of melasma patients and control subjects, respectively. A positive family history of melasma in first-degree relatives was present in 46 (39%) of the cases, and a history of taking oral contraceptive pill was found in 95 (81%) of women with melasma. The aggravating factors for melasma were stated as: sun exposure (11.1%), pregnancy (15.3%), nutrition (2.5%), oral contraceptive pills (18.6%), and emotional stress (5.9%). The malar and centrofacial patterns were seen in 3.4% and 72% of cases, respectively, whereas 24.6% of the patients had both centrofacial distribution and malar distribution, and there was no patient with mandibular pattern. Among patients with melasma, 20.3% had thyroid dysfunction, while in the control subjects, 8.4% had thyroid dysfunction (P=.001). There is a significant relationship between low levels of zinc and melasma. Zinc deficiency may be involved in the pathogenesis of melasma. Also, treatment with oral zinc supplements can be tried in these patients to see the outcome. However, to make recommendations on

Zinc deficiency is common in several psychiatric disorders.

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Ole Grønli

Full Text Available BACKGROUND: Mounting evidence suggests a link between low zinc levels and depression. There is, however, little knowledge about zinc levels in older persons with other psychiatric diagnoses. Therefore, we explore the zinc status of elderly patients suffering from a wide range of psychiatric disorders. METHODS: Clinical data and blood samples for zinc analyzes were collected from 100 psychogeriatric patients over 64 of age. Psychiatric and cognitive symptoms were assessed using the Montgomery and Aasberg Depression Rating Scale, the Cornell Scale for Depression in Dementia, the Mini-Mental State Examination, the Clockdrawing Test, clinical interviews and a review of medical records. In addition, a diagnostic interview was conducted using the Mini International Neuropsychiatric Interview instrument. The prevalence of zinc deficiency in patients with depression was compared with the prevalence in patients without depression, and the prevalence in a control group of 882 older persons sampled from a population study. RESULTS: There was a significant difference in zinc deficiency prevalence between the control group (14.4% and the patient group (41.0% (χ(2 = 44.81, df = 1, p<0.001. In a logistic model with relevant predictors, zinc deficiency was positively associated with gender and with serum albumin level. The prevalence of zinc deficiency in the patient group was significantly higher in patients without depression (i.e. with other diagnoses than in patients with depression as a main diagnosis or comorbid depression (χ(2 = 4.36, df = 1, p = 0.037. CONCLUSIONS: Zinc deficiency is quite common among psychogeriatric patients and appears to be even more prominent in patients suffering from other psychiatric disorders than depression. LIMITATIONS: This study does not provide a clear answer as to whether the observed differences represent a causal relationship between zinc deficiency and psychiatric symptoms. The blood sample collection time points

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

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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.

A bipyridine-ligated zinc(II) complex with bridging flavonolate ligation: synthesis, characterization, and visible-light-induced CO release reactivity.

Science.gov (United States)

Sorenson, Shayne; Popova, Marina; Arif, Atta M; Berreau, Lisa M

2017-09-01

Metal-flavonolate compounds are of significant current interest as synthetic models for quercetinase enzymes and as bioactive compounds of importance to human health. Zinc-3-hydroxyflavonolate compounds, including those of quercetin, kampferol, and morin, generally exhibit bidentate coordination to a single Zn II center. The bipyridine-ligated zinc-flavonolate compound reported herein, namely bis(μ-4-oxo-2-phenyl-4H-chromen-3-olato)-κ 3 O 3 :O 3 ,O 4 ;κ 3 O 3 ,O 4 :O 3 -bis[(2,2'-bipyridine-κ 2 N,N')zinc(II)] bis(perchlorate), {[Zn 2 (C 15 H 9 O 3 ) 2 (C 10 H 8 N 2 ) 2 ](ClO 4 ) 2 } n , (1), provides an unusual example of bridging 3-hydroxyflavonolate ligation in a dinuclear metal complex. The symmetry-related Zn II centers of (1) exhibit a distorted octahedral geometry, with weak coordination of a perchlorate anion trans to the bridging deprotonated O atom of the flavonolate ligand. Variable-concentration conductivity measurements provide evidence that, when (1) is dissolved in CH 3 CN, the complex dissociates into monomers. 1 H NMR resonances for (1) dissolved in d 6 -DMSO were assigned via HMQC to the H atoms of the flavonolate and bipyridine ligands. In CH 3 CN, (1) undergoes quantitative visible-light-induced CO release with a quantum yield [0.004 (1)] similar to that exhibited by other mononuclear zinc-3-hydroxyflavonolate complexes. Mass spectroscopic identification of the [(bpy) 2 Zn(O-benzoylsalicylate)] + ion provides evidence of CO release from the flavonol and of ligand exchange at the Zn II center.

A unique $Z_4^R$ symmetry for the MSSM

CERN Document Server

Lee, Hyun Min; Ratz, Michael; Ross, Graham G; Schieren, Roland; Schmidt-Hoberg, Kai; Vaudrevange, Patrick K S

2011-01-01

We consider the possible anomaly free Abelian discrete symmetries of the MSSM that forbid the mu-term at perturbative order. Allowing for anomaly cancellation via the Green-Schwarz mechanism we identify discrete R-symmetries as the only possibility and prove that there is a unique Z_4^R symmetry that commutes with SO(10). We argue that non-perturbative effects will generate a mu-term of electroweak order thus solving the mu-problem. The non-perturbative effects break the Z_4^R symmetry leaving an exact Z_2 matter parity. As a result dimension four baryon- and lepton-number violating operators are absent while, at the non-perturbative level, dimension five baryon- and lepton-number violating operators get induced but are highly suppressed so that the nucleon decay rate is well within present bounds.

