Measured aerodynamic coefficients of without and with spiked blunt body at Mach 6

Kalimuthu, R.,Mehta, R.C.,Rathakrishnan, E. Techno-Press 2019 Advances in aircraft and spacecraft science Vol.6 No.3

A spike attached to a blunt nosed body significantly alters its flow field and influences the aerodynamic coefficients at hypersonic speed. The basic body is an axisymmetric, with a hemisphere nose followed by a cylindrical portion. Five different types of spikes, namely, conical aerospike, hemisphere aerospike, flat-face aerospike, hemisphere aerodisk and flat-face aerodisk are attached to the basic body in order to assess the aerodynamic characteristic. The spiked blunt body without the aerospike or aerodisk has been set to be a basic model. The coefficients of drag, lift and pitching moment were measured with and without blunt spike body for the length-to-diameter ratio (L/D) of 0.5, 1.0, 1.5 and 2.0, at Mach 6 and angle of attack up to 8 degrees using a strain gauge balance. The measured forces and moment data are employed to determine the relative performance of the aerodynamic with respect to the basic model. A maximum of 77 percent drag reduction was achieved with hemisphere aerospike of L/D = 2.0. The comparison of aerodynamic coefficients between the basic model and the spiked blunt body reveals that the aerodynamic drag and pitching moment coefficients decrease with increasing the L/D ratio and angle of attack but the lift coefficient has increasing characteristics.

Regulated Mesenchymal Stem Cells Mediated Colon Cancer Therapy Assessed by Reporter Gene Based Optical Imaging

Kalimuthu, Senthilkumar,Zhu, Liya,Oh, Ji Min,Lee, Ho Won,Gangadaran, Prakash,Rajendran, Ramya Lakshmi,Baek, Se Hwan,Jeon, Yong Hyun,Jeong, Shin Young,Lee, Sang-Woo,Lee, Jaetae,Ahn, Byeong-Cheol MDPI 2018 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.19 No.4

<P>Colorectal cancer is the most common cancer in both men and women and the second most common cause of cancer-related deaths. Suicide gene-based therapy with suicide gene-transduced mesenchymal stem cells (MSCs) is a promising therapeutic strategy. A tetracycline-controlled Tet-On inducible system used to regulate gene expression may be a useful tool for gene-based therapies. The aim of this study was to develop therapeutic MSCs with a suicide gene that is induced by an artificial stimulus, to validate therapeutic gene expression, and to monitor the MSC therapy for colon cancer using optical molecular imaging. For our study, we designed the Tet-On system using a retroviral vector and developed a response plasmid RetroX-TRE (tetracycline response element) expressing a mutant form of herpes simplex virus thymidine kinase (HSV1-sr39TK) with dual reporters (eGFP-Fluc2). Bone marrow-derived MSCs were transduced using a RetroX-Tet3G (Clontech, CA, USA) regulatory plasmid and RetroX-TRE-HSV1-sr39TK-eGFP-IRES-Fluc2, for a system with a Tet-On (MSC-Tet-TK/Fluc2 or MSC-Tet-TK) or without a Tet-On (MSC-TK/Fluc2 or MSC-TK) function. Suicide gene engineered MSCs were co-cultured with colon cancer cells (CT26/Rluc) in the presence of the prodrug ganciclovir (GCV) after stimulation with or without doxycycline (DOX). Treatment efficiency was monitored by assessing Rluc (CT26/Rluc) and Fluc (MSC-Tet-TK and MSC-TK) activity using optical imaging. The bystander effect of therapeutic MSCs was confirmed in CT26/Rluc cells after GCV treatment. Rluc activity in CT26/Rluc cells decreased significantly with GCV treatment of DOX(+) cells (<I>p</I> < 0.05 and 0.01) whereas no significant changes were observed in DOX(−) cells. In addition, Fluc activity in also decreased significantly with DOX(+) MSC-Tet-TK cells, but no signal was observed in DOX(−) cells. In addition, an MSC-TK bystander effect was also confirmed. We assessed therapy with this system in a colon cancer xenograft model (CT26/Rluc). We successfully transduced cells and developed a Tet-On system with the suicide gene HSV1-sr39TK. Our results confirmed the therapeutic efficiency of a suicide gene with the Tet-On system for colon cancer. In addition, our results provide an innovative therapeutic approach using the Tet-On system to eradicate tumors by administration of MSC-Tet-TK cells with DOX and GCV.</P>

