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.

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 Biointerfaces 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>

Myanmar’s 2021 Military Coup, Its Impact on Domestic Politics, and a Revolutionary Road to Democratization?

( Narayanan Ganesan ) 서울대학교 통일평화연구원 2023 Asian Journal of Peacebuilding Vol.11 No.2

The Myanmar military staged a coup against the elected civilian government in February 2021. Since then, the country has been in a state of emergency and ruled by a military junta. Resistance to the coup was swift and widespread, beginning with the Civil Disobedience Movement that has now morphed into the People’s Defense Forces. A state of civil war has remained for well over two years now, reversing the previous trend toward democratic transition. Nonetheless, the democratic interlude has spawned strong resistance to military rule. The armed conflict and contestation for power looks set to continue into the medium term and may eventually lead to domestic political changes toward democratization.

Flashover Prediction of Polymeric Insulators Using PD Signal Time-Frequency Analysis and BPA Neural Network Technique

Narayanan, V. Jayaprakash,Karthik, B.,Chandrasekar, S. The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.4

Flashover of power transmission line insulators is a major threat to the reliable operation of power system. This paper deals with the flashover prediction of polymeric insulators used in power transmission line applications using the novel condition monitoring technique developed by PD signal time-frequency map and neural network technique. Laboratory experiments on polymeric insulators were carried out as per IEC 60507 under AC voltage, at different humidity and contamination levels using NaCl as a contaminant. Partial discharge signals were acquired using advanced ultra wide band detection system. Salient features from the Time-Frequency map and PRPD pattern at different pollution levels were extracted. The flashover prediction of polymeric insulators was automated using artificial neural network (ANN) with back propagation algorithm (BPA). From the results, it can be speculated that PD signal feature extraction along with back propagation classification is a well suited technique to predict flashover of polymeric insulators.

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.

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>

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

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.