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Arjunan V, Rani T, Santhanalakshmi K, Mohan S. A combined experimental and theoretical quantum chemical studies on 4-morpholinecarboxaldehyde. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:1395-1401. [PMID: 21601511 DOI: 10.1016/j.saa.2011.04.074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 04/16/2011] [Accepted: 04/29/2011] [Indexed: 05/30/2023]
Abstract
Extensive spectroscopic investigations have been carried out by recording the Fourier transform infrared (FTIR) and FT-Raman spectra and carrying out the theoretical quantum chemical studies on 4-morpholinecarboxaldehyde (4MC). From the ab initio and DFT analysis using HF, B3LYP and B3PW91 methods with 6-31G(d,p) and 6-311G++(d,p) basis sets the energies, structural, thermodynamical and vibrational characteristics of the compound were determined. The energy difference between the chair equatorial and chair axial conformers of 4MC have been calculated by density functional theory (DFT) method. The optimised geometrical parameters, theoretical wavenumbers and thermodynamic properties of the molecule were compared with the experimental values. The effect of carbonyl group on the characteristic frequencies of the morpholine ring has been analysed. The mixing of the fundamental modes with the help of potential energy distribution (PED) through normal co-ordinate analysis has been discussed.
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Arjunan V, Rani T, Santhanalakshmi K, Mohan S. Spectroscopic and quantum chemical studies on 4-acryloyl morpholine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:1386-1394. [PMID: 21621452 DOI: 10.1016/j.saa.2011.04.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 04/27/2011] [Accepted: 04/29/2011] [Indexed: 05/30/2023]
Abstract
Fourier transform infrared (FTIR) and FT-Raman spectra have been recorded and an extensive spectroscopic investigations have been carried out on 4-acryloyl morpholine (4AM). Theoretical quantum chemical studies have also been performed. From the ab initio and DFT analysis using HF, B3LYP and B3PW91 methods with 6-31G(d,p) and 6-311G++(d,p) basis sets the energies, structural, thermodynamical and vibrational characteristics of the compound were determined. The energy difference between the chair equatorial and chair axial conformers of 4AM have been calculated by density functional theory (DFT) method. The optimized geometrical parameters, theoretical wavenumbers and thermodynamic properties of the molecule are compared with the experimental values. The effect of acryloyl group on the characteristic frequencies of the morpholine ring has been analysed. The mixing of the fundamental modes with the help of potential energy distribution (PED) through normal co-ordinate analysis has been discussed.
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Arjunan V, Balamourougane P, Mythili C, Mohan S. Experimental spectroscopic (FTIR, FT-Raman, FT-NMR, UV–Visible) and DFT studies of 2-amino-5-chlorobenzoxazole. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2011.07.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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204
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Govindarajan M, Ganasan K, Periandy S, Mohan S, Tedlamelekot F. Vibrational spectroscopic analysis of 2-bromobenzoic and anthranilic acids: a combined experimental and theoretical study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:2003-2011. [PMID: 21703917 DOI: 10.1016/j.saa.2011.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Revised: 04/12/2011] [Accepted: 06/02/2011] [Indexed: 05/31/2023]
Abstract
In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000 cm(-1) and 50-4000 cm(-1) respectively, for the title molecules. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartee-Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The effects due to the substitutions of amino group and halogen bond were investigated. The results of the calculations were applied to simulate spectra of the title compounds, which show excellent agreement with observed spectra.
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Arjunan V, Rani T, Mythili CV, Mohan S. Synthesis, FTIR, FT-Raman, UV-visible, ab initio and DFT studies on benzohydrazide. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:486-496. [PMID: 21531171 DOI: 10.1016/j.saa.2011.03.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 02/18/2011] [Accepted: 03/09/2011] [Indexed: 05/30/2023]
Abstract
A systematic vibrational spectroscopic assignment and analysis of benzohydrazide (BH) has been carried out by using FTIR and FT-Raman spectral data. The vibrational analysis were aided by electronic structure calculations--ab initio (RHF) and hybrid density functional methods (B3LYP and B3PW91) performed with 6-31G(d,p) and 6-311++G(d,p) basis sets. Molecular equilibrium geometries, electronic energies, IR intensities, harmonic vibrational frequencies, depolarization ratios and Raman activities have been computed. Potential energy distribution (PED) and normal mode analysis have also been performed. The assignments proposed based on the experimental IR and Raman spectra have been reviewed and complete assignment of the observed spectra have been proposed. UV-visible spectrum of the compound was also recorded and the electronic properties, such as HOMO and LUMO energies and λ(max) were determined by time-dependent DFT (TD-DFT) method. The geometrical, thermodynamical parameters and absorption wavelengths were compared with the experimental data. The interactions of carbonyl and hydrazide groups on the benzene ring skeletal modes were investigated.
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Sunilson JAJ, Anandarajagopal K, Kumari AVAG, Mohan S. Antidiarrhoeal Activity of Leaves of Melastoma malabathricum Linn. Indian J Pharm Sci 2011; 71:691-5. [PMID: 20376227 PMCID: PMC2846479 DOI: 10.4103/0250-474x.59556] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Revised: 09/02/2009] [Accepted: 12/02/2009] [Indexed: 11/04/2022] Open
Abstract
The antidiarrhoeal effect of the water extract of Melastoma malabathricum Linn. (Melastomataceae) leaves were investigated by employing four experimental models of diarrhea in Swiss mice. Melastoma malabathricum water extract treated mice showed significant reduction in the fecal output and protected them from castor oil-induced diarrhoea. The extract also reduced the intestinal fluid secretion induced by magnesium sulphate and gastrointestinal motility after charcoal meal administration in the mice. No mortality and visible signs of general weakness was observed in the mice following the test extract administration up to 2000 mg/kg dose.
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Palepu GB, Deven J, Subrahmanyam M, Mohan S. Impact of ultrasonography on central venous catheter insertion in intensive care. Indian J Radiol Imaging 2011; 19:191-8. [PMID: 19881083 PMCID: PMC2766872 DOI: 10.4103/0971-3026.54877] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background and Aims: The insertion of central venous catheters (CVCs) is an integral part of the management of critically ill patients. We aimed to study the impact of ultrasonography (USG) on CVC insertion in intensive care. Setting and Design: A prospective study of 450 patients requiring CVC in the intensive care unit (ICU) of a tertiary care hospital. Methods and Materials: The patients were randomized into two groups: to have CVC insertion with USG-guidance or with the anatomic landmark technique (ALT). Data were collected on patient demographics; operator experience; and method, site and side of insertion. Outcome measures included successful insertion of CVC, number of attempts needed and complications. Results: Internal jugular vein (IJV) cannulation was successful in 177/194 patients (91.2%) using ALT and in 200/205 patients (97.6%) using USG guidance, a significant difference of 6.4% (P = 0.006). Using ALT, 72.7% of cannulations could be accomplished in the first attempt as compared with 84.4% with USG guidance (P = 0.004). The overall complication rate was 28/399 (7%), with 19 (9.8%) complications in the ALT group and 9 (4.4%) in the USG group (age-, sex-, and operator-adjusted OR = 0.35, 95% CI: 0.13–0.96; P = 0.03). For subclavian vein catheterization, the success rate was 26/28 (92.9%) in the ALT group and 17/17 (100%) in the USG group (P = 0.52). Using ALT, 71.4% cannulation could be accomplished in the first attempt as compared with 82.4% under USG guidance (P = 0.49). The overall complication rate was 6/45 (13.3%), with 4 (14.3%) complications in the ALT group and 2 (11.8%) in the USG group (P > 0.99). Conclusions: Real-time USG guidance improves success rates, reduces the number of attempts and decreases the complications associated with CVC insertion, especially for the IJV, and should become the standard of care in intensive care.
