Charge and mass transport properties of La₂Ni_0.95Al_0.05O_4.025+δ

Jeon, S.Y.,Singh, B.,Im, H.N.,Seong, K.P.,Song, S.J. Elsevier Sequoia 2014 Journal of alloys and compounds Vol.589 No.-

<P>In this work, mass and charge transport properties of acceptor doped lanthanum nickelate, La2Ni0.95Al0.05O4.025+delta d (LNAO), were analyzed. The thermal expansion, electrical conductivity and thermoelectric power of LNAO were measured as a function of temperature in 25-1000 degrees C range and oxygen partial pressure ( pO(2)) in -14 <= log (pO(2)/atm)6 <= -1 range. The average thermal expansion coefficient was 13.77 x 10 (6) K (1). The electrical conductivity was analyzed in relation to the thermoelectric power to elucidate the positive deviation of the activity coefficient of hole on the basis of the delocalized electron model. The thermoelectric power measurement shows a p-type to n- type transition. The chemical diffusion coefficient (D-chem) and surface exchange coefficient (ksurf.) were calculated by 4-probe DC conductivity measurement and ksurf. was slightly higher than ((D) over tilde Dchem). The best- estimated hole-mobility values showed very weak temperature dependence. The results were compared with the literature results on La2NiO4+ d. (C) 2013 Elsevier B.V. All rights reserved.</P>

A sensitive fluorescent probe for the polar solvation dynamics at protein-surfactant interfaces

Singh, P.,Choudhury, S.,Singha, S.,Jun, Y.,Chakraborty, S.,Sengupta, J.,Das, R.,Ahn, K. H.,Pal, S. Royal Society of Chemistry 2017 Physical chemistry chemical physics Vol.19 No.19

<P>Relaxation dynamics at the surface of biologically important macromolecules is important taking into account their functionality in molecular recognition. Over the years it has been shown that the solvation dynamics of a fluorescent probe at biomolecular surfaces and interfaces account for the relaxation dynamics of polar residues and associated water molecules. However, the sensitivity of the dynamics depends largely on the localization and exposure of the probe. For noncovalent fluorescent probes, localization at the region of interest in addition to surface exposure is an added challenge compared to the covalently attached probes at the biological interfaces. Here we have used a synthesized donor-acceptor type dipolar fluorophore, 6-acetyl-(2-((4-hydroxycyclohexyl)(methyl) amino) naphthalene) (ACYMAN), for the investigation of the solvation dynamics of a model protein-surfactant interface. A significant structural rearrangement of a model histone protein (H1) upon interaction with anionic surfactant sodium dodecyl sulphate (SDS) as revealed from the circular dichroism (CD) studies is nicely corroborated in the solvation dynamics of the probe at the interface. The polarization gated fluorescence anisotropy of the probe compared to that at the SDS micellar surface clearly reveals the localization of the probe at the protein-surfactant interface. We have also compared the sensitivity of ACYMAN with other solvation probes including coumarin 500 (C500) and 4-(dicyanomethylene)-2-methyl-6-(p-dimethylamino-styryl)-4H-pyran (DCM). In comparison to ACYMAN, both C500 and DCM fail to probe the interfacial solvation dynamics of a model protein-surfactant interface. While C500 is found to be delocalized from the protein-surfactant interface, DCM becomes destabilized upon the formation of the interface (protein-surfactant complex). The timescales obtained from this novel probe have also been compared with other femtosecond resolved studies and molecular dynamics simulations.</P>

Monocrotophos Induces the Expression of Xenobiotic Metabolizing Cytochrome P450s (CYP2C8 and CYP3A4) and Neurotoxicity in Human Brain Cells

Tripathi, V. K.,Kumar, V.,Pandey, A.,Vatsa, P.,Dhasmana, A.,Singh, R. P.,Appikonda, S. H.,Hwang, I.,Lohani, M. Humana Press 2017 Molecular Neurobiology Vol. No.