4th June: AIS and NICE/MAIL unique authentication

CERN Multimedia

AIS and NICE teams

2007-01-01

Over the past few years, the IT department has been in the process of streamlining CERN users' access to all central computing services. The long term goal is to converge on a unique computer account, which will increase computer security and simplify account maintenance. The next step of this process will occur on 4th June 2007, as of when authenticating on the AIS applications (EDH, HRT, CET, APT, ERT, CRA, Foundation, ...) and on NICE (Windows) and MAIL will be done using the same username and password. As a reminder, this account can also be used on EDMS, INDICO, CDS and SIMBA. So starting on 4th June 2007, authentication on the AIS applications must be done using your AIS username and your MAIL/NICE password. Thanks for your understanding, The AIS and NICE teams

Diffusion zinc plating of structural steels

International Nuclear Information System (INIS)

Kazakovskaya, Tatiana; Goncharov, Ivan; Tukmakov, Victor; Shapovalov, Vyacheslav

2004-01-01

The report deals with the research on diffusion zinc plating of structural steels when replacing their cyanide cadmium plating. The results of the experiments in the open air, in vacuum, in the inert atmosphere, under various temperatures (300 - 500 deg.C) for different steel brands are presented. It is shown that diffusion zinc plating in argon or nitrogen atmosphere ensures obtaining the qualitative anticorrosion coating with insignificant change of mechanical properties of steels. The process is simple, reliable, ecology pure and cost-effective. (authors)

Zinc and antioxidant vitamin deficiency in patients with severe sickle cell anemia

International Nuclear Information System (INIS)

Hasanato, R.M. W.

2006-01-01

Patients with severe sickle cell anemia (SCA) have a higher potential for oxidative damage due to chronic redox imbalance in red blood cells that often leads to hemolysis, endothelial injury and recurrent vaso-occlusive episodes. This study evaluated the plasma levels of Vitamin A, C and E as indicators of antioxidants status. In addition, serum levels of zinc and copper were also estimated. Twenty-five adult patients with severe sickle cell anemia (12 males and 13 females aged 29.72+-12.94 years) and 25 matched controls were studied. Plasma levels of vitamin A, C and E were measured by HPLC technique. Serum zinc and copper levels were measured by atomic absorption spectrometry. There was significant decrease in plasma levels of vitamins A, C and E and in serum levels of zinc in patients with SCA as compared with controls (P<0.0001). Serum copper levels were significantly elevated compared with controls (P<0.0001). These findings emphasized the significant deficiencies of the antioxidant vitamins A, C and E and the trace element zinc along with the significant elevation of serum copper in patients with severe sickle cell disease. Further studies are needed to find out whether supplementation of antioxidant vitamins and zinc may ameliorate some sickle cell disease complications. (author)

Mononuclear zinc(II) complexes of 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols: Synthesis, structural characterization, DNA binding and cheminuclease activities

Science.gov (United States)

Ravichandran, J.; Gurumoorthy, P.; Karthick, C.; Kalilur Rahiman, A.

2014-03-01

Four new zinc(II) complexes [Zn(HL1-4)Cl2] (1-4), where HL1-4 = 2-((2-(piperazin-1-yl)ethylimino)methyl)-4-substituted phenols, have been isolated and fully characterized using various spectro-analytical techniques. The X-ray crystal structure of complex 4 shows the distorted trigonal-bipyramidal coordination geometry around zinc(II) ion. The crystal packing is stabilized by intermolecular NH⋯O hydrogen bonding interaction. The complexes display no d-d electronic band in the visible region due to d10 electronic configuration of zinc(II) ion. The electrochemical properties of the synthesized ligands and their complexes exhibit similar voltammogram at reduction potential due to electrochemically innocent Zn(II) ion, which evidenced that the electron transfer is due to the nature of the ligand. Binding interaction of complexes with calf thymus DNA was studied by UV-Vis absorption titration, viscometric titration and cyclic voltammetry. All complexes bind with CT DNA by intercalation, giving the binding affinity in the order of 2 > 1 ≫ 3 > 4. The prominent cheminuclease activity of complexes on plasmid DNA (pBR322 DNA) was observed in the absence and presence of H2O2. Oxidative pathway reveals that the underlying mechanism involves hydroxyl radical.

Zinc metabolism in genetically obese mice

International Nuclear Information System (INIS)

Kennedy, M.L.; Failla, M.L.

1986-01-01

Recent reports indicate that the concentrations and total amounts of several essential trace metals in various tissues of genetically obese rodents differ markedly from lean controls. In the present studies the absorption, retention and tissue distribution of zinc was compared in obese (ob/ob) and lean (+/?) C57BL/6J mice. When administered 0.1 and 1 umole 65 Zn by stomach tube and killed after 4 h, fasted 10 week old obese mice had 2.7 and 2.2 times more radioactivity in their carcasses, respectively, than age-matched lean mice. Higher levels of 65 Zn were also present in the intestinal mucosa of obese mice. To eliminate possible differences in the effects of fasting and gastric emptying rates between the phenotypes, zinc absorption and retention were determined according to the method of Heth and Hoekstra. Analysis of data revealed that obese and lean mice absorbed 43 and 18% of the oral dose, respectively. Also, the rate of 65 Zn excretion between 2 and 6 days post-treatment was similar for obese and lean mice. After 6 days obese mice had significantly lower levels of radioisotope in skin, muscle plus bone, spleen and testes and higher levels of 65 Zn in liver, small intestine and adipose tissue compared to tissues from lean mice. These results demonstrate increased absorption, altered tissue distribution and similar excretion of zinc in ob/ob mice

Serum zinc levels in gestational diabetes

Directory of Open Access Journals (Sweden)

