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Disrupted NF-κB activation after partial hepatectomy does not impair hepatocyte proliferation in rats

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World Journal of Gastroenterology 2005年第46期11卷 7345-7350页

作者： stéphanie Laurent yves Horsmans Peter strkel Isabelle Leclercq Christine Sempoux Luc Lambotte GastroenterologyPathology and Experimental Surgery Laboratories Universite catholique de Louvain1200 BrusselsBelgium

AIM： To analyze the effects of NF-kB inhibition by antioxidant pyrrolidine dithiocarbamate （PDTC） or TNF inhibitor pentoxifylline （PTX） on liver regeneration after partial hepatectomy （PH）. METHODS： Saline, PDTC or PTX were injected 1 h before PH and rats were killed at 0.5 and 24 h after PH. Several control groups were used for comparison （injection control groups）. RESULTS： Compared to saline injected controls, NF-kB activation was absent 0.5 h after PH in rats treated with PDTC or PTX. At 24 h after PH, DNA synthesis and PCNA expression were identical in treated and control rats and thus occurred irrespectively of the status of NF-kB activation at 0.5 h. Signal transducer and activator of transcription 3 （stat3） acUvatJon was observed already 0.5 h after PH in saline, PDTC or PTX group and was similar to stat3 activation in response to injection without PH. CONCLUSION： These data strongly suggest that （1） NF-kB p65/p50 DNA binding produced in response to PH is not a signal necessary to initiate the liver regeneration, （2） star3 activation is a stress response unrelated to the activation of NF-kB. In conclusion, NF-kB activation is not critically required for the process of liver regeneration after PH.

关键词： Partial hepatectomy Nuclear factor kappa B Signal transducer and activator of transcription 3 Hepatocyte proliferation Antioxidant

Carboxymethyl glycoside lactone(CMGL) synthons:Scope of the method and preliminary results on step growth polymerization of α-azide-ω-alkyne glycomonomers

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Science China Chemistry 2010年第9期53卷 1880-1887页

作者： CHAMBERT stéphane BERNARD Julien FLEURY Etienne QUENEAU yves INSA-Lyon Laboratoire de Chimie Organique et Bioorganique Bat.J.Verne 20 Avenue A.Einstein69621 Villeurbanne CedexFrance ICBMS Institut de Chimie et de Biochimie Moléculaires et SupramoléculairesUMR5246 CNRS université de Lyon université Lyon 1 INSA-Lyon CPE-Lyon Bat.Curien 43 Bd du 11 Novembre 1918F 69622 VilleurbanneFrance INSA-LYON IMP1ngénierie des Matériaux Polymères UMR5223 université de Lyon université Claude Bernard Lyon 1F-69621 Villeurbanne CedexFrance

Carboxymethyl glycoside lactones(CMGLs) are bicyclic synthons which open readily for accessing new types of pseudo-glycoconjugates,such as sugar-amino acid hybrids,neoglycolipids,pseudodisaccharides,and membrane imaging *** lactone opening,free OH-2 is available for further functionalization,leading to 1,2-bisfunctionalized *** strategy is illustrated herein with new polymerizable systems of the AB type bearing both azide and alkyne functions prepared from α or β gluco-CMGL *** the reaction of lactones with propargylamine,an azido group was introduced by two different sequences leading to either the 2-manno-azido or the 6-gluco-azido *** capability of these AB monomers to undergo step growth polymerization through copper(I) catalyzed alkyne-azide cycloaddition(CuAAC) and generate glycopolytriazoles was evidenced.

关键词： carbohydrates glycopolymers lactones click chemistry step growth polymerization glycoconjugates azides alkynes Huisgen cycloaddition

On the Multi-Dimensional Duality Principle of Sawyer Type

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Acta Mathematica Sinica,English Series 2001年第1期17卷 81-88页

作者： yves RAKOTONDRATSIMBA Institut Polytechnique st-Louis EPMI 13 boulevard de l'Hautil 95 092 Cergy-Pontoise cedex France

A multi-dimensional version of the duality principle of Sawyer type [1] is obtained whenever the corresponding weight satisfies some doubling property.

关键词： Multi--dimensional duality principle Doubling weights Weighted inequalities Decreasing functions

statistical physics in QCD evolution towards high energies

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Science China(Physics,Mechanics & Astronomy) 2015年第8期58卷 1-32页

作者： MUNIER stphane Centre de physique thorique ′Ecole PolytechniqueCNRS Palaiseau France

The concepts and methods used for the study of disordered systems have proven useful in the analysis of the evolution equations of quantum chromodynamics in the high-energy regime: Indeed, parton branching in the semi-classical approximation relevant at high energies and at a fixed impact parameter is a peculiar branching-diffusion process, and parton branching supplemented by saturation effects(such as gluon recombination) is a reaction-diffusion process. In this review article, we first introduce the basic concepts in the context of simple toy models, we study the properties of the latter, and show how the results obtained for the simple models may be taken over to quantum chromodynamics.

