124 research outputs found

    Efficacy of different antifouling treatments for seawater cooling systems

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    In an industrial seawater cooling system, the effects of three different antifouling treatments, viz. sodium hypochlorite (NaClO), aliphatic amines (Mexel1432) and UV radiation, on the characteristics of the fouling formed were evaluated. For this study a portable pilot plant, as a side-stream monitoring system and seawater cooling system, was employed. The pilot plant simulated a power plant steam condenser, having four titanium tubes under different treatment patterns, where fouling progression could be monitored. The nature of the fouling obtained was chiefly inorganic, showing a clear dependence on the antifouling treatment employed. After 72 days the tubes under treatment showed a reduction in the heat transfer resistance (R) of around 70% for NaClO, 48% for aliphatic amines and 55% for UV, with respect to the untreated tube. The use of a logistic model was very useful for predicting the fouling progression and the maximum asymptotic value of the increment in the heat transfer resistance (DRmax). The apparent thermal conductivity (l) of the fouling layer showed a direct relationship with the percentage of organic matter in the collected fouling. The characteristics and mode of action of the different treatments used led to fouling with diverse physicochemical properties

    Accumulation of scandium in plasma in patients with chronic renal failure

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    Scandium (Sc) is an element with many industrial applications, but relatively little is known about its physiological and/or toxicological effects, and very little data are available concerning the role of Sc in chronic renal failure (CRF). This paper examines the changes in plasma levels of Sc in predialysis patients with CRF and the relationship with blood parameters. The participants in this trial were 48 patients with CRF in predialysis and 53 healthy controls. Erythrocyte, haemoglobin, and haematocrit counts in blood were determined, and levels of creatinine, urea, uric acid, albumin, total protein and Sc were measured in plasma. The glomerular filtration rate (GFR) was calculated using the Cockcroft-Gault index. The CRF patients were found to have higher plasma levels of creatinine, urea, uric acid, albumin, total protein, and Sc and a lower GFR than that the controls. Scandium in plasma was positively correlated with creatinine and plasma urea and negatively correlated with GFR, haemoglobin, and haematocrit and was associated with the risk of lower levels of erythrocytes, haemoglobin, and haematocrit. CRF was associated with increases in the circulating levels of scandium.This research was supported by Plan Nacional I+D Project 1FD 1997-0642

    Cancer-associated fibroblast-derived gene signatures determine prognosis in colon cancer patients

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    © The Author(s)Paracrine communication between tumor and surrounding stroma arbitrates the malignant behavior of cancer progression [1]. Fibroblasts, which are the main cell type within the stroma and are called cancer-associated fibroblasts (CAFs), orchestrate the crosstalk with cancer cells [2, 3] and express several markers associated with prognosis [4]. There is increasing evidence that a stroma-specific signature could be used for risk assessment in colon cancer (CC). According to the Consensus Molecular Subtype classification (CMS) in CC, the mesenchymal or CMS4 group is characterized by stromal invasion, extracellular matrix remodeling and TGF-β signaling activation. It is associated with the worst prognosis rates [5, 6]. Genes correlating with the mesenchymal subtype are mostly expressed by CAFs and other stromal cells, rather than by tumor cells [7]. Accordingly, our group defined a gene expression profile associated with CAFs with high pro-migratory effects on colon tumor cells, which was associated with patients’ poor prognosis. These were mostly advanced-stage patients [8].This research is supported by PI17/01847, PI18/01020 and PI20/00602 from the Instituto de Salud Carlos III and co-financed by the European Development Regional Fund (FEDER) “A way to achieve Europe” (ERDF); by “CIBER de Cáncer”, CB16/12/00273, CB16/12/00301 and CB16/12/00446, from the Instituto de Salud Carlos III-FEDER; and by the Fundación Científica AECC (a multifaceted approach to targeting pancreatic cancer). The JDLR group also acknowledges the funding provided by the Instituto de Salud Carlos III (ISCiii, AES) in grants PI18/00591 and PT17/0009/0008, co-financed by the European Development Regional Fund (FEDER)

    Clinical Spectrum of Schistosomiasis: An Update

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    Schistosomiasis is a helminthic infection and one of the neglected tropical diseases (NTDs). It is caused by blood flukes of the genus Schistosoma. It is an important public health problem, particularly in poverty-stricken areas, especially those within the tropics and subtropics. It is estimated that at least 236 million people worldwide are infected, 90% of them in sub-Saharan Africa, and that this disease causes approximately 300,000 deaths annually. The clinical manifestations are varied and affect practically all organs. There are substantial differences in the clinical presentation, depending on the phase and clinical form of schistosomiasis in which it occurs. Schistosomiasis can remain undiagnosed for a long period of time, with secondary clinical lesion. Here, we review the clinical profile of schistosomiasis. This information may aid in the development of more efficacious treatments and improved disease prognosis

