Zinc Compounds

The kinetics of transmetallation of [Mn(nota)]and [Mn(dota)] 2was investigated in the presence of Zn 2+ (5-50-fold excess) at variable pH (3.5-5.6) by 1 H relaxometry. The dissociation is much faster for [Mn(nota)]than for [Mn(dota)] 2under both experimental and physiologically relevant conditions (t 1 2 = 74 h and 1037 h for [Mn(nota)]and [Mn(dota)] 2-, respectively, at pH 7.4, c(Zn 2+) = 10-5 M, 25 • C). The dissociation of the complexes proceeds mainly via spontaneous ([Mn(nota)]k 0 = (2.6 ± 0.5) ¥ 10-6 s-1 ; [Mn(dota)] 2k 0 = (1.8 ± 0.6) ¥ 10-7 s-1) and proton-assisted pathways ([Mn(nota)]k 1 = (7.8 ± 0.1) ¥ 10-1 M-1 s-1 ; [Mn(dota)] 2k 1 = (4.0 ± 0.6) ¥ 10-2 M-1 s-1 , k 2 = (1.6 ± 0.1) ¥ 10 3 M-2 s-1). The observed suppression of the reaction rates with increasing Zn 2+ concentration is explained by the formation of a dinuclear Mn 2+-L-Zn 2+ complex which is about 20-times more stable for [Mn(dota)] 2than for [Mn(nota)]-(K MnLZn = 68 and 3.6, respectively), and which dissociates very slowly (k 3 10-5 M-1 s-1). These data provide the first experimental proof that not all Mn 2+ complexes are kinetically labile. The absence of coordinated water makes both [Mn(nota)]and [Mn(dota)] 2complexes inefficient for MRI applications. Nevertheless, the higher kinetic inertness of [Mn(dota)] 2indicates a promising direction in designing ligands for Mn 2+ complexation.

A new ZnL complex containing two molecules of a tridentate Schiff base derived from 5-methyl-1H-pyrazole (HL) is synthesized and characterized. The photophysical properties of HL and ZnL are disclosed and supported by CAMB3LYP DFT/TDDFT calculations. It is shown that there is keto-tautomer stabilization upon excitation with an energetically accessible triplet state in HL, not present in ZnL, this explaining the differences found in the emissions of the compounds. The intrinsic fluorescence of ZnL is used as probe for a detailed study of its binding to human serum albumin. The protein-complex association is thermodynamically favourable and it is shown by fluorescence quenching and time-resolved analysis that the fluorescence quenching involves a mixed mechanism with prevalence of static quenching, which corroborates adduct formation at site I, close to the Trp214 residue. The ability of ZnL to bind DNA was also evaluated, as well as its cytotoxic activity against MCF7 (breast), PC3 (...

Utilization of agrowaste materials for the production of activated carbon, as an excellent adsorbent with large surface area, is well established industrially, for dephenolation of wastewater. In the present work, dried pods of Prosopis cineraria-a novel and low-cost agrowaste material-were used to prepare activated carbons by zinc chloride activation. Batch adsorption experiments were carried out to study the effects of various physicochemical parameters such as initial phenol concentration, adsorbent dose, initial solution pH, and temperature. Pseudo-first-order second-order and diffusion kinetic models were used to identify the possible mechanisms of such adsorption process. The Langmuir and Freundlich equations were used to analyze the adsorption equilibrium. Maximum removal efficiency of 86 % was obtained with 25 mgL −1 of initial phenol concentration. The favorable pH for maximum phenol adsorption was 4.0. Freundlich equation represented the adsorption equilibrium data more ideally than the Langmuir. The maximum adsorption capacity obtained was 78.32 mg g −1 at a temperature of 30°C and 25 mgL −1 initial phenol concentration. The adsorption was spontaneous and endothermic. The pseudo-second-order model, an indication of chemisorption mechanism, fitted the experimental data better than the pseudo-first-order Lagergren model. Regeneration of spent activated carbon was carried out using Pseudomonas putida MTCC 2252 as the phenol-degrading microorganism. Maximum regeneration up to 57.5 % was recorded, when loaded phenol concentration was 25 mgL −1. The data obtained in this study would be useful in designing and fabricating an efficient treatment plant for phenol-rich effluents.

