H2O and D2O spin-isomers as a mediator of the electron transfer in the reaction center of purple bacteria

The dynamics of charge separation states has been numerically simulated in order to calculate the polarization (in the third order of the perturbation theory) and its evolution in a pulsed optical field. Time evolution of the rotational states of the ortho-D₂O isomer with a nonzero magnetic momentum and mixed ortho/para-D₂O states have been calculated on the basis of the Liouville equation for the density matrix and the Redfield relaxation model for molecular aggregates. Frequencies similar to the known experimental frequencies of the modulation of the kinetics (electron transfer) of the reaction centers special pair in purple bacteria are selected from the set of calculated rotational-resonance frequencies. This semiquantitative coincidence of frequencies (within the experimental error) confirms the previously stated hypothesis, according to which the ortho-H₂O (D₂O) spin isomer can play a role of mediator during electron transfer in the reaction centers of purple bacteria.     

H2O monomers in channels of icelike water structures

We consider the dynamics of H₂O monomers in channels of icelike structures using the model of 1D rotator (i.e., a particle with one translational and one rotational degree of freedom). The effect of the channel walls on the motion of the particle is simulated by the interaction of the dipole moment of the particle with a periodic electric field. In this model, the following four regimes of motion are possible: (i) reflection of the particle from the inlet of the channel; (ii) single passage through the channel with a fixed phase; (iii) passage of the particle through the channel after multiple reflections in the channel from its inlet to its outlet; and (iv) reverse motion of the particle after its stay in the channel and multiple reflections from the inlet and outlet. These regimes indicate the possibility of existence of H₂O monomers in the form of particles trapped in the channels of icelike formations.     

Grooved conjugation ferrite element for ultrasound heating of a biological tissue phantom

A possibility of using a parametric ultrasound phase conjugation system with a grooved ferrite element for hyperthermal heating of a biological tissue phantom is experimentally investigated. The grooved surface of the ferrite element improves the quality of phase conjugation. With focused conjugate beams, this is supposed to lead to an increase in the ultrasound intensity and accordingly to more effective heating of the medium due to ultrasound absorption. The results of the investigation prove this supposition: ultrasound heating by 8.0°C in about 80 s is obtained for a sample with an inserted thermocouple placed between a focused piezoelectric transducer, which radiated a test wave with a frequency of 5.0MHz, and a system for phase conjugation and amplification of ultrasound.     

Inverse TERS effect in methyl hydroxyethyl cellulose layers

The Raman scattering signal at the second harmonic (532 nm) of cw Nd:YAG laser in a 0.5-μm-thick methyl hydroxyethyl cellulose film on a gold substrate is found to be attenuated when a platinum-iridium probe (with a tip radius of about 10 nm) of a scanning tunnel microscope is brought close (at a distance of 6 to 8 nm) to the surface. The fluorescence signal barely changes under these conditions.     

Cluster structure of stable dissolved gas nanobubbles in highly purified water

Experiments using phase-modulation interference microscopy and Mueller-matrix polarimetry show that double-distilled water free of foreign solid matter contains macroscopic light scatterers. Numerical calculations suggest that these scatterers can be represented as micrometer-size clusters of polydisperse air bubbles with effective radii between 70 and 90 nm. The fractal dimension of the clusters varies from 2.4 to 2.8, and their concentration is on the order of 10⁶ cm^?3.     

Study of nanostructure of highly purified water by measuring scattering matrix elements of laser radiation

Experiments on modulation interference microscopy and measurement of light scattering matrix elements showed that double distilled water purified from solid impurities contains macroscopic scatterers of optical radiation. It follows from numerical calculation that these scatterers can be micrometer-scale clusters formed by polydisperse air bubbles with effective radii of 70 to 90 nm. The fractal dimension of such clusters is within 2.4–2.8 and their concentration is ∼ 10⁶ cm⁻³.