205 research outputs found

    Determinación del comportamiento de velocidad de sedimentación de micropartículas frente a cambios del potencial de hidrógeno del electrolito en que se suspenden

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    79 p.El objetivo de este trabajo es determinar y analizar el comportamiento de la velocidad de sedimentación terminal de micropartículas de un tamaño medio de 250 nm, las cuales están suspendidas en agua, ante cambios en el potencial iónico de la suspensión, esto se realizó añadiendo nitrato de potasio (KNO3). Cabe mencionar que esta memoria fue realizada en base a datos de carácter secundario. En el trabajo se describe la modelación matemática clásica de los procesos de sedimentación, se estudia además las fuerzas de interacción electroquímicas entre partículas, así como también, se describe la medición de estas. Tras lo cual se describe detalladamente el sistema de partículas empleado, preparación de las suspensiones, la metodología experimental utilizada y los resultados alcanzados, en este caso de velocidad de sedimentación del sistema de partículas. Los resultados obtenidos en esta memoria se analizan y discuten, en este proceso, se desprendió cuán importante son las fuerzas iónicas de la suspensión, las que influyen de manera significativa en la magnitud de las fuerzas de interacción electroquímicas y junto con ello en la variación de la velocidad de sedimentación

    A Fluid-Dynamic Numerical Model for the Selective Laser Melting of High-Thickness Metallic Layers

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    Productivity in the Selective Laser Melting Process (SLM) is directly related with the thickness of the powder bed that is repeatedly applied, at every increment, in the growing of consolidated material in the additive manufacturing process. Although most of the relevant phenomena (limited diffusivity associated to particles contact, phase changes, gradients of surface tension associated with Marangoni convection, or even recoil pressure) are considered in the models with small bed thicknesses (roughly 20 µm ? 40 µm), in the case of larger thicknesses (between 100 µm and 200 µm) these factors strongly influence the size and shape of the fusion bath leading to a non trivial geometry of the final consolidated material. The present work proposes the use of the Arbitrary Lagrangean-Eulerian method (ALE method) to solve the thermal and Navier-Stokes equations in the frame of a free-moving discretization to predict simultaneously the space-time temperature evolution and the associated fusion bath dynamics. It allows for using a continuous domain to represent the powder bed, which, instead of a particle model approach, is advantageously compatible with realistic process parameters, where long paths are covered by the laser. The model was validated with experimental data using Inconel as working material, showing a good degree of agreement

    Effect of Different Technological Factors on the Gelation of a Low-Lectin Bean Protein Isolate

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    Gelling ability of a bean protein isolate (BPI) obtained from a naturally low-lectin variety (Phaseolus vulgaris var. Almonga) was analysed. For that purpose differences on gels processing: concentration (14% and 17%), salt addition (0 and 2%), and pH (6.5 –lot A- and 7 –lot B), were studied to obtain suitable colour, mechanical and viscoelastic properties for making appropriate meat and seafood analogues. Gelation at pH 7 at both 14 and 17% BPI concentrations, produced less rigid, more flexible, time-stable and cohesive gel networks. Colour of the resulting gels was white enough to be considered as an adequate base for making plant-based analogues. The content of total galactoside, inositol phosphates and trypsin inhibitors (bioactive compounds) present in one serving (100 g) of these BPI gels were up to 0.80 mg/g, 8.06 mg/g and 239 TIUs, respectively

    A comparative study of eight serological methods shows that spike protein-based ELISAs are the most accurate tests for serodiagnosing SARS-CoV-2 infections in cats and dogs

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    IntroductionCoronavirus disease 2019 (COVID-19) is an infectious zoonotic disease caused by SARS-CoV-2. Monitoring the infection in pets is recommended for human disease surveillance, prevention, and control since the virus can spread from people to animals during close contact. Several diagnostic tests have been adapted from humans to animals, but limited data on the validation process are available.MethodsHerein, the first comparative study of six “in house” and two commercial serological tests developed to monitor SARS-CoV-2 infection in pets was performed with a well-coded panel of sera (61 cat sera and 74 dog sera) with a conservative criterion (viral seroneutralisation and/or RT–qPCR results) as a reference. Four “in house” tests based on either the RBD fragment of the spike protein (RBD-S) or the N-terminal fragment of the nucleoprotein (N) were developed for the first time. The analytical specificity (ASp) of those tests that showed the best diagnostic performance was assessed. The validation included the analysis of a panel of sera obtained pre-pandemic from cats and dogs infected with other coronaviruses to determine the analytical Sp (17 cat sera and 41 dog sera).Results and discussionELISAS based on the S protein are recommended in serosurveillance studies for cats (RBD-S SALUVET ELISA, ELISA COVID UNIZAR and INgezim® COVID 19 S VET) and dogs (INgezim® COVID 19 S VET and RBD-S SALUVET ELISA). These tests showed higher diagnostic sensitivity (Se) and DSp in cats (>90%) than in dogs. When sera obtained prior to the pandemic and from animals infected with other coronaviruses were analyzed by RBD-S and N SALUVET ELISAs and INgezim® COVID 19 S VET, a few cross reactors or no cross reactions were detected when dog and cat sera were analyzed by tests based on the S protein, respectively. In contrast, the number of cross reactions increased when the test was based on the N protein. Thus, the use of tests based on the N protein was discarded for serodiagnosis purposes. The results obtained revealed the most accurate serological tests for each species. Further studies should attempt to improve the diagnostic performance of serological tests developed for dogs

