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Arbuj S.S.,CMET - Photonics And Advanced Materials Laboratory | Rumale N.,ELANTAS Beck India Ltd. | Pokle A.,Icon Analytical Equipment Pvt. Ltd. | Ambekar J.D.,CMET - Photonics And Advanced Materials Laboratory | And 3 more authors.
Science of Advanced Materials | Year: 2014

A highly crystalline ZnO nano pencils/rods were successfully synthesized via low cost and template free solvothermal method. The reaction was carried out at 200°C for 2, 5 and 12 h respectively. The reaction time enhances the photoluminescent properties of ZnO, mainly the intensity of green emission band increased. X-ray diffraction revealed the formed products have a wurtzite structure. The morphology and microstructure analyses of ZnO nano pencils/rods were performed by field emission scanning electron microscopy and transmission electron microscopy. The ZnO nanorods are about 20 to 70 nm in width and length varies from nm to sub-micron size. TEM confirms formation of pencil and rod shaped ZnO nanostructures. ZnO synthesized using different reaction time showed UV-Visible absorbance at 372 nm. Photoluminescence measurement showed UV emission peak and broad yellow-green emission peak centered at 390 and 500 nm respectively. Photocatalytic activity of synthesized ZnO was evaluated by following the degradation of aqueous methylene blue dye. Change in the photocatalytic activity was observed with change in reaction time of ZnO synthesis. ZnO prepared at 2 h of reaction time showed apparent rate constant (Kapp) of 8.8×10-2 min-1 for MB degradation. © 2014 by American Scientific Publishers.


Dhiman M.,Panjab University | Sharma R.,Panjab University | Kumar V.,Icon Analytical Equipment Pvt. Ltd. | Singhal S.,Panjab University
Ceramics International | Year: 2016

The present work is focused on studying morphology dependent catalysis of spinel ZnFe2O4 nanostructures. Different morphologies i.e. porous nanorods, nanoparticles, nanoflowers and hollow microspheres were designed hydrothermally. The as prepared nanomaterials were characterized using Fourier Transform Infra-Red (FTIR), field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Brunauer-Emmett-Teller (BET) technique and UV-visible spectrophotometer. The results confirmed formation of desired morphologies of cubic spinel ZnFe2O4 with high surface areas (92-138m2/g) and narrow band gaps (1.76-1.97eV). It suggested the use of ZnFe2O4 nanostructures as potential visible light photocatalysts. Therefore, the application of synthesized ZnFe2O4 nanostructures was studied in photo-Fenton degradation of dyes. The results indicated shape dependent relationship with photocatalytic activity as the degradation of dyes followed the order porous nanorods>nanoparticles>nanoflowers>hollow microspheres. The role of main active species in the reaction i.e. (bullet operator)OH was also confirmed. All the materials exhibited stability and magnetic separability hence could act as potential photo-Fenton catalysts for wastewater treatment. © 2016 Elsevier Ltd and Techna Group S.r.l.


Trivedi P.P.,National Institute of Pharmaceutical Education and Research | Jena G.B.,National Institute of Pharmaceutical Education and Research | Tikoo K.B.,National Institute of Pharmaceutical Education and Research | Kumar V.,Icon Analytical Equipment Pvt Ltd
Molecular Carcinogenesis | Year: 2016

Colon carcinogenesis is long known to be associated with ulcerative colitis (UC), a chronic gastrointestinal disorder. Various pre-clinical and clinical studies have shown that melatonin (MEL) has beneficial effects in cancer. However, elucidation of the detailed molecular mechanisms involved in MEL-mediated protection against the colon carcinogenesis deserves further investigation. The present study was aimed at deciphering the effect of MEL on autophagy and Nrf2 signaling pathways in a mouse model of colitis-associated colon carcinogenesis (CACC). For the induction of CACC, male Swiss Albino mice were administered a single ip injection of 20mg 1, 2-dimethylhydrazine dihydrochloride (DMH)/kg bw, followed by 3 cycles of 3% w/v dextran sulfate sodium (DSS) in drinking water treatment initiated 1wk after DMH injection. One week after the initiation of DSS treatment, MEL was administered at the dose of 1mg/kg, bw, po for 8 and 18 wk. Mice were sacrificed at 10 and 20wk after DMH injection. MEL treatment decreased the progression of CACC by down regulating the process of autophagy as revealed by the expression pattern of various autophagy markers such as Beclin-1, LC3B-II/LC3B-I ratio and p62. These findings were accompanied with the increased expression of Nrf2 and the associated antioxidant enzymes, NAD(P)H:quinone oxidoreductase (NQO-1) and heme oxygenase-1 (HO-1) in the colon of mice with CACC. MEL intervention reduced autophagy by ameliorating inflammation and oxidative stress in the colon of mice with CACC. We conclude that MEL treatment attenuates the progression of CACC in mice by modulating autophagy and Nrf2 signaling pathways. © 2016 Wiley Periodicals, Inc.