关键词： quantum chromodynamics color dipole model color glass condensate stochastic fronts traveling waves reaction-diffusion

Comparative study of abrasion via microindentation and microscratch tests of reinforced and unreinforced lamellar cast iron

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Friction 2019年第5期7卷 457-465页

作者： Mohammed MENDAS stéphane BENAYOUN Laboratory of Rheology and Mechanics(LRM) Hassiba Benbouali University of ChlefHay Essalem Chlef BP151(02000)Algeria LTDS UMR CNRS5513Ecole Centrale de LyonUniversity of LyonEcully Cedex F-69134France

This study compares micro-abrasive wear in two kinds of grey cast iron. Classical lamellar cast iron with fully pearlitic matrix(FGL1) and lamellar micro-alloyed cast iron with phosphorus and boron(FGL2) are used. FGL2 has a fully pearlitic matrix reinforced by the hard phosphorus eutectic phase. The microstructures of these two types of iron are mechanically characterized using nanoindentation tests. Vickers microindentation and microscratch tests are also performed on these iron samples. The indent and scratch images obtained via scanning electron microscopy were used to compare the scratch damage to the two kinds of iron. The friction coefficient is discussed in terms of applied load, indenter attack angle, and scratch damage. Nanoindentation tests show an improvement in graphite’s mechanical properties and an increase in the matrix hardness of the FGL2, relatively to FGL1. The same damage forms for both microindentation and microscratch testing were observed for the two iron samples. However, cracking of the hard phase is observed in FGL2. The results show that the scratching of the micro-alloyed iron(FGL2) leads to less matrix damage and to an extended microploughing wear mechanism. However, at low normal load, the reinforcement of the matrix can increase the friction coefficient.

关键词： grey cast iron indentation microscratch abrasive wear

Computer simulation of the coagulation of suspended solids——The applicability of the Müller–Smoluchowski theory

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Journal of Environmental Sciences 2016年第6期28卷 197-203页

作者： Regina Wardzynska Beata Zaleska-Chróst Department of Chemistry University of Warmia and Mazury in Olsztyn

The results of studies carried out using a computer programme simulating the coagulation of suspensions containing spherical sol particles and spherical coagulant particles are *** influence of the degree of dispersion of the system on the coagulation reaction kinetics was investigated. The obtained results of kinetic studies were tested in the light of classical Müller–Smoluchowski equations. The influence of the physical properties of the coagulant,such as size, density and mass, on the coagulation rate was tested. It was found that within the range described in this paper, the rate of the simulated coagulation process fulfils both the kinetic equation of a first-order reaction, and the kinetic equation of a second-order *** the tested range, a significant influence of the mass and size of the coagulant on the coagulation rate was ascertained. The kinetic Müller–Smoluchowski dependence is fulfilled in a broader range of the degree of dispersion, when the coagulant particle mass and the sol particle mass are equal. When the particle mass increases with an increase in the particle radius, the coagulation rate increases faster that it would result from the Müller＇s dependence.

关键词： Aggregation Computer simulation Coagulation rate Sol

Solar chemical looping reforming of methane combined with isothermal H2O/CO2 splitting using ceria oxygen carrier for syngas production

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Journal of Energy Chemistry 2020年第2期29卷 60-72页

作者： Srirat Chuayboon stéphane Abanades Sylvain Rodat Processes Materials and Solar Energy LaboratoryPROMES-CNRSFont-Romeu 66120France Department of Mechanical Engineering King Mongkut's Institute of Technology LadkrabangPrince of Chumphon CampusChumphon 86160Thailand Universite Grenoble Alpes Le-Bourget-du-Lac F-73375France CEA-LJTEN Laboratoire des Systemes Solaires Haute Temperature(LSHT) Grenoble F-38054France