Solid-state 29 Si, 113 Cd, 119 Sn, and 31 P MAS NMR spectra are reported on a series of II-IV-P 2 compounds. In favorable cases (e.g., high degree of crystallinity, low concentration of unpaired electrons), well-defined spectra, with sharp lines for each specific nearest-neighbor configuration, are observed; in such cases, expected J coupling patterns are also seen. High-resolution solid-state NMR studies of this type provide useful information on structure (disorder), doping, and electron-mediated coupling in semiconductor systems.

Solid-state 29 Si, 113 Cd, 119 Sn, and 31 P MAS NMR spectra are reported on a series of II-IV-P 2 compounds. In favorable cases (e.g., high degree of crystallinity, low concentration of unpaired electrons), well-defined spectra, with sharp lines for each specific nearest-neighbor configuration, are observed; in such cases, expected J coupling patterns are also seen. High-resolution solid-state NMR studies of this type provide useful information on structure (disorder), doping, and electron-mediated coupling in semiconductor systems.

Characterization of nanomaterials must include analysis of both size and chemical composition. Many analytical techniques, such as dynamic light scattering (DLS), are capable of measuring the size of suspended nanometer-sized particles, yet provide no information on the composition of the particle. While field flow fractionation (FFF) is a powerful nanoparticle sizing technique, common detectors used in conjunction with the size separation, including UV, light-scattering, and fluorescence spectroscopy, do not provide the needed particle compositional information. Further, these detectors do not respond directly to the mass concentration of nanoparticles. The present work describes the advantages achieved when interfacing sensitive and elemental specific detectors, such as inductively coupled plasma atomic emission spectroscopy and mass spectrometry, to FFF separation analysis to provide high resolution nanoparticle sizing and compositional analysis at the mg/L concentration level, a detection at least 10-100-fold lower than DLS or FFF-UV techniques. The full benefits are only achieved by utilization of all detector capabilities, such as dynamic reaction cell (DRC) ICP-MS. Such low-level detection and characterization capability is critical to nanomaterial investigations at biologically and environmentally relevant concentrations. The techniques have been modified and applied to characterization of all four elemental constituents of cadmium selenide-zinc sulfide core-shell quantum dots, and silver nanoparticles with gold seed cores. Additionally, sulfide coatings on silver nanoparticles can be detected as a potential means to determine environmental aging of nanoparticles.

Characterization of nanomaterials must include analysis of both size and chemical composition. Many analytical techniques, such as dynamic light scattering (DLS), are capable of measuring the size of suspended nanometer-sized particles, yet provide no information on the composition of the particle. While field flow fractionation (FFF) is a powerful nanoparticle sizing technique, common detectors used in conjunction with the size separation, including UV, light-scattering, and fluorescence spectroscopy, do not provide the needed particle compositional information. Further, these detectors do not respond directly to the mass concentration of nanoparticles. The present work describes the advantages achieved when interfacing sensitive and elemental specific detectors, such as inductively coupled plasma atomic emission spectroscopy and mass spectrometry, to FFF separation analysis to provide high resolution nanoparticle sizing and compositional analysis at the mg/L concentration level, a detection at least 10-100-fold lower than DLS or FFF-UV techniques. The full benefits are only achieved by utilization of all detector capabilities, such as dynamic reaction cell (DRC) ICP-MS. Such low-level detection and characterization capability is critical to nanomaterial investigations at biologically and environmentally relevant concentrations. The techniques have been modified and applied to characterization of all four elemental constituents of cadmium selenide-zinc sulfide core-shell quantum dots, and silver nanoparticles with gold seed cores. Additionally, sulfide coatings on silver nanoparticles can be detected as a potential means to determine environmental aging of nanoparticles.

Ochratoxin A (OTA) is a mycotoxin produced by different Aspergillus and Penicillium species. Since its mechanism of action is not fully understood yet, it is important to gain further insight into different interactions of OTA at the molecular level. OTA is found worldwide in many foods and drinks. Moreover, it can also be detected in human and animal tissues and body fluids, as well. Therefore, the development of highly sensitive quantitative methods for the determination of OTA is of utmost importance. OTA most likely forms complexes with divalent cations, both in cells and body fluids. In the present study, the OTA-zinc interaction was investigated and compared to OTA-magnesium complex formation using fluorescence spectroscopy and molecular modeling. Our results show that zinc(II) ion forms a twofold higher stable complex with OTA than magnesium(II) ion. In addition, based on the enhanced fluorescence emission of OTA in its magnesium-bound form, a novel RP-HPLC-fluorescence detector (FLD) method was also established. Our results highlight that the application of magnesium chloride in

