80 research outputs found

    Antiwear performance of ionic liquid+graphene dispersions with anomalous viscosity-temperature behavior

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    New dispersions of few-layers graphene (G) in 1-ethyl-3-methylimidazolium ([EMIM]) ionic liquids (ILs) with dicyanamide ([DCA]) or bis(trifluoromethylsulfonyl)imide ([TFSI]) anions have been obtained by mechanical mixing and sonication. IL+0.5 wt% G dispersions show constant viscosity values from 357K (for IL = [EMIM][DCA]) or from 385K (for IL = [EMIM][TFSI]) to 393K. IL + G dispersions with G > 0.5 wt% show linear viscosity increases with increasing temperature, from 306K (for [EMIM][DCA]+1 wt%G) and from 330K to 393K (for [EMIM][TFSI]+0.75 wt%G and [EMIM][TFSI]+1 wt%G). Addition of graphene improves the poor wear reducing performance of [EMIM][DCA], and prevents surface damage on steel when added to [EMIM][TFSI]. Graphene increases the load-carrying ability of ILs, forms a surface layer on the sliding path and retains wear debris, preventing the formation of large abrasive particles.Ministerio de Economía, Industria y Competitividad (MINECO, Spain), EU FEDER Program (Grant # MAT2017-85130-P) Este trabajo es resultado de la actividad desarrollada en el marco del Programa de Ayudas a Grupos de Excelencia de la Región de Murcia, de la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia (Grant # 19877/GERM/15) M.D. Avilés ha recibido una beca del MINECO (BES-2015-074836)

    Molecular Chaperone HSPA2 Distribution During Hyaluronic Acid Selection in Human Sperm

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    During fertilization, sperm hyaluronidase activity is essential for spermatozoa to successfully penetrate the hyaluronic acid-enriched extracellular matrix of the cumulus cells. Since molecular chaperones, as the heat shock protein A2, are typically involved in bringing hyaluronic acid receptors to the cell surface, here we evaluated the presence and spatial location of HSPA2 on human spermatozoa based on its hyaluronic acid binding capacity. This study included 16 normozoospermic sperm samples from volunteering donors. The location of HSPA2 was studied in cells before and after 1-h incubation under capacitating conditions, as well as in spermatozoa selected according to their ability of binding to hyaluronic acid. Our results showed no significant differences in HSPA2 immunofluorescent cells before and after 1 h of incubation in capacitating conditions. Nevertheless, after hyaluronic acid selection, the percentage of HSPA2-labelled cells increased significantly, indicating that the interaction with hyaluronic acid may induce the unmasking of HSPA2 epitopes. Furthermore, after swim-up and hyaluronic acid selection, spermatozoa presented a highly immunostained equatorial band with a homogeneous fluorescence throughout the acrosomal region. This distribution has been previously suggested to have important implications in male fertility. Noteworthy, a homogeneous fluorescence among the acrosomal region with a more intense labelling at the apical region was observed only in hyaluronic acid bound sperm cells, which may be associated with primary gamete recognition. Our findings suggest that the hyaluronic acid selection technique and HSPA2 biomarker should be considered candidates to complement the classic seminal analysis before recommending an appropriate assisted reproduction technique.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the Human Fertility Cathedra of the University of Alicante and R&D&I projects financed by competitive public entities (ViGrob-186, UAIND17-03, PGC2018-094781-B-100)

