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Latwal A, Rehana S, Rajan KS. Detection and mapping of water and chlorophyll-a spread using Sentinel-2 satellite imagery for water quality assessment of inland water bodies. Environ Monit Assess 2023; 195:1304. [PMID: 37828127 DOI: 10.1007/s10661-023-11874-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 09/12/2023] [Indexed: 10/14/2023]
Abstract
Water quality monitoring of reservoirs is currently a significant challenge in the tropical regions of the world due to limited monitoring stations and hydrological data. Remote sensing techniques have proven to be a powerful tool for continuous real-time monitoring and assessment of tropical reservoirs water quality. Although many studies have detected chlorophyll-a (Chl-a) concentrations as a proxy to represent nutrient contamination, using Sentinel 2 for eutrophic or hypereutrophic inland water bodies, mainly reservoirs, minimal efforts have been made for oligotrophic and mesotrophic reservoirs. The present study aimed to develop a modeling framework to map and estimate spatio-temporal variability of Chl-a levels and associated water spread using the Modified Normalized Difference Water Index (MNDWI) and Maximum Chlorophyll Index (MCI). Moreover, the impact of land use/land cover type of the contributing watershed in the oligo-mesotrophic reservoir, Bhadra (tropical reservoir), for 2018 and 2019 using Sentinel 2 satellite data was analyzed. The results show that the water spread area was higher in the post-monsoon months and lower in the summer months. This was further validated by the correlation with reservoir storage, which showed a strong relationship (R2 = 0.97, 2018; R2 = 0.93, 2019). The estimated Chl-a spread was higher in the winter season, because the reservoir catchment was dominated by deciduous forest, producing a large amount of leaf litter in tropical regions, which leads to an increase in the level of Chl-a. It was found that Chl-a spread in the reservoir, specifically at the inlet sources and near agricultural land practices (western parts of the Bhadra reservoir). Based on the findings of this study, the MCI spectral index derived from Sentinel 2 data can be used to accurately map the spread of Chl-a in diverse water bodies, thereby offering a robust scientific basis for effective reservoir management.
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Affiliation(s)
- Avantika Latwal
- Hydroclimatic Research Group, Lab for Spatial Informatics, International Institute of Information Technology-Hyderabad, Gachibowli, Hyderabad, Telangana, 500032, India
| | - Shaik Rehana
- Hydroclimatic Research Group, Lab for Spatial Informatics, International Institute of Information Technology-Hyderabad, Gachibowli, Hyderabad, Telangana, 500032, India.
| | - K S Rajan
- Lab for Spatial Informatics, International Institute of Information Technology-Hyderabad, Gachibowli, Hyderabad, Telangana, 500032, India
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Lakshmanakumar M, Nesakumar N, Sethuraman S, Rajan KS, Krishnan UM, Rayappan JBB. Development of an Electrodeposited Graphene Quantum Dot Electrode for the Electrochemical Detection of C‐Reactive Protein (CRP) Biomarker. ChemistrySelect 2022. [DOI: 10.1002/slct.202104511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Muthaiyan Lakshmanakumar
- School of Electrical & Electronics Engineering SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB) SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
| | - Noel Nesakumar
- School of Chemical & Biotechnology SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
| | - Swaminathan Sethuraman
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB) SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
- School of Chemical & Biotechnology SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
| | - K. S. Rajan
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB) SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
- School of Chemical & Biotechnology SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
| | - Uma Maheswari Krishnan
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB) SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
- School of Chemical & Biotechnology SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
- School of Arts Science & Humanities (SASH) SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
| | - John Bosco Balaguru Rayappan
- School of Electrical & Electronics Engineering SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB) SASTRA Deemed to be University Thanjavur 613 401 Tamil Nadu India
