2,738 research outputs found

    Study of Friction and Wear Effects in Aluminum Parts Manufactured via Single Point Incremental Forming Process Using Petroleum and Vegetable Oil-Based Lubricants

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    This paper focuses on studying how mineral oil, sunflower, soybean, and corn lubricants influence friction and wear effects during the manufacturing of aluminum parts via the single point incremental forming (SPIF) process. To identify how friction, surface roughness, and wear change during the SPIF of aluminum parts, Stribeck curves were plotted as a function of the SPIF process parameters such as vertical step size, wall angle, and tool tip semi-spherical diameter. Furthermore, lubricant effects on the surface of the formed parts are examined by energy dispersive spectroscopy (EDS) and scanning electron microscope (SEM) images, the Alicona optical 3D measurement system, and Fourier-transform infrared spectroscopy (FTIR). Results show that during the SPIF process of the metallic specimens, soybean and corn oils attained the highest friction, along forces, roughness, and wear values. Based on the surface roughness measurements, it can be observed that soybean oil produces the worst surface roughness finish in the direction perpendicular to the tool passes (Ra =1.45 μm) considering a vertical step size of 0.25 mm with a 5 mm tool tip diameter. These findings are confirmed through plotting SPIFed Stribeck curves for the soybean and corn oils that show small hydrodynamic span regime changes for an increasing sample step-size forming process. This article elucidates the effects caused by mineral and vegetable oils on the surface of aluminum parts produced as a function of Single Point Incremental Sheet Forming process parameters

    A sex-structured model of Wolbachia invasion to design sex-biased release strategies in Aedes spp mosquitoes populations

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    Laboratory experiments as well as some field essays have revealed that the intracellular bacterium Wolbachia, deliberately introduced in Aedes spp female mosquitoes, drastically reduces their vector competence for dengue virus and other pathogens. However, female mosquitoes infected with Wolbachia still need to ingest human blood while male mosquitoes, either wild or Wolbachia-carrying, do not bite people. Moreover, Wolbachia-carrying females may transmit the virus to people during blood-feeding, even though with a far less probability than the wild ones. Therefore, massive releases of Wolbachia-carrying females may increase both the nuisance and the epidemiological risk among human residents. In this paper, we propose a sex-structured model of Wolbachia invasion that brings forward the possibility of developing male-biased release strategies of Wolbachia-carriers leading to Wolbachia invasion. Thanks to this model, we study the minimal amount of mosquitoes necessary to complete this task, according to the relative sex-ratio of the released mosquitoes and to the release schedule. We also pay attention to the estimate of the time needed to achieve the ultimate population replacement

    Clinical and Laboratory Development of Echinocandin Resistance in Candida glabrata: Molecular Characterization

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    The pathogenic yeast Candida glabrata has become a public health issue due to the increasing number of echinocandin resistant clinical strains reported. In this study, acquisition and development of resistance to this antifungal class were studied in serial C. glabrata isolates from five patients admitted in two Spanish hospitals with a resistant profile against echinocandins associated with different mutations in hot-spot 1 of FKS2 gene. For two of these patients susceptible FKS wild-type isolates obtained prior to resistant ones were also investigated. Isolates were genotyped using multilocus sequence typing and microsatellite length polymorphism techniques, which yielded comparable results. Susceptible and resistant isolates from the same patient had the same genotype, being sequence type (ST) 3 the most prevalent among them. Isolates with different FKS mutations but the same ST were present in the same patient. MSH2 gene alterations were also studied to investigate their correlation with antifungal resistance acquisition but no association was found with antifungal resistance nor with specific genotypes. In vitro exposure to increasing concentrations of micafungin to susceptible isolates developed colonies carrying FKS mutations in agar plates containing a minimum concentration of 0.06 mg/L of micafungin after less than 48 h of exposure. We investigated the correlation between development of resistance and genotype in a set of susceptible strains after being in vitro exposed to micafungin and anidulafungin but no correlation was found. Mutant prevention concentration values and spontaneous growth frequencies after selection with both echinocandins were statistically similar, although FKS mutant colonies were more abundant after micafungin exposure (p < 0.001). Mutation S663P and F659 deletion were the most common ones found after selection with both echinocandins.This work was supported by the Fondo de Investigación Sanitaria (Grant FI14CIII/00025 to OR-M and research projects PI13/02145 and PI16CIII/00035 to AA-I), and also supported by the Plan Nacional de I+D+i 2013–2016 and Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases (REIPI RD16CIII/0004/0003) – co-financed by the European Development Regional Fund “A way to achieve Europe,” Operative Program Intelligent Growth 2014–2020.S