    Controlador de Tráfico Inteligente con Prelación para Vehículos de Emergencia

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    This paper describes the development of a traffic controller using fuzzy logic, combined with the analysis of video sequences through machine vision techniques. The controller is able to automatically manage the traffic flow in a set of intersections, giving priority to the traffic lights of roads where there are emergency vehicles waiting. The system uses a classification algorithm, which is trained in order to detect any vehicle the scene and an image processing algorithm that identifies emergency vehicles within the previously detected vehicles. Using the information of video sequences acquired with CCD cameras installed on the intersections, the system choose the sequence of actions that improves the traffic flow, so as to increase the mobility in the road where the emergency vehicle is detected. Results show that the system is able to detect vehicles in real time. Also, the system adapts in an efficient and fast way to the changes in traffic flow in order to establish a priority road for emergency vehicles.Este artículo presenta el desarrollo de un controlador de tráfico por lógica difusa, el cual mediante el análisis de secuencias de video y por medio de técnicas de procesamiento de imagen, es capaz de distinguir y gestionar de manera autónoma y centralizada el flujo vehicular en un grupo de intersecciones a fin de dar prelación en la vía a vehículos de emergencias. El sistema emplea un algoritmo de clasificación entrenado para detectar los vehículos presentes en una escena y un algoritmo de procesamiento de imagen que permite identificar si alguno de ellos corresponde o no, a un vehículo de emergencia. Usando la información proveniente de las secuencias de video adquiridas mediante cámaras CCD ubicadas en las intersecciones, el sistema selecciona la secuencia de acciones que prioricen el flujo vehicular dentro de la zona de control, y que permitan descongestionar las posibles vías de desplazamiento del vehículo de emergencia. Los resultados obtenidos muestran que el sistema es capaz de realizar la detección vehicular en tiempo real y que además permite adaptar rápida y eficientemente los cambios de flujo a fin de establecer una vía prioritaria

    Arylsulfatase A Remodeling during Human Sperm In Vitro Capacitation Using Field Emission Scanning Electron Microscopy (FE-SEM)

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    Capacitation drives sperm biophysical and biochemical changes for sperm-oocyte interactions. It is a well-known fact that the molecular complex arylsulfatase A (ARSA), hyaluronidase sperm adhesion molecule 1 (SPAM1), and heat shock protein 2 (HSPA2) plays a significant role in sperm–zona pellucida (ZP) binding. However, the time-dependent capacitation effects on the sperm surface ARSA presence and specific topographic distributions remain to be elucidated. Here, we quantified the ARSA density and specific membrane domain locations before (US) and after in vitro capacitation (one and four hours; CS1–CS4) in human sperm using high-resolution field emission scanning electron microscopy (FE-SEM) and immunogold labeling. Our results showed a significant and progressive capacitation-mediated increase of labeled spermatozoa from the US (37%) to CS4 (100%) physiological conditions. In addition, surface mapping revealed a close relationship between the ARSA residues and their acrosomal repositioning. Compared with the ARSA surface heterogeneous distribution found in US, the CS1–4 conditions exhibited clustering on the peri-acrosomal region, showing that time-dependent capacitation also induced a ARSA residue dramatic translocation on sperm surfaces. Our findings provide novel insights into the molecular remodeling events preceding sperm-oocyte interactions.This research was funded by the Human Fertility Cathedra of the University of Alicante and R&D&I projects financed by competitive public entities (ViGrob-186, UAIND17-03 and PGC2018-094781-B-100)

    Specific lectin binding sites during in vitro capacitation and acrosome reaction in boar spermatozoa

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    Sperm glycocalyx and plasma membrane undergo outstanding modifications during fertilization. However, it is unclear how in vitro capacitation time and acrosome reaction affect the specific location of boar sperm glycoconjugates. This study aimed to identify lectin binding patterns and to describe the sequential changes during different in vitro capacitation times (1 and 4 h) and acrosome reaction in boar spermatozoa. With Aleuria aurantia agglutinin (AAA), most uncapacitated cells were labelled in the postacrosomal region. Nevertheless, after 1 h of in vitro capacitation and the acrosome reaction, most AAA binding sites were in the acrosomal region. With Concanavalin A (ConA), most sperm were labeled in the postacrosomal region before and after capacitation. After the acrosome reaction induction, this pattern changed to a highly stained acrosomal and postacrosomal regions. Peanut agglutinin (PNA) binding sites were in the acrosomal region in uncapacitated and capacitated sperm. In acrosome reacted sperm after 4h capacitation, the most frequent pattern showed remaining positive labeling in the central area of the head. With Pisum sativum agglutinin (PSA), most uncapacitated cells showed a postacrosomal region staining. Nevertheless, faint stained all over the head and highly acrosomal region labelling was observed in the major part of capacitated and acrosome reacted sperm respectively. With Wheat germ agglutinin (WGA), the most representative pattern in uncapacitated, capacitated and acrosome reacted sperm was labelled in the acrosomal region. Regarding capacitation time, the most significant changes in the most representative pattern were observed in acrosome reacted spermatozoa after 4 h of in vitro capacitation.This research was supported by AGL2015-70159-P, PGC2018-094781-B-100 and PEJ2018-002736-P (MCINN/AEI/FEDER,UE)

