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Kumar MS, Yang CH, Farooq MU, Kavimani V, Adesoji AA. Enhanced structural integrity of Laser Powder Bed Fusion based AlSi10Mg parts by attaining defect free melt pool formations. Sci Rep 2023; 13:16672. [PMID: 37794231 PMCID: PMC10550927 DOI: 10.1038/s41598-023-43718-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 09/26/2023] [Indexed: 10/06/2023] Open
Abstract
This research aims to fabricate an AlSi10Mg parts using Laser Powder Bed Fusion technique with enhanced structural integrity. The prime novelty of this research work is eliminating the balling and sparring effects, keyhole and cavity formation by attaining effective melt pool formation. Modelling of the Laser Powder Bed Fusion process parameters such as Laser power, scanning speed, layer thickness and hatch spacing is carried out through Complex Proportional Assessment technique to optimize the parts' surface attributes and to overcome the defects based on the output responses such as surface roughness on scanning and building side, hardness and porosity. The laser power of 350 W, layer thickness of 30 µm, scan speed of 1133 mm/s, and hatch spacing of 0.1 mm produces significantly desirable results to achieve maximum hardness and minimum surface roughness and holding the porosity of < 1%. The obtained optimal setting from this research improves the structural integrity of the printed AlSi10Mg parts.
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Affiliation(s)
- M Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608, Taiwan.
| | - Che-Hua Yang
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608, Taiwan
| | | | - V Kavimani
- Department of Mechanical Engineering, Karpagam Academy of Higher Education, Coimbatore 21, Tamil Nadu, India
| | - Adediran Adeolu Adesoji
- Department of Mechanical Engineering, Landmark University, P.M.B. 1001, Omu-Aran, Kwara State, Nigeria.
- MTE Division, CSIR-National Metallurgical Laboratory, Jamshedpur, India.
- Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway, Johannesburg, South Africa.
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Farooq MU, Anwar S, Bhatti HA, Kumar MS, Ali MA, Ammarullah MI. Electric Discharge Machining of Ti6Al4V ELI in Biomedical Industry: Parametric Analysis of Surface Functionalization and Tribological Characterization. Materials (Basel) 2023; 16:4458. [PMID: 37374641 DOI: 10.3390/ma16124458] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/15/2023] [Accepted: 06/15/2023] [Indexed: 06/29/2023]
Abstract
The superior engineering properties and excellent biocompatibility of titanium alloy (Ti6Al4V) stimulate applications in biomedical industries. Electric discharge machining, a widely used process in advanced applications, is an attractive option that simultaneously offers machining and surface modification. In this study, a comprehensive list of roughening levels of process variables such as pulse current, pulse ON time, pulse OFF time, and polarity, along with four tool electrodes of graphite, copper, brass, and aluminum are evaluated (against two experimentation phases) using a SiC powder-mixed dielectric. The process is modeled using the adaptive neural fuzzy inference system (ANFIS) to produce surfaces with relatively low roughness. A thorough parametric, microscopical, and tribological analysis campaign is established to explore the physical science of the process. For the case of the surface generated through aluminum, a minimum friction force of ~25 N is observed compared with the other surfaces. The analysis of variance shows that the electrode material (32.65%) is found to be significant for the material removal rate, and the pulse ON time (32.15%) is found to be significant for arithmetic roughness. The increase in pulse current to 14 A shows that the roughness increased to ~4.6 µm with a 33% rise using the aluminum electrode. The increase in pulse ON time from 50 µs to 125 µs using the graphite tool resulted in a rise in roughness from ~4.5 µm to ~5.3 µm, showing a 17% rise.
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Affiliation(s)
| | - Saqib Anwar
- Industrial Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - Haider Ali Bhatti
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore 54890, Pakistan
| | - M Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Muhammad Asad Ali
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore 54890, Pakistan
| | - Muhammad Imam Ammarullah
- Department of Mechanical Engineering, Faculty of Engineering, Universitas Pasundan, Bandung 40153, West Java, Indonesia
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Kumar MS, Farooq MU, Ross NS, Yang CH, Kavimani V, Adediran AA. Achieving effective interlayer bonding of PLA parts during the material extrusion process with enhanced mechanical properties. Sci Rep 2023; 13:6800. [PMID: 37100933 PMCID: PMC10133452 DOI: 10.1038/s41598-023-33510-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/13/2023] [Indexed: 04/28/2023] Open
Abstract
The additive manufacturing technique of material extrusion has challenge of excessive process defects and not achieving the desired mechanical properties. The industry is trying to develop certification to better control variations in mechanical attributes. The current study is a progress towards understanding the evolution of processing defects and the correlation of mechanical behavior with the process parameters. Modeling of the 3D printing process parameters such as layer thickness, printing speed, and printing temperature is carried out through L27 orthogonal array using Taguchi approach. In addition, CRITIC embedded WASPAS is adopted to optimize the parts' mechanical attributes and overcome the defects. Flexural and tensile poly-lactic acid specimens are printed according to ASTM standards D790 and D638, respectively, and thoroughly analyzed based on the surface morphological analysis to characterize defects. The parametric significance analysis is carried out to explore process science where the layer thickness, print speed, and temperature significantly control the quality and strength of the parts. Mathematical optimization results based on composite desirability show that layer thickness of 0.1 mm, printing speed of 60 mm/s, and printing temperature of 200 °C produce significantly desirable results. The validation experiments yielded the maximum flexural strength of 78.52 MPa, the maximum ultimate tensile strength of 45.52 MPa, and maximum impact strength of 6.21 kJ/m2. It is established that multiple fused layers restricted the propagation of cracks with minimum thickness due to enhanced diffusion between the layers.
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Affiliation(s)
- M Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608, Taiwan.
| | | | - Nimel Sworna Ross
- Department of Mechanical Engineering, Saveetha School of Engineering, SIMATS, Chennai, Tamilnadu, India
| | - Che-Hua Yang
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608, Taiwan
| | - V Kavimani
- Department of Mechanical Engineering, Karpagam Academy of Higher Education, Coimbatore, Tamil Nadu, 641021, India
| | - Adeolu A Adediran
- Department of Mechanical Engineering, Landmark University, P.M.B. 1001, Omu-Aran, Kwara State, Nigeria.
- Department of Mechanical Engineering Science, University of Johannesburg, Johannesburg, South Africa.
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Rehman M, Yanen W, Mushtaq RT, Ishfaq K, Zahoor S, Ahmed A, Kumar MS, Gueyee T, Rahman MM, Sultana J. Erratum: Publisher Correction: Additive manufacturing for biomedical applications: a review on classification, energy consumption, and its appreciable role since COVID-19 pandemic. Prog Addit Manuf 2023; 8:1. [PMID: 38625358 PMCID: PMC9851585 DOI: 10.1007/s40964-023-00405-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
[This corrects the article DOI: 10.1007/s40964-022-00373-9.].
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Affiliation(s)
- Mudassar Rehman
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore, 54890 Pakistan
| | - Wang Yanen
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Ray Tahir Mushtaq
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Kashif Ishfaq
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore, 54890 Pakistan
| | - Sadaf Zahoor
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore, 54890 Pakistan
| | - Ammar Ahmed
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - M. Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608 Taiwan
| | - Thierno Gueyee
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Md Mazedur Rahman
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Jakia Sultana
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
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Kumar MS. Utilizing bio-waste as the reinforcement particles for the production of sustainable composite brakes and the investigation of its tribological and corrosive performance. Environ Sci Pollut Res Int 2023; 30:6935-6949. [PMID: 36008584 DOI: 10.1007/s11356-022-22397-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
The goat population has been growing faster than the overall human population over the past couple of decades, particularly in African countries and Southeast Asia. As a result, there has been a sharp rise in bio-waste. So, this holistic research aims to convert the goat dung into a sustainable composite material with enhanced morphological, tribological, and corrosive properties. Al8011 alloy serves as the matrix material for the synthesized hybrid composites, and goat dung ash (GDA) and silicon nitride (Si3N4) serve as the reinforcing particles in varying ratios ranging from 0 to 10%. Microstructural analysis was performed to estimate the grain size distribution using ImageJ software. The inclusion of GDA particles along with the Si3N4 particles decreases the grain size from 18 to 9 µm. Similarly, 56.26% reduction of wear rate was evident due to the lubricating nature of the GDA particles. The plowing, delamination, and wear debris were examined in the worn-out surface of the wear specimens. Corrosion behavior was analyzed using the weight-loss gravimetric technique. The included GDA particles created a stable oxide layer that resists corrosion and it was proved by the microscopic analysis on the corroded surface. In the break shoe performance analysis, the fabricated Al8011(Si3N4 + GDA) composite brake lining material shows 23% more wear resistance when compared with the existing (Al6061-10% SiC) brake lining material. This minimal wear in the brake shoe not only assures their sustainability, but also tends to minimize wear-related emissions and economic losses.