Cell Survival and Apoptosis Signaling as Therapeutic Target for Cancer: Marine Bioactive Compounds

Kalimuthu, Senthilkumar,Se-Kwon, Kim MDPI 2013 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.14 No.2

<P>Inhibition of apoptosis leads to activation of cell survival factors (e.g., AKT) causes continuous cell proliferation in cancer. Apoptosis, the major form of cellular suicide, is central to various physiological processes and the maintenance of homeostasis in multicellular organisms. A number of discoveries have clarified the molecular mechanism of apoptosis, thus clarifying the link between apoptosis and cell survival factors, which has a therapeutic outcome. Induction of apoptosis and inhibition of cell survival by anticancer agents has been shown to correlate with tumor response. Cellular damage induces growth arrest and tumor suppression by inducing apoptosis, necrosis and senescence; the mechanism of cell death depends on the magnitude of DNA damage following exposure to various anticancer agents. Apoptosis is mainly regulated by cell survival and proliferating signaling molecules. As a new therapeutic strategy, alternative types of cell death might be exploited to control and eradicate cancer cells. This review discusses the signaling of apoptosis and cell survival, as well as the potential contribution of marine bioactive compounds, suggesting that new therapeutic strategies might follow.</P>

Drug Discovery by Molecular Imaging and Monitoring Therapy Response in Lymphoma

Kalimuthu, Senthilkumar,Jeong, Ju Hye,Oh, Ji Min,Ahn, Byeong-Cheol MDPI AG 2017 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.18 No.8

<P>Molecular imaging allows a noninvasive assessment of biochemical and biological processes in living subjects. Treatment strategies for malignant lymphoma depend on histology and tumor stage. For the last two decades, molecular imaging has been the mainstay diagnostic test for the staging of malignant lymphoma and the assessment of response to treatment. This technology enhances our understanding of disease and drug activity during preclinical and clinical drug development. Here, we review molecular imaging applications in drug development, with an emphasis on oncology. Monitoring and assessing the efficacy of anti-cancer therapies in preclinical or clinical models are essential and the multimodal molecular imaging approach may represent a new stage for pharmacologic development in cancer. Monitoring the progress of lymphoma therapy with imaging modalities will help patients. Identifying and addressing key challenges is essential for successful integration of molecular imaging into the drug development process. In this review, we highlight the general usefulness of molecular imaging in drug development and radionuclide-based reporter genes. Further, we discuss the different molecular imaging modalities for lymphoma therapy and their preclinical and clinical applications.</P>

Green-synthesized silver nanoparticles using Psychotria nilgiriensis: toxicity against the dengue vector Aedes aegypti (Diptera: Culicidae) and impact on the predatory efficiency of the non-target organism Poecilia sphenops (Cyprinodontiformes: Poeciliid

Kalimuthu Kovendan,Balamurugan Chandramohan,Devakumar Dinesh,Dhandapani Abirami,Periasamy Vijayan,Marimuthu Govindarajan,Savariar Vincent,Giovanni Benelli 한국응용곤충학회 2016 Journal of Asia-Pacific Entomology Vol.19 No.4

