Increase In Zn Research Articles

Effects of Zn2+ doping content on the structure and dielectric tunability of non-stoichiometric [(Na0.7K0.2Li0.1)0.45Bi0.55]TiO3+δ thin film

The Zn2+ doped non-stoichiometric [(Na0.7K0.2Li0.1)0.45Bi0.55](Ti1−xZnx)O3+δ (NKLBTZnx, x = 0–4 at.%) thin films were deposited on fluorine-doped tin oxide/glass substrates via a metal organic decomposition method. The effect of Zn2+ doping content on microstructure, insulating characteristic and dielectric properties were mainly investigated. All the thin films exhibit similar single perovskite structures without detectable secondary phase and the grain size gradually decreases with the increase of Zn2+ doping content. Compared with other films, NKLBTZn0.01 thin film shows enhanced insulating characteristic with lower leakage current, and improved dielectric properties with a relatively higher dielectric tunability and lower dielectric loss. Moreover, with the increasing of electric field or decreasing of measuring frequency, the dielectric tunability is progressively increased. The tunability and figure of merit for the NKLBTZn0.01 thin film at 300 kV/cm and 1 kHz are 40.1 % and 7.0, respectively. These findings suggest that NKLBTZn thin film has potential applications in microwave dielectric devices.

Physico-chemical analysis of pure and Zn Doped Cd ferrites (Cd1 − xZnxFe2O4) nanofabricated by Pechini sol–gel method

Nanofabrication of pure and Zn2+ doped cadmium ferrite (Cd1−x ZnxFe2O4; x=0.0–0.6) have been carried out by Pechini sol–gel method using citric acid-glycol as complexing and template agents. Morphology and microstructure of the fine ferrite materials obtained were analyzed by powder X-ray diffraction (XRD), electron microscopy (SEM, TEM) and N2-physisorption (BET). The single-phase spinel grains averaging 37–51nm in diameter with surface area in the range of 5.3944–8.7693m2/g have been obtained. EDX studies reveal high chemical purity of the prepared ferrites. An increase in Zn2+ substitution leads to a reduction in the lattice parameter, crystallite size, transition temperature as well as increase in surface area, magnetic parameters of doped Cd ferrites. Room temperature magnetic measurements using vibratory sample magnetometer (VSM) and Mössbauer studies demonstrate that both nature and concentration of dopant control the site preference in the crystal lattices.

Rutherford Backscattering Spectrometry Analysis and Structural Properties of ZnxPb1-xS Thin Films Deposited by Chemical Spray Pyrolysis

Zinc lead sulphide ternary thin films were prepared by chemical spray pyrolysis on soda lime glass substrates using zinc acetate, lead acetate, and thiourea sources precursor. The films were characterized using Rutherford backscattering (RBS) spectrometry, energy dispersive X-ray (EDX) spectroscopy, scanning electron microscopy (SEM), and X-ray diffractometry (XRD). RBS studies revealed variation in thickness and stoichiometry of the films with respect to compositional substitution between Zn and Pb, thereby giving effective composition ZnxPb1-xS, where x=0, 0.035, 0.069, 0.109, 0.176, and 0.217. Film thickness obtained by length conversion ranged from 81.02 nm to 90.03 nm. Microstructural analyses also indicated that the growth and particle distribution of the films were uniform across substrate’s surface. Diffraction studies showed that the films possess FCC crystalline structure. Crystallite size reduced from 14.28 to 9.8 nm with increase in Zn2+ in the ZnxPb1-xS samples.