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Affiliation(s)
- M Saravana Kumar
- Department of Production Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India.
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Rehman M, Yanen W, Mushtaq RT, Ishfaq K, Zahoor S, Ahmed A, Kumar MS, Gueyee T, Rahman MM, Sultana J. Additive manufacturing for biomedical applications: a review on classification, energy consumption, and its appreciable role since COVID-19 pandemic. Prog Addit Manuf 2022; 8:1-35. [PMID: 38625342 PMCID: PMC9793824 DOI: 10.1007/s40964-022-00373-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/08/2022] [Indexed: 05/27/2023]
Abstract
The exponential rise of healthcare problems like human aging and road traffic accidents have developed an intrinsic challenge to biomedical sectors concerning the arrangement of patient-specific biomedical products. The additively manufactured implants and scaffolds have captured global attention over the last two decades concerning their printing quality and ease of manufacturing. However, the inherent challenges associated with additive manufacturing (AM) technologies, namely process selection, level of complexity, printing speed, resolution, biomaterial choice, and consumed energy, still pose several limitations on their use. Recently, the whole world has faced severe supply chain disruptions of personal protective equipment and basic medical facilities due to a respiratory disease known as the coronavirus (COVID-19). In this regard, local and global AM manufacturers have printed biomedical products to level the supply-demand equation. The potential of AM technologies for biomedical applications before, during, and post-COVID-19 pandemic alongwith its relation to the industry 4.0 (I4.0) concept is discussed herein. Moreover, additive manufacturing technologies are studied in this work concerning their working principle, classification, materials, processing variables, output responses, merits, challenges, and biomedical applications. Different factors affecting the sustainable performance in AM for biomedical applications are discussed with more focus on the comparative examination of consumed energy to determine which process is more sustainable. The recent advancements in the field like 4D printing and 5D printing are useful for the successful implementation of I4.0 to combat any future pandemic scenario. The potential of hybrid printing, multi-materials printing, and printing with smart materials, has been identified as hot research areas to produce scaffolds and implants in regenerative medicine, tissue engineering, and orthopedic implants.
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Affiliation(s)
- Mudassar Rehman
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore, 54890 Pakistan
| | - Wang Yanen
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Ray Tahir Mushtaq
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Kashif Ishfaq
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore, 54890 Pakistan
| | - Sadaf Zahoor
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore, 54890 Pakistan
| | - Ammar Ahmed
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - M. Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei, 10608 Taiwan
| | - Thierno Gueyee
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Md Mazedur Rahman
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
| | - Jakia Sultana
- Department of Industry Engineering, School of Mechanical Engineering, Northwestern Polytechnical University, Xian, 710072 China
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Farooq MU, Anwar S, Kumar MS, AlFaify A, Ali MA, Kumar R, Haber R. A Novel Flushing Mechanism to Minimize Roughness and Dimensional Errors during Wire Electric Discharge Machining of Complex Profiles on Inconel 718. Materials (Basel) 2022; 15:7330. [PMID: 36295397 PMCID: PMC9607874 DOI: 10.3390/ma15207330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/12/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
One of the sustainability goals in the aeronautical industry includes developing cost-effective, high-performance engine components possessing complex curved geometries with excellent dimensional precision and surface quality. In this regard, several developments in wire electric discharge machining have been reported, but the influence of flushing attributes is not thoroughly investigated and is thus studied herein. The influence of four process variables, namely servo voltage, flushing pressure, nozzle diameter, and nozzle-workpiece distance, were analyzed on Inconel 718 in relation to geometrical errors (angular and radial deviations), spark gap formation, and arithmetic roughness. In this regard, thorough statistical and microscopical analyses are employed with mono- and multi-objective process optimization. The grey relational analysis affirms the reduction in the process's limitations, validated through confirmatory experimentation results as 0.109 mm spark gap, 0.956% angular deviation, 3.49% radial deviation, and 2.2 µm surface roughness. The novel flushing mechanism improved the spark gap by 1.92%, reducing angular and radial deviations by 8.24% and 29.11%, respectively.
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Affiliation(s)
| | - Saqib Anwar
- Industrial Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - M. Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Abdullah AlFaify
- Industrial Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - Muhammad Asad Ali
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore 54890, Pakistan
| | - Raman Kumar
- Department of Mechanical and Production Engineering, Guru Nanak Dev Engineering College, Ludhiana 141006, India
| | - Rodolfo Haber
- Center for Automation and Robotics (CSIC-UPM), Spanish National Research Council-Technical University of Madrid, 28500 Madrid, Spain
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Ogunsanya OA, Akinwande AA, Balogun OA, Romanovski V, Kumar MS. Mechanical and damping behavior of artificially aged Al 6061/TiO2 reinforced composites for aerospace applications. Particulate Science and Technology 2022. [DOI: 10.1080/02726351.2022.2065652] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Abayomi Adewale Akinwande
- Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, Ondo State, Nigeria
| | - Oluwatosin Abiodun Balogun
- Department of Metallurgical and Materials Engineering, Federal University of Technology, Akure, Ondo State, Nigeria
| | - Valentin Romanovski
- Center of Functional Nano-Ceramics, National University of Science and Technology «MISIS», Moscow, Russia
- Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - M. Saravana Kumar
- Department of Production Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India
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9
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Rashia Begum S, Saravana Kumar M, Vasumathi M, Umar Farooq M, Pruncu CI. Revealing the compressive and flow properties of novel bone scaffold structure manufactured by selective laser sintering technique. Proc Inst Mech Eng H 2022; 236:9544119211070412. [PMID: 35014560 DOI: 10.1177/09544119211070412] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Additive manufacturing is revolutionizing the field of medical sciences through its key application in the development of bone scaffolds. During scaffold fabrication, achieving a good level of porosity for enhanced mechanical strength is very challenging. The bone scaffolds should hold both the porosity and load withstanding capacity. In this research, a novel structure was designed with the aim of the evaluation of flexible porosity. A CAD model was generated for the novel structure using specific input parameters, whereas the porosity was controlled by varying the input parameters. Poly Amide (PA 2200) material was used for the fabrication of bone scaffolds, which is a biocompatible material. To fabricate a novel structure for bone scaffolds, a Selective Laser Sintering machine (SLS) was used. The displacement under compression loads was observed using a Universal Testing Machine (UTM). In addition to this, numerical analysis of the components was also carried out. The compressive stiffness found through the analysis enables the verification of the load withstanding capacity of the specific bone scaffold model. The experimental porosity was compared with the theoretical porosity and showed almost 29% to 30% reductions when compared to the theoretical porosity. Structural analysis was carried out using ANSYS by changing the geometry. Computational Fluid Dynamics (CFD) analysis was carried out using ANSYS FLUENT to estimate the blood pressure and Wall Shear Stress (WSS). From the CFD analysis, maximum pressure of 1.799 Pa was observed. Though the porosity was less than 50%, there was not much variation of WSS. The achievement from this study endorses the great potential of the proposed models which can successfully be adapted for the required bone implant applications.
