Reengineered graft copolymers as a potential alternative for the bone tissue engineering application by inducing osteogenic markers expression and biocompatibility

Thangavelu, M.,R. Narasimha, R.,Adithan, A.,A., C.,Jong-Hoon, K.,Thotapalli Parvathaleswara, S. Elsevier 2016 Colloids and surfaces Biointerfaces Vol.143 No.-

<P>Composite scaffolds of nano-hydroxyapatite with demineralized bone matrix were prepared and they were graft copolymerized for better bone regeneration and drug delivery applications. The graft copolymers were characterized for their physiochemical properties using conventional methods like FTIR, TGA, XRD and SEM. The scaffolds were seeded with 3T3 and MG63 cells for studying their biocompatibility and their temporal expression of ALP activity, the rate of calcium deposition and their gene expression of collagen type I (Coll-1), osteopontin (OP), osteonectin (ON), and osteocalcin (OC) were studied. In vivo studies were conducted using sub-cutaneous implantation models in male Wister rats for 6 months. Periodic radiography and post-autopsy histopathology was analysed at 15 days, 1, 2, 3, 4, 5, and 6 months. The obtained in vitro results clearly confirm that the bone scaffolds prepared in this study are biocompatible, superior osteoinductivity, capable of supporting growth, maturation of MG 63 osteoblast like cells; the gene expression profile revealed that the material is capable of supporting the in vitro growth and maturation of osteoblast-like cells and maturation. The in vivo results stand a testimony to the in vitro results in proving the biocompatibility and osteoinductivity of the materials. (C) 2016 Elsevier B.V. All rights reserved.</P>

Seasonal Changes in Cyanobacterial Diversity of a Temperate Freshwater Paldang Reservoir (Korea) Explored by using Pyrosequencing

Thangavelu Boopathi,Hui Wang,Man-Duck Lee,Jang-Seu Ki 한국환경생물학회 2018 환경생물 : 환경생물학회지 Vol.36 No.3

The incidence of freshwater algal bloom has been increasing globally in recent years and poses a major threat to environmental health. Cyanobacteria are the major component of the bloom forming community that must be monitored frequently. Their morphological identities, however, have remained elusive, due to their small size in cells and morphological resemblances among species. We have analyzed molecular diversity and seasonal changes of cyanobacteria in Paldang Reservoir, Korea, using morphological and 16S rRNA pyrosequencing methods. Samples were collected at monthly intervals from the reservoir March-December 2012. In total, 40 phylotypes of cyanobacteria were identified after comparing 49,131 pyrosequence reads. Cyanobacterial genera such as Anabaena, Aphanizomenon, Microcystis and Synechocystis were predominantly present in samples. However, the majority of cyanobacterial sequences (65.9%) identified in this study were of uncultured origins, not detected morphologically. Relative abundance of cyanobacterial sequences was observed as high in August, with no occurrence in March and December. These results suggested that pyrosequencing approach may reveal cyanobacterial diversity undetected morphologically, and may be used as reference for studying and monitoring cyanobacterial communities in aquatic environments.

Miniaturized Rectangular Slotted Nameplate Antenna Design for Satellite and Radio Determination Applications

Thangavelu Shanmuganantham,Deepanshu Kaushal 한국전자통신연구원 2017 ETRI Journal Vol.39 No.6

A slotted rectangular nameplate antenna design with a patch bearing the name of the first author is presented. A 6.8 mm × 26 mm × 1.6 mm substrate of FR-4 epoxy material having a relative permittivity of 4.4 and a dielectric loss tangent of 0.02 is used. Additionally, the feeding technique used is a coaxial mechanism. The standard antenna design parameters, including the reflection coefficient, bandwidth, radiation pattern, gain, directivity, and voltage standing wave radio (VSWR) for the proposed prototype are analyzed using a high-frequency structure simulator (HFSS) v-15, and are compared to the measured results. The designed structure may be considered for different satellite- and radio-determination applications at the respective resonant frequencies.

