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Numerical Model of Ultra-High Molecular Weight Polyethylene Abrasive Wear Tests

Modeling and Numerical Simulation of Material Science 2020年第1期10卷 1-14页

作者： Tomas De la Mora Ramirez Isaias Hilerio Cruz Marco Antonio Donu Ruiz Noe Lopez Perrusquia David Garcia Bustos martin flores martinez Autonomous Metropolitan University Azcapotzalco UnitAzcapotzalcoMexico CityMexico Science and Engineering of Materials Technological of Studies of JocotitlanJocotitlan State of MexicoMexico Group of Materials Science and Engineering Polytechnic University of the Valley of MexicoTultitlanMariano EscobedoMexico University of Guadalajara University Center of Exact Sciences and EngineeringGuadalajaraMéxico

Ultra-high molecular weight polyethylene (UHMWPE) has been used in orthopedics as one of the materials for artificial joints in knee, hip and spine prostheses, most of the implanted joints are designed so that the metal of the prosthesis is articulate against a polymeric material, however the main problems is the average life time of the UHMWPE due to wear, and the particles generated by the friction of the metal on the articulation of the polymer are the most common inducer of osteolysis, generating a loosening of the implant leading to an imminent failure resulting in the total replacement of the prosthesis. In this investigation a numerical model of abrasive wear was made using the classic Archard wear equation applied to dynamic simulation of finite element analysis (FEA) of the micro-abrasion test using a subroutine written in Fortran language linked to the finite element software to predict the rate of wear. The results of the numerical model were compared with tests of abrasive wear in the laboratory, obtaining a margin of error below 5%,concluding that the numerical model is feasible for the prediction of the rate of wear and could be applied in knowing the life cycle of joint prostheses or for the tribological analysis in industrial machinery or cutting tools. The wear coefficient (K) was obtained from the grinding tests depending on the depth of stroke of the crater, which was analyzed by 3D profilometry to obtain the wear rate and the wear constant.

关键词： Abrasive Wear Finite Element Numerical Wear Model UHMWPE

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Ecological distribution and population structure of Litsea glaucescens(Lauraceae)in the ravines of Sierra Fría and Sierra Laurel,Central Mexico

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Journal of Mountain Science 2022年第7期19卷 1945-1960页

作者： Mara Irais flores-GALLEGOS Edmundo GARCIA-MOYA Angelica ROMERO-MANZANARES Mario LUNA-CAVAZOS martin Alfonso MENDOZA-BRISENO Heike VIBRANS Posgrado en Botánica Colegio de PostgraduadosCampus Montecillo.Km 36.5carretera México-TexcocoMontecilloTexcocoEdo.de México56230México Colegio de Postgraduados Campus Veracruz.Carretera Jalapa Veracruz Km 88.5Altamirano91690VeracruzMéxico

Litsea glaucescens Kunth(Mexican bay leaf,laurel)has a wide distribution in Mexico,growing at both riparian and rupicolous environments in the mountainous region of the Central Highlands of the *** Fría-Sierra Laurel is a protected natural area covered by a dry *** Mexican bay leaf is associated with the oak forest,especially on *** species has been considered at risk in recent *** research is focused on analyzing the elements of the environment of the ravines,which are influencing the distribution and establishment of laurel populations in the *** mountainous regions of Aguascalientes were selected,Sierra Fría and Sierra *** ravines of the basin were selected to obtain environmental *** registered were topographic,edaphic,and *** component analysis was used to identify ecological factors associated with the presence of *** bay leaf populations were registered in 10 *** the structural level in the community,29 woody species were registered,Mexican bay leaf had an Importance Value Index of 15.8,ranking 10th among all *** of laurel were classified by size classes(S,individuals with heights ranging from 0 to 20 cm;S,heights ranging from 0.2 to 1.0 m;S,heights between 1 and 2 m with light trace of flowering;S,heights greater than 2 m with flowering greater than 30% of the canopy;and S,individuals with heights greater than 5 m,curved trunk and basal regrowth)to obtain the population *** importance index value for all the species in the riparian community was calculated to the community *** factors that characterized the presence of Mexican bay leaf were a high percentage of rock coverage(90%),less mulch depth,and sandy loam shallow *** that showed higher cation exchange capacity had a higher presence of individuals of the S,S,and Ssize *** Sindividuals were found in shady places with 97% of intercepted *** o

关键词： Dry Forest Ephemeral stream Importance Value Index Mexican bay leaf Population structure Principal Component Analysis

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Human umbilical artery smooth muscle exhibits a 2-APBsensitive capacitative contractile response evoked by vasoactive substances and expresses mRNAs for STIM, Orai and TRPC channels

