检索结果-南通市图书馆

Journal of Iron and Steel Research(International) 2019年第4期26卷 365-373页

作者： Rie Endo Yo Kan Takashi Watanabe Miyuki Hayashi Masahiro susa Department of Materials Science and Engineering Tokyo Institute of TechnologyTokyo 152-8552Japan Department of Metallurgy and Ceramics Science Tokyo Institute of TechnologyTokyo 152-8552Japan

Mould flux with high absorptivity had been obtained in the reduction process of mould flux by silicon.For further utilisation of the mould flux with high absorptivity,the effect of silicon addition on the optical property has been investigated.The synthesised mould flux powder with iron oxide was melted with the addition of silicon powder at 1703 K followed by quenching,thus forming a glassy sample.After 5-30-min reduction,the samples exhibited black opaque colour.Meanwhile,the samples that were reduced for 45-60 min had a bluish grey colour.Many iron-based particles dispersed in the samples were micrometre order in diameter.To determine the effect of iron particles on the optical properties of the sample,extinction,scattering and absorption efficiencies were calculated according to Mie theory.Result showed that both scattering on the iron particle and absorption by iron effectively increase the extinction efficiency in the mould flux.Moreover,the silicon particle in the flux has large scattering efficiency.The black opaque colour is contributed by the existence of silicon and iron particles.The apparent thermal conductivity was calculated for the solid flux.Results also indicated that the entire glassy mould flux would effectively work for mild cooling in a continuous casting process owing to high absorptivity and small thermal conductivity.

关键词： Mould flux Reduction Iron oxide Thermal conductivity Optical property

Chebyshev multidomain pseudospectral method to solve cardiac wave equations with rotational anisotropy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2018年第4期9卷 58-82页

作者： Jairo Rodrıguez-Padilla Daniel olmos-Liceaga Departamento de Matematicas Universidad de Sonora.Blvd.Rosales y Luis Encinas S/N Col CentroC.P.83000HermosilloSonoraMexico

The implementation of numerical methods to solve and study equations for cardiac wave propagation in realistic geometries is very costly,in terms of computational resources.The aim of this work is to show the improvement that can be obtained with Chebyshev polynomials-based methods over the classical finite difference schemes to obtain numerical solutions of cardiac models.To this end,we present a Chebyshev multidomain(CMD)Pseudospectral method to solve a simple two variable cardiac models on threedimensional anisotropic media and we show the usefulness of the method over the traditional finite differences scheme widely used in the literature.

关键词： Chebyshev-pseudospectral cardiac models anisotropic media.

低度全身炎症刺激小胶质细胞更新并加速阿尔茨海默病样病理的发生

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

神经损伤与功能重建 2024年第5期19卷 F0003-F0003页

作者： Monica Guerrero-Carrasco Imogen Targett Adrian olmos-Alonso Mariana Vargas-Caballero Diego Gomez-Nicola 杜一星(译) School of Biological Sciences University of SouthamptonSouthampton General HospitalSouthamptonUK Institute for Life Sciences(IfLS) University of SouthamptonSouthamptonUK 不详

数项在体研究表明,脂多糖模拟的全身炎症会引发中枢神经系统中由小胶质细胞驱动的炎症反应,其特征是炎症细胞因子和相关疾病行为的增加。然而,大多数研究诱发相对较高的全身炎症,并没有直接与人类在生命过程中经历的更常见的低度炎症事... 详细信息

数项在体研究表明,脂多糖模拟的全身炎症会引发中枢神经系统中由小胶质细胞驱动的炎症反应,其特征是炎症细胞因子和相关疾病行为的增加。然而,大多数研究诱发相对较高的全身炎症,并没有直接与人类在生命过程中经历的更常见的低度炎症事件进行比较。本研究利用小鼠研究低度全身炎症在生命早期对健康的影响,以及该事件如何影响阿尔茨海默病(AD)样病理的发生和严重程度。本研究结果表明,低度全身炎症会诱导阈下脑炎症,并促进CSF1R通路驱动的小胶质细胞增殖,这与高度全身炎症引起的影响相反。此外,低度脂多糖引起的反复全身性挑战会诱导疾病相关的小胶质细胞。最后,使用AD样病理诱导模型(102系小鼠),我们观察到在APP诱导之前重复剂量的低度全身性炎症预处理会在以后的生活中产生有害影响,导致Aβ沉积以及和疾病相关的小胶质细胞增加。本研究结果提示,阵发性低度全身炎症有可能影响与年龄相关的神经系统疾病(例如AD)的发作和严重程度。

关键词：阿尔茨海默病脂多糖疾病相关的小胶质细胞小胶质细胞增殖

Influence of steel jacket thickness on the RC bridges' seismic vulnerability

在线全文

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2019年第1期6卷 15-34页

作者： Bertha olmos José Manuel Jara Gerardo Gómez Guillermo Martínez Department of Civil Engineering Universidad Michoacana de San Nicolas de Hidalgo