    Neumonía nosocomial en pacientes ingresados en la terapia intermedia del Hospital Universitario "General Calixto García". 2016 – 2017

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    La neumonía nosocomial es una infección común y grave. Con el objetivo de caracterizar las neumonías nosocomiales en pacientes ingresados en la terapia intermedia del Hospital "General Calixto García" en los años 2016 - 17; se realizó un estudio descriptivo y observacional en 202 enfermos que cumplieron con los criterios de inclusión. Del análisis descriptivo y de asociación de variables resultó que: predominaron los hombres (56,4 %), entre 71 – 80 años (34,6 %), siendo la ventilación mecánica (79,2 %), edad mayor de 60 años (78,2 %), y el sondaje nasogástrico (65,3 %) sus principales factores favorecedores. La combinación de elementos clínicos, humorales, radiológicos y microbiológicos estableció el diagnóstico en el 65,3 % de los casos. Prevaleció la neumonía tardía (77,2 %) por Acinetobacter spp (21,7 %) y Estafilococo coagulasa positivo (17,9 %). El antibiótico más utilizado fue la ceftriaxona sola o en combinación (34,6 %). La mortalidad fue del 35,7 %. Concluyéndose que: la neumonía resultó frecuente en pacientes cerebrovasculares, con factores de riesgo para su adquisición, de aparición tardía y por gérmenes gramnegativos. No se demostró una adecuada relación entre la antibioticoterapia empírica y los patrones de sensibildad in vitro. La edad mayor de 65 años, el uso de la ventilación mecánica, la afectación pulmonar bilateral en la radiografía de tórax, el inicio tardío y la presencia de Acinetobacter spp, se asociaron a una menor supervivencia de nuestros enfermos

    La política social en el estado de México en torno a la pandemia por covid-19

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    Objective: To describe the impact of social policy in the State of Mexico in the context of the covid-19 pandemic. Methodology: A documentary and retrospective analysis was developed on the main social deprivations in the State of Mexico and their impact on the covid-19 pandemic. Results: Until 2020, the fatality rate due to Covid-19 in the State of Mexico was 13.5%, compared to the national average (9.1%) (SEGOB CDMX, 2021: 6-7) and the second entity with the highest excess mortality from all causes (78.8%) (INSP, 2021: 35). Likewise, poverty grew 7.1%, and at the national level it was 2%, but food was doubled (Coneval, 2021b; Coneval, 2021a), a situation linked to the absence of actions related to the right to health (p.26), despite the fact that the population without access to health services grew from 19% to 34% (Coneval, 2021a)Objetivo: Describir el impacto de la política social en el Estado de México en el contexto de la pandemia por covid-19. Metodología: Se desarrolló un análisis documental y retrospectivo sobre las principales carencias sociales en el Estado de México y su impacto en torno a la pandemia por covid-19. Resultados: Hasta el 2020 la tasa de letalidad por Covid-19 en el Estado de México fue del 13.5%, en comparación con la media nacional (9.1%) (SEGOB CDMX, 2021:6-7) y la segunda entidad con el mayor exceso de mortalidad por todas las causas (78.8%) (INSP, 2021:35). Así mismo, la pobreza creció 7.1%, y a nivel nacional fue del 2%, pero la alimentaria fue del doble (Coneval, 2021b; Coneval, 2021a), situación vinculada a ausencia de acciones relacionadas con el derecho a la salud (p.26), pese a que la población sin acceso a servicio de salud creció del 19% al 34% (Coneval, 2021a)

    Direct medical cost of COVID-19 in children hospitalized at a tertiary referral healthcare center in Mexico City

