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1
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EN
The aim of this contribution is to propose a new averaged model of dynamic problems for thin linear-elastic cylindrical shells having a periodic structure along one direction tangent to the shell midsurface. In contrast with the known homogenized models, the proposed one makes it possible to describe the effect of the periodicity cell size on the global dynamic shell behavior (a length-scale effect). In order to derive governing equations with constant or slowly varying coefficients, the known tolerance averaging procedure is applied. The comparison between the proposed model and the model without the length-scale effect as well as the known length-scale model for cylindrical shells with the periodic structure in both directions tangent to the shell midsurface is present.
PL
Celem pracy jest wyprowadzenie uśrednionego modelu służącego do analizy dynamiki cienkich liniowo-sprężystych powłok walcowych mających periodyczną strukturę w jednym kierunku stycznym do powierzchni środkowej powłoki. Proponowany model, w przeciwieństwie do znanych modeli zhomogenizowanych, umożliwia badanie wpływu wielkości komórki periodyczności na dynamikę powłoki walcowej (wpływ ten zwany jest efektem skali). W celu wyprowadzenia równań o stałych lub wolnozmiennych współczynnikach zastosowano znaną metodę tolerancyjnego uśredniania. Wyprowadzony model porównano z modelem dla powłoki walcowej z periodyką w dwóch kierunkach wzajemnie prostopadłych i stycznych do powierzchni środkowej powłoki oraz z modelem bez efektu skali.
2
Content available remote The automatic measurement of a staining reaction level
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EN
The paper presents an application of an algorithm for automatic segmentation of biological cell structures. The algorithm, based on two morphological operations - conditional opening and con­ditional closing, is described in detail in [8]. The results of the segmentation of biological cell structure images as well as the evaluation of a staining reaction saturation level and its metrological properties are studied.
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PL
W zależności od rodzaju oczyszczalni ścieków, bakteria nitkowata Typu 021N różni się kształtem swoich komórek, który może być szerszy w komunalnych oczyszczalniach lub węższy i dłuższy w przemysłowych. Może to być spowodowane niedoborem substancji odżywczych. Czasami można zaobserwować komórki krótkie krążkokształtne lub długie pałeczkowate. Możliwe jest występowanie wszystkich form pośrednich jednak najczęściej występują komórki prawie kwadratowe. Typ 021N łatwo pomylić z Typem 0041, Sphaerotilus natans, Thiotrix. Typ 0041 jest jednak Gram-dodatni, S. natans ma komórki innego kształtu, a Thiotrix reaguje wyraźnie dodatnio na test siarkowy.
EN
The purpose of this article is to provide-on the basis of the literature review—the current state of knowledge concerning the experimental and numerical studies of selected types of batteries. The authors focused their actions on batteries that could to be the base for an energy storage system possible to apply in hybrid shunting locomotive. Following standards, e.g. IEEE 1625, IEEE 1725, UL 1973 and UL 2271 were taken into consideration within the context of the experimental research. Numerical analysis based mostly on the original solutions proposed by research teams. In recent times, the significant growth of interest in hybrid vehicles can be observed. Therefore, appropriate design of the energy storage system for each case is necessary. Moreover, the battery working process in hybrid vehicles is very specific, hence determination of their working conditions depending on the vehicle application is required. Very often, the experimental studies related with the batteries are based on the parameters recorded during the test conducted during the regular operation of the vehicle. Furthermore, research teams also carry out numerical analysis based on e.g. the finite element method (FEM). Such analyses can be focused on the thermal analyses of single cell or cells, analyses of the electrochemical effects as well as a coupled electro-thermal analyses.
EN
Human promyelocytic leukemia cells,. HL-60, were treated with cisplattn [cis-diamminedichloroplatinum (II)] (2 itiM, 1 h). DNA- eisplatin-protein complexes were isolated and exposed to thiourea (1M), NaCN (100 mM), diethyldithio-carbamate (500 mM), or tf-methyl-D- glucamine dithiocarbamate (500 mM) for 12 h. The release of platinum was measured by atomic absorption spectroscopy. Sodium cyanide was the most effective agent, releasing about 90% of the DNA-bound platinum. Thiourea was the least effective agent, while dithiocar- bamates exhibited an intermediate. The ability of the same group of agents to split the proteins off from the protein-cisplatin-DNA complex was also evaluated and similarly dithiocarbamate were also the most effective.
