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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 héctor 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

Myelin histology:a key tool in nervous system research

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Neural Regeneration Research 2024年第2期19卷 277-281页

作者： Óscar Darío García-García Víctor Carriel jesús Chato-Astrain Department of histology Tissue Engineering GroupUniversity of Granada&Instituto de Investigación Biosanitaria ibs.GRANADAGranadaSpain

The myelin sheath is a lipoprotein-rich,multilayered structure capable of increasing conduction velocity in central and peripheral myelinated nerve *** to the complex structure and composition of myelin,various histological techniques have been developed over the centuries to evaluate myelin under normal,pathological or experimental ***,methods to assess myelin integrity or content are key tools in both clinical diagnosis and neuroscience *** this review,we provide an updated summary of the composition and structure of the myelin sheath and discuss some histological procedures,from tissue fixation and processing techniques to the most used and practical myelin histological staining *** the lipoprotein nature of myelin,the main features and technical details of the different available methods that can be used to evaluate the lipid or protein components of myelin are described,as well as the precise ultrastructural techniques.

关键词： fluorescence microscopy histology light microscopy lipid histochemistry metallographic techniques myelin histochemistry myelin immunohistochemistry myelin structure&composition myelin ultrastructural evaluation tissue fixation&processing

hepatogenous diabetes: Is it a neglected condition in chronic liver disease?

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World Journal of Gastroenterology 2016年第10期22卷 2869-2874页

作者： Diego García-Compeán José Alberto González-González Fernando Javier Lavalle-González Emmanuel Irineo González-Moreno jesús Zacarías Villarreal-Pérez héctor jesús maldonado-garza Gastroenterology service and Department of Internal Medicine University Hospital "Dr. José E. González" and Medical SchoolUniversidad Autónoma de Nuevo León Endocrinology service and Department of Internal Medicine University Hospital "Dr. José E. González" and Medical SchoolUniversidad Autónoma de Nuevo León

Diabetes mellitus(DM) that occurs because of chronic liver disease(CLD) is known as hepatogenous diabetes(hD). Although the association of diabetes and liver cirrhosis was described forty years ago, it was scarcely studied for long time. Patients suffering from this condition have low frequency of risk factors of type 2 DM. Its incidence is higher in CLD of viral, alcoholic and cryptogenic etiology. Its pathophysiology relates to liver damage, pancreatic dysfunction, interactions between hepatitis C virus(hCV) and glucose metabolism mechanisms and genetic susceptibility. It associates with increased rate of liver complications and hepatocellular carcinoma, and decreased 5-year survival rate. It reduces sustained virological response in hCV infected patients. In spite of these evidences, the American Diabetes Association does not recognize hD. In addition, the impact of glucose control on clinical outcomes of patients has not been evaluated. Treatment of diabetes may be difficult due to liver insufficiency and hepatotoxicity of antidiabetic drugs. Notwithstanding, no therapeutic guidelines have been implemented up to date. In this editorial, authors discuss the reasons why they think that hD may be a neglected pathological condition and call attention to the necessity for more clinical research on different fields of this disease.

关键词： hepatogenous diabetes Diabetes mellitus Outcomes Therapy hepatitis C virus Chronic liver disease

Processes involving soil CO_(2)dynamic in a sector of Chaco-Pampean plain,Argentina:An isotope geochemical approach

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Acta Geochimica 2024年第5期43卷 947-958页

作者： sanci Romina Panarello héctor Instituto de Geociencias Básicas Aplicadas y Ambientales de Buenos Aires(IGEBA)Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresCABAIntendente Güiraldes 2160Pabellón IIPiso 1C1428EGA Ciudad UniversitariaArgentina Instituto de Geocronología y Geología Isotópica(INGEIs) Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos AiresCABAIntendente Güiraldes 2160Pabellón INGEISC1428EGA Ciudad UniversitariaArgentina

The magnitude and spatial variability of CO_(2)surface emissions and processes involving CO_(2)released to the atmosphere from the soils are relevant issues in the context of climate *** work evaluated CO_(2)fluxes and^(13)C/^(12)C ratio of vegetation,organic matter,and soil gases from no disturbed soils of Chaco Pampean Plain(Argentina)with different soil properties and environmental conditions(PL and PA units).soil organic decomposition from individual layers was accompanied byδ^(13)C of total organic carbon(δ^(13)C-TOC)values more enriched to depth.δ^(13)C-TOC values in the upper soil profile~ca.0–15 cm were like the plant community of this area(~−33 to−29‰)whileδ^(13)CTOC varied stronger bellow horizon A,till~−24‰.Bothδ^(13)C-TOC and soilδ^(13)C-CO_(2)were similar(~−24 to 26‰)at deeper horizons(~50–60 cm).Toward the superficial layers,δ^(13)C-TOC andδ^(13)C-CO_(2)showed more differences(till~4‰),due influence of the diffusion *** A layer(~0–20 cm)from both PL and PA units contained the most enrichedδ^(13)C-CO_(2)values(~−15–17‰)because atmospheric CO_(2)permeated the soil air.A simple two-component mixing model between sources(atmosphericδ^(13)C-CO_(2)and soil CO_(2))confirmed that ***,CO_(2)fluxes reflected the biodegradation of C3 plants(source),diffusive transport,and CO_(2)exchange(atmosphere/soil).soil moisture content appeared as a determining factor in the diffusion process and the magnitude of CO_(2)surface emissions(12–60 g·m^(−2)·d^(−1)).That condition was confirmed by CO_(2)diffusion coefficients estimated by air-filled porosity parameters and soil radon gradient model.

