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Upadhyay S.,John lch Technology Center | Adda R.,Indian Institute of Technology Kanpur | Mishra S.,Indian Institute of Technology Kanpur | Joshi A.,Indian Institute of Technology Kanpur
2010 9th International Power and Energy Conference, IPEC 2010 | Year: 2010

This paper proposes a novel switched-boost converter suitable for microgrid application. The proposed converter can provide a DC output, which is greater than the input voltage. Apart from a DC, it can be, simultaneously, used to supply an AC load. In order to supply an AC load it has to be cascaded with a Voltage source inverter (VSI). While operating with a VSI, it avails all the advantages of a Z-source inverter, with half the number of passive components. During AC operation, it prevents the shoot-though current due to mis-gating and provides superior noise immunity. The circuit operation, analysis, PWM control strategy, and experimental results are provided to verify the proposed topology. ©2010 IEEE.

Patil S.,Shivaji University | Srinivas S.,John lch Technology Center | Jadhav J.,Shivaji University
International Journal of Biological Macromolecules | Year: 2014

Tyrosinase inhibitors have potential applications in the cosmetics and food industries for preventing browning reactions and also as therapeutic drugs for neurodegenerative diseases such as Parkinson's. In this article, crocin and curcumin were evaluated as mushroom tyrosinase inhibitors. Results showed that, both compounds strongly inhibited the diphenolase activity than monophenolase. The IC50 values for diphenolase activity were estimated to be 0.11mM and 0.18mM for crocin and curcumin respectively. The binding kinetics of crocin and curcumin was studied with mushroom tyrosinase using surface plasmon resonance (SPR). Tyrosinase was immobilized on the gold surface of a Biacore sensor chip through amine coupling. Binding of inhibitors was analyzed by SPR without the need to further modify the surface or the use of other reagents. The binding constant KD (M) for mushroom tyrosinase obtained was 1.21×10-4M for crocin and 1.64×10-4M for curcumin, while showing a higher affinity for L-DOPA 1.95×10-8M, a substrate for tyrosinase (positive control). The study reveals the SPR sensor's ability to detect binding of the inhibitors. © 2014 Elsevier B.V.

Liu C.H.,Massachusetts General Hospital | Liu C.H.,U.S. National Institutes of Health | Ren J.Q.,Massachusetts General Hospital | You Z.,Massachusetts General Hospital | And 5 more authors.
FASEB Journal | Year: 2012

The presence of pericytes in brain regions undergoing repair is evident of the recruitment of bone marrow-derived multipotent regenerative cells to the neurovascular unit during angiogenesis. At present, post mortem sampling is the only way to identify them. Therefore, such cell typing is inadequate for preserving neural progenitor cells for any meaningful stem cell therapy. We aimed to target cerebral pericytes in vivo using dual gene transcript-targeted MRI (GTtMRI) in male C57black6 mice after a 60-min bilateral carotid artery occlusion (BCAO). We attached superparamagnetic iron oxide nanoparticles (SPIONs) to phosphorothioate-modified micro-DNA that targets actin or nestin mRNA. Because BCAO compromises the blood-brain barrier (BBB) and induces expression of α-smooth muscle (αSM)-actin and nestin antigens by pericytes in new vessels, we delivered pericyte-specific magnetic resonance contrast agents (SPION-actin or SPION-nestin at 4 mg Fe/kg) by i.p. injection to C57black6 mice that had experienced BCAO. We demonstrated that the surge in cerebral iron content by inductively coupled plasma-mass spectrometry matched the increase in the frequency of relaxivity. We also found that SPION-nestin was colocalized in αSM-actin- and nestin-expressing pericytes in BCAO-treated C57black6 or transgenic mice [B6.Cg-Tg(CAG-mRFP1) 1F1Hadj/J, expressing red fluorescent protein by actin promoter]. We identified pericytes in the repair patch in living brains after BCAO with a voxel size of 0.03 mm3. The presence of electron-dense nanoparticles in vascular pericytes in the region of BBB injury led us to draw the conclusion that GT-tMRI can noninvasively reveal neural progenitor cells during vascularization. © FASEB.

Surwase S.V.,Shivaji University | Patil S.A.,Shivaji University | Srinivas S.,John lch Technology Center | Jadhav J.P.,Shivaji University
Enzyme and Microbial Technology | Year: 2015

Laccases have a great potential for use in industrial and biotechnological applications. It has affinity towards phenolics and finds major applications in the field of bioremediation. Here, Surface Plasmon Resonance (SPR) as a biosensor with immobilized laccase on chip surface has been studied. Laccase was immobilized by thiol coupling method and compounds containing increasing number of hydroxyl groups were analyzed for their binding affinity at various concentrations in millimolar range. The small molecules like phloroglucinol (1.532×10-8 M), crocin (3.204×10-3 M), ascorbic acid (8.331×10-8 M), kojic acid (6.411×10-7 M) and saffron (3.466×10-7 M) were studied and respective K D values are obtained. The results were also confirmed by inhibition assay and IC50 values were calculated. All these molecules showed different affinity towards laccase in terms of K D values. This method may be useful for preliminary screening and characterization of small molecules as laccase substrates, inhibitors or modulators of activity. This method will be useful for rapid screening of phenolics in waste water because of high sensitivity. © 2015 Elsevier Inc.

Chanda C.,Birla Institute of Technology and Science | Sarkar A.,Birla Institute of Technology and Science | Sistla S.,John lch Technology Center | Chakrabarty D.,Birla Institute of Technology and Science
Biochemical and Biophysical Research Communications | Year: 2013

A low molecular weight anti-platelet peptide (6.9. kDa) has been purified from Naja kaouthia venom and was named KT-6.9. MALDI-TOF/TOF mass spectrometry analysis revealed the homology of KT-6.9 peptide sequence with many three finger toxin family members. KT-6.9 inhibited human platelet aggregation process in a dose dependent manner. It has inhibited ADP, thrombin and arachidonic acid induced platelet aggregation process in dose dependent manner, but did not inhibit collagen and ristocetin induced platelet aggregation. Strong inhibition (70%) of the ADP induced platelet aggregation by KT-6.9 suggests competition with ADP for its receptors on platelet surface. Anti-platelet activity of KT-6.9 was found to be 25 times stronger than that of anti-platelet drug clopidogrel. Binding of KT-6.9 to platelet surface was confirmed by surface plasma resonance analysis using BIAcore X100. Binding was also observed by a modified sandwich ELISA method using anti-KT-6.9 antibodies. KT-6.9 is probably the first 3FTx from Indian monocled cobra venom reported as a platelet aggregation inhibitor. © 2013 Elsevier Inc.

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