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Molecular alterations in gastric cancer with special reference to the early-onset subtype

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World Journal of Gastroenterology 2016年第8期22卷 2460-2474页

作者： Malgorzata Skierucha Anya NA Milne G Johan A Offerhaus wojciech p polkowski Ryszard Maciejewski Robert Sitarz Department of Human Anatomy Medical University of Lublin 20-950 Lublin Poland Department of pathology Diakonessenhuis 3582 KE Utrecht The Netherlands Department of pathology H04-312 University Medical Centre Utrecht Post box 85500 3508 GA Utrecht The Netherlands Department of Surgical Oncology Medical University of Lublin 20-081 Lublin Poland Department of pathology H04-312 University Medical Centre Utrecht Post box 85500 3508 GA Utrecht The Netherlands

Currently, gastric cancer(GC) is one of the most frequently diagnosed neoplasms, with a global burden of 723000 deaths in 2012. It is the third leading cause of cancer-related death worldwide. There are numerous possible factors that stimulate the procarcinogenic activity of important genes. These factors include genetic susceptibility expressed in a singlenucleotide polymorphism, various acquired mutations(chromosomal instability, microsatellite instability, somatic gene mutations, epigenetic alterations) and environmental circumstances(e.g., helicobcter pylori infection, EBV infection, diet, and smoking). Most of the aforementioned pathways overlap, and authors agree that a clear-cut pathway for GC may not exist. Thus, the categorization of carcinogenic events is complicated. Lately, it has been claimed that research on early-onset gastric carcinoma(EOGC) and hereditary GC may contribute towards unravelling some part of the mystery of the GC molecular pattern because young patients are less exposed to environmental carcinogens and because carcinogenesis in this setting may be more dependent on genetic factors. The comparison of various aspects that differ and coexist in EOGCs and conventional GCs might enable scientists to: distinguish which features in the pathway of gastric carcinogenesisare modifiable, discover specific GC markers and identify a specific target. This review provides a summary of the data published thus far concerning the molecular characteristics of GC and highlights the outstanding features of EOGC.

关键词： Gastric cancer Early-onset gastric cancer Molecular alterations Chromosomal instability Single-nucleotide polymorphism Microsatellite instability Epigenetic alterations Loss of heterozygosity

Enhancement of wettability in AZ91/B_(4)C system by a mechanical purification of liquid alloy

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Journal of Magnesium and Alloys 2022年第11期10卷 3133-3142页

作者： Artur Kudyba wojciech polkowski Grzegorz Bruzda Adelajda polkowska Donatella Giuranno Łukasiewicz Research Network-Krakow Institute of Technology Zakopian´ska 73 Str.30-418 KrakówPoland National Research Council of Italy Institute of Condensed Matter Chemistry and Technologies for EnergyVia De Marini 616149GenovaItaly

Mg-based alloys are potential candidate materials for a fabrication of lightweight boron carbide based composites through a reactive melt infiltration approach. In this paper, the effect of a mechanical purification of molten AZ91 alloy’s surface on its wettability with polycrystalline B_(4)C is experimentally evaluated for the first time. For this purpose, sessile drop experiments were performed under the same operating conditions(700℃/5 min;Ar atmosphere), by using both the classical contact heating(CH) and the improved capillary purification(Cp) procedure. It was found that the evolution of contact angle values was strongly influenced by the applied procedure. In particular, by using the classical CH procedure, the presence of a native oxide layer on the metal surface hinders the observations of melting process, resulting in a misleading conclusion that the system is non-wettable. Contrarily, during the wetting test performed by applying the Cp procedure, the surface oxide layer was mechanically removed by squeezing the molten AZ91 alloy through a capillary. Accordingly, the oxide-free AZ91 drop with a regular and spherical shape was successfully obtained and dispensed on the B_(4)C substrate. A reliable contact angle value of θ =83° was measured at the AZ91/B_(4)C triple line at 700 ℃, which in turn proves that B_(4)C is wetted by the liquid AZ91 alloy. In contradiction to the literature, these good wetting conditions were assisted by a non-reactive wetting mechanism occurring at the AZ91/B_(4)C interface. To succeed in the fabrication of AZ91/B_(4)C composites by liquid metal infiltration, such experimental observations make it reasonable to expect a spontaneous infiltration process exclusively driven by capillarity, which in turn increases the efficiency of the process by the absence of reaction products that could be a potentially detrimental factor.

