Medical student’s perception to different types of set induction in anatomy lectures

Suresh Narayanan,Suresh Narayanan,Nachiket Shankar,Vimala Ananthy 대한해부학회 2019 Anatomy & Cell Biology Vol.52 No.3

Set induction refers to the process of using a thought-provoking statement, interesting fact, or an audio-visual stimulus at the beginning of lecture to gain student’s attention and give an overview about the lecture topic. In the present study, students were introduced to three types of set induction namely narratives, food-based analogies and humor-based images or activities at the beginning of anatomy lecture and their response to it is collected and analyzed. The objective of the study is to estimate the difference in a questionnaire-based perception score between the three different types of set induction; estimate sex differences in the questionnaire-based perception score. Students rated the validated, 7-item perception questionnaire using a 5-point Likert scale. Students felt that food-based analogies and humor-based images were more interesting, motivated them to participate in lecture-discussion than the narrative set induction. The familiarity of set induction varied between all the three different types of set induction. There was no significant difference in the perception of different types of set induction between male and female undergraduate students. Based on the student’s feedback, it could also serve as a memory aid and ease the students learning experience. Majority of students responded positively to the use of set induction and recommended for its use in future classes.

Fretting-corrosion mapping of tin-plated copper alloy contacts

Narayanan, T.S.N.S.,Park, Y.W.,Lee, K.Y. Elsevier Sequoia [etc.] 2007 Wear: An international journal on the science and Vol.262 No.1

The fretting corrosion of tin-plated contacts is influenced by several factors including frequency, amplitude, temperature, humidity, normal load, current load, etc. The present paper aims to develop fretting-corrosion maps to assess the fretting corrosion behaviour of tin-plated copper alloy contacts under varying experimental conditions. The extent of change in contact resistance up to 20000 fretting cycles and the nature of changes, such as, the extent of fretting wear and oxidation, assessed by surface analytical techniques, are used to develop the fretting-corrosion maps. The fretting-corrosion maps are segmented into various zones depending on the predominant processes that occur under a given set of conditions. The proposed fretting-corrosion maps are not quantitative to predict the exact life-time of the contact. However, they will be useful to draw some guidelines about the performance of the tin-plated copper alloy contacts under various conditions.

Dual-crosslinked poly(vinyl alcohol)/sodium alginate/silver nanocomposite beads – A promising antimicrobial material

Narayanan, Kannan Badri,Han, Sung Soo Elsevier 2017 Food chemistry Vol.234 No.-

<P><B>Abstract</B></P> <P>In this paper, we report the immobilization of borate-stabilized silver nanoparticles (AgNPs) as nanofillers in dual-crosslinked polymers comprised of poly(vinyl alcohol) (PVA) and sodium alginate (SA) at different ratios. Ionic-crosslinking using Ca<SUP>2+</SUP> ions and physical-crosslinking by freeze-thawing were used to entrap silver nanoparticles in the prepared PVA/SA/AgNPs nanocomposite beads. These polymeric nanocomposites were characterized by UV–Vis, XRD, FE–SEM, FT-IR, TGA, and using rheological and swelling properties. The antibacterial activities of these PVA/SA/AgNPs nanocomposites were evaluated against <I>Escherichia coli</I> O157: H7, which causes escherichiosis through contaminated food and water. The results obtained indicated that PVA/SA/AgNPs nanocomposite formed with a ratio 10/90 of PVA to SA (formulation F5) exhibited high bactericidal activity, with entrapment of AgNPs and had excellent rheological and thermal stabilities. Due to the low cost and effectiveness of these antimicrobial nanocomposites, they have potential as an active food-packaging material for food safety and to extend shelf-life of packaged foods.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Antimicrobial polymeric/metal nanocomposites can be used in active food packaging. </LI> <LI> PVA and SA at different ratios were used to prepare various PVA/SA/AgNPs composites. </LI> <LI> Dual-crosslinking of polymer/silver nanocomposites entraps silver nanoparticles. </LI> <LI> <I>Escherichia coli</I> (∼10<SUP>11</SUP> CFU/ml) were killed by PVA/SA/AgNPs beads in batch culture. </LI> <LI> Effective killing of <I>E. coli</I> (∼10<SUP>8</SUP> CFU/ml) cells in contact with PVA/SA/AgNPs surface. </LI> </UL> </P>

