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Attenuation of dextran sodium sulphate induced colitis in matrix metalloproteinase-9 deficient mice

world Journal of Gastroenterology 2006年第40期12卷 6464-6472页

作者： Alfredo Santana Carlos Medina Maria Cristina Paz-Cabrera Federico Díaz-Gonzalez Esther Farré Antonio Salas marek w radomski Enrique Quintero Gastroenterology Department and Research Unit Hospital Universitario de Canarias Tenerife Spain Reumathology Department Hospital Universitario de Canrias Tenerife Spain Pathology Department Hospital Mutua de Terrassa Barcelona Spain Institute of Molecular Medicine University of Texas Houston-Texas United States

AIM: To study whether matrix metalloproteinase-9 (MMP-9) is a key factor in epithelial damage in the dextran sodium sulphate (DSS) model of colitis in ***: MMP-9-deficient and wild-type (wt) mice were given 5% DSS in drinking water for 5 d followed by recovery up to 7 d. On d 5 and 12 after induction of colitis, gelatinases, MMP-2 and MMP-9, were measured in homogenates of colonic tissue by zymography and western blot, whereas tissue inhibitor of metalloproteinases (TIMPs) were measured by reverse zymography. The gelatinolytic activity was also determined in supernatants of polymorphonuclear leukocytes (PMN) isolated from mice blood. Moreover, intestinal epithelial cells were stimulated with TNF-α to study whether these cells were able to produce MMPs. Finally, colonic mucosal lesions were measured by microscopic examination. RESULTS: On d 5 of colitis, the activity of MMP-9 was increased in homogenates of colonic tissues (0.24 ± 0.1 vs 21.3 ± 6.4, P wt (0.5 ± 0.1 vs 10.4 ± 0.7, P was also up-regulated by TNF-α in epithelial intestinal cells (2.5 ± 0.5 vs 14.7 ± 3.0, P were significantly attenuated when compared with wt mice. CONCLUSION: we conclude that DSS induced colitis is markedly attenuated in animals lacking MMP-9. This suggests that intestinal injury induced by DSS is modu-lated by MMP-9 and that inhibition of this gelatinase may reduce inflammation.

关键词： Matrix metalloproteinases MMP-9-deficient Dextran sodium sulphate Inflammatory bowel disease Experimental colitis

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A novel method for clustering cellular data to improve classification

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Neural Regeneration Research 2025年第9期20卷 2697-2705页

作者： Diek w.wheeler Giorgio A.Ascoli Center for Neural Informatics Structures&PlasticityKrasnow Institute for Advanced Study Bioengineering Department Volgenau School of Engineering George Mason University FairfaxVAUSA

Many fields,such as neuroscience,are experiencing the vast prolife ration of cellular data,underscoring the need fo r organizing and interpreting large datasets.A popular approach partitions data into manageable subsets via hierarchical clustering,but objective methods to determine the appropriate classification granularity are *** recently introduced a technique to systematically identify when to stop subdividing clusters based on the fundamental principle that cells must differ more between than within *** we present the corresponding protocol to classify cellular datasets by combining datadriven unsupervised hierarchical clustering with statistical *** general-purpose functions are applicable to any cellular dataset that can be organized as two-dimensional matrices of numerical values,including molecula r,physiological,and anatomical *** demonstrate the protocol using cellular data from the Janelia MouseLight project to chara cterize morphological aspects of neurons.

关键词： cellular data clustering dendrogram data classification Levene's one-tailed statistical test unsupervised hierarchical clustering

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Genistein:a possible solution for the treatment of Alzheimer’s disease

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Neural Regeneration Research 2025年第10期20卷 2903-2905页

作者： Karolina Pierzynowska Bartosz Karaszewski Grzegorz węgrzyn Department of Molecular Biology University of GdanskGdanskPoland Gdansk Polandand Department of Adult NeurologyFaculty of MedicineMedical University of GdanskGdanskPoland

Neurodegenerative diseases are defined as disorders resulting from the slow and progressive loss of function and eventual death of neural cells that result from the primary pathology of nervous *** can lead to severe nervous system dysfunction,eventually affecting multiple organs and *** hundred neurodegenerative diseases have been described,and owing to their prevalence,severity.

