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.

Self-oligomerization of ASC PYD Domain Prevents the Assembly of Inflammasome In Vitro

Narayanan, K. B.,Jang, T. H.,Park, H. H. HUMANA PRESS INC 2014 Applied biochemistry and biotechnology Vol.172 No.8

Fretting corrosion of lubricated tin-plated contacts

Narayanan, T.S.N. Sankara,Park, Young Woo,Lee, Kang Yong Emerald Group Publishing Limited 2008 Industrial lubrication and tribology Vol.60 No.5

<B>Purpose</B> - The objective of this paper is to study the effect of a commercial lubricant, which contains a 50-50 mixture of zinc diamyldithiocarbamate and petroleum oil, on the fretting corrosion of tin-plated copper alloy contacts. <B>Design/methodology/approach</B> - The change in contact resistance as a function of fretting cycles was used to assess the effectiveness of the lubricant in preventing the fretting corrosion of tin-plated contacts. The surface profile, surface roughness, extent of fretting damage and extent of oxidation of the contact zone were assessed by a laser scanning microscope and surface analytical techniques to correlate the change in contact resistance with fretting cycles. <B>Findings</B> - The lubricant film provides a surface coverage of 6.76±1?mg/cm<SUP>2</SUP> and it easily establishes metallic asperity contact between the mated tin-plated contacts. The contact resistance of lubricated contacts remains stable for several thousand fretting cycles. Lubricated contacts reach a threshold value of 0.1?O around 100,000 cycles, whereas unlubricated contact reaches this value around 13,500 cycles itself. For lubricated contacts, the extent of mechanical wear of the tin coating is significantly reduced. As a result, they experience a lesser damage at the contact zone and exhibit a smoother profile. The formation of tin oxide is not appreciable and there is no oxide accumulation at the contact zone even at 380,000 cycles. The lubricant is very effective in delaying the fretting wear during the initial stages and in preventing the oxidation and accumulation of oxidation products at the contact zone in the later stages. <B>Originality/value</B> - Metallic dialkyldithiocarbamates are useful anti-wear and extreme pressure additives for lubricating oils. Dithiocarbamates improve the antioxidant properties of the lubricants and are effective in reducing the wear and increasing the friction-reducing and load-carrying ability of the base stock. The use of molybdenum dithiocarbamate as a grease additive is found to be effective in reducing fretting corrosion of ball bearings under random rotary vibrating conditions. The effect of dithiocarbamate containing lubricant oils or greases on the fretting corrosion of electrical contacts has not far been studied. The paper explores the effect of a lubricant that contains a 50-50 mixture of petroleum oil and zinc diamyldithiocarbamate on the fretting corrosion of tin-plated contact.

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>

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.

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>

Optimal Placement of Distributed Generators in Radial Distribution System for Reducing the Effect of Islanding

Narayanan. K,Shahbaz A. Siddiqui,Manoj Fozdar 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3

The present trend of increasing the penetration levels of Distributed Generator (DG) in the distribution network has made the issue of Islanding crucial for the reliable operation of the network. The islanding, if not detected early may lead to the collapse of the system as it can drive the distribution system to the cascaded failure. In this paper, an extensive study of the effect of DG placement and sizing is performed by dividing the system into different zones to obtain a reduced effect of islanding. The siting and sizing of DG is carried out to improve the overall voltage profile or/and reduction in active power loss using two stage Genetic Algorithm (GA). In the first stage a basic knockout selection is considered and the best population is taken for next stage, where roulette selection for crossover and mutation is performed for optimal placement and sizing of DGs. The effect of the islanding, due to load variations is reduced by optimal siting and sizing of DG. The effectiveness of the proposed scheme is tested on the IEEE 33 and 69 radial bus systems and the results obtained are promising.

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.

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.

Mitochondrial ND1 gene mutation analysis in type II diabetes of Karaikudi population

Narayanan Marimuthu Prabhu,Kasinathan Devi,Elango Santhini,Devaraj Ramanan,Ramachandran Ishwarya 한국유전학회 2016 Genes & Genomics Vol.38 No.1

Mitochondrial single nucleotide polymorphisms (SNPs) are significantly correlated with the development of diabetes mellitus. However, these polymorphisms are emerging to be considerably diverse among different population and regions. Sivaganga district is recently being given importance for genetic studies due to its rigid family structure. Hence, the present study is planned to investigate the correlation between mitochondrial SNP of ND1 gene with type II diabetes (T2D) of Karaikudi population of Sivaganga district. For this study, 206 samples including 105 T2D and 101 healthy volunteers were collected and screened for ND1 gene mutation. Genotyping for the ND1 gene was characterized by polymerase chain reaction, Restriction fragment length polymorphism (RFLP) followed by sequencing. In addition, clinical and biochemical variables were analyzed. RFLP and sequencing results showed G[A transition at 3316 position of ND1 gene in both T2D (6.67 %) and in control subjects (1.9 %). Since the frequency of the mutation was found high in T2D patients, we screened for the mutation in their family members and identified its maternal mode of inheritance. The result warrants for the detailed study to identify population based mitochondrial mutation association with disease development.