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Lakshmanakumar M, Sethuraman S, Rajan KS, Krishnan UM, Rayappan JBB. Activation of edge plane pyrolytic graphite in screen printed carbon electrodes on OHP sheet, Whatman paper and textile substrates. J APPL ELECTROCHEM 2020. [DOI: 10.1007/s10800-020-01413-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Lakshmanakumar M, Nesakumar N, Sethuraman S, Rajan KS, Krishnan UM, Rayappan JBB. Functionalized Graphene Quantum Dot Interfaced Electrochemical Detection of Cardiac Troponin I: An Antibody Free Approach. Sci Rep 2019; 9:17348. [PMID: 31758063 PMCID: PMC6874552 DOI: 10.1038/s41598-019-53979-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [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: 05/16/2019] [Accepted: 10/29/2019] [Indexed: 12/03/2022] Open
Abstract
According to the World Health Organization (WHO), cardiovascular disease (CVD) is the leading cause of death in the world every year. The design and development of biosensors for the detection of CVD markers could be one of the major contributions of the scientific community to society. In this context, acetic acid functionalized graphene quantum dots (fGQDs) were used as an interface for the electrochemical detection of cardiac Troponin I (cTnI). The interaction of cTnI with fGQDs for the early diagnosis of acute myocardial infarction was investigated using cyclic voltammetry (CV) and amperometry. The carbodiimide conjugation between the N-H group of cTnI and the functionalized COOH group on GQDs enabled the detection of cTnI biomarker. The same sensing mechanism was confirmed using Fourier Transform Infrared Spectrometry (FTIR). The fGQDs modified Au electrode showed remarkable electrocatalytic oxidation of cTnI with good stability and sensitivity over a linear range of 0.17 to 3 ng mL−1 and a low detection limit of 0.02 ng mL−1. Bland-Altman plots substantiate a bias between the intra-/inter-cTnI assay and calibrated cTnI assay with 95% limits of agreement (mean difference ± 1.96 SD). The aim of this study is to describe an innovative method to detect cardiac biomarker cTnI and provide preliminary data on its diagnostic capacity. At the same time, its applicability in clinical setting will have to be validated with a significant number of samples collected from patients.
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Affiliation(s)
- Muthaiyan Lakshmanakumar
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, 613 401, India.,School of Electrical & Electronics Engineering (SEEE), SASTRA Deemed University, Thanjavur, 613 401, India
| | - Noel Nesakumar
- Electrodics & Electrocatalysis Division, Central Electrochemical Research Institute, Karaikudi, 630 006, India
| | - Swaminathan Sethuraman
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, 613 401, India.,School of Chemical & Biotechnology (SCBT), SASTRA Deemed University, Thanjavur, 613 401, India
| | - K S Rajan
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, 613 401, India.,School of Chemical & Biotechnology (SCBT), SASTRA Deemed University, Thanjavur, 613 401, India
| | - Uma Maheswari Krishnan
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, 613 401, India.,School of Chemical & Biotechnology (SCBT), SASTRA Deemed University, Thanjavur, 613 401, India.,School of Arts, Science & Humanities (SASH), SASTRA Deemed University, Thanjavur, 613 401, India
| | - John Bosco Balaguru Rayappan
- Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, 613 401, India. .,School of Electrical & Electronics Engineering (SEEE), SASTRA Deemed University, Thanjavur, 613 401, India.
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Rajan KS, Swaminathan S, Vaidhyasubramaniam S. Research Output of Indian Institutions during 2011–2016:Quality and Quantity Perspective. CURR SCI INDIA 2018. [DOI: 10.18520/cs/v114/i04/740-746] [Citation(s) in RCA: 4] [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: 11/15/2022]
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Vardhan PV, Idris MB, Manikandan S, Rajan KS, Devaraj S. Enhancement in the supercapacitive storage performance of MnCO3 using SiOx nanofluid-based electrolyte. J Solid State Electrochem 2018. [DOI: 10.1007/s10008-018-3887-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Suraj Reddy R, Rakesh A, Jha CS, Rajan KS. Automatic Estimation of Tree Stem Attributes Using Terrestrial Laser Scanning in Central Indian Dry Deciduous Forests. CURR SCI INDIA 2018. [DOI: 10.18520/cs/v114/i01/201-206] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Krishnan RY, Rajan KS. Influence of microwave irradiation on kinetics and thermodynamics of extraction of flavonoids from Phyllanthus emblica. Braz J Chem Eng 2017. [DOI: 10.1590/0104-6632.20170343s20150628] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ramyadevi D, Rajan KS, Vedhahari BN, Ruckmani K, Subramanian N. Heterogeneous polymer composite nanoparticles loaded in situ gel for controlled release intra-vaginal therapy of genital herpes. Colloids Surf B Biointerfaces 2016; 146:260-70. [PMID: 27351137 DOI: 10.1016/j.colsurfb.2016.06.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [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: 03/05/2016] [Revised: 05/23/2016] [Accepted: 06/14/2016] [Indexed: 10/21/2022]