<P>Expression of various cytochrome P450s (CYPs) in mammalian brain cells is well documented. However, such studies are hampered in neural/glial cells of human origin due to nonavailability of human brain cells. To address this issue, we investigated the expression and inducibility of CYP2C8 and CYP3A4 and their responsiveness against cyclophosphamide (CPA) and organophosphorus pesticide monocrotophos (MCP), a known developmental neurotoxicant in human neural (SH-SY5Y) and glial (U373-MG) cell lines. CPA induced significant expression of CYP2C8 and CYP3A4 in both types of cells in a time-dependent manner. Neural cell line exhibited relatively higher constitutive and inducible expression of CYPs than the glial cell line. MCP exposure alone could not induce the significant expression of CYPs, whereas the cells preexposed to CPA showed a significant response to MCP. Similar to the case of CPA induced expressions, neural cells were found to be more vulnerable than glial cells. Our data indicate differential expressions of CYPs in cultured human neural and glial cell lines. The findings were synchronized with protein ligand docking studies, which showed a significant modulatory capacity of MCP by strong interaction with CYP regulators-CAR and PXR. Similarly, the known CYP inducer CPA has also shown significant high docking scores with the two studied CYP regulators. We also observed a significant induction in reactive oxygen species (ROS), lipid peroxides (LPO), micronucleus (MN), chromosomal aberration (CA), and reduction in reduced glutathione (GSH) and catalase following the exposure of MCP. Moreover, the expressions of apoptotic markers such as caspase-3, caspase-9, Bax, and p53 were significantly upregulated, whereas the levels of antiapoptotic marker, Bcl2, was downregulated after the exposure of MCP in both cell lines. These findings confirm the involvement of ROS-mediated oxidative stress, which subsequently triggers apoptosis pathways in both human neural (SH-SY5Y) and glial (U373-MG) cell lines following the exposure of MCP.</P>

Electronic structure studies of chemically synthesized MgFe₂O₄ nanoparticles

Singh, J.P.,Won, S.O.,Lim, W.C.,Lee, I.J.,Chae, K.H. Elsevier Scientific Pub. Co 2016 Journal of molecular structure Vol.1108 No.-

For present work, magnesium ferrite nanoparticles were synthesized using nitrates of metal ions and citric acid. Crystallite size of these nanoparticles varies from 2.1 +/- 0.1 to 62 +/- 10 nm as annealing temperatures increases from 300 to 1200 <SUP>o</SUP>C. Mg K-edge near-edge X-ray absorption fine-structure spectra reflect the presence of Mg<SUP>2+</SUP> ions in both tetrahedral (A-site) and octahedral (B-site) environment for nanoparticles synthesized at all temperatures. The integral area of spectral features of O K-edge spectra is associated with the change of unoccupied O p-projected density of states. Fe L-edge spectra envisage the presence of Fe<SUP>3+</SUP> state in these nanoparticles. Observed changes in the electronic structure of these nanoparticles are discussed on the basis of cation migration from A-site to B-site, degree of crystallization, and unsaturated bonds at crystallite surface. Fe-O distances at A-site and B-site changes with annealing temperature.

Investigation of phase segregation in sol–gel derived ZnMgO thin films

Singh, Amanpal,Vij, Ankush,Kumar, Dinesh,Khanna, P K,Kumar, Mukesh,Gautam, Sanjeev,Chae, K H Institute of Physics 2013 Semiconductor science and technology Vol.28 No.2

<P>Highly c-axis-oriented Zn<SUB>1-x</SUB>Mg<SUB>x</SUB>O multilayered thin films have been deposited on p-type Si substrates with different concentration of Mg (x = 0.00−0.40) using a sol–gel spin-coating technique. The x-ray diffraction (XRD) shows that single-phase wurtzite thin films start showing phase segregation for a Mg content of x = 0.25 for the sol–gel-derived ZnMgO thin films. The element specific near edge x-ray fine structure (NEXAFS) collected at O K-edge also clearly evidence the phase segregation at x = 0.25. These results also show that films are deposited with wurtzite structure as dominant phase even after phase segregation. The NEXAFS spectra collected at Zn L<SUB>3</SUB>-edge rule out the presence of any Zn-related defect due to Mg doping. The atomic force microscopy (AFM) depicts the spherical shape of nanosized grains, and grain size varies slightly with Mg content. The single-phase ZnMgO thin films show a band gap tuning from 3.38 to 3.84 eV, which is also consistent with blue shifting of near-band edge PL emission. The electrical resistivity of thin films increases with Mg content before phase segregation. However, the optical band gap, photoluminescence and electrical resistivity show anomalous behavior at phase segregation limit which has been discussed and correlated with each other.</P>

