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排序方式: 共有441条查询结果,搜索用时 31 毫秒
161.
Sylwia Kliska Kamil Demski Katarzyna Jasieniecka-Gazarkiewicz Antoni Bana 《International journal of molecular sciences》2021,22(15)
Acyl-CoA:lysophosphatidylethanolamine acyltransferases (LPEATs) are known as enzymes utilizing acyl-CoAs and lysophospholipids to produce phosphatidylethanolamine. Recently, it has been discovered that they are also involved in the growth regulation of Arabidopsis thaliana. In our study we investigated expression of each Camelina sativa LPEAT isoform and their behavior in response to temperature changes. In order to conduct a more extensive biochemical evaluation we focused both on LPEAT enzymes present in microsomal fractions from C. sativa plant tissues, and on cloned CsLPEAT isoforms expressed in yeast system. Phylogenetic analyses revealed that CsLPEAT1c and CsLPEAT2c originated from Camelina hispida, whereas other isoforms originated from Camelina neglecta. The expression ratio of all CsLPEAT1 isoforms to all CsLPEAT2 isoforms was higher in seeds than in other tissues. The isoforms also displayed divergent substrate specificities in utilization of LPE; CsLPEAT1 preferred 18:1-LPE, whereas CsLPEAT2 preferred 18:2-LPE. Unlike CsLPEAT1, CsLPEAT2 isoforms were specific towards very-long-chain fatty acids. Above all, we discovered that temperature strongly regulates LPEATs activity and substrate specificity towards different acyl donors, making LPEATs sort of a sensor of external thermal changes. We observed the presented findings not only for LPEAT activity in plant-derived microsomal fractions, but also for yeast-expressed individual CsLPEAT isoforms. 相似文献
162.
Athanasios Smyrnakis Angelos Zeniou Kamil Awsiuk Vassilios Constantoudis Evangelos Gogolides 《Frontiers of Chemical Science and Engineering》2019,13(3):475-484
In this work, we present plasma etching alone as a directed assembly method to both create the nanodot pattern on an etched polymeric (PMMA) film and transfer it to a silicon substrate for the fabrication of silicon nanopillars or cone-like nanostructuring. By using a shield to control sputtering from inside the plasma reactor, the size and shape of the resulting nanodots can be better controlled by varying plasma parameters as the bias power. The effect of the shield on inhibitor deposition on the etched surfaces was investigated by time-of-flight secondary ion mass spectroscopy (ToF-SIMS) measurements. The fabrication of quasi-ordered PMMA nanodots of a diameter of 25 nm and period of 54 nm is demonstrated. Pattern transfer to the silicon substrate using the same plasma reactor was performed in two ways:(a) a mixed fluorine-fluorocarbon-oxygen nanoscale etch plasma process was employed to fabricate silicon nanopillars with a diameter of 25 nm and an aspect ratio of 5.6, which show the same periodicity as the nanodot pattern, and (b) high etch rate cryogenic plasma process was used for pattern transfer. The result is the nanostructuring of Si by high aspect ratio nanotip or nanocone-like features that show excellent antireflective properties. 相似文献
163.
Kamil Kaygusuz 《Renewable & Sustainable Energy Reviews》2010,14(7):2104-2112
Main electrical energy sources of Turkey are thermal and hydraulic. Most of the thermal sources are derived from natural gas. Turkey imports natural gas; therefore, decreasing usage of natural gas is very important for both economical and environmental aspects. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Turkey has very high wind energy potential. The estimated wind power capacity of Turkey is about 83,000 MW while only 10,000 MW of it seems to be economically feasible to use. Start 2009, the total installed wind power capacity of Turkey was only 4.3% of its total economical wind power potential (433 MW). However, the strong development of wind energy in Turkey is expected to continue in the coming years. In this study, Turkey's installed electric power capacity, electric energy production is investigated and also Turkey current wind energy status is examined. 相似文献
164.