Rahimi Sharbaf F

2008-12-01

Full Text Available "nBackground: Maternal zinc deficiency during pregnancy has been related to adverse pregnancy outcomes. Most studies in which pregnant women have been supplemented with zinc to examine its effects on the outcome of the pregnancy have been carried out in industrialized countries and the results have been inconclusive. It has been shown that women with gestational diabetes (GDM have lower serum zinc levels than healthy pregnant women, and higher rates of macrosomia. Zinc is required for normal glucose metabolism, and strengthens the insulin-induced transportation of glucose into cells by its effect on the insulin signaling pathway. The purpose of this study was to assess the serum zinc levels of GDM patients and evaluate the effect of zinc supplementation. "nMethods: In the first stage of this prospective controlled study, we enrolled 70 women who were 24-28 weeks pregnant at the Prenatal Care Center of Mirza Kochak Khan Hospital, Tehran, Iran. The serum zinc level of each subject was determined. In the second stage, among these 70 subjects, the diabetics receiving insulin were divided into two groups, only one of which received a zinc supplement and the other group was the control group. Birth weight of neonates and insulin dosages were recorded. "nResults: The mean serum zinc level in the GDM group was lower than that of the control group (94.83 vs. 103.49mg/dl, respectively and the mean birth weight of neonates from the GDM women who received the zinc supplement was lower than that of the control group (3849g vs. 4136g. The rate of macrosomia was lower in the zinc supplemented group (20% vs. 53%. The mean of increase of insulin after receiving the zinc supplement was lower (8.4u vs. 13.53. "nConclusion: Maternal insulin resistance is associated with the accumulation of maternal fat tissue during early stages of pregnancy and greater fetoplacental nutrient availability in later stages, when 70% of fetal growth occurs, resulting in macrosomia. In

Effect of application of fertilizer nitrogen, zinc and selenium on zinc nutrition of ryegrass

International Nuclear Information System (INIS)

Wei Dongpu; Bai Lingyu; Yao Yunyin; Hua Luo

2001-01-01

A pot experiment was carried out to study the effect of zinc or selenium fertilizer applied alone, combined application of nitrogen, zinc and selenium fertilizer on zinc nutrition of ryegrass in mono culture or in mixed culture in mountain yellow-brown earth of Hubei province. The results showed that: 1) Zn content was enhanced by mixed culture (white clover: ryegrass = 1:4), at the same time, Zn content of ryegrass in mixed culture was increased with increasing of Zn fertilizer. 2) The main reason of Zn content of ryegrass decreased in mixed culture was dilution effect due to the increase of dry weight. 3) In mono-Se treatment, Zn content of ryegrass in mixed culture was decreased with increasing of Se fertilizer. 4) In 9 treatment of combined applications of N, Zn and Se fertilizer, treatment of the highest Zn content of ryegrass in mixed culture was N46Zn25Se1; treatment of the highest Zn content of ryegrass in mono culture was N30Zn25Se5

Antibatic photovoltaic response in zinc-porphyrin-liked oligothiophenes

DEFF Research Database (Denmark)

Krebs, Frederik C; Spanggaard, H.

2005-01-01

-stannylchloride and subsequent palladium catalysed Stille coupling. We further synthesised 5,15-bis(3, 4', 4", 4"', 4", 4""', 4""", 4"""'-octahexyl-[2, 2'; 5', 2" 5", 2'"; 5"', 2""; 5"", 2""'; 5""', 2"""; 5""", 2"""']octithiophene-5-yl)-10, 20-bis(3, 5-ditertbutylphenyl)zinc(II)porphyrin (5) from trimethyl(3, 4', 4", 4'", 4......"", 4""', 4""", 4"""'-Octahexyl-[2, 2'; 5', 2"; 5"; 2'"; 5"', 2""; 5"", 2"'"; 5""', 2"""; 5""", 2"""']octithiophene-5-yl)stannane (3-SnMe3) and 5, 15-dibromo-10, 20-bis(3, 5-ditertbutylphenyl)zinc(II)porphyrin (6) by Stille coupling. All the products were characterised by size exclusion chromatography...

Zinc Deficiency in Humans and its Amelioration

OpenAIRE

Yashbir Singh Shivay

2015-01-01

Zinc (Zn) deficiency in humans has recently received considerable attention. Global mortality in children under 5 years of age in 2004 due to Zn deficiency was estimated at 4,53,207 as against 6,66,771 for vitamin A deficiency; 20,854 for iron deficiency and 3,619 for iodine deficiency. In humans 2800-3000 proteins contain Zn prosthetic group and Zn is an integral component of zinc finger prints that regulate DNA transcription. Zinc is a Type-2 nutrient, which means that its concentration in ...

The therapeutic effect on bone mineral formation from biomimetic zinc containing tricalcium phosphate (ZnTCP in zinc-deficient osteoporotic mice.

Directory of Open Access Journals (Sweden)

Joshua Chou

Full Text Available The aim of this study was to evaluate the therapeutic efficacy of biomimetic zinc-containing tricalcium phosphate (ZnTCP produced by hydrothermally converting calcium carbonate exoskeletons from foraminifera, in the treatment of osteoporotic mice. X-Ray powder diffraction showed crystallographic structures matching JCPDS profile for tricalcium phosphate. Mass spectroscopy used to calculate total composition amount showed similar amount of calcium (5×10(4 µg/g and phosphate (4×10(4 ppm after conversion and the presence of zinc (5.18×10(3 µg/g. In vitro zinc release showed no release in PBS buffer and <1% zinc release in 7 days. In vivo evaluation was done in ovariectomized mice by implanting the ZnTCP samples in the soft tissues near the right femur bone for four weeks. Thirty ddY mice (5 weeks old, average weight of 21 g were divided into six experimental groups (normal, sham, OVX, β-TCP, ZnTCP and direct injection of zinc. CT images were taken every two weeks where the bone mineral density (BMD and bone mineral content (BMC were calculated by software based on CT images. The ZnTCP group exhibits cortical and cancellous bone growth of 45% and 20% respectively. While sham, OVX and β-TCP suffered from bone loss. A correlation was made between the significant body weight increase in ZnTCP with the significant increase in plasma zinc level compared with OVX. The presented results indicate that biomimetic ZnTCP were effective in preventing and treating bone loss in osteoporotic mice model.

