The content of zinc in mushrooms of the Semey region near the Irtysh in the Republic of Kazakhstan

International Nuclear Information System (INIS)

Sibirkina, A.R.

2008-01-01

We received a data about the metal-accumulating ability of the 12 species of mushrooms of the Semey Region near the Irtysh. 66,7 % from general number of learn species of mushrooms relate to the group of intensive absorption of zinc, on index of the biotic of elements. Low content of zinc in the trutovik-saprofites. The coefficient of biological absorption meaning of zinc by learn species of mushrooms to testify about the so it is not powerful, entering source, as an atmospheric air. The investigations are not display of general correlating dependence between the content of zinc in mushrooms and its have very low trust worthiness in the soil.

Factors that Affect the Content of Cadmium, Nickel, Copper and Zinc in Tissues of the Knee Joint.

Science.gov (United States)

Roczniak, Wojciech; Brodziak-Dopierała, Barbara; Cipora, Elżbieta; Jakóbik-Kolon, Agata; Kluczka, Joanna; Babuśka-Roczniak, Magdalena

2017-08-01

Osteoarthritis causes the degradation of the articular cartilage and periarticular bones. Trace elements influence the growth, development and condition of the bone tissue. Changes to the mineral composition of the bone tissue can cause degenerative changes and fractures. The aim of the research was to determine the content of cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) in the tibia, the femur and the meniscus in men and women who underwent a knee replacement surgery. Samples were collected from 50 patients, including 36 women and 14 men. The determination of trace elements content were performed by ICP-AES method, using Varian 710-ES. Average concentration in the tissues of the knee joint teeth amounted for cadmium 0.015, nickel 0.60, copper 0.89 and zinc 80.81 mg/kg wet weight. There were statistically significant differences in the content of cadmium, copper and zinc in different parts of the knee joint. There were no statistically significant differences in the content of cadmium, nickel, copper and zinc in women and men in the examined parts of the knee joint. Among the elements tested, copper and nickel showed a high content in the connective tissue (the meniscus) compared to the bone tissue (the tibia and the femur).

Serum and tissue contents of copper, calcium, iron and magnesium elements in cases of acne vulgaris after zinc therapy

International Nuclear Information System (INIS)

El-Said, S.M.; El-Bedewi, A.F.

2002-01-01

The effect of zinc therapy on some trace elements contents in serum and skin was studied in normal group (forty) and patients group with acne vulgaris (26 males and 14 females) with age ranged between 14-30 year. They were under medical treatment with 330 mg oral zinc sulfate for 12 weeks. Highly significant decreases in both serum and tissue contents of copper and calcium were detected, as well as, highly significant decrease in the serum content of magnesium was recorded. The serum content of iron was highly significantly increased and that for tissue content was slightly significantly increased. It could be concluded that zinc therapy could be valuable through modulation of copper. calcium, iron and magnesium in acne patients

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)

Alumina/silica aerogel with zinc chloride as an alkylation catalyst

Directory of Open Access Journals (Sweden)

DEJAN U. SKALA

2001-10-01

Full Text Available The alumina/silica with zinc chloride aerogel alkylation catalyst was obtained using a one step sol-gel synthesis, and subsequent drying with supercritical carbon dioxide. The aerogel catalyst activity was found to be higher compared to the corresponding xerogel catalyst, as a result of the higher aerogel surface area, total pore volume and favourable pore size distribution. Mixed Al–O–Si bonds were present in both gel catalyst types. Activation by thermal treatment in air was needed prior to catalytic alkylation, due to the presence of residual organic groups on the aerogel surface. The optimal activation temperature was found to be in the range 185–225°C, while higher temperatures resulted in the removal of zinc chloride from the surface of the aerogel catalyst with a consequential decrease in the catalytic activity. On varying the zinc chloride content, the catalytic activity of the aerogel catalyst exhibited a maximum. High zinc chloride contents decreased the catalytic activity of the aerogel catalyst as the result of the pores of the catalyst being plugged with this compound, and the separation of the alumina/silica support into Al-rich and Si-rich phases. The surface area, total pore volume, pore size distribution and zinc chloride content had a similar influence on the activity of the aerogel catalyst as was the case of xerogel catalyst and supported zinc chloride catalysts.

Discrimination between low dietary zinc and endotoxin exposure : a model study on weaning rats

NARCIS (Netherlands)

Wouwe, van J.P.; Veldhuizen, M.; Hamer, van den C.J.A.; de Goeij, J.J.M.

1990-01-01

To establish a parameter for zinc status that is independent of the occurrence of infection, we studied the effects of low dietary zinc and endotoxin in weaning rats 21 d after 65Zn intubation. We monitored aspects of zinc status (tissue zinc content, 65Zn distribution, and specific 65Zn activity in

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

International Nuclear Information System (INIS)

Pally, Monique; Foulquier, Luc

1976-07-01

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

Zinc biofortification of cereals

DEFF Research Database (Denmark)

Palmgren, Michael; Clemens, Stephan; Williams, Lorraine E.

2008-01-01

The goal of biofortification is to develop plants that have an increased content of bioavailable nutrients in their edible parts. Cereals serve as the main staple food for a large proportion of the world population but have the shortcoming, from a nutrition perspective, of being low in zinc...... and other essential nutrients. Major bottlenecks in plant biofortification appear to be the root-shoot barrier and - in cereals - the process of grain filling. New findings demonstrate that the root-shoot distribution of zinc is controlled mainly by heavy metal transporting P1B-ATPases and the metal...... tolerance protein (MTP) family. A greater understanding of zinc transport is important to improve crop quality and also to help alleviate accumulation of any toxic metals....

Spatial soil zinc content distribution from terrain parameters: A GIS-based decision-tree model in Lebanon

Energy Technology Data Exchange (ETDEWEB)

Bou Kheir, Rania, E-mail: rania.boukheir@agrsci.d [Lebanese University, Faculty of Letters and Human Sciences, Department of Geography, GIS Research Laboratory, P.O. Box 90-1065, Fanar (Lebanon); Department of Agroecology and Environment, Faculty of Agricultural Sciences (DJF), Aarhus University, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Greve, Mogens H. [Department of Agroecology and Environment, Faculty of Agricultural Sciences (DJF), Aarhus University, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark); Abdallah, Chadi [National Council for Scientific Research, Remote Sensing Center, P.O. Box 11-8281, Beirut (Lebanon); Dalgaard, Tommy [Department of Agroecology and Environment, Faculty of Agricultural Sciences (DJF), Aarhus University, Blichers Alle 20, P.O. Box 50, DK-8830 Tjele (Denmark)

2010-02-15

Heavy metal contamination has been and continues to be a worldwide phenomenon that has attracted a great deal of attention from governments and regulatory bodies. In this context, our study proposes a regression-tree model to predict the concentration level of zinc in the soils of northern Lebanon (as a case study of Mediterranean landscapes) under a GIS environment. The developed tree-model explained 88% of variance in zinc concentration using pH (100% in relative importance), surroundings of waste areas (90%), proximity to roads (80%), nearness to cities (50%), distance to drainage line (25%), lithology (24%), land cover/use (14%), slope gradient (10%), conductivity (7%), soil type (7%), organic matter (5%), and soil depth (5%). The overall accuracy of the quantitative zinc map produced (at 1:50.000 scale) was estimated to be 78%. The proposed tree model is relatively simple and may also be applied to other areas. - GIS regression-tree analysis explained 88% of the variability in field/laboratory Zinc concentrations.

Spatial soil zinc content distribution from terrain parameters: A GIS-based decision-tree model in Lebanon

International Nuclear Information System (INIS)

Bou Kheir, Rania; Greve, Mogens H.; Abdallah, Chadi; Dalgaard, Tommy

2010-01-01

Heavy metal contamination has been and continues to be a worldwide phenomenon that has attracted a great deal of attention from governments and regulatory bodies. In this context, our study proposes a regression-tree model to predict the concentration level of zinc in the soils of northern Lebanon (as a case study of Mediterranean landscapes) under a GIS environment. The developed tree-model explained 88% of variance in zinc concentration using pH (100% in relative importance), surroundings of waste areas (90%), proximity to roads (80%), nearness to cities (50%), distance to drainage line (25%), lithology (24%), land cover/use (14%), slope gradient (10%), conductivity (7%), soil type (7%), organic matter (5%), and soil depth (5%). The overall accuracy of the quantitative zinc map produced (at 1:50.000 scale) was estimated to be 78%. The proposed tree model is relatively simple and may also be applied to other areas. - GIS regression-tree analysis explained 88% of the variability in field/laboratory Zinc concentrations.

Distribution of zinc-65 in Agrostis tenuis Sibth. and A. stolonifera L. tissues

Energy Technology Data Exchange (ETDEWEB)

Peterson, P J

1969-11-01

The distribution of /sup 65/Zn in zinc-tolerant and copper-tolerant plants of Agrotis spp. from toxic mine-tailings in England and Wales was compared with zinc distribution in non-tolerant plants. Isotope was applied in culture solution in which the plants were growing. No differences could be demonstrated between the plants by whole-plant radioautography, or by zinc analyses of the tops. Root/shoot ratios calculated from specific activity values varied with population, the non-tolerant plants having the lowest and the zinc-tolerant plants the highest ratio. After solvent (80% ethanol and water) extractions, the root residue of zinc-tolerant plants contained a higher percentage of /sup 65/Zn than that of non-tolerant plants. Chemical fractionation of the roots revealed that the main difference was that the amount of /sup 65/Zn in the pectate extract of the cell wall was high in zinc-tolerant plants and low in non-tolerant plants. The /sup 65/Zn distribution in the copper-tolerant plants was similar to that in the non-tolerant plants, indicating that the tolerance mechanisms for the two elements are different. Soluble protein and RNA preparations were made but they contained low levels of /sup 65/Zn. An exception was the relatively high value for RNA from zinc-tolerant A. stolonifera shoots. An anionic complex of /sup 65/Zn in the soluble fraction was investigated. This complex accounted for most of the radioactivity in A. tenuis extracts of shoots but the concentration of the complex was low in A. stolonifera shoots, and in root extracts of all plants examined. 18 references, 2 figures, 4 tables.

The zinc distribution in prostate tissues using X-ray microfluorescence with synchrotron radiation

International Nuclear Information System (INIS)

Leitao, Roberta G.; Anjos, Marcelino J.; Canellas, Catarine G.L.; Pereira, Marcelo O.; Pereira, Gabriela R.; Lopes, Ricardo T.

2009-01-01

Many elements play an essential role in a number of biological processes as activators or inhibitors of cellular and enzymatic activity. The topographic and quantitative elemental analysis of pathologically changed tissues may shed some new light on processes leading to the degeneration of cells in case of selected diseases. Zinc concentration in a prostate gland is much higher than that in other human tissues. The high concentration of zinc in the prostate suggests that zinc may play a role in prostate health. The aim of this work was to study the elemental distribution for Zinc in prostate tissues from patterns of relative fluorescence intensities. The measurements were performed in standard geometry of 45 deg incidence, exciting with a white beam and using a conventional system collimation orthogonal slits) in the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The prostate glands were cut into pieces (slice) with thickness of 0.5 mm. The results showed the zinc distribution was not uniform for different zones of the prostate analyzed. (author)

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

International Nuclear Information System (INIS)

Filova, A.; Molnarova, M.

2015-01-01

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

Zinc and copper distribution in swine wastewater treated by anaerobic digestion.

Science.gov (United States)

Cestonaro do Amaral, André; Kunz, Airton; Radis Steinmetz, Ricardo Luís; Justi, Karin Cristiane

2014-08-01

Swine wastewater contain high levels of metals, such as copper and zinc, which can cause a negative impact on the environment. Anaerobic digestion is a process commonly used to remove carbon, and can act on metal availability (e.g., solubility or oxidation state). The present study aimed to evaluate the influence of anaerobic digestion on total Zn and Cu contents, and their chemical fractioning due to the biodegradation of the effluent over different hydraulic retention times (HRTs). The sequential extraction protocol proposed by the Community Bureau of Reference (BCR), plus two additional fractions, was the method chosen for this study of Cu and Zn distribution evaluation in swine wastewater. The Zn and Cu concentrations in raw swine manure were 63.58 ± 27.72 mg L(-1) and 8.98 ± 3.99 mg L(-1), respectively. The metal retention capacity of the bioreactor decreased when the HRT was reduced from 17.86 d to 5.32 d. Anaerobic digestion had a direct influence on zinc and copper distribution when raw manure (RM) and digested manure (DM) were compared. The reducible fraction showed a reduction of between 3.17% and 7.84% for Zn and between 2.52% and 11.92% for Cu when DM was compared with RM. However, the metal concentration increased in the oxidizable fraction of DM, viz. from 3.01% to 10.64% for Zn and from 4.49% to 16.71% for Cu, thus demonstrating the effect of anaerobic conditions on metal availability. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of Different Organic Materials and Exogenous Zn on Zn Distribution in Soil

OpenAIRE

HAO Jia-li; BU Yu-shan; JIA Zheng-rong; XI Ji-long; YAO Jing-zhen; DUAN Chao

2015-01-01

A pot experiment with a complete combinatorial design of two factors was conducted to study the effects of different organic materials and different concentrations of exogenous zinc on the soil total zinc, available zinc, zinc forms and zinc content distribution of pak-choi. The results showed that the total zinc, available zinc, and different forms of zinc contents in soil all increased as the concentration of exogenous zinc increased. Both lawn grass and maize straw decreased the total zinc...

Zinc and Copper Effects on Stability of Tubulin and Actin Networks in Dendrites and Spines of Hippocampal Neurons.

Science.gov (United States)

Perrin, Laura; Roudeau, Stéphane; Carmona, Asuncion; Domart, Florelle; Petersen, Jennifer D; Bohic, Sylvain; Yang, Yang; Cloetens, Peter; Ortega, Richard

2017-07-19

Zinc and copper ions can modulate the activity of glutamate receptors. However, labile zinc and copper ions likely represent only the tip of the iceberg and other neuronal functions are suspected for these metals in their bound state. We performed synchrotron X-ray fluorescence imaging with 30 nm resolution to image total biometals in dendrites and spines from hippocampal neurons. We found that zinc is distributed all along the dendrites while copper is mainly pinpointed within the spines. In spines, zinc content is higher within the spine head while copper is higher within the spine neck. Such specific distributions suggested metal interactions with cytoskeleton proteins. Zinc supplementation induced the increase of β-tubulin content in dendrites. Copper supplementation impaired the β-tubulin and F-actin networks. Copper chelation resulted in the decrease of F-actin content in dendrites, drastically reducing the number of F-actin protrusions. These results indicate that zinc is involved in microtubule stability whereas copper is essential for actin-dependent stability of dendritic spines, although copper excess can impair the dendritic cytoskeleton.

Evolution of broadcast content distribution

CERN Document Server

Beutler, Roland

2017-01-01

This book discusses opportunities for broadcasters that arise with the advent of broadband networks, both fixed and mobile. It discusses how the traditional way of distributing audio-visual content over broadcasting networks has been complemented by the usage of broadband networks. The author shows how this also gives the possibility to offer new types of interactive or so-called nonlinear services. The book illustrates how change in distribution technology is accelerating the need for broadcasters around the world to adapt their content distribution strategy and how it will impact the portfolios of content they offer. Outlines the shift in broadcast content distribution paradigms and related strategic issues Provides an overview of the new broadcasting ecosystem encompassing new types of content, user habits, expectations, and devices Discusses complementary usage of different distribution technologies and platforms.

Copper and zinc distribution coefficients for sandy aquifer materials

DEFF Research Database (Denmark)

Christensen, Thomas Højlund; Astrup, Thomas; Boddum, J. K.

2000-01-01

Distribution coe�cients (Kd) were measured for copper (Cu) and zinc (Zn) in laboratory batch experiments for 17 sandy aquifer materials at environmentally relevant solute concentrations (Cu: 5±300 mg/l, Zn: 20±3100 mg/l). The Kd values ranged two to three orders of magnitude (Cu: 70±10,800 l/ kg...

The zinc-myoglobin relationships in porcine muscles

International Nuclear Information System (INIS)

Fogd Joergensen, P.; Wegger, I.

1976-01-01

Zinc and myoglobin content in muscles from pigs were studied under various conditions. Zinc concentration was considerably higher in red than in white muscles. In muscles, where the metabolic pattern changes from glycolytic to oxidative during the period from birth to weaning, a simultaneous increase in zinc content was seen. A significant positive correlation exists between myoglobin and zinc content under normal conditions. However, while myoglobin concentration decreases due to iron deficiency anaemia no changes occur in zinc content. It is concluded that no functional link seems to exist between zinc metabolism and myoglobin synthesis in porcine muscles. (author)

Cathodic protection of steel by electrodeposited zinc-nickel alloy coatings

Energy Technology Data Exchange (ETDEWEB)

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

1995-12-01

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

CONTENT OF ZINC, LEAD AND CADMIUM IN SELECTED AGRICULTURAL SOILS IN THE AREA OF THE ŚLĄSKIE AND CIĘŻKOWICKIE FOOTHILLS

Directory of Open Access Journals (Sweden)

Agnieszka Józefowska

2014-01-01

Full Text Available The purpose of this study was to evaluate the state of contamination with zinc, lead, and cadmium in selected soils of the Śląskie and Ciężkowickie Foothills and to determine the impact of the type of agricultural use and selected physico-chemical properties of soils on heavy metal content. The test soils were characterized by natural content of zinc, lead, and cadmium in most cases. Only one type of soil located on Śląskie Foothills developed increased levels of Cd (1.1 mg · kg-1. The content of zinc, lead, and cadmium in the surface layer (0-30 cm was higher in the soils of Śląskie Foothills than in soils of Ciężkowickie Foothills. The bedrocks from which the soils of these two mesoregions are formed differed significantly only in the content of zinc (it was higher in the soils of Śląskie Foothills. The content of Zn, Pb, and Cd in the surface layer of soil depends on its texture and organic carbon and total nitrogen content. There was also a positive correlation between the content of Pb and Cd and hydrolytic acidity and between the content of Zn and Ca and CEC. Different types of land uses did not influence the content of the metals.

[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.

Effect of gamma radiation and nano-zinc oxide content on the properties of recycled polycarbonate

International Nuclear Information System (INIS)

Carvalho, Ana Luiza F.; Mendes, Luis C.; Cestari, Sibele P.

2015-01-01

In order to promote the barrier action to the ultraviolet radiation and increase of mechanical characteristics, nanocomposites of recycled polycarbonate (rPC) and nano-zinc oxide (nZnO) containing 1, 2 and 3 % (wt/wt) of nano oxide were prepared. Since for obtaining nanocomposites and irradiating polymers are promising tools and attractive for improving the material performance, the effects of nano-zinc oxide and gamma radiation, at doses ranged from 10 to 50 kGy, were evaluated in terms of thermal characteristics of the rPC. The rPC/nZnO nanocomposites were characterized by thermogravimetric analysis (TGA), differential exploratory calorimetry (DSC), infrared spectrometry (FT-IR) and wide angle X-ray diffraction (WAXD). There was a progressive decrease of the T_g as function of gamma dosage and nano-zinc oxide content. Initially, the T_o_n_s_e_t and T_m_a_x decayed as function of gamma dosage but a recovery was observed. The amount of nano-zinc oxide induced a decreasing of T_o_n_s_e_t and T_m_a_x. (author)

Effect of Initial Iron Content in a Zinc Bath on the Dissolution Rate of Iron During a Hot Dip Galvanizing Process

Science.gov (United States)

Lee, Sang Myung; Lee, Suk Kyu; Paik, Doo-Jin; Park, Joo Hyun

2017-04-01

The mechanism of iron dissolution and the effect of initial Fe content in a Zn bath on the dissolution rate of iron were investigated using a finger rotating method (FRM). When the initial iron content, [Fe]°, in the zinc bath was less than the solubility limit, the iron content in the zinc bath showed a rapid increase, whereas a moderate increase was observed when [Fe]° was close to the solubility limit. Based on Eisenberg's kinetic model, the mass transfer coefficient of iron in the present experimental condition was calculated to be k M = 1.2 × 10-5 m/s, which was similar to the results derived by Giorgi et al. under industrial practice conditions. A dissolution of iron occurred even when the initial iron content in the zinc bath was greater than the solubility limit, which was explained by the interfacial thermodynamics in conjunction with the morphology of the surface coating layer. By analyzing the diffraction patterns using TEM, the outermost dendritic-structured coating layer was confirmed as FeZn13 ( ζ). In order to satisfy the local equilibrium based on the Gibbs-Thomson equation, iron in the dendrite-structured phase spontaneously dissolved into the zinc bath, resulting in the enrichment of iron in front of the dendrite tip. Through the diffusion boundary layer in front of the dendritic-structured layer, dissolved Fe atoms diffused out and reacted with Zn and small amounts of Al, resulting in the formation of dross particles such as FeZn10Al x ( δ). It was experimentally confirmed that the smaller the difference between the initial iron content in the zinc bath and the iron solubility limit at a given temperature, the lower the number of formed dross particles.

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

DEFF Research Database (Denmark)

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

2014-01-01

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

[Interaction among the trace elements zinc, copper and iron after depletion and repletion of dairy cows with zinc].

Science.gov (United States)

Kirchgessner, M; Schwarz, F J; Roth, H P; Schwarz, W A

1978-12-01

Imbalances in the supply with trace elements may be caused by the excessive administration of one or several elements or the insufficient administration in relation to other trace elements. This article deals with the interactions between the trace elements zinc and copper resp. zinc and iron under the conditions of the insufficient supply with Zn (6 mg per kg dry matter of the fodder) and the supply according to the demand with other trace elements (14 mg copper resp. 83 mg iron per dry matter of the fodder). For this purpose we investigated the copper, iron and zinc content of the milk and the serum of cows that were first depleted of zinc through a semi-synthetic zinc deficiency diet and then repleted with extra allowances of zinc. The closest connections exist between the copper and zinc content of the milk. Thus extreme Zn-deficiency feeding conditions the decreased Zn-content on the one hand and increased Cu-content on the other. In contrast to this, the cows' Zn-excretion in the milk increases after Zn-repletion whereas the Cu-content decreases. This shows a distinctly negative correlation. A loose connection could only be detected for the Cu- and Zn-content of the serum. Though the Zn-content changed considerably in dependence on the Zn-supply, the Cu-content remained largely uninfluenced. The Fe-content of both milk and serum shows no interaction with the nutritive Zn-supply. Only after 19 test weeks of extreme Zn-deficiency could a slight increase of the Fe-concentration be indicated.

Preparatory studies for the on-line determination of zinc content in zinc ore slurries by radioisotope excited X-ray fluorescence

International Nuclear Information System (INIS)

Donhoffer, D.K.

1977-01-01

Laboratory tests were carried out to prove the feasibility of determination of Zn-content in zinc ore slurries by isotope excited x-ray fluorescence. Matrix effects were investigated on dry samples. A slurry testloop was built and measurements on slurries were made. The results indicated that the measurement on Zn in ore slurries can be made with a precision of 0,05% Zn. A working equation for interpretation of the measurements is derived. (author)

The effect of zinc (Zn) content to cell potential value and efficiency aluminium sacrificial anode in 0.2 M sulphuric acid environment

Science.gov (United States)

Akranata, Ahmad Ridho; Sulistijono, Awali, Jatmoko

2018-04-01

Sacrificial anode is sacirifial component that used to protect steel from corrosion. Generally, the component are made of aluminium and zinc in water environment. Sacrificial anode change the protected metal structure become cathodic with giving current. The advantages of aluminium is corrosion resistance, non toxicity and easy forming. Zinc generally used for coating in steel to prevent steel from corrosion. This research was conducted to analyze the effect of zinc content to the value of cell potential and efficiency aluminium sacrificial anode with sand casting method in 0.2 M sulphuric acid environment. The sacrificial anode fabrication made with alloying aluminium and zinc metals with variation composition of alloy with pure Al, Al-3Zn, Al-6Zn, and Al-9Zn with open die sand casting process. The component installed with ASTM A36 steel. After the research has been done the result showed that addition of zinc content increase the cell potential, protection efficiency, and anode efficiency from steel plate. Cell potential value measurement and weight loss measurement showed that addition of zinc content increase the cell potential value into more positive that can protected the ASTM A36 steel more efficiently that showed in weight loss measurement where the protection efficiency and anodic efficiency of Al-9Zn sacrificial anode is better than protection efficiency and anodic efficiency of pure Al. The highest protection efficiency gotten by Al-9Zn alloy

Content of zinc, iron, calcium and their absorption inhibitors in foods commonly consumed in Ethiopia

NARCIS (Netherlands)

Umeta, M.; West, C.E.; Fufa, H.

2005-01-01

The zinc, iron, calcium, phosphorus, phytate, tannin and moisture content of 36 foods consumed in rural Ethiopia were analysed. The foods analysed included those based on cereals, starchy tubers and roots, and legumes and vegetables as well as some fruits. Although many foods were relatively rich in

Transient current distributions in porous zinc electrodes in KOH electrolyte

Energy Technology Data Exchange (ETDEWEB)

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

1981-02-01

A zero-resistance ammeter circuit with a 10-channel operational amplifier was used to measure the current distribution during a discharge of 10 to 100 mA with simulated zinc porous electrodes in 7.24 M KOH saturated with ZnO. The reaction distribution was found to be highly nonuniform, with 70 to 78% of the charge transfer reaction completed in a depth of 0.01 cm. The high nonuniformity of the initial reaction profile was believed to be due to low conductivity of the electrolyte in the electrode pores. The current distribution changes during passivation of the electrode were experimentally obtained. A mathematical model based upon a macroscope averaging technique was used to predict the time dependence of charge transfer reaction profiles. With mathematical model, current distributions and overpotentials were predicted as a function of time for the segmented zinc electrode discharged at a current of 10 to 100 mA; for these predictions, assumed values of both precipitation rate constants for porous ZnO and diffusion coefficients for hydroxide and zincate ions were used. A gradual decrease in the specific conductivity of the pore electrolyte to 20% of the initial value during discharge yields predictions of current distributions and overpotentials in good agreement with the experimental data. The extent of reduction in the specific conductivity of the pore electrolyte implies a supersaturation of zincate of four times chemical saturation, which was been observed experimentally.At high discharge current (25 to 100 mA), the passivation behavior of the electrode has been simulated. The results of the experiments and mathematical model show that the effective reaction penetration depth is less than 0.02 cm.

Protein, Calcium, Zinc, and Iron Contents of Finger Millet Grain Response to Varietal Differences and Phosphorus Application in Kenya

Directory of Open Access Journals (Sweden)

Wekha N. Wafula

2018-02-01

Full Text Available This study was carried out to investigate the influence of phosphorus fertilizers on the concentrations of nutrients, particularly calcium, protein, zinc, and iron in finger millet grains grown in different agro-ecologies in Kenya. The on-station experiments were carried out at Kiboko (Eastern Kenya, Kakamega, and Alupe (Western Kenya in 2015 during the short and long rainy seasons. The trials were laid out in a randomized complete block design (RCBD in a 4 × 3 factorial arrangement with three replicates. The treatments comprised of four levels of phosphorus (0, 12.5, 25.0 and 37.5 kg ha−1 P2O5 and three finger millet varieties (U-15, P-224 and a local variety. Application of phosphorus significantly (p ≤ 0.05 increased the protein content of finger millet grain in varieties in all the three sites. Variety U-15 had the highest protein content (11.0% at 25 kg ha−1 P2O5 with the control (zero P on variety P-224 eliciting the lowest (4.4% at Kiboko. At Kakamega, the 25 kg ha−1 P2O5 treatment with U-15 variety had the highest protein content (15.3% while the same variety at 12.5 kg ha−1 P2O5 rate elicited the highest protein content (15.0% at Alupe. Phosphorus application significantly enhanced the nutritional quality of finger millet grains specifically protein, calcium, iron, and zinc. Variety P-224 had the highest calcium content in all sites and highest iron content at Kakamega while the local varieties had the highest zinc content in all sites. The varieties responded differently to each quality component but generally, based on the protein content, the 25 kg ha−1 P2O5 is recommended.

Characterization of Cloud Water-Content Distribution

Science.gov (United States)

Lee, Seungwon

2010-01-01

The development of realistic cloud parameterizations for climate models requires accurate characterizations of subgrid distributions of thermodynamic variables. To this end, a software tool was developed to characterize cloud water-content distributions in climate-model sub-grid scales. This software characterizes distributions of cloud water content with respect to cloud phase, cloud type, precipitation occurrence, and geo-location using CloudSat radar measurements. It uses a statistical method called maximum likelihood estimation to estimate the probability density function of the cloud water content.

Incremental distribution of strontium and zinc in great ape and fossil hominin cementum using synchrotron X-ray fluorescence mapping.

Science.gov (United States)

Dean, Christopher; Le Cabec, Adeline; Spiers, Kathryn; Zhang, Yi; Garrevoet, Jan

2018-01-01

Cementum and the incremental markings it contains have been widely studied as a means of ageing animals and retrieving information about diet and nutrition. The distribution of trace elements in great ape and fossil hominin cementum has not been studied previously. Synchrotron X-ray fluorescence (SXRF) enables rapid scanning of large tissue areas with high resolution of elemental distributions. First, we used SXRF to map calcium, phosphorus, strontium and zinc distributions in great ape dentine and cementum. At higher resolution, we compared zinc and strontium distributions in cellular and acellular cementum in regions where clear incremental markings were expressed. We then mapped trace element distributions in fossil hominin dentine and cementum from the 1.55-1.65 million year old site of Koobi Fora, Kenya. Zinc, in particular, is a precise marker of cementum increments in great apes, and is retained in fossil hominin cementum, but does not correspond well with the more diffuse fluctuations observed in strontium distribution. Cementum is unusual among mineralized tissues in retaining so much zinc. This is known to reduce the acid solubility of hydroxyapatite and so may confer resistance to resorption by osteoclasts in the dynamic remodelling environment of the periodontal ligament and alveolar bone. © 2018 The Author(s).

Electrocontact material based on silver dispersion-strengthened by nickel, titanium, and zinc oxides

Science.gov (United States)

Zeer, G. M.; Zelenkova, E. G.; Belousov, O. V.; Beletskii, V. V.; Nikolaev, S. V.; Ledyaeva, O. N.

2017-09-01

Samples of a composite electrocontact material based on silver strengthened by the dispersed phases of zinc and titanium oxides have been investigated by the electron microscopy and energy dispersive X-ray spectroscopy. A uniform distribution of the oxide phases containing 2 wt % zinc oxide in the initial charge has been revealed. The increase in the amount of zinc oxide leads to an increase of the size of the oxide phases. It has been shown that at the zinc oxide content of 2 wt %, the minimum wear is observed in the process of electroerosion tests; at 3 wt %, an overheating and welding of the contacts are observed.

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)

Structural characterization of hog iron oxide content glasses obtained from zinc hydrometallurgy wastes

International Nuclear Information System (INIS)

Romero, M.; Rincon, J.M.; Musik, S.; Kozhujharov, W.

1997-01-01

It has been carried out the structural characterization of high oxide content glasses obtained by melting of a goethite industrial waste from the zinc hydrometallurgy with other raw materials as dolomite and glass cullet. The structural characterization has been carried out by X-ray Diffraction (XRD), X-Ray Diffraction by Amorphous Dispersion (RDF) and Mossbauer spectroscopy. It has been determined the interatomic distance, the oxidation state and the coordination of iron atoms in these glasses. (Author) 16 refs

Chlorophyll content in pine (Pinus silvestris L. needles exposed to flue dust from lead and zinc works

Directory of Open Access Journals (Sweden)

M. Świeboda

2015-01-01

Full Text Available Chlorophyll a and b, sulphur, zinc and lead contents were determined in annual and biennial needles of Scotch pine (Pinus silevstris L. exposed to flue dust-polluted air. Intoxication indexes were calculated on the basis of the obtained results.

[Effect of cultivation in zinc media on the growth of and the degree of zinc in organic form in transgenic metallothionein mushroom].

Science.gov (United States)

Sheng, Ji-Ping; Shen, Lin; Ru, Bing-Gen

2009-03-01

Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich and metal-binding functional proteins. Transgenic MT mushroom can be used as functional food additives, but its zinc-enriching ability has not been studied systemically until now. The zinc contents in mycelia of transgenic MT mushroom (Pleurotus ostreatus) and wild type mushroom mycelia cultivated in different zinc concentration media were analyzed by ICP-OES. The growth status, zinc-enriching ability and degree of zinc in organic form (DZOF) were also analyzed. Results showed that MT mushroom mycelia grew rapidly, but the growth was inhibited when the zinc content in solid media was higher than 1.6 mmol x L(-1). MT mushroom mycelia could enrich more zinc than that of wild type, and the zinc content in MT mushroom mycelia could be 2.56-27.49 mg x kg(-1) when it was cultivated in a liquid media with 0.6-1.2 mmol x L(-1) zinc. DZOF of MT mushroom mycelia in a liquid media with 0.6 mmol x L(-1) zinc at 7 d was significantly higher (88.7%) than that in the wild type (82.1%, alpha = 0.05), but there was no significant difference in DZOF when the MT mushroom mycelia was cultivated in a liquid media with different zinc content at 7 d.

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

Lead and Zinc pollution of soils in the Kabwe lead-zinc mining area

International Nuclear Information System (INIS)

Musonda, B.M.; Tembo, F

2004-01-01

Lead and Zinc pollution of soils related to mining activities in Kabwe district is one of the major environmental problems in Zambia today. In this study, we investigated the distribution of lead and zinc in topsoil and subsoil. Samples were collected from topsoil(0-20cm) and subsoil(20-50cm)at predetermined sites using a 5km x 5km regional grid and a 500m x 500m local grid. After preparation 260 local and 200 regional samples were analysed for heavy metals by atomic absorption spectrophotometry. The background levels of cold HNO3 extractable lead and zinc are 50mg/kg and 70mg/kg respectively. The degree of Pb and Zn contamination of the soils varies with proximity of the soils to Kabwe mining centre. The content of Pb and Zn in topsoil that is very close to the mine is up to 1.6% and 3.9% respectively while soils that are very far from the mine generally contain less than 10mg/kg Pb and 20mg/kg Zn. The heavy metal contamination patterns in soils adjacent to the mine have been formed by wind dispersion of particulate matter and dry deposition. The risk of exposure of humans to lead and zinc is very high in areas that are adjacent to the mining centre. (author)

Uptake and partitioning of zinc in Lemnaceae.

Science.gov (United States)

Lahive, Elma; O'Callaghan, Michael J A; Jansen, Marcel A K; O'Halloran, John

2011-11-01

Macrophytes provide food and shelter for aquatic invertebrates and fish, while also acting as reservoirs for nutrients and trace elements. Zinc accumulation has been reported for various Lemnaceae species. However, comparative accumulation across species and the link between zinc accumulation and toxicity are poorly understood. Morphological distribution and cellular storage, in either bound or soluble form, are important for zinc tolerance. This study shows differences in the uptake and accumulation of zinc by three duckweed species. Landoltia punctata and Lemna minor generally accumulated more zinc than Lemna gibba. L. minor, but not L. gibba or L. punctata, accumulated greater concentrations of zinc in roots compared to fronds when exposed to high levels of zinc. The proportion of zinc stored in the bound form relative to the soluble-form was higher in L. minor. L. punctata accumulated greater concentrations of zinc in fronds compared to roots and increased the proportion of zinc it stored in the soluble form, when exposed to high zinc levels. L. gibba is the only species that significantly accumulated zinc at low concentrations, and was zinc-sensitive. Overall, internal zinc concentrations showed no consistent correlation with toxic effect. We conclude that relationships between zinc toxicity and uptake and accumulation are species specific reflecting, among others, zinc distribution and storage. Differences in zinc distribution and storage are also likely to have implications for zinc bioavailability and trophic mobility.

PIXE characterization of by-products resulting from the zinc recycling of industrial cemented carbides

International Nuclear Information System (INIS)

Freemantle, C.S.; Sacks, N.; Topic, M.; Pineda-Vargas, C.A.

2015-01-01

By-product materials of the widely used zinc recycling process of cemented carbides have been studied. Scanning electron microscopy and micro-PIXE techniques have identified elemental concentrations, distributions and purity of by-product materials from an industrial zinc recycling plant. Cobalt surface enrichment, lamellar microstructures of varying composition, including alternating tungsten carbide (WC) grains and globular cobalt, and regions of excess zinc contamination were found in materials with incomplete zinc penetration. Liquid Co–Zn formation occurred above 72 wt.% Zn at the furnace temperature of 930 °C, and was extracted towards the surface of poorly zinc infiltrated material, primarily by the vacuum used for zinc distillation. Surface enrichment was not observed in material that was zinc infiltrated to the sample center, which was more friable and exhibited more homogeneous porosity and elemental concentrations. The result of incomplete zinc infiltration was an enriched surface zone of up to 60 wt.% Co, compared to an original sample composition of ∼10–15 wt.% Co. The impact on resulting powders could be higher or inhomogeneous cobalt content, as well as unacceptably high zinc concentrations. PIXE has proven it can be a powerful technique for solving industrial problems in the cemented carbide cutting tool industry, by identifying trace elements and their locations (such as Zn to 0.1 wt.% accuracy), as well as the distribution of major elements within WC–Co materials.

PIXE characterization of by-products resulting from the zinc recycling of industrial cemented carbides

Energy Technology Data Exchange (ETDEWEB)

Freemantle, C.S. [School of Chemical & Metallurgical Engineering and DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, P/Bag 3, Wits 2050 (South Africa); Pilot Tools (Pty) (Ltd), P.O. Box 27420, Benrose 2011 (South Africa); Sacks, N. [School of Chemical & Metallurgical Engineering and DST-NRF Centre of Excellence in Strong Materials, University of the Witwatersrand, P/Bag 3, Wits 2050 (South Africa); Topic, M. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health & Wellness Sciences, CPUT, Bellville (South Africa)

2015-11-15

By-product materials of the widely used zinc recycling process of cemented carbides have been studied. Scanning electron microscopy and micro-PIXE techniques have identified elemental concentrations, distributions and purity of by-product materials from an industrial zinc recycling plant. Cobalt surface enrichment, lamellar microstructures of varying composition, including alternating tungsten carbide (WC) grains and globular cobalt, and regions of excess zinc contamination were found in materials with incomplete zinc penetration. Liquid Co–Zn formation occurred above 72 wt.% Zn at the furnace temperature of 930 °C, and was extracted towards the surface of poorly zinc infiltrated material, primarily by the vacuum used for zinc distillation. Surface enrichment was not observed in material that was zinc infiltrated to the sample center, which was more friable and exhibited more homogeneous porosity and elemental concentrations. The result of incomplete zinc infiltration was an enriched surface zone of up to 60 wt.% Co, compared to an original sample composition of ∼10–15 wt.% Co. The impact on resulting powders could be higher or inhomogeneous cobalt content, as well as unacceptably high zinc concentrations. PIXE has proven it can be a powerful technique for solving industrial problems in the cemented carbide cutting tool industry, by identifying trace elements and their locations (such as Zn to 0.1 wt.% accuracy), as well as the distribution of major elements within WC–Co materials.

Selenium and Zinc content and radical scavenging capacity of edible mushrooms Armilaria mellea and Lycoperdon saccatum

Directory of Open Access Journals (Sweden)

Z. Zeković

2010-01-01

Full Text Available Armillaria mellea and Lycoperdon saccatum are two delicious mushrooms growing widely trough all Balkan region. Investigation of A. mellea and L. saccatum antioxidant properties includes preparation of mushrooms extracts, determination of Selenium and Zinc content and evaluation of theirs antioxidant activity involving scavenging activity of ˙O2- radicals, DPPH and reducing power assay. Higher extraction yield of 24.48 % has been achieved for L. saccatum, but higher content of Selenium and Zinc was determined in A. mallea extract, 2.359 mg/kg and 50.380 mg/kg, respectively. The radical scavenging activity was found to exhibit 50 % of inhibition value (IC50 value at the extracts concentration of 0.0161±0.0001 mg/ml for the L. saccatum extract and 0.0108±0.0002 mg/ml for A. mallea extract. The determined relative inhibition of ˙O2- radicals for L. sacatum extract is lower than for A. malea. It was determined that both mushrooms extract posses’ reductive capabilities and thus were capable of reducing iron (III.

Localized zinc distribution in shark vertebrae suggests differential deposition during ontogeny and across vertebral structures.