    Further Characterization of the Electrogenicity and pH Sensitivity of the Human Organic Anion-Transporting Polypeptides OATP1B1 and OATP1B3

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    Organic anion-transporting polypeptides (OATPs) are involved in the liver uptake of many endogenous and xenobiotic compounds, such as bile acids and drugs, respectively. Using Xenopus laevis oocytes and Chinese hamster ovary (CHO) cells expressing rat Oatp1a1, human OATP1B1, or OATP1B3, the sensitivity of these transporters to extracellular/intracellular pH (pHo/pHi) and changes in plasma membrane potential (ΔΨ) was investigated. In X. laevis oocytes, nonspecific plasma membrane permeability increased only at pHo below 4.5. Above this value, both using oocytes and CHO cells, extracellular acidification affected differently the specific transport of taurocholic acid (TCA) and estradiol 17β-d-glucuronide (E217βG) by Oatp1a1 (stimulation), OATP1B1 (inhibition), and OATP1B3 (stimulation). Changes in substrate uptake in the presence of valinomycin (K+-ionophore), carbonyl cyanide 3-chlorophenylhydrazone and nigericin (protonophores), and amiloride (Na+/H+-inhibitor) and cation replacement in the medium were studied with fluorescent probes for measuring substrate uptake (cholylglycyl amidofluorescein) and changes in pHi (SNARF-4F) and ΔΨ [DilC1(5)]. The results suggest that activity of these three carriers is sodium/potassium-independent and affected differently by changes in pHo and ΔΨ: Oatp1a1 was confirmed to be an electroneutral anion exchanger, whereas the function of both OATP1B1 and OATP1B3 was markedly affected by the magnitude of ΔΨ. Moreover, electrophysiological measurements revealed the existence of a net anion influx associated to OATP1B1/OATP1B3-mediated transport of TCA, E217βG, and estrone-3-sulfate. Furthermore, a leakage of Na+ through OATP1B1 and OATP1B3, which is not coupled to substrate transport, was found. In conclusion, these results suggest that OATP1B1 and OATP1B3 are electrogenic transporters whose activity may be strongly affected under circumstances of displacement of local pH

    Cambios en el estilo de vida y nutrición durante el confinamiento por SARS-CoV-2 (COVID-19) en México: un estudio observacional

