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Kinetic study of austenite formation during continuous heating of unalloyed ductile iron

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International Journal of Minerals,Metallurgy and Materials 2015年第1期22卷 27-31页

作者： Octvio Vazquez-Gómez jos. Antonio Barrera-Godínez h.ctor Javier Vergara-hernndez Faculty of Chemistry Metallurgical Engineering DepartmentAutonomous National University of Mexico Metallurgy Science Postgraduate Programme Morelia Institute of Technology

The austenite formation kinetics in unalloyed cast ductile iron was studied on the basis of dilatometry measurements, and Avrami＇s equation was used to estimate the material＇s kinetic parameters. A continuous heating transformation diagram was constructed us-ing heating rates in the range of 0.06 to 0.83℃·s^-1. As the heating rate was augmented, the critical temperatures, c1A and Aα, as well as the intercritical range, which was evaluated as the difference between the critical temperatures, α c1Δ T =A_a- A_c1 , increased. At a low heating rate, the kinetics of austenite formation was slow as a consequence of the iron＇s silicon content. The effect of heating rate on k and n, the kinetic parameters of Avrami＇s equation, was also determined. Parameter n, which is associated with nucleation sites and growth geometry, de-creased with an increase in heating rate. In addition, parameter k increased with the increase of heating rate, suggesting that the nucleation and growth rates are carbon-and silicon-diffusion controlled during austenite formation under continuous heating.

关键词： ductile iron austenite continuous heating heating rate kinetics dilatometry

Segmental Pigmentation Disorder with Congenital heterochromia Iridis

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Open Journal of Pediatrics 2015年第3期5卷 213-217页

作者： Carmen Madrigal Díez Sara Rodríguez Prado jos. h.ctor fernández llaca Primary Paediatric health Care Centro de Salud Bezana Servicio Cántabro de Salud Spain Department of Opthalmology Hospital de Sierrallana Torrelavega Cantabria Spain Department of Dermatology Hospital Universitario Marqués de Valdecilla Santander Cantabria Spain

We report the case of a 10-year-old girl with congenital complete heterochromia iridis and segmental pigmentation disorder in its hyperpigmented form. We have found no publication that mentions the combination of thes... 详细信息

关键词： Congenital heterochromia Iridis Segmental Pigmentation Disorder Café-au-Lait Macules

Getting started in mapping-by-sequencing

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Journal of Integrative Plant Biology 2015年第7期57卷 606-612页

作者： h.ctor Candela Rubén Casanova-Sáez jos. Luis Micol Instituto de Bioingeniería Universidad Miguel Hernández Department of Forest Genetics and Plant Physiology Umea Plant Science CenterSwedish University of Agricultural Sciences

Next-generation sequencing （NGS） technologies allow the cost-effective sequencing of whole genomes and have expanded the scope of genomics to novel applications, such as the genome-wide characterization of intraspecific polymorphisms and the rapid mapping and identification of point mutations. Next-generation sequencing platforms, such as the Illumina hiSeq2ooo platform, are now commercially available at affordable prices and routinely produce an enormous amount of sequence data, but their wide use is often hindered by a lack of knowledge on how to manipulateand process the information produced. In this review, we focus on the strategies that are available to geneticists who wish to incorporate these novel approaches into their research but who are not familiar with the necessary bioinformatic concepts and computational tools. In particular, we comprehensively summarize case studies where the use of NGS technologies has led to the identification of point mutations, a strategy that has been dubbed ＂mapping-by-sequencing＇, and review examples from plants and other model species such as Caenorhabditis elegans, Saccharomyces cerevisiae, and Drosophila mela- nogaster. As these technologies are becoming cheaper and more powerful, their use is also expanding to allow mutation identification in species with larger genomes, such as many crop plants.