Effects of manure‐ and lignocellulose‐derived biochars on adsorption and desorption of zinc by acidic types of soil with different properties

SummaryThere is limited information on zinc (Zn2+) adsorption and desorption by different types of soil, especially acidic ones following amendment with manure‐ and lignocellulose‐derived biochars. The novelty of this research is a comparison of the mechanisms of adsorption and desorption of Zn2+ by different types of acidic soil amended with biochar derived from either swine manure or rape straw. Both biochars were prepared at a pyrolysis temperature of 500°C before being incorporated into four types of soil with low pH (pHH2O from 4.61 to 5.91) at an incorporation rate of 3%. Following incubation for 360 days, we carried out batch experiments of Zn2+ adsorption and desorption. The dual‐mode model (DMM) was more suitable for describing the adsorption isotherms of the four soil types following biochar incorporation than the distributed reactivity model (DRM). Swine‐manure biochar enhanced Zn2+ adsorption by soil more than rape‐straw biochar. The increases in Zn2+ adsorption by the different soil types following biochar incorporation were in the order Psammaquent > Plinthudult > Paleudalf > Argiustoll soil, whereas it was most difficult to desorb the Zn2+ already present, in reverse order: Argiustoll > Paleudalf > Plinthudult > Psammaquent soil. This could be attributed to differences in soil pH, organic carbon, cation exchange capacity (CEC) and soil texture. Both non‐electrostatic and electrostatic adsorption mechanisms were identified in the four soil types. The negative surface charge of biochar is responsible for the electrostatic adsorption, whereas functional oxygen groups and mineral components of biochar were responsible for non‐electrostatic adsorption. Non‐electrostatic adsorption was more important for the swine‐manure biochar than for the rape‐straw biochar, which was attributed to the larger content of mineral components (phosphate and silicate anions) of the former. In conclusion, the biochar effects on Zn2+ adsorption depended on the initial Zn2+ concentration, soil pH, soil type and biochar origin.

A Novel Synthesis of Zn2+-Doped CoFe2O4 Spinel Nanoparticles: Structural, Morphological, Opto-magnetic and Catalytic Properties

Zn2+-doped CoFe2O4 (Zn x Co1−x Fe2O4: where x= 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) spinel nanoparticles (NPs) were synthesized by microwave combustion method using nitrates of cobalt, zinc, and iron as the starting materials and urea used as the fuel. Powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), energy dispersive X-ray (EDX), and selected area electron diffraction (SAED) pattern analyses showed that all composition was found to have pure cubic spinel structure with well crystalline nature. The average crystallite size of the samples was found to be in the range of 25.43 and 29.46 nm. The lattice parameter increased from 8.432 to 8.441 A with increasing the Zn2+ content, due to the smaller ionic radius of Co2+ substituted by larger ionic radius of Zn2+, which was determined by Rietveld analysis. High-resolution scanning electron microscopy (HR-SEM) and transmission electron microscopy (HR-TEM) analyses were used to study the morphological variation, and the results showed a nano-sized spherical-shaped particle-like morphology. The band gap (E g) of the undoped CoFe2O4 was estimated to be 2.69 eV from UV-Vis diffuse reflectance spectroscopy (DRS). With the increase of Zn2+ dopant, the E g value decreased from 2.61 to 2.01 eV, due to the difference of particle size of the samples. The magnetic hysteresis (M−H) loop confirmed the ferromagnetic nature of undoped CoFe2O4 with magnetization (M s) of 64.85 emu/g, and it is decreased with increasing the Zn2+ content in CoFe2O4 spinel, which was confirmed by a vibrating sample magnetometer (VSM). All composition of spinel Zn x Co1−x Fe2O4 samples were successfully tested as catalyst for the conversion of benzyl alcohol, which has resulted 91.73 and 95.82 % conversion efficiency of CoFe2O4 and Zn0.4Co0.6Fe2O4 nano-catalysts, respectively.