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    Introduction: To evaluate the changes implemented in lifestyle and nutrition in the mexican population during the lockdown due to SARS-CoV-2 (COVID-19).Material and methods: Transversal study performed during the lockdown in Mexico. Data was obtained through a digital questionnaire, which was spread through social media. The questionnaire evaluated aspects related to: nutrition, well-being and lifestyle (tobacco and alcohol consumption, physical activity and sleep problems) as well as demographic variables. For the statistical analyses, the chi-square test was used to compare differences between genders, with a statistical significance of 5%, using SPSS 23.0 software.Results: A total of 1084 surveys were analyzed. The average age was 35.5±13.9 years and 66.5% (n=721) were women. In relation to eating before lockdown, 69.8% (n=757) considered their diet healthy, 6.5% (n=99) very healthy and 23.7% (n=228) unhealthy, and 2.3% (n=26) have improved their diet, despite this 17.1% (n=186) of people say they eat all the time these days. In relation to sleep, women sleep less during the period of lockdown (p=0.002) and wake up more during the night when compared to men (p&lt;0.001).Conclusions: Factors like nutrition and sleep have alteration in that time of the lockdown. It is important to mention the relevance of these factors because the good nutrition and rest contribute for a better/ strengthening immunological system.Introducción: Evaluar el consumo de alimentos no saludables y prácticas de estilo de vida en mexicanos durante el confinamiento por SARS-CoV-2 (COVID-19).Material y métodos: Estudio transversal realizado durante parte del confinamiento en México. La recolección de datos fue realizada a través de una encuesta digital. Fueron evaluados aspectos de alimentación, bienestar y estilo de vida (consumo de alcohol y tabaco, actividad física y sueño), además de variables sociodemográficas. Para los análisis estadísticos fueron utilizadas la prueba χ2 para comparar diferencias entre género, con significancia estadística del 5%, utilizando el software SPSS 23.0.Resultados: Fueron analizadas 1084 encuestas. La edad promedio fue de 35,5±13,9 años y el 66,5% (n=721) fueron mujeres. En relación a la alimentación antes del confinamiento, 69,8% (n=757) consideraban su alimentación saludable, 6,5% (n=99) muy saludable y 23,7% (n=228) poco saludable, y el 2,3% (n=26) ha mejorado su alimentación, a pesar de esto el 17,1% (n=186) de las personas dice que en estos días come todo el tiempo. En relación al sueño, las mujeres duermen menos durante el periodo del confinamiento (p=0,002) y despiertan más durante la noche cuando se compara con los hombres (p&lt;0,001).Conclusiones: Factores como la alimentación y el sueño presentaron alteraciones en ese período del confinamiento. Es importante destacar la relevancia de esos factores pues una buena alimentación y el descanso contribuyen para un mejor/fortalecimiento del sistema inmunológico

    Angiocrine polyamine production regulates adiposity.

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    Reciprocal interactions between endothelial cells (ECs) and adipocytes are fundamental to maintain white adipose tissue (WAT) homeostasis, as illustrated by the activation of angiogenesis upon WAT expansion, a process that is impaired in obesity. However, the molecular mechanisms underlying the crosstalk between ECs and adipocytes remain poorly understood. Here, we show that local production of polyamines in ECs stimulates adipocyte lipolysis and regulates WAT homeostasis in mice. We promote enhanced cell-autonomous angiogenesis by deleting Pten in the murine endothelium. Endothelial Pten loss leads to a WAT-selective phenotype, characterized by reduced body weight and adiposity in pathophysiological conditions. This phenotype stems from enhanced fatty acid β-oxidation in ECs concomitant with a paracrine lipolytic action on adipocytes, accounting for reduced adiposity. Combined analysis of murine models, isolated ECs and human specimens reveals that WAT lipolysis is mediated by mTORC1-dependent production of polyamines by ECs. Our results indicate that angiocrine metabolic signals are important for WAT homeostasis and organismal metabolism.We thank members of the Endothelial Pathobiology and Microenvironment Group for helpful discussions. We thank the CERCA Program/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. The research leading to these results has received funding from la Fundación BBVA (Ayuda Fundacion BBVA a Equipos de Investigación Científica 2019, PR19BIOMET0061) and from SAF2017-82072-ERC from Ministerio de Ciencia, Innovación y Universidades (MCIU) (Spain). The laboratory of M.G. is also supported by the research grants SAF2017-89116R-P (FEDER/EU) co-funded by European Regional Developmental Fund (ERDF), a Way to Build Europe and PID2020-116184RB-I00 from MCEI; by the Catalan Government through the project 2017-SGR; PTEN Research Foundation (BRR-17-001); La Caixa Foundation (HR19-00120 and HR21-00046); by la Asociación Española contra el Cancer-Grupos Traslacionales (GCTRA18006CARR, also to A.C.); European Foundation for the Study of Diabetes/Lilly research grant, also to M.C.); and by the People Programme (Marie Curie Actions; grant agreement 317250) of the European Union’s Seventh Framework Programme FP7/2007-2013 and the Marie Skłodowska-Curie (grant agreement 675392) of the European Union’s Horizon 2020 research. The laboratory of A.C. is supported by the Basque Department of Industry, Tourism and Trade (Elkartek) and the department of education (IKERTALDE IT1106-16), the MCIU (PID2019-108787RB-I00 (FEDER/ EU); Severo Ochoa Excellence Accreditation SEV-2016-0644; Excellence Networks SAF2016-81975-REDT), La Caixa Foundation (ID 100010434), under the agreement LCF/PR/HR17, the Vencer el Cancer foundation and the European Research Council (ERC) (consolidator grant 819242). CIBERONC was co-funded with FEDER funds and funded by Instituto de Salud Carlos III (ISCIII). The laboratory of M.C. is supported by the ERC under the European Union’s Horizon 2020 research and innovation programme (grant agreement 725004) and CERCA Programme/Generalitat de Catalunya (M.C.). The laboratory of D.S. is supported by research grants from MINECO (SAF2017- 83813-C3-1-R, also to L.H., cofounded by the ERDF), CIBEROBN (CB06/03/0001), Government of Catalonia (2017SGR278) and Fundació La Marató de TV3 (201627- 30). The laboratory of R.N. is supported by FEDER/Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación (RTI2018-099413-B-I00 and and RED2018-102379-T), Xunta de Galicia (2016-PG057 and 2020-PG015), ERC under the European Union’s Horizon 2020 research and innovation programme (grant agreement 810331), Fundación BBVA, Fundacion Atresmedia and CIBEROBN, which is an initiative of the ISCIII of Spain, which is supported by FEDER funds. The laboratory of J.A.V. is supported by research grants from MICINN (RTI2018-099250-B100) and by La Caixa Foundation (ID 100010434, LCF/PR/HR17/52150009). P.M.G.-R. is supported by ISCIII grant PI15/00701 cofinanced by the ERDF, A Way to Build Europe. Personal support was from Marie Curie ITN Actions (E.M.), Juan de la Cierva (IJCI-2015-23455, P.V.), CONICYT fellowship from Chile (S.Z.), Vetenskapsradet (Swedish Research Council, 2018-06591, L.G.) and NCI K99/R00 Pathway to Independence Award (K99CA245122, P. Castel).S