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Affiliation(s)
- S Rashia Begum
- Department of Mechanical Engineering, College of Engineering, Anna University, Chennai, Tamil Nadu, India
| | - M Saravana Kumar
- Department of Production Engineering, National Institute of Technology, Tiruchirappalli, Tamil Nadu, India
| | - M Vasumathi
- Department of Mechanical Engineering, College of Engineering, Anna University, Chennai, Tamil Nadu, India
| | | | - Catalin I Pruncu
- Design, Manufacturing & Engineering Management, University of Strathclyde, Glasgow, Scotland, UK
- Department of Mechanical Engineering, Imperial College London, London, UK
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Prabukanthan P, Bhakyajothi V, Kumar MS, Harichandran G, Dinakaran K, Seenuvasakumaran P. Synthesis, spectroscopic analysis and DFT studies of N-(2-methyl-5-nitro-phenyl)benzamide organic single crystal. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.131172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Affiliation(s)
| | | | - M S Manu
- State TB Training and Demonstration Centre, Directorate of Health Services - Kerala, Thiruvananthapuram
| | - P S Rakesh
- State TB Cell, WHO NTEP Technical Support Network, Thiruvananthapuram
| | - S Balakrishnan
- Regional Team Lead (South), WHO NTEP Technical Support Network, Cochin, India
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Solomon SS, Sulkowski MS, Amrose P, Srikrishnan AK, McFall AM, Ramasamy B, Kumar MS, Anand S, Thomas DL, Mehta SH. Directly observed therapy of sofosbuvir/ribavirin +/- peginterferon with minimal monitoring for the treatment of chronic hepatitis C in people with a history of drug use in Chennai, India (C-DOT). J Viral Hepat 2018; 25:37-46. [PMID: 28719029 PMCID: PMC5743582 DOI: 10.1111/jvh.12761] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 07/03/2017] [Indexed: 12/14/2022]
Abstract
We assessed the feasibility of field-based directly observed therapy (DOT) with minimal monitoring to deliver HCV treatment to people with a history of drug use in Chennai, India. Fifty participants were randomized 1:1 to sofosbuvir+peginterferon alfa 2a+ribavirin (SOF+PR) for 12 weeks (Arm 1) vs sofosbuvir+ribavirin (SOF+R) for 24 weeks (Arm 2). SOF+R was delivered daily at participant chosen venues and weekly peginterferon injections at the study clinic. HCV RNA testing was performed to confirm active HCV infection and sustained virologic response 12 weeks after treatment completion (SVR12). No baseline genotyping or on-treatment viral loads were performed. Median age was 46 years. All were male and 20% had significant fibrosis/cirrhosis. All self-reported history of injection drug use, 18% recent noninjection drug use and 38% alcohol dependence. Six discontinued treatment (88% completed treatment in each arm). Of 22 who completed SOF+PR, all achieved SVR12 (22/25=88%); 15 of 22 who completed SOF+R achieved SVR12 (15/25=60%; P=.05). Among those completing SOF+R, SVR12 was significantly less common in participants reporting ongoing substance use (36% vs 100%) and missed doses. Active substance use and missed doses did not impact SVR with SOF+PR. Field-based DOT of HCV therapy without real-time HCV RNA monitoring was feasible; however, achieving 100% adherence was challenging. SOF+PR appeared superior to SOF+R in achieving SVR12, even when doses were missed with no discontinuations due to side effects. Further exploration of short duration treatment with peginterferon plus direct-acting antivirals is warranted.
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Affiliation(s)
- S S Solomon
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
- YR Gaitonde Centre for AIDS Research and Education, Chennai, India
| | - M S Sulkowski
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - P Amrose
- YR Gaitonde Centre for AIDS Research and Education, Chennai, India
| | - A K Srikrishnan
- YR Gaitonde Centre for AIDS Research and Education, Chennai, India
| | - A M McFall
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - B Ramasamy
- YR Gaitonde Centre for AIDS Research and Education, Chennai, India
| | - M S Kumar
- YR Gaitonde Centre for AIDS Research and Education, Chennai, India
| | - S Anand
- YR Gaitonde Centre for AIDS Research and Education, Chennai, India
| | - D L Thomas
- Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - S H Mehta
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Krishna MV, Sowhardhra M, Kumar MS, Madhavi G, Jadhav T, Thakkar D. Effect of surfactants and hydrophilic polymers on the stability of an antihypertensive drug candesartan cilexetil: Evaluation by HPLC. Ann Pharm Fr 2017; 76:32-43. [PMID: 29174608 DOI: 10.1016/j.pharma.2017.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 08/31/2017] [Accepted: 09/17/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVES The objective of this study is to investigate the effect of surfactants (polysorbate 80 and sodium lauryl sulphate) and hydrophilic polymers (polyvinylpyrrolidone and polyethylene glycol 6000) on the stability of candesartan cilexetil under isothermal stress conditions (100°C, 48h). METHODS HPLC method was employed to evaluate the drug content and formation of degradation products in stress samples. Drug and degradation products were separated on Hypersil BDS C18 (250×4.6mm, 5μ) column using acetonitrile-water (pH 2.8) in the ratio of 85:15% v/v as a mobile phase. RESULT Similar degradation behaviour of drug was observed with polyvinylpyrrolidone, polyethylene glycol 6000 and polysorbate 80; four common degradation peaks were observed at the retention time of 3.7, 4.5, 7.8 and 11minutes. One extra common degradation peak of very low intensity was also observed with polyethylene glycol 6000 and polysorbate 80 at the retention time of 4.2min. The drug was eluting at the retention time of 5.4min. In the case of sodium lauryl sulphate, two prominent degradation peaks were observed at the retention time of 3.7 and 13.25min along with few very low-intensity degradation peaks. CONCLUSION The drug showed 41%, 64%, 72% and 98% degradation in presence of polyvinylpyrrolidone, polyethylene glycol 6000, polysorbate 80 and sodium lauryl sulphate, respectively.
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Affiliation(s)
- M V Krishna
- National Institute of Pharmaceutical Education and Research-Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar 382355, Gujarat, India.
