Erythrocyte morphological states, phases, transitions and trajectories

AbstractMorphological response (MR) of red blood cells represents a triphasic sequence of spontaneously occurring shape transformation between different shape states upon transfer the cells into isotonic sucrose solution in the order: S0 (initial discoid shape in physiological saline)→S1 (echinocytic shape at the beginning of MR, phase 1)→S2 (intermediate discoid shape, phase 2)→S3 (final stomatocytic shape, phase 3). In this paper, the dynamics of cell shape changes was investigated by non-invasive light fluctuation method and optical microscopy. Among 12 possible transitions between four main shape states, we experimentally demonstrate here an existence of nine transitions between neighbour or remote states in this sequence. Based on these findings and data from the literature, we may conclude that red blood cells are able to change their shape through direct transitions between four main states except transition S1→S0, which has not been identified yet. Some shape transitions and their temporal sequence are in accord with predictions of bilayer couple concept, whereas others for example transitions between remote states S3→S1, S1→S3 and S3→S0 are difficult to explain based solely on the difference in relative surface areas of both leaflets of membrane suggesting more complex mechanisms involved. Our data show that MR could represents a phenomenon in which the major role can play pH and chloride-sensitive sensor and switching mechanisms coupled with transmembrane signaling thus involving both cytoskeleton and membrane in coordinated shape response on changes in cell ionic environment

Tests of cryogenic Fabry-Perot cavity with mirrors on different substrates

Experiments were performed with Fabry-Perot optical resonators in vacuum at low temperatures. Mirrors were applied on substrates of various optical materials. The infrared laser with a wavelength of 1.064 microns was used. The pump power at the maximum could reach 450 mW. The evolution of the optical properties of the FP cavity was traced in the temperature range (300 - 10)K. The main parameters measured were the integral characteristics of the FP resonances: sharpness (finesse) and contrast of interference. Three types of substrates were tested: a sitall -- the optical glass with ultra low thermal expansion (ULE), sapphire and calcium fluoride. During cooling, the degradation of the integral characteristics of the FP cavity was observed for the sitall mirrors due to the loss of the properties of (ULE), for sapphire mirrors due to the birefringence effect. The satisfactory constancy of the integral characteristics of the FP resonator on calcium fluoride was demonstrated in the entire temperature range studied 1Comment: 12 pages, 6 figure

Nanoskyrmion engineering with spsp-electron materials: Sn monolayer on SiC(0001) surface

Materials with $sp$-magnetism demonstrate strongly nonlocal Coulomb interactions, which opens a way to probe correlations in the regimes not achievable in transition metal compounds. By the example of Sn monolayer on SiC(0001) surface, we show that such systems exhibit unusual but intriguing magnetic properties at the nanoscale. Physically, this is attributed to the presence of a significant ferromagnetic coupling, the so-called direct exchange, which fully compensates ubiquitous antiferromagnetic interactions of the superexchange origin. Having a nonlocal nature, the direct exchange was previously ignored because it cannot be captured within the conventional density functional methods and significantly challenges ground state models earlier proposed for Sn/SiC(0001). Furthermore, heavy adatoms induce strong spin-orbit coupling, which leads to a highly anisotropic form of the spin Hamiltonian, in which the Dzyaloshinskii-Moriya interaction is dominant. The latter is suggested to be responsible for the formation of a nanoskyrmion state at realistic magnetic fields and temperatures.Comment: 4 pages, supplemental materia

Аналіз практичного використовування методу відбору проектів на базі теорії можливостей

The object of this research is the method of selecting projects based on the possibility theory. This method is applicable to turbulent environment conditions, the «project map» method is based on a structured set of project characteristics. Nevertheless, this method has not been tested for a specific management situation. Therefore, in order to better understand the essence of the proposed method and to study its applicability in practice, experimental studies related to its empirical verification are carried out.As part of the pilot studies of the project selection method on the basis of the possibility theory, the main stages of this method are characterized:– formation of initial data on the «project map» in the form of trapezoidal fuzzy numbers, which corresponds to optimistic, pessimistic and most probable options for the implementation of projects;– formation of a system of criteria and limitations, the establishment of confidence levels;– «filtering» projects through a system of restrictions;– selection of the best project from the set, passed «filtration» on the basis of the given criterion, the possibility of using the system of criteria is characterized.As a result of the research, the characteristics of the projects under consideration and the requirements for them are interpreted in terms of the possibility theory. In accordance with the procedure of the method, a project is selected, accompanied by graphic interpretations of operations within the framework of fuzzy logic. The analysis of the influence on the choice of such characteristics used in the method as «reliability» and «possibility» is graphically demonstrated.The carried out experimental studies of the project selection method shows its applicability and reliability of the obtained results. Graphical analysis of fuzzy estimates of the project allows to conduct reasoning about the acceptability of the project under various assumptions about the reliability of the constraints and the possibilities of obtaining the desired result. This increases the value of this method for practical use.Выполнена практическая апробация метода отбора проектов на базе теории возможностей. Рассмотрены в терминах теории возможностей характеристики рассматриваемых проектов и требования к ним. Осуществлен отбор проекта, сопровождаемый графическими интерпретациями операций в рамках нечеткой логики. Графическим образом продемонстрирован анализ влияния на выбор проекта таких характеристик, как «достоверность» и «возможность».Виконана практична апробація методу відбору проектів на базі теорії можливостей. Розглянуто в термінах теорії можливостей характеристики розглянутих проектів і вимоги до них. Здійснено відбір проекту, супроводжуваний графічними інтерпретаціями операцій в рамках нечіткої логіки. Графічним чином продемонстрований аналіз впливу на вибір проекту таких характеристик, як «достовірність» і «можливість»

On Formation of Anthrasemiquinone in the Conditions of Wood Alkaline Pulping

Electron spin resonance (ESR) and electronic absorbance spectral experiments demonstrate that reversible temperature variation of anion-radica1 concentration in the system anthraqui; none (AQ) - anthrasemiquinone (AS) - anthrahydroquinone (AHQ) in aqueous alka1i is a property of that system and not of the more complicated catalyst-wood system. Lignin model compounds present in low concentrations have no influence on this variation. A raise of radical concentration is accompanied by a change of the solution colour from red into yellow. In pulping conditions AQ can be reduced either by the hydrocarbon or by the lignin component of wood, probably also by numerous organic compounds and even by the alka1i itself. As a result of this process, an AQ-AS-AHQ system is being formed

Interaction of Kelvin waves and nonlocality of energy transfer in superfluids

We argue that the physics of interacting Kelvin Waves (KWs) is highly nontrivial and cannot be understood on the basis of pure dimensional reasoning. A consistent theory of KW turbulence in superfluids should be based upon explicit knowledge of their interactions. To achieve this, we present a detailed calculation and comprehensive analysis of the interaction coefficients for KW turbuelence, thereby, resolving previous mistakes stemming from unaccounted contributions. As a first application of this analysis, we derive a local nonlinear (partial differential) equation. This equation is much simpler for analysis and numerical simulations of KWs than the Biot-Savart equation, and in contrast to the completely integrable local induction approximation (in which the energy exchange between KWs is absent), describes the nonlinear dynamics of KWs. Second, we show that the previously suggested Kozik-Svistunov energy spectrum for KWs, which has often been used in the analysis of experimental and numerical data in superfluid turbulence, is irrelevant, because it is based upon an erroneous assumption of the locality of the energy transfer through scales. Moreover, we demonstrate the weak nonlocality of the inverse cascade spectrum with a constant particle-number flux and find resulting logarithmic corrections to this spectrum