Corticosterone increases intracellular Zn2+ release in hippocampal HT-22 cells

The previous studies suggested that the hippocampal zinc dyshomeostasis and high glucocorticoid level might hurt hippocampal function. However, the effect of corticosterone (CORT) on hippocampus zinc homeostasis is not fully characterized. In this study, we investigated the intracellular Zn2+ concentration in hippocampal HT-22 cells after CORT treatment. The cells were incubated with 10μM CORT for 0h–24h, 0μM–50μM CORT for 6h and 2.5μM glucocorticoid receptor antagonist RU486 administered 30min before CORT application. The results showed that 10μM CORT increased the intracellular Zn2+ level after 6h, which was diminished by 2.5μM RU486. Co-treatment of ZnSO4 and CORT augmented the increase in Zn2+ level. TPEN, a membrane-permeable chelator for intracellular Zn2+ greatly attenuated the Zn2+ increase by CORT, while DTPA, a chelator for extracellular Zn2+, had no same effects. CCK-8 tests demonstrated that 10μM CORT treatment for 6h had no inhibition effect on cells. However, intracellular reactive oxygen species (ROS) production increased and adenosine triphosphate (ATP) level decreased significantly after same CORT treatment, which was corrected by TPEN and aggravated by ZnSO4. It could be suggested that the increased intracellular Zn2+ by CORT was greatly dependent on intracellular Zn2+ release, but not extracellular Zn2+ intake. Meanwhile, our results demonstrated that increased intracellular Zn2+ by CORT resulted in ROS generation and decreased ATP level in cells, which have possible roles in the hippocampal function disorder induced by stress.

Effect of Zn2+ ions on the structure, morphology and optical properties of CaWO4 microcrystals

The effect of zinc ions (Zn2+) on the structure, morphology and optical properties of (Ca1−x Zn x )WO4 microcrystals with (x = 0, 0.01, 0.02, and 0.03) obtained by the microwave-hydrothermal method at 170 °C for 1 h is reported in this letter. These microcrystals were characterized by X-ray diffraction (XRD), Rietveld refinement, energy dispersive X-rays spectroscopy (EDXS) and field emission scanning electron microscopy (FE-SEM) images. The optical properties were investigated by ultraviolet–visible (UV–Vis) diffuse reflectance spectroscopy and photoluminescence (PL) measurements. XRD patterns and Rietveld refinement data indicated that all the (Ca1−x Zn x )WO4 microcrystals present a tetragonal structure and a reduction of lattice parameters and unit cell volume occurs with the increase of Zn2+. EDXS data confirms that the elemental chemical composition was achieved for (Ca1−x Zn x )WO4 microcrystals. FE-SEM images showed that the replacement of Ca2+ by the Zn2+ promotes a reduction of average crystals size and considerable changes in crystal shape starting from dumbbell-like to decorative ball-like (Ca1−x Zn x )WO4 microcrystals. UV–Vis spectra evidenced a small increase in optical band gap values (from 5.72 to 5.76 eV). Finally, PL emission of (Ca1−x Zn x )WO4 microcrystals was improved until x = 0.02 due to the presence of defects at medium range and new intermediate electronic levels in the band gap associated to the Zn2+ content.

Zn<sup>2+</sup>掺杂Sr<sub>3</sub>Co<sub>2</sub>Fe<sub>24</sub>O<sub>41</sub>六角铁氧体的磁性质研究

本文采用固相反应法制备了Z型六角铁氧体Sr3Co2-xZnxFe24O41(x = 0~1.6)材料，研究了不同Zn2+含量和不同温度下Sr3Co2-xZnxFe24O41的磁学性能。结果表明，不同Zn2+掺杂量的粉末样品颗粒都是层状生长，样品颗粒为类六角形状。不同Zn2+掺杂量的样品在不同温度时，都具有明显的软磁特征。随着Zn2+掺杂量x值的增加，样品的饱和磁化强度总体有先增大再减小的趋势，x = 1.2时，饱和磁化强度达到最大。在不同温度下，饱和磁化强度随组分变化有相似的变化规律。样品的矫顽力随组分变化而变化，但是没有明显的变化规律。当x = 0和1.2时，样品具有相对较低的矫顽力。当x 时，升高温度导致矫顽力降低。当x > 1.2时，温度对样品的矫顽力的影响变的很小。综上所述，当x值为1.2时，Sr3Co2-xZnxFe24O41的饱和磁化强度最大，矫顽力相对最小，软磁性能最好。 Zn2+ doped Z-type hexaferrites Sr3Co2-xZnxFe24O41 (x = 0 - 1.6) were prepared with the conventional solid state reaction method. The magnetic properties of Sr3Co2-xZnxFe24O41 with different Zn2+ content at different temperatures were investigated. Results show that the particles of powder samples with different Zn2+ content are layered growth and have a similar hexagonal shape. Samples with different Zn2+ content at different temperatures show soft magnetic properties. The saturation magnetization increases firstly and then decreases with the increase in Zn2+ content. The maximum saturation magnetization is obtained at x = 1.2. The variation of saturation magnetization with composition at different temperatures is similar. The coercive fields vary with composition. However, no distinct variation trend is observed. The samples have the relative low coercive fields when x is 0 and 1.2. When x 1.2, the influence of temperature on the coercive fields is negligible. The above results show that, when the value of x is 1.2, the Zn2+ doped Z-type hexaferrite has both the largest saturation magnetization and the relatively small coercive field, and as a result, the best soft magnetic property.

