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Jalaiah K.,Andhra University | Chandra mouli K.,Andhra University | Subba Rao P.S.V.,Andhra University | Sreedhar B.,IICT
Journal of Magnetism and Magnetic Materials | Year: 2017

Zr and Cu Ni0.5Zn0.5Fe2O4 ferrites have been prepared by the sol-gel auto combustion method using the nitrates. The ethylene glycol and citric acid were mixed as the combustion agents. The synthesized powders were calcinate at 800 °C for 3 h and they are pressed in desired shaped and sintered at 1200 °C for 2 h in air atmosphere. The X-ray diffraction analysis confirms the single phase cubic spinel structure. The SEM pictures revels that the substitution of higher valence ions results fine grained intragranular pore free microstructure. The dielectric properties of substituted ferrites exhibits decreasing trend at lower frequencies up to 1000 Hz beyond which it should in stable response. All the results are explained in terms of compositional and frequency variation. © 2017 Elsevier B.V.


Andey T.,Florida A&M University | Marepally S.,Florida A&M University | Patel A.,Florida A&M University | Jackson T.,Florida A&M University | And 6 more authors.
Journal of Controlled Release | Year: 2014

The role of side populations (SP) or cancer stem-like cells (CSC) in promoting the resistance phenotype presents a viable anticancer target. Human-derived H1650 SP cells over-express annexin A2 (AnxA2) and SOX2, and are resistant to conventional cytotoxic chemotherapeutics. AnxA2 and SOX2 bind to proto-oncogenes, c-Myc and c-Src, and AnxA2 forms a functional heterotetramer with S100A10 to promote tumor motility. However, the combined role of AnxA2, S100A10 and SOX2 in promoting the resistant phenotype of SP cells has not been investigated. In the current studies, we examined for the first time a possible role of AnxA2 in regulating SA100A10 and SOX2 in promoting a resistant phenotype of lung tumors derived from H1650 SP cells. The resistance of H1650 SP cells to chemotherapy compared to H1650 MP cells was investigated by cell viability studies. A short hairpin RNA targeting AnxA2 (shAnxA2) was formulated in a liposomal (cationic ligand-guided, CLG) carrier and characterized for size, charge and entrapment and loading efficiencies; CLG carrier uptake by H1650 SP cells was demonstrated by fluorescence microscopy, and knockdown of AnxA2 confirmed by qRT-PCR and Western blot. Targeting of xenograft and orthotopic lung tumors was demonstrated with fluorescent (DiR) CLG carriers in mice. The therapeutic efficacy of CLG-AnxA2, compared to that of placebo, was investigated after 2 weeks of treatment in terms of tumor weights and tumor burden in vivo. Compared to mixed population cells, H1650 SP cells showed exponential resistance to docetaxel (15-fold), cisplatin (13-fold), 5-fluorouracil (31-fold), camptothecin (7-fold), and gemcitabine (16-fold). CLG carriers were nanoparticulate (199 nm) with a slight positive charge (21.82 mV); CLG-shAnx2 was of similar size (217 nm) with decreased charge (12.11 mV), and entrapment and loading efficiencies of 97% and 6.13% respectively. Fluorescence microscopy showed high uptake of CLG-shAnxA2 in H1650 SP cells after 2 h resulting in a 6-fold reduction in AnxA2 mRNA expression and 92% decreased protein expression. Fluorescence imaging confirmed targeting of tumors and lungs by DiR-CLG carriers with sustained localization up to 4 h in mice. CLG-shAnxA2 treatment of mice significantly reduced the weights of lung tumors derived from H1650 SP cells and tumor burden was reduced to only 19% of controls. The loss in tumor weights in response to CLG-shAnxA2 was associated with a significant loss in the relative levels of AnxA2, SOX2, total β-catenin and S100A10, both at the RNA and protein levels. These results suggest the intriguing possibility that AnxA2 may directly or indirectly regulate relative levels of β-catenin, S100A10 and SOX2, and that the combination of these factors may contribute to the resistant phenotype of H1650 SP cells. Thus down-regulating AnxA2 using RNAi methods may provide a useful method for targeting cancer stem cells and help advance therapeutic efficacy against lung cancers. Copyright © 2014 Published by Elsevier B.V.


