Biosorptive profile of synthetic and natural humiresin for the remediation of metallic water pollutants

To evaluate the bioremediation efficiency of natural humic substances, over it’s synthetic counterpart, a comparative batch equilibration biosorption assay have been carried out employing radiotracers on different humi-resins. The biosorptive profile of various humiresins as devised hereby, attempts to justify an innovative and concrete role of dry cow dung powder (DCP), in ‘as it is form’, for the bioremediation of metal pollutants such as Cr(III), Cr(VI), Cd(II), Hg(II) and Sr(II). Our comparative results conclude that, with all other optimized parameters as obtained 100 mg of DCP removes Cr(III) at pH 6, Cd(II) at pH 3 and Hg(II) at pH 3 to 70–75 and 80–85 % respectively. Also, at pH 1 with 250 mg of DCP 70–75 % Cr(VI) is removed. Similarly, 90–95 % of Sr(II) is sequestered at pH 6, with 350 mg of DCP. The study on thermodynamic, kinetic and isotherm modelling of DCP indicates feasible, eco-friendly and efficient process.     

Nanosized rare earth cobaltite LaCoO<Subscript>3</Subscript> synthesized by urea combustion method

The structural, magnetic, and electrical properties of nano- and bulk samples of LaCoO₃, prepared by a urea combustion method, are investigated in this paper. The structures of phases, calcined at different temperatures, were refined in two different space groups rhombohedral R-3c and monoclinic I2/a, and a good agreement was obtained between the observed and calculated XRD patterns. Magnetic measurements reveal that the magnetic susceptibility increases with reduction in particle size. It is observed that there are two types of mechanisms which govern the conduction in different temperature ranges of these samples, and no single law of conduction fits the entire range of temperature. In high temperature range (200–300 K), Arrhenius law fits well, while in the low temperature region (100–200 K), the conduction is governed by Efros-Shklovskii’s (ES) hopping.     

Quantification of hepcidin using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Hepcidin is known to be a key systemic iron‐regulatory hormone which has been demonstrated to be associated with a number of iron disorders. Hepcidin concentrations are increased in inflammation and suppressed in hemochromatosis. In view of the role of hepcidin in disease, its potential as a diagnostic tool in a clinical setting is evident. This study describes the development of a matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) assay for the quantitative determination of hepcidin concentrations in clinical samples. A stable isotope labeled hepcidin was prepared as an internal standard and a standard quantity was added to urine samples. Extraction was performed with weak cation‐exchange magnetic nanoparticles. The basic peptides were eluted from the magnetic nanoparticles using a matrix solution directly onto a target plate and analyzed by MALDI‐TOF MS to determine the concentration of hepcidin. The assay was validated in charcoal stripped urine, and good recovery (70–80%) was obtained, as were limit of quantitation data (5 nmol/L), accuracy (RE <10%), precision (CV <21%), within ‐day repeatability (CV <13%) and between‐day repeatability (CV <21%). Urine hepcidin levels were 10 nmol/mmol creatinine in healthy controls, with reduced levels in hereditary hemochromatosis (P < 0.000005) and elevated levels in inflammation (P < 0.0007). In summary a validated method has been developed for the determination of hepcidin concentrations in clinical samples. Copyright © 2009 John Wiley & Sons, Ltd.     

Gel‐based separation of phosphoproteins in samples stored in urea/thiourea after precipitation by lanthanum chloride

The recent introduction of the La³⁺ precipitation method for the enrichment of phosphoproteins allows a gel‐based analysis of these posttranslationally modified proteins. However, if this method is applied to cell lysates stored in urea‐containing lysis buffer for an extended period of time, incomplete phosphoprotein recovery is observed. We ascribe this effect to the presence of urea in the lysis buffer. To overcome this problem various strategies were tested, where cell lysates stored at least for one year were utilized. By applying an optimized protocol approximately 250 proteins could be observed following separation by 2DE.     

Characterization of a mould flux glass

A simplified mould flux glass composition used for the continuous casting of steel was synthesized and then characterized using X-ray powder diffraction (XRD) differential thermal analysis (DTA) and ¹⁹F and ²⁹Si magic angle spinning nuclear magnetic resonance spectroscopy (MAS-NMR). DTA showed the glass to have a low glass transition temperature and to crystallize readily at 600 °C. XRD of the heat-treated glass showed it to crystallize to cuspidine. ¹⁹F MAS-NMR showed the principal fluorine species to be F-Ca(n) with no evidence of Si-F or Al-F species. Fluoride ions therefore, complex calcium in this glass, rather than forming non-bridging fluorines. The network connectivity of the glass was calculated on this basis and found to be 2.07 this would be expected to correspond to a Q² Si species which was supported by the ²⁹Si data that gave a chemical shift of −78 ppm corresponding to Q² Si.     