Abstract
Herpes simplex virus causes serious and contagious genital infections in high percentage of female population world-wide. Acyclovir is a clinically successful antiviral molecule till date, in-spite of limitations as poor solubility, low half-life, reduced oral bioavailability and side effects at higher doses. In the present work, controlled release in situ gelling system loaded with polymeric nanoparticles of acyclovir containing a dose of drug equivalent to 105mg/day has been developed. The formulation containing drug loaded polyvinyl pyrrolidone-Eudragit RSPO hybrid polymeric nanoparticles (Size ∼99±3nm, Zeta ∼+26.1±1.5mV) in 15% Pluronic F-127 gel exhibited improved permeability through vaginal membrane (KP=2.20±0.19×10(-6)cm/s). The nanoparticles showed enhanced viability for vaginal epithelial cell lines up to concentration of 100-250μg/mL. The formulation was evaluated for bioavailability and biodistribution through intra-vaginal administration in rat models. The nanoparticle in situ gel formulation maintained an average therapeutic drug level of 0.6±0.2μg/mL in plasma for 24h. Significant improvement in mean residence time of the drug (12.52±1.12h) was observed with a two-fold increase in the relative bioavailability (AUC0-24h=14.92±2.44μgh/mL) compared to that of the pure drug (7.18±1.79μgh/mL). The tissue distribution was 2-3 folds higher in animals treated with nanoparticles in situ gel compared to that of pure drug. Sustained release of drug in vivo was demonstrated, ensuring the suitability of the formulation for clinical therapy in female population.
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Affiliation(s)
- D Ramyadevi
- School of Chemical and Biotechnology (SCBT), SASTRA University, Thanjavur, 613 401 Tamil Nadu, India.
| | - K S Rajan
- School of Chemical and Biotechnology (SCBT), SASTRA University, Thanjavur, 613 401 Tamil Nadu, India.
| | - B N Vedhahari
- School of Chemical and Biotechnology (SCBT), SASTRA University, Thanjavur, 613 401 Tamil Nadu, India.
| | - K Ruckmani
- Department of Pharmaceutical Technology, Anna University, BIT Campus, Trichy, 620 024 Tamil Nadu, India.
| | - N Subramanian
- Department of Pharmaceutical Technology, Anna University, BIT Campus, Trichy, 620 024 Tamil Nadu, India.
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Shylaja A, Manikandan S, Suganthi KS, Rajan KS. Preparation and Thermo-Physical Properties of Fe2O3-Propylene Glycol Nanofluids. J Nanosci Nanotechnol 2015; 15:1653-1659. [PMID: 26353708 DOI: 10.1166/jnn.2015.8918] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Iron oxide (Fe2O3) nanoparticles were prepared from ferric chloride and ferrous sulphate by precipitation reaction. Fe2O3-propylene glycol nanofluid was prepared by dispersing Fe2O3 nanoparticles in propylene glycol through stirred bead milling, shear homogenization and probe ultrasonication. The nanofluid was characterized through measurement of viscosity, particle size distribution and thermal conductivity. The interactions between Fe2O3 nanoparticles and propylene glycol on the nanoparticle surfaces lead to reduction in viscosity, the magnitude of which increases with nanoparticle concentration (0-2 vol%) at room temperature. The thermal conductivity enhancement for 2 vol% nanofluid was about 21% at room temperature, with liquid layering being the major contributor for thermal conductivity enhancement.
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Nagarajan S, Krishnaswamy S, Pemiah B, Rajan KS, Krishnan U, Sethuraman S. Scientific Insights in the Preparation and Characterisation of a Lead-based Naga Bhasma. Indian J Pharm Sci 2014; 76:38-45. [PMID: 24799737 PMCID: PMC4007254] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2013] [Revised: 11/29/2013] [Accepted: 12/06/2013] [Indexed: 11/25/2022] Open
Abstract
Naga bhasma is one of the herbo-metallic preparations used in Ayurveda, a traditional Indian System of Medicine. The preparation of Naga bhasma involves thermal treatment of 'Naga' (metallic lead) in a series of quenching liquids, followed by reaction with realgar and herbal constituents, before calcination to prepare a fine product. We have analysed the intermediates obtained during different stages of preparation to understand the relevance and importance of different steps involved in the preparation. Our results show that 'Sodhana' (purification process) removes heavy metals other than lead, apart from making it soft and amenable for trituration. The use of powders of tamarind bark and peepal bark maintains the oxidation state of lead in Jarita Naga (lead oxide) as Pb(2+). The repeated calcination steps result in the formation of nano-crystalline lead sulphide, the main chemical species present in Naga bhasma.
