151
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Chandrasekaran K, Thomas J. Photophysical and photochemical properties of pyrene-doped TiO2 particle suspensions in water. J Colloid Interface Sci 1985. [DOI: 10.1016/s0021-9797(85)80028-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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152
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Chandrasekaran K, Thomas J. Photophysical properties of polyaromatic molecules adsorbed on TiO2 powder: the effect of coadsorbant. J Colloid Interface Sci 1984. [DOI: 10.1016/0021-9797(84)90417-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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153
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Chandrasekaran K, Tajik AJ, Edwards WD, Seward JB. Two-dimensional echocardiographic diagnosis of quadricuspid aortic valve. Am J Cardiol 1984; 53:1732-3. [PMID: 6731321 DOI: 10.1016/0002-9149(84)90617-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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154
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Chandrasekaran K, Thomas JK. Photochemical reactions of amorphous and crystalline titanium dioxide powder suspensions in water. ACTA ACUST UNITED AC 1984. [DOI: 10.1039/f19848001163] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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155
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Levitsky K, Chandrasekaran K, Mora PT, Simmons DT. Immunoaffinity chromatography of a cellular tumor antigen from mouse neuroblastoma cells. Int J Cancer 1983; 32:597-602. [PMID: 6358054 DOI: 10.1002/ijc.2910320513] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The cellular tumor antigen p53 was isolated from mouse neuroblastoma cells and was found in a form not complexed to another protein. The p53 in these cells was stable, turning over about every 10 h. Its methionine-labelled tryptic peptides were very similar to those of the p53 isolated from SV40-transformed mouse cells. The labelled protein was purified from neuroblastoma cells by immunoaffinity using specific monoclonal antibodies and was about 80% radiochemically pure. Furthermore, the purified p53 sedimented in sucrose gradients with a sedimentation coefficient of approximately 8S. This correlated with the sedimentation coefficient of p53 prior to purification, showing that the purified protein retained its native size.
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156
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Chandrasekaran K, Thomas J. Photochemical reduction of carbonate to formaldehyde on TiO2 powder. Chem Phys Lett 1983. [DOI: 10.1016/0009-2614(83)80259-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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157
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Chandrasekaran K, Thomas J. The mechanism of the photochemical oxidation of water to oxygen with silver chloride colloids. Chem Phys Lett 1983. [DOI: 10.1016/0009-2614(83)80507-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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158
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Chandrasekaran K, Mora PT, Nagarajan L, Anderson WB. The amount of a specific cellular protein (p53) is a correlate of differentiation in embryonal carcinoma cells. J Cell Physiol 1982; 113:134-40. [PMID: 6290508 DOI: 10.1002/jcp.1041130122] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A specific cellular protein of molecular weight of 53-55,000 (p53) has been shown to be induced in all SV40 transformed cells. A similar protein has also been shown to be present in embryonal carcinoma cells and in midgestation murine embryo primary cells, which are not infected by SV40. In embryo cell primaries the amount of the protein was shown to decrease with the increase in the stage of embryo development. As differentiation or decrease in cell growth rate can account for this, and since the growth rate of embryo primary cells cannot be measured, we chose to investigate various embryonal carcinoma cells. We report that the p53 is present in a pluripotent embryonal carcinoma cell OTT6050, and in its differentiated parietal endoderm derivative, PYS-2 cells. The amount of p53 is higher in the undifferentiated EC stem cells than in the differentiated PYS-2 (parietal endoderm) cells. The amount of the protein decreases in F9 embryonal carcinoma cells induced to differentiate to a parietal endoderm cell type by treatment with retinoic acid, as it does following spontaneous differentiation of OTT6050 EC cells. To determine if a change in growth rate, rather than differentiation, might account for the diminished levels of this protein, the amount of p53 was measured in growing and in growth arrested cell populations. When the growth rate of F9 cells was reduced by treatment with 8-bromocyclic AMP there was no change in the amount of p53. The half life of the p53 was compared in the undifferentiated and the differentiated cell types to determine if a change in stability might account, in part, for the altered levels of this protein. The p53 is found to be most stable in the SV40 transformed established clonal cells. It is less stable in the fibroblast clonal cells which were not transformed by SV40. The results of these experiments indicate that a decrease in the amount of p53 primarily correlates with differentiation in the embryonal carcinoma cell lines studied and not with cell growth rate. Furthermore, the decrease appears to be related (in part) to the decreased stability of the p53.
