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Das S.,Indian Association for The Cultivation of Science | Samanta S.,Indian Association for The Cultivation of Science | Chatterjee D.P.,Indian Association for The Cultivation of Science | Chatterjee D.P.,Krishnanagar Government College | Nandi A.K.,Indian Association for The Cultivation of Science
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2013

Diethyleneglycol methylethermethacrylate(MeO2MA) and oligoethylene glycol methylethermethacrylate(OEGMA) are polymerized on polythiophene(PT) backbone to produce water-soluble PT-g-PMeO2MA(PTD) and PT-g-P(MeO2MA-co-OEGMA)(PTDO) using atom transfer radical polymerization. They are characterized by 1H NMR and GPC techniques. TEM micrographs indicate that PT-chains self-organize as nanospheres, and atomic force micrographs suggest that aggregated PT-chains are present at the centre surrounded by dispersed PMeO2MA fibers producing miceller-type aggregates. Dynamic light scattering study indicates an initial decrease followed by sharp increase of Z-average particle size of PTD with temperature for attaining lower critical solution temperature (LCST) at 20 °C. The LCST increases with OEGMA concentration in PTDO. The temperature dependent PL emission of PTD shows a minimum at 19 °C, followed by a sharp increase till 21 °C, and in the cooling cycle, it shows a complete reversibility. In the PTDO copolymers, the PL intensity shows the hike at progressively higher temperatures due to the increase of LCST with increasing OEGMA concentration. © 2012 Wiley Periodicals, Inc.


Bhattacharjee S.,Hooghly Mohsin College West Bengal Education Service | Bhattacharjee S.,Krishnanagar Government College
Physiology and Molecular Biology of Plants | Year: 2013

Extremes of temperature (both heat and chilling) during early inbibitional phase of germination caused disruption of redox-homeostasis by increasing accumulation of reactive oxygen species (superoxide and hydrogen peroxide) and significant reduction of antioxidative defense (assessed in terms of total thiol content and activities of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase) in germinating tissues of rice (Oryza sativa L., cultivar Ratna). Imbibitional heat and chilling stress also induced oxidative damage to newly assembled membrane system by aggravating membrane lipid peroxidation and protein oxidation [measured in terms of thiobarbituric acid reactive substances (TBARS), free carbonyl content (C = O groups) and membrane protein thiol level (MPTL)]. Treatment with standardized low titer hydrogen peroxide during early imbibitional phase of germination caused significant reversal in oxidative damages to the newly assembled membrane system imposed by heat and chilling stress [evident from the data of TBARS, C = O, MPTL, ROS accumulation, membrane permeability status, membrane injury index and oxidative stress index] in seedlings of experimental rice cultivar. Imbibitional H2O2 pretreatment also caused up-regulation of antioxidative defense (activities of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and total thiol content) in the heat and chilling stress-raised rice seedlings. When the parameters of early growth performances were assessed (in terms of relative growth index, biomass accumulation, relative germination performance, mean daily germination, T50 value), it clearly exhibited significant improvement of early growth performances of the experimental rice cultivar. The result proposes that an 'inductive pulse' of H2O2 is required to switch on some stress acclimatory metabolism through which plant restores redox homeostasis and prevents or repairs oxidative damages to newly assembled membrane system caused by unfavorable environmental cues during early germination to the rice cultivar Ratna. The importance of mitigating oxidative damages to membrane lipid and protein necessary for post-germinative growth under extremes of temperature is also suggested. © 2013 Prof. H.S. Srivastava Foundation for Science and Society.


Das M.,Presidency University of India | Bhattacharya R.,Presidency University of India | Biswas R.,Presidency University of India | Chakraborty I.,Presidency University of India | And 2 more authors.
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2015

High unutilized glucose in the body in diabetes along with increased level of Na+ and urea cause altered osmotic equilibrium in the vascular bed contributing altered cellular microenvironment which may further affect membrane function. As plasma membrane is a dynamic structure, it is responsive to chemical exposure. Any chemical exposure may trigger alteration in membrane function and subsequently down-hill reactions. We are therefore studying the role of high glucose concentration in membrane alteration, altered cellular function and cell death in diabetic patients. In our present study we have recruited newly diagnosed 30 type II diabetes mellitus patients, chosen from diabetic clinic, Howrah Zila Hospital, Howrah, West Bengal and 31 age and sex matched healthy control without any history of diabetes from same socio economic background. Significantly high glycemic index (studied by serum glucose level and glycated haemoglobin level), high blood osmolality, osmotic fragility and oxidative stress have been noted in every diabetic participant in comparison to non-diabetic individual of our study population. A significant cell membrane alteration (p<0.05) with altered serum free sialic acid concentration has been noted in diabetic patients. Degree of membrane deformity, frequency of nonviable WBC, frequency of apoptotic cells and length of comet tail all are significantly higher (p<0.01) in diabetic persons in comparison to normal non-diabetic counterpart of the population. Diabetes is an altered homeostatic state which contributes to cellular dis-integrity and cell death and is associated with osmotic dis-equilibrium.


