New Mechanism for the Reduction of Vanadyl Acetylacetonate to Vanadium Acetylacetonate for Room Temperature Flow Batteries.

PubMed

Shamie, Jack S; Liu, Caihong; Shaw, Leon L; Sprenkle, Vincent L

2017-02-08

In this study, a new mechanism for the reduction of vanadyl acetylacetonate, VO(acac) 2 , to vanadium acetylacetonate, V(acac) 3 , is introduced. V(acac) 3 has been studied for use in redox flow batteries (RFBs) for some time; however, contamination by moisture leads to the formation of VO(acac) 2 . In previous work, once this transformation occurs, it is no longer reversible because there is a requirement for extreme low potentials for the reduction to occur. Here, we propose that, in the presence of excess acetylacetone (Hacac) and free protons (H + ), the reduction can take place between 2.25 and 1.5 V versus Na/Na + via a one-electron-transfer reduction. This reduction can take place in situ during discharge in a novel hybrid Na-based flow battery (HNFB) with a molten Na-Cs alloy as the anode. The in situ recovery of V(acac) 3 during discharge is shown to allow the Coulombic efficiency of the HNFB to be ≈100 % with little or no capacity decay over cycles. In addition, utilizing two-electron-transfer redox reactions (i.e., V 3+ /V 4+ and V 2+ /V 3+ redox couples) per V ion to increase the energy density of RFBs becomes possible owing to the in situ recovery of V(acac) 3 during discharge. The concept of in situ recovery of material can lead to more advances in maintaining the cycle life of RFBs in the future. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly efficient inverted top emitting organic light emitting diodes using a transparent top electrode with color stability on viewing angle

NASA Astrophysics Data System (ADS)

Kim, Jung-Bum; Lee, Jeong-Hwan; Moon, Chang-Ki; Kim, Jang-Joo

2014-02-01

We report a highly efficient phosphorescent green inverted top emitting organic light emitting diode with excellent color stability by using the 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile/indium zinc oxide top electrode and bis(2-phenylpyridine)iridium(III) acetylacetonate as the emitter in an exciplex forming co-host system. The device shows a high external quantum efficiency of 23.4% at 1000 cd/m2 corresponding to a current efficiency of 110 cd/A, low efficiency roll-off with 21% at 10 000 cd/m2 and low turn on voltage of 2.4 V. Especially, the device showed very small color change with the variation of Δx = 0.02, Δy = 0.02 in the CIE 1931 coordinates as the viewing angle changes from 0° to 60°. The performance of the device is superior to that of the metal/metal cavity structured device.

Rapidly synthesized ZnO nanowires by ultraviolet decomposition process in ambient air for flexible photodetector.

PubMed

Wu, Jyh Ming; Chen, Yi-Ru; Lin, Yu-Hung

2011-03-01

We are the first group to use a simple direct ultraviolet light (UV, λ=365 nm, I=76 mW cm(-2)) in a decomposition process to fabricate ZnO nanowires on a flexible substrate using a zinc acetylacetonate hydrate precursor in ambient air. ZnO nanocrystal (or nanowire) production only requires three to ten minutes. A field emission scanning electron microscopy (FESEM) image reveals a high aspect ratio of the ZnO nanowires, which are grown on a substrate with a diameter of ∼50-100 nm, and a length of up to several hundred microns. High resolution transmission electron microscopy (HRTEM) images reveal that the nanowires consist of many single crystalline ZnO nanoparticles that grow along the c axis, which suggests an oriented attachment process. A potential application for flexible UV photodetectors was investigated using a UV lamp (λ=365 nm, I=2.34 mW cm(-2)). A significant ratio of photocurrent to dark current--around 11,300%--was achieved.

Yb3+ can be much better than Dy3+: SMM properties and controllable self-assembly of novel lanthanide 3,5-dinitrobenzoate-acetylacetonate complexes.

PubMed

Gavrikov, Andrey V; Efimov, Nikolay N; Ilyukhin, Andrey B; Dobrokhotova, Zhanna V; Novotortsev, Vladimir M

2018-05-01

The first representatives of the binuclear lanthanide 3,5-dinitrobenzoate-acetylacetonate complexes, namely isostructural compounds [Ln(dnbz)(acac)2(H2O)(EtOH)]2 (Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5), Er (6), Tm (7), and Yb (8); dnbz - 3,5-dinitrobenzoate anion; acac - acetylacetonate (pentane-2,4-dionate) anion) were prepared and characterized. The SMM behavior of the Yb compound 8 was shown to be surprisingly less sensitive to the composition of the Yb3+ coordination environment in comparison with that of the Dy derivative. For Yb compound 8, the anisotropy barrier is Δeff/kB = 26 K under the dc field of 2000 Oe. This value is the highest one currently known for binuclear Yb complexes.

Design, Fabrication, Characterization and Modeling of Integrated Functional Materials

DTIC Science & Technology

2009-10-01

cobalt ferrite (CoFe2O4) nanoparticles dispersed in a low-loss commercial polymer matrix obtained from Rogers Corporation. 2 mmol of Cobalt (II...oleylamine and 20 ml benzyl ether were added to the Iron (III) acetylacetonate and Cobalt (II) acetylacetonate mixture. The mixture was stirred...microwave applications Multiferroic bilayers of Cobalt Ferrite and PZT: The objective of this project is to fabricate bilayers of ferroelectric

Combustion synthesized indium-tin-oxide (ITO) thin film for source/drain electrodes in all solution-processed oxide thin-film transistors

NASA Astrophysics Data System (ADS)

Tue, Phan Trong; Inoue, Satoshi; Takamura, Yuzuru; Shimoda, Tatsuya

2016-06-01

We report combustion solution synthesized (SCS) indium-tin-oxide (ITO) thin film, which is a well-known transparent conductive oxide, for source/drain (S/D) electrodes in solution-processed amorphous zirconium-indium-zinc-oxide TFT. A redox-based combustion synthetic approach is applied to ITO thin film using acetylacetone as a fuel and metal nitrate as oxidizer. The structural and electrical properties of SCS-ITO precursor solution and thin films were systematically investigated with changes in tin concentration, indium metal precursors, and annealing conditions such as temperature, time, and ambient. It was found that at optimal conditions the SCS-ITO thin film exhibited high crystalline quality, atomically smooth surface (RMS ~ 4.1 Å), and low electrical resistivity (4.2 × 10-4 Ω cm). The TFT using SCS-ITO film as the S/D electrodes showed excellent electrical properties with negligible hysteresis. The obtained "on/off" current ratio, subthreshold swing factor, subthreshold voltage, and field-effect mobility were 5 × 107, 0.43 V/decade, 0.7 V, and 2.1 cm2/V s, respectively. The performance and stability of the SCS-ITO TFT are comparable to those of the sputtered-ITO TFT, emphasizing that the SCS-ITO film is a promising candidate for totally solution-processed oxide TFTs.

Plasma impact on structural, morphological and optical properties of copper acetylacetonate thin films

NASA Astrophysics Data System (ADS)

Abdel-Khalek, H.; El-Samahi, M. I.; El-Mahalawy, Ahmed M.

2018-06-01

The influence of plasma exposure on structural, morphological and optical properties of copper (II) acetylacetonate thin films deposited by thermal evaporation technique was investigated. Copper (II) acetylacetonate as-grown thin films were exposed to the atmospheric plasma for different times. The exposure of as-grown cu(acac)2 thin film to atmospheric plasma for 5 min modified its structural, morphological and optical properties. The effect of plasma exposure on structure and roughness of cu(acac)2 thin films was evaluated by XRD and AFM techniques, respectively. The XRD results showed an increment in crystallinity due to exposure for 5 min, but, when the exposure time reaches 10 min, the film was transformed to an amorphous state. The AFM results revealed a strong modification of films roughness when the average roughness decreased from 63.35 nm to 1 nm as a result of interaction with plasma. The optical properties of as-grown and plasma exposured cu(acac)2 thin films were studied using spectrophotometric method. The exposure of cu(acac)2 thin films to plasma produced the indirect energy gap decrease from 3.20 eV to 2.67 eV for 10 min exposure time. The dispersion parameters were evaluated in terms of single oscillator model for as-grown and plasma exposured thin films. The influence of plasma exposure on third order optical susceptibility was studied.

Plasma impact on structural, morphological and optical properties of copper acetylacetonate thin films.

PubMed

Abdel-Khalek, H; El-Samahi, M I; El-Mahalawy, Ahmed M

2018-06-15

The influence of plasma exposure on structural, morphological and optical properties of copper (II) acetylacetonate thin films deposited by thermal evaporation technique was investigated. Copper (II) acetylacetonate as-grown thin films were exposed to the atmospheric plasma for different times. The exposure of as-grown cu(acac) 2 thin film to atmospheric plasma for 5min modified its structural, morphological and optical properties. The effect of plasma exposure on structure and roughness of cu(acac) 2 thin films was evaluated by XRD and AFM techniques, respectively. The XRD results showed an increment in crystallinity due to exposure for 5min, but, when the exposure time reaches 10min, the film was transformed to an amorphous state. The AFM results revealed a strong modification of films roughness when the average roughness decreased from 63.35nm to ~1nm as a result of interaction with plasma. The optical properties of as-grown and plasma exposured cu(acac) 2 thin films were studied using spectrophotometric method. The exposure of cu(acac) 2 thin films to plasma produced the indirect energy gap decrease from 3.20eV to 2.67eV for 10min exposure time. The dispersion parameters were evaluated in terms of single oscillator model for as-grown and plasma exposured thin films. The influence of plasma exposure on third order optical susceptibility was studied. Copyright © 2018 Elsevier B.V. All rights reserved.

New cyclometalated Iridium(III) beta-dicetone complex as phosphorescent dopant in Organic light emitting devices

NASA Astrophysics Data System (ADS)

Ivanov, P.; Petrova, P.; Stanimirov, S.; Tomova, R.

2017-01-01

A new Bis[4-(benzothiazolato-N,C2‧-2-yl)-N,N-dimethylaniline]Iridium(III) acetylacetonate (Me2N-bt) 2Ir(acac) was synthesized and identified by 1H NMR and elemental analysis. The application of the new compound as a dopant in the hole transporting layer (HTL) of Organic light emitting diode (OLED) structure: HTL/EL/ETL, where HTL was N,N’-bis(3-methylphenyl)-N,N’-diphenylbenzidine (TPD), incorporated in Poly(N-vinylcarbazole) (PVK) matrix, EL - electroluminescent layer of Bis(8-hydroxy-2-methylquinoline)-(4-phenylpheno-xy)aluminum (BAlq) and ETL - electron-transporting layer of Tris-(8-hydroxyquinoline) aluminum (Alq3) or Bis[2-(2-benzothiazoly) phenolato]zinc (Zn(btz)2). We established that the electroluminescent spectra of OLEDs at different concentrations of the dopant were basically the sum of the greenish-blue emission of BAlq and yellowish-green emission of Ir complex. It was found that with increasing of the dopant concentration the relative electroluminescent intensity of Iridium complex emission increased and this of BAlq decreased and as a result the fine tuning of OLED color was observed.

Synthesis and characterization of potential iron–platinum drugs and supplements by laser liquid photolysis

PubMed Central

Nkosi, Steven S; Mwakikunga, Bonex W; Sideras-Haddad, Elias; Forbes, Andrew

2012-01-01

Highly crystalline nanospherical iron–platinum systems were produced by 248 nm laser irradiation of a liquid precursor at different laser fluences, ranging from 100–375 mJ/cm2. The influence of laser intensity on particle size, iron composition, and structure was systematically investigated. Different nanostructures of iron–platinum alloy and chemically disordered iron–platinum L10 phase were obtained without annealing. The prepared precursor solution underwent deep photolysis to polycrystalline iron–platinum nanoalloys through Fe(III) acetylacetonate and Pt(II) acetylacetonate. Fe(II) and Pt(I) acetylacetone decomposed into Fe0 and Pt0 nanoparticles. We found that the (001) diffraction peak shifted linearly to a lower angle, with the last peak shifting in opposition to the others. This caused the face-centered cubic L10 structure to change its composition according to laser fluence. The nanostructures were shown to contain iron and platinum only by energy-dispersive spectroscopy at several spots. The response of these iron–platinum nanoparticles to infrared depends on their stoichiometric composition, which is controlled by laser fluence. PMID:24198494

Graphene oxide/manganese ferrite nanohybrids for magnetic resonance imaging, photothermal therapy and drug delivery.

PubMed

Yang, Yan; Shi, Haili; Wang, Yapei; Shi, Benzhao; Guo, Linlin; Wu, Dongmei; Yang, Shiping; Wu, Huixia

2016-01-01

Superparamagnetic manganese ferrite (MnFe2O4) nanoparticles have been deposited on graphene oxide (GO) by the thermal decomposition of manganese (II) acetylacetonate and iron (III) acetylacetonate precursors in triethylene glycol. The resulting GO/MnFe2O4 nanohybrids show very low cytotoxicity, negligible hemolytic activity, and imperceptible in vivo toxicity. In vitro and in vivo magnetic resonance imaging experiments demonstrate that GO/MnFe2O4 nanohybrids could be used as an effective T2 contrast agent. The strong optical absorbance in the near-infrared (NIR) region and good photothermal stability of GO/MnFe2O4 nanohybrids result in the highly efficient photothermal ablation of cancer cells. GO/MnFe2O4 nanohybrids can be further loaded with doxorubicin (DOX) by π-π conjugate effect for chemotherapy. DOX release from GO/MnFe2O4 is significantly influenced by pH and can be triggered by NIR laser. The enhanced cancer cell killing by GO/MnFe2O4/DOX composites has been achieved when irradiated with near-infrared light, suggesting that the nanohybrids could deliver both DOX chemotherapy and photothermal therapy with a synergistic effect. © The Author(s) 2015.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Peigong; Fan, Caimei, E-mail: fancm@163.com; Wang, Yawen

Graphical abstract: The cubic phase BaTiO{sub 3} nanoparticles can be obtained at 600 °C and changed into tetragonal phase at 900 °C by a dual chelating sol–gel method, and the photocatalytic activities of the photocatalysts calcined at different temperatures were investigated by the removal of humic acid (HA) from water under UV light irradiation. Highlights: ► The humic acid in water was firstly degradated by BaTiO{sub 3} photocatalyst. ► The cubic BaTiO{sub 3} was obtained and changed into tetragonal phase at lower temperature. ► The chelating agents had an important influence on the phase formation of BaTiO{sub 3}. ► Themore » tetragonal phase BaTiO{sub 3} calcined at 900 °C exhibited higher photocatalytic activity under UV irradiation. -- Abstract: In this paper, a dual chelating sol–gel method was used to synthesize BaTiO{sub 3} nanoparticles by using acetylacetone and citric acid as chelating agents. The samples calcined at different temperatures were analyzed by thermogravimetric and differential thermal analysis (TG-DTA), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), scanning electron microscope (SEM) and UV–vis diffuse reflectance spectra (UV–vis). The results indicated that cubic phase BaTiO{sub 3} nanoparticles about 19.6 nm can be obtained at 600 °C and changed into tetragonal phase at 900 °C about 97.1 nm. All the BaTiO{sub 3} nanoparticles showed effective photocatalytic activities on the removal of humic acid (HA) under UV light irradiation. A comparison of single (acetylacetone or citric acid) and dual chelating (acetylacetone and citric acid) synthetic processes was also studied and the results demonstrated that the dual chelating agents indeed reduced phase transformation temperature from cubic to tetragonal BaTiO{sub 3}.« less

Preparation and Biodistribution Studies of a Radiogallium-Acetylacetonate Bis (Thiosemicarbazone) Complex in Tumor-Bearing Rodents

PubMed Central

Jalilian, Amir Reza; Yousefnia, Hassan; Shafaii, Kamaleddin; Novinrouz, Aytak; Rajamand, Amir Abbas

2012-01-01

Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [67Ga] acetylacetonate bis(thiosemicarbazone) complex ([67Ga] AATS) was prepared starting [67Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) and the presence of human serum (37°C) up to 24 h. The biodistribution of the labeled compound in wild-type and fibrosarcoma-bearing rodents were determined up to 72 h. The radiolabled Ga complex was prepared in high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumor accumulation of the tracer in 2 h which is far higher than free Ga-67 cation while the compound wash-out is significantly faster. Above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex while prepared by the PET Ga radioisotope, 68Ga, in accordance with the physical half life, for use in fibrosarcoma tumors, and possibly other malignancies. PMID:24250475

Theoretical study on ultrafast intersystem crossing of chromium(III) acetylacetonate

NASA Astrophysics Data System (ADS)

Ando, Hideo; Iuchi, Satoru; Sato, Hirofumi

2012-05-01

In the relaxation process from the 4T2g state of chromium(III) acetylacetonate, CrIII(acac)3, ultrafast intersystem crossing (ISC) competes with vibrational relaxation (VR). This contradicts the conventional cascade model, where ISC rates are slower than VR ones. We hence investigate the relaxation process with quantum chemical calculations and excited-state wavepacket simulations to obtain clues about the origins of the ultrafast ISC. It is found that a potential energy curve of the 4T2g state crosses those of the 2T1g states near the Franck-Condon region and their spin-orbit couplings are strong. Consequently, ultrafast ISC between these states is observed in the wavepacket simulation.

Thermal aging effect of vanadyl acetylacetonate precursor for deposition of VO{sub 2} thin films with thermochromic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Jung-Hoon; Nam, Sang-Hun; Kim, Donguk

Highlights: • 7 day aged VO(acac){sub 2} sol shows enhanced adhesivity on the SiO{sub 2} compared with non-aged sol. • The aging process has significantly affected the morphologies of VO{sub 2} films. • From the FT-IR spectra, thermal aging process provides the deformation of precursor. • The metal insulator transition (MIT) efficiency (ΔT{sub at2000} {sub nm}) reached a maximum value of 51% at 7 day aging. • Thermal aging process could shorten the aging time of sol solution. - Abstract: Thermochromic properties of vanadium dioxide (VO{sub 2}) have been studied extensively due to their IR reflection applications in energy smartmore » windows. In this paper, we studied the optical switching property of VO{sub 2} thin film, depending on the thermal aging time of the vanadyl acetylacetonate (VO(acac){sub 2}) precursor. We found the alteration of the IR spectra of the precursor by tuning the aging time as well as heat treatments of the precursor. An aging effect of vanadium precursor directly affects the morphologies, optical switching property and crystallinity of VO{sub 2} films. The optimum condition was achieved at the 7 day aging time with metal insulator transition (MIT) efficiency of 50%.« less

Structural study of Ni- or Mg-based complexes incorporated within UiO-66-NH{sub 2} framework and their impact on hydrogen sorption properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Žunkovič, E.; Mazaj, M.; Mali, G.

2015-05-15

Nickel and magnesium acetylacetonate molecular complexes were post-synthetically incorporated into microporous zirconium-based MOF (UiO-66-NH{sub 2}) in order to introduce active open-metal sites for hydrogen sorption. Elemental analysis, nitrogen physisorption and DFT calculations revealed that 5 molecules of Ni(acac){sub 2} or 2 molecules of Mg(acac){sub 2} were incorporated into one unit cell of UiO-66-NH{sub 2}. {sup 1}H–{sup 13}C CPMAS and {sup 1}H MAS NMR spectroscopy showed that, although embedded within the pores, both Ni- and Mg-complexes interacted with the UiO-66-NH{sub 2} framework only through weak van der Waals bonds. Inclusion of metal complexes led to the decrease of hydrogen sorption capacitiesmore » in Ni-modified as well as in Mg-modified samples in comparison with the parent UiO-66-NH{sub 2}. The isosteric hydrogen adsorption enthalpy slightly increased in the case of Ni-modified material, but not in the case of Mg-modified analogue. - Graphical abstract: A post-synthesis impregnation of Mg- and Ni-acetylacetonate complexes performed on zirconium-based MOF UiO-66-NH{sub 2} does influence the hydrogen sorption performance with respect to the parent matrix. The structural study revealed that Mg- and Ni-acetylacetonate molecules interact with zirconium-terephthalate framework only by weak interactions and they are not covalently bonded to aminoterephthalate ligand. Still, they remain confined into the pores even after hydrogen sorption experiments. - Highlights: • Mg- and Ni-acetylacetonate molecules embedded in the pores of UiO-66-NH{sub 2} by PSM. • Molecules of complexes interact with framework only by van der Waals interactions. • Type/structure of deposited metal-complex impact hydrogen enthalpy of adsorption.« less

Effects of Palladium Loading on the Response of a Thick Film Flame-made ZnO Gas Sensor for Detection of Ethanol Vapor

PubMed Central

Liewhiran, Chaikarn; Phanichphant, Sukon

2007-01-01

ZnO nanoparticles doped with 0-5 mol% Pd were successfully produced in a single step by flame spray pyrolysis (FSP) using zinc naphthenate and palladium (II) acetylacetonate dissolved in toluene-acetonitrile (80:20 vol%) as precursors. The effect of Pd loading on the ethanol gas sensing performance of the ZnO nanoparticles and the crystalline sizes were investigated. The particle properties were analyzed by XRD, BET, AFM, SEM (EDS line scan mode), TEM, STEM, EDS, and CO-pulse chemisorption measurements. A trend of an increase in specific surface area of samples and a decrease in the dBET with increasing Pd concentrations was noted. ZnO nanoparticles were observed as particles presenting clear spheroidal, hexagonal and rod-like morphologies. The sizes of ZnO spheroidal and hexagonal particle crystallites were in the 10-20 nm range. ZnO nanorods were in the range of 10-20 nm in width and 20-50 nm in length. The size of Pd nanoparticles increased and Pd-dispersion% decreased with increasing Pd concentrations. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder. The paste was doctor-bladed onto Al2O3 substrates interdigitated with Au electrodes. The film morphology was analyzed by SEM and EDS analyses. The gas sensing of ethanol (25-250 ppm) was studied in dry air at 400°C. The oxidation of ethanol on the sensing surface of the semiconductor was confirmed by MS. A well-dispersed of 1 mol%Pd/ZnO films showed the highest sensitivity and the fastest response time (within seconds).

Optimization of the Energy Level Alignment between the Photoactive Layer and the Cathode Contact Utilizing Solution-Processed Hafnium Acetylacetonate as Buffer Layer for Efficient Polymer Solar Cells.

PubMed

Yu, Lu; Li, Qiuxiang; Shi, Zhenzhen; Liu, Hao; Wang, Yaping; Wang, Fuzhi; Zhang, Bing; Dai, Songyuan; Lin, Jun; Tan, Zhan'ao

2016-01-13

The insertion of an appropriate interfacial buffer layer between the photoactive layer and the contact electrodes makes a great impact on the performance of polymer solar cells (PSCs). Ideal interfacial buffer layers could minimize the interfacial traps and the interfacial barriers caused by the incompatibility between the photoactive layer and the electrodes. In this work, we utilized solution-processed hafnium(IV) acetylacetonate (Hf(acac)4) as an effective cathode buffer layer (CBL) in PSCs to optimize the energy level alignment between the photoactive layer and the cathode contact, with the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) all simultaneously improved with Hf(acac)4 CBL, leading to enhanced power conversion efficiencies (PCEs). Ultraviolet photoemission spectroscopy (UPS) and scanning Kelvin probe microscopy (SKPM) were performed to confirm that the interfacial dipoles were formed with the same orientation direction as the built-in potential between the photoactive layer and Hf(acac)4 CBL, benefiting the exciton separation and electron transport/extraction. In addition, the optical characteristics and surface morphology of the Hf(acac)4 CBL were also investigated.

Acetylacetone as an efficient electron shuttle for concerted redox conversion of arsenite and nitrate in the opposite direction.

PubMed

Chen, Zhihao; Song, Xiaojie; Zhang, Shujuan; Wu, Bingdang; Zhang, Guoyang; Pan, Bingcai

2017-11-01

The redox conversion of arsenite and nitrate has direct effects on their potential environment risks. Due to the similar reduction potentials, there are few technologies that can simultaneously oxidize arsenite and reduce nitrate in one process. Here, we demonstrate that a diketone-mediated photochemical process could efficiently do this. A combined experimental and theoretical investigation was conducted to elucidate the mechanisms behind the redox conversion in the UV/acetylacetone (AA) process. Our key finding is that UV irradiation significantly changed the redox potential of AA. The excited AA, 3 (AA)*, acted as a semiquinone radical-like electron shuttle. For arsenite oxidation, the efficiency of 3 (AA)* was 1-2 orders of magnitude higher than those of quinone-type electron shuttles, whereas the consumption of AA was 2-4 orders of magnitude less than those of benzonquinones. The oxidation of arsenite and reduction of nitrate could be both accelerated when they existed together in UV/AA process. The results indicate that small diketones are some neglected but potent electron shuttles of great application potential in regulating aquatic redox reactions with the combination of UV irradiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shamie, Jack S.; Liu, Caihong; Shaw, Leon L.

In this study, a new mechanism for the reduction of vanadyl acetylacetonate, VO(acac)2, to vanadium acetylacetonate, V(acac)3, is introduced. V(acac)3 has been studied for use in redox flow batteries (RFBs) for some time; however, contamination by moisture leads to the formation of VO(acac)2. In previous work, once this transformation occurs, it is no longer reversible because there is a requirement for extreme low potentials for the reduction to occur. Here, we propose that, in the presence of excess acetylacetone (Hacac) and free protons (H+), the reduction can take place between 2.25 and 1.5 V versus Na/Na+ via a one-electron-transfer reduction.more » This reduction can take place in situ during discharge in a novel hybrid Na-based flow battery (HNFB) with a molten Na–Cs alloy as the anode. The in situ recovery of V(acac)3 during discharge is shown to allow the Coulombic efficiency of the HNFB to be ≈100 % with little or no capacity decay over cycles. In addition, utilizing two-electron-transfer redox reactions (i.e., V3+/V4+ and V2+/V3+ redox couples) per V ion to increase the energy density of RFBs becomes possible owing to the in situ recovery of V(acac)3 during discharge. The concept of in situ recovery of material can lead to more advances in maintaining the cycle life of RFBs in the future.« less

Adsorption properties of Silochrom chemically modified with nickel acetylacetonate

NASA Astrophysics Data System (ADS)

Pakhnutova, Evgeniya; Slizhov, Yuriy

2017-11-01

One of the areas of development of gas chromatography is the creation of new chromatographic materials that have improved sorption and analytical characteristics. In this work, for the first time, a new sorbent based on Silochrom C-120 modified with nickel acetylacetonate was studied using a complex of physico-chemical methods. It has been established that due to chemical modification of silica gel surface with nickel acetylacetonate the surface area of the specific surface decreases from 112 to 98 m2/g and surface acidity diminishes by 1.2 pH units. Using the thermogravimetric analysis it has been revealed that the obtained sorbent can be used in gas chromatography up to 290°C. Gas chromatography method was used to investigate the adsorption properties of the modified materials. According to the retention data of adsorbates: n-alkanes (C6-C9), benzene, ethanol, nitropropane and butanone-2 the differential molar adsorption energy q¯dif, 1, Henry adsorption constants K1,C, the differential molar entropy ΔS¯S1 and Δ q¯dif, 1 (special) of adsorbates in dispersion and specific interactions were calculated. The influence of the modifying additive on the changings in the thermodynamic retention characteristics of all sorbates because of the manifestation of specific sorbate-sorbent interactions has been shown. The highest values of the thermodynamic parameters were indicative for sorbates forming hydrogen bonds and capable of donor-acceptor interaction.

Synthesis, Structure and Electrochemistry of Tetranuclear Oxygen-Centered Copper(II) Clusters with Acetylacetone and Benz-pyrazole Hydrolyzed Derivatives as Ligand.

PubMed

Vafazadeh, Rasoul; Willis, Anthony C

2016-01-01

Two copper(II) clusters Cu(4)OCl(6)(pyrazole)4, 1, and Cu(4)OBr(6)(Br-pyrazole)4, 2, have been synthesized by reacting acetylacetone and benzohydrazide (1:1 ratio) with CuX(2) (X = Cl for 1 and X= Br for 2) in methanol solutions. The structures of both clusters have been established by X-ray crystallography. The clusters contain four Cu, one O, six μ(2)-X atoms, and four pyrazole ligands. The pyrazoles was prepared in situ by the reaction of acetylacetone with benzohydrazide in methanol under reflux. In 2, the methine hydrogens of the pyrazole ligands have been replaced by bromine atoms. The four copper atoms encapsulate the central O atom in a tetrahedral arrangement. All copper atoms are five-coordinate and have similar coordination environments with slightly distorted trigonal bipyramidal geometry. The cyclic voltammogram of the clusters 1 and 2 show a one-electron quasi-reversible reduction wave in the region 0.485 to 0.731 V, and a one-electron quasi-reversible oxidation wave in the region 0.767 to 0.898 V. In 1, one irreversible oxidative response is observed on the positive of side of the voltammogram at 1.512 V and this can be assigned to Cu(II) to Cu(III) oxidation.

INORGANIC COORDINATION POLYMERS. IV. THE ATTEMPTED REPLACEMENT OF ACETYLACETONATE LIGANDS WITH PICOLINATE LIGANDS,

DTIC Science & Technology

HETEROCYCLIC COMPOUNDS, PHOSPHENE OXIDES, BENZENE, CHROMIUM COMPOUNDS, CHEMICAL REAC, SYNTHESIS (CHEMISTRY), CHEMICAL ANALY, SPECTRA (INFRARED), ABSORPTION, DISPLACE, POLYMERIZATION, ORGANIC NITROGEN, AROMATIC COMPOUNDS.

Effects of acetylacetone on the photoconversion of pharmaceuticals in natural and pure waters.

PubMed

Zhang, Guoyang; Wu, Bingdang; Zhang, Shujuan

2017-06-01

Acetylacetone (AcAc) has proven to be a potent photo-activator in the degradation of color compounds. The effects of AcAc on the photochemical conversion of five colorless pharmaceuticals were for the first time investigated in both pure and natural waters with the UV/H 2 O 2 process as a reference. In most cases, AcAc played a similar role to H 2 O 2 . For example, AcAc accelerated the photodecomposition of carbamazepine, oxytetracycline, and tetracycline in pure water. Meanwhile, the toxicity of tetracyclines and carbamazepine were reduced to a similar extent to that in the UV/H 2 O 2 process. However, AcAc worked in a way different from that of H 2 O 2 . Based on the degradation kinetics, solvent kinetic isotope effect, and the inhibiting effect of O 2 , the underlying mechanisms for the degradation of pharmaceuticals in the UV/AcAc process were believed mainly to be direct energy transfer from excited AcAc to pharmaceuticals rather than reactive oxygen species-mediated reactions. In natural waters, dissolved organic matter (DOM) played a crucial role in the photoconversion of pharmaceuticals. The role of H 2 O 2 became negligible due to the scavenging effects of DOM and inorganic ions. Interestingly, in natural waters, AcAc first accelerated the photodecomposition of pharmaceuticals and then led to a dramatic reduction with the depletion of dissolved oxygen. Considering the natural occurrence of diketones, the results here point out a possible pathway in the fate and transport of pharmaceuticals in aquatic ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

A universal approach to the synthesis of nanodendrites of noble metals.

PubMed

Feng, Yan; Ma, Xiaohong; Han, Lin; Peng, Zhijian; Yang, Jun

2014-06-07

Nanomaterials usually exhibit structure-dependent catalytic activity, selectivity, and stability. Herein, we report a universal approach for the synthesis of noble metal nanoparticles with a dendritic structure, which is based on the reduction of metal acetylacetonate precursors in oleylamine at a temperature of 160 °C. In this strategy, the metal acetylacetonate precursors are reduced into metal atoms by oleylamine and grow into metal nanoparticles, while oleylamine is simultaneously converted into oleylamide to protect the nanoparticles. The competition between particle aggregation and oleylamide passivation is essential to the formation of a large number of particle aggregates, which eventually grow into nanodendrites via Ostwald ripening process. In particular, in comparison with commercial PtRu/C catalysts, the alloy PtRuOs nanodendrites exhibited superior catalytic activity toward methanol oxidation.

Antitumor efficacy and tolerability of systemically administered gallium acetylacetonate-loaded gelucire-stabilized nanoparticles.

PubMed

Wehrung, Daniel; Bi, Lipeng; Geldenhuys, Werner J; Oyewumi, Moses O

2013-06-01

The widespread clinical success with most gallium compounds in cancer therapy is markedly hampered by lack of tumor specific accumulation, poor tumor permeability and undesirable toxicity to healthy tissues. The aim of this work was to investigate for the first time antitumor mechanism of a new gallium compound (gallium acetylacetonate; GaAcAc) while assessing effectiveness of gelucire-stabilized nanoparticles (NPs) for potential application in gallium-based lung cancer therapy. NPs loaded with GaAcAc (Ga-NPs) were prepared using mixtures of cetyl alcohol with Gelucire 44/14 (Ga-NP-1) or Gelucire 53/13 (Ga-NP-2) as matrix materials. Of special note from this work is the direct evidence of involvement of microtubule disruption in antitumor effects of GaAcAc on human lung adenocarcinoma (A549). In-vivo tolerability studies were based on plasma ALT, creatinine levels and histopathological examination of tissues. The superior in-vivo antitumor efficacy of Ga-NPs over GaAcAc was depicted in marked reduction of tumor weight and tumor volume as well as histological assessment of excised tumors. Compared to free GaAcAc, Ga-NPs showed a 3-fold increase in tumor-to-blood gallium concentrations with minimized overall exposure to healthy tissues. Overall, enhancement of antitumor effects of GaAcAc by gelucire-stabilized NPs coupled with reduced exposure of healthy tissues to gallium would likely ensure desired therapeutic outcomes and safety of gallium-based cancer treatment.

Synthesis of oxide and spinel nanocrystals for use in solid state lighting

NASA Astrophysics Data System (ADS)

Foley, Megan Elizabeth

In this dissertation, microwave chemistry is employed to synthesize a variety of different crystalline nanoparticles (NPs). This introduction will describe the structures, properties and applications of the NPs studied within the dissertation, with a main focus being on ligand sensitization for the goal of enhanced luminescence. The use of metal acetylacetonate complexes to make Europium (III) doped Ytrrium (Y2O3) NPs is explored, where the acetylacetonate acts both as a source of oxygen for the synthesis of Y2O3, as well as an organic chromophore acting as an "antenna" for the absorption of light and subsequent excitation transfer to the incorporated Europium (III) (Chapter 2). Other host materials are investigated by method of metal acetylacetonate decomposition to synthesize a variety of different nanospinels, having the general formula AB2X4, with sulfide variants made by decomposition of diethyldithiocarbamate, (Chapter 3). The antenna ligand thenoyltrifluoroacetone (tta), which is known to undergo a Dexter energy transfer (DET) mechanism to efficiently sensitize Europium (III) emission, is used to determine the distance of energy transfer in Europium (III) doped nanospinels by passivating the surface of the nanospinel with a tta (Chapter 4). A variety of ligands are explored in order to optimize the sensitization efficiency in relation to the difference in energy between the singlet and triplet levels of the ligands versus the 5D0 and 5D4 energy levels of Europium (III) and Terbium (III) respectively (Chapter 5).

1T1R Nonvolatile Memory with Al/TiO₂/Au and Sol-Gel-Processed Insulator for Barium Zirconate Nickelate Gate in Pentacene Thin Film Transistor.

PubMed

Lee, Ke-Jing; Chang, Yu-Chi; Lee, Cheng-Jung; Wang, Li-Wen; Wang, Yeong-Her

2017-12-09

A one-transistor and one-resistor (1T1R) architecture with a resistive random access memory (RRAM) cell connected to an organic thin-film transistor (OTFT) device is successfully demonstrated to avoid the cross-talk issues of only one RRAM cell. The OTFT device, which uses barium zirconate nickelate (BZN) as a dielectric layer, exhibits favorable electrical properties, such as a high field-effect mobility of 5 cm²/Vs, low threshold voltage of -1.1 V, and low leakage current of 10 -12 A, for a driver in the 1T1R operation scheme. The 1T1R architecture with a TiO₂-based RRAM cell connected with a BZN OTFT device indicates a low operation current (10 μA) and reliable data retention (over ten years). This favorable performance of the 1T1R device can be attributed to the additional barrier heights introduced by using Ni (II) acetylacetone as a substitute for acetylacetone, and the relatively low leakage current of a BZN dielectric layer. The proposed 1T1R device with low leakage current OTFT and excellent uniform resistance distribution of RRAM exhibits a good potential for use in practical low-power electronic applications.

Influence of Water on Chemical Vapor Deposition of Ni and Co thin films from ethanol solutions of acetylacetonate precursors

PubMed Central

Weiss, Theodor; Zielasek, Volkmar; Bäumer, Marcus

2015-01-01

In chemical vapor deposition experiments with pulsed spray evaporation (PSE-CVD) of liquid solutions of Ni and Co acetylacetonate in ethanol as precursors, the influence of water in the feedstock on the composition and growth kinetics of deposited Ni and Co metal films was systematically studied. Varying the water concentration in the precursor solutions, beneficial as well as detrimental effects of water on the metal film growth, strongly depending on the concentration of water and the β-diketonate in the precursor, were identified. For 2.5 mM Ni(acac)2 precursor solutions, addition of 0.5 vol% water improves growth of a metallic Ni film and reduces carbon contamination, while addition of 1.0 vol% water and more leads to significant oxidation of deposited Ni. By tuning the concentration of both, Ni(acac)2 and water in the precursor solution, the fraction of Ni metal and Ni oxide in the film or the film morphology can be adjusted. In the case of Co(acac)2, even smallest amounts of water promote complete oxidation of the deposited film. All deposited films were analyzed with respect to chemical composition quasi in situ by XPS, their morphology was evaluated after deposition by SEM. PMID:26658547

Low cost disposal of MMH

NASA Technical Reports Server (NTRS)

Thomas, J. J.; French, T.

1980-01-01

Concentration of gaseous toxic monomethylhydrazine (MMH) can be removed at 99.9% efficiency using scrubbers containing acetylacetone solutions as scrubbing liquors. Resulting product is easily disposable and expensive liners for protecting scrubber from strong oxidizing agents are not needed.

Vibrational assignment of aluminum(III) Tris-acetylacetone

NASA Astrophysics Data System (ADS)

Tayyari, Sayyed Faramarz; Raissi, Haydar; Ahmadabadi, Zahra

2002-10-01

The geometry, frequency and intensity of the vibrational bands of aluminum(III) Tris-acetylacetone Al(AA) 3 and its 1, 3, 5- 13C derivative were obtained by the Hartree-Fock (HF) and Density Functional Theory (DFT) with the B3LYP, B1LYP, and G96LYP functionals and using the 6-31G* basis set. The calculated frequencies are compared with the solid IR and Raman spectra. All of the measured IR and Raman bands were interpreted in terms of the calculated vibrational modes. Most computed bands are predicted to be at higher wavenumbers than the experimental bands. The calculated bond lengths and bond angles are in good agreement with the experimental results. Analysis of the vibrational spectra indicates a strong coupling between the chelated ring modes. Four bands in the 500-390 cm -1 frequency range are assigned to the vibrations of metalligand bonds.

An improved soft-chemistry approach to the preparation of spinel powders

NASA Astrophysics Data System (ADS)

Cook, Ronald

2007-04-01

Spinel powders for the production of transparent polycrystalline ceramic windows have been produced using a number of traditional ceramic and sol-gel methods. We have demonstrated that magnesium aluminate spinel powders produced from the reaction of organo-magnesium compounds with surface modified boehmite precursors can be used to produce high quality transparent spinel parts. In previous work, the spinel powders were prepared by the reaction of surface-modified boehmite nanoparticles with magnesium acetylacetonate. While the magnesium acetylacetonate can produce small quantities of high quality spinel powders, it use for large scale production of spinel powders is problematic. Through a thermodynamic analysis we have identified a new high-purity, low-cost, low-toxicity organomagnesium compound that reacts the with surface modified boehmite nanoparticles to produce a spinel precursor. The magnesium doped precursor readily transforms into pure phase spinel at temperature between 900°C and 1200°C.

Spectroscopic studies on some fluorescent mixed-ligand titanium(IV) complexes.

PubMed

Baranwal, Balram Prasad; Singh, Alok Kumar; Varma, Anand

2011-12-15

A novel route to synthesize some titanium(IV) complexes containing acetylacetone, straight chain carboxylic acid and hydroxycarboxylic acid ligands has been investigated. Complexes with the general formula [Ti(acac)Cl(2-n)(OOCR*)(n)(OOCC(15)H(31))] (where Hacac=acetylacetone, R*COOH=hydroxycarboxylic acids and n=1 or 2) have been isolated and characterized. Molecular weight determinations indicated mononuclear nature of the complexes. LMCT bands were observed in the electronic spectra. Infrared spectra suggested bidentate nature of the ligands. Fluorescent behaviour of the complexes was noticed on the basis of fluorescence spectra. Powder XRD indicated them to be semi-crystalline having the crystallite size in 136-185 nm range. Transmission electron microscopy (TEM) indicated spherical particles of ~ 200 nm diameter. On the basis of physico-chemical studies, it is suggested that titanium is having coordination number 7 or 8 in these complexes. Copyright © 2011 Elsevier B.V. All rights reserved.

Economically attractive route for the preparation of high quality magnetic nanoparticles by the thermal decomposition of iron(III) acetylacetonate.

PubMed

Effenberger, Fernando B; Couto, Ricardo A; Kiyohara, Pedro K; Machado, Giovanna; Masunaga, Sueli H; Jardim, Renato F; Rossi, Liane M

2017-03-17

The thermal decomposition (TD) methods are among the most successful in obtaining magnetic nanoparticles with a high degree of control of size and narrow particle size distribution. Here we investigated the TD of iron(III) acetylacetonate in the presence of oleic acid, oleylamine, and a series of alcohols in order to disclose their role and also investigate economically attractive alternatives for the synthesis of iron oxide nanoparticles without compromising their size and shape control. We have found that some affordable and reasonably less priced alcohols, such as 1,2-octanediol and cyclohexanol, may replace the commonly used and expensive 1,2-hexadecanediol, providing an economically attractive route for the synthesis of high quality magnetic nanoparticles. The relative cost for the preparation of Fe 3 O 4 NPs is reduced to only 21% and 9% of the original cost when using 1,2-octanediol and cyclohexanol, respectively.

Efficient alkene epoxidation catalyzed by molybdenyl acetylacetonate supported on aminated UiO-66 metal-organic framework

NASA Astrophysics Data System (ADS)

Kardanpour, Reihaneh; Tangestaninejad, Shahram; Mirkhani, Valiollah; Moghadam, Majid; Mohammadpoor-Baltork, Iraj; Zadehahmadi, Farnaz

2015-03-01

Metal-organic frameworks (MOFs) containing Mo Schiff base complexes were prepared by post-synthesis method and applied as efficient catalysts in the epoxidation of alkenes with tert-BuOOH. In this manner, UiO-66-NH2 (UiO=University of Oslo) MOF was reacted with salicylaldehyde and thiophene-2-carbaldehyde to produce bidentate Schiff bases. Then, the Schiff base ligands were used for immobilization of molybdenyl acetylacetonate. These new catalysts were characterized by FT-IR, UV-vis spectroscopic techniques, X-ray diffraction (XRD), BET, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). These catalytic systems showed excellent activity in the epoxidation of alkenes such as cyclic and linear ones with tert-butyl hydroperoxide (TBHP) in 1,2-dichloroethane, and reused several times without any appreciable loss of their activity.

Sensing Characteristics of Flame-Spray-Made Pt/ZnO Thick Films as H2 Gas Sensor

PubMed Central

Tamaekong, Nittaya; Liewhiran, Chaikarn; Wisitsoraat, Anurat; Phanichphant, Sukon

2009-01-01

Hydrogen sensing of thick films of nanoparticles of pristine, 0.2, 1.0 and 2.0 atomic percentage of Pt concentration doped ZnO were investigated. ZnO nanoparticles doped with 0.2–2.0 at.% Pt were successfully produced in a single step by flame spray pyrolysis (FSP) technique using zinc naphthenate and platinum(II) acetylacetonate as precursors dissolved in xylene. The particle properties were analyzed by XRD, BET, SEM and TEM. Under the 5/5 (precursor/oxygen) flame condition, ZnO nanoparticles and nanorods were observed. The crystallite sizes of ZnO spheroidal and hexagonal particles were found to be ranging from 5 to 20 nm while ZnO nanorods were seen to be 5–20 nm wide and 20–40 nm long. ZnO nanoparticles paste composed of ethyl cellulose and terpineol as binder and solvent respectively was coated on Al2O3 substrate interdigitated with gold electrodes to form thin films by spin coating technique. The thin film morphology was analyzed by SEM technique. The gas sensing properties toward hydrogen (H2) was found that the 0.2 at.% Pt/ZnO sensing film showed an optimum H2 sensitivity of ∼164 at hydrogen concentration in air of 1 volume% at 300 °C and a low hydrogen detection limit of 50 ppm at 300 °C operating temperature. PMID:22399971

Preparation of Metalloporphyrin-Bound Superparamagnetic Silica Particles via "Click" Reaction.

PubMed

Hollingsworth, Javoris V; Bhupathiraju, N V S Dinesh K; Sun, Jirun; Lochner, Eric; Vicente, M Graça H; Russo, Paul S

2016-01-13

A facile approach using click chemistry is demonstrated for immobilization of metalloporphyrins onto the surface of silica-coated iron oxide particles. Oleic-acid stabilized iron oxide nanocrystals were prepared by thermal decomposition of iron(III) acetylacetonate. Their crystallinity, morphology, and superparamagnetism were determined using X-ray diffraction, transmission electron microscopy, and a superconducting quantum interference device. Monodisperse core-shell particles were produced in the silica-coating of iron oxide via microemulsion synthesis. Surface modification of these particles was performed in two steps, which included the reaction of silica-coated iron oxide particles with 3-bromopropyltrichlorosilane, followed by azido-functionalization with sodium azide. Monoalkylated porphyrins were prepared using the Williamson ether synthesis of commercially available tetra(4-hydroxyphenyl) porphyrin with propargyl bromide in the presence of a base. (1)H NMR and matrix-assisted laser desorption ionization confirmed the identity of the compounds. The prepared monoalkyne porphyrins were zinc-metalated prior to their introduction to azide-functionalized, silica-coated iron oxide particles in the click reaction. X-ray photoelectron spectroscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy were used to characterize the surface chemistry after each step in the reaction. In addition, particle size was determined using dynamic light scattering and microscopy. The presented methodology is versatile and can be extended to other photoreactive systems, such as phthalocyanines and boron-dipyrromethane, which may lead to new materials for optical, photonic, and biological applications.

Maternal Zinc Intakes and Homeostatic Adjustments during Pregnancy and Lactation

PubMed Central

Donangelo, Carmen Marino; King, Janet C.

2012-01-01

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

Homogeneity of Pb(Zr ,Ti)O3 thin films by chemical solution deposition: Extended x-ray absorption fine structure spectroscopy study of zirconium local environment

NASA Astrophysics Data System (ADS)

Malic, Barbara; Arcon, Iztok; Kodre, Alojz; Kosec, Marija

2006-09-01

Sols for Pb(Zr0.53Ti0.47)O3 (PZT) thin films were prepared by 2-methoxyethanol route from lead acetate, titanium n-propoxide, and zirconium n-propoxide, the latter either unmodified or modified with acetylacetone or acetic acid in a 2/1 molar ratio and deposited on sapphire (0001). By Zr K-edge extended x-ray absorption fine structure (EXAFS) spectroscopy, the structural changes in the Zr local environment, induced by the addition of the two modifiers, were followed from the synthesis of the PZT sol to the transition to the amorphous film. In the unmodified PZT sol segregation of Zr species occurs from the original dimers present in the Zr propoxide solution in 2-methoxyethanol. The immediate neighborhood of Zr atoms changes markedly at the transition from the sol to the amorphous film: the local structure around Zr atoms is similar to the one found in tetragonal zirconia particles. The modification of Zr propoxide with acetylacetone in 2-methoxyethanol results in Zr monomers. In PZT sol, clustering of Zr species is observed continuing into the amorphous film. By modification with acetic acid the original dimeric structure of the Zr precursor is retained in the PZT sol and further in the amorphous film. Selective modification of Zr propoxide with acetic acid therefore results in a more homogeneous distribution of Zr atoms in the PZT sol and amorphous film than in both as-received and acetylacetone-modified Zr propoxide.

The effectiveness of high dose zinc acetate lozenges on various common cold symptoms: a meta-analysis.

PubMed

Hemilä, Harri; Chalker, Elizabeth

2015-02-25

A previous meta-analysis found that high dose zinc acetate lozenges reduced the duration of common colds by 42%, whereas low zinc doses had no effect. Lozenges are dissolved in the pharyngeal region, thus there might be some difference in the effect of zinc lozenges on the duration of respiratory symptoms in the pharyngeal region compared with the nasal region. The objective of this study was to determine whether zinc acetate lozenges have different effects on the duration of common cold symptoms originating from different anatomical regions. We analyzed three randomized trials on zinc acetate lozenges for the common cold administering zinc in doses of 80-92 mg/day. All three trials reported the effect of zinc on seven respiratory symptoms, and three systemic symptoms. We pooled the effects of zinc lozenges for each symptom and calculated point estimates and 95% confidence intervals (95% CI). Zinc acetate lozenges shortened the duration of nasal discharge by 34% (95% CI: 17% to 51%), nasal congestion by 37% (15% to 58%), sneezing by 22% (-1% to 45%), scratchy throat by 33% (8% to 59%), sore throat by 18% (-10% to 46%), hoarseness by 43% (3% to 83%), and cough by 46% (28% to 64%). Zinc lozenges shortened the duration of muscle ache by 54% (18% to 89%), but there was no difference in the duration of headache and fever. The effect of zinc acetate lozenges on cold symptoms may be associated with the local availability of zinc from the lozenges, with the levels being highest in the pharyngeal region. However our findings indicate that the effects of zinc ions are not limited to the pharyngeal region. There is no indication that the effect of zinc lozenges on nasal symptoms is less than the effect on the symptoms of the pharyngeal region, which is more exposed to released zinc ions. Given that the adverse effects of zinc in the three trials were minor, zinc acetate lozenges releasing zinc ions at doses of about 80 mg/day may be a useful treatment for the common cold, started within 24 hours, for a time period of less than two weeks.

Plasma zinc's alter ego is a low-molecular-weight humoral factor.

PubMed

Ou, Ou; Allen-Redpath, Keith; Urgast, Dagmar; Gordon, Margaret-Jane; Campbell, Gill; Feldmann, Jörg; Nixon, Graeme F; Mayer, Claus-Dieter; Kwun, In-Sook; Beattie, John H

2013-09-01

Mild dietary zinc deprivation in humans and rodents has little effect on blood plasma zinc levels, and yet cellular consequences of zinc depletion can be detected in vascular and other tissues. We proposed that a zinc-regulated humoral factor might mediate the effects of zinc deprivation. Using a novel approach, primary rat vascular smooth muscle cells (VSMCs) were treated with plasma from zinc-deficient (<1 mg Zn/kg) or zinc-adequate (35 mg Zn/kg, pair-fed) adult male rats, and zinc levels were manipulated to distinguish direct and indirect effects of plasma zinc. Gene expression changes were analyzed by microarray and qPCR, and incubation of VSMCs with blood plasma from zinc-deficient rats strongly changed the expression of >2500 genes, compared to incubation of cells with zinc-adequate rat plasma. We demonstrated that this effect was caused by a low-molecular-weight (∼2-kDa) zinc-regulated humoral factor but that changes in gene expression were mostly reversed by adding zinc back to zinc-deficient plasma. Strongly regulated genes were overrepresented in pathways associated with immune function and development. We conclude that zinc deficiency induces the production of a low-molecular-weight humoral factor whose influence on VSMC gene expression is blocked by plasma zinc. This factor is therefore under dual control by zinc.

The significance of the source of zinc and its anti-VSC effect.

PubMed

Rölla, G; Jonski, G; Young, A

2002-06-01

The anti-VSC (volatile sulphur compounds) effect of zinc is known to be associated with free zinc ions. To examine whether zinc salts with low stability constants were more suitable as sources of zinc in zinc lozenges than zinc salts with high stability constants. The former provide free zinc ions upon dissolution in water, whereas the latter provide few such ions. Identical lozenges were produced which contained either zinc acetate, zinc gluconate (low stability constants), zinc citrate or amino-acid chelated zinc (extremely high stability constants). All the lozenges contained 0.1 per cent of zinc. A test panel of 10 volunteers used the different lozenges randomly. VSC were measured by GC. The lozenge with the highest stability constant was as effective as those with very low stability constants. The anti-VSC effect was thus not related to this constant. These findings may be explained by the possibility that alternative ligands with stronger affinity for zinc than the original ligands in the lozenges may be present in the oral cavity. An in vitro experiment indicated that the sulphide ion (S2-) may be such a ligand.

New polymer systems: Chain extension by dianhydrides

NASA Technical Reports Server (NTRS)

Rhein, R. A.; Ingham, J. D.

1972-01-01

The results are presented for a systematic investigation on the use of anhydrides to prepare stable elastomeric materials for space use, under mild reaction conditions. The three anhydrides investigated were found to provide effective chain extension of hydroxy-terminated poly(alkylene oxides) and poly(butadienes). These were tetrahydrofuran tetracarboxylic dianhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic diahydride. The most effective catalyst investigated was ferric acetylacetonate, which resulted in chain extension at 333 K (60 C). One feature of these anhydride reactants is that they are difunctional as anhydrides, but tetrafunctional if conditions are selected that lead to reaction of all carboxyl groups. Therefore, chain extension can be effected and then followed by crosslinking via the residual carboxyl groups.

One-Step Facile Synthesis of Cobalt Phosphides for Hydrogen Evolution Reaction Catalysts in Acidic and Alkaline Medium.

PubMed

Sumboja, Afriyanti; An, Tao; Goh, Hai Yang; Lübke, Mechthild; Howard, Dougal Peter; Xu, Yijie; Handoko, Albertus Denny; Zong, Yun; Liu, Zhaolin

2018-05-09

Catalysts for hydrogen evolution reaction are in demand to realize the efficient conversion of hydrogen via water electrolysis. In this work, cobalt phosphides were prepared using a one-step, scalable, and direct gas-solid phosphidation of commercially available cobalt salts. It was found that the effectiveness of the phosphidation reaction was closely related to the state of cobalt precursors at the reaction temperature. For instance, a high yield of cobalt phosphides obtained from the phosphidation of cobalt(II) acetate was related to the good stability of cobalt salt at the phosphidation temperature. On the other hand, easily oxidizable salts (e.g., cobalt(II) acetylacetonate) tended to produce a low amount of cobalt phosphides and a large content of metallic cobalt. The as-synthesized cobalt phosphides were in nanostructures with large catalytic surface areas. The catalyst prepared from phosphidation of cobalt(II) acetate exhibited an improved catalytic activity as compared to its counterpart derived from phosphidation of cobalt(II) acetylacetonate, showing an overpotential of 160 and 175 mV in acidic and alkaline electrolytes, respectively. Both catalysts also displayed an enhanced long-term stability, especially in the alkaline electrolyte. This study illustrates the direct phosphidation behavior of cobalt salts, which serve as a good vantage point in realizing the large-scale synthesis of transition-metal phosphides for high-performance electrocatalysts.

1T1R Nonvolatile Memory with Al/TiO2/Au and Sol-Gel-Processed Insulator for Barium Zirconate Nickelate Gate in Pentacene Thin Film Transistor

PubMed Central

Lee, Ke-Jing; Chang, Yu-Chi; Lee, Cheng-Jung; Wang, Li-Wen; Wang, Yeong-Her

2017-01-01

A one-transistor and one-resistor (1T1R) architecture with a resistive random access memory (RRAM) cell connected to an organic thin-film transistor (OTFT) device is successfully demonstrated to avoid the cross-talk issues of only one RRAM cell. The OTFT device, which uses barium zirconate nickelate (BZN) as a dielectric layer, exhibits favorable electrical properties, such as a high field-effect mobility of 2.5 cm2/Vs, low threshold voltage of −2.8 V, and low leakage current of 10−12 A, for a driver in the 1T1R operation scheme. The 1T1R architecture with a TiO2-based RRAM cell connected with a BZN OTFT device indicates a low operation current (10 μA) and reliable data retention (over ten years). This favorable performance of the 1T1R device can be attributed to the additional barrier heights introduced by using Ni (II) acetylacetone as a substitute for acetylacetone, and the relatively low leakage current of a BZN dielectric layer. The proposed 1T1R device with low leakage current OTFT and excellent uniform resistance distribution of RRAM exhibits a good potential for use in practical low-power electronic applications. PMID:29232828

Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage.

PubMed

Hemilä, Harri

2017-05-01

To compare the efficacy of zinc acetate lozenges with zinc gluconate lozenges in common cold treatment and to examine the dose-dependency of the effect. Meta-analysis. Placebo-controlled zinc lozenge trials, in which the zinc dose was > 75 mg/day. The pooled effect of zinc lozenges on common cold duration was calculated by using inverse-variance random-effects method. Seven randomised trials with 575 participants with naturally acquired common colds. Duration of the common cold. The mean common cold duration was 33% (95% CI 21% to 45%) shorter for the zinc groups of the seven included trials. Three trials that used lozenges composed of zinc acetate found that colds were shortened by 40% and four trials that used zinc gluconate by 28%. The difference between the two salts was not significant: 12 percentage points (95% CI: -12 to + 36). Five trials used zinc doses of 80-92 mg/day, common cold duration was reduced by 33%, and two trials used zinc doses of 192-207 mg/day and found an effect of 35%. The difference between the high-dose and low-dose zinc trials was not significant: 2 percentage points (95% CI: -29 to + 32). Properly composed zinc gluconate lozenges may be as effective as zinc acetate lozenges. There is no evidence that zinc doses over 100 mg/day might lead to greater efficacy in the treatment of the common cold. Common cold patients may be encouraged to try zinc lozenges for treating their colds. The optimal lozenge composition and dosage scheme need to be investigated further.

Arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Xi; Zhou, Xixi; Du, Libo

2014-01-15

Inhibition of DNA repair is a recognized mechanism for arsenic enhancement of ultraviolet radiation-induced DNA damage and carcinogenesis. Poly(ADP-ribose) polymerase-1 (PARP-1), a zinc finger DNA repair protein, has been identified as a sensitive molecular target for arsenic. The zinc finger domains of PARP-1 protein function as a critical structure in DNA recognition and binding. Since cellular poly(ADP-ribosyl)ation capacity has been positively correlated with zinc status in cells, we hypothesize that arsenite binding-induced zinc loss from PARP-1 is equivalent to zinc deficiency in reducing PARP-1 activity, leading to inhibition of DNA repair. To test this hypothesis, we compared the effects ofmore » arsenite exposure with zinc deficiency, created by using the membrane-permeable zinc chelator TPEN, on 8-OHdG formation, PARP-1 activity and zinc binding to PARP-1 in HaCat cells. Our results show that arsenite exposure and zinc deficiency had similar effects on PARP-1 protein, whereas supplemental zinc reversed these effects. To investigate the molecular mechanism of zinc loss induced by arsenite, ICP-AES, near UV spectroscopy, fluorescence, and circular dichroism spectroscopy were utilized to examine arsenite binding and occupation of a peptide representing the first zinc finger of PARP-1. We found that arsenite binding as well as zinc loss altered the conformation of zinc finger structure which functionally leads to PARP-1 inhibition. These findings suggest that arsenite binding to PARP-1 protein created similar adverse biological effects as zinc deficiency, which establishes the molecular mechanism for zinc supplementation as a potentially effective treatment to reverse the detrimental outcomes of arsenic exposure. - Highlights: • Arsenite binding is equivalent to zinc deficiency in reducing PARP-1 function. • Zinc reverses arsenic inhibition of PARP-1 activity and enhancement of DNA damage. • Arsenite binding and zinc loss alter the conformation of zinc finger structure.« less

Zinc: health effects and research priorities for the 1990s.

PubMed Central

Walsh, C T; Sandstead, H H; Prasad, A S; Newberne, P M; Fraker, P J

1994-01-01

This review critically summarizes the literature on the spectrum of health effects of zinc status, ranging from symptoms of zinc deficiency to excess exposure. Studies on zinc intake are reviewed in relation to optimum requirements as a function of age and sex. Current knowledge on the biochemical properties of zinc which are critical to the essential role of this metal in biological systems is summarized. Dietary and physiological factors influencing the bioavailability and utilization of zinc are considered with special attention to interactions with iron and copper status. The effects of zinc deficiency and toxicity are reviewed with respect to specific organs, immunological and reproductive function, and genotoxicity and carcinogenicity. Finally, key questions are identified where research is needed, such as the risks to human health of altered environmental distribution of zinc, assessment of zinc status in humans, effects of zinc status in relation to other essential metals on immune function, reproduction, neurological function, and the cardiovascular system, and mechanistic studies to further elucidate the biological effects of zinc at the molecular level. PMID:7925188

A novel mechanism for the pyruvate protection against zinc-induced cytotoxicity: mediation by the chelating effect of citrate and isocitrate.

PubMed

Sul, Jee-Won; Kim, Tae-Youn; Yoo, Hyun Ju; Kim, Jean; Suh, Young-Ah; Hwang, Jung Jin; Koh, Jae-Young

2016-08-01

Intracellular accumulation of free zinc contributes to neuronal death in brain injuries such as ischemia and epilepsy. Pyruvate, a glucose metabolite, has been shown to block zinc neurotoxicity. However, it is largely unknown how pyruvate shows such a selective and remarkable protective effect. In this study, we sought to find a plausible mechanism of pyruvate protection against zinc toxicity. Pyruvate almost completely blocked cortical neuronal death induced by zinc, yet showed no protective effects against death induced by calcium (ionomycin, NMDA) or ferrous iron. Of the TCA cycle intermediates, citrate, isocitrate, and to a lesser extent oxaloacetate, protected against zinc toxicity. We then noted with LC-MS/MS assay that exposure to pyruvate, and to a lesser degree oxaloacetate, increased levels of citrate and isocitrate, which are known zinc chelators. While pyruvate added only during zinc exposure did not reduce zinc toxicity, citrate and isocitrate added only during zinc exposure, as did extracellular zinc chelator CaEDTA, completely blocked it. Furthermore, addition of pyruvate after zinc exposure substantially reduced intracellular zinc levels. Our results suggest that the remarkable protective effect of pyruvate against zinc cytotoxicity may be mediated indirectly by the accumulation of intracellular citrate and isocitrate, which act as intracellular zinc chelators.

Supplemental levels of iron and calcium interfere with repletion of zinc status in zinc-deficient animals.

PubMed

Jayalakshmi, S; Platel, Kalpana

2016-05-18

Negative interactions between minerals interfering with each other's absorption are of concern when iron and calcium supplements are given to pregnant women and children. We have previously reported that supplemental levels of iron and calcium inhibit the bioaccessibility of zinc, and compromise zinc status in rats fed diets with high levels of these two minerals. The present study examined the effect of supplemental levels of iron and calcium on the recovery of zinc status during a zinc repletion period in rats rendered zinc-deficient. Iron and calcium, both individually and in combination, significantly interfered with the recovery of zinc status in zinc deficient rats during repletion with normal levels of zinc in the diet. Rats maintained on diets containing supplemental levels of these two minerals had significantly lower body weight, and the concentration of zinc in serum and organs was significantly lower than in zinc-deficient rats not receiving the supplements. Iron and calcium supplementation also significantly inhibited the activity of zinc-containing enzymes in the serum as well as liver. Both iron and calcium independently exerted this negative effect on zinc status, while their combination seemed to have a more prominent effect, especially on the activities of zinc containing enzymes. This investigation is probably the first systematic study on the effect of these two minerals on the zinc status of zinc deficient animals and their recovery during repletion with normal amounts of zinc.

Zinc Levels Modulate Lifespan through Multiple Longevity Pathways in Caenorhabditis elegans

PubMed Central

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

2016-01-01

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

Non-hydroxyl radical mediated photochemical processes for dye degradation.

PubMed

Liu, Xitong; Song, Xiaojie; Zhang, Shujuan; Wang, Mengshu; Pan, Bingcai

2014-04-28

Using solar energy for the decontamination of wastewater is a promising solution to the water-energy nexus. Current advanced oxidation processes have an unsatisfactory efficiency in the treatment of dye wastewater due to the non-selectivity of hydroxyl radicals. More efficient photochemical approaches for dye degradation are highly needed. Three diketones, biacetyl, acetylacetone, and acetonylacetone, were proven to be potent activators for the photodecoloration of azo, triarylmethane and anthraquinone dyes. The photodegradation kinetics of Acid Orange 7 in the UV/diketone processes was much faster than that in the UV/H2O2 system. Photo-induced energy and electron transfer were possible mechanisms for dye degradation in the diketone systems. Adducts of dye and acetylacetone were identified, indicating a unique dye degradation route through adduct formation and decomposition. Unlike acting only as the target substrate of ˙OH in advanced oxidation processes, the dyes played vital roles in the UV/diketone processes. The findings here provide new insights for designing more efficient technologies for environmental remediation, based on diketone photochemistry.

ESI-MS studies of the reactions of novel platinum(II) complexes containing O,O'-chelated acetylacetonate and sulfur ligands with selected model proteins.

PubMed

Marzo, Tiziano; De Pascali, Sandra A; Gabbiani, Chiara; Fanizzi, Francesco P; Messori, Luigi; Pratesi, Alessandro

2017-08-01

A group of mixed-ligand Pt(II) complexes bearing acetylacetonate and sulphur ligands were recently developed in the University of Lecce as a new class of prospective anticancer agents that manifested promising pharma-cological properties in preliminary in vitro and in vivo tests. Though modelled on the basis of cisplatin, these Pt(II) complexes turned out to exhibit a profoundly distinct mode of action as they were found to act mainly on non-genomic targets rather than on DNA. Accordingly, we have explored here their reactions with two representative model proteins through an established ESI-MS procedure with the aim to describe their general interaction mechanism with protein targets. A pronounced reactivity with the tested proteins was indeed documented; the nature of the resulting metallodrug-protein interactions could be characterised in depth in the various cases. Preferential binding to protein targets compared to DNA is supported by independent ICP-OES measurements. The implications of these findings are discussed.

L-Lactide Ring-Opening Polymerization with Tris(acetylacetonate)Titanium(IV) for Renewable Material.

PubMed

Kim, Da Hee; Yoo, Ji Yun; Ko, Young Soo

2016-05-01

A new Ti-type of catalyst for L-lactide polymerization was synthesized by reaction of titanium(IV) isopropoxide (TTIP) with acetylacetone (AA). Moreover, PLA was prepared by the bulk ring-opening polymerization using synthesized Ti catalyst. Polymerization behaviors were examined depending on monomer/catalyst molar ratio, polymerization temperature and time. The structure of synthesized catalysts was verified with FT-IR and 1H NMR and the properties of poly(L-lactide) (PLLA) were examined by GPC, DSC and FT-IR. There existed about 30 minutes of induction time at the monomer/catalyst molar ratio of 300. The molecular weight (MW) increased as monomer/catalyst molar ratio increased. The MW increased almost linearly as polymerization progressed. Increasing polymerization temperature increased the molecular weight of PLLA as well as monomer/catalyst molar ratio. The melting point (T(m)) of polymers was in the range of 142 to 167 degrees C. Lower T(m) was expected to be resulted from relatively lower molecular weight.

Synthesis, characterization and biological studies of copper(II) complexes with 2-aminobenzimidazole derivatives

NASA Astrophysics Data System (ADS)

Joseph, J.; Suman, A.; Nagashri, K.; Joseyphus, R. Selwin; Balakrishnan, Nisha

2017-06-01

Novel series of four copper(II) complexes with 2-aminobenzimidazole derivatives (obtained from the Knoevenagel condensate of acetylacetone (obtained from acetylacetone and halogen substituted benzaldehydes) and 2-aminobenzimidazole) were synthesized. They were structurally characterized using elemental analysis, molar conductance, FAB mass, FT- IR, 1H &13C-NMR, UV-Vis., and EPR techniques. On the basis of analytical and spectral studies, the distorted square planar geometry was assigned for all the complexes. The antibacterial screening of the ligands and their copper complexes indicated that all the complexes showed higher anti microbial activities than the free ligands. Superoxide dismutase and antioxidant activities of the copper complexes have also been performed. In the electrochemical technique, the shift in ΔEp, E1/2 and Ipc values were explored for the interaction of the complexes with CT-DNA. During the electrolysis process, the present ligand system stabilizes unusual oxidation state of copper in the complexes. It is believed that the copper complexes with curcumin analogs may enhance chemotherapeutic behavior.

Zinc and Chlamydia trachomatis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugarman, B.; Epps, L.R.

1985-07-01

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

Efficacy of highly bioavailable zinc from fortified water: a randomized controlled trial in rural Beninese children.

PubMed

Galetti, Valeria; Kujinga, Prosper; Mitchikpè, Comlan Evariste S; Zeder, Christophe; Tay, Fabian; Tossou, Félicien; Hounhouigan, Joseph D; Zimmermann, Michael B; Moretti, Diego

2015-11-01

Zinc deficiency and contaminated water are major contributors to diarrhea in developing countries. Food fortification with zinc has not shown clear benefits, possibly because of low zinc absorption from inhibitory food matrices. We used a novel point-of-use water ultrafiltration device configured with glass zinc plates to produce zinc-fortified, potable water. The objective was to determine zinc bioavailability from filtered water and the efficacy of zinc-fortified water in improving zinc status. In a crossover balanced study, we measured fractional zinc absorption (FAZ) from the zinc-fortified water in 18 healthy Swiss adults using zinc stable isotopes and compared it with zinc-fortified maize porridge. We conducted a 20-wk double-blind randomized controlled trial (RCT) in 277 Beninese school children from rural settings who were randomly assigned to receive a daily portion of zinc-fortified filtered water delivering 2.8 mg Zn (Zn+filter), nonfortified filtered water (Filter), or nonfortified nonfiltered water (Pump) from the local improved supply, acting as the control group. The main outcome was plasma zinc concentration (PZn), and the 3 groups were compared by using mixed-effects models. Secondary outcomes were prevalence of zinc deficiency, diarrhea prevalence, and growth. Geometric mean (-SD, +SD) FAZ was 7-fold higher from fortified water (65.9%; 42.2, 102.4) than from fortified maize (9.1%; 6.0, 13.7; P < 0.001). In the RCT, a significant time-by-treatment effect on PZn (P = 0.026) and on zinc deficiency (P = 0.032) was found; PZn in the Zn+filter group was significantly higher than in the Filter (P = 0.006) and Pump (P = 0.025) groups. We detected no effect on diarrhea or growth, but our study did not have the duration and power to detect such effects. Consumption of filtered water fortified with a low dose of highly bioavailable zinc is an effective intervention in children from rural African settings. Large community-based trials are needed to assess the effectiveness of zinc-fortified filtered water on diarrhea and growth. These trials were registered at clinicaltrials.gov as NCT01636583 and NCT01790321. © 2015 American Society for Nutrition.

Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly:A randomized double-blind placebo-controlled trial

USDA-ARS?s Scientific Manuscript database

Background: Zinc is essential for the regulation of immune response. T cell function declines with age. Zinc supplementation has the potential to improve serum zinc concentrations and immunity of nursing home elderly with low serum zinc concentration. Objective: We aimed to determine the effect of ...

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Selective metallisation of diamonds with the aid of laser radiation

NASA Astrophysics Data System (ADS)

Shafeev, Georgii A.; Pimenov, S. M.; Lubnin, Evgenii N.; Smolin, A. A.; Konov, Vitalii I.; Laptev, V. A.

1995-02-01

An experimental investigation was made of laser activation of diamond surfaces (single crystals and polycrystalline diamond films) prior to electroless before catalytic deposition of metals from solutions. The activation was carried out by a copper vapour laser or a KrF excimer laser in two ways: decomposition of a thin film of palladium acetylacetonate and local laser stimulated modification of the diamond surface by laser evaporation. An ohmic contact (Cu or Ni) with an adhesive strength of 3 N mm-2 was formed and the spatial resolution achieved was 10 μm.

Role of nutritional zinc in the prevention of osteoporosis.