Vanadia impregnated iron-pillared montmorillonite for aniline methylation

Vanadia impregnated iron-pillared montmorillonites with different weight percentages of vanadia have been prepared. Subsequent characterization by XRD, FT-IR, surface area and pore volume measurements was carried out. Acidity was determined by three independent techniques namely thermogravimetric desorption of 2,6-dimethylpyridine, spectrophotometric monitoring of adsorption of perylene and temperature-programmed desorption of ammonia. Conversion of cumene in the vapor phase has been performed as a test reaction of acidity. Aniline methylation was carried out to check the catalytic efficiency of the solids. This revised version was published online in August 2006 with corrections to the Cover Date.     

Trends in the electronic structure of extended gold compounds: implications for use of gold in heterogeneous catalysis

First-principles electronic structure calculations are presented on a variety of Au compounds and species--encompassing a wide range of formal oxidation states, coordination geometries, and chemical environments--in order to understand the potentially systematic behavior in the nature and energetics of d states that are implicated in catalytic activity. In particular, we monitor the position of the d-band center, which has been suggested to signal catalytic activity for reactions such as CO oxidation. We find a surprising absence of any kind of correlation between the formal oxidation state of Au and the position of the d-band center. Instead, we find that the center of the d band displays a nearly linear dependence on the degree of its filling, and this is a general relationship for Au irrespective of the chemistry or geometry of the particular Au compound. Across the compounds examined we find that even small calculated changes in the d-band filling result in a relatively large effect on the position of the d-band center. The results presented here have some important implications for the question of the catalytic activity of Au and indicate that the formal oxidation state is not a determining factor.     

Proteome and phosphoproteome of primary cultured pig urothelial cells

Epithelial tissue lining the inner side of the urinary bladder is the most common target for bladder cancer-related diseases. Bladders of freshly slaughtered pigs were utilised for a comprehensive analysis of the proteome and phosphoproteome of bladder epithelial cells. Following protein separation by 2-D gel electrophoresis and identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF-MS) the first proteome and phosphoproteome maps of pig urinary bladder epithelial cells (PUBEC) were established. A total of 120 selected protein spots were identified. By using the La(3+) enrichment method further developed in our laboratory we identified 31 phosphoproteins with minimal contamination by non-phosphopeptides. The 2-DE map of pig urothelial cells may prove as a useful tool for studies on uroepithelial biology, and the analysed phosphoproteins expression pattern, together with the whole cell proteome, will be helpful for identifying the proteins involved in bladder-related diseases.     

Synthesis, spectroscopy and structures of palladium(II) and platinum(II) complexes containing mercapto-o-carborane

The reactions of [M₂Cl₂(μ-Cl)₂(PMe₂Ph)₂] with mercapto-o-carboranes in the presence of pyridine afforded mono-nuclear complexes of composition, [MCl(SCb°R)(py)(PMe₂Ph)] (M = Pd or Pt; Cb° = o-C₂B₁₀H₁₀; R = H or Ph). The treatment of [PdCl₂(PEt₃)₂] with PhCb°SH yielded trans-[Pd(SCb°Ph)₂(PEt₃)₂] (4) which when left in solution in the presence of pyridine gave another substitution product, [Pd(SCb°Ph)₂(py)(PEt₃)] (5). The structures of [PdCl(SCb°Ph)(py)(PMe₂Ph)] (1), [Pd(SCb°Ph)₂(PEt₃)₂] (4) and [Pd(SCb^oPh)₂(py)(PEt₃)] (5) were established unambiguously by X-ray crystallography. The palladium atom in these complexes adopts a distorted square-planar configuration with neutral donor atoms occupying the trans positions. Thermolysis of [PdCl(SCb°)(py)(PMe₂Ph)] (2) in TOPO (trioctylphosphine oxide) at 200 °C gave nanocrystals of TOPO capped Pd₄S which were characterized by XRD pattern and SEM.     

Chemistry of dihydrogen complexes containing only phosphorus co-ligands

A series of new dicationic dihydrogen complexes of ruthenium of the typecis-[(dppm)₂Ru(η₂-H₂)(L)][BF₄]₂ (dppm = Ph₂PCH₂PPh₂; L = phosphite) have been prepared by protonating the precursor hydride complexescis-[(dppm)₂Ru(H)(L)][BF₄] using HBF₄•Et₂O. The precursor hydride complexes have been obtained fromtrans-[(dppm)₂Ru(H)(L)][BF₄] (L = phosphite) via a rare acid-catalysed isomerization reaction in six coordinate species. Thetrans-[(dppm)₂Ru(H)(L)][BF₄] complexes (L = phosphine) upon protonation gave the isomerized derivatives, however, further addition of acid resulted in a five-coordinate species, [(dppm)₂RuCl]⁺ presumably via an intermediate phosphine dihydrogen complex. The electronic as well as the steric properties of the co-ligands seem to strongly influence the structure-reactivity behaviour of this series of complexes.