关键词： soil CO_(2) Carbon isotopes Isotope fractionation Radon gases

Morphometric Attributes of Two Native Forage species According to Water source Distance in semiarid Central Grasslands of Argentina

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Phyton-International Journal of Experimental Botany 2024年第8期93卷 2063-2074页

作者： Carla Etel suárez María sol Rossini Ernesto Francisco Atilio Morici héctor Daniel Esterlich Laboratorio de Ecología en Ambientes semiáridos Ecología VegetalFacultad de AgronomíaUNLPamSanta Rosa6300Argentina Facultad de Ciencias Veterinarias UNLPamGeneral Pico6360Argentina Becaria Doctoral CONICET APNFacultad de AgronomíaUNLPamSanta Rosa6300Argentina

The semiarid grasslands of Argentina’s central region have been modified by domestic livestock grazing,both in their composition and *** increase in the proportion of woody and non-forage species and the decrease in forage species are some of the most evident results of this *** is limited available information about the effect of differential grazing pressures on morphometric attributes of native species,and it also depends on the life histories of the species in this *** objective of this work was to evaluate some morphometric aspects in the grasses Poa ligularis Nees ex steud and Piptochaetium napostaense(speg.).hack according to distance from the water source in communities in the central semiarid region of *** study area included areas of low grassland,golden forests,and secondary forests in grasslands(6 fields with 9 paddocks).Grazing pressure was established based on the distance to the water source,so sampling areas were designated near the water source(grazing pressure is greater)and far from the water source(grazing pressure light)in each of the *** both species,specimens were selected at random,and the following attributes were measured:crown diameter at ground level(cm),burial depth(cm),average tiller weight per plant(***^(−1)),and the density of tillers per unit of crown surface(***^(−2)crown).The morphometric attributes evaluated showed differences according to the distance to the watering hole and in the different *** species presented similar behaviors for the *** were significant differences in the depth of burial and the average weight of tillers per plant,being greater in the areas close to the water *** the distance to the watering hole,there were no significant differences in crown diameter and tiller density,but the highest values were recorded for the former near the watering hole and for the second far from the watering *** pastures with low

关键词： Grazing pressure tiller density tiller weight crown burial depth Poa ligularis Piptochaetium napostaense

Biomaterial engineering strategies for modeling the Bruch's membrane in age-related macular degeneration

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Neural Regeneration Research 2024年第12期19卷 2626-2636页

作者： Blanca Molins Andrea Rodríguez Víctor Llorenç Alfredo Adán Group of Ocular Inflammation:Clinical and Experimental studies Institut d’Investigacions Biomèdiques AgustíPi I Sunyer(IDIBAPS)BarcelonaSpain Institut Clínic d’Oftalmologia(ICOF) Hospital Clínic BarcelonaSpain

Age-related macular degeneration,a multifactorial inflammatory degenerative retinal disease,ranks as the leading cause of blindness in the ***,there is a scarcity of curative therapies,especially for the atrophic advanced form of age-related macular degeneration,likely due to the lack of models able to fully recapitulate the native structure of the outer blood retinal barrier,the prime to rget tissue of age-related macular *** in vitro systems rely on 2D monocultures unable to adequately reproduce the structure and function of the outer blood retinal barrier,integrated by the dynamic interaction of the retinal pigment epithelium,the Bruch's membrane,and the underlying *** Bruch's membrane provides structu ral and mechanical support and regulates the molecular trafficking in the outer blood retinal barrier,and therefo re adequate Bruch's membrane-mimics are key for the development of physiologically relevant models of the outer blood retinal barrie *** the last years,advances in the field of biomaterial engineering have provided novel approaches to mimic the Bruch's membrane from a variety of *** review provides a discussion of the integrated properties and function of outer blood retinal barrier components in healt hy and age-related macular degeneration status to understand the requirements to adequately fabricate Bruch's membrane biomimetic ***,we discuss novel materials and techniques to fabricate Bruch's membrane-like scaffolds for age-related macular degeneration in vitro modeling,discussing their advantages and challenges with a special focus on the potential of Bruch's membrane-like mimics based on decellularized tissue.

