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Tavassoli N, Chen Z, Bain A, Melo L, Chen D, Grant ER. Template-Oriented Genetic Algorithm Feature Selection of Analyte Wavelets in the Raman Spectrum of a Complex Mixture. Anal Chem 2014; 86:10591-9. [DOI: 10.1021/ac502203d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- N. Tavassoli
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Z. Chen
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - A. Bain
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - L. Melo
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - D. Chen
- State Key Laboratory
of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China
| | - E. R. Grant
- Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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2
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Sadeghi H, Kruyen A, Hung J, Gurian JH, Morrison JP, Schulz-Weiling M, Saquet N, Rennick CJ, Grant ER. Dissociation and the development of spatial correlation in a molecular ultracold plasma. Phys Rev Lett 2014; 112:075001. [PMID: 24579607 DOI: 10.1103/physrevlett.112.075001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Indexed: 06/03/2023]
Abstract
Penning ionization initiates the evolution of a dense molecular Rydberg gas to plasma. This process selects for pairs of excited molecules separated by a distance of two Rydberg orbital diameters or less. The deactivated Penning partners predissociate, depleting the leading edge of the distribution of nearest-neighbor distances. For certain density and orbital radii, this sequence of events can form a plasma in which large distances separate a disproportionate fraction of the ions. Experimental results and model calculations suggest that the reduced potential energy of this Penning lattice significantly affects the development of strong coupling in an ultracold plasma.
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Affiliation(s)
- H Sadeghi
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - A Kruyen
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - J Hung
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - J H Gurian
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - J P Morrison
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - M Schulz-Weiling
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - N Saquet
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - C J Rennick
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
| | - E R Grant
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z3, Canada
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3
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Morrison JP, Rennick CJ, Keller JS, Grant ER. Evolution from a molecular Rydberg gas to an ultracold plasma in a seeded supersonic expansion of NO. Phys Rev Lett 2008; 101:205005. [PMID: 19113349 DOI: 10.1103/physrevlett.101.205005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Indexed: 05/27/2023]
Abstract
We report the spontaneous formation of a plasma from a gas of cold Rydberg molecules. Double-resonant laser excitation promotes nitric oxide, cooled to 1 K in a seeded supersonic molecular beam, to single Rydberg states extending as deep as 80 cm;{-1} below the lowest ionization threshold. The density of excited molecules in the illuminated volume approaches 1x10;{13} cm;{-3}. This population evolves to produce free electrons and a durable cold plasma of electrons and intact NO+ ions.
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Affiliation(s)
- J P Morrison
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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4
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Viteri CR, Gilkison AT, Schröder FS, Grant ER. Discrete–continuum and discrete–discrete interactions in the autoionization spectrum of 11 BH. Mol Phys 2007. [DOI: 10.1080/00268970701361314] [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: 10/22/2022]
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5
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Affiliation(s)
- K. Prentice
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - R. Nicodemus
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - B. Rajaram
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - E. R. Grant
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
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6
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Affiliation(s)
- Patrice Bell
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - F. Aguirre
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - E. R. Grant
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
| | - S. T. Pratt
- Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, and Department of Chemistry, Purdue University, West Lafayette, Indiana 47907
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7
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Gilkison AT, Viteri CR, Grant ER. Coupling of electron orbital motion with rotation in the high Rydberg states of BH. Phys Rev Lett 2004; 92:173005. [PMID: 15169146 DOI: 10.1103/physrevlett.92.173005] [Citation(s) in RCA: 8] [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] [Received: 10/28/2003] [Indexed: 05/24/2023]
Abstract
We have applied optical-optical-optical triple resonance spectroscopy to resolve a system of high Rydberg states in BH that serves quantitatively to characterize a fundamental example of electron-orbital-cation core rotational coupling. The third-color ionization-detected absorption spectrum originating from the photoselected 3s B1Sigma+ Rydberg state with vibrational and total angular momentum quantum numbers, v'=1 and N'=0 consists entirely of vibrationally autoionizing resonances for which final N=1 that converge in series to the BH+v+=1 rotational limits, N+=0, 1, and 2. For series with l=1 converging to N+=0 and 2, Rydberg orbital and rotational angular momenta couple to systematically perturb level energies and distribute lifetime in a well-isolated two-channel rotronic interaction that spans hundreds of wave numbers.