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.

Recovery of zinc in phosphor wastes via electrokinetic treatments

International Nuclear Information System (INIS)

Yu, M.Y.; Wang, H. Paul; Chen, C.Y.; Hsiung, T.-L.; Wei, Yu-Ling; Tai, H.-S.; Chiang, K.-C.

2007-01-01

Speciation of zinc in phosphor wastes during electrokinetic treatments has been studied by in situ X-ray absorption near edge structure (XANES) spectroscopy in the present work. The least-square fits of the in situ XANES spectra show that the major zinc species in the phosphor waste are ZnS (77%), ZnO (10%), and Zn(OH) 2 (13%). During the electrokinetic treatment for 90 min, 25% of ZnS and 4% of ZnO are dissolved. About 42% of zinc is enriched on the cathode under the electric field (5 V/cm). Prolonging the electrokinetic treatment time to 4 h under the electric field of 5 V/cm, at least 80% of zinc in the phosphor waste can be recovered

Studies on the Interaction between Zinc-Hydroxybenzoite Complex and Genomic DNA

Directory of Open Access Journals (Sweden)

Hacali Necefoglu

2006-04-01

Full Text Available Zinc-Hydroxybenzoite ([Zn (H206] (p-HO-C6H4COO22H20 complex which wassynthesized and characterized by instrumental methods and the DNA samples which hadbeen isolated from cattle were allowed to interact at 37 oC for different time periods. Theinteraction of genomic DNA with this complex has been followed by agarose gelelectrophoresis at 50 V for 2 h. When DNA samples were allowed to interact with this metalcomplex, it was found that band intensities changed with the concentrations of the complex.In the result of interaction between this complex and genomic DNA samples, it wasdetermined that the intensities of bands were changed at the different concentrations of thecomplex. The brightness of the bands was increased and mobility of the bands wasdecreased, indicating the occurrence of increased covalent binding of the metal complexwith DNA. In this study it was concluded that the damage effect of ascorbate was reducedby Zinc-Hydroxybenzoite.

Stability constants of salicylate of zinc(II), cobalt(II), uranyl(II) and thorium(IV) by paper electrophoresis

International Nuclear Information System (INIS)

Singh, R.K.P.; Yadava, J.R.; Yadava, P.C.; Yadava, K.L.

1983-01-01

Stability constants of zinc(II), cobalt(II), uranyl(II) and thorium(IV) have been determined by paper electrophoresis. Salicylic acid (0.005 mol dm - 3 ) was added to the background electrolyte: 0.1 mol dm - 3 HClO 4 . The proportions of C 6 H 4 OHCOO - and C 6 H 4 OCOO/sup =/ were varied by changing the pH of the electrolyte. These anions yielded the complexes, ZnC 6 H 4 OHCOO + , CoC 6 H 4 OHCOO + , Th(C 6 H 4 OHCOO) 4 and UO 2 (C 6 H 4 OCOO) 2 /sup =/ whose stability constants are found to be 10/sup 3.1/, 10/sup 3.2/, 10/sup 11.6/ and 10/sup 22.2/, respectively (μ = 0.1, temp. 40 0 C). (author)

Novel Effects of Nanoparticulate Delivery of Zinc on Growth, Productivity, and Zinc Biofortification in Maize (Zea mays L.).

Science.gov (United States)

Subbaiah, Layam Venkata; Prasad, Tollamadugu Naga Venkata Krishna Vara; Krishna, Thimmavajjula Giridhara; Sudhakar, Palagiri; Reddy, Balam Ravindra; Pradeep, Thalappil

2016-05-18

In the present investigation, nanoscale zinc oxide particulates (ZnO-nanoparticulates) were prepared using a modified oxalate decomposition method. Prepared ZnO-nanoparticulates (mean size = 25 nm) were characterized using techniques such as transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and zeta potential analyzer. Different concentrations (50, 100, 200, 400, 600, 800, 1000, 1500, and 2000 ppm) of ZnO-nanoparticulates were examined to reveal their effects on maize crop on overall growth and translocation of zinc along with bulk ZnSO4 and control. Highest germination percentage (80%) and seedling vigor index (1923.20) were observed at 1500 ppm of ZnO-nanoparticulates. The yield was 42% more compared to control and 15% higher compared to 2000 ppm of ZnSO4. Higher accumulation of zinc (35.96 ppm) in grains was recorded with application of 100 ppm followed by 400 ppm (31.05 ppm) of ZnO-nanoparticulates. These results indicate that ZnO-nanoparticulates have significant effects on growth, yield, and zinc content of maize grains, which is an important feature in terms of human health.

Quadrupole interaction in zinc metal

International Nuclear Information System (INIS)

Vetterling, W.T.; Pound, R.V.

1977-01-01

To allow measurement of the quadrupole interaction in zinc metal, the enriched ZnO was reduced to zinc metal powder and compressed into a pill of thickness 1.4 gm/cm 2 . Sources were made by diffusing 20 mCi of 67 Ga into sintered copper pills. The transducer was based on a cylinder of PZT-4 with 1 / 2 -inch length and could cover linearly a velocity range of +-100 μ/s at 200 Hz. The multiscalar was a modified Northern model NS600, with a minimum dwell time of 20 μs, and with a 10-count buffer at the input to eliminate deadtime from memory cycling

Twinned low-temperature structures of tris(ethylenediamine)zinc(II) sulfate and tris(ethylenediamine)copper(II) sulfate

NARCIS (Netherlands)

Lutz, M.