关键词： Mapping-by-sequencing massively parallel sequencing mutation identification ShOREmapping whole-genome re-sequencing

Geochemistry and mineralogy of beach sediments in the northern Gulf of Mexico,Tamaulipas state,Mexico:implication for provenance

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Journal of Palaeogeography 2024年第3期13卷 375-400页

作者： Mayank Shukla Sanjeet K.Verma Mayla A.Ramos-Vázquez John S.Armstrong-Altrin Karla R.hernández-Martínez Sumit Mishra Vivek P.Malviya h.ctor hernández-Mendoza Posgrado de la Division de Geociencias Aplicadas Instituto Potosino de Investigacion Científica y Tecnologica(IPICYT)Camino a la Presa San José2055San Luis Potosí78216Mexico Division de Geociencias Aplicadas Instituto Potosino de Investigación Científica y Tecnologica(IPICYT)Camino a la Presa San Jose 2055San Luis Potosí78216Mexico Universidad Nacional Autonoma de México Instituto de Ciencias del Mar y LimnologíaUnidad de ProcesosOceanicos y CosterosCiudad UniversitariaCiudad de México 04510Mexico Department of Marine Sciences Bharathidasan UniversityTiruchirappalli620024Tamil NaduIndia Instituto de Geociencias Universidad Nacional Autonoma de MéxicoBoulevard Juriquilla 300176230JuriquillaQueretaroMexico Department of Applied Geology Dr.Harisingh Gour Central UniversitySagar470002Madhya PradeshIndia Instituto de Investigacion de Zonas Desérticas Universidad Autònoma de San Luis PotosíAltair 200CP 78377San LuisS.L.P.Mexico Universidad del Centro de Mexico Capitán Caldera 75CP 78250San LuisS.L.P.Mexico

Geochemical and mineralogical studies were performed in the La Pesca(LP)and Tesoro Altamira(TA)beach sediments,located in the Tamaulipas state,northern Gulf of *** main aim of this study is to infer the weathering history and provenance and to discriminate the tectonic environment of the beach *** sediments are composed of quartz with small amounts of accessory minerals such as plagioclase,calcite,orthoclase,microcline,and *** beach sediments are classified as fine-grained and very well sorted,however LP has coarse skewed and leptokurtic sediments,whereas TA has fine-skewed and very leptokurtic *** chemical index of weathering(CIW’)indicates intense weathering in the source *** quartz grain microtextures in the LP and TA are classified into mechanical,chemical,and mechanical/chemical *** features such as fractures,pits,percussion marks,abrasion fatigue,and V-shaped marks favor high-energy littoral,fluvial,subaqueous-marine,and aeolian *** chemical features indicate solution pits and crystalline overgrowth,which suggests a silica saturated marine *** mechanical/chemical features display adhering particles and elongated depressions suggest formation in a sub-aqueous nearshore marine *** and trace elements-based provenance discrimination diagrams indicate a felsic source derived from the Mesa Central(MC),Sierra Madre Oriental(SMOr)and Oaxaquia *** major and trace element concentrations imply a passive margin setting for the northern Gulf of Mexico,which is consistent with the general geology.

关键词： Beach sediments Geochemistry Mineralogy Provenance Tamaulipas Tectonic setting

Isotropic compression behavior of granular assembly with non-spherical particles by X-ray micro-computed tomography and discrete element modeling

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 972-984页

作者： Nan Zhang Ahmadreza hedayat Shaoyang han Runlin Yang h.ctor Gelber Bolaños Sosa Juan jos.González Cárdenas Guido Edgard SalasÁlvarez Department of Civil and Environmental Engineering Colorado School of Mines1500 Illinois St.GoldenCO80401USA Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China Universidad Nacional de San Agustín de Arequipa ArequipaPeru

The particle morphological properties,such as sphericity,concavity and convexity,of a granular assembly significantly affect its macroscopic and microscopic compressive behaviors under isotropic loading ***,limited studies on investigating the microscopic behavior of the granular assembly with real particle shapes under isotropic compression were *** this study,X-ray computed tomography(mCT)and discrete element modeling(DEM)were utilized to investigate isotropic compression behavior of the granular assembly with regard to the particle morphological properties,such as particle sphericity,concavity and interparticle *** mCT was first used to extract the particle morphological parameters and then the DEM was utilized to numerically investigate the influences of the particle morphological properties on the isotropic compression *** image reconstruction from mCT images indicated that the presented particle quantification algorithm was robust,and the presented microscopic analysis via the DEM simulation demonstrated that the particle surface concavity significantly affected the isotropic compression *** observations of the particle connectivity and local void ratio distribution also provided insights into the granular assembly under isotropic *** found that the particle concavity and interparticle friction influenced the most of the isotropic compression behavior of the granular assemblies.