关键词： organs Alzheimer death

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Glia-to-neuron reprogramming to the rescue?

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Neural Regeneration Research 2025年第5期20卷 1395-1396页

作者： Jack w.Hickmott Cindi M.Morshead Department of Surgery University of TorontoTorontoONCanada Donnelly Centre for Cellular and Biomolecular Research TorontoONCanada Institute of Biomedical Engineering University of TorontoTorontoONCanada The KITE Research Institute Toronto Rehabilitation InstituteUniversity Health NetworkTorontoONCanada

Over the last two decades,the dogma that cell fate is immutable has been increasingly challenged,with important implications for regenerative *** brea kth rough discovery that induced pluripotent stem cells could be generated from adult mouse fibroblasts is powerful proof that cell fate can be *** exciting extension of the discovery of cell fate impermanence is the direct cellular reprogram ming hypothesis-that terminally differentiated cells can be reprogrammed into other adult cell fates without first passing through a stem cell state.

关键词： programming passing proof

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Non-linear Constitutive Model for the Oligocarbonate Polyurethane Material

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Chinese Journal of Polymer Science 2014年第12期32卷 1666-1677页

作者： marek Pawlikowski warsaw University of Technology Institute of Mechanics and Printing

The polyurethane, which was the subject of the constitutive research presented in the paper, was based on oligocarbonate diols Desmophen C2100 produced by Bayer？. The constitutive modelling was performed with a view to applying the material as the inlay of intervertebral disc prostheses. The polyurethane was assumed to be non-linearly viscohyperelastic, isotropic and incompressible. The constitutive equation was derived from the postulated strain energy function. The elastic and rheological constants were identified on the basis of experimental tests, i.e. relaxation tests and monotonic uniaxial tests at two different strain rates, i.e. λ= 0.1 min-1 and λ= 1.0 min-1. The stiffness tensor was derived and introduced to Abaqus？finite element（FE） software in order to numerically validate the constitutive model. The results of the constants identification and numerical implementation show that the derived constitutive equation is fully adequate to model stress-strain behavior of the polyurethane material.

关键词： Constitutive model Viscoelastic material Stress relaxation Finite elements.

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Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 123-138页

作者： Chentong GAO Huiyu SUN Jianping GU w.M.HUANG College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics School of Mechanical and Aerospace Engineering Nanyang Technological University Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology

Currently, there are a limited number of dynamic models available for braided composite plates with large overall motions, despite the incorporation of three-dimensional(3D) braided composites into rotating blade components. In this paper, a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established. Based on Kirchhoff's plate assumptions, the displacement variables of the plate are expressed. By incorporating the braiding directions into the constitutive equation of the braided composites, the dynamic model of the plate considering braiding directions is obtained. The effects of the speeds, braiding directions, and braided angles on the responses of the plate with fixed-axis rotation and translational motion, respectively, are investigated. This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions. It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.

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Statistical variation of characteristics of random packed beds of Raschig rings:The influence of the sample size

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Particuology 2021年第3期19卷 50-61页

作者： PawełNiegodajew Maciej marek Czestochowa University of Technology Department of Thermal Machineryal.Armii Krajowej 2142-200 CzestochowaPoland

Many studies on random packed beds have been dedicated to local porosity(void fraction)or orientation distribution of ***,despite the random nature of the considered packings,very little attention has been devoted to examination whether the number of particles used in experiments/simulations is sufficiently large to get reproducible *** reproducibility of the key packing parameters depends on the size of the population of particles(sample size)and ordering effects induced by the confining *** work investigates quantitatively the influence of the sample size on the statistical variation of the packed bed *** beds of Raschig rings were generated with a sequential algorithm and three column diameters were *** has been found that in the case of the orientation distribution the results depend strongly on the sample size,especially for slender columns,while the porosity profiles are well-reproducible characteristics even for relatively small packings of *** complementary results for full cylinders are also included.

