Effects of targeted remediation in anatomy for first year medical students

Nachiket Shankar,Nachiket Shankar,Yogitha Ravindranath,Roopa Ravindranath,Henal Shah 대한해부학회 2019 Anatomy & Cell Biology Vol.52 No.1

The aim of this study was to assess the effectiveness of a questionnaire to guide targeted remediation among undergraduate medical students in anatomy. Seventy-five students from a medical college in South India who failed in the first internal theory examination were administered a validated 35-item questionnaire. The total and domain specific questionnaire scores were calculated. Specific weekly interventions for each student based on the questionnaire scores were conducted by appointed academic mentors for three months prior to the second internal examination. The dependent variable was performance in the second internal examination. The students were re-administered the questionnaire after the second internal examination. The independent variables were the marks obtained in the first internal examination, domain specific and total questionnaire scores, sex, and regularity of the student in attending the remedial sessions. Inferential statistical tests used were the chi-square test, independent sample t test, paired t test, multiple regression and binomial logistic regression. Of the 75 students who underwent remediation, 54 (72%) passed in the second internal examination. The scores in the second internal examination among these students was found to be significantly higher as compared to the first internal examination. The total, subject related and study skills questionnaire score were significantly lower after remediation. Students who were irregular had a significantly lower pass rate. The multivariate analysis showed that only the first internal marks added significantly to the prediction about second internal performance. This study provides evidence to show that struggling students perceive a benefit from targeted remediation.

Constrained Geometric Attitude Control on SO(3)

Shankar Kulumani,이태영 제어·로봇·시스템학회 2017 International Journal of Control, Automation, and Vol.15 No.6

This paper presents a new geometric adaptive control system with state inequality constraints for theattitude dynamics of a rigid body. The control system is designed such that the desired attitude is asymptoticallystabilized, while the controlled attitude trajectory avoids undesired regions defined by an inequality constraint. Inaddition, we develop an adaptive update law that enables attitude stabilization in the presence of unknown disturbances. The attitude dynamics and the proposed control systems are developed on the special orthogonal group suchthat singularities and ambiguities of other attitude parameterizations, such as Euler angles and quaternions are completelyavoided. The effectiveness of the proposed control system is demonstrated through numerical simulationsand experimental results.

Protein Modifications in Isolated Heavy Metal Resistant Microorganisms from the Contaminated Environment

Shankar Congeevaram,Sridevi Dhanarani,Joon Hong Park,Michael Dexilin,Kaliannan Thamaraiselvi 대한환경공학회 2007 대한환경공학회 학술발표논문집 Vol.2007 No.12

The Inhibitory Effects of Hydrogen Sulfide on Pacemaker Activity of Interstitial Cells of Cajal from Mouse Small Intestine

Shankar Prasad Parajuli,최석,이준,김영대,박찬국,김만우,김현일,염철호,전제열 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.2

In this study, we studied whether hydrogen sulfide (H2S) has an effect on the pacemaker activity of interstitial cells of Cajal (ICC), in the small intestine of mice. The actions of H2S on pacemaker activity were investigated using whole-cell patch-clamp technique, intracellular Ca2+ analysis at 30oC and RT-PCR in cultured mouse intestinal ICC. Exogenously applied sodium hydrogen sulfide (NaHS), a donor of hydrogen sulfide, caused a slight tonic inward current on pacemaker activity in ICC at low concentrations (50 and 100μM), but at high concentration (500μM and 1 mM) it seemed to cause light tonic inward currents and then inhibited pacemaker amplitude and pacemaker frequency, and also an increase in the resting currents in the outward direction. Glibenclamide or other potassium channel blockers (TEA, BaCl2, apamin or 4-aminopydirine) did not have an effect on NaHS-induced action in ICC. The exogenous application of carbonilcyanide p-triflouromethoxyphenylhydrazone (FCCP) and thapsigargin also inhibited the pacemaker activity of ICC as NaHS. Also, we found NaHS inhibited the spontaneous intracellular Ca2+ ([Ca2+]i) oscillations in cultured ICC. In doing an RT-PCR experiment, we found that ICC enriched population lacked mRNA for both CSE and CBS, but was prominently detected in unsorted muscle. In conclusion, H2S inhibited the pacemaker activity of ICC by modulating intracellular Ca2+. These results can serve as evidence of the physiological action of H2S as acting on the ICC in gastrointestinal (GI) motility.

