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Varsi F, Ahmad S, Chakraborty M, Chandra A, Dugad SR, Goswami UD, Gupta SK, Hariharan B, Hayashi Y, Jagadeesan P, Jain A, Jain P, Kawakami S, Kojima H, Lipari P, Mahapatra S, Mohanty PK, Moharana R, Muraki Y, Nayak PK, Nonaka T, Oshima A, Pant BP, Pattanaik D, Paul S, Pradhan GS, Rameez M, Ramesh K, Reddy LV, Saha S, Sahoo R, Scaria R, Shibata S, Zuberi M. Evidence of a Hardening in the Cosmic Ray Proton Spectrum at around 166 TeV Observed by the GRAPES-3 Experiment. Phys Rev Lett 2024; 132:051002. [PMID: 38364164 DOI: 10.1103/physrevlett.132.051002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 10/16/2023] [Accepted: 01/04/2024] [Indexed: 02/18/2024]
Abstract
We present the measurement of the cosmic ray proton spectrum from 50 TeV to 1.3 PeV using 7.81×10^{6} extensive air shower events recorded by the ground-based GRAPES-3 experiment between 1 January 2014 and 26 October 2015 with a live time of 460 day. Our measurements provide an overlap with direct observations by satellite and balloon-based experiments. The electromagnetic and muon components in the shower were measured by a dense array of plastic scintillator detectors and a tracking muon telescope, respectively. The relative composition of the proton primary from the air shower data containing all primary particles was extracted using the multiplicity distribution of muons which is a sensitive observable for mass composition. The observed proton spectrum suggests a spectral hardening at ∼166 TeV and disfavors a single power law description of the spectrum up to the Knee energy (∼3 PeV).
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Affiliation(s)
- F Varsi
- Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - S Ahmad
- Aligarh Muslim University, Aligarh 202002, India
| | - M Chakraborty
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - A Chandra
- Aligarh Muslim University, Aligarh 202002, India
| | - S R Dugad
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - U D Goswami
- Dibrugarh University, Dibrugarh 786004, India
| | - S K Gupta
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - B Hariharan
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - Y Hayashi
- Graduate School of Science, Osaka Metropolitan University, Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
| | - P Jagadeesan
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - A Jain
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - P Jain
- Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - S Kawakami
- Graduate School of Science, Osaka Metropolitan University, Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
| | - H Kojima
- College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - P Lipari
- INFN, Sezione Roma "Sapienza", Piazzale Aldo Moro 2, 00185 Roma, Italy
| | | | - P K Mohanty
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - R Moharana
- Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - Y Muraki
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya 464-8601, Japan
| | - P K Nayak
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - T Nonaka
- Institute for Cosmic Ray Research, Tokyo University, Kashiwa, Chiba 277-8582, Japan
| | - A Oshima
- College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - B P Pant
- Indian Institute of Technology Jodhpur, Jodhpur 342037, India
| | - D Pattanaik
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Utkal University, Bhubaneswar 751004, India
| | - S Paul
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - G S Pradhan
- Indian Institute of Technology Indore, Indore 453552, India
| | - M Rameez
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - K Ramesh
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - L V Reddy
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
| | - S Saha
- Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - R Sahoo
- Indian Institute of Technology Indore, Indore 453552, India
| | - R Scaria
- Indian Institute of Technology Indore, Indore 453552, India
| | - S Shibata
- College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - M Zuberi
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
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Kumar U, Kaviraj M, Rout S, Chakraborty K, Swain P, Nayak PK, Nayak AK. Combined application of ascorbic acid and endophytic N-fixing Azotobacter chroococcum Avi2 modulates photosynthetic efficacy, antioxidants and growth-promotion in rice under moisture deficit stress. Microbiol Res 2021; 250:126808. [PMID: 34146939 DOI: 10.1016/j.micres.2021.126808] [Citation(s) in RCA: 4] [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] [Received: 01/23/2021] [Revised: 05/06/2021] [Accepted: 06/08/2021] [Indexed: 10/21/2022]
Abstract
