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Soumya S, Vinod K, Harsita M, Sreelatha K, Durga Rao T, Ramesh Kumar K, Rout J, Gangopadhyay P, Bhatnagar A, Sattibabu B. Studies on the effect of In3+ ion on magnetic and magneto caloric properties of polycrystalline TbMnO3. J SOLID STATE CHEM 2023. [DOI: 10.1016/j.jssc.2023.123971] [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: 03/12/2023]
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Magudapathy P, Srivastava S, Gangopadhyay P, Amirthapandian S, Saravanan K, Das A, Panigrahi B. Alloying of metal nanoparticles by ion-beam induced sputtering. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.11.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Srivastava S, Gangopadhyay P, Amirthapandian S, Sairam T, Basu J, Panigrahi B, Nair K. Effects of high-energy Si ion-irradiations on optical responses of Ag metal nanoparticles in a SiO2 matrix. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.05.059] [Citation(s) in RCA: 7] [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: 10/25/2022]
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Affiliation(s)
- S Baruah
- Worcester Royal Hospital, Worcester, UK.
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Gangopadhyay P, Kesavamoorthy R, Bera S, Magudapathy P, Nair KGM, Panigrahi BK, Narasimhan SV. Optical absorption and photoluminescence spectroscopy of the growth of silver nanoparticles. Phys Rev Lett 2005; 94:047403. [PMID: 15783595 DOI: 10.1103/physrevlett.94.047403] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Indexed: 05/24/2023]
Abstract
Results obtained from the optical absorption and photoluminescence (PL) spectroscopy experiments have shown the formation of excitons in the silver-exchanged glass samples. These findings are reported here for the first time. Further, we investigate the dramatic changes in the photoemission properties of the silver-exchanged glass samples as a function of postannealing temperature. Observed changes are thought to be due to the structural rearrangements of silver and oxygen bonding during the heat treatments of the glass matrix. In fact, photoelectron spectroscopy does reveal these chemical transformations of silver-exchanged soda glass samples caused by the thermal effects of annealing in a high vacuum atmosphere. An important correlation between temperature-induced changes of the PL intensity and thermal growth of the silver nanoparticles has been established in this Letter through precise spectroscopic studies.
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Affiliation(s)
- P Gangopadhyay
- Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, India.
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Rao DN, Naga Srinivas NKM, Gangopadhyay P, Radhakrishnan TP. Internal Cancellation of Electric Field Induced Second Harmonic Generation in Solvent Mixtures and Solutions: An Efficient Protocol for the Determination of Molecular Hyperpolarizability. J Phys Chem A 2004. [DOI: 10.1021/jp037635f] [Citation(s) in RCA: 5] [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: 11/29/2022]
Affiliation(s)
- D. Narayana Rao
- School of Physics and School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| | - N. K. M. Naga Srinivas
- School of Physics and School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| | - P. Gangopadhyay
- School of Physics and School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
| | - T. P. Radhakrishnan
- School of Physics and School of Chemistry, University of Hyderabad, Hyderabad 500 046, India
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Jayanty S, Gangopadhyay P, Radhakrishnan TP. Steering molecular dipoles from centrosymmetric to a noncentrosymmetric and SHG active assembly using remote functionality and complexationElectronic supplementary information (ESI) available: powder SHG variation with particle size for DMEDQ-TPA. See http://www.rsc.org/suppdata/jm/b2/b202804m/. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b202804m] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Gangopadhyay P, Rao DN, Agranat I, Radhakrishnan TP. Strategic placement of stereogenic centers in molecular materials for second harmonic generation. Enantiomer 2002; 7:119-27. [PMID: 12108629 DOI: 10.1080/10242430212190] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Basic aspects of the nonlinear optical phenomenon of second harmonic generation (SHG) and the assembly of molecular materials for SHG are reviewed. Extensive use of chirality as a convenient tool to generate noncentrosymmetricity in molecular lattices, an essential requirement for the development of quadratic nonlinear optical materials, is noted. An overview of our investigations of chiral diaminodicyanoquinodimethanes is presented, which provides insight into a systematic approach to the effective deployment of chirality to achieve optimal molecular orientations for enhanced solid state SHG. Extension of these ideas to the realization of strong SHG in materials based on helical superstructures is outlined.