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BIOCELL 2012年第2期36卷 73-81页

作者： ANA ROCÍO ROLDÁN PALOMO PEDRO martin ALEJANDRO REBOLLEDO NICOLÁS ENRIQUE LUIS E.flores VERÓNICA MILESI GINFIV–Grupo de Investigación en Fisiología Vascular Facultad de Ciencias ExactasUniversidad Nacional de La Plata.Argentina CENEXA–Centro de Endocrinología Experimental y Aplicada (UNLP-CONICET La PlataCentro Colaborador OPS/OMS)Facultad de Ciencias MédicasUniversidad Nacional de La Plata.Argentina

After depletion of intracellular Ca^(2+)stores the capacitative response triggers an extracellular Ca^(2+)influx through store-operated channels(SOCs)which refills these *** objective was to explore if human umbilical artery smooth muscle presented this response and if it was involved in the mechanism of serotonin-and histamine-induced *** Ca^(2+)depletion by a Ca^(2+)-free extracellular solution followed by Ca^(2+)readdition produced a contraction in artery rings which was inhibited by the blocker of Orai and TRPC channels 2-aminoethoxydiphenyl borate(2-APB),suggesting a capacitative *** presence of 2-APB the magnitude of a second paired contraction by serotonin or histamine was significantly less than a first one,likely because 2-APB inhibited store refilling by capacitative Ca^(2+)entry.2-APB inhibition of sarcoplasmic reticulum Ca^(2+)release was excluded because this blocker did not affect serotonin force development in a Ca^(2+)-free *** PCR technique showed the presence of mRNAs for STIM proteins(1 and 2),for Orai proteins(1,2 and 3)and for TRPC channels(subtypes 1,3,4 and 6)in the smooth muscle of the human umbilical ***,this artery presents a capacitative contractile response triggered by stimulation with physiological vasoconstrictors and expresses mRNAs for proteins and channels previously identified as SOCs.

关键词： human umbilical artery capacitative response TRPC channels serotonin histamine

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Erosion problem in tool steel using cold box core-making process

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China Foundry 2019年第3期16卷 204-210页

作者： Eduardo Rodríguez Alberto Pérez Rafael David Mercado-Solis Velasco-Téllez Abraham Omar Jimenez martin flores Marco Aurelio Gonzalez Jesus Ibarra Universidad de Guadalajara Departamento de Ingeniería de Proyectos/CUCEI CONACyT México Facultad de Ingeniería Mecánica y Eléctrica UANL México Nemak México S.A. García México Instituto Tecnológico José Mario Molina Pasquel y Henríquez Unidad Zapopan México

This paper presents the erosion results of the AISI H13 steel impinged by resin-bonded silica sand, using a testing rig that closely simulates the real blowing conditions during industrial core-making. Steel specimens were heat treated to obtain hardness of 294, 445 and 595 HV200 (29, 45 and 55 HRC). Erosion tests were carried out at impingement angles from 20° to 90° and air drag pressures of 1.38, 2.07 and 2.76 bar (20, 30 and 40 psi). The main results are summarized as follows:(i) The harder material, the lower erosion;(ii) the maximum erosion rate is at 30°;(iii) Little difference in erosion rate at impact angle of 60° and 90° for a constant pressure tested regardless of the hardness level;(iv) As the pressure increases, so does the erosion rate, being more sensitive for low impact angles. Finally, a differential form of the general erosion equation is applied on a practical core-making case to evaluate the erosion rate of the H13 steel at 30° and 90° impingement angles.

关键词： erosion cold box core-making H13 tool steel resin coated silica sand

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Schedule-Induced Polydipsia:Searching for the Endophenotype of Compulsive Behavior

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World Journal of Neuroscience 2014年第3期4卷 253-260页

作者： Pilar flores Ana Sanchez-Kuhn Ana Merchan Olga Vilches Sergio Garcia-martin Margarita Moreno Department of Psychology University of AlmeríaAgrifood Campus of International Excellence CeiA3La CanadaSpain

The development of excessive and persistent drinking under intermittent food-reinforcement schedules, known Schedule-induced polydipsia (SIP), has been proposed as a successful animal model to study compulsive behaviors. On the last decade, we have been working in our laboratory on the stratification of the compulsive rats on SIP in order to know whether differences in the acquisition of compulsive drinking behavior could predict alterations in other behavioral measures as well as in the neurochemical function typically associated with compulsive spectrum disorders. The aim of this review is to collate the main findings relevant to the characterization and use of the high compulsive drinking rats (HD) in SIP as a possible compulsive endophenotype. The review of the genetic, behavioral and neurochemical differences found in the selection allows us to conclude that HD rats could be a valid model for studying the compulsive phenotype and modelling psychopathology common to a variety of compulsivity spectrum disorders such as obsessivecompulsive disorder (OCD), schizophrenia and alcohol abuse.

