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Rawat P, Nambiar S, Venkatachalam P, Singh R, Kumar Selvaraja S. Embedded silicon gratings for high-efficiency light-chip coupling to thin film silicon nitride waveguides. Opt Express 2023; 31:29392-29402. [PMID: 37710740 DOI: 10.1364/oe.488999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 06/11/2023] [Indexed: 09/16/2023]
Abstract
Thin film silicon nitride (<150 nm) waveguide has emerged as a dominant ultra-low-loss platform for many loss-critical applications. While thin-film silicon nitride propagation loss is a crucial characteristic, coupling light between an optical fiber and the waveguide is still challenging. While the larger mode size of the decoupled thin waveguide offers better coupling than a highly-confined waveguide, the coupling efficiency is still sub-optimal. The poor diffraction efficiency of such thin films limits the scope of implementing standalone surface gratings. We demonstrate an efficient way to couple into thin film silicon nitride waveguides using amorphous silicon strip gratings. The high contrast gratings provide an efficient means to boost the directionality from thin films leading to an enhanced coupling performance. In addition, we incorporate a bottom reflector to further improve the coupling. We present an optimal design for uniform strip gratings with a maximum coupling efficiency of -1.7 dB/coupler. We achieved a maximum coupling efficiency of -0.28 dB/coupler by engineering the scattering strength along the grating through apodization. We have experimentally shown the highest coupling efficiency reported yet of -2.22 dB/coupler and -1.84 dB/coupler for uniform and apodized grating couplers in the C-L band. We present a detailed design strategy, simulation, fabrication and characterization data on the effect of various parameters on the coupling efficiency.
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Rout D, Venkatachalam P, Singh R, Shree Lakshmi P, Selvaraja SK. Guided mode resonance aided polarization insensitive in-plane spectral filters for an on-chip spectrometer. Opt Lett 2022; 47:4704-4707. [PMID: 36107068 DOI: 10.1364/ol.471355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/19/2022] [Indexed: 06/15/2023]
Abstract
We demonstrate an on-chip in-plane polarization independent multi-spectral color filter in the visible to near-infrared wavelength band. We experimentally show a four-channel transmission and in-plane spectral filter characteristics spanning a 400-nm spectral range. Engineered 2D guided mode resonance structures in a silicon nitride-on-sapphire substrate are used to realize the filters. The in-plane color filters could provide the necessary impetus for developing robust integrated photonic platforms for on-chip devices and applications.
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Mamidi S, Mohapatra P, Bhuniya S, Majumdar S, Mishra P, Panigrahi M, Bal S, Datta A, Venkatachalam P, Chatterjee D, Sarkar S, Shirgaonkar R, Girija A, Ghosh S, Padmaja M, Acharyulu V, Durgeshwar G. EP08.04-004 Impact of Comorbidity Scores on Overall Survival in Advanced Non-Small Cell Lung Cancer Patients -A Real-World Experience from Eastern India. J Thorac Oncol 2022. [DOI: 10.1016/j.jtho.2022.07.869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Meenakshi C, Venkatachalam P, Satish Srinivas K, Chandrasekaran S, Venkatraman B. Chromosome length ratio as a biomarker of DNA damage in cells exposed to high dose ionizing radiation. Mutat Res Genet Toxicol Environ Mutagen 2022; 879-880:503501. [PMID: 35914861 DOI: 10.1016/j.mrgentox.2022.503501] [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: 06/23/2021] [Revised: 04/28/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023]
Abstract
The premature chromosome condensation (PCC) assay is considered as complementary bio-dosimetry tool for chromosome aberration assay and the PCC assay can be used to estimate high dose exposure. Though the PCC ring is considered as prospective biomarker, chromosome length ratio (ratio of longest and shortest chromosome length in PCC spreads) of chemically induced PCC is shown to be very good indicator of ionizing radiation. In view of this, an in-vitro study has been performed using PCC assay to suggest chromosome length ratio (LR) as potential bio-dosimeter induced by high dose ionizing radiation. Blood samples were collected from healthy subjects (n = 3) after prior consent and irradiated to ten different doses ranging between 0 and 20 Gy using 6 MV LINAC X-rays with dose rate of 5.6 Gy/min. Irradiated lymphocytes were cultured and calyculin induced PCC spreads were prepared. PCC spreads were captured using image analysis system and chromosome lengths were measured using open-source ImageJ software. For each dose, LR for 50 chromosome spreads were computed and mean LR value was calculated. LR varies between 6.0 ± 0.08 and 23.6 ± 0.55 for the dose range between 2 and 20 Gy. The dose response curve for LR was observed to be linear with y = 1.02x + 3.36, R2 = 0.97. Linear dose response relationship obtained in the present study confirms the prospective use of LR measurement. This study is first of its kind to examine chromosome length ratio as a biomarker of DNA damage in cells exposed to high dose X-ray exposure.
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Affiliation(s)
- C Meenakshi
- Human Genetics Department, Sri Ramachandra Institute of Higher Education and Research, Chennai 600116, India.
| | - P Venkatachalam
- Human Genetics Department, Sri Ramachandra Institute of Higher Education and Research, Chennai 600116, India
| | - K Satish Srinivas
- Department of Radiation Oncology, Sri Ramachandra Institute of Higher Education and Research, Chennai 600116, India
| | - S Chandrasekaran
- Health, Safety and Environmental Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
| | - B Venkatraman
- Health, Safety and Environmental Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102, India
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Meenakshi C, Venkatachalam P, Chandrasekaran S, Venkatraman B. Construction of dose response curve for 6 MV LINAC X-rays using Premature Chromosome Condensation assay for radiation dosimetry. Appl Radiat Isot 2021; 173:109729. [PMID: 33906115 DOI: 10.1016/j.apradiso.2021.109729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 03/28/2021] [Accepted: 04/09/2021] [Indexed: 10/21/2022]
Abstract
Quantification of chromosomal aberrations in the exposed personnel blood samples is considered as a 'gold standard' and sensitive biomarker in biological dosimetry. Despite technological developments, culture of cells for 48-52 h remains an unmet need in case of triage biodosimetry. Moreover, it is difficult to get sufficient number of metaphase spreads for scoring after high doses of exposures. The technique which causes condensation of chromatin before mitosis using biological or chemical agent is named as Premature Chromosome Condensation (PCC) assay. This assay is considered as an alternative to chromosome aberration assay, particularly at high acute doses of low and high LET radiation. To establish the PCC assay, blood samples were collected from healthy non-smoking individuals (n = 3) and exposed to various doses (0-20 Gy) of 6 MV X-rays at a dose rate of 5.6 Gy/min, using a high energy Linear accelerator (LINAC). Irradiated blood samples were subjected to Calyculin-A induced PCC. About 500 cells or more than 100 Ring Chromosomes (RC) were scored at each dose. Dicentric chromosomes (DC) and acentric fragments were also scored at each dose; the number of chromosomal aberrations in G1, M, G2/M and M/A phase of cell cycle were recorded and the frequency was used to construct the dose response curve. A dose dependent increase in RC and DC frequency were observed with a slope of 0.049 ± 0.002 and 0.30 ± 0.02 respectively. This study is first of its kind to construct a dose response curve for LINAC X-rays using a PCC assay.