PubMed

Yamaguchi, Masayoshi

2010-05-01

Zinc is known as an essential nutritional factor in the growth of the human and animals. Bone growth retardation is a common finding in various conditions associated with dietary zinc deficiency. Bone zinc content has been shown to decrease in aging, skeletal unloading, and postmenopausal conditions, suggesting its role in bone disorder. Zinc has been demonstrated to have a stimulatory effect on osteoblastic bone formation and mineralization; the metal directly activates aminoacyl-tRNA synthetase, a rate-limiting enzyme at translational process of protein synthesis, in the cells, and it stimulates cellular protein synthesis. Zinc has been shown to stimulate gene expression of the transcription factors runt-related transcription factor 2 (Runx2) that is related to differentiation into osteoblastic cells. Moreover, zinc has been shown to inhibit osteoclastic bone resorption due to inhibiting osteoclast-like cell formation from bone marrow cells and stimulating apoptotic cell death of mature osteoclasts. Zinc has a suppressive effect on the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-induced osteoclastogenesis. Zinc transporter has been shown to express in osteoblastic and osteoclastic cells. Zinc protein is involved in transcription. The intake of dietary zinc causes an increase in bone mass. beta-Alanyl-L: -histidinato zinc (AHZ) is a zinc compound, in which zinc is chelated to beta-alanyl-L: -histidine. The stimulatory effect of AHZ on bone formation is more intensive than that of zinc sulfate. Zinc acexamate has also been shown to have a potent-anabolic effect on bone. The oral administration of AHZ or zinc acexamate has the restorative effect on bone loss under various pathophysiologic conditions including aging, skeletal unloading, aluminum bone toxicity, calcium- and vitamin D-deficiency, adjuvant arthritis, estrogen deficiency, diabetes, and fracture healing. Zinc compounds may be designed as new supplementation factor in the prevention and therapy of osteoporosis.

Zinc induces long-term upregulation of T-type calcium current in hippocampal neurons in vivo.

PubMed

Ekstein, Dana; Benninger, Felix; Daninos, Moshe; Pitsch, Julika; van Loo, Karen M J; Becker, Albert J; Yaari, Yoel

2012-11-15

Extracellular zinc can induce numerous acute and persistent physiological and toxic effects in neurons by acting at their plasma membrane or intracellularly following permeation or uptake into them. Zinc acutely and reversibly blocks T-type voltage-gated calcium current (I(CaT)), but the long-term effect of zinc on this current has not been studied. Because chemically induced status epilepticus (SE) results in the release of zinc into the extracellular space, as well as in a long-lasting increase in I(CaT) in CA1 pyramidal cells, we hypothesized that zinc may play a causative role in I(CaT) upregulation. We tested this hypothesis by monitoring for 18 days the effects of zinc and ibotenic acid (a neurotoxic agent serving as control for zinc), injected into the right lateral ventricle, on I(CaT) in rat CA1 pyramidal cells. Both zinc and ibotenic acid caused marked hippocampal lesions on the side of injection, but only minor damage to contralateral hippocampi. Zinc, but not ibotenic acid, caused upregulation of a nickel-sensitive I(CaT) in a subset of contralateral CA1 pyramidal cells, appearing 2 days after injection and lasting for about 2 weeks thereafter. In contrast, acute application of zinc to CA1 pyramidal cells promptly blocked I(CaT). These data indicate that extracellular zinc has a dual effect on I(CaT), blocking it acutely while causing its long-term upregulation. Through the latter effect, zinc may regulate the intrinsic excitability of principal neurons, particularly in pathological conditions associated with enhanced release of zinc, such as SE.

Effect of preventive zinc supplementation on linear growth in children under 5 years of age in developing countries: a meta-analysis of studies for input to the lives saved tool

PubMed Central

2011-01-01

Introduction Zinc plays an important role in cellular growth, cellular differentiation and metabolism. The results of previous meta-analyses evaluating effect of zinc supplementation on linear growth are inconsistent. We have updated and evaluated the available evidence according to Grading of Recommendations, Assessment, Development and Evaluation (GRADE) criteria and tried to explain the difference in results of the previous reviews. Methods A literature search was done on PubMed, Cochrane Library, IZiNCG database and WHO regional data bases using different terms for zinc and linear growth (height). Data were abstracted in a standardized form. Data were analyzed in two ways i.e. weighted mean difference (effect size) and pooled mean difference for absolute increment in length in centimeters. Random effect models were used for these pooled estimates. We have given our recommendations for effectiveness of zinc supplementation in the form of absolute increment in length (cm) in zinc supplemented group compared to control for input to Live Saves Tool (LiST). Results There were thirty six studies assessing the effect of zinc supplementation on linear growth in children < 5 years from developing countries. In eleven of these studies, zinc was given in combination with other micronutrients (iron, vitamin A, etc). The final effect size after pooling all the data sets (zinc ± iron etc) showed a significant positive effect of zinc supplementation on linear growth [Effect size: 0.13 (95% CI 0.04, 0.21), random model] in the developing countries. A subgroup analysis by excluding those data sets where zinc was supplemented in combination with iron showed a more pronounced effect of zinc supplementation on linear growth [Weighed mean difference 0.19 (95 % CI 0.08, 0.30), random model]. A subgroup analysis from studies that reported actual increase in length (cm) showed that a dose of 10 mg zinc/day for duration of 24 weeks led to a net a gain of 0.37 (±0.25) cm in zinc supplemented group compared to placebo. This estimate is recommended for inclusion in Lives Saved Tool (LiST) model. Conclusions Zinc supplementation has a significant positive effect on linear growth, especially when administered alone, and should be included in national strategies to reduce stunting in children < 5 years of age in developing countries. PMID:21501440

Suppressive effect of zinc ion on iNOS expression induced by interferon-gamma or tumor necrosis factor-alpha in murine keratinocytes.

PubMed

Yamaoka, J; Kume, T; Akaike, A; Miyachi, Y

2000-05-01

Zinc, an essential metal, is a critical component of zinc binding proteins such as zinc fingers, zinc enzymes and metallothioneins. Recently, evidence for its anti-inflammatory property in skin has been accumulating, as shown in the treatment of acne, alopecia and zinc deficiency. In cutaneous inflammations, a large amount of nitric oxide (NO) is produced through induction of inducible nitric oxide synthase (iNOS) under the influence of proinflammatory cytokines, resulting in tissue damages in skin, as clarified in other organs. Therefore, we asked if the effect of zinc on NO production and/or on iNOS expression in keratinocytes may explain the anti-inflammatory property of zinc in skin. Accordingly, we sought to determine in this study whether zinc ion may have effect on IFN-gamma or TNF-alpha induced NO production and iNOS expression in cultured murine keratinocytes. Ten microM of zinc ion remarkably suppressed cytokine-induced NO production in keratinocytes. Furthermore, zinc ion also suppressed cytokine-induced iNOS expression in the protein level as well as in the messenger RNA level. These results suggest the possibility that the suppressive effect of zinc ion on cytokine-induced NO production in keratinocytes may be in part implicated in the anti-inflammatory property of zinc in some of skin disorders.

Stereoselective Synthesis of Cyclometalated Iridium (III) Complexes: Characterization and Photophysical Properties

PubMed Central

Yang, Liangru; von Zelewsky, Alex; Nguyen, Huong P.; Muller, Gilles; Labat, Gaël; Stoeckli-Evans, Helen

2009-01-01

The stereoselective synthesis of a highly luminescent neutral Ir(III) complex comprising two bidentate chiral, cyclometalating phenylpyridine derivatives, and one acetylacetonate as ligands is described. The final complex and some intermediates were characterized by X-ray structural analysis, NMR-, CD-, and CPL-spectroscopy. PMID:20161195

Zinc as a Gatekeeper of Immune Function

PubMed Central

Wessels, Inga; Maywald, Martina; Rink, Lothar

2017-01-01

After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells. Zinc homeostasis is largely controlled via the expression and action of zinc “importers” (ZIP 1–14), zinc “exporters” (ZnT 1–10), and zinc-binding proteins. Anti-inflammatory and anti-oxidant properties of zinc have long been documented, however, underlying mechanisms are still not entirely clear. Here, we report molecular mechanisms underlying the development of a pro-inflammatory phenotype during zinc deficiency. Furthermore, we describe links between altered zinc homeostasis and disease development. Consequently, the benefits of zinc supplementation for a malfunctioning immune system become clear. This article will focus on underlying mechanisms responsible for the regulation of cellular signaling by alterations in zinc homeostasis. Effects of fast zinc flux, intermediate “zinc waves”, and late homeostatic zinc signals will be discriminated. Description of zinc homeostasis-related effects on the activation of key signaling molecules, as well as on epigenetic modifications, are included to emphasize the role of zinc as a gatekeeper of immune function. PMID:29186856

Development of multicomponent hybrid density functional theory with polarizable continuum model for the analysis of nuclear quantum effect and solvent effect on NMR chemical shift.

PubMed

Kanematsu, Yusuke; Tachikawa, Masanori

2014-04-28

We have developed the multicomponent hybrid density functional theory [MC_(HF+DFT)] method with polarizable continuum model (PCM) for the analysis of molecular properties including both nuclear quantum effect and solvent effect. The chemical shifts and H/D isotope shifts of the picolinic acid N-oxide (PANO) molecule in chloroform and acetonitrile solvents are applied by B3LYP electron exchange-correlation functional for our MC_(HF+DFT) method with PCM (MC_B3LYP/PCM). Our MC_B3LYP/PCM results for PANO are in reasonable agreement with the corresponding experimental chemical shifts and isotope shifts. We further investigated the applicability of our method for acetylacetone in several solvents.

Effects of zinc supplementation on diabetes mellitus: a systematic review and meta-analysis

PubMed Central

2012-01-01

The number of people with diabetes and pre-diabetes are exponentially increasing. Studies on humans have shown the beneficial effects of Zinc supplementation in patients with diabetes. The present study aims to systematically evaluate the literature and meta-analyze the effects of Zinc supplementation on diabetes. A systematic review of published studies reporting the effects of Zinc supplementations on diabetes mellitus was undertaken. The literature search was conducted in the following databases; PubMed, Web of Science and SciVerse Scopus. A meta-analysis of studies examining the effects of Zinc supplementation on clinical and biochemical parameters in patients with diabetes was performed. The total number of articles included in the present review is 25, which included 3 studies on type-1 diabetes and 22 studies on type-2 diabetes. There were 12 studies comparing the effects of Zinc supplementation on fasting blood glucose in patients with type-2 diabetes. The pooled mean difference in fasting blood glucose between Zinc supplemented and placebo groups was 18.13mg/dl (95%CI:33.85,2.41; p<0.05). 2-h post-prandial blood sugar also shows a similar distinct reduction in (34.87mg/dl [95%CI:75.44; 5.69]) the Zinc treated group. The reduction in HbA1c was 0.54% (95%CI:0.86;0.21) in the Zinc treated group. There were 8 studies comparing the effects of Zinc supplementation on lipid parameters in patients with type-2 diabetes. The pooled mean difference for total cholesterol between Zinc supplemented and placebo groups was 32.37mg/dl (95%CI:57.39,7.35; p<0.05). Low-density lipoprotein cholesterol also showed a similar distinct reduction in the Zinc treated group, the pooled mean difference from random effects analysis was 11.19mg/dl (95%CI:21.14,1.25; p<0.05). Studies have also shown a significant reduction in systolic and diastolic blood pressures after Zinc supplementation. This first comprehensive systematic review and meta-analysis on the effects of Zinc supplementation in patients with diabetes demonstrates that Zinc supplementation has beneficial effects on glycaemic control and promotes healthy lipid parameters. Further studies are required to identify the exact biological mechanisms responsible for these results. PMID:22515411

Zinc Acetate Lozenges May Improve the Recovery Rate of Common Cold Patients: An Individual Patient Data Meta-Analysis.

PubMed

Hemilä, Harri; Fitzgerald, James T; Petrus, Edward J; Prasad, Ananda

2017-01-01

A previous meta-analysis of 3 zinc acetate lozenge trials estimated that colds were on average 40% shorter for the zinc groups. However, the duration of colds is a time outcome, and survival analysis may be a more informative approach. The objective of this individual patient data (IPD) meta-analysis was to estimate the effect of zinc acetate lozenges on the rate of recovery from colds. We analyzed IPD for 3 randomized placebo-controlled trials in which 80-92 mg/day of elemental zinc were administered as zinc acetate lozenges to 199 common cold patients. We used mixed-effects Cox regression to estimate the effect of zinc. Patients administered zinc lozenges recovered faster by rate ratio 3.1 (95% confidence interval, 2.1-4.7). The effect was not modified by age, sex, race, allergy, smoking, or baseline common cold severity. On the 5th day, 70% of the zinc patients had recovered compared with 27% of the placebo patients. Accordingly, 2.6 times more patients were cured in the zinc group. The difference also corresponds to the number needed to treat of 2.3 on the 5th day. None of the studies observed serious adverse effects of zinc. The 3-fold increase in the rate of recovery from the common cold is a clinically important effect. The optimal formulation of zinc lozenges and an ideal frequency of their administration should be examined. Given the evidence of efficacy, common cold patients may be instructed to try zinc acetate lozenges within 24 hours of onset of symptoms. © The Author 2017. Published by Oxford University Press on behalf of Infectious Diseases Society of America.

Profiling of zinc altered gene expression in human prostate normal versus cancer cells: a time course study

PubMed Central

Lin, Shu-fei; Wei, Hua; Maeder, Dennis; Franklin, Renty B.; Feng, Pei

2010-01-01

We have demonstrated that zinc exposure induces apoptosis in human prostate cancer cells (PC-3) and benign hyperplasia cells (BPH), but not in normal prostate cells (HPR-1). However, the mechanisms underlying the effects of zinc on prostate cancer cell growth and zinc homeostasis remain unclear. To explore the zinc effect on gene expression profiles in normal (HPR-1) and malignant prostate cells (PC-3), we conducted a time course study of Zn treatment with microarray analysis. Microarray data were evaluated and profiled using computational approach for the primary and secondary data analyses. Final analyses were focused on the genes: 1. highly sensitive to zinc, 2. associated with zinc homeostasis, i.e. metallothioneins (MTs), solute zinc carriers (ZIPs) and zinc exporters (ZnTs), 3. relevant to several oncogenic pathways. Zinc-mediated mRNA levels of MT isotypes were further validated by semi-quantitative RT-PCR. Results showed that zinc effect on genome-wide expression patterns was cell type specific, and zinc appeared to have mainly down-regulatory effects on thousands of genes (1,953 in HPR-1; 3,534 in PC-3) with a threshold of ±2.5-fold, while fewer genes were up-regulated (872 in HPR-1; 571 in PC-3). The patterns of zinc effect on functional MT genes’ expression provided evidence for the cell-type dependent zinc accumulation and zinc-induced apoptosis in prostate cells. In PC-3 cells, zinc significantly up-regulated the expression of MT-1 isotypes -J and -M, denoted previously as “non-functional” MT genes, and now a depictive molecular structure of MT-1J was proposed. Examination of genes involved in oncogenic pathways indicated that certain genes, e.g. Fos, Akt1, Jak3 and PI3K were highly regulated by zinc with cell type specificity. This work provided an extensive database on zinc related prostate cancer research. The strategy of data analysis was devoted to find genes highly sensitive to Zn, and the genes associated with zinc accumulation and zinc-induced apoptosis. The results indicate that zinc regulation of gene expression is cell-type specific, and MT genes play important roles in prostate malignancy. PMID:19071009

Ketamine-induced behavioural and brain oxidative changes in mice: an assessment of possible beneficial effects of zinc as mono- or adjunct therapy.

PubMed

Onaolapo, Olakunle James; Ademakinwa, Olayemi Quyyom; Olalekan, Temitayo Opeyemi; Onaolapo, Adejoke Yetunde

2017-09-01

We studied the influence of zinc, haloperidol or olanzapine on neurobehaviour (open-field, radial arm maze and elevated plus maze) and brain antioxidant status in vehicle- or ketamine-treated mice, with the aim of ascertaining the potentials of zinc in counteracting ketamine's effects. Experiment 1 assessed the effects of zinc in healthy animals and the relative degrees of modulation of ketamine's effects by zinc, haloperidol or olanzapine, respectively. Experiment 2 assessed the modulation of ketamine's effects following co-administration of zinc with haloperidol or olanzapine. Male mice weighing 18-20 g each were used. Animals were pretreated with ketamine (except vehicle, zinc, haloperidol and olanzapine controls) for 10 days before commencement of 14-day treatment (day 11-24) with vehicle, zinc, haloperidol or olanzapine (alone or in combination). Ketamine injection also continued alongside zinc and/or standard drugs in the ketamine-treated groups. Zinc, haloperidol and olanzapine were administered by gavage. Treatments were given daily and behaviours assessed on days 11 and 24. On day 24, animals were sacrificed and whole brain homogenates used for estimation of glutathione, nitric oxide and malondialdehyde (MDA) levels. Ketamine increased open-field behaviours, nitric oxide and MDA levels, while it decreased working memory, social interaction and glutathione. Administration of zinc alone or in combination with haloperidol or olanzapine was associated with variable degrees of reversal of these effects. Zinc may have the potential of a possible therapeutic agent and/or adjunct in the reversal of schizophrenia-like changes in behaviour and brain oxidative status.

Dietary Zinc Deficiency Exaggerates Ethanol-Induced Liver Injury in Mice: Involvement of Intrahepatic and Extrahepatic Factors

PubMed Central

Sun, Xinguo; Song, Zhenyuan; McClain, Craig J.; Zhou, Zhanxiang

2013-01-01

Clinical studies have demonstrated that alcoholics have a lower dietary zinc intake compared to health controls. The present study was undertaken to determine the interaction between dietary zinc deficiency and ethanol consumption in the pathogenesis of alcoholic liver disease. C57BL/6N mice were subjected to 8-week feeding of 4 experimental liquid diets: (1) zinc adequate diet, (2) zinc adequate diet plus ethanol, (3) zinc deficient diet, and (4) zinc deficient diet plus ethanol. Ethanol exposure with adequate dietary zinc resulted in liver damage as indicated by elevated plasma alanine aminotransferase level and increased hepatic lipid accumulation and inflammatory cell infiltration. Dietary zinc deficiency alone increased hepatic lipid contents, but did not induce hepatic inflammation. Dietary zinc deficiency showed synergistic effects on ethanol-induced liver damage. Dietary zinc deficiency exaggerated ethanol effects on hepatic genes related to lipid metabolism and inflammatory response. Dietary zinc deficiency worsened ethanol-induced imbalance between hepatic pro-oxidant and antioxidant enzymes and hepatic expression of cell death receptors. Dietary zinc deficiency exaggerated ethanol-induced reduction of plasma leptin, although it did not affect ethanol-induced reduction of white adipose tissue mass. Dietary zinc deficiency also deteriorated ethanol-induced gut permeability increase and plasma endotoxin elevation. These results demonstrate, for the first time, that dietary zinc deficiency is a risk factor in alcoholic liver disease, and multiple intrahepatic and extrahepatic factors may mediate the detrimental effects of zinc deficiency. PMID:24155903

Zinc attenuates forskolin-stimulated electrolyte secretion without involvement of the enteric nervous system in small intestinal epithelium from weaned piglets.

PubMed

Feng, Zike; Carlson, Dorthe; Poulsen, Hanne Damgaard

2006-11-01

In a previous study, we found that secretagogue-stimulated electrolyte secretion was attenuated by dietary and serosal zinc in piglet small intestinal epithelium in Ussing chambers. Several studies show that the enteric nervous system (ENS) is involved in regulation of electrolyte and/or fluid transport in intestinal epithelium from many species. The aim of the present study is to examine the mechanisms behind the attenuating effect of zinc on electrolyte secretion and to study whether the ENS is involved in this effect of zinc in vitro. Twenty-four piglets (six litters of four piglets) were allocated randomly to one of two dietary treatments consisting of a basic diet supplemented with 100 mg zinc/kg (Zn(100)) or 2500 mg zinc/kg (Zn(2500)), as ZnO. All the piglets were killed at 5-6 days after weaning and in vitro experiments with small intestinal epithelium in Ussing chambers were carried out. Furthermore, zinc, copper, alkaline phosphatase (AP) and metallothionein (MT) in mucosa, liver, and plasma were measured. These measurements showed that zinc status was increased in the Zn(2500) compared to the Zn(100) fed piglets. The in vitro studies did not confirm previous findings of attenuating effects of dietary zinc and zinc in vitro on the 5-HT induced secretion. But it showed that the addition of zinc at the serosal side attenuated the forskolin (FSK) (cAMP-dependent) induced ion secretion in epithelium from piglets fed with Zn(100) diet. Blocking the ENS with lidocaine or hexamethonium apparently slightly reduced this effect of zinc in vitro, but did not remove the effect of zinc. Consequently, it is suggested that zinc attenuates the cAMP dependent ion secretion mainly due to an effect on epithelial cells rather than affecting the mucosal neuronal pathway.

Crosstalk between Zinc Status and Giardia Infection: A New Approach

PubMed Central

Astiazarán-García, Humberto; Iñigo-Figueroa, Gemma; Quihui-Cota, Luis; Anduro-Corona, Iván

2015-01-01

Zinc supplementation has been shown to reduce the incidence and prevalence of diarrhea; however, its anti-diarrheal effect remains only partially understood. There is now growing evidence that zinc can have pathogen-specific protective effects. Giardiasis is a common yet neglected cause of acute-chronic diarrheal illness worldwide which causes disturbances in zinc metabolism of infected children, representing a risk factor for zinc deficiency. How zinc metabolism is compromised by Giardia is not well understood; zinc status could be altered by intestinal malabsorption, organ redistribution or host-pathogen competition. The potential metal-binding properties of Giardia suggest unusual ways that the parasite may interact with its host. Zinc supplementation was recently found to reduce the rate of diarrhea caused by Giardia in children and to upregulate humoral immune response in Giardia-infected mice; in vitro and in vivo, zinc-salts enhanced the activity of bacitracin in a zinc-dose-dependent way, and this was not due to zinc toxicity. These findings reflect biological effect of zinc that may impact significantly public health in endemic areas of infection. In this paper, we shall explore one direction of this complex interaction, discussing recent information regarding zinc status and its possible contribution to the outcome of the encounter between the host and Giardia. PMID:26046395

The zinc pool is involved in the immune-reconstituting effect of melatonin in pinealectomized mice.

PubMed

Mocchegiani, E; Bulian, D; Santarelli, L; Tibaldi, A; Muzzioli, M; Lesnikov, V; Pierpaoli, W; Fabris, N

1996-06-01

Melatonin (MEL) affects the immune system by direct or indirect mechanisms. An involvement of the zinc pool in the immune-reconstituting effect of MEL in old mice has recently been documented. An altered zinc turnover and impaired immune functions are also evident in pinealectomized (px) mice. The present work investigates further the effect of "physiological" doses of MEL on the zinc pool and on thymic and peripheral immune functions in px mice. Daily injections of MEL (100 micrograms/mouse) for 1 month in px mice restored the crude zinc balance from negative to positive values. Thymic and peripheral immune functions, including plasma levels of interleukin-2, also recovered. The nontoxic effect of MEL on immune functions was observed in sham-operated mice. Because the half-life of MEL is very short (12 min), interruption of MEL treatment in px mice resulted, after 1 month, in a renewed negative crude zinc balance and a regression of immune functions. Both the zinc pool and immunological parameters were restored by 30 further days of MEL treatment. The existence of a significant correlation between zinc and thymic hormone after both cycles of MEL treatment clearly shows an involvement of the zinc pool in the immunoenhancing effects of MEL and thus suggests an inter-relationship between zinc and MEL in px mice. Moreover, the existence of significant positive correlations between zinc or thymulin and interleukin-2 suggests that interleukin-2 may participate in the action of MEL, via zinc, on thymic functions in px MEL-treated mice.

Interaction of zinc with dental mineral.

PubMed

Ingram, G S; Horay, C P; Stead, W J

1992-01-01

As some currently available toothpastes contain zinc compounds, the reaction of zinc with dental mineral and its effect on crystal growth rates were studied using three synthetic calcium-deficient hydroxyapatites (HAP) as being representative of dental mineral. Zinc was readily acquired by all HAP samples in the absence of added calcium, the amount adsorbed being proportional to the HAP surface area; about 9 mumol Zn/m2 was adsorbed at high zinc concentrations. As zinc was acquired, calcium was released, consistent with 1:1 Ca:Zn exchange. Soluble calcium reduced zinc uptake and similarly, calcium post-treatment released zinc. Pretreatment of HAP with 0.5 mM zinc reduced its subsequent ability to undergo seeded crystal growth, as did extracts of a toothpaste containing 0.5% zinc citrate, even in the presence of saliva. The reverse reaction, i.e. displacement of adsorbed zinc by salivary levels of calcium, however, indicates the mechanism by which zinc can reduce calculus formation in vivo by inhibiting plaque mineralisation without adversely affecting the anti-caries effects of fluoride.

Involvement of l-arginine-nitric oxide pathway in anxiolytic-like effects of zinc chloride in rats.

PubMed

Navabi, Seyedeh Parisa; Eshagh Harooni, Hooman; Moazedi, Ahmad Ali; Khajepour, Lotfolah; Fathinia, Kosar

2016-10-01

Zinc is crucial for normal development of the brain, and Zinc deficiency has been shown to associate with neurological disorders (e.g. anxiety) through interactions with several neurotransmitter systems such as nitric oxide (NO). In this regard, our study aimed to evaluate the possible involvement of l-arginine NO pathway on anxiolytic effects of zinc in adult male rats. Zinc chloride at doses of 2.5 and 10mg/kg (intraperitoneal or ip) or saline (1ml/kg, ip) were injected 30min before the anxiety test. Zinc administrated rats (10mg/kg) were pre-treated with intra-CA1 microinjection of l-arginine in sub-effective dose of 1μg/rat (dorsal hippocampus, vehicle: saline1μl/rat). In addition, zinc chloride and NG-nitro-l-arginine methyl ester (l-NAME) were intraperitoneally co-administrated in sub-effective doses of 2.5mg/kg and 80mg/kg, respectively. The percentage of open arm time (OAT%), percentage of open arm entry (OAE%), as measures of anxiety, and total number of arm entries, as measures of locomotor activity, were recorded. Treatment with zinc (10mg/kg) markedly produced an increase in OAT% and OAE% in the Elevated plus maze test (EPM). A decrease of OAT% and OAE% was shown in groups which received zinc (10mg/kg) and l-arginine (1μg/rat) concomitantly as compared to the control group. Moreover, an increase of OAE% was revealed in the group exposed to Zinc (2.5mg/kg) and l-NAME (80mg/kg) co-administration. Although, Two-way ANOVA showed no significant differences of anxiety indices in rats received drug+zinc chloride in compare to the zinc pretreated with saline group. Anxiolytic- like effect of zinc reversed by nitric oxide precursor l-arginine. Additionally, the synergistic effects of l-NAME and ZnCl 2 were shown in the EPM. Thus our findings suggest that at least in part the anxiolytic effects of zinc can be mediated through the nitric oxide system. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Metal-Acetylacetonate Synthesis Experiments: Which Is Greener?

ERIC Educational Resources Information Center

Ribeiro, M. Gabriela T. C.; Machado, Adlio A. S. C.

2011-01-01

A procedure for teaching green chemistry through laboratory experiments is presented in which students are challenged to use the 12 principles of green chemistry to review and modify synthesis protocols to improve greenness. A global metric, green star, is used in parallel with green chemistry mass metrics to evaluate the improvement in greenness.…

Corrigendum to "Electronic structure and photoelectron spectra of nickel (II) acetylacetonate and its thio- and amino-substituted analogues" [J. Mol. Struct. 1099 (2015) 579-587

NASA Astrophysics Data System (ADS)

Vovna, Vitaliy I.; Korochentsev, Vladimir V.; Komissarov, Alexander A.; L'vov, Igor B.; Myshakina, Nataliya S.

2016-01-01

The authors regret to inform that it was given erroneous spelling of Vitaliy I. Vovna author name in the published version of the article. It was written "Vitaliy V. Vovna" instead of "Vitaliy I. Vovna".

Phenanthridine synthesis through iron-catalyzed intramolecular N-arylation of O-acetyl oxime.

PubMed

Deb, Indubhusan; Yoshikai, Naohiko

2013-08-16

O-Acetyl oximes derived from 2'-arylacetophenones undergo N-O bond cleavage/intramolecular N-arylation in the presence of a catalytic amount of iron(III) acetylacetonate in acetic acid. In combination with the conventional cross-coupling or directed C-H arylation, the reaction offers a convenient route to substituted phenanthridines.

Synthesis, spectral, thermal and optical properties of Schiff-base complexes derived from 2(E)-2-((z)-4-hydroxypent-3-en-2-ylideneamino)-5-guanidinopentanoic acid and acetylacetone

NASA Astrophysics Data System (ADS)

Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

2017-09-01

New metal complexes derived from the in situ reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H2L) resulted from the condensation of 2-amino-5-guanidinopentanoic acid (arginine) and acetylacetone have been synthesized. The resulting complexes have been characterized by, elemental analyses, ES-MS, IR, Raman spectra, UV-Vis., 1HNMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that, The Schiff-base ligand acts as bi-negative tridentate coordinating via azomethine nitrogen, enolic carbonyl oxygen and carboxylate oxygen after displacement of hydrogen. The thermodynamic parameters E∗, ΔH, ΔG and ΔS of the isolated complexes have been calculated. The optical band gap (Eg) values of Cu, Co, Ni and Zn were found to be 3.3, 3.4, 3.7 and 4.3 eV, respectively, arising from direct transitions. Optical band gap measurements indicate the semi-conductivity nature of these complexes.

Nano-sized, quaternary titanium(IV) metal-organic frameworks with multidentate ligands.

PubMed

Baranwal, Balram Prasad; Singh, Alok Kumar

2010-12-01

Some mononuclear nano-sized, quaternary titanium(IV) complexes having the general formula [Ti(acac)(OOCR)2(SB)] (where Hacac=acetylacetone, R=C15H31 or C17H35, HSB=Schiff bases) have been synthesized using different multidentate ligands. These were characterized by elemental analyses, molecular weight determinations and spectral (FTIR, 1H NMR and powder XRD) studies. Conductance measurement indicated their non-conducting nature which may behave like insulators. Structural parameters like the values of limiting indices h, k, l, cell constants a, b, c, angles α, β, γ and particle size are calculated from powder XRD data for complex 1 which indicated nano-sized triclinic system in them. Bidentate chelating nature of acetylacetone, carboxylate and Schiff base anions in the complexes was established by their infrared spectra. Molecular weight determinations confirmed mononuclear nature of the complexes. On the basis of physico-chemical studies, coordination number 8 was assigned for titanium(IV) in the complexes. Transmission electron microscopy (TEM) and the selected area electron diffraction (SAED) studies indicated spherical particles with poor crystallinity. Copyright © 2010 Elsevier B.V. All rights reserved.

Synthesis, spectral characterization and DNA binding of Schiff-base metal complexes derived from 2-amino-3-hydroxyprobanoic acid and acetylacetone

NASA Astrophysics Data System (ADS)

Hosny, Nasser Mohammed; Hussien, Mostafa A.; Radwan, Fatima M.; Nawar, Nagwa

2014-11-01

Four new metal complexes derived from the reaction of Cu(II), Co(II), Ni(II) and Zn(II) acetates with the Schiff-base ligand (H3L) resulted from the condensation of the amino acid 2-amino-3-hydroxyprobanoic acid (serine) and acetylacetone have been synthesized and characterized by, elemental analyses, ES-MS, IR, UV-Vis., 1H NMR, 13C NMR, ESR, thermal analyses (TGA and DTG) and magnetic measurements. The results showed that the Schiff-base ligand acts as bi-negative tridentate through the azomethine nitrogen, the deprotonated carboxylate oxygen and the enolic carbonyl oxygen. The optical band gaps measurements indicated the semi-conducting nature of these complexes. Molecular docking was used to predict the binding between the Schiff base ligand with the receptor of prostate cancer mutant H874Y. The interactions between the Cu(II) complex and calf thymus DNA (CT-DNA) have been studied by UV spectra. The results confirm that the Cu(II) complex binds to CT-DNA in an intercalative mode.

High performance polymer solar cells with as-prepared zirconium acetylacetonate film as cathode buffer layer

PubMed Central

Tan, Zhan'ao; Li, Shusheng; Wang, Fuzhi; Qian, Deping; Lin, Jun; Hou, Jianhui; Li, Yongfang

2014-01-01

Low-work-function active metals are commonly used as cathode in polymer solar cells (PSCs), but sensitivity of the active metals towards moisture and oxygen results in poor stability of the devices. Therefore, solution-proceessable and stable cathode buffer layer is of great importance for the application of PSCs. Here we demonstrate high performance PSCs by employing as-prepared zirconium acetylacetonate (a-ZrAcac) film spin-cast from its ethanol solution as cathode buffer layer. The PSCs based on a low bandgap polymer PBDTBDD as donor and PC60BM as acceptor with a-ZrAcac/Al cathode demonstrated an average power conversion efficiency (PCE) of 8.75% which is significantly improved than that of the devices with traditional Ca/Al cathode. The improved photovoltaic performance is benefitted from the decreased series resistance and enhanced light harvest of the PSCs with the a-ZrAcac/Al cathode. The results indicate that a-ZrAcac is a promising high performance cathode buffer layer for fabricating large area flexible PSCs. PMID:24732976

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

PubMed

Tripathi, Bhumika; Platel, Kalpana

2010-01-01

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

Calcium, Iron, and Zinc Bioaccessibilities of Australian Sweet Lupin (Lupinus angustifolius L.) Cultivars.

PubMed

Karnpanit, Weeraya; Coorey, Ranil; Clements, Jon; Benjapong, Wenika; Jayasena, Vijay

2017-06-14

In this study, we aimed to determine the effect of the cultivar and dehulling on calcium, iron, and zinc bioaccessibilities of Australian sweet lupin (ASL). Ten ASL cultivars grown in 2011, 2012, and 2013 in Western Australia were used for the study. The bioaccessibilities of calcium, iron, and zinc in whole seed and dehulled lupin samples were determined using a dialysability method. The cultivar had significant effects on calcium, iron, and zinc contents and their bioaccessibilities. Average bioaccessibilities of 6% for calcium, 17% for iron, and 9% for zinc were found for whole seeds. Dehulled ASL had average calcium, iron, and zinc bioaccessibilities of 11%, 21%, and 12%, respectively. Compared to some other pulses, ASL had better iron bioaccessibility and poorer calcium and zinc bioaccessibilities. Dehulling increased calcium bioaccessibilities of almost all lupin cultivars. The effect of dehulling on iron and zinc bioaccessibilities depends on the ASL cultivar.

Reverse saturable absorption (RSA) in fluorinated iridium derivatives

NASA Astrophysics Data System (ADS)

Ferry, Michael J.; O'Donnell, Ryan M.; Bambha, Neal; Ensley, Trenton R.; Shensky, William M.; Shi, Jianmin

2017-08-01

The photophysical properties of cyclometallated iridium compounds are beneficial for nonlinear optical (NLO) applications, such as the design of reverse saturable absorption (RSA) materials. We report on the NLO characterization of a family of compounds of the form [Ir(pbt)2(LX)], where pbt is 2-phenylbenzothiazole and LX is a beta-diketonate ligand. In particular, we investigate the effects of trifluoromethylation on compound solubility and photophysics compared to the parent acetylacetonate (acac) version. The NLO properties, such as the singlet and triplet excited-state cross sections, of these compounds were measured using the Z-scan technique. The excited-state lifetimes were determined from visible transient absorption spectroscopy.

Incorporation of zinc oxide nanoparticles into chitosan-collagen 3D porous scaffolds: Effect on morphology, mechanical properties and cytocompatibility of 3D porous scaffolds.

PubMed

Ullah, Saleem; Zainol, Ismail; Idrus, Ruszymah Hj

2017-11-01

The zinc oxide nanoparticles (particles size <50nm) incorporated into chitosan-collagen 3D porous scaffolds and investigated the effect of zinc oxide nanoparticles incorporation on microstructure, mechanical properties, biodegradation and cytocompatibility of 3D porous scaffolds. The 0.5%, 1.0%, 2.0% and 4.0% zinc oxide nanoparticles chitosan-collagen 3D porous scaffolds were fabricated via freeze-drying technique. The zinc oxide nanoparticles incorporation effects consisting in chitosan-collagen 3D porous scaffolds were investigated by mechanical and swelling tests, and effect on the morphology of scaffolds examined microscopically. The biodegradation and cytocompatibility tests were used to investigate the effects of zinc oxide nanoparticles incorporation on the ability of scaffolds to use for tissue engineering application. The mean pore size and swelling ratio of scaffolds were decreased upon incorporation of zinc oxide nanoparticles however, the porosity, tensile modulus and biodegradation rate were increased upon incorporation of zinc oxide nanoparticles. In vitro culture of human fibroblasts and keratinocytes showed that the zinc oxide nanoparticles facilitated cell adhesion, proliferation and infiltration of chitosan-collagen 3D porous scaffolds. It was found that the zinc oxide nanoparticles incorporation enhanced porosity, tensile modulus and cytocompatibility of chitosan-collagen 3D porous scaffolds. Copyright © 2017 Elsevier B.V. All rights reserved.

Protective effect of zinc against ischemic neuronal injury in a middle cerebral artery occlusion model.

PubMed

Kitamura, Youji; Iida, Yasuhiko; Abe, Jun; Ueda, Masashi; Mifune, Masaki; Kasuya, Fumiyo; Ohta, Masayuki; Igarashi, Kazuo; Saito, Yutaka; Saji, Hideo

2006-02-01

In this study, we investigated the effect of vesicular zinc on ischemic neuronal injury. In cultured neurons, addition of a low concentration (under 100 microM) of zinc inhibited both glutamate-induced calcium influx and neuronal death. In contrast, a higher concentration (over 150 microM) of zinc decreased neuronal viability, although calcium influx was inhibited. These results indicate that zinc exhibits biphasic effects depending on its concentration. Furthermore, in cultured neurons, co-addition of glutamate and CaEDTA, which binds extra-cellular zinc, increased glutamate-induced calcium influx and aggravated the neurotoxicity of glutamate. In a rat transient middle cerebral artery occlusion (MCAO) model, the infarction volume, which is related to the neurotoxicity of glutamate, increased rapidly on the intracerebral ventricular injection of CaEDTA 30 min prior to occlusion. These results suggest that zinc released from synaptic vesicles may provide a protective effect against ischemic neuronal injury.

Zinc activates damage-sensing TRPA1 ion channels.

PubMed

Hu, Hongzhen; Bandell, Michael; Petrus, Matt J; Zhu, Michael X; Patapoutian, Ardem

2009-03-01

Zinc is an essential biological trace element. It is required for the structure or function of over 300 proteins, and it is increasingly recognized for its role in cell signaling. However, high concentrations of zinc have cytotoxic effects, and overexposure to zinc can cause pain and inflammation through unknown mechanisms. Here we show that zinc excites nociceptive somatosensory neurons and causes nociception in mice through TRPA1, a cation channel previously shown to mediate the pungency of wasabi and cinnamon through cysteine modification. Zinc activates TRPA1 through a unique mechanism that requires zinc influx through TRPA1 channels and subsequent activation via specific intracellular cysteine and histidine residues. TRPA1 is highly sensitive to intracellular zinc, as low nanomolar concentrations activate TRPA1 and modulate its sensitivity. These findings identify TRPA1 as an important target for the sensory effects of zinc and support an emerging role for zinc as a signaling molecule that can modulate sensory transmission.

Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells.

PubMed

Krýsová, Hana; Krýsa, Josef; Kavan, Ladislav

2018-01-01

For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO 2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO 2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20-200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO 2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO 2 films. The blocking properties of the as-deposited TiO 2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO 2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar cells.

A novel mass spectrometric method for formaldehyde in children's personal-care products and water via derivatization with acetylacetone.

PubMed

Backe, Will J

2017-06-30

New legislation in the state of Minnesota prohibits the sale of children's personal-care products (PCPs) that contain more than 500 ng/mg formaldehyde. Previous attempts to quantify formaldehyde in PCPs use nonspecific derivatization procedures that employ harsh reagents and/or nonspecific detection. Derivatization of formaldehyde by acetylacetone occurs under mild conditions and is specific for formaldehyde but it has not been investigated using high-performance liquid chromatography/tandem mass-spectrometry (HPLC/MS/MS). To determine formaldehyde, PCPs were dissolved and then interferences were minimized by graphitized-carbon solid-phase extraction. Formaldehyde was derivatized to 3,5-diacetyl-1,4-dihydrolutidine (DDL) using an acetylacetone solution. Post-derivatization, samples were diluted and analyzed by HPLC/MS/MS. Quantification was performed by isotopic dilution. Product-ion spectra were acquired for DDL and D 12 -DDL. The mass shifts between the two product-ion spectra were used to assign fragment structures. To confirm molecular formulas, high-resolution accurate-mass analysis of the DDL product ions was performed by quadrupole time-of-flight MS. Structures were proposed for all product ions of DDL above 10% relative intensity. Method accuracy ranged between 96-104% for all matrices at all concentrations tested. Method precision was less than 4% relative standard deviation. The reporting limit was 10 ng/mg in PCPs and 100 μg/L in water. Twenty children's PCPs were tested to demonstrate the method and formaldehyde was reported in five from 23-1500 ng/mg. Of those five, two samples contained formaldehyde above the Minnesota regulatory limit. The developed method allows for the accurate quantification of formaldehyde in PCPs at levels below those required by a new regulation on children's products in Minnesota. The method includes a derivatization procedure that is newly adapted to HPLC/MS/MS; therefore, structures were proposed for the product ions of the derivative (DDL). Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

The effect of different mouth rinse products on intra-oral halitosis.

PubMed

Erovic Ademovski, S; Lingström, P; Renvert, S

2016-05-01

To evaluate the effect of different mouth rinses 12 h after rinsing on genuine intra-oral halitosis. Twenty-four adults with halitosis were included in a double-blind, crossover, randomized clinical trial. Halitosis was evaluated 12 h after rinsing with placebo and five mouth rinse products containing zinc acetate and chlorhexidine diacetate; zinc lactate, chlorhexidine and cetylpyridinium chloride; zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol; zinc chloride and essential oil; and chlorine dioxide using the organoleptic method and a gas chromatograph. Test periods were separated by 1 week. Hydrogen sulphide (H2 S), methyl mercaptan (MM) and the organoleptic scores (OLS) were significantly reduced 12 h following rinsing with all substances compared to placebo (P < 0.05). H2 S was more effectively reduced after rinsing with zinc acetate and chlorhexidine diacetate and zinc acetate and chlorhexidine diacetate with reduced amounts of mint and menthol compared to rinsing with zinc chloride and essential oil (P < 0.05), and significantly lower values of MM were obtained after rinsing with zinc acetate and chlorhexidine diacetate compared to zinc lactate, chlorhexidine and cetylpyridinium chloride (P < 0.05). The percentage effectively treated individuals (H2 S (<112 ppb), MM (<26 ppb) and OLS score <2) varied from 58% percentage (zinc acetate and chlorhexidine diacetate) to 26% (zinc chloride and essential oil). All treatments resulted in reduction in halitosis 12 h after rinsing compared to placebo. H2 S and MM were most effectively reduced by zinc acetate and chlorhexidine diacetate. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A dynamic model for predicting growth in zinc-deficient stunted infants given supplemental zinc.

PubMed

Wastney, Meryl E; McDonald, Christine M; King, Janet C

2018-05-01

Zinc deficiency limits infant growth and increases susceptibility to infections, which further compromises growth. Zinc supplementation improves the growth of zinc-deficient stunted infants, but the amount, frequency, and duration of zinc supplementation required to restore growth in an individual child is unknown. A dynamic model of zinc metabolism that predicts changes in weight and length of zinc-deficient, stunted infants with dietary zinc would be useful to define effective zinc supplementation regimens. The aims of this study were to develop a dynamic model for zinc metabolism in stunted, zinc-deficient infants and to use that model to predict the growth response when those infants are given zinc supplements. A model of zinc metabolism was developed using data on zinc kinetics, tissue zinc, and growth requirements for healthy 9-mo-old infants. The kinetic model was converted to a dynamic model by replacing the rate constants for zinc absorption and excretion with functions for these processes that change with zinc intake. Predictions of the dynamic model, parameterized for zinc-deficient, stunted infants, were compared with the results of 5 published zinc intervention trials. The model was then used to predict the results for zinc supplementation regimes that varied in the amount, frequency, and duration of zinc dosing. Model predictions agreed with published changes in plasma zinc after zinc supplementation. Predictions of weight and length agreed with 2 studies, but overpredicted values from a third study in which other nutrient deficiencies may have been growth limiting; the model predicted that zinc absorption was impaired in that study. The model suggests that frequent, smaller doses (5-10 mg Zn/d) are more effective for increasing growth in stunted, zinc-deficient 9-mo-old infants than are larger, less-frequent doses. The dose amount affects the duration of dosing necessary to restore and maintain plasma zinc concentration and growth.

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

USDA-ARS?s Scientific Manuscript database

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...

Effect of dietary proteins on zinc bioavailability in pregnant rats.

PubMed

Uenishi, K; Horio, H; Manabe, S; Sakamoto, S

1993-12-01

In order to clarify the effects of dietary proteins on zinc bioavailability during pregnancy, two experiments were carried out. In Experiment 1, changes in zinc retention due to pregnancy (difference in retention between pregnant and nonpregnant animals) during early-mid and late pregnancy were examined in rats fed 10 and 20% egg white diets. Total amounts of retained zinc due to pregnancy were about 1000 micrograms or slightly more, equal to the zinc content in the products of conception at term. However, extra zinc retention during late pregnancy ranged between only 20 to 40% of overall retention, suggesting that almost all zinc retained during early-mid pregnancy moved from the mothers to the fetuses near term. Zinc retention in early-mid and late periods of pregnancy was higher in pregnant than nonpregnant rats, due mainly to increases in intake and bioavailability. In Experiment 2, to examine the effects of quality and quantity of dietary proteins, pregnant rats were fed either 10 or 20% egg white (EW), whole egg (WE), casein (C) and soy protein isolate with or without methionine (SM and S, respectively) diets. Total zinc retention during pregnancy was affected by both zinc and nitrogen intakes, though the former effect was greater than the latter. Because rats fed the EW diets retained dietary zinc efficiently, a relationship between zinc retention (Y, microgram/100 g BW/21 d.) and zinc intake (X, microgram/100 g BW/21 d.) was also examined in the non-EW protein groups, resulting in the following regression equation: Y = 0.471X-1790 (n: 51, r = 0.81, p < 0.001). Dietary protein quality affected the food intake resulting in different zinc intake and retention during pregnancy. Zinc from EW diets was more available than from the other four protein diets, because similar plots for rats fed the 10 and 20% EW diets fell above this line. Reasons for efficient bioavailability of zinc in EW were discussed in connection with the forms of zinc in diets and the pancreatic or intestinal responses to ingested EW.

[Health hazards resulting from exposure to zinc and its inorganic compounds in industry].

PubMed

Pakulska, Daria; Czerczak, Sławomir

2017-10-17

This article deals with health risks resulting from exposure to zinc and its inorganic compounds in industry. The main source of zinc exposure are fumes generated during thermal and chemical processes, mainly zinc oxide fume formed by immediate oxidation of metallic zinc vapor formed during high-temperature processes, as well as dust generated during the mechanical processing of zinc-containing materials. It is recognized that zinc ions are responsible for health effects of exposure to dust/fumes of the majority of zinc compounds, and the final effect of exposure depends on the degree of dispersion of dusts/fumes suspended in the air. Since the effects of exposure depends on the particle size, occupational exposure limits have began to be established separately for respirable and inhalable fractions. A critical effect of acute exposure to respirable fraction is a "fume fever" which in chronic exposure occurs as an effect associated with recurrent symptoms of acute poisoning. Impaired lung function and asthma symptoms are considered to be the main effects of exposure to inhalable fraction. Due to the limited number of the available data it is not possible to assess carcinogenicity, reproductive toxicity and teratogenicity of zinc and its compounds. The aim of the study was to analyze the major health hazards resulting from occupational exposure to zinc and its inorganic compounds in the context of their physico-chemical properties, a wide range of applications and occupational exposure data. Med Pr 2017;68(6):779-794. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Removal of lead and zinc ions from water by low cost adsorbents.

PubMed

Mishra, P C; Patel, R K

2009-08-30

In this study, activated carbon, kaolin, bentonite, blast furnace slag and fly ash were used as adsorbent with a particle size between 100 mesh and 200 mesh to remove the lead and zinc ions from water. The concentration of the solutions prepared was in the range of 50-100 mg/L for lead and zinc for single and binary systems which are diluted as required for batch experiments. The effect of contact time, pH and adsorbent dosage on removal of lead and zinc by adsorption was investigated. The equilibrium time was found to be 30 min for activated carbon and 3h for kaolin, bentonite, blast furnace slag and fly ash. The most effective pH value for lead and zinc removal was 6 for activated carbon. pH value did not effect lead and zinc removal significantly for other adsorbents. Adsorbent doses were varied from 5 g/L to 20 g/L for both lead and zinc solutions. An increase in adsorbent doses increases the percent removal of lead and zinc. A series of isotherm studies was undertaken and the data evaluated for compliance was found to match with the Langmuir and Freundlich isotherm models. To investigate the adsorption mechanism, the kinetic models were tested, and it follows second order kinetics. Kinetic studies reveals that blast furnace slag was not effective for lead and zinc removal. The bentonite and fly ash were effective for lead and zinc removal.

Possible role of zinc in diminishing lead-related occupational stress-a zinc nutrition concern.

PubMed

Wani, Ab Latif; Ahmad, Ajaz; Shadab, G G H A; Usmani, Jawed Ahmad

2017-03-01

Lead and zinc are mostly present at the same occupational source and usually found as co-contaminants. Lead is known to associate with detrimental effects to humans. Zinc however is an essential nutrient and its deficiency causes debilitating effects on growth and development. Besides, it acts as core ion of important enzymes and proteins. The purpose of this study was to examine if zinc concentrations are associated with blood lead levels and if zinc may prevent lead-induced DNA damage. Blood samples were collected from 92 workers as participants occupationally exposed to lead or lead and zinc and 38 comparison participants having no history of such exposure. Lead and zinc levels were determined from blood by atomic absorption spectrophotometry and genetic damage was assessed by comet assay. Correlation was calculated by Spearman's rho. Lead concentrations were observed to increase among workers with increase in years of exposure. There was a significant difference (p < 0.001) in blood lead levels between workers and controls. In addition, significant difference (p < 0.001) in the genetic damage was observed among workers and controls. A clear effect of increased occupational exposure was visible among workers. Multiple regression analysis further reveals the positive effect of lead, while as the inverse effect of zinc on DNA damage. The results suggest that zinc may influence body lead absorption and may have a role in preventing the genetic damage caused by lead.

[Effects of zinc deficiency in pregnancy on the mother and the newborn infant].

PubMed

Favier, A; Favier, M

1990-01-01

There seems to be a zinc deficiency during pregnancy in view of the low serum zinc levels, but especially low zinc levels in hair and leucocytes. The need for zinc supplements is still ill-defined but represents at least 5 mg per day which are not covered by the diet and taken from the maternal reserves. Therefore the risk of deficiency is real and its manifestations are numerous. There is a risk of spontaneous abortion, gravidic toxemia, treatment-resistant anemia, abnormally prolonged gestation and difficult delivery for the mother. As for the fetus, with zinc deficiency there is a risk of hypotrophism and malformations with potentialization of the teratogenic effect of alcohol and many medications. Besides, in animals, zinc deficiency during pregnancy results in late effects several months after birth: decrease immunity, learning or memory disorders. In view of all these consequences, administration of supplements is imperative and must be evaluated providing that it does not exceed 50 mg of zinc per day. Besides, it seems preferable to provide balanced multisupplements in minerals and vitamins, since supplement in iron alone results in zinc deficiency.

Zinc Regulation of Aminopeptidase B Involved in Neuropeptide Production

PubMed Central

Hwang, Shin-Rong; Hook, Vivian

2009-01-01

Aminopeptidase B (AP-B) is a metallopeptidase that removes basic residues from the N-termini of neuropeptide substrates in secretory vesicles. This study assessed zinc regulation of AP-B activity, since secretory vesicles contain endogenous zinc. AP-B was inhibited by zinc at concentrations typically present in secretory vesicles. Zinc effects were dependent on concentration, incubation time, and the molar ratio of zinc to enzyme. AP-B activity was recovered upon removal of zinc. AP-B with zinc became susceptible to degradation by trypsin, suggesting that zinc alters enzyme conformation. Zinc regulation demonstrates the metallopeptidase property of AP-B. PMID:18571504

Serum zinc, copper and iron status of children with coeliac disease on three months of gluten-free diet with or without four weeks of zinc supplements: a randomised controlled trial.

PubMed

Negi, K; Kumar, R; Sharma, L; Datta, S P; Choudhury, M; Kumar, P

2018-04-01

Data about the effect of zinc supplementation with gluten-free diet on normalisation of plasma zinc, copper and iron in patients with coeliac disease are scanty. We evaluated the effect of zinc supplementation on serum zinc, copper and iron levels in patients with coeliac disease, by randomising 71 children newly diagnosed with coeliac disease into two groups: Group A = gluten-free diet (GFD); and Group B = gluten-free diet with zinc supplements (GFD +Zn). The rise in iron and zinc was significantly higher in the latter, but the mean rise of copper levels was slightly higher in the former, but the difference was not significant.

The beneficial effects of zinc on diabetes-induced kidney damage in murine rodent model of type 1 diabetes mellitus.

PubMed

Yang, Fan; Li, Bing; Dong, Xiaoming; Cui, Wenpeng; Luo, Ping

2017-07-01

Diabetes mellitus is a chronic multi-factorial metabolic disorder resulting from impaired glucose homeostasis. Zinc is a key co-factor for the correct functioning of anti-oxidant enzymes. Zinc deficiency therefore, impairs their synthesis, leading to increased oxidative stress within cells. Zinc deficiency occurs commonly in diabetic patients. The aim of this study is to investigate the effects of varying concentrations of zinc on diabetic nephropathy (DN) and the underlying mechanisms involved. FVB male mice aged 8 weeks were injected intraperitoneally with multiple low-dose streptozotocin at a concentration of 50mg/kg body weight daily for 5 days. Diabetic and age-matched control mice were treated with special diets supplemented with zinc at varying concentrations (0.85mg/kg, 30mg/kg, 150mg/kg) for 3 months. The mice were fed with zinc diets to mimic the process of oral administration of zinc in human. Zinc deficiency to some extent aggravated the damage of diabetic kidney. Feeding with normal (30mg/kg zinc/kg diet) and especially high (150mg/kg zinc/kg diet) concentration zinc could protect the kidney against diabetes-induced damage. The beneficial effects of zinc on DN are achieved most likely due to the upregulation of Nrf2 and its downstream factors NQO1, SOD1, SOD2. Zinc upregulated the expression of Akt phosphorylation and GSK-3β phosphorylation, resulting in a reduction in Fyn nuclear translocation and export of Nrf2 to the cytosol. Thus, regular monitoring and maintaining of adequate levels of zinc are recommended in diabetic individuals in order to delay the development of DN. Copyright © 2017 Elsevier GmbH. All rights reserved.

Effect of zinc supplementation on insulin resistance, energy and macronutrients intakes in pregnant women with impaired glucose tolerance.

PubMed

Roshanravan, Neda; Alizadeh, Mohammad; Hedayati, Mehdi; Asghari-Jafarabadi, Mohammad; Mesri Alamdari, Naimeh; Anari, Farideh; Tarighat-Esfanjani, Ali

2015-02-01

Hyperglycemia and gestational diabetes mellitus are complications of pregnancy. Both mothers and newborns are typically at increased risk for complications. This study sought to determine effect of zinc supplementation on serum glucose levels, insulin resistance, energy and macronutrients intakes in pregnant women with impaired glucose tolerance. In this clinical trial 44 pregnant women with impaired glucose tolerance, from December 2012 -April 2013 were randomly divided into zinc (n=22) and placebo (n=22) groups and recived 30mg/day zinc gluconate and (n=22), and placebo for eight consecutive weeks respectively. Dietary food intake was estimated from 3-days diet records. Serum levels of zinc, fasting blood sugar, and insulin were measured by conventional methods. Also homeostatic model assessment of insulin resistance was calculated. Serumlevels of fasting blood sugar, insulin and homeostatic model assessment of insulin resistance slightly decreased in zinc group, but these changes were not statistically significant. Serum zinc levels (P =0.012), energy (P=0.037), protein (P=0.019) and fat (P=0.017) intakes increased statistically significant in the zinc group after intervention but not in the placebo group. Oral supplementation with zinc could be effective in increasing serum zinc levels and energy intake with no effects on fasting blood sugar, homeostatic model assessment of insulin resistance and insulin levels.

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

PubMed

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

2000-01-01

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

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

PubMed

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

2017-08-30

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

Kinetic and Mechanistic Studies of the Deuterium Exchange in Classical Keto-Enol Tautomeric Equilibrium Reactions

ERIC Educational Resources Information Center

Nichols, Michael A.; Waner, Mark J.

2010-01-01

An extension of the classic keto-enol tautomerization of beta-dicarbonyl compounds into a kinetic analysis of deuterium exchange is presented. It is shown that acetylacetone and ethyl acetoacetate undergo nearly complete deuterium exchange of the alpha-methylene carbon when dissolved in methanol-d[subscript 4]. The extent of deuteration may be…

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

PubMed

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

2016-01-01

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

Zinc pharmacokinetic parameters in the determination of body zinc status in children.

PubMed

Vale, S H L; Leite, L D; Alves, C X; Dantas, M M G; Costa, J B S; Marchini, J S; França, M C; Brandão-Neto, J

2014-02-01

Serum or tissue zinc concentrations are often used to assess body zinc status. However, all of these methods are relatively inaccurate. Thus, we investigated three different kinetic methods for the determination of zinc clearance to establish which of these could detect small changes in the body zinc status of children. Forty apparently healthy children were studied. Renal handling of zinc was investigated during intravenous zinc administration (0.06537 mg Zn/kg of body weight), both before and after oral zinc supplementation (5 mg Zn/day for 3 months). Three kinetic methods were used to determine zinc clearance: CZn-Formula A and CZn-Formula B were both used to calculate systemic clearance; the first is a general formula and the second is used for the specific analysis of a single-compartment model; CZn-Formula C is widely used in medical practices to analyze kinetic routine. Basal serum zinc values, which were within the reference range for healthy children, increased significantly after oral zinc supplementation. The three formulas used gave different results for zinc clearance both before and after oral zinc supplementation. CZn-Formula B showed a positive correlation with basal serum zinc concentration after oral supplementation (R2=0.1172, P=0.0306). In addition, CZn-Formula B (P=0.0002) was more effective than CZn-Formula A (P=0.6028) and CZn-Formula C (P=0.0732) in detecting small variations in body zinc status. All three of the formulas used are suitable for studying zinc kinetics; however, CZn-Formula B is particularly effective at detecting small changes in body zinc status in healthy children.

Contribution of Zinc Solubilizing Bacteria in Growth Promotion and Zinc Content of Wheat.

PubMed

Kamran, Sana; Shahid, Izzah; Baig, Deeba N; Rizwan, Muhammad; Malik, Kauser A; Mehnaz, Samina

2017-01-01

Zinc is an imperative micronutrient required for optimum plant growth. Zinc solubilizing bacteria are potential alternatives for zinc supplementation and convert applied inorganic zinc to available forms. This study was conducted to screen zinc solubilizing rhizobacteria isolated from wheat and sugarcane, and to analyze their effect on wheat growth and development. Fourteen exo-polysaccharides producing bacterial isolates of wheat were identified and characterized biochemically as well as on the basis of 16S rRNA gene sequences. Along these, 10 identified sugarcane isolates were also screened for zinc solubilizing ability on five different insoluble zinc sources. Out of 24, five strains, i.e., EPS 1 ( Pseudomonas fragi) , EPS 6 ( Pantoea dispersa) , EPS 13 ( Pantoea agglomerans) , PBS 2 ( E. cloacae) and LHRW1 ( Rhizobium sp.) were selected (based on their zinc solubilizing and PGP activities) for pot scale plant experiments. ZnCO 3 was used as zinc source and wheat seedlings were inoculated with these five strains, individually, to assess their effect on plant growth and development. The effect on plants was analyzed based on growth parameters and quantifying zinc content of shoot, root and grains using atomic absorption spectroscopy. Plant experiment was performed in two sets. For first set of plant experiments (harvested after 1 month), maximum shoot and root dry weights and shoot lengths were noted for the plants inoculated with Rhizobium sp. (LHRW1) while E. cloacae (PBS 2) increased both shoot and root lengths. Highest zinc content was found in shoots of E. cloacae (PBS 2) and in roots of P. agglomerans (EPS 13) followed by zinc supplemented control. For second set of plant experiment, when plants were harvested after three months, Pantoea dispersa (EPS 6), P. agglomerans (EPS 13) and E. cloacae (PBS 2) significantly increased shoot dry weights. However, significant increase in root dry weights and maximum zinc content was recorded for Pseudomonas fragi (EPS 1) inoculated plants, isolated from wheat rhizosphere. While maximum zinc content for roots was quantified in the control plants indicating the plant's inability to transport zinc to grains, supporting accelerated bioavailability of zinc to plant grains with zinc solubilizing rhizobacteria.

The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis.

PubMed

Petry, Nicolai; Olofin, Ibironke; Boy, Erick; Donahue Angel, Moira; Rohner, Fabian

2016-11-30

Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI) of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating) and children (6-23 months) delivering iron or zinc in doses up to the recommended nutrient intake (RNI) levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L ( p < 0.001) and mean serum ferritin concentration by 17.6 µg/L ( p < 0.001) and reduced the risk for anemia by 41% ( p < 0.001), iron deficiency by 78% (ID; p < 0.001) and iron deficiency anemia by 80% (IDA; p < 0.001), but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L ( p < 0.001) and reduced the risk of zinc deficiency by 47% ( p < 0.001). Further, we observed positive effects on child weight for age z -score (WAZ) ( p < 0.05), weight for height z -score (WHZ) ( p < 0.05), but not on height for age z -score (HAZ) or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6-23 months of age has a positive effect on child iron and zinc status.

The Effect of Low Dose Iron and Zinc Intake on Child Micronutrient Status and Development during the First 1000 Days of Life: A Systematic Review and Meta-Analysis

PubMed Central

Petry, Nicolai; Olofin, Ibironke; Boy, Erick; Donahue Angel, Moira; Rohner, Fabian

2016-01-01

Adequate supply of micronutrients during the first 1000 days is essential for normal development and healthy life. We aimed to investigate if interventions administering dietary doses up to the recommended nutrient intake (RNI) of iron and zinc within the window from conception to age 2 years have the potential to influence nutritional status and development of children. To address this objective, a systematic review and meta-analysis of randomized and quasi-randomized fortification, biofortification, and supplementation trials in women (pregnant and lactating) and children (6–23 months) delivering iron or zinc in doses up to the recommended nutrient intake (RNI) levels was conducted. Supplying iron or zinc during pregnancy had no effects on birth outcomes. There were limited or no data on the effects of iron/zinc during pregnancy and lactation on child iron/zinc status, growth, morbidity, and psychomotor and mental development. Delivering up to 15 mg iron/day during infancy increased mean hemoglobin by 4 g/L (p < 0.001) and mean serum ferritin concentration by 17.6 µg/L (p < 0.001) and reduced the risk for anemia by 41% (p < 0.001), iron deficiency by 78% (ID; p < 0.001) and iron deficiency anemia by 80% (IDA; p < 0.001), but had no effect on growth or psychomotor development. Providing up to 10 mg of additional zinc during infancy increased plasma zinc concentration by 2.03 µmol/L (p < 0.001) and reduced the risk of zinc deficiency by 47% (p < 0.001). Further, we observed positive effects on child weight for age z-score (WAZ) (p < 0.05), weight for height z-score (WHZ) (p < 0.05), but not on height for age z-score (HAZ) or the risk for stunting, wasting, and underweight. There are no studies covering the full 1000 days window and the effects of iron and zinc delivered during pregnancy and lactation on child outcomes are ambiguous, but low dose daily iron and zinc use during 6–23 months of age has a positive effect on child iron and zinc status. PMID:27916873

Effect of zinc supplementation on neuronal precursor proliferation in the rat hippocampus after traumatic brain injury.

PubMed

Cope, Elise C; Morris, Deborah R; Gower-Winter, Shannon D; Brownstein, Naomi C; Levenson, Cathy W

2016-05-01

There is great deal of debate about the possible role of adult-born hippocampal cells in the prevention of depression and related mood disorders. We first showed that zinc supplementation prevents the development of the depression-like behavior anhedonia associated with an animal model of traumatic brain injury (TBI). This work then examined the effect of zinc supplementation on the proliferation of new cells in the hippocampus that have the potential to participate in neurogenesis. Rats were fed a zinc adequate (ZA, 30ppm) or zinc supplemented (ZS, 180ppm) diet for 4wk followed by TBI using controlled cortical impact. Stereological counts of EdU-positive cells showed that TBI doubled the density of proliferating cells 24h post-injury (p<0.05), and supplemental zinc significantly increased this by an additional 2-fold (p<0.0001). While the survival of these proliferating cells decreased at the same rate in ZA and in ZS rats after injury, the total density of newly born cells was approximately 60% higher in supplemented rats 1wk after TBI. Furthermore, chronic zinc supplementation resulted in significant increases in the density of new doublecortin-positive neurons one week post-TBI that were maintained for 4wk after injury (p<0.01). While the effect of zinc supplementation on neuronal precursor cells in the hippocampus was robust, use of targeted irradiation to eliminate these cells after zinc supplementation and TBI revealed that these cells are not the sole mechanism through which zinc acts to prevent depression associated with brain injury, and suggest that other zinc dependent mechanisms are needed for the anti-depressant effect of zinc in this model of TBI. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of zinc supplementation on Shiga toxin 2e-producing Escherichia coli in vitro.

PubMed

Uemura, Ryoko; Katsuge, Tomoko; Sasaki, Yosuke; Goto, Shinya; Sueyoshi, Masuo

2017-10-07

Swine edema disease is caused by Shiga toxin (Stx) 2e-producing Escherichia coli (STEC). Addition of highly concentrated zinc formulations to feed has been used to treat and prevent the disease, but the mechanism of the beneficial effect is unknown. The purpose of the present study was to investigate the effects of highly concentrated zinc formulations on bacterial growth, hemolysin production, and an Stx2e release by STEC in vitro. STEC strain MVH269 isolated from a piglet with edema disease was cultured with zinc oxide (ZnO) or with zinc carbonate (ZnCO 3 ), each at up to 3,000 ppm. There was no effect of zinc addition on bacterial growth. Nonetheless, the cytotoxic activity of Stx2e released into the supernatant was significantly attenuated in the zinc-supplemented media compared to that in the control, with the 50% cytotoxic dose values of 163.2 ± 12.7, 211.6 ± 33.1 and 659.9 ± 84.2 after 24 hr of growth in the presence of ZnO, ZnCO 3 , or no supplemental zinc, respectively. The hemolytic zones around colonies grown on sheep blood agar supplemented with zinc were significantly smaller than those of colonies grown on control agar. Similarly, hemoglobin absorbance after exposure to the supernatants of STEC cultures incubated in sheep blood broth supplemented with zinc was significantly lower than that resulting from exposure to the control supernatant. These in vitro findings indicated that zinc formulations directly impair the factors associated with the virulence of STEC, suggesting a mechanism by which zinc supplementation prevents swine edema disease.

Effects of soil type, prepercolation, and ageing on bioaccumulation and toxicity of zinc for the springtail Folsomia candida

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smit, C.E.; Van Gestel, C.A.M.

1998-06-01

Soil properties are a major influence on the bioavailability and toxicity of metals and represent one of the important factors that complicate the extrapolation of results from laboratory tests to field situations. The influence of soil characteristics and way of contamination on the bioaccumulation and toxicity of zinc was investigated for the springtail Folsomia candida, and the applicability of chemical extraction techniques for the prediction of zinc uptake and toxicity was evaluated. Bioaccumulation of zinc in F. candida was related to water-soluble zinc concentrations, and uptake was dependent on the test soil used. Effects of zinc for F. candida couldmore » not be fully explained by bioaccumulation. This indicates that the existence of a fixed internal threshold concentration of zinc above which physiological functions are impaired is not likely for F. candida. In freshly contaminated soils, zinc toxicity was related to organic matter and clay content of the soil; however, the use of these soils overestimated the effects of zinc for F. candida by a factor of 5 to 8 compared to a test soil that was subjected to ageing under field conditions for 1.5 years. Equilibration of the zinc contamination by percolating the soils with water before use in the toxicity experiment strongly reduced the difference in zinc toxicity between laboratory-treated and aged soils. Water-soluble concentrations are most appropriate to predict effects of zinc on reproduction of F. candida in soils with unknown contamination histories. For laboratory toxicity tests, it is recommended to percolate soils with water after contamination and to include an equilibration period prior to use to achieve a more realistic exposure situation.« less

Differential sensitivities of cellular XPA and PARP-1 to arsenite inhibition and zinc rescue.

PubMed

Ding, Xiaofeng; Zhou, Xixi; Cooper, Karen L; Huestis, Juliana; Hudson, Laurie G; Liu, Ke Jian

2017-09-15

Arsenite directly binds to the zinc finger domains of the DNA repair protein poly (ADP ribose) polymerase (PARP)-1, and inhibits PARP-1 activity in the base excision repair (BER) pathway. PARP inhibition by arsenite enhances ultraviolet radiation (UVR)-induced DNA damage in keratinocytes, and the increase in DNA damage is reduced by zinc supplementation. However, little is known about the effects of arsenite and zinc on the zinc finger nucleotide excision repair (NER) protein xeroderma pigmentosum group A (XPA). In this study, we investigated the difference in response to arsenite exposure between XPA and PARP-1, and the differential effectiveness of zinc supplementation in restoring protein DNA binding and DNA damage repair. Arsenite targeted both XPA and PARP-1 in human keratinocytes, resulting in zinc loss from each protein and a pronounced decrease in XPA and PARP-1 binding to chromatin as demonstrated by Chip-on-Western assays. Zinc effectively restored DNA binding of PARP-1 and XPA to chromatin when zinc concentrations were equal to those of arsenite. In contrast, zinc was more effective in rescuing arsenite-augmented direct UVR-induced DNA damage than oxidative DNA damage. Taken together, our findings indicate that arsenite interferes with PARP-1 and XPA binding to chromatin, and that zinc supplementation fully restores DNA binding activity to both proteins in the cellular context. Interestingly, rescue of arsenite-inhibited DNA damage repair by supplemental zinc was more sensitive for DNA damage repaired by the XPA-associated NER pathway than for the PARP-1-dependent BER pathway. This study expands our understanding of arsenite's role in DNA repair inhibition and co-carcinogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

Effects of Zinc Chelators on Aflatoxin Production in Aspergillus parasiticus

PubMed Central

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

2016-01-01

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

Effect of subchronic zinc toxicity on rat salivary glands and serum composition.

PubMed

Mizari, Nazer; Hirbod-Mobarakeh, Armin; Shahinpour, Shervin; Ghalichi-Tabriz, Mostafa; Beigy, Maani; Yamini, Ali; Dehpour, Ahmad Reza

2012-11-01

Zinc plays an important role in a wide variety of metabolic processes in animal systems. The role of zinc in preservative treatment, fungicidal action and medicine, and addition of supplementary zinc have increased the probability of zinc toxicity, specially the chronic type. It is known that the composition and quantity of saliva influence the oral health. Regarding people's exposure to zinc in routine life and the importance of saliva, our purpose was to investigate the effects of oral zinc intoxication on secretory function in rat salivary glands and also on serum composition. In this study, there were five groups of female rats. Four groups received zinc acetate dehydrate through their drinking water. After 3 months of experiment, the chemical characteristics and flow rate of saliva and weight of salivary glands were determined. The effects of zinc on hematological and chemical factors of plasma were assessed too. Flow rate of submandibular glands was significantly lower in experimental groups and there were significant changes in Na(+), Ca(2+) and K(+) concentration both in saliva and in plasma. The serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, glucose levels in the plasma and urine creatinine levels were also altered in experimental groups in comparison with the control group. Our results show that zinc toxicity will affect the quantity and quality of saliva probably through changes in the various neurologic pathways to the salivary glands or effects on acinar cells of the salivary glands. Furthermore, our results showed that zinc toxicity will affect the liver and renal function.

Total Zinc Intake May Modify the Glucose-Raising Effect of a Zinc Transporter (SLC30A8) Variant

PubMed Central

Kanoni, Stavroula; Nettleton, Jennifer A.; Hivert, Marie-France; Ye, Zheng; van Rooij, Frank J.A.; Shungin, Dmitry; Sonestedt, Emily; Ngwa, Julius S.; Wojczynski, Mary K.; Lemaitre, Rozenn N.; Gustafsson, Stefan; Anderson, Jennifer S.; Tanaka, Toshiko; Hindy, George; Saylor, Georgia; Renstrom, Frida; Bennett, Amanda J.; van Duijn, Cornelia M.; Florez, Jose C.; Fox, Caroline S.; Hofman, Albert; Hoogeveen, Ron C.; Houston, Denise K.; Hu, Frank B.; Jacques, Paul F.; Johansson, Ingegerd; Lind, Lars; Liu, Yongmei; McKeown, Nicola; Ordovas, Jose; Pankow, James S.; Sijbrands, Eric J.G.; Syvänen, Ann-Christine; Uitterlinden, André G.; Yannakoulia, Mary; Zillikens, M. Carola; Wareham, Nick J.; Prokopenko, Inga; Bandinelli, Stefania; Forouhi, Nita G.; Cupples, L. Adrienne; Loos, Ruth J.; Hallmans, Goran; Dupuis, Josée; Langenberg, Claudia; Ferrucci, Luigi; Kritchevsky, Stephen B.; McCarthy, Mark I.; Ingelsson, Erik; Borecki, Ingrid B.; Witteman, Jacqueline C.M.; Orho-Melander, Marju; Siscovick, David S.; Meigs, James B.; Franks, Paul W.; Dedoussis, George V.

