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Mechanisms of heme iron absorption:Current questions and controversies

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World Journal of Gastroenterology 2008年第26期14卷 4101-4110页

作者： adrian R West Phillip S Oates M311 Physiology School of BiomedicalBiomolecular and Chemical SciencesThe University of Western Australia35 Stirling HighwayCrawley 6009 Australia

Iron is a critical micronutrient, and iron derived from heme contributes a large proportion of the total iron absorbed in a typical Western diet. Heme iron is absorbed by different mechanisms than non-heme iron, but despite considerable study over many years these mechanisms remain poorly understood. This review provides an overview of the importance of heme iron in the diet and discusses the two prevailing hypotheses of heme absorption; namely receptor mediated endocytosis of heme, and direct transport into the intestinal enterocyte by recently discovered heme transporters. A specific emphasis is placed on the questions surrounding the site of heme catabolism and the identity of the enzyme that performs this task. Additionally, we present the hypothesis that a non-heme iron transport protein may be required for heme iron absorption and discuss the experiences of our laboratory in examining this hypothesis.

关键词： Iron Heme absorption Receptor mediatedendocytosis Heine transporter Heine oxygenase

Heme in intestinal epithelial cell turnover, differentiation, detoxification, inflammation, carcinogenesis, absorption and motility

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World Journal of Gastroenterology 2006年第27期12卷 4281-4295页

作者： Phillip S Oates adrian R West Physiology M311 School of Biomedical Biomolecular and Chemical SciencesUniversity of Western Australia35 Stirling HighwayNedlands 6009Australia

The gastrointestinal tract is lined by a simple epithelium that undergoes constant renewal involving cell division, differentiation and cell death. In addition, the epithelial lining separates the hostile processes of digestion and absorption that occur in the intestinal lumen from the aseptic environment of the internal milieu by defensive mechanisms that protect the epithelium from being breached. Central to these defensive processes is the synthesis of heme and its catabolism by heme oxygenase （HO）. Dietary heme is also an important source of iron for the body which is taken up intact by the enterocyte. This review describes the recent literature on the diverse properties of heme/HO in the intestine tract. The roles of heme/HO in the regulation of the cell cycle/ apoptosis, detoxification of xenobiotics, oxidative stress, inflammation, development of colon cancer, hemeiron absorption and intestinal motility are specifically examined.

关键词： Absorption Heme Uptake Release Heme oxygenase Oxidant Cytoprotection Inflammation Cancer Detoxification

The effect of mining face＇s direction on the observed seismic activity

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International Journal of Coal Science & Technology 2016年第3期3卷 322-329页

作者： Witold Pytel Joanna Switon adrian Wojcik KGHM Cuprum Ltd. Research and Development Centre 53-659 Wroclaw Poland KGHM Polish Copper Ltd. O/ZG Rudna Department 59-100 Polkowice Poland

A major natural hazard associated with LGOM （Legnica-Glogow Copper Mining） mining is the dynamic phenomena occurrence, physically observed as seismic tremors. Some of them generate effects in the form of relaxations or bumps. Long-term observations of the rock mass behaviour indicate that the degree of seismic hazard, and therefore also seismic activity in the LGOM area, is affected by the great depth of the copper deposit, high-strength rocks as well as the ability of rock mass to accumulate elastic energy. In this aspect, the effect of the characteristics of initial stress tensor and the orientation of considered mining panel in regards to its components must be emphasised. The primary objective of this study is to answer the question, which of the factors considered as ＂influencing＂ the dynamic phenomena occurrence in copper mines have a statistically significant effect on seismic activity and to what extent. Using the general linear model procedure, an attempt has been made to quantify the impact of different parameters, including the depth of deposit, the presence of goaf in the vicinity of operating mining panels and the direction of mining face advance, on seismic activity based on historical data from 2000 to 2010 concerned with the dynamic phenomena recorded in different mining panels in Rudna mine. The direction of mining face advance as well as the goaf situation in the vicinity of the mining panel are of the greatest interest in the case of the seismic activity in LGOM. It can be assumed that the appropriate manipulation of parameters of mining systems should ensure the safest variant of mining method under specific geological and mining conditions.

关键词： Induced seismicity Polish copper mines General linear model procedure

Corrosion study of resorbable Ca60Mg15Zn25 bulk metallic glasses in physiological fluids

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Progress in Natural Science:Materials International 2017年第5期27卷 627-634页

作者： Rafa? Babilas Anna Bajorek adrian Radoń Ryszard Nowosielski Institute of Engineering Materials and Biomaterials Silesian University of Technology A.Chelkowski Institute of Physics University of Silesia

