59 research outputs found

    Régimen cambiario colombiano y venezolano y sus implicaciones en la repatriación de capitales por inversión extranjera

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    En el presente documento se analiza y compara el sistema de control de cambios actualmente vigente en Colombia y Venezuela, con base en un estudio de ambos sistemas legales. Se explica los pasos y requerimientos que componen todo proceso destinado a la adquisición de divisas en estos países. Por lo demás, se precisa el tratamiento legal atribuido a los inversionistas extranjeros en Colombia y Venezuela, así como las implicaciones que estas normativas legales tienen en los inversionistas extranjeros al momento de decidir en invertir en estos Estados. Explicamos la normatividad y el proceso relacionado con la repatriación de capitales y dividendos que sean resultado de una inversión desarrollada de conformidad con las leyes de Colombia y Venezuela. Como parte de las conclusiones alcanzadas, consideramos que las excesivas y estrictas políticas en relación con el sistema de control cambiario en Venezuela, ha afectado de manera negativa el mercado y la economía del país, ya que los inversionistas no están dispuestos a lidiar con una inestabilidad legal, la cual es motivada por las constantes modificaciones realizadas al sistema de cambio y la excesiva interferencia del gobierno en la economía del país, lo cual al final sólo crea desconfianza para el inversionista extranjero. Por el contrario, Colombia es reconocida actualmente por ofrecer amigables regulaciones y estabilidad legal a la inversión extranjera desarrollada en este país, lo que ha llevado a esta nación a ser uno de los principales destinos para la inversión extranjera en Latinoamérica.We analyze and compare the currently currency exchange system in forced in Colombia and Venezuela, based upon the study of both countries legal system. We explain the steps and requirements that compose the process in order to acquire foreign currency in these countries. Further, we outline the compiled legal treatment offered to foreign investment in Colombia and Venezuela, and the implications that these normative policies have in foreign investors at the moment of deciding whether or not to invest in these countries. We explain the legal rules and the process related to the repatriation of dividends and profits earned as a result of investment developed under Colombian and Venezuelan laws. As a part of the conclusions reached, we consider that the excessive and strict policies regarding currency exchange system control in Venezuela have affected in negative manners the market and the economy of the country, since investors are not willing to struggle with the legal instability, motivated by the constants modifications made to the currency exchange legal system and the excessive interference of the government in the economic, which at the end only creates uncertainty for the foreign investor. As contrast, Colombia is currently recognized for offering friendly regulations and legal stability to international investment, which have lead this country to the major destinations of foreign investment in Latin America.Especialista en Derecho ComercialEspecializació

    Feasibility of Calcium Sulfate Moulds Made by Inkjet 3D Printing for Rapid Casting of Aluminium Alloys

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    [EN] In this research, a comparative analysis has been carried out between a traditional sand casting process and a modern mould obtained by additive manufacturing (AM), in the context of aluminium parts production. In this case of AM, an inkjet 3D printing (3DP) process allowed us to create a ceramic mould. A numerical simulation was carried out to study the filling and cooling rates of both parts. The design freedom typical of the 3DP technique allowed us to optimize the f illing system. The results showed that in sand moulding, the speed in the gate suddenly increased when the liquid metal entered the part cavity, leading to severe turbulence due to the fountain e ect. The input of air is related to the speed in the gate. Nevertheless, the results showed that when using the 3DP mould, the speed in the gate remained constant and the filling process was homogenous. With regard to the dimensional precision, while the staircase e ect in the surface of the 3DP mould is the most critical aspect to control, in the sand casting mould the critical aspect is the dimensional precision of the pattern. Microstructures of the cross-section of the moulded parts showed folded shapes and air input in sand casting, which could be produced by the severe turbulence and the oxide f ilm present in the melt during the filling process. On the other hand, the porosity found in parts produced with the 3DP mould corresponds to shrinkage; during the filling process, the remaining binder is vaporized, creating nucleation points. In this way, pores are formed by shrinkage and a mixture of shrinkage and gas entrapment. With these considerations, it can be concluded that AM shows feasibility and advantages as an alternative to the sand casting method for aluminium alloysSIAgencia Estatal de Investigació

    Antitumor effects of lactate transport inhibition on esophageal adenocarcinoma cells