关键词： age-related macular degeneration Bruch's membrane decellularization retinal pigment epithelium scaffold

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 héctor 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

Freeze-thaw cycles and associated geomorphology in a post-glacial environment:current glacial,paraglacial,periglacial and proglacial scenarios at Pico de Orizaba volcano,Mexico

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Journal of Mountain science 2024年第6期21卷 1954-1977页

作者： Víctor sOTO Carlos M.WELsh R. Kenji YOshIKAWA hugo DELGADO GRANADOs Centro de Ciencias de la Tierra Universidad VeracruzanaCircuito Gonzalo Aguirre BeltránS/NZona Universitaria91090XalapaMéxico Water and Environmental Research Center University of Alaska FairbanksFairbanksAlaska 99775USA Instituto de Geofísica Universidad Nacional Autónoma de MéxicoCiudad de México 04150México Department of Earth and Environmental sciences Ludwig Maximilians UniversitätMunich 80333Germany

The glacial history of Pico de Orizaba indicates that during the Last Glacial Maximum,its icecap covered up to~3000 m asl;due to the air temperature increasing,its main glacier has retreated to 5050 m *** retraction of the glacier has left behind an intense climatic instability that causes a high frequency of freeze-thaw cycles of great intensity;the resulting geomorphological processes are represented by the fragmentation of the bedrock that occupies the upper parts of the *** is a notable lack of studies regarding the fragmentation and erosion occurring in tropical high mountains,and the associated geomorphological risks;for this reason,as a first stage of future continuous research,this study analyzes the freezing and thawing cycles that occur above 4000 m asl,through continuous monitoring of surface ground *** results allow us to identify and characterize four zones:glacial,paraglacial,periglacial and *** was found that the paraglacial zone presents an intense drop of temperature,of up to~9℃ in only sixty *** rock fatigue and intense freeze-thaw cycles that occur in this area are responsible for the high rate of rock disintegration and represent the main factor of the constant slope dynamics that occur at the *** activity decreases,both in frequency and intensity,according to the distance to the glacier,which is where the temperature presents a certain degree of stability,until reaching the proglacial zone,where cycles are almost non-existent,and therefore there is no gelifraction *** geomorphological processes have resulted in significant alterations to the mountain slopes,which can have severe consequences in terms of risk and water.

关键词： Freeze-Thaw Gelifraction Mountain mechanical erosion Periglacial geomorphology Postglacial scenarios

Impacts of brood parasitism by shiny cowbird Molothrus bonariensis on the breeding success of a small host, the black-backed water tyrant Fluvicola albiventer

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Current Zoology 2024年第4期70卷 539-547页

作者： Lorena Vanesa sovrano Evelina jesica Leon Rodrigo Ezequiel Lorenzón Pamela Fernanda Olguin Adolfo héctor Beltzer Alejandro Raúl Giraudo Laboratorio de Biodiversidad y Conservacion de Tetrapodos Instituto Nacional de Limnologia(INALICONICET-UNL)Paraje El Pozo s/nSanta Fe(3000)Argentina Departamento de Biologia Universidad Autonoma de Entre RiosKm 10.5 RP 11Oro Verde(3100)Entre RiosArgentina Departamento de Biologia Universidad Nacional del LitoralFacultad de Humanidades y CienciasParaje Ei Pozo s/nSanta Fe(3000)Argentina

The shiny cowbird Molothrus bonariensis parasitizes many species with different life-history traits and has a detrimental effect on the survival of the progeny of the *** response,hosts have developed numerous antiparasitic ***,we examined the effects of brood parasitism by shiny cowbird on the clutch and brood sizes(83 nests)in a small host,the black-backed water tyrant Fluvicola *** also studied whether the death of parasite nestlings was related to the care of the foster parents and whether the host had any antiparasitic defense against the shiny *** results indicate that brood parasitism significantly decreased the host hatching and fledging *** majority of nest failures(57%)were caused by brood *** cowbird parasitism occurred in 52%of nests and the intensity of parasitism was 1.23±0.53 eggs per parasitized *** the total host eggs,54%were *** the incubation stage,20 nests(47%)were abandoned because of egg punctures by shiny cowbirds *** two parasitic fledglings were recorded,while the remaining nestlings either died from starvation(n=12)or predation(n=3).Foster parents abandoned parasitic nestlings between 5 and 10 days *** findings demonstrate that the shiny cowbird has very low rates of fledging success when parasitizing black-backed water ***,parasitism had a high reproductive cost in the black-backed water tyrant because a very low proportion(7%)of the parasitized nests(n=43)were successful.

关键词： brood parasitism host defenses nest desertion shiny cowbird small host.