Nayek C.,Indian Institute of Technology Madras | Samanta S.,Indian Institute of Technology Madras | Manna K.,Indian Institute of Science | Pokle A.,Icon Analytical Equipment Pvt. Ltd. | And 3 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2016

We report the transition from robust ferromagnetism to a spin-glass state in nanoparticulate La0.7Sr0.3MnO3 through solid solution with BaTiO3. The field- and temperature-dependent magnetization and the frequency-dependent ac magnetic susceptibility measurements strongly indicate the existence of a spin-glass state in the system, which is further confirmed from memory effect measurements. The breaking of long-range ordering into short-range magnetic domains is further investigated using density-functional calculations. We show that Ti ions remain magnetically inactive due to insufficient electron leakage from La0.7Sr0.3MnO3 to the otherwise unoccupied Ti-d states. This results in the absence of a Mn-Ti-Mn spin exchange interaction and hence the breaking of the long-range ordering. Total-energy calculations suggest that the segregation of nonmagnetic Ti ions leads to the formation of short-range ferromagnetic Mn domains. © 2016 American Physical Society.


Khan S.,National Institute of Pharmaceutical Education and Research | Jena G.,National Institute of Pharmaceutical Education and Research | Tikoo K.,National Institute of Pharmaceutical Education and Research | Kumar V.,Icon Analytical Equipment Pvt Ltd
Biochimie | Year: 2015

Epigenetic modifications are increasingly recognized to play a significant contribution in diabetic nephropathy (DN). Histone deacetylases (HDACs) are the emerging target in the pathogenesis and progression of DN. Valproic acid (VPA), a widely used anti-epileptic drug and has been proven as an HDAC inhibitor. This study was aimed to evaluate the protective roles of VPA on HDAC-mediated NF-κB/iNOS signaling and autophagy in DN. Diabetes was induced by a single injection of STZ (50 mg/kg), whereas VPA at the doses of 150 and 300 mg/kg/day for 8 weeks was administered by oral route in Sprague-Dawley rat. Blood and urine were collected before animal were sacrificed, while kidneys were dissected after sacrificed. The podocyte and renal injuries were assessed using biochemical markers, histology, podocyte effacement, DNA damage and apoptosis as well as protein expression evaluation. VPA treatment improves the plasma and urinary biomarkers of renal function, decreased expression of iNOS, 3-nitrotyrosine, NF-κB, p-NF-κB, HDAC4/5, calmodulin, calbindin, apoptosis and DNA damage. Further, VPA treatment increased histone acetylation and ameliorated the histological alterations and podocyte effacement. Interestingly, VPA treatment also restored diabetes-associated perturbations in autophagy by HDAC inhibition. To the best of our knowledge, this is the first report, which highlights the beneficial role of VPA in DN. The present results clearly exhibited that VPA treatment ameliorates the podocyte and renal injuries mainly by facilitating the autophagy and inactivation of NF-κB/iNOS signaling. The present findings demonstrated that VPA may be useful in the treatment of DN, since the present experimental doses are clinically relevant. © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM).


Ghatak A.,Sn Bose National Center For Basic Science Salt Lake | Roy Moulik S.,Sn Bose National Center For Basic Science Salt Lake | Roy Moulik S.,ICON Analytical Equipment Pvt. Ltd. | Ghosh B.,Sn Bose National Center For Basic Science Salt Lake
RSC Advances | Year: 2016

We report here a systematic study of the growth of aligned WO3 (002)-oriented nanowires (NWs) on a (111)-oriented platinised silicon substrate using a pulsed laser deposition (PLD) method. Transmission electron microscopy (TEM) analysis has shown that the wires are single crystalline and grow along the [001]t or [100]t directions. X-ray diffraction (XRD) measurements confirm phase and structural analysis. We investigated the effect of ablated particle flux on nanowire growth, in particular, the role of the nucleating centre at the interface as it gets modified by the ablated particle flux. We observe a critical value of the laser energy (that determines a critical flux and energy of ablated moieties) at which a compact nanograin film gets converted to an aligned nanowire film. We attribute the existence of such a threshold to the desorption process from the catalyst droplet. By cross-sectional TEM and compositional mapping accompanied by simulation, we confirm that the interfacial layer between the substrate and NW is modified by the ablated particle flux and energy. Aligned NWs above the threshold energy can be attributed to the formation of favorable nucleation sites for a preferred orientation. © 2016 The Royal Society of Chemistry.