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    As a consequence of altered glucose metabolism, cancer cell intake is increased, producing large amounts of lactate which is pumped out the cytosol by monocarboxylate transporters (MCTs). MCT 1 and MCT4 are frequently overexpressed in tumors, and recently, MCT inhibition has been reported to exert antineoplastic effects. In the present study, MCT1 and MCT4 levels were assessed in esophageal adenocarcinoma (EAC) cells and the effects of the MCT-1 selective inhibitor AZD3965, hypoxia, and a glucose overload were evaluated in vitro. Two EAC cell lines (OE33 and OACM5.1C) were treated with AZD3965 (10–100 nM) under different conditions (normoxia/hypoxia) and also different glucose concentrations, and parameters of cytotoxicity, oxidative stress, intracellular pH (pHi), and lactate levels were evaluated. MCT1 was present in both cell lines whereas MCT4 was expressed in OE33 cells and only in a small proportion of OACM5.1C cells. Glucose addition did not have any effect on apoptosis nor cell proliferation. AZD3965 increased apoptosis and reduced proliferation of OACM5.1C cells, effects which were abrogated when cells were growing in hypoxia. MCT1 inhibition increased intracellular lactate levels in all the cells evaluated, but this increase was higher in cells expressing only MCT1 and did not affect oxidative stress. AZD3965 induced a decrease in pHi of cells displaying low levels of MCT4 and also increased the sodium/hydrogen exchanger 1 (NHE-1) expression on these cells. These data provide in vitro evidence supporting the potential of MCT inhibitors as novel antineoplastic drugs for EAC and highlight the importance of achieving a complete MCT inhibition

    Application of Vacuum Techniques in Shell Moulds Produced by Additive Manufacturing

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    [EN] This research shows the feasibility of the additive manufacturing technique (AM), Binder Jetting (BJ), for the production of shell moulds, which are filled by vacuum suction in the field of aluminium parts production. In addition, this study compares the gravity pouring technique and highlights the advantages of using vacuum techniques in AM moulds. A numerical simulation was carried out to study the behaviour of the liquid metal inside the moulds and the cooling rate of parts was analysed. The results show that in the gravity-pouring mould, the velocity in the gate causes moderate turbulence with small waves. However, vacuum suction keeps the velocity constant by eliminating waves and the filling process is homogeneous. Regarding dimensional accuracy, the staircase e ect on the surface of the 3D moulds was the most critical aspect. The vacuum provides very homogeneous values of roughness across the entire surface of the part. Similarly, 3D scanning of castings revealed more accurate dimensions thanks to the help of vacuum forces. Finally, the microstructure of the cross section of the moulded parts shows that the porosity decreases with the vacuum filled. In both cases, the origin of the pores corresponds to gas entrapment and shrinkage during the filling process, the binder vaporization and nucleation points creation, leading to pores by shrinkage, gas entrapment or a mixture of both. This is the first study that uses vacuum f illing techniques in moulds created by BJ, demonstrating the feasibility and advantages of AM using vacuum techniques, as an alternative to traditional casting.SIAgencia Estatal de Investigació

    Intrinsic value of the impact factor of scientific journals

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    Se analiza el porqué de las citaciones de los artículos. Se realizan también algunas consideraciones sobre el factor de impacto de las revistas, sus ventajas y sus posibles defectos. El factor de impacto de las revistas, desde su popularización por el Institute for Scientific Information, ha tomado una gran importancia como parámetro objetivo de evaluación de las revistas científicas y, por extensión, de todo lo que las rodea. No hay correlación con el desfase en factores de impacto de algunas revistas anglosajonas y el de las revistas escritas en otros idiomas. Probablemente se benefician de publicar en inglés y del llamado “efecto Mateo”, según el cual los investigadores científicos eminentes cosechan aplausos mucho más nutridos que otros investigadores, menos conocidos, por contribuciones equivalentes. Es paradójico también que los grandes descubrimientos de nuestra época no figuren entre los 100 artículos más citados. No hay tampoco una correlación entre todos los artículos aparecidos en una publicación y su factor de impacto; la mitad de los artículos de una revista son citados diez veces más que la otra mitad. Los artículos citados 0 veces reciben el mérito de los mejores. Lo ortodoxo sería utilizar en cada artículo el número de citas que recibe, que sería su propio factor de impacto y, para los autores, el índice H.The reason of higher number of citations of some articles is discussed. Some considerations about the journals’ impact factor, its merits and its pitfalls are also made. Scientific journals’ impact factor, popularized by the Institute for Scientific Information, has become an objective parameter for authors’ evaluation and also for institutions and other related circumstances. There is no reason for the impact factor’s gap between some English journals and those written in other languages. English journals probably benefit of the “Mathew’s effect”, according to which eminent scientists are more rewarded by similar contributions than others less known. It is paradoxical that most of the major achievements of our age do not appear among the 100 most cited articles. There is no homogeneity among all the articles appearing in each scientific journal: half of the articles are cited ten times more than the other half. However, those articles cited 0 times are credited like the better ones. Each article should be evaluated by its own citations, which would be its impact factor; the authors should be evaluated by their H index