2011-01-01

OBJECTIVE Many genetic variants have been associated with glucose homeostasis and type 2 diabetes in genome-wide association studies. Zinc is an essential micronutrient that is important for β-cell function and glucose homeostasis. We tested the hypothesis that zinc intake could influence the glucose-raising effect of specific variants. RESEARCH DESIGN AND METHODS We conducted a 14-cohort meta-analysis to assess the interaction of 20 genetic variants known to be related to glycemic traits and zinc metabolism with dietary zinc intake (food sources) and a 5-cohort meta-analysis to assess the interaction with total zinc intake (food sources and supplements) on fasting glucose levels among individuals of European ancestry without diabetes. RESULTS We observed a significant association of total zinc intake with lower fasting glucose levels (β-coefficient ± SE per 1 mg/day of zinc intake: −0.0012 ± 0.0003 mmol/L, summary P value = 0.0003), while the association of dietary zinc intake was not significant. We identified a nominally significant interaction between total zinc intake and the SLC30A8 rs11558471 variant on fasting glucose levels (β-coefficient ± SE per A allele for 1 mg/day of greater total zinc intake: −0.0017 ± 0.0006 mmol/L, summary interaction P value = 0.005); this result suggests a stronger inverse association between total zinc intake and fasting glucose in individuals carrying the glucose-raising A allele compared with individuals who do not carry it. None of the other interaction tests were statistically significant. CONCLUSIONS Our results suggest that higher total zinc intake may attenuate the glucose-raising effect of the rs11558471 SLC30A8 (zinc transporter) variant. Our findings also support evidence for the association of higher total zinc intake with lower fasting glucose levels. PMID:21810599

Effects of Dietary Zinc Manipulation on Growth Performance, Zinc Status and Immune Response during Giardia lamblia Infection: A Study in CD-1 Mice

PubMed Central

Iñigo-Figueroa, Gemma; Méndez-Estrada, Rosa O.; Quihui-Cota, Luis; Velásquez-Contreras, Carlos A.; Garibay-Escobar, Adriana; Canett-Romero, Rafael; Astiazarán-García, Humberto

2013-01-01

Associations between Giardia lamblia infection and low serum concentrations of zinc have been reported in young children. Interestingly, relatively few studies have examined the effects of different dietary zinc levels on the parasite-infected host. The aims of this study were to compare the growth performance and zinc status in response to varying levels of dietary zinc and to measure the antibody-mediated response of mice during G. lamblia infection. Male CD-1 mice were fed using 1 of 4 experimental diets: adequate-zinc (ZnA), low-zinc (ZnL), high-zinc (ZnH) and supplemented-zinc (ZnS) diet containing 30, 10, 223 and 1383 mg Zn/kg respectively. After a 10 days feeding period, mice were inoculated orally with 5 × 106 G. lamblia trophozoites and were maintained on the assigned diet during the course of infection (30 days). Giardia-free mice fed ZnL diets were able to attain normal growth and antibody-mediated response. Giardia-infected mice fed ZnL and ZnA diets presented a significant growth retardation compared to non-infected controls. Zinc supplementation avoided this weight loss during G. lamblia infection and up-regulated the host’s humoral immune response by improving the production of specific antibodies. Clinical outcomes of zinc supplementation during giardiasis included significant weight gain, higher anti-G. lamblia IgG antibodies and improved serum zinc levels despite the ongoing infection. A maximum growth rate and antibody-mediated response were attained in mice fed ZnH diet. No further increases in body weight, zinc status and humoral immune capacity were noted by feeding higher zinc levels (ZnS) than the ZnH diet. These findings probably reflect biological effect of zinc that could be of public health importance in endemic areas of infection. PMID:24002196

Adverse effects of parental zinc deficiency on metal homeostasis and embryonic development in a zebrafish model.

PubMed

Beaver, Laura M; Nkrumah-Elie, Yasmeen M; Truong, Lisa; Barton, Carrie L; Knecht, Andrea L; Gonnerman, Greg D; Wong, Carmen P; Tanguay, Robert L; Ho, Emily

2017-05-01

The high prevalence of zinc deficiency is a global public health concern, and suboptimal maternal zinc consumption has been associated with adverse effects ranging from impaired glucose tolerance to low birthweights. The mechanisms that contribute to altered development and poor health in zinc deficient offspring are not completely understood. To address this gap, we utilized the Danio rerio model and investigated the impact of dietary zinc deficiency on adults and their developing progeny. Zinc deficient adult fish were significantly smaller in size, and had decreases in learning and fitness. We hypothesized that parental zinc deficiency would have an impact on their offspring's mineral homeostasis and embryonic development. Results from mineral analysis showed that parental zinc deficiency caused their progeny to be zinc deficient. Furthermore, parental dietary zinc deficiency had adverse consequences for their offspring including a significant increase in mortality and decreased physical activity. Zinc deficient embryos had altered expression of genes that regulate metal homeostasis including several zinc transporters (ZnT8, ZnT9) and the metal-regulatory transcription factor 1 (MTF-1). Zinc deficiency was also associated with decreased expression of genes related to diabetes and pancreatic development in the embryo (Insa, Pax4, Pdx1). Decreased expression of DNA methyltransferases (Dnmt4, Dnmt6) was also found in zinc deficient offspring, which suggests that zinc deficiency in parents may cause altered epigenetic profiles for their progeny. These data should inform future studies regarding zinc deficiency and pregnancy and suggest that supplementation of zinc deficient mothers prior to pregnancy may be beneficial. Published by Elsevier Inc.

Adverse effects of parental zinc deficiency on metal homeostasis and embryonic development in a zebrafish model

PubMed Central

Beaver, Laura M.; Nkrumah-Elie, Yasmeen M.; Truong, Lisa; Barton, Carrie L.; Knecht, Andrea L.; Gonnerman, Greg D.; Wong, Carmen P.; Tanguay, Robert L.; Ho, Emily

2017-01-01

The high prevalence of zinc deficiency is a global public health concern, and suboptimal maternal zinc consumption has been associated with adverse effects ranging from impaired glucose tolerance to low birthweights. The mechanisms that contribute to altered development and poor health in zinc deficient offspring are not completely understood. To address this gap, we utilized the Danio rerio model and investigated the impact of dietary zinc deficiency on adults and their developing progeny. Zinc deficient adult fish were significantly smaller in size, and had decreases in learning and fitness. We hypothesized that parental zinc deficiency would have an impact on their offspring’s mineral homeostasis and embryonic development. Results from mineral analysis showed that parental zinc deficiency caused their progeny to be zinc deficient. Furthermore, parental dietary zinc deficiency had adverse consequences for their offspring including a significant increase in mortality and decreased physical activity. Zinc deficient embryos had altered expression of genes that regulate metal homeostasis including several zinc transporters (ZnT8, ZnT9) and the metal-regulatory transcription factor 1 (MTF-1). Zinc deficiency was also associated with decreased expression of genes related to diabetes and pancreatic development in the embryo (Insa, Pax4, Pdx1). Decreased expression of DNA methyltransferases (Dnmt4, Dnmt6) was also found in zinc deficient offspring, which suggests that zinc deficiency in parents may cause altered epigenetic profiles for their progeny. These data should inform future studies regarding zinc deficiency and pregnancy and suggest that supplementation of zinc deficient mothers prior to pregnancy may be beneficial. PMID:28268202

A question mark on zinc deficiency in 185 million people in Pakistan--possible way out.

PubMed

Khalid, Nauman; Ahmed, Anwaar; Bhatti, Muhammad Shahbaz; Randhawa, Muhammad Atif; Ahmad, Asif; Rafaqat, Rabab

2014-01-01

This paper reviews research published in recent years concerning the effects of zinc deficiency, its consequences, and possible solutions. Zinc is an essential trace element necessary for over 300 zinc metalloenzymes and required for normal nucleic acid, protein, and membrane metabolism. Zinc deficiency is one of the ten biggest factors contributing to burden of disease in developing countries. Populations in South Asia, South East Asia, and sub-Saharan Africa are at greatest risk of zinc deficiency. Zinc intakes are inadequate for about a third of the population and stunting affects 40% of preschool children. In Pakistan, zinc deficiency is an emerging health problem as about 20.6% children are found in the levels of zinc, below 60 μg/dL. Signs and symptoms caused by zinc deficiency are poor appetite, weight loss, and poor growth in childhood, delayed healing of wounds, taste abnormalities, and mental lethargy. As body stores of zinc decline, these symptoms worsen and are accompanied by diarrhea, recurrent infection, and dermatitis. Daily zinc requirements for an adult are 12-16 mg/day. Iron, calcium and phytates inhibit the absorption of zinc therefore simultaneous administration should not be prescribed. Zinc deficiency and its effects are well known but the ways it can help in treatment of different diseases is yet to be discovered. Improving zinc intakes through dietary improvements is a complex task that requires considerable time and effort. The use of zinc supplements, dietary modification, and fortifying foods with zinc are the best techniques to combat its deficiency.

The zinc-loss effect and mobility enhancement of DUV-patterned sol-gel IGZO thin-film transistors

NASA Astrophysics Data System (ADS)

Wang, Kuan-Hsun; Zan, Hsiao-Wen; Soppera, Olivier

2018-03-01

We investigate the composition of the DUV-patterned sol-gel indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) and observe a significant zinc loss effect during developing when the DUV exposure is insufficient. The zinc loss, however, is beneficial for increasing the mobility. Reducing zinc to indium composition ratio from 0.5 to 0.02 can effectively increase mobility from 0.27 to 7.30 cm2 V-1 s-1 when the gallium to indium ratio is fixed as 0.25 and the post annealing process is fixed as 300 °C for 2 h. On the other hand, an IGO TFT fails to deliver a uniform film and a reproducible TFT performance, revealing the critical role of zinc in forming homogeneous IGZO TFTs.

Comparison of dye doping and ultrathin emissive layer in white organic light-emitting devices with dual emissive layers

NASA Astrophysics Data System (ADS)

Wang, Xu; Qi, Yige; Yu, Junsheng

2014-09-01

White organic light-emitting devices (WOLEDs) with combined doping emissive layer (EML) and ultrathin EML have been fabricated to investigate the effect of each EML on the electroluminescent (EL) performance of the WOLEDs. Through tailoring doping concentration of bis[(4,6-difluorophenyl)-pyridinato-N,C2'](picolinate) iridium(III) (FIrpic) and thickness of ultrathin bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2'] iridium (acetylacetonate) [(tbt)2Ir(acac)] EML, it is found that the change in the doping ratio of FIrpic significantly influenced the EL efficiencies and spectra, while the alteration of ultrathin EML thickness had much milder effect on the EL performance. The results indicated that ultrathin EML is in favor of reproducibility in mass production compared with doping method.

Lifetime enhanced phosphorescent organic light emitting diode using an electron scavenger layer

NASA Astrophysics Data System (ADS)

Hong, Seokhwan; Kim, Ji Whan; Lee, Sangyeob

2015-07-01

We demonstrate a method to improve lifetime of a phosphorescent organic light emitting diode (OLED) using an electron scavenger layer (ESL) in a hole transporting layer (HTL) of the device. We use a bis(1-(phenyl)isoquinoline)iridium(III)acetylacetonate [Ir(piq)2(acac)] doped HTL to stimulate radiative decay, preventing thermal degradation in HTL. The ESL effectively prevented non-radiative decay of leakage electron in HTL by converting non-radiative decay to radiative decay via a phosphorescent red emitter, Ir(piq)2(acac). The lifetime of device (t95: time after 5% decrease of luminance) has been increased from 75 h to 120 h by using the ESL in a phosphorescent green-emitting OLED.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Genevée, Pascal, E-mail: pascal-genevee@chimie-paristech.fr, E-mail: a.szeghalmi@uni-jena.de; Ahiavi, Ernest; Janunts, Norik

The authors report on the formation of blisters during the atomic layer deposition of iridium using iridium acetylacetonate and oxygen precursors. Films deposited on fused silica substrates led to sparsely distributed large blisters while in the case of silicon with native oxide additional small blisters with a high density was observed. It is found that the formation of blisters is favored by a higher deposition temperature and a larger layer thickness. Postdeposition annealing did not have a significant effect on the formation of blisters. Finally, changing purge duration during the film growth allowed us to avoid blistering and evidenced thatmore » impurities released from the film in gas phase were responsible for the formation of blisters.« less

Zinc and Autophagy

PubMed Central

Liuzzi, Juan P.; Guo, Liang; Yoo, Changwon; Stewart, Tiffanie S

2014-01-01

Autophagy is a highly conserved degradative process through which cells overcome stressful conditions. Inasmuch as faulty autophagy has been associated with aging, neuronal degeneration disorders, diabetes, and fatty liver, autophagy is regarded as a potential therapeutic target. This review summarizes the present state of knowledge concerning the role of zinc in the regulation of autophagy, the role of autophagy in zinc metabolism, and the potential role of autophagy as a mediator of the protective effects of zinc. Data from in vitro studies consistently support the notion that zinc is critical for early and late autophagy. Studies have shown inhibition of early and late autophagy in cells cultured in medium treated with zinc chelators. Conversely, excess zinc added to the medium has shown to potentiate the stimulation of autophagy by tamoxifen, H2O2, ethanol and dopamine. The potential role of autophagy in zinc homeostasis has just begun to be investigated.Increasing evidence indicates that autophagy dysregulation causes significant changes in cellular zinc homeostasis. Autophagy may mediate the protective effect of zinc against lipid accumulation, apoptosis and inflammation by promoting degradation of lipid droplets, inflammasomes, p62/SQSTM1 and damaged mitochondria.Studies with humans and animal models are necessary to determine whether autophagy is influenced by zinc intake. PMID:25012760

Effects of zinc and multimineral vitamin supplementation on glycemic and lipid control in adult diabetes.

PubMed

Gunasekara, Priyanka; Hettiarachchi, Manjula; Liyanage, Chandrani; Lekamwasam, Sarath

2011-01-26

To evaluate the effects of zinc with or without other antioxidants on blood glucose, lipid profile, and serum creatinine in adult diabetics on long-term follow-up. Patients (n = 96) were randomly allocated to three groups: group A (n = 29) was supplemented with oral zinc sulfate (22 mg/day) and multivitamin/mineral (zinc+MVM) preparation; group B (n = 31) was given the same preparation without zinc (MVM); and group C (n = 36) was given a matching placebo for a period of 4 months in a single-blinded study. Blood samples were taken at baseline and after 4 months of supplementation to assess blood glucose (fasting and postprandial) and glycosylated hemoglobin (Hb(A1C)%) and serum levels of zinc, creatinine, and lipids. The zinc+MVM group had a mean change of fasting blood sugar -0.33 mmol/L (standard error of the mean 0.21 mmol/L) and was significant (P = 0.05) when compared with the other two groups (mean change in the MVM group +0.19 (0.31) mmol/L and +0.43 (0.23) mmol/L in the control group, respectively). The Hb(A1C)% level reduced significantly, irrespective of the baseline level, in zinc+MVM-supplemented individuals. In the other two groups, the change of Hb(A1C)% level was not significant. Serum lipid levels reduced significantly in the zinc+MVM and MVM groups. Zinc+MVM supplementation showed beneficial effects in the metabolic control of adult diabetics in addition to elevating their serum zinc level. Zinc supplementation improved glycemic control measured by Hb(A1C)% and fasting and postprandial glucose. Furthermore, zinc supplementation lowered serum cholesterol and cholesterol/high-density lipoprotein ratio.

Coordination Complexes as Catalysts: The Oxidation of Anthracene by Hydrogen Peroxide in the Presence of VO(acac)[subscript 2

ERIC Educational Resources Information Center

Charleton, Kimberly D. M.; Prokopchuk, Ernest M.

2011-01-01

A laboratory experiment aimed at students who are studying coordination chemistry of transition-metal complexes is described. A simple vanadyl acetylacetonate complex can be used as a catalyst in the hydrogen peroxide oxidation of anthracene to produce anthraquinone. The reaction can be performed under a variety of reaction conditions, ideally by…

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

PubMed

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

2017-11-01

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

Zinc treatment increases the titre of 'Candidatus Liberibacter asiaticus' in huanglongbing-affected citrus plants while affecting the bacterial microbiomes.

PubMed

Zhang, M Q; Guo, Y; Powell, C A; Doud, M S; Yang, C Y; Zhou, H; Duan, Y P

2016-06-01

Huanglongbing (HLB)-affected citrus often display zinc deficiency symptoms. In this study, supplemental zinc was applied to citrus to determine its effect on Candidatus Liberibacter asiaticus (Las) titre, HLB symptoms, and leaf microbiome. HLB-affected citrus were treated with various amounts of zinc. The treatments promoted Las growth and affected microbiomes in citrus leaves. Phylochip(™) -based results indicated that 5475 of over 50 000 known Operational Taxonomic Units (OTUs) in 52 phyla were detected in the midribs of HLB-affected citrus, of which Proteobacteria was the most abundant, followed by Firmicutes and Actinobacteria. In comparison, the microbiomes of zinc-treated diseased plants had overall more OTUs with higher amounts of Proteobacteria, but decreased percentages of Firmicutes and Actinobacteria. In addition, more OTUs of siderophore-producing bacteria were present. Only zinc-sensitive Staphylococcaceae had higher OTU's in the diseased plants without zinc treatments. Although HLB-affected citrus appear zinc deficient, zinc amendments increased the pathogen levels and shifted the microbiome. HLB is currently the most devastating disease of citrus worldwide. Zinc is often applied to HLB-affected citrus due to zinc deficiency symptoms. This study provided new insights into the potential effects of zinc on HLB and the microbial ecology of citrus. © 2016 The Society for Applied Microbiology.

Preparation of alumina-hercynite nano-spinel via one-step thermal conversion of Fe-doped metal-organic framework MIL-53(Al)

NASA Astrophysics Data System (ADS)

Chen, Shuyi; Lu, Huigong; Wu, Yi-nan; Gu, Yifan; Li, Fengting; Morlay, Catherine

2016-09-01

Alumina-hercynite nano-spinel powders were prepared via one-step pyrolysis of iron-acetylacetone-doped Al-based metal-organic framework (MOF), i.e., MIL-53(Al). Organic ferric source, iron acetylacetone, was incorporated in situ into the framework of MIL-53(Al) during the solvothermal synthesis process. Under high-temperature pyrolysis, alumina derived from the MIL-53(Al) matrix and ferric oxides originated from the decomposition of organic ferric precursor in the framework were thermally converted into hercynite (FeAl2O4). The prepared samples were characterized using transmission electron microscopy, X-ray diffraction, N2 sorption, thermogravimetry, Raman spectroscopy and X-ray photoelectron spectroscopy. The final products were identified to be composed of alumina, hercynite and trace amounts of carbon depending on pyrolysis temperature. The experimental results showed that hercynite phase can be obtained and stabilized at low temperatures between 900 and 1100 °C under inert atmosphere. The final products were composed of nano-sized particles with an average size below 100 nm of individual crystal and specific surface areas of 18-49 m2 g-1.

Molecular structure, spectroscopic studies, and coppersbnd oxygen bond strength of α-methyl and α-ethyl derivatives of copper (II) acetylacetonate; Experimental and theoretical approach

NASA Astrophysics Data System (ADS)

Seyedkatouli, Seyedabdollah; Vakili, Mohammad; Tayyari, Sayyed Faramarz; Afzali, Raheleh

2018-05-01

This paper presents a combined experimental and theoretical study on the Cusbnd O bond strength of copper (II) α-methylacetylacetonate, Cu(3-Meacac)2, and copper (II) α-ethylacetylacetonate, Cu(3-Etacac)2, complexes in comparison to that in copper (II) acetylacetonate, Cu(acac)2. For this purpose, the molecular structure, UV spectra, and complete vibrational assignment of target molecules were investigated by DFT, Natural Bond Orbital (NBO) theory, and Atoms-in-Molecules (AIM) analysis at the B3LYP/6-311G* level of theory. The mentioned results are compared with those in Cu(acac)2. Fourier transform-Raman, IR, and UV spectra of these complexes have been also recorded. A complete assignment of the observed band frequencies has been done. All theoretical and experimental spectroscopic results are consisting with a stronger metal-oxygen bond in Cu(3-Meacac)2 and Cu(3-Etacac)2 complexes compared with Cu(acac)2. In addition, these results confirm that there is no significant difference between the Cusbnd O bond strength of the Cu(3-Meacac)2 and Cu(3-Etacac)2 complexes.

Area-Selective Atomic Layer Deposition of SiO2 Using Acetylacetone as a Chemoselective Inhibitor in an ABC-Type Cycle

PubMed Central

2017-01-01

Area-selective atomic layer deposition (ALD) is rapidly gaining interest because of its potential application in self-aligned fabrication schemes for next-generation nanoelectronics. Here, we introduce an approach for area-selective ALD that relies on the use of chemoselective inhibitor molecules in a three-step (ABC-type) ALD cycle. A process for area-selective ALD of SiO2 was developed comprising acetylacetone inhibitor (step A), bis(diethylamino)silane precursor (step B), and O2 plasma reactant (step C) pulses. Our results show that this process allows for selective deposition of SiO2 on GeO2, SiNx, SiO2, and WO3, in the presence of Al2O3, TiO2, and HfO2 surfaces. In situ Fourier transform infrared spectroscopy experiments and density functional theory calculations underline that the selectivity of the approach stems from the chemoselective adsorption of the inhibitor. The selectivity between different oxide starting surfaces and the compatibility with plasma-assisted or ozone-based ALD are distinct features of this approach. Furthermore, the approach offers the opportunity of tuning the substrate-selectivity by proper selection of inhibitor molecules. PMID:28850774

The effect of chronic prostatitis on zinc concentration of prostatic fluid and seminal plasma: a systematic review and meta-analysis.

PubMed

Cui, Dong; Han, GuangWei; Shang, YongGang; Mu, LiJun; Long, QingZhi; Du, YueFeng

2015-01-01

Prostatitis is a common disease in urology departments. Prostatic zinc accumulation is connected with the secretory function of the prostate, and zinc concentrations present in prostatic diseases differ greatly from the normal level. Studies have investigated the effect of chronic prostatitis on zinc concentration of prostatic fluid and seminal plasma, but have shown inconsistent results. Hence, we performed a systematic literature review and meta-analysis to assess the effect of chronic prostatitis on the zinc concentration of prostatic fluid and seminal plasma. Systematic literature searches were conducted with PubMed, Embase, Science Direct/Elsevier, CNKI and the Cochrane Library up to March 2015 for case-control studies that involved the relationship between chronic prostatitis and zinc concentration of prostatic fluid and seminal plasma. Meta-analysis was performed with Review Manager and Stata software. Standard mean differences (SMDs) of zinc concentration were identified with 95% confidence intervals (95% CIs) in a random- or fixed-effects model. Our results illustrated that the zinc concentrations in prostatic fluid and seminal plasma from chronic prostatitis patients were significantly lower than normal controls (SMD [95% CI] -246.71 [-347.97, -145.44], -20.74 [-35.11, -6.37], respectively). The sample size of each study was relatively small, and a total of 731 chronic prostatitis patients and 574 normal controls were investigated in all fourteen studies. Several studies related to the subject were excluded due to lack of control data or means and standard deviations. The present study illustrates that there was a significant negative effect of chronic prostatitis on zinc concentrations of prostatic fluid and seminal plasma. Further studies with larger sample sizes are needed to better illuminate the negative impact of chronic prostatitis on zinc concentrations.

Mutation of a Zinc-Binding Residue in the Glycine Receptor α1 Subunit Changes Ethanol Sensitivity In Vitro and Alcohol Consumption In Vivo

PubMed Central

McCracken, Lindsay M.; Blednov, Yuri A.; Trudell, James R.; Benavidez, Jillian M.; Betz, Heinrich

2013-01-01

Ethanol is a widely used drug, yet an understanding of its sites and mechanisms of action remains incomplete. Among the protein targets of ethanol are glycine receptors (GlyRs), which are potentiated by millimolar concentrations of ethanol. In addition, zinc ions also modulate GlyR function, and recent evidence suggests that physiologic concentrations of zinc enhance ethanol potentiation of GlyRs. Here, we first built a homology model of a zinc-bound GlyR using the D80 position as a coordination site for a zinc ion. Next, we investigated in vitro the effects of zinc on ethanol action at recombinant wild-type (WT) and mutant α1 GlyRs containing the D80A substitution, which eliminates zinc potentiation. At D80A GlyRs, the effects of 50 and 200 mM ethanol were reduced as compared with WT receptors. Also, in contrast to what was seen with WT GlyRs, neither adding nor chelating zinc changed the magnitude of ethanol enhancement of mutant D80A receptors. Next, we evaluated the in vivo effects of the D80A substitution by using heterozygous Glra1(D80A) knock-in (KI) mice. The KI mice showed decreased ethanol consumption and preference, and they displayed increased startle responses compared with their WT littermates. Other behavioral tests, including ethanol-induced motor incoordination and strychnine-induced convulsions, revealed no differences between the KI and WT mice. Together, our findings indicate that zinc is critical in determining the effects of ethanol at GlyRs and suggest that zinc binding at the D80 position may be important for mediating some of the behavioral effects of ethanol action at GlyRs. PMID:23230213

Metal cofactor modulated folding and target recognition of HIV-1 NCp7.

PubMed

Ren, Weitong; Ji, Dongqing; Xu, Xiulian

2018-01-01

The HIV-1 nucleocapsid 7 (NCp7) plays crucial roles in multiple stages of HIV-1 life cycle, and its biological functions rely on the binding of zinc ions. Understanding the molecular mechanism of how the zinc ions modulate the conformational dynamics and functions of the NCp7 is essential for the drug development and HIV-1 treatment. In this work, using a structure-based coarse-grained model, we studied the effects of zinc cofactors on the folding and target RNA(SL3) recognition of the NCp7 by molecular dynamics simulations. After reproducing some key properties of the zinc binding and folding of the NCp7 observed in previous experiments, our simulations revealed several interesting features in the metal ion modulated folding and target recognition. Firstly, we showed that the zinc binding makes the folding transition states of the two zinc fingers less structured, which is in line with the Hammond effect observed typically in mutation, temperature or denaturant induced perturbations to protein structure and stability. Secondly, We showed that there exists mutual interplay between the zinc ion binding and NCp7-target recognition. Binding of zinc ions enhances the affinity between the NCp7 and the target RNA, whereas the formation of the NCp7-RNA complex reshapes the intrinsic energy landscape of the NCp7 and increases the stability and zinc affinity of the two zinc fingers. Thirdly, by characterizing the effects of salt concentrations on the target RNA recognition, we showed that the NCp7 achieves optimal balance between the affinity and binding kinetics near the physiologically relevant salt concentrations. In addition, the effects of zinc binding on the inter-domain conformational flexibility and folding cooperativity of the NCp7 were also discussed.

Neuroprotective Effects of Reactive Oxygen Species Mediated by BDNF-Independent Activation of TrkB

PubMed Central

Huang, Yang Zhong; McNamara, James O.

2012-01-01

Reactive oxygen species (ROS) have diverse biological consequences in the mammalian CNS, but the molecular targets mediating these pleiotropic effects are incompletely understood. Like ROS, the neurotrophin receptor, TrkB receptor tyrosine kinase, has diverse effects in the developing and mature mammalian brain. Our discovery that zinc can transactivate TrkB, together with the finding that ROS can trigger zinc release from cytosolic zinc binding proteins, led us to hypothesize that ROS can transactivate TrkB in CNS neurons by a zinc-dependent mechanism. We found that both exogenous H2O2 and endogenous ROS activate TrkB signaling by a Src family kinase-dependent but brain-derived neurotrophic factor-independent mechanism in cultured rat cortical neurons. Exogenous H2O2 enhances cytosolic zinc content in a metallothionein-3 (MT-3)-requiring manner. Both exogenous H2O2 and endogenous ROS mediated transactivation of TrkB requires intracellular zinc and MT-3. The ROS-triggered transactivation of TrkB exerts neuroprotective effects, because inhibition of TrkB kinase activity or uncoupling Shc signaling from TrkB exacerbates neuronal cell death induced by H2O2. Thus, we propose a molecular signaling event whereby ROS induce release of zinc from cytosolic MT-3, the increased cytosolic zinc transactivates TrkB, and the enhanced Shc signaling downstream from TrkB promotes prosurvival effects. We suggest that such neuroprotective effects mediated by ROS are operative in diverse acute and chronic neurological disorders. PMID:23115189

The relevance of the colon to zinc nutrition

USDA-ARS?s Scientific Manuscript database

Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income countries. Apart from inadequate dietary intake of bioavailable zinc, other significant contributors to zinc deficiency include the exce...

Zinc Signals and Immunity.

PubMed

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.

Protective effect of zinc on N-methyl-N-nitrosourea and testosterone-induced prostatic intraepithelial neoplasia in the dorsolateral prostate of Sprague Dawley rats.

PubMed

Banudevi, Sivanantham; Elumalai, Perumal; Sharmila, Govindaraj; Arunkumar, Ramachandran; Senthilkumar, Kalimuthu; Arunakaran, Jagadeesan

2011-09-01

Previous studies have suggested that zinc exerts anticarcinogenic and antiproliferative effects against prostate cancer both in vitro and in rat ventral prostate. Zinc accumulation diminishes early in the course of prostate malignancy and it inhibits the growth of several carcinoma cells through induction of cell cycle arrest and apoptosis. In this study, we have investigated the influence of zinc on N-methyl-N-nitrosourea (MNU) and testosterone (T)-induced prostatic intraepithelial neoplasia in the dorsolateral prostate of Sprague Dawley (SD) rats. The results indicate that zinc plays an important role in prostate carcinogenesis. Increased tumor incidence was accompanied by a decrease in prostatic acid phosphatase activity, citrate, zinc, glutathione-S-transferase, reduced glutathione, p53, B-cell lymphoma protein (Bcl-2)-associated X protein and caspase-3 levels in MNU + T-treated rats. On the contrary, significantly increased phase I drug metabolizing enzyme activities, lipid peroxide, hydrogen peroxide, proliferating cell nuclear antigen, Bcl-2 and Bcl-X(L) protein levels were observed in the dorsolateral prostate of MNU + T-treated rats. Simultaneous zinc supplementation significantly reversed these effects in MNU + T-treated rats. Signs of dysplasia, a characteristic of prostatic intraepithelial neoplasia, were evident in the dorsolateral prostatic tissue sections by MNU + T administration. However, zinc supplementation has reversed these effects in the dorsolateral prostatic histoarchitecture. These results suggest that zinc may act as an essential trace element against MNU and testosterone-induced prostatic preneoplastic progression in SD rats.

Coadministration of puerarin (low dose) and zinc attenuates bone loss and suppresses bone marrow adiposity in ovariectomized rats.

PubMed

Liu, Hao; Li, Wei; Ge, Xiyuan; Jia, Shengnan; Li, Binbin

2016-12-01

Puerarin is a phytoestrogen that shows osteogenic effects. Meanwhile, zinc stimulates bone formation and inhibits bone resorption. The study aims to investigate the effects of coadministration of puerarin (low dose) and zinc on bone formation in ovariectomized rats. Co-administration or use alone of puerarin (low dose) and/or zinc were gavaged in OVX rats. The estrogen-like effects were detected by the uterus weight, the histologic observation and the IGF-1 protein expression. The osteogenic effects were determined by bone histomorphometric and mechanical parameters, osteogenic and adipogenic blood markers, and so on. The results showed that oral administration of puerarin (low dose) plus zinc didn't significantly increase uterus weight. The glandular epithelial of endometrium had no proliferation and no protein expression of IGF-1. Moreover, co-administration attenuated bone loss and biomechanical decrease more than single use of puerarin or zinc (p<0.05). Next, combined administration of puerarin and zinc promoted the serological level of osteocalcin, bone marrow stromal cell (BMSC) proliferation, and the expression of alkaline phosphatase (ALP), and suppressed the serological level of adiponectin and adiposity in bone marrow (BM). In conclusion, co-administrated puerarin (low dose) and zinc can partially reverse OVX-induced bone loss and suppress the adiposity of BM in rats, which shed light on the potential use of puerarin and zinc in the treatment of osteoporosis. Copyright © 2016 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsou, Tsui-Chun, E-mail: tctsou@nhri.org.tw; Liou, Saou-Hsing; Yeh, Szu-Ching

Our previous studies indicated that zinc induced inflammatory response in both vascular endothelial cells and promonocytes. Here, we asked if other metals could cause the similar effect on vascular endothelial cells and tried to determine its underlying mechanism. Following screening of fifteen metals, zinc and nickel were identified with a marked proinflammatory effect, as determined by ICAM-1 and IL-8 induction, on human umbilical vein endothelial cells (HUVECs). Inhibiting protein expression of myeloid differentiation primary response protein-88 (MyD88), a Toll-like receptor (TLR) adaptor acting as a TLR-signaling transducer, significantly attenuated the zinc/nickel-induced inflammatory response, suggesting the critical roles of TLRs inmore » the inflammatory response. Blockage of TLR-4 signaling by CLI-095, a TLR-4 inhibitor, completely inhibited the nickel-induced ICAM-1 and IL-8 expression and NFκB activation. The same CLI-095 treatment significantly blocked the zinc-induced IL-8 expression, however with no significant effect on the ICAM-1 expression and a minor inhibitory effect on the NFκB activation. The finding demonstrated the differential role of TLR-4 in regulation of the zinc/nickel-induced inflammatory response, where TLR-4 played a dominant role in NFκB activation by nickel, but not by zinc. Moreover, inhibition of NFκB by adenovirus-mediated IκBα expression and Bay 11-7025, an inhibitor of cytokine-induced IκB-α phosphorylation, significantly attenuated the zinc/nickel-induced inflammatory responses, indicating the critical of NFκB in the process. The study demonstrates the crucial role of TLRs in the zinc/nickel-induced inflammatory response in vascular endothelial cells and herein deciphers a potential important difference in NFκB activation via TLRs. The study provides a molecular basis for linkage between zinc/nickel exposure and pathogenesis of the metal-related inflammatory vascular disease. - Highlights: • Both zinc and nickel cause ICAM-1/IL‑8 expression in endothelial cells via TLRs. • Nickel induces the inflammatory responses via a TLR-4/NF-κB pathway. • Zinc causes the inflammatory responses via a broader TLRs/NF-κB signaling. • Nickel shows a significantly higher inflammatory effect than zinc. • NF-κB activation is the primary mechanism involved in the inflammatory responses.« less

A comprehensive review of the role of zinc in normal prostate function and metabolism; and its implications in prostate cancer☆

PubMed Central

Costello, Leslie C.; Franklin, Renty B.

2016-01-01

The human prostate gland contains extremely high zinc levels; which is due to the specialized zinc-accumulating acinar epithelial of the peripheral zone. These cells evolved for their unique capability to produce and secrete extremely levels of citrate, which is achieved by the high cellular zinc level effects on the cell metabolism. This review highlights the specific functional and metabolic alterations that result from the accumulation of the high zinc levels, especially its effects on mitochondrial citrate metabolism and terminal oxidation. The implications of zinc in the development and progression of prostate cancer are described, which is the most consistent hallmark characteristic of prostate cancer. The requirement for decreased zinc resulting from down regulation of ZIP1 to prevent zinc cytotoxicity in the malignant cells is described as an essential early event in prostate oncogenesis. This provides the basis for the concept that an agent (such as the zinc ionophore, clioquinol) that facilitates zinc uptake and accumulation in ZIP1-deficient prostate tumors cells will markedly inhibit tumor growth. In the current absence of an efficacious chemotherapy for advanced prostate cancer, and for prevention of early development of malignancy; a zinc treatment regimen is a plausible approach that should be pursued. PMID:27132038

Factors influence flexibility resistivity and zinc dendrite penetration rate of inorganic separators for alkaline batteries

NASA Technical Reports Server (NTRS)

Sheibley, D. W.

1975-01-01

Developmental work resulted in a formulation which can improve the flexibility of the inorganic-organic-type separator for silver-zinc and nickel-zinc alkaline batteries. The effects of various fillers and reactive organic additives on separator volume resistivity are described. The effects of various inert fillers on the zinc dendrite penetration rate of the separator are shown. Conclusions regarding the operating mechanism of the separator are presented.

Effect of maternal zinc supplementation on the cardiometabolic profile of Peruvian children: results from a randomized clinical trial

PubMed Central

Mispireta, ML; Caulfield, LE; Zavaleta, N; Merialdi, M; Putnick, DL; Bornstein, MH; DiPietro, JA

2018-01-01

Zinc is an essential micronutrient for the development of the fetal renal, cardiovascular, and metabolic systems; however, there is limited evidence of its effects on the postnatal cardiometabolic function. In this study, we evaluated the effect of maternal zinc supplementation during pregnancy on the cardiometabolic profile of the offspring in childhood. A total of 242 pregnant women were randomly assigned to receive a daily supplement containing iron + folic acid with or without zinc. A follow-up study was conducted when children of participating mothers were 4.5 years of age to evaluate their cardiometabolic profile, including anthropometric measures of body size and composition, blood pressure, lipid profile, and insulin resistance. No difference in measures of child cardiometabolic risk depending on whether mothers received supplemental zinc during pregnancy. Our results do not support the hypothesis that maternal zinc supplementation reduces the risk of offspring cardiometabolic disease. PMID:27748235

Effects of Zinc Gluconate and 2 Other Divalent Cationic Compounds on Olfactory Function in Mice

PubMed Central

Duncan-Lewis, Christopher A; Lukman, Roy L; Banks, Robert K

2011-01-01

Intranasal application of zinc gluconate has commonly been used to treat the common cold. The safety of this treatment, however, has come into question recently. In addition to a United States recall of a homeopathic product that contains zinc gluconate, abundant literature reports cytotoxic effects of zinc on the olfactory epithelium. Additional research suggests that divalent cations (such as zinc) can block ion channels that facilitate the transduction of odors into electrical signals on the olfactory epithelium. The purpose of the current study was 2-fold: to confirm whether zinc gluconate causes anosmia and to reveal whether any other divalent cationic compounds produce a similar effect. Groups of mice underwent a buried food-pellet test to gauge olfactory function and then were nasally irrigated with 1 of 3 divalent cationic compounds. When tested after treatment, mice irrigated with zinc gluconate and copper gluconate experienced a marked increase in food-finding time, indicating that they had lost their ability to smell a hidden food source. Control mice irrigated with saline had a significantly lower increase in times. These results confirm that zinc gluconate can cause anosmia and reveal that multiple divalent cations can negatively affect olfaction. PMID:22330252

Impact of glutathione metabolism on zinc homeostasis in Saccharomyces cerevisiae.

PubMed

Steiger, Matthias G; Patzschke, Anett; Holz, Caterina; Lang, Christine; Causon, Tim; Hann, Stephan; Mattanovich, Diethard; Sauer, Michael

2017-06-01

Zinc is a crucial mineral for all organisms as it is an essential cofactor for the proper function of a plethora of proteins and depletion of zinc causes oxidative stress. Glutathione is the major redox buffering agent in the cell and therefore important for mitigation of the adverse effects of oxidative stress. In mammalian cells, zinc deficiency is accompanied by a glutathione depletion. In the yeast Saccharomyces cerevisiae, the opposite effect is observed: under low zinc conditions, an elevated glutathione concentration is found. The main regulator to overcome zinc deficiency is Zap1p. However, we show that Zap1p is not involved in this glutathione accumulation phenotype. Furthermore, we found that in glutathione-accumulating strains also the metal ion-binding phytochelatin-2, which is an oligomer of glutathione, is accumulated. This increased phytochelatin concentration correlates with a lower free zinc level in the vacuole. These results suggest that phytochelatin is important for zinc buffering in S. cerevisiae and thus explains how zinc homeostasis is connected with glutathione metabolism. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effects of Different Zinc Species on Cellar Zinc Distribution, Cell Cycle, Apoptosis and Viability in MDAMB231 Cells.

PubMed

Wang, Yan-hong; Zhao, Wen-jie; Zheng, Wei-juan; Mao, Li; Lian, Hong-zhen; Hu, Xin; Hua, Zi-chun

2016-03-01

Intracellular metal elements exist in mammalian cells with the concentration range from picomoles per litre to micromoles per litre and play a considerable role in various biological procedures. Element provided by different species can influence the availability and distribution of the element in a cell and could lead to different biological effects on the cell's growth and function. Zinc as an abundant and widely distributed essential trace element, is involved in numerous and relevant physiological functions. Zinc homeostasis in cells, which is regulated by metallothioneins, zinc transporter/SLC30A, Zrt-/Irt-like proteins/SLC39A and metal-response element-binding transcription factor-1 (MTF-1), is crucial for normal cellular functioning. In this study, we investigated the influences of different zinc species, zinc sulphate, zinc gluconate and bacitracin zinc, which represented inorganic, organic and biological zinc species, respectively, on cell cycle, viability and apoptosis in MDAMB231 cells. It was found that the responses of cell cycle, apoptosis and death to different zinc species in MDAMB231 cells are different. Western blot analysis of the expression of several key proteins in regulating zinc-related transcription, cell cycle, apoptosis, including MTF-1, cyclin B1, cyclin D1, caspase-8 and caspase-9 in treated cells further confirmed the observed results on cell level.

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

PubMed

De Mel, Damitha; Suphioglu, Cenk

2014-08-15

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

Clioquinol-zinc chelate: a candidate causative agent of subacute myelo-optic neuropathy.

PubMed Central

Arbiser, J. L.; Kraeft, S. K.; van Leeuwen, R.; Hurwitz, S. J.; Selig, M.; Dickersin, G. R.; Flint, A.; Byers, H. R.; Chen, L. B.

1998-01-01

BACKGROUND: 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol) was used clinically three decades ago as an oral antiparasitic agent and to increase intestinal absorption of zinc in patients with acrodermatitis enteropathica, a genetic disorder of zinc absorption. Use of clioquinol was epidemiologically linked to subacute myelo-optic neuropathy (SMON), characterized by peripheral neuropathy and blindness, which affected 10,000 patients in Japan. Discontinuation of oral clioquinol use led to elimination of SMON, however, the mechanism of how clioquinol induces neurotoxicity is unclear. MATERIALS AND METHODS: We tested the effect of clioquinol-metal chelates on neural crest-derived melanoma cells. The effect of clioquinol chelates on cells was further studied by electron microscopy and by a mitochondrial potential-sensitive fluorescent dye. RESULTS: Of the ions tested, only clioquinol-zinc chelate demonstrated cytotoxicity. The cytotoxicity of clioquinol-zinc chelate was extremely rapid, suggesting that its primary effect was on the mitochondria. Electron microscopic analysis demonstrated that clioquinol-zinc chelate caused mitochondrial damage. This finding was further confirmed by the observation that clioquinol-zinc chelate caused a decrease in mitochondrial membrane potential. CONCLUSIONS: We demonstrate that clioquinol, in the presence of zinc, is converted to a potent mitochondrial toxin. The phenomenon of clioquinol mediated toxicity appears to be specific to zinc and is not seen with other metals tested. Since clioquinol has been shown to cause increased systemic absorption of zinc in humans, it is likely that clioquinol-zinc chelate was present in appreciable levels in patients with SMON and may be the ultimate causative toxin of SMON. Images Fig. 2 Fig. 3 PMID:9848083

Cetyltrimethyl Ammonium Bromide as Corrosion Inhibitor for Zinc Used in Hydrochloric Acid

NASA Astrophysics Data System (ADS)

Sun, C. X.; Du, J. J.; Ma, Z. W.; Huang, C. S.; Wu, J. Y.

2018-05-01

A compound inhibitor composed of cetyltrimethyl ammonium bromide (CTAB) and bromohexadecyl pyridine was tested as corrosion inhibitor for zinc in hydrochloric acid. The results of static coupon test show that the compound inhibitor can effectively protect zinc from corrosion and the best concentration ratio is CTAB 50 mg/L and bromohexadecyl pyridine 200 mg/L. The polarization results show that the compound inhibitor will cause a negative shift of E0 of zinc in hydrochloric acid. The EIS (electrchemical impedance spectra) results show that the inhibitor leads to a bigger radius and has one time constant. SEM results show that the CTAB and bromohexadecyl pyridine form a uniform and compact membrane on the surface of zinc that can protect zinc from corroding effectively.

Estimating the Global Prevalence of Inadequate Zinc Intake from National Food Balance Sheets: Effects of Methodological Assumptions

PubMed Central

Wessells, K. Ryan; Singh, Gitanjali M.; Brown, Kenneth H.

2012-01-01

Background 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. Methodology and Principal Findings 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%. Conclusions and Significance 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-specific rank order of estimated prevalence of inadequate zinc intake. PMID:23209781

Controlling charge balance and exciton recombination by bipolar host in single-layer organic light-emitting diodes

NASA Astrophysics Data System (ADS)

Qiao, Xianfeng; Tao, Youtian; Wang, Qiang; Ma, Dongge; Yang, Chuluo; Wang, Lixiang; Qin, Jingui; Wang, Fosong

2010-08-01

Highly efficient single-layer organic light-emitting diodes with reduced efficiency roll-off are demonstrated by using a bipolar host material of 2,5-bis(2-(9H-carbazol-9-yl)phenyl)-1,3,4-oxadiazole (o-CzOXD) doped with iridium complexes as the emissive layer. For example, the green single-layer device, employing fac-tris(2-phenylpyridine)iridium Ir(ppy)3 as dopant, shows a peak current efficiency of 45.57 cd A-1, corresponding to external quantum efficiency (EQE) of 12.42%, and still exhibits efficiencies of 45.26 cd A-1 and 40.42 cd A-1 at luminance of 1000 and 10 000 cd m-2, respectively. In addition, the yellow and red single-layer devices, with bis(2-(9,9- diethyl-9H-fluoren-2-yl)-1-phenyl-1H-benzoimidazol-N ,C3)iridium(acetylacetonate) (fbi)2Ir(acac) and bis(1-phenylisoquinolinolato-C2,N)iridium(acetylacetonate) (piq)2Ir(acac) as emitter, also show high EQE of 7.04% and 7.28%, respectively. The transport properties of o-CzOXD film are well investigated by current-voltage measurement, from which both hole and electron mobility are determined. It is found that the o-CzOXD shows appealing bipolar transport character, which is favor for the balanced charge distribution in the whole doped zone. More importantly, the multifunctional role of hole trapping and electron transporting of the iridium complex in o-CzOXD further balances the charge carriers and broadens the recombination zone. As a result, the recombination of electrons and holes is significantly improved and the triplet-triplet annihilation and triplet-polaron quenching processes are effectively suppressed, eventually leading to the high efficiency as well as the reduced efficiency roll-off.

Potential of acetylacetone as a mediator for Trametes versicolor laccase in enzymatic transformation of organic pollutants.

PubMed

Yang, Hua; Sun, Hongfei; Zhang, Shujuan; Wu, Bingdang; Pan, Bingcai

2015-07-01

Low-cost and environmentally friendly mediators could facilitate the application of laccase (EC 1.10.3.2) in variant biotechnological processes. Acetylacetone (AA) represents an inexpensive and low toxic small molecular diketone that has been proven as an effective mediator for laccase in free radical polymerization. However, the potential of AA as a mediator for laccase in pollutant detoxification and/or degradation is still unknown. In this work, the roles of AA in laccase-induced polymerization and transformation were investigated. AA was demonstrated to be a highly efficient mediator in the laccase-induced grafting copolymerization of acrylamide and chitosan. The efficacy of AA in the laccase-induced decoloration of malachite green (MG) was compared with that of the widely used 1-hydroxybenzotriazole (HBT). The laccase-AA system had the highest turnover number (TON, 39.1 μmol/U), followed by the laccase-only system (28.5 μmol/U), while the TON of the laccase-HBT system was the lowest (14.9 μmol/U). The pseudo-first-order transformation rate constant (k 1) of MG in the laccase-AA system was up to 0.283 h(-1) under the given conditions, while the k 1 of AA caused by laccase was only 0.008 h(-1). In the five-cycle run, the concentration of AA remained stable. The larger TON of the laccase-AA system and the stability of AA in the cycling runs demonstrate that AA was more recyclable than HBT in the LMS, leading to a prolonged serving life of laccase. These results suggest that AA might be a potential redox mediator for laccase.

Zinc and Wound Healing: A Review of Zinc Physiology and Clinical Applications.

PubMed

Kogan, Samuel; Sood, Aditya; Garnick, Mark S

2017-04-01

Our understanding of the role of zinc in normal human physiology is constantly expanding, yet there are major gaps in our knowledge with regard to the function of zinc in wound healing. This review aims to provide the clinician with sufficient understanding of zinc biology and an up-to-date perspective on the role of zinc in wound healing. Zinc is an essential ion that is crucial for maintenance of normal physiology, and zinc deficiency has many manifestations ranging from delayed wound healing to immune dysfunction and impairment of multiple sensory systems. While consensus has been reached regarding the detrimental effects of zinc deficiency on wound healing, there is considerable discord in the literature on the optimal methods and true benefits of zinc supplementation.

Effect of red maca (Lepidium meyenii) on prostate zinc levels in rats with testosterone-induced prostatic hyperplasia.

PubMed

Gonzales, C; Leiva-Revilla, J; Rubio, J; Gasco, M; Gonzales, G F

2012-05-01

Lepidium meyenii (maca) is a plant that grows exclusively above 4000 m in the Peruvian central Andes. Red maca (RM) extract significantly reduced prostate size in rats with benign prostatic hyperplasia (BPH) induced by testosterone enanthate (TE). Zinc is an important regulator of prostate function. This study aimed to determine the effect of RM on prostate zinc levels in rats with BPH induced by TE. Also, the study attempted to determine the best marker for the effect of RM on sex accessory glands. Rats treated with RM extract from day 1 to day 14 reversed the effect of TE administration on prostate weight and zinc levels. However, RM administered from day 7 to day 14 did not reduce the effect of TE on all studied variables. Finasteride (FN) reduced prostate, seminal vesicle and preputial gland weights in rats treated with TE. Although RM and FN reduced prostate zinc levels, the greatest effect was observed in TE-treated rats with RM from day 1 to day 14. In addition, prostate weight and zinc levels showed the higher diagnosis values than preputial and seminal vesicle weights. In conclusion, RM administered from day 1 to day 14 reduced prostate size and zinc levels in rats where prostatic hyperplasia was induced with TE. Also, this experimental model could be used as accurately assay to determine the effect of maca obtained under different conditions and/or the effect of different products based on maca. © 2011 Blackwell Verlag GmbH.

Effect of zinc intake on hepatic autophagy during acute alcohol intoxication.

PubMed

Liuzzi, Juan P; Narayanan, Vijaya; Doan, Huong; Yoo, Changwon

2018-04-01

Autophagy is a conserved mechanism that plays a housekeeping role by eliminating protein aggregates and damaged organelles. Recent studies have demonstrated that acute ethanol intoxication induces hepatic autophagy in mice. The effect of dietary zinc intake on hepatic autophagic flux during ethanol intoxication has not been evaluated using animal models. Herein, we investigated whether zinc deficiency and excess can affect autophagic flux in the liver in mice and in human hepatoma cells acutely exposed to ethanol. A mouse model of binge ethanol feeding was utilized to analyze the effect of low, adequate, and high zinc intake on hepatic autophagic flux during ethanol intoxication. Autophagic flux was inferred by analyzing LC3II/LC3I ratio, protein levels of p62/SQSTM1, Beclin1 and Atg7, and phosphorylation of 4EBP1. In addition, the degradation of the fusion protein LC3-GFP and the formation of autophagosomes and autolysosomes were evaluated in cells. Ethanol treatment stimulated autophagy in mice and cells. High zinc intake resulted in enhanced autophagy in mice exposed to ethanol. Conversely, zinc deficiency was consistently associated with impaired ethanol-induced autophagy in mice and cells. Zinc-deficient mice exhibited a high degree of ethanol-driven steatosis. Furthermore, zinc depletion increased apoptosis in cells exposed to ethanol. The results of this study suggest that adequate zinc intake is necessary for proper stimulation of autophagy by ethanol. Poor zinc status is commonly found among alcoholics and could likely contribute to faulty autophagy.

Extracellular chelation of zinc does not affect hippocampal excitability and seizure-induced cell death in rats

PubMed Central

Lavoie, Nathalie; Peralta, Modesto R; Chiasson, Marilou; Lafortune, Kathleen; Pellegrini, Luca; Seress, László; Tóth, Katalin

2007-01-01

In the nervous system, zinc can influence synaptic responses and at extreme concentrations contributes to epileptic and ischaemic neuronal injury. Zinc can originate from synaptic vesicles, the extracellular space and from intracellular stores. In this study, we aimed to determine which of these zinc pools is responsible for the increased hippocampal excitability observed in zinc-depleted animals or following zinc chelation. Also, we investigated the source of intracellularly accumulating zinc in vulnerable neurons. Our data show that membrane-permeable and membrane-impermeable zinc chelators had little or no effect on seizure activity in the CA3 region. Furthermore, extracellular zinc chelation could not prevent the accumulation of lethal concentrations of zinc in dying neurons following epileptic seizures. At the electron microscopic level, zinc staining significantly increased at the presynaptic membrane of mossy fibre terminals in kainic acid-treated animals. These data indicate that intracellular but not extracellular zinc chelators could influence neuronal excitability and seizure-induced zinc accumulation observed in the cytosol of vulnerable neurons. PMID:17095563

Analysis of cellular responses of macrophages to zinc ions and zinc oxide nanoparticles: a combined targeted and proteomic approach.

PubMed

Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Gerdil, Adèle; Diemer, Hélène; Proamer, Fabienne; Collin-Faure, Véronique; Habert, Aurélie; Strub, Jean-Marc; Hanau, Daniel; Herlin, Nathalie; Carrière, Marie; Van Dorsselaer, Alain; Rabilloud, Thierry

2014-06-07

Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate catabolism and proteasome are critical determinants of sensitivity to zinc, which also induces DNA damage. Conversely, glutathione levels and phagocytosis appear unaffected at moderately toxic zinc concentrations.

Dietary catechins and procyanidins modulate zinc homeostasis in human HepG2 cells.

PubMed

Quesada, Isabel M; Bustos, Mario; Blay, Mayte; Pujadas, Gerard; Ardèvol, Anna; Salvadó, M Josepa; Bladé, Cinta; Arola, Lluís; Fernández-Larrea, Juan

2011-02-01

Catechins and their polymers procyanidins are health-promoting flavonoids found in edible vegetables and fruits. They act as antioxidants by scavenging reactive oxygen species and by chelating the redox-active metals iron and copper. They also behave as signaling molecules, modulating multiple cell signalling pathways and gene expression, including that of antioxidant enzymes. This study aimed at determining whether catechins and procyanidins interact with the redox-inactive metal zinc and at assessing their effect on cellular zinc homeostasis. We found that a grape-seed procyanidin extract (GSPE) and the green tea flavonoid (-)-epigallocatechin-3-gallate (EGCG) bind zinc cations in solution with higher affinity than the zinc-specific chelator Zinquin, and dose-dependently prevent zinc-induced toxicity in the human hepatocarcinoma cell line HepG2, evaluated by the lactate dehydrogenase test. GSPE and EGCG hinder intracellular accumulation of total zinc, measured by atomic flame absorption spectrometry, concomitantly increasing the level of cytoplasmic labile zinc detectable by Zinquin fluorescence. Concurrently, GSPE and EGCG inhibit the expression, evaluated at the mRNA level by quantitative reverse transcriptase-polymerase chain reaction, of zinc-binding metallothioneins and of plasma membrane zinc exporter ZnT1 (SLC30A1), while enhancing the expression of cellular zinc importers ZIP1 (SLC39A1) and ZIP4 (SLC39A4). GSPE and EGCG also produce all these effects when HepG2 cells are stimulated to import zinc by treatment with supplemental zinc or the proinflammatory cytokine interleukin-6. We suggest that extracellular complexation of zinc cations and the elevation of cytoplasmic labile zinc may be relevant mechanisms underlying the modulation of diverse cell signaling and metabolic pathways by catechins and procyanidins. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of hypotensive therapy combined with modified diet or zinc supplementation on biochemical parameters and mineral status in hypertensive patients.

PubMed

Suliburska, Joanna; Skrypnik, Katarzyna; Szulińska, Monika; Kupsz, Justyna; Bogdański, Paweł

2018-05-01

Hypotensive therapy leads to a number of trace elements metabolism disturbances. Zinc balance is frequently affected by antihypertensive treatment. To evaluate the effect of a hypotensive treatment, modified diet and zinc supplementation on mineral status and selected biochemical parameters in newly diagnosed hypertensive patients on monotherapy. In the first stage, arterial hypertension in ninety-eight human subjects was diagnosed. In the second stage, antihypertensive monopharmacotherapy was implemented. In the third stage, patients were randomized into three groups and continued antihypertensive monotherapy: group D received an optimal-mineral-content diet, group S received zinc supplementation, and group C had no changes in diet or zinc supplementation. Iron, zinc, and copper concentrations in serum, erythrocytes, urine, and hair were determined. Lipids, glucose, ceruloplasmin, ferritin, albumin, C-reactive protein (CRP), tumor necrosis factor α (TNF-α), nitric oxide (NO), superoxide dismutase (SOD) and catalase (CAT) were assayed in serum. Antihypertensive monotherapy decreased zinc concentration in serum and erythrocytes and increased the level of zinc in urine, decreased CAT and SOD activity, TNF-α concentration in serum, and increased the level of NO in the serum. Zinc supply led to an increase in zinc concentration in serum, erythrocytes, and hair (in group S only). In the groups with higher zinc intake, decreased glucose concentration in the serum was observed. Significant correlation was seen between the zinc and glucose serum concentrations. Hypotensive drugs disturb zinc status in newly diagnosed hypertensive patients. Antihypertensive monotherapy combined with increased zinc supply in the diet or supplementation favorably modify zinc homeostasis and regulate glucose status without blood pressure affecting in patients with hypertension. Copyright © 2018 Elsevier GmbH. All rights reserved.

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

PubMed Central

Truong, Lisa; Barton, Carrie L.; Chase, Tyler T.; Gonnerman, Greg D.; Wong, Carmen P.; Tanguay, Robert L.; Ho, Emily

2017-01-01

Zinc deficiency and chronic low level exposures to inorganic arsenic in drinking water are both significant public health concerns that affect millions of people including pregnant women. These two conditions can co-exist in the human population but little is known about their interaction, and in particular, whether zinc deficiency sensitizes individuals to arsenic exposure and toxicity, especially during critical windows of development. To address this, we utilized the Danio rerio (zebrafish) model to test the hypothesis that parental zinc deficiency sensitizes the developing embryo to low-concentration arsenic toxicity, leading to altered developmental outcomes. Adult zebrafish were fed defined zinc deficient and zinc adequate diets and were spawned resulting in zinc adequate and zinc deficient embryos. The embryos were treated with environmentally relevant concentrations of 0, 50, and 500 ppb arsenic. Arsenic exposure significantly reduced the amount of zinc in the developing embryo by ~7%. The combination of zinc deficiency and low-level arsenic exposures did not sensitize the developing embryo to increased developmental malformations or mortality. The combination did cause a 40% decline in physical activity of the embryos, and this decline was significantly greater than what was observed with zinc deficiency or arsenic exposure alone. Significant changes in RNA expression of genes that regulate zinc homeostasis, response to oxidative stress and insulin production (including zip1, znt7, nrf2, ogg1, pax4, and insa) were found in zinc deficient, or zinc deficiency and arsenic exposed embryos. Overall, the data suggests that the combination of zinc deficiency and arsenic exposure has harmful effects on the developing embryo and may increase the risk for developing chronic diseases like diabetes. PMID:28837703

Synergic effect of salinity and zinc stress on growth and photosynthetic responses of the cordgrass, Spartina densiflora

PubMed Central

Redondo-Gómez, Susana; Andrades-Moreno, Luis; Mateos-Naranjo, Enrique; Parra, Raquel; Valera-Burgos, Javier; Aroca, Ricardo

2011-01-01

Spartina densiflora is a C4 halophytic species that has proved to have a high invasive potential which derives from its physiological plasticity to environmental factors, such as salinity. It is found in coastal marshes of south-west Spain, growing over sediments with between 1 mmol l−1 and 70 mmol l−1 zinc. A glasshouse experiment was designed to investigate the synergic effect of zinc from 0 mmol l−1 to 60 mmol l−1 at 0, 1, and 3% NaCl on the growth and the photosynthetic apparatus of S. densiflora by measuring chlorophyll fluorescence parameters and gas exchange, and its recovery after removing zinc. Antioxidant enzyme activities and total zinc, sodium, calcium, iron, magnesium, manganese, phosphorus, potassium, and nitrogen concentrations were also determined. Spartina densiflora showed the highest growth at 1 mmol l−1 zinc and 1% NaCl after 90 d of treatment; this enhanced growth was supported by the measurements of net photosynthetic rate (A). Furthermore, there was a stimulatory effect of salinity on accumulation of zinc in tillers of this species. Zinc concentrations >1 mmol l−1 reduced growth of S. densiflora, regardless of salinity treatments. This declining growth may be attributed to a decrease in A caused by diffusional limitation of photosynthesis, owing to the modification of the potassium/calcium ratio. Also, zinc and salinity had a marked overall effect on the photochemical (photosystem II) apparatus, partially mediated by the accumulation of H2O2 and subsequent oxidative damage. However, salinity favoured the recovery of the photosynthetic apparatus to the toxic action of zinc, and enhanced the nutrient uptake. PMID:21841175

The Influence of Nitrogen on the Biological Properties of Soil Contaminated with Zinc.

PubMed

Strachel, Rafał; Wyszkowska, Jadwiga; Baćmaga, Małgorzata

2017-03-01

This study analyzed the relationship between nitrogen fertilization and the biological properties of soil contaminated with zinc. The influence of various concentrations of zinc and nitrogen on the microbiological and biochemical activity of soil was investigated. In a laboratory experiment, loamy sand with pH KCl 5.6 was contaminated with zinc (ZnCl 2 ) and fertilized with urea as a source of nitrogen. The activity of acid phosphatase, alkaline phosphatase, urease and β-glucosidase, and microbial counts were determined in soil samples after 2 and 20 weeks of incubation. Zinc generally stimulated hydrolase activity, but the highest zinc dose (1250 mg kg -1 ) led to the inhibition of hydrolases. Nitrogen was not highly effective in neutralizing zinc's negative effect on enzyme activity, but it stimulated the growth of soil-dwelling microorganisms. The changes in soil acidity observed after the addition of urea modified the structure of microbial communities.

Self-assembly of a constitutional dynamic library of Cu(II) coordination polygons and reversible sorting by crystallization.

PubMed

Rancan, Marzio; Tessarolo, Jacopo; Zanonato, Pier Luigi; Seraglia, Roberta; Quici, Silvio; Armelao, Lidia

2013-06-07

A small coordination constitutional dynamic library (CDL) is self-assembled from Cu(2+) ions and the ortho bis-(3-acetylacetone)benzene ligand. Two coordination polygons, a rhomboid and a triangle, establish a dynamic equilibrium. Quantitative sorting of the rhomboidal polygon is reversibly obtained by crystallization. Thermodynamic and kinetic aspects ruling the CDL system have been elucidated.

Synthesis of novel heterocycles through reaction of indolin-2-one derivatives with active methylene and amino reagents.

PubMed

Abdel-Latif, F F; Ahmed, E K; Mekheimer, R; Mashaly, M M

1997-10-01

Several new spiro compounds were synthesized via one-pot ternary condensation of isatin, malononitrile and each of thiobarbituric acid, barbituric acid, 3-methyl-pyrazolin-5-one, 1-phenyl-3-methyl-pyrazolin-5-one, acetylacetone, benzoylacetone, ethyl acetoacetate, phenacyl cyanide or ethyl-cyanoacetate dimer. Structures and reaction mechanism were reported and supported via a second synthetic route.

Semi-automatic spray pyrolysis deposition of thin, transparent, titania films as blocking layers for dye-sensitized and perovskite solar cells

PubMed Central

Krýsová, Hana; Kavan, Ladislav

2018-01-01

For proper function of the negative electrode of dye-sensitized and perovskite solar cells, the deposition of a nonporous blocking film is required on the surface of F-doped SnO2 (FTO) glass substrates. Such a blocking film can minimise undesirable parasitic processes, for example, the back reaction of photoinjected electrons with the oxidized form of the redox mediator or with the hole-transporting medium can be avoided. In the present work, thin, transparent, blocking TiO2 films are prepared by semi-automatic spray pyrolysis of precursors consisting of titanium diisopropoxide bis(acetylacetonate) as the main component. The variation in the layer thickness of the sprayed films is achieved by varying the number of spray cycles. The parameters investigated in this work were deposition temperature (150, 300 and 450 °C), number of spray cycles (20–200), precursor composition (with/without deliberately added acetylacetone), concentration (0.05 and 0.2 M) and subsequent post-calcination at 500 °C. The photo-electrochemical properties were evaluated in aqueous electrolyte solution under UV irradiation. The blocking properties were tested by cyclic voltammetry with a model redox probe with a simple one-electron-transfer reaction. Semi-automatic spraying resulted in the formation of transparent, homogeneous, TiO2 films, and the technique allows for easy upscaling to large electrode areas. The deposition temperature of 450 °C was necessary for the fabrication of highly photoactive TiO2 films. The blocking properties of the as-deposited TiO2 films (at 450 °C) were impaired by post-calcination at 500 °C, but this problem could be addressed by increasing the number of spray cycles. The modification of the precursor by adding acetylacetone resulted in the fabrication of TiO2 films exhibiting perfect blocking properties that were not influenced by post-calcination. These results will surely find use in the fabrication of large-scale dye-sensitized and perovskite solar cells. PMID:29719764

Effect of increased concentrations of atmospheric carbon dioxide on the global threat of zinc deficiency: a modelling study.

PubMed

Myers, Samuel S; Wessells, K Ryan; Kloog, Itai; Zanobetti, Antonella; Schwartz, Joel

2015-10-01

Increasing concentrations of atmospheric carbon dioxide (CO2) lower the content of zinc and other nutrients in important food crops. Zinc deficiency is currently responsible for large burdens of disease globally, and the populations who are at highest risk of zinc deficiency also receive most of their dietary zinc from crops. By modelling dietary intake of bioavailable zinc for the populations of 188 countries under both an ambient CO2 and elevated CO2 scenario, we sought to estimate the effect of anthropogenic CO2 emissions on the global risk of zinc deficiency. We estimated per capita per day bioavailable intake of zinc for the populations of 188 countries at ambient CO2 concentrations (375-384 ppm) using food balance sheet data for 2003-07 from the Food and Agriculture Organization. We then used previously published data from free air CO2 enrichment and open-top chamber experiments to model zinc intake at elevated CO2 concentrations (550 ppm, which is the concentration expected by 2050). Estimates developed by the International Zinc Nutrition Consultative Group were used for country-specific theoretical mean daily per-capita physiological requirements for zinc. Finally, we used these data on zinc bioavailability and population-weighted estimated average zinc requirements to estimate the risk of inadequate zinc intake among the populations of the different nations under the two scenarios (ambient and elevated CO2). The difference between the population at risk at elevated and ambient CO2 concentrations (ie, population at new risk of zinc deficiency) was our measure of impact. The total number of people estimated to be placed at new risk of zinc deficiency by 2050 was 138 million (95% CI 120-156). The people likely to be most affected live in Africa and South Asia, with nearly 48 million (32-63) residing in India alone. Global maps of increased risk show significant heterogeneity. Our results indicate that one heretofore unquantified human health effect associated with anthropogenic CO2 emissions will be a significant increase in the human population at risk of zinc deficiency. Our country-specific findings can be used to help guide interventions aimed at reducing this vulnerability. Bill & Melinda Gates Foundation, Winslow Foundation. Copyright © 2015 Myers et al. Open access article published under the terms of CC BY-NC-ND. Published by Elsevier Ltd.. All rights reserved.

The effect of zinc limitation on the transcriptome of Pseudomonas protegens Pf-5

USDA-ARS?s Scientific Manuscript database

Zinc is an important nutrient but can be lacking in some soil environments, influencing the physiology of soil-dwelling bacteria. Hence, we studied the global effect of zinc limitation on the transcriptome of the rhizosphere biocontrol strain Pseudomonas protegens Pf-5. We observed that the expressi...

Prenatal zinc supplementation of zinc-adequate rats adversely affects immunity in offspring

USDA-ARS?s Scientific Manuscript database

We previously showed that zinc (Zn) supplementation of Zn-adequate dams induced immunosuppressive effects that persist in the offspring after weaning. We investigated whether the immunosuppressive effects were due to in utero exposure and/or mediated via milk using a cross-fostering design. Pregnant...

Zinc acetate lozenges for treating the common cold: an individual patient data meta-analysis.

PubMed

Hemilä, Harri; Petrus, Edward J; Fitzgerald, James T; Prasad, Ananda

2016-11-01

The aim of this study was to determine whether the allergy status and other characteristics of common cold patients modify the effects of zinc acetate lozenges. We had available individual patient data for three randomized placebo-controlled trials in which zinc acetate lozenges were administered to common cold patients. We used both one stage and two stage meta-analysis to estimate the effects of zinc lozenges. The total number of common cold patients was 199, the majority being females. Eighty percent of them fell into the age range 20-50 years. One third of the patients had allergies. The one stage meta-analysis gave an overall estimate of 2.73 days (95% CI 1.8, 3.3 days) shorter colds by zinc acetate lozenge usage. The two stage meta-analysis gave an estimate of 2.94 days (95% CI 2.1, 3.8 days) reduction in common cold duration. These estimates are to be compared with the 7 day average duration of colds in the three trials. The effect of zinc lozenges was not modified by allergy status, smoking, baseline severity of the common cold, age, gender or ethnic group. Since the effects of zinc acetate lozenges were consistent between the compared subgroups, the overall estimates for effect seemed applicable over a wide range of common cold patients. While the optimal composition of zinc lozenges and the best frequency of their administration should be further investigated, given the current evidence of efficacy, common cold patients may be encouraged to try zinc lozenges for treating their colds. © 2016 The British Pharmacological Society.

Zinc acetate lozenges for treating the common cold: an individual patient data meta‐analysis

PubMed Central

Petrus, Edward J.; Fitzgerald, James T.; Prasad, Ananda

2016-01-01

Aims The aim of this study was to determine whether the allergy status and other characteristics of common cold patients modify the effects of zinc acetate lozenges. Methods We had available individual patient data for three randomized placebo‐controlled trials in which zinc acetate lozenges were administered to common cold patients. We used both one stage and two stage meta‐analysis to estimate the effects of zinc lozenges. Results The total number of common cold patients was 199, the majority being females. Eighty percent of them fell into the age range 20–50 years. One third of the patients had allergies. The one stage meta‐analysis gave an overall estimate of 2.73 days (95% CI 1.8, 3.3 days) shorter colds by zinc acetate lozenge usage. The two stage meta‐analysis gave an estimate of 2.94 days (95% CI 2.1, 3.8 days) reduction in common cold duration. These estimates are to be compared with the 7 day average duration of colds in the three trials. The effect of zinc lozenges was not modified by allergy status, smoking, baseline severity of the common cold, age, gender or ethnic group. Conclusion Since the effects of zinc acetate lozenges were consistent between the compared subgroups, the overall estimates for effect seemed applicable over a wide range of common cold patients. While the optimal composition of zinc lozenges and the best frequency of their administration should be further investigated, given the current evidence of efficacy, common cold patients may be encouraged to try zinc lozenges for treating their colds. PMID:27378206

Temperature effect on the structure and conformational fluctuations in two zinc knuckles from the mouse mammary tumor virus.

PubMed

Nedjoua, Drici; Krallafa, Abdelghani Mohamed

2018-06-01

Zinc fingers are small protein domains in which zinc plays a structural role, contributing to the stability of the zinc-peptide complex. Zinc fingers are structurally diverse and are present in proteins that perform a broad range of functions in various cellular processes, such as replication and repair, transcription and translation, metabolism and signaling, cell proliferation, and apoptosis. Zinc fingers typically function as interaction modules and bind to a wide variety of compounds, such as nucleic acids, proteins, and small molecules. In this study, we investigated the structural properties, in solution, of the proximal and distal zinc knuckles of the nucleocapsid (NC) protein from the mouse mammary tumor virus (MMTV) (MMTV NC). For this purpose, we performed a series of molecular dynamics simulations in aqueous solution at 300 K, 333 K, and 348 K. The temperature effect was evaluated in terms of root mean square deviation of the backbone atoms and root mean square fluctuation of the coordinating residue atoms. The stability of the zinc coordination sphere was analyzed based upon the time profile of the interatomic distances between the zinc ions and the chelator atoms. The results indicate that the hydrophobic character of the proximal zinc finger is dominant at 333 K. The low mobility of the coordinating residues suggests that the strong electrostatic effect exerted by the zinc ion on its coordinating residues is not influenced by the increase in temperature. The evolution of the structural parameters of the coordination sphere of the distal zinc finger at 300 K gives us a reasonable picture of the unfolding pathway, as proposed by Bombarda and coworkers (Bombarda et al., 2005), which can predict the binding order of the four conserved ligand-binding residues. Our results support the conclusion that the structural features can vary significantly between the two zinc knuckles of MMTV NC. Copyright © 2018 Elsevier Ltd. All rights reserved.