关键词： AZ91 magnesium alloy Magnesium matrix composites Sessile drop Capillary purification procedure Wettability Contact angle MMCs B_(4)C

Improved methodological concepts for processing liquid Mg at high temperature

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Journal of Magnesium and Alloys 2021年第1期9卷 183-191页

作者： Artur Kudyba Natalia Sobczak wojciech polkowski Grzegorz Bruzda Adelajda polkowska Donatella Giuranno Lukasiewicz Research Network-Krakow Institute of Technology Zakopianska 73 Str.30-418 KrakowPoland Institute of Metallurgy and Materials Science Polish Academy of Science25 Reymonta St.30-059 KrakówPoland National Research Council of Italy Institute of Condensed Matter Chemistry and Technologies for EnergyVia De Marini 616149GenovaItaly

In this paper,new improvements of methodological concepts upon examining wettability of high vapor pressure liquid metal systems(***-based alloys)in contact with refractory materials,are presented and *** this regard,high-temperature experiments on molten magnesium(Mg)in contact with graphite as a refractory substrate,were performed by utilizing a newly developed testing device and by applying a suitable experimental *** wetting experiments were carried out by the sessile drop method and under identical testing conditions(700℃/10 min under a protective gas atmosphere).Two different procedures were applied:the classical contact heating(CH)or a newly introduced capillary purification(Cp)*** contact angle behaviors observed under the same conditions were strongly influenced by the applied ***,in the case of using the CH procedure,a presence of native surface oxide layer on the metal surface hinders the observations of melting process,making not possible to experimentally determine the wetting kinetics curveθ=f(t).Contrarily,during the wetting test performed on the Mg/graphite couple by applying the Cp procedure,the native surface oxide layer was mechanically removed during the squeezing of the molten Mg through the hole of a ***,an oxide-free squeezed Mg-drop with regular and spherical shape was successfully obtained and dispensed on the graphite ***,the reliable contact angle value aroundθ=150°for the Mg/graphite system,was measured within the wetting test.

关键词： Mg-alloys Magnesium matrix composites Sessile drop Capillary purification procedure Wettability Contact angle

Numerical simulation of a dense solid particle flow inside a cyclone separator using the hybrid Euler-Lagrange approach

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particuology 2017年第2期15卷 170-180页

作者： pawel Kozolub Adam Klimanek Ryszard A. Bialecki wojciech p. Adamczyk Institute of Thermal Technology Silesian University of Technology Konarskiego 22 Gliwice Poland AMEC Foster Wheeler Energia polska Staszica 31 Sosnowiec Poland

This paper presents a numerical simulation of the flow inside a cyclone separator at high particle loads. The gas and gas–particle flows were analyzed using a commercial computational fluid dynamics code. The turbulence effects inside the separator were modeled using the Reynolds stress model. The two phase gas–solid particles flow was modeled using a hybrid Euler–Lagrange approach, which accounts for the four-way coupling between phases. The simulations were performed for three inlet velocities of the gaseous phase and several cyclone mass particle loadings. Moreover, the influences of several submodel parameters on the calculated results were investigated. The obtained results were compared against experimental data collected at the in-house experimental rig. The cyclone pressure drop evaluated numerically underpredicts the measured values. The possible reason of this discrepancies was disused.