We report a high-performance magnetic nanoparticle as a hyperthermic agent under low applied field and frequency. CTAB (cetyltrimethylammonium bromide)-coated Ni x Zn 1Àx Fe 2 O 4 nanoparticles of average particle size < 25 nm with various stoichiometric ratios were successfully synthesized using a coprecipitation technique. Characterization results indicate a close interaction of CTAB ions with the surface metal ions resulting in a cation distribution deviating from their equilibrium positions. Magnetic measurements were done at 300 K and 5 K using a superconducting quantum interference device. Saturation magnetization gradually increases with increasing substitution of Ni 2+ ions with Zn 2+ ions, attributed to the cation distribution and high super-exchange interaction between the A-and B-sites. The average size of the nanoparticles is estimated to be <10 nm with a magnetically dead layer (>1 nm @ 300 K), reflecting the effect of CTAB coating on the surface of the nanoparticles. The magnetocrystalline anisotropy (K eff), obtained from the law of approach to saturation, is inversely proportional to the M s value. The increasing incorporation of Ni 2+ ions in the lattice system is found to influence various structural parameters, which is reflected in the magnetic performance of the nanoparticles. A specific absorption rate of 347 W g À1 and intrinsic loss power of 4.6 nH m 2 kg À1 was attained with a minimal concentration of 2 mg ml À1 in a very short time period of 1.5 min in Ni 0.75 Zn 0.25 Fe 2 O 4 nanoparticles.

This study made use of a nitric oxide-sensitive electrode to examine possible means of generating nitric oxide from nitroxyl anion (NO 7) released upon the decomposition of Angeli's salt. 2 Our results show that copper ions (from CuSO 4) catalyze the rapid and ecient oxidation of nitroxyl to nitric oxide. Indeed, the concentrations of copper required to do so (0.1 ± 100 mM) are roughly 100-times lower than those required to generate equivalent amounts of nitric oxide from Snitroso-N-acetyl-D,L-penicillamine (SNAP). 3 Experiments with ascorbate (1 mM), which reduces Cu 2+ ions to Cu + , and with the Cu 2+ chelators, EDTA and cuprizone, and the Cu + chelator, neocuproine, each at 1 mM, suggest that the oxidation is catalyzed by copper ions in both valency states. 4 Some compounds containing other transition metals, i.e. methaemoglobin, ferricytochrome c and Mn(III)TMPyP, were much less ecient than CuSO 4 in catalyzing the formation of nitric oxide from nitroxyl, while FeSO 4 , FeCl 3 , MnCl 2 , and ZnSO 4 were inactive. 5 Of the copper containing enzymes examined, Cu-Zn superoxide dismutase and ceruloplasmin were weak generators of nitric oxide from nitroxyl, even at concentrations (2500 and 30 u ml 71 , respectively) vastly greater than are present endogenously. Two others, ascorbate oxidase (10 u ml 71) and tyrosinase (250 u ml 71) were inactive. 6 Our ®ndings suggest that a copper-containing enzyme may be responsible for the rapid oxidation of nitroxyl to nitric oxide by cells, but the identity of such an enzyme remains elusive.

As part of an ongoing investigation to characterize the properties and structure of zinc halide-tellurium oxide glasses, we report preliminary measurements of the optical properties of several Nd- and Er-doped tellurites. Measurements include florescence lifetimes and estimates of the theoretical radiative lifetimes (as obtained by traditional Judd-Ofelt analysis of optical absorption spectra) as well as phonon sideband studies sensitive to vibrational characteristics near the rare earth ion. The response of these optical features to the substitution of alternative halides is examined.

Nanostructured zinc oxide samples were synthesized through CVD and annealed in argon. The samples were investigated using SEM, TEM, XRD, and UV/VIS/FTIR photoacoustic spectroscopy. The SEM/TEM images show relatively spherical particles that form elongated, connected domains post-anneal. XRD measurements indicate a typical wurtzite structure and reveal an increase in average grain size from 16.3 nm to 21.2 nm in Ar-annealed samples over pristine samples. Visible photoacoustic spectra reveal the contribution of defect levels on the absorption edge of the fundamental gap of zinc oxide. The steepness parameter of the absorption edge, which is inversely proportional to the width of the absorption edge, decreased from 0.1582 (pristine) to 0.1539 (annealed for 90 minutes) revealing increased density of defect states upon annealing. The FTIR photoacoustic spectra show an intense peak at 412 cm-1 and a shoulder at 504 cm-1 corresponding to the two transverse optical stretching modes of ZnO. ...