Jerzy Wiater Marcin Samiec Kamil Wartalski Zdzisaw Smorg Jacek Jura Ryszard Somski Maria Skrzyszowska Marek Romek 《International journal of molecular sciences》2021,22(18)
Pig-to-human xenotransplantation seems to be the response to the contemporary shortage of tissue/organ donors. Unfortunately, the phylogenetic distance between pig and human implies hyperacute xenograft rejection. In this study, we tested the hypothesis that combining expression of human α1,2-fucosyltransferase (hFUT2) and α-galactosidase A (hGLA) genes would allow for removal of this obstacle in porcine transgenic epidermal keratinocytes (PEKs). We sought to determine not only the expression profiles of recombinant human α1,2-fucosyltransferase (rhα1,2-FT) and α-galactosidase A (rhα-Gal A) proteins, but also the relative abundance (RA) of Galα1→3Gal epitopes in the PEKs stemming from not only hFUT2 or hGLA single-transgenic and hFUT2×hGLA double-transgenic pigs. Our confocal microscopy and Western blotting analyses revealed that both rhα1,2-FT and rhα-Gal A enzymes were overabundantly expressed in respective transgenic PEK lines. Moreover, the semiquantitative levels of Galα1→3Gal epitope that were assessed by lectin fluorescence and lectin blotting were found to be significantly diminished in each variant of genetically modified PEK line as compared to those observed in the control nontransgenic PEKs. Notably, the bi-transgenic PEKs were characterized by significantly lessened (but still detectable) RAs of Galα1→3Gal epitopes as compared to those identified for both types of mono-transgenic PEK lines. Additionally, our current investigation showed that the coexpression of two protective transgenes gave rise to enhanced abrogation of Galα→3Gal epitopes in hFUT2×hGLA double-transgenic PEKs. To summarize, detailed estimation of semiquantitative profiles for human α-1,2-FT and α-Gal A proteins followed by identification of the extent of abrogating the abundance of Galα1→3Gal epitopes in the ex vivo expanded PEKs stemming from mono- and bi-transgenic pigs were found to be a sine qua non condition for efficiently ex situ protecting stable lines of skin-derived somatic cells inevitable in further studies. The latter is due to be focused on determining epigenomic reprogrammability of single- or double-transgenic cell nuclei inherited from adult cutaneous keratinocytes in porcine nuclear-transferred oocytes and corresponding cloned embryos. To our knowledge, this concept was shown to represent a completely new approach designed to generate and multiply genetically transformed pigs by somatic cell cloning for the needs of reconstructive medicine and dermoplasty-mediated tissue engineering of human integumentary system. 相似文献
165.
Kamil Babski Anna Boczkowska Krzysztof J. Kurzydlowski 《Journal of Materials Science》2009,44(6):1456-1461
The ceramic–elastomer composites with 3D phase connectivity were tested under compressive loads. Such composites exhibit high
initial strength and stiffness with the ability to sustain large deformations. Samples of the composites were made of porous
SiO2 ceramic matrix infiltrated by polyurethane elastomer. The ceramic matrix preforms used differed in the porosity and three
different composite microstructures have been obtained. Selected parameters of microstructure composites were evaluated using
image analysis. The compressive strength and capacity for energy absorption are characterized under various strain rates (0.001–235 s−1). It was found that stress–strain characteristic depends on the strain rate and the specific interface area (Sv). Pore size
and the specific interface area have a strong effect on the compressive strength of composites and these parameters can be
used for tailoring their mechanical properties. The acoustic emission was applied to identify stages in the process of microstructure
damage during compression. The interpretation of damage stages was proposed, which also explains the character of the stress–strain
curves. 相似文献
166.
