76
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Parthasarathy R, Suess L, Liu Y, Dunning FB. Formation of dipole-bound negative ions in Rydberg atom collisions: A signature. J Chem Phys 2003. [DOI: 10.1063/1.1595093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
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77
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Suess L, Parthasarathy R, Dunning FB. Free ion formation in K(np)/SF6 collisions at low-to-intermediate n: Velocity dependence of the number and lifetime of the product ions. J Chem Phys 2003. [DOI: 10.1063/1.1574804] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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78
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Suess L, Parthasarathy R, Dunning F. Rydberg electron transfer to CS2: properties of the product CS2− ions. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00480-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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79
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Suess L, Parthasarathy R, Dunning FB. Nondissociative low energy electron attachment to C2Cl4:C2Cl4− ion lifetime. J Chem Phys 2003. [DOI: 10.1063/1.1557454] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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80
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Suess L, Parthasarathy R, Dunning FB. Nondissociative low-energy electron attachment to SF6, C6F6, C10F8, and c-C7F14: Negative ion lifetimes. J Chem Phys 2002. [DOI: 10.1063/1.1522713] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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81
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Ghosh S, Parthasarathy R, Rosenbaum TF, Aeppli G. Coherent spin oscillations in a disordered magnet. Science 2002; 296:2195-8. [PMID: 12077409 DOI: 10.1126/science.1070731] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Most materials freeze when cooled to sufficiently low temperature. We find that magnetic dipoles randomly distributed in a solid matrix condense into a spin liquid with spectral properties on cooling that are the diametric opposite of those for conventional glasses. Measurements of the nonlinear magnetic dynamics in the low-temperature liquid reveal the presence of coherent spin oscillations composed of hundreds of spins with lifetimes of up to 10 seconds. These excitations can be labeled by frequency and manipulated by the magnetic fields from a loop of wire and can permit the encoding of information at multiple frequencies simultaneously.
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82
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Srikrishnan T, Fridey SM, Parthasarathy R. Conformation of 3'-nucleotides. Crystal structure of uncharged 3'-uridine monophosphate monohydrate and hydrogen bonding to the furanose ring oxygen. J Am Chem Soc 2002. [DOI: 10.1021/ja00508a006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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83
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Row TNG, Parthasarathy R. Directional preferences of nonbonded atomic contacts with divalent sulfur in terms of its orbital orientations. 2. Sulfur.cntdot..cntdot..cntdot.sulfur interactions and nonspherical shape of sulfur in crystals. J Am Chem Soc 2002. [DOI: 10.1021/ja00392a047] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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84
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Parthasarathy R, Paul B, Korytnyk W. X-ray and NMR studies on thiazolidines: crystal structure and conformational equilibriums of N-acetyl-2-(p-tolyl)thiazolidine-4-carboxylic acid ad related thiazolidine derivatives. J Am Chem Soc 2002. [DOI: 10.1021/ja00437a036] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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85
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Desiraju GR, Parthasarathy R. The nature of halogen.cntdot..cntdot..cntdot.halogen interactions: are short halogen contacts due to specific attractive forces or due to close packing of nonspherical atoms? J Am Chem Soc 2002. [DOI: 10.1021/ja00205a027] [Citation(s) in RCA: 637] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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86
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Rosenfield RE, Parthasarathy R, Dunitz JD. Directional preferences of nonbonded atomic contacts with divalent sulfur. 1. Electrophiles and nucleophiles. J Am Chem Soc 2002. [DOI: 10.1021/ja00456a072] [Citation(s) in RCA: 420] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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87
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Ohrt JM, Srikrishnan T, Parthasarathy R, Dutta SP, Chheda GB. Unequivocal structural assignments of N7- and N9-acyladenines. J Am Chem Soc 2002. [DOI: 10.1021/ja00484a066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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88
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Ohrt JM, Parthasarathy R, Chheda GB. Crystal and molecular structure of a tricyclic purine intermediate. 3-Methyl-3H-imidazo[2,1-i]purine-8(7H)-one. J Am Chem Soc 2002. [DOI: 10.1021/ja00725a037] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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89
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Nash CP, Olmstead MM, Weiss-Lopez B, Musker WK, Ramasubbu N, Parthasarathy R. Structures and Raman spectra of two crystalline modifications of dithiodiglycolic acid. J Am Chem Soc 2002. [DOI: 10.1021/ja00310a083] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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90
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Bobek M, Glowka M, Parthasarathy R. Synthesis and the crystal structure of 4-(2-deoxy-.beta.-D-erythro-pentofuranosyl)-6-methyl-1,2,4-triazin-3-(4H)-one 1-oxide, a structural analog of thymidine. J Org Chem 2002. [DOI: 10.1021/jo00345a002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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91