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Renganathan NG, Subramanian MV, Mohan S. Electrodeposition route to synthesize cigs films – an economical way to harness solar energy. ACTA ACUST UNITED AC 2011. [DOI: 10.4314/ijest.v3i1.67647] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Arjunan V, Mythili CV, Mageswari K, Mohan S. Experimental and theoretical investigations of benzamide oxime. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 79:245-253. [PMID: 21450516 DOI: 10.1016/j.saa.2011.02.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 02/16/2011] [Accepted: 02/25/2011] [Indexed: 05/30/2023]
Abstract
The FT-IR (4000-400 cm(-1)) and FT-Raman (4000-100 cm(-1)) spectral measurements of benzamide oxime and complete assignments of the observed spectra have been proposed. Ab initio and DFT calculations have been performed giving energies, optimized structures, harmonic vibrational frequencies, depolarization ratios, IR intensities, Raman activities and atomic displacements. Furthermore, force field calculations have been performed by normal coordinate analysis. Force field calculations showed that several normal modes are mixed in terms of the internal coordinates. A complete assignment of the observed spectra, based on spectral correlations, electronic structure calculations and normal coordinate analysis, has been provided.
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Yu W, Pandita A, Penuel E, Raja R, Zha J, Mohan S, Patel RD, Desai R, Fu L, Do A, Mango J, Parab V, Lipkind M, Huang J, Lazarov M, Ramakrishnan V, Amler LC, Peterson AC, Patel PH, Yauch RL. Exploratory biomarker analyses from OAM4558g: A placebo-controlled phase II study of erlotinib with or without MetMAb in patients with advanced non-small cell lung cancer (NSCLC). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.7529] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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211
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Arjunan V, Rani T, Varalakshmy L, Mohan S, Tedlamelekot F. DFT and ab initio quantum chemical studies on p-cyanobenzoic acid. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1449-1454. [PMID: 21349760 DOI: 10.1016/j.saa.2011.01.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/30/2010] [Accepted: 01/17/2011] [Indexed: 05/30/2023]
Abstract
The Fourier transform infrared (FTIR) and FT-Raman spectra of p-cyanobenzoic acid (CBA) have been recorded in the range 4000-400 and 4000-100 cm(-1), respectively. The complete vibrational assignment and analysis of the fundamental modes of the compound were carried out using the observed FTIR and FT-Raman data. The vibrational frequencies determined experimentally were compared with theoretical wavenumbers obtained from ab initio HF and DFT-B3LYP gradient calculations employing 6-31G**, 6-311++G** and cc-pVTZ basis sets for the optimised geometry of the compound. The geometry and normal modes of vibration obtained from the HF and DFT methods are in good agreement with the experimental data. The normal coordinate analysis was also carried out with ab initio force fields utilising Wilson's FG matrix method. The interactions of cyano and carboxylic acid groups with the skeletal vibrational modes were investigated.
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Arjunan V, Isaac ASR, Rani T, Mythili CV, Mohan S. Density functional theory studies on vibrational and electronic spectra of 2-chloro-6-methoxypyridine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1625-1632. [PMID: 21382743 DOI: 10.1016/j.saa.2011.02.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Revised: 01/13/2011] [Accepted: 02/07/2011] [Indexed: 05/30/2023]
Abstract
The Fourier transform infrared (FTIR) and FT-Raman spectra of 2-chloro-6-methoxypyridine have been recorded in the range 3700-400 and 3700-100 cm(-1), respectively. The complete vibrational assignment and analysis of the fundamental modes of the compound was carried out using the observed FTIR and FT-Raman data. The vibrational frequencies determined experimentally were compared with the theoretical frequencies computed by DFT gradient calculations (B3LYP method) employing the 6-31G(d,p), cc-pVTZ and/6-311++G(d,p) basis sets for the optimised geometry of the compound. The geometry and normal modes of vibration obtained from the DFT methods are in good agreement with the experimental data. The normal co-ordinate analysis was also carried out using DFT force fields utilising Wilson's FG matrix method. The influence of the substituents bulky chlorine atom and the methoxy group on the spectral characteristics of the compound has been discussed. The electronic spectrum determined by TD-DFT method is compared with the observed electronic spectrum.
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Remya N, Kumar M, Mohan S, Azzam R. Influence of organic matter and solute concentration on nitrate sorption in batch and diffusion-cell experiments. BIORESOURCE TECHNOLOGY 2011; 102:5283-5289. [PMID: 21232937 DOI: 10.1016/j.biortech.2010.12.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 12/08/2010] [Accepted: 12/09/2010] [Indexed: 05/30/2023]
Abstract
Nitrate sorption potentials of three surface soils (soils-1-3) were evaluated under different solute concentrations, i.e. 1-100 mg L(-1). Batch and diffusion-cell adsorption experiments were conducted to delineate the diffusion property and maximum specific nitrate adsorption capacity (MSNAC) of the soils. Ho's pseudo-second order model well fitted the batch adsorption kinetics data (R(2)>0.99). Subsequently, the MSNAC was estimated using Langmuir and Freundlich isotherms; however, the best-fit was obtained with Langmuir isotherm. Interestingly, the batch adsorption experiments over-estimated the MSNAC of the soils compared with the diffusion-cell tests. On the other hand, a proportionate increase in the MSNAC was observed with the increase in soil organic matter content (OM) under the batch and diffusion-cell tests. Therefore, increasing the soil OM by the application of natural compost could stop nitrate leaching from agricultural fields and also increase the fertility of soil.
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Arjunan V, Ravindran P, Rani T, Mohan S. FTIR, FT-Raman, FT-NMR, ab initio and DFT electronic structure investigation on 8-chloroquinoline and 8-nitroquinoline. J Mol Struct 2011. [DOI: 10.1016/j.molstruc.2010.12.032] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Prabhu T, Periandy S, Mohan S. Spectroscopic (FTIR and FT Raman) analysis and vibrational study on 2,3-dimethyl naphthalene using ab-initio HF and DFT calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:566-574. [PMID: 21185771 DOI: 10.1016/j.saa.2010.11.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2010] [Revised: 10/30/2010] [Accepted: 11/18/2010] [Indexed: 05/30/2023]
Abstract
A combined experimental and theoretical study on molecular and vibrational structure of 2,3-dimethyl naphthalene (2,3-DMN) has been undertaken in the present work. The FTIR and FT Raman spectra of 2,3-DMN were recorded in the region 4000-100 cm(-1). The optimized geometries were calculated by HF and DFT (B3LYP) methods with 6-31++G (d, p), 6-311G (d, p) and 6-311++G (d, p) basis sets. The harmonic vibrational frequencies, infrared intensities and Raman activities of the 2,3-DMN were evaluated with these methods. After scaling the computational wave numbers are in very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of 2,3-DMN is presented. The effects of substitution of methyl group on the molecule have also been discussed.
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Babu PDS, Periandy S, Mohan S, Ramalingam S, Jayaprakash BG. Molecular structure and vibrational investigation of benzenesulfonic acid methyl ester using DFT (LSDA, B3LYP, B3PW91 and MPW1PW91) theory calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:168-178. [PMID: 20943432 DOI: 10.1016/j.saa.2010.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 08/04/2010] [Accepted: 09/08/2010] [Indexed: 05/30/2023]
Abstract
The FT-Raman and FT-IR spectra for benzenesulfonic acid methyl ester (BSAME) have been recorded in the region 4000-100 cm(-1) and compared with the harmonic vibrational frequencies calculated using DFT (LSDA, B3LYP, B3PW91 and MPW1PW91) method by employing 6-311G (d, p) basis set with appropriate scale factors. IR intensities and Raman activities are also calculated by DFT (LSDA, B3LYP, B3PW91 and MPW1PW91) methods. Optimized geometries of the molecule have been interpreted and compared with the reported experimental values for sulfonic acid and some substituted sulfonic acids. The experimental geometrical parameters show satisfactory agreement with the theoretical prediction from DFT. The scaled vibrational frequencies at LSDA/B3LYP/6-311G (d, p) seem to coincide with the experimentally observed values with acceptable deviations. The theoretical spectrograms (IR and Raman) have been constructed and compared with the experimental FT-IR and FT-Raman spectra. Some of the vibrational frequencies of the sulfonic acid are effected upon profusely with the methyl substitution in comparison to benzene sulfonamide and these differences are interpreted.