Prevention of Chemotherapy-Induced Nausea and Vomiting in Cancer Patients

Shankar, Abhishek,Roy, Shubham,Malik, Abhidha,Julka, PK,Rath, GK Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.15

The supportive care of patients receiving antineoplastic treatment has dramatically improved over the past few years and development of effective measures to prevent nausea and vomiting after chemotherapy serves as one of the most important examples of this progress. A patient who starts cancer treatment with chemotherapy lists chemotherapy-induced nausea and vomiting as among their greatest fears. Inadequately controlled emesis impairs functional activity and quality of life, increases the use of health care resources, and may occasionally compromise adherence to treatment. New insights into the pathophysiology of chemotherapy-induced nausea and vomiting, a better understanding of the risk factors for these effects, and the availability of new antiemetic agents have all contributed to substantial improvements in emetic control. This review focuses on current understanding of chemotherapy-induced nausea and vomiting and the status of pharmacological interventions for their prevention and treatment.

Antimicrobial wrapping paper coated with a ternary blend of carbohydrates (alginate, carboxymethyl cellulose, carrageenan) and grapefruit seed extract

Shankar, Shiv,Rhim, Jong-Whan Elsevier 2018 Carbohydrate Polymers Vol.196 No.-

<P><B>Abstract</B></P> <P>A functional biopolymer-coated paper was prepared by coating a ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) for the substitute use of synthetic polymer-coated paper. The microstructure of the surface and cross-section of the coated paper analyzed by field emission scanning electron microscope (FE-SEM) indicated that the biopolymer was compatible with the base paper and filled the pores of the porous fiber to make a smooth-surfaced coating paper. The properties of the biopolymer-coated paper, such as water and oil resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with not only the base paper but also commercially used PE-coated paper. The blended biopolymer coating material exhibited strong antibacterial activity against food-borne pathogenic bacteria, <I>Listeria monocytogenes</I> and <I>Escherichia coli</I>, which were destroyed completely within 3 and 9 h, respectively. The packaging test for a minced fish cake packed with the biopolymer-coated paper showed the complete destruction of surface inoculated bacteria in 6–9 days. The biopolymer-coated paper showed a high potential for disposable food packaging applications to increase the shelf-life of packaged food.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A ternary blend of the alginate, carboxymethyl cellulose, and carrageenan with grapefruit seed extract (GSE) was used for coating of paper. </LI> <LI> Water and oil resistance properties of paper increased after coating. </LI> <LI> Water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly after coating. </LI> <LI> Blended biopolymer coating material exhibited strong antibacterial activity. </LI> <LI> The biopolymer-coated paper showed a high potential for disposable food packaging applications. </LI> </UL> </P>

Preparation and properties of carbohydrate-based composite films incorporated with CuO nanoparticles

Shankar, Shiv,Wang, Long-Feng,Rhim, Jong-Whan Applied Science Publishers 2017 Carbohydrate Polymers Vol.169 No.-

<P><B>Abstract</B></P> <P>The present study aimed to develop the carbohydrate biopolymer based antimicrobial films for food packaging application. The nanocomposite films of various biopolymers and copper oxide nanoparticles (CuONPs) were prepared by solvent casting method. The nanocomposite films were characterized using SEM, FTIR, XRD, and UV–vis spectroscopy. The thermal stability, UV barrier, water vapor permeability, and antibacterial activity of the composite films were also evaluated. The surface morphology of the films was dependent on the types of polymers used. The XRD revealed the crystallinity of CuONPs in the composite films. The addition of CuONPs increased the thickness, tensile strength, UV barrier property, relative humidity, and water vapor barrier property. The CuONPs incorporated composite films exhibited strong antibacterial activity against <I>Escherichia coli</I> and <I>Listeria monocytogenes</I>. The developed composite films could be used as a UV-light barrier antibacterial films for active food packaging.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanocomposite films of biopolymers and CuO nanoparticles were prepared. </LI> <LI> Mechanical, UV barrier, and water vapor barrier properties increased. </LI> <LI> Different biopolymer interacted with CuO nanoparticles differently. </LI> <LI> CuO nanoparticles incorporated films exhibited strong antibacterial activity. </LI> </UL> </P>

Analysis of pile-up/sink-in during spherical indentation for various strain hardening levels

Shankar, S.,Loganathan, P.,Mertens, A. Johnney Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.3

The measurement from the indentation process depends on the amount of pile-up or sink-in around the contact impressions. In this paper, finite element concept is utilized to study the pile-up and sink-in behaviour for the wide range of materials with different young's modulus, yield stresses, strain-hardening exponents and coefficient of friction values. The exact indentation model is created by using the two dimensional axisymmetrical model for simulating the spherical indentation process on the lines of Taljat and Pharr (2004) work. The result shows that during spherical indentation process the amount of pile-up is greatly influenced by the strain hardening exponents in addition to other material properties and depth of penetration. The numerical results from the finite element analysis are also validated using the exact multilinear material properties obtained from the tensile testing for the materials like mild steel, brass and aluminium.