关键词： X-ray computed tomography(mCT) Discrete element modeling(DEM) Isotropic compression Particle surface curvature Particle morphology

Prevalence of refractive errors in children of Puerto Rico

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International Journal of Ophthalmology(English edition) 2023年第3期16卷 434-441页

作者： h.ctor C.Santiago Mayra Rullán Katerin Ortiz Andrés Rivera Mónica Nieves jos.Piña Zulmaris Torres Yvette Mercado Inter American University of Puerto Rico School of Optometry500 John Will HarrisBayamónPuerto Rico 00957USA

AIM:To determine the prevalence of refractive error in 5-to 17-year-old schoolchildren in Puerto ***:A quantitative descriptive study of 2867 children aged 5 to 17y from all seven educational regions of Puerto Rico was conducted from 2016–*** error was determined via static and subjective *** with distance acuity≤20/40 or near visual acuity≤20/32 had a cycloplegic *** analysis included descriptive statistics,correlation coefficient,Kruskal-Wallis,Chi-square,and t test ***:Twenty percent of the children had a spherical equivalent refractive error≤-0.50 D,3.2%had a spherical equivalent≥+2.00 D,and 10.4%had astigmatism≥1 *** was a statistically(but non-clinically)significant myopic change in spherical equivalent refractive error with age(Phe prevalence of myopia increased with age(Phyperopia(P=0.59)or astigmatism(P=0.51).Males had a significantly higher hyperopic spherical equivalent than females(Phad a higher prevalence of myopia(Phan males,but there was no difference in the hyperopia(P=0.74)or astigmatism prevalence(P=0.87).CONCLUSION:The prevalence of a spherical equivalent equal to or less than-0.50 D(myopia,20.7%)is one of the highest among similar-aged children *** studies should explore the rate of myopia progression in children in Puerto *** children must be monitored to examine the need for treatment of myopia progression.

关键词： children refractive error Puerto Rico myopia hyperopia

Neutral protamine hagedorn/regular insulin in the treatment of inpatient hyperglycemia: Comparison of 3 basal-bolus regimens

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World Journal of Diabetes 2017年第10期8卷 455-463页

作者： Dania Lizet Quintanilla-Flores jos.Gerardo González-González Guillermo García-De la Cruz h.ctor Eloy Tamez-Pérez Department of Internal Medicine 'Dr. José Eleuterio González' University HospitalUniversidad Autónoma de Nuevo León Endocrinology Service 'Dr. José Eleuterio González' University HospitalUniversidad Autónoma de Nuevo León School of Medicine Universidad Autónoma de Nuevo León Research Division School of MedicineUniversidad Autónoma de Nuevo León

AIM To compare the safety and efficacy or 3 basal-bolus regimens of neutral protamine hagedorn(NPh)/regular insulin in the management of inpatient *** We randomized 105 patients with blood glucose levelsbetween 140 and 400 mg/dL to a basal-bolus regimen of NPh insulin given once(n = 30), twice(n = 40) or three times(n = 35) daily, in addition to pre-meal regular insulin. Major outcomes included were differences in glycemic control, frequency of hypoglycemia and total insulin *** NPh insulin given in a once-daily regimen was associated with better glycemic control(58.3%) compared to twice daily(42.4%) and three times daily(48.9) regimens(P = 0.031). The frequency of hypoglycemia was similar between the three groups(2.0%, 0.7% and 1.2%, P = 0.21). The mean insulin dose at discharge was 0.48 ± 0.14 U/kg in the once-daily group compared to 0.69 ± 0.28 in the twice-daily, and 0.65 ± 0.20 in the three times daily regimens(P h insulin administered in a once-daily regimen resulted in improvement in glycemic control with similar rates of hypoglycemia compared to a twice-daily and a three times-daily regimen. Further studies are needed to evaluate whether this regimen could be implemented in all hospitalized patients with hyperglycemia.