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Ramalingam S, Periandy S, Elanchezhian B, Mohan S. FT-IR and FT-Raman spectra and vibrational investigation of 4-chloro-2-fluoro toluene using ab initio HF and DFT (B3LYP/B3PW91) calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:429-436. [PMID: 21146451 DOI: 10.1016/j.saa.2010.11.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 10/19/2010] [Accepted: 11/15/2010] [Indexed: 05/30/2023]
Abstract
FT-IR (4000-100 cm(-1)) and FT-Raman (4000-100 cm(-1)) spectra of solid sample of 4-chloro-2-fluoro toluene (4Cl2FT) have been recorded using Bruker IFS 66 V spectrometer. Ab initio-HF (HF/6-311++G (d, p)) and DFT (B3LYP/6-311++G and B3PW91/6-311++G (d, p)) calculations have been performed giving energies, optimized structures, harmonic vibrational frequencies, depolarization ratios, IR intensities, Raman activities. The vibrational frequencies are calculated and scaled values are compared with FT-IR and FT-Raman experimental values. The isotropic HF and DFT analyses showed good agreement with experimental observations. The differences between the observed and scaled wave number values of most of the fundamentals are very small in B3LYP than HF. Comparison of the simulated spectra provides important information about the ability of the computational method (B3LYP) to describe the vibrational modes. The influences of substitutions on the geometry of molecule and its normal modes of vibrations have also been discussed. The changes made by substitutions on the benzene are much responsible for the non-linearity of the molecule. This is an attractive entity for the future studies of non-linear optics.
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Govindarajan M, Ganasan K, Periandy S, Karabacak M, Mohan S. Vibrational spectroscopic analysis of 2-chlorotoluene and 2-bromotoluene: a combined experimental and theoretical study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:1005-1013. [PMID: 20869295 DOI: 10.1016/j.saa.2010.08.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Revised: 08/14/2010] [Accepted: 08/24/2010] [Indexed: 05/29/2023]
Abstract
In this work, the vibrational spectral analysis was carried out using Raman and infrared spectroscopy in the range 100-4000 cm(-1) and 50-4000 cm(-1), respectively, for the title molecules. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartee Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wave numbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The effects due to the substitutions of methyl group and halogen bond were investigated. The results of the calculations were applied to simulated spectra of the title compounds, which show excellent agreement with observed spectra.
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Kesavan C, Mohan S. Bone mass gained in response to external loading is preserved for several weeks following cessation of loading in 10 week C57BL/6J mice. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2010; 10:274-280. [PMID: 21116064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE Dynamic loads lead to increases in bone mass. How long these gains are maintained after cessation of loading, however, is not fully understood. METHODS A long term study was performed in which skeletal changes were monitored by pQCT every 2-4 weeks (wks) for a 12 wk period after application of external loading using four-point bending device on 10 wk old female C57BL/6J mice. RESULTS 2 wks of loading caused 15-40% increase in bone parameters (vBMD, cross sectional area (CSA)) and bone strength (yield load, maximum load and toughness). Positive correlations between these two parameters (r= 0.72 to 0.88, p<0.05) suggest that the changes in bone parameters induced by loading are responsible, in part, for the increase in bone strength. Once loading is terminated the bone response did not continue. The vBMD gained by loading was significant for a period of 5 wks and returned to the levels of controls at 12 wks. The CSA though declined but was still significantly elevated at 12 wks. Bone strength showed no difference between loaded and non-loaded bones at 12 wks. CONCLUSION Our results show that external loading increased bone mass, was maintained for several weeks after termination of last loading.
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Mohan S, Lynch S, Cummings TA. Time equals myocardium: are we in time? W INDIAN MED J 2010; 59:680-685. [PMID: 21702242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To determine the door to thrombolysis time of patients who presented to the Adult Priority Care Facility of the Eric Williams Medical Sciences Complex from February 1-May 31, 2008. METHOD The patients who presented to the Adult Priority Care Facility of the Eric Williams Medical Sciences Complex with cardiac type chest pain and ST segment elevation that met the international criteria and had positive troponin test were interviewed and their notes reviewed to obtain the relevant information. RESULTS Fifty-one patients were treated with ST segment elevation myocardial infarctions; 78.4% were thrombolysed. Patients were: 59.75 years old, 68.6% male and 66.7% were of East Indian extraction The average time to thrombolysis was 5 hours and 31 minutes from the onset of chest pain. The average door to thrombolysis time was 2 hours and 7 minutes with 20% of patients having a door to thrombolysis time of 30 minutes. The time to thrombolysis from the onset of chest pain and the door to thrombolysis times were adversely affected by the health facility to which the patient first presented CONCLUSION The majority of patients presented within the thrombolysis window. Early recognition of symptoms of myocardial infarction and arrival at a healthcare facility is not being achieved by the majority of patients. The systems that are responsible for the transport, triage and treatment of patients who present with chest pain are inadequate and require urgent review and overhaul to achieve the goals outlined by the American Heart Association and the American College of Cardiologist.