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Gangopadhyay P, Radhakrishnan TP. Helical Superstructures of a C(2)-Symmetric Molecule Exhibiting Strong Second Harmonic Generation in the Solid-State Financial support from the DST (Swarnajayanti Fellowship) and the use of the National Single Crystal Diffractometer Facility (funded by the DST at the School of Chemistry, University of Hyderabad) are gratefully acknowledged. P.G. thanks the University Grants Commission for a senior research fellowship. We thank du Pont Deutschland for a generous gift of 1,2-diaminocyclohexane. Angew Chem Int Ed Engl 2001; 40:2451-2455. [PMID: 11443661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Affiliation(s)
- P. Gangopadhyay
- School of Chemistry University of Hyderabad Hyderabad-500 046 (India)
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Gangopadhyay P, Radhakrishnan TP. Helical Superstructures of aC2-Symmetric Molecule Exhibiting Strong Second Harmonic Generation in the Solid-State. Angew Chem Int Ed Engl 2001; 40:2451-2455. [DOI: 10.1002/1521-3773(20010702)40:13<2451::aid-anie2451>3.0.co;2-m] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2001] [Revised: 04/05/2001] [Indexed: 11/08/2022]
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Sarkar M, Gangopadhyay P, Basak B, Chakrabarty K, Banerji J, Adhikary P, Chatterjee A. The reversible antifertility effect of Piper betle Linn. on Swiss albino male mice. Contraception 2000; 62:271-4. [PMID: 11172798 DOI: 10.1016/s0010-7824(00)00177-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To study the antifertility effect of an extract (alcoholic) of the leaf-stalk of Piper betle Linn., one set of experiments with two different doses in Swiss male albino mice were evaluated. Initially, 500 mg of the leaf-stalk extractive for 30 days and then 1000 mg for next 30 days/animal/day/kg body weight were administered orally. The extract reduced fertility to 0% within 60 days. Suppression of cauda epididymal sperm count and motility (p <0.05) was observed. Biochemical parameters did not show any marked alterations in testosterone content in serum nor 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity in testes although fructose content in seminal vesicles was reduced as are the weights of reproductive organs. The cholesterol content in testes increased, although not appreciably. After cessation of drug (plant extract) treatment, the altered parameters recovered. Results suggest that the contraceptive effect of the extract of leaf-stalk of Piper betle Linn. is mainly on the maturation process of spermatozoa in epididymides without influencing hystemic hormonal profiles. Withdrawal of the extract restored all altered parameters including organ weights and fertility after 60 days.
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Affiliation(s)
- M Sarkar
- Centre of Advanced Studies on Natural Products, Department of Chemistry, University College of Science & Technology, Calcutta University, 92, Acharya Prafulla Chandra Road, 700 009, Calcutta, India
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Sengupta A, Adhikary P, Basak BK, Chakrabarti K, Gangopadhyay P, Banerji J, Chatterjee A. Pre-clinical toxicity evaluation of leaf-stalk extractive of Piper betle Linn. in rodents. Indian J Exp Biol 2000; 38:338-42. [PMID: 11218809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Studies on pre-clinical toxicity were undertaken to determine the haematological and biochemical changes after administration of alcoholic extract of leaf-stalk of P. betle in rats and mice. Acute and chronic toxicity experiments were performed on mice and rats according to WHO protocol. Different doses of plant extractive were administered for toxicity studies on short and long term basis. Haematological, biochemical profiles and enzymatic studies (transaminases and phosphatases) indicated that the drug (plant extractive) was devoid of toxicity.
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Affiliation(s)
- A Sengupta
- Department of Chemistry and Centre of Advanced Studies on Natural Products, University College of Science and Technology, Calcutta University, 92, A.P.C. Road, Calcutta 700 009, India
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Sharma S, Gangopadhyay P, Swathi A, Radhakrishnan TP. Computational study of molecules for quadratic nonlinear optical applications: orthogonal orientation of dipole vector and hyperpolarisability pseudo vector. Phys Chem Chem Phys 2000. [DOI: 10.1039/a907340j] [Citation(s) in RCA: 4] [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: 11/21/2022]
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Misra S, Chakraborty S, Gangopadhyay P, Basu N. Phenytoin sodium induced diabetes insipidus. J Assoc Physicians India 1999; 47:456. [PMID: 10778541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- S Misra
- Bangur Institute of Neurology, Calcutta
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Gangopadhyay P, Venugopal Rao S, Narayana Rao D, Radhakrishnan TP. N-Alkyl-p-nitroanilines: impact of alkyl chain length on crystal structures and optical SHG. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a901591d] [Citation(s) in RCA: 32] [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: 11/21/2022]
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Gangopadhyay S, Gangopadhyay P. A longitudinal study of biological changes with age among the Brahmins of Calcutta. Z Morphol Anthropol 1996; 81:157-66. [PMID: 9270333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this paper, the individual biological sequence of change with age in a sample taken in metropolitan city, Calcutta, West Bengal, is discussed. The study comprises a few anthropometric measurements (stature, weight, biacromial breadth, nasal length, nasal breadth, upper facial height) taken on the same population at an interval of five years (first in the year 1982 and again in the year 1987). The study reveals that the amount of increment or decrement of some characters (the above mentioned traits) are different for different chronological age; and these differences can only be identified with the help of a longitudinal study which is free from the effect of secular change in the younger generations.
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Hall DT, Shemansky DE, Judge DL, Gangopadhyay P, Gruntman MA. Heliospheric hydrogen beyond 15 AU: Evidence for a termination shock. ACTA ACUST UNITED AC 1993. [DOI: 10.1029/93ja01175] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [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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Gangopadhyay P, Tang X, Lambropoulos P, Shakeshaft R. Theory of autoionization of Xe under two- and three-photon excitation. Phys Rev A Gen Phys 1986; 34:2998-3002. [PMID: 9897618 DOI: 10.1103/physreva.34.2998] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Mukherjee K, Gangopadhyay P. Extensor digitorum brevis transfer in chronic unstable ankles. J R Coll Surg Edinb 1983; 28:250-5. [PMID: 6631792] [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: 01/21/2023]
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Pyne AK, Moitra DN, Gangopadhyay P. Studies on the composition of milk with the use of neem seed expeller cake (Az adirachta indica) on lactating buffaloes. Indian Vet J 1979; 56:223-7. [PMID: 573242] [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: 12/23/2022]
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