2010-01-01

Tris(ethylenediamine)zinc(II) sulfate, [Zn(C2H8N2)3]SO4, (I), undergoes a reversible solid–solid phase transition during cooling, accompanied by a lowering of the symmetry from high-trigonal P31c to low-trigonal P3 and by merohedral twinning. The molecular symmetries of the cation and anion change

Protective effects of zinc acetate toward the toxicity of nickelous acetate in rats

International Nuclear Information System (INIS)

Waalkes, M.P.; Kasprzak, K.S.; Ohshima, M.; Poirier, L.A.

1985-01-01

This study was designed to determine the effects of zinc pretreatment on the acute toxicity of nickel. Male Fischer rats received either nickel alone (i.p.), zinc alone (s.c.), zinc plus nickel, or saline (i.p. and s.c.; controls). Zinc pretreatment significantly increased the 14-day survival of nickel-related rats. Zinc did not, however, prevent the reduction in weight gain over 2 weeks seen with nickel treatment. Histopathologically, at 120 h following nickel exposure, kidneys in the group receiving nickel alone generally showed moderate nephropathy (multifocal proximal tubule degeneration with necrosis) while in the zinc plus nickel group the nephropathy was generally mild. Zinc pretreatment had no apparent effect on the pharmacokinetics of nickel over 24 h as assessed by urinary excretion, blood levels or organ distribution. Zinc pretreatment also did not alter the subcellular distribution of renal nickel 6 h after nickel exposure. Enhanced synthesis of metallothionein did not appear to play a critical role in the reduction of nickel toxicity, since renal concentrations of this metalbuilding protein, although elevated compared to control, were not different in rats receiving zinc and nickel or zinc alone. Zinc pretreatment did, however, have marked effect on nickel-induced hyperglycemia, reducing both the duration and severity of elevated blood glucose levels. Results of the study show that zinc can prevent some of the toxic effects of nickel and that the mechanism of this action does not appear to involve either metalothionein or alterations in the pharmacokinetics of nickel. (author)

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.

Solvothermal indium fluoride chemistry: Syntheses and crystal structures of K5In3F14, β-(NH4)3InF6 and [NH4]3[C6H21N4]2[In4F21

International Nuclear Information System (INIS)

Jayasundera, Anil C.A.; Goff, Richard J.; Li Yang; Finch, Adrian A.; Lightfoot, Philip

2010-01-01

The solvothermal syntheses and crystal structures of three indium fluorides are presented. K 5 In 3 F 14 (1) and β-(NH 4 ) 3 InF 6 (2) are variants on known inorganic structure types chiolite and cryolite, respectively, with the latter exhibiting a complex and apparently novel structural distortion. [NH 4 ] 3 [C 6 H 21 N 4 ] 2 [In 4 F 21 ] (3) represents a new hybrid composition displaying a unique trimeric metal fluoride building unit. - Graphical abstract: Solvothermal synthesis has been used to prepare three indium fluorides, including a novel hybrid material containing a unique [In 3 F 15 ] trimer templated by tren.

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 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.

Properties of tire rubber with zinc-containing technological additives

Directory of Open Access Journals (Sweden)

S. N. Kayushnikov

2017-01-01

Full Text Available In this paper, we studied the influence of zinc-containing technological additives on partial replacement of zinc oxide and stearic acid on deformation-strength and performance properties of tire elastomeric compositions based on polyisoprene rubber and combination of oil-filled butadiene-styrene and polybutadiene rubbers. It was revealed that partial replacement of zinc oxide and stearic acid with zinc-containing technological additives does not significantly affect the basic physico-mechanical properties of rubbers based on synthetic rubbers of general use. It was determined that the introduction of zinc-containing technological additives SCC2 in combination with zinc oxide in all the studied ratios and SCC3 in combination with zinc oxide in 4: 1 and 3: 1 ratios leads to increase (up to 10.4% of the resistance of these rubbers under the action of temperature-force fields, which is probably due to a more even distribution of polar components of curing system in non-polar elastomeric matrix, as well as the type of cross-links formed during vulcanization under the action of surface-active additives. It has been found that the introduction of zinc-containing additives into the elastomeric compositions based on SRMS-30 ARKM-15 + SRD in combination with zinc oxide leads to increase to 6.3% of wear resistance of rubbers, which may be due to a lower defectiveness of vulcanization structure of these rubbers, concentration of stress centers in the material. For rubbers based on SRI-3, preservation of bond strength of rubber with a textile cord at a sufficiently high level is shown.

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.

Bioaccumulation and toxicity of zinc in the green alga, Cladophora glomerata.

Science.gov (United States)

McHardy, B M; George, J J

1990-01-01

The bioaccumulation and toxicity of zinc in Cladophora glomerata from two populations in the River Roding, Essex, UK, were examined in experimental laboratory flowing-water channels. Plants were subjected to zinc concentrations ranging from 0 to 4.0 mg litre(-1) at current velocities of 20-33 cm s(-1) for up to 3 h. Zinc in algal tissue was then quantified and toxicity was assessed by the ability of the alga to grow in a recovery medium after the experimental treatment. There was little difference in zinc bioaccumulation between Cladophora from the site showing mild organic pollution and that from the site subjected to considerable inputs from urban and motorway runoff. Uptake of zinc increased with increasing concentration in the test solution and was linear and proportional up to 0.4 mg litre(-1). Three stages of uptake were identified with the most dramatic accumulation occurring in the first 10 min. Experimental concentration factors ranged from 1.9-5.2 x 10(3), which were in agreement with those previously obtained in the field. Cellular damage was evident in Cladophora subjected to 0.4 mg litre(-1) zinc, and this increased with increasing zinc concentration, thus leading to the conclusion that, at times, the levels of zinc found in the river could be potentially damaging.

Nutritional status and phytate:zinc and phytate x calcium:zinc dietary molar ratios of lacto-ovo vegetarian Trappist monks: 10 years later.