Mosquitoes transmit serious diseases to humans and animals, causingmillions of deaths every year. Effective insecticides of natural origin for eco-friendly vector control are a priority. In this study, silver nanoparticles (AgNPs) biosynthesized using as cheap Psychotria nilgiriensis leaf extractwere tested on larvae and pupae of Aedes aegypti (Diptera: Culicidae). Biophysical characterizationwas carried outwith UV–vis spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Larvae were exposed to varying concentrations of aqueous extract of synthesized AgNPs for 24 h. The maximum mortality was observed for green-synthesized AgNPs. Moreover, the combined treatment of leaf extract of P. nilgiriensis and AgNPs lowered the plant extract LC50 to 92.87, 115.27, 140.37, 169.30 and 212.55 μg/ml. The effectiveness of green synthesized AgNPs was confirmed against eggs and adults of A. aegypti. Furthermore, we showed that the predatory efficiency of Poecilia sphenops on A. aegypti was not reduced after the exposure at sublethal doses of AgNPs. Predation in the control was 65% (larva I) and 49.62% (larva II). Predation against late-instar larvae was minimal. In AgNPs-treated environment (3 ppm), predation was boosted to 90.25% (larva I) and 76.50% (larva II), respectively. Overall, P. nilgiriensis-synthesized AgNPs could be proposed at ultra-low doses to reduce larval population of dengue vectors enhancing predation rates of P. sphenops.

Synthesis and characterization of biocompatible zinc oxide nanorod doped-titanium dioxide nanosheet

Kalimuthu Rajendran,Mani Gajendiran,김성준,김교범,Sengottuvelan Balasubramanian 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

The titanium dioxide (TiO2) and zinc oxide (ZnO) nanomaterials are widely used for several biomedicalapplications because of their semiconductor property. The present study demonstrates a strategy forsynthesis of zinc oxide nanorod (ZnONR) doped titanium dioxide nanosheets (ZnONR@TiONS) viahydrothermal method. A series of characterization techniques indicated that TiONS exhibited band gapenergy of 3.09 eV, while the ZnONR@TiONS showed 2.83 eV. XPS analysis confirmed the 4+ oxidationstate of TiONS and 2+ oxidation state of ZnONR. In vitro cytotoxicity test indicated that the ZnONR@TiONSshowed 99% of cell viability without any toxicity under 50 mg/mL of concentrations.

In Vivo Tracking of Chemokine Receptor CXCR4-Engineered Mesenchymal Stem Cell Migration by Optical Molecular Imaging

Kalimuthu, Senthilkumar,Oh, Ji Min,Gangadaran, Prakash,Zhu, Liya,Lee, Ho Won,Rajendran, Ramya Lakshmi,Baek, Se hwan,Jeon, Yong Hyun,Jeong, Shin Young,Lee, Sang-Woo,Lee, Jaetae,Ahn, Byeong-Cheol Hindawi 2017 Stem cells international Vol.2017 No.-

<P>CXCR4, the stromal cell-derived factor-1 receptor, plays an important role in the migration of hematopoietic progenitor/stem cells to injured and inflamed areas. Noninvasive cell tracking methods could be useful for monitoring cell fate. Therefore, in this study, we evaluated the efficacy of an intravenous infusion of genetically engineered mesenchymal stem cells (MSCs) overexpressing CXC chemokine receptor 4 (CXCR4) to home to the tumor, by optical imaging. We constructed a retroviral vector containing CXCR with dual reporter genes, <I>eGFP</I> and <I>Fluc2</I>, under the control of an EF1<I>α</I> promoter (pBABE-EF1<I>α</I>-CXCR4-eGFP-IRES-Fluc2). We also developed an eGFP-Fluc2 construct in the Retro-X retroviral vector (Retro-X-eGFP-Fluc2). MSCs were transduced with retroviruses to generate CXCR4-overexpressing MSCs (MSC-CXCR4/Fluc2) and MSCs (MSC/Fluc2). CXCR4 mRNA and protein expression was confirmed by RT-PCR and Western blotting, respectively, and it was higher in MSC-CXCR4/Fluc2 than in naive MSCs. eGFP expression was confirmed by confocal microscopy. The transfected MSC-CXCR4/Fluc2 cells showed higher migratory capacity than naive MSCs observed in Transwell migration assay. The in vivo migration of CXCR4-overexpressing MSCs to MDAMB231/Rluc tumor model by BLI imaging was also confirmed. Intravenous delivery of genetically modified MSCs overexpressing CXCR4 with a <I>Fluc2</I> reporter gene may be a useful, noninvasive BLI imaging tool for tracking cell fate.</P>

Cobalt carbonate hydroxides as advanced battery-type materials for supercapatteries: Influence of morphology on performance