The seismic demands of bridges subjected to strong earthquakes are mostly concentrated on piers. The main objective of this study is to assess the seismic vulnerability of retrofitted bridges with steel jackets. It analyzes the influence of the steel jacket thickness on the seismic capacity and demand of bridges. The bridges in study have two simple supported spans with superstructure composed by AASHTO type girders and a substructure formed with one circular pier over a stiff foundation. They are located on the Pacific coast of Mexico that is a zone of high seismicity. The bridges seismic capacity are evaluated through nonlinear static analyses and the shear force and displacement demands were determined using capacity spectra with a group of 10 real accelerograms from a subduction source. The response spectra were scaled to several peak ground accelerations(PGA) with the aim to estimate four damage scenarios linked each one to a probability of exceedance in a specific period, for return periods in the range of 72-3500 years that represent service level and maximum considered earthquake. Results show that the confining effect provided by the steel jackets substantially improves the seismic performance of the bridges piers. The increase of jacket thickness guides to important increments on columns base shear capacity, and the influence of the steel jacket thickness depends on the limit state and bridge slenderness ratio.

关键词： Steel jacket Piers’retrofit Subduction earthquakes RC piers’vulnerability

Inference for a truncated positive normal distribution

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2018年第2期33卷 163-176页

作者： Hector J.Gomez Neveka M.olmos Hector Varela Heleno Bolfarine Departamento de Ciencias Matematicas y Ffsicas Facultad de IngenierlaUniversidad Catolica de TemucoTemucoChile Departamento de Matematicas Facultad de Ciencias BasicasUniversidad de AntofagastaAntofagastaChile Departamento de Estatfstica IMEUniversidade de Sao PauloSao PauloBrazil

The main object of this paper is to study an extension of the half normal distribution defined by adding a positive truncation to it. The new model is more flexible than the half-normal distribution and contains the half normal distribution as a special case. Properties of this distribution, such as moments, hazard function and entropy are studied and parameters estimation is dealt with by using inoinents and inaxiinuin likelihood. A real data application indicates good fit performance of the new model when compared to other competitors in litera- tures.

关键词： half-normal distribution maximum likelihood truncation

Role of platelets and breast cancer stem cells in metastasis

在线全文

学校读者我要写书评

暂无评论

World Journal of Stem Cells 2020年第11期12卷 1237-1254页

作者： Gretel Mendoza-Almanza Luis Burciaga-Hernandez Vilma Maldonado Jorge Melendez-Zajgla Jorge olmos CONACYT Universidad Autónoma de Zacatecas.Zacatecas 98060Mexico Maestría en Ciencias Biomédicas Universidad Autónoma de ZacatecasZacatecas 98160Mexico Laboratorio de Epigenética Instituto Nacional de Medicina GenómicaCiudad de México 14610Mexico Génómica funcional del cáncer Instituto Nacional de Medicina GenómicaCiudad de México 14610Mexico Biotecnología Marina Centro de Investigación Científica y de Estudios Superiores de EnsenadaEnsenada 22860Mexico

The high mortality rate of breast cancer is mainly caused by the metastatic ability of cancer cells,resistance to chemotherapy and radiotherapy,and tumor regression capacity.In recent years,it has been shown that the presence of breast cancer stem cells is closely associated with the migration and metastatic ability of cancer cells,as well as with their resistance to chemotherapy and radiotherapy.The tumor microenvironment is one of the main molecular factors involved in cancer and metastatic processes development,in this sense it is interesting to study the role of platelets,one of the main communicator cells in the human body which are activated by the signals they receive from the microenvironment and can generate more than one response.Platelets can ingest and release RNA,proteins,cytokines and growth factors.After the platelets interact with the tumor microenvironment,they are called"tumor-educated platelets."Tumor-educated platelets transport material from the tumor microenvironment to sites adjacent to the tumor,thus helping to create microenvironments conducive for the development of primary and metastatic tumors.It has been observed that the clone capable of carrying out the metastatic process is a cancer cell with stem cell characteristics.Cancer stem cells go through a series of processes,including epithelial-mesenchymal transition,intravasation into blood vessels,movement through blood vessels,extravasation at the site of the establishment of a metastatic focus,and site colonization.Tumor-educated platelets support all these processes.

关键词： Breast cancer stem cells Platelets Metastasis Tumor microenvironment Epithelial-mesenchymal transition

Representative volume element of asphalt pavement for electromagnetic measurements

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Traffic and Transportation Engineering(English Edition) 2015年第1期2卷 30-39页

作者： Terhi Pellinen Eeva Huuskonen-Snicker Pekka Eskelinen Pablo olmos Martinez Department of Civil and Environmental Engineering Aalto University Department of Electrical Engineering and Automation Aalto University

The motivation for this study was to investigate the representative volume element （RVE） needed to correlate the nondestructive electromagnetic （EM） measurements with the con- ventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar （GPR） measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer （VNA） and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore vol- ume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.