This group has previously reported the role of ascorbic acid (AA) as an antioxidant for survivability and ability to enhancing diazotrophic efficacy in Azotobacter chroococcum Avi2 under hydrogen peroxide (H2O2) stress. However, the present study showed the combined application of AA and Avi2 in drought-susceptible (IR64 and Naveen) and drought-tolerant (Ankit and Satyabhama) rice cultivars to determine their photosynthetic efficacy (chlorophyll fluorescence-imaging), antioxidants, and plant growth-promotion (PGP) under moisture deficit stress (MS, -60 kPa). The results indicated that combined application of AA and Avi2 significantly (p < 0.05) increased the total chlorophyll, relative water content, electrolytic leakage, super oxide dismutase, and catalase activities in all rice cultivars as compared to other MS treatments, whereas stress indicators like proline and H2O2 contents were proportionally increased under MS and their concentration were normalized under combined application of AA and Avi2. Photochemical quenching, non-photochemical quenching, photosynthetic electron transport rate, and the effective quantum efficiency were found to be increased significantly (p < 0.05) in Avi2 + AA as compared to other MS treatments. Moreover, rice roots harbored significantly (p < 0.05) higher copy number of nifH gene in Avi2 + AA treatment followed by Avi2 compared to flooded control and other MS treatments. Combined application of AA and Avi2 also increased the grain yield significantly (p < 0.05) by 7.09 % and 3.92 % in drought-tolerant (Ankit and Satyabhama, respectively) and 31.70 % and 34.19 % in drought-susceptible (IR64 and Naveen, respectively) rice cultivars compared to MS treatment. Overall, the present study indicated that AA along with Avi2 could be an effective formulation to alleviate MS vis à vis enhances PGP traits in rice.
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Affiliation(s)
- Upendra Kumar
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India.
| | - Megha Kaviraj
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Snehasini Rout
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - K Chakraborty
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - P Swain
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - P K Nayak
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - A K Nayak
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
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Kumar U, Kaviraj M, Panneerselvam P, Priya H, Chakraborty K, Swain P, Chatterjee SN, Sharma SG, Nayak PK, Nayak AK. Ascorbic acid formulation for survivability and diazotrophic efficacy of Azotobacter chroococcum Avi2 (MCC 3432) under hydrogen peroxide stress and its role in plant-growth promotion in rice (Oryza sativa L.). Plant Physiol Biochem 2019; 139:419-427. [PMID: 30986643 DOI: 10.1016/j.plaphy.2019.04.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 01/31/2019] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 06/09/2023]
Abstract
Oxidative stress generates reactive oxygen species which causes cell damage of living organisms and are normally detoxified by antioxidants. Indirect reports signify the damages caused by reactive oxygen species and neutralized by antioxidant, but the direct evidence to confirm this hypothesis is still unclear. To validate our hypothesis, an attempt was made in a diazotrophic bacterium (Azotobacter chroococcum Avi2) as a biological system, and hydrogen peroxide (H2O2) and ascorbic acid were used as oxidative stress and antioxidant supplement, respectively. Additionally, rice plant-growth attributes by Avi2 was also assessed under H2O2 and ascorbic acid. Results indicated that higher concentration of H2O2 (2.5 mM-4.5 mM) showed the complete mortality of Avi2, whereas one ppm ascorbic acid neutralized the effect of H2O2. Turbidity, colony forming unit, DNA quantity, nifH gene abundance, indole acetic acid and ammonia productions were significantly (p < 0.5) increased by 11.93%, 17.29%, 19.80%, 74.77%, 71.89%, and 42.53%, respectively in Avi2-treated with 1.5 mM H2O2 plus ascorbic acid compared to 1.5 mM H2O2 alone. Superoxide dismutase was significantly (p < 0.5) increased by 60.85%, whereas catalase and ascorbate peroxidase activities were significantly (p < 0.05) decreased by 64.28% and 68.88% in Avi2-treated with 1.5 mM H2O2 plus ascorbic acid compared to 1.5 mM H2O2 alone. Germination percentage of three rice cultivars (FR13a, Naveen and Sahbhagi dhan) were significantly (p < 0.5) increased by 20%, 13.33%, and 4%, respectively in Avi2-treated with 0.6 mM H2O2 plus ascorbic acid compared with uninoculated control. Overall, this study indicated that ascorbic acid formulation neutralizes the H2O2-oxidative stress and enhances the survivability and plant growth-promoting efficacy of A. chroococcum Avi2 and therefore, it may be used as an effective formulation of bio-inoculants in rice under oxidative stress.