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Affiliation(s)
- A T Gilkison
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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8
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Vandenabeele P, Weis TL, Grant ER, Moens LJ. A new instrument adapted to in situ Raman analysis of objects of art. Anal Bioanal Chem 2004; 379:137-42. [PMID: 15045464 DOI: 10.1007/s00216-004-2551-z] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Revised: 02/04/2004] [Accepted: 02/08/2004] [Indexed: 10/26/2022]
Abstract
The analysis of precious artefacts and antiquities demands care in order to minimise the risk of accidental damage during measurement. Mobile fibre-optic-based Raman instruments offer a means to avoid destructive sampling and eliminate the need to transport artefacts for spectrochemical analysis. In this work we present a new mobile instrument developed and optimised for the in situ Raman investigation of objects of art and antiquities. The instrument is controlled by a portable computer. Selected mounts cover many types of artefacts. Newly written software routines organise spectra together with measurement parameters and facilitate calibration of the instrument. The present paper describes this new Raman instrument and discusses some challenges in the transition from a laboratory environment to in situ investigations in museums.
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Affiliation(s)
- P Vandenabeele
- Laboratory of Analytical Chemistry, Ghent University, Proeftuinstraat 86, 9000 Ghent, Belgium.
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9
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Bell P, Aguirre F, Grant ER, Pratt ST. Mode dependent vibrational autoionization of Rydberg states of NO2. II. Comparing the symmetric stretching and bending vibrations. J Chem Phys 2004; 120:2667-76. [PMID: 15268410 DOI: 10.1063/1.1638379] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Triple-resonance excitation and high-resolution photoelectron spectroscopy are combined to characterize the mode selectivity of vibrational autoionization of the high Rydberg states of NO2. Photoelectron spectra and vibrational branching fractions are reported for autoionizing Rydberg states converging to the NO2+ X 1Sigmag +(110) state, that is, with one quantum in the symmetric stretch, nu1, and one quantum in the bending vibration, nu2. These results indicate that autoionization proceeds most efficiently through the loss of one quantum from the symmetric stretch rather than from the bending vibration. The implications of this result are discussed in terms of the autoionization mechanism.
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Affiliation(s)
- Patrice Bell
- Argonne National Laboratory, Argonne, Illinois 60439, USA
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McMillian MK, Grant ER, Zhong Z, Parker JB, Li L, Zivin RA, Burczynski ME, Johnson MD. Nile Red binding to HepG2 cells: an improved assay for in vitro studies of hepatosteatosis. In Vitr Mol Toxicol 2002; 14:177-90. [PMID: 11846991 DOI: 10.1089/109793301753407948] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Nile Red is a fluorescent dye used extensively to study fat accumulation in many types of cells; unfortunately protocols that work well for most cells are not effective for studying drug-induced lipid accumulation in cultured liver cells and hepatocyte-derived cell lines. Using human hepatoma (HepG2) cells, we have developed a simple Nile Red binding assay as a screen for steatosis-inducing compounds. Increases in Nile Red binding in response to known hepatotoxic compounds were observed after incubating treated cells with 1 microM Nile Red for several hours, washing away free Nile Red, and then allowing redistribution, and/or clearance of the lipid-indicator dye. Several compounds known to cause hepatic fat accumulation in vivo were examined and most robustly increased Nile Red binding in HepG2 cells. These include estrogen and other steroids, ethionine, cyclosporin A, and valproic acid. Required concentrations for increased Nile Red binding were generally three-fold or more lower than the cytotoxic concentration determined by a resazurin reduction assay in the same cells. Qualitatively similar Nile Red binding results were obtained when primary canine or rat hepatocytes were used. Morphological differences in Nile Red staining were observed by confocal fluorescence microscopy in HepG2 cells after treatment with different compounds and likely reflect distinct toxicological mechanisms.