Unresolved diversity and monthly dynamics of eukaryotic phytoplankton in a temperate freshwater reservoir explored by pyrosequencing

Boopathi, Thangavelu,Ki, Jang-Seu CSIRO Publishing 2016 Marine & freshwater research Vol.67 No.11

<P>Environmental monitoring of the succession of phytoplankton communities in freshwater ecosystems is critical in efficient water quality management. In the present study we analysed the monthly dynamics of eukaryotic phytoplankton diversity and community structure in a freshwater reservoir (Paldang Reservoir, South Korea) using small subunit (SSU) rRNA pyrosequencing. We analysed physicochemical and biological parameters of water samples collected at monthly intervals from March 2012 to February 2013. The occurrence of phytoplankton exhibited a monthly variation: low in September (13.2%) and February (9.7%) and high in May (75.5%), July (76.5%), August (86.3%) and November (70.6%). We observed greater phytoplankton diversity predominantly represented by diatoms (37.4%), dinoflagellates (29%), cryptophytes (16%) and chlorophytes (10.4%). In early and mid-spring, diatoms, particularly Stephanodiscus spp., were dominant; however, in late spring and early summer the cryptophyte Cryptomonas spp. was dominant; the dinoflagellate Peridionopsis sp. was dominant in late summer and late autumn. Overall, the molecular results of the present study represent a typical pattern of seasonal phytoplankton succession in temperate regions. Pyrosequencing detected more phytoplankton taxa that were unresolved under microscopy, suggesting the usefulness of this method in continuous monitoring of phytoplankton communities in freshwater ecosystems.</P>

Poly(acrylic acid)-Grafted Graphene Oxide as an Intracellular Protein Carrier

Kavitha, Thangavelu,Kang, Inn-Kyu,Park, Soo-Young American Chemical Society 2014 Langmuir Vol.30 No.1

<P>A pH-sensitive poly(acrylic acid)-grafted graphene oxide (GO-PAA) nanocarrier was synthesized by in situ atom transfer radical polymerization to allow the oral delivery of hydrophilic macromolecular proteins in their active forms to specific cells or organs. The synthesis, morphology, and physiochemical properties of GO-PAA were examined. A model protein, bovine serum albumin (BSA) labeled with fluorescein isothiocyanate (FITC) (BSAFITC), was loaded onto GO-PAA through noncovalent interactions and its release was arrested at acidic pH similar to stomach, whereas at pH similar to intestine it was reduced, which paves way for site specific delivery without its degradation in the gastrointestinal tract. Confocal laser microscopy showed that the BSAFITC-loaded GO-PAA was internalized by KB cells by endocytosis and released into cytoplasm. Thus the GO-PAA as a transmembrane transporter is a new class of drug transporters with potential protein delivery applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2014/langd5.2014.30.issue-1/la404337d/production/images/medium/la-2013-04337d_0012.gif'></P>

Seasonal Changes in Cyanobacterial Diversity of a Temperate Freshwater Paldang Reservoir (Korea) Explored by using Pyrosequencing

Boopathi, Thangavelu,Wang, Hui,Lee, Man-Duck,Ki, Jang-Seu Korean Society of Environmental Biology 2018 환경생물 : 환경생물학회지 Vol.36 No.3

The incidence of freshwater algal bloom has been increasing globally in recent years and poses a major threat to environmental health. Cyanobacteria are the major component of the bloom forming community that must be monitored frequently. Their morphological identities, however, have remained elusive, due to their small size in cells and morphological resemblances among species. We have analyzed molecular diversity and seasonal changes of cyanobacteria in Paldang Reservoir, Korea, using morphological and 16S rRNA pyrosequencing methods. Samples were collected at monthly intervals from the reservoir March-December 2012. In total, 40 phylotypes of cyanobacteria were identified after comparing 49,131 pyrosequence reads. Cyanobacterial genera such as Anabaena, Aphanizomenon, Microcystis and Synechocystis were predominantly present in samples. However, the majority of cyanobacterial sequences (65.9%) identified in this study were of uncultured origins, not detected morphologically. Relative abundance of cyanobacterial sequences was observed as high in August, with no occurrence in March and December. These results suggested that pyrosequencing approach may reveal cyanobacterial diversity undetected morphologically, and may be used as reference for studying and monitoring cyanobacterial communities in aquatic environments.

pH-Sensitive nanocargo based on smart polymer functionalized graphene oxide for site-specific drug delivery

Kavitha, Thangavelu,Haider Abdi, Syed Izhar,Park, Soo-Young The Royal Society of Chemistry 2013 Physical chemistry chemical physics Vol.15 No.14