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Ilhan A, Wagner L, Maj M, Woehrer A, Czech T, Heinzl H, Marosi C, Base W, Preusser M, Jeuken JW, Navis AC, Sijben A, Boots-Sprenger SH, Bleeker FE, Gijtenbeek JM, Wesseling P, Seyed Sadr E, Tessier A, Seyed Sadr M, Alshami J, Anan M, Sabau C, Del Maestro R, Agnihotri S, Gajadhar A, Wolf A, Mischel PM, Hawkins C, Guha A, Guan X, Chance MR, Barnholtz-Sloan JS, Larson JD, Rodriguez FJ, Demer AM, Sarver AL, Dubac A, Jenkins RB, Dupuy AJ, Copeland NG, Jenkins NA, Taylor MD, Largaespada DA, Lusis EA, Stuart JE, Scheck AC, Coons SW, Lal A, Perry A, Gutmann DH, Barnholtz-Sloan JS, Adams MD, Cohen M, Devine K, Wolinsky Y, Bambakidis N, Selman W, Miller R, Sloan AE, Suchorska B, Mehrkens JH, Eigenbrod S, Eroes CA, Tonn JC, Kretzschmar HA, Kreth FW, Buczkowicz P, Bartels U, Morrison A, Zarghooni M, Bouffet E, Hawkins C, Kollmeyer TM, Wrensch M, Decker PA, Xiao Y, Rynearson AL, Fink S, Kosel ML, Johnson DR, Lachance DH, Yang P, Fridley BL, Wiemels J, Wiencke J, Jenkins RB, Zhou YH, Hess KR, Yu L, Raj VR, Liu L, Alfred Yung WK, Hutchins LF, Linskey ME, Roldan G, Kachra R, McIntyre JB, Magliocco A, Easaw J, Hamilton M, Northcott PA, Van Meter T, Eberhart C, Weiss W, Rutka JT, Gupta N, Korshunov A, French P, Kros J, Michiels E, Kloosterhof N, Hauser P, Montange MF, Jouvet A, Bouffet E, Jung S, Kim SK, Wang KC, Cho BK, Di Rocco C, Massimi L, Leonard J, Scheurlen W, Pfister S, Robinson S, Yang SH, Yoo JY, Cho DG, Kim HK, Kim SW, Lee SW, Fink S, Kollmeyer T, Rynearson A, Decker P, Sicotte H, Yang P, Jenkins R, Lai A, Kharbanda S, Tran A, Pope W, Solis O, Peale F, Forrest W, Purjara K, Carrillo J, Pandita A, Ellingson B, Bowers C, Soriano R, Mohan S, Yong W, Aldape K, Mischel P, Liau L, Nghiemphu P, James CD, Prados M, Westphal M, Lamszus K, Cloughesy T, Phillips H, Thon N, Kreth S, Eigenbrod S, Lutz J, Ledderose C, Tonn JC, Kretzschmar H, Kreth FW, Mokhtari K, Ducray F, Kros JM, Gorlia T, Idbaih A, Marie Y, Taphoorn M, Wesseling P, Brandes AA, Hoang-Xuan K, Delattre JY, Van den Bent M, Sanson M, Lavon I, Shahar T, Granit A, Smith Y, Nossek E, Siegal T, Ram Z, Marko NF, Quackenbush J, Weil RJ, Ducray F, Criniere E, Idbaih A, Paris S, Marie Y, Carpentier C, Houillier C, Dieme M, Adam C, Hoang-Xuan K, Delattre JY, Duyckaerts C, Sanson M, Mokhtari K, Zinn PO, Kozono D, Kasper EM, Warnke PC, Chin L, Chen CC, Saito K, Mukasa A, Saito N, Stieber D, Lenkiewicz E, Evers L, Vallar L, Bjerkvig R, Barrett M, Niclou SP, Gorlia T, Brandes A, Stupp R, Rampling R, Fumoleau P, Dittrich C, Campone M, Twelves C, Raymond E, Lacombe D, van den Bent MJ, Potter N, Ashmore S, Karakoula K, Ward S, Suarez-Merino B, Luxsuwong M, Thomas DG, Darling J, Warr T, Gutman DA, Cooper L, Kong J, Chisolm C, Van Meir EG, Saltz JH, Moreno CS, Brat DJ, Brennan CW, Brat DJ, Aldape KD, Cohen M, Lehman NL, McLendon RE, Miller R, Schniederjan M, Vandenberg SR, Weaver K, Phillips S, Pierce L, Christensen B, Smith A, Zheng S, Koestler D, Houseman EA, Marsit CJ, Wiemels JL, Nelson HH, Karagas MR, Wrensch MR, Kelsey KT, Wiencke JK, Al-Nedawi K, Meehan B, Micallef J, Guha A, Rak J. -Omics and Prognostic Markers. Neuro Oncol 2010. [DOI: 10.1093/neuonc/noq116.s8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Fishman RA, Happ E, Stevens T, Kunschner L, Jaworski DM, Stradecki HM, Penar PL, Pendlebury WW, Pennington CJ, Edwards DR, Broaddus WC, Fillmore HL, Mukherjee J, Hawkins C, Guha A, Pioli PD, Milani S, Linskey ME, Zhou YH, Marchetti V, Barnett F, Wang M, Scheppke L, Sanchez-Cespedes J, De Rossi C, Nemerow G, Torbett B, Friedlander M, Goldlust SA, Singer S, DeAngelis LM, Lassman AB, Nolan CP, Yang SH, Lee SW, Chen ZP, Liu XM, Wojton JA, Chu Z, Qi X, Kaur B, Zhou YH, Hu Y, Pioli PD, Siegel E, Ro DI, Marlon S, Hsu N, Milani SN, Mohan S, Yu L, Hess KR, Linskey ME, Liu Y, Carson-Walter E, Walter K, Raghu H, Gondi CS, Gujrati M, Dinh DH, Rao JS, Narayana A, Kunnakkat SD, Medabalmi P, Golfinos J, Parker E, Knopp E, Zagzag D, Gruber D, Gruber ML, Burrell K, Jelveh S, Lindsey P, Hill R, Zadeh G, Ivkovic S, Beadle C, Massey SC, Swanson KR, Canoll P, Rosenfeld SS, McAllister S, Soroceanu L, Pakdel A, Limbad C, Adrados I, Desprez PY, Nakada M, Nambu E, Furuyama N, Yoshida Y, Kita D, Hayashi Y, Hayashi Y, Hamada JI, Seyed Sadr M, Maret D, Seyed Sadr E, Siu V, Alshami J, Denault JS, Faury D, Jabado N, Nantel A, Del Maestro R, Kunnakkat SD, Perretta D, Medabalmi P, Gruber ML, Gruber D, Golfinos J, Parker E, Narayana A, Pioli PD, Linskey ME, Zhou YH, Nagaiah G, Almubarak M, Torres-Trejo A, Newton, M, Willey P, Altaha R, Murphy SF, Banasiak M, Yee GT, Wotoczek-Obadia M, Tran Y, Prak A, Albright R, Mullan M, Paris D, Brem S, Yang YP, Ennis M, Tran N, Symons M, Najbauer J, Huszthy PC, Garcia E, Metz MZ, Gutova M, Frank RT, Miletic H, Glackin CA, Barish ME, Bjerkvig R, Aboody KS, Clump DA, Engh JA, Mintz AH, Cunnick J, Flynn DC, Clark AJ, Butowski NA, Chang SM, Prados MD, Clarke J, Polley MYC, Sughrue ME, McDermott MW, Parsa AT, Berger MS, Aghi MK, Megyesi JF, Costello P, Macdonald W, Dyer E, Macdonald D, Hammond R, Kalache Y, Easaw J, McIntyre J, Williams SC, Karajannis MA, Chiriboga L, von Deimling A, Zagzag D, Ajlan A, Husaine S, Petrecca K, Magnus N, Garnier D, Meehan B, Rak J. Angiogenesis and Invasion. Neuro Oncol 2010. [DOI: 10.1093/neuonc/noq116.s1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Ramalingam S, Periandy S, Mohan S. Vibrational spectroscopy (FTIR and FTRaman) investigation using ab initio (HF) and DFT (B3LYP and B3PW91) analysis on the structure of 2-amino pyridine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:73-81. [PMID: 20627807 DOI: 10.1016/j.saa.2010.04.027] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Revised: 04/21/2010] [Accepted: 04/27/2010] [Indexed: 05/29/2023]
Abstract
The FTIR and FTRaman spectra of 2-amino pyridine (2-AP) molecule have been recorded using Bruker IFS 66 V spectrometer in the range of 4000-100 cm(-1). The molecular geometry and vibrational frequencies in the ground state are calculated by using the ab initio Hartree-Fock (HF) and DFT (B3LYP and B3PW91) methods with 6-31++G (d, p) and 6-311++G (d, p) basis sets. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. Making use of the recorded data, the complete vibrational assignments are made and analysis of the observed fundamental bands of molecule is carried out. The geometries and normal modes of vibrations obtained from ab initio HF and B3LYP/B3PW91 calculations are in good agreement with the experimentally observed data. The differences between the observed and scaled wave number values of most of the fundamentals are very small in B3LYP than HF. The influence of N atom and amine group in the skeletal ring vibrations of the title molecule has also been discussed.
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Nagabalasubramanian PB, Periandy S, Mohan S. Ab initio HF and DFT simulations, FT-IR and FT-Raman vibrational analysis of alpha-chlorotoluene. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:150-159. [PMID: 20537941 DOI: 10.1016/j.saa.2010.04.043] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 03/04/2010] [Accepted: 04/30/2010] [Indexed: 05/29/2023]
Abstract
The FT-IR and FT-Raman vibrational spectra of alpha-chlorotoluene have been recorded using Perkin-Elmer 180 spectrometer in the range 3600-10 cm(-1) in the solid phase. A detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The optimized molecular geometry, vibrational frequencies, atomic charges, dipole moment, rotational constants and several thermodynamic parameters in the ground state were calculated using ab initio Hartree-Fock (HF) and Density Functional B3LYP methods (DFT) with 6-311G(d) and 6-311++G(d) basis sets. With the help of specific scaling procedures, the observed vibrational wavenumbers in FT-IR and FT-Raman spectra were analyzed and assigned to different normal modes of the molecule. Most of the modes have wavenumbers in the expected range. The results of the calculations were applied to simulated infrared and Raman spectra of the title compound which showed excellent agreement with the observed spectra.