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Affiliation(s)
- C Meenakshi
- Human Genetics Department, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamilnadu, India
| | - P Venkatachalam
- Human Genetics Department, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamilnadu, India.
| | - S Chandrasekaran
- Health, Safety and Environmental Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu, India
| | - B Venkatraman
- Health, Safety and Environmental Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu, India
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Sowmya M, Jinu U, Sarathikannan D, Geetha N, Girija S, Venkatachalam P. Effect of silver nitrate and growth regulators on direct shoot organogenesis and in vitro flowering from internodal segment explants of Alternanthera sessilis L. Biocatalysis and Agricultural Biotechnology 2020. [DOI: 10.1016/j.bcab.2020.101855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Kanagaraj K, Rajan V, Pandey BN, Thayalan K, Venkatachalam P. Primary and secondary bystander effect and genomic instability in cells exposed to high and low linear energy transfer radiations. Int J Radiat Biol 2019; 95:1648-1658. [PMID: 31486717 DOI: 10.1080/09553002.2019.1665208] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Purpose: Non-Targeted effects (NTE), such as bystander effect (BE) and genomic instability (GI) challenge central dogma of radiation biology. Moreover, there is a need to understand its universality in different type of cells and radiation quality.Materials and method: To study BE (primary and secondary) and GI Human adult dermal fibroblast (HADF) and peripheral blood lymphocytes (PBL) were exposed to low fluence of 241Am alpha (α) particle and 6 MV X-ray. The BE was carried out by means of co-culture methodology after exposing the cells to both types of radiation and damage was measured using micronucleus assay (MN) and chromosomal aberration assay (CA) in the p1 cells while the GI was followed up in their progeny.Results: A dose-dependent increase in DNA damages (MN and CA) was observed in directly irradiated and bystander cells. The magnitude of BE was higher (6 fold) in cells co-cultured with the α-irradiated cells than that of with X-irradiated cells. Cross exposure of both cell types confirms that radiation induced BE is cell type dependent. In addition, induced DNA damage persisted for a longer population doubling in α-particle irradiated cells.Conclusion: This work adds evidence to secondary bystander response generated from primary bystander normal cells and its dependence to radiation quality.
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Affiliation(s)
- K Kanagaraj
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, India
| | - V Rajan
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Badri N Pandey
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
| | - K Thayalan
- Department of Radiation oncology, Kamakshi Memorial Hospital, Chennai, India
| | - P Venkatachalam
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research (Deemed to be University), Chennai, India
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Karthik K, Rajan V, Pandey BN, Sivasubramanian K, Paul SF, Venkatachalam P. Direct and bystander effects in human blood lymphocytes exposed to 241Am alpha particles and the relative biological effectiveness using chromosomal aberration and micronucleus assay. Int J Radiat Biol 2019; 95:725-736. [DOI: 10.1080/09553002.2019.1589018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- K. Karthik
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research, Chennai, India
| | - Vasumathy Rajan
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Badri N. Pandey
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, India
| | - K. Sivasubramanian
- Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam, India
| | - Solomon F.D. Paul
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research, Chennai, India
| | - P. Venkatachalam
- Department of Human Genetics, Sri Ramachandra Institute of Higher Education and Research, Chennai, India
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Jayashree R, Nazeem PA, Rekha K, Sreelatha S, Thulaseedharan A, Krishnakumar R, Kala RG, Vineetha M, Leda P, Jinu U, Venkatachalam P. Over-expression of 3-hydroxy-3- methylglutaryl-coenzyme A reductase 1 (hmgr1) gene under super-promoter for enhanced latex biosynthesis in rubber tree (Hevea brasiliensis Muell. Arg.). Plant Physiol Biochem 2018; 127:414-424. [PMID: 29680705 DOI: 10.1016/j.plaphy.2018.04.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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: 11/24/2017] [Revised: 04/10/2018] [Accepted: 04/10/2018] [Indexed: 05/09/2023]
Abstract
Natural rubber (cis-1, 4-polyisoprene) is being produced from bark laticifer cells of Hevea brasiliensis and the popular high latex yielding Indian rubber clones are easily prone to onset of tapping panel dryness syndrome (TPD) which is considered as a physiological syndrome affecting latex production either partially or completely. This report describes an efficient protocol for development of transgenic rubber plants by over-expression of 3-hydroxy 3-methylglutaryl Co-enzyme A reductase 1 (hmgr1) gene which is considered as rate limiting factor for latex biosynthesis via Agrobacterium-mediated transformation. The pBIB plasmid vector containing hmgr1 gene cloned under the control of a super-promoter was used for genetic transformation using embryogenic callus. Putatively transgenic cell lines were obtained on selection medium and produced plantlets with 44% regeneration efficiency. Transgene integration was confirmed by PCR amplification of 1.8 kb hmgr1 and 0.6 kb hpt genes from all putatively transformed callus lines as well as transgenic plants. Southern blot analysis showed the stable integration and presence of transgene in the transgenic plants. Over expression of hmgr1 transgene was determined by Northern blot hybridization, semi-quantitative PCR and real-time PCR (qRT-PCR) analysis. Accumulation of hmgr1 mRNA transcripts was more abundant in transgenic plants than control. Increased level of photosynthetic pigments, protein contents and HMGR enzyme activity was also noticed in transgenic plants over control. Interestingly, the latex yield was significantly enhanced in all transgenic plants compared to the control. The qRT-PCR results exhibit that the hmgr1 mRNA transcript levels was 160-fold more abundance in transgenic plants over untransformed control. These results altogether suggest that there is a positive correlation between latex yield and accumulation of mRNA transcripts level as well as HMGR enzyme activity in transgenic rubber plants. It is presumed that there is a possibility for enhanced level of latex biosynthesis in transgenic plants as the level of mRNA transcripts and HMGR enzyme activity is directly correlated with latex yield in rubber tree. Further, the present results clearly suggest that the quantification of HMGR enzyme activity in young seedlings will be highly beneficial for early selection of high latex yielding plants in rubber breeding programs.
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Affiliation(s)
- R Jayashree
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India.
| | - P A Nazeem
- Department of Bioinformatics, Centre for Plant Biotechnology Molecular Biology, Kerala Agricultural University, Thrissur, Kerala, India
| | - K Rekha
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India
| | - S Sreelatha
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India
| | - A Thulaseedharan
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India
| | - R Krishnakumar
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India
| | - R G Kala
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India
| | - M Vineetha
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India; Department of Microbiology, Government Arts & Science College, Palakkad, Kerala, India
| | - P Leda
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India
| | - U Jinu
- Department of Biotechnology, Periyar University, Salem 636011, Tamil Nadu, India
| | - P Venkatachalam
- Advanced Center for Molecular Biology and Biotechnology, Rubber Research Institute of India, Kottayam 686 009, Kerala, India; Department of Biotechnology, Periyar University, Salem 636011, Tamil Nadu, India.