Clioquinol, a lipophilic Zn2+ chelator, augments and attenuates the cytotoxicity of H2O2: a bell-shaped response curve of the effects of the drug

Clioquinol, a lipophilic Zn2+ chelator, has emerged as a potential novel therapeutic agent for several diseases such as cancer and Alzheimer's disease. Clioquinol has different effects on the intracellular Zn2+ concentrations in rat thymocytes, depending on its concentration and extracellular Zn2+ levels. In this study, we examined the effect of clioquinol on cells under oxidative stress induced by hydrogen peroxide (H2O2) by using a conventional flow cytometric technique with appropriate fluorescent probes. We observed a bell-shaped relationship between the clioquinol concentration and changes in H2O2 cytotoxicity; H2O2-induced cytotoxicity was the highest at a clioquinol concentration of 100 nM. Zn2+ chelators significantly decreased the clioquinol-induced increase in H2O2 cytotoxicity. A bell-shaped curve was observed between the increase in H2O2-induced cytotoxicity by clioquinol and the intracellular Zn2+ concentrations, although the maximal increases in Zn2+ levels were induced by 300 nM clioquinol. In addition, clioquinol at concentrations ≥100 nM exerted antioxidant activity by decreasing the cellular oxidant levels. Thus, clioquinol can exert pro-oxidant or antioxidant effects, depending on its concentration and the extracellular concentration of Zn2+. Because of the unique Zn2+-dependent effects and toxicological profile of clioquinol, clioquinol should be considered for clinical use. Clioquinol, a lipophilic Zn2+ chelator, has emerged as a potential novel therapeutic agent for several diseases such as cancer and Alzheimer's disease.

Effect of chemical plating Zn on DC-etching behavior of Al foil in HCl–H2SO4

The Al foil for high voltage Al electrolytic capacitor usage was immersed in 5.0% NaOH solution containing trace amount of Zn2+ and Zn was chemically plated on its surface through an immersion–reduction reaction. Such Zn-deposited Al foil was quickly transferred into HCl–H2SO4 solution for DC-etching. The effects of Zn impurity on the surface and cross-section etching morphologies and electrochemical behavior of Al foil were investigated by SEM, polarization curve (PC) and electrochemical impedance spectroscopy (EIS). The special capacitance of 100 V formation voltage of etched foil was measured. The results show that the chemical plating Zn on Al substrate in alkali solution can reduce the pitting corrosion resistance, enhance the pitting current density and improve the density and uniform distribution of pits and tunnels due to formation of the micro Zn–Al galvanic local cells. The special capacitance of etched foil grows with the increase of Zn2+ concentration.