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Affiliation(s)
- M K McMillian
- The R.W. Johnson Pharmaceutical Research Institute, Route 202, P.O. Box 300, Raritan, NJ 08869, USA. mmcmilli@prius,jnj.com
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12
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Williams MT, Parsons DW, Frick RA, Ellis ER, Martin AJ, Giles SE, Grant ER. Acute respiratory infection in patients with cystic fibrosis with mild pulmonary impairment: comparison of two physiotherapy regimens. Aust J Physiother 2002; 47:227-36. [PMID: 11722291 DOI: 10.1016/s0004-9514(14)60270-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chest physiotherapy is an essential part of the management of cystic fibrosis, yet comparatively few studies have investigated the commonly used forms of chest physiotherapy during acute respiratory exacerbations. Fifteen subjects with cystic fibrosis and predominantly mild pulmonary impairment completed a randomised cross-over trial with 24 hours between treatments. The active cycle of breathing techniques (ACBT) assisted by a physiotherapist was compared with the ACBT performed independently by the patient. Measurement outcomes included pulmonary function tests, indirect calorimetry and oximetry parameters. Energy expenditure was not significantly different between the two treatment regimens, though significant improvements in pulmonary function were apparent 24 hours following the therapist-assisted ACBT. In this group of subjects, neither form of treatment proved superior in terms of energy consumption, but a reduction in airways obstruction was observed as a carry-over effect following the therapist-assisted ACBT.
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Affiliation(s)
- M T Williams
- School of Physiotherapy, University of South Australia, North Terrace, Adelaide, South Australia 5000.
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13
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Robinson JD, Foltynowicz RJ, Prentice K, Bell P, Grant ER. Laser-assisted (1+1ʹ)-photon ionization-detected absorption spectrum of the 3pπ [sup 2]Π state of HCO and DCO. J Chem Phys 2002. [DOI: 10.1063/1.1467329] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Nugent-Glandorf L, Scheer M, Samuels DA, Mulhisen AM, Grant ER, Yang X, Bierbaum VM, Leone SR. Ultrafast time-resolved soft x-ray photoelectron spectroscopy of dissociating Br2. Phys Rev Lett 2001; 87:193002. [PMID: 11690408 DOI: 10.1103/physrevlett.87.193002] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2001] [Indexed: 05/23/2023]
Abstract
The dissociation of excited state Br2 is probed with the novel technique of ultrafast soft x-ray photoelectron spectroscopy. Excited Br2 molecules are prepared in the dissociative (1)Pi(u) state with 80 fs, 400 nm pulses, and a series of photoelectron spectra are obtained during dissociation with pulses of soft x-ray light (47 nm, 26.4 eV, 250 fs). The formation of Br atoms is readily detected and the data support an extremely fast dissociation time for Br2 on the order of 40 fs. Amplitudes of the pump-probe features reveal that the ionization cross section of atomic Br at 47 nm is approximately 40 times larger than that of Br2.
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Affiliation(s)
- L Nugent-Glandorf
- JILA, National Institute of Standards and Technology and Department of Chemistry and Biochemistry, Boulder, Colorado 80309-0440, USA
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15
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Grant ER, Guttmann RP, Seifert KM, Lynch DR. A region of the rat N-methyl-D-aspartate receptor 2A subunit that is sufficient for potentiation by phorbol esters. Neurosci Lett 2001; 310:9-12. [PMID: 11524145 DOI: 10.1016/s0304-3940(01)02085-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
N-methyl-D-aspartate (NMDA) receptors are modulated by protein kinase C (PKC) in vivo and in heterologous expression systems. In heterologous expression systems, PKC-mediated modulation is subunit specific with NR2A-containing receptors being potentiated by phorbol 12-myristate 13-acetate (PMA), while NR2C-containing receptors are inhibited or unaffected. In the present study we have produced chimeric receptors containing NR2A and NR2C to define the components of NR2A which are sufficient for potentiation by PMA. Amino acids 1105-1400 of NR2A placed onto the C-terminus of NR2C at amino acid 1102 was the minimum region sufficient for producing a PMA-stimulated receptor. This suggests that this region contains structural determinants for PKC-mediated potentiation of NR2A receptors.