关键词： Neutral protamine hagedorn insulin hospital hyperglycemia Basal-bolus regimen Type 2 diabetes mellitus Inpatient care units

Diagnostic and therapeutic challenges of gastrointestinal angiodysplasias: A critical review and view points

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World Journal of Gastroenterology 2019年第21期25卷 2549-2564页

作者： Diego García-Compeán ángel N Del Cueto-Aguilera Alan R Jiménez-Rodríguez jos. A González-González h.ctor J Maldonado-Garza Gastroenterology Service and Department of Internal Medicine Faculty of Medicine University Hospital "Dr. José E. González"Universidad Autónoma de Nuevo León

Gastrointestinal angiodysplasias (GIADs), also called angioectasias, are the most frequent vascular lesions. Its precise prevalence is unknown since most of them are asymptomatic. however, the incidence may be increasing since GIADs affect individuals aged more than 60 years and population life expectancy is globally increasing worldwide. They are responsible of about 5% to 10% of all gastrointestinal bleeding (GIB) cases. Most GIADs are placed in small bowel, where are the cause of 50 to 60% of obscure GIB diagnosed with video capsule endoscopy. They may be the cause of fatal severe bleeding episodes;nevertheless, recurrent overt or occult bleeding episodes requiring repeated expensive treatments and disturbing patient’s quality-of-life are more frequently observed. Diagnosis and treatment of GIADs (particularly those placed in small bowel) are a great challenge due to insidious disease behavior, inaccessibility to affected sites and limitations of available diagnostic procedures. hemorrhagic causality out of the actively bleeding lesions detected by diagnostic procedures may be difficult to establish. No treatment guidelines are currently available, so there is a high variability in the management of these patients. In this review, the epidemiology and pathophysiology of GIADs and the status in the diagnosis and treatment, with special emphasis on small bowel angiodysplasias based on multiple publications, are critically discussed. In addition, a classification of GIADs based on their endoscopic characteristics is proposed. Finally, some aspects that need to be clarified in future research studies are highlighted.

关键词： Angiodysplasias Angioectasias Vascular malformations Epidemiology Pathogenesis Endoscopic treatment Somatostatin analogues

Current knowledge on the laboratory diagnosis of Clostridium difficile infection

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World Journal of Gastroenterology 2017年第9期23卷 1552-1567页

作者： Adrián Martínez-Meléndez Adrián Camacho-Ortiz Rayo Morfin-Otero h.ctor Jesús Maldonado-Garza Licet Villarreal-Trevino Elvira Garza-González Departamento de Microbiología e Inmunología Facultad de Ciencias BiológicasUniversidad Autónoma de Nuevo León.Pedro de Alba S/NCiudad UniversitariaSan Nicolás de los Garza Servicio de Infectología Hospital Universitario“Dr.JoséEleuterio González”Universidad Autónoma de Nuevo León.Av.Francisco I.Madero Pte.S/NCol.Mitras Centro.Monterrey hospital Civil de Guadalajara “Fray Antonio Alcalde”e Instituto de Patología Infecciosa y ExperimentalCentro Universitario de Ciencias de la SaludUniversidadde Guadalajara.Sierra Mojada 950Col.Independencia Servicio de Gastroenterología Hospital Universitario“Dr.JoséEleuterio González”Universidad Autónoma de Nuevo León.Av.Francisco I.Madero Pte.S/NCol.Mitras Centro.Monterrey

Clostridium difficile (C. difficile) is a spore-forming, toxin-producing, gram-positive anaerobic bacterium that is the principal etiologic agent of antibiotic-associated diarrhea. Infection with C. difficile (CDI) is characterized by diarrhea in clinical syndromes that vary from selflimited to mild or severe. Since its initial recognition as the causative agent of pseudomembranous colitis, C. difficile has spread around the world. CDI is one of the most common healthcare-associated infections and a significant cause of morbidity and mortality among older adult hospitalized patients. Due to extensive antibiotic usage, the number of CDIs has increased. Diagnosis of CDI is often difficult and has a substantial impact on the management of patients with the disease, mainly with regards to antibiotic management. The diagnosis of CDI is primarily based on the clinical signs and symptoms and is only confirmed by laboratory testing. Despite the high burden of CDI and the increasing interest in the disease, episodes of CDI are often misdiagnosed. The reasons for misdiagnosis are the lack of clinical suspicion or the use of inappropriate tests. The proper diagnosis of CDI reduces transmission, prevents inadequate or unnecessary treatments, and assures best antibiotic treatment. We review the options for the laboratory diagnosis of CDI within the settings of the most accepted guidelines for CDI diagnosis, treatment, and prevention of CDI.

关键词： Clostridium difficile Toxigenic culture Nucleic acid amplification tests Enzyme immunoassay Diagnosis Glutamate dehydrogenase