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Kumaran Vediappan,이창우 한국물리학회 2010 Current Applied Physics Vol.10 No.2
The millennium application of new hydrogen absorbing alloys as negative electrodes in rechargeable batteries has allowed the consideration of nickel/metal hydride (Ni–MH) batteries to replace the conventional nickel cadmium alkaline or lead acid batteries. In this study the mechanical alloying process was used for synthesizing nanocrystalline TiCo–Mg-type hydrogen storage materials. The pressing negative and positive electrode, polyethylene as a separator and 6 mol/l KOH as an electrolyte solution constructed the cells. The nanocrystalline alloys electrode was subjected to charge/discharge cycle for more than 200 cycles. The discharge capacities of the nanocrystalline alloys withstand at 240 mAh/g with a nominal fading in capacity on prolonged cycling. The results show that when using sealed batteries nanocrystalline Ti[Co0.65Mg0.35] alloy electrode shows two times more capacity than TiNi counterparts.
Kumaran, Rangarajulu Senthil,Hur, Byung‑,Ki Wiley (John WileySons) 2009 Biotechnology and Applied Biochemistry Vol.54 No.1
<P>Three different strains of the endophytic fungus Phomopsis were isolated from the healthy leaves of Taxus cuspidata (Japanese yew), Ginkgo biloba (ginkgo or maidenhair tree) and Larix leptolepis (Japanese larch) and screened for the production of taxol on a modified liquid medium for the first time. The presence of taxol was confirmed by spectroscopic and chromatographic analyses. The amount of taxol produced by this fungus was quantified by HPLC. The maximum amount of fungal taxol production was recorded as 418 microg/litre in the strain BKH 27. The yield was increased to 8360-fold that found for the fungus Taxomyces andreanae reported previously [Stierle, Strobel and Stierle (1993) Science 260, 214-216]. The fungal taxol extracted also showed a strong cytotoxicity towards the human cancer cells in an apoptosis assay. All the three isolates showed positive sign towards PCR for the conserved sequence of the taxadiene synthase gene. The results suggest that Phomopsis could be an excellent alternative source for taxol and may serve as a potential genetic-engineered species for the enhanced production of taxol.</P>
Taxol from Phyllosticta citricarpa, a leaf spot fungus of the angiosperm Citrus medica
Kumaran, R.S.,Muthumary, J.,Hur, B.K. Society for Bioscience and Bioengineering, Japan ; 2008 Journal of bioscience and bioengineering Vol.106 No.1
Phyllosticta citricarpa, a leaf spot fungus isolated from the diseased leaves of Citrus medica, displayed the production of taxol, an anticancer drug on M1D and potato dextrose broth medium in culture for the first time. The presence of taxol was confirmed by spectroscopic and chromatographic methods of analysis. The maximum amount of taxol production was recorded in the fungus grown on M1D medium (265 μg/l) followed by PDB medium (137 μg/l). The production rate was increased to 5.3x10<SUP>3</SUP> fold than that observed in the culture broth of an earlier reported fungus, Taxomyces andreanae.