    The ten most cited articles of the journal “Nutricion Hospitalaria”

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    Después de 36 años de publicación ininterrumpida de la revista Nutrición Hospitalaria, hemos recopilado los diez artículos más citados. Se muestra también la relación de los diez artículos con más citas a escala mundial; asimismo se estratifican las citaciones según el idioma, inglés o español, la temática o los años analizados. Nutr. Hosp. es, a nivel mundial, la revista de nutrición ibero-latinoamericana mejor valorada. Por el volumen de artículos publicados, con 369 ítems citables en 2014, Nutr Hosp se sitúa en cuarto lugar de todas las revistas de nutrición. Permitir la publicación de artículos en inglés o hacerlo simultáneamente en castellano y en inglés, así como estar en régimen de “Open Access” sin restricción de ningún tipo en la difusión desde el momento de aparición de los artículos, son probablemente elementos favorecedores de las citas.After 36 years of continued publication of the journal Nutrición Hospitalaria, a list with the ten most cited articles published in it is elaborated. The top ten most cited articles in the world literature and stratification according to language, English or Spanish, subject, or period of time published are also analyzed. Nutr Hosp is the most important Ibero latin American nutrition journal. Nutr Hosp published 369 items in 2014 gaining the fourth position among all the world’s journals devoted to nutrition. Article publication in English, or simultaneously in Spanish and English and Open Access policy probably benefit the number of citations

    Occurrence of melatonin and indolic compounds derived from L-tryptophan yeast metabolism in fermented wort and commercial beers

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    Melatonin and serotonin are bioactive compounds present in foods and beverages and related to neuroprotection and anti-angiogenesis, among other activities. They have been described in wines and the role of yeast in their formation is clear. Thus, this study evaluates the content of these bioactives and other related indolic compounds in beer. For this purpose, commercial beers were analyzed by a validated UHPLC-HRMS method and sample treatment optimized due to the low concentrations expected. Moreover, a wort was fermented with different commercial beer yeast (Abbaye, Diamond, SafAle, SafLager) in order to monitor the formation of these bioactives during the elaboration process. Results show that indolic compounds such as N-acetylserotonin and 3-indoleacetic acid are produced during the alcoholic fermentation of wort. Moreover, the occurrence of four indolic compounds (5-hydroxytryptophan, N-acetylserotonin, 3-indoleacetic acid, L-tryptophan ethyl ester) in commercial beers is reported for the first time.Ministerio de Economía y Competitividad AGL2013-47300-C3-2-R, AGL2016-77505-C3-2-

    Pseudomonas aeruginosa Susceptibility in Spain: Antimicrobial Activity and Resistance Suppression Evaluation by PK/PD Analysis

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    Pseudomonas aeruginosa remains one of the major causes of healthcare-associated infection in Europe; in 2019, 12.5% of invasive isolates of P. aeruginosa in Spain presented combined resistance to ≥3 antimicrobial groups. The Spanish nationwide survey on P. aeruginosa antimicrobial resistance mechanisms and molecular epidemiology was published in 2019. Based on the information from this survey, the objective of this work was to analyze the overall antimicrobial activity of the antipseudomonal antibiotics considering pharmacokinetic/pharmacodynamic (PK/PD) analysis. The role of PK/PD to prevent or minimize resistance emergence was also evaluated. A 10,000-subject Monte Carlo simulation was executed to calculate the probability of target attainment (PTA) and the cumulative fraction of response (CFR) considering the minimum inhibitory concentration (MIC) distribution of bacteria isolated in ICU or medical wards, and distinguishing between sample types (respiratory and non-respiratory). Ceftazidime/avibactam followed by ceftolozane/tazobactam and colistin, categorized as the Reserve by the Access, Watch, Reserve (AWaRe) classification of the World Health Organization, were the most active antimicrobials, with differences depending on the admission service, sample type, and dose regimen. Discrepancies between EUCAST-susceptibility breakpoints for P. aeruginosa and those estimated by PK/PD analysis were detected. Only standard doses of ceftazidime/avibactam and ceftolozane/tazobactam provided drug concentrations associated with resistance suppression.This research was funded by the UPV/EHU (GIU 20/048)