This study aimed to investigate the corrosion behavior of zinc nano-crystalline coating on st12 steel substrate by surface mechanical attrition treatment (SMAT) and electroplating process into chloride bath with and without of gelatin. To study the behavior of coatings, they were characterized by using X-ray diffraction, field emission scanning electron microscopy, EDS, potentiodynamic polarization and EIS tests in 3.5 wt. % NaCl solution. The results showed that SMAT process reduced the size of the crystallites and the presence of gelatin caused the induced orientation of Zn deposition so that the grain size in the presence of gelatin and SMAT reached from 55 to 29 nm and the rate of its corrosion reached from 80.8 to 20.1 µA.cm-2 .

Having investigated the different reports and various fluxes, ammonium chloride was eventually selected for pyrometallurgical recovery of metallic zinc from the galvanizing flue dust in the present work. This flue dust constitutes 10 to 15 wt.% of galvanizing wastes. The mechanism of ammonium chloride in the extraction of the metallic zinc from the galvanizing dust was explained. Furthermore, the efficiencies of zinc recoveries in the temperature range of 500 to 700 ºC, treating time of 0 to 40 minutes and mixing percentages of 10 to 30wt% fluxes were investigated. The optimum efficiency of zinc recovery was calculated equal to 85% which was observed in the temperature 600ºC, flux mixing ratio of 20wt% and treating time of 20 to 30 minutes.

Scheme 1. Glucose-mediated assembly of PBA-modified CdTe/ZnTe/ ZnS CSS QDs. The fluorescence of the QDs depends on the assembly induced by the interactions of the analyte with the molecular-recognition groups anchored on the surface of the QDs.

An efficient and practical protocol for the synthesis of Amadori ketoses N-(1-deoxy-D-fructose-1-yl) amino acid (amino acid = L-valine (1), L-leucine (2), L-isoleucine (3), L-tryptophan (4), L-phenylalanine (5), L-arginine (6) has been accomplished by employing ZnCl 2 as a catalyst. The developed method circumvents protection and deprotection steps as well as tedious ion-exchange and column chromatographic techniques. The accomplished Amadori ketoses showed moderate to weak angiotensin I converting enzyme (ACE) inhibitory activity.

The finely controlled nanostructured cubic spinel ferrites pave the way to synthesize nanomaterials with specific properties for particular applications. In this paper, we report sol-gel synthesis of Zn doped spinel Co1-xZnxFe2O4 (where x= 0.0, 0.1, 0.2, and 0.3) ferrite nanoparticles. X-ray diffraction confirms the single phase cubic structure of nano ferrites with average particle size estimated between 55.38 to 32.87 nm and validated by Transmission electron microscopy (TEM) results (±1). The lattice parameter was found to increase with increasing Zn doping concentration. The samples exhibit normal dielectric behaviour of Maxwell-Wagner type of interfacial polarization that decreases with increasing frequency of the applied field. Temperature-dependent magnetic properties were investigated with the aid of physical property system. The hysteresis measurements of the samples show clearly enhancement in magnetic parameters as the temperature goes down to 20 K. Tuning of magnetic pro...

The tumor suppressor protein p53 and the putative lipid tumor suppressor ceramide play pivotal roles in inducing cell cycle arrest or in driving the cell towards apoptosis. Previously we had shown that, in a p53-dependent model of cell death, ceramide accumulated in a p53-dependent manner [Dbaibo GS,

Films of Co0.85Zn0.15Fe2O4 nanoparticles were prepared on silanized glass substrates using aminobenzoic acid/imidazole-modified magnetic nanoparticles. Dispersive Faraday rotations in the nanoparticulate films were observed as 1.0°–3.0° under relatively low applied magnetic field strengths of less than 500 Oe. The magnitude of the Faraday rotation increases with increasing thickness of the prepared films. No differences in the Faraday rotation were observed for Co0.85Zn0.15Fe2O4 nanoparticles as the particle size varied from 12 to 18 nm.