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Affiliation(s)
- E R Grant
- Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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16
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Burczynski ME, McMillian M, Parker JB, Bryant S, Leone A, Grant ER, Thorne JM, Zhong Z, Zivin RA, Johnson MD. Cytochrome P450 induction in rat hepatocytes assessed by quantitative real-time reverse-transcription polymerase chain reaction and the RNA invasive cleavage assay. Drug Metab Dispos 2001; 29:1243-50. [PMID: 11502735] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
The acceleration of drug discovery due to combinatorial chemistry and high-throughput screening methods has increased the numbers of candidate pharmaceuticals entering the drug development phase, and the capability to accurately predict whether drug candidates will induce various members of the drug-metabolizing cytochrome P450 (CYP) enzyme superfamily is currently of great interest to the pharmaceutical industry. In the present study, we describe the rapid and reliable analysis of CYP induction in a readily obtained model system (cultured rat hepatocytes) using both real-time quantitative reverse transcription-polymerase chain reaction (real-time RT-PCR) and the RNA invasive cleavage assay. The levels of members in the three primary inducible rat CYP subfamilies (CYP1A1, CYP2B1/2, and CYP3A1) were analyzed in untreated and induced (beta-naphthoflavone, phenobarbital, and hydrocortisone) hepatocyte cultures under various media conditions to screen for optimal CYP induction profiles. The fold inductions measured by real-time RT-PCR and the RNA invasive cleavage assay were also compared with enzyme activity measurements in parallel cultures using liquid chromatography/double mass spectrometry-based assays, and the sensitivity and the specificity of the two RNA analysis methods were compared. Using these techniques, various culture conditions were examined for optimizing induction of the three CYP subfamily members. Both real-time RT-PCR and the RNA invasive cleavage assay prove to be effective methods for determining the effects of drugs on specific CYPs in primary rat hepatocytes.
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Affiliation(s)
- M E Burczynski
- Department of Pre-Clinical Drug Metabolism and Toxicology, The R. W. Johnson Pharmaceutical Research Institute, Ortho McNeil Pharmaceutical Building, Route 202, Raritan, New Jersey 08869, USA
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17
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Grant ER, Errico MA, Emanuel SL, Benjamin D, McMillian MK, Wadsworth SA, Zivin RA, Zhong Z. Protection against glutamate toxicity through inhibition of the p44/42 mitogen-activated protein kinase pathway in neuronally differentiated P19 cells. Biochem Pharmacol 2001; 62:283-96. [PMID: 11434901 DOI: 10.1016/s0006-2952(01)00665-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Excessive levels of the neurotransmitter glutamate trigger excitotoxic processes in neurons that lead to cell death. N-Methyl-D-aspartate (NMDA) receptor over-activation is a key excitotoxic stimulus that leads to increases in intracellular calcium and activation of downstream signaling pathways, including the p44/42 mitogen-activated protein (MAP) kinase pathway. In the present study, we have demonstrated that 1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio]butadiene (U0126), a potent and selective inhibitor of the p44/42 MAP kinase signaling pathway, prevents glutamate-induced death in neuronally differentiated P19 cells. In addition, we show that differentiated, but not undifferentiated, P19 cells expressed zeta1, epsilon1, and epsilon2 subunits of the NMDA receptor. Differentiated P19 cells exhibited specific NMDA receptor binding and intracellular calcium responses to glutamate that were blocked by the selective NMDA receptor antagonist [5R,10S]-[+]-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine (MK-801), but not U0126. Glutamate treatment of differentiated P19 cells triggered a rapid and sustained induction in p42 MAP kinase phosphorylation that was blocked by U0126. Pretreatment of differentiated P19 cells with U0126, but not other classes of protein kinase inhibitors, protected against glutamate-induced cell death. Post-treatment with U0126, even as late as 6 hr after glutamate application, also protected against glutamate toxicity. These results suggest that the p44/42 MAP kinase pathway may be a critical downstream signaling pathway in glutamate receptor-activated toxicity.
