New Experimental Models of Retinal Degeneration for Screening Molecular Photochromic Ion Channel Blockers.

Application of molecular photochromic ion channel blockers to recover the visual function of a degenerated retina is one of the promising trends in photopharmacology. To this day, several photochromic azobenzene-based compounds have been proposed and their functionality has been demonstrated on cell lines and knockout mouse models. Further advance necessitates testing of the physiological activity of a great number of new compounds.

Role of Copper Dyshomeostasis in the Pathogenesis of Parkinson's Disease.

Serum concentration of copper, immunoreactive polypeptides of ceruloplasmin and its oxidase activity, and the number of copper atoms per ceruloplasmin molecule were decreased in patients with Parkinson's disease in comparison with the corresponding parameters in age-matched healthy individuals, but the ratio of apoceruloplasmin to holoceruloplasmin in patients with Parkinson's disease was similar in both groups. Treatment of blood serum with Helex 100, a high-affinity copper chelator, revealed reduced content of labile copper atoms per ceruloplasmin molecule in patients with Parkinson's disease in comparison with that in healthy controls. The mechanism underlying impaired metabolic incorporation of labile copper atoms into CP molecule is discussed as a possible cause of copper dyshomeostasis associated with Parkinson's disease.

Self-Assembly of Lysine-Based Dendritic Surfactants Modeled by the Self-Consistent Field Approach.

Implementing a united atom model, we apply self-consistent field theory to study structure and thermodynamic properties of spherical micelles composed of surfactants that combine an alkyl tail with a charged lysine-based dendritic headgroup. Following experiments, the focus was on dendron surfactants with varying tail length and dendron generations G0, G1, G2. The heads are subject to acetylation modification which reduces the charge and hydrophilicity.

Investigation of Melts of Polybutylcarbosilane Dendrimers by H NMR Spectroscopy.

Melts of polybutylcarbosilane (PBC) dendrimers from third (G3) up to sixth (G6) generations are investigated by H NMR spectroscopy in a wide temperature range up to 493 K. At room temperature, NMR spectra of G3-G5 dendrimers exhibit resolved, solution-like spectra ("liquid" phase). In contrast, the spectrum of the G6 dendrimer is characterized by a single unresolved broad line at whole temperature range, which supports the presence of an anomalous phase state of G6 at temperatures higher than glass transition temperature.

Hamiltonian for the Zeros of the Riemann Zeta Function.

A Hamiltonian operator H[over ^] is constructed with the property that if the eigenfunctions obey a suitable boundary condition, then the associated eigenvalues correspond to the nontrivial zeros of the Riemann zeta function. The classical limit of H[over ^] is 2xp, which is consistent with the Berry-Keating conjecture. While H[over ^] is not Hermitian in the conventional sense, iH[over ^] is PT symmetric with a broken PT symmetry, thus allowing for the possibility that all eigenvalues of H[over ^] are real.

Rare Earth Doped Silica Nanoparticles via Thermolysis of a Single Source Metallasilsesquioxane Precursor.

Rare earth metal doped silica nanoparticles have significant advantages over traditional organic dyes and quantum dots. Silsesquioxanes are promising precursors in the production of silica nanoparticles by thermolysis, due to their structural similarities with silica materials. This manuscript describes the production of a new Eu-based metallasilsesquioxane species and its use as a single source precursor in the thermolytic production of luminescent rare earth metal doped silica nanoparticles with characteristic emission in the visible region of the spectrum.

Comparative Study of Antitumor Efficiency of Intraperitoneal and Intravenous Cytostatics in Experimental Rats with Disseminated Ovarian Cancer.

Antitumor efficiencies of cytostatics dioxadet, cisplatin, mitomycin C, melphalan, and paclitaxel after a single intraperitoneal or intravenous injection in doses of 1.5, 4, 1.5, 2, and 5 mg/kg, respectively, were studied on the model of transplanted ovarian tumor in 124 rats.

Optical thermometry based on level anticrossing in silicon carbide.

We report a giant thermal shift of 2.1 MHz/K related to the excited-state zero-field splitting in the silicon vacancy centers in 4H silicon carbide. It is obtained from the indirect observation of the optically detected magnetic resonance in the excited state using the ground state as an ancilla.

Local orientational mobility in regular hyperbranched polymers.

We study the dynamics of local bond orientation in regular hyperbranched polymers modeled by Vicsek fractals. The local dynamics is investigated through the temporal autocorrelation functions of single bonds and the corresponding relaxation forms of the complex dielectric susceptibility. We show that the dynamic behavior of single segments depends on their remoteness from the periphery rather than on the size of the whole macromolecule.

Is the manifestation of the local dynamics in the spin-lattice NMR relaxation in dendrimers sensitive to excluded volume interactions?

The effect of excluded volume (EV) interactions on the manifestation of the local dynamics in the spin-lattice NMR relaxation in dendrimers has been studied by using Brownian dynamics simulations. The study was motivated by the theory developed by Markelov et al., [J.

Thermodynamics of the multi-stage self-assembly of pH-sensitive gradient copolymers in aqueous solutions.

The self-assembly thermodynamics of pH-sensitive di-block and tri-block gradient copolymers of acrylic acid and styrene was studied for the first time using isothermal titration calorimetry (ITC) and dynamic light scattering (DLS) performed at varying pH. We were able to monitor each step of micellization as a function of decreasing pH. The growth of micelles is a multi-stage process that is pH dependent with several exothermic and endothermic components.

Charge-controlled nano-structuring in partially collapsed star-shaped macromolecules.