关键词： Random packing Raschig rings Full cylinders Particle orientation Porosity Reproducibility

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Shape Optimization of the Turbomachine Channel by a Gradient Method - Accuracy Improvement

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Journal of Thermal Science 2003年第3期12卷 239-244页

作者： marek Rabiega Institute of Turbomachinery Technical University of Lodz219/223 Wolczanska St93-005 LodzPoland

An algorithm of the gradient method of the channel shape optimization has been built on the basis of 3D equations of mass, momentum and energy conservation in the fluid flow. The gradient of the functional that is posed for minimization has been calculated by two methods, via sensitivities and - for comparison - by the finite difference approximation. The equations for sensitivities have been generated through a differentiate-then-discretize approach. The exemplary optimization of the blade shape of the centrifugal compressor wheel has been carried out for the inviscid gas flow governed by Euler equations with a non-uniform mass flow distribution as the inlet boundary condition. Mixing losses have been minimized downstream the outlet of the centrifugal wheel in this exemplary optimization. The results of the optimization problem accomplished by the two above-mentioned methods have been presented. In the case sparse grids have been used, the method with the gradient approximated by finite differences has been found to be more consistent. The discretization accuracy has turned out to be crucial for the consistency of the gradient method via sensitivities.

关键词： numerical fluid dynamics shape optimization turbomachine channels

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Representative elementary volume analysis of polydisperse granular packings using discrete element method

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Particuology 2016年第4期14卷 88-94页

作者： Joanna wiacek marek Molenda Institute of Agrophysics Polish Academy of Sciences Doswiadczalna 4 20-290 l.ublin Poland

The representative elementary volume （REV） for three-dimensional polydisperse granular packings was determined using discrete element method simulations. Granular mixtures of various sizes and particle size distributions were poured into a cuboid chamber and subjected to uniaxial compression, Findings showed that the minimum REV for porosity was larger compared with the REV for parameters such as coordination number, effective elastic modulus, and pressure ratio. The minimum REV for porosity and other parameters was found to equal 15,10, and 5 times the average grain diameter, respectively. A study of the influence of sample size on energy dissipation in random packing of spheres has also confirmed that the REV size is about 15 times the average grain diameter. The heterogeneity of systems was found to have no effect on the REV for the parameters of interest for the narrow range of coefficient of uniformity analyzed in this paper. As the REV approach is commonly applied in both experimental and numerical studies, determining minimum REV size for polydisperse granular packings remains a crucial issue.

关键词： Representative elementary volume Polydisperse packing Discrete element method Sample size effect

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Temporal inequalities for sequential multi-time actions in quantum information processing

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Frontiers of physics 2014年第5期9卷 629-633页

作者： marek Zukowski Institute for Theoretical Physics and Astrophysics Uniwersytet Gdanski PL-80-952 Gdadsk Poland Hefei National Laboratory of Physical Sciences at the Mieroscale University of Science and Technology of China Hefei 230026 China

A new kind of temporal inequalities are discussed, which apply to algorithmic processes, involving a finite memory processing unit. They are an alternative to the Leggett-Grag ones, as well as to the modified ones by Brukner et al. If one considers comparison of quantum anti classical processes involving systems of finite memory （of the same capacity in both cases）, the inequalities give a clear message why we can expect quantum speed-up. In a classical process one always has clearly defined values of possible measurements, or in terms of the information processing language, if we have a sequential computations of some function depending on data arriving at each step on an algorithm, the function always has a clearly defined value. In the quantum case only the final value, after the end of the algorithm, is defined. All intermediate values, in agreement with Bohr＇s complementarity, cannot be ascribed a definite value.

关键词： temporal inequalities quantum information

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