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Affiliation(s)
- E R Grant
- Drug Discovery, R.W. Johnson Pharmaceutical Research Institute, 1000 Route 202 South, Raritan, NJ 08869, USA
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18
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Anegawa NJ, Guttmann RP, Grant ER, Anand R, Lindstrom J, Lynch DR. N-Methyl-D-aspartate receptor mediated toxicity in nonneuronal cell lines: characterization using fluorescent measures of cell viability and reactive oxygen species production. Brain Res Mol Brain Res 2000; 77:163-75. [PMID: 10837912 DOI: 10.1016/s0169-328x(00)00050-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Cells transfected with specific N-methyl-D-aspartate (NMDA) receptor subtypes undergo cell death that mimics glutamate-induced excitotoxicity pharmacologically. We have further characterized the mechanisms of cell death resulting from NMDA receptor activation in such cells through development of cell counting methods based on co-transfection with green fluorescent protein. When co-transfected with NMDA receptors, GFP expression was limited to live cells as indicated by the observation that GFP was only detected in cells which were positive for markers of live cells, and was found in no cells which were trypan blue or propidium iodide positive. Using co-transfection with green fluorescent protein and cell counting of viable cells with a fluorescence activated cells sorter, we confirmed the subunit-specific profile of NMDA receptor-mediated cell death in cells transfected with NMDA receptors. Toxicity was greatest in the NR1A/2A receptor, less in the NR1A/2B receptor, and least in NR1A/2C receptors. Cell death also differed pharmacologically between subunit combinations. Cell death in cells transfected with NR 1A/2A was blocked by amino-phosphonovaleric acid at lower concentrations than in cells transfected with NR 1A/2B. In cells transfected with the NR1A/2A or NR1A/2B combinations but not NR1A/2C, cell death was also associated with production of reactive oxygen species. In addition, removal of the final 400 amino acids of the C-terminal region of NR2A decreased cell death. The use of GFP based cell counting provides a sensitive mechanism for assessing the mechanism of excitotoxicity in transfected cell models.
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Affiliation(s)
- N J Anegawa
- Department of Pharmacology, University of Pennsylvania School of Medicine, Children's Seashore House, and Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
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Foltynowicz RJ, Robinson JD, Zückerman EJ, Hedderich HG, Grant ER. Experimental Characterization of the Higher Vibrationally Excited States of HCO(+): Determination of omega(2), x(22), g(22), and B(030). J Mol Spectrosc 2000; 199:147-157. [PMID: 10637100 DOI: 10.1006/jmsp.1999.8014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Analyses of high Rydberg series of HCO converging to the (030) vibrational state of the cation establish rovibrational state-detailed thresholds for HCO(+). UV-visible laser double resonance isolates series for assignment. Strongly vertical Rydberg-Rydberg transitions from photoselected N' = 0 and N' = 2 rotational levels of the Sigma(-) Renner-Teller vibronic component of the 3ppi (2)Pi (030) complex define individual series converging to rotational levels, N(+) = 1 through 5 and 3 through 5 of the HCO(+) vibrational states (03(1)0) and (03(3)0), respectively. Extrapolation of autoionizing series locates the positions of these rovibrational states to within +/-0.01 cm(-1). The use of this information combined with precise ionization limits for lower vibrational states determined from earlier Rydberg extrapolations and spectroscopic information available from infrared absorption measurements enables an estimate of the force-field parameters for HCO(+) bending. These parameters include the harmonic bending frequency, omega(2) = 842.57 cm(-1), the vibrational angular momentum splitting constant, g(22) = 3.26 cm(-1), and the diagonal bending anharmonicity, x(22) = -2.53 cm(-1), separated from the off-diagonal contribution, x(12), by reference to ab initio calculations. Results of experiment on the higher vibrationally excited states of HCO(+) are compared with recent theoretical predictions. Copyright 2000 Academic Press.
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Affiliation(s)
- RJ Foltynowicz
- Department of Chemistry, Purdue University, West Lafayette, Indiana, 47906
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20
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Jarvis GK, Song Y, Ng CY, Grant ER. A characterization of vibrationally and electronically excited NO2+ by high-resolution threshold photoionization spectroscopy. J Chem Phys 1999. [DOI: 10.1063/1.480288] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Shim SS, Grant ER, Singh S, Gallagher MJ, Lynch DR. Actions of butyrophenones and other antipsychotic agents at NMDA receptors: relationship with clinical effects and structural considerations. Neurochem Int 1999; 34:167-75. [PMID: 10213076 DOI: 10.1016/s0197-0186(98)00085-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Haloperidol inhibits NMDA receptors with higher affinity for NMDA receptors composed of NR1/2B compared with NR1/2A. To assess whether the clinical effects of haloperidol and other antipsychotic agents are mediated through this site on NMDA receptors and to examine structure activity relationships at this site, we examined the ability of a variety of drugs with neuroleptic actions to inhibit NMDA receptor function. Many antipsychotic agents inhibit 125I-MK 801 binding to the NMDA receptor with IC50 values in the micromolar range. The rank order of potency for inhibition of binding to adult rat forebrain was trifluperidol (TFP) > clozapine = fluphenazine = reduced haloperidol = spiperone = trifluoperazine = butaclamol >> pimozide = risperidone = sulpiride. These findings match the molecular biological specificity of the agents, with trifluperidol having a marked preference for NR1/2B (epsilon2) receptors. Mutations at epsilon2E201, which alter the effects of haloperidol, also decrease the affinity of TFP but not other modulators, showing that the effect of TFP but not other modulators is mediated by this residue of the NMDA receptor. The present results demonstrate that while TFP acts on NMDA receptors in a manner similar to haloperidol, other antipsychotic agents do not share the specific pharmacological properties of this action, suggesting that their clinical mechanism is not mediated by this receptor.