    COVIDGR Dataset and COVID-SDNet Methodology for Predicting COVID-19 Based on Chest X-Ray Images

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    Currently, Coronavirus disease (COVID-19), one of the most infectious diseases in the 21st century, is diagnosed using RT-PCR testing, CT scans and/or Chest X-Ray (CXR) images. CT (Computed Tomography) scanners and RT-PCR testing are not available in most medical centers and hence in many cases CXR images become the most time/cost effective tool for assisting clinicians in making decisions. Deep learning neural networks have a great potential for building COVID-19 triage systems and detecting COVID-19 patients, especially patients with low severity. Unfortunately, current databases do not allow building such systems as they are highly heterogeneous and biased towards severe cases. This article is three-fold: (i) we demystify the high sensitivities achieved by most recent COVID-19 classification models, (ii) under a close collaboration with Hospital Universitario Clínico San Cecilio, Granada, Spain, we built COVIDGR-1.0, a homogeneous and balanced database that includes all levels of severity, from normal with Positive RT-PCR, Mild, Moderate to Severe. COVIDGR-1.0 contains 426 positive and 426 negative PA (PosteroAnterior) CXR views and (iii) we propose COVID Smart Data based Network (COVID-SDNet) methodology for improving the generalization capacity of COVID-classification models. Our approach reaches good and stable results with an accuracy of 97.72%±0.95% , 86.90%±3.20% , 61.80%±5.49% in severe, moderate and mild COVID-19 severity levels. Our approach could help in the early detection of COVID-19. COVIDGR-1.0 along with the severity level labels are available to the scientific community through this link https://dasci.es/es/transferencia/open-data/covidgr/This work was supported by the project DeepSCOP-Ayudas Fundación BBVA a Equipos de Investigación Científica en Big Data 2018, COVID19_RX-Ayudas Fundación BBVA a Equipos de Investigación Científica SARS-CoV-2 y COVID-19 2020, and the Spanish Ministry of Science and Technology under the project TIN2017-89517-P. S. Tabik was supported by the Ramon y Cajal Programme (RYC-2015-18136). A. Gómez-Ríos was supported by the FPU Programme FPU16/04765. D. Charte was supported by the FPU Programme FPU17/04069. J. Suárez was supported by the FPU Programme FPU18/05989. E.G was supported by the European Research Council (ERC Grant agreement 647038 [BIODESERT])

    Mitochondrial Oxidative Stress Promotes Cardiac Remodeling in Myocardial Infarction through the Activation of Endoplasmic Reticulum Stress

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    We have evaluated cardiac function and fibrosis in infarcted male Wistar rats treated with MitoQ (50 mg/kg/day) or vehicle for 4 weeks. A cohort of patients admitted with a first episode of acute MI were also analyzed with cardiac magnetic resonance and T1 mapping during admission and at a 12-month follow-up. Infarcted animals presented cardiac hypertrophy and a reduction in the left ventricular ejection fraction (LVEF) and E- and A-waves (E/A) ratio when compared to controls. Myocardial infarction (MI) rats also showed cardiac fibrosis and endoplasmic reticulum (ER) stress activation. Binding immunoglobulin protein (BiP) levels, a marker of ER stress, were correlated with collagen I levels. MitoQ reduced oxidative stress and prevented all these changes without affecting the infarct size. The LVEF and E/A ratio in patients with MI were 57.6 ± 7.9% and 0.96 ± 0.34, respectively. No major changes in cardiac function, extracellular volume fraction (ECV), or LV mass were observed at follow-up. Interestingly, the myeloperoxidase (MPO) levels were associated with the ECV in basal conditions. BiP staining and collagen content were also higher in cardiac samples from autopsies of patients who had suffered an MI than in those who had died from other causes. These results show the interactions between mitochondrial oxidative stress and ER stress, which can result in the development of diffuse fibrosis in the context of MI
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