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Pereira R.G.,University of Campinas | Nakamura R.N.,University of Campinas | Rodrigues M.V.N.,University of Campinas | Osorio-Tobon J.F.,Major College of Antioquia | And 2 more authors.
Journal of Supercritical Fluids | Year: 2017

The lignans phyllanthin and niranthin were extracted from Phyllanthus amarus using supercritical CO2 as solvent (SFE1) at different pressures (10, 20, 30 MPa) and temperatures (30, 40, 50 °C). The addition of 10% (w/w) of cosolvent (SFE2) was investigated at the same SFE1 conditions. Economic evaluation was performed for both processes. Temperature and pressure have no significant effects on the lignan yield of SFE2 with ethanol:water 50:50 v/v. The use of cosolvent increased the lignan recovery rus, but decreased the selectivity of the process. The SFE2 extracts showed lignan concentrations between 2.5% and 4.0%, whereas in SFE1 the lignan concentration of the extracts varied between 25% (60 °C/30 MPa) and 35% (40 °C/10 MPa). SFE2 (40 °C/10 MPa) presented the lowest cost of manufacturing. However, the SFE1 extract (40 °C/20 MPa) is ten times purer, which is a remarkable advantage given that the subsequent purification processes are expensive. © 2017 Elsevier B.V.


Escobar J.S.,Health and Wellness Research Center | Klotz B.,University of La Sabana | Klotz B.,Alpina S.A. | Valdes B.E.,Health and Wellness Research Center | And 3 more authors.
BMC Microbiology | Year: 2015

Background: The composition of the gut microbiota has recently been associated with health and disease, particularly with obesity. Some studies suggested a higher proportion of Firmicutes and a lower proportion of Bacteroidetes in obese compared to lean people; others found discordant patterns. Most studies, however, focused on Americans or Europeans, giving a limited picture of the gut microbiome. To determine the generality of previous observations and expand our knowledge of the human gut microbiota, it is important to replicate studies in overlooked populations. Thus, we describe here, for the first time, the gut microbiota of Colombian adults via the pyrosequencing of the 16S ribosomal DNA (rDNA), comparing it with results obtained in Americans, Europeans, Japanese and South Koreans, and testing the generality of previous observations concerning changes in Firmicutes and Bacteroidetes with increasing body mass index (BMI). Results: We found that the composition of the gut microbiota of Colombians was significantly different from that of Americans, Europeans and Asians. The geographic origin of the population explained more variance in the composition of this bacterial community than BMI or gender. Concerning changes in Firmicutes and Bacteroidetes with obesity, in Colombians we found a tendency in Firmicutes to diminish with increasing BMI, whereas no change was observed in Bacteroidetes. A similar result was found in Americans. A more detailed inspection of the Colombian dataset revealed that five fiber-degrading bacteria, including Akkermansia, Dialister, Oscillospira, Ruminococcaceae and Clostridiales, became less abundant in obese subjects. Conclusion: We contributed data from unstudied Colombians that showed that the geographic origin of the studied population had a greater impact on the composition of the gut microbiota than BMI or gender. Any strategy aiming to modulate or control obesity via manipulation of this bacterial community should consider this effect. © 2014 Escobar et al.


Bailao E.F.L.C.,Federal University of Goais | Bailao E.F.L.C.,State University of Goiás | Bailao E.F.L.C.,University of Brasilia | Parente J.A.,Federal University of Goais | And 11 more authors.
PLoS Neglected Tropical Diseases | Year: 2014