关键词： Cyclone separator Two-phase flow Solid particle transport Computational fluid dynamics Hybrid Euler-Lagrange

Modeling of particle transport and combustion phenomena in a large-scale circulating fluidized bed boiler using a hybrid Euler-Lagrange approach

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particuology 2014年第5期12卷 29-40页

作者： wojciech p.Adamczyk Gabriel Wecel Marcin Klajny pawel Kozolub Adam Klimanek Ryszard A.Bialecki Institute of Thermal Technology Silesian University ofTechnologyKonarskiego 2244-100 CliwicePoland Foster Wheeler Energia polska Sp.z o.o. Staszica 3141-200 SosnowiecPoland

The constantly developing fiuidized combustion technology has become competitive with a conventional pulverized coal （pC） combustion. Circulating fluidized bed （CFB） boilers can be a good alternative to pC boilers due to their robustness and lower sensitivity to the fuel quality. However, appropriate engineering tools that can be used to model and optimize the construction and operating parameters of a CFB boiler still require development. This paper presents the application of a relatively novel hybrid Euler-Lagrange approach to model the dense gas-solid flow combined with a combustion process in a large-scale indus- trial CFB boiler. In this work, this complex flow has been resolved by applying the ANSYS FLUENT 14.0 commercial computational fluid dynamics （CFD） code. To accurately resolve the multiphase flow, the original CFD code has been extended by additional user-defined functions. These functions were used to control the boiler mass load, particle recirculation process （simplified boiler geometry）, and interphase hydrodynamic properties. This work was split into two parts. In the first part, which is referred to as pseudo combustion, the combustion process was not directly simulated. Instead, the effect of the chemi- cal reactions was simulated by modifying the density of the continuous phase so that it corresponded to the mean temperature and composition of the flue gases, In this stage, the particle transport was simu- lated using the standard Euler-Euler and novel hybrid Euler-Lagrange approaches, The obtained results were compared against measured data, and both models were compared to each other. In the second part, the numerical model was enhanced by including the chemistry and physics of combustion. To the best of the authors＇ knowledge, the use of the hybrid Euler-Lagrange approach to model combustion is a new engineering application of this model, In this work, the combustion process was modeled for air-fuel combustion. The simulation results were co

关键词： CFB Fluidization Combustion particles Large boile rCFD

Comparison of the standard Euler-Euler and hybrid Euler-Lagrange approaches for modeling particle transport in a pilot-scale circulating fluidized bed

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particuology 2014年第4期12卷 129-137页

作者： wojciech p.Adamczyk Adam Klimanek Ryszard A.Biaecki Gabriel Wecel pawe Kozolub Tomasz Czakiert Institute of Thermal Technology Silesian University of Technology44-100 GliwiceKonarskiego 22Poland Institute of Advanced Energy Technologies Czestochowa University of TechnologyCzestochowaPoland

particle transport phenomena in small-scale circulating fiuidized beds （CFB） can be simulated using the Euler-Euler, discrete element method, and Euler-Lagrange approaches. In this work, a hybrid Euler-Lagrange model known as the dense discrete phase model （DDpM）, which has common roots with the multiphase particle-in-cell model, was applied in simulating particle transport within a mid-sized experimental CFB facility. Implementation of the DDpM into the commercial ANSYS Fluent CFD package is relatively young in comparison with the granular Eulerian model. For that reason, validation of the DDpM approach against experimental data is still required and is addressed in this paper. Additional difficulties encountered in modeling fluidization processes are connected with long calculation times. To reduce times, the complete boiler models are simplified to include just the combustion chamber. Such simplifications introduce errors in the predicted solid distribution in the boiler. To investigate the conse- quences of model reduction, simulations were made using the simplified and complete pilot geometries and compared with experimental data. All simulations were performed using the ANSYSFLUENT 14.0 package. A set of user defined functions were used in the hybrid DDpM and Euler-Euler approaches to recirculate solid particles.

关键词： particle Multiphase flow CFD particulate processes CFB Fluidized bed

Numerical approach for modeling particle transport phenomena in a closed loop of a circulating fluidized bed

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particuology 2016年第6期14卷 69-79页

作者： wojciech p. Adamczyk pawel Kozolub Grzegorz Kruczek Monika pilorz Adam Klimanek Tomasz Czakiert Gabriel Wecel Institute of Thermal Technology Silesian University of Technology Gliwice Poland AMEC Foster Wheeler Staszica 31 41-200 Sosnowiee Poland Institute of Advanced Energy Technologies Czestochowa University of Technology Czestochowa Poland