Science.gov (United States)

Harland, B F; Smith, S A; Howard, M P; Ellis, R; Smith, J C

1988-12-01

A nutrition assessment of 16 members of a community of lacto-ovo vegetarian Trappist monks was conducted in 1977. Plasma zinc was found to be low-normal, which was attributed primarily to high intakes of phytate-containing foods. Individual and group counseling were instituted over a 10-year period in an attempt to emphasize the importance of wise food selection within the constraints of lacto-ovo vegetarianism. In 1987, a more comprehensive nutrition assessment of 21 members of the same community was performed. Food composites were analyzed, and 3-day instead of 24-hour dietary records were kept. Intakes of phytate-containing foods had decreased from 4,569 to 972 mg/day; intake of dietary zinc had increased from 7.4 to 9.7 mg/day; and the phytate:zinc molar ratio had decreased from 67 to 14 for the years 1977 and 1987, respectively. An analyzed phytate:zinc molar ratio of 9.8 and an analyzed phytate x calcium:zinc molar ratio of 0.3 were representative of the 1987 community. Both were within normal ranges. Plasma zinc had risen to upper-normal levels. The 1987 nutrition assessment showed that it is possible to be adequately nourished with a lacto-ovo vegetarian diet provided one has proper knowledge of the phytate-containing foods and the methods for compensating with foods of greater mineral density (primarily zinc).

4th June: AIS and NICE/MAIL unique authentication

CERN Multimedia

The AIS and NICE teams

2007-01-01

Over the past few years, the IT department has been in the process of streamlining CERN users' access to all central computing services. The long term goal is to converge on a unique computer account, which will increase computer security and simplify account maintenance. The next step of this process will occur on the 4th June 2007, as of when authenticating on the AIS applications (EDH, HRT, CET, APT, ERT, CRA, Foundation, ...) and on NICE (Windows) and MAIL will be done using the same username and password. As a reminder, this account can also be used on EDMS, INDICO, CDS and SIMBA. Thus starting on the 4th June 2007, authentication on the AIS applications must be done using your AIS username and your MAIL/NICE password. Thanks for your understanding, The AIS and NICE teams

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

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 ...

Cloning and analysis of the mouse Fanconi anemia group A cDNA and an overlapping penta zinc finger cDNA.

Science.gov (United States)

Wong, J C; Alon, N; Norga, K; Kruyt, F A; Youssoufian, H; Buchwald, M

2000-08-01

Despite the cloning of four disease-associated genes for Fanconi anemia (FA), the molecular pathogenesis of FA remains largely unknown. To study FA complementation group A using the mouse as a model system, we cloned and characterized the mouse homolog of the human FANCA cDNA. The mouse cDNA (Fanca) encodes a 161-kDa protein that shares 65% amino acid sequence identity with human FANCA. Fanca is located at the distal region of mouse chromosome 8 and has a ubiquitous pattern of expression in embryonic and adult tissues. Expression of the mouse cDNA in human FA-A cells restores the cellular drug sensitivity to normal levels. Thus, the expression pattern, protein structure, chromosomal location, and function of FANCA are conserved in the mouse. We also isolated a novel zinc finger protein, Zfp276, which has five C(2)H(2) domains. Interestingly, Zfp276 is situated in the Fanca locus, and the 3'UTR of its cDNA overlaps with the last four exons of Fanca in a tail-to-tail manner. Zfp276 is expressed in the same tissues as Fanca, but does not complement the mitomycin C (MMC)-sensitive phenotype of FA-A cells. The overlapping genomic organization between Zfp276 and Fanca may have relevance to the disease phenotype of FA. Copyright 2000 Academic Press.

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.

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

Science.gov (United States)

Sminčáková, Emília; Trpčevská, Jarmila; Pirošková, Jana

2017-10-01

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

A specific assay for quantification of human C4c by use of an anti-C4c monoclonal antibody

DEFF Research Database (Denmark)

Pilely, Katrine; Skjoedt, Mikkel-Ole; Nielsen, Christian

2014-01-01

a mouse monoclonal antibody (mAb) that is able to detect fluid phase C4c without interference from other products generated from the complement component C4. The C4c specific mAb was tested in different enzyme-linked immunosorbent assay (ELISA) combinations with various types of in vitro activated sera...

Characterization of the failure behavior of zinc coating on dual phase steel under tensile deformation

International Nuclear Information System (INIS)

Song Guiming; Sloof, Willem G.

2011-01-01

Highlights: → The microcracks and voids at the zinc grain boundaries are the initial sites for the coating cracking. → The crack spacing of the fragmentally fractured zinc coating is mainly determined by the zinc grain size. → Small zinc grain size and the c-axis direction of zinc grain parallel to the zinc surface are beneficial to the mitigation of the zinc coating delamination. - Abstract: The failure behavior of hot-dip galvanized zinc coatings on dual phase steels under tensile deformation is characterized with in situ scanning electron microscopy (SEM). Under tension, the pre-existed microcracks and voids at the zinc grain boundaries propagate along the zinc grain boundaries to form crack nets within the coating, leading to a segmented fracture of the zinc coating with the crack spacing approximately equal to the zinc grain size. With further loading, the coating segments partially delaminated along the interface between the top zinc layer and the inhibition layer instead of the interface between the inhibition layer and steel substrate. As the c-axis of zinc grains trends to be normal to the tensile loading direction, the twinning deformation became more noticeable, and meanwhile the coating delamination was diminished. The transverse and incline tunneling cracks occurred in the inhibition layer with tensile deformation. The existence of the brittle FeZn 13 particles on top of the inhibition layer was unfavorable to the coating adhesion.

Estimating mercury emissions from a zinc smelter in relation to China's mercury control policies

International Nuclear Information System (INIS)

Wang, S.X.; Song, J.X.; Li, G.H.; Wu, Y.; Zhang, L.; Wan, Q.; Streets, D.G.; Chin, Conrad K.; Hao, J.M.