The corrosion activity of amorphous plates of Ca60Mg15Zn25alloy was *** biocompatible elements were selected for the alloy *** electrochemical corrosion and immersion tests were carried out in a multi-electrolyte fluid and Ringer's *** corrosion behavior was observed for the samples tested in a multi-electrolyte fluid despite the active dissolution of Ca and Mg in Ringer's *** experimental results indicated that reducing concentration of NaCl from 8.6 g/dm3for Ringer's solution to 5.75 g/dm3caused the decrease of the corrosion *** volume of the hydrogen evolved after 480 min in Ringer's solution（40.1 ml/cm2）was higher in comparison with that obtained in a multi-electrolyte fluid（24.4 ml/cm2）.The values of opencircuit potential(EOCP)for the Ca60Mg15Zn25glass after 1 h incubation in Ringer's solution and a multielectrolyte fluid were determined to be-1553 and-1536 m V vs.a saturated calomel electrode（SCE）.The electrochemical measurements indicated a shift of the corrosion current density(jcorr)from 1062μA/cm2for the sample tested in Ringer's solution to 788μA/cm2for the specimen immersed in a multi-electrolyte *** corrosion products analysis was conducted by using the X-ray photoelectron spectroscopy（XPS）.The corrosion products were identified to be CaCO3,Mg（OH）2,CaO,MgO and Zn *** mechanism of corrosion process was proposed and described based on the microscopic *** X-ray diffraction and Fourier transform infrared spectroscopy（FTIR）also indicated that Ca（OH）2,CaCO3,Zn（OH）2and Ca(Zn（OH）3)2·2H2O mainly formed on the surface of the studied alloy.

关键词： Ca-based metallic glasses X-ray photoelectron spectroscopy FTIR spectroscopy X-ray diffraction Corrosion resistance Hydrogen evaluation

Ultraslow electron-phonon scattering and polaron formation in magnetite

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Journal of Materiomics 2022年第1期8卷 150-155页

作者： adrian Radoń DariuszŁukowiec Patryk Włodarczyk Łukasiewicz Research Network-Institute of Non-Ferrous Metals Sowinskiego 5 St.44-100GliwicePoland Faculty of Mechanical Engineering Silesian University of TechnologyKonarskiego 18 a St.44-100GliwicePoland

The comprehensive analysis of AC electrical conductivity in magnetite was performed in order to find relations between the formation of polarons,phonons and conduction by a virtual free electron *** analysis performed here for the first time shows experimental data for the behavior of electrons for magnetite with the scattering time shifted to the GHz *** to our study,the DC electrical conductivity can be described by the virtual free electron gas model,and high frequency conductivity can be described by the combination of the Drude model for disordered materials and Jonscher's universal power *** observed peak at the imaginary part of AC conductivity was related to the scattering time of the electron-phonon *** interaction between electrons and thermally formed phonons results in the formation of large polarons,and these are responsible for high frequency conductivity in magnetite.

关键词： Magnetite Drude model Power law Electrical conductivity Virtual free electron gas

Taylor Dispersion of Contaminants by Dual-peak Spectral Random Waves

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China Ocean Engineering 2019年第5期33卷 537-543页

作者： HUANG Guo-xing adrian Wing-Keung LAW GUO Xiao-meng State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China School of Civil and Environmental Engineering and Environmental Process Modelling Centre Nanyang Environment and Water Resources Institute (NEWRI) Nanyang Technological University Singapore 639798 Singapore State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Nanjing Hydraulic Research Institute Nanjing 210029 China

Recent extensive and important studies have provided detailed information and compelling evidence on how the presence of waves influences the vertical diffusivity/dispersivity in the coastal environment, which can affect various water quality considerations such as the distribution of suspended sediments in the water column as well as the potential of eutrophication. Comparatively, how the presence of waves influences the horizontal diffusivity/dispersivity has received only scant attention in the literature. Our previous works investigated the role played by the Taylor mechanism due to the wave-induced drift profile which leads to the longitudinal dispersion of contaminants in the horizontal direction, under regular sinusoidal waves and random waves with single-peak spectra. Natural waves in the coastal environment, however, often possess dual-peak spectra, comprising both higher frequency wind waves and lower frequency swells. In this study, the Taylor dispersion of contaminants under random waves with dual-peak spectra is examined through analytical derivation and numerical calculations. The effects of various dual-peak spectral parameters on the horizontal dispersion, including the proportion of lower frequency energy, peak frequency ratio and spectral shape parameter, are investigated. The results show that the relative energy distribution between the dual peaks has the most significant effect. Compared with single-peak spectra with equivalent energy, the Taylor dispersion with dual-peak spectra is stronger when the lower frequency is close to the peak frequency of the single-peak spectrum, and weaker with the higher frequency instead. Thus, it can be concluded that with a dual-peak wave spectrum, wind-dominated seas with higher frequency lead to stronger dispersion in the horizontal direction than swell-dominated seas with lower frequency.