Sintering temperature reflected cation distribution of Zn2+ substituted CoFe2O4

The most remarkable effect in spinel ferrites is the strong dependence of properties on the state of structural disorder and, in particular, on the cation distribution. The structural characterization of a Co-Zn ferrite nanoparticle sample was reported which prepared by wet chemical co-precipitation method. The samples were sintered at three different temperatures viz. 650 °C, 850 °C and 1 050 °C for 12 h. The structural details like: lattice constant and distribution of cations in the tetrahedral and octahedral interstitial voids have been deduced through X-ray diffraction (XRD) data analysis. Lattice constant was found to increase with the increase in Zn2+ ions and sintering temperature. Theoretical intensity ratios of (220), (400), (440) planes were considered, as these reflections are sensitive to cations on the A and B sites. Close agreement of the theoretical intensity ratio with the intensity ratio observed from XRD pattern supports the occupancy of Zn2+ ions and Co2+ ions on the octahedral and tetrahedral sites, respectively.

Crystallographic texture and elemental composition mapped in bovine root dentin at the 200 nm level

The relationship between the mineralization of peritubular dentin (PTD) and intertubular dentin (ITD) is not well understood. Tubules are quite small, diameter ∼2 µm, and this makes the near-tubule region of dentin difficult to study. Here, advanced characterization techniques are applied in a novel way to examine what organic or nanostructural signatures may indicate the end of ITD or the beginning of PTD mineralization. X-ray fluorescence intensity (Ca, P, and Zn) and X-ray diffraction patterns from carbonated apatite (cAp) were mapped around dentintubules at resolutions ten times smaller than the feature size (200 nm pixels), representing a 36% increase in resolution over earlier work. In the near tubule volumes of near-pulp, root dentin, Zn intensity was higher than in ITD remote from the tubules. This increase in Zn(2+), as determined by X-ray absorption near edge structure analysis, may indicate the presence of metalloenzymes or transcription factors important to ITD or PTD mineralization. The profiles of the cAp 00.2 X-ray diffraction rings were fitted with a pseudo-Voigt function, and the spatial and azimuthal distribution of these rings' integrated intensities indicated that the cAp platelets were arranged with their c-axes aligned tangential to the edge of the tubule lumen. This texture was continuous throughout the dentin indicating a lack of structural difference between in the Zn rich near-tubular region and the remote ITD.

NAD+ maintenance attenuates light induced photoreceptor degeneration

Light-induced retinal damage (LD) occurs after surgery or sun exposure. We previously showed that zinc (Zn2+) accumulated in photoreceptors and RPE cells after LD but prior to cell death, and pyruvate or nicotinamide attenuated the resultant death perhaps by restoring nicotinamide adenine dinucleotide (NAD+) levels. We first examined the levels of NAD+ and the efficacy of pyruvate or nicotinamide in oxidative toxicities using primary retinal cultures. We next manipulated NAD+ levels in vivo and tested the affect on LD to photoreceptors and RPE. NAD+ levels cycle with a 24-h rhythm in mammals, which is affected by the feeding schedule. Therefore, we tested the affect of increasing NAD+ levels on LD by giving nicotinamide, inverting the feeding schedule, or using transgenic mice which overexpress cytoplasmic nicotinamide mononucleotide adenyl-transferase-1 (cytNMNAT1), an NAD+ synthetic enzyme. Zn2+ accumulation was also assessed in culture and in retinal sections. Retinas of light damaged animals were examined by OCT and plastic sectioning, and retinal NAD+ levels were measured. Day fed, or nicotinamide treated rats showed less NAD+ loss, and LD compared to night fed rats or untreated rats without changing the Zn2+ staining pattern. CytNMNAT1 showed less Zn2+ staining, NAD+ loss, and cell death after LD. In conclusion, intense light, Zn2+ and oxidative toxicities caused an increase in Zn2+, NAD+ loss, and cell death which were attenuated by NAD+ restoration. Therefore, NAD+ levels play a protective role in LD-induced death of photoreceptors and RPE cells.

