A pilot post-mortem study identifies a strong correlation between the attenuation coefficient estimated from the OCT data and some morphological features of the sample, namely the number of nuclei in ...the field of view of the histological image and the fiber structural parameter introduced in the study to quantify the difference in the myelinated fibers arrangements. The morphological features were identified from the histopathological images of the sample taken from the same locations as the OCT images and stained with the immunohistochemical (IHC) staining specific to the myelin. It was shown that the linear regression of the IHC quantitative characteristics allows adequate prediction of the attenuation coefficient of the sample. This discovery opens the opportunity for the usage of the OCT as a neuronavigation tool.
The hemostatic activity of polymeric gold and silver nanocomposites depends on their kinetic stability caused by the interaction of the ligand with nanoparticles. The properties of the nanoparticles ...are determined by the metal nature.
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The results of preclinical study of the original antitumor drug aurumacryl (gold polyacrylate), which belongs to polyacrylates of metals (PAMs), a new class of compounds for use in oncology, are ...presented. PAMs have been studied as cytostatics for the first time in the N.M. Emanuel Institute of Biochemical Physics at the Russian Academy of Sciences. The strong antitumor and cytotoxic activity of aurumacryl has been revealed. Aurumacryl induced in vivo the inhibition of growth of the murine solid tumors, as well as the death of the human tumor cells in vitro. The proliferation kinetics of the surviving fraction of tumor cells also changed after drug treatment. These alterations were expressed as the accumulation of the main part of cells in the phase of the proliferative rest and in the strong decrease of the number of proliferative cells. These data may be evaluated as the evidence of the loss of the reproductive activity by the tumor cells after aurumacryl treatment. The distribution of the aurumacryl between the tumor and some organs (blood, kidneys, liver, lungs, spleen and brain) of mice with the solid tumor has been also studied. The results of our own investigations of aurumacryl are discussed in the context of the contemporary concepts about the gold complexes antitumor effect and mechanism of action of these compounds.
Gold polyacrylate (aurumacryl) belonging to a new class of compounds for oncology — metal polyacrylates — was shown to exhibit strong antitumor activity. Aurumacryl causes 80—90% growth inhibition
in ...vivo
of murine solid tumors (Lewis lung carcinoma, Ca-755 adenocarcinoma, and Acatol adenocarcinoma) compared to the control and induces cell death
in vitro
in 60% of MCF-7 human breast carcinoma cells. Substantial changes in proliferation kinetics of the surviving fraction of tumor cells following treatment with aurumacryl were observed, which are related to the predominant accumulation (93%) of cells in the proliferative resting phase G
0
and a substantial decrease in the percentage of proliferating cells (7%). These data provide evidence that the cells that survive lose reproductive ability under treatment with aurumacryl.
We report the observation of low-energy, low-momenta collective oscillations of an exciton-polariton condensate in a round "box" trap. The oscillations are dominated by the dipole and breathing ...modes, and the ratio of the frequencies of the two modes is consistent with that of a weakly interacting two-dimensional trapped Bose gas. The speed of sound extracted from the dipole oscillation frequency is smaller than the Bogoliubov sound, which can be partly explained by the influence of the incoherent reservoir. These results pave the way for understanding the effects of reservoir, dissipation, energy relaxation, and finite temperature on the superfluid properties of exciton-polariton condensates and other two-dimensional open-dissipative quantum fluids.
Collective (elementary) excitations of quantum bosonic condensates, including condensates of exciton polaritons in semiconductor microcavities, are a sensitive probe of interparticle interactions. In ...anisotropic microcavities with momentum-dependent transverse-electric–transverse-magnetic splitting of the optical modes, the excitations' dispersions are predicted to be strongly anisotropic, which is a consequence of the synthetic magnetic gauge field of the cavity, as well as the interplay between different interaction strengths for polaritons in the singlet and triplet spin configurations. Here, by directly measuring the dispersion of the collective excitations in a high-density optically trapped exciton-polariton condensate, we observe excellent agreement with the theoretical predictions for spinor polariton excitations. We extract the interaction constants for polaritons of the same and opposite spin and map out the characteristic spin textures in an interacting spinor condensate of exciton polaritons.
A bosonic condensate of exciton polaritons in a semiconductor microcavity is a macroscopic quantum state subject to pumping and decay. The fundamental nature of this driven-dissipative condensate is ...still under debate. Here, we gain an insight into spontaneous condensation by imaging long-lifetime exciton polaritons in a high-quality inorganic microcavity in a single-shot optical excitation regime, without averaging over multiple condensate realisations. We demonstrate that condensation is strongly influenced by an incoherent reservoir and that the reservoir depletion, the so-called spatial hole burning, is critical for the transition to the ground state. Condensates of photon-like polaritons exhibit strong shot-to-shot fluctuations and density filamentation due to the effective self-focusing associated with the reservoir depletion. In contrast, condensates of exciton-like polaritons display smoother spatial density distributions and are second-order coherent. Our observations show that the single-shot measurements offer a unique opportunity to study fundamental properties of non-equilibrium condensation in the presence of a reservoir.
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