Revisiting the Bulge-Halo Conspiracy. I. Dependence on Galaxy Properties and Halo Mass

Shankar, Francesco,Sonnenfeld, Alessandro,Mamon, Gary A.,Chae, Kyu-Hyun,Gavazzi, Raphael,Treu, Tommaso,Diemer, Benedikt,Nipoti, Carlo,Buchan, Stewart,Bernardi, Mariangela,Sheth, Ravi,Huertas-Company, American Astronomical Society 2017 The Astrophysical Journal Vol.840 No.1

<P>We carry out a systematic investigation of the total mass density profile of massive (log M-star / M-circle dot greater than or similar to 11.3) early-type galaxies and its dependence on galactic properties and host halo mass with the aid of a variety of lensing/dynamical data and large mock galaxy catalogs. The latter are produced via semi-empirical models that, by design, are based on just a few basic input assumptions. Galaxies. with measured stellar masses, effective radii, and Sersic indices, are assigned, via abundance matching relations, host dark matter halos characterized by a typical Lambda CDM profile. Our main results are as follows. (1) In line with observational evidence, our semi-empirical models naturally predict that the total, mass-weighted density slope at the effective radius gamma' is not universal, steepening for more compact and/or massive galaxies, but flattening with increasing host halo mass. (2) Models characterized by a Salpeter or variable initial mass function (IMF) and uncontracted dark matter profiles are in good agreement with the data, while a Chabrier IMF and/or adiabatic contractions/expansions of the dark matter halos are highly disfavored. (3) Currently available data on the mass density profiles of very massive galaxies (log M-star / M-circle dot greater than or similar to 12), with M-halo greater than or similar to 3 x 10(14) M-circle dot, favor instead models with a stellar profile flatter than a Sersic one in the very inner regions (r less than or similar to 3-5 kpc), and a cored NFW or Einasto dark matter profile with median halo concentration a factor of similar to 2 or less than or similar to 1.3, respectively, higher than those typically predicted by N-body numerical simulations.</P>

Facile approach for large-scale production of metal and metal oxide nanoparticles and preparation of antibacterial cotton pads

Shankar, Shiv,Rhim, Jong-Whan Elsevier 2017 Carbohydrate polymers Vol.163 No.-

<P><B>Abstract</B></P> <P>Metallic nanoparticles such as zinc oxide (ZnONPs), copper oxide (CuONPs), and silver (AgNPs) were synthesized in gram scale using green methods. The antibacterial cotton fibers/nanoparticles (cotton fibers/NPs) composite pads were prepared, and nanoparticle binding/release tests were performed. All the NPs were crystalline and showed characteristic XRD diffraction peaks and showed the characteristic FTIR bands of the respective nanoparticles. All the NPs showed strong antimicrobial activity against Gram-positive and Gram-negative pathogenic bacteria. The NPs were attached to the cotton pad by adsorption at different extent depending on the types of nanoparticles. The adsorption and release of nanoparticles on and from cotton pads were also dependent on the types of nanoparticles. The NPs-adsorbed cotton pads showed potent antibacterial activity against pathogenic bacteria such as <I>Escherichia coli, Listeria monocytogenes, Staphylococcus aureus,</I> and <I>Staphylococcus epidermis.</I> The developed NPs-adsorbed cotton pads have potential to be used as wound dressings and antibacterial food packaging applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Metallic nanoparticles (ZnONPs, CuONPs, and AgNPs) were synthesized in gram scale. </LI> <LI> NPs-adsorbed antimicrobial cotton pads were prepared. </LI> <LI> Binding and releasing of NPs from the cotton pad were dependent on the type of NPs. </LI> <LI> The NPs-adsorbed cotton pads exhibited strong antibacterial activity. </LI> <LI> It has a potential for the wound dressing and food packaging applications. </LI> </UL> </P>