2010-01-01

Mercury concentrations of flue gas at inlet/outlet of the flue gas cleaning, electrostatic demister, reclaiming tower, acid plant, and mercury contents in zinc concentrate and by-products were measured in a hydrometallurgical zinc smelter. The removal efficiency of flue gas cleaning, electrostatic demister, mercury reclaiming and acid plant was about 17.4%, 30.3%, 87.9% and 97.4% respectively. Flue gas cleaning and electrostatic demister captured 11.7% and 25.3% of the mercury in the zinc concentrate, respectively. The mercury reclaiming tower captured 58.3% of the mercury in the zinc concentrate. About 4.2% of the mercury in the zinc concentrate was captured by the acid plant. Consequently, only 0.8% of the mercury in the zinc concentrate was emitted to the atmosphere. The atmospheric mercury emission factor was 0.5 g t -1 of zinc produced for the tested smelter, indicating that this process offers the potential to effectively reduce mercury emissions from zinc smelting. - Modern scale production equipped with acid plant and Hg reclaiming tower will significantly reduce Hg emissions from zinc smelters in China.

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

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF{sub 4}/Ar plasma

Energy Technology Data Exchange (ETDEWEB)

Joo, Young-Hee; Kim, Chang-Il

2015-05-29

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF{sub 4}/Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF{sub 4}/Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF{sub 4}/Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF{sub 4}/Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar{sup +} sputtering and then reacted with the C-F{sub x} radicals. • The physical sputtering is dominant in etch control compared with chemical etching.

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)

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)

Fabrication of hierarchical flower-like porous ZnO nanostructures from layered ZnC2O4·3Zn(OH)2 and gas sensing properties

International Nuclear Information System (INIS)

Cui, Jiashan; Sun, Jianbo; Liu, Xin; Li, Jinwei; Ma, Xinzhi; Chen, Tingting

2014-01-01

ZnO materials with porous and hierarchical flower-like structure were synthesized through mild hydrothermal and simple calcination approach, in which the flower-like layered zinc oxalate hydroxide (ZnC 2 O 4 ·3Zn(OH) 2 ) precursor was first synthesized and then calcined at 600 °C. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopic (TEM), Brunauer–Emmett–Teller (BET) and thermogravimetric (TG) analysis. We proposed the possible growth mechanism of the material via studying the time evolution experiment results. In the process of reaction, oxalic acid as a structure-directing agent hydrolyzed and then formed primarily sheets-like intermediate ZnC 2 O 4 ·2H 2 O. Hexamethylenetetramine (HMT) as surfactant, with directional adsorption, leads to the formation of layered zinc oxalate hydroxide precursor. Furthermore, the gas sensitivity also can be characterized, whose results indicated that the synthesized materials had a preferable selectivity to ethanol gas. The fast response rate and reversible performance can be attributed to the produced greater specific surface area produced, which was caused by the porous and hierarchical flower-like structure.

Fabrication of hierarchical flower-like porous ZnO nanostructures from layered ZnC2O4·3Zn(OH)2 and gas sensing properties

Science.gov (United States)

Cui, Jiashan; Sun, Jianbo; Liu, Xin; Li, Jinwei; Ma, Xinzhi; Chen, Tingting

2014-07-01

ZnO materials with porous and hierarchical flower-like structure were synthesized through mild hydrothermal and simple calcination approach, in which the flower-like layered zinc oxalate hydroxide (ZnC2O4·3Zn(OH)2) precursor was first synthesized and then calcined at 600 °C. The obtained products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopic (TEM), Brunauer-Emmett-Teller (BET) and thermogravimetric (TG) analysis. We proposed the possible growth mechanism of the material via studying the time evolution experiment results. In the process of reaction, oxalic acid as a structure-directing agent hydrolyzed and then formed primarily sheets-like intermediate ZnC2O4·2H2O. Hexamethylenetetramine (HMT) as surfactant, with directional adsorption, leads to the formation of layered zinc oxalate hydroxide precursor. Furthermore, the gas sensitivity also can be characterized, whose results indicated that the synthesized materials had a preferable selectivity to ethanol gas. The fast response rate and reversible performance can be attributed to the produced greater specific surface area produced, which was caused by the porous and hierarchical flower-like structure.

Role of Heavy Metal Pumps in Transport of Zinc from Soil to Seeds of Plants

DEFF Research Database (Denmark)

Olsen, Lene Irene

. In Arabidopsis roots, the heavy metal ATPases AtHMA2 and AtHMA4 are localized to the pericycle cells and are important for the export of zinc, in order for zinc to enter the xylem and get to the shoot. I have identified a new novel role for AtHMA2 and AtHMA4 in the developing seed. The Arabidopsis seed consists...... at this location actively export zinc from the mother plant seed coat. Mutant plants that lack AtHMA2 and AtHMA4 accumulate zinc in the seed coat, and consequently have vastly reduced amounts of zinc inside the seed. The finding that AtHMA2 and AtHMA4 are involved in pumping zinc out of the mother plant seed coat...

Improved electrolyte for zinc-bromine flow batteries

Science.gov (United States)

Wu, M. C.; Zhao, T. S.; Wei, L.; Jiang, H. R.; Zhang, R. H.

