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排序方式: 共有218条查询结果,搜索用时 15 毫秒
1.
Oleksandr Gryshkov Vitalii Mutsenko Dmytro Tarusin Diaa Khayyat Ortwin Naujok Ekaterina Riabchenko Yuliia Nemirovska Arseny Danilov Alexander Y. Petrenko Birgit Glasmacher 《International journal of molecular sciences》2021,22(6)
Alginate as a versatile naturally occurring biomaterial has found widespread use in the biomedical field due to its unique features such as biocompatibility and biodegradability. The ability of its semipermeable hydrogels to provide a favourable microenvironment for clinically relevant cells made alginate encapsulation a leading technology for immunoisolation, 3D culture, cryopreservation as well as cell and drug delivery. The aim of this work is the evaluation of structural properties and swelling behaviour of the core-shell capsules for the encapsulation of multipotent stromal cells (MSCs), their 3D culture and cryopreservation using slow freezing. The cells were encapsulated in core-shell capsules using coaxial electrospraying, cultured for 35 days and cryopreserved. Cell viability, metabolic activity and cell–cell interactions were analysed. Cryopreservation of MSCs-laden core-shell capsules was performed according to parameters pre-selected on cell-free capsules. The results suggest that core-shell capsules produced from the low viscosity high-G alginate are superior to high-M ones in terms of stability during in vitro culture, as well as to solid beads in terms of promoting formation of viable self-assembled cellular structures and maintenance of MSCs functionality on a long-term basis. The application of 0.3 M sucrose demonstrated a beneficial effect on the integrity of capsules and viability of formed 3D cell assemblies, as compared to 10% dimethyl sulfoxide (DMSO) alone. The proposed workflow from the preparation of core-shell capsules with self-assembled cellular structures to the cryopreservation appears to be a promising strategy for their off-the-shelf availability. 相似文献
2.
Gries R Khaskin G Clearwater J Hasman D Schaefer PW Khaskin E Miroshnychenko O Hosking G Gries G 《Journal of chemical ecology》2005,31(3):603-620
(Z, Z)-6,9-Heneicosadien-11-one (Z6Z9-11-one-21Hy) was identified as the major sex pheromone component of the painted apple moth (PAM), Teia anartoides (Lepidoptera: Lymantriidae), on the basis of (1) comparative gas chromatographic-electroantennographic detection (GC-EAD) analyses, GC-mass spectrometry (MS), high-performance liquid chromatography (HPLC)-MS, and HPLC-UV/visible spectroscopy of pheromone gland extracts and authentic standards; (2) GC-EAD analyses of effluvia of calling females; and (3) wind tunnel and field trapping experiments with a synthetic standard. In field experiments in Australia, synthetic Z6Z9-11-one-21Hy as a single component attracted male moths. Wind tunnel experiments suggested that a 4-component blend consisting of Z6Z9-11-one-21Hy, (6Z,9R,10S)-cis-9,10-epoxy-heneicosene (Z6-9R10S-epo-21Hy), (E, E)-7,9-heneicosadien-6,11-dione (E7E9-6,11-dione-21Hy), and 6-hydroxy-(E, E)-7,9-heneicosadien-11-one (E7E9-6-ol-11-one-21Hy) (all present in pheromone gland extracts) might induce more males to orient toward, approach, and contact the source than did Z6Z9-11-one-21Hy as a single component. Additional experiments are needed to determine conclusively whether or not Z6-9R10S-epo-21Hy, E7E9-6,11-dione-21Hy, and E7E9-6-ol-11-one-21Hy might be minor sex pheromone components of PAM. Moreover, attractiveness of synthetic pheromone and virgin PAM females needs to be compared to determine whether synthetic pheromone could replace PAM females as trap baits in the program to monitor eradication of exotic PAM in New Zealand. 相似文献
3.