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Affiliation(s)
- Upendra Kumar
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India.
| | - Megha Kaviraj
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - P Panneerselvam
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Himani Priya
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | | | - P Swain
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | | | - S G Sharma
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - P K Nayak
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - A K Nayak
- ICAR- National Rice Research Institute, Cuttack, Odisha, 753006, India
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Hariharan B, Chandra A, Dugad SR, Gupta SK, Jagadeesan P, Jain A, Mohanty PK, Morris SD, Nayak PK, Rakshe PS, Ramesh K, Rao BS, Reddy LV, Zuberi M, Hayashi Y, Kawakami S, Ahmad S, Kojima H, Oshima A, Shibata S, Muraki Y, Tanaka K. Measurement of the Electrical Properties of a Thundercloud Through Muon Imaging by the GRAPES-3 Experiment. Phys Rev Lett 2019; 122:105101. [PMID: 30932668 DOI: 10.1103/physrevlett.122.105101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 01/21/2019] [Indexed: 06/09/2023]
Abstract
The GRAPES-3 muon telescope located in Ooty, India records rapid (∼10 min) variations in the muon intensity during major thunderstorms. Out of a total of 184 thunderstorms recorded during the interval of April 2011-December 2014, the one on December 1, 2014 produced a massive potential of 1.3 GV. The electric field measured by four well-separated (up to 6 km) monitors on the ground was used to help estimate some of the properties of this thundercloud, including its altitude and area that were found to be 11.4 km above mean sea level and ≥380 km^{2}, respectively. A charging time of 6 min to reach 1.3 GV implied the delivery of a power of ≥2 GW by this thundercloud that was moving at a speed of ∼60 km h^{-1}. This work possibly provides the first direct evidence for the generation of gigavolt potentials in thunderclouds that could also possibly explain the production of highest-energy (100 MeV) gamma rays in the terrestrial gamma-ray flashes.
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Affiliation(s)
- B Hariharan
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - A Chandra
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - S R Dugad
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - S K Gupta
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - P Jagadeesan
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - A Jain
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - P K Mohanty
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - S D Morris
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - P K Nayak
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - P S Rakshe
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - K Ramesh
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - B S Rao
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - L V Reddy
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - M Zuberi
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
| | - Y Hayashi
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - S Kawakami
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - S Ahmad
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- Aligarh Muslim University, Aligarh 202002, India
| | - H Kojima
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - A Oshima
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - S Shibata
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- College of Engineering, Chubu University, Kasugai, Aichi 487-8501, Japan
| | - Y Muraki
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Aichi 446-8601, Japan
| | - K Tanaka
- Cosmic Ray Laboratory, Raj Bhavan, Ooty 643001, India
- Graduate School of Information Sciences, Hiroshima City University, Hiroshima 731-3194, Japan
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Saipriya G, Kumaresan R, Nayak PK, Venkatesan KA, Antony MP, Kumar T. Studies on the adsorption behavior of americium and europium on radiolytically degraded solvent impregnated resin containing neutral and acidic extractants. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5567-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Prathibha T, Kumaresan R, Nayak PK, Venkatesan KA, Subramanian GGS, Rajeswari S, Kalaiyarasu T, Karunakaran R, Antony MP. Modifier-free separation of trivalent actinides and lanthanides from fast reactor simulated high-level liquid waste using N,N-di-octyl-2-hydroxyacetamide. J Radioanal Nucl Chem 2017. [DOI: 10.1007/s10967-017-5528-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Rama Swami K, Kumaresan R, Nayak PK, Venkatesan KA, Antony MP. Effect of pKa on the extraction behavior of Am(III) in organo phosphorus acid and diglycolamide solvent system. RADIOCHIM ACTA 2017. [DOI: 10.1515/ract-2017-2769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