Estimation of Gene Effects in Four Bivoltine Silkworm (Bombyx mori L.) Crosses

G. N. Malik,T. P. Singh,S. Z. Haque. Rufaie,M. Aijaz,H. U. Dar 한국잠사학회 2004 International Journal of Industrial Entomology Vol.8 No.1

Six generations (P1, P2, F1, BC1, BC2 and F2) of four bivoltine silkworm crosses (SKAU-R-1 ´ Yakwei, SKAU-R-6 ´ Yakwei, CSR2 ´ CSR4 and SH6 ´ NB4D2) were evaluated in a completely randomized block design with 5 replications for each treatment. The generation mean 2 in respect of 3 metric traits (single cocoon weight, single shell weight, and shell ratio %), were subjected to Cavallis joint scaling test. Additive dominance model was found to be adequate in CSR2 ´ CSR4 and SH6 ´ NB4D2 for single cocoon weight and shell weight and SKAU-R-6 ´ Yakwei for shell ratio (%). Whereas, in rest of the crosses epistasis was evident in the traits under investigation. Magnitude of additive gene effect (d) was greater than dominance (h) in SH6 ´ NB4D2 and SKUA-R-6 ´ Yakwei for shell ratio (%) and in CSR2 ´ CSR4 for shell weight. Thus selection for these traits in early segregating generations of these crosses would be effective for obtaining considerable genetic gain.

Note : Estimation of Gene Effects in Four Bivoltine Silkworm (Bombyx mori L.) Crosses

( G. N. Malik ),( T. P. Singh ),( S. Z. Haque Rufaie ),( M. Aijaz ),( H. U. Dar ) 한국잠사학회 2007 International Journal of Industrial Entomology Vol.8 No.1

Six generations (P1, P2, F1, BC1, BC2 and F2) of four bivoltine silkworm crosses (SKAU-R-1×Yakwei, SKAU-R-6×Yakwei, CSR2×CSR4 and SH6×NB4D2) were evaluated in a completely randomized block design with 5 replications for each treatment. The generation mean 2 in respect of 3 metric traits (single cocoon weight, single shell weight, and shell ratio %), were subjected to Cavallis joint scaling test. Additive dominance model was found to be adequate in CSR2×CSR4 and SH6×NB4D2 for single cocoon weight and shell weight and SKAU-R-6×Yakwei for shell ratio(%). Whereas, in rest of the crosses epistasis was evident in the traits under investigation. Magnitude of additive gene effect (d) was greater than dominance (h) in SH6×NB4D2 and SKUA-R-6×Yakwei for shell ratio (%) and in CSR2×CSR4 for shell weight. Thus selection for these traits in early segregating generations of these crosses would be effective for obtaining considerable genetic gain.

Estimation of Gene Effects in Four Bivoltine Silkworm (Bombyx mori L.) Crosses

Malik, G.N.,Singh, T.P.,Rufaie, S.Z.Haque,Aijaz, M.,Dar, H.U. Korean Society of Sericultural Science 2004 International Journal of Industrial Entomology Vol.8 No.1

Six generations (P$_1$, P$_2$, F$_1$, BC$_1$, BC$_2$ and F$_2$) of four bivoltine silkworm crosses (SKAU-R-1 ${\times}$ Yakwei, SKAU-R-6 ${\times}$ Yakwei, CSR$_2$ ${\times}$ CSR$_4$ and SH$_{6}$${\times}$ NB$_4$D$_2$) were evaluated in a completely randomized block design with 5 replications for each treatment. The generation mean 2 in respect of 3 metric traits (single cocoon weight, single shell weight, and shell ratio %), were subjected to Cavallis joint scaling test. Additive dominance model was found to be adequate in CSR$_2$${\times}$CSR$_4$ and SH$_{6}$${\times}$ NB$_4$D$_2$ for single cocoon weight and shell weight and SKAU-R-6 ${\times}$ Yakwei for shell ratio(%). Whereas, in rest of the crosses epistasis was evident in the traits under investigation. Magnitude of additive gene effect (d) was greater than dominance(h) in SH$_{6}$${\times}$NB$_4$D$_2$ and SKUA-R-6${\times}$Yakwei for shell ratio (%) and in CSR$_2$${\times}$ CSR$_4$ for shell weight. Thus selection for these traits in early segregating generations of these crosses would be effective for obtaining considerable genetic gain. gain.

