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Addition of collagen type I in agarose created a dose-dependent effect on matrix production in engineered cartilage

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regenerative Biomaterials 2022年第1期9卷 704-709页

作者： Gabriel r.lópez-Marcial Keerthana Elango Grace D.O’Connell Department of Mechanical Engineering University of California-Berkeley6141 Etcheverry HallBerkeley CA 94720USA Department of Orthopaedic Surgery University of California-San Francisco500 Parnassus Ave MU-320WSan Francisco CA 94143USA

Extracellular-matrix composition impacts mechanical performance in native and engineered *** studies showed collagen typeⅠ-agarose blends increased cell-matrix interactions and extracellular matrix ***,long-term impacts on protein production and mechanical properties of engineered cartilage are *** objective was to characterize the effect of collagen type I on the matrix production of chondrocytes embedded in agarose *** hypothesized that the addition of collagen would improve longterm mechanical properties and matrix production(*** and glycosaminoglycans)through increased *** hydrogels(2%w/v)were mixed with varying concentrations of collagen typeⅠ(0,2 and 5 mg/ml).Juvenile bovine chondrocytes were added to the hydrogels to assess matrix production over 4 weeks through biochemical assays,and mechanical properties were assessed through unconfined *** observed a dose-dependent effect on cell bioactivity,where 2 mg/ml of collagen improved bioactivity,but 5 mg/ml had a negative impact on *** resulted in a higher modulus for scaffolds supplemented with lower collagen concentration as compared to the higher collagen concentration,but not when compared to the *** conclusion,the addition of collagen to agarose constructs provided a dose-dependent impact on improving glycosaminoglycan production but did not improve collagen production or compressive mechanics.

关键词： hydrogel tissue engineering composition agarose-collagen matrix mechanics

Algorithm for repairing the damaged images of grain structures obtained from the cellular automata and measurement of grain size

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International Journal of Minerals,Metallurgy and Materials 2012年第10期19卷 899-907页

作者： A.ramírez-lópez M.A.romero-romo D.Muñoz-Negron S.lópez-ramírez r.Escarela-Pérez C.Duran-valencia Department of Materials and Energy Metropolitan Autonomous UniversityMexico City 02200Mexico Department of Industrial Engineering Technological Autonomous Institute of MexicoMexico City 01080Mexico Department of Molecular Engineering Mexican Institute of PetroleumMexico City 07730Mexico

Computational models are developed to create grain structures using mathematical algorithms based on the chaos theory such as cellular automaton, geometrical models, fractals, and stochastic methods. Because of the chaotic nature of grain structures, some of the most popular routines are based on the Monte Carlo method, statistical distributions, and random walk methods, which can be easily programmed and included in nested loops. Nevertheless, grain structures are not well defined as the results of computational errors and numerical incon- sistencies on mathematical methods. Due to the finite definition of numbers or the numerical restrictions during the simulation of solidifica- tion, damaged images appear on the screen. These images must be repaired to obtain a good measurement of grain geometrical properties. Some mathematical algorithms were developed to repair, measure, and characterize grain structures obtained from cellular automata in the present work. An appropriate measurement of grain size and the corrected identification of interfaces and length are very important topics in materials science because they are the representation and validation of mathematical models with real samples. As a result, the developed al- gorithms are tested and proved to be appropriate and efficient to eliminate the errors and characterize the grain structures.

关键词： grain size and shape image restoration mathematical algorithms cellular automata solidification

Bayesian regularized quantile regression:A robust alternative for genome-based prediction of skewed data

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The Crop Journal 2020年第5期8卷 713-722页

作者： Paulino Pérez-rodríguez Osval A.Montesinos-lópez Abelardo Montesinos-lópez JoséCross Colegio de Postgraduados MontecillosEdo.de México 56230Mexico Facultad de Telemática Universidad de ColimaColima 28040Mexico Departamento de Matemáticas Centro Universitario de Ciencias Exactas e Ingenierías(CUCEI)Universidad de GuadalajaraGuadalajaraJalisco 44430Mexico International Maize and Wheat Improvement Center(CIMMYT) Km 45 Carretera México-VeracruzTexcocoEdo.de México 56237Mexico