A combination of neutral and acidic extractant has been proposed for the single-cycle separation of trivalent actinides from high-level liquid waste (HLLW). The nature of acidic extractant in the combined solvent formulation plays a profound role in deciding the extraction and stripping of trivalent actinides. Therefore, the extraction behavior of Am(III) in a solution of tetra-bis(2-ethylhexyl)-diglycolamide (TEHDGA) and acidic extractant (HA) was studied from nitric acid medium. The acidic extractants chosen were bis(2-ethylhexyl)phosphoric acid (HDEHP), bis(2-ethylhexyl)phosphonic acid (PC88A) and bis(2,4,4-trimethylpentyl)phosphinic acid (CYANEX-272) whose pKa values were 3.24, 4.51 and 6.37, respectively. The distribution ratio of Am(III) was measured as a function of various parameters such as concentration of nitric acid, TEHDGA, HA etc. The data were compared with those obtained in individual solvent systems namely 0.1 M TEHDGA/n-DD and HA/n-DD. Slope analysis of the extraction data indicated the synergic participation of both TEHDGA and HDEHP in the extraction of Am(III) at all acidities. However, antagonistic effect was observed at lower acidity when TEHDGA was mixed to PC88A or CYANEX-272 present in n-DD. Accordingly, a suitable mechanism has been proposed for the extraction of Am(III) at all acidities using these combined solvent formulation. Studies with fast reactor simulated high level liquid waste indicated that extraction of Am(III) was accompanied by co-extraction of lanthanides and unwanted metal ions such as Zr(IV), Mo(VI), Y(III) and Pd(II). However, addition of trans-1,2-diaminocyclohexane-N,N,N,N′-tetraaceticacid (CyDTA) reduced the extraction of unwanted metal ions. Batch extraction and stripping studies indicated the possibility of using 0.1 M TEHDGA+0.25 M HDEHP in n-dodecane for the single cycle separation of Am(III) from FR-SHLLW.
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Affiliation(s)
- K. Rama Swami
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research , Kalpakkam 603 102 , India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar , Mumbai 400094 , India
| | - R. Kumaresan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research , Kalpakkam 603 102 , India
| | - P. K. Nayak
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research , Kalpakkam 603 102 , India
| | - K. A. Venkatesan
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research , Kalpakkam 603 102 , India , Tel.: +91 44 27480500 extn. 24082, 24148, Fax: +91 44 27480065
| | - M. P. Antony
- Materials Chemistry and Metal Fuel Cycle Group, Indira Gandhi Centre for Atomic Research , Kalpakkam 603 102 , India
- Homi Bhabha National Institute, Training School Complex, Anushakti Nagar , Mumbai 400094 , India
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Saipriya G, Kumaresan R, Nayak PK, Venkatesan KA, Kumar T, Antony MP. Extraction behaviour of Am(III) and Eu(III) from nitric acid medium in TEHDGA-HDEHP impregnated resins. RADIOCHIM ACTA 2016. [DOI: 10.1515/ract-2016-2612] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The extraction behaviour of Am(III) and Eu(III) from nitric acid medium was studied in the solvent impregnated resins containing extractants such as tetra-bis(2-ethylhexyl)diglycolamide (TEHDGA) or bis-(2-ethylhexyl)phosphoric acid (HDEHP) or mixture of TEHDGA+HDEHP. The rate of extraction of Am(III) and Eu(III) from 1 M nitric acid and the effect of various parameters, such as the concentration of nitric acid in aqueous phase and concentration of TEHDGA and HDEHP in resin phase, on the distribution coefficient of Am(III) and Eu(III) was studied. The distribution coefficient of Am(III) and Eu(III) in HDEHP-impregnated resin decreased and that in TEHDGA-impregnated resin increased, with increase in the concentration of nitric acid. However, in (TEHDGA+HDEHP) – impregnated resin, synergic extraction was observed at lower nitric acid concentration and antagonism at higher nitric acid concentration. The mechanism of Am(III) and Eu(III) extraction in the combined resin was investigated by slope analysis method. The extraction of various metal ions present in the fast reactor simulated high-level liquid waste was studied. The separation factor of Am(III) over Eu(III) was studied using citrate-buffered diethylenetriaminepentaacetic acid (DTPA) solution.
