Electrochemical stripping voltammetry of gold ions for development of ultra-sensitive immunoassay for chlorsulfuron

The paper reports a highly sensitive enzyme free electrochemical immunoassay (EFEIA) for the detection of herbicide chlorsulfuron. The assay is based upon oxidative gold nanoparticle (GNP) dissolution in an acidic solution. The consequent release of large amounts of gold (Au) metal ions after dissolution of gold nanoparticles tagged to antibody leads to the development of sensitive stripping voltammetry based immunoassay. The detection is made possible by the reduction of Au^3 + ions at the screen printed electrode surface followed by metal analysis by using the square wave voltammetry technique. The sensitivity of chlorsulfuron detection by competitive assay procedure was 6.7 pg mL^− 1 for EFEIA in marked contrast to optical detection using Standard ELISA procedure that gives a sensitivity of 4.97 ng mL^− 1.     

Intraspecific competition of predator for prey with variable rates in protected areas

Nonlinear Dynamics - In this present study, we systematically explore the periodicity (almost periodic nature) of a dynamical system in time-varying environment, which portrays a special case of...     

Pyrazine Based Type-I Sensitizing Assemblies for Photoreduction of Cu(II) in ‘One-Pot Three-Component’ CuAAC Reaction Under Aerial Conditions

Photosensitizing assemblies of pyrazine derivative PDA have been developed which exhibit a high photostability, ‘lighted’ excited state, balanced redox potential, high transportation potential and activate oxygen via type-I pathway only. These PDA assemblies in combination with Cu(II) ions catalyze the CuAAC reaction via in situ reduction of Cu(II) ions without any reducing or stabilizing agent. The present protocol has wide substrate scope with recyclability of the catalytic system up to six catalytic cycles and is applicable to gram-scale synthesis.     

Multiplicity dependence of intermittency in one and two dimensions in proton-nucleus interactions at 800 GeV

The intermittency effect has been observed in interactions of 800 GeV protons with emulsion-nuclei in one-(pseudorapidity/azimuthal angle) and two-dimensional (pseudorapidity and azimuthal angle) phase spaces in different multiplicity intervals. The intermittency strength is found to decrease with increasing multiplicity. Compared to one dimension, the two dimensional distribution is found to reflect better the intermittent behavior of the interactions. The dependence of various intermittency parameters on order of moment gives clear evidence of self-similar cascade mechanism in the interactions but there is no definite indication of the presence of different phases in the cascade.     

Preparation of radiolabeled clonidine for use in radioimmunoassay

The preparation of stable and immunoreactive radioiodinated clonidine for the development of a radioimmunoassay of clonidine is described. Tyrosylmethyl ester (TME) conjugate of carboxylic acid derivative of clonidine was radioiodinated using chloramine T as the oxidizing agent. The radioiodinated clonidine was purified by thin layer chromatography, gel filtration and solvent extraction. Radiochemical purity, specific activity and immunoreactivity were determined. The stability of the labeled compound during storage was tested in various solvents at different temperatures.     

Structures of the BrF(4)(+) and IF(4)(+) cations

The large discrepancies between the calculated and observed structures for BrF(4)(+) and IF(4)(+) (Christe, K. O.; Zhang, X.; Sheehy, J. A.; Bau, R. J. Am. Chem. Soc. 2001, 123, 6338) prompted a redetermination of the crystal structures of BrF(4)(+)Sb(2)F(11)(-) (monoclinic, P2(1)/c, a = 5.2289(6) A, b = 14.510(2) A, c = 14.194(2) A, beta = 90.280(1) degrees, Z = 4) and IF(4)(+)SbF(6)(-) (orthorhombic, Ibca, a = 8.2702(9) A, b = 8.3115(9) A, c = 20.607(2) A, Z = 8). It is shown that for BrF(4)(+), the large differences were mainly due to large errors in the original experimental data. For IF(4)(+)SbF(6)(-), the geometry previously reported for IF(4)(+) was reasonably close to that found in this study despite a very large R-factor of 0.15 and a refinement in an incorrect space group. The general agreement between the calculated and the redetermined geometries of BrF(4)(+) and IF(4)(+) is excellent, except for the preferential compression of one bond angle in each ion due to the influence of interionic fluorine bridges. In BrF(4)(+), the fluorine bridges are equatorial and compress this angle. In IF(4)(+), the nature of the fluorine bridges depends on the counterion, and either the axial (in IF(4)(+)SbF(6)(-)) or the equatorial (in IF(4)(+)Sb(2)F(11)(-)) bond angle is preferentially compressed. Therefore, the geometries of the free ions are best described by the theoretical calculations.     

CH activation with an O-donor iridium-methoxo complex

A thermally and air stable O-donor, iridium-methoxo complex is reported that undergoes stoichiometric, intermolecular C-H activation of benzene with co-generation of methanol and the iridium-phenyl complex.     

Synthesis and binding studies of novel thiacalixpodands and bisthiacalixarenes having O,O″-dialkylated thiacalix[4]arene unit(s) of 1,3-alternate conformation

A series of thiacalixpodands and bisthiacalixarenes with imine units have been prepared by condensation of O,O″-bis(2-aminoethyl)-O′,O?-dipropyl-p-tert-butylthiacalix[4]arene of 1,3-alternate conformation with different aromatic (di)aldehydes. The molecules derived from pyridine-2-carbaldehyde and -2,6-dicarbaldehyde quantitatively extract silver ion from aqueous into organic phase with complete selectivity over other metal ions (Na⁺, K⁺ and Cs⁺) under neutral conditions. The former compound forms a 1:2 (L:M) complex with silver ion as proved by NMR spectroscopy, Job’s plot and X-ray crystallography.