668 research outputs found
VIBRONIC SPECTRA OF BENZENE CLUSTERS REVISITED: I. THE TETRAMER
No full textT. Iimori and Y. Ohshima, J. Chem. Phys. 114 2867 (2001). J. B. Hopkins, D. E. Powers and R. E. Smalley, J. Phys. Chem. 84 3739 (1981). O. Engkvist, P. Hobza, H. L. Selzle and E. W. Schlag, J. Chem. Phys. 110 5758 (1999).Author Institution: Graduate School of Science, Kyoto University; Department of Chemistry, Graduate School of Science, Kyoto UniversityWe revisit the vibronic band systems of benzene cluster isotopomers by mass-selective resonant two-photon ionization (R2PI) and ultraviolet-ultraviolet hole burning Hole burning spectra on the transitions previously assigned to the in the -localized region show that there are five distinct isotopomers having molecule(s). R2PI spectra which have similar band structure are recorded in the mass channel as well. The results indicate that the transitions are due to the cluster larger than the trimer, and thus the mass assignments that have been accepted for a couple of decades must be corrected. The number of the isomers and observed splittings are discussed in terms of the tetramer that have the geometry with four equivalent sites belonging to point group, which is also consistent with a NEMO of its most stable structure
Human T-Cell Leukemia Virus Type 1: Epidemiology and Clinical Features of Related Cancer
No full textVIBRONIC SPECTRA OF BENZENE CLUSTERS REVISITED: II. THE TRIMER
No full textT. Iimori and Y. Ohshima, J. Chem. Phys. 114, 2867 (2001). W. Scherzer, O. Kratzschmar, H. L. Selzle, and E. W. Schlag, Z. Naturforsch. 47a, 1248 (1992). O. Engkvist, P. Hobza, H. L. Selzle, and E. W. Schlag, J. Chem. Phys. 110, 5758 (1999).Author Institution: Graduate School of Science, Kyoto University; Department of Chemistry, Graduate School of Science, Kyoto UniversityAs the second part of our recent reinvestigation on the electronic spectra of benzene we present the trimer vibronic system studied by two-color (2C) resonance enhanced two-photon ionization (R2PI) and UV-UV holeburing experiments. This band system is observed only in the dimer-ion channel even with 2C-R2PI because of extensive fragmentation after photoionization, and thus it has been incorrectly assigned to an isomeric form of the Detailed examination with mixed samples of and has revealed that the parent neutral has a single isomeric form for each isotopomer, with . This observation confirms the equivalency in three benzene sites, which is consistent with the most stable cyclic form predicted by a NEMO One of the intermolecular modes shows prominent Franck-Condon activity, implying a substantial conformational change via photoexcitation. Other details observed in the vibrionc spectra, e.g., exitonic splitting, will also be discussed
Turnip mosaic potyvirus probably first spread to Eurasian brassica crops from wild orchids about 1000 years ago
No full textTurnip mosaic potyvirus (TuMV) is probably the most widespread and damaging virus that infects cultivated brassicas worldwide. Previous work has indicated that the virus originated in western Eurasia, with all of its closest relatives being viruses of monocotyledonous plants. Here we report that we have identified a sister lineage of TuMV-like potyviruses (TuMV-OM) from European orchids. The isolates of TuMV-OM form a monophyletic sister lineage to the brassica-infecting TuMVs (TuMV-BIs), and are nested within a clade of monocotyledon-infecting viruses. Extensive host-range tests showed that all of the TuMV-OMs are biologically similar to, but distinct from, TuMV-BIs and do not readily infect brassicas. We conclude that it is more likely that TuMV evolved from a TuMV-OM-like ancestor than the reverse. We did Bayesian coalescent analyses using a combination of novel and published sequence data from four TuMV genes [helper component-proteinase protein (HC-Pro), protein 3(P3), nuclear inclusion b protein (NIb), and coat protein (CP)]. Three genes (HC-Pro, P3, and NIb), but not the CP gene, gave results indicating that the TuMV-BI viruses diverged from TuMV-OMs around 1000 years ago. Only 150 years later, the four lineages of the present global population of TuMV-BIs diverged from one another. These dates are congruent with historical records of the spread of agriculture in Western Europe. From about 1200 years ago, there was a warming of the climate, and agriculture and the human population of the region greatly increased. Farming replaced woodlands, fostering viruses and aphid vectors that could invade the crops, which included several brassica cultivars and weeds. Later, starting 500 years ago, inter-continental maritime trade probably spread the TuMV-BIs to the remainder of the world
PURE ROTATIONAL SPECTRA OF RARE GAS- COMPLEXES
No full textY. Ohshima, Y. Sumiyoshi, and Y. Endo, 51st International Symposium on Molecular Spectroscopy, Paper WF05 (1996). A. Nowek and J. Leszczynski, {J. Chem. Phys}., \textbf{105}, 6388 (1996).Author Institution: Dept. of Pure and Applied Sciences, The University of Tokyo; Dept. of Chemistry, Kyoto UniversityIn addition to the rotational spectrum of Ar- reported , that of Kr- was observed for the first time by using a PDN-FTMW spectroscopy. The complex was produced in a supersonic jet by discharging a mixture containing , CO, and Kr diluted in Ar. Rotational transitions of mono-substituted species on Kr, H, C, and O were also observed, yielding a precise substitution structure of the complex, where however a large amplitude bending motion of the complex had to be considered. The determined Rg-H distances were explained for species by considering a charge induced dipole-charge interaction. Furthermore, for Ar-, the Ar-H distance and the vibrational frequencies of the van der Waals modes, which were extimated by the centrifugal distortion constant and an analysis of the large amplitude bending motion, were in good agreement with a recent {ab initio}
Epidemiology of malignant lymphoma and recent progress in research on adult T-cell leukemia/lymphoma in Japan
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