Science.gov (United States)

Raoult, Vincent; Howell, Nicholas; Zahra, David; Peddemors, Victor M; Howard, Daryl L; de Jonge, Martin D; Buchan, Benjamin L; Williamson, Jane E

2018-01-01

The development of shark vertebrae and the possible drivers of inter- and intra-specific differences in vertebral structure are poorly understood. Shark vertebrae are used to examine life-history traits related to trophic ecology, movement patterns, and the management of fisheries; a better understanding of their development would be beneficial to many fields of research that rely on these calcified structures. This study used Scanning X-ray Fluorescence Microscopy to observe zinc distribution within vertebrae of ten shark species from five different orders. Zinc was mostly localised within the intermedialis and was generally detected at levels an order of magnitude lower in the corpus calcareum. In most species, zinc concentrations were higher pre-birth mark, indicating a high rate of pre-natal zinc deposition. These results suggest there are inter-specific differences in elemental deposition within vertebrae. Since the deposition of zinc is physiologically-driven, these differences suggest that the processes of growth and deposition are potentially different in the intermedialis and corpus calcareum, and that caution should be taken when extrapolating information such as annual growth bands from one structure to the other. Together these results suggest that the high inter-specific variation in vertebral zinc deposition and associated physiologies may explain the varying effectiveness of ageing methodologies applied to elasmobranch vertebrae.

Histochemical distribution of zinc in the brain of the rainbow trout, Oncorhynchos myciss. I. The telencephalon

DEFF Research Database (Denmark)

Piñuela, C; Baatrup, E; Geneser, F A

1992-01-01

was mainly confined to the neuropil, but both moderately and intensely stained nerve cell bodies were of common occurrence. Stained fibers were never observed. The staining revealed a specific distribution pattern which could easily be correlated with the telencephalic nuclei defined on the basis......The present paper which describes the distribution of zinc in the telencephalon of the rainbow trout, Oncorhynchos myciss, is the first report on the distribution of a heavy metal in the fish brain. Zinc was demonstrated histochemically by silver enhancement using the Neo-Timm method. The staining...... of cytoarchitectural features. However, the telencephalon stained much more weakly than the rest of the brain, in striking contrast to the situation in the reptilian, mammalian, and avian brain. In these classes, high staining intensities are observed almost exclusively in the telencephalon. The staining...

The distribution of Magnesium, Zinc & Copper in the skin and hair of ...

African Journals Online (AJOL)

The distribution of magnesium, zinc and copper was investigated in the hair and skin of African dwarf sheep. The 3 elements were found to be present in varying degrees in these organs. All were more abundant in the hair than in the skin. For instance, 2026 ppm were the highest amount of magnesium found in the hair ...

CONTENT OF ZINC, LEAD AND CADMIUM IN SELECTED AGRICULTURAL SOILS IN THE AREA OF THE ŚLĄSKIE AND CIĘŻKOWICKIE FOOTHILLS

OpenAIRE

Agnieszka Józefowska; Anna Miechówka; Michał Gąsiorek; Paweł Zadrożny

2014-01-01

The purpose of this study was to evaluate the state of contamination with zinc, lead, and cadmium in selected soils of the Śląskie and Ciężkowickie Foothills and to determine the impact of the type of agricultural use and selected physico-chemical properties of soils on heavy metal content. The test soils were characterized by natural content of zinc, lead, and cadmium in most cases. Only one type of soil located on Śląskie Foothills developed increased levels of Cd (1.1 mg · kg-1). The conte...

Copper and zinc content in wild game shot with lead or non-lead ammunition - implications for consumer health protection.

Science.gov (United States)

Schlichting, Daniela; Sommerfeld, Christine; Müller-Graf, Christine; Selhorst, Thomas; Greiner, Matthias; Gerofke, Antje; Ulbig, Ellen; Gremse, Carl; Spolders, Markus; Schafft, Helmut; Lahrssen-Wiederholt, Monika

2017-01-01

The aim of this study was to examine the contamination of game meat with copper and zinc and establish whether the use of alternative (non-lead) ammunition can lead to higher or unsafe levels of copper and zinc in the meat of roe deer, wild boar and red deer. The research project "Safety of game meat obtained through hunting" (LEMISI) was conducted in Germany with the purpose of examining the entry of lead as well as copper and zinc into the meat of hunted game when using either lead or non-lead ammunition. The outcome of this study shows that the usage of both lead-based ammunition and alternative non-lead ammunition results in the entry of copper and zinc into the edible parts of the game. Using non-lead ammunition does not entail dangerously elevated levels of copper and zinc, so replacing lead ammunition with alternative ammunition does not introduce a further health problem with regard to these metals. The levels of copper and zinc in game meat found in this study are in the range found in previous studies of game. The content of copper and zinc in game meat is also comparable to those regularly detected in meat and its products from livestock (pig, cattle, sheep) for which the mean human consumption rate is much higher. From the viewpoint of consumer health protection, the use of non-lead ammunition does not pose an additional hazard through copper and zinc contamination. A health risk due to the presence of copper and zinc in game meat at typical levels of consumer exposure is unlikely for both types of ammunition.

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.

Localized zinc distribution in shark vertebrae suggests differential deposition during ontogeny and across vertebral structures.

Directory of Open Access Journals (Sweden)

Vincent Raoult

Full Text Available The development of shark vertebrae and the possible drivers of inter- and intra-specific differences in vertebral structure are poorly understood. Shark vertebrae are used to examine life-history traits related to trophic ecology, movement patterns, and the management of fisheries; a better understanding of their development would be beneficial to many fields of research that rely on these calcified structures. This study used Scanning X-ray Fluorescence Microscopy to observe zinc distribution within vertebrae of ten shark species from five different orders. Zinc was mostly localised within the intermedialis and was generally detected at levels an order of magnitude lower in the corpus calcareum. In most species, zinc concentrations were higher pre-birth mark, indicating a high rate of pre-natal zinc deposition. These results suggest there are inter-specific differences in elemental deposition within vertebrae. Since the deposition of zinc is physiologically-driven, these differences suggest that the processes of growth and deposition are potentially different in the intermedialis and corpus calcareum, and that caution should be taken when extrapolating information such as annual growth bands from one structure to the other. Together these results suggest that the high inter-specific variation in vertebral zinc deposition and associated physiologies may explain the varying effectiveness of ageing methodologies applied to elasmobranch vertebrae.

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

Antibacterial, antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs.

Science.gov (United States)

Nunes, Ricardo; Pasko, Pawel; Tyszka-Czochara, Malgorzata; Szewczyk, Agnieszka; Szlosarczyk, Marek; Carvalho, Isabel S

2017-12-01

Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal. To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc. Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48 h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24 h) was tested using HEP G2 cells and fibroblasts. Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90 mg AAE/g dw and 783.48 mg TE/g dw, respectively). CM had the highest zinc concentration (37.21 mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91 mg/100 g dw). LS was rich in rosmarinic acid (301.71 mg/100 g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830 μg/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content. The most promising plants for further studies are CM, LS and GP.

Laminar-specific distribution of zinc: evidence for presence of layer IV in forelimb motor cortex in the rat.

Science.gov (United States)

Alaverdashvili, Mariam; Hackett, Mark J; Pickering, Ingrid J; Paterson, Phyllis G

2014-12-01

The rat is the most widely studied pre-clinical model system of various neurological and neurodegenerative disorders affecting hand function. Although brain injury to the forelimb region of the motor cortex in rats mostly induces behavioral abnormalities in motor control of hand movements, behavioral deficits in the sensory-motor domain are also observed. This questions the prevailing view that cortical layer IV, a recipient of sensory information from the thalamus, is absent in rat motor cortex. Because zinc-containing neurons are generally not found in pathways that run from the thalamus, an absence of zinc (Zn) in a cortical layer would be suggestive of sensory input from the thalamus. To test this hypothesis, we used synchrotron micro X-ray fluorescence imaging to measure Zn distribution across cortical layers. Zn maps revealed a heterogeneous layered Zn distribution in primary and secondary motor cortices of the forelimb region in the adult rat. Two wider bands with elevated Zn content were separated by a narrow band having reduced Zn content, and this was evident in two rat strains. The Zn distribution pattern was comparable to that in sensorimotor cortex, which is known to contain a well demarcated layer IV. Juxtaposition of Zn maps and the images of brain stained for Nissl bodies revealed a "Zn valley" in primary motor cortex, apparently starting at the ventral border of pyramidal layer III and ending at the close vicinity of layer V. This finding indicates the presence of a conspicuous cortical layer between layers III and V, i.e. layer IV, the presence of which previously has been disputed. The results have implications for the use of rat models to investigate human brain function and neuropathology, such as after stroke. The presence of layer IV in the forelimb region of the motor cortex suggests that therapeutic interventions used in rat models of motor cortex injury should target functional abnormalities in both motor and sensory domains. The finding

Nanocarrier-mediated foliar zinc fertilization influences expression of metal homeostasis related genes in flag leaves and enhances gluten content in durum wheat.

Science.gov (United States)

Deshpande, Paresh; Dapkekar, Ashwin; Oak, Manoj; Paknikar, Kishore; Rajwade, Jyutika

2018-01-01

Wheat is the staple food for most of the world's population; however, it is a poor source of zinc. Foliar fertilization of zinc via zinc loaded chitosan nanocarriers (Zn-CNP) post-anthesis has proved to be a promising approach for grain zinc enhancement in durum wheat as evidenced in our earlier study. However, the molecular mechanism of uptake of zinc via Zn-CNP remains unclear. Foliar application of Zn-CNP was performed at post anthesis stages in two durum wheat cultivars (MACS 3125 and UC1114, containing the Gpc-B1 gene), and expression levels of several metal-related genes were analyzed during early senescence. Zn-CNP application indeed caused changes in gene expression as revealed by qPCR data on representative genes involved in metal homeostasis, phloem transporters, and leaf senescence. Furthermore, zinc-regulated transporters and iron (Fe)-regulated transporter-like protein (ZIP) family [ZIP1, ZIP7, ZIP15], CA (carbonic anhydrase), and DMAS (2'-deoxymugineic acid synthase) in flag leaves exhibited significant correlation with zinc content in the seeds. The analysis of grain endosperm proteins showed enhancement of gamma gliadins while other gluten subunits decreased. Gene expression within ZIP family members varied with the type of cultivar mostly attributed to the Gpc-B1, concentration of external zinc ions as well as the type of tissue analyzed. Correlation analysis revealed the involvement of the selected genes in zinc enhancement. At the molecular level, uptake of zinc via Zn-CNP nanocarrier was comparable to the uptake of zinc via common zinc fertilizers i.e. ZnSO4.

Nanocarrier-mediated foliar zinc fertilization influences expression of metal homeostasis related genes in flag leaves and enhances gluten content in durum wheat.

Directory of Open Access Journals (Sweden)

Paresh Deshpande

Full Text Available Wheat is the staple food for most of the world's population; however, it is a poor source of zinc. Foliar fertilization of zinc via zinc loaded chitosan nanocarriers (Zn-CNP post-anthesis has proved to be a promising approach for grain zinc enhancement in durum wheat as evidenced in our earlier study. However, the molecular mechanism of uptake of zinc via Zn-CNP remains unclear.Foliar application of Zn-CNP was performed at post anthesis stages in two durum wheat cultivars (MACS 3125 and UC1114, containing the Gpc-B1 gene, and expression levels of several metal-related genes were analyzed during early senescence. Zn-CNP application indeed caused changes in gene expression as revealed by qPCR data on representative genes involved in metal homeostasis, phloem transporters, and leaf senescence. Furthermore, zinc-regulated transporters and iron (Fe-regulated transporter-like protein (ZIP family [ZIP1, ZIP7, ZIP15], CA (carbonic anhydrase, and DMAS (2'-deoxymugineic acid synthase in flag leaves exhibited significant correlation with zinc content in the seeds. The analysis of grain endosperm proteins showed enhancement of gamma gliadins while other gluten subunits decreased. Gene expression within ZIP family members varied with the type of cultivar mostly attributed to the Gpc-B1, concentration of external zinc ions as well as the type of tissue analyzed. Correlation analysis revealed the involvement of the selected genes in zinc enhancement.At the molecular level, uptake of zinc via Zn-CNP nanocarrier was comparable to the uptake of zinc via common zinc fertilizers i.e. ZnSO4.

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.

Effects of zinc complexes on the distribution of zinc in calcareous soil and zinc uptake by maize.

Science.gov (United States)

Alvarez, José M; Rico, María I

2003-09-10

The movement and availability of Zn from six organic Zn sources in a Typic Xerorthent (calcareous) soil were compared by incubation, column assay, and in a greenhouse study with maize (Zea mays L.). Zinc soil behavior was studied by sequential, diethylenetriaminepentaacetate, and Mehlich-3 extractions. In the incubation experiment, the differences in Zn concentration observed in the water soluble plus exchangeable fraction strongly correlated with Zn uptake by plants in the greenhouse experiment. Zinc applied to the surface of soil columns scarcely moved into deeper layers except for Zn-ethylenediaminetetraacetate (EDTA) that showed the greatest distribution of labile Zn throughout the soil and the highest proportion of leaching of the applied Zn. In the upper part of the column, changes in the chemical forms of all treatments occurred and an increase in organically complexed and amorphous Fe oxide-bound fractions was detected. However, the water soluble plus exchangeable fraction was not detected. The same results were obtained at the end of the greenhouse experiment. Significant increases were found in plant dry matter yield and Zn concentration as compared with the control treatment without Zn addition. Increasing Zn rate in the soil increased dry matter yield in all cases but Zn concentration in the plant increased only with Zn-EDTA and Zn-ethylenediaminedi-o-hydroxyphenyl-acetate (EDDHA) fertilizers. Higher Zn concentration in plants (50.9 mg kg(-)(1)) occurred when 20 mg Zn kg(-)(1) was added to the soil as Zn-EDTA. The relative effectiveness of the different Zn carriers in increasing Zn uptake was in the order: Zn-EDTA > Zn-EDDHA > Zn-heptagluconate >/= Zn-phenolate approximately Zn-polyflavonoid approximately Zn-lignosulfonate.

Enabling content distribution in vehicular ad hoc networks

CERN Document Server

Luan, Tom H; Bai, Fan

2014-01-01

This SpringerBrief presents key enabling technologies and state-of-the-art research on delivering efficient content distribution services to fast moving vehicles. It describes recent research developments and proposals towards the efficient, resilient and scalable content distribution to vehicles through both infrastructure-based and infrastructure-less vehicular networks. The authors focus on the rich multimedia services provided by vehicular environment content distribution including vehicular communications and media playback, giving passengers many infotainment applications. Common problem

Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue☆

Science.gov (United States)

Pemmer, B.; Roschger, A.; Wastl, A.; Hofstaetter, J.G.; Wobrauschek, P.; Simon, R.; Thaler, H.W.; Roschger, P.; Klaushofer, K.; Streli, C.

2013-01-01

Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radiation induced micro X-ray fluorescence analysis (SR μ-XRF) in combination with quantitative backscattered electron imaging (qBEI) to determine the distribution and accumulation of Zn, Sr, and Pb in human bone tissue. Fourteen human bone samples (10 femoral necks and 4 femoral heads) from individuals with osteoporotic femoral neck fractures as well as from healthy individuals were analyzed. Fluorescence intensity maps were matched with BE images and correlated with calcium (Ca) content. We found that Zn and Pb had significantly increased levels in the cement lines of all samples compared to the surrounding mineralized bone matrix. Pb and Sr levels were found to be correlated with the degree of mineralization. Interestingly, Zn intensities had no correlation with Ca levels. We have shown for the first time that there is a differential accumulation of the trace elements Zn, Pb and Sr in BSUs of human bone indicating different mechanisms of accumulation. PMID:23932972

Inhibitory zinc-enriched terminals in mouse spinal cord

DEFF Research Database (Denmark)

Danscher, G; Jo, S M; Varea, E

2001-01-01

The ultrastructural localization of zinc transporter-3, glutamate decarboxylase and zinc ions in zinc-enriched terminals in the mouse spinal cord was studied by zinc transporter-3 and glutamate decarboxylase immunohistochemistry and zinc selenium autometallography, respectively.The distribution...

Copper, manganese, zinc and magnesium content in endocrine organs of horses, cattle and pigs

Energy Technology Data Exchange (ETDEWEB)

Stoeckl, W; Weiser, M

1968-07-01

In horses, cattle and pigs the content of copper, manganese, zinc and magnesium was determined in the pituitary, adrenal, thyroid, pancreas, ovary and thymus, and the mean values and standard deviations were determined. Within the same animal there were considerable variations of each element as between the different endocrine glands and similar significant differences from one animal to another. These results are not extensive enough to permit any conclusion on the relationship of the examined elements to the endocrine function or their influence on the enzyme activity. 1 table.

The study and microstructure analysis of zinc and zinc oxide

Directory of Open Access Journals (Sweden)

N. Luptáková

2015-01-01

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

Contents of cadmium, copper, zinc, and lead in organs of Rhizophora mangle in Sevilla River mouth - Cienaga Grande de Santa Marta, Colombian Caribbean

International Nuclear Information System (INIS)

Naranjo Sanchez, Yury A; Troncoso, Olivo Walberto

2008-01-01

In order to determine the contents of cadmium, copper, zinc, and lead in leaves, stalks, and root of Rhizophora mangle, samples from three parcels located in the river Sevilla mouth - Cienaga Grande de Santa Marta, were taken in October 2003. Measures of metals concentrations were made through the Inductively Coupled Plasma Atomic Emission Spectrometry technique (ICP-AES). The results indicated that lead concentration in R. mangle organs was below method detection limit ≤38 g/g) except the absorbent root (16.3 g/g); and significant differences exist in the contents of cadmium, copper, zinc, and lead into R. mangle organs, following this concentration order: absorbent roots ≥ stalk ≥ young leaves ≥adult leaves ≥ aerial roots

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.

Cytoarchitectonic distribution of zinc in the hippocampus of man and the rat

International Nuclear Information System (INIS)

Frederickson, C.J.; Klitenick, M.A.; Manton, W.I.; Kirkpatrick, J.B.

1983-01-01

Zinc was measured in whole hippocampus and in hippocampal sub-regions by stable-isotope dilution mass spectrometry. Lyophilized tissues were spiked by a precisely-known amount of zinc-64. The zinc-64/zinc-66 isotope ratio was determined by mass spectrometry. In both man and the rat, the most zinc (102-145 ppm, dry weight) was found in the hilar region, the least (27-35) in the fimbria. The amount of zinc directly associated with mossy-fiber axons was estimated to be approximately 8% of the total zinc in the hippocampus, and the concentration of mossy-fiber zinc was estimated at 220-300 μM. Methodological and theoretical implications of the quantitative findings were discussed. (Auth.)

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.

Differences in zinc status between patients with osteoarthritis and osteoporosis

DEFF Research Database (Denmark)

Ovesen, Janne; Møller-Madsen, Bjarne; Nielsen, Poul Torben

2009-01-01

Zinc has been suggested to play an important role in the development of osteoporosis, whereas the influence of zinc on osteoarthritis has attracted much less attention. The aim of the study was to investigate and compare the zinc status and bone turnover, density, and biomechanical properties...... of osteoarthritic and osteoporotic patients. The study comprised 40 women who underwent hip replacement due to osteoarthritis or osteoporosis. Serum and urine zinc content, and bone resorption markers and serum bone formation markers were determined. The unaffected hip and the exarticulated affected femoral head...... underwent DEXA scanning. Bone biopsies were obtained from the femoral heads and the biomechanical properties were determined. The biopsies were ashed and the bone zinc content was ascertained. Osteoarthritic patients had significantly higher serum zinc concentrations and lower urine zinc concentrations than...

Influence of zinc deficiency on cell-membrane fluidity in Jurkat, 3T3 and IMR-32 cells.

Science.gov (United States)

Verstraeten, Sandra V; Zago, M Paola; MacKenzie, Gerardo G; Keen, Carl L; Oteiza, Patricia I

2004-01-01

We investigated whether zinc deficiency can affect plasma membrane rheology. Three cell lines, human leukaemia T-cells (Jurkat), rat fibroblasts (3T3) and human neuroblastoma cells (IMR-32), were cultured for 48 h in control medium, in zinc-deficient medium (1.5 microM zinc; 1.5 Zn), or in the zinc-deficient medium supplemented with 15 microM zinc (15 Zn). The number of viable cells was lower in the 1.5 Zn group than in the control and 15 Zn groups. The frequency of apoptosis was higher in the 1.5 Zn group than in the control and 15 Zn groups. Membrane fluidity was evaluated using the 6-(9-anthroyloxy)stearic acid and 16-(9-anthroyloxy)palmitic acid probes. Membrane fluidity was higher in 1.5 Zn cells than in the control cells; no differences were observed between control cells and 15 Zn cells. The effect of zinc deficiency on membrane fluidity at the water/lipid interface was associated with a higher phosphatidylserine externalization. The higher membrane fluidity in the hydrophobic region of the bilayer was correlated with a lower content of arachidonic acid. We suggest that the increased fluidity of the membrane secondary to zinc deficiency is in part due to a decrease in arachidonic acid content and the apoptosis-related changes in phosphatidylserine distribution. PMID:14629198

Influence of Silane modified nano silica on the corrosion protection of zinc rich coating

International Nuclear Information System (INIS)

Nguyen Thuy Duong; To Thi Xuan Hang; Trinh Anh Truc; Pham Gia Vu; Bui Van Truoc; Thai Hoang

2015-01-01

Zinc rich coatings are the best effective primers for corrosion protection of carbon steel in aggressive conditions. For traditional zinc rich primer the zinc content is very high, more than 90 wt.%. The coating adhesion is decreased with the increase of zinc content, so that it is necessary to decrease the zinc content by using additives. In this study the nano silica modified by N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane was prepared and incorporated in zinc rich epoxy coatings containing 85 wt.% zinc powder. The corrosion protection performance of coatings was evaluated by electrochemical impedance spectroscopy. The results obtained show that the presence of nano silica improved corrosion protection of zinc rich epoxy coating and the best protection was obtained with 3 wt.% nano silica. (author)

Zinc fractionation in contaminated soils by sequential and single extractions: influence of soil properties and zinc content.

Science.gov (United States)

Voegelin, Andreas; Tokpa, Gerome; Jacquat, Olivier; Barmettler, Kurt; Kretzschmar, Ruben

2008-01-01

We studied the fractionation of zinc (Zn) in 49 contaminated soils as influenced by Zn content and soil properties using a seven-step sequential extraction procedure (F1: NH4NO3; F2: NH4-acetate, pH 6; F3: NH3OHCl, pH 6; F4: NH4-EDTA, pH 4.6; F5: NH4-oxalate, pH 3; F6: NH4-oxalate/ascorbic acid, pH 3; F7: residual). The soils had developed from different geologic materials and covered a wide range in soil pH (4.0-7.3), organic C content (9.3-102 g kg(-1)), and clay content (38-451 g kg(-1)). Input of aqueous Zn with runoff water from electricity towers during 26 to 74 yr resulted in total soil Zn contents of 3.8 to 460 mmol kg(-1). In acidic soils (n = 24; pH soils (n = 25; pH > or =6.0), most Zn was extracted in the mobilizable fraction (F2) and the intermediate fractions (F4 and F5). The extractability of Zn increased with increasing Zn contamination of the soils. The sum of mobile (F1) and mobilizable (F2) Zn was independent of soil pH, the ratio of Zn in F1 over F1+F2 plotted against soil pH, exhibited the typical shape of a pH sorption edge and markedly increased from pH 6 to pH 5, reflecting the increasing lability of mobilizable Zn with decreasing soil pH. In conclusion, the extractability of Zn from soils contaminated with aqueous Zn after decades of aging under field conditions systematically varied with soil pH and Zn content. The same trends are expected to apply to aqueous Zn released from decomposing Zn-bearing contaminants, such as sewage sludge or smelter slag. The systematic trends in Zn fractionation with varying soil pH and Zn content indicate the paramount effect of these two factors on molecular scale Zn speciation. Further research is required to characterize the link between the fractionation and speciation of Zn and to determine how Zn loading and soil physicochemical properties affect Zn speciation in soils.

Uniform distribution of TiCp in TiCp/Zn-Al composites prepared by XDTM

Institute of Scientific and Technical Information of China (English)

王香; 马旭梁; 李庆芬; 曾松岩

2002-01-01

The prefabricated Al/TiC alloy with high TiC particle content was prepared by XDTM process. The uniform distribution process of TiC particles in the stationary zinc melt was studied and analyzed using self-made experimental equipment, and the model of the uniform distribution process was built. The results show that zinc diffuses into the prepared Al/TiC alloy after it is placed in the zinc melt at temperatures below the melting point of aluminum, which leads to the decrease of the liquidus temperature of Al-Zn alloy in the surface layer of Al/TiC alloy. When the liquidus temperature of Al-Zn alloy is equal to or below the temperature of zinc melt, Al-Zn alloy melts and TiC particles drop with it from the Al/TiC alloy and then transfer into the zinc melt and finally distribute uniformly in it.

Effect of phosphorus and organic matter on zinc availability on rice

International Nuclear Information System (INIS)

Gupta, G.N.; Kamath, M.B.; Motsara, M.R.

1977-01-01

Pot culture experiment was conducted on grey brown podzolic soil (Palampur) and Tarai soil (Pantnagar) to study the influence of the addition of organic matter, phosphorus and zinc on the uptake and utilization of zinc by rice crop. In podzolic soils the combined application of Zn-P and Zn-organic matter resulted in reduced zinc content in crop but the crop yield was not affected. The uptake and utilization of applied zinc increased with P application. In Tarai soil, crop response to Zn, P and organic matter was obtained when applied separately. A negative zinc x P and zinc x organic matter interaction was obtained on yield. However, zinc content of the crop increased due to the application of P, organic matter and zinc. The uptake and utilization of applied zinc increased with P application. The analysis of soils after crop harvest indicated an increased amount of 0.1 N HCl extractable zinc in soils treated with zinc in Tarai soils while in podzolic soil from Palampur, the available zinc increased only under the combined application of zinc and P. (author)

Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue.

Science.gov (United States)

Pemmer, B; Roschger, A; Wastl, A; Hofstaetter, J G; Wobrauschek, P; Simon, R; Thaler, H W; Roschger, P; Klaushofer, K; Streli, C

2013-11-01

Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radiation induced micro X-ray fluorescence analysis (SR μ-XRF) in combination with quantitative backscattered electron imaging (qBEI) to determine the distribution and accumulation of Zn, Sr, and Pb in human bone tissue. Fourteen human bone samples (10 femoral necks and 4 femoral heads) from individuals with osteoporotic femoral neck fractures as well as from healthy individuals were analyzed. Fluorescence intensity maps were matched with BE images and correlated with calcium (Ca) content. We found that Zn and Pb had significantly increased levels in the cement lines of all samples compared to the surrounding mineralized bone matrix. Pb and Sr levels were found to be correlated with the degree of mineralization. Interestingly, Zn intensities had no correlation with Ca levels. We have shown for the first time that there is a differential accumulation of the trace elements Zn, Pb and Sr in BSUs of human bone indicating different mechanisms of accumulation. © 2013. Published by Elsevier Inc. All rights reserved.

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.

A multi-technique investigation of copper and zinc distribution, speciation and potential bioavailability in biosolids

International Nuclear Information System (INIS)

Donner, E.; Ryan, C.G.; Howard, D.L.; Zarcinas, B.; Scheckel, K.G.; McGrath, S.P.; Jonge, M.D. de; Paterson, D.; Naidu, R.; Lombi, E.

2012-01-01

The use of biosolids in agriculture continues to be debated, largely in relation to their metal contents. Our knowledge regarding the speciation and bioavailability of biosolids metals is still far from complete. In this study, a multi-technique approach was used to investigate copper and zinc speciation and partitioning in one contemporary and two historical biosolids used extensively in previous research and field trials. Using wet chemistry and synchrotron spectroscopy techniques it was shown that copper/zinc speciation in the biosolids was largely equivalent despite the biosolids being derived from different countries over a 50 year period. Furthermore, copper speciation was consistently dominated by sorption to organic matter whereas Zn partitioned mainly to iron oxides. These data suggest that the results of historical field trials are still relevant for modern biosolids and that further risk assessment studies should concentrate particularly on Cu as this metal is associated with the mineralisable biosolids fraction. - Highlights: ► Complementary techniques were used to investigate Cu and Zn speciation in biosolids. ► Historic and contemporary biosolids with differing metal contents were examined. ► Similarities in Cu/Zn speciation were observed irrespective of biosolids provenance. ► Key binding environments identified were organic matter for Cu and Fe oxides for Zn. ► Similarities show historic field trial results are still relevant for biosolids management. - Historic and contemporary biosolids show similarities in Cu/Zn speciation despite having very different total Zn/Cu contents.

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

International Nuclear Information System (INIS)

Zhu Liqun; Zhang Hui; Li Weiping; Liu Huicong

2008-01-01

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

Path coefficient analysis of zinc dynamics in varying soil environment

International Nuclear Information System (INIS)

Rattan, R.K.; Phung, C.V.; Singhal, S.K.; Deb, D.L.; Singh, A.K.

1994-01-01

Influence of soil properties on labile zinc, as measured by diethylene-triamine pentaacetic acid (DTPA) and zinc-65, and self-diffusion coefficients of zinc was assessed on 22 surface soil samples varying widely in their characteristics following linear regression and path coefficient analysis techniques. DTPA extractable zinc could be predicted from organic carbon status and pH of the soil with a highly significant coefficient of determination (R 2 =0.84 ** ). Ninety seven per cent variation in isotopically exchangeable zinc was explained by pH, clay content and cation exchange capacity (CEC) of soil. The self-diffusion coefficients (DaZn and DpZn) and buffer power of zinc exhibited exponential relationship with soil properties, pH being the most dominant one. Soil properties like organic matter, clay content etc. exhibited indirect effects on zinc diffusion rates via pH only. (author). 13 refs., 6 tabs

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.

EFFECT OF ALUMINIUM AND MAGNESIUM ON THE CORROSION RESISTANCE OF ZINC COATINGS

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Leszek Klimek

2017-06-01

Full Text Available This article presents the research on corrosion resistance of Zn-Al-Mg coatings with varying aluminium and magnesium content. Aluminium and magnesium were added directly to the zinc bath at 10:1 rate. There was found more than sixfold increase in corrosion resistance of zinc coatings with aluminium content at the level of 4% of weight and magnesium content at the level of 0.4% of weight. In contrast to the amounts applied in the literature, such content of these alloy additives in the zinc bath limits to a significant extent the amount of intermetallic phases in zinc coatings obtained from such baths. This, in consequence, results in high resistance to corrosion with simultaneous retention of high plasticity of these coatings.

Zinc in human serum

International Nuclear Information System (INIS)

Kiilerich, S.

1987-01-01

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

The Effect of Phosphorus and Zinc Fertilizers on Nutrient Content and Essential Oil Yield of German Chamomile under Drought Stress (Matricaria recutita L.

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M. Ghaedi Jeshni

2016-07-01

Full Text Available Introduction: The German chamomile (Matricaria recutita L. is mainly cultivated for essential oil. Nowadays, it is a highly favored and much-used medicinal plant in reqular and traditional medicine. Water deficit is one of the most important limiting factors on crops production in arid and semi-arid regions (Sharafi et al. 2002. Drought stress limits the growth of plants by reducing water content of tissues and causes some metabolic and physiological changes. On the other hand, the availability of nutrients in the soil is affected by drought stress. Thus, nutritional management of plants under drought stress conditions is one of the most important factors in crop production. A better understanding of the role of nutrients in plant resistance to drought is associated with improvement of fertilizer management in arid and semi-arid areas. Our objectives were to investigate the effects of phosphorus and zinc fertilizers on nutrient content and essential oil yield of German chamomile under drought stress. Material and Methods: The experiment was conducted in split plot factorial based on randomized complete block design with three replications at Research farm of University of Zabol in 2013. Drought stress consisted of three levels 75% (control, 50% (mild stress and 25% of field capacity (severe stress as main plots, and factorial combinations of three triple superphosphate fertilizer (CaH4P2O8 levels (0, 150, and 300 kg ha-1 and two zinc sulphate fertilizer (ZnSO4H2O levels (0 and 30 kg ha-1 as sub plots (the fertilizers were applied before planting time. The seeds were sown at 20 cm apart in rows 40 cm wide, on first half of March 2013. Drought stress levels were determined by the Time Domain Reflectometry (TDR. The success of chamomile cultivation as a commercial venture lies in how efficiently and effectively one can collect the flowers at the right stage during the peak flowering season extending over a period of 3–6 weeks. So, flowers were

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

Science.gov (United States)

Tripathi, Bhumika; Platel, Kalpana

2010-01-01

Millets, being less expensive compared to cereals and the staple for the poorer sections of population, could be the choice for fortification with micronutrients such as zinc. In view of this, finger millet, widely grown and commonly consumed in southern India, was explored as a vehicle for fortification with zinc in this investigation. Finger millet flour fortified with either zinc oxide or zinc stearate so as to provide 50mg zinc per kg flour, was specifically examined for the bioaccessibility of the fortified mineral, as measured by in vitro simulated gastrointestinal digestion procedure and storage stability. Addition of the zinc salts increased the bioaccessible zinc content by 1.5-3 times that of the unfortified flour. Inclusion of EDTA along with the fortified salt significantly enhanced the bioaccessibility of zinc from the fortified flours, the increase being three-fold. Inclusion of citric acid along with the zinc salt and EDTA during fortification did not have any additional beneficial effect on zinc bioaccessiblity. Moisture and free fatty acid contents of the stored fortified flours indicated the keeping quality of the same, up to 60 days. Both zinc oxide and zinc stearate were equally effective as fortificants, when used in combination with EDTA as a co-fortificant. The preparation of either roti or dumpling from the fortified flours stored up to 60 days did not result in any significant compromise in the bioaccessible zinc content. Thus, the present study has revealed that finger millet flour can effectively be used as a vehicle for zinc fortification to derive additional amounts of bioaccessible zinc, with reasonably good storage stability, to combat zinc deficiency. Copyright 2009 Elsevier GmbH. All rights reserved.

Estimating the global prevalence of zinc deficiency: results based on zinc availability in national food supplies and the prevalence of stunting.

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K Ryan Wessells

Full Text Available BACKGROUND: Adequate zinc nutrition is essential for adequate growth, immunocompetence and neurobehavioral development, but limited information on population zinc status hinders the expansion of interventions to control zinc deficiency. The present analyses were conducted to: (1 estimate the country-specific prevalence of inadequate zinc intake; and (2 investigate relationships between country-specific estimated prevalence of dietary zinc inadequacy and dietary patterns and stunting prevalence. METHODOLOGY AND PRINCIPAL FINDINGS: National food balance sheet data were obtained from the Food and Agriculture Organization of the United Nations. Country-specific estimated prevalence of inadequate zinc intake were calculated based on the estimated absorbable zinc content of the national food supply, International Zinc Nutrition Consultative Group estimated physiological requirements for absorbed zinc, and demographic data obtained from United Nations estimates. Stunting data were obtained from a recent systematic analysis based on World Health Organization growth standards. An estimated 17.3% of the world's population is at risk of inadequate zinc intake. Country-specific estimated prevalence of inadequate zinc intake was negatively correlated with the total energy and zinc contents of the national food supply and the percent of zinc obtained from animal source foods, and positively correlated with the phytate: zinc molar ratio of the food supply. The estimated prevalence of inadequate zinc intake was correlated with the prevalence of stunting (low height-for-age in children under five years of age (r = 0.48, P<0.001. CONCLUSIONS AND SIGNIFICANCE: These results, which indicate that inadequate dietary zinc intake may be fairly common, particularly in Sub-Saharan Africa and South Asia, allow inter-country comparisons regarding the relative likelihood of zinc deficiency as a public health problem. Data from these analyses should be used to determine

The comparative study of contents of zinc and lead in ore samples of Namtu-Bawdwin Mine by wet analysis, X-ray fluorescence and X-ray diffraction methods

Energy Technology Data Exchange (ETDEWEB)

Kyaw-Soe,

1990-05-01

Lead-zinc ores taken from Namtu-Bawdwin area had been analyzed by wet processes in the Department of Chemistry, 1984. These ore samples have been analyzed by energy dispersive X-ray fluorescence method in the Department of Physics and X-ray diffraction method is also used to determine elements of lead and zinc compounds in these ore samples in the University`s Research Centre. In brief, we study comparatively the contents of lead and zinc and their compounds using the methods of wet processes, X-ray fluorescence and X-ray diffraction. (author).

Cadmium and Cadmium/Zinc Ratios and Tobacco-Related Morbidities

Science.gov (United States)

Richter, Patricia; Faroon, Obaid; Pappas, R. Steven

2017-01-01

Metals are one of five major categories of carcinogenic or toxic constituents in tobacco and tobacco smoke. Cadmium is highly volatile and a higher percentage of the total tobacco cadmium content is efficiently transferred to mainstream tobacco smoke than many other toxic metals in tobacco. Inhaled cadmium bioaccumulates in the lungs and is distributed beyond the lungs to other tissues, with a total body biological half-life of one to two decades. Chronic cadmium exposure through tobacco use elevates blood and urine cadmium concentrations. Cadmium is a carcinogen, and an inducer of proinflammatory immune responses. Elevated exposure to cadmium is associated with reduced pulmonary function, obstructive lung disease, bronchogenic carcinoma, cardiovascular diseases including myocardial infarction, peripheral arterial disease, prostate cancer, cervical cancer, pancreatic cancer, and various oral pathologies. Cadmium and zinc have a toxicologically inverse relationship. Zinc is an essential element and is reportedly antagonistic to some manifestations of cadmium toxicity. This review summarizes associations between blood, urine, and tissue cadmium concentrations with emphasis on cadmium exposure due to tobacco use and several disease states. Available data about zinc and cadmium/zinc ratios and tobacco-related diseases is summarized from studies reporting smoking status. Collectively, data suggest that blood, urine, and tissue cadmium and cadmium/zinc ratios are often significantly different between smokers and nonsmokers and they are also different in smokers for several diseases and cancers. Additional biomonitoring data such as blood or serum and urine zinc and cadmium levels and cadmium/zinc ratios in smokers may provide further insight into the development and progression of diseases of the lung, cardiovascular system, and possibly other organs. PMID:28961214

Cadmium and Cadmium/Zinc Ratios and Tobacco-Related Morbidities.

Science.gov (United States)

Richter, Patricia; Faroon, Obaid; Pappas, R Steven

2017-09-29

Metals are one of five major categories of carcinogenic or toxic constituents in tobacco and tobacco smoke. Cadmium is highly volatile and a higher percentage of the total tobacco cadmium content is efficiently transferred to mainstream tobacco smoke than many other toxic metals in tobacco. Inhaled cadmium bioaccumulates in the lungs and is distributed beyond the lungs to other tissues, with a total body biological half-life of one to two decades. Chronic cadmium exposure through tobacco use elevates blood and urine cadmium concentrations. Cadmium is a carcinogen, and an inducer of proinflammatory immune responses. Elevated exposure to cadmium is associated with reduced pulmonary function, obstructive lung disease, bronchogenic carcinoma, cardiovascular diseases including myocardial infarction, peripheral arterial disease, prostate cancer, cervical cancer, pancreatic cancer, and various oral pathologies. Cadmium and zinc have a toxicologically inverse relationship. Zinc is an essential element and is reportedly antagonistic to some manifestations of cadmium toxicity. This review summarizes associations between blood, urine, and tissue cadmium concentrations with emphasis on cadmium exposure due to tobacco use and several disease states. Available data about zinc and cadmium/zinc ratios and tobacco-related diseases is summarized from studies reporting smoking status. Collectively, data suggest that blood, urine, and tissue cadmium and cadmium/zinc ratios are often significantly different between smokers and nonsmokers and they are also different in smokers for several diseases and cancers. Additional biomonitoring data such as blood or serum and urine zinc and cadmium levels and cadmium/zinc ratios in smokers may provide further insight into the development and progression of diseases of the lung, cardiovascular system, and possibly other organs.

Chloroquine is a zinc ionophore.