关键词： Compulsivity Endophenotype Schedule-Induced Polydipsia Obsessive-Compulsive Disorder Schizophrenia

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Cryopreservation by Vitrification of Vitis vinifera cv. ＂Red Globe＂ Zygotic Embryos and Effect on the Expression of DNA Methyltransferase Genes

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Journal of Agricultural Science and Technology(B) 2016年第6期6卷 387-399页

作者： Heriberto Garcia-Coronado Maria-Elena Baez-flores Rosalba Troncoso-Rojas Marisela Rivera-Dominguez martin-Emesto Tiznado-Hernandez Coordinacion de Tecnologia de Alimentos de Origen Vegetal Centro de Investigacion en Alimentacion y Desarrollo A.C. (CLAD)Hermosillo Sonora CP 83304 Mexico Facultad de Ciencias Quimico Biol6gicas Universidad Autonoma de Sinaloa Culiacan Sinaloa CP 80013 Mexico Coordinacion de Ciencia de los Alimentos Centro de Investigacion en Alimentacion y Desarrollo A.C. (CLAD) HermosilloSonora CP 83304 Mexico

Mexico is a large producer of table grape （Vitis vinifera L.） and therefore it is important to develop protocols to store the grape varieties germplasm. The objective of the present work was to design a protocol for the cryopreservation by vitrification of zygotic embryos of V. vinifera cv. ＂Red Globe＂ and evaluate possible epigenetics changes. The plant vitrification solution 2 （PVS2） was utilized before the utilization of liquid nitrogen （LN）. The effect of this protocol on embryo viability was tested by the triphenyl-tetrazolium chloride solution, as well as by the in vitro development of grape embryos into plantlet. A cDNA expression library of grape zygotic embryos was created to isolate expressed sequence tags of several DNA methyltrasferases. Gene expression of domains rearranged methyltransferase type 1 （DMR1） and DNA （cytosine-5）-methyltransferase 1 （MET1-2） isozymes was analyzed by quantitative reverse transcriptase PCR. The optimal conditions for vitrification were 10 min in 50% PVS2, followed by I0 min in 100% PVS2. Under these conditions, about 30% of plantlet was obtained from embryos after cryopreservation. It was recorded a reduction in the MET1-2 gene expression, which plays a role in the maintenance of DNA methylation. It is possible to cryopreserve viable grape zygotic embryos, although the treatment seems to induce alterations in the normal DNA methylation pattern of the zygotic embryo genome.

关键词： Vitis vinifera zygotic embryo cryopreservation vitrification DNA methyltransferase.

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Gut passage of epigeous ectomycorrhizal fungi by two opportunistic mycophagous rodents

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Current Zoology 2011年第3期57卷 293-299页

作者： Citlalli CASTILLO-GUEVARAl Josette SIERRA Gema GALINDO-flores Mariana CUAUTLE Carlos LARA Centro de Investigacion en Ciencias Biologicas Universidad Autonoma de Tlaxcala Km 10.5 Autopista Tlaxcala-San Martin Texmelucan San Felipe Ixtacuixtla Tlaxcala 90120 Mexico Departamento de Quimica y Biologfa Universidad de las Americas-Puebla Ex-hacienda Sta Catarina Martir s/n Cholula Puebla 72810 Mexico Centro Tlaxcala de Biologia de la Conducta Universidad Autdnoma de Tlaxcala-UNAM Carretera Tlaxcala-Puebla Km 1.5 s/n Tlaxcala Tlaxcala 90070 Mexico

Mycophagists can influence fungal diversity within their home ranges by ensuring the continued and effective dispersal of spores from one site to another. However, the passage of spores through the digestive tract of vertebrates can affect the activity and viability of the spores ingested. This phenomenon has been rarely documented in opportunistic mycophagists consuming epigeous fungi. Using laboratory experiments, we investigated the activity and viability of spores of two epigeous ectomycorrhizal fungal species （Laccaria trichodermophora and SuiUus tomentosus） after passage through the digestive tract of two opportunistic mycophagous small rodents, the volcano mouse Peromyscus alstoni and the deer mouse P maniculatus. We found that passage through the gut of either species of rodent had a significant effect on spore activity and viability for both fungal species. The proportion of active spores （0.37-0.40） of L. trichodermophora in the feces of both species of rodents was less than that recorded for the control （0.82）. However, the proportion of active spores （0.644）.73） of S. tomentosus in the feces of each species of rodent was higher than in the control （0.40）. On the other hand, the viability of spores was lower （0.26-0.30 in L. trichodermophora and 0.604）.69 in S. tomentosus） for both fungi when consumed by either rodent relative to the controls （0.90 in L. trichodermophora and 0.82 in S. tomentosus）. These findings suggest that these rodent species may be effective dispersers of both epigeous fungi [Current Zoology 57 （3）： 293-299, 2011].