| | - M Sowhardhra
- Alliance Institute of Advanced Pharmaceutical and Health Sciences, Hyderabad 500038, Telangana, India
| | - M S Kumar
- Alliance Institute of Advanced Pharmaceutical and Health Sciences, Hyderabad 500038, Telangana, India
| | - G Madhavi
- University College of Pharmaceutical Sciences, Acharya Nagarjuna University, Nagarjuna Nagar, Guntur 522 510, Andhra Pradesh, India
| | - T Jadhav
- National Institute of Pharmaceutical Education and Research-Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar 382355, Gujarat, India
| | - D Thakkar
- National Institute of Pharmaceutical Education and Research-Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar 382355, Gujarat, India
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John NL, Joy LK, Kumar MS, Shaiju SS, Subashini A, Sajan D. Quantitative structure and activity relationship on the biological, nonlinear and the spectroscopic properties of the Schiff base material: 4-chloro-4′bromobenzylidene aniline. Molecular Simulation 2017. [DOI: 10.1080/08927022.2017.1337272] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Nimmy L. John
- Centre for Advanced Functional Materials, DST-FIST, DBT STAR College & KSCSTE SARD Supported Postgraduate and Research Department of Physics, Bishop Moore College, Alappuzha, India
| | - Lija K. Joy
- Centre for Advanced Functional Materials, DST-FIST, DBT STAR College & KSCSTE SARD Supported Postgraduate and Research Department of Physics, Bishop Moore College, Alappuzha, India
| | - M. Saravana Kumar
- Centre for Advanced Functional Materials, DST-FIST, DBT STAR College & KSCSTE SARD Supported Postgraduate and Research Department of Physics, Bishop Moore College, Alappuzha, India
| | - S. S. Shaiju
- Centre for Advanced Functional Materials, DST-FIST, DBT STAR College & KSCSTE SARD Supported Postgraduate and Research Department of Physics, Bishop Moore College, Alappuzha, India
| | - A. Subashini
- Crystal Growth and Thin Film Laboratory, School of Physics, Bharathidasan University, Tiruchirappalli, India
| | - D. Sajan
- Centre for Advanced Functional Materials, DST-FIST, DBT STAR College & KSCSTE SARD Supported Postgraduate and Research Department of Physics, Bishop Moore College, Alappuzha, India
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15
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George M, John NL, Saravana Kumar M, Subashini A, Sajan D. Physico-chemical studies of the experimental and theoretical properties of organic nonlinear optical material 4-chloro-4'methoxy benzylideneaniline. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2016.09.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Kumar MS, Das AP. Molecular identification of multi drug resistant bacteria from urinary tract infected urine samples. Microb Pathog 2016; 98:37-44. [PMID: 27354209 DOI: 10.1016/j.micpath.2016.06.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/16/2016] [Accepted: 06/24/2016] [Indexed: 10/21/2022]
Abstract
Urinary tract infections (UTIs) are of great concern in both developing and developed countries all over the world. Even though the infections are more common in women and children, they are at a considerable rate in men and of all ages. The uropathogens causing the infections are spread through various routes. The treatment generally recommended by the physicians is antibiotic usage. But, most of the uropathogens have evolved antibiotic resistance mechanisms. This makes the present situation hectic in control and prevention of UTIs. The present study aims to illustrate the multidrug resistance patterns among isolated bacterial strains from infected urine samples in Odisha state, India. Four bacterial strains were isolated and identified as Proteus sp. SK3, Pseudomonas sp. ADMK77, Proteus sp. BLKB2 and Enterobacter hormaechei strain CW-3 by 16S rRNA gene sequencing. Phylogenetc analysis indicated the strains belong to three various genera namely, Proteus, Pseudomonas and Enterobacter. The evolutionary timeline of the bacteria was studied by constructing phylogenetic trees by Neighborhood Joining method. The presence of ESBL gene and biofilm forming capability were studied for the four strains. Antibiotic susceptibility patterns of the isolates were studied toward the commonly recommended antibiotics. Both the Proteus strains were found commonly susceptible to aminoglycoside and sulphonamide groups. Pseudomonas strain was found to be susceptible to cephems, aminoglycosides and fluoroquinolones. Enterobacter sp was found to be resistant to almost all antibiotic groups and susceptible to only sulphonamides group. The antibiotic susceptibility patterns of the bacteria help in choosing the empirical antibiotic treatment for UTI.
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Affiliation(s)
- M S Kumar
- Bioengineering & Biomineral Processing Laboratory, Centre of Biotechnology, Siksha O Anusandhan University, Khandagiri Square, Bhubaneswar, Odisha, India
| | - A P Das
- Bioengineering & Biomineral Processing Laboratory, Centre of Biotechnology, Siksha O Anusandhan University, Khandagiri Square, Bhubaneswar, Odisha, India.
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Shruthi TK, Kumar MS, Arjunan M, Pratap A, Chandrasekaran N. Graphene oxide aided structural tailoring of 3-D N-doped amorphous carbon network for enhanced energy storage. RSC Adv 2015. [DOI: 10.1039/c5ra18494k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Organic aerogels are a class of material most suited for their transformation into electrically conducting porous carbon networks.
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Affiliation(s)
- T. K. Shruthi
- Electroplating Metal Finishing & Technology Division
- CSIR – Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - M. Saravana Kumar
- Electroplating Metal Finishing & Technology Division
- CSIR – Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - Muneeswaran Arjunan
- Electroplating Metal Finishing & Technology Division
- CSIR – Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - Aswin Pratap
- Electroplating Metal Finishing & Technology Division
- CSIR – Central Electrochemical Research Institute
- Karaikudi 630 006
- India
| | - Naveen Chandrasekaran
- Electroplating Metal Finishing & Technology Division
- CSIR – Central Electrochemical Research Institute
- Karaikudi 630 006
- India
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18
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Patil VM, Chakarborty S, Kumar MS, Geetha M, Dev S, Samuel S, Ahmed G, Nayanar SK, Vineetha R, Nair CK. An audit of febrile neutropenia cases from a rural cancer center in India. Indian J Cancer 2014; 51:487-90. [DOI: 10.4103/0019-509x.175338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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19
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20
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Ashok Kumar SL, Saravana Kumar M, Sreeja PB, Sreekanth A. Novel heterocyclic thiosemicarbazones derivatives as colorimetric and "turn on" fluorescent sensors for fluoride anion sensing employing hydrogen bonding. Spectrochim Acta A Mol Biomol Spectrosc 2013; 113:123-9. [PMID: 23714188 DOI: 10.1016/j.saa.2013.04.103] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 04/17/2013] [Accepted: 04/24/2013] [Indexed: 05/19/2023]
Abstract
Two novel heterocyclic thiosemicarbazone derivatives have been synthesized, and characterized, by means of spectroscopic and single crystal X-ray diffraction methods. Their chromophoric-fluorogenic response towards anions in competing solvent dimethyl sulfoxide (DMSO) was studied. The receptor shows selective recognition towards fluoride anion. The binding affinity of the receptors with fluoride anion was calculated using UV-visible and fluorescence spectroscopic techniques.
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Affiliation(s)
- S L Ashok Kumar
- Department of Chemistry, Centre of Excellence in Corrosion and Surface Engineering, National Institute of Technology - Tiruchirappalli, Tiruchirappalli 620 015, Tamil Nadu, India
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Thushara RM, Hemshekhar M, Sunitha K, Kumar MS, Naveen S, Kemparaju K, Girish KS. Sesamol induces apoptosis in human platelets via reactive oxygen species-mediated mitochondrial damage. Biochimie 2013; 95:2060-8. [PMID: 23933095 DOI: 10.1016/j.biochi.2013.07.032] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/17/2013] [Indexed: 12/21/2022]
Abstract
Platelets play an indispensable role in human health and disease. Platelets are very sensitive to oxidative stress, as it leads to the damage of mitochondrial DNA, which is the initial step of a sequence of events culminating in the cell death through the intrinsic pathway of apoptosis. Owing to a lot of reports on secondary complications arising from oxidative stress caused by therapeutic drug overdose, the present study concentrated on the influence of sesamol on oxidative stress-induced platelet apoptosis. Sesamol, a phenolic derivative present in sesame seeds is an exceptionally promising drug with lots of reports on its protective functions, including its inhibitory effects on platelet aggregation at concentrations below 100 μM, and its anti-cancer effect at 1 mM. However, the present study explored the toxic effects of sesamol on human platelets. Sesamol at the concentration of 0.25 mM and above induced platelet apoptosis through endogenous generation of ROS, depletion of thiol pool, and Ca(2+) mobilization. It also induced mitochondrial membrane potential depolarization, caspase activation, cytochrome c translocation and phosphatidylserine exposure, thus illustrating the pro-apoptotic effect of sesamol at higher concentration. However, even at high concentration of 2 mM sesamol effectively inhibited collagen/ADP/epinephrine-induced platelet aggregation. The study demonstrates that even though sesamol inhibits platelet aggregation, it has the tendency to elicit platelet apoptosis at higher concentrations. Sesamol has a potential as thrombolytic agent, nevertheless the current work highlights the significance of an appropriate dosage of sesamol when it is used as a therapeutic drug.