The chemical looping reforming of methane through the nonstoichiometric ceria redox cycle(CeO2/CeO2-δ) has been experimentally investigated in a directly irradiated solar reactor to convert both solar energy and methane to syngas in the temperature range 900–1050 °C. Experiments were carried out with different ceria shapes via two-step redox cycling composed of endothermic partial reduction of ceria with methane and complete exothermic re-oxidation of reduced ceria with H2 O/CO2 at the same operating temperature, thereby demonstrating the capability to operate the cycle isothermally. A parametric study considering different ceria macrostructure variants(ceria packed powder, ceria packed powder mixed with inert Al2 O3 particles, and ceria reticulated porous foam) and operating parameters(methane flow-rate, reduction temperature, or sintering temperature) was conducted in order to unravel their impact on the bed-averaged oxygen non-stoichiometry(δ), syngas yield, methane conversion, and solar reactor performance. The ceria cycling stability was also experimentally investigated to demonstrate repeatable syngas production by alternating the flow between CH4 and H2 O(or CO2). A decrease in sintering temperature of the ceria foam was beneficial for increasing syngas selectivity, methane conversion,and reactor performance. Increasing both CH4 concentration and reduction temperature enhanced δ with the maximum value up to 0.41 but concomitantly favored CH4 cracking reaction. The ceria reticulated porous foam showed better performance in terms of effective heat transfer, due to volumetric absorption of concentrated solar radiation and uniform heating with lower solar power consumption, thereby promoting the solar-to-fuel energy conversion efficiency that reached up to 5.60%. The energy upgrade factor achieved during cycle was up to 1.19. stable patterns in the δ and syngas yield for consecutive cycles with the ceria foam validated material performance stability.

关键词： Chemical looping Methane reforming Ceria structure Concentrated solar power Syngas production H2O/CO2 splitting

Conversion of the refractory ammonia and acetic acid in catalytic wet air oxidation of animal byproducts

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Journal of Environmental Sciences 2011年第3期23卷 520-528页

作者： Virginie Fontanier Sofiane Zalouk stéphane Barbati Aix-Marseille Universite's-CNRS (UMR 6264)-Laboratoire de Chimie Provence:quipe Chimie de l'Environnement Continental-3 Place Victor Hugo (case 29)-13331 Marseille cedex 3France

Wet air oxidation （WAO） and catalytic wet air oxidation （CWAO） of slaughtered animal byproducts （ABPs） were investigated. Two step experiment was carried out consisting of a non-catalysed WAO run followed by a CWAO run at 170-275 ℃, 20 MPa, and reaction time 180 min. The WAO （lst step） of sample （5 g/L total organic carbon （TOC）） yielded （82.0 ±4）% TOC removal and （78.4 ± 13.2）% conversion of the initial organic-N into NH4＋-N. Four metal catalysts （Pd, Pt, Rh, Ru） supported over alumina have been tested in catalytic WAO （2nd step） at elevated pH to enhance ammonia conversion and organic matter removal, particularly acetic acid. It was found that the catalysts Ru, Pt, and Rh had significant effects on the TOC removal （95.1%, 99.5% and 96.7%, respectively） and on the abatement of ammonia （93.4%, 96.7% and 96.3%, respectively） with high nitrogen selectivity. The catalyst Pd was found to have the less activity while Pt had the best performance. The X-Ray diffraction analysis showed that the support of catalyst was not stable under the experimental conditions since it reacted with phosphate present in solution. Nitrite and nitrate ions were monitored during the oxidation reaction and it was concluded that CWAO of ammonia in real waste treatment framework was in good agreement with the results obtained from the literature for ideal solutions of ammonia.

关键词： wet oxidation, heterogeneous catalysis animal byproducts acetic acid ammonia, nitrite nitrate

Machine Learning for heat radiation modeling of bi-and polydisperse particle systems including walls

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Particuology 2023年第3期74卷 119-140页

作者： Josef Tausendschön Gero stöckl stefan Radl Institute of Process and Particle Engineering Graz University of TechnologyInffeldgasse 13/III8010GrazAustria

We investigated the ability of four popular Machine Learning methods i.e.,Deep Neural Networks(DNNs),Random Forest-based regressors(RFRs),Extreme Gradient Boosting-based regressors(XGBs),and stacked ensembles of DNNs,to model the radiative heat transfer based on view factors in bi-and polydisperse particle beds including *** training and analyzing the predictive capability of each method,an adjustment of markers used in monodisperse systems,as well as an evaluation of new markers was *** the basis of our dataset that considers a wide range of particle radii ratios,system sizes,particle volume fractions,as well as different particle-species volume fractions,we found that(i)the addition of particle size information allows the transition from monodisperse to bi-and polydisperse beds,and(ii)the addition of particle volume fraction information as the fourth marker leads to very accurate *** terms of the overall performance,DNNs and RFRs should be preferred compared to the other two *** particle-particle view factors,DNN and RFR are on par,while for particle-wall the RFR is *** demonstrate that DNNs and RFRs can be built to meet or even exceed the prediction quality standards achieved in a monodisperse system.

关键词： Discrete element method(DEM) Heat radiation modeling Machine learning View factors Wall radiation Polydisperse particles