Search Results

You are looking at 1 - 5 of 5 items for

  • Author: K. Karthikeyan x
Clear All Modify Search
Open access

G. Somasekhar and K. Karthikeyan

Abstract

Big Data becameabuzz word nowadays due to the evolution of huge volumes of data beyond peta bytes. This article focuses on matrix multiplication with big sparse data. The proposed FASTsparse MULalgorithm outperforms the state-of-the-art big matrix multiplication approaches in sparse data scenario.

Open access

C. Selvaraj, K. R. Karthikeyan and S. Lakshmi

Abstract

The main object of this paper is to study Fekete-Szegö problem for a certain subclass of p - valent analytic functions. Fekete-Szegö inequality of several classes are obtained as special cases from our results. Applications of the result are also obtained on the class defined by convolution.

Open access

G. Bhoopathi, V. Jayaramakrishnan, K. Ravikumar, T. Prasanyaa and S. Karthikeyan

Abstract

The ferroelectric glycine phosphite single crystals have been grown from aqueous solution by both conventional and Sankaranarayanan-Ramasamy methods. The modified channelled spectrum method has been adopted for spectral dependence of optical birefringence studies over the wavelength range of 480–620 nm, which show that both the crystals exhibit relatively high birefringence values. The photoluminescence excitation studies were carried out for the grown crystals in a wide wavelength range between 300 nm and 600 nm at 224 K. The crystals were also subjected to scanning electron microscopy analysis in order to determine the ferroelectric domain pattern configuration.

Open access

K. Karthikeyan and Bashir Ahmad

Abstract

We study a boundary value problem of fractional integrodifferential equations involving Caputo's derivative of order α ∈ (n-1,n) in a Banach space. Existence and uniqueness results for the problem are established by means of the Hölder's inequality together with some standard fixed point theorems

Open access

Nachimuthu Ramesh, Manohar Prasanth, Subramani Ramkumar, Maray Suresh, Ashok J. Tamhankar, K. M. Gothandam, Sivashanmugam Karthikeyan and Bulent Bozdogan

Abstract

Background

Colistin is one of the oldest antibiotics in the polymyxin group, and is used mostly against gramnegative bacteria. Because of developing resistance among clinical isolates colistin has become an alternative drug for multidrug resistant bacteria.

Objectives

To determine colistin resistance among isolates from Tamil Nadu, India.

Methods

We included 94 gram-negative isolates from two centers in Tamil Nadu in the present study. Isolates were identified by 16S rRNA sequencing. Minimal inhibitory concentrations (MICs) were determined by agar dilution.

Results

The isolates identified at species level included 48 Escherichia coli, 9 Klebsiella pneumoniae, 10 Pseudomonas aeruginosa, 5 Proteus mirabilis, 4 Salmonella enterica, 3 Enterobacter hormaechei, 3 Enterobacter cloacae, 2 Achromobacter xylosoxidans, 2 Acinetobacter baumannii, 1 Providencia vermicola, 1 Acinetobacter towneri, 1 Enterobacter gergoviae, 2 Providencia rettgeri, 1 Enterobacter asburiae, 1 Pseudomonas stutzeri, and 1 Salmonella typhi. The MIC of colistin ranged from 0.12 μg/ml to 128 μg/ml. The MIC50 was 1 μg/mL and MIC90 was >128 μg/ml. The MIC ≥ 8 μg/mL was resistant breakpoint for all the species. A total of 27 isolates were resistant to colistin. Colistin resistant isolates included E. coli (9/48), K. pneumoniae (6/9), P. aeruginosa (3/10), A. baumannii (1/2), P. mirabilis (4/5), E. cloacae (1/3), P. rettgeri (2/2), and S. enterica (1/4). Carbapenem susceptibility of colistin resistant isolates was tested and 14 were found to be resistant to meropenem.

Conclusions

Our study indicates the emergence of colistin resistant isolates from clinical samples among different groups of gram-negative organisms. Resistance to both carbapenem and colistin occurs. Developing new antibiotics and programs to reduce nosocomial infections is necessary especially for multidrug resistant isolates.