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Affiliation(s)
- R M Thushara
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570 006, Karnataka, India
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Saravana Kumar M, Ashok Kumar S, Sreekanth A. An efficient triazole-based fluorescent “turn-on” receptor for naked-eye recognition of F− and AcO−: UV–visible, fluorescence and 1H NMR studies. Materials Science and Engineering: C 2013; 33:3346-52. [DOI: 10.1016/j.msec.2013.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 03/15/2013] [Accepted: 04/07/2013] [Indexed: 10/26/2022]
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Kumar SLA, Kumar MS, Jenniefer SJ, Muthiah PT, Sreekanth A. Synthesis, Spectral, and Structural Characterization of Bisthiocarbohydrazone Derivatives. PHOSPHORUS SULFUR 2013. [DOI: 10.1080/10426507.2012.736100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- S. L. Ashok Kumar
- a Department of Chemistry , National Institute of Technology- Tiruchirappalli , Tiruchirappalli , 620015 , Tamilnadu , India
| | - M. Saravana Kumar
- a Department of Chemistry , National Institute of Technology- Tiruchirappalli , Tiruchirappalli , 620015 , Tamilnadu , India
| | - S. Jegan Jenniefer
- b School of Chemistry , Bharathidasan University , Tiruchirappalli , 620024 , Tamilnadu , India
| | - P. Thomas Muthiah
- b School of Chemistry , Bharathidasan University , Tiruchirappalli , 620024 , Tamilnadu , India
| | - A. Sreekanth
- a Department of Chemistry , National Institute of Technology- Tiruchirappalli , Tiruchirappalli , 620015 , Tamilnadu , India
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Kumar SLA, Kumar MS, John RP, Muthiah PT, Sreekanth A. 1, 5-Bis (2-hydroxyacetophenone)thiocarbohydrazone: a novel colorimetric and fluorescent dual-mode chemosensor for the recognition of fluoride. Mater Sci Eng C Mater Biol Appl 2013; 33:2519-25. [PMID: 23623063 DOI: 10.1016/j.msec.2013.02.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 12/25/2012] [Accepted: 02/07/2013] [Indexed: 10/27/2022]
Abstract
1,5-Bis (2-hydroxyacetophenone)thiocarbohydrazone (H4L) has been synthesized and characterized by means of spectroscopic and single crystal X-ray diffraction methods. Interactions of the H4L with a variety of anions were investigated using a combination of UV-visible and fluorescence spectroscopic methods in a biological competing solvent DMSO. The H4L has a high degree of selectivity for fluoride over other anions. (1)H NMR titration experiments indicate that a deprotonation process is involved in the chemo sensing process.
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Affiliation(s)
- S L Ashok Kumar
- Department of Chemistry, Centre of Excellence in Corrosion and Surface Engineering, National Institute of Technology, Tiruchirappalli, Tiruchirappalli 620015, Tamilnadu, India
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Gowtham YJ, Kumar MS, Girish KS, Kemparaju K. Hemostatic interference of Indian king cobra (Ophiophagus hannah) Venom. Comparison with three other snake venoms of the subcontinent. Biochemistry (Mosc) 2012; 77:639-47. [PMID: 22817464 DOI: 10.1134/s0006297912060119] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Unlike Naja naja, Bungarus caeruleus, Echis carinatus, and Daboia/Vipera russellii venoms, Ophiophagus hannah venom is medically ignored in the Indian subcontinent. Being the biggest poisonous snake, O. hannah has been presumed to inject several lethal doses of venom in a single bite. Lack of therapeutic antivenom to O. hannah bite in India makes any attempt to save the victim a difficult exercise. This study was initiated to compare O. hannah venom with the above said venoms for possible interference in hemostasis. Ophiophagus hannah venom was found to actively interfere in hemostatic stages such as fibrin clot formation, platelet activation/aggregation, and fibrin clot dissolution. It decreased partial thromboplastin time (aPTT), prothrombin time (PT), and thrombin clotting time (TCT). These activities are similar to that shown by E. carinatus and D. russellii venoms, and thus O. hannah venom was found to exert procoagulant activity through the common pathway of blood coagulation, while N. naja venom increased aPTT and TCT but not PT, and hence it was found to exert anticoagulant activity through the intrinsic pathway. Venoms of O. hannah, E. carinatus, and D. russellii lack plasminogen activation property as they do not hydrolyze azocasein, while they all show plasmin-like activity by degrading the fibrin clot. Although N. naja venom did not degrade azocasein, unlike other venoms, it showed feeble plasmin-like activity on fibrin clot. Venom of E. carinatus induced clotting of human platelet rich plasma (PRP), while the other three venoms interfered in agonist-induced platelet aggregation in PRP. Venom of O. hannah least inhibited the ADP induced platelet aggregation as compared to D. russellii and N. naja venoms. All these three venoms showed complete inhibition of epinephrine-induced aggregation at varied doses. However, O. hannah venom was unique in inhibiting thrombin induced aggregation.
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Affiliation(s)
- Yashonandana J Gowtham
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, Karnataka, India
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Affiliation(s)
- Faiyaz Ahmed
- Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia ; Department of Studies in Food Science and Nutrition, University of Mysore, Mysore, India
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Devi PS, Kumar MS, Das SM. DNA Damage Protecting Activity and Free Radical Scavenging Activity of Anthocyanins from Red Sorghum (Sorghum bicolor) Bran. Biotechnol Res Int 2012; 2012:258787. [PMID: 22400119 PMCID: PMC3286891 DOI: 10.1155/2012/258787] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 09/19/2011] [Indexed: 11/17/2022]
Abstract
There is increasing interest in natural food colorants like carotenoids and anthocyanins with functional properties. Red sorghum bran is known as a rich source for anthocyanins. The anthocyanin contents extracted from red sorghum bran were evaluated by biochemical analysis. Among the three solvent system used, the acidified methanol extract showed a highest anthocyanin content (4.7 mg/g of sorghum bran) followed by methanol (1.95 mg/g) and acetone (1 mg/g). Similarly, the highest total flavonoids (143 mg/g) and total phenolic contents (0.93 mg/g) were obtained in acidified methanol extracts than methanol and acetone extracts. To study the health benefits of anthocyanin from red sorghum bran, the total antioxidant activity was evaluated by biochemical and molecular methods. The highest antioxidant activity was observed in acidified methanol extracts of anthocyanin in dose-dependent manner. The antioxidant activity of the red sorghum bran was directly related to the total anthocyanin found in red sorghum bran.
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Affiliation(s)
- P. Suganya Devi
- P.G. Department of Biotechnology, Dr. Mahalingam Centre for Research and Development, N.G.M. College, Pollachi 642001, India
| | - M. Saravana Kumar
- P.G. Department of Biotechnology, Dr. Mahalingam Centre for Research and Development, N.G.M. College, Pollachi 642001, India
| | - S. Mohan Das
- Kaamadhenu Arts and Science College, Sathyamangalam 638503, India
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Abstract
This paper will contribute to current academic literature in the area of online retailing and consumer behaviour. Our research outlines a survey conducted with respondents from the UK to ascertain their attitudes to grocery shopping both off and online. The findings indicate that, whilst the vast majority of our sample has experience of online shopping, few actively engage in online grocery shopping. Some of the reasons for this are highlighted and the key issues relate to consumer trust and confidence in both online and offline aspects of the service. If these issues are addressed, it is proposed that more people would be encouraged to shop for groceries online.
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Devi PS, Kumar MS, Das SM. Evaluation of antiproliferative activity of red sorghum bran anthocyanin on a human breast cancer cell line (mcf-7). Int J Breast Cancer 2011; 2011:891481. [PMID: 22312562 PMCID: PMC3262581 DOI: 10.4061/2011/891481] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 07/29/2011] [Indexed: 11/29/2022] Open
Abstract
Breast cancer is a leading cause of death in women worldwide both in the developed and developing countries. Thus effective treatment of breast cancer with potential antitumour drugs is important. In this paper, human breast cancer cell line MCF-7 has been employed to evaluate the antiproliferative activity of red sorghum bran anthocyanin. The present investigation showed that red sorghum bran anthocyanin induced growth inhibition of MCF-7 cells at significant level. The growth inhibition is dose dependent and irreversible in nature. When MCF-7 cells were treated with red sorghum bran anthocyanins due to activity of anthocyanin morphological changes were observed. The morphological changes were identified through the formation of apoptopic bodies. The fragmentation by these anthocyanins on DNA to oligonuleosomal-sized fragments, is a characteristic of apoptosis, and it was observed as concentration-dependent. Thus, this paper clearly demonstrates that human breast cancer cell MCF-7 is highly responsive by red sorghum bran anthocyanins result from the induction of apoptosis in MCF-7 cells.