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Sellamuthu K, Suryia S, Duraisami V, Mahendran R, Venkatachalam P. Characterization of Biochar from Different Sources of Plant Communities. ACTA ACUST UNITED AC 2018. [DOI: 10.20546/ijcmas.2018.703.104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Prabhu BK, Gowri B, Muthuvelu K, Venkatachalam P, Paul SF, Jayanth VR. Effect of 2-Deoxy-D-Glucose on The Induction of Chromosomal Aberrations in Lymphocytes Exposedin vitroto Gamma Radiation at a Dose Rate of 1.0 Gy/Minute. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2004.11885867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- B. Karthikeya Prabhu
- Sri Ramachandra Medical College and Research Institute (Deemed University) 1, Ramachandra Nagar, Porur, Chennai 600 116, Tamilnadu, India
| | - B. Gowri
- Sri Ramachandra Medical College and Research Institute (Deemed University) 1, Ramachandra Nagar, Porur, Chennai 600 116, Tamilnadu, India
| | - K. Muthuvelu
- Sri Ramachandra Medical College and Research Institute (Deemed University) 1, Ramachandra Nagar, Porur, Chennai 600 116, Tamilnadu, India
| | - P. Venkatachalam
- Sri Ramachandra Medical College and Research Institute (Deemed University) 1, Ramachandra Nagar, Porur, Chennai 600 116, Tamilnadu, India
| | - Solomon F.D. Paul
- Sri Ramachandra Medical College and Research Institute (Deemed University) 1, Ramachandra Nagar, Porur, Chennai 600 116, Tamilnadu, India
| | - Vikram R. Jayanth
- Sri Ramachandra Medical College and Research Institute (Deemed University) 1, Ramachandra Nagar, Porur, Chennai 600 116, Tamilnadu, India
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Vijayalakshmi J, Venkatachalam P, Reddy S, Rani GU, Manjula G. Microdeletions of AZFc Region in Infertile Men with Azoospermia and Oligoasthenoteratozoospermia. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2013.11886215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- J. Vijayalakshmi
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India
| | - P. Venkatachalam
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India
| | - Sanjeeeva Reddy
- Department of Obsteritics and Gynecology, Sri Ramachandra University, Chennai, Tamil Nadu, India
| | - G. Usha Rani
- Department of Obsteritics and Gynecology, Sri Ramachandra University, Chennai, Tamil Nadu, India
| | - G. Manjula
- Department of Obsteritics and Gynecology, Sri Ramachandra University, Chennai, Tamil Nadu, India
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Venkatachalam P, Jayanth V, Paul SF, Vettriselvi V. Protective Effect of 2-Deoxy-D-Glucose on Chemotherapeutic Drugs Induced Damages on Peripheral Blood Lymphocytes Exposed in-Vitro. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2006.11885953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- P. Venkatachalam
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
| | - V.R. Jayanth
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
| | - Solomon F.D. Paul
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
| | - V. Vettriselvi
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
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Ravi M, Paul SF, Venkatachalam P. A Humoral Immune Index of Clinically Normal Human Subject. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2002.11885804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- M. Ravi
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Tel : +91-44-4765609, +91-44-4767008
| | - Solomon F.D. Paul
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Tel : +91-44-4765609, +91-44-4767008
| | - P. Venkatachalam
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Tel : +91-44-4765609, +91-44-4767008
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Ravi M, Venkateswaran N, Paul SF, Abraham V, Venkatachalam P. In vitro Immunogenetic Effects of 532 nm Short YAG Laser Pulses on Human Lymphocytes. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2002.11885778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- M. Ravi
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Fax: +91-44-4767008
| | - N. Venkateswaran
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Fax: +91-44-4767008
| | - Solomon F.D. Paul
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Fax: +91-44-4767008
| | - Vinsu Abraham
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Fax: +91-44-4767008
| | - P. Venkatachalam
- Genetic Research Cell, Sri Ramachandra Medical College and Research Institute, Porur, Chennai 600 116, Tamil Nadu, India. Fax: +91-44-4767008
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Affiliation(s)
- P. Venkatachalam
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
| | - V.R. Jayanth
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
| | - Solomon F.D. Paul
- Department of Human Genetics, Sri Ramachandra Medical College & Research Institute (Deemed University), Porur, Chennai 600 116, Tamil Nadu, India
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Subramanian N, Krishnan HM, Venkatachalam P, Kamatchi P. A Study of Lactate Dehydrogenase (LDH) Isoenzyme is a Biochemical Tumour Marker in Cervical Carcinoma Patients. INT J HUM GENET 2017. [DOI: 10.1080/09723757.2009.11886055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- N. Subramanian
- P.G. Department of Zoology, Pachaiyappa’s College for Men, Kanchipuram 631 502, Tamil Nadu, India
| | - H. Mohana Krishnan
- P.G. Division for Wildlife Biology, Govt. Arts & Science College, Ooty, Tamil Nadu, India
| | - P. Venkatachalam
- P.G. Department of Human Genetics, Sri Ramachandra Medical College and Research Institute (Deemed University), Chennai, Tamil Nadu, India
| | - P.A.C. Kamatchi
- P.G. Department of Zoology, Pachaiyappa’s College for Men, Kanchipuram 631 502, Tamil Nadu, India
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Subhashree M, Venkateswarlu R, Karthik K, Shangamithra V, Venkatachalam P. DNA damage and the bystander response in tumor and normal cells exposed to X-rays. Mutat Res Genet Toxicol Environ Mutagen 2017; 821:20-27. [PMID: 28735740 DOI: 10.1016/j.mrgentox.2017.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/31/2022]
Abstract
Monolayer and suspension cultures of tumor (BMG-1, CCRF-CEM), normal (AG1522, HADF, lymphocytes) and ATM-mutant (GM4405) human cells were exposed to X-rays at doses used in radiotherapy (high dose and high dose-rate) or radiological imaging (low dose and low dose-rate). Radiation-induced DNA damage, its persistence, and possible bystander effects were evaluated, based on DNA damage markers (γ-H2AX, p53ser15) and cell-cycle-specific cyclins (cyclin B1 and cyclin D1). Dose-dependent DNA damage and a dose-independent bystander response were seen after exposure to high dose and high dose-rate radiation. The level of induced damage (expression of p53ser15, γ-H2AX) depended on ATM status. However, low dose and dose-rate exposures neither increased expression of marker proteins nor induced a bystander response, except in the CCRF-CEM cells. Bystander effects after high-dose irradiation may contribute to stochastic and deterministic effects. Precautions to protect unexposed regions or to inhibit transmission of DNA damage signaling might reduce radiation risks.
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Affiliation(s)
- M Subhashree
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, 600 116, India
| | - R Venkateswarlu
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, 600 116, India
| | - K Karthik
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, 600 116, India
| | - V Shangamithra
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, 600 116, India
| | - P Venkatachalam
- Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, 600 116, India.
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Prasannaraj G, Venkatachalam P. Enhanced Antibacterial, Anti-biofilm and Antioxidant (ROS) Activities of Biomolecules Engineered Silver Nanoparticles Against Clinically Isolated Gram Positive and Gram Negative Microbial Pathogens. J CLUST SCI 2017. [DOI: 10.1007/s10876-017-1160-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [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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20
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Venkatachalam P, Priyanka N, Manikandan K, Ganeshbabu I, Indiraarulselvi P, Geetha N, Muralikrishna K, Bhattacharya RC, Tiwari M, Sharma N, Sahi SV. Enhanced plant growth promoting role of phycomolecules coated zinc oxide nanoparticles with P supplementation in cotton (Gossypium hirsutum L.). Plant Physiol Biochem 2017; 110:118-127. [PMID: 27622847 DOI: 10.1016/j.plaphy.2016.09.004] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [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: 04/03/2016] [Revised: 07/24/2016] [Accepted: 09/03/2016] [Indexed: 05/21/2023]
Abstract
This report focuses on application of zinc oxide nanoparticles (ZnONPs) carrying phycomolecule ligands as a novel plant growth promoter aimed at increasing the crop productivity. The present investigation examined the effect of ZnONPs on plant growth characteristics, and associated biochemical changes in cotton (Gossypium hirsutum L.) following growth in a range of concentrations (25-200 mg L-l ZnONPs) in combination with 100 mM P in a hydroponic system. Treated plants registered an increase in growth and total biomass by 130.6% and 131%, respectively, over control. Results demonstrated a significant increase in the level of chlorophyll a (141.6%), b (134.7%), carotenoids (138.6%), and total soluble protein contents (179.4%); at the same time, a significant reduction (68%) in the level of malondialdehyde (MDA) in leaves with respect to control. Interestingly, a significant increase in superoxide dismutase (SOD, 264.2%), and peroxidase (POX, 182.8%) enzyme activities followed by a decrease in the catalase (CAT) activity, in response to above treatments. These results suggest that bioengineered ZnONPs interact with meristematic cells triggering biochemical pathways conducive to an accumulation of biomass. Further investigations will map out the mode of action involved in growth promotion.