Colorimetric detection of manganese(II) ions using alginate-stabilized silver nanoparticles

Narayanan, K. B.,Han, S. S. Springer Science + Business Media 2017 Research on chemical intermediates Vol.43 No.10

Highly selective and quantitative colorimetric detection of mercury(II) ions by carrageenan-functionalized Ag/AgCl nanoparticles

Narayanan, K.B.,Han, S.S. Applied Science Publishers ; Elsevier Science Ltd 2017 Carbohydrate polymers Vol.160 No.-

The natural algal polysaccharide carrageenan was used for the greener synthesis of silver/silver chloride nanoparticles (Carr-Ag/AgCl NPs) without any toxic chemicals. We report the robust, highly selective, and sensitive colorimetric sensing of Hg<SUP>2+</SUP> ions using Carr-Ag/AgCl NPs without any further surface modification. The dark-brown color of a solution of Carr-Ag/AgCl NPs turned to white in a concentration-dependent manner with the addition of Hg<SUP>2+</SUP> ions, confirming the interaction of Carr-Ag/AgCl NPs with Hg<SUP>2+</SUP> ions. The plot of the extinction ratio of absorbance at 350nm to 450nm (A<SUB>350</SUB>/A<SUB>450</SUB>) for Carr-Ag/AgCl NPs against the concentration of [Hg<SUP>2+</SUP>] ions was linear, and the calibration curve was A<SUB>350</SUB>/A<SUB>450</SUB>=1.05254+0.00318xC<SUB>Hg</SUB> with a lower detection limit of 1μM. This portable and cost-effective method for mercury(II) ion sensing is widely applicable in on-field qualitative and quantitative measurements of [Hg<SUP>2+</SUP>] ions in environmental or biological samples.

($\in,\;{\in} V q$)-FUZZY SUBNEAR-RINGS AND ($\in,\;{\in} V q$)-FUZZY IDEALS OF NEAR-RINGS

NARAYANAN, AL.,MANIKANTAN, T. 한국전산응용수학회 2005 Journal of applied mathematics & informatics Vol.18 No.1

In this paper, we introduce the notions of ($\in,\;{\in} V q$)-fuzzy subnear-ring, ($\in,\;{\in} V q$)-fuzzy ideal and ($\in,\;{\in}V q$)-fuzzy quasi-ideal of near-rings and find more generalized concepts than those introduced by others. The characterization of such ($\in,\;{\in}V q$)-fuzzy ideals are also obtained.

Biofabrication of <i>Lysinibacillus sphaericus</i>-reduced graphene oxide in three-dimensional polyacrylamide/carbon nanocomposite hydrogels for skin tissue engineering

Narayanan, Kannan Badri,Choi, Soon Mo,Han, Sung Soo Elsevier 2019 Colloids and Surfaces B Vol.181 No.-

<P><B>Abstract</B></P> <P>The biological synthesis of reduced graphene oxide (rGO) from graphene oxide (GO) is an emerging phenomenon for developing biocompatible nanomaterials for its potential applications in nanomedicine. In this study, we demonstrated a simple, green, and non-toxic method for graphene synthesis using the live biomass of <I>Lysinibacillus sphaericus</I> as the reducing and stabilizing agent under ambient conditions. Ultraviolet-visible spectroscopic analysis confirmed the formation of graphene from GO suspension. X-ray diffraction studies showed the disappearance of the GO peak and the appearance of characteristic graphene broad peak at 2θ = 22.8°. Infrared analysis showed the decrease/disappearance of peaks corresponding to the oxygen-containing functionalities, and appearance of a peak at 1620 cm<SUP>–1</SUP> from unoxidized graphitic domains. Scanning electron microscopic images showed that <I>L. sphaericus</I>-reduced graphene oxide (L-rGO) contains aggregated graphene nanoflakes. Evaluation of the <I>in vitro</I> cytotoxicity of L-rGO nanosheets on human skin fibroblasts using the WST-1 assay did not show any significant effects after 24 h of exposure, which is indicative of biocompatibility. Polyacrylamide hydrogels with L-rGO were synthesized and used as scaffolds to support the growth and proliferation of skin fibroblasts. Cell viability assays and DAPI staining showed proliferation of fibroblasts and exhibited 83% of cell viability even after 28 days. Biofilm formation by <I>Pseudomonas aeruginosa</I> and <I>Staphylococcus aureus</I> was enhanced in nanocomposite hydrogels in the presence of 0.25 mg/mL GO and L-rGO in 48 h. Overall, this study showed that microbially-synthesized L-rGO can be used as a dopant in polymeric scaffolds for tissue engineering and highlighted their role in biofilm formation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Carbon-based hydrogels with enhanced mechanical properties can be used for tissue engineering. </LI> <LI> Microbial synthesis of reduced graphene oxide using <I>L. sphaericus</I> (L-rGO) bacterium was done. </LI> <LI> L-rGO incorporated into three-dimensional (3D) polyacrylamide (PAAm/L-rGO) hydrogel. </LI> <LI> PAAm/L-rGO nanocomposite hydrogels showed biocompatibility towards human skin fibroblasts. </LI> <LI> PAAm/L-rGO showed enhanced bacterial biofilm formation by <I>P. aeruginosa</I> and <I>S. aureus</I>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Ethanol Extracts of Selected Cyathea Species Decreased Cell Viability and Inhibited Growth in MCF 7 Cell Line Cultures