关键词： Gut passage Epigeous ectomycorrhizal fungi Mexico Spore activity and viability Peromyscus

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河内博物馆

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中国建筑装饰装修 2012年第4期 238-239页

作者： Meinhard von Gerkan Nikolaus Goetze Klaus Lenz Nicole flores martin Friedrich Jessica Last Udo Meyer Duc Tran Cong Marcus Bredt

穿过园林景观来访者可从四个方向进入博物馆。在正方形的建筑体中庭内,一座圆形的挑空大厅将入口层面于其上的三层展览空间连接起来。如同倒置的金字塔般,中庭向上呈阶梯状展开。来访者向外望去,仿佛"漂浮"于主题公园景观之上。盘旋上... 详细信息

穿过园林景观来访者可从四个方向进入博物馆。在正方形的建筑体中庭内,一座圆形的挑空大厅将入口层面于其上的三层展览空间连接起来。如同倒置的金字塔般,中庭向上呈阶梯状展开。来访者向外望去,仿佛"漂浮"于主题公园景观之上。盘旋上升的坡道作为极富表现力的空间元素,将人们吸引至建筑顶部,并且实现了展览空间与中庭的视线交流。由于展览空间全部安排在建筑的首层至三层,会议、科研中心,办公空间以

关键词：博物馆博物院文化机构建筑体中庭

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Association between Helicobacter pylori infection,mismatch repair,HER2 and tumor-infiltrating lymphocytes in gastric cancer

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2487-2503页

作者： Carlos A Castaneda Miluska Castillo Luis A Bernabe Joselyn Sanchez Matteo Fassan Katherine Tello Ignacio Ivan Wistuba Ivan Chavez Passiuri Eloy Ruiz Juvenal Sanchez Fernando Barreda Daniel Valdivia Yaqueline Bazan Milagros Abad-Licham Claudio Mengoa Hugo Fuentes Paola Montenegro Ebert Poquioma Raul Alatrista Claudio J flores Luis Taxa Faculty of Health Sciences Universidad Cientifica del SurLima 15038Peru GECO PERU Grupo de Estudios Clinicos Oncologicos del PeruLima 15038Peru Department of Research Instituto Nacional de Enfermedades NeoplasicasLima 15038Peru Faculty of Human Medicine Universidad Ricardo PalmaLima 15039Peru Department of Medicine Surgical Pathology&Cytopathology UnitUniversity of PaduaPadua 35121Italy Department of Translational Molecular Pathology The University of Texas MD Anderson Cancer CenterHoustonTX 77030United States Department of Abdominal Surgery Instituto Nacional de Enfermedades NeoplasicasLima 15038Peru Department of Pathology Instituto Nacional de Enfermedades NeoplasicasLima 15038Peru Department of Medical Specialties Instituto Nacional de Enfermedades NeoplasicasLima 15038Peru Department of Pathology Instituto Regional de Enfermedades Neoplasicas del NorteTrujillo 13001Peru Faculty of Human Medicine Universidad Privada Antenor OrregoTrujillo 13008Peru Department of Surgery Instituto Regional de Enfermedades Neoplasicas del SurArequipa 04002Peru Department of Medical Oncology Instituto Nacional de Enfermedades NeoplasicasLima 15038Peru Department of Epidemiology Instituto Nacional de Enfermedades NeoplasicasLima 15038Peru Unidad de Investigación Básica y Traslacional Oncosalud-AUNALima 15038Peru Faculty of Medicine Universidad San Martin de PorresLima 15008Peru