Iron is essential for the proliferation of fungal pathogens during infection. The availability of iron is limited due to its association with host proteins. Fungal pathogens have evolved different mechanisms to acquire iron from host; however, little is known regarding how Paracoccidioides species incorporate and metabolize this ion. In this work, host iron sources that are used by Paracoccidioides spp. were investigated. Robust fungal growth in the presence of the iron-containing molecules hemin and hemoglobin was observed. Paracoccidioides spp. present hemolytic activity and have the ability to internalize a protoporphyrin ring. Using real-time PCR and nanoUPLC-MSE proteomic approaches, fungal growth in the presence of hemoglobin was shown to result in the positive regulation of transcripts that encode putative hemoglobin receptors, in addition to the induction of proteins that are required for amino acid metabolism and vacuolar protein degradation. In fact, one hemoglobin receptor ortholog, Rbt5, was identified as a surface GPI-anchored protein that recognized hemin, protoporphyrin and hemoglobin in vitro. Antisense RNA technology and Agrobacterium tumefaciens-mediated transformation were used to generate mitotically stable Pbrbt5 mutants. The knockdown strain had a lower survival inside macrophages and in mouse spleen when compared with the parental strain, which suggested that Rbt5 could act as a virulence factor. In summary, our data indicate that Paracoccidioides spp. can use hemoglobin as an iron source most likely through receptor-mediated pathways that might be relevant for pathogenic mechanisms. © 2014 Bailão et al.


Ruiz H.O.,University of Antioquia | Ruiz H.O.,Cellular and Molecular Biology Unit | Ruiz H.O.,Major College of Antioquia | Gonzalez A.,Medical and Experimental Mycology Group | And 7 more authors.
PLoS Neglected Tropical Diseases | Year: 2011

Background: Paracoccidioides brasiliensis is a human thermal dimorphic pathogenic fungus. Survival of P. brasiliensis inside the host depends on the adaptation of this fungal pathogen to different conditions, namely oxidative stress imposed by immune cells. Aims and Methodology: In this study, we evaluated the role of alternative oxidase (AOX), an enzyme involved in the intracellular redox balancing, during host-P. brasiliensis interaction. We generated a mitotically stable P. brasiliensis AOX (PbAOX) antisense RNA (aRNA) strain with a 70% reduction in gene expression. We evaluated the relevance of PbAOX during interaction of conidia and yeast cells with IFN-γ activated alveolar macrophages and in a mouse model of infection. Additionally, we determined the fungal cell's viability and PbAOX in the presence of H2O2. Results: Interaction with IFN-γ activated alveolar macrophages induced higher levels of PbAOX gene expression in PbWt conidia than PbWt yeast cells. PbAOX-aRNA conidia and yeast cells had decreased viability after interaction with macrophages. Moreover, in a mouse model of infection, we showed that absence of wild-type levels of PbAOX in P. brasiliensis results in a reduced fungal burden in lungs at weeks 8 and 24 post-challenge and an increased survival rate. In the presence of H2O2, we observed that PbWt yeast cells increased PbAOX expression and presented a higher viability in comparison with PbAOX-aRNA yeast cells. Conclusions: These data further support the hypothesis that PbAOX is important in the fungal defense against oxidative stress imposed by immune cells and is relevant in the virulence of P. brasiliensis. © 2011 Hernandez Ruiz et al.


Hernandez O.,Major College of Antioquia | Araque P.,University of Antioquia | Tamayo D.,University of Medellín | Restrepo A.,Cellular and Molecular Biology Unit | And 4 more authors.
Medical mycology | Year: 2015

Paracoccidioides brasiliensis is the etiologic agent of one of the most common systemic mycoses in Latin America. As a dimorphic fungus, it must adapt to different environments during its life cycle, either in nature or within the host, enduring external stresses such as temperature or host-induced oxidative stress. In this study we addressed the role of alternative oxidase (PbAOX) in cellular homeostasis during batch culture growth and the morphological transition of P. brasiliensis. Using a PbAOX-antisense-RNA (PbAOX-aRNA) strain with a 70% reduction in gene expression, we show that PbAOX is crucial for maintaining cell viability and vitality during batch culture growth of yeast cells, in what appears to be a pH-dependent manner. We also show that silencing of PbAOX drastically reduced expression levels of other detoxifying enzymes (PbY20 and PbMSOD). In addition, our data indicate that PbAOX plays a role during the morphological transition, namely, during the yeast-to-mycelia germination and mycelia/conidia-to-yeast transition, essential events during the establishment of infection by dimorphic fungal pathogens. Altogether, our findings support the hypothesis that PbAOX is important for the maintenance of cellular homeostasis, possibly by assisting redox balancing during cell growth and the morphological switch of P. brasiliensis. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.


