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排序方式: 共有332条查询结果,搜索用时 265 毫秒
1.
Modern refractory castables contain between 3.5 and 5?wt.-% water that is necessary for sufficient flow during emplacement and for the formation of hydrate phases, necessary for the green strength of the material. Prior to the high temperature use of this material, it must be dried very carefully to avoid explosive spalling.This paper will demonstrate that beside conventional drying of pre-shaped materials in resistance furnaces microwave radiation is an energy saving and rapid method to remove pore water as well as hydrate bond water from the castable. In comparison to resistance furnaces, the use of microwave radiation does not affect the castable properties as there are mechanical strength (MOR, CCS), open porosity and pore size distribution. This study proved microwave radiation as valuable alternative with a series of tabular alumina based low cement castables (LLC) in which the water-to-cement-ratio (wcr = 0.64, 0.75, 0.82 and 1.13) was systematically altered by changing the cement concentration at constant mixing water concentration of 4.5%. 相似文献
2.
Teresa Mikołajczyk Grażyna Janowska Mariusz Wójcik Maciej Boguń Andrzej Kurzak 《应用聚合物科学杂志》2008,109(4):2513-2521
The rheological properties of spinning solutions of polyacrylonitrile in dimethyl formamide (DMF) containing various amounts of a ferromagnetic nanoaddition were investigated. The porous structure, the strength and thermal properties of fibers obtained from these solutions were assessed, as well as the uniformity of the nanoaddition distribution on the fiber surface was estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
3.
Jan Korbecki Klaudyna Kojder Patrycja Kapczuk Patrycja Kupnicka Barbara Gawroska-Szklarz Izabela Gutowska Dariusz Chlubek Irena Baranowska-Bosiacka 《International journal of molecular sciences》2021,22(2)
Hypoxia is an integral component of the tumor microenvironment. Either as chronic or cycling hypoxia, it exerts a similar effect on cancer processes by activating hypoxia-inducible factor-1 (HIF-1) and nuclear factor (NF-κB), with cycling hypoxia showing a stronger proinflammatory influence. One of the systems affected by hypoxia is the CXC chemokine system. This paper reviews all available information on hypoxia-induced changes in the expression of all CXC chemokines (CXCL1, CXCL2, CXCL3, CXCL4, CXCL5, CXCL6, CXCL7, CXCL8 (IL-8), CXCL9, CXCL10, CXCL11, CXCL12 (SDF-1), CXCL13, CXCL14, CXCL15, CXCL16, CXCL17) as well as CXC chemokine receptors—CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CXCR6, CXCR7 and CXCR8. First, we present basic information on the effect of these chemoattractant cytokines on cancer processes. We then discuss the effect of hypoxia-induced changes on CXC chemokine expression on the angiogenesis, lymphangiogenesis and recruitment of various cells to the tumor niche, including myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), regulatory T cells (Tregs) and tumor-infiltrating lymphocytes (TILs). Finally, the review summarizes data on the use of drugs targeting the CXC chemokine system in cancer therapies. 相似文献
4.
Pawe ukasik Irena Baranowska-Bosiacka Katarzyna Kulczycka Izabela Gutowska 《International journal of molecular sciences》2021,22(6)
Recent studies on cyclin-dependent kinase (CDK) inhibitors have revealed that small molecule drugs have become very attractive for the treatment of cancer and neurodegenerative disorders. Most CDK inhibitors have been developed to target the ATP binding pocket. However, CDK kinases possess a very similar catalytic domain and three-dimensional structure. These features make it difficult to achieve required selectivity. Therefore, inhibitors which bind outside the ATP binding site present a great interest in the biomedical field, both from the fundamental point of view and for the wide range of their potential applications. This review tries to explain whether the ATP competitive inhibitors are still an option for future research, and highlights alternative approaches to discover more selective and potent small molecule inhibitors. 相似文献
5.
Izabela Perkowska Marta Potrykus Joanna Siwinska Dominika Siudem Ewa Lojkowska Anna Ihnatowicz 《International journal of molecular sciences》2021,22(12)
Coumarins belong to a group of secondary metabolites well known for their high biological activities including antibacterial and antifungal properties. Recently, an important role of coumarins in plant resistance to pathogens and their release into the rhizosphere upon pathogen infection was discovered. It is also well documented that coumarins play a crucial role in the Arabidopsis thaliana growth under Fe-limited conditions. However, the mechanisms underlying interplay between plant resistance, accumulation of coumarins and Fe status, remain largely unknown. In this work, we investigated the effect of both mentioned factors on the disease severity using the model system of Arabidopsis/Dickeya spp. molecular interactions. We evaluated the disease symptoms in Arabidopsis plants, wild-type Col-0 and its mutants defective in coumarin accumulation, grown in hydroponic cultures with contrasting Fe regimes and in soil mixes. Under all tested conditions, Arabidopsis plants inoculated with Dickeya solani IFB0099 strain developed more severe disease symptoms compared to lines inoculated with Dickeya dadantii 3937. We also showed that the expression of genes encoding plant stress markers were strongly affected by D. solani IFB0099 infection. Interestingly, the response of plants to D. dadantii 3937 infection was genotype-dependent in Fe-deficient hydroponic solution. 相似文献
6.