Role of oral zinc supplementation for reduction of neonatal hyperbilirubinemia: a systematic review of current evidence.

PubMed

Sharma, Deepak; Farahbakhsh, Nazanin; Sharma, Pradeep; Shastri, Sweta

2017-08-01

Neonatal hyperbilirubinemia is frequently seen condition in the NICU. Oral zinc has been tried for the prevention of hyperbilirubinemia. To evaluate the role of oral zinc supplementation for reduction of neonatal hyperbilirubinemia in term and preterm infants. The literature search was done for various randomized control trial (RCT) by searching the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, Web of Science, Scopus, Index Copernicus, African Index Medicus (AIM), Thomson Reuters (ESCI), Chemical Abstracts Service (CAS) and other data base. This review included six RCT that fulfilled inclusion criteria. One study evaluated the role of zinc in very low birth weight (VLBW) infants and remaining enrolled neonates  ≥35 weeks of gestation. The dose of zinc varied from 5 to 20 mg/day and duration from 5-7 days. All the studies used zinc sulfate, only one study used zinc gluconate. The total neonates enrolled in these different RCT are 749. Role of zinc in the prevention of neonatal hyperbilirubinemia is not supported by the current evidence. Only one study was able to show reduction in the mean TSB level and requirement of phototherapy with zinc, and the remaining studies did not report any positive effect. None of the studies showed any effect on the duration of phototherapy, incidence of phototherapy, age of starting of phototherapy and any serious adverse effect.

The effect of polymers onto the size of zinc layered hydroxide salt and its calcined product

NASA Astrophysics Data System (ADS)

Hussein, Mohd Zobir bin; Ghotbi, Mohammad Yeganeh; Yahaya, Asmah Hj; Abd Rahman, Mohd Zaki

2009-02-01

Zinc hydroxide nitrate, a brucite-like layered material was synthesized using pH control method. Poly(vinyl alcohol) and poly(ethylene glycol) were used at various percentages as size decreasing agents during the synthesis of zinc hydroxide nitrate. SEM and PXRD showed the decrease of size and thickness of the resultant zinc hydroxide nitrates. TG and surface area data confirmed the decrease of the particle sizes, too. When zinc hydroxide nitrates were heat treated at 500 °C, the physical properties of nano zinc oxides obtained depended on the parent material, zinc hydroxide nitrate.

Effects of Dietary Copper and Zinc Supplementation on Growth Performance, Tissue Mineral Retention, Antioxidant Status, and Fur Quality in Growing-Furring Blue Foxes (Alopex lagopus).

PubMed

Liu, Zhi; Wu, Xuezhuang; Zhang, Tietao; Guo, Jungang; Gao, Xiuhua; Yang, Fuhe; Xing, Xiumei

2015-12-01

A 4×2 factorial experiment with four supplemental levels of copper (0, 20, 40, or 60 mg copper per kg dry matter) from copper sulfate and two supplemental levels of zinc (40 or 200 mg zinc per kg dry matter) from zinc sulfate was conducted to investigate the effects of dietary copper and zinc supplementation on growth performance, tissue mineral retention, antioxidant status, and fur quality in growing-furring blue foxes. One hundred and twenty healthy 15-week-old male blue foxes were randomly allocated to eight dietary treatments with 15 replicates per treatment for a 70-day trial from mid-September to pelting in December. The average daily gain and feed conversion ratio were increased with copper supplementation in the first 35 days as well as the overall period (P<0.05). In addition, copper supplementation tended to increase feed intake during the first 35 days (P<0.10). Diets supplemented with 200 mg/kg zinc did not affect body gain (P>0.10) and feed intake (P>0.10) but improved feed conversion (P<0.05) compared with those supplemented 40 mg/kg zinc throughout the experiment. No copper×zinc interaction was observed for growth performance except that a tendency (P=0.09) was found for feed intake in the first 35 days. Supplementation of copper or zinc improved crude fat digestibility (P<0.01) but had no effects on the digestibility of other nutrients. Fecal copper was increased with both copper (P<0.01) and zinc addition (P<0.05). However, fecal zinc was affected only by dietary zinc addition (P<0.01). Mineral contents in serum and kidney were not affected by dietary treatments (P>0.05). However, the level of copper in the liver was increased with copper supplementation (P<0.05) and tended to decrease with zinc supplementation (P=0.08). Dietary zinc addition tended to increase the activity of alkaline phosphatase (P=0.07). The activities of copper-zinc superoxide dismutase and catalase tended to increase by copper (P=0.08) and zinc addition (P=0.05). Moreover, a copper×zinc interaction was observed for catalase in the experiment (P<0.05). Serum malondialdehyde concentration decreased with the increasing of dietary copper and zinc levels (P<0.05). The activity of glutathione peroxidase tended to increase by copper addition (P=0.09). For fur quality, foxes fed diets supplemented with high copper had larger skin length and darker pelts than those fed the basal diet without copper addition (P<0.05). In conclusion, this study demonstrated that dietary copper and zinc supplementation can improve growth by increasing feed intake and improving fat digestibility. Additionally, copper and zinc can enhance the antioxidant capacity of blue foxes. This study also indicates that additional zinc up to 200 mg/kg did not exert significant adverse effects on the copper metabolism of growing-furring blue foxes.

RECYCLING ZINC IN VISCOSE RAYON PLANTS BY TWO STAGE PRECIPITATION

EPA Science Inventory

In an EPA demonstration grant, a process for precipitating a dense sludge of high zinc assay was proven. The zinc in the sludge was recovered and recycled to the rayon manufacturing plant. This recycling of zinc was shown to have no ill effects on rayon yarn. This process greatly...

[The effect of zinc therapy on common cold--a survey of a Cochrane review].

PubMed

Valentiner-Branth, Palle

2012-01-09

The Cochrane review "Zinc and the common cold" included 15 randomized controlled double-blind trials. It was concluded, that zinc would shorten the duration of the episode of common cold and also could be used as a prevention so that the risk of developing an episode of common cold would be decreased. It is too early to give general recommendations for the use of zinc as we do not have sufficient knowledge about the optimal dose, formulation and duration of treatment. Further research should focus on the effect of zinc in patients who are at increased risk of developing complications after common cold.

Effect of Zinc Supplementation on Pregnancy and Infant Outcomes: A Systematic Review

PubMed Central

Chaffee, Benjamin W.; King, Janet C.

2013-01-01

Poor maternal zinc status has been associated with foetal loss, congenital malformations, intrauterine growth retardation, reduced birth weight, prolonged labour and preterm or post-term deliveries. A meta-analysis completed in 2007 showed that maternal zinc supplementation resulted in a small but significant reduction in preterm birth. The purposes of this analysis are to update that previous review and expand the scope of assessment to include maternal, infant and child health outcomes. Electronic searches were carried out to identify peer-reviewed, randomised controlled trials where daily zinc supplementation was given for at least one trimester of pregnancy. The co-authors applied the study selection criteria, assessed trial quality and abstracted data. A total of 20 independent intervention trials involving more than 11 000 births were identified. The 20 trials took place across five continents between 1977 and 2008. Most studies assessed the zinc effect against a background of other micronutrient supplements, but five were placebo-controlled trials of zinc alone. The provided dose of supplemental zinc ranged from 5 to 50 mg/day. Only the risk of preterm birth reached statistical significance (summary relative risk 0.86 [95% confidence interval 0.75, 0.99]). There was no evidence that supplemental zinc affected any parameter of foetal growth (risk of low birth weight, birth weight, length at birth or head circumference at birth). Six of the 20 trials were graded as high quality. The evidence that maternal zinc supplementation lowers the risk of preterm birth was graded low; evidence for a positive effect on other foetal outcomes was graded as very low. The effect of zinc supplementation on preterm birth, if causal, might reflect a reduction in maternal infection, a primary cause of prematurity. While further study would be needed to explore this possibility in detail, the overall public health benefit of zinc supplementation in pregnancy appears limited. PMID:22742606

Differential regulation of ASICs and TRPV1 by zinc in rat bronchopulmonary sensory neurons.

PubMed

Vysotskaya, Zhanna V; Moss, Charles R; Gu, Qihai

2014-12-01

Zinc has been known to act as a signaling molecule that regulates a variety of neuronal functions. In this study, we aimed to study the effect of zinc on two populations of acid-sensitive ion channels, acid-sensing ion channels (ASICs), and transient receptor potential vanilloid receptor-1 (TRPV1), in vagal bronchopulmonary sensory neurons. Rat vagal sensory neurons innervating lungs and airways were retrogradely labeled with a fluorescent tracer. Whole-cell perforated patch-clamp recordings were carried out in primarily cultured bronchopulmonary sensory neurons. The acid-evoked ASIC and TRPV1 currents were measured and compared between before and after the zinc pretreatment. ASIC currents were induced by a pH drop from 7.4 to 6.8 or 6.5 in the presence of capsazepine (10 µM), a specific TRPV1 antagonist. Pretreatment with zinc (50 or 300 µM, 2 min) displayed different effects on the two distinct phenotypes of ASIC currents: a marked potentiation on ASIC channels with fast kinetics of activation and inactivation or no significant effect on ASIC currents with slow activation and inactivation. On the other hand, pretreatment with zinc significantly inhibited the acid (pH 5.5 or 5.3)-induced TRPV1 currents. The inhibition was abolished by intracellular chelation of zinc by TPEN (25 µM), indicating that intracellular accumulation of zinc was likely required for its inhibitory effect on TRPV1 channels. Our study showed that zinc differentially regulates the activities of ASICs and TRPV1 channels in rat vagal bronchopulmonary sensory neurons.

Effects of surface hydroxylation on adhesion at zinc/silica interfaces.

PubMed

Le, Ha-Linh Thi; Goniakowski, Jacek; Noguera, Claudine; Koltsov, Alexey; Mataigne, Jean-Michel

2018-06-06

The weak interaction between zinc and silica is responsible for the poor performance of anti-corrosive galvanic zinc coatings on modern advanced high-strength steels, which are fundamental in the automotive industry, and important for rail transport, shipbuilding, and aerospace. With the goal of identifying possible methods for its improvement, we report an ab initio study of the effect of surface hydroxylation on the adhesion characteristics of model zinc/β-cristobalite interfaces, representative of various surface hydroxylation/hydrogenation conditions. We show that surface silanols resulting from dissociative water adsorption at the most stable stoichiometric (001) and (111) surfaces prevent strong zinc-silica interactions. However, dehydrogenation of such interfaces produces oxygen-rich zinc/silica contacts with excellent adhesion characteristics. These are due to partial zinc oxidation and the formation of strong iono-covalent Zn-O bonds between zinc atoms and the under-coordinated excess anions, remnant of the hydroxylation layer. Interestingly, these interfaces appear as the most thermodynamically stable in a wide range of realistic oxygen-rich and hydrogen-lean environments. We also point out that the partial oxidation of zinc atoms in direct contact with the oxide substrate may somewhat weaken the cohesion in the zinc deposit itself. This fundamental analysis of the microscopic mechanisms responsible for the improved zinc wetting on pre-hydroxylated silica substrates provides useful guidelines towards practical attempts to improve adhesion.

Effect of supplementary zinc on body mass index, pulmonary function and hospitalization in children with cystic fibrosis.

PubMed

Ataee, Pedram; Najafi, Mehri; Gharagozlou, Mohammad; Aflatounian, Majid; Mahmoudi, Maryam; Khodadad, Ahmad; Farahmand, Fatemeh; Motamed, Farzaneh; Fallahi, Glolam Hossein; Kalantari, Najmoddin; Soheili, Habib; Modarresi, Vajiheh; Modarresi, Mozhgan Sabbaghian; Rezaei, Nima

2014-01-01

Zinc deficiency, which is common in patients with cystic fibrosis (CF), can lead to several complications that may increase the number of hospital admissions in this group of patients. As supplementary zinc can prevent such complications, this study was performed to evaluate the effect of supplementary zinc on body mass index (BMI), forced expiratory volume in one second (FEV1) and number of hospitalizations in CF patients. In this study, 30 children with CF, who were referred to the Digestive Diseases Clinic of the Children's Medical Center in Tehran, were enrolled. Supplementary zinc of 2 mg/kg per day was administered to all patients. Serum level of zinc, alkaline phosphatase, and albumin as well as BMI, FEV1, and number of hospitalizations were compared before and after zinc administration. Height (p<0.001), weight (p<0.001) and BMI (p=0.001) were significantly increased after zinc, while the number of hospitalizations was significantly decreased (p=0.023). In contrast to patients with normal pulmonary function tests who received supplement therapy, BMI was not increased in those with abnormal pulmonary function after supplementary zinc. Supplementary zinc can increase BMI in CF patients, mostly in those with normal pulmonary function. While supplementary zinc may decrease the number of hospitalizations, other factors can also influence the hospitalization number.

Zinc monotherapy increases serum brain-derived neurotrophic factor (BDNF) levels and decreases depressive symptoms in overweight or obese subjects: a double-blind, randomized, placebo-controlled trial.

PubMed

Solati, Zahra; Jazayeri, Shima; Tehrani-Doost, Mehdi; Mahmoodianfard, Salma; Gohari, Mahmood Reza

2015-05-01

Previous studies have shown a positive effect of zinc as an adjunctive therapy on reducing depressive symptoms. However, to our knowledge, no study has examined the effect of zinc monotherapy on mood. The aim of the present study was to determine the effects of zinc monotherapy on depressive symptoms and serum brain-derived neurotrophic factor (BDNF) levels in overweight or obese subjects. Fifty overweight or obese subjects were randomly assigned into two groups and received either 30 mg zinc or placebo daily for 12 weeks. At baseline and post-intervention, depression severity was assessed using Beck depression inventory II (BDI II), and serum BDNF and zinc levels were determined by enzyme-linked immunosorbent assay and atomic absorption spectrophotometry, respectively. The trial was completed with 46 subjects. After a 12-week supplementation, serum zinc and BDNF levels increased significantly in the zinc-supplemented group compared with the placebo group. BDI scores declined in both the groups at the end of the study, but reduction in the zinc-supplemented group was significantly higher than the placebo group. More analysis revealed that following supplementation, BDI scores decreased in subgroup of subjects with depressive symptoms (BDI ≥ 10) (n = 30), but did not change in the subgroup of non-depressed subjects (BDI < 10) (n = 16). Moreover, a significant inverse correlation was observed between serum BDNF levels and depression severity in all participants. Interestingly, a significant positive correlation was found between serum BDNF and zinc levels at baseline. Zinc monotherapy improves mood in overweight or obese subjects most likely through increasing BDNF levels.

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

PubMed Central

De Mel, Damitha; Suphioglu, Cenk

2014-01-01

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

The permissive effect of zinc deficiency on uroguanylin and inducible nitric oxide synthase gene upregulation in rat intestine induced by interleukin 1alpha is rapidly reversed by zinc repletion.

PubMed

Cui, Li; Blanchard, Raymond K; Cousins, Robert J

2003-01-01

Deficient intake of zinc from the diet upregulates both uroguanylin (UG) and inducible nitric oxide synthase (iNOS) expression in rats. Because these changes influence intestinal fluid secretion and intestinal cell pathophysiology, they relate to the incidence of diarrheal disease and its reversal by zinc as well as intestinal inflammation in general. A model of moderate zinc deficiency in rats, which changes molecular indices of zinc deficiency, was used to further explore the effects of the proinflammatory cytokine interleukin (IL)-1alpha and zinc repletion on these changes. IL-1alpha has been shown to have a role in the intestinal inflammation that occurs with bacterial infection. Our results showed a permissive effect of zinc deficiency on both UG and iNOS expression. Specifically, UG expression was responsive to zinc deficiency and IL-1alpha challenge, which were additive when combined, whereas iNOS expression was upregulated by IL-1alpha only during the deficiency. Immunohistochemistry showed that the increase in UG was limited to enterocytes of the upper villus but, in contrast, the increase in iNOS was principally in cells of the lamina propria of IL-1alpha-treated rats. Cells exhibiting UG upregulation did not co-express serotonin. Repletion with zinc reversed upregulation of the iNOS gene within 1 d, whereas UG upregulation required 3-4 d to return to normal. This differential response to repletion suggests that mechanisms of UG and iNOS dysregulation are different. Dysregulation of both genes may contribute to the severity of zinc-responsive diarrheal disease and intestinal inflammatory disease.

The Effect of Zinc Lozenge on Postoperative Sore Throat: A Prospective Randomized, Double-Blinded, Placebo-Controlled Study.

PubMed

Farhang, Borzoo; Grondin, Lydia

2018-01-01

Postoperative sore throat (POST) is commonly seen after endotracheal intubation, and oral zinc prevents oral mucositis associated with chemotherapy. This study is designed to evaluate the effects of administration of zinc lozenges on POST. Seventy-nine patients undergoing low- or moderate-risk surgery with endotracheal intubation were randomly assigned into 2 groups: Control group received placebo and zinc group received 40-mg zinc lozenges 30 minutes preoperatively. Patients were assessed for incidence and severity (4-point scale, 0-3) of POST at 0, 2, 4, and 24 hours postoperatively. The primary outcome was incidence of POST at 4 hours after surgery. The secondary outcomes were the incidence of POST at 0, 2, and 24 hours and the severity of POST. At 4 hours, there was a significantly lower incidence of POST in the zinc group, 7%, than the control group, 29% (P = .046). The incidence of POST at 0 hour was 0% in zinc group and 24% in control group (P = .004). The highest incidence of POST occurred at the second hour after surgery, with the rate of 10% in the zinc group and 34% in the control group (P = .0495). The incidence of POST at 24 hours was 13% in zinc group and 24% in control group (not significant). The severity of POST was significantly lower in the zinc group for mild (P = .003) and moderate (P = .004) POST. The administration of a single dose of 40-mg zinc lozenge 30 minutes preoperatively is effective to reduce both incidence of POST in the first 4 hours and severity of mild and moderate POST in the immediate postoperative period.

Effect of Preventive Supplementation with Zinc and Other Micronutrients on Non-Malarial Morbidity in Tanzanian Pre-School Children: A Randomized Trial

PubMed Central

Veenemans, Jacobien; Schouten, Laura R. A.; Ottenhof, Maarten J.; Mank, Theo G.; Uges, Donald R. A.; Mbugi, Erasto V.; Demir, Ayşe Y.; Kraaijenhagen, Rob J.; Savelkoul, Huub F. J.; Verhoef, Hans

2012-01-01

Background The efficacy of preventive zinc supplementation against diarrhea and respiratory illness may depend on simultaneous supplementation with other micronutrients. We aimed to assess the effect of supplementation with zinc and multiple micronutrients on diarrhea and other causes of non-malarial morbidity. Methods and Findings Rural Tanzanian children (n = 612) aged 6–60 months and with height-for-age z-score < –1.5 SD were randomized to daily supplementation with zinc (10 mg) alone, multi-nutrients without zinc, multi-nutrients with zinc, or placebo. Children were followed for an average of 45 weeks. During follow-up, we recorded morbidity episodes. We found no evidence that concurrent supplementation with multi-nutrients influenced the magnitude of the effect of zinc on rates of diarrhea, respiratory illness, fever without localizing signs, or other illness (guardian-reported illness with symptoms involving skin, ears, eyes and abscesses, but excluding trauma or burns). Zinc supplementation reduced the hazard rate of diarrhea by 24% (4%–40%). By contrast, multi-nutrients seemed to increase this rate (HR; 95% CI: 1.19; 0.94–1.50), particularly in children with asymptomatic Giardia infection at baseline (2.03; 1.24–3.32). Zinc also protected against episodes of fever without localizing signs (0.75; 0.57–0.96), but we found no evidence that it reduced the overall number of clinic visits. Conclusions We found no evidence that the efficacy of zinc supplements in reducing diarrhea rates is enhanced by concurrent supplementation with other micronutrients. By reducing rates of fever without localizing signs, supplementation with zinc may reduce inappropriate drug use with anti-malarial medications and antibiotics. Trial Registration ClinicalTrials.gov NCT00623857 PMID:22870238

Zinc supplementation reduces the incidence of persistent diarrhea and dysentery among low socioeconomic children in India.

PubMed

Sazawal, S; Black, R E; Bhan, M K; Jalla, S; Bhandari, N; Sinha, A; Majumdar, S

1996-02-01

Persistent diarrhea (PD) and dysentery (DD) account for most diarrhea-associated deaths among children in developing countries. Zinc deficiency can cause stunting and impaired immune function, both of which are risk factors for these diarrheal illnesses. We investigated the effect of zinc supplementation on the incidence of PD and DD in a community-based, double-blind randomized trial in children 6-35 mo of age. Increase over baseline in plasma zinc concentrations in the supplemented group compared with a control group (3.61 vs. 0.009 mumol.L-1), indicated successful supplementation. The overall reductions in the zinc supplemented group of 21% in the incidence of PD (95% CI -6 to 42%) and 14% in the incidence of dysentery (95% CI -15 to 36%) were not significant. There was a significant interaction of treatment effect with baseline plasma zinc concentration and age for PD and with gender for DD. In the zinc-supplemented group compared with the control group, the incidence of PD was reduced by 73% (P < 0.05; 95% CI 34 to 91%) in children with a baseline zinc < 7.65 mumol.L-1 and by 49% (P < 0.05; 95%CI 24 to 66%) in children > 11 mo of age. Zinc supplementation resulted in a 38% (P < 0.05 95%CI 8 to 59%) reduction in the incidence of DD in boys. There was no effect on PD among children 6-11 mo old or on DD in girls. In conclusion, zinc supplementation had a significant impact on the incidence of persistent diarrhea in children > 1 y old and in children with low plasma zinc, as well as on dysentery in boys. These findings may have important implications for reducing diarrhea-related morbidity and mortality.

Zinc Signals and Immunity

PubMed Central

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-01-01

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. PMID:29064429

The influence of inflammation on plasma zinc concentration in apparently healthy, HIV+ Kenyan adults and zinc responses after a multi-micronutrient supplement.

PubMed

Mburu, A S W; Thurnham, D I; Mwaniki, D L; Muniu, E M; Alumasa, F M

2010-05-01

Plasma zinc is an important biomarker of zinc status, but the concentration is depressed by inflammation. Apparently healthy adults, who tested positive twice for human immunodeficiency virus (HIV) but who had not reached stage IV or clinical AIDS, were randomly allocated to receive a food supplement (n=17 and 21) or the food plus a micronutrient capsule (MN; n=10 men and n=33 women) containing 15 mg zinc/day. We used the inflammation biomarkers, C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP), to identify subjects with and without inflammation and determine the effect of inflammation on the response of plasma zinc concentrations to the MN and food supplements. There were no differences between men and women either in plasma zinc or in the responses to the supplements and their data were combined. Plasma zinc was lower in those with inflammation than without. Repeated measures analysis of variance (ANOVA) showed that inflammation blocked increases in plasma zinc, and there was an approximate 10% increase in plasma zinc concentration in response to the MN supplement (P=0.023) in those without inflammation. Subgroup analysis showed mean changes in plasma zinc of 0.95 and -0.83 micromol/l (P=0.031) in response to the MN and food treatments, respectively, in those without inflammation at both time points. Inflammation seems to block any increase in plasma zinc after MN supplement and it is important to identify those without inflammation to determine the effectiveness of a zinc supplementation program.

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate.

PubMed

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min; Chung, Tae Nyoung; Suh, Sang Won

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30  μ M and 100  μ M of ZnCl 2 . Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth.

Maternal dietary zinc supplementation enhances the epigenetic-activated antioxidant ability of chick embryos from maternal normal and high temperatures.

PubMed

Zhu, Yongwen; Liao, Xiudong; Lu, Lin; Li, Wenxiang; Zhang, Liyang; Ji, Cheng; Lin, Xi; Liu, Hsiao-Ching; Odle, Jack; Luo, Xugang

2017-03-21

The role of maternal dietary zinc supplementation in protecting the embryos from maternal hyperthermia-induced negative effects via epigenetic mechanisms was examined using an avian model (Gallus gallus). Broiler breeder hens were exposed to two maternal temperatures (21°C and 32°C) × three maternal dietary zinc treatments (zinc-unsupplemented control diet, the control diet + 110 mg zinc/kg inorganic or organic zinc) for 8 weeks. Maternal hyperthermia increased the embryonic mortality and induced oxidative damage evidenced by the elevated mRNA expressions of heat shock protein genes. Maternal dietary zinc deficiency damaged the embryonic development associated with the global DNA hypomethylation and histone 3 lysine 9 hyperacetylation in the embryonic liver. Supplementation of zinc in maternal diets effectively eliminated the embryonic mortality induced by maternal hyperthermia and enhanced antioxidant ability with the increased mRNA and protein expressions of metallothionein IV in the embryonic liver. The increased metallothionein IV mRNA expression was due to the reduced DNA methylation and increased histone 3 lysine 9 acetylation of the metallothionein IV promoter regardless of zinc source. These data demonstrate that maternal dietary zinc addition as an epigenetic modifier could protect the offspring embryonic development against maternal heat stress via enhancing the epigenetic-activated antioxidant ability.

Evaluation of the effect of zinc acetate on the stratum corneum penetration kinetics of erythromycin in healthy male volunteers.

PubMed

van Hoogdalem, E J; Terpstra, I J; Baven, A L

1996-01-01

Erythromycin with or without additional zinc acetate is used topically in the treatment of acne vulgaris. A potential effect of zinc on the stratum corneum penetration of erythromycin was investigated in human volunteers. Skin surface washings and tape strippings from the skin of the back were collected after drug applications in 12 subjects for quantification of erythromycin levels. Zinc acetate increased the amount remaining on the back skin at 6 h after application from 40 +/- 19 to 56 +/- 15% of the dose and, vice versa, reduced the amount in stratum corneum strips from 22 +/- 7 to 18 +/- 7%, both with statistical significance. The effect varied with body region. Zinc acetate thus provided to prolong the residence time of erythromycin on the skin.

Uptake and partitioning of zinc in Lemnaceae.

PubMed

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

2011-11-01

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

Effect of morphology and solvent on two-photon absorption of nano zinc oxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kavitha, M.K.; Haripadmam, P.C.; Gopinath, Pramod

Highlights: ► ZnO nanospheres and triangular structures synthesis by novel precipitation technique. ► The effect of precursor concentration on the size and shape of nano ZnO. ► Open aperture Z-scan measurements of the ZnO nanoparticle dispersions. ► Nanospheres exhibit higher two photon absorption coefficient than triangular nanostructures. ► Nanospheres dispersed in water exhibit higher two photon absorption coefficient than its dispersion in 2-propanol. - Abstract: In this paper, we report the effect of morphology and solvent on the two-photon absorption of nano zinc oxide. Zinc oxide nanoparticles in two different morphologies like nanospheres and triangular nanostructures are synthesized by novelmore » precipitation technique and their two-photon absorption coefficient is measured using open aperture Z-scan technique. Experimental results show that the zinc oxide nanospheres exhibit higher two-photon absorption coefficient than the zinc oxide triangular nanostructures. The zinc oxide nanospheres dispersed in water exhibit higher two-photon absorption coefficient than that of its dispersion in 2-propanol. The zinc oxide nanospheres dispersed in water shows a decrease in two-photon absorption coefficient with an increase in on-axis irradiance. The result confirms the dependence of shape and solvent on the two-photon absorption of nano zinc oxide.« less

Effects of zinc and DHA on the epigenetic regulation of human neuronal cells.

PubMed

Sadli, Nadia; Ackland, M Leigh; De Mel, Damitha; Sinclair, Andrew J; Suphioglu, Cenk

2012-01-01

Dietary intake of zinc and omega-3 fatty acids (DHA) have health benefits for a number of human diseases. However, the molecular basis of these health benefits remains unclear. Recently, we reported that zinc and DHA affect expression levels of histones H3 and H4 in human neuronal M17 cells. Here, using immunoblotting and densitometric analysis, we aimed to investigate the effect of zinc and DHA on post-translational modifications of histone H3 in M17 cells. In response to increase in zinc concentration, we observed increase in deacetylation, methylation and phosphorylation of H3 and decrease in acetylation. We also investigated the role of zinc in apoptosis, and found that zinc reduced the levels of the anti-apoptotic marker Bcl-2 while increasing the apoptotic marker caspase-3 levels, correlating with cell viability assays. Conversely, DHA treatment resulted in increase in acetylation of H3 and Bcl-2 levels and decrease in deacetylation, methylation, phosphorylation of H3 and caspase-3 levels, suggesting that DHA promotes gene expression and neuroprotection. Our novel findings show the opposing effects of zinc and DHA on the epigenetic regulation of human neuronal cells and highlight the potential benefit of dietary intake of DHA for management of neurodegenerative diseases. Copyright © 2012 S. Karger AG, Basel.

The Role of Zinc Layer During Wetting of Aluminium on Zinc-coated Steel in Laser Brazing and Welding

NASA Astrophysics Data System (ADS)

Gatzen, M.; Radel, T.; Thomy, C.; Vollertsen, F.

The zinc layer of zinc-coated steel is known to be a crucial factor for the spreading of liquid aluminium on the coated surface. For industrial brazing and welding processes these zinc-coatings enable a fluxless joining between aluminium and steel in many cases. Yet, the reason for the beneficial effect of the zinc to the wetting process is not completely understood. Fundamental investigations on the wetting behaviour of single aluminium droplets on different zinc-coated steel surfaces have revealed a distinct difference between coated surfaces at room temperature and at elevated temperature regarding the influence of different coating thicknesses. In this paper the case of continuous laser brazing and welding processes of aluminium and commercial galvanized zinc-coated steel sheets are presented. It is shown that in the case of bead-on-plate laser beam brazing, the coating thickness has a measureable effect on the resulting wetting angle and length but does not have a significant impact in case of overlap laser beam welding. This might be linked to different heat transfer conditions. The results also strongly indicate that proper initialbreakup of oxide layers is still required to accomplish good wetting on zinc-coated surfaces.

Lifetime enhanced phosphorescent organic light emitting diode using an electron scavenger layer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Seokhwan; Kim, Ji Whan; Lee, Sangyeob, E-mail: sy96.lee@samsung.com

2015-07-27

We demonstrate a method to improve lifetime of a phosphorescent organic light emitting diode (OLED) using an electron scavenger layer (ESL) in a hole transporting layer (HTL) of the device. We use a bis(1-(phenyl)isoquinoline)iridium(III)acetylacetonate [Ir(piq){sub 2}(acac)] doped HTL to stimulate radiative decay, preventing thermal degradation in HTL. The ESL effectively prevented non-radiative decay of leakage electron in HTL by converting non-radiative decay to radiative decay via a phosphorescent red emitter, Ir(piq){sub 2}(acac). The lifetime of device (t{sub 95}: time after 5% decrease of luminance) has been increased from 75 h to 120 h by using the ESL in a phosphorescent green-emitting OLED.

Zinc deficiency in children with environmental enteropathy—development of new strategies: report from an expert workshop1234

PubMed Central

Young, Graeme P; Mortimer, Elissa K; Gopalsamy, Geetha L; Alpers, David H; Binder, Henry J; Manary, Mark J; Ramakrishna, Balakrishnan S; Brown, Ian L; Brewer, Thomas G

2014-01-01

Zinc deficiency is a major cause of childhood morbidity and mortality. The WHO/UNICEF strategy for zinc supplementation as adjunctive therapy for diarrhea is poorly implemented. A conference of experts in zinc nutrition and gastrointestinal disorders was convened to consider approaches that might complement the current recommendation and what research was needed to develop these approaches. Several key points were identified. The design of novel zinc interventions would be facilitated by a better understanding of how disturbed gut function, such as environmental (or tropical) enteropathy, affects zinc absorption, losses, and homeostasis. Because only 10% of zinc stores are able to be rapidly turned over, and appear to be rapidly depleted by acute intestinal illness, they are probably best maintained by complementary regular supplementation in a primary prevention strategy rather than secondary prevention triggered by acute diarrhea. The assessment of zinc status is challenging and complex without simple, validated measures to facilitate field testing of novel interventions. Zinc bioavailability may be a crucial factor in the success of primary prevention strategies, and a range of options, all still inadequately explored, might be valuable in improving zinc nutrition. Some therapeutic actions of zinc on diarrhea seem attributable to pharmacologic effects, whereas others are related to the reversal of deficiency (ie, nutritional). The distinction between these 2 mechanisms cannot be clarified given the insensitivity of serum zinc to identify subclinical deficiency states. Why zinc seems to be less effective than expected at all ages, and ineffective for secondary prevention of diarrhea in children <12 mo of age, remains unclear. It was concluded that a reframing of the current recommendation is warranted with consideration of how to better optimize and deliver zinc and whether to provide a complementary public health primary prevention zinc strategy. This requires careful consideration of the zinc product to be used as well as strategies for its delivery. PMID:25240082

Taurine zinc solid dispersions attenuate doxorubicin-induced hepatotoxicity and cardiotoxicity in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yu; Mei, Xueting; Yuan, Jingquan

2015-11-15

The clinical efficacy of anthracycline anti-neoplastic agents is limited by cardiac and hepatic toxicities. The aim of this study was to assess the hepatoprotective and cardioprotective effects of taurine zinc solid dispersions, which is a newly-synthesized taurine zinc compound, against doxorubicin-induced toxicity in Sprague–Dawley rats intraperitoneally injected with doxorubicin hydrochloride (3 mg/kg) three times a week (seven injections) over 28 days. Hemodynamic parameters, levels of liver toxicity markers and oxidative stress were assessed. Taurine zinc significantly attenuated the reductions in blood pressure, left ventricular pressure and ± dp/dtmax, increases in serum alanine aminotransferase and aspartate aminotransferase activities, and reductions inmore » serum Zn{sup 2+} and albumin levels (P < 0.05 or 0.01) induced by doxorubicin. In rats treated with doxorubicin, taurine zinc dose-dependently increased liver superoxide dismutase activity and glutathione concentration, and decreased malondialdehyde level (P < 0.01). qBase{sup +} was used to evaluate the stability of eight candidate reference genes for real-time quantitative reverse-transcription PCR. Taurine zinc dose-dependently increased liver heme oxygenase-1 and UDP-glucuronyl transferase mRNA and protein expression (P < 0.01). Western blotting demonstrated that taurine zinc inhibited c-Jun N-terminal kinase phosphorylation by upregulating dual-specificity phosphoprotein phosphatase-1. Additionally, taurine zinc inhibited cardiomyocyte apoptosis as there was decreased TUNEL/DAPI positivity and protein expression of caspase-3. These results indicate that taurine zinc solid dispersions prevent the side-effects of anthracycline-based anticancer therapy. The mechanisms might be associated with the enhancement of antioxidant defense system partly through activating transcription to synthesize endogenous phase II medicine enzymes and anti-apoptosis through inhibiting JNK phosphorylation. - Highlights: • Dissolution of taurine zinc complex can be increased by solid dispersions (SDs). • Taurine zinc SDs blocked doxorubicin-induced hepatotoxicity and cardiotoxicity. • Taurine zinc SDs can alleviate oxidative stress and dampen JNK phosphorylation. • Taurine zinc SDs increased the expression of UGT, HO-1 at mRNA and protein level. • Taurine zinc SDs revealed greater hepatoprotective effects than silymarin.« less

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

PubMed

Hejazy, Marzie; Koohi, Mohammad Kazem

2017-12-01

Cadmium (Cd) is a toxic environmental and occupational pollutant with reported toxic effects on the kidneys, liver, lungs, bones, and the immunity system. Based on its physicochemical similarity to cadmium, zinc (Zn) shows protective effects against cadmium toxicity and cadmium accumulation in the body. Nano-zinc and nano-zinc oxide (ZnO), recently used in foods and pharmaceutical products, can release a great amount of Zn 2+ in their environment. This research was carried out to investigate the more potent properties of the metal zinc among sub-acute cadmium intoxicated rats. Seventy-five male Wistar rats were caged in 15 groups. Cadmium chloride (CdCl 2 ) was used in drinking water to induce cadmium toxicity. Different sizes (15, 20, and 30 nm) and doses of nano-zinc particles (3, 10, 100 mg/kg body weight [bw]) were administered solely and simultaneously with CdCl 2 (2-5 mg/kg bw) for 28 days. The experimental animals were decapitated, and the biochemical biomarkers (enzymatic and non-enzymatic) were determined in their serum after oral exposure to nano-zinc and cadmium. Statistical analysis was carried out with a one-way ANOVA and t test. P < 0.05 was considered as statistically significant. The haematocrit (HCT) significantly increased and blood coagulation time significantly reduced in the nano-zinc-treated rats. AST, ALT, triglyceride, total cholesterol, LDL, and free fatty acids increased significantly in the cadmium- and nano-zinc-treated rats compared with the controls. However, albumin, total protein, and HDLc significantly decreased in the cadmium- and nano-zinc-treated rats compared with the controls (P < 0.05). It seems that in the oral administration of nano-zinc, the smaller sizes with low doses and the larger sizes with high doses are more toxic than metallic zinc. In a few cases, an inverse dose-dependent relationship was seen as well. This research showed that in spite of larger sizes of zinc, smaller sizes of nano-zinc particles are not suitable for protection against cadmium intoxication.

Anti-inflammatory effects of zinc in PMA-treated human gingival fibroblast cells

PubMed Central

Kim, Sangwoo; Jeon, Sangmi; Hui, Zheng; Kim, Young; Im, Yeonggwan; Lim, Wonbong; Kim, Changsu; Choi, Hongran; Kim, Okjoon

2015-01-01

Objectives: Abnormal cellular immune response has been considered to be responsible for oral lesions in recurrent aphthous stomatitis. Zinc has been known to be an essential nutrient metal that is necessary for a broad range of biological activities including antioxidant, immune mediator, and anti-inflammatory drugs in oral mucosal disease. The objective of this study was to investigate the effects of zinc in a phorbol-12-myristate-13-acetate (PMA)-treated inflammatory model on human gingival fibroblast cells (hGFs). Study Design: Cells were pre-treated with zinc chloride, followed by PMA in hGFs. The effects were assessed on cell viability, cyclooxygenease-1,2(COX-1/2) protein expression, PGE2 release, ROS production and cytokine release, Results: The effects were assessed on cell viability, COX1/2 protein expression, PGE2 release, ROS production, cytokine release. The results showed that, in the presence of PMA, zinc treatment leads to reduce the production of ROS, which results in decrease of COX-2 expression and PGE2 release. Conclusions: Thus, we suggest that zinc treatment leads to the mitigation of oral inflammation and may prove to be an alternative treatment for recurrent aphthous stomatitis. Key words:Zinc, inflammatory response, cytokines, phorbol-12-myristate-13-acetate, gingival fibroblasts cells. PMID:25662537

The effect of zinc injection on the increasing of Inconel 600 TT corrosion resistances

NASA Astrophysics Data System (ADS)

Febrianto; Sriyono; Widodo, Surip; Sunaryo, Geni Rina

2018-02-01

Many failures were found in reactor pressure vessel head penetration (RPV) head material. Those failures caused by boric acid corrosion, and from visual examination were found a big hole and white deposit crystal of boric acid during shutdown maintenance at David Besse reactor. Zinc Oxide addition in BWR reactor known as Zinc Injection that has purposed to reduce radiation exposure cause of Hydrogen addition. Beside reducing the radiation exposure, Zinc injection also has an effect in reducing material corrosion. The purpose of study is to determine the effect of zinc addition, boric acid, temperature also the effects of Cobalt Nitrate and Zinc Oxide addition to Inconel 600 TT as RPV head penetration material. The result in the BWR reactor experience will be implementated at PWR reactor, weather zinc oxide addition also has an effect in reducing the corrosion of Inconel 600. The method that used in this research is to observe the corrosion rates for Inconel 600 material using Potentiostat. Examination were conducted in 30, 40, 60, 70, 80 and 80 °C using 1000, 1500, 2000, 2500 and 3000 ppm boric acid concentration. The results showed that the corrosion rate for the material were very small, but the highest corrosion rate occurred in 3000 ppm boric acid concentration at 90 °C with Cobalt Nitrate addition, around 5.210 x 10-1 mpy. In the same condition at 3000 ppm boric acid concentration for temperature at 90 °C, Inconel 600 TT corrosion rate is smaller with Zinc oxide addition, around 4.631 x 10-1 mpy.

Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

NASA Astrophysics Data System (ADS)

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

2016-10-01

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

Mechanistic studies of the toxicity of zinc gluconate in the olfactory neuronal cell line Odora

PubMed Central

Hsieh, Heidi; Vignesh, Kavitha Subramanian; Deepe, George S.; Choubey, Divaker; Shertzer, Howard G.; Genter, Mary Beth

2016-01-01

Zinc is both an essential and potentially toxic metal. It is widely believed that oral zinc supplementation can reduce the effects of the common cold; however, there is strong clinical evidence that intranasal (IN) zinc gluconate (ZG) gel treatment for this purpose causes anosmia, or the loss of the sense of smell, in humans. Using the rat olfactory neuron cell line, Odora, we investigated the molecular mechanism by which zinc exposure exerts its toxic effects on olfactory neurons. Following treatment of Odora cells with 100 and 200 μM ZG for 0-24 h, RNA-seq and in silico analyses revealed up-regulation of pathways associated with zinc metal response, oxidative stress, and ATP production. We observed that Odora cells recovered from zinc-induced oxidative stress, but ATP depletion persisted with longer exposure to ZG. ZG exposure increased levels of NLRP3 and IL-1β protein levels in a time-dependent manner, suggesting that zinc exposure may cause an inflammasome-mediated cell death, pyroptosis, in olfactory neurons. PMID:27179668

Mechanistic studies of the toxicity of zinc gluconate in the olfactory neuronal cell line Odora.

PubMed

Hsieh, Heidi; Vignesh, Kavitha Subramanian; Deepe, George S; Choubey, Divaker; Shertzer, Howard G; Genter, Mary Beth

2016-09-01

Zinc is both an essential and potentially toxic metal. It is widely believed that oral zinc supplementation can reduce the effects of the common cold; however, there is strong clinical evidence that intranasal (IN) zinc gluconate (ZG) gel treatment for this purpose causes anosmia, or the loss of the sense of smell, in humans. Using the rat olfactory neuron cell line, Odora, we investigated the molecular mechanism by which zinc exposure exerts its toxic effects on olfactory neurons. Following treatment of Odora cells with 100 and 200μM ZG for 0-24h, RNA-seq and in silico analyses revealed up-regulation of pathways associated with zinc metal response, oxidative stress, and ATP production. We observed that Odora cells recovered from zinc-induced oxidative stress, but ATP depletion persisted with longer exposure to ZG. ZG exposure increased levels of NLRP3 and IL-1β protein levels in a time-dependent manner, suggesting that zinc exposure may cause an inflammasome-mediated cell death, pyroptosis, in olfactory neurons. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

Brown, Kenneth H; Baker, Shawn K

2009-03-01

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

Targeted Zinc Delivery: A Novel Treatment for Prostate Cancer

DTIC Science & Technology

2010-06-01

aconitase, which normally functions to oxidize citrate during the Krebs cycle . Because citrate is a principle component of seminal fluid, prostate...tissue, likely due to the metabolic effects of zinc in the Krebs cycle . That is, because zinc inhibits m- aconitase, loss of zinc allows for greater...secretory cells do not complete the oxidation of citrate in the mitochondria and the zinc-mediated inhibition of m-aconitase is crucial for the

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

PubMed

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

2017-10-01

An experiment was conducted to compare the effects of zinc sulfate (ZS) and tribasic zinc sulfate (TBZ) as sources of supplemental zinc on growth performance, serum zinc (Zn) content and messenger RNA (mRNA) expression of Zn transporters (ZnT1/ZnT2/ZnT5/ZIP4/DMT1) of young growing pigs. A total of 96 Duroc × Landrace × Yorkshire pigs were randomly allotted to two treatments and were fed a basal diet supplemented with 100 mg/kg Zn from either ZS or TBZ for 28 days. Feed : gain ratio in pigs fed TBZ were lower (P < 0.05) than pigs fed ZS, and average daily weight gain tended to increase (0.05 ≤ P ≤ 0.10) in pigs fed TBZ. Compared with pigs fed ZS, pigs fed TBZ had a higher CuZn-superoxide dismutase and Zn content in serum (P < 0.05) while they had a lower Zn content in feces (P < 0.05). In addition, ZIP4 mRNA expression of zinc transporter in either duodenum or jejunum of pigs fed TBZ were higher (P < 0.05) than pigs fed ZS. These results indicate that TBZ is more effective in serum Zn accumulation and intestinal Zn absorption, and might be a potential substitute for ZS in young growing pigs. © 2017 Japanese Society of Animal Science.

Zinc supplementation during pregnancy protects against lipopolysaccharide-induced fetal growth restriction and demise through its anti-inflammatory effect.

PubMed

Chen, Yuan-Hua; Zhao, Mei; Chen, Xue; Zhang, Ying; Wang, Hua; Huang, Ying-Ying; Wang, Zhen; Zhang, Zhi-Hui; Zhang, Cheng; Xu, De-Xiang

2012-07-01

LPS is associated with adverse developmental outcomes, including preterm delivery, fetal death, teratogenicity, and intrauterine growth restriction (IUGR). Previous reports showed that zinc protected against LPS-induced teratogenicity. In the current study, we investigated the effects of zinc supplementation during pregnancy on LPS-induced preterm delivery, fetal death and IUGR. All pregnant mice except controls were i.p. injected with LPS (75 μg/kg) daily from gestational day (GD) 15 to GD17. Some pregnant mice were administered zinc sulfate through drinking water (75 mg elemental Zn per liter) throughout the pregnancy. As expected, an i.p. injection with LPS daily from GD15 to GD17 resulted in 36.4% (4/11) of dams delivered before GD18. In dams that completed the pregnancy, 63.2% of fetuses were dead. Moreover, LPS significantly reduced fetal weight and crown-rump length. Of interest, zinc supplementation during pregnancy protected mice from LPS-induced preterm delivery and fetal death. In addition, zinc supplementation significantly alleviated LPS-induced IUGR and skeletal development retardation. Further experiments showed that zinc supplementation significantly attenuated LPS-induced expression of placental inflammatory cytokines and cyclooxygenase-2. Zinc supplementation also significantly attenuated LPS-induced activation of NF-κB and MAPK signaling in mononuclear sinusoidal trophoblast giant cells of the labyrinth zone. It inhibited LPS-induced placental AKT phosphorylation as well. In conclusion, zinc supplementation during pregnancy protects against LPS-induced fetal growth restriction and demise through its anti-inflammatory effect.

History of Zinc in Agriculture12

PubMed Central

Nielsen, Forrest H.

2012-01-01

Zinc was established as essential for green plants in 1926 and for mammals in 1934. However, >20 y would pass before the first descriptions of zinc deficiencies in farm animals appeared. In 1955, it was reported that zinc supplementation would cure parakeratosis in swine. In 1958, it was reported that zinc deficiency induced poor growth, leg abnormalities, poor feathering, and parakeratosis in chicks. In the 1960s, zinc supplementation was found to alleviate parakeratosis in grazing cattle and sheep. Within 35 y, it was established that nearly one half of the soils in the world may be zinc deficient, causing decreased plant zinc content and production that can be prevented by zinc fertilization. In many of these areas, zinc deficiency is prevented in grazing livestock by zinc fertilization of pastures or by providing salt licks. For livestock under more defined conditions, such as poultry, swine, and dairy and finishing cattle, feeds are easily supplemented with zinc salts to prevent deficiency. Today, the causes and consequences of zinc deficiency and methods and effects of overcoming the deficiency are well established for agriculture. The history of zinc in agriculture is an outstanding demonstration of the translation of research into practical application. PMID:23153732

Oral zinc for treating diarrhoea in children

PubMed Central

Lazzerini, Marzia; Wanzira, Humphrey

2016-01-01

Background In developing countries, diarrhoea causes around 500,000 child deaths annually. Zinc supplementation during acute diarrhoea is currently recommended by the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF). Objectives To evaluate oral zinc supplementation for treating children with acute or persistent diarrhoea. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register, CENTRAL (the Cochrane Library 2016, Issue 5), MEDLINE, Embase, LILACS, CINAHL, mRCT, and reference lists up to 30 September 2016. We also contacted researchers. Selection criteria Randomized controlled trials (RCTs) that compared oral zinc supplementation with placebo in children aged one month to five years with acute or persistent diarrhoea, including dysentery. Data collection and analysis Both review authors assessed trial eligibility and risk of bias, extracted and analysed data, and drafted the review. The primary outcomes were diarrhoea duration and severity. We summarized dichotomous outcomes using risk ratios (RR) and continuous outcomes using mean differences (MD) with 95% confidence intervals (CI). Where appropriate, we combined data in meta-analyses (using either a fixed-effect or random-effects model) and assessed heterogeneity. We assessed the certainty of the evidence using the GRADE approach. Main results Thirty-three trials that included 10,841 children met our inclusion criteria. Most included trials were conducted in Asian countries that were at high risk of zinc deficiency. Acute diarrhoea There is currently not enough evidence from well-conducted RCTs to be able to say whether zinc supplementation during acute diarrhoea reduces death or number of children hospitalized (very low certainty evidence). In children older than six months of age, zinc supplementation may shorten the average duration of diarrhoea by around half a day (MD −11.46 hours, 95% CI −19.72 to −3.19; 2581 children, 9 trials, low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (RR 0.73, 95% CI 0.61 to 0.88; 3865 children, 6 trials, moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (MD −26.39 hours, 95% CI −36.54 to −16.23; 419 children, 5 trials, high certainty evidence). Conversely, in children younger than six months of age, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (MD 5.23 hours, 95% CI −4.00 to 14.45; 1334 children, 2 trials, moderate certainty evidence), or the number of children who still have diarrhoea on day seven (RR 1.24, 95% CI 0.99 to 1.54; 1074 children, 1 trial, moderate certainty evidence). None of the included trials reported serious adverse events. However, zinc supplementation increased the risk of vomiting in both age groups (children greater than six months of age: RR 1.57, 95% CI 1.32 to 1.86; 2605 children, 6 trials, moderate certainty evidence; children less than six months of age: RR 1.54, 95% CI 1.05 to 2.24; 1334 children, 2 trials, moderate certainty evidence). Persistent diarrhoea In children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (MD −15.84 hours, 95% CI −25.43 to −6.24; 529 children, 5 trials, moderate certainty evidence). Authors' conclusions In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency. Oral zinc supplementation for treating diarrhoea in children In low- and middle-income countries, millions of children suffer from severe diarrhoea every year and many die from dehydration. Giving fluids by mouth (using an oral rehydration solution (ORS)) has been shown to save children's lives, but it has no effect on the length of time the children suffer with diarrhoea. Zinc supplementation could help reduce the duration and the severity of diarrhoea, and therefore have an additional benefit over ORS in reducing children mortality. What is oral zinc and how may it shorten the duration and severity of diarrhoea Zinc is usually given as zinc sulphate, zinc acetate, or zinc gluconate, which are all water-soluble compounds. The World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) recommend 10 mg to 20 mg of zinc per day for children with diarrhoea. There are several mechanism of action of zinc on acute diarrhoea, some of which are specific to the gastrointestinal system: zinc restores mucosal barrier integrity and enterocyte brush-border enzyme activity, it promotes the production of antibodies and circulating lymphocytes against intestinal pathogens, and has a direct effect on ion channels, acting as a potassium channel blocker of adenosine 3-5-cyclic monophosphate-mediated chlorine secretion. Cochrane researchers examined the evidence available up to 30 September 2016. What the evidence in the review suggests Thirty-three trials that included 10,841 children met the inclusion criteria of this review. Among children with acute diarrhoea, we don't know if treating children with zinc has an effect on death or number of children hospitalized (very low certainty evidence). In children older than six months, zinc supplementation may shorten the average duration of diarrhoea by around half a day (low certainty evidence), and probably reduces the number of children whose diarrhoea persists until day seven (moderate certainty evidence). In children with signs of malnutrition the effect appears greater, reducing the duration of diarrhoea by around a day (high certainty evidence). Conversely, in children younger than six months, the available evidence suggests zinc supplementation may have no effect on the mean duration of diarrhoea (moderate certainty evidence), or the number of children who still have diarrhoea on day seven (moderate certainty evidence). Zinc supplementation increased the risk of vomiting in both age groups (moderate certainty evidence). No other adverse effects were reported. Among children with persistent diarrhoea, zinc supplementation probably shortens the average duration of diarrhoea by around 16 hours (moderate certainty) but it probably increases the risk of vomiting (moderate certainty evidence). In areas where the prevalence of zinc deficiency or the prevalence of malnutrition is high, zinc may be of benefit in children aged six months or more. The current evidence does not support the use of zinc supplementation in children less six months of age, in well-nourished children, and in settings where children are at low risk of zinc deficiency. PMID:27996088

Synthesis, characterization, and reactivity of pentamethylcyclopentadienyl complexes of divalent cobalt and nickel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Michael Edward

1993-10-01

The thesis is divided into the following 4 chapters: synthesis, characterization, and reactivity of trinuclear pentamethylcyclopentadienyl cobalt and nickel clusters with triply-bridging methylidyne groups; chemical and physical properties of pentamethylcyclopentadienyl acetylacetonate complexes of Co(II) and Ni(II); synthesis, characterization, and reactivity of pentamethylcyclopentadienyl halide complexes of Co and Ni; and crystallographic studies of distortions in metallocenes with C 5-symmetrical cyclopentadienyl rings.

Monodisperse gold-palladium alloy nanoparticles and their composition-controlled catalysis in formic acid dehydrogenation under mild conditions.

PubMed

Metin, Önder; Sun, Xiaolian; Sun, Shouheng

2013-02-07

Monodisperse 4 nm AuPd alloy nanoparticles with controlled composition were synthesized by co-reduction of hydrogen tetrachloroaurate(III) hydrate and palladium(II) acetylacetonate with a borane-morpholine complex in oleylamine. These NPs showed high activity (TOF = 230 h(-1)) and stability in catalyzing formic acid dehydrogenation and hydrogen production in water at 50 °C without any additives.

Mesoporous Titania Powders: The Role of Precursors, Ligand Addition and Calcination Rate on Their Morphology, Crystalline Structure and Photocatalytic Activity

PubMed Central

Masolo, Elisabetta; Meloni, Manuela; Garroni, Sebastiano; Mulas, Gabriele; Enzo, Stefano; Baró, Maria Dolors; Rossinyol, Emma; Rzeszutek, Agnieszka; Herrmann-Geppert, Iris; Pilo, Maria

2014-01-01

We evaluate the influence of the use of different titania precursors, calcination rate, and ligand addition on the morphology, texture and phase content of synthesized mesoporous titania samples, parameters which, in turn, can play a key role in titania photocatalytic performances. The powders, obtained through the evaporation-induced self-assembly method, are characterized by means of ex situ X-Ray Powder Diffraction (XRPD) measurements, N2 physisorption isotherms and transmission electron microscopy. The precursors are selected basing on two different approaches: the acid-base pair, using TiCl4 and Ti(OBu)4, and a more classic route with Ti(OiPr)4 and HCl. For both precursors, different specimens were prepared by resorting to different calcination rates and with and without the addition of acetylacetone, that creates coordinated species with lower hydrolysis rates, and with different calcination rates. Each sample was employed as photoanode and tested in the water splitting reaction by recording I-V curves and comparing the results with commercial P25 powders. The complex data framework suggests that a narrow pore size distribution, due to the use of acetylacetone, plays a major role in the photoactivity, leading to a current density value higher than that of P25. PMID:28344237

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

PubMed

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

2013-01-01

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

Zinc Supplementation in Treatment of Children With Urinary Tract Infection.

PubMed

Yousefichaijan, Parsa; Naziri, Mahdyieh; Taherahmadi, Hassan; Kahbazi, Manijeh; Tabaei, Aram

2016-07-01

Urinary tract infection (UTI) is very common in children. Precocious diagnosis and appropriate treatment are important because of the permanent disease complications. Zinc increases the response to treatment in many infections. In this study, we explored the effect of zinc in treating UTI. Two hundred children with UTI were divided into 2 groups of 100 who were comparable in terms of age, sex, urine laboratory profiles, and clinical signs and symptoms. The control group received a standard treatment protocol for UTI and the intervention group received oral zinc sulfate syrup plus routine treatment of UTI. A faster recovery was observed in the patients receiving zinc, but abdominal pain was exacerbated by zinc and lasted longer. Three months after the treatment, there was no significant difference between the two groups in the time of fever stop and negative urine culture. In children with UTI, zinc supplementation has a positive effect in ameliorating severe dysuria and urinary frequency while the use of this medication is not recommended in the presence of abdominal pain.

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

PubMed

Read, Daniel S; Matzke, Marianne; Gweon, Hyun S; Newbold, Lindsay K; Heggelund, Laura; Ortiz, Maria Diez; Lahive, Elma; Spurgeon, David; Svendsen, Claus

2016-03-01

Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH-dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil), both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities.

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

PubMed

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, p<0.001), serum albumin (13%, p<0.01), total and bone-specific alkaline phosphatase activity (13 and 18%, respectively, p<0.05), erythrocyte metallothionein (13%, p<0.01), and, urinary zinc (34%, p<0.05). OCA use 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.

Double blind study of the effects of zinc sulfate on taste and smell dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henkin, R.I.; Schecter, P.J.; Friedewald, W.T.

1976-01-01

A randomized, double blind crossover study of the effects of zinc sulfate and placebo was carried out in 106 patients with taste and smell dysfunction secondary to a variety of etiological factors. In the patient group prior to treatment, mean serum zinc concentration and leukocyte alkaline phosphatase activity were significantly lower than normal. Results indicate that zinc sulfate was effectively equivalent to placebo in the treatment of these disorders. Although these results demonstrate abnormalities of zinc metabolism in some patients with taste and smell dysfunction they fail to provide evidence for a single, therapeutic approach to the many disorders whichmore » are associated with abnormalities of taste and smell. However, the methods and procedures developed in this study demonstrate that taste and smell dysfunction can be studied in a quantitative, systematic manner.« less

Colchicine induced intraneuronal free zinc accumulation and dentate granule cell degeneration.

PubMed

Choi, Bo Young; Lee, Bo Eun; Kim, Jin Hee; Kim, Hyun Jung; Sohn, Min; Song, Hong Ki; Chung, Tae Nyoung; Suh, Sang Won

2014-08-01

Colchicine has been discovered to inhibit many inflammatory processes such as gout, familial Mediterranean fever, pericarditis and Behcet disease. Other than these beneficial anti-inflammatory effects, colchicine blocks microtubule-assisted axonal transport, which results in the selective loss of dentate granule cells of the hippocampus. The mechanism of the colchicine-induced dentate granule cell death and depletion of mossy fiber terminals still remains unclear. In the present study, we hypothesized that colchicine-induced dentate granule cell death may be caused by accumulation of labile intracellular zinc. 10 μg kg(-1) of colchicine was injected into the adult rat hippocampus and then brain sections were evaluated at 1 day or 1 week later. Neuronal cell death was evaluated by H&E staining or Fluoro-Jade B. Zinc accumulation and vesicular zinc were detected by N-(6-methoxy-8-quinolyl)-para-toluene sulfonamide (TSQ) staining. To test whether an extracellular zinc chelator can prevent this process, CaEDTA was injected into the hippocampus over a 5 min period with colchicine. To test whether other microtubule toxins also produce similar effects as colchicine, vincristine was injected into the hippocampus. The present study found that colchicine injection induced intracellular zinc accumulation in the dentate granule cells and depleted vesicular zinc from mossy fiber terminals. Injection of a zinc chelator, CaEDTA, did not block the zinc accumulation and neuronal death. Vincristine also produced intracellular zinc accumulation and neuronal death. These results suggest that colchicine-induced dentate granule cell death is caused by blocking axonal zinc flow and accumulation of intracellular labile zinc.

Effect of Supplementation with Zinc and Other Micronutrients on Malaria in Tanzanian Children: A Randomised Trial

PubMed Central

Veenemans, Jacobien; Milligan, Paul; Prentice, Andrew M.; Schouten, Laura R. A.; Inja, Nienke; van der Heijden, Aafke C.; de Boer, Linsey C. C.; Jansen, Esther J. S.; Koopmans, Anna E.; Enthoven, Wendy T. M.; Kraaijenhagen, Rob J.; Demir, Ayse Y.; Uges, Donald R. A.; Mbugi, Erasto V.; Savelkoul, Huub F. J.; Verhoef, Hans

2011-01-01

Background It is uncertain to what extent oral supplementation with zinc can reduce episodes of malaria in endemic areas. Protection may depend on other nutrients. We measured the effect of supplementation with zinc and other nutrients on malaria rates. Methods and Findings In a 2×2 factorial trial, 612 rural Tanzanian children aged 6–60 months in an area with intense malaria transmission and with height-for-age z-score≤−1.5 SD were randomized to receive daily oral supplementation with either zinc alone (10 mg), multi-nutrients without zinc, multi-nutrients with zinc, or placebo. Intervention group was indicated by colour code, but neither participants, researchers, nor field staff knew who received what intervention. Those with Plasmodium infection at baseline were treated with artemether-lumefantrine. The primary outcome, an episode of malaria, was assessed among children reported sick at a primary care clinic, and pre-defined as current Plasmodium infection with an inflammatory response, shown by axillary temperature ≥37.5°C or whole blood C-reactive protein concentration ≥8 mg/L. Nutritional indicators were assessed at baseline and at 251 days (median; 95% reference range: 191–296 days). In the primary intention-to-treat analysis, we adjusted for pre-specified baseline factors, using Cox regression models that accounted for multiple episodes per child. 592 children completed the study. The primary analysis included 1,572 malaria episodes during 526 child-years of observation (median follow-up: 331 days). Malaria incidence in groups receiving zinc, multi-nutrients without zinc, multi-nutrients with zinc and placebo was 2.89/child-year, 2.95/child-year, 3.26/child-year, and 2.87/child-year, respectively. There was no evidence that multi-nutrients influenced the effect of zinc (or vice versa). Neither zinc nor multi-nutrients influenced malaria rates (marginal analysis; adjusted HR, 95% CI: 1.04, 0.93–1.18 and 1.10, 0.97–1.24 respectively). The prevalence of zinc deficiency (plasma zinc concentration <9.9 µmol/L) was high at baseline (67% overall; 60% in those without inflammation) and strongly reduced by zinc supplementation. Conclusions We found no evidence from this trial that zinc supplementation protected against malaria. Trial Registration ClinicalTrials.gov NCT00623857 Please see later in the article for the Editors' Summary. PMID:22131908

Dietary zinc deficiency effects dorso-lateral and ventral prostate of Wistar rats: histological, biochemical and trace element study.

PubMed

Joshi, Sangeeta; Nair, Neena; Bedwal, R S

2014-10-01

Zinc deficiency has become a global problem affecting the developed and developing countries due to inhibitors in the diet which prevents its absorption or due to a very low concentration of bioavailable zinc in the diet. Being present in high concentration in the prostate and having diverse biological function, we investigated the effects of dietary zinc deficiency for 2 and 4 weeks on dorso-lateral and ventral prostate. Sixty prepubertal rats were divided into three groups: zinc control (ZC), pair fed (PF) and zinc deficient (ZD) and fed on 100 μg/g (zinc control and pair fed groups) and 1 μg/g (zinc deficient) diet. Zinc deficiency was associated with degenerative changes in dorso-lateral and ventral prostate as made evident by karyolysis, karyorhexis, cytoplasmolysis, loss of cellularisation, decreased intraluminar secretion and degeneration of fibromuscular stroma. In response, protein carbonyl, nitric oxide, acid phosphatase, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase increased, exhibiting variable level of significance. Total protein and total zinc concentration in dorso-lateral and ventral prostate as well as in serum decreased (P < 0.001). Decrease (P < 0.001) was recorded in serum FSH and testosterone after 2 and 4 weeks of zinc deficiency. The changes were more prominent after 4 weeks of synthetic zinc deficient diet. The results indicate that zinc deficiency during prepubertal period affects the prostate structure, total protein concentration, enhanced protein carbonyl concentration, nitric oxide as well as acid phosphatase activities and impaired hydroxysteroid dehydrogenase activities. Evidently these changes could be attributed to dysfunction of dorso-lateral and ventral prostate after dietary zinc deficiency as well as impairment of metabolic and secretory activity, reduced gonadotropin levels by hypothalamus -hypophysial system which is indicative of a critical role of zinc in maintaining the prostate integrity.

Effects of serum zinc level on tinnitus.

PubMed

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

2015-01-01

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

Use of zinc as a treatment for traumatic brain injury in the rat: effects on cognitive and behavioral outcomes.

PubMed

Cope, Elise C; Morris, Deborah R; Scrimgeour, Angus G; Levenson, Cathy W

2012-09-01

While treatments for the behavioral deficits associated with traumatic brain injury (TBI) are currently limited, animal models suggest that zinc supplementation may increase resilience to TBI. This work tests the hypothesis that zinc supplementation after TBI can be used as treatment to improve behavioral outcomes such as anxiety, depression, and learning and memory. TBI was induced by controlled cortical impact to the medial frontal cortex. After TBI, rats were fed either a zinc adequate (ZA, 30 ppm) or zinc supplemented (ZS, 180 ppm) diet. Additional rats in each dietary group (ZA or ZS) were given a single intraperitoneal (ip) injection of zinc (30 mg/kg) 1 hour following injury. Brain injury resulted in significant increases in anxiety-like and depression-like behaviors as well as impairments in learning and memory. None of the zinc treatments (dietary or ip zinc) improved TBI-induced anxiety. The 2-bottle saccharin preference test for anhedonia revealed that dietary ZS also did not improve depression-like behaviors. However, dietary ZS combined with an early ip zinc injection significantly reduced anhedonia (P < .001). Dietary supplementation after injury, but not zinc injection, significantly improved (P < .05) cognitive behavior as measured by the time spent finding the hidden platform in the Morris water maze test compared with injured rats fed a ZA diet. These data suggest that zinc supplementation may be an effective treatment option for improving behavioral deficits such as cognitive impairment and depression following TBI.

Effects of Serum Zinc Supplementation on Pica Behavior of Persons with Mental Retardation.

ERIC Educational Resources Information Center

Lofts, Ronald H.; And Others

1990-01-01

Of 806 institutionalized adults with mental retardation, 15.5 percent exhibited pica. Fifty-four percent of the pica group had serum zinc levels below normal range, whereas 7 percent of a control group had serum zinc levels below the normal range. After supplementation with chelated zinc, residents had significant reductions in pica. (Author/JDD)

Evaluation of korzincalloy prepared by Hohman Plating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Korinko, P. S.; Hollingshad, A. N.

2017-07-17

A commercial vendor, Hohman Plating performed contract engineering work to determine the feasibility of producing pin hole free KorZincAlloy bronze material used for zinc gettering. Samples were tested for Sn plating thickness, heat treatability, and chemistry prior to being subjected to a standardized zinc exposure. The samples absorbed zinc and were examined using visual and scanning electron microscopy. Hohman Plating successfully produced KZA that met the target composition, was pin hole free, and was an effective zinc getter.

Reduction of zinc emissions from buildings; the policy of Amsterdam.

PubMed

Gouman, E

2004-01-01

In Amsterdam zinc coming from the roofs and gutters of the buildings accounts for about 50% of the zinc emissions into the surface water (i.e. canals and rivers). This causes water and sediment pollution. Dumping strongly polluted sediment costs ten times more then dumping less polluted mud. Therefore the City of Amsterdam has developed a policy for reducing the zinc emissions from buildings based on the current environmental legislation and the current national targets for surface water quality. Zinc roofs on new and renovated buildings are not permitted. Run off water from zinc roofs of existing buildings is allowed to contain a maximum of 200 microg/l zinc. For the zinc gutters of houses, Amsterdam will promote measures to reduce zinc emissions. To investigate the feasibility of measures, research has been carried out on the zinc emissions of gutters and the effect of covering gutters with an impermeable foil. This research shows clearly that covering zinc gutters with EPDM foil reduces the zinc emissions by 90% from 8.5 to 0.88 gram per square metre per year including the atmospheric deposition.

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate

PubMed Central

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30 μM and 100 μM of ZnCl2. Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth. PMID:29765417

Alterations in fear response and spatial memory in pre- and post-natal zinc supplemented rats: remediation by copper.

PubMed

Railey, Angela M; Micheli, Teresa L; Wanschura, Patricia B; Flinn, Jane M

2010-05-11

The role of zinc in the nervous system is receiving increased attention. At a time when dietary fortification and supplementation have increased the amount of zinc being consumed, little work has been done on the effects of enhanced zinc on behavior. Both zinc and copper are essential trace minerals that are acquired from the diet; under normal conditions the body protects against zinc overload, but at excessive dosages, copper deficiency has been seen. In order to examine the effect of enhanced metal administration on learning and memory, Sprague Dawley rats were given water supplemented with 10ppm Zn, 10ppm Zn+0.25ppm Cu, or normal lab water, during pre- and post-natal development. Fear conditioning tests at 4months showed significantly higher freezing rates during contextual retention and extinction and cued extinction for rats drinking water supplemented with zinc, suggesting increased anxiety compared to controls raised on lab water. During the MWM task at 9months, zinc-enhanced rats had significantly longer latencies to reach the platform compared to controls. The addition of copper to the zinc supplemented water brought freezing and latency levels closer to that of controls. These data demonstrate the importance of maintaining appropriate intake of both metals simultaneously, and show that long-term supplementation with zinc may cause alterations in memory. Copyright 2010 Elsevier Inc. All rights reserved.

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

PubMed

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.

Zinc in human health: effect of zinc on immune cells.

PubMed

Prasad, Ananda S

2008-01-01

Although the essentiality of zinc for plants and animals has been known for many decades, the essentiality of zinc for humans was recognized only 40 years ago in the Middle East. The zinc-deficient patients had severe immune dysfunctions, inasmuch as they died of intercurrent infections by the time they were 25 years of age. In our studies in an experimental human model of zinc deficiency, we documented decreased serum testosterone level, oligospermia, severe immune dysfunctions mainly affecting T helper cells, hyperammonemia, neurosensory disorders, and decreased lean body mass. It appears that zinc deficiency is prevalent in the developing world and as many as two billion subjects may be growth retarded due to zinc deficiency. Besides growth retardation and immune dysfunctions, cognitive impairment due to zinc deficiency also has been reported recently. Our studies in the cell culture models showed that the activation of many zinc-dependent enzymes and transcription factors were adversely affected due to zinc deficiency. In HUT-78 (T helper 0 [Th(0)] cell line), we showed that a decrease in gene expression of interleukin-2 (IL-2) and IL-2 receptor alpha(IL-2Ralpha) were due to decreased activation of nuclear factor-kappaB (NF-kappaB) in zinc deficient cells. Decreased NF-kappaB activation in HUT-78 due to zinc deficiency was due to decreased binding of NF-kappaB to DNA, decreased level of NF-kappaB p105 (the precursor of NF-kappaB p50) mRNA, decreased kappaB inhibitory protein (IkappaB) phosphorylation, and decreased Ikappa kappa. These effects of zinc were cell specific. Zinc also is an antioxidant and has anti-inflammatory actions. The therapeutic roles of zinc in acute infantile diarrhea, acrodermatitis enteropathica, prevention of blindness in patients with age-related macular degeneration, and treatment of common cold with zinc have been reported. In HL-60 cells (promyelocytic leukemia cell line), zinc enhances the up-regulation of A20 mRNA, which, via TRAF pathway, decreases NF-kappaB activation, leading to decreased gene expression and generation of tumor necrosis factor-alpha (TNF-alpha), IL-1beta, and IL-8. We have reported recently that in both young adults and elderly subjects, zinc supplementation decreased oxidative stress markers and generation of inflammatory cytokines.

Zinc Status and Risk of Cardiovascular Diseases and Type 2 Diabetes Mellitus—A Systematic Review of Prospective Cohort Studies

PubMed Central

Chu, Anna; Foster, Meika; Samman, Samir

2016-01-01

Zinc is an essential trace element with proposed therapeutic effects in Type 2 diabetes mellitus (DM), however, the associations between zinc status and the prospective risks of cardiovascular diseases (CVD) and Type 2 DM have not been evaluated. The current systematic review aims to determine the relationships between zinc intake or plasma/serum zinc levels and prospective incidence of CVD and Type 2 DM. Fourteen papers describing prospective cohort studies were included, reporting either CVD (n = 91,708) and/or Type 2 DM (n = 334,387) outcomes. Primary analyses from four out of five studies reported no association between zinc intake and CVD events, when adjusted for multiple variables. Higher serum zinc level was associated with lower risk of CVD in three out of five studies; pronounced effects were observed in vulnerable populations, specifically those with Type 2 DM and patients referred to coronary angiography. The limited evidence available suggests no association between zinc status and Type 2 DM risk. Further investigations into the mechanisms of zinc’s action on the pathogenesis of chronic diseases and additional evidence from observational studies are required to establish a recommendation for dietary zinc in relation to the prevention of CVD and Type 2 DM. PMID:27827959

Decrease of non-point zinc runoff using porous concrete.