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Jing Xue

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

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

Science.gov (United States)

Maret, Wolfgang

2013-01-01

The nutritional essentiality of zinc for the growth of living organisms had been recognized long before zinc biochemistry began with the discovery of zinc in carbonic anhydrase in 1939. Painstaking analytical work then demonstrated the presence of zinc as a catalytic and structural cofactor in a few hundred enzymes. In the 1980s, the field again gained momentum with the new principle of “zinc finger” proteins, in which zinc has structural functions in domains that interact with other biomolecules. Advances in structural biology and a rapid increase in the availability of gene/protein databases now made it possible to predict zinc-binding sites from metal-binding motifs detected in sequences. This procedure resulted in the definition of zinc proteomes and the remarkable estimate that the human genome encodes ∼3000 zinc proteins. More recent developments focus on the regulatory functions of zinc(II) ions in intra- and intercellular information transfer and have tantalizing implications for yet additional functions of zinc in signal transduction and cellular control. At least three dozen proteins homeostatically control the vesicular storage and subcellular distribution of zinc and the concentrations of zinc(II) ions. Novel principles emerge from quantitative investigations on how strongly zinc interacts with proteins and how it is buffered to control the remarkably low cellular and subcellular concentrations of free zinc(II) ions. It is fair to conclude that the impact of zinc for health and disease will be at least as far-reaching as that of iron. PMID:23319127

Interaction Between Yeasts and Zinc

Science.gov (United States)

Nicola, Raffaele De; Walker, Graeme

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

Research of prohibited content distribution mechanisms in the darknet

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Alexey A. Frolov

2017-12-01

Full Text Available In this paper was researched such an issue as prohibited content spreading in the Darknet. Author reviews different ways of data distribution and effective actions against them. The article describes an experiment which was conducted to analyze the extent of the problem and studying the principles of content distribution, for example, one of the sites where the distribution of child pornography, which was the main object of study. During the experiment for collection and analysis of information of the investigated resource the software package was implemented. Received by results of work of modules of software complex data containing the number of active users of the resource, the number created by the video and other content, allow us to estimate the magnitude of the problem. These results prove the assumption that methods used to combat the spread of illicit content, not cope with its task, and the number continues to grow, especially on the resources of the network Darknet. In the final part of the paper provides a set of methods which the author suggests using in future works in which it is planned to try to stop the distribution of content on such sites.

Various ways to reduce zinc oxide levels in S-SBR rubber compounds

NARCIS (Netherlands)

Heideman, G.; Noordermeer, Jacobus W.M.; Datta, Rabin; van Baarle, Ben

2007-01-01

Because of environmental concerns, the zinc content in rubber compounds has come under scrutiny. The research described in this article encompasses zinc-oxide, various zinc-complexes and alternative metal oxides as activators for sulphur vulcanisation. Regarding zinc complexes, it can be concluded

Phytase activity, phytic acid, zinc, phosphorus and protein contents ...

African Journals Online (AJOL)

STORAGESEVER

2009-09-15

Sep 15, 2009 ... Key words: Zinc, nitrogen, phosphorus, phytic acid, phytase. .... speculated that the synthesizing metabolism of grain PA probably was closely ..... Efficiency when Grown in the Chelate-Buffered Nutrient Solution. II. Nutrient ...

Effects of the antituberculous drug ethambutol on zinc absorption, turnover and distribution in rats fed diet marginal and adequate in zinc

Energy Technology Data Exchange (ETDEWEB)

King, A.B.; Schwartz, R.

1987-04-01

Ethambutol, (CH/sub 3/CH/sub 2/-CH(CH/sub 2/OH)-NH-CH/sub 2/)/sub 2/ (EMB), is an oral antituberculous agent that is administered therapeutically over extended time periods. It has chelating properties and may affect mineral metabolism. Male weanling Sprague-Dawley rats received 0, 400 or 600 mg EMB per kilogram body weight daily by gavage for 30 d. They were fed a casein-based diet with either adequate (49 ppm) or marginal (11 ppm) zinc. Both adequate-Zn (AZn) and marginal-Zn (MZn) rats receiving EMB showed alopecia and dose-dependent reductions in feed intake, weight gain and feed efficiency. None of these changes was seen in rats fed the MZn diet without EMB. Serum and tissue zinc levels were similar in rats not receiving EMB, regardless of the dietary zinc level. Serum zinc was consistently lower in AZn and MZn rats receiving EMB than in rats without EMB. Apparent zinc absorption, measured by /sup 65/Zn balance, was higher in AZn rats receiving EMB than in AZn rats without EMB. Thus, changes in absorption could not account for lower serum zinc levels in EMB-treated rats. However, /sup 65/Zn turnover was also higher in EMB groups. This suggests that EMB may have increased urinary zinc losses resulting in reduced circulating zinc and a consequent increase in zinc absorption.

Effects of the antituberculous drug ethambutol on zinc absorption, turnover and distribution in rats fed diet marginal and adequate in zinc

International Nuclear Information System (INIS)

King, A.B.; Schwartz, R.

1987-01-01

Ethambutol, [CH 3 CH 2 -CH(CH 2 OH)-NH-CH 2 ] 2 (EMB), is an oral antituberculous agent that is administered therapeutically over extended time periods. It has chelating properties and may affect mineral metabolism. Male weanling Sprague-Dawley rats received 0, 400 or 600 mg EMB per kilogram body weight daily by gavage for 30 d. They were fed a casein-based diet with either adequate (49 ppm) or marginal (11 ppm) zinc. Both adequate-Zn (AZn) and marginal-Zn (MZn) rats receiving EMB showed alopecia and dose-dependent reductions in feed intake, weight gain and feed efficiency. None of these changes was seen in rats fed the MZn diet without EMB. Serum and tissue zinc levels were similar in rats not receiving EMB, regardless of the dietary zinc level. Serum zinc was consistently lower in AZn and MZn rats receiving EMB than in rats without EMB. Apparent zinc absorption, measured by 65 Zn balance, was higher in AZn rats receiving EMB than in AZn rats without EMB. Thus, changes in absorption could not account for lower serum zinc levels in EMB-treated rats. However, 65 Zn turnover was also higher in EMB groups. This suggests that EMB may have increased urinary zinc losses resulting in reduced circulating zinc and a consequent increase in zinc absorption

Zinc in human prostate gland. Normal, hyperplastic and cancerous

International Nuclear Information System (INIS)

Zaichick, V.Ye.; Sviridova, T.V.; Zaichick, S.V.

1997-01-01

Zinc concentration in a prostate gland is much higher than that in other human tissues. Data about zinc changes for different prostate diseases are limited and greatly contradictory. Zinc content was determined for biopsy and resected materials of transrectal puncture tissues from benign prostate hyperplasia (BPH) and prostate cancer. There were 109 patients (50 BPH and 59 cancer) available for the present study. Control group consisted of 37 intact glands of men died an unexpected death (accident, murder, acute cardiac insufficiency, etc.). All materials studied were divided into two parts. One of them was morphologically examined, while another one was subjected to zinc analysis by INAA. Zinc contents (M ± SE) of normal, benign hyperplastic and cancerous prostate glands were found to be 1018 ± 124, 1142 ± 77, and 146 ± 10 μg/g dry tissue, respectively. It was shown that zinc assessments in the materials of transrectal puncture biopsy of indurated prostate sites can be used as an additional test for differential diagnostics of BPH and cancer. Accuracy, sensitivity and specificity of the test are 98 ± 2%. (author)

Effects of organic matter fraction and compositional changes on distribution of cadmium and zinc in long-term polluted paddy soils

International Nuclear Information System (INIS)

Zhou, Tong; Wu, Longhua; Luo, Yongming; Christie, Peter

2018-01-01

Soil particulate organic matter (POM) has rapid turnover and metal enrichment, but the interactions between organic matter (OM) and metals have not been well studied. The present study aimed to investigate changes in the OM concentration and composition of the POM fraction and their corresponding effects on metal distribution and extractability in long-term polluted paddy soils. Soil 2000–53 μm POM size fractions had higher contents of C–H and C=O bonds, C–H/C=O ratios and concentrations of fulvic acid (FA), humic acid (HA), cadmium (Cd) and zinc (Zn) than the bulk soils. Cadmium and Zn stocks in soil POM fractions were 24.5–27.9% and 7.12–16.7%, respectively, and were more readily EDTA-extractable. Compared with the control soil, the 2000–250 μm POM size fractions had higher organic carbon concentrations and C/N ratios in the polluted soils. However, there were no significant differences in the contents in C–H and C=O bonds or C–H/C=O ratios of POM fractions among the control, slightly and highly polluted soils. In accordance with the lower contents of C=O bonds and FA and HA concentrations, the Cd and Zn concentrations in 250–53 μm POM size fractions were lower than those in 2000–250 μm POM size fractions. Enrichment of Cd in POM fractions increased with increasing soil pollution level. These results support the view that changes in the OM concentration and the size and composition of POM fractions play a key role in determining the distribution of Cd and Zn in paddy soils. - Highlights: • The OC and FA contents and C/N in POM (2000–250 μm) increased in polluted soil. • Enrichment of Cd and Zn decreased with decreasing POM size. • No significant change in content of C=O group in POM was observed in polluted soil. • Changes in the size and composition of soil POM affected the Cd and Zn distribution. - Interactions between soil organic matter and metals.

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-12-15

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

Acceptability and solubility of iron and zinc contents of modified Moringa oleifera sauces consumed in the Far-north region of Cameroon.

Science.gov (United States)

Mawouma, Saliou; Ponka, Roger; Mbofung, Carl Moses

2017-03-01

Consumption of Moringa oleifera leaves is a local and inexpensive solution to iron and zinc deficiencies in the Far-north region of Cameroon. However, traditional household's cooking techniques result in sauces with high pH levels and low leaves incorporation rates that compromise the bioavailability of iron and zinc. The aim of our study was to investigate the effect of modifying a standard Moringa sauce on consumer acceptability and the solubility of iron and zinc, which is an indicator of their bioavailability. Lime juice or tamarind pulp was added to a standard recipe in order to reduce the pH by about one unit, and Moringa leaf powder was incorporated in each acidulated sauce at three levels (1, 2, and 4 g/100 g of sauce). All the formulations were evaluated for their acceptability by 30 housewives using a five-point hedonic scale. The pH was measured by a digital electronic pH-meter. Moisture and ash were determined by AOAC methods. Total iron and zinc contents were determined by atomic absorption spectrophotometry, and soluble iron and zinc by HCl-extractability. The lime juice-acidulated sauce and the tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder were the most acceptable formulations with scores of 3.4 and 3.6, respectively. Their chemical analysis showed a reduced pH (6.4 and 6.1, respectively), compared to the Control (7.2). Lime juice-acidulated sauce improved iron and zinc solubility from 42.19 to 66.38% and 54.03 to 82.03%, respectively. Tamarind pulp-acidulated sauce enriched with 1 g of Moringa leaf powder showed a decrease in iron solubility from 42.19 to 38.26% and an increase in zinc solubility from 54.03 to 72.86%. These results confirm the beneficial effect of lime juice in improving iron and zinc bioavailability.

Studies on the distribution of zinc radioisotope 65Zn in an organism of pig

International Nuclear Information System (INIS)

Nowosad, R.; Simoni, J.; Kubok-Gottlieb, L.

1978-01-01

The purpose of the studies was analysis of the distribution of radioactive 65 Zinc in an organism of pig and the degree of its bounding with protein fractions of certain parenchymatous organs. The animals were given intramuscularly the radioisotope of 65 Zn (20 uCi). After 48 hr since the injection the animals were slaughtered and selective organs and tissues were examined radiometrically. The results were presented as a percentage of the applied dose per 1.0 g of a sample x 10 2 . Taking into consideration the concentration of 65 Zn in the examined organs and tissues, they were divided into the following groups: I - (over 0.30%), parenchymatous organs, hypophyseal gland, suprarenal glands, II (0.20 - 0.30%) - uterus, lungs, small intestine, bile, III (0.10 - 0.20%) - salivary glands, tongue, stomach, colon, coecum, IV (0.01 - 0.1%) - the rest of the organs and tissues studied which activity differed to a small extent in comparison to the concentration of 65 Zn in blood after 48 hr since the application of the radioactive material. In various proteins and their fractions a degree of 65 Zn binding was insignificant in comparison to the content of Zn in a protein-free supernatant. (author)

Zinc accumulation and distribution over tissues in Noccaea сaerulescens in nature and in hydroponics : a comparison

NARCIS (Netherlands)

Kozhevnikova, Anna D.; Seregin, I. V.; Gosti, F.; Schat, H.

2017-01-01

Aims: Zinc distribution at the tissue level is studied almost exclusively in lab-grown plants. It is essential to establish to what extent the patterns observed in lab-grown plants are corresponding with those in nature. To this end, we compared Zn localization in Noccaea caerulescens growing in its

An analysis of infiltration with moisture content distribution in a two-dimensional discretized water content domain

KAUST Repository

Yu, Han; Douglas, Craig C.

2014-01-01

On the basis of unsaturated Darcy's law, the Talbot-Ogden method provides a fast unconditional mass conservative algorithm to simulate groundwater infiltration in various unsaturated soil textures. Unlike advanced reservoir modelling methods that compute unsaturated flow in space, it only discretizes the moisture content domain into a suitable number of bins so that the vertical water movement is estimated piecewise in each bin. The dimensionality of the moisture content domain is extended from one dimensional to two dimensional in this study, which allows us to distinguish pore shapes within the same moisture content range. The vertical movement of water in the extended model imitates the infiltration phase in the Talbot-Ogden method. However, the difference in this extension is the directional redistribution, which represents the horizontal inter-bin flow and causes the water content distribution to have an effect on infiltration. Using this extension, we mathematically analyse the general relationship between infiltration and the moisture content distribution associated with wetting front depths in different bins. We show that a more negatively skewed moisture content distribution can produce a longer ponding time, whereas a higher overall flux cannot be guaranteed in this situation. It is proven on the basis of the water content probability distribution independent of soil textures. To illustrate this analysis, we also present numerical examples for both fine and coarse soil textures.

An analysis of infiltration with moisture content distribution in a two-dimensional discretized water content domain

KAUST Repository

Yu, Han

2014-06-11

On the basis of unsaturated Darcy\\'s law, the Talbot-Ogden method provides a fast unconditional mass conservative algorithm to simulate groundwater infiltration in various unsaturated soil textures. Unlike advanced reservoir modelling methods that compute unsaturated flow in space, it only discretizes the moisture content domain into a suitable number of bins so that the vertical water movement is estimated piecewise in each bin. The dimensionality of the moisture content domain is extended from one dimensional to two dimensional in this study, which allows us to distinguish pore shapes within the same moisture content range. The vertical movement of water in the extended model imitates the infiltration phase in the Talbot-Ogden method. However, the difference in this extension is the directional redistribution, which represents the horizontal inter-bin flow and causes the water content distribution to have an effect on infiltration. Using this extension, we mathematically analyse the general relationship between infiltration and the moisture content distribution associated with wetting front depths in different bins. We show that a more negatively skewed moisture content distribution can produce a longer ponding time, whereas a higher overall flux cannot be guaranteed in this situation. It is proven on the basis of the water content probability distribution independent of soil textures. To illustrate this analysis, we also present numerical examples for both fine and coarse soil textures.

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

Science.gov (United States)

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

2018-06-01

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

Potential ecological risk assessment and predicting zinc accumulation in soils

OpenAIRE

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

2017-01-01

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...

THE CONTENT OF ZINC, LEAD AND CADMIUM IN BAY BOLETE (XEROCOMUS BADIUS (FR. E. COLLECTED FROM A STRONGLY POLLUTED FOREST COMPLEX

Directory of Open Access Journals (Sweden)

Marek Pająk

2016-09-01

Full Text Available The research was carried out in the Świerklaniec Forest District, the Brynica sub-district, which is located in the immediate vicinity of a metallurgical plant, a zinc mine named Huta Cynku "Miasteczko Śląskie" (HCMŚ. In autumn 2008, in the area in question, 31 permanent trial plots were established, aligned within a regular net of squares, with dimensions of 1500×1500 m. The trial plots were located to the north-east and to the east of the emitter (the HCMŚ zinc mine, accordingly with the direction of prevailing winds. In September 2013, and September and October 2014, sporocarps of bay bolete (Xerocomus badius (Fr. E. were collected from the trial plots. The analyses performed for the material gathered covered a determination of heavy metal content in mushrooms (Zn, Pb and Cd, using a method of inductively coupled plasma atomic emission spectroscopy ICP-AES. This paper aimed to establish the accumulation levels of selected heavy metals (Zn, Pb and Cd in bay bolete growing in forests of the Brynica sub-district, in the Świerklaniec Forest District, and the correlation between their content in soil and in the mushrooms under scrutiny. The analyses revealed that the contamination degree in the investigated species was extremely high. The content of toxic elements in bay bolete significantly exceeded the acceptable standards referring to the maximum content of heavy metals in mushrooms, which was particularly true for cadmium.

Different roles of glutathione in copper and zinc chelation in Brassica napus roots.

Science.gov (United States)

Zlobin, Ilya E; Kartashov, Alexander V; Shpakovski, George V

2017-09-01

We investigated the specific features of copper and zinc excess action on the roots of canola (Brassica napus L.) plants. Copper rapidly accumulated in canola root cells and reached saturation during several hours of treatment, whereas the root zinc content increased relatively slowly. Excessive copper and zinc entry inside the cell resulted in significant cell damage, as evidenced by alterations in plasmalemma permeability and decreases in cellular enzymatic activity. Zinc excess specifically damaged root hair cells, which correlated with a pronounced elevation of their labile zinc level. In vitro, we showed that reduced glutathione (GSH) readily reacted with copper ions to form complexes with blocked sulfhydryl groups. In contrast, zinc ions were ineffective as glutathione blockers, and glutathione molecules did not lose their specific chemical activity in the presence of Zn 2+ ions. The effect of copper and zinc excess on the glutathione pool in canola root cells was analysed by a combination of biochemical determination of total and oxidized glutathione contents and fluorescent staining of free reduced glutathione with monochlorobimane dye. Excess copper led to dose-dependent diminution of free reduced glutathione contents in the root cells, which could not be explained by the loss of total cellular glutathione or its oxidation. In contrast, we observed little effect of much higher intracellular zinc concentrations on the free reduced glutathione content. We concluded that GSH plays an important role in copper excess, but not zinc excess chelation, in canola root cells. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

STUDIES ON DETERMINATION OF ENVIRONMENTAL AND PHYSIOLOGICAL LEVELS OF ZINC IONS IN THE PHARYNGEAL TONSILS

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Ewa Nogaj

2010-03-01

Full Text Available The zinc is one of the most important microelements. Element this conditions has corrected the functioning the nervous system of, immunological, sense of taste and smell. It the weakness of activity was manifested was the shortage of zinc and children’s motive development. The aim of this study was samples of pharyngeal tonsils from children living on Malopolska Region, Silesia and village (made up the area of reference of Southern Poland. We investigated population 95 children, in this 40 girls (42% and 55 boys (58% in age from 2 till 15 years (average 6,8 years. The content of zinc was determined by ICP – AES method. Average the content of zinc in pharyngeal tonsils in whole studied children’s population carried out 74,51 µg/g. The statistical differences were not affirmed among average (the average geometrical content of ions of zinc in studied come from girls – 73,15 µg/g and the boys – 75,49 µg/g. The differences between sex appear, in case of ranges of changes, at boys range this it is clearly larger (55,86–97,59 µg/g in comparison to girls (58,34–88,68 µg/g how also near comparison of content answering 95 percentylowi (the incidental resulting with large environmental exposition contents it in the pharyngeal boys’ tonsils is larger – (87,73 µg/g in comparison to young girls (81,98 µg/g. It was established, on basis of report of changes quotient content zinc in pharyngeal tonsils in function of changes of content zinc in air dust, the physiological quantities of zinc in pharyngeal tonsil on level 42 µg/g.

Evaluation of zinc toxicity in soils by means of the CaCl/sub 2/ method

Energy Technology Data Exchange (ETDEWEB)

Merkel, D; Koester, W

1976-01-01

Soils in the valleys of the rivers Innerste and Oker, north of the Harz mountains, are seriously contaminated by heavy metals. Above all high zinc contents cause severe plant damages. They are like injuries caused by air pollution in the environment of smelting-houses. Usually the heavy metal content of the soil is estimated by extraction with diluted acids, e.g., 0.43 N HNO/sub 3/. In this way nearly the whole zinc store is recorded. For an evaluation of the plant available zinc content we extracted contaminated soils with 0.025 N CaCl/sub 2/. This procedure records the influence of soil properties on the plant availability of the zinc like pH value and clay content. With 0.43 NHNO/sub 3/ 260-7500 ppM zinc were estimated. The maximum content of the CaCl/sub 2/ solution was 109 ppM. Cereals at stage of shooting contained 68-1210 ppM (DM), sugar beet leaves 72-812 ppM (DM). The CaCl/sub 2/ method brought about a closer relationship between soils and plants compared with the HNO/sub 3/ method. Beyond it these method permits the establishment of a preliminary toxicity limit which is supposed in the range of 1 ppM. The percent quota of Zn-CaCl/sub 2/ on Zn-HNO/sub 3/ as a measure of the zinc availability was closely related to the pH value of the soil. The relationship was closer the more soils with lower pH values were present, but there was an essential relationship even at pH levels above 7.0. In the environment of a smelting-house the zinc content of plants was closer related to Zn-HNO/sub 3/ compared with Zn-CaCl/sub 2/. In this case the zinc content of the plants was partly caused by the zinc pollution. But at increasing pH value of the soil even here the availability of the soil zinc decreased too. 33 references.

Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro

Energy Technology Data Exchange (ETDEWEB)

Uski, O., E-mail: oskari.uski@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Jalava, P.I., E-mail: pasi.jalava@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Happo, M.S., E-mail: mikko.happo@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Torvela, T., E-mail: tiina.torvela@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Leskinen, J., E-mail: jani.leskinen@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Mäki-Paakkanen, J., E-mail: jorma.maki-paakkanen@thl.fi [National Institute for Health and Welfare, Department of Environmental Health, P.O. Box 95, FI-70701 Kuopio (Finland); Tissari, J., E-mail: jarkko.tissari@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Sippula, O., E-mail: olli.sippula@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Lamberg, H., E-mail: heikki.lamberg@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); Jokiniemi, J., E-mail: jorma.jokiniemi@uef.fi [University of Eastern Finland, Department of Environmental Science, P.O. Box 1627, FI-70211 Kuopio (Finland); VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Espoo (Finland); and others

2015-04-01

Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24 h to different doses (15, 50,150 and 300 μg ml{sup −1}) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. - Highlights: • Zinc powder was added into the

Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro

International Nuclear Information System (INIS)

Uski, O.; Jalava, P.I.; Happo, M.S.; Torvela, T.; Leskinen, J.; Mäki-Paakkanen, J.; Tissari, J.; Sippula, O.; Lamberg, H.; Jokiniemi, J.

2015-01-01

Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24 h to different doses (15, 50,150 and 300 μg ml −1 ) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. - Highlights: • Zinc powder was added into the pure

Nanocomposites of recycled polycarbonate and nano-zinc oxide (rPC/nZnO): effect of gamma radiation and nano oxide content on the thermal properties

International Nuclear Information System (INIS)

Carvalho, A.L.F.; Mendes, L.C.; Cestari, S.P.

2014-01-01

In order to promote the barrier action to the ultraviolet radiation and increase of mechanical characteristics, nanocomposites of recycled polycarbonate (rPC) and nano-zinc oxide (nZnO) containing 1, 2 and 3 % (wt/wt) of nano oxide were prepared. Since for obtaining nanocomposites and irradiating polymers are promising tools and attractive for improving the material performance, the effects of nano-zinc oxide and gamma radiation, at doses ranged from 10 to 50 kGy, were evaluated in terms of thermal characteristics of the rPC. The rPC/nZnO nanocomposites were characterized by thermogravimetric analysis (TGA) and differential explanatory calorimetry (DSC). There was a progressive decrease of the T_g as function of gamma dosage and nano-zinc oxide content. Initially, the Tonset and Tmax decayed as function of gamma dosage but a recovery was observed. The amount of nano-zinc oxide induced a decreasing of T_o_n_s_e_t and T_m_a_x. (author)

Binders of intravenously administered zinc 65 in rat liver cytoplasm

International Nuclear Information System (INIS)

Stortenbeek, A.J.; Hamer, C.J.A. van den.

1976-01-01

The fate of intravenously injected trace amounts of 65 Zn 2+ in the rat was studied over a period of ten days after injection. Tissue distributions were determined and a special study was made of 65 Zn-binders in liver cytoplasm. A total of six 65 Zn-binding fractions was found and a tentative identification of the main 65 Zn-binders in these six fractions is given using the collected data regarding their apparent molecular weight, time dependent prominence and content of stable zinc

Zinc in calcium phosphate mediates bone induction: in vitro and in vivo model

NARCIS (Netherlands)

Luo, Xiaoman; Barbieri, D.; Davison, N.; Yan, Y.; de Bruijn, Joost Dick; Yuan, Huipin

2014-01-01

Zinc-containing tricalcium phosphate (Zn-TCP) was synthesized to investigate the role of zinc in osteoblastogenesis, osteoclastogenesis and in vivo bone induction in an ectopic implantation model. Zinc ions were readily released in the culture medium. Zn-TCP with the highest zinc content enhanced

Effects of zinc and nitrogen application on agronomic traits and ...

African Journals Online (AJOL)

Among yield components only number of seed per silique was affected by zinc and increased in the first year. Oil percentage decreased due to nitrogen, zinc and salinity in the first year but zinc had no significant effect on oil in the second year. Salinity stress increased glucosinolate and protein content. Other treatments had ...

The structural analysis of zinc borate glass by laboratory EXAFS and X-ray diffraction measurements

International Nuclear Information System (INIS)

Kajinami, Akihiko; Harada, Yasushi; Inoue, Shinsuke; Deki, Shigehito; Umesaki, Norimasa

1999-01-01

The structure of zinc borate glass has been investigated by laboratory EXAFS and X-ray diffraction measurement as preliminary investigations for the detailed study in SPring-8. The zinc borate glass was prepared in the range from 40 to 65 mol% of zinc oxide content. The X-ray diffraction was measured by horizontal θ-θ goniometer with 60 kV and 300 mA output of Mo target. The EXAFS of zinc borate glass was measured by laboratory EXAFS system with 20 kV, 100 mA output of Mo target for the K absorption edge of zinc atom. From the X-ray diffraction and the EXAFS measurements, it is found that the zinc ion is surrounded by four oxygen atoms and formed a tetrahedral structure whose (Zn-O) distance is about 2 A and that the structure is unchanged with the zinc oxide content. The diffraction data show that the neighboring structure of boron atom transforms from BO 4 tetrahedra to BO 3 tetragonal planar structure with increasing of the zinc oxide content. (author)

Lead and zinc contamination of vegetation in the southern Pennines

Energy Technology Data Exchange (ETDEWEB)

Shimwell, D W; Laurie, A E

1972-01-01

Three types of heavy metal tolerant vegetation occurring on the spoil heaps in the Pennines are described sociologically and ecologically and their distribution in the Peak District National Park mapped. Concentrations of lead and zinc extractable from soils by acetic acid are recorded, as are total values for these two heavy metals in the tissues of the main component phanerogams and cryptogams of the vegetation. The range of values for zinc in plant tissues are uniformly higher than those for lead. Concentrations of lead accumulated by these plants are higher than those reported for the accumulation of atmospheric lead. The differences in heavy metal absorption, retention and excretion between ectohydric and myxohydric mosses are shown to be quite distinct. The heavy metals are excreted in the former type and form a crust in periods of drought with up to 6% lead and 1.5% zinc content, while, in the latter, the metals tend to be located mainly in the older growth at the base of the moss carpets. The concentrations of the two metal ions in two Peak District rivers proved to be less than 1 ppm in all samples.

Zinc levels in foods from southeastern Spain: relationship to daily dietary intake.

Science.gov (United States)

Terrés, C; Navarro, M; Martín-Lagos, F; Giménez, R; López, H; López, M C

2001-08-01

The zinc content of 300 food and 79 beverage samples was determined using flame atomic absorption spectrometry. Sample recoveries, repeatability, and analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of this technique. Mean zinc concentrations varied from 0.02 microg/ml in fresh water to 71.0 microg/g (fresh weight) in pork liver. The daily dietary intake of zinc for inhabitants of southeastern Spain was estimated to be 10.1 mg (5.5, 4.0, 0.5, and 0.1 mg Zn/day per person from foods of animal and vegetable origin, drinks, and other foods, respectively). Zinc levels found in high protein foods (meat, fish, milk products, eggs, dry fruits, cereals and legumes) were significantly higher than those found in food with a low protein content (vegetables, fruits and drinks) (p protein content of cereals, legumes and dry fruits was found (r = 0.754, p < 0.005). Zinc concentrations in milk samples were significantly modified by the thermal treatment (p < 0.001), and the skimming (p < 0.05) and calcium enrichment processes (p < 0.001). Shellfish zinc levels were also significantly higher than those measured in fish (p < 0.05). Mean zinc concentrations found in cheese were statistically higher than those determined in the remaining milk products (p < 0.001). Zinc levels measured in distilled beverages were also statistically lower than those found in fermented ones (p < 0.001).

Modelling drivers and distribution of lead and zinc concentrations in soils of an urban catchment (Sydney estuary, Australia).

Science.gov (United States)

Johnson, L E; Bishop, T F A; Birch, G F

2017-11-15

The human population is increasing globally and land use is changing to accommodate for this growth. Soils within urban areas require closer attention as the higher population density increases the chance of human exposure to urban contaminants. One such example of an urban area undergoing an increase in population density is Sydney, Australia. The city also possesses a notable history of intense industrial activity. By integrating multiple soil surveys and covariates into a linear mixed model, it was possible to determine the main drivers and map the distribution of lead and zinc concentrations within the Sydney estuary catchment. The main drivers as derived from the model included elevation, distance to main roads, main road type, soil landscape, population density (lead only) and land use (zinc only). Lead concentrations predicted using the model exceeded the established guideline value of 300mgkg -1 over a large portion of the study area with concentrations exceeding 1000mgkg -1 in the south of the catchment. Predicted zinc did not exceed the established guideline value of 7400mgkg -1 ; however concentrations were higher to the south and west of the study area. Unlike many other studies we considered the prediction uncertainty when assessing the contamination risk. Although the predictions indicate contamination over a large area, the broadness of the prediction intervals suggests that in many of these areas we cannot be sure that the site is contaminated. More samples are required to determine the contaminant distribution with greater precision, especially in residential areas where contamination was highest. Managing sources and addressing areas of elevated lead and zinc concentrations in urban areas has the potential to reduce the impact of past human activities and improve the urban environment of the future. Copyright © 2017 Elsevier B.V. All rights reserved.

Heavy metal contamination of topsoils around a lead and zinc smelter in the Republic of Macedonia

International Nuclear Information System (INIS)

Stafilov, Trajce; Sajn, Robert; Pancevski, Zlatko; Boev, Blazo; Frontasyeva, Marina V.; Strelkova, Lyudmila P.

2010-01-01

The results of a first systematic study of spatial distribution of different elements in surface soil over the Veles region (50 km 2 ) known for its lead and zinc industrial activity in the recent past are reported. A total of 201 soil samples were collected according to a dense net in urban area and less dense net in rural area. The total of 42 elements were analyzed by epithermal neutron activation analysis (ENAA) and by atomic absorption spectrometry (AAS). The content of elements such as As, Au, Cd, Cu, Hg, In, Pb, Sb, Se, Zn in soil samples around the lead and zinc smelter and in the adjacent part of the town of Veles has appeared to be much higher than in those collected in the surrounding areas due to the pollution from the plant. Thus, the content of Cd (three times); Pb and Zn (two times) is even higher than the corresponding intervention (critical) values according to the Dutch standards. The results obtained by two complementary analytical techniques, AAS and ENAA, are discussed in terms of multivariate statistics. GIS technology was applied to depict the areas most affected by contamination from the lead and zinc smelter.

Evaluation of Cadmium, Lead and Zinc Content of Compost Produced in Babol Composting Plant

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Fatemeh Asgharzadeh

2014-03-01

Full Text Available Background and purpose: The most important parameter is heavy metal contents in compost production technology. These heavy metals residue from substances like soap, detergents, cosmetics, packaging, leather and butteries are existed in municipal solid waste. The heavy metals can produce toxin for animal, human and plant. The aim of this research was study of produced compost quality based on heavy metals (Pb, Cd and Zn in Babol compost plant in 2012. Materials and Methods: The present research is a descriptive- cross sectional study in which was performed in six months. Total sample numbers (5 samples were randomly provided from final compost of Babol plant and then after extraction and filtration, the concentration of heavy metals like cadmium, lead and zinc was measured by atomic absorption spectrophotometer PG- 999. Results: In analyzed samples the maximum, minimum and average of cadmium in the final compost were 7.25, 0.47 and 1.9 mg/kg. The maximum, minimum and mean of lead were 239.2, 31.9 and 67.1 mg/kg; in zinc were 972.7, 483.5 and 603.7 mg/kg respectively. Conclusion: The concentration of heavy metals in Babol compost samples was under Iranian national and World Health Organization standards and could be used for different species of plants. However, the usability of compost depends on other parameters such as carbon to nitrogen and other components like glass, plastics and textiles.

Different Phosphorus Supplies Altered the Accumulations and Quantitative Distributions of Phytic Acid, Zinc, and Iron in Rice (Oryza sativa L.) Grains.

Science.gov (United States)

Su, Da; Zhou, Lujian; Zhao, Qian; Pan, Gang; Cheng, Fangmin

2018-02-21

Development of rice cultivars with low phytic acid (lpa) is considered as a primary strategy for biofortification of zinc (Zn) and iron (Fe). Here, two rice genotypes (XS110 and its lpa mutant) were used to investigate the effect of P supplies on accumulations and distributions of PA, Zn, and Fe in rice grains by using hydroponics and detached panicle culture system. Results showed that higher P level increased grain PA concentration on dry matter basis (g/kg), but it markedly decreased PA accumulation on per grain basis (mg/grain). Meanwhile, more P supply reduced the amounts and bioavailabilities of Zn and Fe both in milled grains and in brown grains. Comparatively, lpa mutant was more susceptive to exogenous P supply than its wild type. Hence, the appropriate P fertilizer application should be highlighted in order to increase grain microelement (Zn and Fe) contents and improve nutritional quality in rice grains.

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

Balance and forms of zinc in soil and its uptake by plants

Directory of Open Access Journals (Sweden)

Šárka Poláková

2006-01-01

Full Text Available In this paper, zinc flows in arable soils of the Czech Republic and zinc fractions in arable soils are studied. Furthermore, a zinc uptake by agricultural plants is focused. Based on a database of the programme The basal soil monitoring system (BSMS a static zinc balance for arable soils on the national level was assessed. This programme is carried out by The Central Institute for Supervising and Testing in Agriculture (CISTA in Brno. As a representative for the zinc balance calculation, 121 monitoring plots were chosen. The Czech Republic net zinc fluxes ranged from –1250 g.ha– 1.y– 1 to +5595 g.ha– 1.y– 1, median +453 g.ha– 1.y– 1. The maximum zinc fluxes are typical of plots with manure applications. An atmospheric deposition is the most important input of zinc into arable soils. It makes 96,6% of the whole inputs. Leaching and run-off are neglected in this zinc balance by reason of missing credible data. The project Examination of zinc availability in dependence on its form in soil was established to provide more information about behavior of zinc in soil. The first step was starting a greenhouse pot experiment, which was focused on comparison of several extraction agents (AR, 2M HNO3, 0.43M HNO3, Mehlich III, DTPA, CAT, 1M NH4NO3, 0.01M CaCl2. Four soils with increasing zinc content were picked out for this experiment (Domanínek, Chrlice, Kutná Hora, Hlízov. Total zinc contents in these selected soils ranged from 156.8 to 583.7 ppm in dry matter (Aqua regia extraction. Contents in plants were in wide range from 20.7 to 273 ppm in dry matter according to the plant variety and used soil. Strong correlations between 0.43M HNO3, Mehlich III, DTPA and CAT were proved. Using of weaker extraction agents enabled to distinguish geogenic and anthropogenic origin of the contamination.

Trace element contents in raw materials and products of the confectionary industry

International Nuclear Information System (INIS)

Bodnar, J.; Kiss, B.

1984-01-01

Based on measurements by X-ray radiation analysis, the zinc content of raw ingredients for the confectionary industry varies between 27,2 and 56,4 mg/kg and their copper content between 6,2 and 34,3 mg/kg. The same values for bitter chocolates: 22,3 to 28,8 mg/kg for zinc and 10,8 to 18,8 mg/kg for copper resp.; values in milk chocolates: 15,9 to 19,8 mg/kg (zinc) and 2,6 to 6,1 mg/kg (copper). Contents of zinc and copper in cocoa powders are much higher than the above values: 78,1 to 102,5 mg/kg (zinc) and 45,9 to 48,6 mg/kg (copper), resp. Zinc and copper contents in the end products depend in the first place on the raw ingredients; contamination during manufacturing is unlikely. (author)

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.

Simultaneous determination of arsenic, copper, manganese, selenium, and zinc in biological materials by neutron activation analysis

International Nuclear Information System (INIS)

Damsgaard, E.; Heydorn, K.

1976-08-01

A method for the simultaneous determination of arsenic, copper, manganese, selenium, and zinc in biological material was developed by the incorporation of separation procedures for copper and zinc into an existing procedure. Investigation of the performance characteristics of the method was carried out with reference to copper and zinc. For certain materials characterized by a high Cu/Zn ratio, or a high zinc content, or both, such as liver, copper ihterferes in the determination of zinc thus requiring a small correction by an iterative procedure. Blank values for copper depend on the rinsing of the irradiation container, and a single rinsing with redistilled water was found superior to other rinsing procedures. Nuclear interference was negligible. The accuracy of the method was checked by analysis of Standard Reference Materials and the precision verified by analysis of Intercomparison Samples. Results are presented for 5 male foetuses of 3-5 months' gestational age. The distribution of arsenic, manganese and selenium is similar to that previously reported for adults. With the exception of liver, concentrations of copper in foetal organs were lower than values in the literature indicate. (author)

A model for the distribution of watermarked digital content on mobile networks

Science.gov (United States)

Frattolillo, Franco; D'Onofrio, Salvatore

2006-10-01

Although digital watermarking can be considered one of the key technologies to implement the copyright protection of digital contents distributed on the Internet, most of the content distribution models based on watermarking protocols proposed in literature have been purposely designed for fixed networks and cannot be easily adapted to mobile networks. On the contrary, the use of mobile devices currently enables new types of services and business models, and this makes the development of new content distribution models for mobile environments strategic in the current scenario of the Internet. This paper presents and discusses a distribution model of watermarked digital contents for such environments able to achieve a trade-off between the needs of efficiency and security.

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

Interaction Effect between Phosphorus and Zinc on their Availability in Soil in Relation to their Contents in Stevia (Stevia rebaudiana)

Science.gov (United States)

Das, Kuntal; Dang, Raman; Shivananda, T. N.; Sur, Pintu

2005-01-01

A greenhouse experiment was conducted at the Indian Institute of Horticultural Research (IIHR), Bangalore to study the interaction effect between phosphorus and zinc on their availability in soil in relation to their contents in stevia (Stevia rebaudiana). The results show that the amount of available P and Zn content in soil has been found to increase initially and, thereafter, the amount of the same decreased with the progress of plant growth up to 60 days irrespective of treatments. The amount of P and Zn in soils showed an increase with their separate applications either as soil or foliar spray while that of the same value significantly decreased both in soils and plants due to their combined applications, suggesting a mutual antagonistic effect between Zn and P affecting each other's availability in soil and content in the stevia plant. PMID:15980919

Biofortification of wheat grain with iron and zinc: integrating novel genomic resources and knowledge from model crops

Directory of Open Access Journals (Sweden)

Philippa eBorrill

2014-02-01

Full Text Available Wheat, like many other staple cereals, contains low levels of the essential micronutrients iron and zinc. Up to two billion people worldwide suffer from iron and zinc deficiencies, particularly in regions with predominantly cereal-based diets. Although wheat flour is commonly fortified during processing, an attractive and more sustainable solution is biofortification, which requires developing new varieties of wheat with inherently higher iron and zinc content in their grains. Until now most studies aimed at increasing iron and zinc content in wheat grains have focused on discovering natural variation in progenitor or related species. However, recent developments in genomics and transformation have led to a step change in targeted research on wheat at a molecular level. We discuss promising approaches to improve iron and zinc content in wheat using knowledge gained in model grasses. We explore how the latest resources developed in wheat, including sequenced genomes and mutant populations, can be exploited for biofortification. We also highlight the key research and practical challenges that remain in improving iron and zinc content in wheat.

Absorption and distribution of Zn by spring wheat in high zinc soil and effect of rhizosphere soil

International Nuclear Information System (INIS)

Bai Lingyu; Wei Dongpu; Hua Luo; Chen Shibao

1999-01-01

The isotope tracer technique was used to study the absorption and distribution of 65 Zn by spring wheat in high zinc soil. The results showed that the distribution of 65 Zn in the organs of spring wheat was in the order as stem leaf>grain>root>wheat husk; the specific activity of 65 Zn and the transfer factor of 65 Zn in the organs of spring wheat were in the order as root>grain>wheat husk>stem leaf. With added 65 Zn increased, the absorption amount of 65 Zn by spring wheat and the distribution of 65 Zn in root increased. The 65 Zn applied was enriched by rhizosphere soil of spring wheat

Impact of application of zinc oxide nanoparticles on callus induction, plant regeneration, element content and antioxidant enzyme activity in tomato (Solanum lycopersicum Mill. under salt stress

Directory of Open Access Journals (Sweden)

Alharby Hesham F.