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Affiliation(s)
- G. Saipriya
- Kalpakkam Reprocessing Plant, Nuclear Recycle Board, BARC Facilities, Kalpakkam 603 102, India
| | - R. Kumaresan
- Fuel Chemistry Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, India
| | - P. K. Nayak
- Fuel Chemistry Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, India
| | - K. A. Venkatesan
- Fuel Chemistry Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, India , Tel.: +91 44 27480098, Fax: +91 44 27480065
| | - T. Kumar
- Kalpakkam Reprocessing Plant, Nuclear Recycle Board, BARC Facilities, Kalpakkam 603 102, India
| | - M. P. Antony
- Fuel Chemistry Division, Indira Gandhi Center for Atomic Research, Kalpakkam 603 102, India
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Nayak PK, Chaurasia S, Kumaresan R, Venkatesan KA, Subramanian GGS, Antony MP, Vasudeva Rao PR, Bhanage BM. Studies on the Radiochemical Degradation of Tetraethylhexyl Diglycolamide and Ethylhexylphosphoric Acid inn-Dodecane Solution. SEP SCI TECHNOL 2014. [DOI: 10.1080/01496395.2014.959603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Nayak PK, Kumaresan R, Venkatesan KA, Antony MP, Vasudeva Rao PR. Extraction Behavior of Am(III) and Eu(III) from Nitric Acid Medium in Tetraoctyldiglycolamide-Bis(2-Ethylhexyl)Phosphoric Acid Solution. SEP SCI TECHNOL 2014. [DOI: 10.1080/01496395.2013.874357] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Nayak PK, Kumaresan R, Venkatesan KA, Antony MP, Vasudeva Rao PR. A New Method for Partitioning of Trivalent Actinides from High-Level Liquid Waste. SEP SCI TECHNOL 2013. [DOI: 10.1080/01496395.2012.737401] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Nayak PK, Kerr DS. Low-dose GYKI-52466: prophylactic preconditioning confers long-term neuroprotection and functional recovery following hypoxic-ischaemic brain injury. Neuroscience 2012; 232:128-38. [PMID: 23246617 DOI: 10.1016/j.neuroscience.2012.11.063] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 11/28/2012] [Accepted: 11/29/2012] [Indexed: 10/27/2022]
Abstract
Experimental preconditioning provides beneficial outcomes in conditions such as cardiac surgery, brain surgery and stroke. Here we evaluated the protective effects of low-dose subcutaneous GYKI-52466 preconditioning in a rat model of hypoxic-ischaemic (HI) brain injury. Male Sprague-Dawley rats (postnatal day 26) were administered saline or GYKI-52466 (GYKI; 3-mg/kg, 90 min; 1-mg/kg, twice in 120 min; or 0.5-mg/kg, thrice in 180 min) prior to left common carotid artery occlusion. Animals were allowed to recover for 2h, and then placed in a hypoxia chamber (8% O₂/92% N₂; 33 ± 1°C) for 1h. A sham surgery group received saline without HI. Seizure activity was scored during hypoxia and sensorimotor tests performed before surgery and at 1, 7, 14 and 90 days post-HI. On days 14 and 90 brains were fixed and sectioned for the assessment of infarct size and ventricular enlargement. Low-dose GYKI-52466 preconditioning significantly reduced infarct volume and ventricular enlargement relative to saline-treated controls at day 14 after HI. On day 90, tissue loss was significantly reduced by GYKI 3-mg/kg compared to saline. Foot-faults, paw use asymmetry, and postural reflex scores were significantly improved in all GYKI treatment groups. Our results show that GYKI-52466 is effective at doses well-below, and at pre-administration intervals well-beyond previous studies, and suggest that a classical blockade of ionotropic AMPA receptors does not underlie its neuroprotective effects. Low-dose GYKI-52466 preconditioning represents a novel, prophylactic strategy for neuroprotection in a field almost devoid of effective pharmaceuticals.