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Arjunan V, Saravanan I, Ravindran P, Mohan S. FTIR, FT-Raman, ab initio and density functional studies on 4-methyl-1,3-dioxolan-2-one and 4,5-dichloro-1,3-dioxolan-2-one. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 77:28-35. [PMID: 20605517 DOI: 10.1016/j.saa.2010.04.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2010] [Revised: 04/11/2010] [Accepted: 04/14/2010] [Indexed: 05/29/2023]
Abstract
The Fourier transform infrared (FTIR) and FT-Raman spectra of 4-methyl-1,3-dioxolan-2-one and 4,5-dichloro-1,3-dioxolan-2-one have been recorded in the range 3700-400 and 3700-100 cm(-1), respectively. The complete vibrational assignment and analysis of the fundamental modes of the compounds were carried out using the observed FTIR and FT-Raman data. The vibrational frequencies determined experimentally were compared with those obtained theoretically from ab initio HF and DFT-B3LYP gradient calculations employing 6-311++G** and cc-pVTZ basis sets for the optimised geometries of the compounds. The geometries and normal modes of vibration obtained from the HF and DFT methods are in good agreement with the experimental data. The normal coordinate analysis was also carried out with ab initio force fields utilising Wilson's FG matrix method. The interactions of the skeletal vibrational modes were investigated.
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Thirugnanasambandam P, Mohan S. Molecular Force Field - Some Octahedral XY6 Type Molecules and Ions. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bscb.19750841007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Juneja D, Mohan S, Veturi VV, Gopal PB. Concurrent administration of heparin and activated protein C in a patient with pulmonary embolism and severe sepsis with positive outcome. Indian J Crit Care Med 2010; 13:163-6. [PMID: 20040816 PMCID: PMC2823100 DOI: 10.4103/0972-5229.58544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Results of the PROWESS trial suggested that heparin may reduce the efficacy of recombinant human activated protein C (rhAPC) and the XPRESS study also showed increased bleeding complications in patients receiving heparin with rhAPC. Although it has been shown that heparin prophylaxis may be used along with rhAPC, no study has shown the interaction between continuous heparin infusion and rhAPC. Here, we report a case of severe sepsis with pulmonary embolism who was concurrently administered heparin and rhAPC infusions, with positive results and no bleeding complications.
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Arif S, Maher AR, Ormerod JOM, Mohan S, Madhani M, Frenneaux MP. 060 The acute haemodynamic effects of intravenous sodium nitrite in healthy volunteers during normoxia and hypoxia. BRITISH HEART JOURNAL 2010. [DOI: 10.1136/hrt.2010.195966.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Mohan S, Verma A, Lim C, Hui F, Kumar S. Lipid Resonance on In Vivo Proton MR Spectroscopy: Value of other Metabolites in Differential Diagnosis. Neuroradiol J 2010; 23:269-78. [DOI: 10.1177/197140091002300302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 01/30/2010] [Indexed: 11/17/2022] Open
Abstract
In vivo proton MR spectroscopy (1H-MRS) can non-invasively provide biochemical information at the same examination as conventional magnetic resonance imaging (MRI). Lipid resonance (0.9–1.5 ppm) is a marker of cell membrane breakdown and tissue necrosis, but its diagnostic significance has not been well described. We retrospectively analyzed spectra to study the different pathological conditions in patients with abnormal lipid resonance. All patients with neurological diseases showing lipid resonance on 1H-MRS (1.5T) in a tertiary hospital over two years were retrospectively analyzed. 1H-MRS was performed using the single voxel PRESS technique (TR/TE=3000/144 ms, eight excitations). Spectra were analysed for the presence of NAA (2.0 ppm), creatine (3.0 ppm), choline (3.2 ppm), acetate (1.92 ppm), succinate (2.4 ppm), cytosolic amino acids (0.9 ppm), lactate (1.3 ppm) and lipid (0.9–1.5 ppm) peaks. Ninety-two spectra from 69 patients (38 males, 31 females; aged 9 to 89 years) were analyzed. The final diagnosis was infective (n = 33), (tuberculoma n = 17, pyogenic abscess n = 8, fungal abscess n = 3, sterile abscess n = 3, tubercular abscess n = 2), neoplastic (n = 21) (glial tumors n = 9, metastasis n = 8, lymphoma n = 4), and other (n = 15) abnormalities (subacute and chronic stroke n = 6, postictal edema n = 4, multiple sclerosis n = 2, Erdhiem Chester disease n ? 2, Rosai Dorfmann disease n = 1). Succinate and acetate were detected only in pyogenic abscesses (2/4 cases), but amino acids were present in both pyogenic (4/8) and fungal (3/3) abscesses. Choline was seen not only in neoplasms (18) but also in tuberculomas (11/17), but was consistently absent in the abscesses. Lactate was present in glioblastoma (7/9), pyogenic (3/8) tubercular (2/2) and fungal (3/3) abscess. Isolated lipid resonance was found in Erdheim Chester disease (2/2) of the orbit, and lipid and choline was seen in Rosai Dorfmann's disease (1/1). Brain lesions containing lipid on 1H-MRS could be differentiated by the presence of succinate and acetate in pyogenic abscess, and amino acids in pyogenic/fungal abscesses. Choline was seen in neoplasms and in tuberculomas, but not in the abscesses. Thus, the presence of a lipid peak, when combined with features on other MR pulse sequences and available clinical data can help arrive at a specific diagnosis. 1H-MRS should not be interpreted in isolation: it should always be correlated with conventional imaging features, and performing 1H-MRS in isolation remains an important pitfall.
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Govindarajan M, Ganasan K, Periandy S, Mohan S. DFT (LSDA, B3LYP and B3PW91) comparative vibrational spectroscopic analysis of alpha-acetonaphthone. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 76:12-21. [PMID: 20308014 DOI: 10.1016/j.saa.2010.02.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 02/06/2010] [Accepted: 02/16/2010] [Indexed: 05/29/2023]
Abstract
FT-IR and FT-Raman spectra of alpha-acetonaphthone have been recorded and analyzed. The geometry, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) B3PW91/6-311G method and also a comparative studies between different levels and various basis sets combination. The scaled B3PW91/6-11G results are best, even though LSDA/6-311G wavenumbers are well in agreement before scaling. The complete vibrational assignments of wavenumbers are made on the basis of potential energy distribution (PED). The effects due to the substitutions of methyl group and carbon-oxygen bond are investigated. The results of the calculations are applied to simulated spectra of the title compound, which shows excellent agreement with observed spectra.
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Ramalingam S, Periandy S, Narayanan B, Mohan S. FTIR and FTRaman spectroscopic investigation of 2-bromo-4-methylaniline using ab initio HF and DFT calculations. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 76:84-92. [PMID: 20335064 DOI: 10.1016/j.saa.2010.02.050] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 02/17/2010] [Accepted: 02/26/2010] [Indexed: 05/29/2023]
Abstract
The FTIR and FTRaman spectra of 2-bromo-4-methyl aniline (2-B-4-MA) molecule have been recorded using Brucker IFS 66V spectrometer in the range of 4000-100 cm(-1). The molecular geometry and vibrational frequencies in the ground state are calculated using the Hartree-Fock (HF) and B3LYP with 6-31+G*(d, p), 6-311+G*(d, p) and 6-311++G* (d, p) basis sets. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The isotropic HF and DFT analysis showed good agreement with experimental observations. Comparison of the fundamental vibrational frequencies with calculated results by HF and B3LYP methods indicates that B3LYP/6-311++G* (d, p) is superior to HF/6-31+G* for molecular vibrational problems. The complete data of this title compound provide the information for future development of substituted aniline. The influences of bromine atom, methyl group and amine group on the geometry of benzene and its normal modes of vibrations have also been discussed.