Hydrophobic polyelectrolytes exhibit intra-molecular nano-scale self-organization instead of macroscopic phase separation because of the interplay between short-range hydrophobic attraction and long-range electrostatic repulsion. We aim to unravel how the morphology of the intra-molecular nanostructures can be controlled through the topology of the macromolecule on one hand and by adjustable ionization on the other hand. Specifically, we focus on hydrophobic star-branched polyelectrolytes, composed of either strong or weak acidic monomers.

Unexpected Temperature Behavior of Polyethylene Glycol Spacers in Copolymer Dendrimers in Chloroform.

We have studied copolymer dendrimer structure: carbosilane dendrimers with terminal phenylbenzoate mesogenic groups attached by poly(ethylene) glycol (PEG) spacers. In this system PEG spacers are additional tuning to usual copolymer structure: dendrimer with terminal mesogenic groups. The dendrimer macromolecules were investigated in a dilute chloroform solution by (1)H NMR methods (spectra and relaxations).

Adjunctive dental therapy via tooth plaque reduction and gingivitis treatment by blue light-emitting diodes tooth brushing.

The efficacy of blue light-emitting toothbrushes (B-LETBs) (405 to 420 nm, power density 2  mW/cm(2)) for reduction of dental plaques and gingival inflammation has been evaluated. Microbiological study has shown the multifactor therapeutic action of the B-LETBs on oral pathological microflora: in addition to partial mechanical removal of bacteria, photodynamic action suppresses them up to 97.5%.

Persistence length of dendronized polymers: the self-consistent field theory.

We present numerical results for the thermodynamic rigidity and induced persistence length of dendronized polymers with systematically varied topology of their grafts obtained by the Scheutjens-Fleer self-consistent field method. The results were compared to predictions of an analytical mean-field theory. The two approaches have marked different predictions.

pH- and Electro-Responsive Properties of Poly(acrylic acid) and Poly(acrylic acid)-block-poly(acrylic acid-grad-styrene) Brushes Studied by Quartz Crystal Microbalance with Dissipation Monitoring.

We report on the synthesis of novel pH- and electro-responsive polyelectrolyte brushes from a gold substrate by direct one-step nitroxide-mediated polymerization of acrylic acid (AA) or copolymerization of AA and styrene (S). In the latter case, amphiphilic brushes of block-gradient copolymers PAA-b-(PAA-grad-PS) comprising one PAA block and one block with the gradient sequence of AA and S were obtained. The block-gradient copolymers are initiated from the surface by the start of the PAA block.

Analytical representations of the spread harmonic measure density.

We study the spread harmonic measure that characterizes the spatial distribution of reaction events on a partially reactive surface. For Euclidean domains in which Brownian motion can be split into independent lateral and transverse displacements, we derive analytical formulas for the spread harmonic measure density and analyze its asymptotic behavior. This analysis is applicable to slab domains, general cylindrical domains, and a half-space.

Uncovering dental implants using a new thermo-optically powered (TOP) technology with tissue air-cooling.

Background And Objectives: Uncovering implants with lasers, while bloodless, has been associated with a risk of implant and bone overheating. The present study evaluated the effect of using a new generation of high-power diode lasers on the temperature of a dental implant and the surrounding tissues using an in vitro model.

Study Design/materials And Methods: The implant temperature was measured at three locations using micro thermocouples.

Solution to the quantum Zermelo navigation problem.

The solution to the problem of finding a time-optimal control Hamiltonian to generate a given unitary gate, in an environment in which there exists an uncontrollable ambient Hamiltonian (e.g., a background field), is obtained.

Semantically linking in silico cancer models.

Multiscale models are commonplace in cancer modeling, where individual models acting on different biological scales are combined within a single, cohesive modeling framework. However, model composition gives rise to challenges in understanding interfaces and interactions between them. Based on specific domain expertise, typically these computational models are developed by separate research groups using different methodologies, programming languages, and parameters.

Formation of a "Hollow" Interior in the Fourth-Generation Dendrimer with Attached Oligomeric Terminal Segments.

By using the Scheutjens-Fleer self-consistent field approach, the structure of the fourth-generation dendrimer with attached terminal chemically different oligomeric segments is studied theoretically. It is demonstrated that an incompatibility of terminal segments with inner dendrimer units leads to formation of a "hollow" core with reduced polymer density in the dendrimer center. This effect is enhanced with a deterioration in the solvent quality for terminal segments.

Crystal structure of 1,3-dimethyl-3-phenyl-pyrrolidine-2,5-dione: a clinically used anti-convulsant.

In the title compound, C12H13NO2, the five-membered ring has an envelope conformation; the disubstituted C atom lies out of the mean plane through the four other ring atoms (r.m.s.

The framework for simulation of bioinspired security mechanisms against network infrastructure attacks.

The paper outlines a bioinspired approach named "network nervous system" and methods of simulation of infrastructure attacks and protection mechanisms based on this approach. The protection mechanisms based on this approach consist of distributed procedures of information collection and processing, which coordinate the activities of the main devices of a computer network, identify attacks, and determine necessary countermeasures. Attacks and protection mechanisms are specified as structural models using a set-theoretic approach.

Blood biocompatibility of surface-bound multi-walled carbon nanotubes.

Blood clots when it contacts foreign surfaces following platelet activation. This can be catastrophic in clinical settings involving extracorporeal circulation such as during heart-lung bypass where blood is circulated in polyvinyl chloride tubing. Studies have shown, however, that surface-bound carbon nanotubes may prevent platelet activation, the initiator of thrombosis.

Magnetic Nanomaterials and Their Applications.

This Special Issue of is dedicated to the development of new magnetic nanomaterials and their applications in biomedicine, catalysis, spintronics and other areas. The publications in this Issue demonstrate that the interest in magnetic nanomaterials is continuously growing and their realm is expanding rapidly. Some highlights of the publications in this issue are discussed below.