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Affiliation(s)
- P Venkatachalam
- Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India.
| | - N Priyanka
- Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - K Manikandan
- Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - I Ganeshbabu
- Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - P Indiraarulselvi
- Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - N Geetha
- Department of Biotechnology, Mother Teresa Women's University, Kodaikanal, 624 102, Tamil Nadu, India
| | - K Muralikrishna
- National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110 012, India
| | - R C Bhattacharya
- National Research Centre on Plant Biotechnology, Indian Agricultural Research Institute, Pusa Campus, New Delhi, 110 012, India
| | - M Tiwari
- Department of Biology, Western Kentucky University, Bowling Green, KY, 42101, USA
| | - N Sharma
- Department of Biology, Western Kentucky University, Bowling Green, KY, 42101, USA
| | - S V Sahi
- Department of Biology, Western Kentucky University, Bowling Green, KY, 42101, USA
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Cox A, Venkatachalam P, Sahi S, Sharma N. Reprint of: Silver and titanium dioxide nanoparticle toxicity in plants: A review of current research. Plant Physiol Biochem 2017; 110:33-49. [PMID: 27569179 DOI: 10.1016/j.plaphy.2016.08.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 05/11/2016] [Accepted: 05/17/2016] [Indexed: 05/01/2023]
Abstract
Nanoparticles (NPs) have become widely used in recent years for many manufacturing and medical processes. Recent literature suggests that many metallic nanomaterials including those of silver (Ag) and titanium dioxide (TiO2) cause significant toxic effects in animal cell culture and animal models, however, toxicity studies using plant species are limited. This review examines current progress in the understanding of the effect of silver and titanium dioxide nanoparticles on plant species. There are many facets to this ongoing environmental problem. This review addresses the effects of NPs on oxidative stress-related gene expression, genotoxicity, seed germination, and root elongation. It is largely accepted that NP exposure results in the cellular generation of reactive oxygen species (ROS), leading to both positive and negative effects on plant growth. However, factors such as NP size, shape, surface coating and concentration vary greatly among studies resulting in conflicting reports of the effect at times. In addition, plant species tend to differ in their reaction to NP exposure, with some showing positive effects of NP augmentation while many others showing detrimental effects. Seed germination studies have shown to be less effective in gauging phytotoxicity, while root elongation studies have shown more promise. Given the large increase in nanomaterial applications in consumer products, agriculture and energy sectors, it is critical to understand their role in the environment and their effects on plant life. A closer look at nanomaterial-driven ecotoxicity is needed. Ecosystem-level studies are required to indicate how these nanomaterials transfer at the critical trophic levels affecting human health and biota.
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Affiliation(s)
- Ashley Cox
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA
| | - P Venkatachalam
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA; Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - Shivendra Sahi
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA
| | - Nilesh Sharma
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA.
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Venkatachalam P, Jayaraj M, Manikandan R, Geetha N, Rene ER, Sharma NC, Sahi SV. Zinc oxide nanoparticles (ZnONPs) alleviate heavy metal-induced toxicity in Leucaena leucocephala seedlings: A physiochemical analysis. Plant Physiol Biochem 2017; 110:59-69. [PMID: 27622846 DOI: 10.1016/j.plaphy.2016.08.022] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [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: 03/18/2016] [Revised: 08/19/2016] [Accepted: 08/31/2016] [Indexed: 05/22/2023]
Abstract
The present study describes the role of zinc oxide nanoparticles (ZnONPs) in reversing oxidative stress symptoms induced by heavy metal (Cd and Pb) exposure in Leucaena leucocephala (Lam.) de Wit. Seedling growth was significantly enhanced with the augmentation of ZnONPs following Cd and Pb exposure. Heavy metal accumulations were recorded as 1253.1 mg Cd per kg DW and 1026.8 mg Pb per kg DW for the respective treatments. Results demonstrated that ZnONPs augmentation caused an increase in photosynthetic pigment and total soluble protein contents while a significant decrease in malondialdehyde (MDA-lipid peroxidation) content in leaves. Antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were, in turn, elevated in heavy metal-exposed leaves amended with ZnONPs. The ameliorating effect of ZnO nanoparticles on oxidative stress induced toxicity was also confirmed by the reduced MDA content and the elevated level of antioxidative enzyme activities in leaf tissues of L. leucocephala seedlings. Further, addition of ZnONPs in combination with Cd and Pb metals induced distinct genomic alterations such as presence of new DNA bands and/or absence of normal bands in the RAPD pattern of the exposed plants. This study uniquely suggests a potential role of zinc oxide nanoparticles in the remediation of heavy metal contaminated media.
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Affiliation(s)
- P Venkatachalam
- Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, PeriyarPalkalai Nagar, Salem, 636 011, Tamil Nadu, India.
| | - M Jayaraj
- Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, PeriyarPalkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - R Manikandan
- Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, PeriyarPalkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - N Geetha
- Department of Biotechnology, Mother Teresa Women's University, Kodaikanal, 624 102, Tamil Nadu, India
| | - Eldon R Rene
- Department of Environmental Engineering and Water Technology, UNESCO-IHE Institute for Water Education, PO Box 3015, 2601 DA Delft, The Netherlands
| | - N C Sharma
- Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA
| | - S V Sahi
- Department of Biology, Western Kentucky University, Bowling Green, KY 42101, USA
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Ganesan S, Babu IG, Mahendran D, Arulselvi PI, Elangovan N, Geetha N, Venkatachalam P. Green engineering of titanium dioxide nanoparticles using Ageratina altissima (L.) King & H.E. Robines. medicinal plant aqueous leaf extracts for enhanced photocatalytic activity. ACTA ACUST UNITED AC 2016. [DOI: 10.21276/ap.2016.5.2.8] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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24
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Jinu U, Jayalakshmi N, Sujima Anbu A, Mahendran D, Sahi S, Venkatachalam P. Biofabrication of Cubic Phase Silver Nanoparticles Loaded with Phytochemicals from Solanum nigrum Leaf Extracts for Potential Antibacterial, Antibiofilm and Antioxidant Activities Against MDR Human Pathogens. J CLUST SCI 2016. [DOI: 10.1007/s10876-016-1125-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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25
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Cox A, Venkatachalam P, Sahi S, Sharma N. Silver and titanium dioxide nanoparticle toxicity in plants: A review of current research. Plant Physiol Biochem 2016; 107:147-163. [PMID: 27288991 DOI: 10.1016/j.plaphy.2016.05.022] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [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: 03/14/2016] [Revised: 05/11/2016] [Accepted: 05/17/2016] [Indexed: 05/20/2023]
Abstract
Nanoparticles (NPs) have become widely used in recent years for many manufacturing and medical processes. Recent literature suggests that many metallic nanomaterials including those of silver (Ag) and titanium dioxide (TiO2) cause significant toxic effects in animal cell culture and animal models, however, toxicity studies using plant species are limited. This review examines current progress in the understanding of the effect of silver and titanium dioxide nanoparticles on plant species. There are many facets to this ongoing environmental problem. This review addresses the effects of NPs on oxidative stress-related gene expression, genotoxicity, seed germination, and root elongation. It is largely accepted that NP exposure results in the cellular generation of reactive oxygen species (ROS), leading to both positive and negative effects on plant growth. However, factors such as NP size, shape, surface coating and concentration vary greatly among studies resulting in conflicting reports of the effect at times. In addition, plant species tend to differ in their reaction to NP exposure, with some showing positive effects of NP augmentation while many others showing detrimental effects. Seed germination studies have shown to be less effective in gauging phytotoxicity, while root elongation studies have shown more promise. Given the large increase in nanomaterial applications in consumer products, agriculture and energy sectors, it is critical to understand their role in the environment and their effects on plant life. A closer look at nanomaterial-driven ecotoxicity is needed. Ecosystem-level studies are required to indicate how these nanomaterials transfer at the critical trophic levels affecting human health and biota.
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Affiliation(s)
- Ashley Cox
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA
| | - P Venkatachalam
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA; Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India
| | - Shivendra Sahi
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA
| | - Nilesh Sharma
- Department of Biology, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, KY, 42101, USA.
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26
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Gopalan MN, Venkatachalam P. Probabilistic analysis of a two-server n -unit system subject to preventive maintenance and repair. ADV APPL PROBAB 2016. [DOI: 10.2307/1425899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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Ananthajothi P, Venkatachalam P. Tin chloride perovskite-sensitized core/shell photoanode solar cell with spiro-MeOTAD hole transport material for enhanced solar light harvesting. J Solid State Electrochem 2016. [DOI: 10.1007/s10008-016-3262-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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28
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Mythili R, Subramanian P, Venkatachalam P. Art of Waste to Fortune: Conversion of Redgram Stalk into Value Added Chemicals Through Fast Pyrolysis. Natl Acad Sci Lett 2016. [DOI: 10.1007/s40009-016-0440-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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30
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Anbu AS, Venkatachalam P. Biological macromolecule cross linked TPP–chitosan complex: a novel nanohybrid for improved ovulatory activity against PCOS treatment in female rats. RSC Adv 2016. [DOI: 10.1039/c6ra07228c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Polycystic ovary syndrome (PCOS) is a relatively common endocrine disorder among young women and leads to metabolic problems associated with the onset of infertility.