PubMed

Harada, Shigeki; Komuro, Yoshinori

2010-01-01

The use of porous concrete columns to decrease the amount of zinc in stormwater runoff is examined. The concentration of zinc in a simulated stormwater fluid (zinc acetate solution), fed through concrete columns (slashed circle10x10cm) decreased by 50-81%, suggesting physical adsorption of zinc by the porous concrete. We propose the use of porous concrete columns (slashed circle50x10cm) as the base of sewage traps. Longer-term, high-zinc concentration monitoring revealed that porous concrete blocks adsorb 38.6mgcm(-3) of zinc. A period of no significant zinc runoff (with an acceptable concentration of zinc in runoff of 0.03mgL(-1), a zinc concentration equal to the Japanese Environmental Standard) is estimated for 41years using a 1-ha catchment area with 20 porous concrete sewage traps. Scanning electron microscopy of the porous concrete used in this study indicates that the needle-like particles formed by hydration action significantly increase zinc adsorption. Evidence suggests that the hydrant is ettringite and has an important role in zinc adsorption, the resulting immobilization of zinc and the subsequent effects on groundwater quality. Copyright 2009 Elsevier Ltd. All rights reserved.

The Relationship between Zinc Intake and Serum/Plasma Zinc Concentration in Children: A Systematic Review and Dose-Response Meta-Analysis

PubMed Central

Moran, Victoria Hall; Stammers, Anna-Louise; Medina, Marisol Warthon; Patel, Sujata; Dykes, Fiona; Souverein, Olga W.; Dullemeijer, Carla; Pérez-Rodrigo, Carmen; Serra-Majem, Lluis; Nissensohn, Mariela; Lowe, Nicola M.

2012-01-01

Recommendations for zinc intake during childhood vary widely across Europe. The EURRECA project attempts to consolidate the basis for the definition of micronutrient requirements, taking into account relationships among intake, status and health outcomes, in order to harmonise these recommendations. Data on zinc intake and biomarkers of zinc status reported in randomised controlled trials (RCTs) can provide estimates of dose-response relationships which may be used for underpinning zinc reference values. This systematic review included all RCTs of apparently healthy children aged 1–17 years published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient () was calculated for each individual study and calculated the overall pooled and SE () using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status indicated that a doubling of the zinc intake increased the serum/plasma zinc status by 9%. This evidence can be utilised, together with currently used balance studies and repletion/depletion studies, when setting zinc recommendations as a basis for nutrition policies. PMID:23016120

Topical zinc oxide vs. salicylic acid-lactic acid combination in the treatment of warts.

PubMed

Khattar, Joe A; Musharrafieh, Umayya M; Tamim, Hala; Hamadeh, Ghassan N

2007-04-01

Warts are a common dermatologic problem. Treatment is painful, prolonged, and can cause scarring. To evaluate topical zinc oxide for the treatment of warts. This was a randomized, double-blind controlled trial of 44 patients. Twenty-two patients were given topical zinc oxide 20% ointment, and the other 22 received salicylic acid 15% + lactic acid 15% ointment twice daily. All patients were followed up for 3 months or until cure, whichever occurred first. All patients were observed for side-effects. Sixteen patients in the zinc group and 19 in the salicylic acid-lactic acid group completed the study. In the zinc oxide-treated group, 50% of the patients showed complete cure and 18.7% failed to respond, compared with 42% and 26%, respectively, in the salicylic acid-lactic acid-treated group. No patients developed serious side-effects. Topical zinc oxide is an efficacious, painless, and safe therapeutic option for wart treatment.

Effect of dietary phytate on zinc homeostasis in young and elderly Korean women.

PubMed

Kim, Jihye; Paik, Hee Young; Joung, Hyojee; Woodhouse, Leslie R; Li, Shanji; King, Janet C

2007-02-01

Previous studies suggest that consumption of predominantly plant-based diets with high phytate content contribute to zinc deficiency by inhibiting zinc absorption. Age of the individual may also affect the ability to maintain zinc homeostasis. This study was designed to determine the effect of dietary phytate on zinc homeostasis and to evaluate the effect of age on the capacity to maintain the zinc homeostasis with changes in dietary phytate in young and elderly Korean women. Seven healthy young women (22-24 yr) and 10 healthy elderly women (66-75 yr) were studied consecutively for 3 months in 2 metabolic periods (MP) in two different metabolic units. During MP1 the women consumed a high phytate (HP) diet (P:Zn molar ratio = 23) for 9 days. After a 10 d wash-out period at home eating their usual diets, a lower phytate diet (LP) (P:Zn molar ratio = 10) was fed in MP2 for 9 d. Phytase was added to selected foods in the high phytate diet to reduce the phytate content of the meals in the LP period. The zinc content of both diets was about 6.5 mg/d. Stable isotopes of Zn ((70)Zn) were administered intravenously on d 5 of MP 1 and 2 for measuring endogenous fecal zinc excretion. Plasma samples were also collected on d 5 for measuring plasma zinc concentrations by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES). 24 hr urine samples were collected for 5 d and complete fecal samples were collected for 9 d after isotope administration. Fractional zinc absorption (FZA) was calculated from mass balance corrected for endogenous fecal zinc (EFZ) excretion and EFZ was determined by using an isotopic dilution technique. Isotopic ratios for FZA and EFZ were measured by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Statistical analyses were done using ANOVA. Both the young and elderly women were in negative zinc balance during the HP period. This was due to a significant decrease in FZA and total absorbed zinc (TAZ) with a HP diet (43 vs 22% in young women, 34 vs 20% in elderly women, p < 0.001). EFZ excretion did not differ in the young and elderly women during the LP and HP periods. Dietary phytate did not alter plasma zinc concentrations or and urinary zinc excretion in either group. Adjustments in zinc homeostasis with an increase in dietary phytate did not differ between young and elderly women in this study.

The effect of zinc on the aluminum anode of the aluminum-air battery

NASA Astrophysics Data System (ADS)

Tang, Yougen; Lu, Lingbin; Roesky, Herbert W.; Wang, Laiwen; Huang, Baiyun

Aluminum is an ideal material for batteries, due to its excellent electrochemical performance. Herein, the effect of zinc on the aluminum anode of the aluminum-air battery, as an additive for aluminum alloy and electrolytes, has been studied. The results show that zinc can decrease the anodic polarization, restrain the hydrogen evolution and increase the anodic utilization rate.

Effect of soil and foliar application of zinc on grain zinc and cadmium concentration of wheat genotypes differing in Zn-efficiency

USDA-ARS?s Scientific Manuscript database

A two-year field experiment was carried out to investigate the effectiveness of soil and foliar applications of zinc sulfate and soil application of waste rubber ash to increase Zn and decrease cadmium (Cd) concentration in grain of 10 wheat genotypes with different Zn-efficiency. Foliar spray of zi...

Nutritional status in patients with cutaneous leishmaniasis and a study of the effects of zinc supplementation together with antimony treatment.

PubMed

Guzman-Rivero, Miguel; Rojas, Ernesto; Verduguez-Orellana, Aleida; Pardo, Henry; Torrico, Mary Cruz; Cloetens, Lieselotte; Akesson, Björn; Sejas, Edgar

2014-01-01

The role of micronutrient status for the incidence and clinical course of cutaneous leishmaniasis is not much studied. Still zinc supplementation in leishmaniasis has shown some effect on the clinical recovery, but the evidence in humans is limited. To compare biochemical nutritional status in cutaneous leishmaniasis patients with that in controls and to study the effects of zinc supplementation for 60 days. Twenty-nine patients with cutaneous leishmaniasis were treated with antimony for 20 days. Fourteen of them got 45 mg zinc daily and 15 of them got placebo. Biomarkers of nutritional and inflammatory status and changes in size and characteristics of skin lesions were measured. The level of transferrin receptor was higher in patients than in controls but otherwise no differences in nutritional status were found between patients and controls. No significant effects of zinc supplementation on the clinical recovery were observed as assessed by lesion area reduction and characteristics or on biochemical parameters. It is concluded that nutritional status was essentially unaffected in cutaneous leishmaniasis and that oral zinc supplementation administered together with intramuscular injection of antimony had no additional clinical benefit.

In-situ evaluation of barrier-cream performance on human skin using laser-induced breakdown spectroscopy.

PubMed

Sun, Q; Tran, M; Smith, B; Winefordner, J D

2000-11-01

Laser-induced breakdown spectroscopy (LIBS) was used to evaluate the effect of barrier creams (skin protective creams) on human skin. A Nd: YAG laser at 1,064 nm was used with a pulse energy of 100 mJ. A method was developed to measure the effectiveness of barrier creams against zinc ion absorption from aqueous zinc chloride solution and oil paste zinc oxide, which represent model hydrophilic and lipophilic metal compounds, respectively. Zinc was chosen since it posed no risk to human skin. 3 representative commercial barrier creams advertised as being effective against lipophilic and hydrophilic substances were evaluated by measuring zinc absorbed through the stratum corneum. 4 consecutive skin surface biopsies (SSB) were taken from biceps of the forearms of 6 volunteers at time periods of 0.5 h and 3 h after application of the protective cream. Results were compared with control skin where no barrier cream was used. The zinc atomic emission line at 213.9 nm was selected. Gate delay and gate width time was optimized to obtain the best signal-to-noise ratio (SNR) and precision. This method provided a facile and rapid screening of the effectiveness of skin barrier creams against zinc ion penetration. The barrier creams were shown to provide appreciable protection against the penetration of both ZnCl2 and ZnO into the skin.

Maternal and fetal plasma zinc in pre-eclampsia.

PubMed

Bassiouni, B A; Foda, A I; Rafei, A A

1979-04-01

Zinc is important for fetal growth and is involved in several important enzyme systems. Maternal and umbilical plasma zinc concentrations were determined in 52 parturient women with mild and severe pre-eclampsia, and were compared with those obtained from 20 women in labor whose pregnancies had progressed normally. A decrease in maternal as well as umbilical plasma zinc concentrations was observed in pre-eclamptic women, and this decrease was statistically significant in severe pre-eclampsia. The causes of these changes in plasma zinc concentrations in pre-eclampsia were discussed, and the possible adverse effects of zinc deficiency on the mother and fetus were mentioned. Low plasma zinc concentrations in pre-eclampsia may be a sign of zinc deficiency, implying possible risks to the mother and her fetus. It is recommended that maintenance of adequate dietary zinc nutrition during pregnancy, and particularly in pre-eclampsia, is important.

Acquired Bilateral Longitudinal True Leukonychia in a 35-year-old Woman

PubMed Central

Mokhtari, Fatemeh; Mozafarpoor, Samaneh; Nouraei, Saeid; Nilforoushzadeh, Mohammad Ali

2016-01-01

Acquired bilateral longitudinal true leukonychia is a rare disorder. We present a case of a 35-year-old healthy woman presented with this unusual and rare manifestation. She mentioned a history of unprotected exposure to detergents and bleaching chemical agents. Considering her low zinc level, she was prescribed with zinc capsules and recommended to avoid chemical substances for 6 months. During bimonthly follow-up, her zinc level turned normal, and leukonychia subsequently disappeared. Bilateral longitudinal true leukonychia in the nails due to zinc deficiency and exposure to chemical substances has not been reported previously. Direct and indirect effects of chemical substances on matrix and the effect of zinc deficiency on healing process should be considered in these cases. PMID:27857831

Effects of Zinc Supplementation on Endocrine Outcomes in Women with Polycystic Ovary Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial.

PubMed

Jamilian, Mehri; Foroozanfard, Fatemeh; Bahmani, Fereshteh; Talaee, Rezvan; Monavari, Mahshid; Asemi, Zatollah

2016-04-01

The current study was conducted to evaluate the effects of zinc supplementation on endocrine outcomes, biomarkers of inflammation, and oxidative stress in patients with polycystic ovary syndrome (PCOS). This study was a randomized double-blind, placebo-controlled trial. Forty-eight women (18-40 years) with PCOS diagnosed according to Rotterdam criteria were randomly assigned to receive either 220 mg zinc sulfate (containing 50 mg zinc) (group 1; n = 24) and/or placebo (group 2; n = 24) for 8 weeks. Hormonal profiles, biomarkers of inflammation, and oxidative stress were measured at study baseline and after 8-week intervention. After 8 weeks of intervention, alopecia (41.7 vs. 12.5%, P = 0.02) decreased compared with the placebo. Additionally, patients who received zinc supplements had significantly decreased hirsutism (modified Ferriman-Gallwey scores) (-1.71 ± 0.99 vs. -0.29 ± 0.95, P < 0.001) and plasma malondialdehyde (MDA) levels (-0.09 ± 1.31 vs. +2.34 ± 5.53 μmol/L, P = 0.04) compared with the placebo. A trend toward a significant effect of zinc intake on reducing high-sensitivity C-reactive protein (hs-CRP) levels (P = 0.06) was also observed. We did observe no significant changes of zinc supplementation on hormonal profiles, inflammatory cytokines, and other biomarkers of oxidative stress. In conclusion, using 50 mg/day elemental zinc for 8 weeks among PCOS women had beneficial effects on alopecia, hirsutism, and plasma MDA levels; however, it did not affect hormonal profiles, inflammatory cytokines, and other biomarkers of oxidative stress.

Effect of zinc supplementation on the status of thyroid hormones and Na, K, And Ca levels in blood following ethanol feeding.

PubMed

Pathak, R; Dhawan, D; Pathak, A

2011-05-01

The influence of zinc (Zn) on the serum levels of triiodothyronine (T(3)), thyroxine (T(4)), thyroid-stimulating hormone (TSH) and sodium (Na), potassium (K), and calcium (Ca) was evaluated following ethanol toxicity to the rats. To achieve this, male Wistar rats (150-195 g) were given 3 ml of 30% ethanol orally, and zinc was given in the form of zinc sulfate (227 mg/l) in their drinking water daily for 8 weeks. Ethanol feeding resulted in a slight decrease in T(3) and T(4) levels and a significant increase in thyroid-stimulating hormone concentration, which may be due to the direct stimulatory effect of ethanol on thyroid. Interestingly, when zinc was given to these rats, all the above levels were brought quite close to their normal levels, thus indicating the positive role of zinc in thyroid hormone metabolism. Serum Zn and Ca levels were found to be reduced, but Na levels were raised upon ethanol feeding. Restoration of normal levels of these metals upon zinc supplementation to ethanol fed rats confirms that zinc has potential in alleviating some of the altered thyroid functions following ethanol administration.

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

NASA Astrophysics Data System (ADS)

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

2013-06-01

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

Immobilization Effect of Morphological, Thermal and Optical Properties in Biotemplate on Zinc Oxide Nanocomposite from Chitosan

NASA Astrophysics Data System (ADS)

Karpuraranjith, M.; Thambidurai, S.

Biotemplate-based zinc oxide nanocomposite was effectively prepared via simple chemical precipitation route. The functional groups of amino (-NH2), hydroxyl (-OH) and O-Zn-O were confirmed and characterized by FTIR spectroscopy. The structural and morphological properties were confirmed by XRD, UV-Vis DRS, HR-SEM and TEM analyses. The elemental composition of carbon, nitrogen, zinc and oxygen was confirmed by energy-dispersive X-ray analysis (EDAX) and Brunauer-Emmett-Teller high surface area of materials was estimated to be 52.49m2/g, respectively. Thermogravimetric analysis (TGA) shows that biotemplate on zinc oxide nanocomposite has higher thermal stability than chitosan matrix. The results demonstrate that biotemplate on zinc oxide matrix causes immobilization effect among the two components. Therefore, chitosan-ZnO nanocomposite has a microcrystalline morphological structure and also good thermal stability, so it can be a promising material for sensors, medical, tissue engineering and wastewater treatment applications.

Zinc is an Antioxidant and Anti-Inflammatory Agent: Its Role in Human Health

PubMed Central

Prasad, Ananda S.

2014-01-01

Zinc supplementation trials in the elderly showed that the incidence of infections was decreased by approximately 66% in the zinc group. Zinc supplementation also decreased oxidative stress biomarkers and decreased inflammatory cytokines in the elderly. In our studies in the experimental model of zinc deficiency in humans, we showed that zinc deficiency per se increased the generation of IL-1β and its mRNA in human mononuclear cells following LPS stimulation. Zinc supplementation upregulated A20, a zinc transcription factor, which inhibited the activation of NF-κB, resulting in decreased generation of inflammatory cytokines. Oxidative stress and chronic inflammation are important contributing factors for several chronic diseases attributed to aging, such as atherosclerosis and related cardiac disorders, cancer, neurodegeneration, immunologic disorders and the aging process itself. Zinc is very effective in decreasing reactive oxygen species (ROS). In this review, the mechanism of zinc actions on oxidative stress and generation of inflammatory cytokines and its impact on health in humans will be presented. PMID:25988117

Effects of Zinc on Particulate Methane Monooxygenase Activity and Structure*

PubMed Central

Sirajuddin, Sarah; Barupala, Dulmini; Helling, Stefan; Marcus, Katrin; Stemmler, Timothy L.; Rosenzweig, Amy C.

2014-01-01

Particulate methane monooxygenase (pMMO) is a membrane-bound metalloenzyme that oxidizes methane to methanol in methanotrophic bacteria. Zinc is a known inhibitor of pMMO, but the details of zinc binding and the mechanism of inhibition are not understood. Metal binding and activity assays on membrane-bound pMMO from Methylococcus capsulatus (Bath) reveal that zinc inhibits pMMO at two sites that are distinct from the copper active site. The 2.6 Å resolution crystal structure of Methylocystis species strain Rockwell pMMO reveals two previously undetected bound lipids, and metal soaking experiments identify likely locations for the two zinc inhibition sites. The first is the crystallographic zinc site in the pmoC subunit, and zinc binding here leads to the ordering of 10 previously unobserved residues. A second zinc site is present on the cytoplasmic side of the pmoC subunit. Parallels between these results and zinc inhibition studies of several respiratory complexes suggest that zinc might inhibit proton transfer in pMMO. PMID:24942740

Randomized trial of the effect of zinc supplementation on the mental health of school-age children in Guatemala123

PubMed Central

DiGirolamo, Ann M; Ramirez-Zea, Manuel; Wang, Meng; Flores-Ayala, Rafael; Martorell, Reynaldo; Neufeld, Lynnette M; Ramakrishnan, Usha; Sellen, Daniel; Black, Maureen M; Stein, Aryeh D

2010-01-01

Background: Rates of mental illness in children are increasing throughout the world. Observational studies of depression, anxiety, and attention-deficit hyperactivity disorder suggest that zinc is an alternative treatment. Objective: We examined the effect of zinc supplementation on the mental health of school-age children in Guatemala. Design: From January to October 2006, we conducted a 6-mo randomized, double-blind, controlled trial comparing zinc supplementation (10 mg ZnO/d for 5 d/wk) with a placebo (10 mg glucose) in 674 Guatemalan children in grades 1–4. Outcome measures included internalizing (ie, depression and anxiety) and externalizing (ie, hyperactivity and conduct disorder) problem behaviors, positive behaviors (ie, socialization and leadership), and serum zinc concentrations. Results: Zinc and placebo groups did not differ significantly in any behavioral measures at baseline or at follow-up. At baseline, 21.4% of children had serum zinc concentrations <65 μg/dL. At follow-up, both groups improved significantly, and zinc concentrations were higher in the zinc group. Increases in serum zinc concentrations were inversely associated with decreases in depressive symptoms (estimate: −0.01 points per μg Zn/dL; P = 0.01), anxiety (estimate: −0.012 points per μg Zn/dL; P = 0.02), internalizing symptoms (estimate: −0.021 points per μg Zn/dL; P = 0.02), and social skills (estimate: −0.019 points per μg Zn/dL; P = 0.01) in adjusted models that were controlled for child age, sex, socioeconomic status, household, and treatment group. Conclusions: Six months of zinc supplementation did not induce differences in mental health outcomes between zinc and placebo groups. However, increases in serum zinc concentrations were associated with decreases in internalizing symptoms (ie, depression and anxiety) in a community-based sample of children at risk of zinc deficiency. This trial was registered at clinicaltrials.gov as NCT00283660. PMID:20881069

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

PubMed

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

2015-02-01

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

Reduction of arsenite-enhanced ultraviolet radiation-induced DNA damage by supplemental zinc

PubMed Central

Cooper, Karen L.; King, Brenee S.; Sandoval, Monica M.; Liu, Ke Jian; Hudson, Laurie G.

2013-01-01

Arsenic is a recognized human carcinogen and there is evidence that arsenic augments the carcinogenicity of DNA damaging agents such as ultraviolet radiation (UVR) thereby acting as a co-carcinogen. Inhibition of DNA repair is one proposed mechanism to account for the co-carcinogenic actions of arsenic. We and others find that arsenite interferes with the function of certain zinc finger DNA repair proteins. Furthermore, we reported that zinc reverses the effects of arsenite in cultured cells and a DNA repair target protein, poly (ADP-ribose) polymerase-1. In order to determine whether zinc ameliorates the effects of arsenite on UVR-induced DNA damage in human keratinocytes and in an in vivo model, normal human epidermal keratinocytes and SKH-1 hairless mice were exposed to arsenite, zinc or both before solar-simulated (ss) UVR exposure. Poly (ADP-ribose) polymerase activity, DNA damage and mutation frequencies at the hprt locus were measured in each treatment group in normal human keratinocytes. DNA damage was assessed in vivo by immunohistochemical staining of skin sections isolated from SKH-1 hairless mice. Cell-based findings demonstrate that ssUVR-induced DNA damage and mutagenesis are enhanced by arsenite, and supplemental zinc partially reverses the arsenite effect. In vivo studies confirm that zinc supplementation decreases arsenite-enhanced DNA damage in response to ssUVR exposure. From these data we can conclude that zinc offsets the impact of arsenic on ssUVR-stimulated DNA damage in cells and in vivo suggesting that zinc supplementation may provide a strategy to improve DNA repair capacity in arsenic exposed human populations. PMID:23523584

Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

PubMed

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight loss in hyperthyroidism.

Thyroid Hormone Upregulates Zinc-α2-glycoprotein Production in the Liver but Not in Adipose Tissue

PubMed Central

Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M.

2014-01-01

Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight loss in hyperthyroidism. PMID:24465683

Comparison of proteome response to saline and zinc stress in lettuce

PubMed Central

Lucini, Luigi; Bernardo, Letizia

2015-01-01

Zinc salts occurring in soils can exert an osmotic stress toward plants. However, being zinc a heavy metal, some more specific effects on plant metabolisms can be forecast. In this work, lettuce has been used as a model to investigate salt and zinc stresses at proteome level through a shotgun tandem MS proteomic approach. The effect of zinc stress in lettuce, in comparison with NaCl stress, was evaluated to dissect between osmotic/oxidative stress related effects, from those changes specifically related to zinc. The analysis of proteins exhibiting a fold change of 3 as minimum (on log 2 normalized abundances), revealed the involvement of photosynthesis (via stimulation of chlorophyll synthesis and enhanced role of photosystem I) as well as stimulation of photophosphorylation. Increased glycolytic supply of energy substrates and ammonium assimilation [through formation of glutamine synthetase (GS)] were also induced by zinc in soil. Similarly, protein metabolism (at both transcriptional and ribosomal level), heat shock proteins, and proteolysis were affected. According to their biosynthetic enzymes, hormones appear to be altered by both the treatment and the time point considered: ethylene biosynthesis was enhanced, while production of abscisic acid was up-regulated at the earlier time point to decrease markedly and gibberellins were decreased at the later one. Besides aquaporin PIP2 synthesis, other osmotic/oxidative stress related compounds were enhanced under zinc stress, i.e., proline, hydroxycinnamic acids, ascorbate, sesquiterpene lactones, and terpenoids biosynthesis. Although the proteins involved in the response to zinc stress and to salinity were substantially the same, their abundance changed between the two treatments. Lettuce response to zinc was more prominent at the first sampling point, yet showing a faster adaptation than under NaCl stress. Indeed, lettuce plants showed an adaptation after 30 days of stress, in a more pronounced way in the case of zinc. PMID:25932029

Systematic review of zinc fortification trials.

PubMed

Das, Jai K; Kumar, Rohail; Salam, Rehana A; Bhutta, Zulfiqar A

2013-01-01

Zinc is one of the essential trace elements required by the human body as it is present in more than a hundred specific enzymes and serves as an important structural ion in transcription factors. Around one third of the world population lives in countries with a high prevalence of zinc deficiency. Food fortification with zinc seems to be an attractive public health strategy and a number of programs have been initiated, especially in developing countries. We conducted a systematic review to assess the efficacy of zinc fortification. A total of 11 studies with 771 participants were included in our analysis. Zinc fortification was associated with significant improvements in plasma zinc concentrations [standard mean difference (SMD) 1.28, 95% CI 0.56, 2.01] which is a functional indicator of zinc status. Significant improvement was observed for height velocity (SMD 0.52, 95% CI 0.01, 1.04); however, this finding was weak and based on a restricted analysis. Further subgroup analysis showed significant improvement in height velocity among very-low-birth-weight infants (SMD 0.70, 95% CI 0.02, 1.37), while for healthy newborns, the impact was insignificant. Zinc fortification had insignificant impacts on serum alkaline levels, serum copper levels, hemoglobin and weight gain. Although the findings highlight that zinc fortification is associated with an increased serum concentration of the micronutrient, overall evidence of the effectiveness of this approach is limited. Data on pregnant and lactating women is scarce. Large-scale fortification programs with robust impact assessment should be initiated to cover larger populations in all age groups. Mass fortification of zinc may be a cost-effective strategy to overcome zinc deficiency. Copyright © 2013 S. Karger AG, Basel.

The effect of zinc deficiency on salt taste acuity, preference, and dietary sodium intake in hemodialysis patients.

PubMed

Kim, So Mi; Kim, Miyeon; Lee, Eun Kyoung; Kim, Soon Bae; Chang, Jai Won; Kim, Hyun Woo

2016-07-01

Introduction High sodium intake is the main cause of fluid overload in hemodialysis (HD) patients, leading to increased cardiovascular mortality. High sodium intake is known to be associated with low salt taste acuity and/or high preference. As the zinc status could influence taste acuity, we analyzed the effect of zinc deficiency on salt taste acuity, preference, and dietary sodium intake in HD patients. Methods A total of 77 HD patients was enrolled in this cross-sectional study. Zinc deficiency was defined as serum zinc level with below 70 µg/mL. The patients were divided into two groups based on serum zinc level. Salt taste acuity and preference were determined by a sensory test using varying concentrations of NaCl solution, and dietary sodium intake was estimated using 3-day dietary recall surveys. Findings The mean salt recognition threshold and salt taste preference were significantly higher in the zinc deficient group than in the non-zinc deficient group. And there was significant positive correlation between salt taste preference and dietary sodium intake in zinc deficient group (r = 0.43, P = 0.002). Although, the dietary sodium intake showed a high tendency with no significance (P = 0.052), interdialytic weight gain was significantly higher in the zinc deficient group than in the non-zinc deficient group (2.68 ± 1.02 kg vs. 3.18 ± 1.02 kg; P = 0.047). Discussion Zinc deficiency may be related to low salt taste acuity and high salt preference, leading to high dietary sodium intake in HD patients. © 2016 International Society for Hemodialysis.

Zinc regulates Nox1 expression through a NF-κB and mitochondrial ROS dependent mechanism to induce senescence of vascular smooth muscle cells.

PubMed

Salazar, G; Huang, J; Feresin, R G; Zhao, Y; Griendling, K K

2017-07-01

The role of oxidative stress and inflammation in the development and progression of cardiovascular diseases (CVD) is well established. Increases in oxidative stress can further exacerbate the inflammatory response and lead to cellular senescence. We previously reported that angiotensin II (Ang II) and zinc increase reactive oxygen species (ROS) and cause senescence of vascular smooth muscle cells (VSMCs) and that senescence induced by Ang II is a zinc-dependent process. Zinc stimulated NADPH oxidase (Nox) activity; however, the role of Nox isoforms in zinc effects was not determined. Here, we show that downregulation of Nox1, but not Nox4, by siRNA prevented both Ang II- and zinc-induced senescence in VSMCs. On the other hand, overexpression of Nox1 induced senescence, which was associated with reduced proliferation, reduced expression of telomerase and increased DNA damage. Zinc increased Nox1 protein expression, which was inhibited by chelation of zinc with TPEN and by overexpression of the zinc exporters ZnT3 and ZnT10. These transporters work to reduce cytosolic zinc, suggesting that increased cytosolic zinc mediates Nox1 upregulation. Other metals including copper, iron, cobalt and manganese failed to upregulate Nox1, suggesting that this pathway is zinc specific. Nox1 upregulation was inhibited by actinomycin D (ACD), an inhibitor of transcription, by inhibition of NF-κB, a known Nox1 transcriptional regulator and by N-acetyl cysteine (NAC) and MitoTEMPO, suggesting that NF-κB and mitochondrial ROS mediate zinc effects. Supporting this idea, we found that zinc increased NF-κB activation in the cytosol, stimulated the translocation of the p65 subunit to the nucleus, and that zinc accumulated in mitochondria increasing mitochondrial ROS, measured using MitoSox. Further, zinc-induced senescence was reduced by inhibition of NF-κB or reduction of mitochondrial ROS with MitoTEMPO. NF-κB activity was also reduced by MitoTEMPO, suggesting that mitochondrial ROS is upstream of NF-κB. Our data demonstrate that altered zinc distribution leading to accumulation of zinc in the mitochondria increases mitochondrial ROS production causing NF-κB activation which in turn upregulates Nox1 expression inducing senescence of VSMCs. Copyright © 2017 Elsevier Inc. All rights reserved.

Interaction Between Yeasts and Zinc

NASA Astrophysics Data System (ADS)

Nicola, Raffaele De; Walker, Graeme

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

Zinc supplementation alleviates the progression of diabetic nephropathy by inhibiting the overexpression of oxidative-stress-mediated molecular markers in streptozotocin-induced experimental rats.

PubMed

Barman, Susmita; Pradeep, Seetur R; Srinivasan, Krishnapura

2018-04-01

Zinc deficiency during diabetes projects a role for zinc nutrition in the management of diabetic nephropathy. The current study explored whether zinc supplementation protects against diabetic nephropathy through modulation of kidney oxidative stress and stress-induced expression related to the inflammatory process in streptozotocin-induced diabetic rats. Groups of hyperglycemic rats were exposed to dietary interventions for 6 weeks with zinc supplementation (5 times and 10 times the normal level). Supplemental-zinc-fed diabetic groups showed a significant reversal of increased kidney weight and creatinine clearance. There was a significant reduction in hyperlipidemic condition along with improved PUFA:SFA ratio in the renal tissue. Expression of the lipid oxidative marker and expression of inflammatory markers, cytokines, fibrosis factors and apoptotic regulatory proteins observed in diabetic kidney were beneficially modulated by zinc supplementation, the ameliorative effect being concomitant with elevated antiapoptosis. There was a significant reduction in advanced glycation, expression of the receptor of the glycated products and oxidative stress markers. Zinc supplementation countered the higher activity and expression of polyol pathway enzymes in the kidney. Overexpression of the glucose transporters, as an adaptation to the increased need for glucose transport in diabetic condition, was minimized by zinc treatment. The pathological abnormalities in the renal architecture of diabetic animals were corrected by zinc intervention. Thus, dietary zinc supplementation has a significant beneficial effect in the control of diabetic nephropathy. This was exerted through a protective influence on oxidative-stress-induced cytokines, inflammatory proliferation and consequent renal injury. Copyright © 2017 Elsevier Inc. All rights reserved.

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

PubMed

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

The effect of micronutrient supplementation on treatment outcome in patients with pulmonary tuberculosis: a randomized controlled trial in Mwanza, Tanzania.

PubMed

Range, Nyagosya; Andersen, Ase B; Magnussen, Pascal; Mugomela, Apolinary; Friis, Henrik

2005-09-01

The aim of the study was to assess the effects of micronutrient supplementation on culture conversion in tuberculosis (TB) patients. The study was a randomized, double-blind placebo-controlled 2 x 2 trial of zinc and multi-micronutrient (MMN) supplementation in pulmonary TB patients in Tanzania. A total of 499 pulmonary TB patients were included in the trial after being confirmed sputum-positive by microscopy or culture. At 8 weeks, 25% were sputum-smear positive but only 11% were culture-positive (P<0.0001). No significant differences were observed in culture conversion rate among those allocated to MMN or placebo (89.5 vs. 86.2%, P=0.29) at 8 weeks, although at week 4 those allocated to MMN had a slightly reduced culture conversion rate (42.8 vs. 52.8%, P=0.058). Zinc had no effects on culture conversion. MMN increased weight gain by 0.78 kg [95% confidence interval (CI): 0.12--1.43] at week 8, while zinc supplementation had no effect. The effects of MMN and zinc did not interact and neither MMN nor zinc interacted with human immunodeficiency virus status, sex and culture-intensity at baseline. Neither zinc nor MMN supplementation had significant effects on culture conversion, but MMN supplementation increased weight gain in TB patients.

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

PubMed Central

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

2015-01-01

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

Electro Spray Method for Flexible Display

DTIC Science & Technology

2016-05-12

conditions which expensive and complicated.8-9) Kim et al. reported the fabrication of IZO thin films via combustion processing and obtained mobility values...metal nitrates as metal sources in solutions. Through the high self-generated energies by the combustion of acetylacetone or urea in solution...barrier to increase the mobility of solution-process-derived TFTs. Therefore, we used H2O as the solvent in our precursor solution. The use of H2O

Synthesis and characterization of titanium dioxide (TiO2) nanopowder

NASA Astrophysics Data System (ADS)

Munirah, S.; Nadzirah, Sh.; Khusaimi, Z.; Fazlena, H.; Rusop, M.

2018-05-01

Titanium dioxide (TiO2) powder was synthesized via sol-gel technique using Titanium tetraisopropoxide (TTIP) and ethanol as precursors. Acetylacetone, distilled water, polyethylene glycol (PEG) and stabilizers (glacial acetic acid and nitric acid) were then added to the solution. The solution was left for ageing for 24 hours and then dried into powder. The synthesized powders were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TGA).

Effect of pulsed electric fields upon accumulation of zinc in Saccharomyces cerevisiae.

PubMed

Pankiewicz, Urszula; Jamroz, Jerzy

2011-06-01

Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 microns pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 microgram/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

Compromised zinc status of experimental rats as a consequence of prolonged iron & calcium supplementation.

PubMed

Jayalakshmi, S; Platel, Kalpana

2016-02-01

Iron supplementation is usually given to pregnant and lactating women who may also have marginal deficiency of zinc. The negative impact of supplemental iron and calcium on zinc status is a cause of concern. The present investigation was undertaken to examine the effect of inclusion of iron and calcium in the diet at supplementary levels on zinc status of experimental rats. Groups of experimental rats were maintained on diets supplemented with iron (Molar ratio - Zn:Fe 1:30) and calcium (Molar ratio - Zn:Ca 1:667) both individually and in combination for six weeks. Zinc status of these rats was assessed by determining zinc concentration in circulation and in organs, and the activities of zinc containing enzymes in serum and liver. The zinc status of experimental rats receiving supplemental levels of iron and calcium was significantly compromised. Zinc concentration in serum, kidney, spleen and liver was reduced significantly by both these minerals. Six weeks of supplementation of iron and calcium individually, significantly reduced the activity of liver and serum superoxide dismutase and alkaline phosphatase. Activity of liver alcohol dehydrogenase was lowered in calcium supplemented group and in calcium + iron supplemented group, while that of carbonic anhydrase was significantly reduced by iron, calcium and their combination. Supplemental levels of iron and calcium, both individually and in combination, significantly compromised the zinc status of experimental rats. This negative effect of these two minerals was more prominent when these were supplemented for a period of six weeks.

Dietary zinc deficiency predisposes mice to the development of preneoplastic lesions in chemically-induced hepatocarcinogenesis.

PubMed

Romualdo, Guilherme Ribeiro; Goto, Renata Leme; Henrique Fernandes, Ana Angélica; Cogliati, Bruno; Barbisan, Luis Fernando

2016-10-01

Although there is a concomitance of zinc deficiency and high incidence/mortality for hepatocellular carcinoma in certain human populations, there are no experimental studies investigating the modifying effects of zinc on hepatocarcinogenesis. Thus, we evaluated whether dietary zinc deficiency or supplementation alter the development of hepatocellular preneoplastic lesions (PNL). Therefore, neonatal male Balb/C mice were submitted to a diethylnitrosamine/2-acetylaminefluorene-induced hepatocarcinogenesis model. Moreover, mice were fed adequate (35 mg/kg diet), deficient (3 mg/kg) or supplemented (180 mg/kg) zinc diets. Mice were euthanized at 12 (early time-point) or 24 weeks (late time-point) after introducing the diets. At the early time-point, zinc deficiency decreased Nrf2 protein expression and GSH levels while increased p65 and p53 protein expression and the number of PNL/area. At the late time-point, zinc deficiency also decreased GSH levels while increased liver genotoxicity, cell proliferation into PNL and PNL size. In contrast, zinc supplementation increased antioxidant defense at both time-points but not altered PNL development. Our findings are the first to suggest that zinc deficiency predisposes mice to the PNL development in chemically-induced hepatocarcinogenesis. The decrease of Nrf2/GSH pathway and increase of liver genotoxicity, as well as the increase of p65/cell proliferation, are potential mechanisms to this zinc deficiency-mediated effect. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced zinc consumption causes memory deficits and increased brain levels of zinc

USGS Publications Warehouse

Flinn, J.M.; Hunter, D.; Linkous, D.H.; Lanzirotti, A.; Smith, L.N.; Brightwell, J.; Jones, B.F.

2005-01-01

Zinc deficiency has been shown to impair cognitive functioning, but little work has been done on the effects of elevated zinc. This research examined the effect on memory of raising Sprague-Dawley rats on enhanced levels of zinc (10 ppm ZnCO3; 0.153 mM) in the drinking water for periods of 3 or 9 months, both pre- and postnatally. Controls were raised on lab water. Memory was tested in a series of Morris Water Maze (MWM) experiments, and zinc-treated rats were found to have impairments in both reference and working memory. They were significantly slower to find a stationary platform and showed greater thigmotaxicity, a measure of anxiety. On a working memory task, where the platform was moved each day, zinc-treated animals had longer latencies over both trials and days, swam further from the platform, and showed greater thigmotaxicity. On trials using an Atlantis platform, which remained in one place but was lowered on probe trials, the zinc-treated animals had significantly fewer platform crossings, spent less time in the target quadrant, and did not swim as close to the platform position. They had significantly greater latency on nonprobe trials. Microprobe synchrotron X-ray fluorescence (??SXRF) confirmed that brain zinc levels were increased by adding ZnCO 3 to the drinking water. These data show that long-term dietary administration of zinc can lead to impairments in cognitive function. ?? 2004 Elsevier Inc. All rights reserved.

Studies on the bioavailability of zinc in humans: intestinal interaction of tin and zinc.

PubMed

Solomons, N W; Marchini, J S; Duarte-Favaro, R M; Vannuchi, H; Dutra de Oliveira, J E

1983-04-01

Mineral/mineral interactions at the intestinal level are important in animal nutrition and toxicology, but only limited understanding of their extent or importance in humans has been developed. An inhibitory interaction of dietary tin on zinc retention has been recently described from human metabolic studies. We have explored the tin/zinc interaction using the change-in-plasma-zinc-concentration method with a standard dosage of 12.5 mg of zinc as zinc sulfate in 100 ml of Coca-Cola. Sn/Zn ratios of 2:1, 4:1, and 8:1, constituted by addition of 25, 50, and 100 mg of tin as stannous chloride, had no significant overall effect on zinc uptake. The 100-mg dose of tin produced noxious gastrointestinal symptoms. Addition of iron as ferrous sulfate to form ratios of Sn/Fe/Zn of 1:1:1 and 2:2:1 with the standard zinc solution and the appropriate doses of tin produced a reduction of zinc absorption not dissimilar from that seen previously with zinc and iron alone, and addition of picolinic acid did not influence the uptake of zinc from the solution with the 2:2:1 Sn/Fe/Zn ratio.

Zinc hazards to plants and animals with emphasis on fishery and wildlife resources

USGS Publications Warehouse

Eisler, R.; Cheremisinoff, Paul N.

1997-01-01

Ecological and toxicological aspects of zinc in the environment are reviewed with emphasis on natural resources. Subtopics include sources and uses; chemical and biochemical properties; carcinogenicity, mutagenicity, teratogenicity; background concentrations in biological and nonbiological compartments; effects of zinc deficiency; toxic and sublethal effects on terrestrial plants and invertebrates, aquatic organisms, birds, and mammals; and recommendations for the protection of sensitive resources.

Effect of Zinc in Enteropathogenic Escherichia coli Infection▿ †

PubMed Central

Crane, John K.; Naeher, Tonniele M.; Shulgina, Irina; Zhu, Chengru; Boedeker, Edgar C.

2007-01-01

Enteropathogenic Escherichia coli (EPEC) infection triggers the release of ATP from host intestinal cells, and the ATP is broken down to ADP, AMP, and adenosine in the lumen of the intestine. Ecto-5′-nucleotidase (CD73) is the main enzyme responsible for the conversion of 5′-AMP to adenosine, which triggers fluid secretion from host intestinal cells and also has growth-promoting effects on EPEC bacteria. In a recent study, we examined the role of the host enzyme CD73 in EPEC infection by testing the effect of ecto-5′-nucleotidase inhibitors. Zinc was a less potent inhibitor of ecto-5′-nucleotidase in vitro than the nucleotide analog α,β-methylene-ADP, but in vivo, zinc was much more efficacious in preventing EPEC-induced fluid secretion in rabbit ileal loops than α,β-methylene-ADP. This discrepancy between the in vitro and in vivo potencies of the two inhibitors prompted us to search for potential targets of zinc other than ecto-5′-nucleotidase. Zinc, at concentrations that produced little or no inhibition of EPEC growth, caused a decrease in the expression of EPEC protein virulence factors, such as bundle-forming pilus (BFP), EPEC secreted protein A, and other EPEC secreted proteins, and reduced EPEC adherence to cells in tissue culture. The effects of zinc were not mimicked by other transition metals, such as manganese, iron, copper, or nickel, and the effects were not reversed by an excess of iron. Quantitative real-time PCR showed that zinc reduced the abundance of the RNAs encoded by the bfp gene, by the plasmid-encoded regulator (per) gene, by the locus for the enterocyte effacement (LEE)-encoded regulator (ler) gene, and by several of the esp genes. In vivo, zinc reduced EPEC-induced fluid secretion into ligated rabbit ileal loops, decreased the adherence of EPEC to rabbit ileum, and reduced histopathological damage such as villus blunting. Some of the beneficial effects of zinc on EPEC infection appear to be due to the action of the metal on EPEC bacteria as well as on the host. PMID:17875638

Involvement of amygdalar extracellular zinc in rat behavior for passive avoidance.

PubMed

Takeda, Atsushi; Minami, Akira; Yamaide, Rie; Oku, Naoto

2004-03-25

On the basis of the evidence that zinc is released from glutamatergic neuron terminals in the amygdala, the effect of chelation of amygdalar extracellular zinc on glutamate release from the neuron terminals was studied by using in vivo microdialysis. When the amygdala was perfused with 100 microM CaEDTA to chelate extracellular zinc, glutamate concentration in the perfusate was decreased significantly, whereas that tended to be increased by perfusion with 100 microM ZnEDTA as a control. The effect of CaEDTA on extracellular glutamate levels was different between the amygdala and hippocampus, implying that modulation of glutamate signaling by zinc is different between them. To evaluate chelation of zinc in rat behavior, perfusion of the amygdala with CaEDTA was started 40 min before behavioral test for passive avoidance. The behavior for passive avoidance was impaired during perfusion with CaEDTA. On the other hand, the behavior during perfusion with ZnEDTA was more rapidly developed than that with vehicle only. These results suggest that amygdalar extracellular zinc is involved in the behavior for passive avoidance.

Removal of toxic zinc from water/wastewater using eucalyptus seeds activated carbon: non-linear regression analysis.

PubMed

Senthil Kumar, Ponnusamy; Saravanan, Anbalagan; Anish Kumar, Kodyingil; Yashwanth, Ramesh; Visvesh, Sridharan

2016-08-01

In the present study, a novel activated carbon was prepared from low-cost eucalyptus seeds, which was utilised for the effectively removal of toxic zinc from the water/wastewater. The prepared adsorbent was studied by Fourier transform infrared spectroscopy and scanning electron microscopic characterisation studies. Adsorption process was experimentally performed for optimising the influencing factors such as adsorbent dosage, solution pH, contact time, initial zinc concentration, and temperature for the maximum removal of zinc from aqueous solution. Adsorption isotherm of zinc removal was ensued Freundlich model, and the kinetic model ensued pseudo-second order model. Langmuir monolayer adsorption capacity of the adsorbent for zinc removal was evaluated as 80.37 mg/g. The results of the thermodynamic studies suggested that the adsorption process was exothermic, thermodynamically feasible and impulsive process. Finally, a batch adsorber was planned to remove zinc from known volume and known concentration of wastewater using best obeyed model such as Freundlich. The experimental details showed the newly prepared material can be effectively utilised as a cheap material for the adsorption of toxic metal ions from the contaminated water.

A Specific Role for Hippocampal Mossy Fiber's Zinc in Rapid Storage of Emotional Memories

ERIC Educational Resources Information Center

Ceccom, Johnatan; Halley, Hélène; Daumas, Stéphanie; Lassalle, Jean Michel

2014-01-01

We investigated the specific role of zinc present in large amounts in the synaptic vesicles of mossy fibers and coreleased with glutamate in the CA3 region. In previous studies, we have shown that blockade of zinc after release has no effect on the consolidation of spatial learning, while zinc is required for the consolidation of contextual fear…

Zinc or copper deficiency-induced impaired inflammatory response to brain trauma may be caused by the concomitant metallothionein changes.

PubMed

Penkowa, M; Giralt, M; Thomsen, P S; Carrasco, J; Hidalgo, J

2001-04-01

The role of zinc- and copper-deficient diets on the inflammatory response to traumatic brain injury (TBI) has been evaluated in adult rats. As expected, zinc deficiency decreased food intake and body weight gain, and the latter effect was higher than that observed in pair-fed rats. In noninjured brains, zinc deficiency only affected significantly lectin (increasing) and glial fibrillary acidic protein (GFAP) and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (decreasing) immunoreactivities (irs). In injured brains, a profound gliosis was observed in the area surrounding the lesion, along with severe damage to neurons as indicated by neuron specific enolase (NSE) ir, and the number of cells undergoing apoptosis (measured by TUNEL) was dramatically increased. Zinc deficiency significantly altered brain response to TBI, potentiating the microgliosis and reducing the astrogliosis, while increasing the number of apoptotic cells. Metallothioneins (MTs) are important zinc- and copper-binding proteins in the CNS, which could influence significantly the brain response to TBI because of their putative roles in metal homeostasis and antioxidant defenses. MT-I+II expression was dramatically increased by TBI, and this response was significantly blunted by zinc deficiency. The MT-III isoform was moderately increased by both TBI and zinc deficiency. TBI strongly increased oxidative stress levels, as demonstrated by malondialdehyde (MDA), protein tyrosine nitration (NITT), and nuclear factor kappaB (NF-kappaB) levels irs, all of which were potentiated by zinc deficiency. Further analysis revealed unbalanced expression of prooxidant and antioxidant proteins besides MT, since the levels of inducible nitric oxide synthase (iNOS) and Cu,Zn-SOD were increased and decreased, respectively, by zinc deficiency. All these effects were attributable to zinc deficiency, since pair-fed rats did not differ from normally fed rats. In general, copper deficiency caused a similar pattern of responses, albeit more moderate. Results obtained in mice with a null mutation for the MT-I+II isoforms strongly suggest that most of the effects observed in the rat brain after zinc and copper deficiencies are attributable to the concomitant changes in the MT expression.

Oxidative stress in newly-hatched Chorthippus brunneus--the effects of zinc treatment during diapause, depending on the female's age and its origins.

PubMed

Augustyniak, Maria; Babczyńska, Agnieszka; Augustyniak, Michał

2011-09-01

The responses of glutathione, glutathione S-transferases (GSTs), and catalase (CAT) were determined in 1-day-old larvae of Chorthippus brunneus Thunberg, 1815, a grasshopper exposed to zinc during diapause, from unpolluted (Pilica) or polluted (Olkusz, Szopienice) sites. The aim of the work was to search for differences among populations of the insects as a result of various multistress pressures in their habitats. The question of zinc toxicity in the context of energy allocation was also considered. Zinc caused a decrease in glutathione concentration in the body of zinc-treated larvae. Significant differences between control and zinc-treated groups were confirmed for young females' progeny from Pilica and Olkusz as well as old females' progeny from Olkusz. GSTs activity was generally not influenced by zinc. It is possible that GSTs were not the most important target of zinc action. On the contrary, the influence of zinc on CAT activity was found. The increase in CAT activity after zinc treatment was similar for all studied populations. An increase in CAT activity after zinc exposure seems to be the most universal reaction. CAT activity in zinc-treated grasshoppers may explain the mechanism of zinc toxicity based on reactive oxygen forms generation. Copyright © 2011 Elsevier Inc. All rights reserved.

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

PubMed

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

2008-10-22

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

A systematic review on zinc for the prevention and treatment of age-related macular degeneration.

PubMed

Vishwanathan, Rohini; Chung, Mei; Johnson, Elizabeth J

2013-06-12

The objective of this systematic review was to examine the evidence on zinc intake from foods and supplements in the primary prevention and treatment of AMD. Randomized controlled trials (RCTs), prospective cohort, retrospective cohort, and case-control studies that investigated zinc intake from foods and/or supplements, and AMD in men and women with a mean age of 50 years or older were included. Medline and Cochrane Central were searched from inception to February 2012 and November 2012, respectively. Data extraction and quality appraisal were done on all eligible studies. TEN STUDIES WERE INCLUDED: four RCTs, four prospective cohort, and two retrospective cohort studies. Age-related Eye Disease Study (AREDS) showed zinc treatment to significantly reduce the risk of progression to advanced AMD. The risk of visual acuity loss was of similar magnitude, but not statistically significant. Two RCTs reported statistically significant increases in visual acuity in early AMD patients and one RCT showed no effect of zinc treatment on visual acuity in advanced AMD patients. Results from six cohort studies on associations between zinc intake and incidence of AMD were inconsistent. Current evidence on zinc intake for the prevention of AMD is inconclusive. Based on the strength of AREDS, we can conclude that zinc treatment may be effective in preventing progression to advanced AMD. Zinc supplementation alone may not be sufficient to produce clinically meaningful changes in visual acuity.

Zinc decreases C-reactive protein, lipid peroxidation, and inflammatory cytokines in elderly subjects: a potential implication of zinc as an atheroprotective agent123

PubMed Central

Bao, Bin; Prasad, Ananda S; Beck, Frances WJ; Fitzgerald, James T; Snell, Diane; Bao, Ginny W; Singh, Tapinder; Cardozo, Lavoisier J

2010-01-01

Background: Chronic inflammation and oxidative stress are common risk factors for atherosclerosis. Zinc is an essential micronutrient that can function as an antiinflammatory and antioxidative agent, and as such, it may have atheroprotective properties. Objective: We hypothesized that zinc down-regulates the production of atherosclerosis-related cytokines/molecules in humans. Design: To examine these effects, we conducted a randomized, double-blinded, placebo trial of zinc supplementation in elderly subjects. We recruited 40 healthy elderly subjects (aged 56–83 y) and randomly assigned them to 2 groups. One group was given an oral dose of 45 mg zinc/d as a gluconate for 6 mo. The other group was given a placebo. Cell culture models were conducted to study the mechanism of zinc as an atheroprotective agent. Results: After 6 mo of supplementation, the intake of zinc, compared with intake of placebo, increased the concentrations of plasma zinc and decreased the concentrations of plasma high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, macrophage chemoattractant protein 1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1), secretory phospholipase A2, and malondialdehyde and hydroxyalkenals (MDA+HAE) in elderly subjects. Regression analysis showed that changes in concentrations of plasma zinc were inversely associated with changes in concentrations of plasma hsCRP, MCP-1, VCAM-1, and MDA+HAE after 6 mo of supplementation. In cell culture studies, we showed that zinc decreased the generation of tumor necrosis factor-α, IL-1β, VCAM-1, and MDA+HAE and the activation of nuclear transcription factor κB and increased antiinflammatory proteins A20 and peroxisome proliferator–activated receptor-α in human monocytic leukemia THP-1 cells and human aortic endothelial cells compared with zinc-deficient cells. Conclusion: These findings suggest that zinc may have a protective effect in atherosclerosis because of its antiinflammatory and antioxidant functions. PMID:20427734

Single and Combined Exposure to Zinc- and Copper-Containing Welding Fumes Lead to Asymptomatic Systemic Inflammation.

PubMed

Markert, Agnieszka; Baumann, Ralf; Gerhards, Benjamin; Gube, Monika; Kossack, Veronika; Kraus, Thomas; Brand, Peter

2016-02-01

Recently, it has been shown that exposure to welding fumes containing both zinc and copper leads to asymptomatic systemic inflammation in humans as shown by an increase of blood C-reactive protein. In the present study, it was investigated which metal is responsible for this effect. Fifteen healthy male subjects were exposed under controlled conditions to welding fumes containing either zinc, or copper, or copper and zinc. For each exposure blood C-reactive protein increased. Copper- and zinc-containing welding fumes are able to induce systemic inflammation.

Zinc supplementation for the prevention of acute lower respiratory infection in children in developing countries: meta-analysis and meta-regression of randomized trials.

PubMed

Roth, Daniel E; Richard, Stephanie A; Black, Robert E

2010-06-01

Routine zinc supplementation is a potential intervention for the prevention of acute lower respiratory infection (ALRI) in developing countries. However, discrepant findings from recent randomized trials remain unexplained. Randomized trials of zinc supplementation in young children in developing countries were identified by a systematic literature review. Trials included in the meta-analysis met specific criteria, including participants <5 years of age, daily/weekly zinc and control supplementation for greater than 3 months, active household surveillance for respiratory morbidity and use of a case definition that included at least one sign of lower respiratory tract illness. ALRI case definitions were classified on the basis of specificity/severity. Incidence rate ratios (IRRs) were pooled by random-effects models. Meta-regression and sub-group analysis were performed to assess potential sources of between-study heterogeneity. Ten trials were eligible for inclusion (n = 49 450 children randomized). Zinc reduced the incidence of ALRI defined by specific clinical criteria [IRR 0.65, 95% confidence interval (CI) 0.52-0.82], but had no effect on lower-specificity ALRI case definitions based on caregiver report (IRR 1.01, 95% CI 0.91-1.12) or World Health Organization 'non-severe pneumonia' (0.96, 95% CI 0.86-1.08). By meta-regression, the effect of zinc was associated with ALRI case definition, but not with mean baseline age, geographic location, nutritional status or zinc dose. Routine zinc supplementation reduced the incidence of childhood ALRI defined by relatively specific clinical criteria, but the effect was null if lower specificity case definitions were applied. The choice of ALRI case definition may substantially influence inferences from community trials regarding the efficacy of preventive interventions.

UV-A induced oxidative stress is more prominent in naturally pigmented aged human RPE cells compared to non-pigmented human RPE cells independent of zinc treatment.

PubMed

Biesemeier, Antje; Kokkinou, Despina; Julien, Sylvie; Heiduschka, Peter; Berneburg, Mark; Bartz-Schmidt, Karl Ulrich; Schraermeyer, Ulrich

2008-02-27

To investigate the effects of zinc supplementation on human amelanotic (ARPE-19) and native pigmented retinal pigment epithelial cells (hRPE) under normal light conditions and after ultraviolet A light exposure. hRPE cells, containing both melanin and lipofuscin granules, were prepared from human donor eyes of 60-70 year old patients. Cells of the amelanotic ARPE-19 cell line and pigmented hRPE cells were treated with zinc chloride and subjected to oxidative stress by UV-A irradiation. Intracellular H(2)O(2) formation was measured using a fluorescence oxidation assay. Additionally, apoptosis and viability assays were performed. Control cells were treated identically except for irradiation and zinc supplementation. Under normal light conditions, zinc treated hRPE cells produced less H(2)O(2) than unsupplemented hRPE cells. Viability and apoptosis events did not change. After UV-A irradiation, ARPE and hRPE cells were greatly impaired in all tests performed compared to the non-irradiated controls. No differences were found after zinc supplementation. hRPE cells showed a higher apoptosis and mortality rate than non-pigmented cells when stressed by UV-A light. ARPE cells never showed any zinc related effects. In contrast, without irradiation, zinc supplementation reduced H(2)O(2) production in pigmented hRPE cells slightly. We did not find any zinc effect in irradiated hRPE cells. After UV light exposure, pigmented cells showed a higher apoptosis and mortality than cells lacking any pigmentation. We conclude that cells with pigmentation consisting of melanin and lipofuscin granules have more prooxidative than antioxidative capacity when stressed by UV light exposure compared to cells lacking any pigmentation.

A double-blind block randomized clinical trial on the effect of zinc as a treatment for diarrhea in neonatal Holstein calves under natural challenge conditions.

PubMed

Glover, A D; Puschner, B; Rossow, H A; Lehenbauer, T W; Champagne, J D; Blanchard, P C; Aly, S S

2013-11-01

Diarrhea is the leading cause of death in neonatal calves and contributes to major economic losses. The objective of this double-blind randomized clinical trial was to evaluate the effect of oral inorganic or organic zinc supplementation as a treatment for neonatal diarrhea in calves. Seventy nine 1 to 8 day old male Holstein calves on a California calf ranch were block randomized to one of 3 treatments within 24h from their first onset of diarrhea. Calves received a daily dose of either a placebo composed of 80 mg of zinc-free powder, 381.54 mg of zinc methionine (Met) (equivalent to 80 mg of zinc), or 99.69 mg of zinc oxide (ZO) (equivalent to 80 mg of zinc) in 2L of a zinc-free oral rehydration solution (ORS). Calves were treated once daily until normal fecal consistency or for a maximum of 14 days. Upon enrollment and exit, calves were weighed, and blood, feces, and liver biopsies were collected for trace mineral analysis. Fecal samples at enrollment and exit were tested for E. coli K99, Cryptosporidium spp., rotavirus and coronavirus. Pre-treatment liver zinc concentrations for the 71 calves in the placebo, zinc Met, and ZO treatment groups were 710.6 (SEM=147.7), 852.3 (SEM=129.6), and 750.7 (SEM=202.9)mg/kg dry weight (DW), respectively. Exit liver zinc concentrations for the calves in the placebo, zinc Met, and ZO treatment groups were 728.9 (SEM=182.9), 1141.0 (SEM=423.8), and 636.8 (SEM=81.5)mg/kg dry weight, respectively. Although statistically non-significant, there were clinically important findings identified for each of zinc Met and ZO treatments. Calves treated with zinc Met gained on average 40 g/day during a diarrhea episode compared to a weight loss of 67 g/day on average in the placebo-treated calves (Power 19.9%). Calves treated with ZO had 1.4 times higher hazard of clinical cure compared to calves in the placebo group (Power 5.3%). Calves that were fecal positive to cryptosporidium spp. at enrollment and treated with zinc Met had higher odds of testing negative at exit compared to placebo calves (Odds Ratio (OR)=16.0). In contrast, calves treated with ZO tended to recover (fecal score=1) one day earlier compared to calves treated with a placebo (8.5 d vs. 9.7 d). The current trial identified clinically important findings that warrant further research to investigate zinc's therapeutic effect for calf diarrhea. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Cytoprotection by Endogenous Zinc in the Vertebrate Retina

PubMed Central

Anastassov, Ivan; Ripps, Harris; Chappell, Richard L.

2014-01-01

Our recent studies have shown that endogenous zinc, co-released with glutamate from the synaptic terminals of vertebrate retinal photoreceptors, provides a feedback mechanism that reduces calcium entry and the concomitant vesicular release of glutamate. We hypothesized that zinc feedback may serve to protect the retina from glutamate excitotoxicity, and conducted in vivo experiments on the retina of the skate (Raja erinacea) to determine the effects of removing endogenous zinc by chelation. These studies showed that removal of zinc by injecting the zinc chelator histidine results in inner retinal damage similar to that induced by the glutamate receptor agonist kainic acid. In contrast, when an equimolar quantity of zinc followed the injection of histidine, the retinal cells were unaffected. Our results are a good indication that zinc, co-released with glutamate by photoreceptors, provides an auto-feedback system that plays an important cytoprotective role in the retina. PMID:24286124

Ultrasonic measurements of thin zinc layers on concrete

NASA Astrophysics Data System (ADS)

Jansen, Henri; Brooks, Bill; Nguyen, Vinh; Koretsky, Milo

2008-05-01

In order to protect bridges at the coast from corrosion, a thin layer (approximately 0.5 mm) of zinc is sprayed on the concrete of the bridge. When this zinc layer is electrically connected to the reinforcing steel (rebar) and placed at a positive potential with respect to the rebar, oxidation is favored at the zinc layer and reduced at the rebar. The resulting protection of the rebar fails when the zinc layer delaminates from the concrete or when the zinc oxidation product layer becomes too thick. We have used ultrasonic detection to investigate the properties of the zinc layer. This method has been applied very successfully in the semiconductor industry. We present the details of the method and the expected response. Unfortunately, we are not able to measure changes in the zinc layer, because either the frequency we use (10-20 MHz) is too low, or scattering in the concrete is a dominant effect.

Serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin concentrations in infants receiving intravenous zinc and copper supplementation.

PubMed

Lockitch, G; Godolphin, W; Pendray, M R; Riddell, D; Quigley, G

1983-02-01

One hundred twenty-seven newborn infants requiring parenteral nutrition were randomly assigned to receive differing amounts of zinc (40 to 400 micrograms/kg/day) and copper (20 or 40 micrograms/kg/day) supplementation within five birth weight groups (600 to 2,500 gm). The serum zinc concentration remained relatively constant in the group receiving the most zinc supplementation after two weeks of therapy, but declined sharply in the groups receiving less supplementation. No effect of increased copper intake was noted on ceruloplasmin values, but a difference in serum copper concentrations was noted at two weeks. No correlation was noted between serum zinc and copper values or among those for serum zinc, retinol-binding protein, and prealbumin. Reference ranges were defined for serum zinc, copper, retinol-binding protein, prealbumin, and ceruloplasmin in the preterm infant.

Potential reproduction and response of selenium and zinc mineral supplementation on quality of goat samosir semen

NASA Astrophysics Data System (ADS)

Siswoyo, P.; Tafsin, M.; Handarini, R.

2018-02-01

The present study was conducted to investigate the effect of suppllementattion of selenium and zinc on semen quality and growth of samosir goat. The experimental design used latin square design (4x4). The treatment supplementation mineral on multi nutrient block (MNB) composed of without sipplementation (p0), +10ppm selenium (p1), +10ppm zinc (p2), +10ppm selenium and +10ppm zinc (p3). The result showed that supplementation mineral selenium and zinc increased significantly (p<0.05) average daily growth, feed consumtion, and lower feed convertion ratio. Semen quality of goat were supplemented by selenium and zinc influenced motility, viability, volume concentration, and responding hypo osmotic swelling (HOS). Combination supplementation selenium and zinc significanly had higher semen quality than ither treatment. It is concluded that supplementation selenium and zinc improve growth and semen quality of samosir goat.

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.

PubMed

Song, Chang-Zheng; Liu, Mei-Ying; Meng, Jiang-Fei; Chi, Ming; Xi, Zhu-Mei; Zhang, Zhen-Wen

2015-02-02

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.

Metallic Zinc Exhibits Optimal Biocompatibility for Bioabsorbable Endovascular Stents

PubMed Central

Bowen, Patrick K.; Guillory, Roger J.; Shearier, Emily R.; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

2015-01-01

Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5 months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5 months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells. PMID:26249616

Zinc Transport Differs in Rat Spermatogenic Cell Types and Is Affected by Treatment with Cyclophosphamide1

PubMed Central

Downey, Anne Marie; Hales, Barbara F.; Robaire, Bernard

2016-01-01

Adequate zinc levels are required for proper cellular functions and for male germ cell development. Zinc transport is accomplished by two families of zinc transporters, the ZIPs and the ZnTs, that increase and decrease cytosolic zinc levels, respectively. However, very little is known about zinc transport in the testis. Furthermore, whether cytotoxic agents such as cyclophosphamide (CPA), a known male germ cell toxicant, can affect zinc transport and homeostasis is unknown. We examined zinc transporter expression and zinc transport in pachytene spermatocytes (PS) and round spermatids (RS) in a normal state and after exposure to CPA. We observed differences in the expression of members of the ZnT and ZIP families in purified populations of PS and RS. We also observed that RS accumulate more zinc over time than PS. The expression of many zinc binding genes was altered after CPA treatment. Interestingly, we found that the expression levels of ZIP5 and ZIP14 were increased in PS from animals treated daily with 6 mg/kg CPA for 4 wk but not in RS. This up-regulation led to an increase in zinc uptake in PS but not in RS from treated animals compared to controls. These data suggest that CPA treatment may alter zinc homeostasis in male germ cells leading to an increased need for zinc. Altered zinc homeostasis may disrupt proper germ cell development and contribute to infertility and effects on progeny. PMID:27281708

Zinc-catalyzed allenylations of aldehydes and ketones.

PubMed

Fandrick, Daniel R; Saha, Jaideep; Fandrick, Keith R; Sanyal, Sanjit; Ogikubo, Junichi; Lee, Heewon; Roschangar, Frank; Song, Jinhua J; Senanayake, Chris H

2011-10-21

The general zinc-catalyzed allenylation of aldehydes and ketones with an allenyl boronate is presented. Preliminary mechanistic studies support a kinetically controlled process wherein, after a site-selective B/Zn exchange to generate a propargyl zinc intermediate, the addition to the electrophile effectively competes with propargyl-allenyl zinc equilibration. The utility of the methodology was demonstrated by application to a rhodium-catalyzed [4+2] cycloaddition. © 2011 American Chemical Society

Galvanic zinc-copper microparticles inhibit melanogenesis via multiple pigmentary pathways.

PubMed

Won, Yen-Kim; Lin, Connie B; Seiberg, Miri; Chen, Nannan; Hu, Yaping; Rossetti, Dianne; Saliou, Claude; Loy, Chong-Jin

2014-01-01

The endogenous electrical field of human skin plays an important role in many skin functions. However, the biological effects and mechanism of action of externally applied electrical stimulation on skin remain unclear. Recent study showed that galvanic zinc-copper microparticles produce electrical stimulation and reduce inflammatory and immune responses in intact skin, suggesting the important role of electrical stimulation in non-wounded skin. The objective of this study is to investigate the biological effect of galvanic zinc-copper microparticles on skin pigmentation. Our findings showed that galvanic zinc-copper microparticles inhibited melanogenesis in a human melanoma cell line (MNT-1), human keratinocytes and melanoma cells co-cultures, and in pigmented epidermal equivalents. Treatment of galvanic zinc-copper microparticles inhibited melanogenesis by reducing the promoter transactivation of tyrosinase and tyrosinase-related protein-1 in human melanoma cells. In a co-culture Transwell system of keratinocytes and melanoma cells, galvanic zinc-copper microparticles reduced melanin production via downregulation of endothelin-1 secretion from keratinocytes and reduced tyrosinase gene expression in melanoma cells. In addition, exposure of pigmented epidermal equivalents to galvanic zinc-copper microparticles resulted in reduced melanin deposition. In conclusion, our data demonstrated for the first time that galvanic zinc-copper microparticles reduced melanogenesis in melanoma cells and melanin deposition in pigmented epidermal equivalents by affecting multiple pigmentary pathways.

Oral Zinc Supplementation Decreases the Serum Iron Concentration in Healthy Schoolchildren: A Pilot Study

PubMed Central

de Brito, Naira Josele Neves; de Medeiros Rocha, Érika Dantas; de Araújo Silva, Alfredo; Costa, João Batista Sousa; França, Mardone Cavalcante; das Graças Almeida, Maria; Brandão-Neto, José

2014-01-01

The recognized antagonistic actions between zinc and iron prompted us to study this subject in children. A convenience sample was used. Thirty healthy children between 8 and 9 years of age were studied with the aim of establishing the effect of a 3-mo oral zinc supplementation on iron status. Fifteen individuals were given a placebo (control group), and 15 were given 10 mg Zn/day (experimental group). Blood samples were collected at 0, 60, 120, 180 and 210 min after a 12-h overnight fast, before and after placebo or zinc supplementation. This supplementation was associated with significant improvements in energy, protein, fat, carbohydrate, fiber, calcium, iron, and zinc intake in accordance with the recommendations for age and sex. The basal serum zinc concentration significantly increased after oral zinc supplementation (p < 0.001). However, basal serum iron concentrations and area under the iron curves significantly decreased in the experimental group (p < 0.0001) and remained at the same level throughout the 210-min study. The values obtained for hemoglobin, mean corpuscular volume, ferritin, transferrin, transferrin saturation, ceruloplasmin and total protein were within normal reference ranges. In conclusion, the decrease in serum iron was likely due to the effects of chronic zinc administration, and the decrease in serum iron was not sufficient to cause anemia. PMID:25192026

Effect of zinc supplementation on lipid peroxidation and lactate levels in rats with diabetes induced by streptozotocin and subjected to acute swimming exercise.

PubMed

Bicer, M; Gunay, M; Baltaci, A K; Uney, K; Mogulkoc, R; Akil, M

2012-01-01

The present study aims to explore the effect of zinc supplementation on lipid peroxidation and lactate levels in rats having diabetes induced by streptozotocin and subjected to acute swimming exercise. A total of 80 adult male rats of Sprague-Dawley type were equally allocated to 8 groups: Group 1, general control. Group 2, zinc-supplemented group. Group 3, zinc-supplemented, diabetic group. Group 4, swimming control group. Group 5, zinc-supplemented swimming group. Group 6, zinc-supplemented diabetic swimming group. Group 7, diabetic swimming group. Group 8, diabetic group. At the end of the 4-week study, blood samples were collected to determine MDA, GSH, GPx, SOD, lactate and zinc levels. The highest MDA values were found in group 7 and 8 (p<0.001). GSH values in groups 5 and 6 were higher (p<0.001). The highest GPx values were established in groups 2, 5 and 6 (p<0.001). SOD values were the highest in groups 5 and 6 (p<0.001) and lowest in groups 2, 3 and 8 (p<0.001). The highest plasma lactate levels were found in group 7 (p<0.001). The highest zinc levels were obtained in groups 1, 2 and 5 (p<0.001), and the lowest zinc levels were found in groups 7 and 8 (p<0.001). Results of the study reveal that zinc supplementation prevents the increase of free radical formation, suppression of antioxidant activity and muscle exhaustion, all of which result from diabetes and acute exercise. Zinc supplementation may contribute to health performance in diabetes and acute exercise (Tab. 2, Fig. 1 Ref. 47). Full Text in PDF www.elis.sk.

Behavioral impairments in animal models for zinc deficiency

PubMed Central

Hagmeyer, Simone; Haderspeck, Jasmin Carmen; Grabrucker, Andreas Martin

2015-01-01

Apart from teratogenic and pathological effects of zinc deficiency such as the occurrence of skin lesions, anorexia, growth retardation, depressed wound healing, altered immune function, impaired night vision, and alterations in taste and smell acuity, characteristic behavioral changes in animal models and human patients suffering from zinc deficiency have been observed. Given that it is estimated that about 17% of the worldwide population are at risk for zinc deficiency and that zinc deficiency is associated with a variety of brain disorders and disease states in humans, it is of major interest to investigate, how these behavioral changes will affect the individual and a putative course of a disease. Thus, here, we provide a state of the art overview about the behavioral phenotypes observed in various models of zinc deficiency, among them environmentally produced zinc deficient animals as well as animal models based on a genetic alteration of a particular zinc homeostasis gene. Finally, we compare the behavioral phenotypes to the human condition of mild to severe zinc deficiency and provide a model, how zinc deficiency that is associated with many neurodegenerative and neuropsychological disorders might modify the disease pathologies. PMID:25610379

Effects of zinc supplementation on obesity: study protocol for a randomized controlled clinical trial.