Genomic prediction(GP)has become a valuable tool for predicting the performance of selection candidates for the next breeding cycle.A vast majority of statistical linear models on which GP is based rely on the assumption of normality of the residuals and therefore on the response variable *** this study,we propose to use Bayesian regularized quantile regression(BrQr)in the context of GP;the model has been successfully used in other research *** evaluated the prediction ability of the proposed model and compared it with the Bayesian ridge regression(Brr;equivalent to genomic best linear unbiased predictor,GBlUP).In addition,BlUP can be used with pedigree information obtained from the coefficient of coancestry(ABlUP).We have found that the prediction ability of BrQr is comparable to that of Brr and,in some cases,better;it also has the potential to efficiently deal with outliers.A program written in the r statistical package is available as Supplementary material.

关键词： laplace distribution robust regression Bayesian quantile regression Genomic-enabled prediction

Synchronization of robot Manipulators Actuated By Induction Motors with velocity Estimator

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Computer Modeling in Engineering & Sciences 2019年第11期121卷 609-630页

作者： Felipe J.Torres Gerardo v.Guerrero Carlos D.García ricardo Zavala-Yoe Mario A.García Adolfo r.lópez University of Guanajuato Division of Engineering Campus Irapuato-SalamancaCarretera Salamanca-Valle de Santiago km 3.5+1.8GuanajuatoSalamanca36885México National Technological of Mexico/National Center of research and Technological Development Av.Palmira S/N colonia PalmiraMorelosCuernavaca62490México School of Engineering and Sciences Monterrey TechnologicalPuente 222 Ejidos de HuipulcoCiudad de México14380México Superior Technological Institute of Irapuato Carretera Irapuato-Silao km 12.5GuanajuatoIrapuato36821México

A complete modeling(including the actuator dynamics)of a robot manipulator that uses three-phase induction motors is presented in this paper.A control scheme is designed to synchronize robot manipulators actuated by induction motors under a masterslave scheme in the case where the joint velocity of the slave robots is *** of the research on the synchronization of robot manipulators assumes the use of ideal actuators to drive the joints;for that reason,in this work,a three-phase induction motor is considered to be a direct-drive actuator for each *** entire model of the mated system is obtained by a combination of the dynamics of the induction motor and robot ***,the synchronization control algorithm for a master-slave scheme in both the joint space and workspace of robot manipulators driven by induction motors is *** observer based on the entire model is proposed to estimate the joint velocity of the slave robot *** the lyapunov criterion,a stability analysis of the synchronization control with a velocity estimator is *** analytical results show the synchronization and estimation errors are globally,uniformly,and ultimately *** with multiple robots demonstrate the performance of the proposed control algorithm.

关键词： Synchronization robot manipulator induction motor lyapunov stability observer based on the model

p21 is necessary for the beneficial effects of fasting during chemotherapy

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Cancer Communications 2023年第1期43卷 164-168页

作者： Adrián Plaza Andrés Pastor-Fernández Josél.lópez-Aceituno Marta Barradas Cristina Pantoja Pablo J.Fernandez-Marcos Metabolic Syndrome Group(BIOPrOMET) Madrid Institute for Advanced Studies(IMDEA)FoodCEI UAM+CSICMadrid E28049Spain

Dear Editor,Short-term fasting(up to 48 hours)activates strong physiological and molecular responses[1].We and others showed a p53-independent transcriptional activation of the cell cycle inhibitor p21 upon fasting,most strongly in the liver,muscles,and many other tissues[2,3].Studies with mice[4,5]and human patients[6]have shown the beneficial effects of short-term fasting during anti-cancer chemotherapy treatments.