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Juneja D, Prabhu MV, Gopal PB, Mohan S, Sridhar G, Nayak KS. Outcome of patients with end stage renal disease admitted to an intensive care unit in India. Ren Fail 2010; 32:69-73. [PMID: 20113269 DOI: 10.3109/08860220903367502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS We sought to determine outcome and evaluate performance of Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores upon admission in predicting 30-day mortality of end-stage renal disease (ESRD) patients admitted in ICU. METHODS This prospective observational cohort study examined 73 consecutive ESRD patients admitted in an ICU of a tertiary care institute over 15 months. Primary outcome measure was 30-day mortality. Data on patient characteristics, reason for ICU admission, cause of ESRD, mode of renal replacement, and use of mechanical ventilation (MV) or inotropes were recorded. The APACHE 2 and SOFA scores were calculated based on admission characteristics. RESULTS First-day median APACHE II, SOFA, and APACHE II-predicted hospital mortality rates were 26 (14-49), 7 (4-17), and 56.9% (18.6-97.4%), respectively. Observed ICU and 30-day mortality rates were 27.4%, and 41.1%, respectively. During the ICU course, MV and inotropic support was required in 27 (37%) and 23 (35.1%) patients, respectively. Need for MV (p < 0.001) and inotropic support (p < 0.001) were predictors of 30-day mortality in univariate analysis. Area under receiver operating characteristic curve for APACHE II in predicting 30-day mortality was 0.86 (95% CI, 0.76-0.93) compared with 0.92 (95% CI, 0.83-0.97) for SOFA score (p = 0.16). CONCLUSIONS Outcome of ESRD patients admitted to ICU is poor, especially if they require other organ support. APACHE II and SOFA scores perform well as predictors of 30-day mortality.
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Ramalingam S, Periandy S, Govindarajan M, Mohan S. FT-IR and FT-Raman vibrational spectra and molecular structure investigation of nicotinamide: A combined experimental and theoretical study. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 75:1552-1558. [PMID: 20227335 DOI: 10.1016/j.saa.2010.02.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Revised: 02/05/2010] [Accepted: 02/15/2010] [Indexed: 05/28/2023]
Abstract
In this work, the experimental and theoretical spectra of nicotinamide (C(6)H(6)N(2)O) are studied. FT-IR and FT-Raman spectra of title molecule in the liquid phase have been recorded in the region 4000-100cm(-1). The structural and spectroscopic data of the molecule in the ground state have been calculated by using Hartree-Fock and density functional method (B3LYP) with the 6-31+G*(d, p) and 6-31++G* (d, p)basis set. The vibrational frequencies have been calculated and scaled values have been compared with the experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found in good agreement. The DFT-B3LYP/6-31++G (d, p) calculations have been found are more reliable than the ab initio HF/6-31+G (d, p) calculations for the vibrational study of nicotinamide. The optimized geometric parameters (bond lengths and bond angles) are compared with experimental values of the molecule. The alteration of vibrational bands due to the substitutions in the base molecule is also investigated from their characteristic region of linked spectrum.
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Ramalingam S, Periandy S, Govindarajan M, Mohan S. FTIR and FTRaman spectra, assignments, ab initio HF and DFT analysis of 4-nitrotoluene. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 75:1308-1314. [PMID: 20133182 DOI: 10.1016/j.saa.2009.12.072] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2009] [Revised: 12/29/2009] [Accepted: 12/31/2009] [Indexed: 05/28/2023]
Abstract
In this work, the experimental and theoretical study on molecular structure and vibrational spectra of 4-nitrotoluene are studied. The FTIR and FTRaman experimental spectra of the molecule have been recorded in the range of 4000-100 cm(-1). Making use of the recorded data, the complete vibrational assignments are made and analysis of the observed fundamental bands of molecule is carried out. The experimental determinations of vibrational frequencies are compared with those obtained theoretically from ab initio HF and DFT quantum mechanical calculations using HF/6-31G (d, p), B3LYP/6-31++G* (d, p) and B3LYP/6-311++G* (d, p) methods. The differences between the observed and scaled wave number values of most of the fundamentals are very small in B3LYP than HF. The geometries and normal modes of vibrations obtained from ab initio HF and B3LYP calculations are in good agreement with the experimentally observed data. Comparison of the simulated spectra provides important information about the ability of the computational method (B3LYP) to describe the vibrational modes. The vibrations of NO(2) and CH(3) groups coupled with skeletal vibrations are also investigated.
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Agarwala R, Da-Rocha D, Mohan S, Anderson H, Clarke A, Fergus I, Pogue V, Cheng J. 8: Prevalence of Pulmonary Hypertension in Patients With High Fistula Flow Rates. Am J Kidney Dis 2010. [DOI: 10.1053/j.ajkd.2010.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Mauchline TH, Mohan S, Davies KG, Schaff JE, Opperman CH, Kerry BR, Hirsch PR. A method for release and multiple strand amplification of small quantities of DNA from endospores of the fastidious bacterium Pasteuria penetrans. Lett Appl Microbiol 2010; 50:515-21. [PMID: 20302597 DOI: 10.1111/j.1472-765x.2010.02830.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To establish a reliable protocol to extract DNA from Pasteuria penetrans endospores for use as template in multiple strand amplification, thus providing sufficient material for genetic analyses. To develop a highly sensitive PCR-based diagnostic tool for P. penetrans. METHODS AND RESULTS An optimized method to decontaminate endospores, release and purify DNA enabled multiple strand amplification. DNA purity was assessed by cloning and sequencing gyrB and 16S rRNA gene fragments obtained from PCR using generic primers. Samples indicated to be 100%P. penetrans by the gyrB assay were estimated at 46% using the 16S rRNA gene. No bias was detected on cloning and sequencing 12 housekeeping and sporulation gene fragments from amplified DNA. The detection limit by PCR with Pasteuria-specific 16S rRNA gene primers following multiple strand amplification of DNA extracted using the method was a single endospore. CONCLUSIONS Generation of large quantities DNA will facilitate genomic sequencing of P. penetrans. Apparent differences in sample purity are explained by variations in 16S rRNA gene copy number in Eubacteria leading to exaggerated estimations of sample contamination. Detection of single endospores will facilitate investigations of P. penetrans molecular ecology. SIGNIFICANCE AND IMPACT OF THE STUDY These methods will advance studies on P. penetrans and facilitate research on other obligate and fastidious micro-organisms where it is currently impractical to obtain DNA in sufficient quantity and quality.
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Vishwas M, Sharma SK, Rao KN, Mohan S, Gowda KVA, Chakradhar RPS. Influence of surfactant and annealing temperature on optical properties of sol-gel derived nano-crystalline TiO2 thin films. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 75:1073-1077. [PMID: 20071216 DOI: 10.1016/j.saa.2009.12.057] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 12/12/2009] [Accepted: 12/17/2009] [Indexed: 05/28/2023]
Abstract
Titanium dioxide thin films have been synthesized by sol-gel spin coating technique on glass and silicon substrates with and without surfactant polyethylene glycol (PEG). XRD and SEM results confirm the presence of nano-crystalline (anatase) phase at an annealing temperature of 300 degrees C. The influence of surfactant and annealing temperature on optical properties of TiO(2) thin films has been studied. Optical constants and film thickness were estimated by Swanepoel's (envelope) method and by ellipsometric measurements in the visible spectral range. The optical transmittance and reflectance were found to decrease with an increase in PEG percentage. Refractive index of the films decreased and film thickness increased with the increase in percentage of surfactant. The refractive index of the un-doped TiO(2) films was estimated at different annealing temperatures and it has increased with the increasing annealing temperature. The optical band gap of pure TiO(2) films was estimated by Tauc's method at different annealing temperature.