BACKGROUND The influence of Helicobacter-pylori(***)infection and the characteristics of gastric cancer(GC)on tumor-infiltrating lymphocyte(TIL)levels has not been extensively *** of infiltrating-immune-cell subtypes as well as survival is necessary to obtain comprehensive *** To determine the rates of deficient mismatch-repair(dMMR),HER2-status and *** infection and their association with TIL levels in *** Samples from 503 resected GC tumors were included and TIL levels were evaluated following the international-TILs-working-group recommendations with assessment of the intratumoral(IT),stromal(ST)and invasive-border(IB)*** density of CD3,CD8 and CD163 immune cells,and dMMR and HER2-status were determined by immunohistochemistry(IHC).*** infection was evaluated by routine histology and quantitative PCR(qPCR)in a subset of *** dMMR was found in 34.4%,HER2+in 5%and ***-positive in 55.7%of *** IT-TIL was associated with grade-3(P=0.038),while ST-TIL with grade-1(P<0.001),intestinal-histology(P<0.001)and no-recurrence(P=0.003).dMMR was associated with high TIL levels in the ST(P=0.019)and IB(P=0.01)compartments,and STCD3(P=0.049)and ST-CD8(P=0.05)***2-was associated with high IT-CD8(P=0.009).*** was associated with high IT-TIL levels(P=0.009)when assessed by routine-histology,and with high TIL levels in the 3 compartments(P=0.002-0.047)and CD8 density in the IT and ST compartments(P=0.001)when assessed by qPCR.A longer overall survival was associated with low IT-CD163(P=0.003)and CD8/CD3(P=0.001 in IT and P=0.002 in ST)and high IT-CD3(P=0.021),ST-CD3(P=0.003)and CD3/CD163(P=0.002).CONCLUSION TIL levels were related to dMMR and *** CD8/CD3 and high CD163/CD3 were associated with lower recurrence and longer survival.

关键词： Lymphocytes Macrophages Gastric cancer Helicobacter pylori HER2 Mismatch repair

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Effects of Imazethapyr-Based Herbicide Formulation in the Zebrafish (Danio rerio) Hepatocyte Cell Line (ZF-L): Cytotoxicity and Oxidative Stress

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Journal of Environmental Protection 2024年第6期15卷 747-765页

作者： Edila Maria Kickhöfel Ferrer Milena Mattes Cerveira Pedro Henrique flores Da Cruz Cleiton Jesus Andrade Pereira Lucas Moraes Berneira Claudio martin Pereira de Pereira Nathalia Stark Pedra Roselia Maria Spanevello Jean Carlos Bauer Vieira Clarissa Piccinin Frizzo Mateus Tavares Kütter Janice Luehring Giongo Rodrigo de Almeida Vaucher Center of Chemical Pharmaceutical and Food Sciences Microorganism Biochemistry and Molecular Biology Research Laboratory (LAPEBBIOM) Federal University of Pelotas (UFPEL) Pelotas Rio Grande do Sul Brazil Center of Chemical Pharmaceutical and Food Sciences Laboratory for Lipidomic and Bio-Organic Research Bioforensic Research Group Federal University of Pelotas (UFPEL) Pelotas Rio Grande do Sul Brazil Center of Chemical Pharmaceutical and Food Sciences Neurochemistry Inflammation and Cancer Laboratory Federal University of Pelotas (UFPEL) Pelotas Rio Grande do Sul Brazil Department of Chemistry Heterocycle Chemistry Center (NUQUIMHE) Federal University of Santa Maria (UFSM) Santa Maria Rio Grande do Sul Brazil Department of Microbiology and Parasitology Biology Institute Federal University of Pelotas (UFPEL) Pelotas Rio Grande do Sul Brazil

Seizures of agrochemical formulations have increased in Brazil and Rio Grande do Sul is among the Brazilian states with the highest number of seizures of these products obtained illicitly. The use of illicit formulations can cause significant harm to agricultural production, the environment, and non-target species. This study evaluated the cytotoxicity and oxidative stress of a seized formulation containing the herbicide imazethapyr (IMZT). Characterization of the herbicide included gas chromatography-mass spectrometry (GC-MS) and thermal analyses (thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)). Hemolytic and cytotoxicity assays in ZF-L hepatic cells showed IC50 values of 12.75 µg/mL, 3.01 µg/mL, 2.67 µg/mL, and 1.61 µg/mL for erythrocytes, [3(4,5-dimethyl)-2 bromide-5 diphenyl tetrazolium] (MTT), neutral red (NR), and lactate dehydrogenase (LDH) assays, respectively. The median IC50 of 2.84 µg/mL was used in oxidative stress assays, revealing increased reactive oxygen species (ROS) production, reduced total sulfhydryl content, and decreased superoxide dismutase (SOD) and catalase (CAT) activity. This study is the first to report in vitro oxidative stress induced by IMZT in the ZF-L cell line, emphasizing the importance of in vitro assays for assessing the toxic effects of seized agrochemicals on human health and the environment.

关键词： Agrochemical Imidazolinone Zebrafish Cell Viability Oxidative Damage

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