This study introduces a sustainable method of producing a graphene nano sheet (GNS) from coconut shells and investigates its application in GNS, Ni/GNS, and Zn/GNS electrodes for advanced energy storage devices. The GNS was synthesized in a scalable manner using a pyrolysis
and impregnation technique, with its successful synthesis verified by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and electrical conductivity measurement
characterizations. The study highlights the enhanced performance of Zn/GNS electrodes, which outperform both pure GNS and Ni/GNS variants. This superior performance is attributed to the smaller particle size of Zn (mean = 2.356 μm) compared to Ni (mean = 3.09 μm) and Zn’s more
favourable electron configuration for electron transfer. These findings demonstrate the potential of bio-derived GNS composites as efficient, high-performance electrodes, paving the way for more sustainable and cost-effective energy storage solutions.

Two materials were produced from sewage sludge by: (1) pyrolysis of dried sewage sludge (PS); (2) chemical activation of dried sewage sludge with ZnCl 2 followed by pyrolysis (AS). The aim was to study the application of these materials for metal purification from water and to determine the efficiency of each material. Although AS displayed higher capacity, both PS and AS were able to adsorb these metals and the preferential order was equal: Hg(II) > Pb(II) > Cu(II) > Cr(III). For each metal-adsorbent pair, metal adsorption was highly pH dependent. In all cases the equilibrium was well described both by the Langmuir and the Freundlich isotherms. At the corresponding optimum pH, AS showed the following adsorption capacities: 175.4, 64.1, 30.7 and 15.4 mg/g of Hg(II), Pb(II), Cu(II) and Cr(III), respectively. These results indicate the potential application of these sewage sludge based adsorbents for the treatment of metal polluted effluents.

Two materials were produced from sewage sludge by: (1) pyrolysis of dried sewage sludge (PS); (2) chemical activation of dried sewage sludge with ZnCl 2 followed by pyrolysis (AS). The aim was to study the application of these materials for metal purification from water and to determine the efficiency of each material. Although AS displayed higher capacity, both PS and AS were able to adsorb these metals and the preferential order was equal: Hg(II) > Pb(II) > Cu(II) > Cr(III). For each metal-adsorbent pair, metal adsorption was highly pH dependent. In all cases the equilibrium was well described both by the Langmuir and the Freundlich isotherms. At the corresponding optimum pH, AS showed the following adsorption capacities: 175.4, 64.1, 30.7 and 15.4 mg/g of Hg(II), Pb(II), Cu(II) and Cr(III), respectively. These results indicate the potential application of these sewage sludge based adsorbents for the treatment of metal polluted effluents.

Aluminium doped zinc oxide thin films are prepared by Radio Frequency magnetron sputtering in pure argon atmosphere at 100 W. The structural results reveal good film adhesion on a silicon substrate (001). The thin films were then subjected to heat treatment in a furnace under ambient air. The structural, morphological, and optical properties of the thin films as a function of deposition time and annealing temperatures have been investigated using Grazing incidence X-Ray Diffraction (GIXRD), Atomic Force Microscopy, and Scanning Electronic Microscopy. The photoluminescence properties of the annealed films showed significant changes in the optical properties attributed to mid gap defects. Annealing increases the crystallite size and the roughness of the film. The crystallinity of the films also improved as evident from the Raman and XRD studies.

Little information is available concerning co-sorbing oxyanion and metal contaminants in the environment, yet in most metal-contaminated areas, co-contamination by phosphate is common. In this study, the mutual effects of phosphate and Zn(II) on their interaction with γ-Al2O3 are investigated by batch experiments and X-ray absorption fine structure spectroscopy (XAFS) technique. The results show that the co-sorption of phosphate on γ-Al2O3 modifies both the extent of Zn(II) sorption and the local atomic structures of sorbed Zn(II) ions. Multiple mechanisms are involved in Zn(II) retention in the presence of phosphate, including electrostatic interaction, binary and ternary surface complexation, and the formation of Zn(II)-phosphate polynuclear complexes. At pH 6.5, type III ternary surface complexation occurs concurrently with binary Zn-alumina surface complexation at low phosphate concentrations, whereas the formation of type III ternary surface complexes is promoted as the phospha...