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Affiliation(s)
- P K Nayak
- Department of Pharmacology and Toxicology, University of Otago School of Medical Sciences, Dunedin, New Zealand
| | - D S Kerr
- Department of Pharmacology and Toxicology, University of Otago School of Medical Sciences, Dunedin, New Zealand.
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Nayak PK, Pinto JV, Goncalves G, Martins R, Fortunato E. Environmental, Optical, and Electrical Stability Study of Solution-Processed Zinc–Tin–Oxide Thin-Film Transistors. ACTA ACUST UNITED AC 2011. [DOI: 10.1109/jdt.2011.2160151] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nayak PK, Das G, Parhi L, Mahapatra AK. Traumatic spinal extradural hematoma following epidural anesthesia. The Indian Journal of Neurotrauma 2009. [DOI: 10.1016/s0973-0508(09)80040-3] [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: 10/28/2022]
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Abstract
Associated cranial abnormalities with spinal dysraphism are not uncommon. We came across an unusual case of a 1-year-old male child with spinal dysraphism having lumbar meningomyelocele, who also had split cord malformation (hemicord with intervening bony spur) with lipoma of one of the hemicord and filum terminale. The patient also had communicating hydrocephalus without Chiari malformation and also near-total frontal bone agenesis. Single photon emission computed tomography scanning of brain revealed normal perfusion. In the first stage of repair, the patient had postoperative CSF leak for which ventriculo-peritoneal shunt was performed. This constitutes a rare anomaly associated with spinal dysraphism.
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Affiliation(s)
- P K Nayak
- Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India
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Nayak PL, Lenka S, Nayak PK. Calculation of reactivity ratio of resin copolymers derived from substituted acetophenones using Kelen–Tüdos equation. J Appl Polym Sci 1992. [DOI: 10.1002/app.1992.070450412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Nayak PK, Lenka S, Nayak PL. Biomedical polymers. III. Bacteriocidal property of the resins derived from substituted acetophenones. J Appl Polym Sci 1991. [DOI: 10.1002/app.1991.070431223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nayak PK, Singh TP. Effect of pinealectomy on testosterone, estradiol-17 beta, esterone, and 17 alpha-hydroxyprogesterone levels during the annual reproductive cycle in the freshwater catfish, Clarias batrachus. J Pineal Res 1988; 5:419-26. [PMID: 3171888 DOI: 10.1111/j.1600-079x.1988.tb00785.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The present study examines the relationship of the pineal gland to gonadal activity during the annual reproductive cycle in the freshwater catfish Clarias batrachus. The hormonal profiles of testosterone, estradiol-17 beta, estrone, and 17 alpha-hydroxyprogesterone along with the gonadosomatic index (GSI) were monitored to assess the effect of pinealectomy. Pinealectomy appeared to accelerate the gonadal development from January to May. Removal of pineal prior to the start of gonadal recrudescence (January and February), induced initiation of ovarian recrudescence earlier than scheduled in nature. On the other hand pinealectomy during the vitellogenic phase (May to June) reduced the gonadal activity, suggesting the stimulatory role of pineal on gonads. During the remaining period of July to December (postvitellogenic and early resting phase) pinealectomy had no effect on gonadal activity. Thus, in this species the pineal gland during the annual reproductive cycle appears to have either inhibitory, stimulatory, or no effect on gonadal physiology depending upon the sexual conditions.