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Affiliation(s)
- S S Shim
- Department of Neurology, University of Pennsylvania, The Children's Hospital of Philadelphia, 19104, USA
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Abstract
N-Methyl-D-aspartate (NMDA) receptors mediate increases in intracellular calcium that can be modulated by protein kinase C (PKC). As PKC modulation of NMDA receptors in neurons is complex, we studied the effects of PKC activation on recombinant NMDA receptor-mediated calcium rises in a nonneuronal mammalian cell line, human embryonic kidney 293 (HEK-293). Phorbol 12-myristate 13-acetate (PMA) pretreatment of HEK-293 cells enhanced or suppressed NMDA receptor-mediated calcium rises based on the NMDA receptor subunit composition. NR2A or NR2B, in combination with NR1(011), conveyed enhancement whereas NR2C and NR2D conveyed suppression. The PKC inhibitor bisindolylmaleimide blocked each of these effects. The region on NR2A that conveyed enhancement localized to a discrete segment of the C terminus distal to the portion of NR2C that is homologous to NR2A. Calcium-45 accumulation, but not intracellular calcium store depletion, matched PMA effects on NMDA receptor-mediated calcium changes, suggesting that these effects were not due to effects on intracellular calcium stores. The suppression of intracellular calcium transients seen with NR2C was eliminated when combined with NR1 splice variants lacking C-terminal cassette 1. Thus, the intracellular calcium effects of PMA were distinguishable based on both the NR1 splice variant and the NR2 subunit type that were expressed. Such differential effects resemble the diversity of PKC effects on NMDA receptors in neurons.
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Affiliation(s)
- E R Grant
- Department of Pharmacology, University of Pennsylvania, School of Medicine, Children's Seashore House, Philadelphia, USA
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Abstract
Many compounds exhibit NR2B-specific modulation of the N-methyl-D-aspartate receptor, although their mechanism(s) of action are largely unknown. Using chimeric NR2A/NR2B subunits, we have located a region of NR2B (amino acids 138-238) which regulated glycine-independent polyamine stimulation. Mutation of glutamate 201 in this region affected stimulation by polyamines in the order E201D < E201A < E201N < E201R. The relief of proton inhibition of the N-methyl-D-aspartate-induced currents mediated by these mutant receptors correlated with the reduction in glycine-independent polyamine stimulation. Electrophysiological evidence with a triple mutant of NR2A further supports the hypothesis that polyamine stimulation may be linked to the relief of tonic inhibition by protons and demonstrates the crucial role of amino acids 200 and 201 in polyamine stimulation. Polyamines and protons, therefore, share common NR2B determinants.
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Affiliation(s)
- M J Gallagher
- Department of Pharmacology, University of Pennsylvania School of Medicine, Children's Seashore House, Philadelphia, Pennsylvania 19104, USA
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Grant ER, Bacskai BJ, Pleasure DE, Pritchett DB, Gallagher MJ, Kendrick SJ, Kricka LJ, Lynch DR. N-methyl-D-aspartate receptors expressed in a nonneuronal cell line mediate subunit-specific increases in free intracellular calcium. J Biol Chem 1997; 272:647-56. [PMID: 8995308 DOI: 10.1074/jbc.272.1.647] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
N-methyl-D-aspartate (NMDA) receptors can mediate cell death in neurons and in non-neuronal cells that express recombinant NMDA receptors. In neurons, increases in intracellular calcium correlate with NMDA receptor-mediated death, supporting a key role for loss of cellular calcium homeostasis in excitotoxic cell death. In the present study, free intracellular calcium concentrations were examined in response to activation of recombinant NMDA receptors expressed in human embryonic kidney 293 cells. Intracellular calcium was measured in transfected cell populations by cotransfection with the calcium-sensitive, bioluminescent protein aequorin and by single cell imaging with the fluorescent calcium indicator fluo-3. Agonist application to NR1/2A or NR1/2B-transfected cells elicited robust rises in intracellular calcium. NR1/2A responses were inhibited by the noncompetitive antagonists MK-801 and dextromethorphan and were dependent on extracellular calcium but not on intracellular calcium stores. In contrast, no detectable intracellular calcium responses were observed in NR1/2C-transfected cells. These findings indicate that NMDA receptors in the absence of other neuron-specific factors can mediate increases in intracellular calcium with subunit specificity and extracellular calcium dependence.
