Synthesis and evaluation of tetrahydropyrrolo[1,2-]quinolin-1(2)-ones as new tubulin polymerization inhibitors.

Here we explored new 1,5-disubstituted pyrrolidin-2-ones 1, 2 and 5-aryl-3,3,4,5-tetrahydropyrrolo[1,2-]quinoline-1(2)-ones 3 as inhibitors of tubulin polymerization. We evaluated their effects on microtubule dynamics and on the proliferation of A549 cells, using flow cytometry-based cell cycle analysis. The results were verified with phase-contrast microscopy in three cancer cell lines: A549, HeLa and MCF-7.

Converting Strain Release into Aromaticity Loss for Activation of Donor-Acceptor Cyclopropanes: Generation of Quinone Methide Traps for C-Nucleophiles.

Here, we present a new approach for the activation of donor-acceptor cyclopropanes in ring-opening reactions, which does not require the use of a Lewis or Brønsted acid as a catalyst. Donor-acceptor cyclopropanes containing a phenolic group as the donor undergo deprotonation and isomerization to form the corresponding quinone methides. This innovative strategy was applied to achieve (4 + 1)-annulation of cyclopropanes with sulfur ylides, affording functionalized dihydrobenzofurans.

Donor-Acceptor Cyclopropane Ring Expansion to 1,2-Dihydronaphthalenes. Access to Bridged Seven-Membered Lactones.

A Lewis-acid-promoted domino ring-opening cyclization of readily available donor-acceptor cyclopropanes with a preinstalled electrophilic center, embedded in a donor group, to functionalized 1,2-dihydronaphthalenes is reported herein. The obtained compounds are transformed to pharmacologically attractive bridged tricyclic esters in a diastereospecific manner.

Synthesis of 1,5-Substituted Pyrrolidin-2-ones from Donor-Acceptor Cyclopropanes and Anilines/Benzylamines.

We developed a straightforward synthetic route to pharmacologically important 1,5-substituted pyrrolidin-2-ones from donor-acceptor cyclopropanes bearing an ester group as one of the acceptor substituents. This method includes a Lewis acid-catalyzed opening of the donor-acceptor cyclopropane with primary amines (anilines, benzylamines, etc.) to γ-amino esters, followed by in situ lactamization and dealkoxycarbonylation.

Sequential reduction of the silicon single-electron transistor structure to atomic scale.

Here we present an original CMOS compatible fabrication method of a single-electron transistor structure with extremely small islands, formed by solitary phosphorus dopants in the silicon nanobridge. Its key feature is the controllable size reduction of the nanobridge in sequential cycles of low energy isotropic reactive ion etching that results in a decreased number of active charge centers (dopants) in the nanobridge from hundreds to a single one. Electron transport through the individual phosphorous dopants in the silicon lattice was studied.

Single-electron tunneling through an individual arsenic dopant in silicon.

We report the single-electron tunneling behaviour of a silicon nanobridge where the effective island is a single As dopant atom. The device is a gated silicon nanobridge with a thickness and width of ∼20 nm, fabricated from a commercially available silicon-on-insulator wafer, which was first doped with As atoms and then patterned using a unique CMOS-compatible technique. Transport measurements reveal characteristic Coulomb diamonds whose size decreases with gate voltage.

[Frequency range of the auditory effect of UHF].

Zero beats of radiosound with an acoustic signal from an electrodynamic emitter in the frequency range up to 8 kHz were recorded in a natural experiment, which were not obtained earlier. It has been shown that the zero beats between the acoustic tonal signal and the first harmonics of the impulse succession of UHF are recorded in the points which correspond to low values on the threshold curve of UHF auditory effect.

[Study of the characteristics of the effect of radio-sound using spherical models].

Experimental data are presented on sound wave excitement in liquid sphere models by pulse HF-fields and interpreted in relation to microwave auditory effects.

[A physical model of acoustic effects of ultrahigh frequency fields on biological systems].

A physical model of radiosound based on the stimulation of mechanical oscillations in liquid media at adsorption of SHF impulse energy is presented. It is shown that a limited liquid volume can be considered as an acoustic resonator with self oscillation frequency. At definite relationships between the succession frequency and impulse duration interference takes place.