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Affiliation(s)
- S. Nagarajan
- Centre for Nanotechnology and Advanced Biomaterials, Thanjavur-613 401, India
- School of Chemical and Biotechnology, Thanjavur-613 401, India
| | - S. Krishnaswamy
- School of Chemical and Biotechnology, Thanjavur-613 401, India
| | - Brindha Pemiah
- School of Chemical and Biotechnology, Thanjavur-613 401, India
- Centre for Advanced Research in Indian System of Medicine, Sastra University, Thanjavur-613 401, India
| | - K. S. Rajan
- Centre for Nanotechnology and Advanced Biomaterials, Thanjavur-613 401, India
- School of Chemical and Biotechnology, Thanjavur-613 401, India
| | - Umamaheswari Krishnan
- Centre for Nanotechnology and Advanced Biomaterials, Thanjavur-613 401, India
- School of Chemical and Biotechnology, Thanjavur-613 401, India
| | - S. Sethuraman
- Centre for Nanotechnology and Advanced Biomaterials, Thanjavur-613 401, India
- School of Chemical and Biotechnology, Thanjavur-613 401, India
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Raheja V, Rajan KS. Extraction of Disease Occurrence Patterns Using MiSTIC: Salmonellosis in Florida. Online J Public Health Inform 2013; 5:e19. [PMCID: PMC3692842] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Objective Introduction Methods Results Conclusions
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Manikandan S, Karthikeyan N, Silambarasan M, Suganthi KS, Rajan KS. Preparation and characterization of sub-micron dispersions of sand in ethylene glycol-water mixture. Braz J Chem Eng 2012. [DOI: 10.1590/s0104-66322012000400003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Prasad PRC, Nagabhatla N, Reddy CS, Gupta S, Rajan KS, Raza SH, Dutt CBS. Assessing forest canopy closure in a geospatial medium to address management concerns for tropical islands--Southeast Asia. Environ Monit Assess 2010; 160:541-553. [PMID: 19190992 DOI: 10.1007/s10661-008-0717-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Accepted: 12/23/2008] [Indexed: 05/27/2023]
Abstract
The present study outlines an approach to classify forest density and to estimate canopy closure of the forest of the Andaman and Nicobar archipelago. The vector layers generated for the study area using satellite data was validated with the field knowledge of the surveyed ground control points. The methodology adopted in this present analysis is three-tiered. First, the density stratification into five zones using visual interpretation for the complete archipelago. In the second step, we identified two island groups from the Andaman to investigate and compare the forest strata density. The third and final step involved more of a localised phytosociological module that focused on the North Andaman Islands. The results based on the analysis of the high-resolution satellite data show that more than 75% of the mangroves are under high- to very high-density canopy class. The framework developed would serve as a significant measure to forest health and evaluate management concerns whilst addressing issues such as gap identification, conservation prioritisation and disaster management--principally to the post-tsunami assessment and analysis.
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Affiliation(s)
- P Rama Chandra Prasad
- Laboratory for Spatial Informatics, International Institute of Information Technology, Gachibowli, Hyderabad, 500 032, India.
