Piperine, an alkaloid derived from the fruits of Piper nigrum, has been tested as an extracting bioreagent for gold. It has been observed that piperine as well as the fruits of Piper nigrum itself can act as an efficient exchanger for gold both in trace and macro scale. The accumulation of gold by these bioreagents
is highly pH dependent.
The present study is performed to examine the accumulation efficiency of 51Cr(III) and 51Cr(VI) by the alkaloid piperine, derived from the fruits of Piper nigrum (Family Piperaceae) as well as using the fruit commonly known as black pepper by radiometric technique. The pH dependence
and the effect of the concentration of chromium on the accumulation have also been examined. The maximum accumulation (52%)
of Cr(III) is found by black pepper at pH 4 whereas piperine shows slight accumulation at this condition. Accumulation of
Cr(VI) by black pepper is always negligible. It has also been observed that some other constituents of the black pepper like
gum, terpenoid, etc., besides piperine is responsible for the accumulation of chromium.
Glucocorticoid hormones are important for vital functions and act to modulate inflammatory and immune responses. In contrast to other hormonal systems no endogenous mediators have been identified that can directly counter-regulate their potent anti-inflammatory and immunosuppressive properties. Glucocorticoids are known to interfere with the ability of the macrophage not only to induce and amplify an immune response but also to inhibit macrophage inflammatory effector functions. Although the actual immunocompetence of animals undergoing endocrine gland ectomy has never been directly studied, there is no doubt that adrenal hormones are deeply involved in the development and maintenance of the immunitory functions and this may in turn influence the inflammatory reaction. To study the effect of endogenous glucocorticoids on the functions of rat peritoneal macrophages and induction of humoral immune response we observed some of the rat peritoneal macrophage effector functions, provided that endogenous glucocorticoids are depleted by adrenalectomy. The mean phagocytic index (PI) of control macrophage (Mf) is increased from 23,825±427 to 31,895±83 after adrenalectomy (P£0.001). Intracellular killing capacity in control cell is 82% which is found to be 73% in case of adrenalectomised cell (p<0.05). The amount of nitric oxide released from control Mf 20.25±1 mM following adrenalectomy shows the amount of nitric oxide release was 18.25 mM (p£0.01). The percentage of DNA fragmentation in control Mf was 68.82±4 which was reduced to 56.76±1 after adrenalectomy (p£0.01). In sheep red blood cell (SRBC) immunised and adrenalectomised animal, agglutination titre was obtained at lowest antibody concentration (1:128) whereas serum from SRBC immunised normal rats showed early agglutination (1:32). Endogenous glucocorticoid depleted rats show enhanced phagocytic capacity, antibody raising capacity as well as on the other hand adrenal hormone insufficiency reduces the intracellular killing capacity, nitric oxide (NO) release, improper cell maturation and heightens the probability of infection. These observations demonstrate a counter-regulatory system via glucocorticoid that functions to control inflammatory and immune responses.
Bio-composite fibers were developed from wood pulp and polypropylene (PP) by an extrusion process. The thermo-physical and mechanical properties of wood pulp-PP composite fibers, neat PP and wood pulp were studied using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The thermal stability of bio-composite fibers was found to be significantly higher than pure wood pulp. An understanding into the melting behaviour of the composite system was obtained which would assist in selecting a suitable temperature profile for the extruder during processing. The visco-elastic properties of bio-composite fibers were also revealed from the study. The generated bio-composite fibers were also characterized using Fourier transform infrared spectroscopy (FTIR) to understand the nature of chemical interaction between wood pulp reinforcement and PP matrix. The use of maleated polypropylene (MAPP) as a compatibilizer was investigated in relation to the fiber microstructure. Changes in absorption peaks were observed in FTIR spectra of bio-composite fibers as compared to the pure wood pulp which indicated possible chemical linkages between the fiber and polymer matrix.
Authors:S. Das, C. Kedari, S. Shinde, S. Ghosh, and U. Jambunathan
The efficiency of tailor made immobilized Saccharomycescerevisiae(biomatrix) for the sorption of radionuclides 233U, 239Pu, 241Am, 137Ce, 144Cs, 103,106Ru and 90Sr from aqueous nitrate solutions at different pH was studied. Effect of ionic strength, anionic components, initial metal concentration and particle size of the biomatrix on the sorption of metal ions were investigated. At pH in the range of 1 to 2 more than 95% sorption of U, Pu, Am and Ce could be accomplished, while that of Ru was 65%. Sorption of Cs and Sr were negligible under similar conditions. The metal ion-biomatrix system for Pu, Am and Ce reached equilibrium within 60 minutes. In the case of U, equilibrium attained in 100 minutes. The presence of anionic components, Cl-, C2O42-, CH3COO-, NO3- and SO42- (up to 0.5 mol.dm-3 of their individual concentration) in the aqueous solutions has no effect on the sorption of Pu by the biomatrix. Sorption of U, Pu, Am were observed in the presence of several cationic impurities such as Al, Be, Cd, Cr, Fe, Mn, Pb, Ce, Dy, Eu, Gd and Sm. Metal sorbed on the biomatrix could be leached out using 5 mol.dm-3 nitric acid. The I.R spectra of U bearing biomatrix suggest chemical interaction of uranyl ion with the biomatrix.
The solid-state dehydration of the hydrated Ca(II), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) salts of pyridine-2-carboxylic acid (picolinic acid) and subsequent decarboxylation of the corresponding anhydrous salts have been studied by simultaneous TG, DTA and DTG. The sequences of thermal stability of the hydrated and the anhydrous compounds have been established from analysis of the TG, DTA and DTG traces for dehydration of the hydrated salts and for decarboxylation of the anhydrous compounds. Thermal parameters such as activation energy, enthalpy change and order of reaction for the different stages of each process have been computed by standard methods. An attempt has been made to account for the observed trend in the thermal stability of the anhydrous salts towards decarboxylation. A mechanism of thermal decraboxylation of calcium picolinate has been proposed.
Authors:M. Chakraborty, I. Ghosh, S. Ojha, S. Dutta, and N. Chatterjee
Influence of an endomycorrhizal species
on the growth of two vegetable plants, namely,
and for reduction of the incidence of fusarial wilt disease under field condition was studied. VAM treated plants showed more vigor in terms of productivity parameters viz., plant height, number of branching twigs and fruit production. VAM and pathogen treated plants also showed positive effect of VAM-symbiont over control indicating reduction of pathogenic stress of the plant and give resistance. Leaf phosphate, chlorophyll content and percentage of mycorrhization were recorded highest when plants were singly inoculated with
. Synergistic effect of VAM and pathogen to increase on productivity vis-à-vis resistance was also studied in respect of polyphenol oxidase. The experimental findings indicated the potential use of
for improving the growth and imparting resistance of brinjal and tomato.