关键词： Taylor dispersion dual-peak spectrum random waves

Combined support mechanism of rock bolts and anchor cables for adjacent roadways in the external staggered split-level panel layout

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International Journal of Coal Science & Technology 2021年第4期8卷 659-673页

作者： adrian Batugin Zhiqiang Wang Zehua Su Shermatova Sayyora Sidikovna National University of Science and Technology MISIS MoscowRussia School of Energy and Mining Engineering China University of Mining and Technology-BeijingBeijing 100083China

Using the spatial structure of the external staggered split-level panel layout,a combined support technology for adjacent roadways was developed and analyzed for a rock bolt and anchor cable *** influence of the side rock bolt and anchor cable parameters on the mechanical properties of the anchorage body and the support stress distribution of the lateral coal body were revealed using the FLAC3D *** optimal support parameters of the side rock bolts and anchor cables were subsequently determined,and the support effect of gob-side entry in a mining scenario was *** results show that the support of the side rock bolts and anchor cables improves the mechanical properties and stress state of the anchorage body,producing a good protective effect on the coal body of the air-intake entry roof and side *** is beneficial to the stability of the side wall and the realization of the suspension effect for roof rock bolts and anchor cables,which in turn makes the surrounding rock maintenance of the gob-side entry to a thick coal seam more favorable.

关键词： Combined support Split-level panel layout External staggered gob-side entry Adjacent roadways

Generalized Multiscale RBF Networks and the DCT for Breast Cancer Detection

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International Journal of Automation and computing 2020年第1期17卷 55-70页

作者： Carlos Beltran-Perez Hua-Liang Wei adrian Rubio-Solis Department of Automatic Control and Systems Engineering University of SheffieldSheffield S13JDUK Tecnologico de Monterrey Campus TolucaEduardo Monroy Cardenas 2000San Antonio BuenavistaToluca 50110Mexico

The use of the multiscale generalized radial basis function(MSRBF)neural networks for image feature extraction and medical image analysis and classification is proposed for the first time in this *** MSRBF networks hold a simple and flexible architecture that has been successfully used in forecasting and model structure detection of input-output nonlinear *** this work instead,MSRBF networks are part of an integrated computer-aided diagnosis(CAD)framework for breast cancer detection,which holds three stages:an input-output model is obtained from the image,followed by a high-level image feature extraction from the model and a classification module aimed at predicting breast *** the first stage,the image data is rendered into a multiple-input-single-output(MISO)*** order to improve the characterisation,the nonlinear autoregressive with exogenous inputs(NARX)model is introduced to rearrange the available input-output data in a nonlinear *** forward regression orthogonal least squares(FROLS)algorithm is then used to take advantage of the previous arrangement by solving the system as a model structure detection problem and finding the output layer weights of the NARX-MSRBF *** the second stage,once the network model is available,the feature extraction takes place by stimulating the input to produce output signals to be compressed by the discrete cosine transform(DCT).In the third stage,we leverage the extracted features by using a clustering algorithm for classification to integrate a CAD system for breast cancer *** test the method performance,three different and well-known public image repositories were used:the mini-MIAS and the MMSD for mammography,and the BreaKHis for histopathology images.A comparison exercise was also made between different database partitions to understand the mammogram breast density effect in the performance since there are few remarks in the literature on this *** results show that

关键词： Nonlinear system identification image processing discrete cosine transform radial basis functions computer-aided diagnosis neural networks

Self-assembly of highly ordered DNA origami lattices at solid-liquid interfaces by controlling cation binding and exchange

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Nano Research 2020年第11期13卷 3142-3150页

作者： Yang Xin Salvador Martinez Rivadeneira Guido Grundmeier Mario Castro adrian Keller Technical and Macromolecular Chemistry Paderborn UniversityPaderborn33098Germany Grupo Interdisciplinar de Sistemas Complejos and Instituto de Investigación Tecnológica Universidad Pontificia Comillas de MadridMadrid28015Spain

The surface-assisted hierarchical self-assembly of DNA origami lattices represents a versatile and straightforward method for the organization of functional nanoscale objects such as proteins and ***,we demonstrate that controlling the binding and exchange of different monovalent and divalent cation species at the DNA-mica interface enables the self-assembly of highly ordered DNA origami lattices on mica *** development of lattice quality and order is quantified by a detailed topological analysis of high-speed atomic force microscopy(HS-AFM)*** find that lattice formation and quality strongly depend on the monovalent cation ***^(+)is more effective than Li^(+)and K^(+)in facilitating the assembly of high-quality DNA origami lattices,because it is replacing the divalent cations at their binding sites in the DNA backbone more *** regard to divalent cations,Ca^(2+)can be displaced more easily from the backbone phosphates than Mg^(2+)and is thus superior in guiding lattice *** independently adjusting incubation time,DNA origami concentration,and cation species,we thus obtain a highly ordered DNA origami lattice with an unprecedented normalized correlation length of *** the correlation length,we use computer vision algorithms to compute the time course of different topological observables that,overall,demonstrate that replacing MgCl_(2) by CaCl_(2) enables the synthesis of DNA origami lattices with drastically increased lattice order.

关键词： DNA origami self-assembly lattice formation high-speed atomic force microscopy topological analysis