EN
Molecular imprinting of small organic compounds is now a standard procedure for preparation of tailor-designed affinity materials. Molecularly imprinted polymers (MIPs) have outstanding stability and can be prepared in a large quantity, therefore are useful replacements for biological receptors for a number of applications including product purification, analytical separation, chemical sensing and controlled delivery and biomineralization. Although preparation of MIPs, in particular using the non-covalent imprinting strategy, has become a routine practice in many research laboratories, new synthetic methods continued to be invented, which contribute to new MIPs with unprecedented functional performances. As the size of the template increases from small organic compounds to biomacromolecules to large virus particles and cells, the traditional methods of imprinting often fail to give useful MIP products. Another important aspect is the shift from organic solvents to water for MIPs designed for treatment or analysis of biological samples. The demand on water-compatibility and recognition of larger entities for MIPs call for new and efficient synthetic methods. This mini review will summarize the recent progress of molecular imprinting using particle-stabilized emulsion as a general synthetic platform to furnish the new MIPs with the desired functions.
17
Content available Design and Simulation of Cyclic Battery Tester
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EN
The paper presents an approach to the modelling of a cyclic battery tester and contains observations about lithium-ion (Li-ion) batteries, charging/discharging procedures, conditions and protections which must be observed during the testing process. The main goal was to create and simulate a schematic which will be capable of cyclically testing Li-ion battery cells. Regulation of the final schematic is based on cascade connections of operation amplifiers, which work as a voltage source with current-limiting functions. The power part is created by two MOSFETs connected as a half-bridge. This topology allows current to flow in both directions (from and to the battery). Final simulation is supplemented by protections such as reverse polarity protection, short circuit protection and overvoltage protection during charging. Proper operation of the whole connection is demonstrated by the simulation outputs in the final section.
EN
The aim of this contribution is to propose a new averaged nonasymptotic model of stationary stability problems for thin linear-elastic cylindrical shells reinforced by stiffeners which are periodically, densely spaced along one direction tangent to the shell midsurface. As a tool of modelling we shall apply the tolerance averaging technique. The resulting equations have constant coefficients in the periodicity direction. Moreover, in contrast with models obtained by the asymptotic homogenization technique, the proposed one makes it possible to describe the effect of the periodicity cell size on the global shell stability (a length-scale effect). It will be shown that this effect plays an important role in the shell stability analysis and cannot be neglected.
PL
W pracy zaproponowano nowy uśredniony nieasymptotyczny model służący do analizy stateczności cienkich liniowo-sprężystych powłok walcowych, periodycznie, gęsto użebrowanych w jednym kierunku stycznym do powierzchni środkowej. Przy wyprowadzaniu równań modelu wykorzystano znaną metodę tolerancyjnego uśredniania, zaproponowaną przez Woźniaka i Wierzbickiego (2000). Zastosowanie tej metody do znanych równań teorii powłok Kirchhoffa-Love'a doprowadziło do modelu reprezentowanego przez równania różniczkowe cząstkowe o stałych współczynnikach w kierunku periodyczności, zależnych od długościokresu periodyczności. Oznacza to, że proponowany model, w przeciwieństwie do znanych modeli zhomogenizowanych, umożliwia badanie wpływu wielkości komórki periodyczności na wartości sił krytycznych w powłoce walcowej (wpływ ten zwany jest efektem skali). Wyprowadzony model porównano z modelem bez efektu skali i pokazano, że wpływ długości okresu periodyczności odgrywa znaczącą rolę w zgadnieniach stateczności periodycznie, gęsto użebrowanych powłok walcowych.
EN
The aim of the present work was to evaluate the topography of spirochetes’ cells Borrelia burgdorferi s.s. B31 in atomic force microscope (AFM). Results: The length of spirochetes B. burgdorferi has ranged between 15.38-22.68μm. The cells of spirochetes do not constitute structures of a fixed diameter and height. Thus, in order to identify real parameters of cells, the horizontal distance and vertical distance have been used in the measurements. The average value of a spirochetes’ diameter has been estimated by taking series of measures and it is 0.40 μm. The average value of a spirochetes’ height has been estimated by taking series of measures and it is 70.14 nm. The analysis of a relation between measured parameters of spirochetes: diameter and height revealed that along with the growth of diameter of a bacteria cell, its height also grows. The average value of a fibers’ diameter has been estimated by taking series of measurements and it is 0.09 μm and the average height of fibers was 7.91 nm. Conclusions: The atomic force microscope (AFM) is a modern tool with a broad spectrum of observatory and measure abilities and is a technique which has been used in biology and microbiology to investigate the topography of surface and in the evaluation properties of cells.
EN
We studied the effect of the modification of focal adhesion kinase (FAK) on the growth, migration and adhesion of C3H 10T1/2 cells. Cells transfected with plasmid coding for antisense FAK displayed a low level of FAK protein. Interestingly, the transfected cells achieved a higher saturation density at confluence, and displayed reduced adhesion and enhanced emigration from a confluent layer of cells when stimulated with fibronectin. In conclusion, it can be postulated that FAK plays an important role in the mechanism of contact inhibition.
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