Nirupama V.,Sri Venkateswara University | Gunasekhar K.R.,Indian Institute of Science | Sreedhar B.,IICT | Uthanna S.,Sri Venkateswara University
Current Applied Physics | Year: 2010

Molybdenum oxide films (MoO3) were deposited on glass and crystalline silicon substrates by sputtering of molybdenum target under various oxygen partial pressures in the range 8 × 10-5-8 × 10-4 mbar and at a fixed substrate temperature of 473 K employing dc magnetron sputtering technique. The influence of oxygen partial pressure on the composition stoichiometry, chemical binding configuration, crystallographic structure and electrical and optical properties was systematically studied. X-ray photoelectron spectra of the films formed at 8 × 10-5 mbar showed the presence of Mo6+ and Mo5+ oxidation states of MoO3 and MoO3-x. The films deposited at oxygen partial pressure of 2 × 10-4 mbar showed Mo6+ oxidation state indicating the films were nearly stoichiometric. It was also confirmed by the Fourier transform infrared spectroscopic studies. X-ray diffraction studies revealed that the films formed at oxygen partial pressure of 2 × 10-4 mbar showed the presence of (0 k 0) reflections indicated the layered structure of α-phase MoO3. The electrical conductivity of the films decreased from 3.6 × 10-5 to 1.6 × 10-6 Ω-1 cm-1, the optical band gap of the films increased from 2.93 to 3.26 eV and the refractive index increased from 2.02 to 2.13 with the increase of oxygen partial pressure from 8 × 10-5 to 8 × 10-4 mbar, respectively. © 2009 Elsevier B.V.


Naresh B.,Osmania University | Reddy M.S.,Osmania University | Vijayalakshmi P.,IICT | Reddy V.,Osmania University | Devi P.,Osmania University
Biomass and Bioenergy | Year: 2012

Biodiesel is an alternative environmentally friendly fuel made from renewable biological sources such as vegetable oils and animal fats. The present report deals with screening of 14 accessions of Jatropha curcas collected from all over India to find the most suitable ones for production of Biodiesel. From the 14 accessions of J. curcas located in the plantation at Osmania University, 4 accessions were initially selected on the basis of traits like general appearance, pest resistance, seed yield and seed-oil content. Further, the seed-oil of these 4 accessions was characterized by physico-chemical analysis to identify the elite accessions for production of biodiesel. Highest 1000-seed weight (640 g) and highest percentage seed-oil content (50.16) (extracted by Soxhlet method with hexane as the solvent) was recorded in the "KM" accession. The transesterification process is affected by the presence of high free fatty acids (recorded in "MB" accession) and high moisture content (recorded in "KM" accession) of the seed-oil which also interfere with the separation of fatty esters and glycerol during production of Biodiesel. Further, high phosphorus content and iodine number (recorded in "MB" accession) interfere with conversion of seed-oil to Biodiesel. In the above context, in spite of its yield being lower, the seed-oil of the "RSAD" accession was found to be most suitable for Biodiesel production followed by "KM", "F.W.B" and "MB" accessions, since it contains lower free fatty acids, acid value, viscosity, diglycerides and iodine number. © 2012 Elsevier Ltd.


Smorgonskiy A.,Ecole Polytechnique Federale de Lausanne | Rachidi F.,Ecole Polytechnique Federale de Lausanne | Rubinstein M.,IICT
2014 International Conference on Lightning Protection, ICLP 2014 | Year: 2014

In this paper we present a numerical analysis of lightning current distribution in the conductive elements of a wind turbine blade. They include lightning down conductor, blades spar caps made of carbon fiber reinforced polymers (CFRP) and protective copper mesh placed on the spar caps. The problem is solved in frequency domain by using the finite element method. Anisotropic electrical conductivity of CFRP laminates was considered in the modeling. We have analyzed two cases when CFRP elements are covered by the copper mesh and without such protection. In the first case due to the skin-effect the most of the current flows through the external highly-conductive surface of the copper mesh. However the thin mesh can be easily damaged by lightning. In the second case an extreme result of such failure is modeled. It was found that even the placement of additional down conductors will not prevent lightning current from flowing through CFRP elements leading to delamination of the laminates. © 2014 IEEE.


Ramesh T.,National Institute of Technology Warangal | Nageswara Rao P.,National Institute of Technology Warangal | Nageswara Rao R.,IICT
Journal of Pharmaceutical and Biomedical Analysis | Year: 2014

A rapid, specific and reliable isocratic LC-MS/MS method has been developed and validated for the identification and characterization of stressed degradation products of Zofenopril. Zofenopril, an anti-hypertensive drug, was subjected to hydrolysis (acidic, alkaline and neutral), oxidation, photolysis and thermal stress, as per ICH-specified conditions. The drug showed extensive degradation under oxidative and base hydrolysis stress conditions. However, it was stable to thermal, acid, neutral and photolysis stress conditions. A total of 6 degradation products were observed and the chromatographic separation of the drug and its degradation products were achieved on Phenomenex (Luna) C18 (250mm×4.6mm, i.d., 5μm) column using 20mM ammonium acetate: acetonitrile (50:50, v/v) as a mobile phase. The degradation products were characterized by LC-MS/MS and its fragmentation pathways were proposed. The LC-MS method was validated with respect to specificity, linearity, accuracy and precision. No previous reports were found in the literature regarding the degradation behavior of zofenopril. © 2013 Elsevier B.V.


