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  • Author or Editor: G. Banerjee x
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Portulaca oleracea L. (Portulacaceae), although an alien, has turned to be a very useful plant in Indian folk medicine. The present work deals with the evaluation of the antifungal activity of this plant. Fungitoxicity of aqueous and organic solvent (e.g. hexane, ethanol and chloroform) extracts were tested against Aspergillus niger, Rhizopus artocarpi and Fusarium sp. by Agar Cup Assay and Filter Disc methods. Hexane and aqueous extracts show antifungal activity against Fusarium sp., while ethanol and chloroform extracts of the same herb inhibit the growth of Rhizopus artocarpi. These findings can have practical application.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: M. Chatterjee, S. Bhattacharyya, A. Bhattacharyya, M. Banerjee, G. Muthukrishnan and S. Banerjee

Abstract  

A method is described for the recovery of NH4 99TcO4 from its reaction waste. From the collected waste solution99Tc was precipitated as99Tc2S7 which on digestion with ammoniacal hydrogen peroxide produced a mixture of NH4 99TcO4 and (NH4)2SO4 from which the latter was removed by treatment with Ba(OH)2. The solution fumished NH4 99TcO4 as a crystalline material in 54% overall yield and with 96–98% purity after chromatographic purification over Dowex 50W column. Recrystallisation of this material from aqueous ammoniacal ethanol gave the analytical material which compared well with a standard sample and with literature data in terms of its -counts/mg and its molar extinction co-efficients () at 244 and 286 nm.

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Abstract  

The formation of nano-quasicrystals on isothermal annealing of melt-spun ribbons of Zr69.5Al7.5Ni11Cu12 metallic glass has been investigated using transmission electron microscopy (TEM). The crystallization study of this metallic glass has been carried out using differential scanning calorimetry (DSC) in non-isothermal (linear heating) mode. It exhibits two-stage crystallization where the first stage corresponds to the precipitation of icosohedral nano-quasicrystalline phase. This has been confirmed with the help of TEM investigations. The crystallization parameters like the activation energy (E c) and frequency factor (k 0) have been derived using the Kissinger peak shift analysis. The activation energies for the first and second crystallization peak are found to be 278 and 295 kJ mol-1, respectively. The frequency factors obtained for the two peaks are respectively 7.161019 and 1.421020 s-1. E c, k 0 and the Avrami exponent (n) have also been derived by fitting the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation for the transformed volume fraction (x) to the crystallization data. JMAK results of E c for the first and second crystallization peak turn out to be 270 and 290 kJ mol-1 respectively. However, k 0 and n are found to be heating rate dependent as reported in similar studies. The values of n for the first crystallization stage ranges between 1.66 and 2.57 indicating diffusion-controlled transformation in agreement with earlier reports.

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Crystallization kinetics of Cu3Ti2 forming from Cu60Ti40 glass

Continuous heating experiments in XRD and DSC

Journal of Thermal Analysis and Calorimetry
Authors: E. Baburaj, G. Prasad, S. Banerjee, T. Raghu and M. Patni

Abstract  

Amorphous to crystalline transformation in Cu60Ti40 alloy has been studied under conditions of constant heating rate experiments, using XRD and DSC. In the high temperature XRD experiment, the transformation has been monitored continuously as the integrated X-ray intensity corresponding to a chosen reflection from one of the two crystalline products forming at close by temperatures. Differentiation of the curve thus obtained gives the transformation rate curve which passes through a maximum. From the peak shift with heating rate, the activation energy for the formation of Cu3Ti2 crystalline phase has been obtained. The results have been compared with those obtained by DSC.

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Present study demonstrated the isolation of most promising β-galactosidase producing bacterial strain SB from soil. Morphological, biochemical, and 16s rRNA sequence analysis identified the bacterial strain as Arthrobacter oxydans. Several chemicals, including SDS, Triton X-100, Tween 20, isoamyl alcohol, and toluene-acetone mixture, were applied for extraction of intracellular β-galactosidase from the bacterial strain Arthrobacter oxydans. Among these, Tween 20 was recorded to be most effective. Role of pH, temperature, and shaker speed on production of β-galactosidase was evaluated using Box-Behnken design of response surface methodology. According to Box-Behnken analysis, optimum production of β-galactosidase (21.38 U (mg–1 protein)) is predicted at pH 6.76, temperature 36.1 °C, and shaker speed 121.37 r.p.m. The parameters are validated with the nearest value.

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Abstract  

Lanreotide, a somatostatin analogue, was radioiodinated with 125I to explore the possibility of using 123I labeled lanreotide as a diagnostic radiopharmaceutical for tumors overexpressing somatostatin (SST) receptors. Radioiodination was carried out with 125I using chloramine T as the oxidant. The labeling yield was >90%. Characterization of 125I-Lanreotide was carried out by paper electrophoresis as well as HPLC. 125I-Lanreotide was purified by chromatography using a C18 Sep-Pak column. Radiochemical purity of the purified 125I-Lanreotide thus obtained was >99%. Significant tumor uptake of 125I-Lanreotide was observed in C57BL/6 mice bearing melanoma.

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