Sankar, Kalimuthu Vijaya,Seo, Youngho,Lee, Su Chan,Liu, Shude,Kundu, Aniruddha,Ray, Chaiti,Jun, Seong Chan Pergamon Press 2018 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>Layered materials provide good electrochemical performance, but insufficient rate capability, which is the main issue in energy storage. Herein, we propose a facile synthesis of Co<SUB>2</SUB>(CO<SUB>3</SUB>)(OH)<SUB>2</SUB> nanoflakes and polyhedron flowers supported on Ni foam, a novel binder-free electrode. Power law revealed that Co<SUB>2</SUB>(CO<SUB>3</SUB>)(OH)<SUB>2</SUB> stores charge by a battery-type mechanism at the peak potential. The nanoflakes store more internal surface charge than the polyhedron-flower, which was confirmed via Trasatti plot. Benefiting from amorphous nanostructure, unique morphology and high surface area, the nanoflakes shows good performance. The areal capacitance (2111 mF cm<SUP>−2</SUP>), rate capability (80%), and energy density (0.152 mWh cm<SUP>−2</SUP>) are comparable to recent reports. The results suggest that the amorphous Co<SUB>2</SUB>(CO<SUB>3</SUB>)(OH)<SUB>2</SUB> nanoflakes are a suitable cathode candidate for the supercapattery. The assembled supercapattery (ASC) provides high specific capacitance (91 F g<SUP>−1</SUP>), high energy density (26.22 Wh kg<SUP>−1</SUP> at power density 828 W kg<SUP>−1</SUP>), and long cycle life (specific capacitance retention of 85% over 4000 cycles). The ASC device shows good potential in the field of energy storage devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A single step, low temperature and time consuming method adopted to prepare material. </LI> <LI> Solvents viscosity, saturated vapor pressure, and polarity influenced on morphology. </LI> <LI> Nanoflake encouraged large charge storage than polyhedron flower morphology. </LI> <LI> Battery-type charge storage process confirmed using Power's law. </LI> <LI> Assembled device showed only 15% capacitance loss over 4000 cycles. </LI> </UL> </P>

Synergistic effect of quercetin and silver nanoparticles on HeLa cancer cells

Senthilkumar KALIMUTHU,Manivasagan PANCHANATHAN,Jayachandran VENKATESAN,Se-Kwon KIM 한국생물공학회 2013 한국생물공학회 학술대회 Vol.2013 No.10

Characterization of Rajath Bhasma and Evaluation of Its Toxicity in Zebrafish Embryos and Its Antimicrobial Activity

Kalishwaralal Kalimuthu,김지민,Chandramohan Subburaman,권우영,황성연,정세한,조민근,김형주,박기수 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.6

In India, nanotechnology has been used in therapeutic applications for several millennia. One example of a traditional nanomedicine is Rajath Bhasma (also called calcined silver ash), which is used as an antimicrobial and for the treatment of various ailments and conditions such as memory loss, eye diseases, and dehydration. In this study, we aimed to characterize the physical composition and morphology of Rajath Bhasma and its suitability for use as a non-toxic antimicrobial agent. First, Rajath Bhasma was physically characterized via i) Fourier-transform infrared spectroscopy to analyze the surface functional groups, ii) scanning electron microscopy coupled with energydispersive X-ray spectroscopy to observe the morphology and elemental composition, and iii) X-ray diffraction to determine the crystalline phases. Thereafter, functional characterization was performed through toxicity screening using zebrafish embryos and through antimicrobial activity assessment against gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. Rajath Bhasma was found to harbor alkene, hydroxyl, aldehyde, and amide functional groups originating from biological components on its surface. The main component of Rajath Bhasma is silver, with particle size of 170-210 nm, and existing in the form of spherical aggregates with pure crystalline silver structures. Furthermore, Rajath Bhasma did not exert toxic effects on zebrafish embryos at concentrations below 5 μg/ml and exhibited effective antimicrobial activity against both gram-positive and gram-negative bacteria. The present results indicate that Rajath Bhasma is a potentially effective antimicrobial agent without toxicity when used at concentrations below 5 μg/ml.