    Diferencias entre los modelos de riesgo Framingham y DAD en la evaluación del riesgo cardiovascular en pacientes con VIH bajo terapia antirretroviral: experiencia en una población del caribe colombiano

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    Objective: To assess the five- and ten-year cardiovascular disease risk in HIV-positive patients on antiretroviral therapy, using the Framingham risk score and the Data collection on adverse effects of anti-HIV drugs (D:A:D) study. Materials and methods: An observational prospective cross-sectional study. HIV-positive patients on antiretroviral treatment from a referral center for HIV patients were included in the study between January 1 and April 30, 2019. A five- and ten-year cardiovascular risk assessment was performed using the Framingham risk score and the D:A:D study. Additionally, both risk models were compared through statistical models. Results: The study population consisted of 159 patients with a mean age of 48.90 years ± 9.90. The mean cardiovascular risk according to the five-year Framingham risk score was 2.70 % ± 2.80, the ten-year Framingham risk score was 6.10 % ± 5.70, the five-year D:A:D study was 3.50 % ± 4.10, the ten-year D:A:D study was 6.90 % ± 7.70, and the ten-year Framingham risk score recalculated for Colombia (multiplied by 0.75) was 4.50 % ± 4.20. Using a logistic regression model, it was determined that the ten-year D:A:D study provided the greatest number of variables significantly related to a high cardiovascular risk. Conclusions: The study showed a significant difference between the risk models. Both the five- and ten-year D:A:D study provided a better cardiovascular disease risk estimation than the five- and ten-year Framingham model.Objetivo: Evaluar el riesgo de enfermedad cardiovascular a cinco y a diez años en pacientes con infección por VIH en terapia antirretroviral, por medio de las escalas Framingham y Data collection on Adverse Effects of Anti-HIV Drugs Study. Materiales y métodos: Estudio observacional de corte transversal y prospectivo. Se incluyeron pacientes con infección por el VIH en tratamiento antirretroviral de un centro de referencia para pacientes con VIH, entre el 1 de enero y el 30 de abril de 2019. Se realizó evaluación del riesgo cardiovascular a cinco y a diez años a través de los modelos de predicción de Framingham y la escala Data collection on Adverse Effects of Anti-HIV Drugs Study (DAD), y una comparación entre ellos a través de modelos estadísticos. Resultados: Se incluyeron 159 pacientes, con un promedio de edad de 48,90 años ± 9,90. La media de valoración del riesgo cardiovascular por escala de Framingham a 5 años fue de 2,70 % ± 2,80; Framingham a 10 años fue 6,10 % ± 5,70; DAD a 5 años, 3,50 % ± 4,10; DAD a 10 años, de 6,90 % ± 7,70; y el riesgo escala de Framingham a 10 años recalculado para Colombia (multiplicado por 0,75) fue de 4,50 ± 4,20. A través de un modelo de regresión logística, se determinó que la puntuación con mayor número de variables significativamente relacionadas con el resultado de riesgo cardiovascular alto es el modelo DAD a 10 años. Conclusiones: El estudio evidenció una diferencia significativa, con mayor riesgo estimado de enfermedad cardiovascular al utilizar el modelo DAD en comparación con el Framingham, tanto para la estimación a cinco años como a diez