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Affiliation(s)
- E R Grant
- Department of Pharmacology, University of Pennsylvania School of Medicine, Children's Seashore House, Philadelphia 19104, USA
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Magarey ME, Jones MA, Grant ER. Biomedical considerations and clinical patterns related to disorders of the glenoid labrum in the predominantly stable glenohumeral joint. Man Ther 1996; 1:242-249. [PMID: 11440513 DOI: 10.1054/math.1996.0274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
SUMMARY. The roles of the glenoid labrum and long head of biceps are reviewed together with their significance in stability of the glenohumeral joint. Clinical presentations related to disorders of the glenoid labrum and long head of biceps not associated with frank instability but commonly responsible for dysfunction in the athletic shoulder, are reviewed from the perspective of pertinent anatomical, biomechanical and kinematic knowledge. Copyright 1996 Harcourt Publishers Ltd.
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Affiliation(s)
- M. E. Magarey
- School of Physiotherapy, Faculty of Health and Biomedical Sciences, University of South Australia, Adelaide, Australia
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Affiliation(s)
- R. Lindner
- R. Lindner and K. Müller-Dethlefs are in the Institut für Physikalische und Theoretische Chemie, Technischen Universität München, D-85748 Garching, Germany
| | - K. Müller-Dethlefs
- R. Lindner and K. Müller-Dethlefs are in the Institut für Physikalische und Theoretische Chemie, Technischen Universität München, D-85748 Garching, Germany
| | - E. Wedum
- E. Wedum, K. Haber, and E. R. Grant are in the Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - K. Haber
- E. Wedum, K. Haber, and E. R. Grant are in the Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
| | - E. R. Grant
- E. Wedum, K. Haber, and E. R. Grant are in the Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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Zhu Y, Grant ER, Wang K, McKoy V, Lefebvre‐Brion H. Spin–orbit autoionization and intensities in the double‐resonant delayed pulsed‐field threshold photoionization of HCl. J Chem Phys 1994. [DOI: 10.1063/1.466717] [Citation(s) in RCA: 21] [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: 11/14/2022] Open
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28
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Wedum EE, Grant ER, Cheng PY, Willey KF, Duncan MA. On the assignment of Jahn–Teller effects in the ultraviolet absorption spectrum of Ag3. J Chem Phys 1994. [DOI: 10.1063/1.467093] [Citation(s) in RCA: 31] [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: 11/14/2022] Open
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29
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Abstract
The effect of the opioid receptor antagonist, naltrexone, on ethanol-induced changes in extracellular dopamine and serotonin in the nucleus accumbens was investigated using in vivo microdialysis in awake, freely moving rats. Locally applied ethanol (5% infused transprobe) resulted in substantial increases in dopamine in dialysate. Administration of naltrexone (cumulative dosing with 0.25-1.0 mg/kg i.p.) during ethanol administration dose-dependently reversed ethanol-induced increases in extracellular dopamine and its metabolite homovanillic acid but not serotonin. These data demonstrate an essential role for the endogenous opioid system in stimulation of dopamine release by ethanol in a brain area associated with reward and support the opioid system as a prime target for pharmacological modulation of the rewarding effects and consumption of ethanol.