Peter E. Neerincx Martin Hofmann Oleksandr Gorodetskyi Kirill Feldman Jan Vermant Han E. H. Meijer 《Polymer Engineering and Science》2021,61(4):1257-1269
Relatively recently, we advanced a route to create, in a controlled fashion, combined horizontal and vertical stratified structures by simple and energy-efficient processing operations employing static mixing elements. While in state-of-the-art static mixing the focus is on layer multiplication, here the aim is to create hierarchical fractal structures. Therefore, the main question addressed in this article is how structures, rather than layers, can be multiplied. The key aspect is the addition of layers on the sides or in the midplane of the flow during the process; every addition step increases the hierarchy by one level. This article derives the general formalism for forming fractal structures with controlled hierarchy, and we develop the language required to design and construct the dies. The main part of the article addresses this main topic and is based on the splitting serpentine static mixer geometry that can be easily made on the parting surfaces of a mold on both the micro- and the macroscale. The second part of the article addresses the strategy to minimize the number of mirroring steps, eventually avoiding mirroring completely, and is based on the rotation-free multiflux static mixer geometry. With the design language derived, complex hierarchical fractal structures can be generated simply by changing the number and sequence of operators within extrusion dies or molds, providing a one-step solution to produce material structures for potential use in diverse applications ranging from advanced mechanical systems to photovoltaic devices, where controlled assembly of dissimilar materials, and the realization of huge interfaces and genuine cocontinuity throughout the cross section, is critical. 相似文献
4.
This work investigates applicability of magnetic hysteresis method for non-destructive testing of plastically deformed low-carbon steel. Recently introduced Magnetic Adaptive Testing procedure was used for evaluation of hysteresis minor loop data-sets to find the most sensitive parameter/s for indication of the material degradation stage. Inductive measurements were carried out on two identically degraded series of samples: magnetically closed window-shaped specimens, equipped with the magnetizing and the induction coils, and magnetically open strips, measured by an attached magnetizing yoke. The aim was to compare the results between these sample series in order to determine applicability and limitations of the single-yoke measurement technique. As a result, new magnetic parameters with the best sensitivity–stability ratio in a wide deformation range were introduced and proposed for utilization. Good qualitative coincidence between the measurement results on the closed and the open sample series was obtained in all range of magnetization. Several quantitative distinctions were explained and analyzed in order to improve the single-yoke technique. 相似文献
5.
Localized Synthesis of Iron Oxide Nanowires and Fabrication of High Performance Nanosensors Based on a Single Fe2O3 Nanowire
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Oleg Lupan Vasile Postica Niklas Wolff Oleksandr Polonskyi Viola Duppel Victor Kaidas Eugen Lazari Nicolai Ababii Franz Faupel Lorenz Kienle Rainer Adelung 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(16)
A composed morphology of iron oxide microstructures covered with very thin nanowires (NWs) with diameter of 15–50 nm has been presented. By oxidizing metallic Fe microparticles at 255 °C for 12 and 24 h, dense iron oxide NW networks bridging prepatterned Au/Cr pads are obtained. X‐ray photoelectron spectroscopy studies reveal formation of α‐Fe2O3 and Fe3O4 on the surface and it is confirmed by detailed high‐resolution transmission electron microscopy and selected area electron diffraction (SAED) investigations that NWs are single phase α‐Fe2O3 and some domains of single phase Fe3O4. Localized synthesis of such nano‐ and microparticles directly on sensor platform/structure at 255 °C for 24 h and reoxidation at 650 °C for 0.2–2 h, yield in highly performance and reliable detection of acetone vapor with fast response and recovery times. First nanosensors on a single α‐Fe2O3 nanowire are fabricated and studied showing excellent performances and an increase in acetone response by decrease of their diameter was developed. The facile technological approach enables this nanomaterial as candidate for a range of applications in the field of nanoelectronics such as nanosensors and biomedicine devices, especially for breath analysis in the treatment of diabetes patients. 相似文献
6.