2018-04-01

Conventional zinc bromide electrolytes offer low ionic conductivity and often trigger severe zinc dendrite growth in zinc-bromine flow batteries. Here we report an improved electrolyte modified with methanesulfonic acid, which not only improves the electrolyte conductivity but also ameliorates zinc dendrite. Experimental results also reveal that the kinetics and reversibility of Zn2+/Zn and Br2/Br- are improved in this modified electrolyte. Moreover, the battery's internal resistance is significantly reduced from 4.9 to 2.0 Ω cm2 after adding 1 M methanesulfonic acid, thus leading to an improved energy efficiency from 64% to 75% at a current density of 40 mA cm-2. More impressively, the battery is capable of delivering an energy efficiency of about 78% at a current density of as high as 80 mA cm-2 when the electrode is replaced by a thermally treated one. Additionally, zinc dendrite growth is found to be effectively suppressed in methanesulfonic acid supported media, which, as a result, enables the battery to be operated for 50 cycles without degradation, whereas the one without methanesulfonic acid suffers from significant decay after only 40 cycles, primarily due to severe zinc dendrite growth. These superior results indicate methanesulfonic acid is a promising supporting electrolyte for zinc-bromine flow batteries.

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.

Zinc chlorophyll aggregates as hole transporters for biocompatible, natural-photosynthesis-inspired solar cells

Science.gov (United States)

Li, Yue; Sasaki, Shin-ichi; Tamiaki, Hitoshi; Liu, Cheng-Liang; Song, Jiaxing; Tian, Wenjing; Zheng, Enqiang; Wei, Yingjin; Chen, Gang; Fu, Xueqi; Wang, Xiao-Feng

2015-11-01

The intriguing properties of extremely efficient delocalization and migration of excitons in chlorophyll (Chl) J-type aggregates have inspired intense research activities toward their structural understanding, functional interpretation and mimicry synthesis. Herein, we demonstrated the J-aggregates of zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide a (ZnChl-1) generated by spin-coating method for the application as a hole transporter in titania-based solar cells using methyl trans-32-carboxypyropheophorbide a (H2Chl-2) or its zinc complex (ZnChl-2) as the sensitizer. The effective carrier mobility of the J-aggregates films was determined by the organic field-effect transistor to be 6.2 × 10-4 cm2 V-1 s-1. Solar cells sharing the architecture of FTO/H2Chl-2 or ZnChl-2 on TiO2/(ZnChl-1)n/Ag were fabricated and the factors that presumably determine their photovoltaic performances were discussed. The photovoltaic devices studied herein employing inexpensive and pollution-free biomaterials provide a unique solution of utilizing solar energy with a care of the important environmental issue.

hZip2 and hZip3 zinc transporters are down regulated in human prostate adenocarcinomatous glands

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Franklin Renty B

2007-06-01

Full Text Available Abstract Background The normal human prostate glandular epithelium has the unique function of accumulating high levels of zinc. In prostate cancer this capability is lost as an early event in the development of the malignant cells. The mechanism and factors responsible for the ability of the normal epithelial cells to accumulate zinc and the loss of this capability in the malignant cells need to be identified. We previously reported that Zip1 is an important zinc uptake transporter in prostate cells and is down regulated in the malignant cells in situ along with the depletion of zinc levels. In this report we investigated the expression of two other Zip family zinc transporters, Zip2 and Zip3 in malignant versus nonmalignant (normal and BPH glands. Zip2 and Zip3 relative protein levels were determined by immunohistochemistry analysis of human prostate tissue sections. Results Normal and BPH glandular epithelium consistently exhibited the strong presence of both Zip 2 and Zip3; whereas both transporters consistently were essentially non-detectable in the malignant glands. This represents the first report of the expression of Zip3 in human prostate tissue; and more importantly, reveals that ZiP2 and Zip3 are down regulated in malignant cells in situ as we also had demonstrated for Zip1. Zip2 and Zip3 transporter proteins were localized predominantly at the apical cell membrane, which is in contrast to the Zip1 localization at the basolateral membrane. Zip2 and Zip3 seemingly are associated with the re-uptake of zinc from prostatic fluid. Conclusion These results coupled with previous reports implicate Zip2 and Zip3 along with Zip1 as important zinc uptake transporters involved in the unique ability of prostate cells to accumulate high cellular zinc levels. Zip1 is important for the extraction of zinc from circulation as the primary source of cellular zinc. Zip 2 and Zip3 appear to be important for retention of the zinc in the cellular compartment

Clomazone selectivity in cotton seeds treated with dietholate and zinc acetate

Directory of Open Access Journals (Sweden)

Miriam Hiroko Inoue

2014-12-01

Full Text Available The objective of this study objective was to evaluate the selectivity of pre-emergence applications the herbicide clomazone cotton seeds treated with dietholate and zinc acetate. The 4 x 2 factorial arrangement was adopted (4 seed treatment methods and 2 clomazone dosages, distributed in a randomized block design with 4 repetitions. In treatments where dietholate and zinc acetate were applied, rates of 0.4 kg ha-1 and 8 ml per kg of seeds were used respectively. The clomazone rates used refer to 0.8 and 1.0 kg ha- 1. The cotton cultivar used was the Fiber Max 966 LL. Independent of treatment, all seeds were treated with tiametoxam insecticide and fludioxonil + metalaxyl-M fungicide at rates of 2.24 and 0.08 + 0.03 g per kg of seed, respectively, to control pests early and limit losses caused by pathogens in germination and seedling emergence. Dietholate and zinc acetate treatment had greater initial effect on cotton plants at 21, 30 and 45 days after application. In phytointoxication symptoms were observed for treatment with dietholate and zinc acetate during the evaluation periods. Seeds treated with dietholate, dietholate and zinc acetate or zinc acetate alone provided a higher number of bolls and seed cotton production compared to the control.

Single crystal X-ray structure of the artists' pigment zinc yellow

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Simonsen, Kim Pilkjær; Christiansen, Marie Bitsch; Vinum, Morten Gotthold; Sanyova, Jana; Bendix, Jesper

2017-08-01

The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography determined the structure of zinc yellow as KZn2(CrO4)2(H2O)(OH) or as KZn2(CrO4)2(H3O2) emphasizing the μ-H3O2- moiety. Notably, the zinc yellow is isostructural to the recently structurally characterized cadmium analog and both belong to the natrochalcite structure type.