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Affiliation(s)
- D Benjamin
- Center of Alcohol Studies, Rutgers University, New Brunswick, NJ 08855
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Lee M, Wang K, McKoy V, Tonkyn RG, Wiedmann RT, Grant ER, White MG. Ion rotational distributions for near‐threshold photoionization of H2O. J Chem Phys 1992. [DOI: 10.1063/1.462381] [Citation(s) in RCA: 45] [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: 11/14/2022] Open
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Haber KS, Jiang Y, Bryant G, Grant E, Lefebvre-Brion H, Grant ER. Threshold-field-ionization photoelectron spectroscopy and delayed forced autoionization of HCl. Phys Rev A 1991; 44:R5331-R5334. [PMID: 9906688 DOI: 10.1103/physreva.44.r5331] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [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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Wang L, Niu B, Lee YT, Shirley DA, Ghelichkhani E, Grant ER. Photoelectron spectroscopy and electronic structure of clusters of the group V elements. III. Tetramers: The 2T2 and 2A1 excited states of P+4, As+4, and Sb+4. J Chem Phys 1990. [DOI: 10.1063/1.458975] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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35
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Wang L, Niu B, Lee YT, Shirley DA, Ghelichkhani E, Grant ER. Photoelectron spectroscopy and electronic structure of clusters of the group V elements. II. Tetramers: Strong Jahn–Teller coupling in the tetrahedral 2E ground states of P+4, As+4, and Sb+4. J Chem Phys 1990. [DOI: 10.1063/1.459698] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
Mass spectrometry is undergoing rapid development, especially with the extension of its range into the hundreds of kilodaltons, the emergence of the quadrupole ion trap as a high-performance instrument, and the development of techniques for recording three-dimensional spectra. These advances are summarized in this review; in addition, the power of the combination of lasers and mass spectrometers is given particular emphasis. Their combination has contributed recently to chemical dynamics, to the study of cluster structure and reactivity, and to the elucidation of the properties of highly excited molecules and ions.
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Affiliation(s)
- E R Grant
- Chemistry Department, Purdue University, West Lafayette, IN 47907
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Patsilinakou E, Wiedmann RT, Fotakis C, Grant ER. Jet‐resolved vibronic structure in the higher excited states of N2O: Ultraviolet three‐photon absorption spectroscopy from 80 000 to 90 000 cm−1. J Chem Phys 1989. [DOI: 10.1063/1.456823] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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38
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Alexander MH, Andresen P, Bacis R, Bersohn R, Comes FJ, Dagdigian PJ, Dixon RN, Field RW, Flynn GW, Gericke K, Grant ER, Howard BJ, Huber JR, King DS, Kinsey JL, Kleinermanns K, Kuchitsu K, Luntz AC, McCaffery AJ, Pouilly B, Reisler H, Rosenwaks S, Rothe EW, Shapiro M, Simons JP, Vasudev R, Wiesenfeld JR, Wittig C, Zare RN. A nomenclature for Λ‐doublet levels in rotating linear molecules. J Chem Phys 1988. [DOI: 10.1063/1.455121] [Citation(s) in RCA: 205] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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39
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Horan DJ, Forsythe CD, Grant ER. Two ships passing in the night: an interpretavist review of the White-Stevens colloquy on Roe v. Wade. St Louis Univ Public Law Rev 1987; 6:229-311. [PMID: 16086461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Affiliation(s)
- D J Horan
- Hinshaw, Culbertson, Moelmann, Hoban & Fuller, Chicago, IL, USA
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Delacrétaz G, Grant ER, Whetten RL, Wöste L, Zwanziger JW. Fractional quantization of molecular pseudorotation in Na3. Phys Rev Lett 1986; 56:2598-2601. [PMID: 10033040 DOI: 10.1103/physrevlett.56.2598] [Citation(s) in RCA: 143] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Whetten RL, Grubb SG, Otis CE, Albrecht AC, Grant ER. Higher excited states of benzene: Polarized ultraviolet two‐photon absorption spectroscopy. J Chem Phys 1985. [DOI: 10.1063/1.448484] [Citation(s) in RCA: 69] [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: 11/14/2022] Open
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Grubb SG, Otis CE, Whetten RL, Grant ER, Albrecht AC. Higher excited states of benzene: Symmetry assignments of six gerade Rydberg series by four‐photon absorption spectroscopy. J Chem Phys 1985. [DOI: 10.1063/1.448485] [Citation(s) in RCA: 49] [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: 11/14/2022] Open
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44
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46
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Sudbo̸ AS, Schulz PA, Grant ER, Shen YR, Lee YT. Simple bond rupture reactions in multiphoton dissociation of molecules. J Chem Phys 1979. [DOI: 10.1063/1.437482] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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