No abstract

No abstract

No abstract

Recent experimental findings suggest that strontium titanate SrTiO3 (STO) photocatalytic activity for water splitting could be improved by creating multifaceted nanoparticles. To understand the underlying mechanisms and energetics, the model for faceted nanoparticles was created. The multifaceted nanoparticles’ surface is considered by us as a combination of flat and “stepped” facets. Ab initio calculations of the adsorption of water and oxygen evolution reaction (OER) intermediates were performed. Our findings suggest that the “slope” part of the step showed a natural similarity to the flat surface, whereas the “ridge” part exhibited significantly different adsorption configurations. On the “slope” region, both molecular and dissociative adsorption modes were possible, whereas on the “ridge”, only dissociative adsorption was observed. Water adsorption energies on the “ridge” ( −1.50 eV) were significantly higher than on the “slope” ( −0.76 eV molecular; −0.83 eV dissociative) or flat surface ( −0.79 eV molecular; −1.09 eV dissociative).

No abstract

No abstract

We demonstrate optical coherent control of the two-photon fluorescence of the blue fluorescent protein (BFP), which is of interest in investigations of protein-protein interactions. In addition to biological relevance, BFP represents an interesting target for coherent control from a chemical perspective due to its many components of highly nonexponential fluorescence decay and low quantum yield resulting from excited state isomerization. Using a genetic algorithm with a multiplicative (rather than ratiometric) fitness parameter, we are able to control the ratio of BFP fluorescence to second harmonic generation without a considerable drop in the maximized signal. The importance of linear chirp and power scaling on the discrimination process is investigated in detail.

Blue fluorescent protein (BFP) is a mutant of green fluorescent protein (GFP), where the chromophore has been modified to shift the emitted fluorescence into the blue spectral region. In this study, MD calculations were performed with the GROMACS simulation package and AMBER force field to investigate the dependence of BFPs physicochemical properties on temperature and applied pressure. The MD approach enabled us to calculate the compressibility of protein itself, separately from the nontrivial contribution of the hydration shell, which is difficult to achieve experimentally. The computed compressibility of BFP (3.94 x10(-5) MPa(-1)) is in agreement with experimental values of globular proteins. The center-of-mass diffusion coefficient of BFP and its dependence on temperature and pressure, which plays an important role in its application as a probe for intracellular liquid viscosity measurement, was calculated and found to be in good agreement with photobleaching recovery experimental data. We have shown that decreased temperature as well as applied pressure increases the water viscosity, but the concomitant decrease of the BFP diffusion coefficient behaves differently from Stokes-Einstein formula. It is shown that the number of hydrogen bonds around the protein grows with pressure, which explains the aforementioned deviation. Pressure also reduces root mean square (RMS) fluctuations, especially those of the most flexible residues situated in the loops. The analysis of the RMS fluctuations of the backbone Calpha atoms also reveals that the most rigid part of BFP is the center of the beta-barrel, in accord with temperature B factors obtained from the Protein Data Bank.