Effect of Flushing on Nutrient Utilization and Reproductive Performance of Ewes Grazing on Community Rangeland

Chaturvedi, O.H.,Bhatta, Raghavendra,Verma, D.L.,Singh, N.P. Asian Australasian Association of Animal Productio 2006 Animal Bioscience Vol.19 No.4

The present study was undertaken to evaluate the effect of flushing of ewes with concentrate pellets just before the mating season on their nutrient utilization and reproductive performance on farms. Forty-eight Malpura ewes, 1-5 years old were randomly divided into 2 groups of 24 each (G1and G2). Ewes in both the groups were grazed on natural rangeland from 07.00 to 18.00 hr followed by night shelter in animal shed. G1 ewes were maintained on sole grazing while G2 ewes, in addition to grazing, received concentrate pellets at the rate of 1.5% of their body weight. The mean biomass yield of the community rangeland was 0.46 ton DM/hectare. The intakes of DM (g/kg $W^{0.75}$), DCP (g/kg $W^{0.75}$) and ME (MJ/kg $W^{0.75}$) were higher (p<0.01) in G2 as compared to that of G1 being 86.5, 10.2 and 1.15 and 57.5, 4.7 and 0.75, respectively. The digestibility of DM, OM, CP, NDF and hemicellulose were also higher (p<0.01) in G2 as compared to that of G1 being 57.2, 76.7, 78.9, 51.9 and 81.6 and 50.8, 68.7, 68.4, 45.4 and 74.4, respectively. The conception rate was higher (79.2%) in flushed ewes as compared to that of non-flushed (66.7%). Five of the pregnant ewes died and another 5 aborted in G1 while in G2, 5 ewes aborted with no mortality. The lambing was higher (73.7%) in G2 than that in G1 (37.5%). The birth weight of lambs was higher (p<0.05) in G2 (3.47 kg) than that in G1 (2.95 kg). Further, the birth weight of male lambs was higher (3.28) than that of female lambs (3.14). It is concluded that the biomass yield of the community rangeland in semi-arid region of India is low and insufficient to meet the nutrient requirement of ewes prior to mating season. However, concentrate supplementation at the rate of 1.5% of body weight to ewes during this critical stage enhanced their plane of nutrition, reproductive performance, body condition and birth weights of lambs.

Effect of Dietary L-ascorbic Acid (L-AA) on Production Performance, Egg Quality Traits and Fertility in Japanese Quail (Coturnix japonica) at Low Ambient Temperature

Shit, N.,Singh, R.P.,Sastry, K.V.H.,Agarwal, R.,Singh, R.,Pandey, N.K.,Mohan, J. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.7

Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body's homeostasis. L-ascorbic acid (L-AA) has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production performance, egg quality traits and fertility in Japanese quail at low ambient temperature. Sixty matured females (15 wks) were equally divided into three groups (20/group) based on the different dietary levels of L-AA (0, 250 and 500 ppm) and coupled with an equal number of males (1:1) obtained from the same hatch. They were managed in uniform husbandry conditions without restriction of feed and water at 14 h photo-schedule. Except for feed efficiency, body weight change, feed consumption and hen-day egg production were recorded highest in 500 ppm L-AA supplemented groups. Among the all egg quality traits studied, only specific gravity, shell weight and thickness differed significantly (p<0.05) in the present study. Fertility was improved significantly ($p{\leq}0.01$) to a dose dependent manner of L-AA. The findings of the present study concluded that dietary L-AA can be a caring management practice at least in part to alleviate the adverse effect of cold induced stress on production performance in Japanese quail.