Electrochemical behaviour of zinc gluconate complexes

Voltammetric studies revealed that under transient conditions in the pH range 3.7 to 5.0, the deposition of zinc from ZnSO₄ solutions involves the formation of adsorbed monovalent zinc. The conversion of divalent zinc to monovalent is a slow step. In the presence of gluconate, the reduction of divalent complex involves the monovalent zinc complex and the second electron transfer is slow. In the pH range 10 to 12.5, the zinc complex may be [(Zn(GH₄)₄]2^- and is found to vary with gluconate and OH^- ions. The conversion of [Zn(GH₄)(OH)_abs ^-] to Zn(OH)₂ or Zn(GH₄)₂ is the slow step in the reduction of the complexes. In strong alkali solutions sodium gluconate forms zinc hydroxy gluconate complexes. [Zn(OH)₃(GH₄)]^2- to adsorbed [Zn(OH)(GH₄)]^- is the slow step in the reduction.     

Characterization of alpha helices interacting with nucleic acids

Protein-nucleic acid interactions play a vital role in most genetic processes. An enhanced insight into such interactions can be obtained from the structure database of these complexes. Here, we report an overall survey on the geometry of alpha helices which interact with nucleic acids through hydrogen bonds and/or non-bonded interactions. Using the program RADIL based on an algorithm developed from this laboratory, 161 alpha helices in 70 non-redundant nucleic acid binding protein chains solved using X-ray crystallography are analysed. The helical geometry has been characterized as bent, canonical, terminally or completely distorted. The analysis reveals that approximately 70% of the alpha helices possess distortions of any one kind, viz., bend, terminal distortion or complete distortion. Nearly one-third of the total helices possess bends, with a majority of the bending occurring in 5-15 degrees range. In addition, a majority of the bent helices approach the nucleic acid helix in a perpendicular direction. The program RADIL has been useful in characterizing the nucleic acid-induced structural variations in alpha helices, however small they may be.     

Structural and thermal characterization of a semiorganic NLO material: L-alanine cadmium chloride

L-Alaninium cadmium chloride (LACC), a semiorganic nonlinear optical material has been synthesized and its single crystal grown and characterized for its thermal, structural, linear and second order nonlinear optical properties. Powder SHG study shows that LACC is 1.5 times efficient as KDP. Its optical transparency goes down to 200 nm comparable to the typical borate crystals like potassium pentaborate.     

Fabrication of Nickel Tetrasulfonated Phthalocyanine Functionalized Multiwalled Carbon Nanotubes on Activated Glassy Carbon Electrode for the Detection of Dopamine

The nickel tetrasulfonated phthalocyanine (NiTsPc) functionalized multiwalled carbon nanotube (MWCNT) nanocomposite was prepared by a simple sonochemical method. Here, NiTsPc served as a dispersing agent for MWCNT via π? π interaction between MWCNT and NiTsPc. The activated glassy carbon electrode (AGCE) modified with MWCNT‐NiTsPc composite exhibited a good electrocatalytic ability toward dopamine and displayed a good linear dependence in the concentration range of 20 nM–1.384 mM with a sensitivity of 0.17 µA µM^?1 cm^?2. The detection limit is 1 nM based on the signal‐to‐noise ratio of 3.     

Spectroscopic and optical studies on pure and doped single crystals of sulphate-mixed L-arginine phosphate monohydrate--a nonlinear optical crystal

Single crystals of pure and transition metal ions (Cu(2+) and VO(2+))-doped L-arginine sulpho phosphate monohydrate (sulphate-mixed L-arginine phosphate monohydrate, abbreviated as LASP) have been grown by solvent evaporation of the saturated aqueous solution at room temperature and characterized by single-crystal XRD, FT-IR, UV-Vis-NIR and EPR (single-crystal rotation) spectral studies. Kurtz powder technique shows an enhanced second harmonic generation (SHG) efficiency for LASP and its doped analogues than pure LAP. The EPR studies on LASP:VO(2+) reveal that the in-plane sigma-bonding is moderately covalent and the out-of-plane pi-bonding is highly covalent, which could be attributed to the cause of enhanced powder efficiency.     

子半理想环

本文提出了环论中的一个新概念：子半理想，得到了群环为子半理想环的一个充要条件。     

Synthesis, characterization and pharmacologically active sulfamethoxazole polymers

Three anti-microbial pharmaceutical drugs were synthesized from two different synthetic routes. 4-acrylamido-N-(5-methyl-3-isoxazolyl)benzenesulfonamide (AMBS) and 4-methacrylamido-N-(5-methyl-3-isoxazolyl)benzenesulfonamide (MMBS) were prepared by reacting acryloyl chloride and methacryloyl chloride with 4-amino-N-(5-methyl-3-isoxazolyl)benzenesulfonamide in the presence of triethylamine. N-[4-sulfamido-N-(5-methyl-3-isoxazolyl)phenyl]maleimide (SMPM) was prepared by reacting maleic anhydride with 4-amino-N-(5-methyl-3-isoxazolyl)benzenesulfanamide. These monomers (AMBS, MMBS and SMPM) were polymerized using BPO as a free radical initiator. The pharmacological activity of SMPM compound depends on the functional group in the structure and small structural changes has resulted in higher pharmacological activity of sulfamethoxazole. Thus, maleimide polymer drug conjugate showed greater anti-microbial activity when compared with that of the native drug.