Ramesh T.,National Institute of Technology Warangal | Rao P.N.,National Institute of Technology Warangal | Rao R.N.,IICT
Biomedical Chromatography | Year: 2014

A rapid and highly sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for determination of dapiprazole on rat dried blood spots and urine was developed and validated. The chromatographic separation was achieved on a reverse-phase C18 column (250×4.6mm i.d., 5μm), using 20mm ammonium acetate (pH adjusted to 4.0 with acetic acid) and acetonitrile (80:20, v/v) as a mobile phase at 25°C. LC-MS detection was performed with selective ion monitoring using target ions at m/z 326 and m/z 306 for dapiprazole and mepiprazole used as internal standard, respectively. The calibration curve showed a good linearity in the concentration range of 1-3000ng/mL. The effect of hematocrit on extraction of dapiprazole from DBS was evaluated. The mean recoveries of dapiprazole from DBS and urine were 93.88 and 90.29% respectively. The intra- and inter-day precisions were <4.19% in DBS as well as urine. The limits of detection and quantification were 0.30 and 1.10ng/mL in DBS and 0.45 and 1.50ng/mL in urine samples, respectively. The method was validated as per US Food and Drug Administration guidelines and successfully applied to a pharmacokinetic study of dapiprazole in rats. © 2013 John Wiley & Sons, Ltd.


Ramesh T.,National Institute of Technology Warangal | Rao P.N.,National Institute of Technology Warangal | Rao R.N.,IICT
Journal of Separation Science | Year: 2014

A rapid, specific, and reliable isocratic LC-MS/MS method has been developed and validated for the identification and characterization of the stressed degradation products of Entecavir (ETV). ETV, an antiviral drug, was subjected to hydrolysis (acidic, alkaline, and neutral), oxidation, photolysis and thermal stress, as per the international conference on harmonization specified conditions. The drug showed extensive degradation under oxidative and acid hydrolysis stress conditions. However, it was stable to thermal, acidic, neutral, and photolysis stress conditions. A total of five degradation products were observed and the chromatographic separation of the drug and its degradation products were achieved on a Waters Symmetry C18 (250 mm × 4.6 mm, id, 5 μm) column using 20 mM ammonium acetate (pH 3)/acetonitrile (50:50, v/v) as a mobile phase. The degradation products were characterized by LC-MS/MS and its fragmentation pathways were proposed. The LC-MS method was validated with respect to specificity, linearity, accuracy, and precision. No previous reports were found in the literature regarding the degradation behavior of ETV. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Kalmula B.,I.I.C.T. | Kondapuram V.R.,I.I.C.T.
Renewable and Sustainable Energy Reviews | Year: 2015

Fuel processors (FPs) are integrated with fuel cells (FCs) for onsite and onboard power generation. The process technologies employed in FPs have to be properly selected on the basis of fuel characteristics, impurity tolerances and operating specifications of FCs. Chemical, thermal and process parameters need to be given due consideration to ensure smooth FP-FC integration. The chemistry and catalytic reaction engineering of H2 generation in FPs and its utilization in FCs through electrocatalysis provide major challenges. The reactor configurations, extent of their miniaturization and their internal hydrodynamics and other design factors need to be considered for proper integration. This article highlights the current state of engineering knowledge in FP-FC integration and future prospects for achieving more efficient FP-FC systems for large scale onboard deployment. © 2015 Elsevier Ltd. All rights reserved.


Thippani R.,National Institute of Technology Warangal | Pothuraju N.R.,National Institute of Technology Warangal | Ramisetti N.R.,IICT | Shaik S.,IICT
Journal of Pharmaceutical Analysis | Year: 2013

A novel isocratic reverse phase high performance liquid chromatography (RP-HPLC) with photo diode array (PDA) detection method for the determination of dobutamine (DBT) in rat plasma was developed and validated after optimization of various chromatographic conditions and other experimental parameters. Homoveratrylamine was used as an internal standard. Methanol was used as the extracting solvent for the preparation of plasma samples. Samples were separated on a Symmetry C18 (250 mm×4.6 mm i.d., 5 μm) analytical column. Acetonitrile and 15 mM potassium dihydrogen phosphate (pH 5.0 with 0.3% TEA) (20:80, v/v) was used. The column oven temperature was optimized at 35 C and the flow rate was 0.8 mL/min. The detection wavelength was fixed at 230 nm for entire analysis. The calibration curve was found to be linear over the concentration range of 50-2000 ng/mL (r2=0.9992). The limit of quantification (LOQ) of the method was 50 ng/mL. The % RSD values of accuracy and precision values for intra and inter days were <15% at quality control (QC) concentrations. Recovery, stability and robustness were studied within the acceptable range according to ICH guidelines. The method was efficiently applied to a pharmacokinetic study in healthy Wistar rats. © 2013 Xi'an Jiaotong University.

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