Ionic liquids as electrolytes 总被引:5,自引:0,他引:5
Salts having a low melting point are liquid at room temperature, or even below, and form a new class of liquids usually called room temperature ionic liquids (RTIL). Information about RTILs can be found in the literature with such key words as: room temperature molten salt, low-temperature molten salt, ambient-temperature molten salt, liquid organic salt or simply ionic liquid. Their physicochemical properties are the same as high temperature ionic liquids, but the practical aspects of their maintenance or handling are different enough to merit a distinction. The class of ionic liquids, based on tetraalkylammonium cation and chloroaluminate anion, has been extensively studied since late 1970s of the XX century, following the works of Osteryoung. Systematic research on the application of chloroaluminate ionic liquids as solvents was performed in 1980s. However, ionic liquids based on aluminium halides are moisture sensitive. During the last decade an increasing number of new ionic liquids have been prepared and used as solvents. The general aim of this paper was to review the physical and chemical properties of RTILs from the point of view of their possible application as electrolytes in electrochemical processes and devices. The following points are discussed: melting and freezing, conductivity, viscosity, temperature dependence of conductivity, transport and transference numbers, electrochemical stability, possible application in aluminium electroplating, lithium batteries and in electrochemical capacitors. 相似文献
7.
Magorzata T. Kaczmarek Izabela Pospieszna-Markiewicz Maciej Kubicki Wanda Radecka-Paryzek 《Inorganic chemistry communications》2004,7(12):1247-1249
The one-step metal promoted reaction between salicylaldehyde and 4-methyl-1,3-phenylenediamine in the presence of lanthanum(III) or gadolinium(III) nitrate yields new salicylaldimine complexes containing N,N′-bis(salicylidene)-4-methyl-1,3-phenylenediamine as a result of the [2 + 1] Schiff base condensation. The crystal structure of the gadolinium complex reveals a dinuclear species with four unionized ligands coordinating in the monodentate and bridging bidentate fashion, using exclusively the oxygens as donor atoms with the nitrogen atoms not being involved in coordination. The coordination number of nine is achieved by involving three bidentate nitrate counterions in the coordination sphere. 相似文献
8.
Hamza El Marouazi Benoit van der Schueren Damien Favier Anaëlle Bolley Samuel Dagorne Thierry Dintzer Izabela Janowska 《应用聚合物科学杂志》2021,138(44):51300
Four series of polylactide (PLA) based composite films containing horizontally aligned few layer graphene (FLG) flakes of high aspect ratio and adsorbed albumin are prepared. The mechanical and thermal properties varies with percentage, dispersion degree and size of FLG flakes. Great improvement up to 290% and 360% of tensile modulus and strength respectively were obtained for the composite containing high lateral size of FLG at 0.17% wt, and up to 60% and 80% for the composite with very well dispersed 0.02% wt FLG. The composites of PLA and PEG-PLLA containing very well dispersed FLG flakes at 0.07% wt are ductile showing enhancement of elongation at break up to respectively 80% and 88%. Relatively high electrical conductivity, 5 × 10−3 S/cm, is measured for PLA film charged with 3% of FLG. 相似文献
9.
Application of artificial neural network for determination of standard time in machining 总被引:1,自引:1,他引:0
Izabela Kutschenreiter-Praszkiewicz 《Journal of Intelligent Manufacturing》2008,19(2):233-240
The purpose of this article is to present the application of neural network for time per unit determination in small lot production
in machining. A set of features considered as input vector and time consumption in manufacturing process was presented and
treated as output of the neural net. A neural network was used as a machining model. Sensitivity analysis was made and proper
topology of neural network was determined. 相似文献
10.
De Oliveira PR Calligaris IB Roma GC Bechara GH Mathias MI 《Microscopy research and technique》2012,75(6):727-736
This study presents the morpho-histological and histochemical characterization of the testes, integument, Malpighian tubules, and midgut of engorged Rhipicephalus sanguineus nymphs on the detachment day, showing the morphological and physiological characteristics to this phase in the life cycle of these individuals. The testis is constituted by germinative cells (only spermatogonia) with large, round-shaped and strongly stained nuclei which are organized into cysts by a thin layer of somatic cells. The integument consists of a cuticle subdivided into epicuticle (lipoprotein) and procuticle (glycoproteic), and a layer of epithelial cells which present glycolipoprotein elements. The procuticle presents two distinct regions: the exocuticle (next to the epicuticle) and the endocuticle (next to the epithelial layer). The Malpighian tubules present a simple epithelium with small flat and/or cubic cells, which form its wall and delimitates a lumen full of lipoprotein material. The midgut consists of an epithelial wall formed by two types of digestive cells, spent cells and empty digest cells, and by generative cells supported by a basal lamina and a thin layer of muscular tissue. This study described the main organs of engorged nymphs of R. sanguineus, to generate information that can help researchers to better understand the biology of these ectoparasites; which is fundamental for the development of compounds that are less aggressive to the environment. In addition, if the immature stages of the ticks are controlled, the number of adult ticks able to cause damages to the animals--and to the man as well--is also under control. 相似文献