Experimental section General Procedures. Compounds 3-5 were prepared under N 2 atmosphere using an M. Braun UNILAB glove-box and Schlenk techniques. The ligands, K(Ttz R,Me), were prepared by following known procedures. 1 TlNO 3 , Et 2 Zn and Me 2 Zn were purchased from Acros and Aldrich and used without further purification. Solvents were dried using an M. Braun solvent purification system with alumina columns or were freshly distilled from drying agents using standard methods. NMR spectra were recorded using either a 300 MHz or a 500 MHz Varian Unity Inova NMR spectrophotometer. IR spectra were recorded on a Perkin-Elmer Spectrum one Fourier-transform IR absorption spectrophotometer. High resolution mass spectrometry was performed on VG70SE double focusing, triple quadruple mass spectrometer equipped with FAB or CI ionization capability. Elemental analyses were performed by Robertson Microlit. Single crystal X-ray diffraction studies. Diffraction data for all compounds were collected using a Bruker AXS SMART APEX CCD diffractometer using monochromatic Mo Kα radiation with the omega scan technique. Single crystals were mounted on Mitegen micromesh mounts and data were collected at 100 K. Data were collected, unit cells determined, and the data integrated and corrected for absorption and other

Experimental section General Procedures. Compounds 3-5 were prepared under N 2 atmosphere using an M. Braun UNILAB glove-box and Schlenk techniques. The ligands, K(Ttz R,Me), were prepared by following known procedures. 1 TlNO 3 , Et 2 Zn and Me 2 Zn were purchased from Acros and Aldrich and used without further purification. Solvents were dried using an M. Braun solvent purification system with alumina columns or were freshly distilled from drying agents using standard methods. NMR spectra were recorded using either a 300 MHz or a 500 MHz Varian Unity Inova NMR spectrophotometer. IR spectra were recorded on a Perkin-Elmer Spectrum one Fourier-transform IR absorption spectrophotometer. High resolution mass spectrometry was performed on VG70SE double focusing, triple quadruple mass spectrometer equipped with FAB or CI ionization capability. Elemental analyses were performed by Robertson Microlit. Single crystal X-ray diffraction studies. Diffraction data for all compounds were collected using a Bruker AXS SMART APEX CCD diffractometer using monochromatic Mo Kα radiation with the omega scan technique. Single crystals were mounted on Mitegen micromesh mounts and data were collected at 100 K. Data were collected, unit cells determined, and the data integrated and corrected for absorption and other

Experimental section General Procedures. Compounds 3-5 were prepared under N 2 atmosphere using an M. Braun UNILAB glove-box and Schlenk techniques. The ligands, K(Ttz R,Me), were prepared by following known procedures. 1 TlNO 3 , Et 2 Zn and Me 2 Zn were purchased from Acros and Aldrich and used without further purification. Solvents were dried using an M. Braun solvent purification system with alumina columns or were freshly distilled from drying agents using standard methods. NMR spectra were recorded using either a 300 MHz or a 500 MHz Varian Unity Inova NMR spectrophotometer. IR spectra were recorded on a Perkin-Elmer Spectrum one Fourier-transform IR absorption spectrophotometer. High resolution mass spectrometry was performed on VG70SE double focusing, triple quadruple mass spectrometer equipped with FAB or CI ionization capability. Elemental analyses were performed by Robertson Microlit. Single crystal X-ray diffraction studies. Diffraction data for all compounds were collected using a Bruker AXS SMART APEX CCD diffractometer using monochromatic Mo Kα radiation with the omega scan technique. Single crystals were mounted on Mitegen micromesh mounts and data were collected at 100 K. Data were collected, unit cells determined, and the data integrated and corrected for absorption and other

Experimental section General Procedures. Compounds 3-5 were prepared under N 2 atmosphere using an M. Braun UNILAB glove-box and Schlenk techniques. The ligands, K(Ttz R,Me), were prepared by following known procedures. 1 TlNO 3 , Et 2 Zn and Me 2 Zn were purchased from Acros and Aldrich and used without further purification. Solvents were dried using an M. Braun solvent purification system with alumina columns or were freshly distilled from drying agents using standard methods. NMR spectra were recorded using either a 300 MHz or a 500 MHz Varian Unity Inova NMR spectrophotometer. IR spectra were recorded on a Perkin-Elmer Spectrum one Fourier-transform IR absorption spectrophotometer. High resolution mass spectrometry was performed on VG70SE double focusing, triple quadruple mass spectrometer equipped with FAB or CI ionization capability. Elemental analyses were performed by Robertson Microlit. Single crystal X-ray diffraction studies. Diffraction data for all compounds were collected using a Bruker AXS SMART APEX CCD diffractometer using monochromatic Mo Kα radiation with the omega scan technique. Single crystals were mounted on Mitegen micromesh mounts and data were collected at 100 K. Data were collected, unit cells determined, and the data integrated and corrected for absorption and other

