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.

Changes in Plasma Levels of Inhibin and Follicle Stimulating Hormone in Buffaloes Superovulated with eCG

Singh, Baljit,Dixit, V.D.,Dixit, V.P.,Singh, P.,Georgie, G.C.,Lohan, I.S. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.9

The present study was undertaken to investigate the effect of stimulation of follicular development with eCG on the peripheral levels of inhibin and FSH in Murrah buffaloes. Estrus was synchronized in five normally cycling females by insertion of Crestar (Intervet, Boxmeer, Holland) implants for nine days. Estradiol valerate was administered i.m. on the day of implant insertion. On the 10th day of the induced estrous cycle a single dose of 3000 IU eCG (Folligon, Intervet, Boxmeer, Holland) was given, followed by treatment with 25 mg of $PGF_2$ alpha (Lutalyse, Upjohn, Belgium) 48 h later. Blood samples were obtained during the induced estrus, on cycle day 10 (luteal phase), at the superovulatory estrus (43 h after PGF) and during the periovulatory period (64 h after PGF). Ultrasonography was done daily to monitor follicular development. Plasma concentrations of inhibin and FSH were determined by specific radioimmunoassays. Differences between $mean{\pm}SEM$ values of different phases of the cycle were compared by ANOVA. The mean number of small (2-5 mm), medium (6-9 mm) and large (>10 mm) follicles observed two days after eCG treatment and on the day of superovulatory estrus was $2.8{\pm}0.31$, $5.2{\pm}0.30$ and $1.4{\pm}0.09$ and $1.9{\pm}0.21$, $2.8{\pm}0.40$ and $5.0{\pm}0.83$, respectively. The mean number of ovulations was $3.6{\pm}0.37$ and the mean number of unovulated follicles was $6.1{\pm}0.47$. Most of the follicles >10 mm in diameter had ovulated (72%). The mean ${\pm}SEM $ of plasma inhibin concentration $(2584.15{\pm}17.92pg/ml)$ during the superovulatory estrus was significantly higher $(p{\leq}0.05)$ than during the induced estrus $(749.87{\pm}17.29pg/ml)$, the luteal phase $(1099.54{\pm}24.98pg/ml)$ and periovulatory period $(1682.71{\pm}29.88pg/ml)$, respectively. $Mean{\pm}SEM$ plasma FSH concentration during the induced estrus $(10.35{\pm}0.41ng/ml)$ was not different from that during the superovulatory estrus $(8.52{\pm}0.39ng/ml)$, but was significantly higher $(p{\leq}0.05)$ than during the luteal phase $(2.81{\pm}0.42ng/ml)$ and periovulatory period $(5.7{\pm}0.28ng/ml)$. These data indicate that treatment with eCG in buffaloes for inducing superovulation results in a significant elevation in plasma inhibin levels and a decrease in plasma FSH levels during the superovulatory estrus. Thus, we suggest that the elevated plasma inhibin coming from fully developed follicles continued for a long time which results in inhibition of FSH leading to poor ovulation in the remaining follicles, which may be the cause of suboptimal superovulatory response.

Effect of dimethyl sulfoxide on the electrical properties of PEDOT:PSS/ n-Si heterojunction diodes

C.S. Pathak,J.P. Singh,R. Singh 한국물리학회 2015 Current Applied Physics Vol.15 No.4

Effect of dimethyl sulfoxide (DMSO) on the electrical properties of PEDOT:PSS/n-Si heterojunction diodes has been studied. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) was deposited on n-type Si wafer using facile process of spin coating. The DMSO content was varied from 0 to 8 vol%. Electrical characterization of these heterojunction diodes as performed using both currentevoltage (I-V) and capacitanceevoltage (C-V) measurements. All diodes showed rectifying behavior. AFM measurement revealed that the surface became more rough after the DMSO treatment of PEDOT:PSS films. The RMS values were found in the range of 4-6 nm. The resistivity of the PEDOT:PSS films decreased with increase in temperature. The addition of DMSO into PEDOT:PSS solution results in a decrease in resistivity of films by approximately two orders of magnitude. PEDOT:PSS films showed high transmission more than 85% in the entire visible region. Raman spectroscopy indicated effect of the DMSO treatment on the chemical structure of PEDOT chains, suggesting a conformational change of PEDOT chain in the film. An optimal value of DMSO was obtained with 5 vol% content, and it showed the best PEDOT:PSS films properties and good quality heterojunction diodes characteristics with ideality factor of 2.4 and barrier height 0.80 eV.