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    IntroductionDespite the end of the COVID-19 pandemic being declared by the WHO, the economic consequences are far from over. One of these implications was the cost of inpatient care for health institutions. To date, some studies have examined the economic burden of COVID-19 in the adult population but only a few have focused on child populations.ObjectiveTo estimate the direct medical costs of COVID-19, focusing on children in Mexico.MethodData about resources consumed during hospital stays were extracted from the medical records of patients hospitalized at a Mexican tertiary healthcare institution. Other sources of information were the unit prices of inputs and the salaries of health personnel. A micro-costing methodology was used to obtain cost results by age group over different hospital areas. Data analysis was performed with descriptive statistics and regression models to evaluate the predictors of total cost.ResultsOne hundred and ten medical records were reviewed of which 57.3% corresponded to male patients and the mean age was 7.2 years old. The estimated average cost per patient was US5,943(955,943 (95% CI: US4,249–7,637). When the costs of the three clinical areas were summed, only the 5–10 years old group showed a maximum cost of US$14,000. The regression analysis revealed the following factors as significant: sex, age, staying at an emergency room, having a positive bacterial culture, and having comorbidities.DiscussionThe cost results were somewhat similar to those reported in children from the USA, but only regarding low severity COVID-19 cases. However, comparability between these types of studies should be done with caution due to the huge differences between the healthcare systems of countries. The study cost results may help public decision-makers in budget planning and as inputs for future cost-effectiveness studies about interventions regarding COVID-19

    Botanical composition of honeys from the Yucatan Peninsula, by qPCR and dissociation curve analysis

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    El método cuantitativo de reacción en cadena de la polimerasa (qPCR), seguido por análisis de curvas de disociación, fue desarrollado para la detección rápida y simultánea de la composición botánica en mieles de la Península de Yucatán, México. Cinco muestras de miel ciclo apícola 2013 y cinco del 2014, se caracterizaron para definir el contenido de cinco especies de plantas de importancia apícola; Viguiera dentata, Gymonopodium floribundum, Piscidia piscipula, Acacia angustissima y Mimosa bahamensis. Siete iniciadores de genes genéricos (Adh1, Hmg2, Brass lip, Plant 1, Plant nest, Act1, y Helli-all) se emplearon para caracterizar las especies vegetales y las muestras de miel. Al finalizar la amplificación se obtuvo una curva de disociación por reacción representando productos específicos de amplificación. Los resultados obtenidos indicaron que el contenido taxonómico en las muestras de miel fue diferencial M-1 (V. dentata), M-3 (M. bahamensis y G. floribundum), M-4 (G. floribundum), M-8 (M. bahamensis) y M-13 (V. dentata y G. floribundum). M-7, M-11 y M-12 no revelaron tener ninguna de las especies analizadas, mientras que M-14 y M-15 presentaron un patrón de amplificación diferente a las especies incluidas en este estudio; concordando con los análisis palinológicos. P. piscipula no mostró ningún patrón de amplificación con ninguno de los iniciadores de este estudio y A. angustissima no fue identificada en ninguna muestra de miel, aun cuando el análisis palinológico reveló presencia de esta especie en M-3 y M-4, posiblemente derivado de la ausencia de similitud con los genes de estudio.El método cuantitativo de reacción en cadena de la polimerasa (qPCR), seguido por análisis de curvas de disociación, fue desarrollado para la detección rápida y simultánea de la composición botánica en mieles de la Península de Yucatán, México. Cinco muestras de miel ciclo apícola 2013 y cinco del 2014, se caracterizaron para definir el contenido de cinco especies de plantas de importancia apícola; Viguiera dentata, Gymonopodium floribundum, Piscidia piscipula, Acacia angustissima y Mimosa bahamensis. Siete iniciadores de genes genéricos (Adh1, Hmg2, Brass lip, Plant 1, Plant nest, Act1, y Helli-all) se emplearon para caracterizar las especies vegetales y las muestras de miel. Al finalizar la amplificación se obtuvo una curva de disociación por reacción representando productos específicos de amplificación. Los resultados obtenidos indicaron que el contenido taxonómico en las muestras de miel fue diferencial M-1 (V. dentata), M-3 (M. bahamensis y G. floribundum), M-4 (G. floribundum), M-8 (M. bahamensis) y M-13 (V. dentata y G. floribundum). M-7, M-11 y M-12 no revelaron tener ninguna de las especies analizadas, mientras que M-14 y M-15 presentaron un patrón de amplificación diferente a las especies incluidas en este estudio; concordando con los análisis palinológicos. P. piscipula no mostró ningún patrón de amplificación con ninguno de los iniciadores de este estudio y A. angustissima no fue identificada en ninguna muestra de miel, aun cuando el análisis palinológico reveló presencia de esta especie en M-3 y M-4, posiblemente derivado de la ausencia de similitud con los genes de estudio
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