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51.
Mechanism of MxOy nanoparticles/CNTs for catalytic carbonization of polyethylene and application to flame retardancy
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Karolina Wenelska Xuecheng Chen Beata Zielinska Ryszard J. Kaleńczuk Paul K. Chu Tao Tang Ewa Mijowska 《应用聚合物科学杂志》2017,134(34)
Three kinds of metal oxide nanoparticles (Fe3O4, Co3O4, and Ni2O3) are produced on carbon nanotubes (CNTs). The synergistic effects rendered by the CNTs and metal oxide nanoparticles on carbonization of polyethylene (PE) are studied and applications to flame retardancy of PE are investigated systematically. The CNT‐Ni2O3 delivers the best performance and the mechanism pertaining to the enhanced flame retardancy is proposed and discussed. It is found that under the same conditions, the carbonization rate can be a factor to influence the flame retardancy performance. Among Fe, Co, and Ni, Ni has the fastest carbonation rate, which leads to the best flame retardancy performance. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45233. 相似文献
52.
Synthesis of Novel Phosphonic‐Type Activity‐Based Probes for Neutrophil Serine Proteases and Their Application in Spleen Lysates of Different Organisms
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Dr. Renata Grzywa Dr. Ewa Burchacka Maria Łęcka Dr. Łukasz Winiarski Maciej Walczak Agnieszka Łupicka‐Słowik Dr. Magdalena Wysocka Prof. Timo Burster Dr. Kamila Bobrek Dr. Keri Csencsits‐Smith Prof. Adam Lesner Dr. Marcin Sieńczyk 《Chembiochem : a European journal of chemical biology》2014,15(17):2605-2612
Neutrophils are a type of granulocyte important in the “first line of defense” of the innate immune system. Upon activation, they facilitate the destruction of invading microorganisms by the production of superoxide radicals, as well as the release of the enzymatic contents of their lysozymes. These enzymes include specific serine proteases: cathepsin G, neutrophil elastase, proteinase 3, as well as the recently discovered neutrophil serine protease 4 (NSP4). Under normal conditions, the proteolytic activity of neutrophil proteases is tightly regulated by endogenous serpins; however, this mechanism can be subverted during tissue stress, thereby resulting in the uncontrolled activity of serine proteases, which induce chronic inflammation and subsequent pathology. Herein, we describe the development of low‐molecular‐weight activity‐based probes that specifically target the active sites of neutrophil proteases. 相似文献
53.
Natalia Pawlik Barbara Szpikowska-Sroka Ewa Pietrasik Tomasz Goryczka Wojciech A. Pisarski 《中国稀土学报(英文版)》2019,37(11):1137-1144
In the present work,the transparent oxyfluoride glass-ceramic samples containing GdF_3:RE~(3+)(RE=Tb,Eu) nanocrystals(nGCs) were fabricated via controlled heat-treatment of precursor xerogels prepared using a sol-gel method.The formation of GdF_3 nanocrystalline phase from gadolinium(III) trifluoroacetate was verified based on XRD measurements.The average crystal sizes calculated from Scherrer formula were estimated to~10 nm as well as~6 nm for Tb~(3+)-and Eu~(3+)-doped samples,respectively.The optical behavior of prepared sol-gel samples was evaluated based on photoluminescence excitation(PLE) and emission spectra(PL) as well as luminescence decay analysis.Obtained samples exhibit the ~5D_4→~7F_J(J=6-3,Tb~(3+))and the ~5D_0→~7F_J(J=0-4,Eu~(3+)) emission bands recorded within the visible spectral area under excitation at near-UV(393 nm(Eu~(3+)),351,369,378 nm(Tb~(3+))) as well as middle-UV illumination(273 nm(Gd~(3+))).Additionally,based on recorded decay curves,the luminescence lifetimes(τ_m) for the ~5D_4(Tb3+) and the ~5D_0(Eu~(3+))excited states were also evaluated.In general,recorded luminescence spectra and double-exponential character of decay curves for nGCs indicate a successful migration of Tb~(3+) and Eu~(3+) dopant ions from amorphous silicate framework to lowphonon energy GdF_3 nanocrystal phase. 相似文献
54.
Andrzej Gawor Zdzislaw Gajewski Leszek Paczek Bozena Czarkowska-Paczek Anna Konopka Grzegorz Wryk Ewa Bulska 《International journal of molecular sciences》2022,23(8)
In many pharmaceuticals, a hydrogen atom or hydroxyl group is replaced by a fluorine to increase bioavailability and biostability. The fate of fluorine released from fluorine-containing drugs is not well investigated. The aim of this study was to examine possible fluorination of proteins in rat liver and brain after administration of the fluorinated drug cinacalcet. We assigned 18 Wistar rats to a control group (n = 6) and a group treated with cinacalcet (2 mg kg−1/body weight, 5 days/week), divided into 7 day (n = 6) and 21 day (n = 6) treatment subgroups. Fluorinated proteins were identified using a free proteomics approach; chromatographic separation and analysis by high-resolution mass spectrometry; peptide/protein identification using the Mascot search algorithm; manual verification of an experimentally generated MS/MS spectrum with the theoretical MS/MS spectrum of identified fluorinated peptides. Three fluorinated proteins (spectrin beta chain; carbamoyl-phosphate synthase [ammonia], mitochondrial; 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 1) were identified in the liver and four (spectrin beta chain, dihydropyrimidinase-related protein 4, prominin-2, dihydropyrimidinase-related protein 4) in the brain tissue after 21 days of cinacalcet treatment, but not in the control group. Introduction of fluorine into an organism by administration of fluorinated drugs results in tissue-specific fluorination of proteins. 相似文献
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57.