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Affiliation(s)
- P Suganya Devi
- P.G. Department of Biotechnology, Dr. Mahalingam Centre for Research and Development, NGM College, Pollachi 642001, India
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Kumar MS, Tamilarasan R, Sreekanth A. 4-Salicylideneamino-3-methyl-1,2,4-triazole-5-thione as a sensor for aniline recognition. Spectrochim Acta A Mol Biomol Spectrosc 2011; 79:370-375. [PMID: 21482181 DOI: 10.1016/j.saa.2011.03.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2010] [Revised: 03/02/2011] [Accepted: 03/11/2011] [Indexed: 05/30/2023]
Abstract
Tridentate triazole based Schiff base 4-salicylideneamino-3-methyl-1,2,4-triazole-5-thione has been found to selectively detect toxic aromatic amines such as aniline and benzene-1,4-diamine by simple titration techniques like UV-visible, fluorescence spectral studies (PL) and 1H NMR titrations. The Schiff base receptor utilizes, thione sulfur, NH-thione and the phenolic hydroxyl group to form hydrogen bonded adduct of aniline and benzene-1,4-diamine with high binding affinity, followed by a slow removal of the corresponding hydrogens thus providing a promising candidate and an unique receptor for toxic aromatic amines.
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Affiliation(s)
- M Saravana Kumar
- Department of Chemistry, National Institute of Technology - Tiruchirappalli, Tiruchirappalli 620015, Tamilnadu, India
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Mahadeswaraswamy YH, Kumar MS, Gowtham YJ, Nagaraju S, Girish KS, Kemparaju K. The polyphenol 3, 4, 5 - tri-hydroxy benzoic acid inhibits indian daboia russelli venom and its hemorrhagic complex induced local toxicity. Curr Top Med Chem 2011; 11:2520-30. [PMID: 21682684 DOI: 10.2174/156802611797633447] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 09/06/2010] [Indexed: 11/22/2022]
Abstract
Despite a long history on treatment and management of snakebite, as of now, no satisfactory cure exists to treat local toxicity, including anti-venom therapy. Several natural compounds from plants and their synthetic analogs have shown to be protective. In this study 3, 4, 5-tri-hydroxy benzoic acid, the gallic acid (GA) was tested against the local toxicity of Daboia russelli (DR) venom and its purified hemorrhagic complex (HC). GA inhibited in vitro proteolytic activity of both DR venom and HC but, it did not inhibit phospholipase activity of DR venom. GA inhibited hemorrhage, edema forming, dermo- and myonecrotic activities of both HC and DR venom in in vivo experiments. GA was particularly effective against hemorrhagic activity but, GA inhibition had a greater effect on HC when compared to DR venom. The inhibition was likely due to GA induced structural changes in HC as revealed by alterations in fluorescence emission and CD spectral properties. However, the inhibition was not due to chelating property of GA as suggested by UV-visible spectral studies. Inhibition of collagen type IV, laminin and fibronectin degradation essentially provided the biochemical basis for GA which inhibited local effects of HC as well as DR venom. Thus, the study appears highly promising to explore GA and its generics against ruthless local effects and perhaps systemic hemorrhage of DR and other snake bites as well. Further, these agents will possibly find an immense value in the regulation of matrix metalloproteases (MMPs) in processes such as wound healing, inflammation and in the treatment of cancer.
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Affiliation(s)
- Y H Mahadeswaraswamy
- Department of Biochemistry, University of Mysore, Manasagangothri, Mysore 570 006, Karnataka, India
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Kumar MS, Girish KS, Vishwanath BS, Kemparaju K. The metalloprotease, NN-PF3 from Naja naja venom inhibits platelet aggregation primarily by affecting α2β1 integrin. Ann Hematol 2010; 90:569-77. [PMID: 20957364 DOI: 10.1007/s00277-010-1103-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 10/05/2010] [Indexed: 11/30/2022]
Abstract
NN-PF3 is a non-toxic, anticoagulant, high-molecular-mass (67.81 kDa) metalloprotease from Indian cobra (Naja naja) venom. In the present study, NN-PF3 was investigated for the mechanism of inhibition of collagen-induced aggregation of human platelets. The complete inhibition of collagen-induced aggregation and partial inhibition of ADP- and epinephrine-induced aggregation has the respective IC(50) of 75 ± 5, 185 ± 10, and 232 ± 12 nM, whereas no inhibition of thrombin-, arachidonic acid-, and ristocetin-induced aggregation of platelets was observed in platelet-rich plasma. Further, native NN-PF3 and EDTA-inactivated NN-PF3 inhibited collagen-induced aggregation of washed platelets with respective IC(50) of 75 ± 4 and 180 ± 6 nM. The higher inhibitory effect of native NN-PF3 compared with EDTA-inactivated NN-PF3 suggests the enzymatic and non-enzymatic mechanism of inhibition. NN-PF3 pretreatment affected the collagen binding but not the fibrinogen, and fibronectin binding of washed platelets in adhesion assay suggested that the collagen receptors are affected. Western blot study using anti-integrin α2β1 mAb 6F1 suggested that NN-PF3 binds to integrin α2β1 in a primary structure-dependent manner only and is not cleaved. There was a drastic reduction in the intensity of several intracellular signaling phosphotyrosine protein bands when monoclonal anti-phosphotyrosine antibody was used, suggesting that the major activation pathway of platelets get affected, which occurs through glycoprotein VI. NN-PF3 did not bind to collagen as revealed by Western blot using anti-collagen mAb. Furthermore, neither the proteolytic cleavage of fibrinogen nor its degradation products by NN-PF3 contributed for the collagen-induced platelet aggregation inhibition.
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Affiliation(s)
- M S Kumar
- Department of Biochemistry, Government College for Women, Mandya, 571401, Karnataka, India
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Ward AJ, Kumar MS. Bio-conversion rate and optimum harvest intervals for Moina australiensis using digested piggery effluent and Chlorella vulgaris as a food source. Bioresour Technol 2010; 101:2210-2216. [PMID: 20006491 DOI: 10.1016/j.biortech.2009.11.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 11/11/2009] [Accepted: 11/12/2009] [Indexed: 05/28/2023]
Abstract
The bio-conversion rate of Moina australiensis fed with Chlorella vulgaris grown on digested piggery effluent at three different feeding rates was determined and a 2, 3 and 4-day harvest interval strategy was investigated. This study indicates that C. vulgaris is a suitable food source for M. australiensis. A significant difference (P < or = 0.001) in the feeding rate against mean total populations was found among treatments. The increase in the amount of algae fed accelerated the production rate, and the population density peaked faster in the high C. vulgaris fed treatment. The BCR calculated from this experiment indicates that for every 1000 mg of C. vulgaris fed there was an increase of 437.9 mg of M. australiensis biomass produced. A significant difference (P < or = 0.001) in biomass production among the different harvest interval treatments was observed. The 2-day harvest interval treatment produced 7.78 g of M. australiensis followed by 6.89 g in the 3 day and 5.01 g in the 4-day harvest interval treatment. This study provides strong evidence that M. australiensis can utilise the bacterial blooms and bio-films associated with digested piggery effluent as a food source.
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Affiliation(s)
- A J Ward
- South Australian Research and Development Institute (SARDI), Integrated Bio-Systems Roseworthy, Australia.
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Mahadeswaraswamy YH, Devaraja S, Kumar MS, Goutham YNJ, Kemparaju K. Inhibition of local effects of Indian Daboia/Vipera russelli venom by the methanolic extract of grape (Vitis vinifera L.) seeds. Indian J Biochem Biophys 2009; 46:154-60. [PMID: 19517992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Although anti-venom therapy is available for the treatment of fatal bite by snakes, it offers less or no protection against the local effects such as dermo- and myonecrosis, edema, hemorrhage and inflammation at the bitten region. The viper species are known for their violent local effects and such effects have been commonly treated with plant extracts without any scientific validation in rural India. In this investigation, the methanolic extract of grapes (Vitis vinifera L.) seed was studied against the Indian Daboia/Vipera russelli venom-induced local effects. The extract abolished the proteolytic and hyaluronidase activities and also efficiently neutralized the hemorrhage, edema-inducing and myonecrotic properties of the venom. In addition, the extract also inhibited partially the pro-coagulant activity of the venom and abolished the degradation of Aalpha and Bbeta chains of human fibrinogen. Thus, the extract possesses potent anti-snake venom property, especially against the local effects of viper bites.