Structural and optical properties of TiO₂ thin films derived by sol-gel dip coating process

Saini, K.K.,Sharma, S.D.,Chanderkant,Kar, M.,Singh, D.,Sharma, C.P. North-Holland 2007 Journal of non-crystalline solids Vol.353 No.24

Nanocrystalline thin films of titanium dioxide have been fabricated on glass and silica substrates from partially hydrolyzed precursor solution. These films were subjected to heat treatment for 1h at temperatures 100, 200, 300, 400, 500, 600, 700, 800 and 900<SUP>o</SUP>C and characterized by XRD, SEM, XPS and optical techniques. As deposited films are found to be amorphous and also contain hydroxyl and organic functional groups. Films heat treated above 100<SUP>o</SUP>C do not contain hydroxyl and organic functional groups. Microcrystalline behavior is observed in the films heat treated above 300<SUP>o</SUP>C. Crystallite size increases from ∼5 to 50nm as sintering temperature is increased from 300 to 700<SUP>o</SUP>C. Formation of anatase phase with c-axis length 7.03A is observed in the films annealed up to 700<SUP>o</SUP>C. These films peel off from the substrate beyond 700<SUP>o</SUP>C annealing temperature. Density as well as refractive index of the films increases with increase in annealing temperature up to 700<SUP>o</SUP>C. Refractive index is found to show Cauchys behavior. Transmission better than 70% is observed in the visible range. There is a strong absorption around 370nm, which is attributed to band gap absorption of the material.

Leucaena Seeds as Protein Supplement in the Rations of Growing Sheep

Singh, Sultan,Kundu, S.S.,Negi, A.S.,Gupta, S.K.,Singh, N.P.,Pachouri, V.C. Asian Australasian Association of Animal Productio 2002 Animal Bioscience Vol.15 No.10

The study was carried out to evaluate leucaena seeds as a protein replacement of mustard seed cake (MSC) in the concentrate mixture of growing lambs. Fifteen owing male lambs (Local${\times}$Corridale) with an average body weight of 16.3 kg were allocated into three dietary treatments (T1, T2, and T3) with five animals in each group. Animals were offered dry mixed grass, berseem hay and concentrate mixture to meet their nutrient requirements. In concentrate mixture of T1, (Control) MSC was used as protein source, while in T2 and T3 groups, 25 and 50% of MSC was replaced by leucaena leucocephala seeds. On completion of three months (90 days) of feeding, a digestion cum-metabolism trial was conducted to determine DMI, nutrient utilization, and nitrogen balance. Changes in body weight were recorded at 15 day internals and eating patterns were recorded for 3 consecutive days at the end of the feeding trial. MSC had higher CP contents than leucaena seeds (27.0%). Mimosine contents in leucaena seeds were 1.1 compared to 0.2 and 0.4% in concentrate mixture of T2 and T3 group, respectively. Dry matter intake varied non-significantly ($79.3{\pm}1.2$ to $83.4{\pm}1.3g/kg$ $w^{0.75}$) across the dietary treatments. Digestibility of DM and cell wall polysaccharides (NDF, ADF. Cellulose and hemicellulose) were comparable, however CP digestibility was relatively lower in leucaena luecocephala seeds based groups (T2 $45.5{\pm}1.7$ and T3 $46.7{\pm}3.5$) compared to MSC supplemented group (T1 $47.7{\pm}0.9%$). The growth rate of lambs was non-significantly higher in T1 ($79.2{\pm}5.4$) compared to T2 ($73.8{\pm}8.8$) and T3 ($73.9{\pm}7.0$), respectively. The animals were in positive nitrogen balance and N-balance varied from 1.8 to 2.9 g/d across treatment groups. The eating rate (% of total offered) of concentrate up-to 15 min was relatively higher in T1 (82.4) than T2 (74.2) and T3 (77.8%). However no effect of leucaena seeds was recorded on total DMI of animals. The results of the study revealed that the inclusion of up to 50% leucaena seeds, as protein source in concentrate mixture of lambs had no adverse effect on DMI, nutrient utilization, eating patterns, nitrogen balance and growth performance of lambs.

Neutral beam injector system for Steady State Tokamak -1

S. K. Mattoo,A.K. Chakraborty,B. Prajapati,BVSNNP Sridhar,C. Rotti,Ch. Chakrapani,G. Patel,M. Bandyopadhyay,M.J. Singh,M.R. Jana,N.P. Singh,P. Bharati,P.J. Patel,P.K. Jayakumar,R. Onali,S. Ramababu,S. 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.III

This paper discusses the experimental results obtained from the various components developed for a 1.7 MW neutral beam injector (NBI). Several technologies related to fabrication of back plate, extractor grids, high-current filament feedthru’s, heat-transfer elements, ceramic insulators, cryopumps, rectangular vessels and power supplies have been developed in collaboration with the Indian industry. Control experiments on the prototype plasma box are described.