2016-01-01

Full Text Available The properties of nanomaterials and their potential applications have been given considerable attention by researchers in various fields, especially agricultural biotechnology. However, not much has been done to evaluate the role or effect of zinc oxide nanoparticles (ZnO-NP in regulating physiological and biochemical processes in response to salt-induced stress. For this purpose, some callus growth traits, plant regeneration rate, mineral element (sodium, potassium, phosphorous and nitrogen contents and changes in the activity of superoxide dismutase (SOD and glutathione peroxidase (GPX in tissues of five tomato cultivars were investigated in a callus culture exposed to elevated concentrations of salt (3.0 and 6.0 g L-1NaCl, and in the presence of zinc oxide nanoparticles (15 and 30 mg L-1. The relative callus growth rate was inhibited by 3.0 g L-1 NaCl; this was increased dramatically at 6.0 g L-1. Increasing exposure to NaCl was associated with a significantly higher sodium content and SOD and GPX activities. Zinc oxide nanoparticles mitigated the effects of NaCl, and in this application of lower concentrations (15 mg L-1 was more effective than a higher concentration (30 mg L-1. This finding indicates that zinc oxide nanoparticles should be investigated further as a potential anti-stress agent in crop production. Different tomato cultivars showed different degrees of tolerance to salinity in the presence of ZnO-NP. The cultivars Edkawy, followed by Sandpoint, were less affected by salt stress than the cultivar Anna Aasa.

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.

Effect of zinc on grain characteristics of draught-resistant rice mutants

International Nuclear Information System (INIS)

Abo-Hegazi, A.M.T.; Rofail, N.B.; Eissa, E.A.; Hassan, A.M.

1996-01-01

Through the use of Instrumental Neutron Activation Analysis (INAA), zinc concentration was determined in kernels resulted on plants of six drought-resistant rice mutant lines fertilized with zinc sulphate. It was found that zinc fertilization increased zinc residues in the kernels with varying concentrations depending on the line, each line reacted and responded to zinc independently. Zinc content in the kernels ranged from 5.63 to 91.4 ppm in the unfertilized control lines. This range was enlarged due to zinc fertilization of the plants to be from 93.51 to 554.53 ppm. It was also noticed that zinc fertilization increased seed heaviness in varying degrees depending on the line itself. This increase may be due to the increase in kernel thickness rather than in kernel width or length. (author). 26 refs., 3 figs

Synthesis and characterization of resorcinol–formaldehyde resin chars doped by zinc oxide

International Nuclear Information System (INIS)

Gun’ko, Vladimir M.; Bogatyrov, Viktor M.; Oranska, Olena I.; Urubkov, Iliya V.; Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga

2014-01-01

Polycondensation polymerization of resorcinol–formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol–formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10–40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20–130 nm in diameter and 1–3 μm in length. At a small content of zinc acetate (1 mol per 100–500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

[Spatial distribution of birth defects among children aged 0 to 5 years and its relationship with soil chemical elements in Chongqing].

Science.gov (United States)

Dong, Yan; Zhong, Zhao-hui; Li, Hong; Li, Jie; Wang, Ying-xiong; Peng, Bin; Zhang, Mao-zhong; Huang, Qiao; Yan, Ju; Xu, Fei-long

2013-10-01

To explore the correlation between the incidence of birth defects and the contents of soil elements so as to provide a scientific basis for screening the related pathogenic factors that inducing birth defects for the development of related preventive and control strategies. MapInfo 7.0 software was used to draw the maps on spatial distribution regarding the incidence rates of birth defects and the contents of 11 chemical elements in soil in the 33 studied areas. Variables on the two maps were superposed for analyzing the spatial correlation. SAS 8.0 software was used to analyze single factor, multi-factors and principal components as well as to comprehensively evaluate the degrees of relevance. Different incidence rates of birth defects showed in the maps of spatial distribution presented certain degrees of negative correlation with anomalies of soil chemical elements, including copper, chrome, iodine, selenium, zinc while positively correlated with the levels of lead. Results from the principal component regression equation indicating that the contents of copper(0.002), arsenic(-0.07), cadmium(0.05), chrome (-0.001), zinc (0.001), iodine(-0.03), lead (0.08), fluorine(-0.002)might serve as important factors that related to the prevalence of birth defects. Through the study on spatial distribution, we noticed that the incidence rates of birth defects were related to the contents of copper, chrome, iodine, selenium, zinc, lead in soil while the contents of chrome, iodine and lead might lead to the occurrence of birth defects.

[Effect of cigarette smoking on coexistence of cadmium and zinc in retained wisdom teeth].

Science.gov (United States)

Malara, Piotr; Kwapuliński, Jerzy; Drugacz, Jan; Malara, Beata

2005-01-01

The change in coexistence pattern of elements (antagonism-synergism) in conditions of excessive level of toxic element is observed in many biological samples. The aim of this study was to establish the cadmium and zinc content in hard tissues of retained wisdom teeth of smokers and non-smokers and to find out if active exposure to cigarette smoke has an influence on coexistence of both metals in these tissues. Material consisted of 127 retained wisdom teeth (65 from smokers and 62 from non-smokers). Cadmium and zinc contents were determined by means of atomic absorption spectrometry. We found out that retained wisdom tooth from smokers exhibited higher cadmium and zinc contents compared to non-smokers' teeth. Moreover, coexistence pattern of cadmium and zinc in teeth depends on exposure to heavy metals and exhibits strong synergism in smokers.

Interrelationships between the changes in the myocardium of the experimental animals and the amount of the accumulated zinc during chronic zinc intoxication

Energy Technology Data Exchange (ETDEWEB)

Zlateva, M; Galabova, V

1974-01-01

White rats, aged 45 days, and another group, aged 3 months, were poisoned with 1/100 of LD/sub 50/ of water extract of zinc acetate for a period of 6 months. There was a considerable increase of the zinc content in the myocardial tissue. This increase depended on the age at which the intoxication began: it was larger in animals which were immature at the onset of the experiments. It was established that the increased amount of zinc caused distrophyci and sclerotic changes in the myocardium and coronary blood vessels. 10 references, 1 figure.

Peer-Assisted Content Distribution with Random Linear Network Coding

DEFF Research Database (Denmark)

Hundebøll, Martin; Ledet-Pedersen, Jeppe; Sluyterman, Georg

2014-01-01

Peer-to-peer networks constitute a widely used, cost-effective and scalable technology to distribute bandwidth-intensive content. The technology forms a great platform to build distributed cloud storage without the need of a central provider. However, the majority of todays peer-to-peer systems...

Counter diffusion of zinc and iron in alluvial soil

International Nuclear Information System (INIS)

Rattan, R.K.; Deb, D.L.

1980-01-01

Half cell technique showed that an increase in moisture tension and CaCO 3 content caused reduction in the counter diffusion coefficients of zinc and iron in an alluvial soil. Increases in bulk density, ambient temperature and concentration of synthetic chelating agents e.g. EDTA and DTPA increased the counter diffusion coefficients of both zinc and iron. (author)

Determination of zinc by substoichiometric extraction with malonic anilide

International Nuclear Information System (INIS)

Dutta, J.; Basu, S.

1994-01-01

A substoichiometric radiochemical extraction method has been developed for the determination of zinc employing a new chelating agent e.g. malonic anilide, dissolved in a mixed organic solvent, MIBK and ether (3:1). The reagent was synthesized and characterized in our laboratory. The method developed was utilized to determine the zinc content in few common vegetable samples. (orig.)

Zinc distribution and localization in primed maize seeds and its translocation during early seedling development

DEFF Research Database (Denmark)

Imran, Muhammad; Garbe-Schönberg, Dieter; Neumann, Günter

2017-01-01

Zinc (Zn) priming is a technique used to increase seed Zn reserves for improving seed quality, crop growth, and enhancing stress tolerance in crop plants. The present study demonstrated the effect of water and Zn priming on the distribution and accumulation of endogenous and primed Zn in maize...... seeds (Zea mays L.). Zn concentration in unprimed, water and Zn primed seeds and germinated seedlings were analyzed by ICP-MS (Inductivity Coupled Plasma Mass Spectroscopy). DTZ (Diphenyle Thio-Carbazone) staining method and LA-ICP-MS (Laser Ablation Inductivity Coupled Plasma Mass Spectroscopy...

Importance of zinc for foetal and post-natal development in swine

International Nuclear Information System (INIS)

Palludan, B.; Wegger, I.

1976-01-01

Maternal zinc deficiency during the third trimester led to redeced zinc concentration in foetal plasma, liver, pancreas and bone. Zinc deposition in foetuses was an exponential function of time, the relative rate being 5.8 and 3.0% daily in normal and deficient foetuses respectively. Distribution of orally administered 65 Zn between maternal and foetal organs was studied. The percentage of absorbed 65 Zn transferred to the foeto-placental unit tended to be highest in zinc-deficient gilts. The greater the liver zinc pool the more 65 Zn accumulated in liver and the less in most other organs in both gilts and foetuses. The gestation period was prolonged and parturition impaired in gilts depleted of zinc late in pregnancy. Persistent loss of umbilical blood was seen and viability of the offspring was poor. However, clinical symptoms and morphological malformations were few. Abnormal ossification occurred as a result of the zinc deficiency. The nature of the changes depended on the period of gestation during which the gilts were depleted of zinc. Absorption of 65 Zn in newborn pigs was unaffected by the zinc status, and the same pattern of distribution among organs as in foetuses was seen. Litter size and weight were not influenced by maternal zinc depletion, and growth of surviving piglets was normal. Zinc stores were low in the newborn, but even when zinc depletion of the mother was continued during lactation, clinical symptoms of zinc deficiency in the piglets were not seen until shortly before weaning. (author)

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

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...

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

International Nuclear Information System (INIS)

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

2013-01-01

In this study, the characterization of zinc chloride incorporated into a poly(acrylic acid) (PAAc) hydrogel prepared by gamma-ray irradiation was investigated. Zinc chloride powder with different concentrations was dissolved in the PAAc solution, and it was crosslinked with gamma-ray irradiation. The effects of various parameters such as zinc ion concentration and irradiation doses on characteristics of the hydrogel formed were investigated in detail for obtaining an antibacterial wound dressing. In addition, the gel content, pH-sensitive (pH 4 or 7) swelling ratio, and UV–vis absorption spectra of the zinc particles in the hydrogels were characterized. Moreover, antibacterial properties of these new materials against Staphylococcus aureus and Escherichia coli strains were observed on solid growth media. The antibacterial tests indicated that the zinc chloride containing PAAc hydrogels have good antibacterial activity. - Highlights: • The characterization of zinc chloride containing PAA hydrogel was investigated. • The gel content increased with an increase in absorbed dose up to 75 kGy. • Finally, the zinc chloride based hydrogels have an antibacterial activity

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

Directory of Open Access Journals (Sweden)

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.

Making Peer-Assisted Content Distribution Robust to Collusion Using Bandwidth Puzzles

Science.gov (United States)

Reiter, Michael K.; Sekar, Vyas; Spensky, Chad; Zhang, Zhenghao

Many peer-assisted content-distribution systems reward a peer based on the amount of data that this peer serves to others. However, validating that a peer did so is, to our knowledge, an open problem; e.g., a group of colluding attackers can earn rewards by claiming to have served content to one another, when they have not. We propose a puzzle mechanism to make contribution-aware peer-assisted content distribution robust to such collusion. Our construction ties solving the puzzle to possession of specific content and, by issuing puzzle challenges simultaneously to all parties claiming to have that content, our mechanism prevents one content-holder from solving many others' puzzles. We prove (in the random oracle model) the security of our scheme, describe our integration of bandwidth puzzles into a media streaming system, and demonstrate the resulting attack resilience via simulations.

Content-Related Repairing of Inconsistencies in Distributed Data

Institute of Scientific and Technical Information of China (English)

Yue-Feng Du; De-Rong Shen; Tie-Zheng Nie; Yue Kou; Ge Yu

2016-01-01

Conditional functional dependencies (CFDs) are a critical technique for detecting inconsistencies while they may ignore some potential inconsistencies without considering the content relationship of data. Content-related conditional functional dependencies (CCFDs) are a type of special CFDs, which combine content-related CFDs and detect potential inconsistencies by putting content-related data together. In the process of cleaning inconsistencies, detection and repairing are interactive: 1) detection catches inconsistencies, 2) repairing corrects caught inconsistencies while may bring new incon-sistencies. Besides, data are often fragmented and distributed into multiple sites. It consequently costs expensive shipment for inconsistencies cleaning. In this paper, our aim is to repair inconsistencies in distributed content-related data. We propose a framework consisting of an inconsistencies detection method and an inconsistencies repairing method, which work iteratively. The detection method marks the violated CCFDs for computing the inconsistencies which should be repaired preferentially. Based on the repairing-cost model presented in this paper, we prove that the minimum-cost repairing using CCFDs is NP-complete. Therefore, the repairing method heuristically repairs the inconsistencies with minimum cost. To improve the efficiency and accuracy of repairing, we propose distinct values and rules sequences. Distinct values make less data shipments than real data for communication. Rules sequences determine appropriate repairing sequences to avoid some incorrect repairs. Our solution is proved to be more effective than CFDs by empirical evaluation on two real-life datasets.

Nutrition intervention strategies to combat zinc deficiency in developing countries.

Science.gov (United States)

Gibson, R S; Ferguson, E L

1998-06-01

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

Sequestration of zinc from zinc oxide nanoparticles and life cycle effects in the sediment dweller amphipod Corophium volutator.

Science.gov (United States)

Fabrega, Julia; Tantra, Ratna; Amer, Aisha; Stolpe, Bjorn; Tomkins, Jordan; Fry, Tony; Lead, Jamie R; Tyler, Charles R; Galloway, Tamara S

2012-01-17

We studied the effects of ZnO nanoparticles [ZnO NPs, primary particle size 35 ± 10 nm (circular diameter, TEM)], bulk [160 ± 81 nm (circular diameter, TEM)], and Zn ions (from ZnCl(2)) on mortality, growth, and reproductive endpoints in the sediment dwelling marine amphipod Corophium volutator over a complete lifecycle (100 days). ZnO NPs were characterized by size, aggregation, morphology, dissolution, and surface properties. ZnO NPs underwent aggregation and partial dissolution in the seawater exposure medium, resulting in a size distribution that ranged in size from discrete nanoparticles to the largest aggregate of several micrometers. Exposure via water to all forms of zinc in the range of 0.2-1.0 mg L(-1) delayed growth and affected the reproductive outcome of the exposed populations. STEM-EDX analysis was used to characterize insoluble zinc precipitates (sphaerites) of high sulfur content, which accumulated in the hepatopancreas following exposures. The elemental composition of the sphaerites did not differ for ZnO NP, Zn(2+), and bulk ZnO exposed organisms. These results provide an illustration of the comparable toxicity of Zn in bulk, soluble, and nanoscale forms on critical lifecycle parameters in a sediment dwelling organism.

Impact of zinc supplementation on the improvement of ethanol tolerance and yield of self-flocculating yeast in continuous ethanol fermentation.

Science.gov (United States)

Zhao, X Q; Xue, C; Ge, X M; Yuan, W J; Wang, J Y; Bai, F W

2009-01-01

The effects of zinc supplementation were investigated in the continuous ethanol fermentation using self-flocculating yeast. Zinc sulfate was added at the concentrations of 0.01, 0.05 and 0.1 g l(-1), respectively. Reduced average floc sizes were observed in all the zinc-supplemented cultures. Both the ethanol tolerance and thermal tolerance were significantly improved by zinc supplements, which correlated well with the increased ergosterol and trehalose contents in the yeast flocs. The highest ethanol concentration by 0.05 g l(-1) zinc sulfate supplementation attained 114.5 g l(-1), in contrast to 104.1 g l(-1) in the control culture. Glycerol production was decreased by zinc supplementations, with the lowest level 3.21 g l(-1), about 58% of the control. Zinc content in yeast cells was about 1.4 microMol g(-1) dry cell weight, about sixfold higher than that of control in all the zinc-supplemented cultures, and close correlation of zinc content in yeast cells with the cell viability against ethanol and heat shock treatment was observed. These studies suggest that exogenous zinc addition led to a reprogramming of cellular metabolic network, resulting in enhanced ethanol tolerance and ethanol production.

High dietary levels of biotin and zinc to improve health of foot pads in broilers exposed experimentally to litter with critical moisture content.

Science.gov (United States)

Abd El-Wahab, A; Radko, D; Kamphues, J

2013-07-01

Foot pad dermatitis (FPD) is a widespread problem in poultry production and constitutes a welfare issue. The objective of this study was to test potentially prophylactic effects of higher biotin and Zn levels in the diet of broilers exposed to critical litter moisture content (35% water) on the development of FPD. Two trials were performed in each 4 groups of 1-wk-old male broilers (Ross 708) during 33 d. The pens of all groups (25 birds in each) were littered with wood shavings of critical moisture content. Two groups were fed high levels of Zn as zinc-oxide (150 mg/kg of diet), with normal levels of biotin (300 µg/kg of diet) or high biotin (2,000 µg/kg of diet). The other 2 groups were fed Zn as zinc-methionine (150 mg/kg of diet), with normal levels of biotin (300 µg/kg of diet) or high biotin (2,000 µg/kg of diet). External assessment of foot pads and measurements the moisture contents of excreta and litter were performed weekly. The signs of foot pad lesions were recorded on a 7-point scale (0 = normal skin; 7 = more than half of the foot pad is necrotic). High biotin supplementation resulted in a reduction of 30 and 18% of cases of foot pad lesions in trials 1 and 2, respectively. The combination of Zn-methionine and high biotin supplementation led to a decreased severity of FPD in a range of about 50 and 30% in trials 1 and 2, respectively. In broilers fed the diet containing zinc-oxide and normal biotin levels about 28 and 24% of the birds had the scores of 6 and 7 (= high foot pad alterations), whereas in birds fed Zn-methionine and high biotin no high alterations (score = 7) in the foot pad (0%) occurred in either trial. The presented results suggest that it is advisable to combine the maximum levels of Zn (especially of Zn-methionine) and high levels of biotin when clinically relevant alterations in the foot pad occur.

Zinc availability in relation to selected soil properties in a crude oil polluted eutric tropofluvent

International Nuclear Information System (INIS)

Chukwuma, M.C.; Eshett, E.T.; Onweremadu, E.U.; Okon, M.A.

2010-01-01

This study examined zinc availability in crude oil-polluted soils. The aim of the study was to determine the effect of zinc on the physiochemical properties of soils in relation to remediation activities. The study was located at a site in Nigeria where crude oil spillage had occurred over a period of 2 months. The region was characterized by quarternary, alluvium, meander belt, wooded back swamps as well as fresh water swamps and Sombreiro-Warri Deltaic plains with large deposits of petroleum and natural gas. Three different land units were studied, notably (1) unpolluted, (2) polluted without vegetation and (3) polluted with vegetation. Soil sampling was conducted using a transect method. Hydrometer analyses were conducted to determine particle size distribution, while a core method was used to determine bulk density. Soil pH, total carbon, phosphorus, and total nitrogen were also measured. An analysis of variance (ANOVA) was used to correlate and regress zinc availability against the selected soil properties. The study showed that zinc availability increased with increases in the value of the effective carbon cation exchange capacity in the unpolluted and polluted samples without vegetation. Zinc decreased with increased clay and organic matter content. Results suggested that soils must be reclaimed quickly in order to prevent additional degradation. 48 refs., 5 tabs., 4 figs.

Zinc availability in relation to selected soil properties in a crude oil polluted eutric tropofluvent

Energy Technology Data Exchange (ETDEWEB)

Chukwuma, M.C.; Eshett, E.T.; Onweremadu, E.U.; Okon, M.A. [Federal Univ. of Technology, Owerri (Nigeria). Dept. of Soil Science and Technology

2010-04-01

This study examined zinc availability in crude oil-polluted soils. The aim of the study was to determine the effect of zinc on the physiochemical properties of soils in relation to remediation activities. The study was located at a site in Nigeria where crude oil spillage had occurred over a period of 2 months. The region was characterized by quarternary, alluvium, meander belt, wooded back swamps as well as fresh water swamps and Sombreiro-Warri Deltaic plains with large deposits of petroleum and natural gas. Three different land units were studied, notably (1) unpolluted, (2) polluted without vegetation and (3) polluted with vegetation. Soil sampling was conducted using a transect method. Hydrometer analyses were conducted to determine particle size distribution, while a core method was used to determine bulk density. Soil pH, total carbon, phosphorus, and total nitrogen were also measured. An analysis of variance (ANOVA) was used to correlate and regress zinc availability against the selected soil properties. The study showed that zinc availability increased with increases in the value of the effective carbon cation exchange capacity in the unpolluted and polluted samples without vegetation. Zinc decreased with increased clay and organic matter content. Results suggested that soils must be reclaimed quickly in order to prevent additional degradation. 48 refs., 5 tabs., 4 figs.

Distributing Characteristics of Heavy Metal Elements in A Tributary of Zhedong River in Laowangzhai Gold Deposit, Yunnan (China): An Implication to Environmentology from Sediments

Science.gov (United States)

Yang, Shuran; Danĕk, Tomáš; Yang, Xiaofeng; Cheng, Xianfeng

2016-10-01

Five heavy metal contents from five sediments and seven sediment profiles in an upstream reach of Zhedong river in Laowangzhai gold deposit were investigated in this research, along with analysis of the horizontal distribution, the surface distribution, the vertical distribution and the interlayer distribution of five heavy metal contents: arsenic (As), mercury (Hg), copper (Cu), lead (Pb) and zinc (Zn). The potential ecological risk of five heavy metals was evaluated to help understanding pollution control of Laowangzhai deposit.

Zinc-enriched (ZEN) terminals in mouse spinal cord

DEFF Research Database (Denmark)

Jo, S M; Danscher, G; Schrøder, H D

2000-01-01

The general distribution of zinc-enriched (ZEN) terminals in mouse spinal cord was investigated at light microscopic level by means of zinc transporter-3 immunohistochemistry (ZnT3(IHC)) and zinc selenium autometallography (ZnSe(AMG)). Staining for ZnT3(IHC) corresponded closely to the Zn...... dendrites. These ZEN terminals in the ventral horn were in general larger than those in the dorsal horn. This is the first description of the pattern of ZEN terminals in mouse spinal cord....

Zinc

Science.gov (United States)

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

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

Contamination of Soil, Water, Plant and Dust by Zinc, Lead and Cadmium in Southwest Isfahan

Directory of Open Access Journals (Sweden)

Nastaran Esmaeilpourfard

2016-02-01

Full Text Available Introduction Due to mining, considerable amounts of heavy metal bearing mineralsare scattered in the atmosphere in the form of dust and make the surrounding air, water and soils polluted.Runoff water movingfrom the mountainstowardsplains may also transport heavy metals from mines to the soils.One type ofpollutions is contamination withheavy metals.The purpose of the present research has been to investigate the effect of heavy metals of mine on soil, water, plant and dust pollution. Materials and Methods: Gushfil mine is located 3 kilometers southwest of Sepahanshahr, Isfahan. Soil profiles were dug 500 meters apart along three parallel transects, between east of Sepahanshahr and Gushfil mine. The profiles were described and samples were collected from their horizons. Ore, wells, plant and dust were sampled as well. Total concentrations of lead, zinc and cadmium were measured in the samples. To find the origin of polluted dust and soil, lead isotopes contents in the samples were measured and regressional relationships between the ratios of these contents were investigated. Results and Discussion Sepahanshahr soils are not contaminated by zinc, lead and cadmium, but within a distance of one to two kilometers from the Gushfil mine, the soils are polluted by zinc and lead. Cadmium contamination was not observed in the studied soils. In all of the soils, the heavy metals content varies downwards irregularly. The reason for this variation trend is that the studied soils are alluvial. In different periods of time, alluvium parent materials have been transported by runoff water from the lead and zinc mines towards the alluvial piedmont plain. The studied heavy metals have been distributed irregularly in different horizons of the soils that have been formed in these parent materials. Lead and cadmium concentrations of drinking water in the studied area are much higher than the maximum amount allowed by the World Health Organization. Cadmium content in

Fast crawling methods of exploring content distributed over large graphs

KAUST Repository

Wang, Pinghui

2018-03-15

Despite recent effort to estimate topology characteristics of large graphs (e.g., online social networks and peer-to-peer networks), little attention has been given to develop a formal crawling methodology to characterize the vast amount of content distributed over these networks. Due to the large-scale nature of these networks and a limited query rate imposed by network service providers, exhaustively crawling and enumerating content maintained by each vertex is computationally prohibitive. In this paper, we show how one can obtain content properties by crawling only a small fraction of vertices and collecting their content. We first show that when sampling is naively applied, this can produce a huge bias in content statistics (i.e., average number of content replicas). To remove this bias, one may use maximum likelihood estimation to estimate content characteristics. However, our experimental results show that this straightforward method requires to sample most vertices to obtain accurate estimates. To address this challenge, we propose two efficient estimators: special copy estimator (SCE) and weighted copy estimator (WCE) to estimate content characteristics using available information in sampled content. SCE uses the special content copy indicator to compute the estimate, while WCE derives the estimate based on meta-information in sampled vertices. We conduct experiments on a variety of real-word and synthetic datasets, and the results show that WCE and SCE are cost effective and also “asymptotically unbiased”. Our methodology provides a new tool for researchers to efficiently query content distributed in large-scale networks.

Protection against T1DM-Induced Bone Loss by Zinc Supplementation: Biomechanical, Histomorphometric, and Molecular Analyses in STZ-Induced Diabetic Rats.

Directory of Open Access Journals (Sweden)

Raul Hernandes Bortolin

Full Text Available Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM, and T1DM plus zinc supplementation (T1DMS. Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young's modulus, and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic

Levels of lead, cadmium and zinc in vegetables

Energy Technology Data Exchange (ETDEWEB)

Fuchs, G.; Haegglund, J.; Jorhem, L.

1976-01-01

The concentrations of lead, cadmium and zinc have been determined in 455 samples of fresh fruit, vegetables and mushrooms by dry ashing and atomic absorption spectrophotometry. The lead content in all samples was in the range < 0.001-0.288 mg/kg, the mean being 0.02 mg/kg. Leaf vegetables (lettuce and spinach) showed higher values, mean 0.04 mg/kg. The mean values of the cadmium content in fruit, green vegetables, potatoes and root vegetables were 0.003, 0.013, 0.016 and 0.038 mg/kg respectively. The zinc contents were in the ppm range. The ratio Zn/Cd was also determined in some samples. All values concern edible parts and are calculated on wet weight basis. The fruit and vegetables were estimated to constitute about 2 percent and 8 percent respectively of the provisional tolerable weekly intake of these metals recommended by an FAO/WHO Expert Committee.

Influence of ageing on zinc bioavailability in soils

Energy Technology Data Exchange (ETDEWEB)

Lock, K.; Janssen, C.R

2003-12-01

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

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.)

IRON, ZINC, AND FERRITIN ACCUMULATION IN COMMON BEANS

DEFF Research Database (Denmark)

Urbanski, Dorian Fabian; Sørensen, Kirsten; Jurkiewicz, Anna Malgorzata

Iron and zinc malnutrition are major threats to human health and development around the world. The World Health Organization states that over two billion people are affected by iron deficiency. In particular children and pregnant women in developing countries are affected by iron deficiency...... in mature seeds, but the ferritin protein was suggested to be the major iron storing protein in legumes [1]. Both iron and zinc localization, as well as speciation, can have an impact on their nutritional availability. We will present detailed information about iron, zinc, and ferritin distribution...

Comparison of the effects and distribution of zinc oxide nanoparticles and zinc ions in activated sludge reactors.

Science.gov (United States)

Zhang, Dongqing; Trzcinski, Antoine P; Oh, Hyun-Suk; Chew, Evelyn; Liu, Yu; Tan, Soon Keat; Ng, Wun Jern

2017-09-19

Zinc Oxide nanoparticles (ZnO NPs) are being increasingly applied in the industry, which results inevitably in the release of these materials into the hydrosphere. In this study, simulated waste-activated sludge experiments were conducted to investigate the effects of Zinc Oxide NPs and to compare it with its ionic counterpart (as ZnSO 4 ). It was found that even 1 mg/L of ZnO NPs could have a small impact on COD and ammonia removal. Under 1, 10 and 50 mg/L of ZnO NP exposure, the Chemical Oxygen Demand (COD) removal efficiencies decreased from 79.8% to 78.9%, 72.7% and 65.7%, respectively. The corresponding ammonium (NH 4 + N) concentration in the effluent significantly (P zinc ions were more toxic towards microorganisms compared to ZnO NPs. Under 50 mg/L exposure, the effluent Zn level was 5.69 mg/L, implying that ZnO NPs have a strong affinity for activated sludge. The capacity for adsorption of ZnO NPs onto activated sludge was found to be 2.3, 6.3, and 13.9 mg/g MLSS at influent ZnO NP concentrations of 1.0, 10 and 50 mg/L respectively, which were 1.74-, 2.13- and 2.05-fold more than under Zn ion exposure.

Micronutrient research in India - the identification and understanding of the problem with particular reference to zinc deficiency

International Nuclear Information System (INIS)

Motsara, M.R.

1975-01-01

Studies are in progress using isotopes of zinc and other nutrient elements to investigate such problems as the retention and movement of zinc in soils, zinc uptake, its distribution and metabolism in plants, zinc-organic matter, zinc-lime and zinc-phosphorus interaction in soils and plants

Electrophoretic deposition of zinc-substituted hydroxyapatite coatings.

Science.gov (United States)

Sun, Guangfei; Ma, Jun; Zhang, Shengmin

2014-06-01

Zinc-substituted hydroxyapatite nanoparticles synthesized by the co-precipitation method were used to coat stainless steel plates by electrophoretic deposition in n-butanol with triethanolamine as a dispersant. The effect of zinc concentration in the synthesis on the morphology and microstructure of coatings was investigated. It is found that the deposition current densities significantly increase with the increasing zinc concentration. The zinc-substituted hydroxyapatite coatings were analyzed by X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. It is inferred that hydroxyapatite and triethanolamine predominate in the chemical composition of coatings. With the increasing Zn/Ca ratios, the contents of triethanolamine decrease in the final products. The triethanolamine can be burnt out by heat treatment. The tests of adhesive strength have confirmed good adhesion between the coatings and substrates. The formation of new apatite layer on the coatings has been observed after 7days of immersion in a simulated body fluid. In summary, the results show that dense, uniform zinc-substituted hydroxyapatite coatings are obtained by electrophoretic deposition when the Zn/Ca ratio reaches 5%. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Science.gov (United States)

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

2016-01-01

The plant hormones gibberellins (GA) and abscisic acid (ABA) play important roles in plant development and stress responses. Here we report a novel A20/AN1-type zinc finger protein ZFP185 involved in GA and ABA signaling in the regulation of growth and stress response. ZFP185 was constitutively expressed in various rice tissues. Overexpression of ZFP185 in rice results in a semi-dwarfism phenotype, reduced cell size, and the decrease of endogenous GA3 content. By contrast, higher GA3 content was observed in RNAi plants. The application of exogenous GA3 can fully rescue the semi-dwarfism phenotype of ZFP185 overexpressing plants, suggesting the negative role of ZFP185 in GA biosynthesis. Besides GA, overexpression of ZFP185 decreased ABA content and expression of several ABA biosynthesis-related genes. Moreover, it was found that ZFP185, unlike previously known A20/AN1-type zinc finger genes, increases sensitivity to drought, cold, and salt stresses, implying the negative role of ZFP185 in stress tolerance. ZFP185 was localized in the cytoplasm and lacked transcriptional activation potential. Our study suggests that ZFP185 regulates plant growth and stress responses by affecting GA and ABA biosynthesis in rice. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Zinc absorption in experimental osmotic diarrhea: effect of long-chain fatty acids.

Science.gov (United States)

Lee, S Y; Wapnir, R A

1993-03-01

The effect of free fatty acids on zinc absorption was studied in a rat model of chronic osmotic diarrhea induced with magnesium citrate and phenolphthalein. In vivo rates of zinc removal from the lumen and analysis of tissue for zinc uptake and metallothionein alterations were monitored. One mmol/L stearate enhanced zinc absorption in rats with or without diarrhea, from 207 +/- 22 and 353 +/- 13 pmol/min x cm to 676 +/- 34 and 610 +/- 26 pmol/min x cm, respectively. Palmitate was only effective in normal rats. Zinc absorption inversely correlated with mucosal zinc content in the perfused intestinal segments, in both type of rats. Hepatic metallothionein was enhanced by zinc and even more by oleate plus zinc in both groups; kidney metallothionein in animals with diarrhea was normalized by either oleate or zinc. The data support previous reports on the effect of long-chain fatty acids on the enhancement of zinc absorption: saturation and a longer chain appear to be positive factors. A membrane modification role of long-chain fatty acids could have nutritional implications in the formulation of special diets.

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.

Effect of zinc fertilizer applications on yield and element contents of ...

African Journals Online (AJOL)

Jane

2011-10-05

Oct 5, 2011 ... Zinc was applied to the soil at four doses 0, 0.5, 1.0 and 1.5 kg da-1 before sowing. During the ... biomass production and compromised the plant's capa- city to respond to water stress by ..... and Pakistan. J Plant Nutr . 23(10): ...

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.

Performance of Grass Filter Strip in Copper and Zinc Removal in Surface and Subsurface Runoff

Directory of Open Access Journals (Sweden)

Huo Weijie

2017-01-01

Full Text Available Three filter strips were conducted on self-designed soil bins. Taking a filter strip with no vegetation as contrast, the effectiveness of vegetation and soil conditions on heavy metals (including copper and zinc removal efficiencies were investigated by simulated runoff experiment. The results showed that the adsorbed state is the main existing form of heavy metal. For surface runoff, most of total copper and total zinc are trapped in first 4m and it is ineffective to increase the distance beyond 4m for removal. Vegetation has no significant effect on total copper and total zinc removal, while the soil with higher content of organic matter is contributing to total Zn interception. For subsurface runoff, the removal efficiencies of total copper and total zinc can reach to above 95.38% and both vegetation and soil conditions have no significant effects. Vegetation is contributing to copper ion and zinc ion removal significantly. Soil condition is only a significant factor to zinc ion, with higher content of organic matter as a contributing factor.

Potassium and zinc increase tolerance to salt stress in wheat (Triticum aestivum L.).

Science.gov (United States)

Jan, Amin Ullah; Hadi, Fazal; Midrarullah; Nawaz, Muhammad Asif; Rahman, Khaista

2017-07-01

Potassium and zinc are essential elements in plant growth and metabolism and plays a vital role in salt stress tolerance. To investigate the physiological mechanism of salt stress tolerance, a pot experiment was conducted. Potassium and zinc significantly minimize the oxidative stress and increase root, shoot and spike length in wheat varieties. Fresh and dry biomass were significantly increased by potassium followed by zinc as compared to control C. The photosynthetic pigment and osmolyte regulator (proline, total phenolic, and total carbohydrate) were significantly enhanced by potassium and zinc. Salt stress increases MDA content in wheat varieties while potassium and zinc counteract the adverse effect of salinity and significantly increased membrane stability index. Salt stress decreases the activities of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase) while the exogenous application of potassium and zinc significantly enhanced the activities of these enzymes. A significant positive correlation was found of spike length with proline (R 2  = 0.966 ∗∗∗ ), phenolic (R 2  = 0.741 ∗ ) and chlorophyll (R 2  = 0.853 ∗∗ ). The MDA content showed significant negative correlation (R 2  = 0.983 ∗∗∗ ) with MSI. It is concluded that potassium and zinc reduced toxic effect of salinity while its combine application showed synergetic effect and significantly enhanced salt tolerance. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

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

Amorphous indium-tin-zinc oxide films deposited by magnetron sputtering with various reactive gases: Spatial distribution of thin film transistor performance

International Nuclear Information System (INIS)

Jia, Junjun; Torigoshi, Yoshifumi; Shigesato, Yuzo; Kawashima, Emi; Utsuno, Futoshi; Yano, Koki

2015-01-01

This work presents the spatial distribution of electrical characteristics of amorphous indium-tin-zinc oxide film (a-ITZO), and how they depend on the magnetron sputtering conditions using O 2 , H 2 O, and N 2 O as the reactive gases. Experimental results show that the electrical properties of the N 2 O incorporated a-ITZO film has a weak dependence on the deposition location, which cannot be explained by the bombardment effect of high energy particles, and may be attributed to the difference in the spatial distribution of both the amount and the activity of the reactive gas reaching the substrate surface. The measurement for the performance of a-ITZO thin film transistor (TFT) also suggests that the electrical performance and device uniformity of a-ITZO TFTs can be improved significantly by the N 2 O introduction into the deposition process, where the field mobility reach to 30.8 cm 2 V –1 s –1 , which is approximately two times higher than that of the amorphous indium-gallium-zinc oxide TFT

Sorption of copper, zinc and cobalt by oat and oat products.

Science.gov (United States)

Górecka, Danuta; Stachowiak, Jadwiga

2002-04-01

We determined copper, zinc and cobalt sorption by oat and its products under variable pH conditions as well as the content of neutral dietary fiber (NDF) and its fractional composition. Adsorbents in a model sorption system were: oat, dehulled oat, oats bran and oats flakes. Three various buffers (pH 1.8, 6.6 and 8.7) were used as dispersing solutions. Results collected during this study indicate that copper, zinc and cobalt sorption is significantly affected by the type of cereal raw material. Zinc and copper ions are subjected to higher sorption than cobalt ions. Examined metal ions were subjected to high sorption under conditions corresponding to the duodenum environment (pH 8.7), regardless of the kind of adsorbent. A little lower sorption capacity is observed under conditions close to the neutral environment, while the lowest one is found in environment reflecting conditions of stomach juice (pH 1.8). Zinc ions are bound intensively by dehulled oat, while oats flakes bound mostly copper and cobalt, independently on environmental conditions. Contents of dietary fiber in oat, dehulled oat, oat bran and oat flakes were: 40.1, 19.3, 20.3 and 14.3%, respectively. The dominating fraction in all oat products was the fraction of hemicelluloses. The content of remaining fractions varies in dependence on the product.

Work within the coordinated programme on isotope-aided micronutrient studies in rice production with special reference to zinc deficiency

International Nuclear Information System (INIS)

Rahman, L.

1980-04-01

A series of pot and field experiments with flooded rice were carried out on contrasting soil types of Bangladesh to study the zinc status of soils, evaluate chemical methods for extracting zinc from soils in terms of ability to identify zinc deficiency, 65 Zn-aided experiments including the residual effect of zinc fertilizers to evaluate the efficiency of zinc sources and methods of zinc application to rice. The results show that (1) the available zinc extracted successively with 0.1 N HCl showed a significant, positive correlation between available soil zinc and plant zinc content; (2) among rice soils of Bangladesh the zinc content from critical limits to adequate levels in the south and south-eastern part of the country was determined. In the northern part of the country, deficiency problems were clearly seen; (3) the rates and methods of zinc application under experimental conditions influences the yield parameters differently and may show an apparent or significant change; (4) 5-7 kg Zn/ha as zinc sulfate were introduced as optimal rates for the soils under experiments; (5) significant yield increases due to the residual effect of zinc fertilizer were obtained on the experiments under dry season conditions but not under wet conditions

METALS IN THE METABOLISM OF HIPPOCAMPUS AND ROLE OF ZINC IN THE PATHOGENESIS OF EPILEPTIC SEIZURES

Directory of Open Access Journals (Sweden)

O. M. Kuchkovsky

2016-05-01

Full Text Available Physiological mechanisms of convulsions status during epilepsy or episindrom significantly different from the mechanisms, which were describe for other disorders associated with glutamatergic system, such as schizophrenia (a decrease of glutamate in neurons and increased dopaminergic load, drug addiction and alcoholism (the formation of endogenous opioids and dopamine, strengthening the role of GABA-ergic system. With glutamatergic transmission are сconnect not only convulsive state, but also the realization of higher integrative functions. Therefore, the development of epilepsy, particularly  which caused glutamate, implemented by activating Zn-ergic hippocampal neurons, associate with complex changes in human mental functions. Based on a scientific literature about  of the role of chelating zinc in the mechanisms of glutamatergic transmission, we can  suggest it participation in the mechanisms of formation of epilepsy  convulsions. In experience on animals, was show that in the animal organism of stressing correlative changes observe zinc content and secretory material in the hippocampus, Paneth cells  and B cells of pancreas. The nature of the changes depend on the stressor. When this change of zinc content in the hippocampus and hypothalamus (as the main regulator of stress reaction were multidirectional that this can be explained by the release of metal together with secretory material in the hypothalamus into the bloodstream. Research epileptic activity  of hippocampus by administering to the animal chelate 8 BSQ allowed to establish the dependence between convulsant action  and first  stress condition of the animal. Evocation of stress by 8-BSQ and physical activity, immobilization and alcohol abuse found that the convulsive effect of this reagent during intravitreal research increased in the case of prior exposure by specified kinds of stressors. In this pre-convulsive effect on exertion increased by 266% and the zinc content

Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber

International Nuclear Information System (INIS)

Johansson, J.; Hagman, O.; Fjellner, B.A.

