98 research outputs found
Electron transfer theory revisit: Quantum solvation effect
The effect of solvation on the electron transfer (ET) rate processes is
investigated on the basis of the exact theory constructed in J. Phys. Chem. B
Vol. 110, (2006); quant-ph/0604071. The nature of solvation is studied in a
close relation with the mechanism of ET processes. The resulting Kramers'
turnover and Marcus' inversion characteristics are analyzed accordingly. The
classical picture of solvation is found to be invalid when the solvent
longitudinal relaxation time is short compared with the inverse temperature.Comment: 5 pages, 3 figures. J. Theo. & Comput. Chem., accepte
Lactobacillus pentosus expressing porcine lactoferrin elevates antibacterial activity and improves the efficacy of vaccination against Aujeszky’s disease
In this study, Lactobacillus pentosus expressing porcine lactoferrin (pLF) was tested for in vitro antibacterial activity and for its ability to enhance immunity induced by an orally administered Aujeszky’s disease virus (ADV) vaccine. The cDNA encoding N-terminus of pLF was cloned into a Lactobacillus-specific plasmid to produce L. pentosus pLF expressing transformants (pPG612.1-pLFN/ L. pentosus). The antimicrobial activity of the recombinant pLF protein inhibited bacterial growth in vitro. The supernatant of pPG612.1-pLF-N/L. pentosus had an inhibitory effect on Staphylococcus aureus strain CVCC26003, Bacillus subtilis strain CVCC63501, Escherichia coli strain CVCC10141 and Salmonella enterica ssp. enterica Choleraesuis strain CVCC79102, while it did not inhibit the growth of Lactobacillus casei strain ATCC393. A mouse model was established to test the effectiveness of the orally administered probiotic L. pentosus recombinant strain in the gastrointestinal tract. Mice were immunised with an attenuated porcine Aujeszky’s disease virus (ADV) vaccine. Serum antibody levels determined using a mouse Aujeszky’s disease IgG ELISA showed that IgG levels were significantly higher in the pPG612.1-pLFN/L. pentosus group than in the PBS and Lactobacillus pentosus groups at days 7 and 21 (P < 0.01) and at day 14 (P < 0.05), indicating that this oral recombinant strain can improve the effectiveness of the vaccine and play a role in immune enhancement through humoral immunity. These results suggest that the recombinant Lactobacillus pentosus not only has the beneficial characteristics of lactic acid bacteria but also produces biologically functional lactoferrin
Transverse localization and slow propagation of light
The effect of finite control beam on the transverse spatial profile of the
slow light propagation in an electromagnetically induced transparency medium is
studied. We arrive at a general criterion in terms of eigenequation, and
demonstrate the existence of a set of localized, stationary transverse modes
for the negative detuning of the probe signal field. Each of these
diffraction-free transverse modes has its own characteristic group velocity,
smaller than the conventional theoretical result without considering the
transverse spatial effect
Kinetics and thermodynamics of electron transfer in Debye solvents: An analytical and nonperturbative reduced density matrix theory
A nonperturbative electron transfer rate theory is developed based on the
reduced density matrix dynamics, which can be evaluated readily for the Debye
solvent model without further approximation. Not only does it recover for
reaction rates the celebrated Marcus' inversion and Kramers' turnover
behaviors, the present theory also predicts for reaction thermodynamics, such
as equilibrium Gibbs free-energy and entropy, some interesting
solvent-dependent features that are calling for experimental verification.
Moreover, a continued fraction Green's function formalism is also constructed,
which can be used together with Dyson equation technique, for efficient
evaluation of nonperturbative reduced density matrix dynamics.Comment: 8 pages, 5 figures. J. Phys. Chem. B, accepte
Microscopic insights on field induced switching and domain wall motion in orthorhombic ferroelectrics
Surprisingly little is known about the microscopic processes that govern
ferroelectric switching in orthorhombic ferroelectrics.
To study microscopic switching processes we combine ab initio-based molecular
dynamics simulations and data science on the prototypical material BaTiO.
We reveal two different field regimes: For moderate field strengths, the
switching is dominated by domain wall motion while a fast bulk-like switching
can be induced for large fields. Switching in both field regimes follows a
multi-step process via polarization directions perpendicular to the applied
field. In the former case, the moving wall is of Bloch character and hosts
dipole vortices due to nucleation, growth, and crossing of two dimensional
90 domains. In the second case, the local polarization shows a
continuous correlated rotation via a an intermediate tetragonal multidomain
state.Comment: 12 pages, 14 figure
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