Numerical modeling of a large scale circulating fiuidized bed （CFB） imposes many complexities and difficulties. presence of a dense solid phase, a variety of spatial and time scales as well as complex model geometries requires advanced numerical techniques. Moreover, the appropriate selection of a numerical model capable of solving granular flow, and geometrical model simplification can have a huge impact on the predicted flow field within the CFB boiler. In order to reduce the cost of the numerical simulations, the complex CFB boiler geometry is reduced to that of the combustion chamber. However, a question arises as to bow much one can simplify the geometrical model without losing accuracy of numerical simulations. To accurately predict the gas-solid and solid-solid mixing processes within subsequent sections of the CFB boiler （combustion chamber, solid separator, drain section）, a complete 3D geometrical model should be used. Nevertheless, because of the presence of various spatial and temporal scales within subsequent boiler sections, the complete model of the 3D CFB boiler is practically unrealizable in numerical simulations. To resolve the aforementioned problems, this paper describes a new approach that can be applied for complete boiler modeling. The proposed approach enables complex particle transport and gas flow problems within each of the boiler sections to be accurately resolved, It has been achieved by dividing the CFB boiler geometry into several submodels, where different numerical approaches can be used to resolve gas-solid transport. The interactions between computational domains were taken into account by connecting the inlets/outlets of each section using a set of user-defined functions implemented into the solution procedure. The proposed approach ensures stable and accurate solution within the separated boiler zones.

关键词： Fluidization CFB Numerical modeling Multiphase flow particle transport Cyclone

Complete Oxidation of Methane over palladium Supported on Alumina Modified with Calcium,Lanthanum,and Cerium Ions

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Journal of Natural Gas Chemistry 2007年第4期16卷 342-348页

作者： Beata Stasinska wojciech Gac Theophilos Ioannides Andrzej Machocki University of Maria Curie-Sklodowska Faculty of Chemistry Department of Chemical Technology3 Maria Curie-Sklodowska Square20-031 LublinPoland Foundation for Research & Technology-Hellas Institute of Chemical Engineering and High Temperature Chemical processes(FORTH/ICE-HT) P.O.Box 1414PatrasGR-26500Greece

The activity and thermal stability of pd/Al2O3 and pd/（Al2O3＋MOx）（M=Ca, La, Ce） palladium catalysts in the reaction of complete oxidation of methane are presented in this study. The catalyst supports were prepared by sol-gel method and they were dried either conventionally or with supercritical carbon dioxide. Then they were impregnated with palladium nitrate solution. The catalysts with unmodified alumina had a high surface area. The activity and thermal stability of the aluminasupported catalyst was also very high. The introduction of calcium, lanthanum, or cerium oxide into alumina support caused a decrease of the surface area in the way dependent on the support precursor drying method. These modifiers decreased the activity of palladium catalysts, and they required higher temperatures for the complete oxidation of methane than unmodified pd/Al2O3. The improvement of the palladium activity by lanthanum and cerium support modifier was observed only at low temperatures of the reaction.

关键词： catalytic oxidation of methane palladium catalysts alumina support modification lan- thanum modifier cerium modifier calcium modifier

Approximative compactness and continuity of metric projector in Banach spaces and applications

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Science China Mathematics 2008年第2期51卷 293-303页

作者： HUDZIK Henryk KOWALEWSKI wojciech WISLA Marek Faculty of Mathematics and Computer Science Adam Mickiewicz UniversityUmultowska 8761-614 PoznańPoland

First we prove that the approximative compactness of a nonempty set C in a normed linear space can be reformulated equivalently in another *** is known that if C is a semi-Chebyshev closed and approximately compact set in a Banach space X,then the metric projectorπC from X onto C is *** the assumption that X is midpoint locally uniformly rotund,we prove that the approximative compactness of C is also necessary for the continuity of the projectorπC by the method of geometry of Banach *** this general result we find some necessary and sufficient conditions for T to have a continuous Moore-penrose metric generalized inverse T^+,where T is a bounded linear operator from an approximative compact and a rotund Banach space X into a midpoint locally uniformly rotund Banach space Y.

关键词： approximative compactness continuity metric projector midpoint locally uniformly rotundity 46B20