2003-01-01

This study was carried out to investigate the possibility of calibrating a prediction model for the moisture content and density distribution of Scots pine (Pinus sylvestris) using microwave sensors. The material was initially of green moisture content and was thereafter dried in several steps to zero moisture content. At each step, all the pieces were weighed, scanned with a microwave sensor (Satimo 9,4GHz), and computed tomography (CT)-scanned with a medical CT scanner (Siemens Somatom AR.T.). The output variables from the microwave sensor were used as predictors, and CT images that correlated with known moisture content were used as response variables. Multivariate models to predict average moisture content and density were calibrated using the partial least squares (PLS) regression. The models for average moisture content and density were applied at the pixel level, and the distribution was visualized. The results show that it is possible to predict both moisture content distribution and density distribution with high accuracy using microwave sensors. (author)

Analysis of reaction and transport processes in zinc air batteries

CERN Document Server

Schröder, Daniel

2016-01-01

This book contains a novel combination of experimental and model-based investigations, elucidating the complex processes inside zinc air batteries. The work presented helps to answer which battery composition and which air-composition should be adjusted to maintain stable and efficient charge/discharge cycling. In detail, electrochemical investigations and X-ray transmission tomography are applied on button cell zinc air batteries and in-house set-ups. Moreover, model-based investigations of the battery anode and the impact of relative humidity, active operation, carbon dioxide and oxygen on zinc air battery operation are presented. The techniques used in this work complement each other well and yield an unprecedented understanding of zinc air batteries. The methods applied are adaptable and can potentially be applied to gain further understanding of other metal air batteries. Contents Introduction on Zinc Air Batteries Characterizing Reaction and Transport Processes Identifying Factors for Long-Term Stable O...

Electrical features of an amorphous indium-gallium-zinc-oxide film transistor using a double active matrix with different oxygen contents

International Nuclear Information System (INIS)

Koo, Ja Hyun; Kang, Tae Sung; Hong, Jin Pyo

2012-01-01

The electrical characteristics of amorphous indium-gallium-zinc-oxide (a-IGZO) thin film transistor (TFTs) are systematically studied using a double a-IGZO active layer that is composed of a-IGZO x (oxygen-ion-poor region) and a-IGZO y (oxygen-ion-rich-region). An active layer is designed to have a serially-stacked bi-layer matrix with different oxygen contents, providing the formation of different electron conduction channels. Two different oxygen contents in the active layer are obtained by varying the O 2 partial pressure during sputtering. The a-IGZO TFT based on a double active layer exhibits a high mobility of 9.1 cm 2 /Vsec, a threshold voltage (V T ) of 16.5 V, and ΔV T shifts of less than 1.5 V under gate voltage stress. A possible electrical sketch for the double active layer channel is also discussed.

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 ultrafine zinc powder from wastes containing zinc by electrowinning in alkaline solution

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Zhao Youcai

2013-12-01

Full Text Available Production of ultrafine zinc powder from industrial wastes by electrowinning in alkaline solution was studied. Stainless steel and magnesium electrodes were used as anode and cathode, respectively. Morphology, size distribution and composition of the Zn particles were characterized by Scanning Electron Microscopy, Laser Particle Size Analyzer, and Inductive Coupled Plasma Emission Spectrometer. The required composition of the electrolyte for ultrafine particles was found to be 25-35 g/L Zn, 200-220 g/L NaOH and 20-40 mg/L Pb. The optimal conditions were a current density of 1000-1200 A/m² and an electrolyte temperature of 30-40 °C. The results indicated that the lead additive exerted a beneficial effect on the refining of the particles, by increasing the cathodic polarization. Through this study, ultrafine zinc powder with a size distribution of around 10 μm could be produced, and considerably high current efficiencies (97-99 % were obtained.

Different physiological and photosynthetic responses of three cyanobacterial strains to light and zinc

International Nuclear Information System (INIS)

Xu, Kui; Juneau, Philippe

2016-01-01

Highlights: • The response mechanisms to high zinc was investigated among three cyanobacterial strains grown under two light regimes. • Photosystem II is more sensitive to high zinc compared to Photosystem I in the three studied strains. • High light increases the zinc uptake in two Microcystis aeruginosa strains, but not in Synechocystis sp.. • Combined high light and high zinc treatment is lethal for the toxic M. aeruginosa CPCC299. - Abstract: Zinc pollution of freshwater aquatic ecosystems is a problem in many countries, although its specific effects on phytoplankton may be influenced by other environmental factors. Light intensity varies continuously under natural conditions depending on the cloud cover and the season, and the response mechanisms of cyanobacteria to high zinc stress under different light conditions are not yet well understood. We investigated the effects of high zinc concentrations on three cyanobacterial strains (Microcystis aeruginosa CPCC299, M. aeruginosa CPCC632, and Synechocystis sp. FACHB898) grown under two light regimes. Under high light condition (HL), the three cyanobacterial strains increased their Car/Chl a ratios and non-photochemical quenching (NPQ), with CPCC299 showing the highest growth rate—suggesting a greater ability to adapt to those conditions as compared to the other two strains. Under high zinc concentrations the values of maximal (Φ_M) and operational (Φ'_M) photosystem II quantum yields, photosystem I quantum yield [Y(I)], and NPQ decreased. The following order of sensitivity to high zinc was established for the three strains studied: CPCC299 > CPCC632 > FACHB898. These different sensitivities can be partly explained by the higher internal zinc content observed in CPCC299 as compared to the other two strains. HL increased cellular zinc content and therefore increased zinc toxicity in both M. aeruginosa strains, although to a greater extent in CPCC299 than in CPCC632. Car/Chl a ratios decreased with high

Electrodeposition behavior of nickel and nickel-zinc alloys from the zinc chloride-1-ethyl-3-methylimidazolium chloride low temperature molten salt

International Nuclear Information System (INIS)

Gou Shiping; Sun, I.-W.

2008-01-01

The electrodeposition of nickel and nickel-zinc alloys was investigated at polycrystalline tungsten electrode in the zinc chloride-1-ethyl-3-methylimidazolium chloride molten salt. Although nickel(II) chloride dissolved easily into the pure chloride-rich 1-ethyl-3-methylimidazolium chloride ionic melt, metallic nickel could not be obtained by electrochemical reduction of this solution. The addition of zinc chloride to this solution shifted the reduction of nickel(II) to more positive potential making the electrodeposition of nickel possible. The electrodeposition of nickel, however, requires an overpotential driven nucleation process. Dense and compact nickel deposits with good adherence could be prepared by controlling the deposition potential. X-ray powder diffraction measurements indicated the presence of crystalline nickel deposits. Non-anomalous electrodeposition of nickel-zinc alloys was achieved through the underpotential deposition of zinc on the deposited nickel at a potential more negative than that of the deposition of nickel. X-ray powder diffraction and energy-dispersive spectrometry measurements of the electrodeposits indicated that the composition and the phase types of the nickel-zinc alloys are dependent on the deposition potential. For the Ni-Zn alloy deposits prepared by underpotential deposition of Zn on Ni, the Zn content in the Ni-Zn was always less than 50 atom%

A study of quantitative radiography for moisture content distributions in plant

International Nuclear Information System (INIS)

Kawabata, Y.; Hino, M.; Horie, T.

2003-01-01

Vacuum pre-cooling in cut flower or perishable vegetables industry are used for protecting from the deterioration of the perishables during transportation. Some improvements of the pre-cooling way, however, are required for a bruise in plant on the way of handling. Neutron radiography is suitable to detect and observe the bruise in plant, especially, moisture content distributions in leaves, flowers and stalks. Neutron spectrum in irradiation neutron beams is required for obtaining quantitative moisture contents in plant. The neutron spectrum measurements for determination of effective cross-section of water are carried out at CN-3 experimental hole of Kyoto University Reactor (KUR) by time of flight method. Moisture content distributions in leaves of chrysanthemum, before and after the vacuum pre-cooling are measured by cold neutron radiography at the experimental hole. The local decreases of moisture contents caused by a bruise on the surface of the leaves are measured quantitatively by the cold neutron radiography. The quantitative changes of the moisture content in the leaves are able to read out from the cold neutron radiography image. (M. Suetake)

Behavior of arsenic in hydrometallurgical zinc production and environmental impact

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Peltekov A.B.

2014-12-01

Full Text Available The presence of arsenic in zinc sulphide concentrates is particularly harmful, because it creates problems in zinc electrolysis. The main source of arsenic in non-ferrous metallurgy is arsenopyrite (FeAsS. In oxidative roasting of zinc concentrates, FeAsS oxidizes to arsenic oxides (As2O3, As2O5. In this connection a natural FeAsS was examined, and also the distribution of arsenic in the products of the roasting process, the cycle of sulphuric acid obtaining and the leaching of zinc calcine were studied. The arsenic contamination of soils in the vicinity of nonferrous metals smelter KCM SA, Plovdiv, Bulgaria as a result of zinc and lead productions has been studied.

Studies on some influential factors of the zinc-activated carbon composite adsorbent on adsorptivity for uranium

International Nuclear Information System (INIS)

Miyai, Yoshitaka; Kitamura, Takao; Takagi, Norio; Katoh, Shunsaku; Miyazaki, Hidetoshi

1978-01-01

Factors, which influence the uranium adsorption of powdery composite adsorbent of basic zinc carbonate and activated carbon were studied. In the range studied, zinc content of the adsorbent was the most influential factor on the uranium adsorption, and the second influential factor was sea water volume and the third factor was adsorption period. Interactive effects were observed between zinc content and sea water volume, and between zinc content and adsorption period, and it was deduced that there existed the optimum value of sea water volume and adsorption period respectively for the zinc content of the adsorbent. Maximum uranium adsorption of adsorbent with 40% zinc content was observed at sea water volume of 15 liters and adsorption period of 25 hrs. As for temperature in the range of 15 - 35 0 C, the lower the temperature, the larger amount of adsorbed uranium was. The powdery adsorbent was made into granule, and its strength and its uranium adsorptivity were studied in relation to the granulating conditions. By use of PVA with degree of polymerization above 1,700 as binder, the granular adsorbent with the same strength as commercial granular activated carbon was obtained. PVA amount and its degree of polymerization gave only small effect on uranium adsorption of the adsorbent. Effect of granule size on the uranium adsorption rate in the range of 1 - 4 mm was that the uranium adsorption rate changed proportionally to surface area of assumed sphere. As a test for practical use, five times repetitions of adsorption and desorption were carried out on the same granular adsorbent. During the repetition the amount of adsorbed uranium rather increased, and desorption ratio of adsorbed uranium was constant at 91 - 93%. The weight loss of the adsorbent in a cycle of adsorption and desorption was about 3%. (author)

Effect of domestic processing on total and extractable calcium and zinc content of bathua (Chenopodium album) and fenugreek (Trigonella foenum graecum) leaves.

Science.gov (United States)

Yadav, S K; Sehgal, S

1999-01-01

Bathua (Chenopodium album) and fenugreek (Trigonellafoenum graecum) stored in polyethylene bags and without packaging for 24 or 48 hours in a refrigerator at 5 or 30 degrees C in polyethylene bags. The fresh leaves were also dried (oven and sun); blanched (5, 10 or 15 min) and cooked in an open pan and a pressure cooker. The processed leaves were analyzed for total and extractable calcium and zinc content. The Ca and Zn content of these leaves varied from 970 to 2230 and 10.50 to 12.30 mg/100 g DM and the percentage HCl-extractability was 80.34 to 83.04 and 82.43 to 83.90, respectively. Non significant effects of drying and storage were observed on total Ca and Zn content and HCl-extractability while blanching and cooking resulted in significant improvement of HCl-extractability of these two minerals. Thus, cooking and blanching are good ways to improve the HCl-extractability of Ca and Zn.

New mechanical chemical equilibrium in the copper-zinc alloys obtained by mechanical alloying

International Nuclear Information System (INIS)

Dianez, M.J; Criado, J.M; Donoso, E; Diaz, G

2006-01-01

A series of copper zinc alloys have been synthesized in the entire composition range Cu10Zn to Cu70Zn respectively, by mechanical alloying at room temperature in a planetary high-energy mill. A mechanism is proposed for the mechanical alloying reaction of the copper and zinc. It is made clear that the mechanical treatment considerably extends the range of composition of the α phase up to a content of 41% zinc, instead of the 36% accepted by the conventional phase diagrams. Exact determinations of the phase α reticular parameter were carried out as a function of its composition which can be used to determine the zinc content of the brass α. The results show that a brass phase α may be obtained containing 49% zinc in samples that include a mixture of phases α and β' after reaching stationary state as a function of the milling time. The stability field of phases β' and γ also displace noticeably higher values than those expected from the conventional binary Cu-Zn diagram. This behavior has been explained as a function of the nanometric texture generated by the milling (CW)

Magnesium removal in the electrolytic zinc industry

NARCIS (Netherlands)

Booster, J.L.

2003-01-01

Electrolytic zinc plants need to take measures to control the magnesium content in their process liquors, because the natural magnesium bleed does not balance the input from concentrates. Presently used methods are environmentally unfriendly (due to the production of large amounts of waste gypsum)

The zinc dyshomeostasis hypothesis of Alzheimer's disease.

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Travis J A Craddock

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

The zinc dyshomeostasis hypothesis of Alzheimer's disease.

Science.gov (United States)

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

2012-01-01

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

Estimating the global prevalence of inadequate zinc intake from national food balance sheets: effects of methodological assumptions.

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K Ryan Wessells

Full Text Available The prevalence of inadequate zinc intake in a population can be estimated by comparing the zinc content of the food supply with the population's theoretical requirement for zinc. However, assumptions regarding the nutrient composition of foods, zinc requirements, and zinc absorption may affect prevalence estimates. These analyses were conducted to: (1 evaluate the effect of varying methodological assumptions on country-specific estimates of the prevalence of dietary zinc inadequacy and (2 generate a model considered to provide the best estimates.National food balance data were obtained from the Food and Agriculture Organization of the United Nations. Zinc and phytate contents of these foods were estimated from three nutrient composition databases. Zinc absorption was predicted using a mathematical model (Miller equation. Theoretical mean daily per capita physiological and dietary requirements for zinc were calculated using recommendations from the Food and Nutrition Board of the Institute of Medicine and the International Zinc Nutrition Consultative Group. The estimated global prevalence of inadequate zinc intake varied between 12-66%, depending on which methodological assumptions were applied. However, country-specific rank order of the estimated prevalence of inadequate intake was conserved across all models (r = 0.57-0.99, P<0.01. A "best-estimate" model, comprised of zinc and phytate data from a composite nutrient database and IZiNCG physiological requirements for absorbed zinc, estimated the global prevalence of inadequate zinc intake to be 17.3%.Given the multiple sources of uncertainty in this method, caution must be taken in the interpretation of the estimated prevalence figures. However, the results of all models indicate that inadequate zinc intake may be fairly common globally. Inferences regarding the relative likelihood of zinc deficiency as a public health problem in different countries can be drawn based on the country

Village-randomized clinical trial of home distribution of zinc for treatment of childhood diarrhea in rural Western kenya.

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Daniel R Feikin

Full Text Available BACKGROUND: Zinc treatment shortens diarrhea episodes and can prevent future episodes. In rural Africa, most children with diarrhea are not brought to health facilities. In a village-randomized trial in rural Kenya, we assessed if zinc treatment might have a community-level preventive effect on diarrhea incidence if available at home versus only at health facilities. METHODS: We randomized 16 Kenyan villages (1,903 eligible children to receive a 10-day course of zinc and two oral rehydration solution (ORS sachets every two months at home and 17 villages (2,241 eligible children to receive ORS at home, but zinc at the health-facility only. Children's caretakers were educated in zinc/ORS use by village workers, both unblinded to intervention arm. We evaluated whether incidence of diarrhea and acute lower respiratory illness (ALRI reported at biweekly home visits and presenting to clinic were lower in zinc villages, using poisson regression adjusting for baseline disease rates, distance to clinic, and children's age. RESULTS: There were no differences between village groups in diarrhea incidence either reported at the home or presenting to clinic. In zinc villages (1,440 children analyzed, 61.2% of diarrheal episodes were treated with zinc, compared to 5.4% in comparison villages (1,584 children analyzed, p<0.0001. There were no differences in ORS use between zinc (59.6% and comparison villages (58.8%. Among children with fever or cough without diarrhea, zinc use was low (<0.5%. There was a lower incidence of reported ALRI in zinc villages (adjusted RR 0.68, 95% CI 0.46-0.99, but not presenting at clinic. CONCLUSIONS: In this study, home zinc use to treat diarrhea did not decrease disease rates in the community. However, with proper training, availability of zinc at home could lead to more episodes of pediatric diarrhea being treated with zinc in parts of rural Africa where healthcare utilization is low. TRIAL REGISTRATION: ClinicalTrials.gov NCT

Study on the pre-treatment of oxidized zinc ore prior to flotation

Science.gov (United States)

He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

2018-02-01

The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

3D Game Content Distributed Adaptation in Heterogeneous Environments

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Berretty Robert-Paul

2007-01-01

Full Text Available Most current multiplayer 3D games can only be played on a single dedicated platform (a particular computer, console, or cell phone, requiring specifically designed content and communication over a predefined network. Below we show how, by using signal processing techniques such as multiresolution representation and scalable coding for all the components of a 3D graphics object (geometry, texture, and animation, we enable online dynamic content adaptation, and thus delivery of the same content over heterogeneous networks to terminals with very different profiles, and its rendering on them. We present quantitative results demonstrating how the best displayed quality versus computational complexity versus bandwidth tradeoffs have been achieved, given the distributed resources available over the end-to-end content delivery chain. Additionally, we use state-of-the-art, standardised content representation and compression formats (MPEG-4 AFX, JPEG 2000, XML, enabling deployment over existing infrastructure, while keeping hooks to well-established practices in the game industry.

Heavy Metal Contamination in Urban Soils I Zinc Accumulation Phenomenon in Urban Environments as Clues of Study

OpenAIRE

KOMAI, Yutaka

1981-01-01

As an introduction of the continuing study on the heavy metal contamination in urban soils, zinc accumulation phenomenon observed in urban areas in south Osaka was reported. The survey of zinc concentration in soybean leaves taken in urban and suburban arable lands indicated its accumulation in a wide area. And a correlation between easy soluble zinc level in soils and leaf zinc content were shown. Zinc concentrations in suspended particles in air, falling dust and some water samples were che...

A biokinetic model for zinc for use in radiation protection

International Nuclear Information System (INIS)

Leggett, R.W.

2012-01-01

The physiology of the essential trace element zinc has been studied extensively in human subjects using kinetic analysis of time-dependent measurements of administered zinc tracers. A number of biokinetic models describing zinc exchange between plasma and tissues and endogenous excretion of zinc have been derived as fits to data for specific study groups. More rudimentary biokinetic models for zinc have been developed to estimate radiation doses from internally deposited radioisotopes of zinc. The latter models are designed to provide broadly accurate estimates of cumulative decays of zinc radioisotopes in tissues and are not intended as realistic descriptions of the directions of movement of zinc in the body. This paper reviews biokinetic data for zinc and proposes a physiologically meaningful biokinetic model for systemic zinc for use in radiation protection. The proposed model bears some resemblance to zinc models developed in physiological studies but depicts a finer division of systemic zinc and is based on a broader spectrum of data than previous models. The proposed model and the model for zinc currently recommended by the International Commission on Radiological Protection yield reasonably similar estimates of total-body retention and effective dose for internally deposited radioisotopes of zinc but much different systemic distributions of activity and much different dose estimates for some individual tissues, particularly the liver. - Highlights: ► Zinc is an essential trace element with numerous functions in the human body. ► Several biokinetic models for zinc have been developed from tracer studies on humans. ► More rudimentary biokinetic models for zinc have been developed in radiation protection. ► Biokinetic data for zinc are reviewed and a new biokinetic model is proposed for radiation protection. ► The proposed model may also be useful for investigation of zinc physiology and homeostasis.

Zinc absorption and kinetics during pregnancy and lactation in Brazilian women.

Science.gov (United States)

Donangelo, Carmen M; Zapata, Carmiña L Vargas; Woodhouse, Leslie R; Shames, David M; Mukherjea, Ratna; King, Janet C

2005-07-01

Adjustments in zinc absorption and endogenous excretion maintain zinc homeostasis in nonpregnant adults fed low-zinc diets. The effects on zinc homeostasis of a low zinc intake during pregnancy and lactation have not been described in a longitudinal study. We examined longitudinal changes in fractional zinc absorption (FZA) and zinc kinetics in 10 healthy Brazilian women who habitually consumed a marginal zinc diet ( approximately 9 mg Zn/d). Zinc status was measured at 10-12 (early pregnancy; EP) and 34-36 (late pregnancy; LP) wk of pregnancy and at 7-8 wk after delivery (early lactation; EL). Zinc kinetics and FZA were studied by using stable isotopic tracers. Zinc intake averaged 9 +/- 3 mg/d throughout the study. FZA increased from 29 +/- 6% at EP to 43 +/- 10% at LP and to 39 +/- 13% at EL (P zinc at EL (r = -0.73, P = 0.02) and LP (r = -0.72, P = 0.07). Plasma zinc mass was 23% greater at LP than at EP or EL (P zinc (mg/d) that fluxed between plasma and the most-rapidly-turning-over extravascular pool was 53% greater at LP than at EP or EL (P zinc flux between plasma and the less-rapidly-turning-over zinc pool at EL was 27% greater than that at EP or LP, but this difference was not significant. FZA increased significantly in women with marginal zinc intakes during pregnancy and lactation; the increase was higher in women with low plasma zinc. Plasma zinc was distributed into a different exchangeable pool at LP than at EL.

Mechanical Coating of Zinc Particles with Bi2O3-Li2O-ZnO Glasses as Anode Material for Rechargeable Zinc-Based Batteries

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Tobias Michlik

2018-02-01

Full Text Available The electrochemical performance of zinc particles with 250 μm and 30 μm diameters, coated with Bi2O3-Li2O-ZnO glass is investigated and compared with noncoated zinc particles. Galvanostatic investigations were conducted in the form of complete discharge and charging cycles in electrolyte excess. Coated 30 μm zinc particles provide the best rechargeability after complete discharge. The coatings reached an average charge capacity over 20 cycles of 113 mAh/g compared to the known zero rechargeability of uncoated zinc particles. Proposed reasons for the prolonged cycle life are effective immobilization of discharge products in the glass layer and the formation of percolating metallic bismuth and zinc phases, forming a conductive network through the glass matrix. The coating itself is carried out by mechanical ball milling. Different coating parameters and the resulting coating quality as well as their influence on the passivation and on the rechargeability of zinc–glass composites is investigated. Optimized coating qualities with respect to adhesion, homogeneity and compactness of the glass layer are achieved at defined preparation conditions, providing a glass coating content of almost 5 wt % for 250 μm zinc particles and almost 11 wt % for 30 μm zinc particles.

Pan-Domain Analysis of ZIP Zinc Transporters

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Laura E. Lehtovirta-Morley

2017-12-01

Full Text Available The ZIP (Zrt/Irt-like protein family of zinc transporters is found in all three domains of life. However, little is known about the phylogenetic relationship amongst ZIP transporters, their distribution, or their origin. Here we employed phylogenetic analysis to explore the evolution of ZIP transporters, with a focus on the major human fungal pathogen, Candida albicans. Pan-domain analysis of bacterial, archaeal, fungal, and human proteins revealed a complex relationship amongst the ZIP family members. Here we report (i a eukaryote-wide group of cellular zinc importers, (ii a fungal-specific group of zinc importers having genetic association with the fungal zincophore, and, (iii a pan-kingdom supercluster made up of two distinct subgroups with orthologues in bacterial, archaeal, and eukaryotic phyla.

Zinc chelates as new activators for sulphur vulcanization of acrylonitrile-butadiene elastomer

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2009-04-01

Full Text Available The goal of this work was to apply several zinc chelates as activators for sulphur vulcanization of acrylonitrilebutadiene elastomer (NBR, in order to find alternatives for the conventionally used zinc oxide. In this article, we discuss the effects of different zinc complexes on the cure characteristics, crosslinks distribution in the elastomer network and mechanical properties of acrylonitrile-butadiene rubber. Zinc chelates seem to be good substitutes for zinc oxide as activators for sulphur vulcanization of NBR rubber, without detrimental effects on the crosslinking process and physical properties of the obtained vulcanizates. Moreover, application of zinc complexes allows to reduce the amount of zinc ions in rubber compounds by 40% compared to conventionally crosslinked vulcanizates with zinc oxide. It is a very important ecological goal since zinc oxide is classified as toxic to aquatic species and its amount in rubber products must be reduced below 2.5% at least. From a technological point of view it is a very important challenge.

The cellular and subcellular localization of zinc transporter 7 in the mouse spinal cord

Science.gov (United States)

The present work addresses the cellular and subcellular localization of the zinc transporter 7 (ZNT7, SLC30a7) protein and the distribution of zinc ions (Zn2+) in the mouse spinal cord. Our results indicated that the ZNT7 immunoreactive neurons were widely distributed in the Rexed’s laminae of the g...

Synthesis and characterization of fly ash-zinc oxide nanocomposite

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Kunal Yeole

2014-04-01

Full Text Available Fly ash, generated in thermal power plants, is recognized as an environmental pollutant. Thus, measures are required to be undertaken to dispose it in an environmentally friendly method. In this paper an attempt is made to coat zinc oxide nano-particles on the surface of fly ash by a simple and environmentally friendly facile chemical method, at room temperature. Zinc oxide may serve as effective corrosion inhibitor by providing sacrificial protection. Concentration of fly ash was varied as 5, 10 and 15 (w/w % of zinc oxide. It was found that crystallinity increased, whereas particle size, specific gravity and oil absorption value decreased with increased concentration of fly ash in zinc oxide, which is attributed to the uniform distribution of zinc oxide on the surface of fly ash. These nanocomposites can potentially be used in commercial applications as additive for anticorrosion coatings.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-15

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Kinetic analysis of zinc metabolism and its regulation in normal humans

International Nuclear Information System (INIS)

Wastney, M.E.; Aamodt, R.L.; Rumble, W.F.; Henkin, R.I.

1986-01-01

Zinc metabolism was studied in 32 normal volunteers after oral or intravenous administration of 65 Zn. Data were collected from the blood, urine, feces, whole body, and over the liver and thigh regions for 9 mo while the subjects consumed their regular diets (containing 10 mg Zn ion/day) and for an additional 9 mo while the subjects received an exogenous oral supplement of 100 mg Zn ion/day. Data from each subject were fitted by a compartmental model for zinc metabolism that was developed previously for patients with taste and smell dysfunction. These data from normal subjects were used to determine the absorption, distribution, and excretion of zinc and the mass of zinc in erythrocytes, liver, thigh, and whole body. By use of additional data obtained from the present study, the model was refined further such that a large compartment, which was previously determined to contain 90% of the body zinc, was subdivided into two compartments to represent zinc in muscle and bone. When oral zinc intake was increased 11-fold three new sites of regulation of zinc metabolism were identified in addition to the two sites previously defined in patients with taste and smell dysfunction (absorption of zinc from gut and excretion of zinc in urine). The three new sites are exchange of zinc with erythrocytes, release of zinc by muscle, and secretion of zinc into gut. Regulation at these five sites appears to maintain some tissue concentrations of zinc when dietary zinc increases

Different physiological and photosynthetic responses of three cyanobacterial strains to light and zinc

Energy Technology Data Exchange (ETDEWEB)

Xu, Kui; Juneau, Philippe, E-mail: juneau.philippe@uqam.ca

2016-01-15

Highlights: • The response mechanisms to high zinc was investigated among three cyanobacterial strains grown under two light regimes. • Photosystem II is more sensitive to high zinc compared to Photosystem I in the three studied strains. • High light increases the zinc uptake in two Microcystis aeruginosa strains, but not in Synechocystis sp.. • Combined high light and high zinc treatment is lethal for the toxic M. aeruginosa CPCC299. - Abstract: Zinc pollution of freshwater aquatic ecosystems is a problem in many countries, although its specific effects on phytoplankton may be influenced by other environmental factors. Light intensity varies continuously under natural conditions depending on the cloud cover and the season, and the response mechanisms of cyanobacteria to high zinc stress under different light conditions are not yet well understood. We investigated the effects of high zinc concentrations on three cyanobacterial strains (Microcystis aeruginosa CPCC299, M. aeruginosa CPCC632, and Synechocystis sp. FACHB898) grown under two light regimes. Under high light condition (HL), the three cyanobacterial strains increased their Car/Chl a ratios and non-photochemical quenching (NPQ), with CPCC299 showing the highest growth rate—suggesting a greater ability to adapt to those conditions as compared to the other two strains. Under high zinc concentrations the values of maximal (Φ{sub M}) and operational (Φ'{sub M}) photosystem II quantum yields, photosystem I quantum yield [Y(I)], and NPQ decreased. The following order of sensitivity to high zinc was established for the three strains studied: CPCC299 > CPCC632 > FACHB898. These different sensitivities can be partly explained by the higher internal zinc content observed in CPCC299 as compared to the other two strains. HL increased cellular zinc content and therefore increased zinc toxicity in both M. aeruginosa strains, although to a greater extent in CPCC299 than in CPCC632. Car/Chl a ratios

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

Copper, zinc, molybdenum and uranium distribution in bottom sediments of the Black Sea

International Nuclear Information System (INIS)

Zhorov, V.A.; Sovga, E.E.; Solov'eva, L.B.; Oguslavskij, P.G.; Babinets, A.E.; AN Ukrainskoj SSR, Kiev. Inst. Geologicheskikh Nauk)

1983-01-01

The results of investigations of bottom sediments of the Black Sea by four expeditions aboard scientific ships ''Academician Vernadsky'', ''Michael Lomonosov'', ''Academician Vavilov'' in 1972-1978, are presented. 70 columns of bottom sediments are studied, about 200 samples are analyzed for Cu, Zn, Mo and U using chemical methods with photometric ending. Charts of Cu, Zn, Mo and U distribution in modern, ancient Black Sea and neoeuxenic sediments of the basin are prepared. Preferable uranium concentration in modern sediments, copper and molybdenum - in sapropelic muds of ancient Black Sea sediments and zinc - in neoeuxenic layers, is shown. Uranium geochemical behaviour is determined by physico-chemical regime of the basin, the presence of restoring situation which promotes the formation of uranium sorption-active forms in the upper layer of modern sediments. Neither sapropelite (organic matter), nor the peculiarities of lithological composition of sediments affect uranium behaviour

Effect of boron and zinc fertilization on white oats grown in soil with average content of these nutrients

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Deise Dalazen Castagnara

2012-07-01

Full Text Available The objective of this study was to evaluate the effect of fertilization with zinc or boron on the growth and dry matter production, nutritional value and accumulation of nutrients in white oats. The study comprised two experiments conducted in glasshouses, the first consisting of the application of four doses of zinc (0, 0.2, 0.4 and 0.6 mg/dm³ in the form of zinc sulphate (20% Zn, and the second consisting of the application of four doses of boron (0, 0.2, 0.4 and 0.6 mg/dm³ in the form of Borax (11% B. The experimental design in each case was a randomized block design, with five replicates. Fertilization with zinc and boron increased the growth of white oats, but had no significant effect on the nutritional value of the forage. Higher levels of absorption and accumulation of nutrients in plant tissues were observed following the application of boron and zinc at rates of up to 0.60 mg/dm³ of soil.

Zinc, copper and lead contents of wines. Comparison between the total concentrations by atomic absorption spectrometry and the concentrations of the free ions by polarography

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J.-B. Fournier

1998-03-01

Full Text Available In the introduction of this article, some examples of the use of trace element data in the characterisation of viticultural produce are reminded. This paper described the determination of zinc, copper and lead by two techniques based on radically different principles. The atomic absorption spectrometry, applied after the mineralisation of the samples by wet process, allows the determination of the total element contents in wine. The polarography allows the analysis of the concentrations of these elements that are under labile chemical forms, and which are dissolved under the ionic forms Zn++, Cu++ and Pb++. The wines analysed in this study were produced from three different parcels chosen in relation to their geological qualities. The vines implanted on these parcels are strictly identical, and three fermentation techniques were applied to each lots of grapes. The results obtained shows that the copper is only under ionic form and that the temperature of the fermentation influences the total copper level in the final wine. At the opposite, there is no ion Pb++ in the samples, but a long duration of maceration increases the lead content. Concerning zinc, only the ions Zn++ are present in the wine in case of a short duration of the maceration. When this duration increases, some other chemical forms of zinc are dissolved in addition to the ions Zn++ which are instantaneously dissociated in aqueous solutions. The problem of the contamination of grapes by the materials used, the phytosanitary treatments and the atmospheric pollution is discussed. The knowledge of the proportion of a trace element that is under ionic forms is indispensable to evaluate the bio-availability of the considered element and the toxicologic risks. The advent and the expansion of the electrochemical methods is expected as an important advance in this field of research.

Visualizing the Microdistribution of Zinc Borate in Oriented Strand Board Using X-Ray Microcomputed Tomography and SEM-EDX

OpenAIRE

Philip D. Evans; Vinicius Lube; Holger Averdunk; Ajay Limaye; Michael Turner; Andrew Kingston; Timothy J. Senden

2015-01-01

Oriented strand board (OSB) is an important wood composite used in situations where fungal decay and termite attack can occur. To counter these threats, powdered zinc borate biocide is commonly added to OSB. The effectiveness of biocides depends on their even distribution within composites and resistance to leaching, but little is known about the distribution of zinc borate in OSB. Zinc is denser than wood and it should be possible to map its distribution in OSB using X-ray micro-CT. We test ...

Environmental exposure of road borders to zinc

International Nuclear Information System (INIS)

Blok, J.

2005-01-01

The emissions of zinc along roads originating from tyre wear, corrosion of safety fence and other traffic-related sources have been quantified and validated by measured long-term loads in road run-off and airborne solids (drift) for 29 published case studies. The distribution pattern over the road border at various distances from the edge of the paved surface is assessed on the basis of 38 published case studies with measured concentrations in soil. For the impact assessment, the road border is differentiated into a zone that is part of the 'technosphere' and the 'target zone' beyond that technosphere that can be considered as part of the receiving environment. The 'technosphere' of the road includes the central reservation, the hard and the soft shoulder or, if one or both shoulders are not present, the so-called obstacle 'free zone' that is defined by road engineers. Pollution within the technosphere may require appropriate management of solid disposal and isolation from groundwater to prevent further distribution of pollutants to the environment. In the target zone along regional roads, the zinc load is about 4 mg/m 2 year and this is of the same order of magnitude as that of atmospheric deposition in areas beyond the influence of roads (background). In the target zone along highways, the zinc load is increased in comparison to the background deposition. The average load of about 38 mg/m 2 year is similar to that in fertilised agricultural land. Because most of the emitted zinc stays in the technosphere, the total amount entering this target zone along highways is limited. From the 140 tons of zinc per year that is released from tyre wear in The Netherlands, 64 tons is emitted in the urban area, 6.5 tons reaches to the target zones of all roads and only 1.1 tons of zinc will enter the target zone along highways. This amount will be further decreased by the application of porous asphalt in the near future. The emission from safety fence corrosion does not enter

Bioaccumulation of zinc in foodstuffs by nuclear and related techniques

International Nuclear Information System (INIS)

Diaz Rizo, O.; Olivares Reumont, S.; Lima Cazorla, L.; Gelen Rudnikas, A.; D'Alessandro Rodriguez, K.; Arado Lopez, J. O.; Denis Alpizar, O.; Diaz Arado, O.; Viguri Fuente, J.

2011-01-01

The bioaccumulation of zinc in regular consumption foodstuff (sugar, rice, some vegetables, roots and shellfishes) in Cuba is reported. Zinc content in food samples and its corresponding soils or sediments are determined by Instrumental Neutron Activation analysis (INAA), X-Ray Fluorescence analysis (XRF), inductively coupled plasma emission spectrometry (ICP-AES) and Atomic Absorption spectrometry (AES). The obtained results show rice as the major Zn bioaccumulator of the studied products and the main Zn source in Cuban human diet. (Author)

Zinc Absorption from Representative Diet in a Chinese Elderly Population Using Stable Isotope Technique.

Science.gov (United States)

Li, Ya Jie; Li, Min; Liu, Xiao Bing; Ren, Tong Xiang; Li, Wei Dong; Yang, Chun; Wu, Meng; Yang, Lin Li; Ma, Yu Xia; Wang, Jun; Piao, Jian Hua; Yang, Li Chen; Yang, Xiao Guang

2017-06-01

To determine the dietary zinc absorption in a Chinese elderly population and provide the basic data for the setting of zinc (Zn) recommended nutrient intakes (RNI) for Chinese elderly people. A total of 24 elderly people were recruited for this study and were administered oral doses of 3 mg 67Zn and 1.2 mg dysprosium on the fourth day. The primary macronutrients, energy, and phytic acid in the representative diet were examined based on the Chinese National Standard Methods. Fecal samples were collected during the experimental period and analyzed for zinc content, 67Zn isotope ratio, and dysprosium content. The mean (± SD) zinc intake from the representative Chinese diet was 10.6 ± 1.5 mg/d. The phytic acid-to-zinc molar ratio in the diet was 6.4. The absorption rate of 67Zn was 27.9% ± 9.2%. The RNI of zinc, which were calculated by the absorption rate in elderly men and women, were 10.4 and 9.2 mg/d, respectively. This study got the dietary Zn absorption in a Chinese elderly population. We found that Zn absorption was higher in elderly men than in elderly women. The current RNI in elderly female is lower than our finding, which indicates that more attention is needed regarding elderly females' zinc status and health. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Problem of cadmium, arsenic and zinc determination in enviroment samples

International Nuclear Information System (INIS)

Malyugin, M.S.; Luzhnova, M.A.; Lontsikh, S.V.

1983-01-01

Using the emission spectroscopy technique new information has been obtained on cadmium-, arsenic and zinc content in some reference samples (RS) of rocks and soils not previously certified as to the content of the elements, as well as in nealy issued RS of soils. Metrologic estimation of the results obtained is carried out. A comparison with the atomic-absorption analysis data as well as with those of the neutron-activation-, colorimetric and other methods of the analysis permits to refer to the advantages of using the spectrographic determination technique based on fractionated evaporation, in case of determining cadmium and arsenic in rocks and soils. Consideration of the results of cadmium, arsenic and zinc spectrography contributed greatly to the certification of reference samples of soils

Zinc and glutamate dehydrogenase in putative glutamatergic brain structures.

Science.gov (United States)

Wolf, G; Schmidt, W

1983-01-01

A certain topographic parallelism between the distribution of histochemically (TIMM staining) identified zinc and putative glutamatergic structures in the rat brain was demonstrated. Glutamate dehydrogenase as a zinc containing protein is in consideration to be an enzyme synthesizing transmitter glutamate. In a low concentration range externally added zinc ions (10(-9) to 10(-7) M) induced an increase in the activity of glutamate dehydrogenase (GDH) originating from rat hippocampal formation, neocortex, and cerebellum up to 142.4%. With rising molarity of Zn(II) in the incubation medium, the enzyme of hippocampal formation and cerebellum showed a biphasic course of activation. Zinc ions of a concentration higher than 10(-6) M caused a strong inhibition of GDH. The effect of Zn(II) on GDH originating from spinal ganglia and liver led only to a decrease of enzyme activity. These results are discussed in connection with a functional correlation between zinc and putatively glutamatergic system.

Zinc allocation and re-allocation in rice

Science.gov (United States)

Stomph, Tjeerd Jan; Jiang, Wen; Van Der Putten, Peter E. L.; Struik, Paul C.