Kumaran, Rangarajulu Senthil,Choi, Yong-Keun,Kim, Hyung Joo,Kim, Kwang Jin Humana Press 2014 Applied biochemistry and biotechnology Vol.173 No.3
<P>The objective of this study was to assess the cytotoxicity of water-dispersible CuO nanoparticles by quantifying the reactive oxygen species (ROS)-related genes (glutathione S-transferase (GST) and catalase) using real-time polymerase chain reaction (RT-PCR). Monodisperse CuO nanoparticles of 14?nm in size were used. Cytotoxicity of CuO nanoparticles was evaluated under in vitro condition at different concentrations (10, 50, and 100?μg/ml) and incubation times (12, 24, and 48?h) with human cancer cell lines (breast cancer epithelial cells). The genetic level cytotoxic screening produced consistent results showing that GST and catalase ROS gene expression was maximized in 24?h incubation at 100?μg/ml concentration of CuO nanoparticles. However, the cytotoxicity of water-dispersible CuO nanoparticle was not significant compared with control experiments, demonstrating its high potential in the application of nanomedicines for a diagnostic and therapeutic tool.</P>
Electrochemical approaches for the determination of ranitidine drug reaction mechanism
Kumaran Vediappan,이창우 한국물리학회 2011 Current Applied Physics Vol.11 No.4
The electrochemical reduction reaction of ranitidine, an antileprotic drug, was studied in an aqueous potassium chloride buffer with a stationary glassy carbon electrode. Cyclic voltammetric studies showed a well-defined reduction peak in the potential range from 0.0 to ―1.8 V at pH values ranging from 1.0 to 11.0. The reduction was irreversible and has exhibited a diffusion-controlled adsorption. Controlled potential coulometry revealed four electron reductions with a total charge consumption of 785 mC. A systematic study of the experimental parameters that affected the square wave stripping response was carried out, and the conditions were optimized. A calibration plot was derived for the determination of the compound. The best determination range was obtained between 0.033 and 3.33 mg/L ranitidine with a relative standard deviation (n = 10) of 3 ppt (0.3%). Analytical applicability of the method was verified by the determination of ranitidine in tablets, dosing of drugs, gene profiling, monitoring of biologically important metabolites and urine samples. Also these techniques could make easier many arduous procedures such as in-situ assessment of weapons or toxic substances, environment pollution and others.
Kumaran, Aswathy,Guruvare, Shyamala,Sharan, Krishna,Rai, Lavanya,Hebbar, Shripad Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.11
Purpose: To assess chemoradiation related acute morbidity in women with carcinoma cervix and to find and correlation between hematologic toxicity and organ system specific damage. Materials and Methods: A prospective study was carried out between August 2012 and July 2013 enrolling 79 women with cancer cervix receiving chemo-radiotherapy. Weekly assessment of acute morbidity was done using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) version 4 and the toxicities were graded. Results: Anemia [77 (97.5%)], vomiting [75 (94.8%)] and diarrhea [72 (91.1%)], leukopenia [11 (13.9%)], cystitis [28 (35.4%], dermatitis [19 (24.1%)] and fatigue [29 (36.71%)] were the acute toxicities noted. The toxicities were most severe in $3^{rd}$ and $5^{th}$ week. All women could complete radiotherapy except two due to causes unrelated to radiation morbidity; seven (8.86%) had to discontinue chemotherapy due to leukopenia and intractable diarrhea. Though there was no correlation between anemia and other toxicities, it was found that all with leukopenia had diarrhea. Conclusions: Chemoradiation for cancer cervix is on the whole well tolerated. Leukopenia and severe diarrhea were the acute toxicities that compelled discontinuation of chemotherapy in two women. Though anemia had no correlation with gastrointestinal toxicity, all of those with leukopenia had diarrhea.
Kumaran, Rangarajulu Senthil,Choi, Yong-Keun,Singh, Vijay,Song, Hak-Jin,Song, Kyung-Guen,Kim, Kwang Jin,Kim, Hyung Joo MDPI 2015 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.16 No.4
<P>Water-dispersible MgO nanoparticles were tested to investigate their cytotoxic effects on oxidative stress gene expression. In this <I>in vitro</I> study, genes related to reactive oxygen species (ROS), glutathione <I>S</I>-transferase (GST) and catalase, were quantified using real-time polymerase chain reactions (molecular level) and molecular beacon technologies (cellular level). The monodispersed MgO nanoparticles, 20 nm in size, were used to treat human cancer cell lines (liver cancer epithelial cells) at different concentrations (25, 75 and 150 µg/mL) and incubation times (24, 48 and 72 h). Both the genetic and cellular cytotoxic screening methods produced consistent results, showing that GST and catalase ROS gene expression was maximized at 150 µg/mL nanoparticle treatment with 48 h incubation. However, the genotoxic effect of MgO nanoparticles was not significant compared with control experiments, which indicates its significant potential applications in nanomedicine as a diagnostic and therapeutic tool.</P>