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Ramasubbu N, Parthasarathy R, Murray-Rust P. Angular preferences of intermolecular forces around halogen centers: preferred directions of approach of electrophiles and nucleophiles around carbon-halogen bond. J Am Chem Soc 2002. [DOI: 10.1021/ja00275a012] [Citation(s) in RCA: 427] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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92
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Parthasarathy R, Rao KJ, Rao CNR. Dielectric and electron spin resonance spectroscopic studies of glassy crystalline states of organic compounds. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j150645a012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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93
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Koul D, Parthasarathy R, Shen R, Davies MA, Jasser SA, Chintala SK, Rao JS, Sun Y, Benvenisite EN, Liu TJ, Yung WK. Suppression of matrix metalloproteinase-2 gene expression and invasion in human glioma cells by MMAC/PTEN. Oncogene 2001; 20:6669-78. [PMID: 11709701 DOI: 10.1038/sj.onc.1204799] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2000] [Revised: 06/07/2001] [Accepted: 06/11/2001] [Indexed: 01/21/2023]
Abstract
Human gliomas are highly invasive, and remain to be a major obstacle for any effective therapeutic remedy. Among many other factors, gliomas express elevated levels of matrix metalloproteinases (MMPs), which have been implicated to play an important role in tumor invasion as well as neovascularization. The tumor suppressor gene mutated in multiple advanced cancers/phosphatase and tensin homologue (MMAC/PTEN) has been shown to inhibit cell migration, spreading, and focal adhesion. In this study, we determined whether MMAC/PTEN inhibits tumor invasion by modulating MMP-2 activity. Our results showed that reintroduction of the MMAC/PTEN gene into human glioma U251 and U87 cells modified their phenotype and growth characteristics. The ability of MMAC/PTEN to induce anoikis in U251 cells was accompanied by a significant inhibition of in vitro invasion (70%). Expression of MMAC/PTEN in U251 and U87 cells inhibited MMP-2 enzymatic activity as determined by zymography. Furthermore, MMAC/PTEN expression strongly decreased MMP-2 mRNA levels, which correlated well with the inhibition of invasion capacity in these cells. Concomitant with MMP-2 expression and activity, MMP-2 promoter activity was also reduced in MMAC/PTEN expressing cells. Our observations suggest that MMAC/PTEN inhibits tumor cell invasion in part by regulating MMP-2 gene transcription and thereby its enzymatic activity. Further characterization of this regulation will facilitate the development of MMAC/PTEN based gene therapy for gliomas.
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94
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Parthasarathy R, Suess L, Hill SB, Dunning FB. Low-energy dissociative electron attachment to BrCN and CBrCl3: Temperature dependences and reaction dynamics. J Chem Phys 2001. [DOI: 10.1063/1.1364686] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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95
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96
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97
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Abstract
Based upon experimental results on certain visual spatial discrimination tasks, we have developed a formalism for a non-Euclidian perceptual space. In this formalism, the transformation from real to perceptual space is given by a generalized covariant tensor. The concept of parallel transport of vectors in a curved space is used to prove that closed loops in real space imply closed loops with the same orientation in the perceptual space also.
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98
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Voci SL, Gottlieb RH, Fultz PJ, Mehta A, Parthasarathy R, Rubens DJ, Strang JG. Delayed computed tomographic characterization of renal masses: preliminary experience. ABDOMINAL IMAGING 2000; 25:317-21. [PMID: 10823459 DOI: 10.1007/s002610000009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
BACKGROUND To evaluate the performance of delayed contrast enhanced computed tomography (DCT) in characterizing renal masses. METHODS Twenty-four patients with suspected renal masses or indeterminate renal masses on previous imaging studies were prospectively evaluated with preintravenous contrast imaging, conventional contrast-enhanced computed tomography (imaging initiated 2 min after intravenous contrast injection), and DCT (imaging initiated 13 min after injection of intravenous contrast). Only lesions larger than 1.0 cm were evaluated, with scanning parameters kept constant across the three scans. RESULTS All pathologically confirmed renal cell carcinomas (n = 6) were detected on DCT using a threshold attenuation decrease of 10 Hounsfield units (HU). A significant decrease (p = 0.031) in attenuation occurred in renal cell carcinomas (mean = 29.6 +/- 23.6 HU) compared with the attenuation change (mean decrease = 1.1 +/- 7.1 HU), which occurred in non-neoplastic renal cysts (n = 34). Non-neoplastic renal cysts were correctly classified by DCT 32 of 34 times (94%). CONCLUSIONS In this study, DCT distinguished renal cell carcinomas from non-neoplastic cysts in a vast majority of cases and may aid in characterizing incidentally discovered renal lesions on postcontrast CT.
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Parthasarathy R, Kayasth S, Verma R, Mathur PK, Anupama P, Anilkumar S. J Radioanal Nucl Chem 2000; 246:239-242. [DOI: 10.1023/a:1006796324755] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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100
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Finch CD, Parthasarathy R, Hill SB, Dunning FB. Nondissociative low-energy electron attachment to c-C7F14 and C6F6: Intermediate lifetimes. J Chem Phys 1999. [DOI: 10.1063/1.480054] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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