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31
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Venkatachalam P, Kalaiarasi K, Sreeramanan S. Influence of plant growth regulators (PGRs) and various additives on in vitro plant propagation of Bambusa arundinacea (Retz.) Wild: A recalcitrant bamboo species. J Genet Eng Biotechnol 2015; 13:193-200. [PMID: 30647583 PMCID: PMC6299815 DOI: 10.1016/j.jgeb.2015.09.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 09/05/2015] [Accepted: 09/29/2015] [Indexed: 11/16/2022]
Abstract
An efficient micropropagation protocol for high frequency plant regeneration was developed using nodal explants derived in vitro seedlings of Bambusa arundinacea which is an important multipurpose and edible bamboo species and recalcitrant to tissue culture. The nodal explants excised from 20-day-old seedlings were cultured on Murashige and Skoog (MS) medium fortified with various concentrations of 6-benzyl amino purine (BAP) and kinetin (KIN) (0.5–5.0 mg/l) alone and/or in combination with 0.5 mg/l of different auxins [indole-3-butyric acid (IBA) α-naphthalene acetic acid (NAA) and indole-3-acetic acid (IAA)] for shoot bud induction. The combination of BAP (3.0 mg/l) and IBA (0.5 mg/l) was found to be the best for the highest percent of shoot bud initiation (87.2%), with 24.2 shoots/explant. The highest frequency (95.2%) of shoot bud multiplication with maximum number of shoots (90.5 shoots/culture) was noticed on medium containing 4% coconut water with 4% sucrose. The regenerated shoot buds were cultured on MS medium supplemented with various concentrations of auxins alone and/or in combination with AgNO3 (0.5–4.0 mg/l) for in vitro rooting. Maximum percent of rooting (85%) was noticed on MS medium augmented with 3.0 mg/l IBA and 2.0 mg/l AgNO3 after 14 days of culture. Well rooted plantlets obtained were established in the field with 92% survival rate. The present plant regeneration protocol could be used for large scale propagation and ex-situ conservation of this important bamboo species in the near future.
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Affiliation(s)
- P Venkatachalam
- Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem 636 011, TN, India
| | - K Kalaiarasi
- Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem 636 011, TN, India
| | - S Sreeramanan
- School of Biological Sciences, Universiti Sains Malaysia (USM), Georgetown 11800, Penang, Malaysia
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32
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Bakkiam D, Bhavani M, Anantha Kumar AA, Sonwani S, Venkatachalam P, Sivasubramanian K, Venkatraman B. Dicentric assay: inter-laboratory comparison in Indian laboratories for routine and triage applications. Appl Radiat Isot 2015; 99:77-85. [PMID: 25728004 DOI: 10.1016/j.apradiso.2015.02.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 11/16/2022]
Abstract
An Inter-Laboratory Comparison (ILC) study on Dicentric Chromosome Assay (DCA) was carried out between two Indian biodosimetry labs. Human peripheral blood samples exposed to 10 different doses of X-rays up to 5Gy were shared between the labs to generate calibration data. Validation of calibration curves was done by dose estimation of coded samples exposed to X- or gamma radiation. Reliability of the DCA data for triage application was evaluated by scoring 20, 50 and 100 metaphases in the dose range of 0.5-3.0Gy. No significant difference was observed between labs regarding the established calibration data as well as the DCA triage dose assessments. Scoring of 20 metaphases (MP) was adequate to detect radiation exposure of >2Gy whereas 50 MP were sufficient to determine exposures of 0.5Gy. Both labs performed the DCA in a reliable manner and made the first step in setting up a biodosimetry network in India.
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Affiliation(s)
- D Bakkiam
- Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Tamilnadu, India
| | - M Bhavani
- Sri Ramachandra University, Porur, Chennai 600116, Tamilnadu, India
| | - A Arul Anantha Kumar
- Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Tamilnadu, India.
| | - Swetha Sonwani
- Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Tamilnadu, India
| | - P Venkatachalam
- Sri Ramachandra University, Porur, Chennai 600116, Tamilnadu, India
| | - K Sivasubramanian
- Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Tamilnadu, India
| | - B Venkatraman
- Radiological Safety Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Tamilnadu, India
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Dhamodharan P, Manoharan C, Dhanapandian S, Venkatachalam P. Dye-sensitized solar cell using sprayed ZnO nanocrystalline thin films on ITO as photoanode. Spectrochim Acta A Mol Biomol Spectrosc 2015; 136 Pt C:1671-1678. [PMID: 25459731 DOI: 10.1016/j.saa.2014.10.063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 10/08/2014] [Accepted: 10/15/2014] [Indexed: 06/04/2023]
Abstract
ZnO thin films had been successfully prepared by spray pyrolysis (SP) technique on ITO/Glass substrates at different substrate temperature in the range 250-400°C using Zinc acetylacetonate as precursor. The X-ray diffraction studies confirmed the hexagonal wurtzite structure with preferred orientation along (002) plane at substrate temperature 350°C and the crystallite size was found to vary from 18 to 47nm. The morphology of the films revealed the porous nature with the roughness value of 8-13nm. The transmittance value was found to vary from 60% to 85% in the visible region depending upon the substrate temperature and the band gap value for the film deposited at 350°C was 3.2eV. The obtained results revealed that the structures and properties of the films were greatly affected by substrate temperature. The near band edge emission observed at 398nm in PL spectra showed better crystallinity. The measured electrical resistivity for ZnO film was ∼3.5×10(-4)Ωcm at the optimized temperature 350°C and was of n-type semiconductor. The obtained porous nature with increased surface roughness of the film and good light absorbing nature of the dye paved way for implementation of quality ZnO in DSSCs fabrication. DSSC were assembled using the prepared ZnO film on ITO coated glass substrate as photoanode and its photocurrent - voltage performance was investigated.
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Affiliation(s)
- P Dhamodharan
- Department of Physics, Annamalai University, Annamalai Nagar, Chidambaram 608 002, Tamil Nadu, India
| | - C Manoharan
- Department of Physics, Annamalai University, Annamalai Nagar, Chidambaram 608 002, Tamil Nadu, India.
| | - S Dhanapandian
- Department of Physics, Annamalai University, Annamalai Nagar, Chidambaram 608 002, Tamil Nadu, India
| | - P Venkatachalam
- Department of Physics (DDE), Annamalai University, Annamalai Nagar, Chidambaram 608 002, Tamil Nadu, India
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Manikandan R, Sahi SV, Venkatachalam P. Impact assessment of mercury accumulation and biochemical and molecular response of Mentha arvensis: a potential hyperaccumulator plant. ScientificWorldJournal 2015; 2015:715217. [PMID: 25654134 PMCID: PMC4306221 DOI: 10.1155/2015/715217] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 09/15/2014] [Indexed: 01/24/2023] Open
Abstract
The present study was focused on examining the effect of Hg oxidative stress induced physiochemical and genetic changes in M. arvensis seedlings. The growth rate of Hg treated seedlings was decreased to 56.1% and 41.5% in roots and shoots, respectively, compared to the control. Accumulation of Hg level in both roots and shoots was increased with increasing the concentration of Hg. Superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activities were found to be increased with increasing the Hg concentration up to 20 mg/L; however, it was decreased at 25 mg/L Hg concentration. The POX enzyme activity was positively correlated with Hg dose. The changes occurring in the random amplification of ploymorphic DNA (RAPD) profiles generated from Hg treated seedlings included variations in band intensity, disappearance of bands, and appearance of new bands compared with the control seedlings. It was concluded that DNA polymorphisms observed with RAPD profile could be used as molecular marker for the evaluation of heavy metal induced genotoxic effects in plant species. The present results strongly suggested that Mentha arvensis could be used as a potential phytoremediator plant in mercury polluted environment.