关键词： Asphalt Dielectric constant Permittivity Vector Network Analyzer Bulk density

A look into the past, present and future potential distributions of Talinopsis frutescens, a North American endemic lineage closely related to Cactaceae

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2020年第1期12卷 104-114页

作者： Mónica I MIGUEL-VÁZQUez Yasser S LÓPez DE olmos R Gilberto OCAMPO Department of Biology Basic Sciences CenterAutonomous University of Aguascalientes940 University AvenueAguascalientes 20130Mexico Biological and Health Sciences PhD Program Department of BiologyBiological and Health Sciences DivisionAutonomous Metropolitan UniversityIztapalapa 09340Mexico

Talinopsis frutescens(Anacampserotaceae,a family that is close related to Cactaceae)is a succulent species endemic to North America.The aim of this study was to explore,using Ecological Niche Modeling(ENM),changes in potential distribution ranges considering different climate scenarios:past conditions during the Last Inter Glacial(LIG)and the Last Glacial Maximum(LGM),the present and projections for 2070(RCP 2.6 to 8.5).A pattern of contraction is observed during the LIG,which agrees with other studies focused in species from arid environments.This pattern was followed by a migration towards the south during the LGM and a possible recent expansion to the north as is observed in the present scenario.All future projections show the same contraction and fragmentation patterns,resulting in three discontinuous areas:the northern part of the Chihuahuan Desert,the southern-central part of the Mexican Plateau,and the smallest one in the Tehuacán-Cuicatlán Valley.Our projections for future scenarios agree with other studies and support that global climate change tends to alter the current distribution of arid environment species.

关键词： Anacampserotaceae Caryophyllales ecological niche modeling succulent plants potential distribution

镰状细胞对内皮诱导一氧化氮的清除能力低下(英文)

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2002年第11期23卷 9-15页

作者： Leopoldo olmos,Jean-Vivien MOMBOULI,Nathan WASSERSTRUM,Paul MVANHOUTTE Baylor College of Medicine Houston TX 77030 USA lnstitut de Recherches Internationales Servier 92415 Courbevoie Cedex France Center for Experimental Therapeutics Baylor College of Medicine Houston TX 77030 USA University of Marien Ngouabi Brazzaville Republic of Congo Center for Experimental Therapeutics

AIM: To assess the ability of sickle cells to interfere with the release or transfer of endothelium-derived relaxing factor (EDRF) in comparison to normal erythrocytes. METHODS: A perfusion-superfusion bioassay system was used a canine carotid artery with endothelium (donor of EDRF) and a ring of the same vessel without endothelium (detector) were separated by tubing resulting in a five second interval for transfer of EDRF from donor to detector. Changes in isometric tension were monitored in both the donor and the detector preparations. Release of EDRF, as determined by sustained relaxations during the contractions to phenylephrine, was induced by infusing acetylcho-line through the donor artery. RESULTS: Supervision with normal and sickle erythrocytes caused impairment of the endothelium-dependent relaxations in both detector and donor tissues. When infused through the transfer line, sickle cells were less potent than normal erythrocytes in inhibiting relaxation in the detector tissues. In contrast, i

关键词：镰状细胞贫血内皮血管平滑肌红细胞微循环一氧化氮

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2019年第9期14卷 1544-1555页

作者： Laia Farras-Permanyer Nuria Mancho-Fora Marc Montala-Flaquer David Bartres-Faz Lidia Vaque-Alcazar Maribel Pero-Cebollero Joan Guardia-olmos Quantitative Psychology Section Faculty of PsychologyUniversity of BarcelonaBarcelonaSpain Department of Medicine Faculty of Medicine and Healthy SciencesUniversity of BarcelonaBarcelonaSpain Institute of Neuroscience UB Institute of Complex SystemsUniversity of BarcelonaBarcelonaSpain Institut d’Investigacions Biomediques August Pi i Sunyer BarcelonaSpain

Age-related changes in the brain connectivity of healthy older adults have been widely studied in recent years,with some differences in the obtained results.Most of these studies showed decreases in general functional connectivity,but they also found increases in some particular regions and areas.Frequently,these studies compared young individuals with older subjects,but few studies compared different age groups only in older populations.The purpose of this study is to analyze whole-brain functional connectivity in healthy older adult groups and its network characteristics through functional segregation.A total of 114 individuals,48 to 89 years old,were scanned using resting-state functional magnetic resonance imaging in a resting state paradigm and were divided into six different age groups(<60,60–64,65–69,70–74,75–79,≥80 years old).A partial correlation analysis,a pooled correlation analysis and a study of 3-cycle regions with prominent connectivity were conducted.Our results showed progressive diminution in the functional connectivity among different age groups and this was particularly pronounced between 75 and 79 years old.The oldest group(≥80 years old)showed a slight increase in functional connectivity compared to the other groups.This occurred possibly because of compensatory mechanism in brain functioning.This study provides information on the brain functional characteristics of every age group,with more specific information on the functional progressive decline,and supplies methodological tools to study functional connectivity characteristics.Approval for the study was obtained from the ethics committee of the Comision de Bioetica de la Universidad de Barcelona(approval No.PSI2012-38257)on June 5,2012,and from the ethics committee of the Barcelona’s Hospital Clinic(approval No.2009-5306 and 2011-6604)on October 22,2009 and April 7,2011 respectively.

关键词： brain connectivity resting state default mode network aging healthy functional connectivity resting state network age groups