    A phylogenetic and proteomic reconstruction of eukaryotic chromatin evolution

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    Histones and associated chromatin proteins have essential functions in eukaryotic genome organization and regulation. Despite this fundamental role in eukaryotic cell biology, we lack a phylogenetically comprehensive understanding of chromatin evolution. Here, we combine comparative proteomics and genomics analysis of chromatin in eukaryotes and archaea. Proteomics uncovers the existence of histone post-translational modifications in archaea. However, archaeal histone modifications are scarce, in contrast with the highly conserved and abundant marks we identify across eukaryotes. Phylogenetic analysis reveals that chromatin-associated catalytic functions (for example, methyltransferases) have pre-eukaryotic origins, whereas histone mark readers and chaperones are eukaryotic innovations. We show that further chromatin evolution is characterized by expansion of readers, including capture by transposable elements and viruses. Overall, our study infers detailed evolutionary history of eukaryotic chromatin: from its archaeal roots, through the emergence of nucleosome-based regulation in the eukaryotic ancestor, to the diversification of chromatin regulators and their hijacking by genomic parasites.Research in the A.S.-P. group was supported by the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement no. 851647) and the Spanish Ministry of Science and Innovation (PGC2018-098210-A-I00). We also acknowledge support of the Spanish Ministry of Science and Innovation to the EMBL partnership, the Centro de Excelencia Severo Ochoa and the CERCA Programme (Generalitat de Catalunya). C.N. is supported by an FPI PhD fellowship from the Spanish Ministry of Economy, Industry and Competitiveness (MEIC). X.G.-B. is supported by a Juan de la Cierva fellowship (FJC2018-036282-I) from MEIC. I.R.-T. was supported by a European Research Council (grant no. 616960). B.F.L. was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC; RGPIN-2017-05411) and by the ‘Fonds de Recherche Nature et Technologie’, Quebec. P.L.-G. and D.M. were supported by a Moore and Simons foundations grant (GBMF9739) and by European Research Council advanced grants (322669, 787904). Research in the C.S. group was supported by the ERC through project TACKLE (advanced grant no. 695192)

    Tendencias de la investigación sobre educación en los posgrados médicos

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    RESUMEN: Este estudio se enmarcó en la investigación: Caracterización del modelo en competencias profesionales de educación médica desarrollado en doce especializaciones clínicas y nueve quirúrgicas de la Facultad de Medicina, Universidad de Antioquia. Su objetivo fue indagar el estado del arte de la formación médica en los posgrados. La pregunta orientadora fue la siguiente: ¿hacia dónde se dirige actualmente la investigación en educación médica de posgrado? Se hizo un estudio descriptivo, no experimental, para el que se revisaron 12 bases de datos y se seleccionaron 28 artículos relacionados con la formación médica de posgrado. Se compararon, analizaron e interpretaron los hallazgos. Se evidenció un aumento del número de publicaciones sobre educación en las especialidades médicas. La tendencia investigativa en educación médica de posgrado apunta a la necesidad de hacer propuestas multi-intertransdisciplinarias y humanísticas basadas en el constructivismo; situar la evaluación como proceso haciendo énfasis en el aprendizaje y la participación de los estudiantes y construir sistemas de formación pedagógica de tutores y currículos interactivos y flexibles; es notoria la ausencia de estudios que promuevan la formación por competencias en los posgrados médicos.ABSTRACT: This study was framed in the research: Characterization of professional competency-based model in medical education developed in twelve clinical and nine surgical specializations at the Faculty of Medicine, University of Antioquia. Its aim was to inquire about the state of the art in medical postgraduate education. The guiding question was: Where is present-day research headed in medical postgraduate education. For this descriptive, nonexperimental work, 12 bibliographic databases were reviewed and 28 research articles related to graduate medical formation were selected. The findings were compared, analyzed and interpreted. The tendency in research on graduate medical education points to the need of having multi-inter-trans-disciplinary and humanistic proposals based on constructivism; to consider evaluation as a process emphasizing on learning and the participation of students, and to build systems of pedagogical formation of tutors and interactive and flexible curricula. The lack of studies that promote competencies-based training in postgraduate medical education is notorious

    Quality assurance through laboratory reference materials (LRMs): dataset for non-certified elements (Al, Fe, Li, Mn and Pb) in estuarine sediment BCR-277R

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    Datasets for aluminium (Al), iron (Fe), lithium (Li), manganese (Mn) and lead (Pb) in the commercial estuarine sediment BCR-277RThree specialized laboratories examined the determination of non-certified trace elements (Al, Fe, Li, Mn and Pb) in a commercial CRM and therefore, produced a so-called laboratory reference material (LRM). The dataset (total mass fractions and their associated uncertainties) were estimated both using parametric and non-parametric methods. The results provided a coherent assessment for all except for Pb, in agreement with the results found by the CRM producer. We discuss the feasibility of the implementation of small-sized specialized laboratory comparisons to produce LRMs (from CRMs) for non-certified chemicals and strongly discourage attempts by a single laboratory

    Synthesis and Characterization of Multilayered CrAlN/Al₂O₃ Tandem Coating Using HiPIMS for Solar Selective Applications at High Temperature