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Affiliation(s)
- R. Manikandan
- Plant Genetic Engineering and Molecular Biotechnology Lab, Department of Biotechnology, Periyar University, Salem, Tamil Nadu 636 011, India
| | - S. V. Sahi
- Department of Biology, Western Kentucky University, 1906 College Boulevard, No. 11080, Bowling Green, KY 42101-1080, USA
| | - P. Venkatachalam
- Plant Genetic Engineering and Molecular Biotechnology Lab, Department of Biotechnology, Periyar University, Salem, Tamil Nadu 636 011, India
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Maheswari D, Venkatachalam P. Fabrication of High Efficiency Dye-Sensitised Solar Cell with Zirconia-Doped TiO2 Nanoparticle and Nanowire Composite Photoanode Film. Aust J Chem 2015. [DOI: 10.1071/ch14364] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Dye-sensitised solar cells (DSSCs) were fabricated based on coumarin NKX-2700 dye-sensitised zirconia-doped TiO2 nanoparticle and nanowire composite photoanode film and quasi-solid-state electrolyte, sandwiched together with cobalt sulfide-coated counter electrode. Novel photoanodes were prepared using composite mixtures of 90 wt-% TiO2 nanoparticles + 10 wt-% TiO2 nanowires (TNPWs) as base material and zirconia as doping metal. Hafnium oxide (HfO2) was applied on the zirconia-doped TNPWs (zirconia/TNPWs) film structure as a blocking layer. TiO2 nanoparticles, TiO2 nanowires, and zirconia/TNPWs were characterised by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The sensitising organic dye coumarin, NKX-2700, displayed maximum absorption wavelength (λmax) at 525 nm, which could be observed from the UV-visible spectrum. DSSC-1 built with zirconia/TNPWs-doped photoanode with blocking layer revealed enhanced photo-current efficiency (PCE) as compared with other DSSCs and illustrated photovoltaic parameters: short circuit current JSC = 20 mA m–2, open circuit voltage (VOC = 730 mV, fill factor (FF) = 68 %, and PCE (η) = 9.93 %. The electron transport and charge recombination behaviours of DSSCs were investigated by electrochemical impedance spectroscopy and the results exhibited that DSSC-1 possessed the lowest charge transfer resistance (Rrec) and longest electron lifetime (τrec) compared with other DSSCs. Therefore, from the present investigation, it could be concluded that the improved performance of DSSC-1 is ascribed to the zirconia/TNPWs-doped photoanode with the blocking layer increasing the short circuit current, electron transport, and suppressing the recombination of charge carriers at the photoanode/dye/electrolyte interface.
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Bhuvaneswari T, Thiyagarajan M, Geetha N, Venkatachalam P. Bioactive compound loaded stable silver nanoparticle synthesis from microwave irradiated aqueous extracellular leaf extracts of Naringi crenulata and its wound healing activity in experimental rat model. Acta Trop 2014; 135:55-61. [PMID: 24681224 DOI: 10.1016/j.actatropica.2014.03.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/04/2014] [Accepted: 03/17/2014] [Indexed: 12/18/2022]
Abstract
An efficient and eco-friendly protocol for the synthesis of bioactive silver nanoparticles was developed using Naringi crenulata leaf extracts via microwave irradiation method. Silver nanoparticles were synthesized by treating N. crenulata leaf extracts with 1mM of aqueous silver nitrate solution. An effective bioactive compound such as alkaloids, phenols, saponins and quinines present in the N. crenulata reduces the Ag(+) into Ag(0). The synthesized silver nanoparticles were monitored by UV-vis spectrophotometer and further characterized by X-ray diffraction (XRD), Fourier Transform Infra Red (FTIR), Energy-dispersive X-ray spectroscopy (EDX) and field emission scanning electron microscopy (FESEM). UV-vis spectroscopy showed maximum absorbance at 390nm due to surface plasmon resonance of AgNPs. From FESEM results, an average crystal size of the synthesized nanoparticle was 72-98nm. FT-IR results showed sharp absorption peaks and they were assigned to phosphine, alkyl halides and sulfonate groups. Silver nanoparticles synthesized were generally found to be spherical and cubic shape. Topical application of ointment prepared from silver nanoparticles of N. crenulata were formulated and evaluated in vivo using the excision wound healing model on Wistar albino rats. The measurement of the wound areas was performed on 3rd, 6th, 9th, 12th and 15th days and the percentage of wound closures was calculated accordingly. By the 15th day, the ointment base containing 5% (w/w) of silver nanoparticles showed 100% wound healing activity compared with that of the reference as well as control bases. The results strongly suggested that the batch C ointment containing silver nanaoparticles synthesized from the leaf extracts of N. crenulata was found to be very effective in wound repair and encourages harnessing the potentials of the plant biomolecules loaded silver nanoparticle in the treatment of tropical diseases including wound healing.
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Bhavani M, Tamizh Selvan G, Kaur H, Adhikari JS, Vijayalakshmi J, Venkatachalam P, Chaudhury NK. Dicentric chromosome aberration analysis using giemsa and centromere specific fluorescence in-situ hybridization for biological dosimetry: An inter- and intra-laboratory comparison in Indian laboratories. Appl Radiat Isot 2014; 92:85-90. [PMID: 25014548 DOI: 10.1016/j.apradiso.2014.06.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/19/2014] [Accepted: 06/04/2014] [Indexed: 11/25/2022]
Abstract
To facilitate efficient handling of large samples, an attempt towards networking of laboratories in India for biological dosimetry was carried out. Human peripheral blood samples were exposed to (60)Co γ-radiation for ten different doses (0-5Gy) at a dose rate of 0.7 and 2Gy/min. The chromosomal aberrations (CA) were scored in Giemsa-stained and fluorescence in-situ hybridization with centromere-specific probes. No significant difference (p>0.05) was observed in the CA yield for given doses except 4 and 5Gy, between the laboratories, among the scorers and also staining methods adapted suggest the reliability and validates the inter-lab comparisons exercise for triage applications.
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Affiliation(s)
- M Bhavani
- Department of Human Genetics, College of Biomedical Sciences Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, Tamil Nadu, India.
| | - G Tamizh Selvan
- Department of Human Genetics, College of Biomedical Sciences Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, Tamil Nadu, India; Chemical Radioprotector and Radiation Dosimetry Research Group, Institute of Nuclear Medicine and Allied Sciences, Brig Mazumdar Road, DRDO, Timarpur, New Delhi 110054, India.
| | - Harpreet Kaur
- Department of Human Genetics, College of Biomedical Sciences Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, Tamil Nadu, India.
| | - J S Adhikari
- Chemical Radioprotector and Radiation Dosimetry Research Group, Institute of Nuclear Medicine and Allied Sciences, Brig Mazumdar Road, DRDO, Timarpur, New Delhi 110054, India.
| | - J Vijayalakshmi
- Department of Human Genetics, College of Biomedical Sciences Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, Tamil Nadu, India.
| | - P Venkatachalam
- Department of Human Genetics, College of Biomedical Sciences Technology and Research, Sri Ramachandra University, Porur, Chennai 600116, Tamil Nadu, India.
| | - N K Chaudhury
- Chemical Radioprotector and Radiation Dosimetry Research Group, Institute of Nuclear Medicine and Allied Sciences, Brig Mazumdar Road, DRDO, Timarpur, New Delhi 110054, India.