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Affiliation(s)
- Y H Mahadeswaraswamy
- Department of Studies in Biochemistry, University of Mysore, Mysore 570006, India
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35
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Raj TJS, Bharathi C, Kumar MS, Prabahar J, Kumar PN, Sharma HK, Parikh K. Identification, isolation and characterization of process-related impurities in Rizatriptan benzoate. J Pharm Biomed Anal 2009; 49:156-62. [DOI: 10.1016/j.jpba.2008.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2007] [Revised: 10/08/2008] [Accepted: 10/09/2008] [Indexed: 11/28/2022]
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Bharathi C, Jayaram P, Sunder Raj J, Saravana Kumar M, Bhargavi V, Handa VK, Dandala R, Naidu A. Identification, isolation and characterization of impurities of clindamycin palmitate hydrochloride. J Pharm Biomed Anal 2008; 48:1211-8. [PMID: 18947955 DOI: 10.1016/j.jpba.2008.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 08/12/2008] [Accepted: 08/12/2008] [Indexed: 11/28/2022]
Abstract
Clindamycin palmitate hydrochloride is a water soluble hydrochloride salt of the ester of clindamycin and palmitic acid. It is inactive in vitro, rapid in vivo hydrolysis converts this compound to the antibacterially active clindamycin. Total 12 impurities at levels ranging from 0.05% to 0.5% were detected by isocratic reverse-phase high performance liquid chromatography (HPLC) using RI detector. The molecular weights of impurities were determined by LC-MS analysis. Two impurities were starting materials and the remaining impurities were isolated from crude samples/enriched mother liquors using reverse-phase preparative HPLC. Based on the spectral data the structures of these impurities were characterized as, clindamycin palmitate sulphoxides alpha-/beta-isomers (impurity I); clindamycin laurate (impurity II); lincomycin palmitate (impurity III); clindamycin myristate (impurity IV); epiclindamycin palmitate (impurity V); clindamycin palmitate 3-isomer (impurity VI); clindamycin pentadecanoate (impurity VII); clindamycin B-palmitate (impurity VIII); clindamycin heptadecanoate (impurity IX) and clindamycin stearate (impurity X). Structural elucidation of all impurities by spectral data ((1)H NMR, (13)C NMR, MS and IR) and formation of these impurities have been discussed in detail.
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Affiliation(s)
- Ch Bharathi
- A.P.L. Research Centre, 313 Bachupally, Hyderabad 500072, India
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Bharathi C, Chary DK, Kumar MS, Shankar R, Handa V, Dandala R, Naidu A. Identification, isolation and characterization of potential degradation product in risperidone tablets. J Pharm Biomed Anal 2008; 46:165-9. [DOI: 10.1016/j.jpba.2007.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Revised: 08/08/2007] [Accepted: 08/08/2007] [Indexed: 10/23/2022]
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Bharathi C, Prabahar KJ, Prasad CS, Kumar MS, Magesh S, Handa VK, Dandala R, Naidu A. Impurity profile study of zaleplon. J Pharm Biomed Anal 2007; 44:101-9. [PMID: 17367980 DOI: 10.1016/j.jpba.2007.01.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2006] [Revised: 01/24/2007] [Accepted: 01/30/2007] [Indexed: 10/23/2022]
Abstract
Zaleplon is a pyrazolopyrimidine derivative and possesses sedative and hypnotic properties. Seven unknown impurities in zaleplon bulk drug at levels below 0.1% were detected by reverse-phase high performance liquid chromatography (HPLC). The starting material, 3-amino-4-cyanopyrazole and an intermediate, N-[3-[3-(dimethylamino)-1-oxo-2-propenyl]-phenyl]-N-ethylacetamide (DOPEA) were also present in the sample at a level below 0.1%. The molecular weights of impurities were determined by LC-MS analysis. These impurities were isolated from crude samples of zaleplon using reverse-phase preparative HPLC. Based on the spectral data the structures of these impurities were characterized as, N-(3-(3-(4-amino-2H-pyrazolo [3,4-d]pyrimidin-6-yl) pyrazolo[1,5-a] pyrimidin-7-yl)phenyl)-N-ethylacetamide (impurity I); N-[3-(3-carboxamidopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]-N-ethylacetamide (impurity II); N-[3-(3-cyanopyrazolo[1,5-a]pyrimidin-7-yl)phenyl]acetamide (impurity III); N-[3-(3-cyanopyrazolo [1,5-a]pyrimidin-7-yl)phenyl]-N-methylacetamide (impurity IV); N-[3-(3-cyanopyrazolo[1,5-a] pyrimidin-5-yl)phenyl]-N-ethylacetamide (impurity V); N-[3-(3-cyanopyrazolo[1,5-a] pyrimidin-7-yl)phenyl]-N-ethylamine (impurity VI); N-[3-(3-cyano-6-[(E)-3-((N-ethyl-N-acetyl)amino)phenyl-3-oxoprop-1-enyl] pyrazolo[1,5-a]pyrimidin-7-yl) phenyl]-N-ethylacetamide (impurity VII). Structural elucidation of all impurities by spectral data ((1)H NMR, (13)C NMR, MS and IR) and formation of these impurities are discussed in detail.
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Affiliation(s)
- Ch Bharathi
- A.P.L. Research Centre, 313 Bachupally, Hyderabad 500072, India
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Kumar MS, Lakshmi V, Rajagopalan R. Occurrence of extended spectrum beta-lactamases among Enterobacteriaceae spp. isolated at a tertiary care institute. Indian J Med Microbiol 2006; 24:208-11. [PMID: 16912442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Increasing resistance to third generation cephalosporins has become a cause for concern especially among Enterobacteriaceae that cause nosocomial infections. The prevalence of extended spectrum beta-lactamases (ESBLs) among members of Enterobacteriaceae constitutes a serious threat to current beta-lactam therapy leading to treatment failure and consequent escalation of costs. A detailed study was initiated to identify the occurrence of ESBLs among the Enterobacteriaceae isolates at a tertiary care hospital using the double disk potentiation technique. Antibiogram profiles were determined to commonly used antibiotics and confirmation of ESBLs production was carried out by the disk diffusion assay using ceftazidime and cefotaxime in the presence and absence of clavulanic acid. Our results indicate that the majority of ESBLs were expressed in Escherichia coli.
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Affiliation(s)
- M S Kumar
- Discovery Research, Dr. Reddy's Laboratories Ltd., Hyderabad - 500 049, India.
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Kumar RS, Sivakumar T, Sunderam RS, Gupta M, Mazumdar UK, Gomathi P, Rajeshwar Y, Saravanan S, Kumar MS, Murugesh K, Kumar KA. Antioxidant and antimicrobial activities of Bauhinia racemosa L. stem bark. Braz J Med Biol Res 2005; 38:1015-24. [PMID: 16007272 DOI: 10.1590/s0100-879x2005000700004] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present study was carried out to evaluate the antioxidant and antimicrobial activities of a methanol extract of Bauhinia racemosa (MEBR) (Caesalpiniaceae) stem bark in various systems. 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical, superoxide anion radical, nitric oxide radical, and hydroxyl radical scavenging assays were carried out to evaluate the antioxidant potential of the extract. The antioxidant activity of the methanol extract increased in a concentration-dependent manner. About 50, 100, 250, and 500 microg MEBR inhibited the peroxidation of a linoleic acid emulsion by 62.43, 67.21, 71.04, and 76.83%, respectively. Similarly, the effect of MEBR on reducing power increased in a concentration-dependent manner. In DPPH radical scavenging assays the IC50 value of the extract was 152.29 microg/ml. MEBR inhibited the nitric oxide radicals generated from sodium nitroprusside with an IC50 of 78.34 microg/ml, as opposed to 20.4 microg/ml for curcumin. Moreover, MEBR scavenged the superoxide generated by the PMS/NADH-NBT system. MEBR also inhibited the hydroxyl radical generated by Fenton's reaction, with an IC50 value of more than 1000 microg/ml, as compared to 5 microg/ml for catechin. The amounts of total phenolic compounds were also determined and 64.7 microg pyrocatechol phenol equivalents were detected in MEBR (1 mg). The antimicrobial activities of MEBR were determined by disc diffusion with five Gram-positive, four Gram-negative and four fungal species. MEBR showed broad-spectrum antimicrobial activity against all tested microorganisms. The results obtained in the present study indicate that MEBR can be a potential source of natural antioxidant and antimicrobial agents.
