Synthesis,characterization and biological activity studies of octahedral nickel(II) complexes

Abstract  

Three nickel(II) complexes, namely [Ni(BH)₃](H₂O)(NO₃)(ClO₄) 1, [Ni(BH)₂(NO₃)₂] 2 and [Ni(BH)(Tren)](ClO₄)₂ 3 (BH = Benzoylhydrazine, Tren = Tris(2-aminoethyl)amine) have been synthesized and characterized by physico-chemical techniques. X-ray crystallographic analysis shows the nickel to be six-coordinated in these complexes. The complexes are efficient catalysts for the dismutation of superoxide in alkaline DMSO-NBT assays. The IC₅₀ values are 74,108 and 105 μM for 1, 2 and 3, respectively.     

Optical thermometry using FIR of two close lying levels of different ions in Y2O3:Ho3+–Tm3+–Yb3+ phosphor

The possibility of combustion synthesized Ho³⁺–Tm³⁺–Yb³⁺ codoped Y₂O₃ phosphor as temperature sensor using fluorescence intensity ratio (FIR) technique under a 980 nm excitation has been reported. The variation in FIR of blue upconversion emissions generated from two closely spaced levels of the Tm³⁺ and Ho³⁺ ions (¹G₄ and ⁵F₃) as a function of temperature has been monitored up to 703 K. The maximum relative sensitivity has been found to be 3.38 × 10^?3 K^?1 which indicates that the present phosphor material can play a vital role for high optical thermometric purpose. The results imply that the FIR of two closely spaced levels of two different rare earth ions can also be used as temperature sensor.     

Approximate analysis of planar photonic bandgap waveguides: a simple semi-analytical method

A semi-analytical approximate method, Vopt, is applied to a planar photonic bandgap (PBG) waveguide and a coupler configuration. The variational process of the Vopt method presents simple effective index analysis of the complex two dimensional (2-D) structures. The Vopt method expresses the refractive index profile of the 2-D structure as two 1-D refractive index profiles and obtains the optimized indices for the two structures iteratively. The Vopt method separates the planar PBG waveguide into an effective multilayer waveguide confining optical field in the lateral direction and a 1-D Bragg reflector that gives characteristic reflection/transmission spectra. The results obtained by the Vopt method show good agreement with the numerical results of the finite difference time domain analysis. The present analysis is helpful in understanding the optical properties of such complex waveguides and can be used as starting approximation for optimizing the structures for various applications.     

Comparison between duobinary and IMDD technique for CATV transmission system

As we all know duobinary is preferred more as compare to NRZ model. In this paper we analyze duobinary and IMDD (Intensity Modulation Direct Detection) model for CATV transmission system. Comparison between duobinary and IMDD on the basis of eye diagram, Jitter, Q-value, electrical and optical spectrum.     

Some nondifferentiable multiobjective programming under generalized d-V-type-I univexity

In this paper, we introduce new classes of functions called d-V-type-I univex by extending the definition of d-V-type-I functions and consider a multiobjective optimization problem involving generalized d-V-type-I univex functions. A number of Karush–Kuhn–Tucker-type sufficient optimality conditions are obtained for a feasible solution to be a weak Pareto efficient solution. The Mond–Weir-type duality results are also presented. The results obtained in this paper generalize and extend the previously known result in this area.     

Analytical tools for monitoring changes in physical and chemical properties of chromatography resin upon reuse

Protein A resins are often reused for multiple cycles to improve process economy during mAb purification. Significant reduction in binding capacity and product recovery are typically observed due to the presence of unwanted materials (foulants) deposited on the resin upon reuse. In this paper, we have used a wide spectrum of qualitative and quantitative analytical tools (particle size analysis, HPLC, fluorescence, SEM, MS, and FTIR) to compare the strengths and shortcomings of different analytical tools in terms of their capability to detect the fouling of the resin and relate it to chromatographic cycle performance. While each tool offers an insight into this complex phenomena, fluorescence is the only one that can be used for real‐time monitoring of resin fouling. A correlation could be established between fluorescence intensity and the process performance attributes (like yield or binding capacity) impacted upon resin reuse. This demonstration of the application of fluorescence for real‐time monitoring correlated empirically with process performance attributes and the results support its use as a PAT tool as part of a process control strategy. While the focus of this paper is on fouling of protein A chromatography resin, the approach and strategy are pertinent to other modes of chromatography as well.     

Isolation and Characterization of Cross-Neutralizing Human Anti-V3 Single-Chain Variable Fragments (scFvs) Against HIV-1 from an Antigen Preselected Phage Library

Applied Biochemistry and Biotechnology - Recently conducted human phase- I trials showed protective effect of anti-HIV-1 broadly neutralizing antibodies (bnAbs). The V3 region of the HIV-1 envelope...     

Observation of inverse a.c. Josephson effect in bulk Y-Ba-Cu-O possessing highT c

Microwave-induced d.c. voltage due to inverse a.c. Josephson effect has been observed across bulk samples of Y-Ba-Cu-O. Variation of the d.c. voltage with small external magnetic field and temperature has been investigated. Our results indicate that weakly coupled superconducting grains exist up to 230 K.     

Split step non-paraxial finite difference method for 3D scalar wave propagation

We describe a simple and efficient wide-angle, split-step finite-difference based explicit transfer matrix method to solve the 3D scalar wave equation. The formulation is completely analytic and does not involve any numerical matrix inversion or diagonalization. It also does not use the ADI scheme. The PML boundary condition can be easily implemented with only a marginal increase in computational effort.     

Improved optimal variational method to analyze optical rib waveguides

We present an improved optimal variational method (Vopt) to overcome the assumption of field separability in the two orthogonal directions. The improved Vopt method is shown to give accurate results with less computational effort. The method is applied to rib waveguides and the results are compared with those obtained using the computationally intensive finite-element method.