Experimental section General Procedures. Compounds 3-5 were prepared under N 2 atmosphere using an M. Braun UNILAB glove-box and Schlenk techniques. The ligands, K(Ttz R,Me), were prepared by following known procedures. 1 TlNO 3 , Et 2 Zn and Me 2 Zn were purchased from Acros and Aldrich and used without further purification. Solvents were dried using an M. Braun solvent purification system with alumina columns or were freshly distilled from drying agents using standard methods. NMR spectra were recorded using either a 300 MHz or a 500 MHz Varian Unity Inova NMR spectrophotometer. IR spectra were recorded on a Perkin-Elmer Spectrum one Fourier-transform IR absorption spectrophotometer. High resolution mass spectrometry was performed on VG70SE double focusing, triple quadruple mass spectrometer equipped with FAB or CI ionization capability. Elemental analyses were performed by Robertson Microlit. Single crystal X-ray diffraction studies. Diffraction data for all compounds were collected using a Bruker AXS SMART APEX CCD diffractometer using monochromatic Mo Kα radiation with the omega scan technique. Single crystals were mounted on Mitegen micromesh mounts and data were collected at 100 K. Data were collected, unit cells determined, and the data integrated and corrected for absorption and other

Zinc (Zn) is an essential trace mineral that contributes to the regulation of several cellular functions, however it may be also implicated in the progression of breast cancer through different mechanisms. It has been largely reported that the classical estrogen receptor (ER) as well as the G protein estrogen receptor (GPER, previously known as GPR30) can exert a main role in the development of breast tumors. In the present study, we demonstrate that zinc chloride (ZnCl2 ) involves GPER in the activation of insulin-like growth factor receptor I (IGF-IR)/epidermal growth factor receptor (EGFR)-mediated signalling, which in turn triggers downstream pathways like ERK and AKT in breast cancer cells and main components of the tumor microenvironment namely cancer-associated fibroblasts (CAFs). Further corroborating these findings, ZnCl2 stimulates a functional crosstalk of GPER with IGF-IR and EGFR toward the transcription of diverse GPER target genes. Then, we show that GPER contributes ...

The nano particles of Ni. Cu Zn. Fe O (x = 0.1, 0.15, 0.2, 0.25, 0.3) were prepared by sol-gel auto-combustion method. Cubic spinel structure was confirmed using X-ray powder diffraction patterns. The increase in lattice constant with increase in copper content was observed. The crystallite size calculated using Debye-Scherrer formula was found to be in the range from 18 nm to 23 nm. The chemical compositions of the samples were confirmed using energy-dispersive x-ray spectroscopy method. SEM images of the samples showed spherical shaped nano particles. The agglomerations of particles were observed in SEM images. The saturation magnetization values of as prepared samples obtained using vibrating sample magnetometer (VSM) at room temperature are found to be in the range between 39.79 emu/g and 53.93 emu/g. The low value of coercivity confirmed soft nature of prepared ferrites.

Using Raman spectrometry, we obtained results showing the influence of organic ligands on the vibrational properties of small zinc oxide nanocrystals (2.1–6.8nm). It is shown that it is possible to distinguish both mechanical and dielectric effects from the E2 nonpolar phonon mode and from a surface mode, theoretically predicted but rarely observed. It has been found that E2 phonon is not dependent on the nanocrystal size, but its frequency decreases with increasing ligand length, characteristic of a tensile stress on the nanocrystal. We report also the observation of a surface optical mode, the experimental frequency of which is in reasonable agreement with available calculations.