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Selvan GT, Bhavani M, Vijayalakshmi J, Paul Solomon FD, Chaudhury NK, Venkatachalam P. Delayed mitogenic stimulation decreases DNA damage assessed by micronucleus assay in human peripheral blood lymphocytes after (60)co irradiation. Dose Response 2014. [PMID: 25249838 DOI: 10.2203/dose-response.13-060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
While contradictory reports are available on the yield of dicentric chromosomes (DC) in blood samples stored at different temperature and stimulated to enter into cell cycle, various times gap followed by exposure, limited information is available on the micronucleus (MN) assay. As scoring the micronuclei frequency from the blood lymphocytes of exposed individuals is an alternative to the gold standard DC assay for triage applications, we examined radiation induced MN yield in delayed mitogenic stimulation after irradiation of in vitro. Peripheral blood lymphocytes (PBL) were exposed to low LET ((60)Co) radiation dose (0.1 to 5Gy) and incubated at 37°C for 2, 6 and 24 hours. The MN frequency obtained in blood samples stimulated 2 hours post-irradiation showed a dose dependent increase and used to construct the dose-response curve. Further, the results also showed that blood samples stimulated twenty four hours of post-irradiation, a significant reduction (p<0.05) in MN frequencies were obtained when compared to that of blood samples stimulated two hours and six hours after post-irradiation (0.5, 1, 3 and 5Gy). The observed result suggests that the prolonged PBL storage without mitogenic stimulation could lead to interphase cell death and a delayed blood sampling could results in underestimation of dose in biological dosimetry.
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Affiliation(s)
- G Tamizh Selvan
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India; ; Institute of Nuclear Medicine and Allied Sciences, DRDO, Timarpur, New Delhi 110 054, India
| | - M Bhavani
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
| | - J Vijayalakshmi
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
| | - F D Paul Solomon
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
| | - N K Chaudhury
- Institute of Nuclear Medicine and Allied Sciences, DRDO, Timarpur, New Delhi 110 054, India
| | - P Venkatachalam
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
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Selvan GT, Bhavani M, Vijayalakshmi J, Paul Solomon FD, Chaudhury NK, Venkatachalam P. Delayed mitogenic stimulation decreases DNA damage assessed by micronucleus assay in human peripheral blood lymphocytes after (60)co irradiation. Dose Response 2014; 12:498-508. [PMID: 25249838 DOI: 10.2203/dose-response.13-060.selvan] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
While contradictory reports are available on the yield of dicentric chromosomes (DC) in blood samples stored at different temperature and stimulated to enter into cell cycle, various times gap followed by exposure, limited information is available on the micronucleus (MN) assay. As scoring the micronuclei frequency from the blood lymphocytes of exposed individuals is an alternative to the gold standard DC assay for triage applications, we examined radiation induced MN yield in delayed mitogenic stimulation after irradiation of in vitro. Peripheral blood lymphocytes (PBL) were exposed to low LET ((60)Co) radiation dose (0.1 to 5Gy) and incubated at 37°C for 2, 6 and 24 hours. The MN frequency obtained in blood samples stimulated 2 hours post-irradiation showed a dose dependent increase and used to construct the dose-response curve. Further, the results also showed that blood samples stimulated twenty four hours of post-irradiation, a significant reduction (p<0.05) in MN frequencies were obtained when compared to that of blood samples stimulated two hours and six hours after post-irradiation (0.5, 1, 3 and 5Gy). The observed result suggests that the prolonged PBL storage without mitogenic stimulation could lead to interphase cell death and a delayed blood sampling could results in underestimation of dose in biological dosimetry.
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Affiliation(s)
- G Tamizh Selvan
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India; ; Institute of Nuclear Medicine and Allied Sciences, DRDO, Timarpur, New Delhi 110 054, India
| | - M Bhavani
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
| | - J Vijayalakshmi
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
| | - F D Paul Solomon
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
| | - N K Chaudhury
- Institute of Nuclear Medicine and Allied Sciences, DRDO, Timarpur, New Delhi 110 054, India
| | - P Venkatachalam
- Sri Ramachandra University, Porur, Chennai 600 116, Tamil Nadu, India
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Elangovan R, Joby NG, Venkatachalam P. Performance of dye-sensitized solar cells based on various sensitizers applied on TiO2-Nb2O5 core/shell photoanode structure. J Solid State Electrochem 2014. [DOI: 10.1007/s10008-014-2394-2] [Citation(s) in RCA: 6] [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: 10/25/2022]
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Patnam A, Vinu R, Vijayalakshmi J, Venkatachalam P, Rani G. Association of ESR and FOXP3 gene polymorphisms with outcome of ovarian stimulation in infertile females undergoing IVF. Mol Cytogenet 2014. [PMCID: PMC4045825 DOI: 10.1186/1755-8166-7-s1-p61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Krishnakumar N, Sulfikkarali NK, Manoharan S, Venkatachalam P. Raman spectroscopic investigation of the chemopreventive response of naringenin and its nanoparticles in DMBA-induced oral carcinogenesis. Spectrochim Acta A Mol Biomol Spectrosc 2013; 115:648-653. [PMID: 23880406 DOI: 10.1016/j.saa.2013.05.076] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [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: 12/04/2012] [Revised: 05/19/2013] [Accepted: 05/23/2013] [Indexed: 06/02/2023]
Abstract
Raman spectroscopy is a vibrational spectroscopic technique that can be used to optically probe the biomolecular changes associated with tumor progression. The aim of the present study is to investigate the biomolecular changes in chemopreventive response of prepared naringenin-loaded nanoparticles (NARNPs) relative to efficacy of free naringenin (NAR) during 7,12-dimethyl benz(a)anthracene (DMBA)-induced oral carcinogenesis by Fourier Transform Raman (FT-Raman) spectroscopy. Oral squamous cell carcinoma (OSCC) was developed in the buccal pouch of golden Syrian hamsters by painting with 0.5% DMBA in liquid paraffin three times a week for 14weeks. Raman spectra differed significantly between the control and tumor tissues, with tumors showing higher percentage signals for nucleic acids, phenylalanine and tryptophan and a lower in the percentage of phospholipids. Moreover, oral administration of free NAR and NARNPs significantly increased phospholipids and decreased the levels of tryptophan, phenylalanine and nucleic acid contents. On a comparative basis, NARNPs was found to have a more potent antitumor effect than free NAR in completely preventing the formation of squamous cell carcinoma and in improving the biochemical status to a normal range in DMBA-induced oral carcinogenesis. The present study further suggest that Raman spectroscopy could be a valuable tool for rapid and sensitive detection of specific biomolecular changes in response to chemopreventive agents.
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Affiliation(s)
- N Krishnakumar
- Department of Physics, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India.
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Maheswari D, Venkatachalam P. Fabrication and characterization of TiO2 nanotube by hydrothermal method in the design of DSSC. ACTA ACUST UNITED AC 2013. [DOI: 10.3103/s0003701x13020072] [Citation(s) in RCA: 8] [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: 11/30/2022]
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Mythili R, Venkatachalam P, Subramanian P, Uma D. Characterization of bioresidues for biooil production through pyrolysis. Bioresour Technol 2013; 138:71-78. [PMID: 23612164 DOI: 10.1016/j.biortech.2013.03.161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Revised: 03/22/2013] [Accepted: 03/23/2013] [Indexed: 06/02/2023]
Abstract
Biomass is a renewable resource utilized to produce energy, fuels and chemicals. In this study, 25 bioresidues were selected and the physical, chemical, thermal and elemental analyses of the residues were studied as per standard methods. The bioresidues were pyrolyzed at 450°C in a fixed bed reactor to produce biooil. Among the residues, paper (pinfed computer) and Parthenium produced maximum (45%) and minimum biooil (6.33%), respectively. Arecanut stalk, redgram stalk, rice husk, wheat husk, maize cob, coir pith, Cumbu Napier grass Co5, Prosopis wood and paper resulted in a better biooil yield. Models were developed to predict the effect of constituents of bioresidues on the yield of biooil. The volatile matter and cellulose had significant effect on biooil yield. Biooil thus obtained can be used as fuel that may replace considerable fossil fuels.
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Affiliation(s)
- R Mythili
- Department of Bioenergy, Agricultural Engineering College and Research Institute, TamilNadu Agricultural University, Coimbatore 641 003, TamilNadu, India.
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Affiliation(s)
- Gareth Walker
- Department of Gastroenterology, Bristol Royal Infirmary, University Hospitals Bristol Trust, Bristol, UK.