Yafet–Kittel-type magnetic order in Zn-substituted cobalt ferrite nanoparticles with uniaxial anisotropy

Zn-substituted cobalt ferrite (Zn x Co1−x Fe2O4 with 0.0 ≤ x ≤ 1.0) nanoparticles coated with triethylene glycol (TREG) were prepared by the hydrothermal technique. The effect of Zn substitution on temperature-dependent magnetic properties of the TREG-coated Zn x Co1−x Fe2O4 nanoparticles has been investigated in the temperature range of 10–400 K and in magnetic fields up to 9 T. The structural, morphological, and magnetic properties of TREG-coated Zn x Co1−x Fe2O4 NPs were examined using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The average crystallite size estimated from X-ray line profile fitting was found to be in the range of 7.0–10 nm. The lattice constant determined using the Nelson–Riley extrapolation method continuously increases with the increase in Zn2+ content, obeying Vegard’s law. TEM analysis revealed that the synthesized particles were nearly monodisperse, roughly spherical shaped nanoparticles in the size range of 9.0–15 nm. FT-IR spectra confirm that TREG is successfully coated on the surface of nanoparticles (NPs). The substitution of non-magnetic Zn2+ ions for magnetic Co2+ ions substantially changes the magnetic properties of the TREG-coated Zn x Co1−x Fe2O4 NPs. The saturation magnetization and the experimental magnetic moment are observed to initially increase (up to x = 0.2), which is explained by Neel’s collinear two-sublattice model, and then continuously decrease with further increase in Zn content x. This decrease obeys the three-sublattice model suggested by Yafet–Kittel (Y–K). While the Y–K angle is zero for the CoFe2O4 NPs coated with TREG, it increases gradually with increasing Zn concentrations and extrapolates to 82.36° for ZnFe2O4 NPs coated with TREG. The increase in spin canting angles (Y–K angles) suggests the existence of triangular (or canted) spin arrangements in all the samples (except for the samples with x = 0.0) under consideration in this work. From the computation of Y–K angles for the TREG-coated Zn x Co1−x Fe2O4 NPs, it can be concluded that all the zinc-doped cobalt ferrite nanoparticles (for x > 0.0) have a Y–K-type magnetic order, while the pure cobalt ferrite nanoparticles (x = 0.0) have a Neel-type magnetic order. Zero field cooled (ZFC) and field cooled (FC) measurement results further verify that the samples with 0.6 ≤ x ≤ 1.0 have superparamagnetic behavior at room temperature, which shows weak interaction between magnetic particles. The blocking temperatures obtained from ZFC–FC curves decrease as a function of Zn concentration. It was found that the effective magnetic anisotropy, the coercivity, and remanence magnetization continuously decrease with increasing Zn concentration. Lower reduced remanent magnetization (M r/M s) values (<0.5) suggest that all the samples have uniaxial anisotropy. Ferromagnetic resonance (FMR) measurement shows that the FMR spectra of all the samples have broad linewidth because of the magnetic nanoparticles with randomly distributed anisotropy axes, and the decrease in the internal field conversely leads to the increase in the resonance field with respect to increasing Zn concentration.