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Rao ARR, Rajan KS, Raju MB, Singh SD. New antihistaminic agents: Synthesis and evaluation of h 1 -antihistaminic actions of 3-[(n,n-dialkylamino)alkyl)-1,2,3,4-tetrahydro-(1h)-thioquinazolin-4(3h)-ones and their oxo analogues. Indian J Pharm Sci 2007. [DOI: 10.4103/0250-474x.39454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Saini GS, Wani TA, Gautam A, Varshney B, Ahmed T, Rajan KS, Pillai KK, Paliwal JK. Validation of the LC-MS/MS method for the quantification of mevalonic acid in human plasma and determination of the matrix effect. J Lipid Res 2006; 47:2340-5. [PMID: 16861623 DOI: 10.1194/jlr.d600018-jlr200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [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: 11/20/2022] Open
Abstract
A simple, specific, and sufficiently sensitive liquid chromatography-tandem mass spectrometry (negative-ion electrospray ionization) methodology to determine mevalonic acid (MVA) in human plasma is described, and its application to the analysis of rat plasma MVA levels after rosuvastatin administration is demonstrated. The method was validated over the linearity range of 0.5-50.0 ng/ml (r(2) > 0.99) using deuterated MVA as an internal standard. The lower limit of quantification was 0.5 ng/ml. The assay procedure involved the isolation of MVA from plasma samples using solid-phase extraction. Chromatographic separation was achieved on a HyPurity Advance column with a mobile phase consisting of ammonium formate buffer (10 mM, pH 8.0) and acetonitrile (70:30, v/v). Excellent precision and accuracy were observed. MVA and deuterated mevalonolactone were stable in water and plasma under different storage and processing conditions. The recovery observed was low, which was attributable to a significant matrix effect. A significant decrease (30-40%; P < 0.05) was observed in rat plasma MVA levels after rosuvastatin administration.
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Affiliation(s)
- G S Saini
- Department of Metabolism and Pharmacokinetics, Ranbaxy Research Laboratories, Jamia Hamdard, Delhi, India
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Rajan KS, Murase I, Martell AE. New multidentate ligands. VII. Ethylenediamine-N,N'-diacetic-N,N'-bis(methylenephosphonic) acid. J Am Chem Soc 2002. [DOI: 10.1021/ja01044a014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Glucosamine oligomers--monomer through tetramer--form complexes with Cu2+ that catalyse the hydrolysis of the 'nerve gas' 1,2,2-trimethylpropyl- methylphosphonofluroidate (soman) by cleaving the P-F bond. A 1/1 glucosamine/Cu2+ ratio whether as glucosamine or glucosamine units, gives the highest hydrolytic rate over the 11.5/1 to 1/1 range. This trend also appears to hold for a glucosamine polymer, chitosan, which, when complexed with Cu2+ also hydrolyzes soman. The relatively low rate of hydrolysis by this polymer-Cu2+ complex, while not yet explainable, is consistent with an extrapolation of the monomer-through-tetramer series. The question may be raised as to whether these biopolymer metal complexes provide any clues to the involvement of Mn2+ in the functioning of one class of P-F cleaving enzymes.
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Affiliation(s)
- F C Hoskin
- Biology Department, Illinois Institute of Technology, Chicago 60616
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Abstract
The formation and strength of chelation of A1(III) with salicylic acid (SA), citric acid (CIT), ethylenediaminetetraacetic acid (EDTA), ethylenediamine-di-(o-hydroxyphenylacetic acid) (EDDHA), N,N'-di-(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid (HBED), and some mixed ligand systems consisting of the above ligands were examined at an ionic strength of 0.12 M NaCl and 25.0 +/- 0.1 degrees C. All the ligands under consideration form strong chelates with A1(III). The order of the stabilities (log KML) of their A1(III) chelates are SA (13.7) less than EDTA (15.3) less than CIT (18.0) less than EDDHA (24.5) approximately equal to HBED (24.8). An equilibrium analysis of the A1(III)-SA (1:1), A1(III)-CIT (1:1) and A1(III)-SA-CIT (1:1:1) systems indicated the occurrence of hydrolysis and polymerization reactions in each one of them. The A1(III)-EDTA (1:1) chelate was found to undergo hydrolysis even at pH 5. However, EDDHA and HBED each formed a very stable mononuclear chelate with A1(III) and did not show hydrolytic or polymerization tendencies.