Narayanan Janakiraman,Marimuthu Johnson 사단법인약침학회 2016 Journal of Acupuncture & Meridian Studies Vol.9 No.3

Cancer is the cause of more than 6 million deaths worldwide every year. For centuries, medicinal plants have been used in the treatment of cancer. Chemotherapy, radiotherapy, surgery and acupuncture point stimulation are also used to treat cancer. The present study was intended to reveal the cytotoxic and anticancer potential of selected Cyathea species and to highlight their importance in the pharmaceutical industry for the development of cost-effective drugs. Cytotoxic studies using brine shrimp lethality bioassays and MCF 7 cell line cultures were carried out. Compared to petroleum ether, chloroform and acetone extracts, the ethanol extracts of selected Cyathea species were found to be more effective against brine shrimps. The ethanol extracts were further subjected to 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell proliferation assays. A decrease in cell viability and an increase in growth inhibition were observed for the MCF 7 cell line. The maximum percentage of cell inhibition was observed in Cyathea crinit, followed by Cyathea nilgirensis and Cyathea gigantea. The results of the present study suggest that Cyathea species are an effective source of cytotoxic compounds.

Purification and analysis of the interactions of caspase-1 and ASC for assembly of the inflammasome.

Narayanan, Kannan Badri,Park, Hyun Ho Humana Press 2015 Applied biochemistry and biotechnology Vol.175 No.6

<P>Inflammasomes are intracellular macromolecular complexes assembled to activate inflammatory caspases such as caspase-1 and caspase-5, which perform critical roles during innate immune response. The NALP3 inflammasome comprises three protein components, NALP3, ASC, and caspase-1. ASC, which contains both a pyrin domain (PYD) and a caspase recruitment domain (CARD), acts as a bridge to recruit NALP3 using the PYD/PYD interaction and to recruit caspase-1 via the CARD/CARD interaction. In this study, we successfully purified and characterized ASC CARD and caspase-1 CARD. The results showed that ASC CARD was unable to interact with caspase-1 CARD in vitro; therefore, we proposed an interaction mode between ASC CARD and caspase-1 CARD from a structural based modeling study.</P>

Democratic Deficits: Structural and Agency Factors in Myanmar’s Ethnic Peace Process during Regime Transition

( Narayanan Ganesan ) 서울대학교 통일평화연구원 2021 Asian Journal of Peacebuilding Vol.9 No.2

Myanmar has undergone democratic transition since 2010 when the country introduced elections and a parliamentary form of government. The country has now had two successive governments, the first led by President Thein Sein and the second by Aung San Suu Kyi’s National League for Democracy. Both governments have made the ethnic peace process, based on the 2015 Nationwide Ceasefire Agreement, a key policy issue. Nonetheless, only limited success has been obtained thus far, and important structural and agency factors inhibit greater progress. These factors, termed “democracy deficits” in this article, suggest that the peace process has limited scope for further success in the medium term, and that the interactions between these two factors has only worsened the situation. A postscript brings the article up to date.