Anti-Allergic Effects of Herbal Product from Allium cepa (Bulb)

P. Kaiser,M.S. Youssouf,S.A. Tasduq,S. Singh,S.C. Sharma,G.D. Singh,V.K. Gupta,B.D. Gupta,R.K. Johri 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.2

Allium cepa (Family Liliaceae) is a reputed Indian medicinal herb that is prescribed as an effective remedy for several ailments in the Ayurvedic system of medicine. The aim of this study was to evaluate its efficacy against various events responsible for Type I allergic reactions. A herbal fraction (ALC-02) from A. cepa (bulb) inhibited histamine release and attenuated intracellular calcium levels in Compound 48/80-induced rat peritoneal mast cells. It also prevented Compound 48/80-mediated systemic anaphylaxis while lowering histamine levels in plasma. ALC-02 suppressed carrageenan-induced rat paw edema. It inhibited eosinophil peroxidase activity and protein content in bronchoalveolar lavage fluid (BALF) of ovalbumin-challenged mice. In this experiment ALC-02 also caused a substantial reduction in lipid peroxidation in BALF/lung tissue and augmented superoxide dismutase activity in lung tissue. ALC-02 suppressed erythrocytic lysis caused by Triton X-100. A significant quenching of 1,1-diphenyl-2-picrylhydrazyl radical by ALC-02 was observed. The results have shown a promising anti-allergic profile of ALC-02 that could be attributed to its potential antihistaminic, anti-inflammatory, and antioxidant activities.

Interface control of bulk ferroelectric polarization.

Yu, P,Luo, W,Yi, D,Zhang, J X,Rossell, M D,Yang, C-H,You, L,Singh-Bhalla, G,Yang, S Y,He, Q,Ramasse, Q M,Erni, R,Martin, L W,Chu, Y H,Pantelides, S T,Pennycook, S J,Ramesh, R National Academy of Sciences 2012 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.109 No.25

<P>The control of material interfaces at the atomic level has led to novel interfacial properties and functionalities. In particular, the study of polar discontinuities at interfaces between complex oxides lies at the frontier of modern condensed matter research. Here we employ a combination of experimental measurements and theoretical calculations to demonstrate the control of a bulk property, namely ferroelectric polarization, of a heteroepitaxial bilayer by precise atomic-scale interface engineering. More specifically, the control is achieved by exploiting the interfacial valence mismatch to influence the electrostatic potential step across the interface, which manifests itself as the biased-voltage in ferroelectric hysteresis loops and determines the ferroelectric state. A broad study of diverse systems comprising different ferroelectrics and conducting perovskite underlayers extends the generality of this phenomenon.</P>

3',5-dihydroxy-3,4',7-trimethoxyflavone-induces ER-stress-associated HCT-116 programmed cell death via redox signaling

Singh, M.P.,Han, J.,Kang, S.C. Masson Pub. USA, Inc 2017 BIOMEDICINE AND PHARMACOTHERAPY Vol.88 No.-

<P>Quercetin, a well cognized bioactive flavone possessing great medicinal value, has limited usage. The rapid gastrointestinal digestion of quercetin is also a major obstacle for its clinical implementation due to low bioavailability and poor aqueous solubility. 30,5-dihydroxy-3,40,7-trimethoxyflavone (DTMF), a novel semi-synthetic derivative of quercetin, is known to modulate several biological activities. Therefore, in the present study we examined the cytotoxic mechanism of DTMF in concentration-dependent manner (25, 50, and 100 mu M; 24 h) against HCT-116 human colon carcinoma cells. The cytotoxic potential of DTMF was characterized based on deformed cell morphology, increased ROS accumulation, loss of mitochondrial membrane potential (Delta psi m), increased mitochondrial mass, chromatin condensation, and typical DNA-fragmentation in HCT-116 cells. The results showed that DTMF-induced enhanced ROS production at higher concentration (100 mu M) as evidenced by upregulated expression of ER stress and apoptotic proteins with concomitant increase in PERK, CHOP, and JNK levels, when compared to N-acetyl cysteine (NAC, ROS inhibitor) treated HCT-116 cells, which depicts that DTMF might act as a crucial mediator of apoptosis signaling. Collectively, our results suggest that DTMF stimulates ROS-mediated oxidative stress, which in turn induces PERK-CHOP and JNK pathway of apoptosis to promote HCT-116 cell death. (C) 2017 Elsevier Masson SAS. All rights reserved.</P>

Surface modulation and back reflection from foil targets irradiated by a Petawatt femtosecond laser pulse at oblique incidence

Ter-Avetisyan, S.,Andreev, A.,Platonov, K.,Sung, J. H.,Lee, S. K.,Lee, H. W.,Yoo, J. Y.,Singh, P. K.,Ahmed, H.,Scullion, C.,Kakolee, K. F.,Jeong, T. W.,Hadjisolomou, P.,Borghesi, M. The Optical Society 2016 Optics express Vol.24 No.24

<P>A significant level of back reflected laser energy was measured during the interaction of ultra-short, high contrast PW laser pulses with solid targets at 30 degrees incidence. 2D PIC simulations carried out for the experimental conditions show that at the laser-target interface a dynamic regular structure is generated during the interaction, which acts as a grating (quasi-grating) and reflects back a significant amount of incident laser energy. With increasing laser intensity above 1018 W/cm(2) the back reflected fraction increases due to the growth of the surface modulation to larger amplitudes. Above 1020 W/cm(2) this increase results in the partial destruction of the quasi-grating structure and, hence, in the saturation of the back reflection efficiency. The PIC simulation results are in good agreement with the experimental findings, and, additionally, demonstrate that in presence of a small amount of pre-plasma this regular structure will be smeared out and the back reflection reduced. (C) 2016 Optical Society of America</P>