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Rajan KS, Jaw R, Grecz N. Role of chelation and water binding of calcium in dormancy and heat resistance of bacterial endospores. Bioinorg Chem 1978; 8:477-91. [PMID: 359055 DOI: 10.1016/0006-3061(78)80002-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The possible relationship between the water binding by bacterial endospores and their dormancy and heat resistances has been examined in terms of the coordination characteristics of the spore-bound calcium. Stabilities of the calcium complexes of typical cytoplasmic and structural spore components were determined by potentiometric equilibrium pH measurements in model systems consisting of DPA, glycine, alanine, glutamic acid, alanyl-glutamic acid, triglycine, and tetraglycine. The Ca++-form and H+-form spores of Clostridium botulinum 33A were investigated in vivo with respect to their water sorption and heat-resistance characteristics. The results suggest that the complexing of calcium and Ca(II)-DPA may be biologically significant for spore resistance and dormancy at the following three levels: (1) complexing with spore cytoplasmic pool constituents consistent with the idea of a metal-chelate cross-linked cytoplasm or spore cement stabilizing the essential biological macromolecules, (2) complexing with structural components of the spore as indicated by the interaction with model peptides, and (3) coordination with water to produce an apparently dehydrated environment in the spore as evident from the much greater water-sorption capacity of the Ca++-form spores vs the much smaller water sorption of the H+-form spores. Interestingly enough, DPA itself, in the absence of metal ion, showed some interaction with di-, tri-, and tetrapeptides and a weak but detectable interaction with amino acids. Although the exact mode of the DPA-peptide interaction is not clear, it is attractive to speculate about its possible involvement in the control of spore dormancy and resistance.
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Rajan KS, Wiehle RD, Riesen WH, Colburn RW, Davis JM. Effect of metal chelating agents on the storage of norepinephrine in vitro by cerebral synaptic vesicles. Biochem Pharmacol 1977; 26:1703-8. [PMID: 901589 DOI: 10.1016/0006-2952(77)90148-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
The half-life, distribution, size and composition of the bile salt pool were determined in intact and cholecystectomized Syrian hamsters. Cholecystectomy had no effect on the half-life of either the cholate or chenodeoxycholate pool. Fasting in intact hamsters resulted, as expected, in a shift of bile salts from the small intestine, cecum and liver to the gallbladder. In cholecystectomized hamsters there was a moderate shift of salts from the liver and small intestine to the cecum. Cholecystectomy had no significant effect on the size of the total bile salt pool. The total bile salt pool size of fed and fasted intact hamsters was the same; fasting in cholecystectomized hamsters resulted in a large decrease in the pool. There was no significant difference in the bile salt pool composition of intact and cholecystectomized hamsters, and hamsters were shown to efficiently convert deoxycholate to cholate.
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Abstract
The CPA technique was shown to be very useful in nondestructively determining the concentration profiles of fluoride in extracted teeth. By means of this technique, it was found that in vitro treatment with K2ZrF6 incorporated substantially more fluoride into the enamel than NaF or APF by factors of 5 and more than 50, respectively. The concentration profile was determined from the tooth surface to a depth of 2.1 mum, with a resolution of 0.07 mum at the surface and 0.15 mum at a 2.1-mum depth. Proton-stimulated X-ray fluorescence was used to detect the elements heavier than Mg, for example, P, Cl, K, Ca, Ti, Fe, Ni, Ca, Zn, Zr, and Pb.
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Abstract
An exploratory study consisting of physiochemical and animal experiments was undertaken with the objective of developing one or more metal-L-DOPA chelate systems for an improved transport of L-DOPA into the brain. This approach is based on a theoretical speculation that the pyridoxal-dependent decarboxylation of L-DOPA in the precerebral areas might be obviated by an appropriate metal chelation of the aminocarboxylate end of the L-DOPA molecule. Equilibium studies on the interactions of L-DOPE with Cu2+,Zn2+, Co2+, Mg2+ and Fe2+ ions and their ATP chelates were carried out in order to examine the conditions for the selective binding of the terminal amine group. Metal chelate systems for in vivo transport experiments were selected viz., Cu2+ or Zn2+-L-DOPA (1:2) and Cu2+ or Zn2+-ATP-L-DOPA (1:1:1) which contained the amine-bound metal ion in a completely coordinated form. Results of in vivo studies involving the intraperitoneal administration of 14C-and 3H-LABELED L-DOPA compounds have shown a 100-150% increase in the transport of L-DOPA into the brain by using the Cu2+ and Zn2+ chelates over that effected by using the unchelated L-DOPA. A chromatographic analysis of the brain homogenates showed that only 6% of the overall radioactivity of the brain could be attributed to 3-methoxytyrosine, and the remaining activity was due to DOPA, dopamine and norepinephrine. The transport effectiveness was also compared with that obtained by using the combination drug, RO4-4602 + L-DOPA.