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Mohan S, Overman R, Dean R, Smith S, Kalaycio M, Pohlman B, Sweetenham J, Sobecks R, Andresen S, Copelan E, Bolwell B. Readmission Rates After Autologous Hematopoietic Stem Cell Transplantation. Biol Blood Marrow Transplant 2010. [DOI: 10.1016/j.bbmt.2009.12.165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Tamfu R, Natarajan A, Yu H, Mohan S, Shanmugasundaram K, Natarajan M, Natarajan M, Natarajan M. Radiation-Induced S-Nitrosylation of ER-α Predisposes MCF-7 Breast Cancer Cells to Aggressive Invasion and Migration. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-09-6162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The objective of this study is to decipher the potentials of breast cancer cells that survive radiation exposure at clinical doses to acquire invasive and metastatic determinants. In this study we exposed estrogen receptor positive (MCF-7) and negative (MDAMB-231) breast cancer cells to clinical doses of low LET radiation including doses used as single fraction (2Gy), cumulative dose (10Gy) and scattered dose (10cGy). The cells were exposed to 137Cs source at a dose rate of 1.27 Gy/min. The mock irradiated cells were used as controls. The mRNA transcript level, protein expression and protein-protein interaction were analyzed by QPCR/RT-PCR, immunoblotting, immunoprecipitation and mammalian two-hybrid system, respectively. Intracellular nitric oxide (NO) levels were determined by immunofluorescence and electron spin resonance spectroscopy (ESR) using DAF-FM and Fe-MGD as NO traps, respectively. NO-dependent ER-α s-nitrosylation was determined through immunoprecipitating s-nitrosylated proteins from the cell lysates with an s-nitrosylated-cysteine IgG antibody followed by ER-α western blot analysis. Transactivation of ER-α was measured by EMSA and luciferase reporter assay. Cell invasion and migration were examined by co-culture system using thin inserts.Radiation induces eNOS expression and activation through the phosphorylation of eNOS at Ser1177 site resulting in increased bioavailability of NO in a dose- and time-dependent manner. The three-fold bioavailability of NO s-nitrosylates ER-α leading to a two-fold binding of ER-α to ERE. Paradoxically, this binding did not translate into the transcriptional activation of ER-α dependent gene regulation. Altered structure due to s-nitrosylation of ER-α contributes to enhanced cell invasion and cell migration. In consistent with these results, there was an associated 2.3-fold increase in the expression of MMP-2 and MMP-9 and corresponding TIMP-1 decreased expression leading to a 3.5-fold increase in MMP activity. Radiation, while controlling tumor growth, could simultaneously play a significant role in breast cancer relapse and metastasis through the activation of eNOS and the generation of NO. The bioavailability of NO s-nitrosylates ER-α leading to re-defining the genomic functions of ER-α and thereby impart metastatic transformation potentials to ER-α positive breast cancer cells.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6162.
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Yu H, Tamfu R, Mohan S, Natarajan M. Low LET Radiation-Induced Abscopal Effect and Tumor Recurrence: Nuclear Factor Kappa B (NF-κB) and Tumor Necrosis Factor alpha (TNF-α) Mediated Positive Feedback Mechanism. Cancer Res 2009. [DOI: 10.1158/0008-5472.sabcs-09-2149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The overall objective is to determine whether the surviving cancer cell after radiotherapy can initiate bystander response that result in clonal selection and tumor recurrence at the treatment site. We have two kinds of cell lines: human breast adenocarcinoma cells (MCF-7) and human aortic endothelism cells. First, in the MCF-7 cells we examined whether a bystander effect is initiated by TNF-a through activation of NF-kB which in-turn is triggered by therapeutic doses of radiation exposure, and also whether TNF-a and NF-kB can induce one another through positive feed back mechanisms and maintain a “memory” of the initial irradiation insult for an extended period. Second, between the MCF-7 and HAEC, we demonstrated whether radiation can induce the VEGF secreted by MCF-7, and concordant expression of the VEGFR in the bystander HAEC. MCF-7 cells were exposed to 137Cs γ ray to a total dose of 2 Gy at a dose rate of 1.06 Gy/min. Both NF-κB DNA-binding activity and the transcriptional activation measured by mobility shift assay and luciferase reporter assay, respectively showed radiation could induce nuclear translocation and transactivate κB-dependent gene expression. The activation was found to be bi-phasic, reached its maximum at 15 min (4.7-folds), decreased to basal level at 16 h, and reached a second phase maximum at 24 h (2.6-folds). Similarly, the levels of TNF-α determined by bioactivity assay revealed a 40% increase in soluble TNF-α in the culture supernatant upon 2 Gy exposure. Incubation of MCF-7 cells with either NF-κB inhibitor isohelenin or TNF-α neutralizing antibody blocked the presence of soluble TNF-α in the culture supernatant and second phase NF-κB activation, respectively. These results clearly indicated the occurrence of positive feed-back cycle between NF-κB and TNF-α through autocrine mechanism. In order to determine the occurrence of a similar mechanism in the non-irradiated bystander MCF-7 cells, supernatant from cells exposed to 2 Gy was added into the non-irradiated cells, and the NF-κB activity of non-irradiated MCF-7 cells increased by 7.2-folds. Next, to examine whether TNF-α is the paracrine signaling mediator in this bystander effect, un-irradiated MCF-7 cells, transiently transfected with NF-κB-luciferase reporter construct, was incubated with the conditioned medium from 2 Gy exposed cells in the presence or absence of TNF-α antibody. The luciferase activity showed a 60% increase in the un-irradiated MCF-7 cells when incubated with medium from irradiated cells in the absence of TNF-α antibody. Molecular analysis of specific angiogensis markers using hAngio-1 probe as a positive control was performed using ribonuclease protection assay. Of the angiogenic RNA molecules identified, the MCF-7 cells expressed VEGF and FGF-2, and the westernblot also showed the VEGF ligand and FGF-2 secreted by MCF-7 incresed by 3.4-folds and 2.6-folds separately after 2Gy exposure. We also co-cultured the irradiated MCF-7 cells with the non-irradiated HAEC, and found VEGFR2 and FGFR1 had corcondant expression increse in HAEC. This mechanism may be responsible for the stimulation of proliferative response, tumor-cell re-growth and subsequent tumor relapse at the treatment site.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2149.
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Nagabalasubramanian PB, Periandy S, Mohan S. A scaled quantum mechanical approach of vibrational analysis of o-tolunitrile based on FTIR and FT Raman spectra, ab initio, Hartree Fock and DFT methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:1280-1287. [PMID: 19875327 DOI: 10.1016/j.saa.2009.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2009] [Revised: 09/02/2009] [Accepted: 10/03/2009] [Indexed: 05/28/2023]
Abstract
The FTIR and FT Raman vibrational spectra of o-tolunitrile have been recorded using Perkin-Elmer 180 Spectrometer in the range 3100-100 cm(-1). A detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The optimized geometrical parameters, force constants, true rotational constants, rotational temperatures, Potential Energy Distribution (PED) and fundamental vibrational frequencies of the title compound were evaluated using Hartree Fock and Density Functional B3LYP methods with 6-31G(d) basis sets. The vibrational harmonic frequencies were scaled using scale factor which yielded a good agreement between observed and calculated frequencies. With hope of providing more and effective information on the fundamental vibrations, a normal co-ordinate analysis has been performed by assuming C(s) point group symmetry. The results of the calculations were applied to simulated Infrared and Raman spectra of the title compound which showed excellent agreement with the observed spectra.
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Arjunan V, Mohan S, Balamourougane PS, Ravindran P. Quantum chemical and spectroscopic investigations of 5-aminoquinoline. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:1215-1223. [PMID: 19854675 DOI: 10.1016/j.saa.2009.09.039] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2009] [Revised: 09/05/2009] [Accepted: 09/24/2009] [Indexed: 05/28/2023]
Abstract
The Fourier transform infrared (FTIR) and FT-Raman spectra of 5-aminoquinoline (5AQ) have been recorded in the range 4000-400 and 3500-100 cm(-1), respectively. The complete vibrational assignment and analysis of the fundamental modes of the compounds were carried out using the observed FTIR and FT-Raman data. (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by using the gauge independent atomic orbital (GIAO) method. UV-vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The geometric parameters, chemical shifts and absorption wavelengths were compared with the experimental data of the molecule. The vibrational frequencies which were determined experimentally are compared with those obtained theoretically from ab initio HF and DFT-B3LYP gradient calculations employing the 6-31G** and 6-311++G** basis sets for optimized geometries of the compound. The interactions of NH-pi and the influence of amino group on the skeletal modes are investigated.