PubMed

Rathnayake, Kumari M; Silva, Kdrr; Jayawardena, Ranil

2016-11-04

The prevalence of obesity is escalating alarmingly worldwide, and it is now becoming a rapidly growing epidemic in developing countries. Recent studies have reported that zinc has been implicated in altered lipid markers, insulin resistance and some obesity markers. There is a lack of evidence on zinc as a potential therapeutic agent to reduce weight and improve metabolic parameters in obese adults. The present study is designed to evaluate the effects of zinc supplementation on obese adults in Sri Lanka. Furthermore, we aim to evaluate the effects of zinc supplementation on metabolic parameters in this population. This study will be conducted as a randomized, double-blind, placebo-controlled clinical trial for a period of 3 months at the clinical laboratory, Department of Applied Nutrition, Wayamba University of Sri Lanka to assess the efficacy of daily zinc 20 mg supplementation in obese subjects. There will be a total of 80 subjects, aged between 18-60 years, of both genders, who are obese (body mass index (BMI) ≥25). Subjects will be stratified according to age, gender and BMI and randomly assigned into the test and placebo groups in a 1:1 ratio. The treatment drug is a capsule containing elemental zinc 20 mg as the active ingredient (as zinc sulphate). The placebo capsule will contain lactose monohydrate. The subjects will receive either zinc capsules or placebo daily for 3 months. The study treatments will be double blinded to both investigator and subject. The visits and the evaluations will be as follows: screening (visit 0), baseline (visit 1) and 3 month (visit 2). The primary outcome will be weight reduction among the obese subjects. Secondary outcome measures include glycaemic status (fasting blood glucose), lipid parameters (total cholesterol, triglyceride levels, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol) and blood pressure. The trial protocol will aim to establish the effects of zinc supplementation on weight reduction and metabolic risk parameters among obese subjects. Sri Lanka Clinical Trials Registry: SLCTR/2014/020 . Registered on 18 September 2014.

Synthesis of hydrophobic zinc borate nanoflakes and its effect on flame retardant properties of polyethylene

NASA Astrophysics Data System (ADS)

Li, Shengli; Long, Beihong; Wang, Zichen; Tian, Yumei; Zheng, Yunhui; Zhang, Qian

2010-04-01

Zinc borate (2ZnO·3B 2O 3·3.5H 2O) has relatively high dehydration on-set temperature which property permits processing in a wide range of polymer system. But zinc borate particles are hardly dispersed in a polymer matrix so that they prevent their using in industry. To address this problem, we synthesized hydrophobic zinc borate (2ZnO·3B 2O 3·3.5H 2O) nanoflakes by employing solid-liquid reaction of zinc oxide (ZnO) and boric acid (H 3BO 3) in the presence of oleic acid. This method does not bring pollution. By conducting morphological and microscopic analyses, we found that this compound displayed nanoflake morphology with particle size of around 100-200 nm, thickness less than 100 nm and there were uniform mesopores with the diameter about 10 nm within the particles. Furthermore, our products had an effect on flame retardant of polyethylene, especially when the zinc borate was modified by oleic acid.

Reductive atmospheric acid leaching of spent alkaline batteries in H2SO4/Na2SO3 solutions

NASA Astrophysics Data System (ADS)

Morcali, Mehmet Hakan

2015-07-01

This work studies the optimum reductive leaching process for manganese and zinc recovery from spent alkaline battery paste. The effects of reducing agents, acid concentration, pulp density, reaction temperature, and leaching time on the dissolution of manganese and zinc were investigated in detail. Manganese dissolution by reductive acidic media is an intermediate-controlled process with an activation energy of 12.28 kJ·mol-1. After being leached, manganese and zinc were selectively precipitated with sodium hydroxide. The zinc was entirely converted into zincate (Zn(OH){4/2-}) ions and thus did not co-precipitate with manganese hydroxide during this treatment (2.0 M NaOH, 90 min, 200 r/min, pH > 13). After the manganese was removed from the solution, the Zn(OH){4/2-} was precipitated as zinc sulfate in the presence of sulfuric acid. The results indicated that this process could be effective in recovering manganese and zinc from alkaline batteries.

Relationship between welding fume concentration and systemic inflammation after controlled exposure of human subjects with welding fumes from metal inert gas brazing of zinc-coated materials.

PubMed

Brand, Peter; Bauer, Marcus; Gube, Monika; Lenz, Klaus; Reisgen, Uwe; Spiegel-Ciobanu, Vilia Elena; Kraus, Thomas

2014-01-01

It has been shown that exposure of subjects to emissions from a metal inert gas (MIG) brazing process of zinc-coated material led to an increase of high-sensitivity C-reactive protein (hsCRP) in the blood. In this study, the no-observed-effect level (NOEL) for such emissions was assessed. Twelve healthy subjects were exposed for 6 hours to different concentrations of MIG brazing fumes under controlled conditions. High-sensitivity C-reactive protein was measured in the blood. For welding fumes containing 1.20 and 1.50 mg m zinc, high-sensitivity C-reactive protein was increased the day after exposure. For 0.90 mg m zinc, no increase was detected. These data indicate that the no-observed-effect level for emissions from a MIG brazing process of zinc-coated material in respect to systemic inflammation is found for welding fumes with zinc concentrations between 0.90 and 1.20 mg m.

Preparation and characterization of an anti-inflammatory agent based on a zinc-layered hydroxide-salicylate nanohybrid and its effect on viability of Vero-3 cells

PubMed Central

Ramli, Munirah; Hussein, Mohd Zobir; Yusoff, Khatijah

2013-01-01

A new organic-inorganic nanohybrid based on zinc-layered hydroxide intercalated with an anti-inflammatory agent was synthesized through direct reaction of salicylic acid at various concentrations with commercially available zinc oxide. The basal spacing of the pure phase nanohybrid was 15.73 Å, with the salicylate anions arranged in a monolayer form and an angle of 57 degrees between the zinc-layered hydroxide interlayers. Fourier transform infrared study further confirmed intercalation of salicylate into the interlayers of zinc-layered hydroxide. The loading of salicylate in the nanohybrid was estimated to be around 29.66%, and the nanohybrid exhibited the properties of a mesoporous-type material, with greatly enhanced thermal stability of the salicylate compared with its free counterpart. In vitro cytotoxicity assay revealed that free salicylic acid, pure zinc oxide, and the nanohybrid have a mild effect on viability of African green monkey kidney (Vero-3) cells. PMID:23345976

Effect of low zinc intake and oral contraceptive agents on nitrogen utilization and clinical findings in young women.

PubMed

Hess, F M; King, J C; Margen, S

1977-12-01

In a previous paper we reported that serum, urine and fecal zinc levels fell markedly in women taking a combination oral contraceptive agent (+OCA) and in women with normal menstrual cycles (-OCA) when they consumed a low-zinc diet (less than 0.2 mg/day) for 35 days. We evaluated other biochemical and clinical data in order to determine if depletion of accessible body zinc and/or physiologic adjustment to conserve body zinc stores had occurred. Neither low zinc intake nor oral contraceptive use appeared to influence nitrogen balance or body weight. Use of contraceptive drugs appeared to influence the response of blood parameters to zinc depletion. Serum transferrin and cholesterol declined significantly in the -OCA group, whereas alkaline phosphatase and gamma-globulin changed significantly in both groups. Clinical problems developed in all the subjects with serum zinc levels below 50 microgram/dl during the study; three of the six with serum zinc levels above 50 microgram/dl also complained of clinical symptoms. The results suggest that zinc deficiency through depletion of accessible body zinc stores developed during the 35-day study.

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

PubMed

Baltaci, Abdulkerim Kasım; Mogulkoc, Rasim

2017-06-01

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

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

PubMed

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 levels which could be responsible for toxicological symptoms.

Human skin penetration and local effects of topical nano zinc oxide after occlusion and barrier impairment.

PubMed

Leite-Silva, V R; Sanchez, W Y; Studier, H; Liu, D C; Mohammed, Y H; Holmes, A M; Ryan, E M; Haridass, I N; Chandrasekaran, N C; Becker, W; Grice, J E; Benson, H A E; Roberts, M S

2016-07-01

Public health concerns continue to exist over the safety of zinc oxide nanoparticles that are commonly used in sunscreen formulations. In this work, we assessed the effects of two conditions which may be encountered in everyday sunscreen use, occlusion and a compromised skin barrier, on the penetration and local toxicity of two topically applied zinc oxide nanoparticle products. Caprylic/capric triglyceride (CCT) suspensions of commercially used zinc oxide nanoparticles, either uncoated or with a silane coating, were applied to intact and barrier impaired skin of volunteers, without and with occlusion for a period of six hours. The exposure time was chosen to simulate normal in-use conditions. Multiphoton tomography with fluorescence lifetime imaging was used to noninvasively assess zinc oxide penetration and cellular metabolic changes that could be indicative of toxicity. We found that zinc oxide nanoparticles did not penetrate into the viable epidermis of intact or barrier impaired skin of volunteers, without or with occlusion. We also observed no apparent toxicity in the viable epidermis below the application sites. These findings were validated by ex vivo human skin studies in which zinc penetration was assessed by multiphoton tomography with fluorescence lifetime imaging as well as Zinpyr-1 staining and toxicity was assessed by MTS assays in zinc oxide treated skin cryosections. In conclusion, applications of zinc oxide nanoparticles under occlusive in-use conditions to volunteers are not associated with any measurable zinc oxide penetration into, or local toxicity in the viable epidermis below the application site. Copyright © 2016 Elsevier B.V. All rights reserved.

Compromised zinc status of experimental rats as a consequence of prolonged iron & calcium supplementation

PubMed Central

Jayalakshmi, S.; Platel, Kalpana

2016-01-01

Background & objectives: Iron supplementation is usually given to pregnant and lactating women who may also have marginal deficiency of zinc. The negative impact of supplemental iron and calcium on zinc status is a cause of concern. The present investigation was undertaken to examine the effect of inclusion of iron and calcium in the diet at supplementary levels on zinc status of experimental rats. Methods: Groups of experimental rats were maintained on diets supplemented with iron (Molar ratio - Zn:Fe 1:30) and calcium (Molar ratio - Zn:Ca 1:667) both individually and in combination for six weeks. Zinc status of these rats was assessed by determining zinc concentration in circulation and in organs, and the activities of zinc containing enzymes in serum and liver. Results: The zinc status of experimental rats receiving supplemental levels of iron and calcium was significantly compromised. Zinc concentration in serum, kidney, spleen and liver was reduced significantly by both these minerals. Six weeks of supplementation of iron and calcium individually, significantly reduced the activity of liver and serum superoxide dismutase and alkaline phosphatase. Activity of liver alcohol dehydrogenase was lowered in calcium supplemented group and in calcium + iron supplemented group, while that of carbonic anhydrase was significantly reduced by iron, calcium and their combination. Interpretation & conclusions: Supplemental levels of iron and calcium, both individually and in combination, significantly compromised the zinc status of experimental rats. This negative effect of these two minerals was more prominent when these were supplemented for a period of six weeks. PMID:27121523

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

PubMed

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.

Comparative studies on acid leaching of zinc waste materials

NASA Astrophysics Data System (ADS)

Rudnik, Ewa; Włoch, Grzegorz; Szatan, Leszek

2017-11-01

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

Zinc-rich oysters as well as zinc-yeast- and astaxanthin-enriched food improved sleep efficiency and sleep onset in a randomized controlled trial of healthy individuals.

PubMed

Saito, Hitomi; Cherasse, Yoan; Suzuki, Rina; Mitarai, Makoto; Ueda, Fumitaka; Urade, Yoshihiro

2017-05-01

Zinc is an essential mineral that plays an important role in the body. We previously reported that orally feeding zinc-enriched yeast to mice induces nonrapid-eye-movement sleep. In addition, astaxanthin, an antioxidant abundant in seafood such as salmon and krill, is able to chelate minerals and may promote zinc absorption, which in return may also improve sleep. The purpose of our study was to examine the effect of zinc-rich and astaxanthin-containing food on sleep in humans. We conducted a randomized, double-blinded, placebo-controlled parallel group trial of 120 healthy subjects and recorded their night activity by actigraphy for 12 weeks. These subjects were divided into four groups: placebo, zinc-rich food, zinc-, and astaxanthin-rich food, and placebo supplemented with zinc-enriched yeast and astaxanthin oil. Compared with the placebo group, the zinc-rich food group efficiently decreased the time necessary to fall asleep and improved sleep efficiency, whereas the group that ingested zinc-enriched yeast and astaxanthin oil significantly improved the sleep onset latency. Actigraphic sleep monitoring demonstrated that eating zinc-rich food improved sleep onset latency as well as improved the sleep efficiency in healthy individuals. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preventive effects of zinc against psychological stress-induced iron dyshomeostasis, erythropoiesis inhibition, and oxidative stress status in rats.

PubMed

Li, Yingjie; Zheng, Yuanyuan; Qian, Jianxin; Chen, Xinmin; Shen, Zhilei; Tao, Liping; Li, Hongxia; Qin, Haihong; Li, Min; Shen, Hui

2012-06-01

Psychological stress (PS) could cause decreased iron absorption and iron redistribution in body resulting in low iron concentration in the bone marrow and inhibition of erythropoiesis. In the present study, we investigated the effect of zinc supplementation on the iron metabolism, erythropoiesis, and oxidative stress status in PS-induced rats. Thirty-two rats were divided into two groups randomly: control group and zinc supplementation group. Each group was subdivided into two subgroups: control group and PS group. Rats received zinc supplementation before PS exposure established by a communication box. We investigated the serum corticosterone (CORT) level; iron apparent absorption; iron contents in liver, spleen, cortex, hippocampus, striatum, and serum; hematological parameters; malondialdehyde (MDA); reduced glutathione (GSH); and superoxide dismutase (SOD). Compared to PS-treated rats with normal diet, the PS-treated rats with zinc supplementation showed increased iron apparent absorption, serum iron, hemoglobin, red blood cell, GSH, and SOD activities; while the serum CORT; iron contents in liver, spleen, and regional brain; and MDA decreased. These results indicated that dietary zinc supplementation had preventive effects against PS-induced iron dyshomeostasis, erythropoiesis inhibition, and oxidative stress status in rats.

Effects of heavy metals on sea urchin embryo development. 1. Tracing the cause by the effects.

PubMed

Kobayashi, Naomasa; Okamura, Hideo

2004-06-01

The toxicity of the polluted waters originating from a disused lead mine was evaluated using both sea urchin bioassays and heavy metal analysis. Samples from three polluted waters (a seawater and two freshwaters) were collected from the mine area and one seawater sample was taken from a non-contaminated reference site. The test waters contained higher concentrations of heavy metals such as manganese, lead, cadmium, zinc, chromium, nickel, iron, and copper than did ambient seawater. The three test waters had inhibitory effects, in a dose-dependent manner, on the first cleavage of sea urchin embryos and on pluteus formation during the development. Some malformations, such as a radialized pluteus, exo-gastrula, and spaceship Apollo-like embryos were induced by the test waters without dilution. Zinc alone also induced the same anomaly. Zinc in the test seawater was ascertained as one of the metals that caused the anomalies, but not all of the toxicity was caused by zinc. It was speculated that interactive effects, involving zinc and possibly manganese and nickel, were occurring.

Effects of rutin supplementation on antioxidant status and iron, copper, and zinc contents in mouse liver and brain.

PubMed

Gao, Zhonghong; Xu, Huibi; Huang, Kaixun

2002-09-01

The effect of rutin on total antioxidant status as well as on trace elements such as iron, copper, and zinc in mouse liver and brain were studied. Mice were administrated with 0.75 g/kg or 2.25 g/kg P. O. of rutin for 30 d consecutively. Following the treatment, the activity of total antioxidant status, catalase, Cu,Zn-superoxide dismutase, Mn-superoxide dismutase, zinc, copper, and iron were measured in mouse liver and brain. The results showed that rutin significantly increased the antioxidant status and Mn-superoxide dismutase activities in mouse liver, but it had no effect on these variables in the brain. Treatment with a higher concentration of rutin significantly decreased catalase activity and iron, zinc, and copper contents in mouse liver; it also resulted in a slower weight gain for the first 20 d. These results indicate that rutin taken in proper amount can effectively improve antioxidant status, whereas at an increased dosage, it may cause trace element (such as iron, zinc, and copper) deficiencies and a decrease in the activities of related metal-containing enzymes.

Zinc toxicity among galvanization workers in the iron and steel industry.

PubMed

El Safty, Amal; El Mahgoub, Khalid; Helal, Sawsan; Abdel Maksoud, Neveen

2008-10-01

Galvanization is the process of coating steel or cast iron pieces with zinc, allowing complete protection against corrosion. The ultimate goal of this work was to assess the effect of occupational exposure to zinc in the galvanization process on different metals in the human body and to detect the association between zinc exposure and its effect on the respiratory system. This study was conducted in 111 subjects in one of the major companies in the iron and steel industry. There were 61 subjects (workers) who were involved in the galvanization process. Fifty adult men were chosen as a matched reference group from other departments of the company. All workers were interviewed using a special questionnaire on occupational history and chest diseases. Ventilatory functions and chest X rays were assessed in all examined workers. Also, complete blood counts were performed, and serum zinc, iron, copper, calcium, and magnesium levels were tested. This study illustrated the relation between zinc exposure in the galvanization process and high zinc levels among exposed workers, which was associated with a high prevalence rate of metal fume fever (MFF) and low blood copper and calcium levels. There was no statistically significant difference between the exposed and control groups with regards to the magnesium level. No long-term effect of metals exposure was detected on ventilatory functions or chest X rays among the exposed workers.

Properties of Zip4 accumulation during zinc deficiency and its usefulness to evaluate zinc status: a study of the effects of zinc deficiency during lactation.

PubMed

Hashimoto, Ayako; Nakagawa, Miki; Tsujimura, Natsuki; Miyazaki, Shiho; Kizu, Kumiko; Goto, Tomoko; Komatsu, Yusuke; Matsunaga, Ayu; Shirakawa, Hitoshi; Narita, Hiroshi; Kambe, Taiho; Komai, Michio

2016-03-01

Systemic and cellular zinc homeostasis is elaborately controlled by ZIP and ZnT zinc transporters. Therefore, detailed characterization of their expression properties is of importance. Of these transporter proteins, Zip4 functions as the primarily important transporter to control systemic zinc homeostasis because of its indispensable function of zinc absorption in the small intestine. In this study, we closely investigated Zip4 protein accumulation in the rat small intestine in response to zinc status using an anti-Zip4 monoclonal antibody that we generated and contrasted this with the zinc-responsive activity of the membrane-bound alkaline phosphatase (ALP). We found that Zip4 accumulation is more rapid in response to zinc deficiency than previously thought. Accumulation increased in the jejunum as early as 1 day following a zinc-deficient diet. In the small intestine, Zip4 protein expression was higher in the jejunum than in the duodenum and was accompanied by reduction of ALP activity, suggesting that the jejunum can become zinc deficient more easily. Furthermore, by monitoring Zip4 accumulation levels and ALP activity in the duodenum and jejunum, we reasserted that zinc deficiency during lactation may transiently alter plasma glucose levels in the offspring in a sex-specific manner, without affecting homeostatic control of zinc metabolism. This confirms that zinc nutrition during lactation is extremely important for the health of the offspring. These results reveal that rapid Zip4 accumulation provides a significant conceptual advance in understanding the molecular basis of systemic zinc homeostatic control, and that properties of Zip4 protein accumulation are useful to evaluate zinc status closely. Copyright © 2016 the American Physiological Society.

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

PubMed

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.

Bioavailability of zinc oxide added to corn tortilla is similar to that of zinc sulfate and is not affected by simultaneous addition of iron

PubMed Central

Rosado, Jorge L.; Díaz, Margarita; Muñoz, Elsa; Westcott, Jamie L.; González, Karla E.; Krebs, Nancy F.; Caamaño, María C.; Hambidge, Michael

2013-01-01

Background Corn tortilla is the staple food of Mexico and its fortification with zinc, iron, and other micronutrients is intended to reduce micronutrient deficiencies. However, no studies have been performed to determine the relative amount of zinc absorbed from the fortified product and whether zinc absorption is affected by the simultaneous addition of iron. Objective To compare zinc absorption from corn tortilla fortified with zinc oxide versus zinc sulfate and to determine the effect of simultaneous addition of two doses of iron on zinc bioavailability. Methods A randomized, double-blind, crossover design was carried out in two phases. In the first phase, 10 adult women received corn tortillas with either 20 mg/kg of zinc oxide added, 20 mg/kg of zinc sulfate added, or no zinc added. In the second phase, 10 adult women received corn tortilla with 20 mg/kg of zinc oxide added and either with no iron added or with iron added at one of two different levels. Zinc absorption was measured by the stable isotope method. Results The mean (± SEM) fractional zinc absorption from unfortified tortilla, tortilla fortified with zinc oxide, and tortilla fortified with zinc sulfate did not differ among treatments: 0.35 ± 0.07, 0.36 ± 0.05, and 0.37 ± 0.07, respectively. The three treatment groups with 0, 30, and 60 mg/kg of added iron had similar fractional zinc absorption (0.32 ± 0.04, 0.33 ± 0.02, and 0.32 ± 0.05, respectively) and similar amounts of zinc absorbed (4.8 ± 0.7, 4.5 ± 0.3, and 4.8 ± 0.7 mg/day, respectively). Conclusions Since zinc oxide is more stable and less expensive and was absorbed equally as well as zinc sulfate, we suggest its use for corn tortilla fortification. Simultaneous addition of zinc and iron to corn tortilla does not modify zinc bioavailability at iron doses of 30 and 60 mg/kg of corn flour. PMID:23424892

HEPARIN-BINDING EGF CLEAVAGE MEDIATES ZINC-INDUCED EGF RECEPTOR PHOSPHORYLATION

EPA Science Inventory

We have previously shown that exposure to zinc ions can activate epidermal growth factor (EGF) receptor (EGFR) signaling in murine fibroblasts and A431 cells through a mechanism involving Src kinase. While studying the effects of zinc ions in normal human bronchial epithelial cel...

SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

EPA Science Inventory

We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

Trace mineral absorption status in infants with ileostomies

USDA-ARS?s Scientific Manuscript database

Infants with ileostomies are often supplemented with zinc and limited in copper, because of potential increased bilious zinc loss and increased cholestasis due to reduced copper excretion. However, no data exist on zinc or copper balance in infants with ileostomies. To determine the effect of an ile...

Subchronic inhalation of zinc sulfate induces cardiac changes in healthy rats

EPA Science Inventory

Zinc is a common metal in most ambient particulate matter (PM), and has been proposed to be a causative component in PM-induced adverse cardiovascular health effects. Zinc is also an essential metal and has the potential to induce many physiological and nonphysiological changes. ...

SUBCHRONIC INHALATION OF ZINC SULFATE CAUSES CARDIAC CHANGES IN HEALTHY RATS

EPA Science Inventory

Zinc is a common metal in most ambient particulate matter (PM), and has been proposed to be a causative component in PM-induced adverse cardiovascular health effects. Zinc is also an essential metal and has the potential to induce many physiological and nonphysiological changes. ...

Mesoporous TiO2 Yolk-Shell Microspheres for Dye-sensitized Solar Cells with a High Efficiency Exceeding 11%

PubMed Central

Li, Zhao-Qian; Chen, Wang-Chao; Guo, Fu-Ling; Mo, Li-E; Hu, Lin-Hua; Dai, Song-Yuan

2015-01-01

Yolk-shell TiO2 microspheres were synthesized via a one-pot template-free solvothermal method building on the aldol condensation reaction of acetylacetone. This unique structure shows superior light scattering ability resulting in power conversion efficiency as high as 11%. This work provided a new synthesis system for TiO2 microspheres from solid to hollow and a novel material platform for high performance solar cells. PMID:26384004

Growth behavior and properties of atomic layer deposited tin oxide on silicon from novel tin(II)acetylacetonate precursor and ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kannan Selvaraj, Sathees; Feinerman, Alan; Takoudis, Christos G., E-mail: takoudis@uic.edu

In this work, a novel liquid tin(II) precursor, tin(II)acetylacetonate [Sn(acac){sub 2}], was used to deposit tin oxide films on Si(100) substrate, using a custom-built hot wall atomic layer deposition (ALD) reactor. Three different oxidizers, water, oxygen, and ozone, were tried. Resulting growth rates were studied as a function of precursor dosage, oxidizer dosage, reactor temperature, and number of ALD cycles. The film growth rate was found to be 0.1 ± 0.01 nm/cycle within the wide ALD temperature window of 175–300 °C using ozone; no film growth was observed with water or oxygen. Characterization methods were used to study the composition, interface quality, crystallinity, microstructure,more » refractive index, surface morphology, and resistivity of the resulting films. X-ray photoelectron spectra showed the formation of a clean SnO{sub x}–Si interface. The resistivity of the SnO{sub x} films was calculated to be 0.3 Ω cm. Results of this work demonstrate the possibility of introducing Sn(acac){sub 2} as tin precursor to deposit conducting ALD SnO{sub x} thin films on a silicon surface, with clean interface and no formation of undesired SiO{sub 2} or other interfacial reaction products, for transparent conducting oxide applications.« less

Surface chemistry of copper metal and copper oxide atomic layer deposition from copper(ii) acetylacetonate: a combined first-principles and reactive molecular dynamics study.

PubMed

Hu, Xiao; Schuster, Jörg; Schulz, Stefan E; Gessner, Thomas

2015-10-28

Atomistic mechanisms for the atomic layer deposition using the Cu(acac)2 (acac = acetylacetonate) precursor are studied using first-principles calculations and reactive molecular dynamics simulations. The results show that Cu(acac)2 chemisorbs on the hollow site of the Cu(110) surface and decomposes easily into a Cu atom and the acac-ligands. A sequential dissociation and reduction of the Cu precursor [Cu(acac)2 → Cu(acac) → Cu] are observed. Further decomposition of the acac-ligand is unfavorable on the Cu surface. Thus additional adsorption of the precursors may be blocked by adsorbed ligands. Molecular hydrogen is found to be nonreactive towards Cu(acac)2 on Cu(110), whereas individual H atoms easily lead to bond breaking in the Cu precursor upon impact, and thus release the surface ligands into the gas-phase. On the other hand, water reacts with Cu(acac)2 on a Cu2O substrate through a ligand-exchange reaction, which produces gaseous H(acac) and surface OH species. Combustion reactions with the main by-products CO2 and H2O are observed during the reaction between Cu(acac)2 and ozone on the CuO surface. The reactivity of different co-reactants toward Cu(acac)2 follows the order H > O3 > H2O.

Laboratory Evaluation of Synthetic Blends of l-(+)-Lactic Acid, Ammonia, and Ketones As Potential Attractants For Aedes aegypti.

PubMed

Venkatesh, P M; Sen, A

2017-12-01

Attraction of Aedes aegypti to various binary, trinary, and quaternary blends of lactic acid and ketones with or without ammonia was studied using a dual choice olfactometer. A dose dependent attraction was observed in cases of single compounds where cyclopentanone attracted the highest percentage (36.9 ± 1.8%) of Ae. aegypti when tested alone. No significant difference was observed between the attraction levels of trinary and binary blends of lactic acid and acetone or butanone when tested against clear air. However, in competitive bioassays, the trinary blend of lactic acid, acetone, and butanone was significantly preferred over binary blends of individual compounds ( P < 0.05). Acetylacetone was weakly attractive when tested alone but showed additive attraction when blended with lactic acid. However, acetylacetone acted as an attraction inhibitor when blended with other compounds. Cyclopentanone was attractive, but enhancement of attraction was not observed when blended with other components. Addition of ammonia to binary or trinary blends of lactic acid, acetone, and/or butanone did not increase the attraction significantly. In competitive bioassays, the blends containing ammonia were significantly preferred over the blends lacking ammonia ( P < 0.05). This highlights ammonia as an essential component of synthetic blends. A quaternary blend of lactic acid, ammonia, acetone, and butanone was most attractive (65 ± 1.5%) and preferred blend of all other combinations.

DFT modeling, UV-Vis and IR spectroscopic study of acetylacetone-modified zirconia sol-gel materials.

PubMed

Georgieva, Ivelina; Danchova, Nina; Gutzov, Stoyan; Trendafilova, Natasha

2012-06-01

Theoretical and spectroscopic studies of a series of monomeric and dimeric complexes formed through the modification of a zirconium butoxide precursor with acetylacetone and subsequent hydrolysis and/or condensation have been performed by applying DFT/B3LYP/6-31++G(d) and highly accurate RI-ADC(2) methods as well as IR and UV-Vis transmittance and diffuse reflectance spectroscopies. Based on DFT model calculations and simulated and experimental UV-Vis and IR spectra of all the studied structures, the most probable building units of the Zr(IV)-AcAc gel were predicted: the dimeric double hydroxo-bridged complex Zr(2)(AcAc)(2)(OH)(4)(OH)(2br) 9 and the monooxo-bridged complex Zr(2)(AcAc)(2)(OH)(4)O(br)·2H(2)O 12. In both structures, the two AcAc ligands are coordinated to one Zr atom. It was shown that building units 9 and 12 determine the photophysical and vibrational properties of the gel material. The observed UV-Vis and IR spectra of Zr(IV)-AcAc gel were interpreted and a relation between the spectroscopic and structural data was derived. The observed UV-Vis bands at 315 nm and 298/288 nm were assigned to partial ligand-metal transitions and to intra-/inter-AcAc ligand transitions, respectively.

Long-chain amine-templated synthesis of gallium sulfide and gallium selenide nanotubes

NASA Astrophysics Data System (ADS)

Seral-Ascaso, A.; Metel, S.; Pokle, A.; Backes, C.; Zhang, C. J.; Nerl, H. C.; Rode, K.; Berner, N. C.; Downing, C.; McEvoy, N.; Muñoz, E.; Harvey, A.; Gholamvand, Z.; Duesberg, G. S.; Coleman, J. N.; Nicolosi, V.

2016-06-01

We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization.We describe the soft chemistry synthesis of amine-templated gallium chalcogenide nanotubes through the reaction of gallium(iii) acetylacetonate and the chalcogen (sulfur, selenium) using a mixture of long-chain amines (hexadecylamine and dodecylamine) as a solvent. Beyond their role as solvent, the amines also act as a template, directing the growth of discrete units with a one-dimensional multilayer tubular nanostructure. These new materials, which broaden the family of amine-stabilized gallium chalcogenides, can be tentatively classified as direct large band gap semiconductors. Their preliminary performance as active material for electrodes in lithium ion batteries has also been tested, demonstrating great potential in energy storage field even without optimization. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01663d

Effect of Zinc Supplements on Preventing Upper Respiratory Infections in Air Force Academy Cadets in Basic Training

DTIC Science & Technology

2009-01-01

and Nutrition Board (2001). Dietary Reference Intakes: A Report of the Panel on Micronutrients , Subcommittees on Upper Reference Levels of Nutrients...Respiratory Infections in Air Force Academy Cadets in Basic Training Summary Background: As a dietary essential, zinc plays a number of important roles...Introduction Zinc is considered one of the essential micronutrients used by the human body. Although zinc fulfills a number of metabolic and

Supplementation of Diabetic Rats with Leucine, Zinc, and Chromium: Effects on Function and Histological Structure of Testes.

PubMed

Kolahian, Saeed; Sadri, Hassan; Larijani, Amir; Hamidian, Gholamreza; Davasaz, Afshin

2015-12-01

The objective was to study whether leucine, zinc, and chromium supplementations influence function and histological structure of testes in a rat model of type 2 diabetes. Seventy seven adult male rats were categorized into 11 groups of 7 animals each: (1) nondiabetic (negative control); (2) non-treated (positive control); (3) treated with insulin; (4) treated with glibenclamide; (5) treated with leucine; (6) treated with zinc; (7) treated with chromium; (8) treated with leucine + zinc; (9) treated with leucine + chromium; (10) treated with zinc + chromium; (11) treated with leucine + zinc + chromium. In the non-treated group, hyperglycemia severely damaged testes morphology as well as the spermatogenic process. Diabetes induction decreased testicular length, height, width, volume, total number of epididymal sperm, and number of live sperm. Seminiferous tubules of diabetic rats showed a decrease in diameter of tubules and height of epithelium. Diabetes induction decreased the number of cells (spermatogonia, spermatocyte, spermatid, and Sertoli) in cross sections of seminiferous tubules. Administration of nutritional supplements to the diabetic rats improved testes morphology and reversed, although not completely, impairment of spermatogenesis. Treatment with nutritional supplements increased testicular length, height, width, and volume. All treatments increased the number of live sperm and the total number of epididymal sperm. Furthermore, nutritional supplements increased diameter of tubules, height of epithelium, and the number of cells in seminiferous tubules. These alleviating effects were more pronounced in animals treated with the leucine-zinc-chromium combination. The present results demonstrate beneficial effects of zinc, leucine, and chromium supplements to improve testes morphology and to restore spermatogenesis in type 2 diabetic rats.

Prenatal zinc prevents communication impairments and BDNF disturbance in a rat model of autism induced by prenatal lipopolysaccharide exposure.

PubMed

Kirsten, Thiago B; Queiroz-Hazarbassanov, Nicolle; Bernardi, Maria M; Felicio, Luciano F

2015-06-01

Aims: Previous investigations by our group have shown that prenatal exposure to lipopolysaccharide (LPS),which mimics infections by Gram-negative bacteria, induced autistic-like behavior. No effective treatment yet exists for autism. Therefore, we used our rat model to test a possible treatment for autism.We selected zinc as the prenatal treatment to prevent or ease the impairments induced by LPS because LPS induces hypozincaemia.Materials and methods:We evaluated the effects of LPS and zinc on female reproductive performance. Communication,which is impaired in autism,was tested in pups by ultrasonic vocalizations. Plasma levels of brain-derived neurotrophic factor (BDNF) were determined because it has been considered an autism important biomarker.Key findings: Prenatal LPS exposure reduced offspring number and treatment with zinc prevented this reduction.Moreover, pups that were prenatally exposed to LPS spent longer periods without calling their mothers, and posttreatment with zinc prevented this impairment induced by LPS to the same levels as controls. Prenatal LPS also increased BDNF levels in adult offspring, and posttreatment with zinc reduced the elevation of BDNF to the same levels as controls.Significance: BDNF hyperactivity was also found in several studies of autistic patients. Together with our previous studies, our model of prenatal LPS induced autistic-like behavioral, brain, and immune disturbances. This suggests that it is a valid rat model of autism. Prenatal zinc prevented reproductive, communication, and BDNF impairments.The present study revealed a potential beneficial effect of prenatal zinc administration for the prevention of autism with regard to the BDNF pathway.

Effect of short-term zinc supplementation on zinc and selenium tissue distribution and serum antioxidant enzymes.

PubMed

Skalny, Andrey A; Tinkov, Alexey A; Medvedeva, Yulia S; Alchinova, Irina B; Karganov, Mikhail Y; Skalny, Anatoly V; Nikonorov, Alexandr A

2015-01-01

A significant association between Zn and Se homeostasis exists. At the same time, data on the influence of zinc supplementation on selenium distribution in organs and tissues seem to be absent. Therefore, the primary objective of the current study is to investigate the influence of zinc asparaginate supplementation on zinc and selenium distribution and serum superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in Wistar rats. 36 rats were used in the experiment. The duration of the experiment was 7 and 14 days in the first and second series, respectively. The rats in Group I were used as the control ones. Animals in Groups II and III daily obtained zinc asparaginate (ZnA) in the doses of 5 and 15 mg/kg weight, respectively. Zinc and selenium content in liver, kidneys, heart, muscle, serum and hair was assessed using inductively coupled plasma mass spectrometry. Serum SOD and GPx activity was analysed spectrophotometrically using Randox kits. Intragastric administration of zinc asparaginate significantly increased liver, kidney, and serum zinc content without affecting skeletal and cardiac muscle levels. Zinc supplementation also stimulated selenium retention in the rats' organs. Moreover, a significant positive correlation between zinc and selenium content was observed. Finally, zinc asparaginate treatment has been shown to modulate serum GPx but not SOD activity. The obtained data indicate that zinc-induced increase in GPx activity may be mediated through modulation of selenium status. However, future studies are required to estimate the exact mechanisms of zinc and selenium interplay.

Discovery of Human Zinc Deficiency: Its Impact on Human Health and Disease123

PubMed Central

Prasad, Ananda S.

2013-01-01

The essentiality of zinc in humans was established in 1963. During the past 50 y, tremendous advances in both clinical and basic sciences of zinc metabolism in humans have been observed. The major factor contributing to zinc deficiency is high phytate-containing cereal protein intake in the developing world, and nearly 2 billion subjects may be zinc deficient. Conditioned deficiency of zinc has been observed in patients with malabsorption syndrome, liver disease, chronic renal disease, sickle cell disease, and other chronic illnesses. Major clinical problems resulting from zinc deficiency in humans include growth retardation; cell-mediated immune dysfunction, and cognitive impairment. In the Middle East, zinc-deficient dwarfs did not live beyond the age of 25 y, and they died because of intercurrent infections. In 1963, we knew of only 3 enzymes that required zinc for their activities, but now we know of >300 enzymes and >1000 transcription factors that are known to require zinc for their activities. Zinc is a second messenger of immune cells, and intracellular free zinc in these cells participate in signaling events. Zinc has been very successfully used as a therapeutic modality for the management of acute diarrhea in children, Wilson’s disease, the common cold and for the prevention of blindness in patients with age-related dry type of macular degeneration and is very effective in decreasing the incidence of infection in the elderly. Zinc not only modulates cell-mediated immunity but is also an antioxidant and anti-inflammatory agent. PMID:23493534

Effects of zinc and cholesterol/choleate on serum lipoproteins and the liver in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cho, C.H.; Chen, S.M.; Ogle, C.W.

1989-01-01

The effects of short-term treatment with orally-administered zinc sulfate and/or a mixture of cholesterol/choleate on serum lipoprotein and hepatic enzyme levels were studied. Administration of graded doses of zinc sulfate for 5 days, dose-dependently increased serum and hepatic zinc levels but depressed the serum high-density lipoprotein-cholesterol (HDL-C) concentration and liver cytochrome P-450 activity. However, it did not affect hepatic concentrations of malondialdehyde and free {beta}-glucuronidase. Cholesterol/choleate treatment for 5 days markedly damaged the liver, as reflected by elevations of hepatic concentrations of malondialdehyde (both in the mitochondrial and microsomal fractions) and of free {beta}-glucuronidase; total cholesterol and low-density lipoprotein-cholesterol inmore » the blood were increased, whereas HDL-C was decreased significantly. Concomitant administration of zinc sulfate with cholesterol/choleate further lowered HDL-C levels, but reversed the high hepatic concentrations of both malondialdehyde and free {beta}-glucuronidase. The present study indicates that both zinc ions and cholesterol can decrease circulatory HDL-C levels and that zinc protects against cholesterol-induced hepatic damage by reducing lysosomal enzyme release and preventing lipid peroxidation in the liver.« less

Zinc in Gut-Brain Interaction in Autism and Neurological Disorders

PubMed Central

Vela, Guillermo; Stark, Peter; Socha, Michael; Sauer, Ann Katrin; Hagmeyer, Simone; Grabrucker, Andreas M.

2015-01-01

A growing amount of research indicates that abnormalities in the gastrointestinal (GI) system during development might be a common factor in multiple neurological disorders and might be responsible for some of the shared comorbidities seen among these diseases. For example, many patients with Autism Spectrum Disorder (ASD) have symptoms associated with GI disorders. Maternal zinc status may be an important factor given the multifaceted effect of zinc on gut development and morphology in the offspring. Zinc status influences and is influenced by multiple factors and an interdependence of prenatal and early life stress, immune system abnormalities, impaired GI functions, and zinc deficiency can be hypothesized. In line with this, systemic inflammatory events and prenatal stress have been reported to increase the risk for ASD. Thus, here, we will review the current literature on the role of zinc in gut formation, a possible link between gut and brain development in ASD and other neurological disorders with shared comorbidities, and tie in possible effects on the immune system. Based on these data, we present a novel model outlining how alterations in the maternal zinc status might pathologically impact the offspring leading to impairments in brain functions later in life. PMID:25878905

Zinc in gut-brain interaction in autism and neurological disorders.

PubMed

Vela, Guillermo; Stark, Peter; Socha, Michael; Sauer, Ann Katrin; Hagmeyer, Simone; Grabrucker, Andreas M

2015-01-01

A growing amount of research indicates that abnormalities in the gastrointestinal (GI) system during development might be a common factor in multiple neurological disorders and might be responsible for some of the shared comorbidities seen among these diseases. For example, many patients with Autism Spectrum Disorder (ASD) have symptoms associated with GI disorders. Maternal zinc status may be an important factor given the multifaceted effect of zinc on gut development and morphology in the offspring. Zinc status influences and is influenced by multiple factors and an interdependence of prenatal and early life stress, immune system abnormalities, impaired GI functions, and zinc deficiency can be hypothesized. In line with this, systemic inflammatory events and prenatal stress have been reported to increase the risk for ASD. Thus, here, we will review the current literature on the role of zinc in gut formation, a possible link between gut and brain development in ASD and other neurological disorders with shared comorbidities, and tie in possible effects on the immune system. Based on these data, we present a novel model outlining how alterations in the maternal zinc status might pathologically impact the offspring leading to impairments in brain functions later in life.

X-ray tomography as a powerful method for zinc-air battery research

NASA Astrophysics Data System (ADS)

Franke-Lang, Robert; Arlt, Tobias; Manke, Ingo; Kowal, Julia

2017-12-01

X-ray tomography is used to investigate material redistribution and effects of electrochemical reactions in a zinc-air battery in-situ. For this, a special battery set-up is developed which meets tomographic and electrochemical requirements. The prepared batteries are discharged and some of them have partially been charged. To analyse the three-dimensional structure of the zinc and air electrode a tomographic measurement is made in charge and discharge condition without disassembling the battery. X-ray tomography gives the opportunity to detect and analyse three different effects within the cell operation: tracking the morphology and transformation of zinc and air electrode, monitoring electrolyte decomposition and movement, finding electrical misbehaviour by parasitic reactions. Therefore, it is possible to identify the loss of capacity and major problems of cyclability. The electrolyte strongly reacts with the pure zinc that leads to gassing and a loss of electrolyte. The loss prevents a charge carrier exchange between the anode and the cathode and reduces the theoretical capacity. One of the chemical reaction produces hydroxylated zinc, namely zincate. The most crucial problems with cyclability are affected by zincate movement into the catalyst layer. This assumption is confirmed by finding pure zinc areas within the catalyst layer.

Comparative analysis of salivary zinc level in recurrent herpes labialis

PubMed Central

Khozeimeh, Faezeh; Jafari, Nasim; Attar, Ahmad Movahedian; Jafari, Shahram; Ataie, Masoud

2012-01-01

Background: Recurrent Herpes Labialis (RHL) is one of most common infective vesiculoulcerative lesions. According to some studies administration of topical and/or systemic zinc compositions has been effective in treatment and prevention. This article aims to comparison of zinc level in healthy subjects and RHL patients in acute and convalescent phases. Materials and Methods: This was a retrospective case – control study, carried on 80 individuals (40 normal and 40 RHL patients) mean age=34.5 and 34.4, respectively. Saliva samples were taken in patients in acute phase once and after healing of lesions in convalescent phase (averagely 21 days later) and in normal individuals. Salivary zinc level concentration was measured by flame atomic absorption spectrophotometer by dry digestion method. The results were statistically analyzed with SPSS software by t-test (α=0.05). Results: Results showed that salivary zinc level in case group in acute and convalescent phases were 160.8 ngr/mland 205.7 ngr/ml respectivly and significant differences between them were existed (P <0.05). Also significant differences were existed between zinc concentration in healthy subjects and patient groups (in both phases) (P=.001 and .002 for acute and convalescent phases respectively). Conclusion: According to the results, zinc level is significantly lower in acute phase than in convalescent phase and significantly lower in both phases compared to healthy individuals,so determination of serum zinc level and prescribing zinc complement in low serum status has both treatmental and preventive effects in RHL patients. PMID:22363358

Copper, iron and zinc absorption, retention and status of young women fed vitamin B-6 deficient diets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turnlund, J.R.; Keyes, W.R.; Hudson, C.A.

1991-03-11

A study was conducted in young women to determine the effect of vitamin B-6 deficient diets on copper, iron and zinc metabolism. Young women were confined to a metabolic research unit for 84 and 98 days. They were fed a vitamin B-6 deficient formula diet initially, followed by food diet containing four increasing levels of vitamin B-6. Copper, iron and zinc absorption, retention and status were determined at intervals throughout the study. Absorption was determined using the stable isotopes {sup 65}Cu, {sup 54}Fe, and {sup 67}Zn. Status was based on serum copper and zinc, hemoglobin, hematocrit and mean corpuscular volume.more » Copper absorption averaged 18 {plus minus} 1% during vitamin B-6 depletion, significantly lower than 24 {plus minus} 1% during repletion, but serum copper was not affected and balance was positive. Iron absorption was not impaired significantly by vitamin B-6 deficient diets, but status declined during the depletion period. Zinc absorption averaged 40 {plus minus} 2% during depletion and 27 {plus minus} 2% during repletion. Zinc absorption and retention were significantly greater during vitamin B-6 depletion, but serum zinc declined suggesting the absorbed zinc was not available for utilization. The results suggest that vitamin B-6 depletion of young women may inhibit copper absorption, affect iron status and alter zinc metabolism. The effects of vitamin B-6 depletion differ markedly among these elements.« less

Efficacy of zinc sulfate supplement on febrile seizure recurrence prevention in children with normal serum zinc level: A randomised clinical trial.

PubMed

Fallah, Razieh; Sabbaghzadegan, Saeideh; Karbasi, Sedighah Akhavan; Binesh, Fariba

2015-01-01

Serum zinc level might be related to pathogenesis of febrile seizure (FS). The purpose of this study was to evaluate efficacy and safety of oral zinc supplementation on FS recurrence prevention in non-zinc-deficient children. In a randomized clinical study, one hundred 18 to 60 mo old children with normal zinc level with first simple FS were referred to Shahid Sadoughi Hospital, Yazd, Iran from May 2012 to June 2013, were randomly assigned to two groups to receive 2 mg/kg/d zinc sulfate for six consecutive months or placebo as control group and were followed up for 1 y for FS recurrence. 41 girls and 59 boys with mean age of 2.47 ± 1.01 y were evaluated. Race, mean weight, height and body fat were similar in both groups. FS recurrence occurred in 19 children (38%) in the control group [95% confidence interval (CI): 19.45%-53.95%] and in 11 children (22%) in the zinc sulfate (95% CI: 57.47%-89.13%) groups, respectively; and the zinc group had lower FS recurrence (P = 0.03). The mean serum zinc level before intervention was lower in children with FS recurrence (72.43 ± 14.58 μg/dL versus 96.33 ± 12.69 μg/dL, P = 0.04). Gastrointestinal side effects (vomiting in five children, heartburn in two children and abdominal pain in one child) were seen in 16% of the zinc group and vomiting occurred in two children (4%) in control group and frequency of adverse events was similar in the two groups (P = 0.1). Zinc supplementation should be considered as effective and safe in prevention of FS recurrence. Copyright © 2015 Elsevier Inc. All rights reserved.

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

PubMed

Xu, Kui; Juneau, Philippe

2016-01-01

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 (ФM) and operational (Ф'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 zinc concentrations under HL only in CPCC299, but not under low light (LL) conditions for all the studied strains, suggesting that the three strains have different response mechanisms to high zinc stress when grown under different light regimes. We demonstrated that interactions between light intensity and zinc need to be considered when studying the bloom dynamics of cyanobacteria in freshwater ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Long-range ordering effect in electrodeposition of zinc and zinc oxide.

PubMed

Liu, Tao; Wang, Sheng; Shi, Zi-Liang; Ma, Guo-Bin; Wang, Mu; Peng, Ru-Wen; Hao, Xi-Ping; Ming, Nai-Ben

2007-05-01

In this paper, we report the long-range ordering effect observed in the electro-crystallization of Zn and ZnO from an ultrathin aqueous electrolyte layer of ZnSO4 . The deposition branches are regularly angled, covered with random-looking, scalelike crystalline platelets of ZnO. Although the orientation of each crystalline platelet of ZnO appears random, transmission electron microscopy shows that they essentially possess the same crystallographic orientation as the single-crystalline zinc electrodeposit underneath. Based on the experimental observations, we suggest that this unique long-range ordering effect results from an epitaxial nucleation effect in electrocrystallization.

Zinc Salts Block Hepatitis E Virus Replication by Inhibiting the Activity of Viral RNA-Dependent RNA Polymerase.

PubMed

Kaushik, Nidhi; Subramani, Chandru; Anang, Saumya; Muthumohan, Rajagopalan; Shalimar; Nayak, Baibaswata; Ranjith-Kumar, C T; Surjit, Milan

2017-11-01

Hepatitis E virus (HEV) causes an acute, self-limiting hepatitis in healthy individuals and leads to chronic disease in immunocompromised individuals. HEV infection in pregnant women results in a more severe outcome, with the mortality rate going up to 30%. Though the virus usually causes sporadic infection, epidemics have been reported in developing and resource-starved countries. No specific antiviral exists against HEV. A combination of interferon and ribavirin therapy has been used to control the disease with some success. Zinc is an essential micronutrient that plays crucial roles in multiple cellular processes. Zinc salts are known to be effective in reducing infections caused by few viruses. Here, we investigated the effect of zinc salts on HEV replication. In a human hepatoma cell (Huh7) culture model, zinc salts inhibited the replication of genotype 1 (g-1) and g-3 HEV replicons and g-1 HEV infectious genomic RNA in a dose-dependent manner. Analysis of a replication-defective mutant of g-1 HEV genomic RNA under similar conditions ruled out the possibility of zinc salts acting on replication-independent processes. An ORF4-Huh7 cell line-based infection model of g-1 HEV further confirmed the above observations. Zinc salts did not show any effect on the entry of g-1 HEV into the host cell. Furthermore, our data reveal that zinc salts directly inhibit the activity of viral RNA-dependent RNA polymerase (RdRp), leading to inhibition of viral replication. Taken together, these studies unravel the ability of zinc salts in inhibiting HEV replication, suggesting their possible therapeutic value in controlling HEV infection. IMPORTANCE Hepatitis E virus (HEV) is a public health concern in resource-starved countries due to frequent outbreaks. It is also emerging as a health concern in developed countries owing to its ability to cause acute and chronic infection in organ transplant and immunocompromised individuals. Although antivirals such as ribavirin have been used to treat HEV cases, there are known side effects and limitations of such therapy. Our discovery of the ability of zinc salts to block HEV replication by virtue of their ability to inhibit the activity of viral RdRp is important because these findings pave the way to test the efficacy of zinc supplementation therapy in HEV-infected patients. Since zinc supplementation therapy is known to be safe in healthy individuals and since high-dose zinc is used in the treatment of Wilson's disease, it may be possible to control HEV-associated health problems following a similar treatment regimen. Copyright © 2017 American Society for Microbiology.

Spectrophotometric studies and applications for the determination of Ni2+ in zinc-nickel alloy electrolyte

NASA Astrophysics Data System (ADS)

Qiao, Xiaoping; Li, Helin; Zhao, Wenzhen; Li, Dejun

The absorption properties of zinc-nickel alloy electrolyte were studied by visible spectrophotometer. The results show that the relationship between the absorbance of the zinc-nickel alloy electrolyte and Ni2+ concentration in the electrolyte obeys Beer's law at 660 nm. In addition, other components except Ni2+ in the zinc-nickel alloy electrolyte such as zinc chloride, ammonium chloride, potassium chloride and boric acid have no obvious effect on the absorbance of zinc-nickel alloy electrolyte. Based on these properties, a new method is developed to determine Ni2+ concentration in zinc-nickel alloy electrolyte. Comparing with other methods, this method is simple, direct and accurate. Moreover, the whole testing process does not consume any reagent and dilution, and after testing, the electrolyte samples can be reused without any pollution to the environment.

Reexamining the functions of zinc sulfate as a selective depressant in differential sulfide flotation--the role of coagulation.

PubMed

Cao, Mingli; Liu, Qi

2006-09-15

Zinc sulfate is a well-known selective depressant for zinc sulfide minerals such as sphalerite during the flotation of complex Cu-Pb-Zn sulfide ores. It deactivates sphalerite flotation by substituting the activating metal ions, and depresses sphalerite flotation by forming hydrophilic coatings of zinc hydroxyl species on sphalerite surfaces. However, we recently observed that zinc sulfate could also induce coagulation of fine sphalerite particles and such coagulation significantly reduced the mechanical entrainment of the fine sphalerite. Therefore, it seems that the effectiveness of zinc sulfate as a selective sphalerite depressant is not only due to its ability to make mineral surface hydrophilic, which reduces genuine flotation, but also due to its ability to coagulate the mineral, which reduces mechanical entrainment. Zinc sulfate is a "dual function" selective flotation depressant.

Zinc transporter ZnT-3 regulates presynaptic Erk1/2 signaling and hippocampus-dependent memory.

PubMed

Sindreu, Carlos; Palmiter, Richard D; Storm, Daniel R

2011-02-22

The physiological role of vesicular zinc at central glutamatergic synapses remains poorly understood. Here we show that mice lacking the synapse-specific vesicular zinc transporter ZnT3 (ZnT3KO mice) have reduced activation of the Erk1/2 MAPK in hippocampal mossy fiber terminals, disinhibition of zinc-sensitive MAPK tyrosine phosphatase activity, and impaired MAPK signaling during hippocampus-dependent learning. Activity-dependent exocytosis is required for the effect of zinc on presynaptic MAPK and phosphatase activity. ZnT3KO mice have complete deficits in contextual discrimination and spatial working memory. Local blockade of zinc or MAPK in the mossy fiber pathway of wild-type mice impairs contextual discrimination. We conclude that ZnT3 is important for zinc homeostasis modulating presynaptic MAPK signaling and is required for hippocampus-dependent memory.

Zinc transporter ZnT-3 regulates presynaptic Erk1/2 signaling and hippocampus-dependent memory

PubMed Central

Sindreu, Carlos; Palmiter, Richard D.; Storm, Daniel R.

2011-01-01

The physiological role of vesicular zinc at central glutamatergic synapses remains poorly understood. Here we show that mice lacking the synapse-specific vesicular zinc transporter ZnT3 (ZnT3KO mice) have reduced activation of the Erk1/2 MAPK in hippocampal mossy fiber terminals, disinhibition of zinc-sensitive MAPK tyrosine phosphatase activity, and impaired MAPK signaling during hippocampus-dependent learning. Activity-dependent exocytosis is required for the effect of zinc on presynaptic MAPK and phosphatase activity. ZnT3KO mice have complete deficits in contextual discrimination and spatial working memory. Local blockade of zinc or MAPK in the mossy fiber pathway of wild-type mice impairs contextual discrimination. We conclude that ZnT3 is important for zinc homeostasis modulating presynaptic MAPK signaling and is required for hippocampus-dependent memory. PMID:21245308

Efficacy and tolerability of nitric-zinc complex in the treatment of external genital warts and "difficult-to-treat" warts: a "proof of concept", prospective, multicentre, open study.

PubMed

Cusini, M; Micali, G; Lacarrubba, F; Puviani, M; Barcella, A; Milani, M

2015-12-01

Treatment of plantar and periungueal warts (so called "difficult-to-treat" warts, DTW) and external genital warts (EGW) remains unsatisfactory. Medical or invasive procedures are partially effective and/or painful. Furthermore recurrences rates after treatments are still a relevant problem for all the available therapies. Nitric-zinc complex is a solution for topical application containing nitric acid, zinc, copper and organic acids able to induce a caustic effect of the wart trough mummification and proteins denaturation/coagulation action. Nitric-zinc complex has been shown to be an effective and well tolerated treatment of common warts. We evaluated in a prospective open label 4-centre trial, the efficacy and local tolerability of nitric-zinc complex in the treatment of EGW and DTW. A total of 37 immunocompetent subjects (20 men and 17 women; mean age: 45 years) with single or multiple lesions, were enrolled, after their informed consent. A total of 30 subjects had EGW, 2 subjects had plantar warts, 2 warts of the hand and 3 periungueal lesions. Nitric-zinc aqueous solution was applied topically using a 30 mL capillary tube over the lesions until a whitening/yellowish reaction appeared. A second (or more, if needed) application was performed at two-week interval until a complete clinical cure rate was observed. Primary outcome of the study was the clinical evaluation with picture documentation of the evolution of lesions classified as total cure, partial disappearance or no effect. Topical tolerability was evaluated through patient's reported adverse events. All subjects completed the study. A complete cure of lesions was observed in 31 subjects (90%) after one and up to four applications. Three patients with EGW (8%) showed a partial disappearance of lesions and one (2%) subject was no responder to four nitric-zinc complex applications. The product was well tolerated. No serious adverse events were observed or recorded. Nitric-zinc complex topical solution has shown to be an effective and well tolerated treatment of EGW and "difficult-to-treat" warts with a 90% of subjects with a total cure after one or up to four applications. A total or partial response was observed in 99% of the subjects. Nitric-zinc complex could be considered an easy-to-use effective treatment strategy of "difficult-to-treat" warts and external genital warts. Additional studies comparing nitric-zinc complex to other strategies are warranted.

Zinc supplementation for the treatment of measles in children.

PubMed

Awotiwon, Ajibola A; Oduwole, Olabisi; Sinha, Anju; Okwundu, Charles I

2017-06-20

Measles is an important cause of childhood morbidity and mortality globally, despite increasing vaccine coverage. Zinc plays a significant role in the maintenance of normal immunological functions, therefore supplements given to zinc-deficient children will increase the availability of zinc and could reduce measles-related morbidity and mortality. This is an update of a review first published in 2015. To assess the effects of zinc supplementation in reducing morbidity and mortality in children with measles. We searched CENTRAL (03 February 2017, Issue 2), MEDLINE (1946 to 03 February 2017), Embase (1974 to 03 February 2017), CINAHL (1981 to 03 February 2017), LILACS (1982 to 03 February 2017), Web of Science (1985 to 03 February 2017), and BIOSIS Previews (1985 to 27 June 2014). We also searched ClinicalTrials.gov, the Australian New Zealand Clinical Trials Registry and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) on 03 February 2017 to identify unpublished and ongoing studies. Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of zinc in reducing morbidity and mortality in children with measles. Two review authors independently assessed the studies for inclusion and extracted data on outcomes, details of the interventions, and other study characteristics using a standardised data extraction form. We used risk ratio (RR) and hazard ratio (HR) as measures of effect with 95% confidence intervals (CI). We included only one study, and did not conduct meta-analysis. We did not identify any new studies for inclusion in this update. One RCT met our inclusion criteria. The study was conducted in India and included 85 children diagnosed with measles and pneumonia. The trial showed no significant difference in mortality between children with measles and pneumonia who received zinc supplements and those who received placebo (RR 0.34, 95% CI 0.01 to 8.14). There was no significant difference in time to absence of fever between children who received zinc supplements and those who did not (HR 1.08, 95% CI 0.67 to 1.74). No treatment-related side effects were reported in either group. We assessed the overall quality of the evidence as very low. We could not draw any definitive conclusions from this review about the effects of zinc supplementation on clinical outcomes of children with measles due to the very low quality of the evidence available. There is insufficient evidence to confirm or refute the effect of zinc supplementation in children with measles.

The Zinc Transporter Zip5 (Slc39a5) Regulates Intestinal Zinc Excretion and Protects the Pancreas against Zinc Toxicity

PubMed Central

Geiser, Jim; De Lisle, Robert C.; Andrews, Glen K.

2013-01-01

Background ZIP5 localizes to the baso-lateral membranes of intestinal enterocytes and pancreatic acinar cells and is internalized and degraded coordinately in these cell-types during periods of dietary zinc deficiency. These cell-types are thought to control zinc excretion from the body. The baso-lateral localization and zinc-regulation of ZIP5 in these cells are unique among the 14 members of the Slc39a family and suggest that ZIP5 plays a role in zinc excretion. Methods/Principal Findings We created mice with floxed Zip5 genes and deleted this gene in the entire mouse or specifically in enterocytes or acinar cells and then examined the effects on zinc homeostasis. We found that ZIP5 is not essential for growth and viability but total knockout of ZIP5 led to increased zinc in the liver in mice fed a zinc-adequate (ZnA) diet but impaired accumulation of pancreatic zinc in mice fed a zinc-excess (ZnE) diet. Loss-of-function of enterocyte ZIP5, in contrast, led to increased pancreatic zinc in mice fed a ZnA diet and increased abundance of intestinal Zip4 mRNA. Finally, loss-of-function of acinar cell ZIP5 modestly reduced pancreatic zinc in mice fed a ZnA diet but did not impair zinc uptake as measured by the rapid accumulation of 67zinc. Retention of pancreatic 67zinc was impaired in these mice but the absence of pancreatic ZIP5 sensitized them to zinc-induced pancreatitis and exacerbated the formation of large cytoplasmic vacuoles containing secretory protein in acinar cells. Conclusions These studies demonstrate that ZIP5 participates in the control of zinc excretion in mice. Specifically, they reveal a paramount function of intestinal ZIP5 in zinc excretion but suggest a role for pancreatic ZIP5 in zinc accumulation/retention in acinar cells. ZIP5 functions in acinar cells to protect against zinc-induced acute pancreatitis and attenuate the process of zymophagy. This suggests that it may play a role in autophagy. PMID:24303081

The effects of chronological age and size on toxicity of zinc to juvenile brown trout

EPA Science Inventory

A series of toxicity tests were conducted to investigate the role of chronological age and organism weight on zinc tolerance in juvenile brown trout (Salmo trutta). Four different incubation temperatures were used to control the maturation of the juveniles prior to zinc exposure...

The effects of zinc status on early growth in infants with sickle cell disease

USDA-ARS?s Scientific Manuscript database

Growth failure, maturational delay, and alterations in body composition occur in older children and adults with Sickle Cell Disease (SCD). Poor nutritional status, specifically zinc deficiency, has been widely implicated, although infants with SCD have not been studied. We determined zinc status in ...

Meals and dephytinization affect calcium and zinc absorption in Nigerian children with rickets

USDA-ARS?s Scientific Manuscript database

Nutritional rickets resulting from calcium insufficiency is common in Nigeria, and high dietary phytate is thought to inhibit calcium and zinc absorption. We compared the effects of a high-phytate meal and enzymatic dephytinization on calcium and zinc absorption in Nigerian children with and without...

Adverse health effects in Canada geese (Branta canadensis) associated with waste from zinc and lead mines in the Tri-State Mining District (Kansas, Oklahoma, and Missouri, USA).

PubMed

van der Merwe, Deon; Carpenter, James W; Nietfeld, Jerome C; Miesner, John F

2011-07-01

Lead and zinc poisoning have been recorded in a variety of bird species, including migrating waterfowl such as Canada Geese (Branta canadensis), at sites contaminated with mine waste from lead and zinc mines in the Tri-State Mining District, Kansas, Oklahoma, and Missouri, USA. The adverse health impacts from mine waste on these birds may, however, be more extensive than is apparent from incidental reports of clinical disease. To characterize health impacts from mine waste on Canada Geese that do not have observable signs of poisoning, four to eight apparently healthy birds per site were collected from four contaminated sites and an uncontaminated reference site, and examined for physical and physiologic evidence of metals poisoning. Tissue concentrations of silver, aluminum, arsenic, barium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, nickel, lead, selenium, thallium, vanadium, and zinc were determined by inductively coupled plasma mass spectroscopy. Adverse health effects due to lead were characterized by assessing blood δ-aminolevulinic acid dehydratase (ALAD) enzyme activity. Adverse effects associated with zinc poisoning were determined from histologic examination of pancreas tissues. Elevated tissue lead concentrations and inhibited blood ALAD enzyme activities were consistently found in birds at all contaminated sites. Histopathologic signs of zinc poisoning, including fibrosis and vacuolization, were associated with elevated pancreatic zinc concentrations at one of the study sites. Adverse health effects associated with other analyzed elements, or tissue concentrations indicating potentially toxic exposure levels to these elements, were not observed.

Effects of intraocular injection of a low concentration of zinc on the rat retina.

PubMed

Nakamichi, N; Chidlow, G; Osborne, N N

2003-10-01

The main aim of this study was to investigate whether intraocular injection of low concentrations of zinc (no greater than 10 microM) aid the survival of ganglion cells in the rat retina after excitotoxic (NMDA) and ischemia/reperfusion injuries. We also determined whether low amounts of zinc cause any detectable retinal toxicity. Intraocular injection of NMDA caused substantial reductions in the mRNA levels of the ganglion cell-specific markers Thy-1 and neurofilament light (NF-L). Co-injection of 0.1 or 1 nmol zinc neither diminished nor exacerbated the effect of NMDA on the levels of these mRNAs. Likewise, ischemia/reperfusion caused significant decreases in the levels of Thy-1 and NF-L mRNAs and in the b-wave amplitude of the electroretinogram. These effects were not counteracted by injection of zinc. Intraocular injection of NMDA caused marked toxicological effects in retinal glial cells, including upregulations of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), glial fibrial acidic protein (GFAP), basic fibroblast growth factor (FGF-2) and ciliary neurotrophic factor (CNTF). Interestingly, injection of 1 nmol zinc caused no changes in the levels of COX-2 and iNOS, yet produced similar, although quantitatively less pronounced, changes in FGF-2, GFAP and CNTF. The upregulations of FGF-2 and CNTF suggest that increasing zinc intake may benefit injured retinal neurons. However, this was not found to be the case in the present studies, perhaps due to the acute nature of the injury paradigms utilised.

Beneficial effects of zinc supplementation on head circumference of Nepalese infants and toddlers: a randomized controlled trial.

PubMed

Surkan, P J; Shankar, M; Katz, J; Siegel, E H; Leclerq, S C; Khatry, S K; Stoltzfus, R J; Tielsch, J M

2012-07-01

To assess the effects of micronutrient supplementation on head circumference of rural Nepali infants and children. We used a randomized controlled trial to assess the effects of micronutrient supplementation on head circumference in 569 rural Nepali infants and children aged 4-17 months. Children were randomized to: (1) zinc, (2) iron-folic acid, (3) zinc plus iron-folic acid or (4) a placebo group. Data on head circumference were collected during five visits at ∼3 month intervals over the course of a year. We calculated change in head circumference in treatment groups receiving zinc and iron comparing the first and fifth visits as well as used generalized estimating equations (GEE) to take advantage of data from all points in time. Models were adjusted for covariates unbalanced in the randomization and for baseline head circumference. Estimating differences in head circumference between baseline and visit 5, children in the zinc treatment group showed smaller decreases in head circumference z-score compared with placebo (adjusted β=0.13, 95% confidence interval (CI): 0.03 to 0.23). Using GEE, zinc treatment was associated with 0.11 (95% CI: 0.05 to 0.17) decrease in the rate of decline in head circumference z-score across visits as compared with placebo. Iron-folic acid supplementation was not associated with head circumference z-scores when comparing visits 1 with 5 or including data across all visits in adjusted models. Our results suggest that zinc supplementation confers a beneficial effect on the rate of head growth in Nepali infants.

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

PubMed

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

2012-05-01

A number of drugs, like sibutramine, which are used clinically in weight control, act on serotonergic metabolism. However, their relation with zinc and free radical (FR) production in central nervous system remains unknown. This study aimed to evaluate the effect of sibutramine and zinc on FR production. Female Wistar rats (about 250 g) were used in this study. The animals received 400 μg/kg of zinc and 10 mg/kg of sibutramine intraperitoneally every 36 hr for 15 days. At the end of the study, the rats were killed and their brains used for the measurement of lipid peroxidation thiobarbituric acid-reactive substances (TBARS), reduced glutathione (GSH), hydrogen peroxide (H(2) O(2) ), calcium and 5-hydroxyindole acetic acid (5-HIAA) levels, all by means of validated methods. Corporal weight and food consumption were found to be decreased in the zinc/sibutramine group. TBARS decreased in cortex, hemispheres and medulla oblongata. GSH decreased in cortex, hemispheres and cerebellum in the sibutramine group. Zinc given alone and in combination with sibutramine decreased H(2) O(2) concentration in cortex, hemispheres and cerebellum but increased calcium and 5-HIAA concentration in all brain regions. Our results suggest that sibutramine and zinc are associated with weight loss, an effect that was more pronounced in the group treated with both drugs. Reduction in oxidative stress may be involved in these effects. © 2011 The Authors. Basic & Clinical Pharmacology & Toxicology © 2011 Nordic Pharmacological Society.

Zinc stress induces copper depletion in Acinetobacter baumannii.

PubMed

Hassan, Karl A; Pederick, Victoria G; Elbourne, Liam D H; Paulsen, Ian T; Paton, James C; McDevitt, Christopher A; Eijkelkamp, Bart A

2017-03-11

The first row transition metal ions zinc and copper are essential to the survival of many organisms, although in excess these ions are associated with significant toxicity. Here, we examined the impact of zinc and copper stress on Acinetobacter baumannii, a common opportunistic pathogen. We show that extracellular zinc stress induces a copper-specific depletion phenotype in A. baumannii ATCC 17978. Supplementation with copper not only fails to rescue this phenotype, but further exacerbates the copper depletion. Extensive analysis of the A. baumannii ATCC 17978 genome identified 13 putative zinc/copper resistance efflux pumps. Transcriptional analyses show that four of these transporters are responsive to zinc stress, five to copper stress and seven to the combination of zinc and copper stress, thereby revealing a likely foundation for the zinc-induced copper starvation in A. baumannii. In addition, we show that zinc and copper play crucial roles in management of oxidative stress and the membrane composition of A. baumannii. Further, we reveal that zinc and copper play distinct roles in macrophage-mediated killing of this pathogen. Collectively, this study supports the targeting of metal ion homeostatic mechanisms as an effective antimicrobial strategy against multi-drug resistant bacterial pathogens.

Effects of cadmium and zinc on solar-simulated light-irradiated cells: potential role of zinc-metallothionein in zinc-induced genoprotection.

PubMed

Jourdan, Eric; Emonet-Piccardi, Nathalie; Didier, Christine; Beani, Jean-Claude; Favier, Alain; Richard, Marie-Jeanne

2002-09-15

Zinc is an essential oligoelement for cell growth and cell survival and has been demonstrated to protect cells from oxidative stress induced by UVA or from genotoxic stress due to UVB. In a recent work we demonstrated that the antioxidant role of zinc could be related to its ability to induce metallothioneins (MTs). In this study we identified the mechanism of zinc protection against solar-simulated light (SSL) injury. Cultured human keratinocytes (HaCaT) were used to examine MTs expression and localization in response to solar-simulated radiation. We found translocation to the nucleus, with overexpression of MTs in irradiated cells, a novel observation. The genoprotective effect of zinc was dependent on time and protein synthesis. DNA damage was significantly decreased after 48 h of ZnCl(2) (100 microM) treatment and is inhibited by actinomycin D. ZnCl(2) treatment (100 microM) led to an intense induction, redistribution, and accumulation of MT in the nucleus of irradiated cells. MT expression correlated with the time period of ZnCl(2) treatment. CdCl(2), a potent MT inducer, did not show any genoprotection, although the MTs were expressed in the nucleus. Overall our findings demonstrate that MTs could be a good candidate for explaining the genoprotection mediated by zinc on irradiated cells.

Influence of extracellular zinc on M1 microglial activation.

PubMed

Higashi, Youichirou; Aratake, Takaaki; Shimizu, Shogo; Shimizu, Takahiro; Nakamura, Kumiko; Tsuda, Masayuki; Yawata, Toshio; Ueba, Tetuya; Saito, Motoaki

2017-02-27

Extracellular zinc, which is released from hippocampal neurons in response to brain ischaemia, triggers morphological changes in microglia. Under ischaemic conditions, microglia exhibit two opposite activation states (M1 and M2 activation), which may be further regulated by the microenvironment. We examined the role of extracellular zinc on M1 activation of microglia. Pre-treatment of microglia with 30-60 μM ZnCl 2 resulted in dose-dependent increases in interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNFα) secretion when M1 activation was induced by lipopolysaccharide administration. In contrast, the cell-permeable zinc chelator TPEN, the radical scavenger Trolox, and the P2X7 receptor antagonist A438079 suppressed the effects of zinc pre-treatment on microglia. Furthermore, endogenous zinc release was induced by cerebral ischaemia-reperfusion, resulting in increased expression of IL-1β, IL-6, TNFα, and the microglial M1 surface marker CD16/32, without hippocampal neuronal cell loss, in addition to impairments in object recognition memory. However, these effects were suppressed by the zinc chelator CaEDTA. These findings suggest that extracellular zinc may prime microglia to enhance production of pro-inflammatory cytokines via P2X7 receptor activation followed by reactive oxygen species generation in response to stimuli that trigger M1 activation, and that these inflammatory processes may result in deficits in object recognition memory.