Bhukal S.,Panjab University | Dhiman M.,Panjab University | Bansal S.,DST | Tripathi M.K.,Icon Analytical Equipment Pvt. Ltd | Singhal S.,Panjab University
RSC Advances | Year: 2016

Co0.6Zn0.4Cu0.2MxFe1.8-xO4 (M = Zn2+, Co2+, Ni2+ and Mn3+. x = 0.2, 0.4, 0.6 and 0.8) magnetically recyclable catalysts have been synthesized via a sol-gel auto combustion method. The structural and magnetic properties of the prepared samples were investigated using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometry (VSM). The XRD analysis of the synthesized samples confirmed the formation of a single-phase cubic spinel structure and the average crystallite sizes of the nanoparticles estimated using the Debye-Scherrer's equation were found to be 40-60 nm after annealing at 1000 °C (within an error of ±2 nm). The lattice constant increases with an increase in all metal ion substitution. The hysteresis curves of the samples exhibited reduction of the saturation magnetization and coercivity with substitution of all the metal ions in Co-Cu-Zn nano ferrites. The DC electrical resistivity decreased with an increase in temperature, indicating the semiconducting nature of the ferrite samples. Manganese substituted Co-Cu-Zn nanoferrites showed the best catalytic activity among all the magnetic nanoferrites. All the magnetic nanoferrites can be easily recovered by using a magnet and no decrease in the efficiency was observed after several consecutive rounds of reaction. © The Royal Society of Chemistry 2016.


Rumale N.,ELANTAS Beck India Ltd. | Arbuj S.,MET Tech | Umarji G.,MET Tech | Shinde M.,MET Tech | And 3 more authors.
Physica Status Solidi (A) Applications and Materials Science | Year: 2013

Herein, we report in situ synthesis of zinc sulphide (ZnS) quantum dots in polyphenylene sulphide (PPS) matrix employing facile solid-solid reaction. The resultant product reveals formation of cubic nanocrystalline zinc sulphide structure. The HRTEM confirms the formation of zinc sulphide quantum dots (size ∼ 3-4 nm) embedded in the polymer matrix. Scheme: ZnS QDs by enriched solid-solid reaction in polymer matrix. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Roy Moulik S.,Sn Bose National Center For Basic Science | Roy Moulik S.,ICON Analytical Equipment Pvt. Ltd. | Ghatak A.,Sn Bose National Center For Basic Science | Ghosh B.,Sn Bose National Center For Basic Science
Surface Science | Year: 2016

We report, the kinetically controlled growth of the (002)-oriented TiO2 nanorods on fluorine-doped tin oxide (FTO) coated glass substrate via a cost effective hydrothermal synthesis route of binary oxides. In addition to this, the nanoflowered like growth of TiO2 nanorods using cubic structure Pt(111)/SiO2/Si substrate has also been demonstrated. Tuning of shape, crystallographic structure issues has been discussed by controlling the surface chemistry of the substrate on which the nanostructures were grown. The crystallographic structural aspects of the grown nanorods was confirmed both on ensemble and single nanowire level using spatially resolved tools and techniques. Growth mechanism for different shape, size and crystallographic structure depending on the surface chemistry of the substrate has been proposed. Understanding of growth of oriented TiO2 nanorods and interaction mechanism is quite promising and encouraging for designing optoelectronic and photocatalytic devices to enhanced electron transport and lower exciton recombination rates. © 2016 Elsevier B.V. All rights reserved.


Roy Moulik S.,se National Center For Basic Science | Roy Moulik S.,ICON Analytical Equipment Pvt. Ltd. | Samanta S.,se National Center For Basic Science | Ghosh B.,se National Center For Basic Science
Applied Physics Letters | Year: 2014

We report, the photoresponse behaviour of Tungsten trioxide (WO 3) films of different surface morphology, grown by using pulsed laser deposition (PLD). The Growth parameters for PLD were changed for two substrates SiO2/Si (SO) and SrTiO3 (STO), such a way which, result nanocrystalline film on SO and needle like structured film on STO. The photoresponse is greatly modified in these two films because of two different surface morphologies. The nanocrystalline film (film on SO) shows distinct photocurrent (PC) ON/OFF states when light was turned on/off, the enhancement of PC is ∼ 27%. Whereas, the film with needle like structure (film on STO) exhibits significantly enhanced persistent photocurrent even in light off condition, in this case, the enhancement of PC ∼ 50% at room temperature at lowest wavelength (λ = 360 nm) at a nominal bias voltage of 0.1 V. © 2014 AIP Publishing LLC.

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