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The resonance states of systems consisting of three identical bosons and three fermions interacting with an attractive 1/ r potential are investigated using highly correlated exponential basis functions. The method of complex-coordinate rotation is used to extract energies and widths for the resonances lying below the N = 3 excited state threshold of the respective two-body subsystem. We have obtained a total of 24 S-wave resonances for the three-boson system and a total of 19 S-wave resonances in total spin-3/2 (the 4 S state) and a total of 15 S-wave resonances in total spin-1/2 (the 2 S state) below the N = 3 threshold. For the resonances associated with the N = 3 threshold, we have obtained two, three and four series of Rydberg states for the three-boson system, three-fermion system for 2 S states and three-fermion system for 4 S states, respectively. The resonance energies and widths of these states for the three-body self-gravitating bosons and fermions are reported.

Effect of screened Coulomb (Yukawa) potentials on the doubly excited meta-stable bound states and the resonance states with unnatural parities of the helium atom have been investigated in the framework of stabilization method using CI-type basis functions. A total of 54 resonances (6 each of 1Do and 3Do states, 12 each of 1Fe and 3Fe states, 9 each of 1Go and 3Go states) below the He+(3P) thresholds have been estimated by calculating the density of resonance states using a stabilization method. The resonances belong to the different 3lnl′ (n ≥ 3) series. We have also calculated the doubly excited 1,3Fe and 1,3Go meta-stable bound states of He atom below the He+ (2P) thresholds. The resonance energies and widths along with the meta-stable bound states energies are reported for various screening parameters. In free atom case, some of the F-wave resonance states and most of the cases, F- and G-wave resonance widths are reported for the first time. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008

We have previously illustrated that the electron donor of carbazole moiety and the electron acceptor of methyl pyridinium cation in 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC) molecule could form an intramolecular charge-transfer state. The intramolecular twist of the vinyl group in bridging the donor and acceptor plays an important role in the BMVC fluorescence. Here, we have synthesized three 9-aryl-substituted BMVC derivatives with different electronic properties for the design of the second generation of fluorescence probes. The steady-state solvatochromic studies show no appreciable change to the charge transfer of BMVC by substituting an anisole electron-donating group at 9-position of BMVC. However, substituting a 9-nitrobenzyl electron-withdrawing group in BMVC could restrict the charge transfer in the excited state. Moreover, the increase of the fluorescence yields of 9-anisole BMVC and 9-phenyl BMVC upon interaction with DNA is even higher than that in glycerol, while the fluorescence yield of 9-nitrobenzyl BMVC upon interaction with DNA is much lower than that in glycerol. Although 9-nitrobenzyl BMVC is a good G-quadruplex stabilizer, substituting an electron-withdrawing group at 9-position of BMVC is not recommended for the design of fluorescence probes. On the other hand, colocalization between 9-phenyl BMVC and MitoTracker Red in the merged image of cells indicates that the 9-phenyl BMVC is a potential fluorescent mitochondrial probe. (C) 2007 Elsevier B.V. All rights reserved.

We have introduced a G- quadruplex- binding ligand, 3,6- bis( 1- methyl- 4- vinylpyridinium) carbazole diiodide ( BMVC), to verify the major structure of d( T(2)AG(3))(4) ( H24) in potassium solution and examine the structural conversion of H24 in sodium solution upon potassium titration. The studies of circular dichroism, induced circular dichroism, spectral titration and gel competition have allowed us to determine the binding mode and binding ratio of BMVC to the H24 in solution and eliminate the parallel form as the major G- quadruplex structure. Although the mixed- type form could not be eliminated as a main component, the basket and chair forms are more likely the main components of H24 in potassium solution. In addition, the circular dichroism spectra and the job plots reveal that a longer telomeric sequence d( T(2)AG(3))(13) ( H78) could form two units of G4 structure both in sodium or potassium solutions. Of particular interest is that no appreciable change on the induced circular dichroism spectra of BMVC is found during the change of the circular dichroism patterns of H24 upon potassium titration. Considering similar spectral conversion detected for H24 and a long sequence H78 together with the G4 structure stabilized by BMVC, it is therefore unlikely that the rapid spectral conversion of H24 and H78 is due to structural change between different types of the G4 structures. With reference to the circular dichroism spectra of d( GAA)(7) and d( GAAA)(5), we suggest that the spectral conversion of H24 upon potassium titration is attributed to fast ion exchange resulting in different loop base interaction and various hydrogen bonding effects.

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The effects of hot-dense plasmas on the bound states and the dipole polarizability of the ground state of Coulomb three-body molecular ion H+2 have been investigated using highly correlated basis functions and by considering the Debye shielding approach of plasma modeling. The ground S state and the first excited P state energies along with the dipole polarizability for different shielding parameters are reported.

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The effect of Debye plasmas on the dispersion coefficient \{C6\} for interactions among H and He atoms has been investigated for the first time using highly correlated exponential basis functions. The \{C6\} coefficient for the interactions among H and He are reported for various Debye lengths.

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A simple handheld device based on the fluorescence analysis of 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide ( BMVC) stained cells was established for routine screening and potentially for early detection of cancer cells at extremely low cost. Flow cytometry assay further supported the utility of this simple device, where a preliminary study of tissue biopsy showed highly encouraging results.