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Kanthamani S, Mohan S, Raju S, Abhaikumar V, Mohan V. Meshless Analysis of Radio Frequency Microelectromechanical Systems Shunt Switch. DEFENCE SCI J 2009. [DOI: 10.14429/dsj.59.1567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wittrant Y, Gorin Y, Mohan S, Wagner B, Abboud-Werner SL. Colony-stimulating factor-1 (CSF-1) directly inhibits receptor activator of nuclear factor-{kappa}B ligand (RANKL) expression by osteoblasts. Endocrinology 2009; 150:4977-88. [PMID: 19819976 PMCID: PMC2775986 DOI: 10.1210/en.2009-0248] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Colony-stimulating factor-1 (CSF-1), released by osteoblasts, stimulates the proliferation of osteoclast progenitors via the c-fms receptor (CSF-1R) and, in combination with receptor activator of nuclear factor-kappaB ligand (RANKL), leads to the formation of mature osteoclasts. Whether the CSF-1R is expressed by osteoblasts and mediates specific biological effects in osteoblasts has not been explored. Wild-type primary calvaria osteoblasts (OB) were analyzed for CSF-1R expression (RT-PCR and Western blot) and functionality (immunocomplex kinase assay). OB were serum starved for 24 h, and the effect of CSF-1 (0-100 ng/ml) on OB biological activities was determined at 48 h. In wild-type mouse bone marrow cultures, CSF-1 was tested for its effect on RANKL mRNA and osteoclast formation. Because ROS influence osteoblast RANKL expression, studies analyzed the effect of CSF-1 on reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and Nox1 and Nox4 proteins. Results indicate that OB express CSF-1R mRNA and protein and that CSF-1R could be phosphorylated in the presence of CSF-1. In osteoblasts, CSF-1 decreased RANKL mRNA in a dose- and time-dependent manner. Incubation of bone marrow cultures with CSF-1 resulted in a significant decline in tartrate-resistant acid phosphatase (TRACP) activity and CTR expression. RANKL-decreased expression by CSF-1 was correlated with a decrease of NADPH oxidase activity as well as Nox1 and Nox4 protein levels. These findings provide the first evidence that osteoblasts express CSF-1R and are a target for CSF-1 ligand. CSF-1-mediated inhibition of RANKL expression on osteoblasts may provide an important mechanism for coupling bone formation/resorption and preventing excessive osteoclastogenesis during normal skeletal growth.
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Arjunan V, Ravindran P, Subhalakshmi K, Mohan S. Synthesis, structural, vibrational and quantum chemical investigations of N-(2-methylphenyl)-2,2-dichloroacetamide and N-(4-methylphenyl)-2,2-dichloroacetamide. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:607-616. [PMID: 19647479 DOI: 10.1016/j.saa.2009.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 06/25/2009] [Accepted: 07/07/2009] [Indexed: 05/28/2023]
Abstract
N-(2-Methylphenyl)-2,2-dichloroacetamide (2MPA) and N-(4-methylphenyl)-2,2-dichloroacetamide (4MPA) of the configuration X(y)C(6)H(5-y)-NHCO-CHCl(2) (where, X=CH(3) and y=1) were synthesised and an extensive spectroscopic investigations have been carried out by recording the Fourier transform infrared (FTIR) and FT-Raman spectra and subjecting them to normal co-ordinate analysis, in an effort to provide mixing of the fundamental modes with the help of potential energy distribution (PED). The ab initio and DFT studies were carried out with 6-311++G(d,p) basis set to determine the structural, thermodynamical and vibrational characteristics of the compounds and also to understand the steric influence of methyl group on the characteristic frequencies of amide (-CONH-) group.
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Vishwas M, Sharma SK, Narasimha Rao K, Mohan S, Gowda KVA, Chakradhar RPS. Optical, dielectric and morphological studies of sol-gel derived nanocrystalline TiO2 films. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:839-842. [PMID: 19717333 DOI: 10.1016/j.saa.2009.07.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/03/2009] [Accepted: 07/29/2009] [Indexed: 05/28/2023]
Abstract
Nanocrystalline TiO(2) films have been synthesized on glass and silicon substrates by sol-gel technique. The films have been characterized with optical reflectance/transmittance in the wavelength range 300-1000 nm and the optical constants (n, k) were estimated by using envelope technique as well as spectroscopic ellipsometry. Morphological studies have been carried out using atomic force microscope (AFM). Metal-Oxide-Silicon (MOS) capacitor was fabricated using conducting coating on TiO(2) film deposited on silicon. The C-V measurements show that the film annealed at 300 degrees C has a dielectric constant of 19.80. The high percentage of transmittance, low surface roughness and high dielectric constant suggests that it can be used as an efficient anti-reflection coating on silicon and other optical coating applications and also as a MOS capacitor.
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Arjunan V, Balamourougane PS, Saravanan I, Mohan S. Investigation of the structural and harmonic vibrational properties of 2-nitro-, 4-nitro- and 5-nitro-m-xylene by ab initio and density functional theory. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:798-807. [PMID: 19716338 DOI: 10.1016/j.saa.2009.08.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2009] [Revised: 07/13/2009] [Accepted: 08/07/2009] [Indexed: 05/28/2023]
Abstract
The Fourier transform infrared (FTIR) and FT-Raman spectra of 2-nitro-m-xylene (2NMX), 4-nitro-m-xylene (4NMX) and 5-nitro-m-xylene (5NMX) have been recorded in the range 4000-400 and 4000-100 cm(-1), respectively. The experimental vibrational frequency was compared with that obtained theoretically by ab initio HF and DFT-B3LYP gradient calculations employing the standard 6-31G(d,p) basis set for the optimised geometries of the compounds. The complete vibrational assignment, analysis and correlation of the fundamental modes of the compounds were carried out using the experimental FTIR and FT-Raman data, and ab initio and DFT quantum chemical studies. The geometrical parameters and the wavenumbers of normal modes of vibration obtained from the HF and DFT methods are in good agreement with the experimental values. The potential energy distribution of the fundamental modes was calculated with ab initio force fields utilising Wilson's FG matrix method. The influence of bulky methyl groups on the nitro group fundamental modes and on the ring skeletal vibrations are investigated.
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Arjunan V, Saravanan I, Ravindran P, Mohan S. Structural, vibrational and DFT studies on 2-chloro-1H-isoindole-1,3(2H)-dione and 2-methyl-1H-isoindole-1,3(2H)-dione. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2009; 74:642-649. [PMID: 19660980 DOI: 10.1016/j.saa.2009.07.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 07/02/2009] [Accepted: 07/07/2009] [Indexed: 05/28/2023]
Abstract
The Fourier transform infrared (FTIR) and FT-Raman spectra of 2-chloro-1H-isoindole-1,3(2H)-dione and 2-methyl-1H-isoindole-1,3(2H)-dione have been measured in the range of 4000-400 and 4000-100 cm(-1), respectively. Complete vibrational assignment and analysis of the fundamental modes of the compounds were performed using the observed FTIR and FT-Raman data. The geometry was optimised without any symmetry constraints using the DFT/B3LYP method with 6-31G(d,p) and 6-311++G(d,p) basis sets. The vibrational frequencies determined experimentally are compared with those obtained theoretically from DFT gradient calculations employing the B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p) methods for the optimised geometry of the compounds. The structural parameters and normal modes of vibration obtained from DFT method are in good agreement with the experimental data. The force fields obtained from DFT method were utilised and the potential energy distributions of all the fundamental vibrations of the compounds were calculated.
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