    Plasma Aβ42/40 ratio alone or combined with FDG-PET can accurately predict amyloid-PET positivity: a cross-sectional analysis from the AB255 Study

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    Background: To facilitate population screening and clinical trials of disease-modifying therapies for Alzheimer’s disease, supportive biomarker information is necessary. This study was aimed to investigate the association of plasma amyloid-beta (Aβ) levels with the presence of pathological accumulation of Aβ in the brain measured by amyloid-PET. Both plasma Aβ42/40 ratio alone or combined with an FDG-PET-based biomarker of neurodegeneration were assessed as potential AD biomarkers. Methods: We included 39 cognitively normal subjects and 20 patients with mild cognitive impairment from the AB255 Study who had undergone PiB-PET scans. Total Aβ40 and Aβ42 levels in plasma (TP42/40) were quantified using ABtest kits. Subjects were dichotomized as Aβ-PET positive or negative, and the ability of TP42/40 to detect Aβ-PET positivity was assessed by logistic regression and receiver operating characteristic analyses. Combination of plasma Aβ biomarkers and FDG-PET was further assessed as an improvement for brain amyloidosis detection and diagnosis classification. Results: Eighteen (30.5%) subjects were Aβ-PET positive. TP42/40 ratio alone identified Aβ-PET status with an area under the curve (AUC) of 0.881 (95% confidence interval [CI] = 0.779–0.982). Discriminating performance of TP42/40 to detect Aβ-PET-positive subjects yielded sensitivity and specificity values at Youden’s cutoff of 77.8% and 87.5%, respectively, with a positive predictive value of 0.732 and negative predictive value of 0.900. All these parameters improved after adjusting the model for significant covariates. Applying TP42/40 as the first screening tool in a sequential diagnostic work-up would reduce the number of Aβ-PET scans by 64%. Combination of both FDG-PET scores and plasma Aβ biomarkers was found to be the most accurate Aβ-PET predictor, with an AUC of 0.965 (95% CI = 0.913–0.100). Conclusions: Plasma TP42/40 ratio showed a relevant and significant potential as a screening tool to identify brain Aβ positivity in preclinical and prodromal stages of Alzheimer’s disease

    Desarrollo multidisciplinario en investigación y docencia del centro universitario UAEM Valle de México