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    The effect of applying a negative bias during deposition of a previously designed multilayer solar selective absorber coating was studied on two types of substrates (316L stainless steel and Inconel 625). The solar selective coating is composed of different chromium aluminum nitride layers deposited using a combination of radiofrequency (RF), direct current (DC), and high-power impulse magnetron sputtering (HiPIMS) technologies. The chemical composition is varied to generate an infrared reflective/absorber layer (with low Al addition and N vacancies) and two CrAlN intermediate layers with medium and high aluminum content (Al/Cr = 0.6 and 1.2). A top aluminum oxide layer (Al₂O₃) is deposited as an antireflective layer. In this work, a simultaneous DC-pulsed bias (−100 V, 250 kHz) was applied to the substrates in order to increase the film density. The optical performance, thermal stability, and oxidation resistance was evaluated and compared with the performance obtained with similar unbiased coating and a commercial Pyromark paint reference at 600, 700, and 800 °C. The coating remained stable after 200 h of annealing at 600 °C, with solar absorptance (α) values of 93% and 92% for samples deposited on stainless steel and Inconel, respectively, and a thermal emittance ε25°C of 18%. The introduction of additional ion bombardment during film growth through bias assistance resulted in increased durability, thermal stability, and working temperature limits compared with unbiased coatings. The solar-to-mechanical energy conversion efficiency at 800 °C was found to be up to 2 times higher than Pyromark at C = 100 and comparable at C = 1000

    Accumulation of Scandium in Plasma in Patients with Chronic Renal Failure

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    Scandium (Sc) is an element with many industrial applications, but relatively little is known about its physiological and/or toxicological effects, and very little data are available concerning the role of Sc in chronic renal failure (CRF). This paper examines the changes in plasma levels of Sc in predialysis patients with CRF and the relationship with blood parameters. The participants in this trial were 48 patients with CRF in predialysis and 53 healthy controls. Erythrocyte, haemoglobin, and haematocrit counts in blood were determined, and levels of creatinine, urea, uric acid, albumin, total protein and Sc were measured in plasma. The glomerular filtration rate (GFR) was calculated using the Cockcroft-Gault index. The CRF patients were found to have higher plasma levels of creatinine, urea, uric acid, albumin, total protein, and Sc and a lower GFR than that the controls. Scandium in plasma was positively correlated with creatinine and plasma urea and negatively correlated with GFR, haemoglobin, and haematocrit and was associated with the risk of lower levels of erythrocytes, haemoglobin, and haematocrit. CRF was associated with increases in the circulating levels of scandium

    Propiedades psicométricas y datos normativos de la prueba ECCO_Senior: un instrumento para evaluar la comprensión gramatical en adultos mayores

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    El test ECCO_Senior se diseñó para evaluar la comprensión de oraciones en adultos mayores. Es una prueba corta y de fácil aplicación, que se ha empleado en distintos estudios previos. En el estudio participaron 670 personas, de 50 a 85 años de edad, que cumplían criterios de inclusión relativos al estatus cognitivo general, el estado de ánimo y porcentaje mínimo de aciertos en el test. Además de los test de cribado (MEC y GDS-15) y un cuestionario socio-demográfico, se aplicó a todos los participantes el test ECCO_Senior con el que se pueden obtener distintos índices (generales y específicos). Además de comprobar si existen diferencias entre los grupos según la edad y el nivel educativo, se evaluaron las propiedades psicométricas del test, incluyendo evidencias de validez en las que se probó la bondad de ajuste de tres modelos estructurales que sirven para identificar los índices que explican un mayor porcentaje de la varianza del constructo (comprensión de oraciones). Se ofrecen normas interpretativas del test por edad y nivel de estudios en los Apéndices. Los resultados indican que el test permite evaluar la comprensión de oraciones con una fiabilidad adecuada y es sensible a las dificultades que puede experimentar un adulto al realizar esta tarea. Los tres modelos muestran un buen ajuste y permiten concluir que las oraciones no ajustadas al orden sintáctico canónico y los distractores léxicos (si se considera el tipo de ítem) serían los mejores indicadores en términos del porcentaje de la varianza del constructo que explican.The ECCO_Senior test was designed to assess sentence comprehension in older adults. It is a short test and easy to apply, which has been used in different previous studies. The study involved 670 people, 50 to 85 years of age, who met inclusion criteria related to general cognitive status, mood and minimum percentage of performance in the test. In addition to the screening tests (MEC and GDS-15) and a socio-demographic questionnaire, the ECCO_Senior test was applied to all participants with which different indices (general and specific) can be obtained. In addition to checking if there are differences between the groups according to age and educational level, we evaluated the psychometric properties of the test, evidences of validity included, thus we tested the goodness of fit of three structural models that serve to identify the indices that explain a greater percentage of the variance of the construct (comprehension of sentences). Interpretive norms of the test are offered by age and level of studies in the Appendices. The results indicate that the test allows to evaluate sentence comprehension with adequate reliability and it is sensitive to the difficulties that an adult may experience when performing this task. The three models show a good fit and allow us to conclude that the sentences not adjusted to the canonical syntactic order and lexical foils (if the type of item is considered) would be the best indexes in terms of the percentage of construct’s variance they explain
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