Le zinc assure les défenses immunitaires, protège contre le vieillissement cellulaire, participe à la santé de la peau, des ongles et des cheveux, la cicatrisation, le métabolisme cellulaire, la croissance et le développement de l’enfant et du fœtus, la synthèse de l’ADN et des protéines, le métabolisme des graisses, de la vitamine A, la santé de la vue, du goût et de l’odorat, l’équilibre acido-basique, la division cellulaire, l’ossature, la fonction cognitive, la fertilité, la testostérone, régule les glandes sébacées. Il est présent dans les fruits de mer, la viande rouge, les fromages, le chocolat en poudre, le pain complet, les fruits à coque, les aliments céréaliers non raffinés, les œufs et les légumes secs. Son déficit est causé par l'alcoolisme, la caféine, les phytates, l’oxalate, les diurétiques, les antibiotiques, une maladie des reins, du foie ou du pancréas, le diabète de type 2, la drépanocytose, la diarrhée, la maladie de Chrohn, un régime végétarien strict, le sport intensif, l’alimentation riche en fibres, phytates, phosphate, oxalate, tanins. Remèdes: recourir aux protéines animales, aux aliments riches en histidine, en méthionine, en cystéine, en acide citrique.

The clinical efficacy of current antidepressant therapies is unsatisfactory; antidepressants induce a variety of unwanted effects, and, moreover, their therapeutic mechanism is not clearly understood. Thus, a search for better and safer agents is continuously in progress. Recently, studies have demonstrated that zinc and magnesium possess antidepressant properties. Zinc and magnesium exhibit antidepressant-like activity in a variety of tests and models in laboratory animals. They are active in forced swim and tail suspension tests in mice and rats, and, furthermore, they enhance the activity of conventional antidepressants (e.g., imipramine and citalopram). Zinc demonstrates activity in the olfactory bulbectomy, chronic mild and chronic unpredictable stress models in rats, while magnesium is active in stress-induced depression-like behavior in mice. Clinical studies demonstrate that the efficacy of pharmacotherapy is enhanced by supplementation with zinc and magnesium. The antidepressant mechanisms of zinc and magnesium are discussed in the context of glutamate, brain-derived neurotrophic factor (BDNF) and glycogen synthase kinase-3 (GSK-3) hypotheses. All the available data indicate the importance of zinc and magnesium homeostasis in the psychopathology and therapy of affective disorders.

Age-specific distribution of clinical measurements in cross-sectional study is described in this paper. Since the distribution of measurements usually varies with age, a model with an age-dependent structure is needed. We propose here a statistical method for describing the age-specific distribution using an extension of the power-normal-model. The age-dependent parameters are to be estimated through a nonparametric smoothing technique based on the local likelihood method. As a consequence, we can compute a smoothed percentile curve of measurements with reference to age. Several kinds of clinical measurements are analyzed to determine the proposed method.

We have developed a state-of-the-art surface plasmon resonance imaging (SPRi) apparatus combined with microfluidics and used it to detect the binding of amyloid beta peptides to the lipid membrane, an interaction known to be involved in the molecular mechanism of amyloid toxicity in Alzheimer’s disease, and to study protective effect of melatonin. Kinetics of binding was measured, and quantitative analysis was developed in order to detect melatonin partitioning into and amyloid binding to the membrane. We provided for the first time clear experimental evidence that the presence of melatonin in supported lipid membrane prevents the amyloid peptide from binding to the lipid membrane, thus gaining insight into the molecular mechanism of melatonin protection against amyloid toxicity in Alzheimer’s disease.

Fluorescence resonance energy transfer (FRET) between matched carbocyanine lipid analogs in the plasma membrane outer leaflet of RBL mast cells was used to investigate lateral distributions of lipids and to develop a general method for quantitative measurements of lipid heterogeneity in live cell membranes. FRET measured as fluorescence quenching of long-chain donor probes such as DiO-C 18 is greater with long-chain, saturated acceptor probes such as DiI-C 16 than with unsaturated or shorter-chain acceptors with the same chromophoric headgroup compared at identical concentrations. FRET measurements between these lipid probes in model membranes support the conclusion that differential donor quenching is not caused by nonideal mixing or spectroscopic differences. Sucrose gradient analysis of plasma membrane-labeled, Triton X-100lysed cells shows that proximity measured by FRET correlates with the extent of lipid probe partitioning into detergent-resistant membranes. FRET between DiO-C 16 and DiI-C 16 is sensitive to cholesterol depletion and disruption of liquid order (Lo) by shortchain ceramides, and it is enhanced by cross linking of Lo-associated proteins. Consistent results are obtained when homo-FRET is measured by decreased fluorescence anisotropy of DiI-C 16. These results support the existence of nanometer-scale Lo/liquid disorder heterogeneity of lipids in the outer leaflet of the plasma membrane in live cells.