2014-01-01

Aims: Agronomy and breeding actively search for options to enhance cereal grain Zn density. Quantifying internal (re-)allocation of Zn as affected by soil and crop management or genotype is crucial. We present experiments supporting the development of a conceptual model of whole plant Zn allocation and re-allocation in rice. Methods: Two solution culture experiments using 70Zn applications at different times during crop development and an experiment on within-grain distribution of Zn are reported. In addition, results from two earlier published experiments are re-analyzed and re-interpreted. Results: A budget analysis showed that plant zinc accumulation during grain filling was larger than zinc allocation to the grains. Isotope data showed that zinc taken up during grain filling was only partly transported directly to the grains and partly allocated to the leaves. Zinc taken up during grain filling and allocated to the leaves replaced zinc re-allocated from leaves to grains. Within the grains, no major transport barrier was observed between vascular tissue and endosperm. At low tissue Zn concentrations, rice plants maintained concentrations of about 20 mg Zn kg−1 dry matter in leaf blades and reproductive tissues, but let Zn concentrations in stems, sheath, and roots drop below this level. When plant zinc concentrations increased, Zn levels in leaf blades and reproductive tissues only showed a moderate increase while Zn levels in stems, roots, and sheaths increased much more and in that order. Conclusions: In rice, the major barrier to enhanced zinc allocation towards grains is between stem and reproductive tissues. Enhancing root to shoot transfer will not contribute proportionally to grain zinc enhancement. PMID:24478788

Effect of gamma radiation and nano-zinc oxide content on the properties of recycled polycarbonate; Efeito de radiacao gama e do teor de oxido de zinco nanometrico nas propriedades do policarbonato reciclado

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Ana Luiza F.; Mendes, Luis C.; Cestari, Sibele P., E-mail: lcmendes@ima.ufrj.br [Universidade Federal do Rio de Janeiro (IFRJ), Rio de Janeiro-RJ (Brazil). Instituto de Macromoleculas Eloisa Mano; Souza, Mauro C.L. [Universidade Estadual da Zona Oeste (UEZO), Campo Grande, RJ (Brazil)

2015-07-01

In order to promote the barrier action to the ultraviolet radiation and increase of mechanical characteristics, nanocomposites of recycled polycarbonate (rPC) and nano-zinc oxide (nZnO) containing 1, 2 and 3 % (wt/wt) of nano oxide were prepared. Since for obtaining nanocomposites and irradiating polymers are promising tools and attractive for improving the material performance, the effects of nano-zinc oxide and gamma radiation, at doses ranged from 10 to 50 kGy, were evaluated in terms of thermal characteristics of the rPC. The rPC/nZnO nanocomposites were characterized by thermogravimetric analysis (TGA), differential exploratory calorimetry (DSC), infrared spectrometry (FT-IR) and wide angle X-ray diffraction (WAXD). There was a progressive decrease of the T{sub g} as function of gamma dosage and nano-zinc oxide content. Initially, the T{sub onset} and T{sub max} decayed as function of gamma dosage but a recovery was observed. The amount of nano-zinc oxide induced a decreasing of T{sub onset} and T{sub max}. (author)

Effect of individual components of soy formula and cows milk formula on zinc bioavailability

International Nuclear Information System (INIS)

Loennerdal, B.; Cederblad, A.; Davidsson, L.; Sandstroem, B.

1984-01-01

Zinc absorption from human milk, cows milk formulas, and soy formulas was studied in human adults by a radioisotope technique using 65 Zn and whole body counting. Individual dietary components were investigated for effects on zinc absorption. Phytate was found to have a strong inhibitory effect on zinc absorption; addition of phytate to cows milk formula (yielding a phytate concentration similar to that of soy formula) resulted in a decrease in zinc absorption from 31 to 16% similar to the absorption for soy formula (14%). Carbohydrate source, calcium, and zinc levels of the diet did not affect zinc absorption significantly. Iron supplementation of cows milk formula decreased zinc absorption from 24 to 18% although this decrease was not found to be significant (p less than 0.1). Absorption of zinc from a whey-adjusted cows milk formula was higher (31%) than from a nonmodified cows milk formula (22%). Increasing the zinc supplementation level in cows milk formula but not in soy formula increased zinc absorption to approximate that from breast milk. It is suggested that reduction of phytate content of soy formula may be a more effective avenue of modification than increased level of zinc supplementation

Efficacy of zinc against common cold viruses: an overview.

Science.gov (United States)

Hulisz, Darrell

2004-01-01

To review the laboratory and clinical evidence of the medicinal value of zinc for the treatment of the common cold. Published articles identified through Medline (1980-2003) using the search terms zinc, rhinovirus, and other pertinent subject headings. Additional sources were identified from the bibliographies of the retrieved articles. By the author. By the author. Human rhinoviruses, by attaching to the nasal epithelium via the intracellular adhesion molecule-1 (ICAM-1) receptor, cause most colds. Ionic zinc, based on its electrical charge, also has an affinity for ICAM-1 receptor sites and may exert an antiviral effect by attaching to the ICAM-1 receptors in the rhinovirus structure and nasal epithelial cells. Clinical tests of zinc for treatment of common colds have been inconsistent, primarily because of study design, blinding, and lozenge contents. Early formulations of lozenges also were unpalatable. In three trials with similar study designs, methodologies, and efficacy assessments, zinc effectively and significantly shortened the duration of the common cold when it was administered within 24 hours of the onset of symptoms. Recent reports of trials with zinc gluconate administered as a nasal gel have supported these findings; in addition, they have shown that treatment with zinc nasal gel is effective in reducing the duration and severity of common cold symptoms in patients with established illness. Clinical trial data support the value of zinc in reducing the duration and severity of symptoms of the common cold when administered within 24 hours of the onset of common cold symptoms. Additional clinical and laboratory evaluations are warranted to further define the role of ionic zinc for the prevention and treatment of the common cold and to elucidate the biochemical mechanisms through which zinc exerts its symptom-relieving effects.

Evaluation of the Content of Lead, Cadmium, Mercury, Arsenic, Tin, Copper and Zinc during the Production Process Flow of Tomato Broth

Directory of Open Access Journals (Sweden)

Corina Andrei

2013-11-01

Full Text Available Heavy metals are among the largest contaminants of food products. Once metals are present in vegetables, their concentrations are rarely modified by industrial processing techniques, although in some cases washing may decrease the metal content. The main objective of this study was to quantify the effect of industrial processing on the content of lead, cadmium, mercury, arsenic, tin, copper and zinc in tomatoes and products resulting on flow technology of tomato broth. For the determination of essential elements and/or potentially toxic was use atomic absorption spectrometry. The analytical results for quantitative evaluation the concentrations of the investigated elements on the samples of tomatoes taken from the technological process of the production of tomato broth indicated the presence of Pb, Cd, Cu and Zn but with a level of concentration that significantly decreased in the finished product and the absence of metals Hg and As in all investigated samples. Effect of industrial processing on the content of tin in tomato samples analyzed was characterized by fluctuations in the residual content that led to a significant increase in concentration of 0.100 ± 0.041 mg kg-1 (tomatoes - unprocessed to 0.200 ± 0.041 mg kg-1 (tomato broth.

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.

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 sensitive determination of zinc with novel water-soluble small molecular fluorescent sensor

International Nuclear Information System (INIS)

Weng Ying; Chen Zilin; Wang Fang; Xue Lin; Jiang Hua

2009-01-01

A high sensitive method of quantitative analysis for the determination of zinc in the nutrition supplements has been developed by using a novel water-soluble fluorescent sensor HQ3: (8-pyridylmethyloxy-2-methyl-quinoline). Under the optimized condition of 67 mM phosphate buffer, pH 7.4, and 5% (v/v) DMSO, the zinc concentration showed good linear relationship with fluorescence intensity in the range of 7.5 x 10 -8 to 2.5 x 10 -5 M with the detection limit of 1.5 x 10 -8 M. HQ3 exhibited high selectivity to zinc comparing with other metal ions except for cadmium. The developed analytical method was successfully used for determining the content of zinc in a real sample of zinc gluconate solution of Sanchine.

[Interaction between fluorine and zinc after long-term oral administration into the digestive system of rats].

Science.gov (United States)

Mazurek-Mochol, Małgorzata

2002-01-01

Drug interactions are the side effect of administration of two or more drugs or a drug-food combination. Although some drug interactions are intentional and beneficial to the patient, the majority are unintentional and associated with a potentially harmful effect. The aim of this study was to search for interactions in rats between fluoride and zinc administered orally for 12 weeks and to elucidate any potential toxicological and therapeutic consequences. 60 male Wistar rats were divided into six groups of ten rats each and exposed to: 1. controls (distilled water); 2. sodium fluoride (NaF); 3. low-dose zinc (Zn); 4. high-dose zinc; 5. NaF + low-dose Zn; 6. NaF + high-dose Zn. At the end of the experiment the content of F- and Zn+ in serum, urine, incisors, femur and mandible was measured and densitometry of femoral bones was performed. Serum alkaline phosphatase, alanine and aspartate aminotransferase activities, as well as bilirubin and creatinine concentrations were determined to confirm non-toxicity of fluoride dose. Animals receiving NaF only demonstrated higher content of fluorine in serum, urine bones and teeth. Zinc concentrations in serum, urine, bones and teeth were elevated in rats receiving zinc with or without NaF. Fluorine accumulation in bones and teeth was reduced by Zn, but in general the effect lacked statistical significance. Zinc slightly reduced the concentrations of fluorine in serum and urine. Sodium fluoride slightly reduced the concentration of zinc in serum and urine. Bone mineral content (BMC) was significantly increased by NaF and was not further increased by co-administration of zinc. No changes in serum alkaline phosphatase, alanine and aspartate aminotransferase activities, bilirubin and creatinine concentrations were detected. In conclusion, simultaneous administration of fluorine and zinc may be beneficial for prevention and treatment of pathologic conditions in bones and teeth and is not accompanied by an increase in fluorine

The electronic structure of co-sputtered zinc indium tin oxide thin films

Energy Technology Data Exchange (ETDEWEB)

Carreras, Paz; Antony, Aldrin; Bertomeu, Joan [Departament de Fisica Aplicada i Optica, Universitat de Barcelona, 08028 Barcelona (Spain); Gutmann, Sebastian [Department of Chemistry, University of South Florida, Tampa, Florida 33620 (United States); Schlaf, Rudy [Department of Electrical Engineering, University of South Florida, Tampa, Florida 33620 (United States)

2011-10-01

Zinc indium tin oxide (ZITO) transparent conductive oxide layers were deposited via radio frequency (RF) magnetron co-sputtering at room temperature. A series of samples with gradually varying zinc content was investigated. The samples were characterized with x-ray and ultraviolet photoemission spectroscopy (XPS, UPS) to determine the electronic structure of the surface. Valence and conduction bands maxima (VBM, CBM), and work function were determined. The experiments indicate that increasing Zn content results in films with a higher defect rate at the surface leading to the formation of a degenerately doped surface layer if the Zn content surpasses {approx}50%. Furthermore, the experiments demonstrate that ZITO is susceptible to ultraviolet light induced work function reduction, similar to what was earlier observed on ITO and TiO{sub 2} films.

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...

TK3 eBook software to author, distribute, and use electronic course content for medical education.

Science.gov (United States)

Morton, David A; Foreman, K Bo; Goede, Patricia A; Bezzant, John L; Albertine, Kurt H

2007-03-01

The methods for authoring and distributing course content are undergoing substantial changes due to advancement in computer technology. Paper has been the traditional method to author and distribute course content. Paper enables students to personalize content through highlighting and note taking but does not enable the incorporation of multimedia elements. Computers enable multimedia content but lack the capability of the user to personalize the content. Therefore, we investigated TK3 eBooks as a potential solution to incorporate the benefits of both paper and computer technology. The objective of our study was to assess the utility of TK3 eBooks in the context of authoring and distributing dermatology course content for use by second-year medical students at the University of Utah School of Medicine during the spring of 2004. We incorporated all dermatology course content into TK3 eBook format. TK3 eBooks enable students to personalize information through tools such as "notebook," "hiliter," "stickies," mark pages, and keyword search. Students were given the course content in both paper and eBook formats. At the conclusion of the dermatology course, students completed a questionnaire designed to evaluate the effectiveness of the eBooks compared with paper. Students perceived eBooks as an effective way to distribute course content and as a study tool. However, students preferred paper over eBooks to take notes during lecture. In conclusion, the present study demonstrated that eBooks provide a convenient method for authoring, distributing, and using course content but that students preferred paper to take notes during lecture.

Mineral content of traditional leafy vegetables from western Kenya

DEFF Research Database (Denmark)

Orech, F.O.; Christensen, Dirk Lund; Larsen, T.

2007-01-01

and diseases. This paper describes the mineral (calcium, iron and zinc) contents in some 54 traditional vegetable species collected from Nyang'oma area of Bondo district, western Kenya. Atomic absorption spectroscopy was used to determine the mineral content. We found that most traditional leafy vegetables......, domesticated and wild, generally contain higher levels of calcium, iron and zinc compared with the introduced varieties such as spinach (Spanacia oleracea), kale (Brassica oleracea var. acephala) and cabbage (Brassica oleracea var. capitata). The results of this study could contribute towards identification...

Electroplated zinc-cobalt alloy

International Nuclear Information System (INIS)

Carpenter, D.E.O.S.; Farr, J.P.G.

2005-01-01

Recent work on the deposition and use of ectrodeposited zinc-cobalt alloys is surveyed. Alloys containing lower of Nuclear quantities of cobalt are potentially more useful. The structures of the deposits is related to their chemical and mechanical properties. The inclusion of oxide and its role in the deposition mechanism may be significant. Chemical and engineering properties relate to the metallurgical structure of the alloys, which derives from the mechanism of deposition. The inclusion of oxides and hydroxides in the electroplate may provide evidence for this mechanism. Electrochemical impedance measurements have been made at significant deposition potentials, in alkaline electrolytes. These reveal a complex electrode behaviour which depends not only on the electrode potential but on the Co content of the electrolyte. For the relevant range of cathodic potential zinc-cobalt alloy electrodeposition occurs through a stratified interface. The formation of an absorbed layer ZnOH/sup +/ is the initial step, this inhibits the deposition of cobalt at low cathodic potentials, so explaining its 'anomalous deposition'. A porous layer of zinc forms on the adsorbed ZnOH/sup +/ at underpotential. As the potential becomes more cathodic, cobalt co- deposits from its electrolytic complex forming a metallic solid solution of Co in Zn. In electrolytes containing a high concentration of cobalt a mixed entity (ZnCo)/sub +/ is assumed to adsorb at the cathode from which a CoZn intermetallic deposits. (author)

Bioavailability of Iron, Zinc, Phytate and Phytase Activity during Soaking and Germination of White Sorghum Varieties

Science.gov (United States)

Afify, Abd El-Moneim M. R.; El-Beltagi, Hossam S.; Abd El-Salam, Samiha M.; Omran, Azza A.

2011-01-01

The changes in phytate, phytase activity and in vitro bioavailability of iron and zinc during soaking and germination of three white sorghum varieties (Sorghum bicolor L. Moench), named Dorado, Shandweel-6, and Giza-15 were investigated. Sorghum varieties were soaked for 20 h and germinated for 72 h after soaking for 20 h to reduce phytate content and increase iron and zinc in vitro bioavailability. The results revealed that iron and zinc content was significantly reduced from 28.16 to 32.16% and 13.78 to 26.69% for soaking treatment and 38.43 to 39.18% and 21.80 to 31.27% for germination treatments, respectively. Phytate content was significantly reduced from 23.59 to 32.40% for soaking treatment and 24.92 to 35.27% for germination treatments, respectively. Phytase enzymes will be activated during drying in equal form in all varieties. The results proved that the main distinct point is the change of phytase activity as well as specific activity during different treatment which showed no significant differences between the varieties used. The in vitro bioavailability of iron and zinc were significantly improved as a result of soaking and germination treatments. PMID:22003395

Uptake and distribution of soil applied zinc by citrus trees-addressing fertilizer use efficiency with 68Zn labeling.

Science.gov (United States)

Hippler, Franz Walter Rieger; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Boaretto, Antonio Enedi; Abreu-Junior, Cassio Hamilton; Mattos, Dirceu

2015-01-01

The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay) that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff) and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays.

Uptake and distribution of soil applied zinc by citrus trees-addressing fertilizer use efficiency with 68Zn labeling.

Directory of Open Access Journals (Sweden)

Franz Walter Rieger Hippler

Full Text Available The zinc (Zn supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays.

Uptake and Distribution of Soil Applied Zinc by Citrus Trees—Addressing Fertilizer Use Efficiency with 68Zn Labeling

Science.gov (United States)

Hippler, Franz Walter Rieger; Boaretto, Rodrigo Marcelli; Quaggio, José Antônio; Boaretto, Antonio Enedi; Abreu-Junior, Cassio Hamilton; Mattos, Dirceu

2015-01-01

The zinc (Zn) supply increases the fruit yield of Citrus trees that are grown, especially in the highly weathered soils of the tropics due to the inherently low nutrient availability in the soil solution. Leaf sprays containing micronutrients are commonly applied to orchards, even though the nutrient supply via soil could be of practical value. This study aimed to evaluate the effect of Zn fertilizers that are applied to the soil surface on absorption and partitioning of the nutrient by citrus trees. A greenhouse experiment was conducted with one-year-old sweet orange trees. The plants were grown in soils with different textures (18.1 or 64.4% clay) that received 1.8 g Zn per plant, in the form of either ZnO or ZnSO4 enriched with the stable isotope 68Zn. Zinc fertilization increased the availability of the nutrient in the soil and the content in the orange trees. Greater responses were obtained when ZnSO4 was applied to the sandy loam soil due to its lower specific metal adsorption compared to that of the clay soil. The trunk and branches accumulated the most fertilizer-derived Zn (Zndff) and thus represent the major reserve organ for this nutrient in the plant. The trees recovered up to 4% of the applied Zndff. Despite this relative low recovery, the Zn requirement of the trees was met with the selected treatment based on the total leaf nutrient content and increased Cu/Zn-SOD activity in the leaves. We conclude that the efficiency of Zn fertilizers depends on the fertilizer source and the soil texture, which must be taken into account by guidelines for fruit crop fertilization via soil, in substitution or complementation of traditional foliar sprays. PMID:25751056

Give-and-take based peer-to-peer content distribution networks

Indian Academy of Sciences (India)

Compared to traditional content distribution schemes, peer- to-peer networks ... are shared among users who desire to download files. In a peer-to-peer ..... randomly generated data points, with 300 segments and 200 peers. From the figure ...

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

Determination of the distribution and content of boron in aluminium casting strands. 1

International Nuclear Information System (INIS)

Rachlitz, R.

1987-01-01

Neutron-induced autoradiography was applied to investigate and optimize grain refining in the production of aluminium casting strands. The behaviour of the alloy AlTi5B1 used for grain refining was studied by analysis of both content and distribution of boron. This paper is concerned with the quantitative determinatin of track densities by means of the image analyzer type A 6471 and the results obtained are discussed in comparison with the amount of tracks visually counted. Boron contents as calculated from track densities are compared with calibration functions relating track density to the boron content determined by chemical analysis. The content of boron depends on the position of the autoradiographed plane in the sample, allowing, with its distribution taken into consideration, grain-refining processes to be studied. (author)

[Limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou].

Science.gov (United States)

Lin, Wen-Jie; Xiao, Tang-Fu; Ao, Zi-Qiang; Xing, Jun; Ma, Huan-Cheng; Hu, Ting-Xing

2007-03-01

With indigenous zinc smelting waste residue, contaminated soil and background soil as test substrates, a pot experiment was conducted to study the growth characteristics of Lolium perenne and Trifolium pretense on these substrates. The results showed that the major limiting factors of waste land revegetation in indigenous zinc smelting areas of western Guizhou were the salt-alkali stress and the lower contents of organic matter, total N, available N and total K. The heavy metals in waste residue had a high concentration, but their available forms only occupied a small proportion, with low toxicity to plant but having potential harmful risk. Contaminated soil had lower concentrations of heavy metals than waste residue, but its contained heavy metals were more in available form. The constraints of revegetation on contaminated soil were the toxicity of heavy metals and the low contents of available P and K. Mixing contaminated soil with zinc smelting waste residue could be one of the effective approaches for the substrate amendment in indigenous zinc smelting areas.

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.

Zinc complexed chitosan/TPP nanoparticles: A promising micronutrient nanocarrier suited for foliar application.

Science.gov (United States)

Deshpande, Paresh; Dapkekar, Ashwin; Oak, Manoj D; Paknikar, Kishore M; Rajwade, Jyutika M

2017-06-01

Cultivation of cereals in zinc deficient soils leads to declined nutritional quality of grain. Zinc deficiency in humans is a consequence of consumption of micronutrient deficient cereals as staple food. To achieve an increase in zinc density in grain, we evaluated zinc complexed chitosan nanoparticles (Zn-CNP) as a potential 'nanocarrier' suited for foliar fertilization. Zn-CNP were synthesized using tri-polyphosphate as a cross-linker. Spherical Zn-CNP (diameter 250-300nm) were positively charged (zeta potential, +42.34mV) and contained ∼20mg Zn/g (w/w). Plant growth in zinc deficient sand media, followed by foliar application of Zn-CNP (twice-a-week, for 5 weeks) after anthesis resulted in 27 and 42% increase in grain zinc content of MACS 3125 and UC1114 (durum wheat cultivars) respectively. Translocation of zinc ions from foliar applied Zn-CNP into the leaf and seed tissue was demonstrated using zinquin and dithizone stains, respectively. The study indicates the suitability of chitosan-based nanocarriers in agronomic biofortification. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Dynamic changes in the distribution of minerals in relation to phytic acid accumulation during rice seed development.

Science.gov (United States)

Iwai, Toru; Takahashi, Michiko; Oda, Koshiro; Terada, Yasuko; Yoshida, Kaoru T

2012-12-01

Phytic acid (inositol hexakisphosphate [InsP(6)]) is the storage compound of phosphorus in seeds. As phytic acid binds strongly to metallic cations, it also acts as a storage compound of metals. To understand the mechanisms underlying metal accumulation and localization in relation to phytic acid storage, we applied synchrotron-based x-ray microfluorescence imaging analysis to characterize the simultaneous subcellular distribution of some mineral elements (phosphorus, calcium, potassium, iron, zinc, and copper) in immature and mature rice (Oryza sativa) seeds. This fine-imaging method can reveal whether these elements colocalize. We also determined their accumulation patterns and the changes in phosphate and InsP(6) contents during seed development. While the InsP(6) content in the outer parts of seeds rapidly increased during seed development, the phosphate contents of both the outer and inner parts of seeds remained low. Phosphorus, calcium, potassium, and iron were most abundant in the aleurone layer, and they colocalized throughout seed development. Zinc was broadly distributed from the aleurone layer to the inner endosperm. Copper localized outside the aleurone layer and did not colocalize with phosphorus. From these results, we suggest that phosphorus translocated from source organs was immediately converted to InsP(6) and accumulated in aleurone layer cells and that calcium, potassium, and iron accumulated as phytic acid salt (phytate) in the aleurone layer, whereas zinc bound loosely to InsP(6) and accumulated not only in phytate but also in another storage form. Copper accumulated in the endosperm and may exhibit a storage form other than phytate.

The effect of zinc supplementation on linear growth, body composition, and growth factors in preterm infants.

Science.gov (United States)

Díaz-Gómez, N Marta; Doménech, Eduardo; Barroso, Flora; Castells, Silvia; Cortabarria, Carmen; Jiménez, Alejandro

2003-05-01

The aim of our study was to evaluate the effect of zinc supplementation on linear growth, body composition, and growth factors in premature infants. Thirty-six preterm infants (gestational age: 32.0 +/- 2.1 weeks, birth weight: 1704 +/- 364 g) participated in a longitudinal double-blind, randomized clinical trial. They were randomly allocated either to the supplemental (S) group fed with a standard term formula supplemented with zinc (final content 10 mg/L) and a small quantity of copper (final content 0.6 mg/L), or to the placebo group fed with the same formula without supplementation (final content of zinc: 5 mg/L and copper: 0.4 mg/L), from 36 weeks postconceptional age until 6 months corrected postnatal age. At each evaluation, anthropometric variables and bioelectrical impedance were measured, a 3-day dietary record was collected, and a blood sample was taken. We analyzed serum levels of total alkaline phosphatase, skeletal alkaline phosphatase (sALP), insulin growth factor (IGF)-I, IGF binding protein-3, IGF binding protein-1, zinc and copper, and the concentrations of zinc in erythrocytes. The S group had significantly higher zinc levels in serum and erythrocytes and lower serum copper levels with respect to the placebo group. We found that the S group had a greater linear growth (from baseline to 3 months corrected age: Delta score deviation standard length: 1.32 +/-.8 vs.38 +/-.8). The increase in total body water and in serum levels of sALP was also significantly higher in the S group (total body water: 3 months; corrected age: 3.8 +/-.5 vs 3.5 +/-.4 kg, 6 months; corrected age: 4.5 +/-.5 vs 4.2 +/-.4 kg; sALP: 3 months; corrected age: 140.2 +/- 28.7 vs 118.7 +/- 18.8 micro g/L). Zinc supplementation has a positive effect on linear growth in premature infants.

[Influence of hormonal contraceptives on indices of zinc homeostasis and bone remodeling in young adult women].

Science.gov (United States)

Simões, Tania Mara Rodrigues; Zapata, Carmiña Lucía Vargas; Donangelo, Carmen Marino

2015-09-01

To investigate the influence of the use of oral hormonal contraceptive agents (OCA) on the biochemical indices related to metabolic zinc utilization and distribution, and to bone turnover in young adult women. Cross-sectional study. Blood and urine samples from non-users (-OCA; control; n=69) and users of hormonal contraceptives for at least 3 months (+OCA; n=62) were collected under controlled conditions. Indices of zinc homeostasis and of bone turnover were analyzed in serum or plasma (total, albumin-bound and α2-macroglobulin-bound zinc, albumin and total and bone alkaline phosphatase activity), in erythrocytes (zinc and metallothionein) and in urine (zinc, calcium and hydroxyproline). The habitual zinc and calcium intakes were evaluated by a food frequency questionnaire. Dietary zinc intake was similar in both groups and on average above recommended values, whereas calcium intake was similarly sub-adequate in +OCA and -OCA. Compared to controls, +OCA had lower concentrations of total and α2-macroglobulin-bound zinc (11 and 28.5%, respectively, puse decreases serum zinc, alters zinc distribution in major serum fractions with possible effects on tissue uptake, enhances zinc retention in the body and decreases bone turnover. Prolonged OCA use may lead to lower peak bone mass and/or to impaired bone mass maintenance in young women, particularly in those with marginal calcium intake. The observed OCA effects were more evident in women younger than 25 years and in nulliparous women, deserving special attention in future studies.

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.

Estimate of oxygen consumption and intracellular zinc concentration of human spermatozoa in relation to motility.

Science.gov (United States)

Henkel, Ralf R; Defosse, Kerstin; Koyro, Hans-Wilhelm; Weissmann, Norbert; Schill, Wolf-Bernhard

2003-03-01

To investigate the human sperm oxygen/energy consumption and zinc content in relation to motility. In washed spermatozoa from 67 ejaculates, the oxygen consumption was determined. Following calculation of the total oxygen consumed by the Ideal Gas Law, the energy consumption of spermatozoa was calculated. In addition, the zinc content of the sperm was determined using an atomic absorption spectrometer. The resulting data were correlated to the vitality and motility. The oxygen consumption averaged 0.24 micromol/10(6) sperm x 24h, 0.28 micromol/10(6) live sperm x 24h and 0.85 micromol/10(6) live motile sperm x 24h. Further calculations revealed that sperm motility was the most energy consuming process (164.31 mJ/10(6) motile spermatozoa x 24h), while the oxygen consumption of the total spermatozoa was 46.06 mJ/10(6) spermatozoa x 24h. The correlation of the oxygen/energy consumption and zinc content with motility showed significant negative correlations (r= -0.759; P<0.0001 and r=-0.441; P<0.0001, respectively). However, when correlating sperm energy consumption with the zinc content, a significant positive relation (r=0.323; P=0.01) was observed. Poorly motile sperm are actually wasting the available energy. Moreover, our data clearly support the "Geometric Clutch Model" of the axoneme function and demonstrate the importance of the outer dense fibers for the generation of sperm motility, especially progressive motility.

Contention Modeling for Multithreaded Distributed Shared Memory Machines: The Cray XMT

Energy Technology Data Exchange (ETDEWEB)

Secchi, Simone; Tumeo, Antonino; Villa, Oreste

2011-07-27

Distributed Shared Memory (DSM) machines are a wide class of multi-processor computing systems where a large virtually-shared address space is mapped on a network of physically distributed memories. High memory latency and network contention are two of the main factors that limit performance scaling of such architectures. Modern high-performance computing DSM systems have evolved toward exploitation of massive hardware multi-threading and fine-grained memory hashing to tolerate irregular latencies, avoid network hot-spots and enable high scaling. In order to model the performance of such large-scale machines, parallel simulation has been proved to be a promising approach to achieve good accuracy in reasonable times. One of the most critical factors in solving the simulation speed-accuracy trade-off is network modeling. The Cray XMT is a massively multi-threaded supercomputing architecture that belongs to the DSM class, since it implements a globally-shared address space abstraction on top of a physically distributed memory substrate. In this paper, we discuss the development of a contention-aware network model intended to be integrated in a full-system XMT simulator. We start by measuring the effects of network contention in a 128-processor XMT machine and then investigate the trade-off that exists between simulation accuracy and speed, by comparing three network models which operate at different levels of accuracy. The comparison and model validation is performed by executing a string-matching algorithm on the full-system simulator and on the XMT, using three datasets that generate noticeably different contention patterns.

Evaluation of moisture content distribution in wood by soft X-ray imaging

International Nuclear Information System (INIS)

Tanaka, T.; Avramidis, S.; Shida, S.

2009-01-01

A technique for nondestructive evaluation of moisture content distribution of Japanese cedar (sugi) during drying using a newly developed soft X-ray digital microscope was investigated. Radial, tangential, and cross-sectional samples measuring 100 x 100 x 10 mm were cut from green sugi wood. Each sample was dried in several steps in an oven and upon completion of each step, the mass was recorded and a soft X-ray image was taken. The relationship between moisture content and the average grayscale value of the soft X-ray image at each step was linear. In addition, the linear regressions overlapped each other regardless of the sample sections. These results showed that soft X-ray images could accurately estimate the moisture content. Applying this relationship to a small section of each sample, the moisture content distribution was estimated from the image differential between the soft X-ray pictures obtained from the sample in question and the same sample in the oven-dried condition. Moisture content profiles for 10-mm-wide parts at the centers of the samples were also obtained. The shapes of the profiles supported the evaluation method used in this study

The importance of zinc on osteoporotic bones

Energy Technology Data Exchange (ETDEWEB)

Lima, I.; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mail: ricardo@lin.ufrj.br; inaya@lin.ufrj.br; Anjos, M.J. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica]. E-mail: marcelin@lin.ufrj.br; Farias, M.L.F. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Hospital Universitario. Servico de Endocrinologia]. E-mail: fleiuss@hucff.ufrj.br; Rosenthal, D. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Fisiologia Endocrina]. E-mail: doris@biof.ufrj.br

2007-07-01

Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabecular region. For that purpose, it was used an XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that the profile of the zinc distribution and its concentration on femoral heads are strongly related to the associated pathology. (author)

The importance of zinc on osteoporotic bones

International Nuclear Information System (INIS)

Lima, I.; Lopes, R.T.; Anjos, M.J.; Farias, M.L.F.; Rosenthal, D.

2007-01-01

Zinc is an essential element that can be found in bones, such as calcium and phosphorus. It seems to have effects on growth, bone turnover and mineralization making its relationship with bones still opening. The goal of this study is, by XRF analysis, characterized bone samples, with and without pathology, in the trabecular region. For that purpose, it was used an XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results show that the profile of the zinc distribution and its concentration on femoral heads are strongly related to the associated pathology. (author)

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

Directory of Open Access Journals (Sweden)

Akbar Badii

2012-01-01

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

Environmental exposure of road borders to zinc

Energy Technology Data Exchange (ETDEWEB)

Blok, J. [Royal Haskoning, P.O. Box 151, 6500 Ad Nijmegen (Netherlands)]. E-mail: Han.Blok@royalhaskoning.com

2005-09-15

The emissions of zinc along roads originating from tyre wear, corrosion of safety fence and other traffic-related sources have been quantified and validated by measured long-term loads in road run-off and airborne solids (drift) for 29 published case studies. The distribution pattern over the road border at various distances from the edge of the paved surface is assessed on the basis of 38 published case studies with measured concentrations in soil. For the impact assessment, the road border is differentiated into a zone that is part of the 'technosphere' and the 'target zone' beyond that technosphere that can be considered as part of the receiving environment. The 'technosphere' of the road includes the central reservation, the hard and the soft shoulder or, if one or both shoulders are not present, the so-called obstacle 'free zone' that is defined by road engineers. Pollution within the technosphere may require appropriate management of solid disposal and isolation from groundwater to prevent further distribution of pollutants to the environment. In the target zone along regional roads, the zinc load is about 4 mg/m{sup 2} year and this is of the same order of magnitude as that of atmospheric deposition in areas beyond the influence of roads (background). In the target zone along highways, the zinc load is increased in comparison to the background deposition. The average load of about 38 mg/m{sup 2} year is similar to that in fertilised agricultural land. Because most of the emitted zinc stays in the technosphere, the total amount entering this target zone along highways is limited. From the 140 tons of zinc per year that is released from tyre wear in The Netherlands, 64 tons is emitted in the urban area, 6.5 tons reaches to the target zones of all roads and only 1.1 tons of zinc will enter the target zone along highways. This amount will be further decreased by the application of porous asphalt in the near future. The

Composition control of tin-zinc electrodeposits through means of experimental strategies

International Nuclear Information System (INIS)

Dubent, S.; De Petris-Wery, M.; Saurat, M.; Ayedi, H.F.

2007-01-01

Tin-zinc coatings offer excellent corrosion protection and do not suffer the drawback of the voluminous white corrosion product of pure zinc or high zinc alloy coatings. The aim of this study was to determine the suitable electroplating conditions (i.e. electrolyte composition and cathode current density) to produce 70Sn-30Zn electrodeposits. Thus, a fractional factorial design (FFD) was carried out to evaluate the effects of experimental parameters (Zn II concentration, Sn IV concentration, pH and current density) on the Zn content of the electrodeposit. On the other hand, the electrodeposits were characterised by glow discharge optical emission spectroscopy (GDOES) and scanning electron microscopy (SEM). Correlation between operating conditions, composition and morphology was attempted

Brightness coatings of zinc-cobalt alloys by electrolytic way

International Nuclear Information System (INIS)

Julve, E.

1993-01-01

Zinc-cobalt alloys provide corrosion resistance for the ferrous based metals. An acidic electrolyte for zinc-cobalt electrodeposition is examined in the present work. The effects of variations in electrolyte composition, in electrolyte temperature, pH and agitation on electrodeposit composition have been studied, as well as the current density influence. It was found that the following electrolyte gave the optimum results: 79 g.1''-1 ZnCl 2 , 15.3 g.1''-1 CoCl 2 .6H 2 O, 160 g.1''-1 KCl, 25 g.1''-1 H 3 BO 3 and 5-10 cm''3.1''-1 of an organic additive (caffeine, coumarin and sodium lauryl-sulphonate). The operating conditions were: pH=5,6 temperature: 30 degree centigree, current density: 0,025-0,035 A. cm''2, anode: pure zinc, agitation: slowly with air and filtration: continuous. The throwing power and cathode current efficiency of the electrolyte were also studied. This electrolyte yielded zinc-cobalt alloys white and lustrous and had a cobalt content of 0,5-0,8% (Author) 3 refs. 5 fig

Nanocarrier-mediated foliar zinc fertilization influences expression of metal homeostasis related genes in flag leaves and enhances gluten content in durum wheat

OpenAIRE

Deshpande, Paresh; Dapkekar, Ashwin; Oak, Manoj; Paknikar, Kishore; Rajwade, Jyutika

2018-01-01

Background Wheat is the staple food for most of the world’s population; however, it is a poor source of zinc. Foliar fertilization of zinc via zinc loaded chitosan nanocarriers (Zn-CNP) post-anthesis has proved to be a promising approach for grain zinc enhancement in durum wheat as evidenced in our earlier study. However, the molecular mechanism of uptake of zinc via Zn-CNP remains unclear. Methods/Principle findings Foliar application of Zn-CNP was performed at post anthesis stages in two du...

Magnetic properties of bioactive glass-ceramics containing nanocrystalline zinc ferrite

International Nuclear Information System (INIS)

Singh, Rajendra Kumar; Srinivasan, A.

2011-01-01

Glass-ceramics with finely dispersed zinc ferrite (ZnFe 2 O 4 ) nanocrystallites were obtained by heat treatment of x(ZnO,Fe 2 O 3 )(65-x)SiO 2 20(CaO,P 2 O 5 )15Na 2 O (6≤x≤21 mole%) glasses. X-ray diffraction patterns of the glass-ceramic samples revealed the presence of calcium sodium phosphate [NaCaPO 4 ] and zinc ferrite [ZnFe 2 O 4 ] as major crystalline phases. Zinc ferrite present in nanocrystalline form contributes to the magnetic properties of the glass-ceramic samples. Magnetic hysteresis cycles of the glass-ceramic samples were obtained with applied magnetic field sweeps of ±20 kOe and ±500 Oe, in order to evaluate the potential of these glass-ceramics for hyperthermia treatment of cancer. The evolution of magnetic properties in these samples, viz., from a partially paramagnetic to fully ferrimagnetic nature has been explored using magnetometry and X-ray diffraction studies. - Research highlights: → The glass-ceramics contain bone mineral and magnetic phases. → Calcium sodium phosphate and zinc ferrite nanocrystallites have been identified in all the sample. → With an increase in ZnO and Fe2O3 content, magnetic property of samples evolved from partially paramagnetic to fully ferrimagnetic nature. → Large magnetic hysteresis loops have been obtained for samples with high ZnO+Fe2O3 content.

Optical, physical and structural studies of boro-zinc tellurite glasses

International Nuclear Information System (INIS)

Gayathri Pavani, P.; Sadhana, K.; Chandra Mouli, V.

2011-01-01

To investigate the modification effect of the modifier ZnO on boro-tellurite glass, a series of glasses with compositions 50B 2 O 3 -(50-x)ZnO-xTeO 2 have been prepared by conventional melt quenching technique. Amorphous nature of the samples was confirmed through X-ray diffraction technique. Optical absorption and IR structural studies are carried out on the glass system. The optical absorption studies revealed that the cutoff wavelength increases while optical band gap (E opt ) and Urbach energy decreases with an increase of ZnO content. Refractive index evaluated from E opt was found to increase with an increase of ZnO content. The compositional dependence of different physical parameters such as density, molar volume, oxygen packing density, optical basicity, have been analyzed and discussed. The IR studies showed that the structure of glass consists of TeO 4 , TeO 3 /TeO 3+1 , BO 3 , BO 4 and ZnO 4 units. -- Research highlights: → Novel boro-zinc tellurite ternary glasses that can compete with boro-tellurite and zinc tellurite glasses are successfully prepared. → Boro-zinc tellurite ternary glasses are of higher refractive index compared with zinc tellurite glasses. → Optical, physical and structural properties of the novel ternary glass system are explained.→ At 30 mol% of ZnO, TeO 4 is replaced by ZnO 4 indicating the presence of ZnO 4 network.

Screening of 33 Medicinal Plants for the Microelements Content

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Ducu Sandu Ştef

2010-05-01

Full Text Available The microelements content of 33 medicinal plants was analyzed. The analysed microelements were: Iron, copper, zinc, manganese, cobalt, chromium, nickel, cadmium and lead. Mineral contents were determinate by flame atomic absorption spectrometry (F-AAS with high resolution continuum source ContrAA 300 spectrometer. The contents in microelements for analysed samples were in range: 18.1 ppm (Symphytum officinale - 1.4 ppm (Rhamnus frangula, for Copper; 26,2 ppm (Valeriana officinalis – 4,3 ppm (Rhamnus frangula, for Zinc; 214 ppm. (Violae tricoloris herba - 18 ppm (Equisetum arvense, for Manganese; 826 ppm (Calendula officinalis - 23 ppm (Rhamnus frangula, for Iron. The microelements contents (Cu, Zn, Mn, Fe, Co, Cr, Ni, Cd and Pb have grouped the analyzed medicinal plants in two main clusters. First main cluster was formed by other two groups.

Silver-zinc electrodeposition from a thiourea solution with added EDTA or HEDTA

International Nuclear Information System (INIS)

Oliveira, G.M. de; Carlos, I.A.

