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排序方式: 共有1062条查询结果,搜索用时 15 毫秒
21.
Dmitry D. Zaitsev Ekaterina A. Gravchikova Pavel E. Kazin Yury D. Tretyakov Martin Jansen 《International Journal of Applied Ceramic Technology》2006,3(4):279-283
Glass samples with nominal compositions SrFe12 O19 +(12− n )SrB2 O4 +nSrSiO3 , n =3, 6, 9 were prepared by rapid quenching of the melt. Processes of glass devitrification were studied. The samples were annealed at temperatures of 600–900°C, and the resulting glass–ceramics was characterized by XRD, SEM, EDX, and magnetic measurements. SrFe12 O19 crystallizes above 700°C and forms nano- and submicron platelet particles with the aspect ratio depending on the thermal treatment conditions. The glass–ceramic samples annealed at 900°C show coercive force values in the range of 422–455 kA/m. 相似文献
22.
Dmitry Oshchepkov Irina Chadaeva Rimma Kozhemyakina Karina Zolotareva Bato Khandaev Ekaterina Sharypova Petr Ponomarenko Anton Bogomolov Natalya V. Klimova Svetlana Shikhevich Olga Redina Nataliya G. Kolosova Maria Nazarenko Nikolay A. Kolchanov Arcady Markel Mikhail Ponomarenko 《International journal of molecular sciences》2022,23(5)
23.
Svetlana G. Yakubova Guzalia R. Abilova Elvira G. Tazeeva Yulia Y. Borisova Dmitry V. Milordov Nikolay A. Mironov 《Petroleum Science and Technology》2018,36(16):1319-1324
Features of the content and distribution of vanadium and vanadyl porphyrins in the fractions of resins, which were obtained by separation using column chromatography on silica, have been studied on heavy sulfurous oils of various deposits of the Volga–Ural basin (Russia). The difference of the vanadium and vanadyl porphyrin contents in the fractions of oils of various production complexes has been shown. Features of structural–group composition and predominant types of vanadyl porphyrins in the fractions of resins have been determined. 相似文献
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Victor I. Sevastianov Anna S. Ponomareva Natalia V. Baranova Lyudmila A. Kirsanova Yulia B. Basok Evgeniy A. Nemets Dmitry N. Kruglov Igor A. Miloserdov Sergey V. Gautier 《International journal of molecular sciences》2023,24(1)
A significant lack of donor organs restricts the opportunity to obtain tissue-specific scaffolds for tissue-engineering technologies. One of the acceptable solutions is the development of decellularization protocols for a human donor pancreas unsuitable for transplantation. A protocol of obtaining a biocompatible tissue-specific scaffold from decellularized fragments with pronounced human pancreas lipomatosis signs with preserved basic fibrillary proteins of a pancreatic tissue extracellular matrix was developed. The scaffold supports the adhesion and proliferation of human adipose derived stem cell (hADSCs) and prolongs the viability and insulin-producing function of pancreatic islets. Experiments conducted allow for the reliance on the prospects of using the donor pancreas unsuitable for transplantation in the technologies of tissue engineering and regenerative medicine, including the development of a tissue equivalent of a pancreas. 相似文献
27.
Alla Zorina Vadim Zorin Dmitry Kudlay Pavel Kopnin 《International journal of molecular sciences》2022,23(11)
Skin aging is a multi-factorial process that affects nearly every aspect of skin biology and function. The processes developing in the skin during aging are based on fundamental molecular mechanisms associated with fibroblasts, the main cellular population of the dermis. It has been revealed that the amount of fibroblasts decreases markedly with age and their functional activity is also reduced. This inevitably leads to a decrease in the regenerative abilities of the skin and the progression of its aging. In this review we consider the mechanisms underlying these processes, mainly the changes observed with age in the stem/progenitor cells that constitute the fibroblastic differon of the dermis and form their microenvironment (niches). These changes lead to the depletion of stem cells, which, in turn, leads to a decrease in the number of differentiated (mature) dermal fibroblasts responsible for the production of the dermal extracellular matrix and its remodeling. We also describe in detail DNA damages, their cellular and systemic consequences, molecular mechanisms of DNA damage response, and also the role of fibroblast senescence in skin aging. 相似文献
28.
Vladimir Sukhorukov Alina Magnaeva Tatiana Baranich Anna Gofman Dmitry Voronkov Tatiana Gulevskaya Valeria Glinkina Sergey Illarioshkin 《International journal of molecular sciences》2022,23(18)
Accumulating data suggest that the brain undergoes various changes during aging. Among them are loss of both white and gray matter, neurons and synapses degeneration, as well as oxidative, inflammatory, and biochemical changes. The above-mentioned age-related features are closely related to autophagy and mitochondria. Therefore, we aimed to reveal the most peculiar morphological features of brain nervous tissue and to characterize the expression of autophagy and mitochondrial immunohistochemical biomarkers in neurons of different human brain zones during aging. Counting the number of neurons as well as Microtubule-associated proteins 1A/1B light chain 3B (LC3B), Heat shock protein 70 (HSP70), Lysosome-associated membrane protein type 2A (LAMP2A), Alpha subunit of ATP synthase (ATP5A), and Parkinson disease protein 7 (DJ1) immunohistochemical staining were performed on FFPE samples of human prefrontal cortex, corpus striatum, and hippocampus obtained from autopsy. Statistical analysis revealed a loss of neurons in the studied elderly group in comparison to the young group. When the expression of macroautophagy (LC3B), chaperon-mediated autophagy (HSP70, LAMP2A), and mitochondrial respiratory chain complex V (ATP5A) markers for the young and elderly groups were compared, the latter was found to have a significantly higher rate of optical density, whilst there was no significance in DJ1 expression. These findings, while preliminary, suggest that both autophagy and mitochondria are involved in neuronal maintenance during aging and could indicate their potential role in adaptive mechanisms that occur in aging. 相似文献
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Dmitry A. Bratsun 《Microgravity science and technology》2009,21(Z1):153-158
We study two-phase flow in a tall vertical slot differently heated from the side walls and subjected to finite-frequency horizontal
vibrations along the layer. One of the phases is fluid and another phase consists of the small solid particles. We show that
there is the maximum vibration frequency higher which the unsteady forces, such as the Basset history force and virtual mass
effect, may, generally, be of great importance and have to be taken into account. By using the asymptotic expansion technique
we derive the set of governing equations describing the dynamics of such a system within the framework of the generalized
Boussinesq approximation. The pulsed base flow is obtained and its linear stability is analysed. The comparison with the recent
experimental data is made. 相似文献