    Diabetes Remission Is Modulated by Branched Chain Amino Acids According to the Diet Consumed: From the CORDIOPREV Study

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    Scope: Branched Chain Amino Acids (BCAA) plasma levels may be differentially associated with type 2 diabetes mellitus (T2DM) remission through the consumption of the Mediterranean diet (Med) and a low-fat (LF) diet. Methods: One hundred eighty-three newly diagnosed T2DM patients within the CORDIOPREV study are randomized to consume the Med or a LF diet. BCAA plasma levels (isoleucine, leucine, and valine) are measured at fasting and after 120 min of an oral glucose tolerance test (OGTT) at the baseline of the study and after 5 years of the dietary intervention. Results: Isoleucine, leucine, and valine plasma levels after 120 min of an OGTT in the Med diet (N = 80) are associated by COX analysis with T2DM remission: HR per SD (95% CI): 0.53 (0.37–0.77), 0.75 (0.52–1.08), and 0.61 (0.45–0.82), respectively; no association is found in patients who consumed a LF diet (N = 103). BCAA plasma levels combined in a score show a HR of 3.33 (1.55–7.19) of T2DM remission for patients with a high score values in the Med diet, while in those with a LF diet, no association is found. Conclusión: The study suggests that BCAA measurements potentially be used as a tool to select the most suitable diet to induce T2DM remission by nutritional strategies

    Parasitología interactiva: Protozoos y afines

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    Desarrollo de una guía interactiva donde se muestran los ciclos biológicos, imágenes y dibujos de los estadios evolutivos de los principales géneros y especies de parásitos protozoos relevantes en al ámbito veterinario

    HIV and HCV screening by non-infectious diseases physicians: can we improve testing and hidden infection rates?

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    BackgroundMissed opportunities for Human Immunodeficiency Virus (HIV) and Hepatitis C Virus (HCV) testing remain high. We aimed to ascertain the knowledge of screening guidelines and attitudes of non-infectious disease (ID) hospital physicians and assess the impact of a 1-h session on screening rates and diagnoses.MethodsThis interventional study consisted of a 1-h training session on HIV and HCV epidemiology and testing guidelines for non-ID physicians. Pre-and post-session questionnaires compared the knowledge of the guidelines and attitudes toward screening before and after the session. Rates of screening and diagnoses were compared in three 6 months periods: before, immediately after, and 24 months ±4 after the session.ResultsA total of 345 physicians from 31 departments participated in these sessions. Before the session, 19.9% (28% medical, 8% surgical) and 17.9% (30% medical, 2.7% surgical) were aware of HIV and HCV testing guidelines, respectively. The willingness to routinely test increased from 5.6 to 22%, whereas not ordering tests decreased from 34.1 to 2.4%. HIV screening rates significantly increased by 20% after the session (7.7 vs. 9.3 tests per 103 patients; p < 0.001), and the effect persisted until the long-term period. The HIV diagnosis rate increased globally (3.6 vs. 5.2 HIV diagnoses per 105 patients; p = 0.157), mainly because of medical services (4.7 vs. 7.7 per 105 patients; p = 0.082). The HCV screening rate increased significantly immediately and in the long term only in medical services (15.7 and 13.6%, respectively). The new active HCV infection rates increased immediately and declined steeply thereafter.ConclusionA short session for non-ID physicians can improve HIV/HCV screening, increase diagnosis, and contribute to disease elimination

    La necrópolis de Los Collados de Almedinilla (Córdoba). Historiografía de un cementerio complejo

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    The excavations in the Necropolis of Los Collados, carried out by Luis Maraver y Alfaro in the second half of the 19th century, and afterwards, those done by Pierre Paris and Arthur Engels at the beginning of the 20th century, serve to define archeologically that which would be considered Iberian culture. Since then, apart from a few reviews of materials, this site has been forgotten to the point that its exact location was unknown to researchers. It was because of this that prospecting work and excavation were carried out in May and July 2019 that allowed archeologists to locate the necropolis and recover various tombs and ritual deposits. In this work we present the preliminary results of both interventions

    Space and time in the tectonic evolution of the northwestern Iberian Massif: Implications for the Variscan belt.

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    Recent advances in geochemical studies of igneous rocks, isotopic age data for magmatism and metamorphism, quantitative pressure-temperature (P-T) estimates of metamorphic evolution, and structural geology in the northwestern Iberian Massif are integrated into a synthesis of the tectonic evolution that places the autochthonous and allochthonous terranes in the framework of Paleozoic plate tectonics. Because northwestern Iberia is free from strike-slip faults of continental scale, it is retrodeformable and preserves valuable information about the orthogonal component of convergence of Gondwana with Laurentia and/or Baltica, and the opening and closure of the Rheic Ocean. The evolution deduced for northwest Iberia is extended to the rest of the Variscan belt in an attempt to develop a three-dimensional interpretation that assigns great importance to the transcurrent components of convergence. Dominant Carboniferous dextral transpression following large Devonian and Early Carboniferous thrusting and recumbent folding is invoked to explain the complexity of the belt without requiring a large number of peri-Gondwanan terranes, and its ophiolites and highpressure allochthonous units are related to a single oceanic closure. Palinspastic reconstruction of the Variscan massifs and zones cannot be achieved without restoration of terrane transport along the colliding plate margins. A schematic reconstruction is proposed that involves postcollisional strike-slip displacement of ~3000 km between Laurussia and Gondwana during the Carboniferous
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