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159
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Mora PT, Chandrasekaran K, Hoffman JC, McFarland VW. Quantitation of a 55K cellular protein: similar amount and instability in normal and malignant mouse cells. Mol Cell Biol 1982; 2:763-71. [PMID: 6100911 PMCID: PMC369858 DOI: 10.1128/mcb.2.7.763-771.1982] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Quantitative expression of a specific 55,000 (55K)-molecular-weight cellular protein was studied in two groups of mouse embryo fibroblast (clonal) cells originating from two parent clones, one of which possessed high tumorigenicity and the other of which possessed very low tumorigenicity. From the clone with low tumorigenicity, tumor lines and clones were obtained by selecting rare spontaneously transformed highly tumorigenic (mutant) cells. Cells were labeled during exponential growth for 3 h at 37 degrees C, with [35S]methionine, and the cellular 55K protein was immunoprecipitated with a monoclonal antibody and quantitated. There were low and approximately equal amounts of 55K protein in cells (clones) with both low and high tumorigenicity from both groups of cells, and there was no correlation at all between quantitative expression of 55K protein and of cellular tumorigenicity. There was approximately 10- to 20-fold more 55K protein in all simian virus 40-transformed T antigen-positive derivative clones, as shown previously. The T antigen-negative revertant tumor lines and clones obtained by an immunological in vivo selection method had low amounts of 55K protein, similar to the parent cell before simian virus 40 transformation. In all of the T antigen-negative cells, including the highly tumorigenic cells, degradation (turnover?) of the 55K protein was rapid, and a half-life of 15 to 60 min was estimated from pulse-chase experiments. In all of the T antigen-positive cells the 55K protein was stable (half-life greater than 10 h). In primary cells established from the tumors induced by highly tumorigenic cells there was a very low or no detectable amount of the 55K protein. This is in contrast to the primary cells obtained from early murine embryos in which we have reported high amounts of (stable) 55K proteins.
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160
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Sunandana C, Chandrasekaran K, Aravamudan G, Rao G. Electrical properties of InxMCh2 (M ≡ Nb, Ta; Ch ≡ S, Se). ACTA ACUST UNITED AC 1982. [DOI: 10.1016/0022-5088(82)90135-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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161
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Chandrasekaran K, McFarland VW, Simmons DT, Dziadek M, Gurney EG, Mora PT. Quantitation and characterization of a species-specific and embryo stage-dependent 55-kilodalton phosphoprotein also present in cells transformed by simian virus 40. Proc Natl Acad Sci U S A 1981; 78:6953-7. [PMID: 6273897 PMCID: PMC349171 DOI: 10.1073/pnas.78.11.6953] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A 55-kilodalton (kDal) protein was detected recently in primary cultures of day 12 mouse embryos by immunoprecipitation with serum from simian virus 40 (SV40) tumor-bearing hamsters (T serum), Preliminary evidence suggested that this protein was similar to a cellular 55-kDal protein induced after SV40 transformation of mouse cells. We now show that specific approximately 55-kDal [35S]methionine-labeled proteins precipitate from primary cultures of midgestation mouse, rat, and hamster embryos on addition of T serum or monoclonal antiserum prepared against the SV40-induced mouse 55-kDal proteins. The two-dimensional maps of the [35S]methionine-labeled tryptic peptides of the mouse, hamster, and rat embryo proteins are similar to the maps of the corresponding proteins from SV40-transformed cells. Primary cells from midgestation mouse, hamster, or rat embryos contain one-third to one-half as much 55-kDal protein as a SV40-transformed mouse fibroblast cell and nearly the same amount as F9 mouse embryonal carcinoma cells. The amount of 55-kDal protein is greatly reduced on replating the mouse, rat, or hamster embryo primary cells. The amount of this protein in mouse embryos is dependent on the stage of the embryo. The embryo proteins are phosphoproteins.