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Affiliation(s)
- P K Nayak
- Centre of Advanced Study in Zoology, Banaras Hindu University, Varanasi, India
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Abstract
Thyroxine and triiodothyronine (T3) were measured by radioimmunoassay in serum and thyroid gland of the freshwater teleost Clarias batrachus. Pinealectomy increased the glandular levels of the thyroid hormones but decreased the plasma levels of T4 concomitantly with the increase of T3 levels. Most of the effects of pinealectomy on thyroid hormones were restricted to the gonadal development periods. Pinealectomy has shown no significant impact on thyroid hormones during the other periods of the reproductive cycle. Thus, it appears that the pineal gland is inhibitory to thyroid hormones during gonadal development and maturation.
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Affiliation(s)
- P K Nayak
- Department of Zoology, Banaras Hindu University, Varanasi, India
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Nayak PK, Singh TP. Effect of melatonin and 5-methoxytryptamine on sex steroids and thyroid hormones during the prespawning phase of the annual reproductive cycle in the freshwater teleost, Clarias batrachus. J Pineal Res 1987; 4:377-86. [PMID: 3478467 DOI: 10.1111/j.1600-079x.1987.tb00877.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Melatonin and 5-methoxytryptamine have been studied in the freshwater teleost Clarias batrachus during the prespawning period. The data have provided evidence of the inhibitory effects on sex steroids and thyroid hormones when the pineal indoleamines melatonin and 5-methoxytryptamine (5-MT) are administered intramuscularly daily in the afternoon for 27 days. The different dose levels had different effects. The higher dose levels of melatonin showed the initiation of counter inhibitory impacts on testosterone and T3, T4 levels. The melatonin acted more effectively than 5-MT.
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Affiliation(s)
- P K Nayak
- Department of Zoology, Banaras Hindu University, Varanasi, India
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Abstract
We report on a sixty-six-year-old man with a poorly differentiated, diffuse lymphoma in whom bilateral multiple renal masses developed six months after starting chemotherapy. Computerized tomography and selective renal arteriograms were suggestive of either recurrence of lymphoma or renal cell carcinoma. Kidney biopsy revealed renal oncocytomas, benign renal tumors. The patient was spared further courses of cytotoxic therapy.
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Abstract
1. Beagle dogs were chronically treated with cocaine, 5 mg/kg subcutaneously twice daily for 6 weeks, followed by same dose of [3H]cocaine given intravenously. 2. The t1/2 values of cocaine in plasma, liver, spleen and heart, in acutely and chronically treated dogs, were: 1-2, 1-1; 2-2, 1-8; 1-8, 1-3; 2-0, 1-2 h, respectively. In both groups, cocaine disappeared from all areas of the central nervous system 12-24 h after injection but significant amounts of radioactivity due to benzoylnorecgonine and benzoylecgonine persisted in the CNS even 1 week after administration of cocaine. Brain-to-plasma ratios of cocaine were lower in chronically-treated than in acutely-treated dogs 2 and 4 h after injection. 3. Norcocaine, benzoylnorecgonine, benzoylecgonine and ecgonine were metabolites of cocaine in dog brain in both groups. Norcocaine and benzoylnorecgonine were present in higher amounts in brains of chronically treated dogs. Rate of disappearance of norcocaine was similar to cocaine in both groups. 4. The amounts of cocaine excreted in urine and faeces as percentage of dose were 0-9-5-0, 1-1-6 in the acute and 2-2-3-3 and 0-2-0-3 in the chronically treated dogs. Major excretion of radiactivity occurred in urine within 24 h in both groups. Total radioactivity (65% of dose) in urine plus faeces was similar in both groups. 5. Norcocaine, benzoylnorecgonine, benzoylecgonine, ecgonine, norecgonine, ecgonine methyl ester and unidentified compounds were urinary metabolites of cocaine in both groups. Benzoylnorecgonine and ecgonine were excreted in higher amounts and benzoylecgonine and norecgonine in lower amounts in the acute than in the chronically treated dogs. 6. The possible role of persistence of benzoylnorecgonine and benzoylecgonine (which possessed potent stimulant activity intracisternally) in the CNS is discussed.