Gabriela Gorczyca Kamil Wartalski Jerzy Wiater Marcin Samiec Zbigniew Tabarowski Magorzata Duda 《International journal of molecular sciences》2021,22(21)
Nandrolone (Ndn) and boldenone (Bdn), the synthetic testosterone analogues with strong anabolic effects, despite being recognized as potentially carcinogenic compounds, are commonly abused by athletes and bodybuilders, which includes women, worldwide. This study tested the hypothesis that different doses of Ndn and Bdn can initiate neoplastic transformation of porcine ovarian putative stem cells (poPSCs). Immunomagnetically isolated poPSCs were expanded ex vivo in the presence of Ndn or Bdn, for 7 and 14 days. Results show that pharmacological doses of both Ndn and Bdn, already after 7 days of poPSCs culture, caused a significant increase of selected, stemness-related markers of cancer cells: CD44 and CD133. Notably, Ndn also negatively affected poPSCs growth not only by suppressing their proliferation and mitochondrial respiration but also by inducing apoptosis. This observation shows, for the first time, that chronic exposure to Ndn or Bdn represents a precondition that might enhance risk of poPSCs neoplastic transformation. These studies carried out to accomplish detailed molecular characterization of the ex vivo expanded poPSCs and their potentially cancerous derivatives (PCDs) might be helpful to determine their suitability as nuclear donor cells (NDCs) for further investigations focused on cloning by somatic cell nuclear transfer (SCNT). Such investigations might also be indispensable to estimate the capabilities of nuclear genomes inherited from poPSCs and their PCDs to be epigenetically reprogrammed (dedifferentiated) in cloned pig embryos generated by SCNT. This might open up new possibilities for biomedical research aimed at more comprehensively recognizing genetic and epigenetic mechanisms underlying not only tumorigenesis but also reversal/retardation of pro-tumorigenic intracellular events. 相似文献
167.
milie Velot Kamil Elkhoury Cyril Kahn Herv Kempf Michel Linder Elmira Arab-Tehrany Arnaud Bianchi 《International journal of molecular sciences》2022,23(5)
The low efficiency in transfecting rat- and human-derived chondrocytes have been hampering developments in the field of cartilage biology. Transforming growth factor (TGF)-β1 has shown positive effects on chondrocytes, but its applications remain limited due to its short half-life, low stability and poor penetration into cartilage. Naturally derived liposomes have been shown to be promising delivery nanosystems due to their similarities with biological membranes. Here, we used agro-based rapeseed liposomes, which contains a high level of mono- and poly-unsaturated fatty acids, to efficiently deliver encapsulated TGF-β1 to rat chondrocytes. Results showed that TGF-β1 encapsulated in nano-sized rapeseed liposomes were safe for chondrocytes and did not induce any alterations of their phenotype. Furthermore, the controlled release of TGF-β1 from liposomes produced an improved response in chondrocytes, even at low doses. Altogether, these outcomes demonstrate that agro-based nanoliposomes are promising drug carriers. 相似文献
168.
169.
Thomas Hulin Cristian Maluk Luke Bisby Kamil Hodicky Jacob W. Schmidt Henrik Stang 《Fire Technology》2016,52(3):683-705
In recent decades, the use of structural high performance concrete (HPC) sandwich panels made with thin plates has increased as a response to modern environmental challenges. Fire endurance is a requirement in structural HPC elements, as for most structural elements. This paper presents experimental investigations on the fire behaviour of HPC thin plates (20 or 30 mm thick) being used in lightweight structural sandwich elements. Tests were undertaken using a standard testing furnace and a novel heat-transfer rate inducing system (H-TRIS), recently developed at the University of Edinburgh. The parametric assessment of the specimen performance included: thickness of the specimen, testing apparatus, and concrete mix (both with and without polypropylene fibres). The results verified the ability of H-TRIS to impose an equivalent thermal boundary condition to that imposed during a standard furnace test, with good repeatability, and at comparatively low economic and temporal costs. The results demonstrated that heat induced concrete spalling occurred 1 to 5 min earlier, and in a more destructive manner, for thinner specimens. An analysis is presented combining the thermal material degradation, vapour pore pressure, stress concentrations, and thermo-mechanical energy accumulation in the tested specimens. Unexpectedly, spalling at the unexposed surface was observed during two of the tests, suggesting a potentially unusual, unwanted failure mode of very thin-plates during fire. On this basis it is recommended to favour 30 mm thick plates in these applications, since they appear to resist spalling better than those with 20 mm thickness. 相似文献
170.