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162
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Chandrasekaran K, Winterbourne DJ, Luborsky SW, Mora PT. Surface proteins of simian-virus-40-transformed cells. Int J Cancer 1981; 27:397-407. [PMID: 6169662 DOI: 10.1002/ijc.2910270320] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Mammalian cells transformed in tissue culture by SV40 were shown to contain, in addition to the SV40-coded 94,000 d large T antigen and the 20,000 d small t antigen, a approximately 56,000 d cellular protein, which specifically precipitates with sera of animals bearing SV40-induced tumor(s) (tumor or T serum). We investigated the presence of these three proteins at the surface of logarithmically growing SV40-transformed cloned mouse cells, after metabolic labelling with [35S]-methionine for 3 h. The 56,000 d protein was found to be susceptible to digestion by trypsin under conditions which did not disrupt the cells, while no small t antigen was found to be digested. Both the 56,000 d cellular protein and the SV40 large T antigen were susceptible to lactoperoxidase-catalyzed iodination from the outside of intact cells. Trypsin treatment removed both the iodinated 56,000 d protein and the iodinated SV40 large T antigen. These experiments indicated that (a certain amount of) the 56,000 d protein and a relatively small amount of the large T antigen (which is present mainly in the nucleus) are present on the cell surface. The results confirm and extend independent experiments using subcellular fractionation techniques (Luborsky and Chandrasekaran, 1980; Soule and Butel, 1979). After heat treatment (at 50 degrees C for 30 min) of the whole-cell extract the 56,000 d cellular protein was precipitated by the tumor serum in the absence of precipitation of SV40 large T antigen. This result showed that the 56,000 d protein is more (thermo)stable (in the whole-cell extract) than the SV40 large T antigen, and also indicated that the tumor serum employed had antibodies against the 56,000 d cellular antigen. The heat-treated whole-cell extract of Sv40-transformed mouse cells was able to immunize and fully protect mice against a lethal tumorigenic dose of SV40-transformed cells. These results suggest the need for further experiments to characterize the chemical and immunologic properties of the 56,000 d protein.
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163
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Chandrasekaran K, Natarajan P. Flash-photolysis studies of the electron-transfer reactions of dioxygen complexes of cobalt(III) with tris(2,2′-bipyridyl)ruthenium(III). ACTA ACUST UNITED AC 1981. [DOI: 10.1039/dt9810000478] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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164
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Mora PT, Chandrasekaran K, McFarland VW. An embryo protein induced by SV40 virus transformation of mouse cells. Nature 1980; 288:722-4. [PMID: 6256642 DOI: 10.1038/288722a0] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A specific protein of molecular weight (MW) approximately 55,000 (55K) was found recently by immunoprecipitation in all SV40 virus-transformed mammalian cells, in addition to the SV40 large T antigen (appoximately 94K) and small antigen (approximately 17K), which are the only proteins coded by the 'early half' of the SV40 genome. The 55K protein is encoded by cellular DNA; its peptide pattern is different from that of the SV40 antigens and it is species specific in mouse, rat, hamster, monkey and human SV40-transformed (or infected) cells. A 55K protein with a similar peptide pattern was found in mouse embryonal carcinoma cells not exposed to SV40. Similar proteins were reported in mouse sarcomas and leukaemias induced by a great variety of aetiological agents and also in a spontaneously transformed mouse fibroblast cell line, and it has been suggested that the protein may be a general correlated of cellular tumorigenicity. We now report that the approximately 55K protein is present in primary cell cultures from 12-14 day old mouse embryos, but not in 16-day old mouse embryos. The embryo protein has a peptide pattern virtually indistinguishable from that of the SV40-induced protein. We also show by comparing closely related cell families that spontaneously transformed highly tumorigenic mouse cells do not possess the 55K protein.