Agnieszka Łącz Łukasz Łańcucki Radosław Lach Bartosz Kamecki Ewa Drożdż 《International Journal of Hydrogen Energy》2018,43(18):8999-9005
Series of single-phase materials with assumed formula SrTi1?xCrxO3 (where x = 0, 1, 4, 6 mol.%) were obtained by sol-gel method. The structure and microstructure of materials were characterised by X-ray diffraction and scanning electron microscopy methods. Moreover, the study of electrical properties and evaluation of chemical stability in CO2/H2O atmosphere was performed by electrochemical impedance spectroscopy and thermogravimery methods, respectively. The possibility of participation of Cr-doped strontium titanate in oxidation–reduction processes was analysed by temperature-programed reduction (TPR) and temperature-programed oxidation (TPOx) measurements. The changes of lattice parameters together with XPS analysis, the Seebeck coefficient measurements results and TPR profiles obtained for SrTi1?xCrxO3 materials prove the presence of chromium on +3 and +6 oxidation stages. Thus, chromium can be treated as both acceptor- and donor-type dopant in the SrTiO3 structure. The Cr3+/Cr6+ ratio strongly affects the electrical properties, as the change of conduction mechanism was observed. The results of performed stability test clearly indicate that incorporation of chromium into SrTiO3 structure results with decrease of chemical stability in CO2 atmosphere. 相似文献
58.
Grażyna Budryn Dorota Żyżelewicz Ewa Nebesny Joanna Oracz Wiesława Krysiak 《Food research international (Ottawa, Ont.)》2013,50(1):149-160
This study investigated the influence of antioxidants of green tea aqueous extract (GTE) and green coffee aqueous extract (GCE) in concentrations of 0.25, 0.5 and 1 g·100 g? 1 on the nutritional properties of fine yeast pastry fried products such as donuts. Yeast donuts were made according to the traditional processing technology. In fried donuts physical properties (water activity, pH, hardness and color with the use of instrumental methods) as well as sensory properties were established. Moreover, quality of fat extracted from donuts (composition of fatty acids and peroxide value), content of acrylamide, composition of polyphenols and antioxidant activity were analyzed. Obtained extracts of GTE and GCE contained 26 and 41% of polyphenols, respectively, and the degree of polyphenol degradation during production of donuts was less when the dilution in dough was greater. Both tests indicated that the highest antioxidant activity had donuts with the highest analyzed addition of extract, however depending on the applied test or GTE or GCE had better antioxidant properties. Fatty acid composition was the most beneficial when the addition of GTE and GCE was on a level of 0.25 and 0.5 g·100 g? 1, respectively. In fried donuts relatively low amounts of acrylamide were obtained, amounting to 18–46 μg·kg? 1. Only the lowest addition of GTE and the highest addition of GCE caused an increase of acrylamide content in donuts, while all other levels of added extracts caused a decrease in the content of formed acrylamide. 相似文献
59.
Ewa Bogel-?ukasik Susana Santos Manuel Nunes da Ponte 《The Journal of Supercritical Fluids》2010,54(2):210-12548
Ionic liquids as coated catalysts or additives tremendously alter the selectivity pattern of the heterogeneous solid catalyst in the selective hydrogenation of limonene. The conventional monometallic ruthenium over alumina catalyst combined with an ionic liquid enables the one-pot synthesis of the intermediate p-menthene through limonene hydrogenation in supercritical carbon dioxide. Among eight screened imidazolium ILs, [C10mim]NTf2 was employed as additive, or as the coating agent of ruthenium catalyst in the reaction under supercritical conditions.The coating of the heterogeneous catalyst allows the selective production of p-menthene and increases the conversion level of limonene (>99%) compared to the conversion of limonene in the reaction carried out in the presence of an ionic liquid as an additive. Results of the catalyst recycling indicate that there is no depletion of catalyst reactivity even after four successive cycles of operation under the studied reaction conditions. Further hydrogenation of p-menthene is strongly inhibited by employing an ionic liquid. The solubility of limonene or p-menthene in an ionic liquid governs the selective hydrogenation of limonene towards p-menthene. 相似文献
60.
Large-scale applications can be expressed as a set of tasks with data dependencies between them, also known as application
workflows. Due to the scale and data processing requirements of these applications, they require Grid computing and storage
resources. So far, the focus has been on developing easy to use interfaces for composing these workflows and finding an optimal
mapping of tasks in the workflow to the Grid resources in order to minimize the completion time of the application. After
this mapping is done, a workflow execution engine is required to run the workflow over the mapped resources. In this paper,
we show that the performance of the workflow execution engine in executing the workflow can also be a critical factor in determining
the workflow completion time. Using Condor as the workflow execution engine, we examine the various factors that affect the
completion time of a fine granularity astronomy workflow. We show that changing the system parameters that influence these
factors and restructuring the workflow can drastically reduce the completion time of this class of workflows. We also examine
the effect on the optimizations developed for the astronomy application on a coarser granularity biology application. We were
able to reduce the completion time of the Montage and the Tomography application workflows by 90% and 50%, respectively. 相似文献