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    DESARROLLO MULTIDISCIPLINARIO EN INVESTIGACIÓN Y DOCENCIA DEL CENTRO UNIVERSITARIO UAEM VALLE DE MÉXICOLa Universidad Autónoma del Estado de México ha evolucionado a través de sus 188 años de historia, dedicada a la educación, la investigación, la cultura y el deporte, como sus grandes ejes rectores, formadora de hombres y mujeres con un alto sentido humanista y ético, contribuyendo a lograr nuevas y mejores formas de existencia y convivencia social. Durante el proceso de desconcentración de la UAEM, se crearon las Unidades Académicas y Centros Universitarios para brindar el servicio de educación a más jóvenes en todo el Estado de México, este Centro Universitario fue uno de los primeros y a sus veinte años de existencia se está consolidando como uno de los mejores. Es en los últimos años que se ha venido impulsando la investigación al contar con cuerpos académicos, en formación y en consolidación, con infraestructura de primera tanto en equipo como en laboratorios especializados, con profesores de tiempo completo que participan en congresos, seminarios y presentan publicaciones en revistas indexadas. Por ello para celebrar esos veinte años de existencia de esta honorable institución, se planeó la compilación de esta obra que es parte del quehacer multidisciplinario en investigación y docencia como parte del Plan de Desarrollo 2013-2017, de esta administración. Esta obra reúne investigaciones tanto de profesores como de alumnos desde las diferentes ramas del saber en las que se inscriben sus siete licenciaturas, Actuaría, Administración, Contaduría, Derecho, Economía, Relaciones Económicas Internacionales e Informática Administrativa, tanto presencial como a distancia, así como sus tres ingenierías, Industrial, en Computación y Sistemas y Comunicaciones, así como gracias a la vinculación y colaboración académico – científica que se tiene con otras instituciones de educación superior a nivel nacional, como el Instituto Tecnológico de Orizaba, la Universidad Autónoma de San Luis Potosí, la Universidad Nacional Autónoma de México, la Universidad Autónoma Metropolitana, Universidad Politécnica de Victoria, el Instituto Politécnico Nacional entre otras. En el capítulo 1 se abordan seis temáticas diferentes de vanguardia en el área de las Ingenierías, en los capítulos 2 y 3 se incluyen temas de interés y gran relevancia en materia de ciencias sociales, política y economía. Se hace extensivo un reconocimiento para todos los que participaron tanto en la revisión de los trabajos, como en la compilación del producto final de este Libro intitulado “Desarrollo Multidisciplinario en Investigación y Docencia del Centro Universitario UAEM Valle de México”

    Gene signatures of early response to anti-TNF drugs in pediatric inflammatory bowel disease

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    T. Around a 20–30% of inflammatory bowel disease (IBD) patients are diagnosed before they are 18 years old. Anti-TNF drugs can induce and maintain remission in IBD, however, up to 30% of patients do not respond. The aim of the work was to identify markers that would predict an early response to anti-TNF drugs in pediatric patients with IBD. The study population included 43 patients aged &lt;18 years with IBD who started treatment with infliximab or adalimumab. Patients were classified into primary responders (n = 27) and non-responders to anti-TNF therapy (n = 6). Response to treatment could not be analyzed in 10 patients. Response was defined as a decrease in over 15 points in the disease activity indexes from week 0 to week 10 of infliximab treatment or from week 0 to week 26 of adalimumab treatment. The expression profiles of nine genes in total RNA isolated from the whole-blood of pediatric IBD patients taken before biologic administration and after 2 weeks were analyzed using qPCR and the 2−∆∆Ct method. Before initiation and after 2 weeks of treatment the expression of SMAD7 was decreased in patients who were considered as non-responders (p value &lt; 0.05). Changes in expression were also observed for TLR2 at T0 and T2, although that did not reach the level of statistical significance. In addition, the expression of DEFA5 decreased 1.75-fold during the first 2 weeks of anti-TNF treatment in responders, whereas no changes were observed in non-responders. Expression of the SMAD7 gene is a pharmacogenomic biomarker of early response to anti-TNF agents in pediatric IBD. TLR2 and DEFA5 need to be validated in larger studies.This work was funded by Instituto de Salud Carlos III (grants numbers PI16/00559 and PI19/00792), Consejería de Educación y Deporte de la Comunidad de Madrid (grant number PEJ16/MED/AI-1260), and by the Gregorio Marañón Health Research Institute (grant number PRE-2018-2), The study was cofunded by ERDF Funds (FEDER) from the European Commission, “A way of making Europe
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