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Rajan KS, Skripkus A, Marks GE, Davis JM. Coordination of biogenic amines with synaptosomal and vesicular metal ions: equilibrium and spectral studies in model systems. Bioinorg Chem 1976; 6:93-117. [PMID: 1053540 DOI: 10.1016/s0006-3061(00)80208-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Thermodynamic equilibrium studies using model systems were carried out on the nature and extent of coordination of twelve different biogenic amines and adenosine-5'-triphosphate (ATP) with the bivalent metal ions, viz., Ca2+ and Zn2+, which occur in the subcellular fractions of the brain, at 25.0 +/- 0.1 degrees C and at an ionic strength of 1.0 (KNO3). In the combined presence of the individual monoamines and ATP the metal ions were predominantly coordinated by ATP in the pH range 3.0 to 6.5 with binding constants (log KML) of 2.84 +/- 0.06 and 3.19 +/- 0.39 for the Ca2+ and Zn2+ chelates, respectively. Each of the monoamines coordinated with the metal-ATP chelate above pH 6. The stabilities of the chelates of some of the amines with Ca2+ -ATP (1:1) system were NE, 2.33 +/- 0.33; AA, 2.24 +/- 0.19; OA, 1.94 +/- 0.29; NMeN, 1.60 +/- 0.22; DA, 2.14 +/- 0.09. Values for the Zn2+-ATP-amine systems were: NE, 8.35 +/- 0.26; OA, 4.53 +/- 0.07; DA, 10.05 +/- 0.39. Absorption spectral studies were carried out in order to examine the nature of coordination of NE, DA, TA, and AA with Cu2+, Fe2+, and Mg2+ ions in the combined presence of ATP. Results of the spectral studies taken together with the (thermodynamic) equilibrium data have indicated that in the pH range of biological interest, the catechol amines (NE and DA) and ATP are both coordinated to the "synaptosomal and vesicular" metal ions. The results further indicated that both the pyrocatechol and the ethanolamine groups of NE might be involved in the coordination of Cu2+. However, the interaction of the ethanolamine group of the NE molecule with the rest of the metal ions was not indicated.
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Baker H, Frank O, Zetterman RK, Rajan KS, ten Hove W, Leevy CM. Inability of chronic alcoholics with liver disease to use food as a source of folates, thiamin and vitamin B6. Am J Clin Nutr 1975; 28:1377-80. [PMID: 802999 DOI: 10.1093/ajcn/28.12.1377] [Citation(s) in RCA: 42] [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] [Indexed: 12/24/2022] Open
Abstract
Absorption of folates, thiamin, vitamin B6, pantothenate and riboflavin from a natural food source--yeast--and their respective synthetic forms was studied in 37 patients with liver disease due to alcoholism, and 12 healthy, nonalcoholic subjects. All alcoholics absorbed riboflavin and pantothenate but had a significantly lowered absorption of thiamin and vitamin B6 from yeast. Alcoholics absorbed synthetic vitamin B6, but not thiamin. Ingested folylpolyglutamates (the predominant folates in yeast) could not serve as a source of folate for the alcoholics, but synthetic folylmonoglutamate served. We suggest that the folate, vitamin B6, and thiamin deficits so common in alcoholic liver disease ensue from inability to absorb these specific vitamins from foods.