7.
Jun Pan Li Na Quan Yongbiao Zhao Wei Peng Banavoth Murali Smritakshi P. Sarmah Mingjian Yuan Lutfan Sinatra Noktan M. Alyami Jiakai Liu Emre Yassitepe Zhenyu Yang Oleksandr Voznyy Riccardo Comin Mohamed N. Hedhili Omar F. Mohammed Zheng Hong Lu Dong Ha Kim Edward H. Sargent Osman M. Bakr 《Advanced materials (Deerfield Beach, Fla.)》2016,28(39):8718-8725
8.
Oleksandr?PanchenkoEmail author Hasso?Plattner Alexander?B.?Zeier 《Information Systems Frontiers》2011,13(3):349-357
Enabling fast and detailed insights over large portions of source code is an important task in a global development ecosystem.
Numerous data structures have been developed to store source code and to support various structural queries, to help in navigation,
evaluation and analysis. Many of these data structures work with tree-based or graph-based representations of source code.
The goal of this project is to elaborate a data storage that enables efficient storing and fast querying of structural information.
The naive adjacency list method has been enhanced with the use of recent data compression approaches for column-oriented databases
to allow no-loss albeit compact storage of fine-grained structural data. The graph indexing has enabled the proposed data
model to expeditiously answer fine-grained structural queries. This paper describes the basics of the proposed approach and
illustrates its technical feasibility. 相似文献
9.
This article provides a comprehensive and comparative overview of question answering technology. It presents the question answering task from an information retrieval perspective and emphasises the importance of retrieval models, i.e., representations of queries and information documents, and retrieval functions which are used for estimating the relevance between a query and an answer candidate. The survey suggests a general question answering architecture that steadily increases the complexity of the representation level of questions and information objects. On the one hand, natural language queries are reduced to keyword-based searches, on the other hand, knowledge bases are queried with structured or logical queries obtained from the natural language questions, and answers are obtained through reasoning. We discuss different levels of processing yielding bag-of-words-based and more complex representations integrating part-of-speech tags, classification of the expected answer type, semantic roles, discourse analysis, translation into a SQL-like language and logical representations. 相似文献
10.
Andriy V. Kozytskiy Oleksandr L. Stroyuk Stepan Ya. Kuchmiy Volodymyr M. Dzhagan Dietrich R. T. Zahn Mykola A. Skoryk Vyacheslav O. Moskalyuk 《Journal of Materials Science》2013,48(21):7764-7773
Nanocrystalline ITO/ZnO films formed by porous zinc oxide microplatelets 1–3 μm in size and 100–200 nm in thickness, which consist of 30–50 nm ZnO crystallites, were sensitized to visible light by Cd x Zn1?x S nanocrystals deposited using the method of successive ionic layer adsorption and reaction (SILAR). The composition of Cd x Zn1?x S nanocrystals as well as the dependence between molar Cd(II) fraction in the films and the ratio of cadmium and zinc nitrate concentrations in solutions used for the SILAR procedure were determined by a combination of electron, Raman, and energy-dispersive X-ray spectroscopies. The photovoltage observed at illumination of the ITO/ZnO/Cd x Zn1?x S heterostructures by white light (λ >400 nm) in aqueous Na2S solution increases with a decrease of Cd(II) content proportionally to an increment in the conduction band potential of the Cd x Zn1?x S nanocrystals. The photocurrent density normalized to the light absorbance of the ITO/ZnO/Cd x Zn1?x S films increases by a factor of around four when the conduction band potential of Cd x Zn1?x S nanocrystals grows by 220 mV as a result of Cd(II) fraction changing from 1.0 to 0.62–0.67. The results show that Cd x Zn1?x S solid solutions are more advantageous sensitizers for the short-wavelength part of the sensitivity window of the liquid-junction solar cells (400–450 nm) than conventionally used cadmium sulfide. 相似文献