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Affiliation(s)
- R S Kumar
- Department of Pharmaceutics and Pharmacology, J.K.K. Natarajah College of Pharmacy, Namakkal, Tamilnadu, India.
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Khardenavis A, Guha PK, Kumar MS, Mudliar SN, Chakrabarti T. Activated sludge is a potential source for production of biodegradable plastics from wastewater. Environ Technol 2005; 26:545-52. [PMID: 15974272 DOI: 10.1080/09593332608618536] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Increased utilization of synthetic plastics caused severe environmental pollution due to their non-biodegradable nature. In the search for environmentally friendly materials to substitute for conventional plastics, different biodegradable plastics have been developed by microbial fermentations. However, limitations of these materials still exist due to high cost. This study aims at minimization of cost for the production of biodegradable plastics P(3HB) and minimization of environmental pollution. The waste biological sludge generated at wastewater treatment plants is used for the production of P(3HB) and wastewater is used as carbon source. Activated sludge was induced by controlling the carbon: nitrogen ratio to accumulate storage polymer. Initially polymer accumulation was studied by using different carbon and nitrogen sources. Maximum accumulation of polymer was observed with carbon source acetic acid and diammonium hydrogen phosphate (DAHP) as nitrogen source. Further studies were carried out to optimize the carbon: nitrogen ratios using acetic acid and DAHP. A maximum of 65.84% (w/w) P(3HB) production was obtained at C/N ratio of 50 within 96 hours of incubation.
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Affiliation(s)
- A Khardenavis
- Environmental Biotechnology Division National Environmental Engineering Research Institute (NEERI), Nagpur 440 020, India
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Kumar MS, Kode RK, Pankewycz OG, Laftavi MR, Kumar AM, Damask AM, Vora M, Tomeny MB, Ferry E, Samartino BC, Sierka D, Lingaraju RM, Fyfe B. Simulect, Neoral, Cellcept, and prednisone in kidney recipients with delayed graft function: a prospective controlled study. Transplant Proc 2001; 33:3762-3. [PMID: 11750602 DOI: 10.1016/s0041-1345(01)02592-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- M S Kumar
- Department of Transplantation, MCP Hahnemann University, Philadelphia, Pennsylvania 19102, USA
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Kumar AM, Fa K, Vankawala R, Vora M, Kode RK, Pankewycz OG, Lattavi MR, Fyfe B, Damask AM, Ferry E, Stabler S, Tomeny MB, Phillips K, Lingaraju R, Kumar MS. Simulect, calcineurin inhibitor, mycophenolate mofetil, and prednisone is more effective than OKT3, calcineurin inhibitor, hycophendate mofetil, and prednisone in African American kidney recipients in reducing acute rejections and prolonging graft survival. Transplant Proc 2001; 33:3195-6. [PMID: 11750370 DOI: 10.1016/s0041-1345(01)02359-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- A M Kumar
- Department of Transplantation, MCP Hahnemann University, Philadelphia, Pennsylvania 19102, USA
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Rao KN, Gopinath R, Kumar MS, Suryanarayana I, Prasad PS. Interaction-induced enhancement in the activity and selectivity of a titania-supported ammonium salt of a 12-molybdophosphoric acid catalyst during ammoxidation of 2-methylpyrazine. Chem Commun (Camb) 2001:2088-9. [PMID: 12240176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
A titania-supported ammonium salt of 12-molybdophosphoric acid has been synthesized, and the salt-support interaction, which enhanced the reaction rate, has been correlated with the activity of the catalyst in the ammoxidation of 2-methylpyrazine.
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Affiliation(s)
- K N Rao
- Catalysis & Physical Chemistry Division, Indian Institute of Chemical Technology, Hyderabad-500 007, India
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Kannan R, Ramprakash B, Kumar MS, Balachander J, Sethuraman KR. Angioplasty of membranous obstruction of inferior vena cava. J Assoc Physicians India 2001; 49:921-2. [PMID: 11837765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Membranous obstruction of vena cava (MOVC) is a common cause of hepatic venous outflow obstruction. Surgical procedures utilized to relieve symptoms carry a high morbidity and mortality. A patient who presented with gradual onset ascites and dilated, tortuous veins over the anterior abdominal wall and the back was found to have MOVC by inferior vena cavogram. Balloon dilatation of the obstruction was done successfully through a transvenous approach. Following this, the patient improved remarkably. The procedure is safe, effective and easy to perform. This balloon angioplasty provides alternative method for treatment of membranous obstruction of vena cava.
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Affiliation(s)
- R Kannan
- Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry
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Nagaraja P, Kumar MS, Rangappa KS. Dapsone and iminodibenzyl as novel reagents for the spectrophotometric determination of trace amounts of nitrite in water samples. ANAL SCI 2001; 17:439-42. [PMID: 11990624 DOI: 10.2116/analsci.17.439] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A rapid, simple, sensitive and selective spectrophotometric determination of nitrite using new diazotizing and coupling reagents is described. The method is based on a diazotization-coupling reaction between dapsone and iminodibenzyl in a hydrochloric acid medium. The molar absorptivity and Sandell's sensitivity were found to be 7.5 x 10(4) l mol(-1) cm(-1) and 0.000613 microg ml(-1), respectively. The interference effects of various cations and anions were also studied and reported. This method has been found to be applicable for the determination of nitrite in various water samples.
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Affiliation(s)
- P Nagaraja
- Department of Chemistry, University of Mysore, Manasagangothri, India.
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Kode RK, Foster CE, Kumar AM, Vankawala R, Damask AM, Fyfe BS, Seirka D, Laftavi MR, Brezin J, Pankewycz O, Chvala R, Kumar MS. Nine year experience with kidney transplantation in patients with positive hepatitis C virus antibody. Transplant Proc 2001; 33:1186-7. [PMID: 11267250 DOI: 10.1016/s0041-1345(00)02378-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- R K Kode
- Division of Transplantation, MCP Hahnemann University, Philadelphia, Pennsylvania, USA
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Kode RK, Kumar AM, Pankewycz O, Damask AM, Seirka D, Lam A, Phillips K, Ardron M, Brezin J, Chvala R, Kumar MS. Simulect induction significantly decreases CMV infection in kidney recipients compared to OKT3. Transplant Proc 2001; 33:1268-9. [PMID: 11267286 DOI: 10.1016/s0041-1345(00)02472-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- R K Kode
- Division of Transplantation, MCP Hahnemann University, Philadelphia, Pennsylvania, USA
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Chowdhury S, Kode RK, Ranganna K, Damask AM, Lam A, Fyfe B, Stabler S, Kumar AM, Tomeny MB, Kumar MS, Pankewycz O. Induction strategy using basiliximab combined with mycophenolate MMF and immediate low-dose cyclosporin is steroid sparing and more effective than OKT3. Transplant Proc 2001; 33:1057-8. [PMID: 11267189 DOI: 10.1016/s0041-1345(00)02414-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- S Chowdhury
- Division of Transplantation, MCP Hahnemann University, Philadelphia, PA, USA
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Abouljoud M, Kumar MS, Brayman K, Emre S, Bynon SJ. Conversion to neoral provides effective rescue therapy for liver and kidney transplant patients intolerant of Prograf. Transplant Proc 2001; 33:1027-8. [PMID: 11267175 DOI: 10.1016/s0041-1345(00)02315-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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