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Affiliation(s)
- H Baker
- Department of Medicine, New Jersey Medical School, East Orange 07018
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Rajan KS, Davis JM, Colburn RW. Metal chelates in the storage and transport of neurotransmitters: interactions of Cu2+ with ATP and biogenic amines. J Neurochem 1974; 22:137-47. [PMID: 4594504 DOI: 10.1111/j.1471-4159.1974.tb12190.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Rajan KS, Davis JM, Colburn RW, Jarke FH. Metal chelates in the storage and transport of neurotransmitters: formation of mixed ligand chelates of Mg 2+ -ATP with biogenic amines. J Neurochem 1972; 19:1099-116. [PMID: 4401681 DOI: 10.1111/j.1471-4159.1972.tb01430.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Chung L, Rajan KS, Merdinger E, Grecz N. Coordinative binding of divalent cations with ligands related to bacterial spores. Equilibrium studies. Biophys J 1971; 11:469-82. [PMID: 5569493 PMCID: PMC1484009 DOI: 10.1016/s0006-3495(71)86229-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
It has been repeatedly postulated that the high heat resistance of bacterial spores is due to stabilization of biopolymers in the spore interior by a solid deposit of protective cement consisting of coordination complexes of ligands with divalent metal ions. This report presents data on metal-binding characteristics of some of the ligands related to spores as determined by means of potentiometric equilibrium measurements under conditions of temperature and ionic strength (t = 25.0 degrees C; mu = 1.0 KNO(3)) identical with those reported earlier by the authors in order to facilitate correlation by using comparable data. The spore ligands investigated in this study included 2,6-pyridinedicarboxylic acid (DPA), alpha,epsilon-diaminopimelic acid, D-glutamic acid, and D-alanine in a ratio of 1:1 with metal ions which are known to play a role in heat resistance of spores. Stability constants of the chelates of these spore ligands with metal ions such as Ca(II), Mg(II), Cu(II), Ni(II), Zn(II), Co(II), and Mn(II) have been determined. In general the metal chelates of DPA exhibited the greatest stability. On the basis of a consideration of the stability data together with the known configurations of the ligand and the coordination requirements of the metal ions, possible structures indicating the coordinate binding of the spore ligands with the metal ions are presented. All the metal chelates except those of Ca(II) were found to undergo hydrolysis and separation of solid phase in the pH range 7-8.5. The relatively greater hydrolytic stability of Ca(II) chelates and the high affinity of DPA for metal ions appear to be of biological significance insofar as these two spore components are more widely associated with the heat resistance of bacterial spores.
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Rajan KS, Davis JM, Colburn RW. Metal chelates in the storage and transport of neurotransmitters: interactions of metal ions with biogenic amines. J Neurochem 1971; 18:345-64. [PMID: 5559248 DOI: 10.1111/j.1471-4159.1971.tb11963.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Abstract
The high resistance of bacterial spores to heat has been repeatedly postulated to be due to stabilization of spore biopolymers by metal chelate compounds. Binding of calcium dipicolinic acid (Ca(II)-DPA) with spore proteins and amino acids has been discussed in the literature, but equilibrium data are generally lacking. By means of potentiometric pH titrations at 25 degrees C and an ionic strength of 1.0 (KNO(3)), the formation of Ca(II)-DPA (1:1 and 1:2) chelates and the interactions of Ca(II)-DPA chelate with a mole of each of three typical amino acids viz., cysteine, alanine, and glycine has been investigated. Analysis of the potentiometric data indicates that calcium and DPA forms 1:1 and 1:2 chelates with log K(ML1) = 4.39 +/- 0.01 and log K(ML2) = 2.25 +/- 0.01. In the presence of an equimolar amount of each of the amino acids under consideration, the Ca(II)-DPA chelate forms mixed ligand (ternary) chelate yielding the following stepwise stability constants: log K(1) = 4.17 +/- 0.01, log K(2) = 0.78 +/- 0.01 for cysteine, log K(1) = 4.06 +/- 0.01, log K(2) = 0.65 +/- 0.01 for alanine, and log K(1) = 4.30 +/- 0.02, log K(2) = 0.11 +/- 0.01 for glycine. Methods for calculating the stability constants of the mixed ligand system have been developed. On the basis of the potentiometric equilibrium data, possible structures for the various calcium chelate species are discussed. The data suggest that the differences in heat resistance of various strains of bacterial spores may conceivably be related to the differences in composition and stability of coordination complexes in the spore.
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Tandon BN, Rajan KS. Diagnosis of 'concealed abscess' in patients of 'amebic hepatitis'. Indian J Med Res 1968; 56:321-6. [PMID: 5658492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
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Tandon BN, Rajan KS. Long term sequelae of amoebic abscess of the liver. Indian J Med Res 1967; 55:1200-4. [PMID: 5582786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Tandon BN, Rajan KS. Scintillation scanning in diseases of the liver. Indian J Med Res 1966; 54:1115-21. [PMID: 5975541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Rajan KS, Tikare SK, Tandon BN. Evaluation of some laboratory aids for the diagnosis of metastatic malignancy of the liver. Indian J Med Res 1966; 54:142-7. [PMID: 5933283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Subbaraman PR, Rajan KS, Gupta J. Ion exchange separation of some light rare earths by elution with sodium triphosphate. II. Effect of PH of Eluant. Z Anorg Allg Chem 1960. [DOI: 10.1002/zaac.19603040310] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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