锌胁迫对小球藻抗氧化酶和类金属硫蛋白的影响

Chlorella vulgaris(C.vulgaris),a fast-growing unicellular micro-alga,is commonly used as a supplement of food for human and animal consumption.As C.vulgaris readily absorbs metals,this micro-algae has also been employed as an important indicator for monitoring the pollution and toxicity of metals in aquatic environments.Due to both natural geological sources as well as anthropogenic sources,the escalating contamination of aquatic environments by metals such as zinc(Zn) is becoming of increasing concern.A limited concentration of Zn is essential for growth of C.vulgaris,but limited knowledge exists concerning toxic impacts of Zn on the alga.The present study investigated various biochemical variables including biomass,the activities of antioxidant enzymes including superoxide dismutase(SOD) and peroxidase(POD),the intracellular Zn assimilated,and the inducement of Zn-MT-like proteins in C.vulgaris when the alga was exposed to various Zn2+ concentrations.Results showed that the growth of C.vulgaris was inhibited by exposure to Zn2+ at concentrations ranging from 5—100 μmol l/L.The algal biomass rapidly decreased with increased Zn2+ exposure concentration.Algal biomass also decreased with increased exposure time to concentrations of Zn2+ 10 μmol/L.The results indicated that the growth of the alga was significantly inhibited by exposure to Zn2+,especially at higher exposure concentrations.The activities of SOD increased with the increase of Zn2+ exposure concentrations within the ranges of 0—50 μmol/L,but slight decreases in SOD activity occurred with exposure concentrations of Zn2+ 50 μmol/L.The highest activity of SOD was evident when the alga was exposed to 50 μmol/L of Zn2+,in which the value of SOD activity was two times more than that of the control group.However,the activities of POD within the alga significantly decreased(P 0.05) with the increase of Zn2+ exposure concentrations.For example,the activity of POD was 7.4 times less than that of the control group when C.vulgaris was exposed to 10 μmol/L of Zn2+.The results also showed that C.vulgaris has a strong ability to assimilate waterborne Zn2+.For example,the concentrations of intracellular Zn were about 17 and 34 times more than that of the control group when the alga were exposed to 5 μmol/L and 10 μmol/L of Zn2+,respectively.However,the concentrations of intracellular Zn did not increase when the exposure concentrations of Zn 10 μmol/L.A slight decrease of intracellular Zn was observed when the alga were exposed to 100 μmol/L of Zn2+.After being homogenized and centrifuged,the cell extracts of C.vulgaris after exposure to Zn2+ were separated with a size-exclusion high-performance liquid chromatography coupled with the detector of inductively coupled plasma mass spectrometry(ICP-MS).Two Zn-binding species were observed within the cells of C.vulgaris,in which the compounds of the Zn-binding fraction at the retention time(tR) of 6.3 min were referred to as the Zn-MT-like proteins because the retention time(tR) was found to be similar to that(tR 6.1 min) of the standard Zn-MTs derived from rabbit liver.In addition,the amounts of Zn-MT-like proteins induced in the alga were found to increase with the increase of the Zn2+ exposure concentrations.The results indicate that the Zn-MT-like proteins induced in C.vulgaris can be used as the indicator to reflect the pollution of Zn2+in aquatic environments.

Magnetic Properties of Cu&amp;lt;sub&amp;gt;1-x&amp;lt;/sub&amp;gt;Zn&amp;lt;sub&amp;gt;x&amp;lt;/sub&amp;gt;Fe&amp;lt;sub&amp;gt;2 &amp;lt;/sub&amp;gt;O&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;Ferrites with the Variation of Zinc Concen-tration

Cu-Zn ferrite with general formula of Cu1-xZnxFe2 O4 with a range from x = 0.0 to 0.7 (in steps of 0.1) was prepared by using standard ceramic techniques. The confirmation of sin-gle-phase formation was carried out by employing X-ray diffraction technique. Some of the magnetic properties were measured, such as Curie temperature, the complex permeability and low field hysteresis loop. It was found that Curie temperature Tc decreases from 464?C to 20?C. The real part of initial permeability, μ′ in-crease with increasing Zn contents up to x = 0.5 after that it decreases with higher Zn content. Low field hysteresis measurement was carried out at room temperature and this measurement with the increase of Zn2+ ions yields the increase of saturation magnetic induction (By) and magnetic remanance (Br) up to x = 0.4 thereafter it decreases. The decrease in corecivity (Hc) and hysteresis loss is observed for all samples. In view of this, the possible changes in magnetic properties with the increase in Zn concentration are un-dertaken.