Das S.,Krishnanagar Government College | Majumder S.,Kalyani University | Gupta S.,Kalyani University | Dutta S.,Maulana Azad National Institute of Technology | Mukherjee D.,Kalyani University
Fish Physiology and Biochemistry | Year: 2016

Ovarian cyp19a mRNA expression and P450 aromatase activity were measured in vivo in common carp Cyprinus carpio exposed to phenol for 96 h. Production of reactive oxygen species (ROS) and parameters of antioxidant defense system in serum ovary and liver of this fish after long-term phenol exposure were also studied. In vivo exposure of fish to sublethal dose of phenol for 96 h caused marked attenuation of ovarian cyp19a1a gene expression and P450 aromatase activity. Production of ROS like hydrogen peroxide and hydroxyl radicals in serum, liver and ovary in fish exposed to phenol for 15 days elevated significantly from day 1 to day 7 with no further significant increase thereafter compared to their respective control values. Total superoxide dismutase (SOD) and catalase activities in serum and ovary decreased gradually and significantly from day 1 to day 4, which then increased significantly for the rest of the exposure days. Liver SOD activity seemed to be distinctly responsive to phenol. SOD activity in liver of phenol-exposed fish started to increase gradually from day 1 to 4 with no further increase thereafter. Catalase activities in all the tissues showed significant inhibition up to day 4 which then increased gradually and significantly up to day 15 of phenol exposure compared to their respective control values. From our results, it appears that sublethal dose of phenol has the endocrine disruptive potential and effect is mediated via inhibition of ovarian P450arom gene expression and aromatase activity in vivo. Sublethal dose of phenol also caused oxidative stress, and antioxidant systems are very much effective to prevent the damages caused by the generation of ROS. © 2015, Springer Science+Business Media Dordrecht.


Samanta S.,Indian Association for The Cultivation of Science | Das S.,Indian Association for The Cultivation of Science | Layek R.K.,Indian Association for The Cultivation of Science | Chatterjee D.P.,Indian Association for The Cultivation of Science | And 2 more authors.
Soft Matter | Year: 2012

The variation of photoluminescence (PL) property of polythiophene-g- poly(dimethylaminoethyl methacrylate) (PT-g-PDMA, PD) with temperature and pH is used to develop a fully polymeric fluorescent AND logic gate type material using methyl cellulose (MC) hydrogel. The PL intensity gradually increases with increasing temperature of the PD doped aqueous MC solution and with increasing pH of the medium. In contrast, the PL-intensity of the PD solution decreases with increase in temperature for all of the pH values studied here due to collapsing of PDMA chains on the PT core, signifying that the PL intensity increases in the MC gel after compensating for the above decrease. The truth table suggests that it acts as an AND fluorescent molecular logic gate type system with fluorescence as output and temperature and pH as inputs. The maximum sensitivity of this logic gate is at higher pH (pH 9.2) than at neutral or acidic pH (pH 4) and at 45°C. The reason is discussed from the viewpoint of the change in polarity at the microenvironment of the polythiophene chain in PD in the MC gel due to the change in temperature and pH. © 2012 The Royal Society of Chemistry.


PubMed | Kalyani University, Krishnanagar Government College and Maulana Azad National Institute of Technology
Type: Journal Article | Journal: Fish physiology and biochemistry | Year: 2016

Ovarian cyp19a mRNA expression and P450 aromatase activity were measured in vivo in common carp Cyprinus carpio exposed to phenol for 96 h. Production of reactive oxygen species (ROS) and parameters of antioxidant defense system in serum ovary and liver of this fish after long-term phenol exposure were also studied. In vivo exposure of fish to sublethal dose of phenol for 96 h caused marked attenuation of ovarian cyp19a1a gene expression and P450 aromatase activity. Production of ROS like hydrogen peroxide and hydroxyl radicals in serum, liver and ovary in fish exposed to phenol for 15 days elevated significantly from day 1 to day 7 with no further significant increase thereafter compared to their respective control values. Total superoxide dismutase (SOD) and catalase activities in serum and ovary decreased gradually and significantly from day 1 to day 4, which then increased significantly for the rest of the exposure days. Liver SOD activity seemed to be distinctly responsive to phenol. SOD activity in liver of phenol-exposed fish started to increase gradually from day 1 to 4 with no further increase thereafter. Catalase activities in all the tissues showed significant inhibition up to day 4 which then increased gradually and significantly up to day 15 of phenol exposure compared to their respective control values. From our results, it appears that sublethal dose of phenol has the endocrine disruptive potential and effect is mediated via inhibition of ovarian P450arom gene expression and aromatase activity in vivo. Sublethal dose of phenol also caused oxidative stress, and antioxidant systems are very much effective to prevent the damages caused by the generation of ROS.

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