Role of zinc in maternal and child mental health1234

PubMed Central

Ramirez-Zea, Manuel

2009-01-01

Mental health problems in women, children, and adolescents are a significant public health issue. Given current barriers to the effective treatment of these problems, researchers are looking to the field of nutrition for potential alternatives to better understand and address mental health issues. The purpose of this article was to review current evidence on the relation between zinc and mental health disorders with a focus on 2 mental health problems that commonly affect women and children: depression and attention-deficit hyperactivity disorder (ADHD). A literature search of the databases Medline and PsychInfo was conducted with the use of key terms. The review included articles from 1975 to May 2008, but focused on articles published in recent years. Relations between zinc concentrations and behavior in animals; the relation between zinc deficiency, depression, and ADHD in patient and community samples; and the potential biological mechanisms for these relations were explored. The data support a relation between low concentrations of zinc and mental health problems, especially in at-risk populations. Evidence for the potential use of zinc in treating mental health problems comes mainly from patient populations and is strongest when zinc is given in combination with pharmacologic treatment. Less conclusive evidence exists for the effectiveness of zinc alone or in general community samples. Recommendations for further research in this area are provided. PMID:19176735

Effect of glycation on human serum albumin-zinc interaction: a biophysical study.

PubMed

Iqbal, Sarah; Qais, Faizan Abul; Alam, Md Maroof; Naseem, Imrana

2018-05-01

Zinc deficiency is common in diabetes. However, the cause of this phenomenon is largely unknown. 80% of the absorbed zinc is transported through the blood in association with human serum albumin (HSA). Under persistent hyperglycemia, HSA frequently undergoes non-enzymatic glycation which can affect its structure and metal-binding function. Hence, in this study, we have examined the interaction of zinc with native and glycated HSA. The protein samples were incubated either in the presence or in the absence of physiologically elevated glucose concentration for 21 days. The samples were then analyzed for structural changes and zinc-binding ability using various spectrometric and calorimetric approaches. The study reveals changes in the three-dimensional structure of the protein upon glycation that cause local unfolding of the molecule. Most such regions are localized in subdomain IIA of HSA which plays a key role in zinc binding. This affects zinc interaction with HSA and could in part explain the perturbed zinc distribution in patients with hyperglycemia. The varying degree of HSA glycation in blood could explain the observed heterogeneity pertaining to zinc deficiency among people suffering from diabetes.

Zinc Bioavailability from Phytate-Rich Foods and Zinc Supplements. Modeling the Effects of Food Components with Oxygen, Nitrogen, and Sulfur Donor Ligands.

PubMed

Tang, Ning; Skibsted, Leif H

2017-10-04

Aqueous solubility of zinc phytate (K sp = (2.6 ± 0.2) × 10 -47 mol 7 /L 7 ), essential for zinc bioavailability from plant foods, was found to decrease with increasing temperature corresponding to ΔH dis of -301 ± 22 kJ/mol and ΔS dis of -1901 ± 72 J/(mol K). Binding of zinc to phytate was found to be exothermic for the stronger binding site and endothermic for the weaker binding site. The solubility of the slightly soluble zinc citrate and insoluble zinc phytate was found to be considerably enhanced by the food components with oxygen donor, nitrogen donor, and sulfur donor ligands. The driving force for the enhanced solubility is mainly due to the complex formation between zinc and the investigated food components rather than ligand exchange and ternary complex formation as revealed by quantum mechanical calculations and isothermal titration calorimetry. Histidine and citrate are promising ligands for improving zinc absorption from phytate-rich foods.

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

PubMed

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.

Zinc and redox signaling: perturbations associated with cardiovascular disease and diabetes mellitus.

PubMed

Foster, Meika; Samman, Samir

2010-11-15

Cellular signal transduction pathways are influenced by the zinc and redox status of the cell. Numerous chronic diseases, including cardiovascular disease (CVD) and diabetes mellitus (DM), have been associated with impaired zinc utilization and increased oxidative stress. In humans, mutations in the MT-1A and ZnT8 genes, both of which are involved in the maintenance of zinc homeostasis, have been linked with DM development. Changes in levels of intracellular free zinc may exacerbate oxidative stress in CVD and DM by impacting glutathione homeostasis, nitric oxide signaling, and nuclear factor-kappa B-dependent cellular processes. Zinc ions have been shown to influence insulin and leptin signaling via the phosphoinositide 3′-kinase/Akt pathway, potentially linking an imbalance of zinc at the cellular level to insulin resistance and dyslipidemia. The oxidative modification of cysteine residues in zinc coordination sites in proteins has been implicated in cellular signaling and regulatory pathways. Despite the many interactions between zinc and cellular stress responses, studies investigating the potential therapeutic benefit of zinc supplementation in the prevention and treatment of oxidative stress-related chronic disease in humans are few and inconsistent. Further well-designed randomized controlled trials are needed to determine the effects of zinc supplementation in populations at various stages of CVD and DM progression.

Zinc-Containing Hydroxyapatite Enhances Cold-Light-Activated Tooth Bleaching Treatment In Vitro

PubMed Central

Shi, Xinchang

2017-01-01

Cold-light bleaching treatment has grown to be a popular tooth whitening procedure in recent years, but its side effect of dental enamel demineralization is a widespread problem. The aim of this study was to synthesize zinc-substituted hydroxyapatite as an effective biomaterial to inhibit demineralization or increase remineralization. We synthesized zinc-substituted hydroxyapatite containing different zinc concentrations and analysed the product using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and energy dispersive spectrometer (EDS). The biological assessment of Zn-HA was conducted by CCK-8 assay and bacterial inhibition tests. pH cycling was performed to estimate the effect of Zn-HA on the enamel surface after cold-light bleaching treatment. The XRD, FTIR, and EDS results illustrated that zinc ions and hydroxyapatite combined in two forms: (1) Zn2+ absorbed on the surface of HA crystal and (2) Zn2+ incorporated into the lattice of HA. The results indicated that 2% Zn-HA, 4% Zn-HA, and 8% Zn-HA effectively inhibited the growth of bacteria yet showed poor biocompatibility, whereas 1% Zn-HA positively affected osteoblast proliferation. The XRD and scanning electron microscopy (SEM) results showed that the use of Zn-HA in pH cycling is obviously beneficial for enamel remineralization. Zinc-substituted hydroxyapatite could be a promising biomaterial for use in cold-light bleaching to prevent enamel demineralization. PMID:29159178

Metal organic chemical vapor deposition of environmental barrier coatings for the inhibition of solid deposit formation from heated jet fuel

NASA Astrophysics Data System (ADS)

Mohan, Arun Ram

Solid deposit formation from jet fuel compromises the fuel handling system of an aviation turbine engine and increases the maintenance downtime of an aircraft. The deposit formation process depends upon the composition of the fuel, the nature of metal surfaces that come in contact with the heated fuel and the operating conditions of the engine. The objective of the study is to investigate the effect of substrate surfaces on the amount and nature of solid deposits in the intermediate regime where both autoxidation and pyrolysis play an important role in deposit formation. A particular focus has been directed to examining the effectiveness of barrier coatings produced by metal organic chemical vapor deposition (MOCVD) on metal surfaces for inhibiting the solid deposit formation from jet fuel degradation. In the first part of the experimental study, a commercial Jet-A sample was stressed in a flow reactor on seven different metal surfaces: AISI316, AISI 321, AISI 304, AISI 347, Inconel 600, Inconel 718, Inconel 750X and FecrAlloy. Examination of deposits by thermal and microscopic analysis shows that the solid deposit formation is influenced by the interaction of organosulfur compounds and autoxidation products with the metal surfaces. The nature of metal sulfides was predicted by Fe-Ni-S ternary phase diagram. Thermal stressing on uncoated surfaces produced coke deposits with varying degree of structural order. They are hydrogen-rich and structurally disordered deposits, spherulitic deposits, small carbon particles with relatively ordered structures and large platelets of ordered carbon structures formed by metal catalysis. In the second part of the study, environmental barrier coatings were deposited on tube surfaces to inhibit solid deposit formation from the heated fuel. A new CVD system was configured by the proper choice of components for mass flow, pressure and temperature control in the reactor. A bubbler was designed to deliver the precursor into the reactor for the deposition of metal and metal oxide functional coatings by MOCVD. Alumina was chosen as a candidate for metal oxide coating because of its thermal and phase stability. Platinum was chosen as a candidate to utilize the oxygen spillover process to maintain a self-cleaning surface by oxidizing the deposits formed during thermal stressing. Two metal organic precursors, aluminum trisecondary butoxide and aluminum acetylacetonate, were used as precursors to coat tubes of varying diameters. The morphology and uniformity of the coatings were characterized by electron microscopy and energy-dispersive x-ray spectroscopy. The coating was characterized by x-ray photoelectron spectroscopy to obtain the surface chemical composition. This is the first study conducted to examine the application of MOCVD to coat internal surfaces of tubes with varying diameters. In the third part of the study, the metal oxide coatings, alumina from aluminum acetylacetonate, alumina from aluminum trisecondary butoxide, zirconia from zirconium acetylacetonate, tantalum oxide from tantalum pentaethoxide and the metal coating, platinum from platinum acetylacetonate were deposited by MOCVD on AISI304. The chemical composition and the surface acidity of the coatings were characterized by x-ray photoelectron spectroscopy. The morphology of the coatings was characterized by electron microscopy. The coated substrates were tested in the presence of heated Jet-A in a flow reactor to evaluate their effectiveness in inhibiting the solid deposit formation. All coatings inhibited the formation of metal sulfides and the carbonaceous solid deposits formed by metal catalysis. The coatings also delayed the accumulation of solid carbonaceous deposits. In particular, it has been confirmed that the surface acidity of the metal oxide coatings affects the formation of carbonaceous deposits. Bimolecular addition reactions promoted by the Bronsted acid sites appear to lead to the formation of carbonaceous solid deposits depending on the surface acidity of the coatings. In the last part of the study, the residual carbon was incorporated in the zirconia coating by deposition with and without oxygen. As carbon surface is less active towards coke deposition, presence of residual carbon in the coating was expected to reduce its activity towards carbon deposition. The residual carbon in the coating was characterized by Raman spectroscopy and thermal analysis. However, it has been observed that residual carbon in the coating beyond a certain concentration compromises the integrity of the coating during the process of cooling the substrate from deposition temperature to room temperature. It has been found that residual carbon in the zirconia coating does not appear to affect the activity of the surface towards carbon deposition.

Long-Range Intramolecular Electronic Communication in a Trinuclear Ruthenium Tropolonate Complex.

PubMed

Yoshida, Jun; Kuwahara, Kyohei; Suzuki, Kota; Yuge, Hidetaka

2017-02-20

Dinuclear and trinuclear ruthenium complexes, [Ru(trop) 2 (C 2 trop)Ru(dppe)Cp] [2b; trop = tropolonato, C 2 trop = ethynyltropolonato, dppe = 1,2-bis(diphenylphosphino)ethane] and [Ru(trop){(C 2 trop)Ru(dppe)Cp} 2 ] (3), were synthesized, and their electronic and electrochemical properties were investigated in comparison with our previously reported complex [Ru(acac) 2 (C 2 trop)Ru(dppe)Cp] (2a). The electron-donating Ru II (dppe)Cp unit and electron-accepting Ru III O 6 unit are connected by C 2 trop in these complexes. 2a incorporates acetylacetonate as an ancillary ligand, while 2b and 3 incorporate tropolonate as an ancillary ligand. Every complex, 2a, 2b, and 3, exhibits similar UV-vis-near-IR (NIR) absorption spectra, demonstrating the lack of explicit intramolecular electronic communication between the units at least in the neutral state. The weak NIR absorption in 2a further diminished upon electrochemical oxidation, indicating almost no electronic communication between the units. In contrast, 2b and 3 exhibit broad NIR absorptions upon oxidation. Additionally, 3 exhibits four stepwise redox couples in the electrochemical study, which are formally attributed to [Ru II (trop) 3 ] - /[Ru III (trop) 3 ], two [Ru II (dppe)Cp]/[Ru III (dppe)Cp] + , and [Ru III (trop) 3 ]/[Ru IV (trop) 3 ] + couples. Clear separation of the redox couples attributed to the two terminal [Ru(dppe)Cp] units demonstrates the thermodynamic stability of the intermediate oxidation states with respect to disproportionation. Further electrochemical studies using an electrolyte including perfluorinated weakly coordinating anions and density functional theory/time-dependent density functional theory calculations confirmed the effect of ancillary ligands, acetylacetonate and tropolonate. In the case of 2a, electronic delocalization over the whole complex, especially over the [Ru(acac) 2 (trop)] unit, appears to be small. In contrast, the electronic communication between [Ru(dppe)Cp] and [Ru(trop) 3 ] units in 3 seems to be enhanced upon oxidation, resulting in the long-range intramolecular electronic communication.

Effects of Antioxidant Components of AREDS Vitamins and Zinc Ions on Endothelial Cell Activation: Implications for Macular Degeneration

PubMed Central

Zeng, Shemin; Hernández, Jasmine

2012-01-01

Purpose. To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Methods. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)–choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl2. The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. Results. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Conclusions. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation. PMID:22247465

Taurine zinc solid dispersions enhance bile-incubated L02 cell viability and improve liver function by inhibiting ERK2 and JNK phosphorylation during cholestasis.

PubMed

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lai, Xiaofang; Xu, Donghui

2016-07-29

Dietary intakes of taurine and zinc are associated with decreased risk of liver disease. In this study, solid dispersions (SDs) of a taurine zinc complex on hepatic injury were examined in vitro using the immortalized human hepatocyte cell line L02 and in a rat model of bile duct ligation. Sham-operated and bile duct ligated Sprague-Dawley rats were treated with the vehicle alone or taurine zinc (40, 80, 160mg/kg) for 17days. Bile duct ligation significantly increased blood lipid levels, and promoted hepatocyte apoptosis, inflammation and compensatory biliary proliferation. In vitro, incubation with bile significantly reduced L02 cell viability; this effect was significantly attenuated by pretreatment with SP600125 (a JNK inhibitor) and enhanced when co-incubated with taurine zinc SDs. In vivo, administration of taurine zinc SDs decreased serum alanine aminotransferase and aspartate aminotransferase activities in a dose-dependent manner and attenuated the increases in serum total bilirubin, total cholesterol and low density lipoprotein cholesterol levels after bile duct ligation. Additionally, taurine zinc SDs downregulated the expression of interleukin-1β and inhibited the phosphorylation of Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase2 (ERK2) in the liver after bile duct ligation. Moreover, taurine zinc SDs had more potent blood lipid regulatory and anti-apoptotic effects than the physical mixture of taurine and zinc acetate. Therefore, we speculate that taurine zinc SDs protect liver function at least in part via a mechanism linked to reduce phosphorylation of JNK and ERK2, which suppresses inflammation, apoptosis and cholangiocyte proliferation during cholestasis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Salmonella employs multiple mechanisms to subvert the TLR-inducible zinc-mediated antimicrobial response of human macrophages.

PubMed

Kapetanovic, Ronan; Bokil, Nilesh J; Achard, Maud E S; Ong, Cheryl-Lynn Y; Peters, Kate M; Stocks, Claudia J; Phan, Minh-Duy; Monteleone, Mercedes; Schroder, Kate; Irvine, Katharine M; Saunders, Bernadette M; Walker, Mark J; Stacey, Katryn J; McEwan, Alastair G; Schembri, Mark A; Sweet, Matthew J

2016-05-01

We aimed to characterize antimicrobial zinc trafficking within macrophages and to determine whether the professional intramacrophage pathogen Salmonella enterica serovar Typhimurium (S Typhimurium) subverts this pathway. Using both Escherichia coli and S Typhimurium, we show that TLR signaling promotes the accumulation of vesicular zinc within primary human macrophages. Vesicular zinc is delivered to E. coli to promote microbial clearance, whereas S. Typhimurium evades this response via Salmonella pathogenicity island (SPI)-1. Even in the absence of SPI-1 and the zinc exporter ZntA, S Typhimurium resists the innate immune zinc stress response, implying the existence of additional host subversion mechanisms. We also demonstrate the combinatorial antimicrobial effects of zinc and copper, a pathway that S. Typhimurium again evades. Our use of complementary tools and approaches, including confocal microscopy, direct assessment of intramacrophage bacterial zinc stress responses, specific E. coli and S Typhimurium mutants, and inductively coupled plasma mass spectroscopy, has enabled carefully controlled characterization of this novel innate immune antimicrobial pathway. In summary, our study provides new insights at the cellular level into the well-documented effects of zinc in promoting host defense against infectious disease, as well as the complex host subversion strategies employed by S Typhimurium to combat this pathway.-Kapetanovic, R., Bokil, N. J., Achard, M. E. S., Ong, C.-L. Y., Peters, K. M., Stocks, C. J., Phan, M.-D., Monteleone, M., Schroder, K., Irvine, K. M., Saunders, B. M., Walker, M. J., Stacey, K. J., McEwan, A. G., Schembri, M. A., Sweet, M. J. Salmonella employs multiple mechanisms to subvert the TLR-inducible zinc-mediated antimicrobial response of human macrophages. © FASEB.

Effects of antioxidant components of AREDS vitamins and zinc ions on endothelial cell activation: implications for macular degeneration.

PubMed

Zeng, Shemin; Hernández, Jasmine; Mullins, Robert F

2012-02-01

To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)-choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl(2). The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation.

Dietary phytate, zinc and hidden zinc deficiency.

PubMed

Sandstead, Harold H; Freeland-Graves, Jeanne H

2014-10-01

Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopez, A.L.; Kohrs, M.B.; Horwitz, D.L.

To determine the effect of glucose loading on serum zinc concentrations, 34 elderly subjects aged 60-86 y were studied. Anthropometric data, medical and dietary histories were obtained. Serum zinc and glucose concentrations were obtained fasting and 1/2, 1, 1 1/2, 2 and 3 h after 75 g oral glucose load; glycohemoglobin and fasting serum lipids were also determined. For comparison, the subjects were categorized as: normal or low serum zinc concentrations; normal or high body mass index BMI; normal or high sum of skinfolds and normal or high serum cholesterol. Results showed that low serum zinc concentrations increased significantly overmore » baseline values after the glucose load and did not return to fasting levels. On the other hand, mean serum zinc concentrations significantly declined without recovery for those with normal zinc values. For the total group, no significant differences were noted between fasting values and subsequent time periods. No correlations were noted between fasting serum zinc and area under the curve for zinc except in the high BMI group (positive correlation observed). For the high BMI group, fasting serum zinc differed significantly from the succeeding measurements except for 30 min. For the group as a whole, mean serum zinc concentration was within normal limits (76.9 +/- 2.8 mcg/ml): mean zinc intake was less than 2/3rds the RDA. They conclude that glucose ingestion may alter serum zinc and should be considered in interpreting these levels.« less

Synthesis, characterization and evaluation of effect of phytogenic zinc nanoparticles on soil exo-enzymes

NASA Astrophysics Data System (ADS)

Sri Sindhura, K.; Prasad, T. N. V. K. V.; Panner Selvam, P.; Hussain, O. M.

2014-10-01

Nanobiotechnology, the bio-branch of nanotechnology is considered to be one of the fastest emerging research fields. Biosynthesis of metallic nanoparticles is currently under exploitation. Use of plant and plant materials for the synthesis of Zinc nanoparticles is relatively new and exciting research field. The biogenic zinc nanoparticles were synthesized using the leaves of Parthenium hysterophorous by green synthesis route. UV-VIS absorption spectroscopy was used to monitor the quantitative formation of zinc nanoparticles. The characteristics of the synthesized zinc nanoparticles were studied using scanning electron microscopy and nanoparticle analyzer. Zinc nanoparticles were observed to be spherical in shape with size range of 16 to 108.5 nm. The measured zeta potentials varied from 100.4 to 117.20 mV indicate high dispersion of the zinc nanoparticles. The synthesized zinc nanoparticles showed good enzymatic activity and microbial activity. The physiological parameters increased from 30 to 60 days of sowing when compared to control.

Infantile zinc deficiency: Association with autism spectrum disorders

PubMed Central

Yasuda, Hiroshi; Yoshida, Kazuya; Yasuda, Yuichi; Tsutsui, Toyoharu

2011-01-01

Elucidation of the pathogenesis and effective treatment of autism spectrum disorders is one of the challenges today. In this study, we examine hair zinc concentrations for 1,967 children with autistic disorders (1,553 males and 414 females), and show considerable association with zinc deficiency. Histogram of hair zinc concentration was non-symmetric with tailing in lower range, and 584 subjects were found to have lower zinc concentrations than −2 standard deviation level of its reference range (86.3–193ppm). The incidence rate of zinc deficiency in infant group aged 0–3 year-old was estimated 43.5 % in male and 52.5 % in female. The lowest zinc concentration of 10.7 ppm was detected in a 2-year-old boy, corresponding to about 1/12 of the control mean level. These findings suggest that infantile zinc deficiency may epigenetically contribute to the pathogenesis of autism and nutritional approach may yield a novel hope for its treatment and prevention. PMID:22355646

Remote Laser Welding of Zinc Coated Steel Sheets in an Edge Lap Configuration with Zero Gap

NASA Astrophysics Data System (ADS)

Roos, Christian; Schmidt, Michael

Remote Laser Welding (RLW) of zinc-coated steel sheets is a great challenge for the automotive industry but offers high potentials with respect to flexibility and costs. In state of the art applications, sheets are joined in overlap configuration with a preset gap for a stable zinc degassing. This paper investigates RLW of fillets without a preset gap and conditions for a stable process. The influence of process parameters on weld quality and process stability is shown. Experimental data give evidence, that the degassing of zinc through the capillary and the rear melt pool are the major degassing mechanisms. Furthermore the paper gives experimental validation of the zinc degassing in advance of the process zone to the open side of the fillet. Chemical analysis of the hot-dip galvanized zinc coating proof the iron-zinc-alloys to be the reason for a limited effectiveness of this mechanism in comparison to pure zinc as intermediate.

Chemical stability and electrical performance of dual-active-layered zinc-tin-oxide/indium-gallium-zinc-oxide thin-film transistors using a solution process.

PubMed

Kim, Chul Ho; Rim, You Seung; Kim, Hyun Jae

2013-07-10

We investigated the chemical stability and electrical properties of dual-active-layered zinc-tin-oxide (ZTO)/indium-gallium-zinc-oxide (IGZO) structures (DALZI) with the durability of the chemical damage. The IGZO film was easily corroded or removed by an etchant, but the DALZI film was effectively protected by the high chemical stability of ZTO. Furthermore, the electrical performance of the DALZI thin-film transistor (TFT) was improved by densification compared to the IGZO TFT owing to the passivation of the pin holes or pore sites and the increase in the carrier concentration due to the effect of Sn(4+) doping.

Zinc supplementation for the treatment of measles in children.

PubMed

Awotiwon, Ajibola A; Oduwole, Olabisi; Sinha, Anju; Okwundu, Charles I

2015-03-20

Measles is still an important cause of childhood morbidity and mortality globally, despite increasing vaccine coverage. Zinc plays a significant role in the maintenance of normal immunological functions, therefore supplements given to zinc-deficient children will increase the availability of zinc and could reduce measles-related morbidity and mortality. To assess the effects of zinc supplementation in reducing morbidity and mortality in children with measles. We searched CENTRAL (2014, Issue 5), MEDLINE (1946 to June week 3, 2014), EMBASE (1974 to June 2014), CINAHL (1981 to June 2014), LILACS (1982 to June 2014), Web of Science (1985 to June 2014) and BIOSIS Previews (1985 to June 2014). We also searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) to identify unpublished and ongoing studies. Randomised controlled trials (RCTs) and quasi-RCTs evaluating the effects of zinc in reducing morbidity and mortality in children with measles. Two review authors independently assessed the studies for inclusion and extracted data on outcomes, details of the interventions and other study characteristics using a standardised data extraction form. We used the risk ratio (RR) and hazard ratio as measures of effect with 95% confidence intervals (CI). We included only one study and we did not conduct any meta-analysis. One RCT met our inclusion criteria. The study was conducted in India and included 85 children diagnosed with measles and pneumonia. The trial showed that there was no significant difference in mortality between the two groups (risk ratio (RR) 0.34, 95% confidence interval (CI) 0.01 to 8.14). Also, there was no significant difference in time to absence of fever between the two groups (hazard ratio (HR) 1.08, 95% CI 0.67 to 1.74). No treatment-related side effects were reported in either group. The overall quality of the evidence can be described as very low. We cannot draw any definite conclusions from this review about the effects of zinc supplementation on clinical outcomes of children with measles due to the very low quality of the evidence available. There is insufficient evidence to confirm or refute the effect of zinc supplementation in measles.

Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Juanjuan; Zhang, Yu; Xu, Wentao, E-mail: xuwentaoboy@sina.com

Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did notmore » affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{sub m}). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage induced by OTA in vitro.« less

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial.

PubMed

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia.

Neurotoxicity of dental amalgam is mediated by zinc.

PubMed

Lobner, D; Asrari, M

2003-03-01

The use of dental amalgam is controversial largely because it contains mercury. We tested whether amalgam caused toxicity in neuronal cultures and whether that toxicity was caused by mercury. In this study, we used cortical cell cultures to show for the first time that amalgam causes nerve cell toxicity in culture. However, the toxicity was not blocked by the mercury chelator, 2,3-dimercaptopropane-1-sulphonate (DMPS), but was blocked by the metal chelator, calcium disodium ethylenediaminetetraacetate (CaEDTA). DMPS was an effective mercury chelator in this system, since it blocked mercury toxicity. Of the components that comprise amalgam (mercury, zinc, tin, copper, and silver), only zinc neurotoxicity was blocked by CaEDTA. These results indicate that amalgam is toxic to nerve cells in culture by releasing zinc. While zinc is known to be neurotoxic, ingestion of zinc is not a major concern because zinc levels in the body are tightly regulated.

Zinc Signal in Brain Diseases.

PubMed

Portbury, Stuart D; Adlard, Paul A

2017-11-23

The divalent cation zinc is an integral requirement for optimal cellular processes, whereby it contributes to the function of over 300 enzymes, regulates intracellular signal transduction, and contributes to efficient synaptic transmission in the central nervous system. Given the critical role of zinc in a breadth of cellular processes, its cellular distribution and local tissue level concentrations remain tightly regulated via a series of proteins, primarily including zinc transporter and zinc import proteins. A loss of function of these regulatory pathways, or dietary alterations that result in a change in zinc homeostasis in the brain, can all lead to a myriad of pathological conditions with both acute and chronic effects on function. This review aims to highlight the role of zinc signaling in the central nervous system, where it may precipitate or potentiate diverse issues such as age-related cognitive decline, depression, Alzheimer's disease or negative outcomes following brain injury.

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

PubMed

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

2010-05-01

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

Zinc treatment increases the titre of ‘Candidatus Liberibacter asiaticus’ in Huanglongbing-affected citrus plants while affecting the bacterial microbiomes

USDA-ARS?s Scientific Manuscript database

Huanglongbing (HLB)-affected citrus often display zinc deficiency symptoms. In this study, supplemental zinc was applied to citrus to determine its effect on Candidatus Liberibacter asiaticus (Las) titer, HLB symptoms, and leaf microbiome. HLB-affected citrus were treated with various amounts of zi...

Zinc supplementation in rats impairs hippocampal-dependent memory consolidation and dampens post-traumatic recollection of stressful event.

PubMed

Contestabile, Antonio; Peña-Altamira, Emiliano; Virgili, Marco; Monti, Barbara

2016-06-01

Zinc is a trace element important for synaptic plasticity, learning and memory. Zinc deficiency, both during pregnancy and after birth, impairs cognitive performance and, in addition to memory deficits, also results in alterations of attention, activity, neuropsychological behavior and motor development. The effects of zinc supplementation on cognition, particularly in the adult, are less clear. We demonstrate here in adult rats, that 4 week-long zinc supplementation given by drinking water, and approximately doubling normal daily intake, strongly impairs consolidation of hippocampal-dependent memory, tested through contextual fear conditioning and inhibitory avoidance. Furthermore, the same treatment started after memory consolidation of training for the same behavioral tests, substantially dampens the recall of the stressful event occurred 4 weeks before. A molecular correlate of the amnesic effect of zinc supplementation is represented by a dysregulated function of GSK-3ß in the hippocampus, a kinase that participates in memory processes. The possible relevance of these data for humans, in particular regarding post-traumatic stress disorders, is discussed in view of future investigation. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

The effect of zinc on healing of renal damage in rats.

PubMed

Salehipour, Mehdi; Monabbati, Ahmad; Ensafdaran, Mohammad Reza; Adib, Ali; Babaei, Amir Hossein

2017-07-01

Several studies have previously been performed to promote kidney healing after injuries. Objectives: The aim of this study was to investigate the effect of zinc on renal healing after traumatic injury in rats. Forty healthy female rats were selected and one of their kidneys was incised. Half of the incisions were limited only to the cortex (renal injury type I) and the other ones reached the pelvocalyceal system of the kidney (renal injury type II). All the rats in the zinc treated group (case group) received 36.3 mg zinc sulfate (contained 8.25 mg zinc) orally. After 28 days, the damaged kidneys were removed for histopathological studies. In the rats with type I injury, kidney inflammation of the case group was significantly lower than that of the control group. However, the result was not significant in rats with type II injury. Tissue loss and granulation tissue formation were significantly lower in the case group than the control group in both type I and II kidney injuries. Overall, Zinc can contribute to better healing of the rat's kidneys after a traumatic injury.

A Novel Polyaminocarboxylate Compound To Treat Murine Pulmonary Aspergillosis by Interfering with Zinc Metabolism.

PubMed

Laskaris, Paris; Vicentefranqueira, Rocío; Helynck, Olivier; Jouvion, Grégory; Calera, José Antonio; du Merle, Laurence; Suzenet, Franck; Buron, Frédéric; de Sousa, Rodolphe Alves; Mansuy, Daniel; Cavaillon, Jean-Marc; Latgé, Jean-Paul; Munier-Lehmann, Hélène; Ibrahim-Granet, Oumaima

2018-06-01

Aspergillus fumigatus can cause pulmonary aspergillosis in immunocompromised patients and is associated with a high mortality rate due to a lack of reliable treatment options. This opportunistic pathogen requires zinc in order to grow and cause disease. Novel compounds that interfere with fungal zinc metabolism may therefore be of therapeutic interest. We screened chemical libraries containing 59,223 small molecules using a resazurin assay that compared their effects on an A. fumigatus wild-type strain grown under zinc-limiting conditions and on a zinc transporter knockout strain grown under zinc-replete conditions to identify compounds affecting zinc metabolism. After a first screen, 116 molecules were selected whose inhibitory effects on fungal growth were further tested by using luminescence assays and hyphal length measurements to confirm their activity, as well as by toxicity assays on HeLa cells and mice. Six compounds were selected following a rescreening, of which two were pyrazolones, two were porphyrins, and two were polyaminocarboxylates. All three groups showed good in vitro activity, but only one of the polyaminocarboxylates was able to significantly improve the survival of immunosuppressed mice suffering from pulmonary aspergillosis. This two-tier screening approach led us to the identification of a novel small molecule with in vivo fungicidal effects and low murine toxicity that may lead to the development of new treatment options for fungal infections by administration of this compound either as a monotherapy or as part of a combination therapy. Copyright © 2018 American Society for Microbiology.

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

PubMed

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.

Zinc deficiency mediates alcohol-induced apoptotic cell death in the liver of rats through activating ER and mitochondrial cell death pathways

PubMed Central

Sun, Qian; Zhong, Wei; Zhang, Wenliang; Li, Qiong; Sun, Xiuhua; Tan, Xiaobing; Sun, Xinguo; Dong, Daoyin

2015-01-01

Hepatic zinc deficiency has been well documented in alcoholic patients, but the mechanisms by which zinc deficiency mediates cell death have not been well defined. The objectives of this study were to determine whether alcohol perturbs subcellular zinc homeostasis and how organelle zinc depletion may link with cell death pathways. Wistar rats were pair-fed with the Lieber-DeCarli control or ethanol diet for 5 mo. Chronic alcohol exposure significantly reduced zinc level in isolated hepatic endoplasmic reticulum (ER) and mitochondria. Among the detected zinc transporters, ER Zrt/Irt-like protein (ZIP)13 and mitochondrial ZIP8, which transport zinc from ER and mitochondria to cytosol, were significantly increased. Mitochondrial zinc transporter (ZnT) 4, which transports zinc from cytosol to mitochondria, was also increased. ER phosphorylated eukaryotic initiation factor 2α, activating transcription factor 4, and C/EBP homologous protein were significantly upregulated, and mitochondrial cytochrome c release and Bax insertion were detected in association with caspase-3 activation and apoptotic cell death. To define the role of zinc deficiency in ER and mitochondrial stress, H4IIEC3 cells were treated with 3 μM N,N,N′,N′-tetrakis (2-pyridylmethyl) ethylenediamine for 6 h with or without supplementation with zinc or N-acetylcysteine (NAC). The results demonstrated that zinc deprivation induced caspase-3 activation and apoptosis in association with ER and mitochondria dysfunction, which were inhibited by zinc as low as 10 μM but not by 2 mM NAC. These results suggest that chronic ethanol exposure induced in ER and mitochondrial zinc deficiency might activate intrinsic cell death signaling pathway, which could not be effectively rescued by antioxidant treatment. PMID:25767260

A case study of preservation of semi-solid preparations using the European Pharmacopoeia test: comparative efficacy of antimicrobial agents in zinc gelatin.

PubMed

Favet, J; Chappuis, M L; Doelker, E

2001-09-01

The present study was undertaken with the aim of finding an alternative preservative system to methyl parahydroxybenzoate in zinc gelatin, which was described in the monographs of the Swiss Pharmacopoeia (until Ph. Helv. 8) and in previous editions of the German Pharmacopoeia (until DAB 7). This antimicrobial agent has now been withdrawn in the DAB, because of its potential allergy risks. As for the USP and DAB-DDR zinc gelatin preparations, they have always been devoid of any preservative agent, probably relying on the mild antimicrobial activity of zinc. A literature survey did not reveal if such an aqueous preparation containing the water-insoluble zinc oxide shows efficacious antimicrobial activity by itself. Thus, a comparative evaluation of differently preserved zinc gelatin preparations was performed using a test for the efficacy of antimicrobial preservation that has been modified with regard to the European Pharmacopoeia (EP) test to take into account the solid state of the preparations and the bactericidal effect of the zinc. Three zinc gelatin preparations were checked, either: (i), without any agent; or (ii), with 0.1% methyl parahydroxybenzoate; or (iii), with 0.5% phenoxyethanol, a broad-spectrum antimicrobial agent almost devoid of allergy risks. The three preparations behave quite differently, in particular with respect to fungi. All three preparations passed the modified EP test as far as bacteria are concerned. Even zinc gelatin without preservative is very effective, not only because of the mild antimicrobial activity of zinc (the soluble fraction of zinc oxide in the liquid phase of zinc gelatin was determined to be 13 microg/ml), but most probably because of the low water activity of the preparation (measured as around 0.81), as shown by the absence of growth of a zinc-resistant strain of Pseudomonas aeruginosa. Zinc gelatin preserved with methyl parahydroxybenzoate has a weak, although satisfactory, activity against Staphylococcus aureus. Regarding fungi, gelatin without an antimicrobial agent and that preserved with methyl parahydroxybenzoate meet the requirements for efficacy against Candida albicans, but are only bacteriostatic against Aspergillus niger. As for zinc gelatin preserved with phenoxyethanol, it displays the best activity against C. albicans and, above all, appears to be the only formulation exhibiting fungicidal activity against A. niger. It is therefore recommended to preserve zinc gelatin with this antimicrobial agent, as recently adopted in Supplement 2000 of the Swiss Pharmacopoeia.

The Effects of Supplemental Zinc and Honey on Wound Healing in Rats

PubMed Central

Sazegar, Ghasem; Seyed Reza, Attarzadeh Hosseini; Behravan, Effat

2011-01-01

Objective(s) Clinicians have long been searching for ways to obtain "super normal" wound healing. Zinc supplementation improves the healing of open wounds. Honey can improve the wound healing with its antibacterial properties. Giving supplemental zinc to normal rats can increase the wound tensile strength. This work is to study the concurrent effects of zinc and honey in wound healing of normal rats. Materials and Methods One hundred and seventy two young rats were randomly divided into four groups: control, zinc-supplement, applied honey, zinc-supplement and applied honey. Two areas of skin about 4 cm² were excised. The wound area was measured every 2 days. After 3 weeks, all animals were killed and tensile strength of wounds, zinc concentration of blood and histological improvement of wounds were evaluated. The results were analyzed using two-way ANOVA and the mean differences were tested. Results It was found that honey could inhibit the bacterial growth in skin excisions. The tensile strength was increased significantly in the second to fourth groups at 21st day (P< 0.001). Also there was a significant increase in tensile strength at the same time in the fourth group. The results of the histological study showed a considerable increase in the collagen fibers, re-epithelialization and re-vascularization in the second to fourth groups. Conclusion The results of the present study indicate that zinc sulfate could retard re-epithelialization, but when used with natural honey (administered topically) it could have influent wound healing in non-zinc-deficient subjects as well. PMID:23493488

Physical chemical effects of zinc on in vitro enamel demineralization.

PubMed

Mohammed, N R; Mneimne, M; Hill, R G; Al-Jawad, M; Lynch, R J M; Anderson, P

2014-09-01

Zinc salts are formulated into oral health products as antibacterial agents, yet their interaction with enamel is not clearly understood. The aim was to investigate the effect of zinc concentration [Zn(2+)] on the in vitro demineralization of enamel during exposure to caries-simulating conditions. Furthermore, the possible mechanism of zinc's action for reducing demineralization was determined. Enamel blocks and synthetic hydroxyapatite (HAp) were demineralized in a range of zinc-containing acidic solutions (0-3565ppm [Zn(2+)]) at pH 4.0 and 37°C. Inductively coupled-plasma optical emission spectroscopy (ICP-OES) was used to measure ion release into solution. Enamel blocks were analysed by Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR), and HAp by X-ray diffraction (XRD) and neutron diffraction (ND). ICP-OES analysis of the acidic solutions showed a decrease in [Ca(2+)] and [PO4(3-)] release with increasing [Zn(2+)]. FTIR revealed a α-hopeite (α-Zn3(PO4)2.4H2O)-like phase on the enamel surfaces at >107ppm [Zn(2+)]. XRD and ND analysis confirmed a zinc-phosphate phase present alongside the HAp. This study confirms that zinc reduces enamel demineralization. Under the conditions studied, zinc acts predominantly on enamel surfaces at PO4(3-) sites in the HAp lattice to possibly form an α-hopeite-like phase. These results have a significant implication on the understanding of the fundamental chemistry of zinc in toothpastes and demonstrate its therapeutic potential in preventing tooth mineral loss. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Scientific skepticism and new discoveries: an analysis of a report of zinc/phytase supplementation and the efficacy of botulinum toxins in treating cosmetic facial rhytides, hemifacial spasm and benign essential blepharospasm.

PubMed

Cohen, Joel L

2014-10-01

A recent paper in the Journal of Drugs in Dermatology by Koshy and colleagues (2012, 11( 4 ):507-512) report on "Effect of Dietary Zinc and Phytase Supplementation on Botulinum Toxin Treatments" and conclude by claiming the discovery of "a potentially meaningful role for zinc and/or phytase supplementation in increasing the degree and duration of botulinum toxin effect in the treatment of cosmetic facial rhytids, benign essential blepharospasm, and hemifacial spasm". The purpose of this paper is to examine these published claims for possible methodological and design errors and potential sources of bias. The authors evaluated the published results in comparison to the published literature on zinc deficiency, the role of phytase, prior reports of an effect of zinc on activity of botulinum toxin, issues of study design and execution and if the reported results of the study supported the study's conclusions. Multiple issues are present in the reported study, which appear to invalidate its conclusions. These areas include lack of direct evidence for the presence of clinical or subclinical zinc deficiency in the study population or for the level of phytate in the study population sufficient to interfere with zinc absorption in these subjects. Additionally, there is ambiguity as to the actual dose of zinc used as well as in the study design itself. Also there is a failure of the study through the "unmasking" of the crossover design. There is potential financial conflict of interest in the study execution that may have biased the reported results. Finally there is inadequate data presented to evaluate the claims made of a "new discovery" as to the three disease entities reported on and the various botulinum toxins used in each of the three treatment arms of the study. Based on this evaluation, it appears that a high level of clinical and scientific skepticism is warranted concerning any claim of a beneficial effect of zinc and phytase supplementation on the efficacy or potency of any botulinum toxins in the reported conditions.

The effect of dietary zinc - and polyphenols intake on DMBA-induced mammary tumorigenesis in rats

PubMed Central

2012-01-01

Background The aim of the study was to investigate the effect of dietary supplementation with zinc and polyphenol compounds, i.e. resveratrol and genistein, on the effectiveness of chemically induced mammary cancer and the changes in the content of selected elements (Zn, Cu, Mg, Fe, Ca) in tumors as compared with normal tissue of the mammary gland. Methods Female Sprague-Dawley rats were divided into study groups which, apart from the standard diet and DMBA (7,12-dimethyl-1,2- benz[a]anthracene), were treated with zinc ions (Zn) or zinc ions + resveratrol (Zn + resveratrol) or zinc ions + genistein (Zn + genistein) via gavage for a period from 40 days until 20 weeks of age. The ICP-OES (inductively coupled plasma optical emission spectrometry) technique was used to analyze the following elements: magnesium, iron, zinc and calcium. Copper content in samples was estimated in an atomic absorption spectrophotometer. Results Regardless of the diet (standard; Zn; Zn + resveratrol; Zn + genistein), DMBA-induced breast carcinogenesis was not inhibited. On the contrary, in the Zn + resveratrol supplemented group, tumorigenesis developed at a considerably faster rate. On the basis of quantitative analysis of selected elements we found - irrespectively of the diet applied - great accumulation of copper and iron, which are strongly prooxidative, with a simultaneous considerable decrease of the magnesium content in DMBA-induced mammary tumors. The combination of zinc supplementation with resveratrol resulted in particularly large differences in the amount of the investigated elements in tumors as compared with their content in normal tissue. Conclusions Diet supplementation with zinc and polyphenol compounds, i.e. resveratrol and genistein had no effect on the decreased copper level in tumor tissue and inhibited mammary carcinogenesis in the rat. Irrespectively of the applied diet, the development of the neoplastic process in rats resulted in changes of the iron and magnesium content in the cancerous tissue in comparison with the healthy mammary tissue. The application of combined diet supplementation with zinc ions and resveratrol considerably promoted the rate of carcinogenesis and increased the number of DMBA-induced mammary tumors. PMID:22507225

Effects of valerian consumption during pregnancy on cortical volume and the levels of zinc and copper in the brain tissue of mouse fetus.

PubMed

Mahmoudian, Alireza; Rajaei, Ziba; Haghir, Hossein; Banihashemian, Shahaboldin; Hami, Javad

2012-04-01

The aim of the present study was to determine the effects of valerian (Valeriana officinalis) consumption in pregnancy on cortical volume and the levels of zinc and copper, two essential elements that affect brain development and function, in the brain tissues of mouse fetuses. Pregnant female mice were treated with either saline or 1.2 g/kg body weight valerian extract intraperitoneally daily on gestation days (GD) 7 to 17. On GD 20, mice were sacrificed and their fetuses were collected. Fetal brains were dissected, weighed and processed for histological analysis. The volume of cerebral cortex was estimated by the Cavalieri principle. The levels of zinc and copper in the brain tissues were measured by atomic absorption spectroscopy. The results indicated that valerian consumption in pregnancy had no significant effect on brain weight, cerebral cortex volume and copper level in fetal brain. However,it significantly decreased the level of zinc in the brain (P<0.05). Using valerian during midgestation do not have an adverse effect on cerebral cortex; however,it caused a significant decrease in zinc level in the fetal brain. This suggests that valerian use should be limited during pregnancy.

Improvement of the in vitro digestible iron and zinc content of okra (Hibiscus esculentus L.) sauce widely consumed in Sahelian Africa.

PubMed

Avallone, Sylvie; Bohuon, Philippe; Hemery, Youna; Treche, Serge

2007-03-01

The effects of the formulation (okra, fish, soumbala, extract of wood ash) and cooking time of okra sauce on total iron and zinc content and on their in vitro digestibility were evaluated following a Doehlert uniform shell design with 5 factors and 33 trials. Cooking time had no significant effect on in vitro digestible iron and zinc content, whereas formulation did. Each ingredient had a specific effect. Extract of wood ash, which is a source of soluble and digestible iron and zinc, is a good way of increasing the digestible mineral content of the dish. Okra, the main ingredient in this sauce, has a negative effect and should be added in moderate quantities (< 37.7% of the DM of the sauce). An optimization using the desirability function allows us to identify the optimal recipe that enabled the quantity of digestible iron to be doubled and the quantity of digestible zinc to be increased by one third. This recipe calls for a mixture of 37.7% okra, 26.3% dried fish, 18.5% soumbala, and 3.7% extract of wood ash cooked for 25 min.

JPRS Report Science & Technology Japan

DTIC Science & Technology

1989-03-02

Oxychlorides MOCln_2 (Organic Metal Salts) Alkoxides M(OR)n Acetylacetonate M(C5H702)n Acetates M(C2H302)n Oxalates M(C204)n/2 2.2 Hydrolysis and Gel...more deeply understanding hydrothermal dynamics during not only a major rupture LOCA but also a minor rupture LOCA and clarifying the combination of... hydrothermal dynamics of the coolant from the beginning of LOCA to its end, using a scale model of PWR (pressurized water reactor). Under the ROSA-III Plan

Effects of Long-Term Exposure to Zinc Oxide Nanoparticles on Development, Zinc Metabolism and Biodistribution of Minerals (Zn, Fe, Cu, Mn) in Mice

PubMed Central

Wang, Chao; Lu, Jianjun; Zhou, Le; Li, Jun; Xu, Jiaman; Li, Weijian; Zhang, Lili; Zhong, Xiang; Wang, Tian

2016-01-01

Zinc oxide nanoparticles (nano-ZnOs) are widely used and possess great potentials in agriculture and biomedicine. It is inevitable for human exposure to these nanoparticles. However, no study had been conducted to investigate the long term effects of nano-ZnOs. This study aimed at investigating effects of nano-ZnOs on development, zinc metabolism and biodistribution of minerals (Zn, Fe, Cu, and Mn) in mice from week 3 to 35. After the characteristics of nano-ZnOs were determined, they were added into the basal diet at 0, 50, 500 and 5000 mg/kg. Results indicated that added 50 and 500 mg/kg nano-ZnOs showed minimal toxicity. However, 5000 mg/kg nano-ZnOs significantly decreased body weight (from week 4 to 16) and increased the relative weights of the pancreas, brain and lung. Added 5000 mg/kg nano-ZnOs significantly increased the serum glutamic-pyruvic transaminase activity and zinc content, and significantly enhanced mRNA expression of zinc metabolism-related genes, including metallothionein 1(32.66 folds), metallothionein 2 (31.42 folds), ZIP8 (2.21folds), ZIP14 (2.45 folds), ZnT1 (4.76 folds), ZnT2 (6.19 folds) and ZnT4 (1.82 folds). The biodistribution determination showed that there was a significant accumulation of zinc in the liver, pancreas, kidney, and bones (tibia and fibula) after receiving 5000 mg/kg nano-ZnO diet, while no significant effects on Cu, Fe, and Mn levels, except for liver Fe content and pancreas Mn level. Our results demonstrated that long term exposure to 50 and 500 mg/kg nano-ZnO diets showed minimal toxicity. However, high dose of nano-ZnOs (5000 mg/kg) caused toxicity on development, and altered the zinc metabolism and biodistribution in mice. PMID:27732669

Effects of Long-Term Exposure to Zinc Oxide Nanoparticles on Development, Zinc Metabolism and Biodistribution of Minerals (Zn, Fe, Cu, Mn) in Mice.

PubMed

Wang, Chao; Lu, Jianjun; Zhou, Le; Li, Jun; Xu, Jiaman; Li, Weijian; Zhang, Lili; Zhong, Xiang; Wang, Tian

2016-01-01

Zinc oxide nanoparticles (nano-ZnOs) are widely used and possess great potentials in agriculture and biomedicine. It is inevitable for human exposure to these nanoparticles. However, no study had been conducted to investigate the long term effects of nano-ZnOs. This study aimed at investigating effects of nano-ZnOs on development, zinc metabolism and biodistribution of minerals (Zn, Fe, Cu, and Mn) in mice from week 3 to 35. After the characteristics of nano-ZnOs were determined, they were added into the basal diet at 0, 50, 500 and 5000 mg/kg. Results indicated that added 50 and 500 mg/kg nano-ZnOs showed minimal toxicity. However, 5000 mg/kg nano-ZnOs significantly decreased body weight (from week 4 to 16) and increased the relative weights of the pancreas, brain and lung. Added 5000 mg/kg nano-ZnOs significantly increased the serum glutamic-pyruvic transaminase activity and zinc content, and significantly enhanced mRNA expression of zinc metabolism-related genes, including metallothionein 1(32.66 folds), metallothionein 2 (31.42 folds), ZIP8 (2.21folds), ZIP14 (2.45 folds), ZnT1 (4.76 folds), ZnT2 (6.19 folds) and ZnT4 (1.82 folds). The biodistribution determination showed that there was a significant accumulation of zinc in the liver, pancreas, kidney, and bones (tibia and fibula) after receiving 5000 mg/kg nano-ZnO diet, while no significant effects on Cu, Fe, and Mn levels, except for liver Fe content and pancreas Mn level. Our results demonstrated that long term exposure to 50 and 500 mg/kg nano-ZnO diets showed minimal toxicity. However, high dose of nano-ZnOs (5000 mg/kg) caused toxicity on development, and altered the zinc metabolism and biodistribution in mice.

Effect of long-term intraperitoneal zinc administration on liver glycogen levels in diabetic rats subjected to acute forced swimming.

PubMed

Bicer, Mursel; Gunay, Mehmet; Akil, Mustafa; Avunduk, Mustafa Cihat; Mogulkoc, Rasim; Baltaci, Abdulkerim Kasim

2011-03-01

This study aims to examine the effect of zinc administration on liver glycogen levels of rats in which diabetes was induced with streptozotocin and which were subjected to acute swimming exercise. The study was conducted on 80 adult Sprague-Dawley male rats, which were equally allocated to eight groups: group 1, general control; group 2, zinc-administrated control; group 3, zinc-administrated diabetic control; group 4, swimming control; group 5, zinc-administrated swimming; group 6, zinc-administrated diabetic swimming; group 7, diabetic swimming; group 8, diabetic control group. In order to induce diabetes, animals were injected with 40 mg/kg intraperitoneal (ip) streptozotocin. The injections were repeated in the same dose after 24 h. Animals which had blood glucose at or above 300 mg/dl 6 days after the last injections were accepted as diabetic. Zinc was administrated ip for 4 weeks as 6 mg/kg/day per rat. Hepatic tissue samples taken from the animals at the end of the study were fixed in 95% ethyl alcohol. Cross sections of 5 µm thickness, taken by the help of a microtome from the tissue samples buried in paraffin, were placed on a microscope slide and stained with periodic acid-Schiff and evaluated by light microscope. All microscopic images were transferred to a PC and assessed with the help of Clemex PE3.5 image analysis software. The lowest liver glycogen levels in the study were obtained in groups 3, 4, 6, 7, and 8. Liver glycogen levels in group 5 were higher than groups 3, 4, 6, 7, and 8, but lower than groups 1 and 2 (p < 0.05). Groups 1 and 2 had the highest liver glycogen levels. The results obtained from the study indicate that liver glycogen levels which dropped in acute swimming exercise were restored by zinc administration and that diabetes induced in rats prevented the protective effect of zinc.

Effects of zinc deficiency on the vallate papillae and taste buds in rats.

PubMed

Chou, H C; Chien, C L; Huang, H L; Lu, K S

2001-05-01

Zinc deficiency is associated with multiple clinical complications, including taste disturbance, anorexia, growth retardation, skin changes, and hypogonadism. We investigated the zinc-deficiency-induced morphologic changes in the vallate taste buds of weanling and young adult male Wistar rats. A total of 24 weanling and 30 young adult rats were used. Each age group was further divided into a control group fed a zinc-adequate (50 ppm) diet, a zinc-deficient (< 1 ppm) diet group, and a zinc-adequate pair-fed group who were fed the same amount of food as that taken by the zinc-deficient group. Weanling rats were fed for 4 weeks and young adult rats were fed for 6 weeks. The morphometry and morphologic changes of vallate taste buds were analyzed using light and transmission electron microscopy. Light microscopy revealed no significant difference in papilla size and morphology among the various groups. In both weanling and young adult rats in the zinc-deficient diet and pair-fed groups, the number of taste buds per papilla (per animal) and the average profile area of the taste bud were significantly smaller than those of the corresponding controls (p < 0.05). Ultrastructural changes were seen only in the taste buds of weanling rats fed the zinc-deficient diet, with derangement of the architecture of the taste bud and widening of the intercellular space between taste bud cells. The proportion of type I taste bud cells in the taste buds of weanling rats fed the zinc-deficient diet decreased from 59% to 39%, and that of type II taste bud cells decreased from 25% to 12%. No obvious changes in the ultrastructure of type III taste bud cells were observed. The main effects of zinc deficiency in weanling and young adult rats and in adequate diet pair-fed rats were changes in the number and size of taste buds, and fine structure changes in the taste bud cells, especially during the accelerated growth stage after weaning.

Effect of Zinc and Melatonin on Oxidative Stress and Serum Inhibin-B Levels in a Rat Testicular Torsion-Detorsion Model.

PubMed

Semercioz, Atilla; Baltaci, Abdulkerim Kasim; Mogulkoc, Rasim; Avunduk, Mustafa Cihat

2017-12-01

The present study was aimed to examine the effects of 3-week zinc and melatonin administration on testicular tissue injury and serum Inhibin-B levels caused by unilateral testicular torsion-detorsion in rats. The study was performed on 60 Wistar Albino-type adult male rats. The animals were allocated to 6 groups in equal numbers. 1. Control; 2. Sham; 3. Ischemia-reperfusion; 4. Zinc + ischemia-reperfusion; 5. Melatonin + ischemia-reperfusion; 6. Zinc + melatonin + ischemia-reperfusion. Zinc and melatonin were administered before ischemia-reperfusion at doses of 5 and 3 mg/kg respectively, by intraperitoneal route for a period of 3 weeks. Testicular torsion-detorsion procedures consisted of ischemia for 1 h and then reperfusion for another hour of the left testis. Blood and testicular tissue samples were collected to analyze erythrocyte and tissue GSH and plasma and tissue MDA, Inhibin-B levels. The highest erythrocyte and testis GSH values were found in zinc, melatonin, and zinc + melatonin groups (p < 0.001). Torsion-detorsion group has significantly lower erythrocyte GSH levels and higher plasma MDA values (p < 0.001). Serum inhibin-B and spermatogenic activity levels in the torsion-detorsion group were also significantly lower than those in the other groups (p < 0.001). However, zinc-, melatonin-, and melatonin + zinc-supplemented groups have higher inhibin-B and spermatogenetic activity (p < 0.001). The results of the study show that zinc, melatonin, and melatonin + zinc administration partially restores the increased oxidative stress, as well as the reduced inhibin-B and spermatogenic activity levels in testes ischemia-reperfusion in rats. Suppressed inhibin-B levels in the testicular tissue may be a marker of oxidative stress.

Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ngoi, Kuan Hoon; Chia, Chin-Hua, E-mail: chia@ukm.edu.my; Zakaria, Sarani

2015-09-25

We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between sphericalmore » and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature.« less

Synthesis and characterization of starch-poly(methyl acrylate) graft copolymers using horseradish peroxidase.

PubMed

Wang, Su; Wang, Qiang; Fan, Xuerong; Xu, Jin; Zhang, Ying; Yuan, Jiugang; Jin, Heling; Cavaco-Paulo, Artur

2016-01-20

Horseradish peroxidase (HRP)-mediated graft polymerization in the presence of hydrogen peroxide (H2O2) and acetylacetone (Acac) has been successfully applied to the synthesis of starch-poly(methyl acrylate) (PMA). The graft copolymer was characterized by Fourier transform infrared (FT-IR), elemental analysis, nuclear magnetic resonance ((1)H NMR and (13)C NMR), and differential scanning calorimetry (DSC). FT-IR, elemental analysis and NMR confirmed that methyl acrylate (MA) was grafted onto starch successfully. DSC results showed the graft reaction had changed the crystalline regions of the gelatinized starch. The effects of pH, MA content, HRP dosage, incubation temperature and time on grafting percentage (GP) and grafting efficiency (GE) were also investigated. The GP and GE under optimal conditions reached 30.21% and 45.13%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electron spectroscopy imaging and surface defect configuration of zinc oxide nanostructures under different annealing ambient

NASA Astrophysics Data System (ADS)

Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd

2013-01-01

In this study, electron spectroscopy imaging was used to visualize the elemental distribution of zinc oxide nanopowder. Surface modification in zinc oxide was done through annealing treatment and type of surface defect was also inferred from the electron spectroscopy imaging investigation. The micrographs revealed the non-stoichiometric distribution of the elements in the unannealed samples. Annealing the samples in nitrogen and oxygen ambient at 700 °C would alter the density of the elements in the samples as a result of removal or absorption of oxygen. The electrical measurement showed that nitrogen annealing treatment improved surface electrical conductivity, whereas oxygen treatment showed an adverse effect. Observed change in the photoluminescence green emission suggested that oxygen vacancies play a significant role as surface defects. Structural investigation carried out through X-ray diffraction revealed the polycrystalline nature of both zinc oxide samples with hexagonal phase whereby annealing process increased the crystallinity of both zinc oxide specimens. Due to the different morphologies of the two types of zinc oxide nanopowders, X-ray diffraction results showed different stress levels in their structures and the annealing treatment give significant effect to the structural stress. Electron spectroscopy imaging was a useful technique to identify the elemental distribution as well as oxygen defect in zinc oxide nanopowder.

Complementary feeding: clinically relevant factors affecting timing and composition.

PubMed

Krebs, Nancy F; Hambidge, K Michael

2007-02-01

Exclusive breastfeeding for the first 6 mo of life followed by optimal complementary feeding are critical public health measures for reducing and preventing morbidity and mortality in young children. Clinical factors, such as birth weight, prematurity, and illness, that affect the iron and zinc requirements of younger infants are discussed. Maternal diet and nutritional status do not have a strong effect on the mineral content of human milk, but physiologic changes in milk and the infants' status determine the dependence of the infant on complementary foods in addition to human milk to meet iron and zinc requirements after 6 mo. The nature of zinc absorption, which is suitably characterized by saturation response modeling, dictates that plant-based diets, which are low in zinc, are associated with low absolute daily absorbed zinc, which is inadequate to meet requirements. Foods with a higher zinc content, such as meats, are much more likely to be sufficient to meet dietary requirements. Current plant-based complementary feeding patterns for older fully breastfed infants in both developed and developing countries pose a risk of zinc deficiency. The strong rationale for the potential benefits of providing meat as an early complementary food, and the examples of successful intervention programs, provide potent incentives to pursue broader implementation programs, with concurrent rigorous evaluation of both efficacy and effectiveness.

Efficient reductive elimination of bromate in water using zero-valent zinc prepared by acid-washing treatments.

PubMed

Lin, Kun-Yi Andrew; Lin, Chu-Hung; Lin, Jia-Yin

2017-10-15

Although zero valent zinc (ZVZ) is a strong reductant, studies using ZVZ for bromate reduction are rare. In this study, ZVZ is prepared by acid-washing zinc powder with HCl and used to reduce bromate. The effect of acid-washing on the morphology of zinc powder is also examined. Zinc powder inefficiently reduces bromate, but ZVZ obtained by acid-washing zinc powder eliminates bromate and converts it to bromide. A higher dose of ZVZ enhances elimination efficiency perhaps because the formation of a passivation layer of zinc oxide could be scattered on the large surface of ZVZ. Elevated temperature also substantially improves both elimination efficiency and kinetics. The effect of pH is shown to have the most significant impact on the bromate elimination; elimination efficiency and kinetics are tremendously bolstered at pH = 3, whereas the elimination of bromate is completely suppressed under alkaline conditions. ZVZ can reduce bromate to bromide even in the presence of other anions and also be reused multiple times. Thus, ZVZ can be easily prepared and used to efficiently reduce bromate to bromide. The findings presented here are essential to the design and implementation of bromate elimination in water using zero-valent metals. Copyright © 2017 Elsevier Inc. All rights reserved.

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

PubMed Central

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

2017-01-01

M-type (Kv7, KCNQ) potassium channels are proteins that control the excitability of neurons and muscle cells. Many physiological and pathological mechanisms of excitation operate via the suppression of M channel activity or expression. Conversely, pharmacological augmentation of M channel activity is a recognized strategy for the treatment of hyperexcitability disorders such as pain and epilepsy. However, physiological mechanisms resulting in M channel potentiation are rare. Here we report that intracellular free zinc directly and reversibly augments the activity of recombinant and native M channels. This effect is mechanistically distinct from the known redox-dependent KCNQ channel potentiation. Interestingly, the effect of zinc cannot be attributed to a single histidine- or cysteine-containing zinc-binding site within KCNQ channels. Instead, zinc dramatically reduces KCNQ channel dependence on its obligatory physiological activator, phosphatidylinositol 4,5-bisphosphate (PIP2). We hypothesize that zinc facilitates interactions of the lipid-facing interface of a KCNQ protein with the inner leaflet of the plasma membrane in a way similar to that promoted by PIP2. Because zinc is increasingly recognized as a ubiquitous intracellular second messenger, this discovery might represent a hitherto unknown native pathway of M channel modulation and provide a fresh strategy for the design of M channel activators for therapeutic purposes. PMID:28716904

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

PubMed

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

2017-08-01

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

Dynamic energy budget as a basis to model population-level effects of zinc-spiked sediments in the gastropod Valvata piscinalis.

PubMed

Ducrot, Virginie; Péry, Alexandre R R; Mons, Raphaël; Quéau, Hervé; Charles, Sandrine; Garric, Jeanne

2007-08-01

This paper presents original toxicity test designs and mathematical models that may be used to assess the deleterious effects of toxicants on Valvata piscinalis (Mollusca, Gastropoda). Results obtained for zinc, used as a reference toxicant, are presented. The feeding behavior, juvenile survival, growth, age at puberty, onset of reproduction, number of breedings during the life cycle, and fecundity were significantly altered when the snails were exposed to zinc-spiked sediments. Dynamic energy budget models (DEBtox) adequately predicted the effects of zinc on the V. piscinalis life cycle. They also provided estimates for lifecycle parameters that were used to parameterize a demographic model, based on a Z-transformed life-cycle graph. The effect threshold for the population growth rate (lambda) was estimated at 259 mg/kg dry sediment of zinc, showing that significant changes in abundance may occur at environmental concentrations. Significant effects occurring just above this threshold value were mainly caused by the severe impairment of reproductive endpoints. Sensitivity analysis showed that the value of lambda depended mainly on the juvenile survival rate. The impairment of this latter parameter may result in extinction of V. piscinalis. Finally, the present study highlights advantages of the proposed modeling approach in V. piscinalis and possible transfer to other test species and contaminants.

Effects of heavy metals on sea urchin embryo development. Part 2. Interactive toxic effects of heavy metals in synthetic mine effluents.

PubMed

Kobayashi, Naomasa; Okamura, Hideo

2005-12-01

Interactive toxic effects between heavy metals were investigated using a sea urchin (Anthocidaris crassispina) bioassay. An effluent from an abandoned mine showed significant inhibitory effects on embryo development as well as producing specific malformations. The effects on the embryos were reproduced by synthetic polluted seawater consisting of eight metals (manganese, lead, cadmium, nickel, zinc, chromium, iron, and copper) at the concentrations detected in the mine effluent. This indicated that the heavy metals were responsible for the effects observed. Five heavy metals were ranked in decreasing order of toxicity as follows: Cu>Zn>Pb>Fe>Mn. Among these, zinc and manganese could cause malformation of the embryos. From bioassay results using 27 combinations of heavy metals, 16 combinations including zinc could produce specific malformations, such as radialized, exo-gastrulal, and spaceship Apollo-like gastrulal embryos. Zinc was one of the elements responsible for causing malformations and its effects were intensified by the presence of the other metals, such as manganese, lead, iron, and copper.

Performance of Flow and Heat Transfer in a Hot-Dip Round Coreless Galvanizing Bath

NASA Astrophysics Data System (ADS)

Yue, Qiang; Zhang, Chengbo; Xu, Yong; Zhou, Li; Kong, Hui; Wang, Jia

2017-04-01

Flow field in a coreless hot-dip galvanizing pot was investigated through a water modeling experiment. The corresponding velocity vector was measured using an acoustic Doppler velocimeter. The flow field of molten zinc in the bath was also analyzed. Steel strip velocities from 1.7 to 2.7 m/s were adopted to determine the effect of steel strip velocity on the molten zinc flow in the bath. A large vortex filled the space at the right side of the sink roll, under linear speed from 1.0 to 2.7 m/s and width from 1.0 to 1.3 m of the steel strip, because of the effects of wall and shear stress. The results of the water modeling experiment were compared with those of numerical simulations. In the simulation, Maxwell equations were solved using finite element method to obtain magnetic flux density, electromagnetic force, and Joule heating. The Joule heating rate reached the maximum and minimum values near the side wall and at the core of the bath, respectively, because of the effect of skin and proximity. In an industrial-sized model, the molten zinc flow and temperature fields driven by electromagnetic force and Joule heating in the inductor of a coreless galvanizing bath were numerically simulated. The results indicated that the direction of electromagnetic force concentrated at the center of the galvanizing pot horizontal planes and exerted a pinch effect on molten zinc. Consequently, molten zinc in the pot was stirred by electromagnetic force. Under molten zinc flow and electromagnetic force stirring, the temperature of the molten zinc became homogeneous throughout the bath. This study provides a basis for optimizing electromagnetic fields in coreless induction pot and fine-tuning the design of steel strip parameters.

Effects of sediment-bound zinc contamination on early life stages of the mummichog (Fundulus heteroclitus L.) in the Christina watershed, Delaware, U.S.A.

PubMed

Guy, Christopher Paul; Pinkney, Alfred Eli; Taylor, Malcolm Herbert

2006-05-01

During the last century, the Christina River, the major estuarine river system in New Castle County (DE, USA), has received loadings of organic and inorganic chemicals, primarily from manufacturing facilities. Among the most abundant chemicals is zinc, which has accumulated in sediments at concentrations as high as 5,440 mg/kg. We studied the possible effects of zinc on early life stages of the mummichog (Fundulus heteroclitus), a resident species in the river and watershed. We conducted three different types of exposures. The first was a 96-h median lethal concentration (LC50) test with larvae exposed to waterborne zinc. The second was a larval exposure with zinc-spiked sediments (obtained from the relatively uncontaminated Magothy River in Anne Arundel County, MD, USA). The third was an embryo-larval exposure with Christina River sediments having a gradient of zinc concentrations. The average 96-h LC50 with newly hatched yolk sac larvae was 970 lig/L. In the larval tests, the average 7- and 21-d LC50s were 1154 and 1012 mg/kg, respectively. In the embryo-larval test, no significant difference was found in survival at concentrations between 38.8 and 1098 mg/kg. However, significant reductions were observed in condition factor at concentrations of 582, 799, and 1098 mg/kg. We calculated an average no-observed-effects concentration of 579 mg/kg and an average lowest-observed-effects concentration of 849 mg/kg for larval survival. Based on these results, we suggest that zinc in the Christina River may be affecting early life stages of the mummichog.

Zinc and linoleic acid pre-treatment attenuates biochemical and histological changes in the midbrain of rats with rotenone-induced Parkinsonism.

PubMed

Mbiydzenyuy, Ngala Elvis; Ninsiima, Herbert Izo; Valladares, Miriela Betancourt; Pieme, Constant Anatole

2018-05-09

Studies have suggested the supplementation of Zinc and Linoleic acid in the management of neurodegenerative disorders but none has investigated the combined effects. Little is known about the neuroprotective effects of either Zinc or Linoleic acid or their combination against development of Parkinsonism. This study was designed to investigate the neuroprotective effects of Zinc and Linoleic acid in rotenone-induced Parkinsonism in rats. Thirty-six young adult female rats weighing 100-150 g divided into six groups were used. Rats were induced with Parkinsonism by subcutaneous administration of rotenone (2.5 mg/kg) once a day for seven consecutive days. The rats received dimethyl sulfoxide (DMSO)/Olive oil or rotenone dissolved in DMSO/Olive oil. Groups III and IV received Zinc (30 mg/kg) or Linoleic acid (150 µl/kg) while group V received a combination of both, 2 weeks prior to rotenone injection. Groups II and VI served as negative (rotenone group) and positive (Levodopa groups) controls respectively. Oxidative stress levels were assessed by estimating Lipid peroxidation (MDA), total antioxidant capacity, Superoxide dismutase, reduced Glutathione (GSH), glutathione peroxidase and catalase in the midbrain. Histological examination was done to assess structural changes in the midbrain. There was a significant prevention in lipid peroxidation and decrease in the antioxidant status in intervention-treated groups as compared to the rotenone treated group. In addition, histological examination revealed that Parkinsonian rat brains exhibited neuronal damage. Cell death and reduction in neuron size induced by rotenone was prevented by treatment with zinc, linoleic acid and their combination. These results suggest that zinc and linoleic acid and their combination showed significant neuroprotective activity most likely due to the antioxidant effect.

Investigation into the role of primer, pre-treatments and coating microstructure in preventing cut edge corrosion of organically coated steels

NASA Astrophysics Data System (ADS)

Khan, Khalil

Investigations were carried out to assess the role of primer, pretreatments and coating microstructure in preventing cutedge corrosion of chrome free organically coated steels. Zinc runoff was monitored from a range of organically coated steels with a large cutedge length exposed over 18 months at Swansea University roof top site. The zinc in the runoff leaches from the zinc-aluminium alloy coating of the substrate. The paint systems' corrosion performance was assessed by monitoring the levels of zinc in the runoff. Consequently the levels of zinc reflected the effectiveness of the applied paint system against corrosion. Runoff was high in initial months with zinc levels reducing with time due to the build up of corrosion products that hindered the progress of corrosion. An accelerated laboratory test using a distilled water electrolyte was developed that predict long-term external weathering runoff from panels of a range of organically coated steels. The corrosion mechanisms of a variety of organically coated Galvalloy steel have been examined using the scanning vibrating electrode technique (SVET) in 0.1%NaCI. The corrosion behaviour of a coating is related to the zinc-aluminium alloy coating structure and combination of pretreatment and primer. The SVET has been used to assess total zinc loss and the corrosion rate for a comparative measure of organically coating system performance. A correlation has been developed from SVET 24hour experiment data to accelerated weathering data and external weather data that can aid more accurately predicting the in service life of the product. Also considered were the effects of electrolyte conductivity on the morphology of corrosion on pure zinc. A mathematical model has been developed to predict corrosion pit population. Altered microstructure of solidifying zinc aluminium alloy melt via ultrasonication was investigated. Ultrasound irradiation significantly altered the final microstructure. The influence of morphed microstructure upon the corrosion behaviour was explored using the SVET in 0.1%NaCI. The ultrasound manipulated microstructure had generally a positive effect on the corrosion behaviour.

Inhibition of orally produced volatile sulfur compounds by zinc, chlorhexidine or cetylpyridinium chloride--effect of concentration.

PubMed

Young, Alix; Jonski, Grazyna; Rölla, Gunnar

2003-10-01

Zinc ions, chlorhexidine (CHX) and cetylpyridinium chloride (CPC) are all known to inhibit production of volatile sulfur compounds (VSCs). The objective was to examine the anti-VSC dose-response effects of each of the above agents. Oral malodor was induced in 13 test subjects using the cysteine challenge method. The oral VSC response to rinses with 6 mm l-cysteine (pH 7.2) before and 1, 2 and 3 h after rinsing with zinc ions (Zn2+: 0.1, 0.3 and 1.0%), CHX and CPC (0.025 and 0.2%) was measured. Mouth air was analysed for VSC by gas chromatography (GC) according to current methodology. Zinc had a marked dose- and time-dependent anti-VSC effect. Zinc at 1% concentration had a somewhat unpleasant taste, whereas the lowest concentration was found acceptable. Chlorhexidine maintained a moderate anti-VSC effect over time. At 3 h, 0.2% CHX was the most effective agent but tasted relatively unpleasant. Cetylpyridinium at a concentration of 0.2% was only marginally more effective than 0.025% CHX over the 3 h, while 0.025% CPC had no better anti-VSC effect than water at both 2 h and 3 h. It was concluded that the three test agents demonstrated different anti-VSC kinetics. Although Zn had the best anti-VSC effect at 1 h, 0.2% CHX was at least as effective as 1% Zn at 3 h, most likely as a result of its unique substantivity.

Nutrition intervention strategies to combat zinc deficiency in developing countries.