Patent
Major College of Antioquia and Diaz Velez | Date: 2015-04-29

The present invention relates to a luminaire based on the same optical principle as the cinema, in which only one image is presented at any given instant of time but the image appears to be in constant movement. According to the invention, each LED lights up simultaneously for an instant of time in a sequential manner, as with television screens. The LED luminaire of the invention includes a configuration of electronic elements in a circuit which controls the lighting of the LED array and which also includes a PIC microcontroller, a CMOS multiplexer and an operational amplifier that can be used to improve the power consumption of the luminaire, lighting control and the lighting quality of the LED luminaire.


Brida J.G.,University of Management and Economics | Pulina M.,University of Sassari | Riano E.,University of the Republic of Uruguay | Zapata-Aguirre S.,Major College of Antioquia
Anatolia | Year: 2012

This study analyses cruise visitors' travel experience, their intention to return to a destination as land tourists, and the probability to recommend the destination to others. Consumer's satisfaction is evaluated by taking into account the economic production factors, human and physical capital. "Satisfaction with prices" is also included to evaluate the monetary value of the overall purchasing experience. Safety in the harbour is considered as a further attribute. The empirical data were collected via a survey of cruise ship passengers that stopped in Cartagena de Indias (Colombia) during 2009. A structural equation model is developed in order to test whether the hypothesized model is consistent with the collected data. The findings reveal that overall satisfaction positively influences customers' loyalty. Loyalty is also positively influenced by prices but negatively by an unsafe perception. Finally, loyalty positively affects both the intention to return as land tourists and to recommend, though with a different magnitude. © 2012 Copyright Taylor and Francis Group, LLC.


Garcia-Gulfo M.H.,Major College of Antioquia | Garcia-Zea J.A.,Major College of Antioquia
Revista de Salud Publica | Year: 2012

Objective Determining cardiovascular risk factor prevalence in university students from Medellin. Design A descriptive study of 112 students determined their lipid profile and a survey was conducted to assess their life-style and family history. There results were analyzed by gender using Chi2 test and simple binary logistic regression. Results 82.1 % of the sample was female. A modifiable risk factor was found for at least 99.1 % of the study population: sedentary life-style (79.5 %), smoking (17 %), alcohol consumption (75.0 %), atherogenic diet (78.6 %), hypertension (1.8 %), some form of dyslipidemia (48.3 % BMI >25 (4.5 %)) and stress (86.7 %). At least one non-modifiable risk factor was identified in 77.7 % of the students. Conclusions New intervention strategies are needed given the significant percentage of the target population ±19 mean age having cardiovascular disease risk factors and young people must be encouraged to develop healthy life-styles to reduce cardiovascular risk factor prevalence.


Brida J.G.,University of Management and Economics | Zapata S.,Major College of Antioquia
Anatolia | Year: 2010

This paper provides an overview of the different impacts of cruise tourism in Costa Rica. The purpose of the study is to provide information, based on primary investigation collected by the Costa Rican Tourism Institute during the period 2006 - 2008, to help the decision making process and the establishment of policies and strategies for cruise ship tourism. We focus on cruise passenger demographic characteristics, preferences and expenditure behaviors, and we compare the expenditures of the average cruise passenger with the average land tourist that visits the country. We show that Costa Rica's cruise tourists tend to visit the same attractions at the same time as the land tourist. We show that cruisers are older and less wealthy, and spend less time and money than the average tourist, raising some concerns as to whether cruise tourism in Costa Rica should be encouraged. © 2010 anatolia.


Patent
Major College of Antioquia | Date: 2013-02-20

The present invention relates to a luminaire based on the same optical principle as the cinema, in which only one image is presented at any given instant of time but the image appears to be in constant movement. According to the invention, each LED lights up simultaneously for an instant of time in a sequential manner, as with television screens. The LED luminaire of the invention includes a configuration of electronic elements in a circuit which controls the lighting of the LED array and which also includes a PIC microcontroller, a CMOS multiplexer and an operational amplifier that can be used to improve the power consumption of the luminaire, lighting control and the lighting quality of the LED luminaire.

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