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Nayak PK, Misra AL, Mulé SJ. Physiological disposition and biotransformation of (3H) cocaine in acutely and chronically treated rats. J Pharmacol Exp Ther 1976; 196:556-69. [PMID: 1263111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A sensitive method was developed for the estimation of [3H] cocaine in biological materials. After an injection of 8 mg/kg i.v. in male Wistar rats, peak levels in brain, tissues and plasma occurred within 15 minutes and cocaine disappeared completely from brain and plasma 6 hours postinjection. The T1/2 of cocaine in brain and plasma was 0.4 and 0.3 hour, respectively. No significant differences were observed in the rates of disappearance of cocaine from the subcutaneous site in acute and chronically treated rats after an injection of 20 mg/kg. After a 20 mg/kg s. c. dose, the peak levels of cocaine were attained gradually in 4 hours in brain, tissues and plasma with the exception of heart (0.5 hour) and fat (2 hours). These peak levels shifted from 4 to 2 hours in the chronically treated group. Consistently higher levels of cocaine were found to be sequestered in fat in the chronically treated animals. The T1/2 of cocaine in brain and plasma of chronically treated rats was approximately 1.8 to 2 hours and that in the acutely treated animals, 0.8 to 1 hour. The brain/plasma ratios were also somewhat higher in chronically treated as compared to the acutely treated animals and were indicative of a high affinity of tissue for cocaine. Although cocaine did not persist in brains of acutely treated animals, measurable amounts were shown to persist in brain and other tissues of chronically treated animals long after the disappearance in plasma. Significantly high concentrations of metabolites of cocaine persisted in brain and plasma of acutely and chronically treated animals. No significant differences were observed in the plasma protein binding of cocaine in control, acutely and chronically treated rats. Unchanged cocaine was excreted in very small amounts in rat bile and approximately 36% of the dose (5 mg/kg i. v.) was excreted as metabolites 3.5 hours after injection. Excretion of free cocaine in urine and feces after a 20 mg/kg s. c. dose in acutely and chronically treated rats was 1.2 and 1.5%, respectively. Significantly higher excretion of total radioactivity occurred in feces in the chronic group (35.9%) as compared to the acute group (22.1%). Benzoylecgonine, benzoyl norecgonine, ecgonine methyl ester and ecgonine were identified as urinary metabolites in both acute and chronic animals. In addition, evidence was obtained for the presence of a phenolic metabolite and two other hydroxylated metabolites (with hydroxylation presumably in positions 6 and 7 of the pyrrolidine ring). Implications of these observations with respect to systemic toxicity, the absence of tolerance and physical dependence liability of cocaine are discussed.
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Misra AL, Nayak PK, Bloch R, Mulé SJ. Estimation and disposition of [3H]benzoylecgonine and pharmacological activity of some cocaine metabolites. J Pharm Pharmacol 1975; 27:784-6. [PMID: 241797 DOI: 10.1111/j.2042-7158.1975.tb09404.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Misra AL, Nayak PK, Patel MN, Vadlamani NL, Mulé SJ. Identification of norcocaine as a metabolite of (3H)-cocaine in rat brain. Experientia 1974; 30:1312-4. [PMID: 4435177 DOI: 10.1007/bf01945203] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Misra AL, Vadlamani NL, Bloch R, Nayak PK, Mule SJ. Physiologic disposition and metabolism of (3H) ecgonine (cocaine metabolite) in the rat. Res Commun Chem Pathol Pharmacol 1974; 8:55-63. [PMID: 4847905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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