关键词： fasting chemotherapy p21

Influence of ZnO nanoparticles on the microstructure of a CoCrFeMoNi matrix via powder metallurgy

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International Journal of Minerals,Metallurgy and Materials 2019年第11期26卷 1467-1476页

作者： C.D.Gómez-Esparza A.Duarte-Moller C.lópez-Díaz de león r.Martínez-Sánchez J.F.Hernández-Paz C.A.rodríguez-González centro de investigación en materiales avanzados(cimav) laboratorio nacional de nanotecnologíamiguel de cervantes no.120chihuahua 31136chi8.mexico facultad de ingeniería civil mecánica e industrialuniversidad de la salle bajíoav.universidad 602león 37150gto.mexico instituto de ingeniería y tecnología universidad autónoma de ciudad juárez(uacj)av.del charro 450 nortec4.juárez 32310chi8.mexico

In the last decade,extensive research has been carried out on the microstructural behavior of high-entropy alloys(HEA),for which the in-situ formation of nanoparticles has been ***,studies of the incorporation of nanoparticles in HEA have been rarely *** this work,the addition of zinc oxide nanoparticles(ZnO NP)as reinforcement in a CoCrFeMoNi high-entropy alloy matrix,as well as the morphological,structural,and microstructural evolution of composites synthesized via powder metallurgy,were *** electron microscopy and X-ray diffraction analysis were performed in order to study the microstructural and phase characterization of the *** sintering,it was found that the ZnO NP addition(0.5 wt%,1 wt%and 2 wt%)had a significant influence on the microstructure and hardness of the CoCrFeMoNi high-entropy *** bonding among metal particles was promoted with the additions of Zn O NP.A reduction in porosity as a function of ZnO NP content was also *** microhardness results showed that the composite reached its highest reinforcement in bulk samples with 1 wt%ZnO NP(Hv 870),which represented a 20%improvement over the unreinforced HEA matrix.

关键词： high-entropy alloy mechanical alloying nanoparticles composites

Multi-temporal NDvI analysis using UAv images of tree crowns in a northern Mexican pine-oak forest

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林业研究:英文版 2023年第6期34卷 1855-1867页

作者： Joséluis Gallardo-Salazar Marcela rosas-Chavoya Marín Pompa-García Pablito Marcelo lópez-Serrano Emily García-Montiel Arnulfo Meléndez-Soto Sergio Iván Jiménez-Jiménez Instituto de Investigaciones Agropecuarias y Forestales Universidad Michoacana de San Nicolás de Hidalgo(UMSNH)58330 MoreliaMichoacánMexico Programa Institucional de Doctorado en Ciencias Agropecuarias y Forestales Universidad Juárez del Estado de DurangoRío Papaloapan y Blvd.DurangoValle del Sur s/n34120 DurangoDurangoMéxico Facultad de Ciencias Forestales Universidad Juárez del Estado de DurangoRío Papaloapan y Blvd.DurangoValle del Sur s/n34120 DurangoDurangoMéxico Instituto de Silvicultura e Industria de la Madera Universidad Juárez del Estado de DurangoBoulevard del Guadiana 501Ciudad UniversitariaTorre de Investigación34120 DurangoMéxico INIFAP-CENID rASPA Centro Nacional de Investigación Disciplinaria en relación Agua-Suelo-Planta-Atmósfera Margen derecha canal Sacramento km 6.5Zona industrial35140 Gómez PalacioDurangoMexico

The use of unmanned aerial vehicles(UAv)for forest monitoring has grown significantly in recent years,providing information with high spatial resolution and temporal *** with multispectral sensors allow the use of indexes such as the normalized difference vegetation index(NDvI),which determines the vigor,physiological stress and photo synthetic activity of *** study aimed to analyze the spectral responses and variations of NDvI in tree crowns,as well as their correlation with climatic factors over the course of one *** study area encompassed a 1.6-ha site in Durango,Mexico,where Pinus cembroides,Pinus engelmannii,and Quercus grisea *** images were acquired with UAv and information on meteorological variables was obtained from NASA/POWEr *** ANOvA explored possible differences in NDvI among the three *** correlation was performed to identify the linear relationship between NDvI and meteorological *** differences in NDvI values were found at the genus level(Pinus and Quercus),possibly related to the physiological features of the species and their *** grisea had the lowest NDvI values throughout the year which may be attributed to its sensitivity to relative humidity and *** the use of UAv with a multispectral sensor for NDvI monitoring allowed genera differentiation,in more complex forest analyses hyperspectral and liDAr sensors should be integrated,as well other vegetation indexes be considered.