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165
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Rao PM, Chandrasekaran K, Radhakrishnan T, Arjundoss G. A case of hypokalemic type of periodic paralysis (case report). THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 1980; 28:549-52. [PMID: 7228844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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166
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Luborsky SW, Chandrasekaran K. Subcellular distribution of simian virus 40 T antigen species in various cell lines: the 56K protein. Int J Cancer 1980; 25:517-27. [PMID: 6154659 DOI: 10.1002/ijc.2910250414] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The subcellular distribution of SV40 anti-T serum-specific species was examined in SV40-transformed, T-antigen-positive tissue culture cell lines of rat and of AL/N and BALB/c mouse origin. Cells were labelled with [35S]methionine. The cytoplasm, nuclear and membrane fractions were obtained, and their radioimmunoprecipitates analyzed by gel electrophoresis. Tests were performed to determine the purity of these subcellular fractions, and negligible cross-contamination was found. The cytoplasm fractions lacked detectable anti-T serum reactivity. Large amounts of both large T antigen and a 56K protein were always present together both in the nuclear fractions and, in a somewhat lesser amount, in the plasma membrane fractions of all cell lines examined. Analysis of density gradient sedimentation profiles of the immunoprecipitates of whole-cell extracts indicated these species were associated in some fashion, probably with each other. The activity of the 56K protein may be associated with its presence on the cell surface where, either alone or acting together with the large T antigen, it might provide the surface activity responsible for tumor-specific surface and/or transplantation antigen activities.
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167
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Chandrasekaran K, Dharmalingam K, Jayaraman J. Assembly of mitochondria in yeast. Complementation of mitochondrial and cytosolic products in a temporal sequence in vitro. EUROPEAN JOURNAL OF BIOCHEMISTRY 1980; 103:471-80. [PMID: 6444578 DOI: 10.1111/j.1432-1033.1980.tb05971.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
1. Sequential transfer of derepressing yeast spheroplasts from a medium containing chloramphenicol to one containing cycloheximide or vice versa, shows that the cytosolically and mitochondrially synthesized products are synthesized independent of each other and accumulate in the absence of their counterparts. 2. This has been demonstrated by immunoprecipitation using specific antisera for cytochrome oxidase and ATPase enzymes. 3. The independently accumulated products have been shown to complement each other for the expression of enzyme activity, upon mixing in vitro. 4. By varying the time of treatment with cycloheximide, thereby allowing the mitochondrial protein synthesis to proceed to different extent, a time sequence in the appearance of the mitochondrially synthesized products is demonstrated.
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168
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Somasundaram T, Chandrasekaran K, Jayaraman J, Rajamanickam C. Role of cyclic AMP in mitochondriogenesis in yeast. Biochem Biophys Res Commun 1980; 92:655-61. [PMID: 6243945 DOI: 10.1016/0006-291x(80)90383-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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169
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Israel MA, Chowdhury K, Ramseur J, Chandrasekaran K, Vanderryn DF, Martin MA. Tumorigenicity of polyoma virus in hamsters. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 1980; 44 Pt 1,:591-6. [PMID: 6253159 DOI: 10.1101/sqb.1980.044.01.061] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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170
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Chandrasekaran K, Murugesh N, Jayaraman J. Glucose effect and mitochondriogenesis in yeast. Biochem Biophys Res Commun 1978; 82:693-9. [PMID: 208574 DOI: 10.1016/0006-291x(78)90930-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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171
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Chandrasekaran K, Jayaraman J. Effect of cyclic AMP on the biogenesis of cytochrome oxidase in yeast. FEBS Lett 1978; 87:52-4. [PMID: 204518 DOI: 10.1016/0014-5793(78)80131-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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172
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173
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Chandrasekaran K, Natarajan P. Photosensitization of superoxo-bridged dicobalt(III) cations by tris-(2,2′-bipyridyl)ruthenium(II) in the excited state. ACTA ACUST UNITED AC 1977. [DOI: 10.1039/c3977000774b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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174
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Natarajan P, Chandrasekaran K, Santappa M. A new initiator for polymerization. Photopolymerization of vinyl monomers using cu(II) — amino acid chelates. ACTA ACUST UNITED AC 1976. [DOI: 10.1002/pol.1976.130140802] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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175
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176
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Venkataraman MS, Bhaskaracharya B, Chandrasekaran K, Sundararaman S, Ramkrishna MS. Pseudocysts of the pancreas. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 1968; 51:71-6. [PMID: 5706162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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