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Abstract  

Application of charged particle activation analysis (CPAA) for the detection of traces of titanium has been demonstrated. Experimental samples containing traces of titanium varying from ppm to ppb levels were prepared by coprecipitating it with aluminium hydroxide, subsequently converted to Al2O3. Titanium in Al2O3 were irradiated with 40 MeV -particles in the Variable Energy Cyclotron, Calcutta. The element was detected through the product radioisotopes,48V,47Ca,47Sc,51Cr,49Cr and48Cr, produced from various nuclear reactions such as (, pxn), (, xn), etc. Suitability of Al2O3 as diluent matrix for the element has been verified.

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Abstract  

This text describes the instrumental determination of some elements in silicate samples of ≃1 g by photon activation. The following elements can be determined: In acidic rocks: Mg, Ca, Ti, Mn, Sr, Zr and Nb, in ultramafic rocks: Mg, Cr, Ni, and Mn. The relative standard deviation is a few percent.

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Abstract  

Two types of gas-liquid separators for use in on-line hydride generation AAS have been examined: the classical one, in which gas and liquid are separated by gravity and that based on diffusion through a pemeable tube. Results are presented for the determination of arsenic species (arsenite, As(III); arsenate, As(V); monomethylarsonic acid, MMAA; dimethylarsinic acid, DMAA). Yield (of hydride generation and gas-liquid separation) and response time are investigated as functions of the experimental variables. It is concluded that in conjunction with a cold trap, only the classical gas-liquid separator is satisfactory.

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Abstract  

Charged particle activation of natural CeO2 with ≈80 MeV16O7+ results in the formation of carrier free isotopes,151, 152, 153Dy and their daughter products,151, 152, 153Tb, in the matrix. The liquid cation exchanger HDEHP, has effectively been utilised as an extractant in the quantitative separation of the activation products namely151, 152, 153Dy,151, 152, 153Tb from the bulk target matrix of ceric oxide.

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Acta Alimentaria
Authors:
D. Das
,
S. Tamuly
,
M. Das Purkayastha
,
B. Dutta
,
C. Barman
,
D.J. Kalita
,
R. Boro
, and
S. Agarwal

Abstract

Green tea or its concentrated extract is coveted for its health promoting catechin-like polyphenols, especially epigallocatechin-3-gallate (EGCG). However, its amicable efficacy is now being doubted considering the recent occurrence of several cases of hepato- and nephrotoxicity, after the ingestion of EGCG-fortified (≥85–90%) nutritional supplements. Therefore, the current study was carried out to ascertain the effect of green tea leaves extract (GTE), having low EGCG content (73.8%), on liver and kidney functions of male Wistar rats using various in vivo experiments and in vitro radical scavenging activity. In terms of acute toxicity, GTE was observed to be safe when delivered at a dosage of 2000 mg kg−1 body weight (BW). Oral delivery of GTE for 28 days at a concentration of 200 mg kg−1 BW/day did not trigger sub-acute toxicity to the liver and kidneys, as per serum biochemical analyses and histopathological examination. In contrast, GTE counteracted the effects of carbon tetrachloride (a potent hepato-degenerative compound) on the liver. Furthermore, increase in high-density lipoprotein―cholesterol with concomitant lowering of serum triglycerides and low-density lipoprotein―cholesterol were noticed in GTE-treated rats. These findings suggest that low EGCG containing GTE, with appreciable antioxidant activity (IC50 = 53.18–71.28 μg mL−1), can serve as a hepatoprotective, hypolipidemic, and hypocholesterolemic ingredient.

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Calcium plays an important role in the regulation of different functions of keratinocytes. In the present work we studied the effect of different extracellular calcium concentrations (0.01 mM-2.0 mM) on the proliferation and differentiation of human keratinocytes in normal human and non-lesional psoriatic skin. Using explant culture model, the proliferative and differentiated subsets of keratinocytes were detected by specific antibodies related to cell proliferation [beta-1 integrin (CD29), proliferating cell antigen (Ki67), proliferating cell nuclear antigen (PCNA)] and differentiation [differentiated cell cytokeratins (K1/K10) and differentiating cell antigen (lectin Ulex europaius agglutinin, UEA-1)]. After 4 days of culturing at high Ca2+ (2.0 mM) we observed marked hyperproliferation among the normally quiescent keratinocytes of non-lesional psoriatic skin. In normal uncultured and cultured skin and in uncultured and two-day-cultured non-lesional psoriatic skin both at normal (1.2 mM) and at high (2.0 mM) Ca2+ concentration only one layer of basal CD29+/Ki67+/K1/K10-/UEA-1- cell was observed. In sections from non-lesional psoriatic skin cultured for 4 days in the presence of high Ca2+ (2.0 mM) this cell population has expanded from at least three layers above the basement membrane. This expanded cell population of the 4-day high Ca2+ cultured non-lesional skin showed clear PCNA positive staining on frozen sections with the strongest positivity among the most basal localized cells. These data suggest that (i) extracellular Ca2+ concentration can influence the proliferation of basal ("stem") keratinocytes, (ii) the proliferative response to high Ca2+ concentration of psoriatic non-lesional basal keratinocytes differs from that of normal basal keratinocytes, (iv) changes in the extracellular Ca2+ milieu might play a role in the induction of the hyperproliferative psoriatic lesion.

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Abstract  

The beach placer deposit at Chhatrapur coast of Orissa state, southeastern coast of India, has a significant concentration of radiogenic heavy minerals. The average activity concentrations of radioactive elements such as 232Th, 238U and 40K were measured by gamma ray spectrometry using a HPGe detector, and found to be 2650±50, 400±30 and 120±30 Bq/kg, respectively, for the bulk sand samples. The activity concentrations in monazite and zircon sands are found to be 305,000±2000 and 2000±150 Bq/kg for the 232Th and 21,500±300 and 3450±250 Bq/kg for the 238U. Electron probe microanalysis results of monazite sands show the average ThO2 and UO3 concentrations to be 10.42 wt.%, and 0.32 wt.%, respectively. The major contributors for the enhanced level of radioactivity are monazite and zircon sands. These heavy mineral sands were derived from the nearby source areas such as Eastern Ghats Group of rocks.

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Strong anomalies in the concentration of helium, radon and gamma were observed in gases at the geochemical monitoring station, Bakreswar, West Bengal, India, about two weeks before the 7.9 M earthquake at Sichuan, China. The distance between the epicenter of the earthquake and the monitoring site is about 1800 km. This long distance preseismic observation indicates that the radius of influence of large magnitude earthquakes may be substantially large and may cut across plate boundaries. This paper presents the observed geochemical anomalies for the Sichuan earthquake and discusses empirical postulates between earthquake magnitude and its radius of influence.

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Pomelo fruit juice is concentrated using two different techniques, i.e. block freeze concentration (BFC) and thermal concentration (TC), and both concentrates were spray dried separately to observe the effects of two different concentration techniques on the physicochemical properties of the spray dried powder. BFC juice had comparatively better values of retention of acidity, colour, vitamin C, DPPH● scavenging activity, total phenolic content (TPC), and total sugar content than TC juice. The powder obtained from the combination of BFC and spray drying had better retention of vitamin C (121.17 mg/100 g), colour, and exhibited higher DPPH● scavenging activity than TC spray dried powder. The physical parameters including solubility index, bulk density, and hygroscopicity were significantly higher in BFC spray dried powder. BFC was observed as an efficient concentration technique in comparison to TC as a pretreatment to produce spray dried powder with a better retention of bioactive components and powder flow properties.

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