<P>Graphene oxide (GO) was functionalized covalently with pH-sensitive poly(2-(diethylamino) ethyl methacrylate) (PDEA) by surface-initiated <I>in situ</I> atom transfer radical polymerization. The structure of the PDEA-grafted GO (GO-PDEA) were examined by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis and atomic force microscopy. The grafted PDEA endowed the GO sheets with good solubility and stability in physiological solutions. Simple physisorption by π–π stacking and hydrophobic interactions on GO-PDEA can be used to load camptothecin (CPT), a widely used water-insoluble cancer drug. The loaded CPT was released only at the lower (acidic) pH normally found in a tumor environment but not in basic and neutral pH. GO-PDEA did not show practical toxicity to N2a cancer cells but the GO-PDEA-CPT complex exhibited high potency in killing N2a cancer cells <I>in vitro</I>. These results suggest that the GO-PDEA nanocargo carrier might be a promising material for site-specific anticancer drug delivery and controlled release.</P> <P>Graphic Abstract</P><P>PDEA-grafted graphene oxide is a promising material for site-specific anticancer drug delivery and controlled release. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cp00008g'> </P>

Impact of FTA on Trade in ASEAN and Australia Using Customs Level Data

Shandre M. Thangavelu,Dionisius Narjoko,Shujiro Urata 세종대학교 경제통합연구소 2021 Journal of Economic Integration Vol.36 No.3

This study examines the impact of the Association of Southeast Asian Nations (ASEAN)-Australia- New Zealand Free Trade Agreement (AANZFTA) on Australian trade with a particular focus on imports from ASEAN member countries to Australia. We examine the AANZFTA’s utilization by ten ASEAN countries at the six-digit trade classification level from 2012 to 2016 using Australian customs data. We implement Ando and Urata’s (2018) and Hayakawa et al.’s (2014) framework of free trade agreement (FTA) utilization based on preferential tariff margins. We also account for overlapping FTAs that are likely to impact the AANZFTA’s utilization. The results indicate that preferential tariff margins positively impact FTA utilization. However, the results also indicate that the AANZFTA’s utilization rate across ASEAN countries is low relative to Australia’s bilateral FTAs with Malaysia, Thailand, and Singapore. We also find evidence that co-sharing rules of origin positively impact FTA utilization.

Labour Market Integration with the World: Case of Singapore

( Shandre Mugan Thangavelu ) 세종대학교 경제통합연구소(구 세종대학교 국제경제연구소) 2017 Journal of Economic Integration Vol.32 No.3

This study analyses the effects of labour market integration on the domestic economy. We explore the effects of skilled and unskilled foreign labour on the sustainability of a small open economy with innovation and growth. Welfare implications such as Gross Domestic Product growth and wage inequality are explicitly modelled in a general equilibrium framework. The model is applied to a small open economy such as Singapore to derive key policy implications to balance economic growth with skilled workers and innovation activities in the economy. The study critically examines the foreign workers` policy in the Singaporean economy in terms of allowing both skilled and unskilled workers into the domestic labour market. The results of the model indicate that balancing foreign skilled and unskilled labour, with the development of indigenous innovation capabilities, is crucial to maintain strong, sustainable growth in the domestic economy. The results of the model also indicate that a labour market policy that allows more skilled workers tends to increase the supply of labour and reduce the skilled wage gap in the economy.

Studies on Long-term Preservation of Eggs of Indian Tropical Multivoltine Silkworm (Bombyx mori L.) Genetic Resources

Kumaresan, P.,Thangavelu, K.,Sinha, R.K. Korean Society of Sericultural Science 2004 International Journal of Industrial Entomology Vol.9 No.1

The silkworm rearing and growth parameters of 63 multivoltine silkworm accessions under extended period of egg preservation at 5$^{\circ}C$ from 30 days to 45 days were studied. The results indicate that, nine accessions did not respond to extended period of egg preservation at low temperature and the remaining 54 accessions responded to the treatment and three rearings were conducted for comparision with the control; to estimate the effect of prolonged egg preservation at low temperature. The non-parametric tests statistics (Wilcoxon tests) was adopted for comparing the mean performance of treated batches (45 days) over the control (30 days). Highly significant variability was found among the accessions for all the parameters under study. The genetically controlled morphological characters were not altered in the treated batches, which were found to be on par with that of control. However, the total larval duration varied significantly over the control in 51 accessions. Similarly, the fifth age larval duration of 27 accessions showed decreasing trend compared to control. Altogether 41 accessions were found to be tolerant to long-term cold preservation upto 45 days, without showing any significant variation for morphological as well as essential quantitative traits. These accessions may be recommended for long-term egg preservation schedule up to 45 days, which will reduce the cost of conservation of these silkworm germplasm.