ZnO nanorod array/CuAlO2 nanofiber heterojunction on Ni substrate: synthesis and photoelectrochemical properties

A novel ZnO nanorod array (NR)/CuAlO2 nanofiber (NF) heterojunction nanostructure was grown on a substrate of Ni plates using sol–gelsynthesis for the NFs and hydrothermal reaction for the NRs. Compared with a traditionalZnO/CuAlO2 laminar film nanostructure, the photocurrent of this fibrous network heterojunction issignificantly increased. A significant blue-shift of the absorption edge anda favorable forward current to reverse current ratio at applied voltages of − 2 to + 2 V were observed in this heterojunction with the increase ofZn2 + ion concentration in the hydrothermal reaction. Furthermore, thephotoelectrochemical properties were investigated and the highest photocurrent of 3.1 mA cm − 2 was obtained under AM 1.5 illumination with 100 mW cm − 2 light intensity at 0.71 V (versus Ag/AgCl). This novel 3D fibrous network nanostructureplays an important role in the optoelectronic field and can be extended to other binary orternary oxide compositions for various applications.

Effect of Solution Hydrodynamics on Corrosion Inhibition Performance of Zinc Sulfate in Neutral Solution

The hydrodynamic conditions and fluid flow are important factors that affect the corrosion of metals. They also influence the inhibition performance of different corrosion inhibitors. In this paper, the corrosion behavior of St52-3 rotating disc electrode, RDE, in NaCl solution containing ZnSO4 salt, as a cathodic inorganic corrosion inhibitor, has been studied under different hydrodynamic conditions. Two electrochemical methods, including potentiodynamic polarization and electrochemical impedance spectroscopy, have been used. The effects of solution hydrodynamic on the open circuit potential, polarization curves and electrochemical impedance diagrams of the steel RDE in blank NaCl solution as well as in the solution containing ZnSO4 have been considered. It has been shown that ZnSO4 inhibits the corrosion of steel in NaCl solution. By increasing the rotational speed, in the absence and presence of inhibitor, the corrosion current density increased and charge transfer resistance decreased. ZnSO4 had relatively low efficiency in stagnant conditions but its influence improved significantly under hydrodynamic conditions. It was mainly attributed to an increase in Zn2+ ions mass transport towards electrode surface, which leads to the formation of more protective films and therefore, enhances the protection against corrosion.

Insight into Glutamate Excitotoxicity from Synaptic Zinc Homeostasis

Zinc is released from glutamatergic (zincergic) neuron terminals in the hippocampus, followed by the increase in Zn2+ concentration in the intracellular (cytosol) compartment, as well as that in the extracellular compartment. The increase in Zn2+ concentration in the intracellular compartment during synaptic excitation is mainly due to Zn2+ influx through calcium-permeable channels and serves as Zn2+ signaling as well as the case in the extracellular compartment. Synaptic Zn2+ homeostasis is important for glutamate signaling and altered under numerous pathological processes such as Alzheimer's disease. Synaptic Zn2+ homeostasis might be altered in old age, and this alteration might be involved in the pathogenesis and progression of Alzheimer's disease; Zinc may play as a key-mediating factor in the pathophysiology of Alzheimer's disease. This paper summarizes the role of Zn2+ signaling in glutamate excitotoxicity, which is involved in Alzheimer's disease, to understand the significance of synaptic Zn2+ homeostasis in the pathophysiology of Alzheimer's disease.

Zinc Signaling in the Hippocampus and Its Relation to Pathogenesis of Depression

Zinc is released from glutamatergic (zincergic) neuron terminals in the brain, followed by the increase in Zn²⁺ concentration in the intracellular (cytosol) compartment as well as that in the extracellular compartment. Intracellular Zn²⁺ concentration mainly increases through calcium-permeable channels and serves as Zn²⁺ signal as well as extracellular Zn²⁺ concentration. Hippocampal Zn²⁺ signaling may participate in synaptic plasticity such as long-term potentiation and cognitive function. On the other hand, subclinical zinc deficiency is common in the old who might be more susceptible to depression. Zinc deficiency causes abnormal glucocorticoid secretion and increases depression-like behavior in animals. Neuropsychological symptoms are observed prior to the decrease in Zn²⁺ signal in the hippocampus under zinc deficiency. This paper summarizes that hippocampal Zn²⁺ signaling serves to maintain healthy brain and that glucocorticoid signaling, which is responsive to zinc homeostasis in the living body, is linked to the pathophysiology of depression.