PubMed

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. In the future, dietary modification/diversification, although long term, may be the preferred strategy because it is more sustainable, economically feasible, culturally acceptable, and equitable, and can be used to alleviate several micronutrient deficiencies simultaneously, without danger of inducing antagonistic micronutrient interactions. Appropriate dietary strategies include consumption of zinc-dense foods and those known to enhance zinc absorption, reducing the phytic acid content of plant based staples via enzymic hydrolysis induced by germination/fermentation or nonenzymic hydrolysis by soaking or thermal processing. All the strategies outlined above should be integrated with ongoing national food, nutrition and health education programmes, to enhance their effectiveness and sustainability, and implemented using nutrition education and social marketing techniques. Ultimately the success of any approach for combating zinc deficiency depends on strong advocacy, top level commitment, a stable infrastructure, long term financial support and the capacity to control quality and monitor and enforce compliance at the national or regional level. To be cost effective, costs for these strategies must be shared by industry, government, donors and consumers.

In vitro and in vivo effects of zinc on cytokine signalling in human T cells.

PubMed

Varin, Audrey; Larbi, Anis; Dedoussis, George V; Kanoni, Stavroula; Jajte, Jolanta; Rink, Lothar; Monti, Daniela; Malavolta, Marco; Marcellini, Fiorella; Mocchegiani, Eugenio; Herbein, Georges; Fulop, Tamas

2008-05-01

Aging is associated with changes in the immune response which are collectively called immunosenescence. The changes mainly affect the adaptive immune response and especially the T cell-mediated cellular immune response. There are a few data indicating that the cytokine signalling in T cells is altered with aging. Zinc has been specifically shown to have potent immunomodulatory effects. The aim of the present work was to study the IL-2 and IL-6 cytokine signalling and activation induced cell death (AICD) in T cells of elderly subjects of various ages and from various European countries. These experiments were performed in the frame of European Community financed project called ZINCAGE "Nutritional zinc, oxidative stress and immunosenescence: biochemical, genetic and lifestyle implications for healthy ageing", assembling 17 laboratories from 8 countries through Europe. The study was carried out in a total of 312 French and a group of 201 (26 from Italy, 63 from France, 57 from Greece, 24 from Poland and 30 from Germany) healthy non-institutionalized men and women older than 60 years of age, with available dietary data. Human peripheral blood mononuclear cells (PBMC) were obtained from heparinized blood and were stimulated in vitro by IL-2 or IL-6 for various periods and the phosphorylation of STAT3 and STAT5 was measured by FACScan. The activation induced cell death (AICD) was measured after anti-CD3 and CD28 restimulation for 48h by using the Annexin:FITC Apoptosis Kit. We found that there is an IL-2 signalling defect with aging up to 90 years of age which cannot be modulated by zinc. In contrast at 90 years and over the zinc could reverse the negative signalling effect of IL-2. There is also a signalling defect for STAT3 and STAT5 activation in T cells under IL-6 stimulation with aging and the zinc supplementation could potentiate only the STAT5 activation in the age-group 90 years and over. Studying signalling in PBL from different countries we detected less activation in T cells of subjects from France and the most changes occurred in T cells of subjects from Poland, suggesting no correlation with the plasma zinc status observed in these countries. In vivo zinc supplementation had no effect on IL-2 and IL-6-modulated STAT3 and STAT5 activation. Zinc added in vitro to these T cells even inhibited the stimulation either by IL-2 or by IL-6. Zinc supplementation improved the susceptibility of T cells to AICD in both age-groups, with more efficiency in later ages. Our results suggest that zinc can have a potent immunomodulatory effect via the modulation of cytokine signalling and AICD, however this effect depends on the function and the activation status of the T cells.

Subacute Zinc Administration and L-NAME Caused an Increase of NO, Zinc, Lipoperoxidation, and Caspase-3 during a Cerebral Hypoxia-Ischemia Process in the Rat

PubMed Central

Blanco-Alvarez, Victor Manuel; Lopez-Moreno, Patricia; Soto-Rodriguez, Guadalupe; Martinez-Fong, Daniel; Rubio, Hector; Gonzalez-Barrios, Juan Antonio; Piña-Leyva, Celia; Torres-Soto, Maricela; Gomez-Villalobos, María de Jesus; Hernandez-Baltazar, Daniel; Eguibar, José Ramon; Ugarte, Araceli; Cebada, Jorge

2013-01-01

Zinc or L-NAME administration has been shown to be protector agents, decreasing oxidative stress and cell death. However, the treatment with zinc and L-NAME by intraperitoneal injection has not been studied. The aim of our work was to study the effect of zinc and L-NAME administration on nitrosative stress and cell death. Male Wistar rats were treated with ZnCl2 (2.5 mg/kg each 24 h, for 4 days) and N-ω-nitro-L-arginine-methyl ester (L-NAME, 10 mg/kg) on the day 5 (1 hour before a common carotid-artery occlusion (CCAO)). The temporoparietal cortex and hippocampus were dissected, and zinc, nitrites, and lipoperoxidation were assayed at different times. Cell death was assayed by histopathology using hematoxylin-eosin staining and caspase-3 active by immunostaining. The subacute administration of zinc before CCAO decreases the levels of zinc, nitrites, lipoperoxidation, and cell death in the late phase of the ischemia. L-NAME administration in the rats treated with zinc showed an increase of zinc levels in the early phase and increase of zinc, nitrites, and lipoperoxidation levels, cell death by necrosis, and the apoptosis in the late phase. These results suggest that the use of these two therapeutic strategies increased the injury caused by the CCAO, unlike the alone administration of zinc. PMID:23997853

LiZIP3 is a cellular zinc transporter that mediates the tightly regulated import of zinc in Leishmania infantum parasites

PubMed Central

Carvalho, Sandra; da Silva, Rosa Barreira; Shawki, Ali; Castro, Helena; Lamy, Márcia; Eide, David; Costa, Vítor; Mackenzie, Bryan; Tomás, Ana M.

2016-01-01

Summary Cellular zinc homeostasis ensures that the intracellular concentration of this element is kept within limits that enable its participation in critical physiological processes without exerting toxic effects. We report here the identification and characterization of the first mediator of zinc homeostasis in Leishmania infantum, LiZIP3, a member of the ZIP family of divalent metal-ion transporters. The zinc transporter activity of LiZIP3 was first disclosed by its capacity to rescue the growth of Saccharomyces cerevisiae strains deficient in zinc acquisition. Subsequent expression of LiZIP3 in Xenopus laevis oocytes was shown to stimulate the uptake of a broad range of metal ions, among which Zn2+ was the preferred LiZIP3 substrate (K0.5 ≈ 0.1 μM). Evidence that LiZIP3 functions as a zinc importer in L. infantum came from the observations that the protein locates to the cell membrane and that its overexpression leads to augmented zinc internalization. Importantly, expression and cell-surface location of LiZIP3 are lost when parasites face high zinc bioavailability. LiZIP3 decline in response to zinc is regulated at the mRNA level in a process involving (a) short-lived protein(s). Collectively, our data reveal that LiZIP3 enables L. infantum to acquire zinc in a highly regulated manner, hence contributing to zinc homeostasis. PMID:25644708

The role of zinc plus octenidine in the regulation of gene expression: an in vitro study.

PubMed

Lauritano, D; Candotto, V; Bignozzi, C A; Pazzi, D; Carinci, F; Cura, F; Tagliabue, A; Tettamanti, L

2018-01-01

Zinc was known in ancient times, and is diffused in the environment. The potential benefits offered by zinc supplementary therapy have been demonstrated in numerous clinical trials using oral or topical zinc products. The benefit of zinc can be in principle increased through association with other actives. The aim of this study is to evaluate the effect on primary human gingival fibroblast cell of a new formulation containing zinc and octenidine cations. Human gingival fibroblast cells were obtained from three healthy patients (14-year-old man, 15-year-old woman and 20-year-old man) during extraction of teeth. The gene expression of 14 genes (ELANE, FN1, FBN, ITGA1, HAS1, ELN, DSP, ITGB1, HYAL1,TGFB1, TGFB2, TGFB3, TGFBR1 and TGFBR2) was investigated in HGF cell culture treated with 80μm of Octenidine, 1000μm of Zinc, 80μm Octenidine + Zinc solution and the medium alone at 30 min. Prestoblue™ data showed that as the active concentration increases (Octenidine, Zinc and Octenidine + Zinc) the percentage of cell vitality compared to that of untreated cells decrease. In this study, no statistically significant gene expression was observed between cells, treated with difference substances, and control cells. Our results points out that zinc plus octenidine shows a positive potential in periodontal disease treatment.

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

PubMed

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 deficiency enhanced inflammatory response by increasing immune cell activation and inducing IL6 promoter demethylation

PubMed Central

Wong, Carmen P.; Rinaldi, Nicole A.; Ho, Emily

2015-01-01

Scope Zinc deficiency results in immune dysfunction and promotes systemic inflammation. The objective of this study was to examine the effects of zinc deficiency on cellular immune activation and epigenetic mechanisms that promote inflammation. This work is potentially relevant to the aging population given that age-related immune defects, including chronic inflammation, coincide with declining zinc status. Methods and results An in vitro cell culture system and the aged mouse model were used to characterize immune activation and DNA methylation profiles that may contribute to the enhanced proinflammatory response mediated by zinc deficiency. Zinc deficiency up-regulated cell activation markers ICAM1, MHC class II, and CD86 in THP1 cells, that coincided with increased IL1β and IL6 responses following LPS stimulation. A decreased zinc status in aged mice was similarly associated with increased ICAM1 and IL6 gene expression. Reduced IL6 promoter methylation was observed in zinc deficient THP1 cells, as well as in aged mice and human lymphoblastoid cell lines derived from aged individuals. Conclusion Zinc deficiency induced inflammatory response in part by eliciting aberrant immune cell activation and altered promoter methylation. Our results suggested potential interactions between zinc status, epigenetics, and immune function, and how their dysregulation could contribute to chronic inflammation. PMID:25656040

Status of zinc injection in PWRs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergmann, C.A.

1995-03-01

Based on laboratory and other studies, it was concluded that zinc addition in a PWR primary coolant should result in reduced Alloy 600 PWSCC and general corrosion rates of the materials of construction. Because of these positive results, a Westinghouse Owner`s Subgroup, EPRI, and Westinghouse provided funds to continue the development and application of zinc in an operating plant. As part of the program, Southern Operating Nuclear Company agreed to operate the Farley 2 plant with zinc addition as a demonstration test of the effectiveness of zinc. Since zinc is incorporated in the corrosion oxide film on the primary systemmore » surfaces and Farley 2 is a mature plant, it was estimated that about 10 kgs of zinc would be needed to condition the plant before an equilibrium value in the coolant would be reached. The engineered aspects of a Zinc Addition and Monitoring System (ZAMS) considered such items as the constitutents, location, sizing and water supply of the ZAMS. Baseline data such as the PWSCC history of the Alloy 600 steam generator tubing, fuel oxide thickness, fuel crud deposits, radiation levels, and RCP seal leak-off rates were obtained before zinc addition is initiated. This presentation summarizes some of the work performed under the program, and the status of zinc injection in the Farley 2 plant.« less

Modeling the temporal variability of zinc concentrations in zinc roof runoff-experimental study and uncertainty analysis.

PubMed

Sage, Jérémie; El Oreibi, Elissar; Saad, Mohamed; Gromaire, Marie-Christine

2016-08-01

This study investigates the temporal variability of zinc concentrations from zinc roof runoff. The influence of rainfall characteristics and dry period duration is evaluated by combining laboratory experiment on small zinc sheets and in situ measurements under real weather conditions from a 1.6-m(2) zinc panel. A reformulation of a commonly used conceptual runoff quality model is introduced and its ability to simulate the evolution of zinc concentrations is evaluated. A systematic and sharp decrease from initially high to relatively low and stable zinc concentrations after 0.5 to 2 mm of rainfall is observed for both experiments, suggesting that highly soluble corrosion products are removed at early stages of runoff. A moderate dependence between antecedent dry period duration and the magnitude of zinc concentrations at the beginning of a rain event is evidenced. Contrariwise, results indicate that concentrations are not significantly influenced by rainfall intensities. Simulated rainfall experiment nonetheless suggests that a slight effect of rainfall intensities may be expected after the initial decrease of concentrations. Finally, this study shows that relatively simple conceptual runoff quality models may be adopted to simulate the variability of zinc concentrations during a rain event and from a rain event to another.

Advantages and limitations of in vitro and in vivo methods of iron and zinc bioavailability evaluation in the assessment of biofortification program effectiveness

USDA-ARS?s Scientific Manuscript database

Biofortification aims to improve the micronutrient concentration of staple food crops through the best practices of breeding and modern biotechnology. However, increased zinc and iron concentrations in food crops may not always translate into proportional increases in absorbed zinc (Zn) and iron (Fe...

Effect of Zinc Phosphate on the Corrosion Behavior of Waterborne Acrylic Coating/Metal Interface

PubMed Central

Wan, Hongxia; Song, Dongdong; Li, Xiaogang; Zhang, Dawei; Gao, Jin; Du, Cuiwei

2017-01-01

Waterborne coating has recently been paid much attention. However, it cannot be used widely due to its performance limitations. Under the specified conditions of the selected resin, selecting the function pigment is key to improving the anticorrosive properties of the coating. Zinc phosphate is an environmentally protective and efficient anticorrosion pigment. In this work, zinc phosphate was used in modifying waterborne acrylic coatings. Moreover, the disbonding resistance of the coating was studied. Results showed that adding zinc phosphate can effectively inhibit the anode process of metal corrosion and enhance the wet adhesion of the coating, and consequently prevent the horizontal diffusion of the corrosive medium into the coating/metal interface and slow down the disbonding of the coating. PMID:28773013

Effect of Zinc-Deficient Diet on Oral Tissues and Periodontal Indices in Rats

PubMed Central

Seyedmajidi, Seyed Ali; Seyedmajidi, Maryam; Moghadamnia, Aliakbar; Khani, Zohreh; Zahedpasha, Samir; Jenabian, Niloofar; Jorsaraei, Gholamali; Halalkhor, Sohrab; Motallebnejad, Mina

2014-01-01

Zinc (Zn) as a nutritional factor affects the health of the oral tissues. This study was done for the evaluation of the effects of zinc deficiency on the oral tissues of rats. The study was carried out on 14 male Wistar rats, cessation of lactation on the 24th day after birth. The rats were randomly divided into two groups. Zinc deficient (ZD) diet was used for one group and another group was fed with a zinc-containing (ZC) diet. The alterations of the oral tissues in both groups were evaluated clinically after four weeks. Also the gingival index and periodontal pocket depth were recorded. The measurement of serum zinc level was done by atomic absorption spectrophotometry. The microscopic slides of oral tissue specimen were evaluated quantitatively. The serum zinc level of the ZD rats was lower than the ZC group (p< 0.001). According clinical findings, the gingival index was lower in ZC rat (p=0.001), but there was no significant difference regarding the periodontal pocket depth between two groups (p=0.07). Aphthous ulcer was observed in ZD rats on the floor of the mouth. There was no significant difference regarding the epithelial and keratin thickening between two groups. This study indicated that oral and periodontal health was better in ZC rats than in ZD rats. Aphthous lesions were more prominent in ZD rats. This study confirmed that zinc deficiency may endanger oral and periodo ntal structures. PMID:25035857

Influence of extracellular zinc on M1 microglial activation

PubMed Central

Higashi, Youichirou; Aratake, Takaaki; Shimizu, Shogo; Shimizu, Takahiro; Nakamura, Kumiko; Tsuda, Masayuki; Yawata, Toshio; Ueba, Tetuya; Saito, Motoaki

2017-01-01

Extracellular zinc, which is released from hippocampal neurons in response to brain ischaemia, triggers morphological changes in microglia. Under ischaemic conditions, microglia exhibit two opposite activation states (M1 and M2 activation), which may be further regulated by the microenvironment. We examined the role of extracellular zinc on M1 activation of microglia. Pre-treatment of microglia with 30–60 μM ZnCl2 resulted in dose-dependent increases in interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNFα) secretion when M1 activation was induced by lipopolysaccharide administration. In contrast, the cell-permeable zinc chelator TPEN, the radical scavenger Trolox, and the P2X7 receptor antagonist A438079 suppressed the effects of zinc pre-treatment on microglia. Furthermore, endogenous zinc release was induced by cerebral ischaemia–reperfusion, resulting in increased expression of IL-1β, IL-6, TNFα, and the microglial M1 surface marker CD16/32, without hippocampal neuronal cell loss, in addition to impairments in object recognition memory. However, these effects were suppressed by the zinc chelator CaEDTA. These findings suggest that extracellular zinc may prime microglia to enhance production of pro-inflammatory cytokines via P2X7 receptor activation followed by reactive oxygen species generation in response to stimuli that trigger M1 activation, and that these inflammatory processes may result in deficits in object recognition memory. PMID:28240322

Thiol Versus Hydroxamate as Zinc Binding Group In HDAC Inhibition: An Ab Initio QM/MM Molecular Dynamics Study

PubMed Central

Gong, Wenjing; Wu, Ruibo; Zhang, Yingkai

2015-01-01

Zinc-dependent histone deacetylases (HDACs) play a critical role in transcriptional repression and gene silencing, and are among the most attractive targets for the development of new therapeutics against cancer and various other diseases. Two HDAC inhibitors have been approved by FDA as anti-cancer drugs: one is SAHA whose hydroxamate is directly bound to zinc, the other is FK228 whose active form may use thiol as the zinc binding group. In spite of extensive studies, it remains to be ambiguous regarding how thiol and hydroxamate are bound to the zinc active site of HDACs. In this work, our computational approaches center on Born-Oppenheimer ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics with umbrella sampling, which allow for modeling of the zinc active site with reasonable accuracy while properly including dynamics and effects of protein environment. Meanwhile, an improved short-long effective function (SLEF2) to describe non-bonded interactions between zinc and other atoms has been employed in initial MM equilibrations. Our ab initio QM/MM MD simulations have confirmed that hydroxamate is neutral when it is bound to HDAC8, and found that thiol is deprotonated when directly bound to zinc in the HDAC active site. By comparing thiol and hydroxamate, our results elucidated the differences in their binding environment in the HDAC active sites, and emphasized the importance of the linker design to achieve more specific binding towards class IIa HDACs. PMID:26452222

Increased Zinc Availability Enhances Initial Aggregation and Biofilm Formation of Streptococcus pneumoniae.

PubMed

Brown, Lindsey R; Caulkins, Rachel C; Schartel, Tyler E; Rosch, Jason W; Honsa, Erin S; Schultz-Cherry, Stacey; Meliopoulos, Victoria A; Cherry, Sean; Thornton, Justin A

2017-01-01

Bacteria growing within biofilms are protected from antibiotics and the immune system. Within these structures, horizontal transfer of genes encoding virulence factors, and promoting antibiotic resistance occurs, making biofilms an extremely important aspect of pneumococcal colonization and persistence. Identifying environmental cues that contribute to the formation of biofilms is critical to understanding pneumococcal colonization and infection. Iron has been shown to be essential for the formation of pneumococcal biofilms; however, the role of other physiologically important metals such as copper, zinc, and manganese has been largely neglected. In this study, we investigated the effect of metals on pneumococcal aggregation and early biofilm formation. Our results show that biofilms increase as zinc concentrations increase. The effect was found to be zinc-specific, as altering copper and manganese concentrations did not affect biofilm formation. Scanning electron microscopy analysis revealed structural differences between biofilms grown in varying concentrations of zinc. Analysis of biofilm formation in a mutant strain lacking the peroxide-generating enzyme pyruvate oxidase, SpxB, revealed that zinc does not protect against pneumococcal H 2 O 2 . Further, analysis of a mutant strain lacking the major autolysin, LytA, indicated the role of zinc as a negative regulator of LytA-dependent autolysis, which could affect biofilm formation. Additionally, analysis of cell-cell aggregation via plating and microscopy revealed that high concentrations of zinc contribute to intercellular interaction of pneumococci. The findings from this study demonstrate that metal availability contributes to the ability of pneumococci to form aggregates and subsequently, biofilms.

Thiol versus hydroxamate as zinc binding group in HDAC inhibition: An ab initio QM/MM molecular dynamics study.

PubMed

Gong, Wenjing; Wu, Ruibo; Zhang, Yingkai

2015-11-15

Zinc-dependent histone deacetylases (HDACs) play a critical role in transcriptional repression and gene silencing, and are among the most attractive targets for the development of new therapeutics against cancer and various other diseases. Two HDAC inhibitors have been approved by FDA as anti-cancer drugs: one is SAHA whose hydroxamate is directly bound to zinc, the other is FK228 whose active form may use thiol as the zinc binding group. In spite of extensive studies, it remains to be ambiguous regarding how thiol and hydroxamate are bound to the zinc active site of HDACs. In this work, our computational approaches center on Born-Oppenheimer ab initio quantum mechanical/molecular mechanical (QM/MM) molecular dynamics with umbrella sampling, which allow for modeling of the zinc active site with reasonable accuracy while properly including dynamics and effects of protein environment. Meanwhile, an improved short-long effective function (SLEF2) to describe non-bonded interactions between zinc and other atoms has been employed in initial MM equilibrations. Our ab initio QM/MM MD simulations have confirmed that hydroxamate is neutral when it is bound to HDAC8, and found that thiol is deprotonated when directly bound to zinc in the HDAC active site. By comparing thiol and hydroxamate, our results elucidated the differences in their binding environment in the HDAC active sites, and emphasized the importance of the linker design to achieve more specific binding toward class IIa HDACs. © 2015 Wiley Periodicals, Inc.

Utilization of household organic compost in zinc adsorption system

NASA Astrophysics Data System (ADS)

Cundari, Lia; Isvaringga, Nyiayu Dita; Arinda, Yesica Maharani

2017-11-01

Zinc (Zn) is one of the heavy metals which is polluted to the environment in an amount greater than 15 mg/L [1]. Zinc contamination caused by the disposal of industrial waste such as batteries, electroplating, paint and other industries. One of the Zinc recovery technique that is relatively inexpensive, simple, high effectiveness and efficiency, and can be regenerated is adsorption using compost. This study has been carried out the preparation of compost from organic household waste and cow manure and its application to Zinc recovery. In this research, the raw material of compost is varied. There is an organic household waste (A1) and a mixture of organic household waste and cow manure with ratio 7:6 (A2). Decomposition of A1 and A2 with addition Effective Microorganism (EM4) requires 21 days, with 3 times inversion. Zinc adsorption is done by using a compost variation of 0.5 g, 1 g, and 2 g in every 100 and 200 mg/L Zn concentration solution. The batch process is applied to analyze the capacity of adsorption. Determination of capacity of adsorption based on the Langmuir, Freundlich, and Temkin isotherm model. Direct observation and spectrophotometry are applied in research methodology. The results show that compost A1 and A2 have fulfilled Indonesian Standart of compost and have the ability to reduce Zinc concentration to 94-96%. It indicates highly recommended biosorbent that can be applied to Zinc adsorption.

Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes.

PubMed

Lee, Sook-Jeong; Koh, Jae-Young

2010-10-26

Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress.Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity.The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the pathogenesis of various neurological diseases, further insight into the contribution of zinc dynamics and metallothionein-3 function may help provide ways to effectively regulate these processes in brain cells.

Zinc Extraction from Zinc Plants Residue Using Selective Alkaline Leaching and Electrowinning

NASA Astrophysics Data System (ADS)

Ashtari, Pedram; Pourghahramani, Parviz

2015-10-01

Annually, a great amount of zinc plants residue is produced in Iran. One of them is hot filter cake (known as HFC) which can be used as a secondary resource of zinc, cobalt and manganese. Unfortunately, despite its heavy metal content, the HFC is not treated. For the first time, zinc was selectively leached from HFC employing alkaline leaching. Secondly, leaching was optimized to achieve maximum recovery using this method. Effects of factors like NaOH concentration (C = 3, 5, 7 and 9 M), temperature (T = 50, 70, 90 and 105 °C), solid/liquid ratio (weight/volume, S/L = 1/10 and 1/5 W/V) and stirring speed (R = 500 and 800 rpm) were studied on HFC leaching. L16 orthogonal array (OA, two factors in four levels and two factors in two levels) was applied to determine the optimum condition and the most significant factor affecting the overall zinc extraction. As a result, maximum zinc extraction was 83.4 %. Afterwards, a rough test was conducted for zinc electrowinning from alkaline solution according to the common condition available in literature by which pure zinc powder (99.96 %) was successfully obtained.

Zinc and copper balances in healthy adult males during and after 17 wk of bed rest

NASA Technical Reports Server (NTRS)

Krebs, J. M.; Schneider, V. S.; LeBlanc, A. D.; Kuo, M. C.; Spector, E.; Lane, H. W.

1993-01-01

The effects of long-term bed rest on zinc and copper balances were measured in seven healthy men. Volunteers aged 22-54 y (mean +/- SD, 34 +/- 12 y), 168-185 cm in height (173 +/- 5 cm), and 64-86 kg in weight (74 +/- 9 kg) remained on a metabolic ward for 29 wk. Subjects were ambulatory during weeks 1-5, remained in continuous bed rest for weeks 6-22, and were reambulated during weeks 23-29. Copper and zinc were measured in weekly urine and fecal composites. Dietary intakes provided (mean +/- SD) 19.2 +/- 1.2 mumol Cu (1.22 +/- 0.08 mg), 211 +/- 11 mumol Zn (13.81 +/- 0.72 mg), 25.2 +/- 1.2 mmol Ca (1011 +/- 46 mg), 1086 +/- 46 mmol N (15.21 +/- 0.65 g), and 48.1 +/- 1.4 mmol K (1489 +/- 44 mg)/d. Bed rest increased fecal zinc excretion and decreased zinc balance, whereas copper balance was unchanged. Reambulation decreased fecal zinc excretion and increased both zinc and copper balances. These results suggest that during long-term bed rest or space flight, individuals will lose total body zinc and will retain more zinc and copper when they reambulate.

Cobalt- and iron-based nanoparticles hosted in SBA-15 mesoporous silica and activated carbon from biomass: Effect of modification procedure

NASA Astrophysics Data System (ADS)

Tsoncheva, Tanya; Genova, Izabela; Paneva, Daniela; Dimitrov, Momtchil; Tsyntsarski, Boyko; Velinov, Nicolay; Ivanova, Radostina; Issa, Gloria; Kovacheva, Daniela; Budinova, Temenujka; Mitov, Ivan; Petrov, Narzislav

2015-10-01

Ordered mesoporous silica of SBA-15 type and activated carbon, prepared from waste biomass (peach stones), are used as host matrix of nanosized iron and cobalt particles. The effect of preparation procedure on the state of loaded nanoparticles is in the focus of investigation. The obtained materials are characterized by Boehm method, low temperature physisorption of nitrogen, XRD, UV-Vis, FTIR, Mossbauer spectroscopy and temperature programmed reduction with hydrogen. The catalytic behaviour of the samples is tested in methanol decomposition. The dispersion, oxidative state and catalytic behaviour of loaded cobalt and iron nanoparticles are successfully tuned both by the nature of porous support and the metal precursor used during the samples preparation. Facile effect of active phase deposition from aqueous solution of nitrate precursors is assumed for activated carbon support. For the silica based materials the catalytic activity could be significantly improved when cobalt acetylacetonate is used during the modification. The complex effect of pore topology and surface functionality of different supports on the active phase formation is discussed.

The Effect of Folate and Folate Plus Zinc Supplementation on Endocrine Parameters and Sperm Characteristics in Sub-Fertile Men: A Systematic Review and Meta-Analysis.

PubMed

Irani, Morvarid; Amirian, Malihe; Sadeghi, Ramin; Lez, Justine Le; Latifnejad Roudsari, Robab

2017-08-29

To evaluate the effect of folate and folate plus zinc supplementation on endocrine parameters and sperm characteristics in sub fertile men. We conducted a systematic review and meta-analysis. Electronic databases of Medline, Scopus , Google scholar and Persian databases (SID, Iran medex, Magiran, Medlib, Iran doc) were searched from 1966 to December 2016 using a set of relevant keywords including "folate or folic acid AND (infertility, infertile, sterility)".All available randomized controlled trials (RCTs), conducted on a sample of sub fertile men with semen analyses, who took oral folic acid or folate plus zinc, were included. Data collected included endocrine parameters and sperm characteristics. Statistical analyses were done by Comprehensive Meta-analysis Version 2. In total, seven studies were included. Six studies had sufficient data for meta-analysis. "Sperm concentration was statistically higher in men supplemented with folate than with placebo (P < .001)". However, folate supplementation alone did not seem to be more effective than the placebo on the morphology (P = .056) and motility of the sperms (P = .652). Folate plus zinc supplementation did not show any statistically different effect on serum testosterone (P = .86), inhibin B (P = .84), FSH (P = .054), and sperm motility (P = .169) as compared to the placebo. Yet, folate plus zinc showed statistically higher effect on the sperm concentration (P < .001), morphology (P < .001), and serum folate level (P < .001) as compared to placebo. Folate plus zinc supplementation has a positive effect on sperm characteristics in sub fertile men. However, these results should be interpreted with caution due to the important heterogeneity of the studies included in this meta-analysis. Further trials are still needed to confirm the current findings.

Investigation of the effects of dietary protein source on copper and zinc bioavailability in rainbow trout

USDA-ARS?s Scientific Manuscript database

Limited research has examined the effects that dietary protein sources have on copper (Cu) and Zinc (Zn) absorption, interactions and utilization in rainbow trout. Therefore, the objective of the first trial was to determine what effect protein source (plant vs. animal based), Cu source (complex vs....

Cost-effectiveness analysis of the diarrhea alleviation through zinc and oral rehydration therapy (DAZT) program in rural Gujarat India: an application of the net-benefit regression framework.

PubMed

Shillcutt, Samuel D; LeFevre, Amnesty E; Fischer-Walker, Christa L; Taneja, Sunita; Black, Robert E; Mazumder, Sarmila

2017-01-01

This study evaluates the cost-effectiveness of the DAZT program for scaling up treatment of acute child diarrhea in Gujarat India using a net-benefit regression framework. Costs were calculated from societal and caregivers' perspectives and effectiveness was assessed in terms of coverage of zinc and both zinc and Oral Rehydration Salt. Regression models were tested in simple linear regression, with a specified set of covariates, and with a specified set of covariates and interaction terms using linear regression with endogenous treatment effects was used as the reference case. The DAZT program was cost-effective with over 95% certainty above $5.50 and $7.50 per appropriately treated child in the unadjusted and adjusted models respectively, with specifications including interaction terms being cost-effective with 85-97% certainty. Findings from this study should be combined with other evidence when considering decisions to scale up programs such as the DAZT program to promote the use of ORS and zinc to treat child diarrhea.

Chelation of neurotoxic zinc levels does not improve neurobehavioral outcome after traumatic brain injury

PubMed Central

Hellmich, Helen L.; Eidson, Kristine; Cowart, Jeremy; Crookshanks, Jeanna; Boone, Deborah K.; Shah, Syed; Uchida, Tatsuo; DeWitt, Douglas S.; Prough, Donald S.

2008-01-01

Increases of synaptically released zinc and intracellular accumulation of zinc in hippocampal neurons after traumatic or ischemic brain injury is neurotoxic and chelation of zinc has been shown to reduce neurodegeneration. Although our previous studies showed that zinc chelation in traumatically brain-injured rats correlated with an increase in whole-brain expression of several neuroprotective genes and reduced numbers of apoptotic neurons, the effect on functional outcome has not been determined, and the question of whether this treatment may actually be clinically relevant has not been answered. In the present study, we show that treatment of TBI rats with the zinc chelator calcium EDTA reduces the numbers of injured, Fluoro-Jade- positive neurons in the rat hippocampus 24 hours after injury but does not improve neurobehavioral outcome (spatial memory deficits) two weeks post-injury. Our data suggest that zinc chelation, despite providing short-term histological neuroprotection, fails to improve long-term functional outcome, perhaps because long-term disruptions in homeostatic levels of zinc adversely influence hippocampus-dependent spatial memory. PMID:18556117

Oocyte exposure to ZnO nanoparticles inhibits early embryonic development through the γ-H2AX and NF-κB signaling pathways.

PubMed

Liu, Jing; Zhao, Yong; Ge, Wei; Zhang, Pengfei; Liu, Xinqi; Zhang, Weidong; Hao, Yanan; Yu, Shuai; Li, Lan; Chu, Meiqiang; Min, Lingjiang; Zhang, Hongfu; Shen, Wei

2017-06-27

The impacts of zinc oxide nanoparticles on embryonic development following oocyte stage exposure are unknown and the underlying mechanisms are sparsely understood. In the current investigation, intact nanoparticles were detected in ovarian tissue in vivo and cultured cells in vitro under zinc oxide nanoparticles treatment. Zinc oxide nanoparticles exposure during the oocyte stage inhibited embryonic development. Notably, in vitro culture data closely matched in vivo embryonic data, in that the impairments caused by Zinc oxide nanoparticles treatment passed through cell generations; and both gamma-H2AX and NF-kappaB pathways were involved in zinc oxide nanoparticles caused embryo-toxicity. Copper oxide and silicon dioxide nanoparticles have been used to confirm that particles are important for the toxicity of zinc oxide nanoparticles. The toxic effects of zinc oxide nanoparticles emanate from both intact nanoparticles and Zn2+. Our investigation along with others suggests that zinc oxide nanoparticles are toxic to the female reproductive system [ovaries (oocytes)] and subsequently embryo-toxic and that precaution should be taken regarding human exposure to their everyday use.

Pseudomonas aeruginosa Trent and zinc homeostasis.

PubMed

Davies, Corey B; Harrison, Mark D; Huygens, Flavia

2017-09-01

Pseudomonas aeruginosa is a Gram-negative pathogen and the major cause of mortality in patients with cystic fibrosis. The mechanisms that P. aeruginosa strains use to regulate intracellular zinc have an effect on infection, antibiotic resistance and the propensity to form biofilms. However, zinc homeostasis in P. aeruginosa strains of variable infectivity has not been compared. In this study, zinc homeostasis in P. aeruginosa Trent, a highly infectious clinical strain, was compared to that of a laboratory P. aeruginosa strain, ATCC27853. Trent was able to tolerate higher concentrations of additional zinc in rich media than ATCC27853. Further, pre-adaptation to additional zinc enhanced the growth of Trent at non-inhibitory concentrations but the impact of pre-adaption on the growth of ATCC27853 under the same conditions was minimal. The results establish clear differences in zinc-induced responses in Trent and ATCC27853, and how zinc homeostasis can be a promising target for the development of novel antimicrobial strategies for P. aeruginosa infection in cystic fibrosis patients. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Oocyte exposure to ZnO nanoparticles inhibits early embryonic development through the γ-H2AX and NF-κB signaling pathways

PubMed Central

Liu, Jing; Zhao, Yong; Ge, Wei; Zhang, Pengfei; Liu, Xinqi; Zhang, Weidong; Hao, Yanan; Yu, Shuai; Li, Lan; Chu, Meiqiang; Min, Lingjiang; Zhang, Hongfu; Shen, Wei

2017-01-01

The impacts of zinc oxide nanoparticles on embryonic development following oocyte stage exposure are unknown and the underlying mechanisms are sparsely understood. In the current investigation, intact nanoparticles were detected in ovarian tissue in vivo and cultured cells in vitro under zinc oxide nanoparticles treatment. Zinc oxide nanoparticles exposure during the oocyte stage inhibited embryonic development. Notably, in vitro culture data closely matched in vivo embryonic data, in that the impairments caused by Zinc oxide nanoparticles treatment passed through cell generations; and both gamma-H2AX and NF-kappaB pathways were involved in zinc oxide nanoparticles caused embryo-toxicity. Copper oxide and silicon dioxide nanoparticles have been used to confirm that particles are important for the toxicity of zinc oxide nanoparticles. The toxic effects of zinc oxide nanoparticles emanate from both intact nanoparticles and Zn2+. Our investigation along with others suggests that zinc oxide nanoparticles are toxic to the female reproductive system [ovaries (oocytes)] and subsequently embryo-toxic and that precaution should be taken regarding human exposure to their everyday use. PMID:28487501

Decreased serum and mucosa immunoglobulin A levels in vitamin Aand zinc-deficient mice

PubMed Central

Kheirouri, Sorayya

2014-01-01

Simultaneous zinc and vitamin A deficiency are common health problems in developing countries. The objective of this study was to assess the effect of vitamin A- and zinc-deficient diet on immunoglobulin A (IgA) response. Six-week-old mice were assigned into two groups receiving a normal vitamin A and zinc or low vitamin A and zinc diet for five months. Serum and intestinal mucosa IgA levels were determined by the enzyme-linked immunosorbent assay method. The concentration of zinc in serum was determined using an inductively coupled plasma mass spectrometer. Vitamin A measurement in serum was carried out by high performance liquid chromatography. Mice maintained on a low vitamin A and zinc diet showed significantly greater food intake but lower production of IgA both in serum and mucosa. A mucosa IgA level was significantly higher in both control and deficient groups than the serum IgA level. Results indicated that zinc and vitamin A deficiency is associated with a lower production of IgA. Micronutrient intervention strategies addressing IgA-related gastrointestinal infections are needed. PMID:26155118

The route of liquid precursor to ZnO nanoparticles in premixed combustion spray pyrolysis

NASA Astrophysics Data System (ADS)

Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2018-04-01

Zinc oxide nanoparticles had been successfully synthesized by premixed combustion spray pyrolysis. Zinc acetate was dissolved in distilled water was selected as a liquid precursor. Zinc nitrate was also used for comparison the effect of precursor type on the generated particles morphology and the crystallinity. The premixed combustion reaction used liquefied petroleum gas (LPG) mainly consisting of butane and propane as a fuel and compressed air used as an oxidizer. The liquid precursor was atomized using a custom two fluid nozzle to generate droplets. Then, the droplets were sprayed by the flow of air as a carrier gas into the premixed combustion reactor. The zinc precursor was decomposed to zinc oxide due to the high temperature as a result of combustion reaction inside the reactor resulting in nanoparticles formation. The particle size decreased with the increase of the fuel flow rate. In addition, it can be found that at the same flow rate of fuel, the particle size of zinc oxide synthesized using zinc nitrate is larger than that of the use of zinc acetate as a precursor.

On The Effect Of Zinc Melt Composition On The Structure Of Hot-Dip Galvanized Coatings

NASA Astrophysics Data System (ADS)

Konidaris, S.; Pistofidis, N.; Vourlias, G.; Pavlidou, E.; Stergiou, A.; Stergioudis, G.; Polychroniadis, E. K.

2007-04-01

Zinc hot-dip galvanizing is an effective method for the corrosion protection of ferrous materials. A way of improving the results is through the addition of various elements in the zinc melt. In the present work the effect of Ni, Bi, Cr, Mn, Se and Si at concentration of 0.5 or 1.5 wt.% was examined. Coupons of carbon steel St-37 were coated with zinc containing the above-mentioned elements and were exposed in a Salt Spray Chamber (SSC). The micro structure of these coatings was examined with SEM and XRD. In every case the usual morphology was observed, while differences at the thickness and the crystal size of each layer were induced. However the alloying elements were present in the coating affecting its reactivity and, at least in the case of Mn and Cr, improving corrosion resistance.

The effect of red cell and plasma transfusion on serum zinc and copper levels in the neonate.

PubMed

Lockitch, G; Godolphin, W J; Pendray, M R; Quigley, G

1983-11-01

Transfusion of packed red cells (15 to 20 ml/kg) in 11 preterm infants resulted in a slight increase in mean serum zinc levels on the 3rd post transfusion day but no effect was noted on serum copper levels. No significant difference was found between the changes in serum zinc in 141 paired specimens collected a week apart when zero, one, two or three packed cell transfusions were given in the intervening week. A slight decrease in the mean copper level was noted when one transfusion was given. Transfusion of fresh frozen plasma in six newborns with abdominal wall defects resulted in initial serum copper levels two to three times greater than the reference mean for newborns. No effect was noted on zinc levels. Serum copper results should be interpreted with caution in infants who have been transfused with plasma.

Calcium and zinc DTPA administration for internal contamination with plutonium-238 and americium-241.

PubMed

Kazzi, Ziad N; Heyl, Alexander; Ruprecht, Johann

2012-08-01

The accidental or intentional release of plutonium or americium can cause acute and long term adverse health effects if they enter the human body by ingestion, inhalation, or injection. These effects can be prevented by rapid removal of these radionuclides by chelators such as calcium or zinc diethylenetriaminepentaacetate (calcium or zinc DTPA). These compounds have been shown to be efficacious in enhancing the elimination of members of the actinide family particularly plutonium and americium when administered intravenously or by nebulizer. The efficacy and adverse effects profile depend on several factors that include the route of internalization of the actinide, the type, and route time of administration of the chelator, and whether the calcium or zinc salt of DTPA is used. Current and future research efforts should be directed at overcoming limitations associated with the use of these complex drugs by using innovative methods that can enhance their structural and therapeutic properties.

Effect of zinc chelate and valnemulin for the treatment of swine dysentery in an experimental challenge study.

PubMed

Šperling, Daniel; Čížek, Alois; Smola, Jiří

2014-02-01

The aim of study was to determine the influence of zinc chelate, valnemulin and it's combination on Brachyspira hyodysenteriae shedding and morphological changes of colonic mucosa in an experimental model of swine dysentery (SD). The study was performed on pigs coming from a dysentery-free herd. Animals were inoculated by B. hyodysenteriae strain B204. When the clinical signs of SD and B. hyodysenteriae shedding developed, the pigs were divided into four treatment groups. The first group was treated with zinc chelate (250 ml/1000 L in water), second group was given valnemulin in feed at 75 ppm; the third group was given a combination of both and the fourth group was control. The results demonstrated therapeutic effect of valnemulin in pigs with serious SD and did not show therapeutic effect of chelated zinc. Copyright © 2013. Published by Elsevier Ltd.

Effect of Zinc Supplementation on Growth Outcomes in Children under 5 Years of Age.

PubMed

Liu, Enju; Pimpin, Laura; Shulkin, Masha; Kranz, Sarah; Duggan, Christopher P; Mozaffarian, Dariush; Fawzi, Wafaie W

2018-03-20

(1) Background: The effects of zinc supplementation on child growth, and prior reviews of these studies, have shown mixed results. We aim to systematically review and meta-analyze randomized controlled trials evaluating effects of preventive zinc supplementation for 3 months or longer during pregnancy or in children up to age 5 years on pregnancy outcomes and child growth; (2) Methods: We searched PubMed, EMBASE, Cochrane Library, Web of Science, and trial registries for eligible trials up to October 10, 2017. Inclusion selection and data extractions were performed independently and in duplicate. Study quality was evaluated by the Cochrane Risk of Bias tool. Findings were pooled using random effects meta-analysis, with heterogeneity assessed by I ² and τ² statistic, stratified analyses, and meta-regression, and publication bias by Egger's and Begg's tests; (3) Results: Seventy-eight trials with 34,352 unique participants were identified, including 24 during pregnancy and 54 in infancy/childhood. Maternal zinc supplementation did not significantly increase birth weight (weighted mean difference (WMD) = 0.08 kg, 95%CI: -0.05, 0.22) or decrease the risk of low birth weight (RR = 0.76, 95%CI: 0.52-1.11). Zinc supplementation after birth increased height (WMD = 0.23 cm, 95%CI: 0.09-0.38), weight (WMD = 0.14 kg, 95%CI: 0.07-0.21), and weight-for-age Z -score (WMD = 0.04, 95%CI: 0.001-0.087), but not height-for-age Z -score (WMD = 0.02, 95%CI: -0.01-0.06) or weight-for-height Z score (WMD = 0.02, 95%CI: -0.03-0.06). Child age at zinc supplementation appeared to modify the effects on height ( P -interaction = 0.002) and HAZ ( P -interaction = 0.06), with larger effects of supplementation starting at age ≥2 years (WMD for height = 1.37 cm, 95%CI: 0.50-2.25; WMD for HAZ = 0.12, 95%CI: 0.05-0.19). No significant effects of supplementation were found on the risk of stunting, underweight or wasting; (4) Conclusion: Although the possibility of publication bias and small study effect could not be excluded, the current meta-analysis indicates that zinc supplementation in infants and early childhood, but not pregnancy, increases specific growth outcomes, with evidence for a potentially stronger effect after 2 years of age. These findings inform recommendation and policy development for zinc supplementation to improve growth among young children.

Electrodeposition of zinc hydroxysulfate nanosheets and reduction to zinc metal microdendrites on polypyrrole films.

PubMed

Andreoli, Enrico; Rooney, Denise A; Redington, Wynette; Gunning, Robert; Breslin, Carmel B

2012-01-01

Nanothin sheets made of zinc sulfate hydroxide hydrate, ZnSO4[Zn(OH)2]3 x 5H2O, are easily and quickly prepared using an innovative electrochemical route onto polypyrrole-polystyrene sulfonate (PPy-PSS) films. The sheets are characterized using a range of experimental techniques. The deposits are formed on the film surface with instantaneous nucleation to grow into a network of entangled nanosheets. The effect of the experimental conditions on the deposition is reported. Interestingly, the formation of the nanosheets is observed on PPy-PSS films only, and not on films doped with other sulfate/sulfonate dopants. The zinc nanosheets can be easily electrochemically reduced to metallic zinc microdentrites.

Formation of ZnO at zinc oxidation by near- and supercritical water under the constant electric field

NASA Astrophysics Data System (ADS)

Shishkin, A. V.; Sokol, M. Ya.; Shatrova, A. V.; Fedyaeva, O. N.; Vostrikov, A. A.

2014-12-01

The work has detected an influence of a constant electric field (up to E = 300 kV/m) on the structure of a nanocrystalline layer of zinc oxide, formed on the surface of a planar zinc anode in water under supercritical (673 K and 23 MPa) and near-critical (673 K and 17. 5 MPa) conditions. The effect of an increase of zinc oxidation rate with an increase in E is observed under supercritical conditions and is absent at near-critical ones. Increase in the field strength leads to the formation of a looser structure in the inner part of the zinc oxide layer.

Beneficial effect of zinc chloride and zinc ionophore pyrithione on attenuated cardioprotective potential of preconditioning phenomenon in STZ-induced diabetic rat heart.

PubMed

Jamwal, Sumit; Kumar, Kushal; Reddy, B V Krishna

2016-05-01

Ischemic preconditioning (IPC) is well demonstrated to produce cardioprotection by phosphorylation and subsequent inactivation of glycogen synthase kinase-3β (GSk-3β) in the normal rat heart, but its effect is attenuated in the diabetic rat heart. This study was designed to investigate the effect of zinc chloride and zinc ionophore pyrithione (ZIP) on the attenuated cardioprotective potential of IPC in the diabetic rat heart. Diabetes mellitus (DM) was induced by a single intraperitoneal administration of streptozotocin (STZ) (50 mg/kg; i.p). The isolated perfused rat heart was subjected to 30 minutes of ischemia followed by 120 minutes of reperfusion. Myocardial infarct size was estimated by triphenyltetrazolium chloride (TTC) staining and cardiac injury was measured by estimating lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in the coronary effluent. Also, GSK-3β was measured and neutrophil accumulation was measured by estimating myeloperoxidase (MPO) levels. IPC significantly decreased the myocardial infarct size, the release of LDH and CK-MB, the GSK-3β levels and the MPO levels in the normal rat heart. Pre- and post-ischemic treatment with zinc chloride and zinc ionophore pyrithione (ZIP) in the normal and diabetic rat hearts significantly decreased the myocardial infarct size, the level of CK-MB and LDH in the coronary effluent and GSK-3β and MPO levels. Our results suggest that pharmacological preconditioning with zinc chloride and ZIP significantly restored the attenuated cardioprotective potential of IPC in the diabetic rat heart. © The Author(s) 2015.

The application of crystal soaking technique to study the effect of zinc and cresol on insulinotropin crystals grown from a saline solution.

PubMed

Kim, Y; Haren, A M

1995-11-01

The purpose of this study is to investigate the effect of zinc and cresol on the structure of insulinotropin crystals. Insulinotropin crystals grown from a saline solution were treated with zinc and/or m-cresol using a crystal soaking technique. The effects of these additives on the crystal structure were investigated with powder X-ray diffraction, photomicrography, and differential scanning calorimetry. The molecular interaction between insulinotropin and m-trifluorocresol in solution was also studied by 19F NMR: The data suggest that the original crystals grown from a saline solution have relatively weak lattice forces. After the addition of m-cresol to the suspension of the insulinotropin crystals, the crystals were immediately rendered amorphous. The m-cresol molecules which diffused into the crystals through solvent channels may have disturbed the lattice interactions that maintain the integrity of the crystal. In contrast, the zinc added to the suspension stabilized the crystal lattice so that the subsequent addition of m-cresol did not alter the integrity of the crystals. A marked increase in melting point (206 degrees versus 184 degrees) and heat of fusion (24.6 J/g versus 1.4 J/g) of the crystals was observed after the treatment with zinc. The solubility of the zinc treated crystals in a pH 7.1 phosphate buffered saline was 1/20 of that of the original crystals. When the insulinotropin crystals were treated with the additives using a crystal soaking method, the crystals underwent structural changes. Zinc stabilized the crystal lattice, and reduced the solubility of the peptide.

Zinc deficiency exacerbates while zinc supplement attenuates cardiac hypertrophy in high-fat diet-induced obese mice through modulating p38 MAPK-dependent signaling.

PubMed

Wang, Shudong; Luo, Manyu; Zhang, Zhiguo; Gu, Junlian; Chen, Jing; Payne, Kristen McClung; Tan, Yi; Wang, Yuehui; Yin, Xia; Zhang, Xiang; Liu, Gilbert C; Wintergerst, Kupper; Liu, Quan; Zheng, Yang; Cai, Lu

2016-09-06

Childhood obesity often leads to cardiovascular diseases, such as obesity-related cardiac hypertrophy (ORCH), in adulthood, due to chronic cardiac inflammation. Zinc is structurally and functionally essential for many transcription factors; however, its role in ORCH and underlying mechanism(s) remain unclear and were explored here in mice with obesity induced with high-fat diet (HFD). Four week old mice were fed on either HFD (60%kcal fat) or normal diet (ND, 10% kcal fat) for 3 or 6 months, respectively. Either diet contained one of three different zinc quantities: deficiency (ZD, 10mg zinc per 4057kcal), normal (ZN, 30mg zinc per 4057kcal) or supplement (ZS, 90mg zinc per 4057kcal). HFD induced a time-dependent obesity and ORCH, which was accompanied by increased cardiac inflammation and p38 MAPK activation. These effects were worsened by ZD in HFD/ZD mice and attenuated by ZS in HFD/ZS group, respectively. Also, administration of a p38 MAPK specific inhibitor in HFD mice for 3 months did not affect HFD-induced obesity, but completely abolished HFD-induced, and zinc deficiency-worsened, ORCH and cardiac inflammation. In vitro exposure of adult cardiomyocytes to palmitate induced cell hypertrophy accompanied by increased p38 MAPK activation, which was heightened by zinc depletion with its chelator TPEN. Inhibition of p38 MAPK with its specific siRNA also prevented the effects of palmitate on cardiomyocytes. These findings demonstrate that ZS alleviates but ZD heightens cardiac hypertrophy in HFD-induced obese mice through suppressing p38 MAPK-dependent cardiac inflammatory and hypertrophic pathways. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Inhibition of poly(ADP-ribose)polymerase-1 and DNA repair by uranium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooper, Karen L.; Dashner, Erica J.; Tsosie, Ranalda

Uranium has radiological and non-radiological effects within biological systems and there is increasing evidence for genotoxic and carcinogenic properties attributable to uranium through its heavy metal properties. In this study, we report that low concentrations of uranium (as uranyl acetate; < 10 μM) is not cytotoxic to human embryonic kidney cells or normal human keratinocytes; however, uranium exacerbates DNA damage and cytotoxicity induced by hydrogen peroxide, suggesting that uranium may inhibit DNA repair processes. Concentrations of uranyl acetate in the low micromolar range inhibited the zinc finger DNA repair protein poly(ADP-ribose) polymerase (PARP)-1 and caused zinc loss from PARP-1 protein.more » Uranyl acetate exposure also led to zinc loss from the zinc finger DNA repair proteins Xeroderma Pigmentosum, Complementation Group A (XPA) and aprataxin (APTX). In keeping with the observed inhibition of zinc finger function of DNA repair proteins, exposure to uranyl acetate enhanced retention of induced DNA damage. Co-incubation of uranyl acetate with zinc largely overcame the impact of uranium on PARP-1 activity and DNA damage. These findings present evidence that low concentrations of uranium can inhibit DNA repair through disruption of zinc finger domains of specific target DNA repair proteins. This may provide a mechanistic basis to account for the published observations that uranium exposure is associated with DNA repair deficiency in exposed human populations. - Highlights: • Low micromolar concentration of uranium inhibits polymerase-1 (PARP-1) activity. • Uranium causes zinc loss from multiple DNA repair proteins. • Uranium enhances retention of DNA damage caused by ultraviolet radiation. • Zinc reverses the effects of uranium on PARP activity and DNA damage repair.« less

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

PubMed Central

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

2014-01-01

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

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

NASA Astrophysics Data System (ADS)

Behnajady, Bahram; Babaeidehkordi, Amin; Moghaddam, Javad

2014-04-01

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

Effect of additional vitamin E and zinc supplementation on immunological changes in peripartum Sahiwal cows.

PubMed

Chandra, G; Aggarwal, A; Kumar, M; Singh, A K; Sharma, V K; Upadhyay, R C

2014-12-01

This study was conducted to exploit ameliorative effect of additional vitamin E and/or zinc supplementation on immune response of peripartum Sahiwal cows. Thirty-two pregnant dry Sahiwal cows were blocked into four treatment groups (n = 8), namely control, zinc (Zn), vitamin E (Vit E) and zinc + vitamin E (Zn + Vit E). Feeding regimen was same in all the groups except that the Sahiwal cows in the zinc-, vitamin E- and zinc + vitamin E-fed groups were additionally supplemented with 60 mg Zn/kg DM, 1000 IU vitamin E and 60 mg/kg + 1000 IU Zn + vitamin E, respectively, from day 60 pre-partum to day 90 post-partum. Blood samples were collected on days -60, -45, -30, -15, -7, -3, 0, 3, 7, 15, 30, 45, 60, 90 and 120 with respect to day of parturition and analysed for total immunoglobulin (TIG), immunoglobulin G (IgG), interleukin-2 (IL-2), vitamin E (Vit E) and zinc (Zn) status. Before calving, cows showed a decrease in plasma TIG, IgG, IL-2, Vit E and Zn levels. However, increased levels of plasma TIG, IgG, IL-2, Vit E and Zn were observed after calving. After calving, Sahiwal cows supplemented with Zn + Vit E had higher plasma TIG, IgG and IL-2 in comparison with cows of control and Zn + Vit E-fed groups. In the present study, plasma vitamin E level was higher in Vit E-fed and Zn + Vit E-fed cows; however, zinc level was higher in Zn- and Zn + Vit E-supplemented cows. In conclusion, a reduced immune response during peripartum period in Sahiwal cows was ameliorated by dietary vitamin E and zinc supplementation. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

Taurine zinc solid dispersions attenuate doxorubicin-induced hepatotoxicity and cardiotoxicity in rats.

PubMed

Wang, Yu; Mei, Xueting; Yuan, Jingquan; Lu, Wenping; Li, Binglong; Xu, Donghui

2015-11-15

The clinical efficacy of anthracycline anti-neoplastic agents is limited by cardiac and hepatic toxicities. The aim of this study was to assess the hepatoprotective and cardioprotective effects of taurine zinc solid dispersions, which is a newly-synthesized taurine zinc compound, against doxorubicin-induced toxicity in Sprague-Dawley rats intraperitoneally injected with doxorubicin hydrochloride (3mg/kg) three times a week (seven injections) over 28 days. Hemodynamic parameters, levels of liver toxicity markers and oxidative stress were assessed. Taurine zinc significantly attenuated the reductions in blood pressure, left ventricular pressure and ± dp/dtmax, increases in serum alanine aminotransferase and aspartate aminotransferase activities, and reductions in serum Zn(2+) and albumin levels (P<0.05 or 0.01) induced by doxorubicin. In rats treated with doxorubicin, taurine zinc dose-dependently increased liver superoxide dismutase activity and glutathione concentration, and decreased malondialdehyde level (P<0.01). qBase(+) was used to evaluate the stability of eight candidate reference genes for real-time quantitative reverse-transcription PCR. Taurine zinc dose-dependently increased liver heme oxygenase-1 and UDP-glucuronyl transferase mRNA and protein expression (P<0.01). Western blotting demonstrated that taurine zinc inhibited c-Jun N-terminal kinase phosphorylation by upregulating dual-specificity phosphoprotein phosphatase-1. Additionally, taurine zinc inhibited cardiomyocyte apoptosis as there was decreased TUNEL/DAPI positivity and protein expression of caspase-3. These results indicate that taurine zinc solid dispersions prevent the side-effects of anthracycline-based anticancer therapy. The mechanisms might be associated with the enhancement of antioxidant defense system partly through activating transcription to synthesize endogenous phase II medicine enzymes and anti-apoptosis through inhibiting JNK phosphorylation. Copyright © 2015 Elsevier Inc. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2013-07-01

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

Recent advances in zinc-air batteries.

PubMed

Li, Yanguang; Dai, Hongjie

2014-08-07

Zinc-air is a century-old battery technology but has attracted revived interest recently. With larger storage capacity at a fraction of the cost compared to lithium-ion, zinc-air batteries clearly represent one of the most viable future options to powering electric vehicles. However, some technical problems associated with them have yet to be resolved. In this review, we present the fundamentals, challenges and latest exciting advances related to zinc-air research. Detailed discussion will be organized around the individual components of the system - from zinc electrodes, electrolytes, and separators to air electrodes and oxygen electrocatalysts in sequential order for both primary and electrically/mechanically rechargeable types. The detrimental effect of CO2 on battery performance is also emphasized, and possible solutions summarized. Finally, other metal-air batteries are briefly overviewed and compared in favor of zinc-air.

Effect of Zinc Oxide Film Deposition Position on the Characteristics of Zinc Oxide Thin Film Transistors Fabricated by Low-Temperature Magnetron Sputtering

NASA Astrophysics Data System (ADS)

Takechi, Kazushige; Nakata, Mitsuru; Eguchi, Toshimasa; Otsuki, Shigeyoshi; Yamaguchi, Hirotaka; Kaneko, Setsuo

2008-09-01

We report on the effect of zinc oxide (ZnO) film deposition position on the characteristics of ZnO thin-film transistors (TFTs) fabricated by magnetron sputtering with no intentional heating of the substrate. We evaluate the properties of ZnO (channel semiconductor) films deposited at various positions with respect to the target position. We show that the film deposition at a position off-centered from the target results in good TFT characteristics. This might be due to the fact that the off-centered deposition position is effective for suppressing the effect of energetic negative ions in the plasma.

Corrosion-resistant uranium

DOEpatents

Hovis, V.M. Jr.; Pullen, W.C.; Kollie, T.G.; Bell, R.T.

1981-10-21

The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

Role of a gas phase in the kinetics of zinc and iron reduction with carbon from slag melts

NASA Astrophysics Data System (ADS)

Chumarev, V. M.; Selivanov, E. N.

2013-03-01

The influence of the mass transfer conditions in the gas phase having formed at the carbon-slag melt interface on CO regeneration is approximately estimated in the framework of a two-stage scheme of metal reduction from slag melts by carbon. The effect of zinc vapors on the combined reduction of iron and zinc from slags is considered. The influence of the slag composition and temperature on the critical concentration of zinc oxide above which no iron forms as an individual phase is explained.

Corrosion-resistant uranium

DOEpatents

Hovis, Jr., Victor M.; Pullen, William C.; Kollie, Thomas G.; Bell, Richard T.

1983-01-01

The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

Gravitational effects on electrochemical batteries

NASA Technical Reports Server (NTRS)

Meredith, R. E.; Juvinall, G. L.; Uchiyama, A. A.

1972-01-01

The existing work on gravitational effects on electrochemical batteries is summarized, certain conclusions are drawn, and recommendations are made for future activities in this field. The effects of sustained high-G environments on cycle silver-zinc and nickel-cadmium cells have been evaluated over four complete cycles in the region of 10 to 75 G. Although no effects on high current discharge performances or on ampere-hour capacity were noted, severe zinc migration and sloughing of active material from the zinc electrode were observed. This latter effect constitutes real damage, and over a long period of time would result in loss of capacity. It is recommended that a zero-G battery experiment be implemented. Both an orbiting satellite and a sounding rocket approach are being considered.

Zinc Ameliorate Oxidative Stress and Hormonal Disturbance Induced by Methomyl, Abamectin, and Their Mixture in Male Rats

PubMed Central

Mansour, Sameeh A.; Abbassy, Mostafa A.; Shaldam, Hassan A.

2017-01-01

Exposure to mixtures of toxicants (e.g., pesticides) is common in real life and a subject of current concern. The present investigation was undertaken to assess some toxicological effects in male rats following exposure to methomyl (MET), abamectin (ABM), and their combination (MET+ABM), and to evaluate the ameliorative effect of zinc co-administration. Three groups of rats were designated for MET, ABM, and the mixture treatments. Three other groups were designated for zinc in conjunction with the pesticides. Additionally, one group received water only (control), and the other represented a positive zinc treatment. The obtained results revealed that MET was acutely more toxic than ABM. The tested pesticides induced significant elevation in lipid peroxidation and catalase levels, while declined the levels of the other tested parameters e.g., Superoxide dismutase (SOD), Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Glutathione reductase (GR), Cytochrome P450 (CYP450), testosterone, and thyroxine). Biochemical alterations induced by the mixture were greater than those recorded for each of the individual insecticides. The joint action analysis, based on the obtained biochemical data, revealed the dominance of antagonistic action among MET and ABM. Zinc supplementation achieved noticeable ameliorative effects. It was concluded that zinc may act as a powerful antioxidant, especially in individuals who are occupationally exposed daily to low doses of such pesticides. PMID:29207507

A Zinc Morpholine Complex Prevents HCl/Ethanol-Induced Gastric Ulcers in a Rat Model

PubMed Central

Salama, Suzy M.; Gwaram, Nura Suleiman; AlRashdi, Ahmed S.; Khalifa, Shaden A. M.; Abdulla, Mahmood A.; Ali, Hapipah M.; El-Seedi, Hesham R.

2016-01-01

Zinc is a naturally occurring element with roles in wound healing and rescuing tissue integrity, particularly in the gastrointestinal system, where it can be detected in the mucosal and submucosal layers. Zinc chelates are known to have beneficial effects on the gastrointestinal mucosa and in cases of gastric ulcer. We synthesized complexes of zinc featuring a heterocyclic amine binding amino acids then investigated their ability to enhance the gastric self-repair. Zinc-morpholine complex, Zn(L)SCN, namely showed strong free-radical scavenging, promotion of the DNA and RNA polymerases reconstruction and suppression of cell damage. The complex’s mode of action is proposed to involve hydrogen bond formation via its bis(thiocyanato-k)zinc moiety. Zn(L)SCN complex had potent effects on gastric enzymatic activity both in vitro and in vivo. The complex disrupted the ulcerative process as demonstrated by changes in the intermediate metabolites of the oxidative pathway – specifically, reduction in the MDA levels and elevation of reduced glutathione together with an attenuation of oxidative DNA damage. Additionally, Zn(L)SCN restored the gastric mucosa, inhibited the production of pro-inflammatory cytokines (IL-6, TNF and the caspases), and preserved the gastric mucous balance. Zn(L)SCN thus exhibited anti-oxidative, anti-inflammatory and anti-apoptotic activities, all of which have cytoprotective effects on the gastric lining. PMID:27460157

The effects of enhanced zinc on spatial memory and plaque formation in transgenic mice

USGS Publications Warehouse

Linkous, D.H.; Adlard, P.A.; Wanschura, P.B.; Conko, K.M.; Flinn, J.M.

2009-01-01

There is considerable evidence suggesting that metals play a central role in the pathogenesis of Alzheimer's disease. Reports suggest that elevated dietary metals may both precipitate and potentiate an Alzheimer's disease phenotype. Despite this, there remain few studies that have examined the behavioral consequences of elevated dietary metals in wild type and Alzheimer's disease animals. To further investigate this in the current study, two separate transgenic models of AD (Tg2576 and TgCRND8), together with wild type littermates were administered 10 ppm (0.153 mM) Zn. Tg2576 animals were maintained on a zinc-enriched diet both pre- and postnatally until 11 months of age, while TgCRND8 animals were treated for five months following weaning. Behavioral testing, consisting of "Atlantis" and "moving" platform versions of the Morris water maze, were conducted at the end of the study, and tissues were collected for immunohistochemical analysis of amyloid-β burden. Our data demonstrate that the provision of a zinc-enriched diet potentiated Alzheimer-like spatial memory impairments in the transgenic animals and was associated with reduced hippocampal amyloid-β plaque deposits. Zinc-related behavioral deficits were also demonstrated in wild type mice, which were sometimes as great as those present in the transgenic animals. However, zinc-related cognitive impairments in transgenic mice were greater than the summation of zinc effects in the wild type mice and the transgene effects.

Effects of zinc supplementation on subscales of anorexia in children: A randomized controlled trial

PubMed Central

Khademian, Majid; Farhangpajouh, Neda; Shahsanaee, Armindokht; Bahreynian, Maryam; Mirshamsi, Mehran; Kelishadi, Roya

2014-01-01

Objectives: This study aims to assess the effects of zinc supplementation on improving the appetite and its subscales in children. Methods: This study was conducted in 2013 in Isfahan, Iran. It had two phases. At the first step, after validation of the Child Eating Behaviour Questionaire (CEBQ), it was completed for 300 preschool children, who were randomly selected. The second phase was conducted as a randomized controlled trial. Eighty of these children were randomly selected, and were randomly assigned to two groups of equal number receiving zinc (10 mg/day) or placebo for 12 weeks. Results: Overall 77 children completed the trial (39 in the case and 3 in the control group).The results showed that zinc supplement can improve calorie intake in children by affecting some CEBQ subscales like Emotional over Eating and Food Responsible. Conclusion: Zinc supplementation had positive impact in promoting the calorie intake and some subscales of anorexia. PMID:25674110

Effect of precursor on epitaxially grown of ZnO thin film on p-GaN/sapphire (0 0 0 1) substrate by hydrothermal technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sahoo, Trilochan; Ju, Jin-Woo; Kannan, V.

2008-03-04

Single crystalline ZnO thin film on p-GaN/sapphire (0 0 0 1) substrate, using two different precursors by hydrothermal route at a temperature of 90 deg. C were successfully grown. The effect of starting precursor on crystalline nature, surface morphology and optical emission of the films were studied. ZnO thin films were grown in aqueous solution of zinc acetate and zinc nitrate. X-ray diffraction analysis revealed that all the thin films were single crystalline in nature and exhibited wurtzite symmetry and c-axis orientation. The thin films obtained with zinc nitrate had a more pitted rough surface morphology compared to the filmmore » grown in zinc acetate. However the thickness of the films remained unaffected by the nature of the starting precursor. Sharp luminescence peaks were observed from the thin films almost at identical energies but deep level emission was slightly prominent for the thin film grown in zinc nitrate.« less

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

USGS Publications Warehouse

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

2006-01-01

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

Mechanisms of Zn(II) binded to collagen and its effect on the capacity of eco-friendly Zn-Cr combination tanning system.

PubMed

Cao, Shan; Liu, Bing; Cheng, Baozhen; Lu, Fuping; Wang, Yanping; Li, Yu

2017-01-05

The eco-friendly combination tanning process has been developed to reduce chromium in existing researches, which is based on zinc tanning agents. This can be considered as a less-chrome substitute for current tanning process. To gain deeper understanding of the binding mechanisms of zinc-collagen interaction, which are affected by tanning pH, experiments have been carried out. Analysis in this paper reveals how chemical bonds from the collagen's main function groups combine with zinc. XPS and NIR data was analyzed for further understanding of where the zinc binding sites lie on collagen fibers at different pH. The results indicate that high pH is helpful to amino-binding sites while low pH promotes carboxyl-binding sites on collagen fibers. Furthermore, from the effect of Zinc-chrome combination tanning, we can see that the new method reduces the chromium dosage in tanning process compared to the conventional chrome tanning method. Copyright © 2016 Elsevier B.V. All rights reserved.

Correlation of Zn2+ content with aflatoxin content of corn.

PubMed Central

Failla, L J; Lynn, D; Niehaus, W G

1986-01-01

Forty-nine samples from the 1983 Virginia corn harvest were analyzed for aflatoxin, zinc, copper, iron, and manganese content. Values (mean +/- standard deviation) were as follows: aflatoxin, 117 +/- 360 micrograms/kg; zinc, 22.5 +/- 3.4 mg/kg; copper, 2.27 +/- 0.56 mg/kg; iron, 40.8 +/- 18.7 mg/kg; and manganese, 5.1 +/- 1.1 mg/kg. Aflatoxin levels positively correlated with zinc (Spearman correlation coefficient, 0.385; P less than 0.006) and copper levels (Spearman correlation coefficient, 0.573; P less than 0.0001). Based on biochemical data in the literature, we believe that the correlation with zinc is important and that there may be a cause-and-effect relationship between zinc levels in corn and aflatoxin levels which are produced upon infection with Aspergillus flavus or A. parasiticus. Control of aflatoxin contamination in field corn by decreasing the zinc levels may be feasible, but no methods to decrease zinc levels are currently available. PMID:3729406

The effect of zinc on healing of renal damage in rats

PubMed Central

Salehipour, Mehdi; Monabbati, Ahmad; Ensafdaran, Mohammad Reza; Adib, Ali; Babaei, Amir Hossein

2017-01-01

Background: Several studies have previously been performed to promote kidney healing after injuries. Objectives: The aim of this study was to investigate the effect of zinc on renal healing after traumatic injury in rats. Materials and Methods: Forty healthy female rats were selected and one of their kidneys was incised. Half of the incisions were limited only to the cortex (renal injury type I) and the other ones reached the pelvocalyceal system of the kidney (renal injury type II). All the rats in the zinc treated group (case group) received 36.3 mg zinc sulfate (contained 8.25 mg zinc) orally. After 28 days, the damaged kidneys were removed for histopathological studies. Results: In the rats with type I injury, kidney inflammation of the case group was significantly lower than that of the control group. However, the result was not significant in rats with type II injury. Tissue loss and granulation tissue formation were significantly lower in the case group than the control group in both type I and II kidney injuries. Conclusions: Overall, Zinc can contribute to better healing of the rat’s kidneys after a traumatic injury. PMID:28975095

Effects of Zinc Supplementation on DNA Damage in Rats with Experimental Kidney Deficiency.

PubMed

Yegin, Sevim Çiftçi; Dede, Semiha; Mis, Leyla; Yur, Fatmagül

2017-04-01

This study was carried out to determine the effect of zinc on oxidative DNA damage in rats with experimental acute and chronic kidney deficiency. Six groups of five Wistar-Albino rats each were assigned as controls (C), acute kidney deficiency (AKD), zinc-supplemented (+Zn), acute kidney deficiency, zinc-supplemented (AKD + Zn), chronic kidney deficiency (CKD) and zinc-supplemented chronic kidney deficiency (CKD + Zn). The levels of 8-Oxo-2'-deoxyguanosine (8-OHdG) were determined, being the lowest in the CKD group (p < 0.05), higher in the C group than those of rats with CKD but lower than that of all the other groups (p < 0.05). There were no significant differences between the controls and the CKD + Zn group, or between the AKD and the +Zn groups. Among all groups, the highest 8-OHdG level was found in the AKD + Zn group (p < 0.05). DNA damage was greater in acute renal failure than in rats with chronic renal failure. The DNA damage in the zinc group was significantly higher than in the controls.

Zinc and lead detoxifying abilities of humic substances relevant to environmental bacterial species.

PubMed

Perelomov, L V; Sarkar, Binoy; Sizova, O I; Chilachava, K B; Shvikin, A Y; Perelomova, I V; Atroshchenko, Y M

2018-04-30

The effect of humic substances (HS) and their different fractions (humic acids (HA) and hymatomelanic acids (HMA)) on the toxicity of zinc and lead to different strains of bacteria was studied. All tested bacteria demonstrated a lower resistance to zinc than lead showing minimum inhibitory concentrations of 0.1 - 0.3mM and 0.3-0.5mM, respectively. The highest resistance to lead was characteristic of Pseudomonas chlororaphis PCL1391 and Rhodococcus RS67, while Pseudomonas chlororaphis PCL1391 showed the greatest resistance to zinc. The combined fractions of HS and HA alone reduced zinc toxicity at all added concentrations of the organic substances (50 - 200mgL -1 ) to all microorganisms, while hymatomelanic acids reduced zinc toxicity to Pseudomonas chlororaphis PCL1391 at 200mgL -1 organic concentration only. The HS fractions imparted similar effects on lead toxicity also. This study demonstrated that heavy metal toxicity to bacteria could be reduced through complexation with HS and their fractions. This was particularly true when the metal-organic complexes held a high stability, and low solubility and bioavailability. Copyright © 2018 Elsevier Inc. All rights reserved.