2009-01-01

This paper shows the study of silver-zinc electrodeposition from a thiourea solution with added (ethylenedinitrilo)tetraacetic acid (EDTA), disodium salt and N-(2-hydroxyethyl)ethylenediaminetriacetic acid (HEDTA), trisodium salt. Voltammetric results indicated that silver-zinc alloy can be obtained applying overpotential higher than 0.495 V, in Tu solution containing 1.0 x 10 -1 mol L -1 Zn(NO 3 ) 2 + 2.5 x 10 -2 mol L -1 AgNO 3 . This was due to silver(I) ion complexation with thiourea, which shifted the silver deposition potential to more negative value and due to silver-zinc alloy deposition, which occurred at potentials more positive than the potential to zinc deposition alone. EDTA or HEDTA did not significantly affect the silver and zinc deposition potentials, but decreased the current density for silver-zinc deposition. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) analyses of the silver-zinc deposits showed that the morphology and composition changed as a function of the conditions of deposition, viz, deposition potential (E d ), deposition charge density (q d ) and solution composition (silver, EDTA and HEDTA concentrations). EDS analysis of the deposits showed sulphur (S) incorporated into the silver-zinc deposit, while SEM images showed that this sulphur content seemed to improve the silver-zinc morphology, as did the presence of EDTA and HEDTA in the solution, which enhanced the sulphur incorporation into the silver-zinc deposit. X-ray diffraction (XRD) analysis of the silver-zinc deposit showed that it was amorphous, irrespective of its composition and morphology

ICP analysis of zinc and zamak alloys

International Nuclear Information System (INIS)

Gomez Coedo, A.; Dorado Lopez, M.T.

1987-01-01

A study was carried out on the possibilities of inductively coupled plasma emission spectrometry (ICP) in the determination of Cu, Cd, Fe, Pb, Sn, Al and Mg in zinc-base materials using direct sample solutions. A selection of analytical lines is made, on account of both their sensitivity and the corresponding study of spectral interferences; measurable minimum contents and calibrated terms are also established, to conduce therefore to a complete methodology which allows determination of the mentioned elements within the contents established on the specifications of these materials. (author)

Influence of thickness of zinc coating on CMT welding-brazing with AlSi5 alloy wire

Science.gov (United States)

Jin, Pengli; Wang, Zhiping; Yang, Sinan; Jia, Peng

2018-03-01

Effect of thickness of zinc coating on Cold Mattel Transfer (CMT) brazing of aluminum and galvanized steel is investigated. The thickness of zinc coating is 10 μm, 30 μm, and 60 μm, respectively. A high-speed camera was used to capture images of welding process of different specimens; the microstructure and composition analyses of the welding seam were examined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS); the mechanical properties were measured in the form of Nano-indentation experiments. The results showed that arc characteristics and metal transfer behavior were unsteady at the beginning of welding process and that became stable after two cycles of CMT. With the thickness of zinc coating thickening, arc characteristics and metal transfer behaviors were more deteriorated. Compared with 10 μm and 30 μm, clad appearance of 60 μm was straight seam edges and a smooth surface which wetting angle was 60°. Zinc-rich zone at the seam edges was formed by zinc dissolution and motel pool oscillating, and zinc content of 10 μm and 30 μm were 5.8% and 7.75%. Zinc content of 60 μm was 14.61%, and it was a belt between galvanized steel and welding seam. The thickness of intermetallic compounds layer was in the range of 1-8 μm, and it changed with the thickness of zinc coating. The average hardness of the reaction layer of 60 μm is 9.197 GPa.

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.

Distribution characteristics of available trace elements in soil from a reclaimed land in a mining area of north Shaanxi, China

Directory of Open Access Journals (Sweden)

Li Zhanbin

2013-06-01

Full Text Available Through field and laboratory tests we studied the temporal and spatial variation in the soil content of four available trace elements :copper(Cu, iron(Fe, manganese(Mn and zinc (Zn, to analyze their distribution characteristics in reclaimed mining land under different reclamation conditions. The available trace elements content varied considerably with different land reclamation patterns. Extended reclamation time was helpful for the recovery of the available trace element content in the soil, and after more than eight years of soil reclamation, the content of available trace elements was closer to or greater than that in soil under natural conditions. Various treatment measures significantly influenced the content and distribution of available trace elements in the soil, and reasonable artificial treatments, including covering the soil and growing shrubs and herbaceous plants, increased the content of available trace elements.

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.

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

Science.gov (United States)

Spiker, R C; Ciuchta, H P

1980-04-01

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

Release of zinc from the brain of El (epilepsy) mice during seizure induction.

Science.gov (United States)

Takeda, A; Hanajima, T; Ijiro, H; Ishige, A; Iizuka, S; Okada, S; Oku, N

1999-05-15

Brain distribution after i.v. injection of 65ZnCl2 into El mice, an animal model of genetically determined epilepsy, was studied by autoradiography to study the utilization of zinc in the brain. The distribution of 65Zn in the brain of El mice 6 days after injection was almost the same as that of ddY (normal) mice, suggesting that the uptake of zinc by the brain of El mice is normal. To study the movement of zinc in the brain in the course of seizure induction, the concentrations of 65Zn in the brain of seizure-afflicted and untreated control El mice were compared 20 days after 65Zn injection. The concentration of 65Zn in the brain of seized El mice was overall lower than that of control El mice; the concentration of 65Zn was decreased notably in the piriform cortex and amygdaloid nuclei complex during convulsion. These results suggest that the release of zinc from the El mouse brain is enhanced during convulsion. The decrease in actively functioning zinc in the brain may be associated with the increase in susceptibility to seizure in the El mouse. Copyright 1999 Elsevier Science B.V.

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.

A marriage of convenience; a simple food chain comprised of Lemna minor (L.) and Gammarus pulex (L.) to study the dietary transfer of zinc.

Science.gov (United States)

Lahive, E; O'Halloran, J; Jansen, M A K

2015-01-01

Macrophytes contribute significantly to the cycling of metals in aquatic systems, through accumulation during growth and release during herbivory or decomposition. Accumulation of high levels of metals has been extensively documented in Lemnaceae (duckweeds). However, the degree of trophic transfer of metals from Lemnaceae to secondary consumers remains poorly understood. This study demonstrates that zinc accumulated in Lemna minor is bioavailable to the herbivore consumer Gammarus pulex. Overall, the higher the zinc content of L. minor, the more zinc accumulated in G. pulex. Accumulation in G. pulex was such that mortality occurred when they were fed high zinc-containing L. minor. Yet, the percentage of consumed zinc retained by G. pulex actually decreased with higher zinc concentrations in L. minor. We hypothesise that this decrease reflects internal zinc metabolism, including a shift from soluble to covalently bound zinc in high zinc-containing L. minor. Consistently, relatively more zinc is lost through depuration when G. pulex is fed L. minor with high zinc content. The developed Lemna-Gammarus system is simple, easily manipulated, and sensitive enough for changes in plant zinc metabolism to be reflected in metal accumulation by the herbivore, and therefore suitable to study ecologically relevant metal cycling in aquatic ecosystems. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

Incorporation of zinc into calcium silicate hydrates, Part I: formation of C-S-H(I) with C/S=2/3 and its isochemical counterpart gyrolite

International Nuclear Information System (INIS)

Stumm, Andreas; Garbev, Krassimir; Beuchle, Guenter; Black, Leon; Stemmermann, Peter; Nueesch, Rolf

2005-01-01

We have investigated the incorporation of zinc into both nanocrystalline and crystalline calcium silicate hydrates with starting C/S ratios of 2/3 (0.66). Zinc was added replacing calcium in the starting mixtures [Zn/(Zn+Ca)=0-1/4; 0-10 wt.% Zn], and the resultant phases were characterised using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), differential thermal analysis-thermogravimetry (DTA-TG) and environmental scanning electron microscopy (ESEM). In both groups of samples, increasing zinc content led to gradual structural changes, until eventually a second phase was formed. Zinc was incorporated to similar limits in both sets of samples. The thermal stability of the structures increased to a certain zinc content, beyond which there was structural destabilisation. Zinc incorporation is possible up to ∼6 wt.%. Our observations strongly indicate similar zinc incorporation mechanisms in both sample series, namely incorporation of zinc into the interlayer of C-S-H(I) and the X-sheet of gyrolite for nanocrystalline and crystalline samples, respectively

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 ...

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.

Distinctive hippocampal zinc distribution patterns following stress exposure in an animal model of PTSD.

Science.gov (United States)

Sela, Hagit; Cohen, Hagit; Karpas, Zeev; Zeiri, Yehuda

2017-03-22

Emerging evidence suggests that zinc (Zn) deficiency is associated with depression and anxiety in both human and animal studies. The present study sought to assess whether there is an association between the magnitude of behavioral responses to stress and patterns of Zn distribution. The work has focused on one case study, the association between an animal model of posttraumatic stress disorder (PTSD) and the Zn distribution in the rat hippocampus. Behaviors were assessed with the elevated plus-maze and acoustic startle response tests 7 days later. Preset cut-off criteria classified exposed animals according to their individual behavioral responses. To further characterize the distribution of Zn that occurs in the hippocampus 8 days after the exposure, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging was used. It has been found that Zn distribution in the dentate gyrus (DG) sub-region in the hippocampus is clearly more widely spread for rats that belong to the extreme behavioral response (EBR) group as compared to the control group. Comparison of the Zn concentration changes in the cornu ammonis 1 (CA1) and the DG sub-regions of the hippocampus shows that the concentration changes are statistically significantly higher in the EBR rats compared to the rats in the control and minimal behavioral response (MBR) groups. In order to understand the mechanism of stress-induced hippocampal Zn dyshomeostasis, relative quantitative analyses of metallothionein (MT), B-cell lymphoma 2 (Bcl-2) and caspase 3 immunoreactivity were performed. Significant differences in the number of caspase-ir and Bcl-2 cells were found in the hippocampal DG sub-region between the EBR group and the control and MBR groups. The results of this study demonstrate a statistically significant association between the degree of behavioral disruption resulting from stress exposure and the patterns of Zn distribution and concentration changes in the various hippocampal regions

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

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)

Study of human prostate spheroids treated with zinc using X-ray microfluorescence

International Nuclear Information System (INIS)

Leitao, Roberta G.; Lopes, Ricardo T.; Pereira, Gabriela R.; Santos, Carlos A.N.; Palumbo Junior, Antonio; Nasciutti, Luiz E.; Souza, Pedro A.V.R.; Anjos, Marcelino J.

2013-01-01

Spheroids cell culture is a useful technique for tissue engineering or regenerative medicine re-search, pharmacological and toxicological studies, and fundamental studies in cell biology. In this study, we investigated Zn distribution in cell spheroids in benign prostate hyperplasia (BPH) and prostate cancer (DU145) and analyzed the differences in the response to Zinc (0-150 μM) treatment. The measurements were performed in standard geometry of 45 deg incidence, exciting with a white beam and using an optical capillary with 20 μm diameter collimation in the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results showed non-uniform distribution of Zn in all the spheroids analyzed. The differential response to zinc of DU145 and BPH cell spheroids suggests that zinc may have an important role in prostate cancer and BPH diagnosis. (author)

Study of human prostate spheroids treated with zinc using X-ray microfluorescence

Energy Technology Data Exchange (ETDEWEB)

Leitao, Roberta G.; Lopes, Ricardo T.; Pereira, Gabriela R., E-mail: roberta@lin.ufrj.br, E-mail: gpereira@metalmat.ufrj.br [Coordenacao dos Cursos de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Santos, Carlos A.N., E-mail: cansantos.bio@gmail.com [Instituto Nacional de Metrologia, Qualidade e Tecnologia (DIPRO/INMETRO), Duque de Caxias, RJ (Brazil). Lab. de Biotecnologia; Palumbo Junior, Antonio; Nasciutti, Luiz E., E-mail: nasciutt@ufrj.br [Universidade Federal do Rio de Janeiro (ICB/CCS/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Interacoes Celulares; Souza, Pedro A.V.R., E-mail: pedroaugustoreis@uol.com.br [Hospital Federal do Andarai (HFA), Rio de Janeiro, RJ (Brazil). Servico de Urologia; Anjos, Marcelino J., E-mail: marcelin@lin.ufrj.br [Universidade Estatual do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica

2013-07-01

Spheroids cell culture is a useful technique for tissue engineering or regenerative medicine re-search, pharmacological and toxicological studies, and fundamental studies in cell biology. In this study, we investigated Zn distribution in cell spheroids in benign prostate hyperplasia (BPH) and prostate cancer (DU145) and analyzed the differences in the response to Zinc (0-150 μM) treatment. The measurements were performed in standard geometry of 45 deg incidence, exciting with a white beam and using an optical capillary with 20 μm diameter collimation in the XRF beam line at the Synchrotron Light National Laboratory (Campinas, Brazil). The results showed non-uniform distribution of Zn in all the spheroids analyzed. The differential response to zinc of DU145 and BPH cell spheroids suggests that zinc may have an important role in prostate cancer and BPH diagnosis. (author)

Zinc presence in invasive ductal carcinoma of the breast and its correlation with oestrogen receptor status

Energy Technology Data Exchange (ETDEWEB)

Farquharson, M J [Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main St W Hamilton, Ontario, L8S 4L8 (Canada); Al-Ebraheem, A [Department of Radiography, City Community and Health Sciences, City University, London, EC1V 0HB (United Kingdom); Geraki, K [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon, OX11 0DE (United Kingdom); Leek, R; Jubb, A; Harris, A L [Cancer Research UK, Oxford Cancer Centre, Molecular Oncology Laboratories, University of Oxford, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, 0X3 9DS (United Kingdom)], E-mail: farquhm@mcmaster.ca

2009-07-07

Zinc is known to play an important role in many cellular processes, and the levels of zinc are controlled by specific transporters from the ZIP (SLC39A) influx transporter group and the ZnT (SLC30A) efflux transporter group. The distribution of zinc was measured in 59 samples of invasive ductal carcinoma of breast using synchrotron radiation micro probe x-ray fluorescence facilities. The samples were formalin fixed paraffin embedded tissue micro arrays (TMAs) enabling a high throughput of samples and allowing us to correlate the distribution of trace metals with tumour cell distribution and, for the first time, important biological variables. The samples were divided into two classes, 34 oestrogen receptor positive (ER+ve) and 25 oestrogen receptor negative (ER-ve) based on quantitative immunohistochemistry assessment. The overall levels of zinc (i.e. in tumour and surrounding tissue) in the ER+ve samples were on average 60% higher than those in the ER-ve samples. The zinc levels were higher in the ER+ve tumour areas compared to the ER-ve tumour areas with the mean levels in the ER+ve samples being approximately 80% higher than the mean ER-ve levels. However, the non-tumour tissue regions of the samples contained on average the same levels of zinc in both types of breast cancers. The relative levels of zinc in tumour areas of the tissue were compared with levels in areas of non-tumour surrounding tissue. There was a significant increase in zinc in the tumour regions of the ER+ve samples compared to the surrounding regions (P < 0.001) and a non-significant increase in the ER-ve samples. When comparing the increase in zinc in the tumour regions expressed as a percentage of the surrounding non-tumour tissue zinc level in the same sample, a significant difference between the ER+ve and ER-ve samples was found (P < 0.01)

Zinc presence in invasive ductal carcinoma of the breast and its correlation with oestrogen receptor status

International Nuclear Information System (INIS)

Farquharson, M J; Al-Ebraheem, A; Geraki, K; Leek, R; Jubb, A; Harris, A L

2009-01-01

Zinc is known to play an important role in many cellular processes, and the levels of zinc are controlled by specific transporters from the ZIP (SLC39A) influx transporter group and the ZnT (SLC30A) efflux transporter group. The distribution of zinc was measured in 59 samples of invasive ductal carcinoma of breast using synchrotron radiation micro probe x-ray fluorescence facilities. The samples were formalin fixed paraffin embedded tissue micro arrays (TMAs) enabling a high throughput of samples and allowing us to correlate the distribution of trace metals with tumour cell distribution and, for the first time, important biological variables. The samples were divided into two classes, 34 oestrogen receptor positive (ER+ve) and 25 oestrogen receptor negative (ER-ve) based on quantitative immunohistochemistry assessment. The overall levels of zinc (i.e. in tumour and surrounding tissue) in the ER+ve samples were on average 60% higher than those in the ER-ve samples. The zinc levels were higher in the ER+ve tumour areas compared to the ER-ve tumour areas with the mean levels in the ER+ve samples being approximately 80% higher than the mean ER-ve levels. However, the non-tumour tissue regions of the samples contained on average the same levels of zinc in both types of breast cancers. The relative levels of zinc in tumour areas of the tissue were compared with levels in areas of non-tumour surrounding tissue. There was a significant increase in zinc in the tumour regions of the ER+ve samples compared to the surrounding regions (P < 0.001) and a non-significant increase in the ER-ve samples. When comparing the increase in zinc in the tumour regions expressed as a percentage of the surrounding non-tumour tissue zinc level in the same sample, a significant difference between the ER+ve and ER-ve samples was found (P < 0.01).

Physical characterization of plakophilin 1 reconstituted with and without zinc.

Science.gov (United States)

Hofmann, I; Mücke, N; Reed, J; Herrmann, H; Langowski, J

2000-07-01

Plakophilin 1 (PKP1) belongs to the arm-repeat protein family which is characterized by the presence of a conserved 42-amino-acid motif. Despite individual members of the family containing a similar type of structural domain, they exhibit diverse cellular functions. PKP1 is ubiquitously expressed in human tissues and, depending on the type of cell, found prominently in the karyoplasm and/or in desmosomes. In surface plasmon resonance detection experiments, we noticed that PKP1 specifically bound zinc but not calcium or magnesium. Therefore we have used circular dichroism spectroscopy, limited proteolysis, analytical ultracentrifugation, electron microscopy and dynamic light scattering to establish the physical properties of recombinant PKP1 depending on the presence or absence of zinc. The alpha helix content of PKP1 was considerably higher when reconstituted with zinc than without. By atomic absorption spectroscopy 7.3 atoms zinc were shown to be tightly associated with one molecule of wild-type PKP1. The zinc-reconstituted protein formed globular particles of 21.9 +/- 8.4 nm diameter, as measured by electron microscopy after glycerol spraying/rotary metal shadowing. In parallel, the average sedimentation coefficient (s20, w) for zinc-containing PKP1 was 41S and its diffusion coefficient, as obtained by dynamic light scattering, 1.48 x 10-7 cm2.s-1. The molecular mass of 2.44 x 106 obtained from s and D yields an average stoichiometry of 30 for the PKP1 oligomer. In contrast, PKP1, reconstituted without zinc, contained no significant amount of zinc, sedimented with 4.6S, and was present in monomeric form as determined by sedimentation equilibrium centrifugation.

Reduction in bioavailability of arsenic in contaminated irrigated soil using zinc and organic manure

International Nuclear Information System (INIS)

Batool, S.Q.

2012-01-01

The experiments were conducted to reduce the bioavailability of arsenic with application of organic and inorganic materials from contaminated soils irrigated with arsenic contaminated water. The results showed that the amount of extractable arsenic increased with submergence and decreased with application of organic material. However, amount of such decrease altered with inorganic material i.e. zinc and decrease was greater with As5Zn10 (0.17 to 0.0 mg/kg) where zinc was applied at the rate of 10 mg/kg. Among the different organic materials, arsenic content in soil remarkably decreased with application of farmyard manure. The decrease in arsenic content was less than upper toxic limit of arsenic in soil i.e.10mg/kg for paddy soils. Other manures also showed decrease in arsenic concentration but with desorption after half interval of treatment. Best remediating agents used for arsenic retention was zinc sulphate> organic compost >farmyard manure. (author)

IMPACT OF BIOSLUDGE APPLICATION ON HEAVY METALS CONTENT IN SUNFLOWER

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Marek Slávik

2012-02-01

Full Text Available The application of decomposed substrate after continual biogas production is one of the possible ways how to use alternative energy sources with following monitoring of its complex influence on the hygienic state of soil with the emphasis on heavy metal input. The substances from bilge and drain sediments from water panels, also biosludge gained by continual co-fermentation of animal excrements belong to these compounds. The biosludge application is connected with possible risk of cadmium and lead, also other risky elements input into the soil. The analyses of applicated sludge prove that the determined heavy metals contents are compared with limitary value. These facts - hygienic state of soil, pH influence this limitary value and biosludge is suitable for soil application. The total heavy metals content in soil is related to the increased cadmium, nickel, chromium and cobalt contents. The analyses of heavy metals contents in sunflower seeds show that the grown yield does not comply with the legislative norms from the stand point of heavy metals content due to high zinc and nickel contents. Copper, cadmium, lead, chromium contents fulfil limitary values, for cobalt content the value is not mentioned in Codex Alimentarius. The nickel value in the control variant seeds is 2.2 times higher than the highest acceptable amount, then in variant where the sludge was applicated the nickel content was increased by 1.6 times. In the case of zinc there was increasing content in individual variants 4.7, or 4.8 times. The direct connection with the higher accumulation of zinc and nickel in soil by the influence of biosludge application is not definitely surveyed, the increased heavy metals contents in sunflower were primarily caused by their increased contents in soils.

Selective Production of Aromatics from 2-Octanol on Zinc Ion-Exchanged MFI Zeolite Catalysts

Directory of Open Access Journals (Sweden)

Masakazu Iwamoto

2015-12-01

Full Text Available The aromatization of 2-octanol derived from castor oil as a byproduct in the formation of sebacic acid was investigated on various zeolite catalysts. Zn ion-exchanged MFI (ZSM-5 zeolites with small silica/alumina ratios and zinc contents of 0.5 to 2.0 wt. % were determined to exhibit good and stable activity for the reaction at 623 to 823 K. The yield of aromatics was 62% at 773 K and the space velocity 350 to 1400 h−1. The temperature and contact time dependences of the product distributions indicated the reaction pathways of 2-octanol→dehydration to 2-octene→decomposition to C5 and C3 compounds→further decomposition to small alkanes and alkenes→aromatization with dehydrogenation. Alcohols with carbon numbers of 5 to 8 exhibited similar distributions of products compared to 2-octanol, while corresponding carbonyl compounds demonstrated different reactivity.

Relationship between insulin release and 65zinc efflux from rat pancreatic islets maintained in tissue culture

International Nuclear Information System (INIS)

Formby, B.; Schmid-Formby, F.; Grodsky, G.M.

1984-01-01

In short-term batch-incubation or perfusion experiments, we studied insulin release and associated 65 Zn efflux from rat pancreatic islets loaded with 65 Zn by 24-h tissue culture in low-glucose medium. The fractional basal insulin release and 65 Zn efflux were 0.4% and 3% of total content/h/islet, respectively. Thus, basal 65 Zn efflux was much greater than that to be accounted for if zinc was released proportionally with insulin release only; extragranular zinc flux was suggested. Two millimolar glucose, with or without 1 mM 3-isobutyl-1-methylxanthine (IBMX), affected neither insulin release nor associated 65 Zn efflux. Twenty-five millimolar glucose produced a significant threefold increase in insulin release above baseline, but somewhat decreased 65 Zn efflux at marginal significance. Glucose (25 mM) plus 1 mM IBMX provoked a high increase in insulin release and an associated 30% increase in fractional 65 Zn efflux over basal. Calculations based on previous estimations of 65 Zn distribution and equilibrium with islet zinc indicated that molar zinc efflux was more than sufficient to account for a 2-zinc-insulin hexamer. L-Leucine (2 or 20 mM) plus 1 mM IBMX caused far greater 65 Zn efflux for the amount of insulin released, indicating additional 65 Zn mobilization not directly related to insulin secretion. To evaluate 65 Zn efflux during inhibited insulin secretion, batch incubations were performed in 100% D 2 O or at 27 degrees C, conditions that inhibited insulin release stimulated by high glucose plus IBMX. These agents decreased the 65 Zn efflux far below the basal value (35% and 50%, respectively) and greater than could be accounted for by the attendent inhibition of insulin secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

The impact of steeping, germination and hydrothermal processing of wheat (Triticum aestivum L.) grains on phytate hydrolysis and the distribution, speciation and bio-accessibility of iron and zinc elements.

Science.gov (United States)

Lemmens, Elien; De Brier, Niels; Spiers, Kathryn M; Ryan, Chris; Garrevoet, Jan; Falkenberg, Gerald; Goos, Peter; Smolders, Erik; Delcour, Jan A

2018-10-30

Chelation of iron and zinc in wheat as phytates lowers their bio-accessibility. Steeping and germination (15 °C, 120 h) lowered phytate content from 0.96% to only 0.81% of initial dry matter. A multifactorial experiment in which (steeped/germinated) wheat was subjected to different time (2-24 h), temperature (20-80 °C) and pH (2.0-8.0) conditions showed that hydrothermal processing of germinated (15 °C, 120 h) wheat at 50 °C and pH 3.8 for 24 h reduced phytate content by 95%. X-ray absorption near-edge structure imaging showed that it indeed abolished chelation of iron to phytate. It also proved that iron was oxidized during steeping, germination and hydrothermal processing. It was further shown that zinc and iron bio-accessibility were respectively 3 and 5% in wheat and 27 and 37% in hydrothermally processed wheat. Thus, hydrothermal processing of (germinated) wheat paves the way for increasing elemental bio-accessibility in whole grain-based products. Copyright © 2018 Elsevier Ltd. All rights reserved.

[FEATURES OF THE CONTENT OF MOVABLE FORMS OF HEAVY METALS AND SELENIUM IN SOILS OF THE YAROSLAVL REGION].

Science.gov (United States)

Bakaeva, E A; Eremeyshvili, A V

2016-01-01

With the use of the method of inversion voltammetry there was analyzed the content of movableforms of trace elements: (selenium, zinc, copper lead, cadmium) in soils in the Yaroslavl district of the Yaroslavl region, and also content of zinc, copper lead, cadmium in soils and snow cover in the city of Yaroslavl. According to values of concentrations of movable compounds in soils determined trace elements can be ranked into the following row: zinc > lead > copper > selenium > cadmium. There was revealed insufficient if compared with literature data concentrations, content of movable compounds of selenium, copper and zinc in examined explored soils. The maximal concentrations of lead are revealed in the close proximity to both the city of Yaroslavl and large highways of the city. It indicates to the anthropogenic pollution of soils by this element.

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

Directory of Open Access Journals (Sweden)

Ľuboš Harangozo

2012-02-01

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

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

Correlations in distribution and concentration of calcium, copper and iron with zinc in isolated extracellular deposits associated with age-related macular degeneration

Science.gov (United States)

Flinn, Jane M; Kakalec, Peter; Tappero, Ryan; Jones, Blair F.; Lengyel, Imre

2014-01-01

Zinc (Zn) is abundantly enriched in sub-retinal pigment epithelial (RPE) deposits, the hallmarks of age-related macular degeneration (AMD), and is thought to play a role in the formation of these deposits. However, it is not known whether Zn is the only metal relevant for sub-RPE deposit formation. Because of their involvement in the pathogenesis of AMD, we determined the concentration and distribution of calcium (Ca), iron (Fe) and copper (Cu) and compared these with Zn in isolated and sectioned macular (MSD), equatorial (PHD) and far peripheral (FPD) sub-RPE deposits from an 86 year old donor eye with post mortem diagnosis of early AMD. The sections were mounted on Zn free microscopy slides and analyzed by microprobe synchrotron X-ray fluorescence (μSXRF). Metal concentrations were determined using spiked sectioned sheep brain matrix standards, prepared the same way as the samples. The heterogeneity of metal distributions was examined using pixel by pixel comparison. The orders of metal concentrations were Ca ⋙ Zn > Fe in all three types of deposits but Cu levels were not distinguishable from background values. Zinc and Ca were consistently present in all deposits but reached highest concentration in MSD. Iron was present in some but not all deposits and was especially enriched in FPD. Correlation analysis indicated considerable variation in metal distribution within and between sub-RPE deposits. The results suggest that Zn and Ca are the most likely contributors to deposit formation especially in MSD, the characteristic risk factor for the development of AMD in the human eye.

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

International Nuclear Information System (INIS)

Deb, D.L.

1990-01-01

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

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

DEFF Research Database (Denmark)

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

2014-01-01

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

Study on bioavailability of zinc for children's diet by using activable isotopic tracer 70Zn and neutron activation analysis techniques

International Nuclear Information System (INIS)

Zhang Yangmei; Ni Bangfa; Wang Pingsheng; Tian Weizhi; Cao Lei

2001-01-01

Bioavailability of zinc for three groups (low amount of diet zinc, balance amount of diet zinc and high amount of diet zinc) of children's diet is studied by using activable isotopic tracer 70 Zn and neutron activation analysis techniques. The results indicate that the fractional absorption of zinc from balance diet zinc group is the highest, up to 33.9%. A procedure of pre-irradiation concentration zinc for fecal samples using anion exchanger is developed, and the enriched 70 Zn with isotopic abundance of 18.3% is used for tracer. The mass ratios between 70 Zn and 68 Zn or 64 Zn and their contents between natural zinc and enriched zinc are used to calculate the bioavailability of zinc. Instrumental neutron activation analysis of 64 Zn of each original fecal samples and pre-irradiation concentrated zinc samples are used to normalize the chemical yield in order to reduce the uncertainty during the chemical separation procedure

Zinc electrowinning analysis in a modified Hull cell

Science.gov (United States)

McColm, Thomas Dean

The Hull cell is an analytical cell designed with trapezoidal geometry to incorporate a range of current densities into a single experiment. It was conceived to examine electroplating processes rather than mass production processes. A modified analytical cell was designed, developed and applied to the diagnosis of zinc electrowinning. Emphasis was placed on obtaining the quantitative variation of current efficiency with current density and the associated microscopic variation in deposit morphology. Current density distributions came by placing an insulating baffle in between parallel electrodes. The baffle position and length were easily adjusted, allowing the generation of 12 different distributions for a single applied potential. Ten electrically isolated 1 cm2 segments comprised the cathode. Measurement of the potential drop across I ohm resistors in each of the ten isolated parallel branches permitted direct quantitative determination of current densities. The small segments permitted simple SEM and X-ray analysis of deposits. The cell was designed to allow the continual cycling of electrolyte. In conjunction with experimental analysis, a technique for the determination of current efficiency was tested and developed. The technique involved the comparison of charge passed for the electrodeposition and subsequent electrodissolution of a given mass of zinc and removed the necessity to determine the mass directly. In no prior studies on zinc electrowinning had current efficiencies been determined this way. The cell and technique were developed and verified by the correct diagnosis of industrial zinc electrowinning. Successful determination of the effects of key variables including temperature, acid to zinc ratio and impurity effects on current efficiency and deposit morphology was demonstrated. In parallel with experimental work, cell electrochemistry was modeled. Primary and secondary input parameters were those pertinent to zinc electrowinning. The resultant

Quantitative assessment of metal elements using moss species as biomonitors in downwind area of lead-zinc mine.

Science.gov (United States)

Balabanova, Biljana; Stafilov, Trajče; Šajn, Robert; Andonovska, Katerina Bačeva

2017-02-23

Distributions of a total of 21 elements were monitored in significantly lead-zinc polluted area using moss species (Hypnum cupressiforme and Camptothecium lutescens) used interchangeably, covering a denser sampling network. Interspecies comparison was conducted using Box-Cox transformed values, due to their skewed distribution. The median concentrations of trace elements in the both mosses examined decreased in the following order: Fe>Mn>Zn>Pb>Cu>Ni∼Cr∼As>Co>Cd>Hg. For almost all analyzed elements, H. cupressiforme revealed higher bio-accumulative abilities. For arsenic contents was obtained ER-value in favor of C. lutescens. The ER for the element contents according to the distance from the pollution source in selected areas was significantly enriched for the anthropogenic introduced elements As, Cd, Cu, Pb and Zn. After Box-Cox transformation of the content values, T B was significantly different for As (4.82), Cd (3.84), Cu (2.95), Pb (4.38), and Zn (4.23). Multivariate factor analysis singled out four elemental associations: F1 (Al-Co-Cr-Fe-Li-Ni-V), F2 (Cd-Pb-Zn), F3 (Ca-Mg-Na-P) and F4 (Cu) with a total variance of 89%. Spatial distribution visualized the hazardously higher contents of "hot spots" of Cd > 1.30 mg/kg, Cu > 22 mg/kg, Pb > 130 mg/kg and Zn > 160 mg/kg. Therefore, main approach in moss biomonitoring should be based on data management of the element distribution by reducing the effect of extreme values (considering Box-Cox data transformation); the interspecies variation in sampling media does not deviate in relation to H. cupressiforme vs. C. lutescens.

Microwave digestion for determination content of iron and zinc total in food

International Nuclear Information System (INIS)

Silva Trejos, Paulina

2012-01-01

The food digestion procedure was optimized by means of a microwave oven, to quantify the iron and total zinc in different matrices by atomic absorption spectroscopy. The optimum amount of concentrated HNO 3 was analyzed at 65% to digest sample mass determined by assessment of the percentage of recovery obtained with different amount of HNO 3 . The results have not differed from those obtained by officially recommended methods of acid digestion in open systems and calcination. (author) [es

Zinc injection in German PWR plants

International Nuclear Information System (INIS)

Streit, K.

2004-01-01

Operating experience acquired at PWR NNPs shows that zinc injection at low concentrations of 5 ppb is a very effective source term reduction measure. This method does not lead to any operating restrictions or other negative effects on plant systems and components. The nuclear industry has been very successful in reducing radiation exposures within the past two decades. Annual exposures could be significantly decreased and are now at a level of around 1 man-Sv per plant and year. This great success can mainly be attributed to the general commitment of plant operators to maintaining radiation exposures of workers in the controlled access area as low as reasonably achievable (ALARA principle). The ALARA principle, of course, also implies evaluation of the economic benefit of radiation protection measures. Radiation source term reduction has drawn increasing attention of plant operators in recent years. For the new PWRs cobalt-based alloys in the primary system have successively been eliminated already at the design and construction phase within the last decade. Use of wear-resistant cobalt-free substitute materials in combination with the general use of advanced alloys for the steam generator tubing of PWRs resulted in low values for the two most common sources of plant radiation fields, namely 58 Co and 60 Co. Investigations showed that the beneficial effect of zinc can be related to its high affinity for mixed spinel oxide phases, resulting in the following two basic effects: -Zinc is incorporated preferentially into the oxide layer on primary system surfaces and thus reduces pickup of 58 Co and 60 Co and - Zinc can displace cobalt isotopes from existing oxide layers. In German PWRs with Incoloy 800 steam generator tubing material (Ni-content -32%), the observed reductions correspond to a decrease in dose rates of around 10 to 15% per year and thus follow, as predicted, the half-life time of 60 Co. Overall reductions in high radiation areas are now in the range of

Radiotracer investigations of the shaft processes in Polish zinc and lead metallurgy. 2

International Nuclear Information System (INIS)

Michalik, J.S.; Bazaniak, Z.; Palige, J.

1990-01-01

The conditions and the physico-chemical processes occurring in the ISP furnace cause the possibility of partial reoxidation of vapourized zinc escaping from the furnace counter-current to the batch material. In order to determine the reoxidation degree and localize the active zone the radiotracer method was applied. The method of solving the convolution integral was used. The experimental part resulted indetermination of impulse characteristics of the zinc condenser; in the next step, the curves of zinc concentration distribution at the ISP furnace outlet were found by calculations. 65 Zn was used as tracer for the industrial experiments. About 25-30% of total amount of zinc obtained as a result of zinc oxides reduction processes undergoes reoxidation in the surface layer of the bath in the furnace shaft. The method of tracer preparation for investigating the behaviour of zinc occurring in the form of silicates and ferrates in the shaft has been proposed. (author)

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

Czech Academy of Sciences Publication Activity Database

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

2016-01-01

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

Transgenic expression of phytase in wheat endosperm increases bioavailability of iron and zinc in grains.

Science.gov (United States)

Abid, Nabeela; Khatoon, Asia; Maqbool, Asma; Irfan, Muhammad; Bashir, Aftab; Asif, Irsa; Shahid, Muhammad; Saeed, Asma; Brinch-Pedersen, Henrik; Malik, Kauser A

2017-02-01

Phytate is a major constituent of wheat seeds and chelates metal ions, thus reducing their bioavailability and so the nutritional value of grains. Transgenic plants expressing heterologous phytase are expected to enhance degradation of phytic acid stored in seeds and are proposed to increase the in vitro bioavailability of mineral nutrients. Wheat transgenic plants expressing Aspergillus japonicus phytase gene (phyA) in wheat endosperm were developed till T 3 generation. The transgenic lines exhibited 18-99 % increase in phytase activity and 12-76 % reduction of phytic acid content in seeds. The minimum phytic acid content was observed in chapatti (Asian bread) as compared to flour and dough. The transcript profiling of phyA mRNA indicated twofold to ninefold higher expression as compared to non transgenic controls. There was no significant difference in grain nutrient composition of transgenic and non-transgenic seeds. In vitro bioavailability assay for iron and zinc in dough and chapatti of transgenic lines revealed a significant increase in iron and zinc contents. The development of nutritionally enhanced cereals is a step forward to combat nutrition deficiency for iron and zinc in malnourished human population, especially women and children.

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

Science.gov (United States)

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

2018-01-01

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

Mechanical properties of bioplastics cassava starch film with Zinc Oxide nanofiller as reinforcement

Science.gov (United States)

Harunsyah; Yunus, M.; Fauzan, Reza

2017-06-01

This study focuses on investigating the influence of zinc oxide nanofiller on the mechanical properties of bioplastic cassava starch films. Bioplastic cassava starch film-based zinc oxide reinforced composite biopolymeric films were prepared by casting technique. The content of zinc oxide in the bioplastic films was varied from 0.2%, 0.4%, 0.6%, 0.8% and 1.0% (w/w) by weight of starch. Surface morphologies of the composites bioplastic films were examined by scanning electron microscope (SEM).The result showed that the Tensile strength (TS) was improved significantly with the additional of zinc oxide but the elongation at break (EB %) of the composites was decreased. The maximum tensile strength obtained was 22.30 kgf / mm on the additional of zinc oxide by 0.6% and plastilizer by 25%. Based on data of FTIR, the produced film plastic did not change the group function and it can be concluded that theinteraction in film plastic produced was only a physical interaction. Biodegradable plastic film based on cassava starch-zinc oxide and plasticizer glycerol showed that interesting mechanical properties being transparent, clear, homogeneous, flexible, and easily handled.

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...

An experiment with content distribution methods in touchscreen mobile devices.

Science.gov (United States)

Garcia-Lopez, Eva; Garcia-Cabot, Antonio; de-Marcos, Luis

2015-09-01

This paper compares the usability of three different content distribution methods (scrolling, paging and internal links) in touchscreen mobile devices as means to display web documents. Usability is operationalized in terms of effectiveness, efficiency and user satisfaction. These dimensions are then measured in an experiment (N = 23) in which users are required to find words in regular-length web documents. Results suggest that scrolling is statistically better in terms of efficiency and user satisfaction. It is also found to be more effective but results were not significant. Our findings are also compared with existing literature to propose the following guideline: "try to use vertical scrolling in web pages for mobile devices instead of paging or internal links, except when the content is too large, then paging is recommended". With an ever increasing number of touchscreen web-enabled mobile devices, this new guideline can be relevant for content developers targeting the mobile web as well as institutions trying to improve the usability of their content for mobile platforms. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

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.

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

Science.gov (United States)

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

2017-11-01

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

The Effect of Zinc Supplementation on the Production Parameters of Bombyx mori L. species

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Mihai Benţea

2012-05-01

Full Text Available This research aimed to evaluate the influence of Zinc, administered as food supplement for silkworm (Bombyx moriL. on the larvae weight, the weight of the serigene gland, cocoon weight, cocoon shell. The research has been carried out on 5 groups of silkworms one control group (Gr.1 and 4 experimental groups (4 groups receiving zinc, consisting of 50 larvae/group. Zinc was administered in doses of 17, 34, 68 and 136 mg kg-1 larvae - Gr.2-Gr.5. The use of Zinc determined a very significant increase of the larvae weight, to group Gr.5 followed by groups Gr.4, Gr.3 and Gr.2 compared to the control group. The use of Zinc positively influenced the mass of the serigene glands, the cocoon weight, cocoon shell. The Zn content of the pupae from the experimental groups was higher compared to the one recorded in the control group.

Identification and management of distributed data NGN, content-centric networks and the web

CERN Document Server

Bartolomeo, Giovanni

2013-01-01

Although several books and academic courses discuss data management and networking, few of them focus on the convergence of networking and software technologies for identifying, addressing, and managing distributed data. Focusing on this convergence, Identification and Management of Distributed Data: NGN, Content-Centric Networks and the Web collates and describes the various distributed data management technologies to help readers from various backgrounds understand the common aspects that govern distributed data management. With a focus on the primary problems in identifying, addressing, and

Source Identification of Heavy Metals in Soils Surrounding the Zanjan Zinc Town by Multivariate Statistical Techniques

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M.A. Delavar

2016-02-01

Discussion: Comparing the measured HMs contents with their normal range in uncontaminated soils demonstrated the contamination of soils by Pb, Zn and Cd, with average concentrations of 152.8, 294.2 and 5.6 mg kg-1, respectively,whereas Ni and Cu did not show any pollution risk. The total concentration of Zn, Pb and Cd in the soil showed a great degree of variability, indicated by large coefficients of variation (CV from 228.5 % of Cd to 354.8 % ofPb. These elevated CVs may indicate that these elements’ distribution in the studied area is influenced by an anthropogenic source. In contrast, the relatively low calculated CVs for Ni and Cu may imply that natural sources are responsible for these elements’ distribution in the studied soils. Correlation matrix (CM analysis revealed high correlation coefficients between Zn-Cd and Ni-Cu, indicating the influence of the same factors in controlling their distribution. On the other hand, Pb contents showed low correlation with Ni and Cu values, whereas its correlation with Zn and Cd was relatively high. Therefore, it seems that Pb distribution in the studied soils is more influenced by the factor which controls the Zn and Cd distribution, rather than another factor that is responsible for accumulation of Ni and Cu in the studied soils. According to the PCA analysis, two significant components were extracted explaining about 84% of total variance. FA analysis showed that studied variables have a relatively high communality with two extracted principal components, indicating that almost all of the measured total variation can be efficiently explained by the extracted principals. Industrial activities in the Zinc Town seem to be the main factor which caused the high concentrations of Pb, Zn and Cd in the soil environment in this area; whereas Ni and Cu were associated with the natural sources including geology of the studied area (parental material’s factor. The obtained results from this study coincide with the prior studies

Alterations in protein kinase C activity and processing during zinc-deficiency-induced cell death.