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Subramanian P, Sampathrajan A, Venkatachalam P. Fluidized bed gasification of select granular biomaterials. Bioresour Technol 2011; 102:1914-1920. [PMID: 20817445 DOI: 10.1016/j.biortech.2010.08.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/05/2010] [Accepted: 08/06/2010] [Indexed: 05/29/2023]
Abstract
Biomaterials can be converted into solid, liquid and gaseous fuels through thermochemical or biochemical conversion processes. Thermochemical conversion of granular biomaterials is difficult because of its physical nature and one of the suitable processes is fluidized bed gasification. In this study, coir pith, rice husk and saw dust were selected and synthetic gas was generated using a fluidized bed gasifier. Gas compositions of product gas were analyzed and the percentage of carbon monoxide and carbon dioxide was in the range of 8.24-19.55 and 10.21-17.14, respectively. The effect of equivalence ratio (0.3, 0.4 and 0.5) and reaction time (at 10 min interval) on gas constituents was studied. The gas yield for coir pith, rice husk and sawdust were found to be in the range of 1.98-3.24, 1.79-2.81 and 2.18-3.70 Nm3 kg(-1), respectively. Models were developed to study the influence of biomaterial properties and operating conditions on molar concentration of gas constituents and energy output.
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Affiliation(s)
- P Subramanian
- Department of Bioenergy, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India.
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Krishnakumar N, Manoharan S, Palaniappan PLRM, Venkatachalam P, Manohar MA. Chemopreventive efficacy of piperine in 7,12-dimethyl benz [a] anthracene (DMBA)-induced hamster buccal pouch carcinogenesis: An FT-IR study. Food Chem Toxicol 2009; 47:2813-20. [DOI: 10.1016/j.fct.2009.08.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 07/20/2009] [Accepted: 08/31/2009] [Indexed: 11/29/2022]
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Venkatachalam P, Priya P, Jayashree R, Rekha K, Thulaseedharan A. Molecular cloning and characterization of a 3-hydroxy-3-methylglutaryl-coenzyme A reductase 1 (hmgr1) gene from rubber tree (Hevea brasiliensis Muell. Arg.): A key gene involved in isoprenoid biosynthesis. Physiol Mol Biol Plants 2009; 15:133-43. [PMID: 23572922 PMCID: PMC3550373 DOI: 10.1007/s12298-009-0015-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Natural rubber (cis-1,4-polyisoprene) is a secondary metabolite produced in the laticiferous tissue of Hevea tree. Mevalonate synthesis, which is the first step in isoprenoid biosynthesis, is catalyzed by the enzyme 3-hydroxy-3-methylglutarylcoenzyme A reductase 1 (hmgr1). We have cloned and characterized a full-length cDNA as well as genomic DNA for hmgr1 gene from an elite Indian rubber clone (RRII 105). The nucleotide sequence of the genomic clone comprises 4 exons and 3 introns, giving a total length of 2440 bp. The sequences of 42 bp 5' UTR and 69 bp of the 3' UTR were also determined. The hmgr1 cDNA contained an open reading frame of 1838 bp coding for 575 amino acid protein with a theoretical pI value of 6.6 and the calculated protein M W was 61.6 kDa. The deduced amino acid sequence showed high identity with other plant hmgr1 sequences. The amino acid sequence of the Hevea hmgr1 revealed several motifs which are highly conserved and common to the other plant species. These sequence conservations suggest a strong evolutionary pressure to maintain amino acid residues at specific positions, indicating that the conserved motifs might play important roles in the structural and/or catalytic properties of the enzyme. Southern blot analysis of genomic DNA from Hevea probed with a genomic fragment indicated that there were at least three isoforms of hmgr in Hevea. This result reveals that hmgr1 is one of the members of a small gene family. (Northern blot analysis showed that hmgr1 mRNA transcripts were noticed in all tissues - latex, leaf, immature leaf, and seedlings), however, the abundance of transcript level was higher in latex cells. As one step towards a better understanding of the role that this enzyme plays in coordinating isoprenoid biosynthesis in plants, hmgr1 cDNA was over expressed in transgenic Arabidopsis plants. Transgenic plants were morphologically distinguishable from control wild-type plants and an increased expression level of hmgr1 mRNA was detected. These data suggest that hmgr1 gene expression is playing an important role in isoprenoid biosynthesis.
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Affiliation(s)
- P. Venkatachalam
- />Department of Biotechnology, Periyar University, Salem, 636 011 Tamil Nadu India
| | - P. Priya
- />Biotechnology Division, Rubber Research Institute of India, Rubber Board PO, Kottayam, 686 009 Kerala India
| | - R. Jayashree
- />Biotechnology Division, Rubber Research Institute of India, Rubber Board PO, Kottayam, 686 009 Kerala India
| | - K. Rekha
- />Biotechnology Division, Rubber Research Institute of India, Rubber Board PO, Kottayam, 686 009 Kerala India
| | - A. Thulaseedharan
- />Biotechnology Division, Rubber Research Institute of India, Rubber Board PO, Kottayam, 686 009 Kerala India
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Venkatachalam P, Srivastava AK, Raghothama KG, Sahi SV. Genes induced in response to mercury-ion-exposure in heavy metal hyperaccumulator Sesbania drummondii. Environ Sci Technol 2009; 43:843-850. [PMID: 19245025 DOI: 10.1021/es801304n] [Citation(s) in RCA: 13] [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] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Sesbania drummondii plants have been recognized as a potential mercury (Hg) hyperaccumulator. To identify genes modulated by Hg, two suppressive subtraction hybridization (SSH) cDNA libraries (forward and reverse) were constructed. A total of 348 differentially expressed clones were isolated and 95 of them were identified as Hg responsive. Reverse Northern results showed that 31 clones from forward library were down-regulated and 64 clones from reverse library were up-regulated in Hg-treated plants. Sixty-seven of them showed high homology to genes with known or putative function, and 28 were uncharacterized genes. Two full-length cDNAs coding for a putative metallothionein type 2 protein (SdMT2) and an auxin responsive protein (SdARP) were isolated and characterized. The expression levels of SdMT2 and SdARP increased 3- and 5-fold, respectively. Results suggest that up-regulated expression of SdARP may contribute to the survival of Sesbania plants under mercury stress, whereas SdMT2 is likely to be involved in alleviation of Hg toxicity. The possible correlation between gene expression and heavy metal tolerance of Sesbania plants is discussed.
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Affiliation(s)
- P Venkatachalam
- Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907, USA
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Venkatachalam P, de Toledo SM, Pandey BN, Tephly LA, Carter AB, Little JB, Spitz DR, Azzam EI. Regulation of normal cell cycle progression by flavin-containing oxidases. Oncogene 2008; 27:20-31. [PMID: 17637756 DOI: 10.1038/sj.onc.1210634] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Mechanisms underlying the role of reactive oxygen species (ROS) generated by flavin-containing oxidases in regulating cell cycle progression were examined in human and rodent fibroblasts. Incubation of confluent cell cultures with nontoxic/nonclastogenic concentrations of the flavoprotein inhibitor, diphenyleneiodonium (DPI), reduced nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase activity and basal ROS levels, but increased proteolysis of cyclin D1, p21(Waf1) and phospho-p38(MAPK). When these cells were allowed to proliferate by subculture in DPI-free medium, an extensive G(1) delay was observed with concomitant activation of p53/p21(Waf1) signaling and reduced phosphorylation of mitogen-activated kinases. Compensation for decreased oxidant generation by simultaneous exposure to DPI and nontoxic doses of the ROS generators, gamma-radiation or t-butyl-hydroperoxide, attenuated the G(1) delay. Whereas the DPI-induced G(1) checkpoint was completely dependent on PHOX91, ATM and WAF1, it was only partially dependent on P53. Interestingly, G(1) to S progression was not affected when another flavin-containing enzyme, nitric oxide synthase, was inhibited nor was it associated with changes in mitochondrial membrane potential. Proliferating cells treated with DPI also experienced a significant but attenuated delay in G(2). We propose that ATM performs a critical function in mediating normal cellular proliferation that is regulated by nonphagocytic NAD(P)H oxidase enzymes activity, which may serve as a novel target for arresting cancer cells in G(1).
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Affiliation(s)
- P Venkatachalam
- Department of Radiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ, USA
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