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111.
The procedures developed and standardised for estimation of ultra trace quantities of Pu and Am in environmental samples involve matrix dependent sample preparation, preconcentration of the nuclides by coprecipitation on iron hydroxide and or bismuth phosphate, ion exchange, electrodeposition and counting by alpha spectrometry. Isotopic analysis of Th in chicken bone using oxalate precipitation, ion exchange, electrodeposition and alpha spectrometry has indicated higher build up of228Th in chicken bone from monazite areas possibly from metabolized228Ra. 相似文献
112.
G. Samuel M. R. A. Pillai U. K. Singh C. N. Desai R. S. Mani 《Journal of Radioanalytical and Nuclear Chemistry》1986,97(2):309-316
We describe a radioimmunoassay procedure for human somatotropin using second antibody — polyethylene glycol (PEG) combination for the separation of antibody bound and free antigen. The assay is done by a single incubation of 18 hours or with one hour pre-incubation and 3 hours post-incubation at room temperature (25 °C) and uses 0.1 m of serum sample. The assay covers a range of 0–40 g/ and has a sensitivity of 0.6 g/ of somatotropin. The assay is validated by inter-assay and intra-assay variations, recovery and parallelism tests. 相似文献
113.
Rhodamine‐B has been proposed as a simple and sensitive colorimetric reagent for the estimation of sulphur dioxide in air. The air sample containing sulphur dioxide is passed through the absorbing solution of aqueous potassium iodate and N‐chlorosuccinimide to liberate iodine. The liberated iodine bleaches the pinkish red coloured rhodamine‐B dye, which measured at 555 nm. Beer's law was obeyed in the range of 0.5–5.0 μg, of sulphite per 25 mL (0.02–0.2 ppm) equivalent to 0.4–4.0 μg of sulphur dioxide (0.016–0.16 ppm). The molar absorptivity and Sandell's sensitivity were found to be 4.56 × 105 l mol?1 cm?1 and 0.00017 μg cm?2, respectively. The method has been suitably modified and successfully applied to the determination of sulphites in water after liberation of sulphur dioxide in acidic medium. 相似文献
114.
Yip VL Varrot A Davies GJ Rajan SS Yang X Thompson J Anderson WF Withers SG 《Journal of the American Chemical Society》2004,126(27):8354-8355
Among the numerous well-characterized families of glycosidases, family 4 appears to be the anomaly, requiring both catalytic NAD+ and a divalent metal for activity. The unusual cofactor requirement prompted the proposal of a mechanism involving key NAD+-mediated redox steps as well as elimination of the glycosidic oxygen. Primary kinetic isotope effects for the 2- and 3-deutero substrate analogues, isotopic exchange with solvent, and structural analysis of a 6-phospho-beta-glucosidase, BglT (E.C. 3.2.1.6), provided evidence in support of the proposed mechanism, which has striking resemblances to that of the sugar dehydratases. Furthermore, analysis of the stereochemical outcome indicated that family 4 enzymes are retaining glycosidases. 相似文献
115.
The standardisation of a direct radioimmunoassay for progesterone using an125I labeled progesterone prepared by iodinating the tyrosine methyl ester (TME) conjugated to a progesterone hemiphthalate derivative
and an antibody prepared using progesterone linked to bovine serum albumin through 11α hemisuccinate derivative is described.
The hemiphthalate derivative of progesterone was prepared by reacting 11α-hydroxy progesterone with phthalic anhydride which
was then conjugated to TME by using isobutyl chloroformate. The conjugate was iodinated with125I using chloramine-T as oxidising agent and purified by thin layer chromatography. Radiochemical purity of the tracer was
>95% in all batches. The tracer gave 70–75% binding with excess antibody. Assays were optimised with 8-anilino-1-naphthalene
sulphonic acid (ANS) and sodium salicylate as blocking agents to release the progesterone from binding proteins. The assay
optimised with sodium salicylate as blocking agent has a sensitivity of 0.25 ng/ml and a working range of 0.25–50 ng/ml, whereas
the assay with ANS has a sensitivity of 0.75 ng/ml and a working range of 0.75–100 ng/ml. Serum samples were analysed and
compared with the values obtained with a homologous bridge assay. 相似文献
116.
M. R. A. Pillai C. L. Barnes C. S. John D. E. Troutner E. O. Schlemper 《Journal of chemical crystallography》1993,23(12):949-953
Palladium(II) complexes of an imine-thiophene ligand N,N bis(1-methylenethiophene)-1,3-diaminopropane and an amine-phenol ligand N,N-bis(2-hydroxybenzyl)1,3-diamino-2,2-dimethylpropane were synthesized by reacting K2PdCl4 with alcoholic solutions of the ligands. X-ray structures of the complexes were determined using data from a CAD-4 Nonius diffractometer (MoK radiation). The structures were solved by conventional methods resulting inR factors of 0.044 and 0.061 using 1841 and 2241 independent reflections, respectively. Crystal data: Complex I, orthorhombic, space groupPbca,a=11.323(2),b=14.819(2),c=23.873(3)Å,V=4006(1)Å3,Z=8. Complex II: Space groupP21/c,a=9.169(2),b=31.920(4),c=8.902(6),=90.38(2)°,V=2605(1)Å3.Z=4. Both complexes showed coordination of the ligands through the nitrogens only while the sulphur and the oxygen atoms were uncoordinated. Square planar coordination is completed bycis chloro ligands.Deceased. 相似文献
117.
Annamalai Senthil Kumar K. Chandrasekara Pillai 《Journal of Solid State Electrochemistry》2000,4(7):408-416
Ruthenium dioxide electrodes, prepared on a Pt substrate using coatings of PVC-RuO2 mixed in THF (designated as RuO2-PVC film electrode) have been studied for their redox behaviour in 1 M NaOH using variable scan cyclic voltammetry. The various
redox transitions in the oxidation state of the central metal ion are characterized using electrochemical parameters such
as peak potential, peak current, and surface charge. The effect of oxide preparation temperature, in the range 300–700 °C,
on the redox characteristics has also been studied and correlated with the electrochemically active surface area (as measured
using small amplitude cyclic voltammetry) and the true surface area (by the BET method).
Received: 12 August 1997 / Accepted: 18 October 1999 相似文献
118.
A simple and direct spectrophotometric method has been developed for the determination of cobalt(II) using N,N′-Bis(2-aminobenzoyl)ethylenediamine
(Baben). The method is based on the colour reaction between Baben and cobalt(II) in borax buffer (pH 9.2). The studies are
carried out at 470 nm at which the calculated value of molar absorptivity is found to be 1.102 × 104 L mol−1 cm−1. The system obeys Beer’s law over a wide range of concentration (2–20 μg/ml). The effect of interfering ions has been studied
and the method was applied to the determination of cobalt in water, industrial effluents and in alloys and the results were
highly satisfactory.
Received May 8, 2000. Revision January 30, 2001. 相似文献
119.
The present paper deals with thermophoresis in natural convection with variable properties for a laminar flow over a cold
vertical flat plate. Variation of properties like density, viscosity and thermal conductivity with temperature is included
in the formulation of the problem. Selection of components for the property ratio is made by fitting the property values between
the desired temperature limits. For a selected fluid, Prandtl number variation with temperature is neglected and the Prandtl
number corresponding to film temperature is used for the analysis. Solution is carried out by finite difference method. Variation
of wall concentration and wall flux along the length of plate is studied. The effect of thermophoretic coefficient on wall
concentration is also studied. Results are presented in the form of graphs. The result is compared with similarity solution
by Runge-Kutta method and found to be accurate upto second decimal place.
Received on 18 May 1998 相似文献
120.