Science.gov (United States)

Chou, Susan S; Clegg, Michael S; Momma, Tony Y; Niles, Brad J; Duffy, Jodie Y; Daston, George P; Keen, Carl L

2004-10-01

Protein kinases C (PKCs) are a family of serine/threonine kinases that are critical for signal transduction pathways involved in growth, differentiation and cell death. All PKC isoforms have four conserved domains, C1-C4. The C1 domain contains cysteine-rich finger-like motifs, which bind two zinc atoms. The zinc-finger motifs modulate diacylglycerol binding; thus, intracellular zinc concentrations could influence the activity and localization of PKC family members. 3T3 cells were cultured in zinc-deficient or zinc-supplemented medium for up to 32 h. Cells cultured in zinc-deficient medium had decreased zinc content, lowered cytosolic classical PKC activity, increased caspase-3 processing and activity, and reduced cell number. Zinc-deficient cytosols had decreased activity and expression levels of PKC-alpha, whereas PKC-alpha phosphorylation was not altered. Inhibition of PKC-alpha with Gö6976 had no effect on cell number in the zinc-deficient group. Proteolysis of the novel PKC family member, PKC-delta, to its 40-kDa catalytic fragment occurred in cells cultured in the zinc-deficient medium. Occurrence of the PKC-delta fragment in mitochondria was co-incident with caspase-3 activation. Addition of the PKC-delta inhibitor, rottlerin, or zinc to deficient medium reduced or eliminated proteolysis of PKC-delta, activated caspase-3 and restored cell number. Inhibition of caspase-3 processing by Z-DQMD-FMK (Z-Asp-Gln-Met-Asp-fluoromethylketone) did not restore cell number in the zinc-deficient group, but resulted in processing of full-length PKC-delta to a 56-kDa fragment. These results support the concept that intracellular zinc concentrations influence PKC activity and processing, and that zinc-deficiency-induced apoptosis occurs in part through PKC-dependent pathways.

Ciprofloxacin conjugated zinc oxide nanoparticle: A camouflage ...

Indian Academy of Sciences (India)

ZNP were small in size with particle size distribution 18–20 nm as obtained ... of zinc oxide and ciprofloxacin is effective against bacterial system. However, no reports are still available on antibacte- ... 20% aqueous TRIS solution was added drop wise to 25 ml .... Phillips CM 200 (Netherlands) at an operational voltage of.

Relationship between assimilable-nutrient content and physicochemical properties of topsoil

Science.gov (United States)

Tkaczyk, Przemysław; Bednarek, Wiesław; Dresler, Sławomir; Krzyszczak, Jaromir; Baranowski, Piotr; Sławiński, Cezary

2017-10-01

In the years 2008-2011, an environmental study was conducted for Polish soils, focusing on the south-eastern Poland soils, as they exhibit significant acidification. This study aimed at assessing the current pHKCl and the supply of basic macro- (P, K, Mg and S-SO4) and microelements (B, Cu, Fe, Mn and Zn) in the collected soil samples, and also at determining their relationship with the soil agronomic category, humus content and pH class. Soil reaction and humus and macronutrient content were positively correlated with the amount of colloidal clay and particles macro-element content in the soil was positively correlated with soil pH and humus content. As for microelements, a usually significant and positive correlation was found between the soil agronomic category and the content of manganese, iron and zinc, whereas for the content of boron and copper, no such relationship was observed. A significant and positive correlation between soil reaction and the content of manganese, iron and boron was also found. Such correlations were not observed in relation to copper and zinc content. Statistical analysis indicated that the content of boron and manganese depended to the greatest extent on the investigated physicochemical properties.

Transformation of zinc hydroxide chloride monohydrate to crystalline zinc oxide.

Science.gov (United States)

Moezzi, Amir; Cortie, Michael; McDonagh, Andrew

2016-04-25

Thermal decomposition of layered zinc hydroxide double salts provides an interesting alternative synthesis for particles of zinc oxide. Here, we examine the sequence of changes occurring as zinc hydroxide chloride monohydrate (Zn5(OH)8Cl2·H2O) is converted to crystalline ZnO by thermal decomposition. The specific surface area of the resultant ZnO measured by BET was 1.3 m(2) g(-1). A complicating and important factor in this process is that the thermal decomposition of zinc hydroxide chloride is also accompanied by the formation of volatile zinc-containing species under certain conditions. We show that this volatile compound is anhydrous ZnCl2 and its formation is moisture dependent. Therefore, control of atmospheric moisture is an important consideration that affects the overall efficiency of ZnO production by this process.

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

International Nuclear Information System (INIS)

Lock, K.; Janssen, C.R.

2005-01-01

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

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.

Fruit peel extract mediated green synthesis of zinc oxide nanoparticles

Science.gov (United States)

Nava, O. J.; Soto-Robles, C. A.; Gómez-Gutiérrez, C. M.; Vilchis-Nestor, A. R.; Castro-Beltrán, A.; Olivas, A.; Luque, P. A.

2017-11-01

This work presents a study of the effects on the photocatalytic capabilities of zinc oxide nanoparticles when prepared via green synthesis using different fruit peel extracts as reducing agents. Zinc nitrate was used as a source of the zinc ions, while Lycopersicon esculentum (tomato), Citrus sinensis (orange), Citrus paradisi (grapefruit) and Citrus aurantifolia (lemon) contributed their peels for extracts. The Synthesized Samples were studied and characterized through Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and High Resolution Transmission Electron Microscopy (HRTEM). All samples presented a band at 618 cm-1, indicating the presence of the Znsbnd O bond. The different samples all presented the same hexagonal crystal growth in their structure, the Wurtzite phase. The surface morphology of the nanoparticles showed that, depending on the extract used, the samples vary in size and shape distribution due to the chemical composition of the extracts. The photocatalytic properties of the zinc oxide samples were tested through UV light aided degradation of methylene blue. Most samples exhibited degradation rates at 180 min of around 97%, a major improvement when compared to chemically synthesized commercially available zinc oxide nanoparticles.

Bioavailability of zinc from sweet potato roots and leaves

International Nuclear Information System (INIS)

Baiden, H.N.; Ercanli-Huffman, F.G.

1986-01-01

Bioavailability of zinc from sweet potato (SP) roots and leaves were determined, by extrinsic labeling technique, in rats fed control and zinc deficient diets. Weanling male Sprague Dawley (SD) rats (60-75g) were divided into 4 groups, and fed laboratory chow, a control diet (ad libitum and pair fed) and a zinc deficient diet, for 4 weeks. Each group then was divided into at least 2 sub groups, containing 6 rats, which were intubated with one of 3 tubing solutions extrinsically labeled with 65 Zn; baked sweet potato roots (BSPR), raw sweet potato leaves (RSPL) and cooked sweet potato leaves (CSPL). Five hours after intubation the rats were sacrificed, blood, liver, testes, spleen, heart, brain, thymus and lungs were removed. Feces, urine, and GI tract contents were collected and their 65 Zn activity was determined in a gamma counter. In all treatment groups zinc bioavailability from BSPR, RSPL or CSPL were not significantly different. Zinc deficient rats absorbed significantly more (P 65 Zn (86-90% of the dose), regardless of type of tubing solution than the pairfed or control animals (35-58% of the dose). The highest retention of 65 Zn was found in the liver (12-20% of absorbed dose), GI tract (6-17% of absorbed dose), kidney (2-8% of absorbed dose), and blood (1-5% of absorbed dose). The lowest retention was found in the brain, heart, thymus and testes. (< 1% of absorbed dose)

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.)

Origin and Distribution of Water Contents in Continental and Oceanic Lithospheric Mantle

Science.gov (United States)

Peslier, Anne H.

2013-01-01

The water content distribution of the upper mantle will be reviewed as based on the peridotite record. The amount of water in cratonic xenoliths appears controlled by metasomatism while that of the oceanic mantle retains in part the signature of melting events. In both cases, the water distribution is heterogeneous both with depth and laterally, depending on localized water re-enrichments next to melt/fluid channels. The consequence of the water distribution on the rheology of the upper mantle and the location of the lithosphere-asthenosphere boundary will also be discussed.

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.

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

Directory of Open Access Journals (Sweden)

Azzouz I

2013-12-01

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

The effect of Al and Cr additions on pack cementation zinc coatings

International Nuclear Information System (INIS)

Chaliampalias, D.; Papazoglou, M.; Tsipas, S.; Pavlidou, E.; Skolianos, S.; Stergioudis, G.; Vourlias, G.

2010-01-01

Zinc is widely used as a protective coating material due to its corrosion resistant properties. The structure and oxidation resistance of Al and Cr mixed zinc coatings, deposited by pack cementation process, is thoroughly examined in this work. The morphology and chemical composition of the as-deposited and oxidized samples was accomplished by electron microscopy while the phase identification was performed by XRD diffraction analysis. The experimental results showed that the addition of aluminum or chromium in the pack mixture forms only Al and Cr rich phases on the surface of the specimens without affecting significantly the phase composition of the rest zinc coatings. In the case of Zn-Al coatings, the overlying layer contains high concentrations of Al together with lower amounts of zinc and iron and in Zn-Cr coatings this layer contains Cr, Fe and Zn atoms and has much smaller thickness. The presence of these additional layers promotes significantly the oxidation resistance of the zinc pack coatings and they preserve most of their initial thickness and chemical content when exposed to an aggressive environment while their oxidation mass gain was measured at low levels during the oxidation tests.

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.)

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

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Cuong D. Tran

2015-05-01

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

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

Science.gov (United States)

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

2015-01-01

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

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

Science.gov (United States)

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

2016-09-01

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

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

African Journals Online (AJOL)

PRECIOUS

2009-11-16

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

Promoting Effect of Foliage Sprayed Zinc Sulfate on Accumulation of Sugar and Phenolics in Berries of Vitis vinifera cv. Merlot Growing on Zinc Deficient Soil

Directory of Open Access Journals (Sweden)

Chang-Zheng Song

2015-02-01

Full Text Available The effect of foliage sprayed zinc sulfate on berry development of Vitis vinifera cv. Merlot growing on arid zone Zn-deficient soils was investigated over two consecutive seasons, 2013 and 2014. Initial zinc concentration in soil and vines, photosynthesis at three berry developmental stages, berry weight, content of total soluble solids, titratable acidity, phenolics and expression of phenolics biosynthetic pathway genes throughout the stages were measured. Foliage sprayed zinc sulfate showed promoting effects on photosynthesis and berry development of vines and the promotion mainly occurred from veraison to maturation. Zn treatments enhanced the accumulation of total soluble solids, total phenols, flavonoids, flavanols, tannins and anthocyanins in berry skin, decreasing the concentration of titratable acidity. Furthermore, foliage sprayed zinc sulfate could significantly influence the expression of phenolics biosynthetic pathway genes throughout berry development, and the results of expression analysis supported the promotion of Zn treatments on phenolics accumulation. This research is the first comprehensive and detailed study about the effect of foliage sprayed Zn fertilizer on grape berry development, phenolics accumulation and gene expression in berry skin, providing a basis for improving the quality of grape and wine in Zn-deficient areas.

A Comparative Analysis of Nutrients and Mineral Elements Content ...

African Journals Online (AJOL)

(Mg), Iron (Fe), Copper (Cu) and Zinc (Zn) content, while P. pedicellatum has high ... INTRODUCTION ... central to animal production and productivity. .... for growth and serve as structural element in all plant ... the animal's body, it ensured correct maintenance of ... Ash content because Ash is the approximation of total.

Effect of zinc-lysine on growth, yield and cadmium uptake in wheat (Triticum aestivum L.) and health risk assessment.

Science.gov (United States)

Rizwan, Muhammad; Ali, Shafaqat; Hussain, Afzal; Ali, Qasim; Shakoor, Muhammad Bilal; Zia-Ur-Rehman, Muhammad; Farid, Mujahid; Asma, Maliha

2017-11-01

Cadmium (Cd) is among the most widespread toxic trace elements found in agricultural soils due to various anthropogenic activities. The role of micronutrient-amino chelates on reducing Cd toxicity in crop plants is recently introduced. The current study was conducted to highlight the role of foliar application of zinc-lysine (Zn-lys) complex on biochemical and growth parameters and Cd uptake in wheat (Triticum aestivum) grown in aged Cd-contaminated soil. Foliar concentration of Zn-lys (0, 10, 20, and 30 mg L -1 ) was applied at different time intervals (2nd, 3rd, 5th and 7th week of sowing) and plants were harvested at maturity. Folliar application of Zinc-lys significantly increased the photosynthesis, grain yield, enzyme activities and Zn contents in different plant tissues. Zinc-lys reduced Cd contents in grains, shoot and root as well as reduced the oxidative stress in wheat linearly in a dose-additive manner. Taken together, Zn-lys chelate efficiently improved wheat growth and fortified Zn contents while reduced Cd concentration in plant in a Zn-deficient Cd-contaminated soil. Although, health risk index (HRI) from the soil sampling area seems to be lower than <1 for Cd but may exceed due to long-term consumption of grains produced from such contaminated soil. Foliar applied Zn-lys reduced HRI which may help to reduce health risks associated with Cd. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultrasound assisted synthesis of nanocrystalline zinc oxide: Experiments and modelling

Energy Technology Data Exchange (ETDEWEB)

Hosni, Mongia [Laboratoire des Sciences des Procédés et des Matériaux, LSPM-CNRS, Université Paris 13, 99 av. J.B. Clément, 93430 Villetaneuse (France); Farhat, Samir, E-mail: farhat@lspm.cnrs.fr [Laboratoire des Sciences des Procédés et des Matériaux, LSPM-CNRS, Université Paris 13, 99 av. J.B. Clément, 93430 Villetaneuse (France); Schoenstein, Frederic; Karmous, Farah; Jouini, Noureddine [Laboratoire des Sciences des Procédés et des Matériaux, LSPM-CNRS, Université Paris 13, 99 av. J.B. Clément, 93430 Villetaneuse (France); Viana, Bruno [LCMCP Chimie-Paristech, UPMC, Collège de France, 11 Rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Mgaidi, Arbi [Laboratoire de chimie minérale industrielle université Tunis el Manar (Tunisia)

2014-12-05

Highlights: • ZnO nanospheres and nanowires were grown using ultrasound and thermal activation techniques. • The growth uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). • A thermochemical model was developed based on thermodynamic equilibrium calculations. • We estimate species distribution in the bubble in temperature range from 5000 K to ambient. • We propose a new mechanism for ZnO growth assisted by ultrasound irradiation. - Abstract: A fast and green approach is proposed for the preparation of nanocrystalline zinc oxide (ZnO) via ultrasonic (US) irradiation in polyol medium. The process uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). The protocol is compared to thermal activation under the same chemical environment. The activation method is found to be playing a critical role in the selective synthesis of morphologically distinct nanostructures. As compared to thermally activated conventional polyol process, (US) permits to considerably reduce reaction time as well as size of particles. In addition, the shape of these nanoparticles was changed from long nanowires to small nanospheres, indicating different reaction mechanisms. To explain this difference, a thermochemical model was developed based on thermodynamic equilibrium calculations. The model estimate species distribution in the bubble in temperature range from 5000 K to ambient simulating quenching process during bubble formation and collapse. Our results indicate the presence of high density of zinc atoms that could be responsible of a high density of nucleation as compared to thermal activation.

Ultrasound assisted synthesis of nanocrystalline zinc oxide: Experiments and modelling

International Nuclear Information System (INIS)

Hosni, Mongia; Farhat, Samir; Schoenstein, Frederic; Karmous, Farah; Jouini, Noureddine; Viana, Bruno; Mgaidi, Arbi

2014-01-01

Highlights: • ZnO nanospheres and nanowires were grown using ultrasound and thermal activation techniques. • The growth uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). • A thermochemical model was developed based on thermodynamic equilibrium calculations. • We estimate species distribution in the bubble in temperature range from 5000 K to ambient. • We propose a new mechanism for ZnO growth assisted by ultrasound irradiation. - Abstract: A fast and green approach is proposed for the preparation of nanocrystalline zinc oxide (ZnO) via ultrasonic (US) irradiation in polyol medium. The process uses forced hydrolysis of zinc acetate in diethylene glycol (DEG). The protocol is compared to thermal activation under the same chemical environment. The activation method is found to be playing a critical role in the selective synthesis of morphologically distinct nanostructures. As compared to thermally activated conventional polyol process, (US) permits to considerably reduce reaction time as well as size of particles. In addition, the shape of these nanoparticles was changed from long nanowires to small nanospheres, indicating different reaction mechanisms. To explain this difference, a thermochemical model was developed based on thermodynamic equilibrium calculations. The model estimate species distribution in the bubble in temperature range from 5000 K to ambient simulating quenching process during bubble formation and collapse. Our results indicate the presence of high density of zinc atoms that could be responsible of a high density of nucleation as compared to thermal activation

Functional role of zinc in poly(A) synthesis catalyzed by nuclear poly(A) polymerase

Energy Technology Data Exchange (ETDEWEB)

Rose, K M; Allen, M S; Crawford, I L; Jacob, S T [Pennsylvania State Univ., Hershey (USA). Dept. of Pharmacology; Pennsylvania State Univ., Hershey (USA). Specialized Cancer Research Center; Texas Univ., Dallas (USA). Dept. of Neurology; Texas Univ., Dallas (USA). Dept. of Pharmacology)

1978-07-01

The functional role of transition metals in poly(A) synthesis was elucidated by investigating the effect of the metal chelator o-Phenanthroline on purified nuclear poly(A) polymerase. This chelator inhibited the enzyme activity in a manner competitive with respect to the polynucleotide primer concentration. o-phenanthroline was a non-competitive inhibitor with regard to ATP concentration and an 'uncompetitive' inhibitor with regard to dithiothreitor levels. The metal content of the purified enzyme preparations from rat liver and Morris hepatoma 3924A was determined using atomic absorption spectrometry. Of the transition metals measured, only zinc was present in detectable quantities at levels less than 1 mol/mol of enzyme. Hepatoma enzyme contained 2-3 times as much zinc as the corresponding liver enzyme. Hepatoma poly(A) polymerase was also radioactively labelled in vivo by injection of tumor-bearing animals with /sup 65/Zn. Dialysis experiments with highly purified radiolabelled poly(A) polymerase showed that the enzyme-zinc complex was labile and that a reduction in /sup 65/Zn content correlated with a loss in enzyme activity.

Functional role of zinc in poly(A) synthesis catalyzed by nuclear poly(A) polymerase

International Nuclear Information System (INIS)

Rose, K.M.; Allen, M.S.; Crawford, I.L.; Jacob, S.T.; Pennsylvania State Univ., Hershey; Texas Univ., Dallas; Texas Univ., Dallas

1978-01-01

The functional role of transition metals in poly(A) synthesis was elucidated by investigating the effect of the metal chelator o-phenanthroline on purified nuclear poly(A) polymerase. This chelator inhibited the enzyme activity in a manner competitive with respect to the polynucleotide primer concentration. o-phenanthroline was a non-competitive inhibitor with regard to ATP concentration and an 'uncompetitive' inhibitor with regard to dithiothreitor levels. The metal content of the purified enzyme preparations from rat liver and Morris hepatoma 3924A was determined using atomic absorption spectrometry. Of the transition metals measured, only zinc was present in detectable quantities, at levels less than 1 mol/mol of enzyme. Hepatoma enzyme contained 2-3 times as much zinc as the corresponding liver enzyme. Hepatoma poly(A) polymerase was also radioactively labelled in vivo by injection of tumor-bearing animals with 65 Zn. Dialysis experiments with highly purified radiolabelled poly(A) polymerase showed that the enzyme-zinc complex was labile and that a reduction in 65 Zn content correlated with a loss in enzyme activity. (orig./AJ) [de

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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.

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Microwave digestion for determination of iron and zinc content of total food

OpenAIRE

Silva-Trejos, Paulina

2012-01-01

En el presente estudio se optimizó el procedimiento de digestión de alimentos por medio de un horno de microondas, para cuantificar el hierro y el zinc totales en diferentes matrices por espectroscopía de absorción atómica. Se analizó la cantidad óptima de HNO3 concentrado al 65% para digerir determinada masa de muestra por evaluación del porcentaje de recuperación obtenido con diferente cantidad de HNO3. Los resultados no difieren de los obtenidos por los métodos recomendados oficialmente de...

Iron and zinc bioaccessibility of fermented maize, sorghum and millets from five locations in Zimbabwe.

Science.gov (United States)

Gabaza, Molly; Shumoy, Habtu; Muchuweti, Maud; Vandamme, Peter; Raes, Katleen

2018-01-01

The present study is an evaluation of iron and zinc bioaccessibility of fermented maize, sorghum, pearl millet and finger millet from five different locations in Zimbabwe. Iron and zinc contents ranged between 3.22 and 49.7 and 1.25-4.39mg/100gdm, respectively. Fermentation caused a reduction of between 20 and 88% of phytic acid (PA) while a general increase in soluble phenolic compounds (PC) and a decrease of the bound (PC) was observed. Bioaccessibility of iron and zinc ranged between 2.77 and 26.1% and 0.45-12.8%, respectively. The contribution of the fermented cereals towards iron and zinc absolute requirements ranged between 25 and 411% and 0.5-23% with higher contribution of iron coming from cereals that were contaminated with extrinsic iron. Populations subsisting on cereals could be more at risk of zinc rather than iron deficiency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of salinity on growth, water content and distribution of Na + ...

African Journals Online (AJOL)

Effects of 4 different concentrations of NaCl on plant height, on water content and on the distribution of monovalent cations (Na + and K +) in organs of Avicennia germinans seedlings in semi-controlled conditions were investigated. After 4 weeks of cultivation, results showed that 200 mmoles sodium chloride reduced the ...

Chelators for investigating zinc metalloneurochemistry

OpenAIRE

Radford, Robert John; Lippard, Stephen J.

2013-01-01

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

Daily dietary intake of iron, copper, zinc and manganese in a Spanish population.

Science.gov (United States)

Rubio, Carmen; Gutiérrez, Angel José; Revert, Consuelo; Reguera, Juan Ignacio; Burgos, Antonio; Hardisson, Arturo

2009-11-01

To evaluate the daily dietary intake of essential metals in the Canary Islands, the iron, copper, zinc and manganese contents in 420 food and drink samples collected in local markets were analysed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The estimated daily dietary intakes of iron, copper, zinc and manganese are 13.161 mg/day, 2.098 mg/day, 8.954 mg/day and 2.372 mg/day, respectively. The iron dietary intake was found to be below the recommendations fixed for adult women, while the copper and manganese dietary intakes fulfilled the Recommended Dietary Allowances. The mean daily intake of zinc was below the Recommended Dietary Allowance. Cereals were found to be the food group that contributed most to the intake of these metals. While the island of El-Hierro presented iron, copper, zinc and manganese mean intakes over the estimated intakes for the whole archipelago, Fuerteventura island showed the lowest intakes. Tenerife and Fuerteventura showed the lowest iron intakes, being below the recommendations.

Zinc and gastrointestinal disease

Institute of Scientific and Technical Information of China (English)

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

2014-01-01

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

Synthesis and optical property of zinc aluminate spinel cryogels

Directory of Open Access Journals (Sweden)

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.

Comparison of the method of diffusive gels in thin films with conventional extraction techniques for evaluating zinc accumulation in plants and isopods

Energy Technology Data Exchange (ETDEWEB)

Koster, Marijke [National Institute of Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Open University Netherlands, Heerlen (Netherlands); Reijnders, Lucas [Open University Netherlands, Heerlen (Netherlands); Oost, Nathalie R. van [National Institute of Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, 3720 BA Bilthoven (Netherlands); Peijnenburg, Willie J.G.M. [National Institute of Public Health and the Environment, Laboratory for Ecological Risk Assessment, P.O. Box 1, 3720 BA Bilthoven (Netherlands)]. E-mail: wjgm.peijnenburg@rivm.nl

2005-01-01

The measurement of diffusive gels in thin films (DGT) has recently been developed to assess metal bioavailability in soils. The DGT-method is based on diffusion in a porous matrix. To test the predictive capabilities of the method with regard to metal bioavailability, a study was set up with 28 soils having a variety of textures and amounts of zinc salts added. Correlation and regression analyses were performed to compare DGT-extracted zinc levels to zinc concentrations obtained by extraction with 0.01 M CaCl{sub 2} and 0.43 M HNO{sub 3}, digestion with aqua regia and the zinc concentration in pore water. The amount of zinc extracted with CaCl{sub 2} correlated well with DGT-extracted zinc levels in all soils spiked with different amounts of ZnCl{sub 2}. A similar correlation was not found for zinc concentrations in soil samples collected in the field. Experiments were performed to compare zinc content in organisms and in soils. The organisms tested were plants (grass, lettuce and lupine) and the hard bodied soil dwelling isopod Oniscus asellus. Good correlations were found between zinc accumulation in grass and lettuce and the C{sub E} (effective concentration) measured by a DGT-device, CaCl{sub 2} extracted zinc and the zinc content in the pore water of all soils. The correlation with C{sub E} was not significant for lupine, neither for spiked soils, nor for field soils (p {<=} 0.001). Zinc levels in the isopods were not significantly related to any set of zinc measurements. From a synthesis of all results obtained it is concluded that the DGT-methodology does not have an additional value in predicting bioavailability of zinc in terrestrial ecosystems as compared to conventional extraction methods. - Capsule: The newly developed method of diffusive gels in Thin films (DGT) does not have an added value over conventional extraction techniques in predicting zinc uptake by plants and isopods.

Comparison of the method of diffusive gels in thin films with conventional extraction techniques for evaluating zinc accumulation in plants and isopods

International Nuclear Information System (INIS)

Koster, Marijke; Reijnders, Lucas; Oost, Nathalie R. van; Peijnenburg, Willie J.G.M.

2005-01-01

The measurement of diffusive gels in thin films (DGT) has recently been developed to assess metal bioavailability in soils. The DGT-method is based on diffusion in a porous matrix. To test the predictive capabilities of the method with regard to metal bioavailability, a study was set up with 28 soils having a variety of textures and amounts of zinc salts added. Correlation and regression analyses were performed to compare DGT-extracted zinc levels to zinc concentrations obtained by extraction with 0.01 M CaCl 2 and 0.43 M HNO 3 , digestion with aqua regia and the zinc concentration in pore water. The amount of zinc extracted with CaCl 2 correlated well with DGT-extracted zinc levels in all soils spiked with different amounts of ZnCl 2 . A similar correlation was not found for zinc concentrations in soil samples collected in the field. Experiments were performed to compare zinc content in organisms and in soils. The organisms tested were plants (grass, lettuce and lupine) and the hard bodied soil dwelling isopod Oniscus asellus. Good correlations were found between zinc accumulation in grass and lettuce and the C E (effective concentration) measured by a DGT-device, CaCl 2 extracted zinc and the zinc content in the pore water of all soils. The correlation with C E was not significant for lupine, neither for spiked soils, nor for field soils (p ≤ 0.001). Zinc levels in the isopods were not significantly related to any set of zinc measurements. From a synthesis of all results obtained it is concluded that the DGT-methodology does not have an additional value in predicting bioavailability of zinc in terrestrial ecosystems as compared to conventional extraction methods. - Capsule: The newly developed method of diffusive gels in Thin films (DGT) does not have an added value over conventional extraction techniques in predicting zinc uptake by plants and isopods

Innovative uses for zinc in dermatology.

Science.gov (United States)

Bae, Yoon Soo; Hill, Nikki D; Bibi, Yuval; Dreiher, Jacob; Cohen, Arnon D

2010-07-01

Severe zinc deficiency states, such as acrodermatitis enteropathica, are associated with a variety of skin manifestations, such as perioral, acral, and perineal dermatitis. These syndromes can be reversed with systemic zinc repletion. In addition to skin pathologies that are clearly zinc-dependent, many dermatologic conditions (eg, dandruff, acne, and diaper rash) have been associated and treated with zinc. Success rates for treatment with zinc vary greatly depending on the disease, mode of administration, and precise zinc preparation used. With the exception of systemic zinc deficiency states, there is little evidence that convincingly demonstrates the efficacy of zinc as a reliable first-line treatment for most dermatologic conditions. However, zinc may be considered as an adjunctive treatment modality. Further research is needed to establish the indications for zinc treatment in dermatology, optimal mode of zinc delivery, and best type of zinc compound to be used. Copyright 2010 Elsevier Inc. All rights reserved.

Antimicrobial electrospun silver-, copper- and zinc-doped polyvinylpyrrolidone nanofibers

International Nuclear Information System (INIS)

Quirós, Jennifer; Borges, João P.; Boltes, Karina; Rodea-Palomares, Ismael; Rosal, Roberto

2015-01-01

Highlights: • Electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc. • Antimicrobial effect for the bacteria Staphylococcus aureus and Escherichia coli. • Silver strongly reduced colony forming units and bacterial viability. • Silver, copper, and zinc led to a significant increase of non-viable cells on mats. - Abstract: The use of electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc nanoparticles was studied to prepare antimicrobial mats using silver and copper nitrates and zinc acetate as precursors. Silver became reduced during electrospinning and formed nanoparticles of several tens of nanometers. Silver nanoparticles and the insoluble forms of copper and zinc were dispersed using low molecular weight PVP as capping agent. High molecular weight PVP formed uniform fibers with a narrow distribution of diameters around 500 nm. The fibers were converted into an insoluble network using ultraviolet irradiation crosslinking. The efficiency of metal-loaded mats against the bacteria Escherichia coli and Staphylococcus aureus was tested for different metal loadings by measuring the inhibition of colony forming units and the staining with fluorescent probes for metabolic viability and compromised membranes. The assays included the culture in contact with mats and the direct staining of surface attached microorganisms. The results indicated a strong inhibition for silver-loaded fibers and the absence of significant amounts of viable but non-culturable microorganisms. Copper and zinc-loaded mats also decreased the metabolic activity and cell viability, although in a lesser extent. Metal-loaded fibers allowed the slow release of the soluble forms of the three metals.

Antimicrobial electrospun silver-, copper- and zinc-doped polyvinylpyrrolidone nanofibers

Energy Technology Data Exchange (ETDEWEB)

Quirós, Jennifer [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Borges, João P. [CENIMAT/I3N, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Boltes, Karina [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Madrid Institute for Advanced Studies of Water (IMDEA Agua), Parque Científico Tecnológico, E-28805, Alcalá de Henares, Madrid (Spain); Rodea-Palomares, Ismael [Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Rosal, Roberto [Department of Chemical Engineering, University of Alcalá, 28871 Alcalá de Henares, Madrid (Spain); Madrid Institute for Advanced Studies of Water (IMDEA Agua), Parque Científico Tecnológico, E-28805, Alcalá de Henares, Madrid (Spain)

2015-12-15

Highlights: • Electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc. • Antimicrobial effect for the bacteria Staphylococcus aureus and Escherichia coli. • Silver strongly reduced colony forming units and bacterial viability. • Silver, copper, and zinc led to a significant increase of non-viable cells on mats. - Abstract: The use of electrospun polyvinylpyrrolidone (PVP) nanofibers containing silver, copper, and zinc nanoparticles was studied to prepare antimicrobial mats using silver and copper nitrates and zinc acetate as precursors. Silver became reduced during electrospinning and formed nanoparticles of several tens of nanometers. Silver nanoparticles and the insoluble forms of copper and zinc were dispersed using low molecular weight PVP as capping agent. High molecular weight PVP formed uniform fibers with a narrow distribution of diameters around 500 nm. The fibers were converted into an insoluble network using ultraviolet irradiation crosslinking. The efficiency of metal-loaded mats against the bacteria Escherichia coli and Staphylococcus aureus was tested for different metal loadings by measuring the inhibition of colony forming units and the staining with fluorescent probes for metabolic viability and compromised membranes. The assays included the culture in contact with mats and the direct staining of surface attached microorganisms. The results indicated a strong inhibition for silver-loaded fibers and the absence of significant amounts of viable but non-culturable microorganisms. Copper and zinc-loaded mats also decreased the metabolic activity and cell viability, although in a lesser extent. Metal-loaded fibers allowed the slow release of the soluble forms of the three metals.

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...

Sulfidation of zinc plating sludge with Na2S for zinc resource recovery

International Nuclear Information System (INIS)

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

2006-01-01

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

Reactive radio frequency sputtering deposition and characterization of zinc nitride and oxynitride thin films

International Nuclear Information System (INIS)

Jiang, Nanke; Georgiev, Daniel G.; Wen, Ting; Jayatissa, Ahalapitiya H.

2012-01-01

Zinc nitride films were deposited on glass or silicon substrates by reactive magnetron radio frequency sputtering of zinc in either N 2 –Ar or N 2 –Ar–O 2 ambient. The effects of varying the nitrogen contents and the substrate temperature were investigated. X-ray diffraction data showed that the as-deposited films contain the zinc nitride cubic crystalline phase with a preferred orientation, and Raman scattering measurements revealed Zn-N related modes. According to energy-dispersive X-ray spectroscopy analysis, the as-deposited films were nitrogen-rich and contained only a small fraction of oxygen. Hall-effect measurements showed that p-type zinc nitride with carrier concentration of ∼ 10 19 cm −3 , mobility of ∼ 10 1 cm 2 /Vs, resistivity of ∼ 10 −2 Ω ∗ cm, was obtained. The photon energy dependence of optical transmittance suggested that the material has an indirect bandgap.

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

Science.gov (United States)

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

2015-01-01

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

Determination of zinc concentration in female reproductive system by instrumental neutron activation

International Nuclear Information System (INIS)

Carvalho, Fernando Ramos de

2009-01-01

Non-surgical female sterilization through the transcervical insertion of quinacrine pellets was considered a definitive, low-cost, safe and effective contraceptive method. The zinc, present in both uterus and Fallopian tubes, inhibit the quinacrine efficiency. The addition of copper increases the efficacy of quinacrine, reducing the risk of pregnancy due to the failure to obstruct the Fallopian tubes. The copper neutralized the deleterious effect of the zinc and so the treatment efficacy is increased. In order to obtain a mapping to study the zinc content in the female reproductive system, samples of both uterus and Fallopian tubes were analyzed by instrumental neutron activation. The results show that, on average, the obtained zinc concentrations in tubes (89 μg-g -1 ) is lower than in the uterus (118 μg-g -1 ), confirming results obtained by other authors. These results will support a research project about non-surgical female sterilization of the 'Faculdade de Medicina da Universidade Federal de Minas Gerais' (Medical School of Federal University of Minas Gerais). The used methodology and obtained results are here reported. (author)

Determination of zinc concentration in female reproductive system by instrumental neutron activation

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Fernando Ramos de, E-mail: framosc@oi.com.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Oliveira, Arno Heeren de, E-mail: heeren@nuclear.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Medicina. Dept. de Ginecologia e Obstetricia; Ferreira, Claudia R.C.; Ferreira, Ricardo Alberto Neto; Menezes, Maria Angela de B.C., E-mail: claudia@medicina.ufmg.b, E-mail: ranf@cdtn.b, E-mail: menezes@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2009-07-01

Non-surgical female sterilization through the transcervical insertion of quinacrine pellets was considered a definitive, low-cost, safe and effective contraceptive method. The zinc, present in both uterus and Fallopian tubes, inhibit the quinacrine efficiency. The addition of copper increases the efficacy of quinacrine, reducing the risk of pregnancy due to the failure to obstruct the Fallopian tubes. The copper neutralized the deleterious effect of the zinc and so the treatment efficacy is increased. In order to obtain a mapping to study the zinc content in the female reproductive system, samples of both uterus and Fallopian tubes were analyzed by instrumental neutron activation. The results show that, on average, the obtained zinc concentrations in tubes (89 mug-g{sup -1}) is lower than in the uterus (118 mug-g{sup -1}), confirming results obtained by other authors. These results will support a research project about non-surgical female sterilization of the 'Faculdade de Medicina da Universidade Federal de Minas Gerais' (Medical School of Federal University of Minas Gerais). The used methodology and obtained results are here reported. (author)

Influence of silane content and filler distribution on chemical-mechanical properties of resin composites

Directory of Open Access Journals (Sweden)

Tathy Aparecida XAVIER

2015-01-01

Full Text Available This study investigated the influence of silane concentration and filler size distribution on the chemical-mechanical properties of experimental composites. Experimental composites with silane contents of 0%, 1% and 3% (in relation to filler mass and composites with mixtures of barium glass particles (median size = 0.4, 1 and 2 μm and nanometric silica were prepared for silane and filler analyses, respectively. The degree of conversion (DC was analyzed by FTIR. Biaxial flexural strength (BFS was tested after 24-h or 90-d storage in water, and fracture toughness, after 24 h. The data were subjected to ANOVA and Tukey’s test (p = 0.05. The DC was not significantly affected by the silane content or filler distribution. The 0% silane group had the lowest immediate BFS, and the 90-d storage time reduced the strength of the 0% and 3% groups. BFS was not affected by filler distribution, and aging decreased the BFS of all the groups. Silanization increased the fracture toughness of both the 1% and 3% groups, similarly. Significantly higher fracture toughness was observed for mixtures with 2 μm glass particles. Based on the results, 3% silane content boosted the initial strength, but was more prone to degradation after water storage. Variations in the filler distribution did not affect BFS, but fracture toughness was significantly improved by increasing the filler size.

Preparation and characterization of a zinc oxide nanopowder supported onto inorganic clay

International Nuclear Information System (INIS)

Hassan, Mohamed; Afify, Ahmed Sabry; Tulliani, Jean-Marc; Ataalla, Mohamed; Staneva, Anna; Dimitriev, Yanko; Mohammed, Amr

2016-01-01

Zinc oxide nanoparticles are obtained by a wet chemical method using zinc sulphate as a raw material. Doping sepiolite, micro-fibrous inorganic clay, with ZnO after precipitation under basic conditions and subsequent thermal treatment is investigated as both materials are abundant. They are used for the development of humidity and gas sensors of great environmental importance. The particle size distribution, the morphology and the composition of the powder samples are characterized by X-Ray diffraction accompanied by Field Emission Scanning Electron Microscopy and High Resolution-Transmission Electron Microscopy techniques. The data obtained confirm the formation of zinc oxide nanoparticles of a size of 10 nm on the modified sepiolite grains. Keywords: ZnO, sepiolite, nanoparticles, doping.

Deformation twinning in zinc-aluminium single crystals after slip

International Nuclear Information System (INIS)

Lukac, P.; Kral, F.; Trojanova, Z.; Kral, R.

1993-01-01

Deformation twinning in Zn-Al single crystals deformed by slip in the basal system is examined. The influence of temperature and the content of aluminium in zinc on the twinning stress is investigated in the temperature range from 198 to 373 K. It is shown that the twinning stress rises with increasing temperature and increases with the concentration of Al atoms. (orig.)

The determination, by x-ray-fluorescence spectrometry, of tin and zinc in ores, middlings, and residues

International Nuclear Information System (INIS)

Balaes, A.M.E.

1984-01-01

The method of analysis is applicable to samples with tin and zinc contents from 15μg/g upwards. Samples with widely ranging concentrations of the analytes are diluted with river sand. The matrix variations are compensated for by the use of briquettes containing coarse river sand, a styrene copolymer binder, and an internal standard. Tungsten is used as the internal standard for zinc, and antimony for tin. Calibration graphs for zinc and tin are obtained by the use of a reference material for tin and of zinc oxide for zinc. The precision of the analysis for each element does not exeed 0,040 relative standard deviation. The agreement between the analysis and the accepted international values and recommended values for in-house reference materials is better than 3 per cent over the concentration range 50μg/g to 16 per cent. The lower limits of detection are 2μg/g for tin and 3μg/g for zinc. The overall time required for the analysis of 10 samples, one control sample, and five calibration standards is approximately 3 hours