关键词： Multispectral images Normalized diff erence vegetation index Phenology Unmanned aerial vehicles Multitemporal analysis

Machine perfusion and the prevention of ischemic type biliary lesions following liver transplant:What is the evidence?

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World Journal of Gastroenterology 2023年第20期29卷 3066-3083页

作者： Manuel Durán rafael Calleja Angus Hann George Clarke ruben Ciria Anisa Nutu rebeca Sanabria-Mateos María Dolores Ayllón Pedro lópez-Cillero Hynek Mergental Javier Briceño M Thamara P r Perera Department of liver Transplantation Reina Sofía University HospitalCórdoba 14004Spain The liver Unit Queen Elizabeth Hospital BirminghamBirmingham B152THUnited Kingdom Centre for liver and Gastrointestinal research Institute of Immunology and ImmunotherapyUniversity of BirminghamBirmingham B152THUnited Kingdom

The widespread uptake of different machine perfusion(MP)strategies for liver transplant has been driven by an effort to minimize graft *** to the cholangiocytes during the liver donation,preservation,or early posttransplant period may result in stricturing of the biliary tree and inadequate biliary *** problem continues to trouble clinicians,and may have catastrophic consequences for the graft and *** injury,as a result of compromised hepatic artery flow,is a well-known cause of biliary strictures,sepsis,and graft ***,very similar lesions can appear with a patent hepatic artery and these are known as ischemic type biliary lesions(ITBl)that are attributed to microcirculatory dysfunction rather than main hepatic arterial *** the warm and cold ischemic period duration appear to influence the onset of *** of the commonly used MP techniques deliver oxygen to the graft cells,and therefore may minimize the cholangiocyte injury and subsequently reduce the incidence of *** clinical experience and published evidence grows for these modalities,the impact they have on ITBl rates is important to *** this review,the evidence for the three commonly used MP strategies(abdominal normothermic regional perfusion[A-NrP],hypothermic oxygenated perfusion[HOPE],and normothermic machine perfusion[NMP])for ITBl prevention has been critically *** with ITBl definitions used in trials,coupled with variations in techniques of MP,make interpretation ***,the evidence suggests that both HOPE and A-NrP prevent ITBl in donated after circulatory death grafts compared to cold *** evidence for ITBl prevention in donor after brain death grafts with any MP technique is weak.

关键词： liver transplant Ischemic type biliary lesions Hypothermic oxygenated machine perfusion Normothermic machine perfusion Abdominal normothermic regional perfusion Donation after circulatory death

Conservation Tillage Influence on Carbon Dynamics Under Mediterranean Conditions

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Pedosphere 2014年第1期24卷 65-75页

作者： r.lópez-GArrIDO E.MADEJON F.MOrENO J.M.MUrIllO Instituto de recursos Naturales y Agrobiologia de Sevilla(IrNAS-CSIC)

Intensity of tillage practices can enhance organic matter decomposition,increasing CO_2 emissions from soil to the *** tillage(CT)has been proposed as a means of counteracting potential damages to the *** this study the effects of two CT systems,reduced tillage in a long-term experiment(rT_l)and no-tillage in a short-term experiment(NTs),were compared to traditional tillage(TT)in the long(TT_l)and short-term experiments(TTs).CO_2 fluxes,total soil organic carbon(SOC)and dehydrogenase activity(DHA)were evaluated at 0-5,5-10 and 10-15 cm depths throughout the three years studied(Oct.2006-Jul.2009).Traditional tillage increased CO_2 emissions compared to *** CT treatments(rTl and NTs)accumulated more SOC in the surface layer(0-5 cm)than the TT treatments(TT_l and TT_S).SOC accumulation was moderate but DHA consistently increased in CT in the surface soil,especially with a legume crop included in the crop *** of stratification ratio of all parameters studied were higher in the CT treatments(rTl and NTs).The agricultural and environmental benefits derived from CT make this system recommendable for semi-arid Mediterranean rain-fed agriculture.

关键词：保护性耕作地中海碳动态土壤有机碳 CT系统二氧化碳传统耕作雨养农业