The purpose of the study. Running speed represents a global marker of individual performance and ... more The purpose of the study. Running speed represents a global marker of individual performance and provides a simple method of objective measurement of motor performance for use in clinical and research environments. Speed is most often at relatively short distances at normal or fast pace, using methods of obtaining manual time (e.g., stopwatch) or automated (e.g., photocells). Materials and methods. The sample consisted of 25 students, 12 males and 13 females, all 13 years old and walked a course 20 meters away, we used to obtain the time elapsed the time, and the method by photocells. The agreement was examined using Bland and Altman graphs and linear regression. Results. There are significant and strong differences between the evaluation methods (T =14,205; p<0,001) and there is a significant and strong correlation between the variables (r = 0.902; p<0.001). Conclusions. This study suggests that for measurement in research context or in sports aimed at high yield it is advisa...
This research presents an approach based on artificial intelligence techniques for wheel polygoni... more This research presents an approach based on artificial intelligence techniques for wheel polygonization detection. The proposed methodology is tested with dynamic responses induced on the track by passing a Laagrss-type rail vehicle. The dynamic response is attained considering the application of a train-track interaction model that simulates the passage of the train over a set of accelerometers installed on the rail and sleepers. This study, which considers an unsupervised methodology, aims to compare the performance of two feature extraction techniques, namely the Autoregressive Exogenous (ARX) model and Continuous Wavelets Transform (CWT). The extracted features are then submitted to data normalization considering the Principal Component Analysis (PCA) applied to suppress environmental and operational effects. Next to data normalization, data fusion using Mahalanobis distance is performed to enhance the sensitivity to the recognition of defective wheels. Finally, an outlier analy...
New approaches aimed at identifying patient-specific drug targets and addressing unmet clinical n... more New approaches aimed at identifying patient-specific drug targets and addressing unmet clinical needs in the framework of precision medicine are a strong motivation for researchers worldwide. As scientists learn more about proteins that drive known diseases, they are better able to design promising therapeutic approaches to target those proteins. The field of nanotechnology has been extensively explored in the past years, and nanoparticles (NPs) have emerged as promising systems for target-specific delivery of drugs. Virus-like particles (VLPs) arise as auspicious NPs due to their intrinsic properties. The lack of viral genetic material and the inability to replicate, together with tropism conservation and antigenicity characteristic of the native virus prompted extensive interest in their use as vaccines or as delivery systems for therapeutic and/or imaging agents. Owing to its simplicity and non-complex structure, one of the viruses currently under study for the construction of VL...
Anais do X Workshop de Visualização, Evolução e Manutenção de Software (VEM 2022)
Continuous Integration (CI) is a powerful tool to leverage software development in a safe, reliab... more Continuous Integration (CI) is a powerful tool to leverage software development in a safe, reliable, and efficient way. However, in day-to-day of software development, bad habits can arise in working with CI, which can make CI not reach its full potential in projects. These bad habits we call CI bad practices. This paper presented an exploratory study on closed-source projects to investigate how CI bad practices can affect software quality. We observe (1) the impact on the quality internal attributes after the implantation of CI, (2) the evolution of software quality indicators over time, and (3) the bad practices considered most harmful to the software quality by the development teams. Our results mean that projects affected by CI bad practices will not necessarily have their quality impaired. However, this does not mean that quality will be maintained or improved over time. Our analysis of the quality indicators has allowed us to observe that, generally, they have remained stable,...
Numa primeira fase é analisada a evolução do luxo ao longo da história, até à atualidade. Será an... more Numa primeira fase é analisada a evolução do luxo ao longo da história, até à atualidade. Será analisado o comportamento do consumidor e os seu motivos de compra que são essencialmente emocionais e não racionais. Será importante perceber como as marcas estimulam os seus clientes de modo a oferecer propostas que ultrapassam o seu valor estético, proporcionando ao consumidor uma experiência ou um legado numa peça carregada de emoção e simbolismo. Serão comparadas várias marcas deste segmento, analisando as suas propostas de valor, o que as distingue e como se posicionam no mercado. O tipo de materiais utilizados, técnicas de fabrico, comunicação que é usada neste setor também será abordada, de modo a definir um "produto de luxo". Uma definição que poderá ser subjetiva, mas que foi suportada através de diversos pontos de vista de vários autores, procurando uma análise que se enquadra dentro do tipo de mobiliário de luxo que as marcas, Muranti e Alma de Luce, apresentam nas su...
Revista Interdisciplinar de Pesquisa em Engenharia - RIPE, Feb 16, 2017
Resumo. O presente artigo descreve a calibração experimental dos modelos numéricos de duas pontes... more Resumo. O presente artigo descreve a calibração experimental dos modelos numéricos de duas pontes ferroviárias em alvenaria de pedra localizadas na rede ferroviária Portuguesa, a ponte do Côa e a ponte de Durrães. Os modelos numéricos tridimensionais desenvolvidos baseiam-se no método dos elementos finitos, com uma representação realística dos componentes estruturais das pontes e dos respetivos materiais. Os ensaios dinâmicos envolveram a realização de ensaios de vibração ambiental, tendo em vista a caraterização dos parâmetros modais, em particular, as frequências, os modos de vibração e os coeficientes de amortecimento. A metodologia de calibração automática baseou-se na utilização de um algoritmo genético que permitiu estimar e atualizar os parâmetros do modelo numérico, particularmente as propriedades elásticas de materiais. Os resultados da calibração evidenciaram uma muito boa concordância entre as respostas modais numéricas e experimentais e uma melhoria significativa em relação aos modelos numéricos antes da calibração.
Estabilidad Fenotípica De Híbridos De Maíz en Venezuela Utilizando El Índice De Superioridad y La Regresión Lineal Bisegmentada
espanolEl analisis de estabilidad fenotipica proporciona informacion detallada del comportamiento... more espanolEl analisis de estabilidad fenotipica proporciona informacion detallada del comportamiento de cada genotipo frente a variaciones ambientales; en tal sentido, el objetivo de esta investigacion fue detectar la presencia de interaccion genotipo por ambiente y conocer la adaptabilidad y estabilidad fenotipica de 18 hibridos de maiz (Zea mays L.), utilizando los modelos: indice de superioridad y regresion lineal bisegmentada. Doce hibridos experimentales y seis testigos comerciales fueron sembrados en siete localidades de Venezuela durante la estacion lluviosa del ano 2012, en un diseno de bloques completamente aleatorizados con tres repeticiones. El caracter evaluado fue rendimiento de grano (t ha-1). El analisis de varianza combinado mostro que el comportamiento de los hibridos fue inconsistente debido a las variaciones ambientales. Con el modelo indice de superioridad, los hibridos ʹDK 1596ʹ y ʹExp A-1ʹ fueron identifi cados como estables, mientras que el modelo de la regresion lineal bisegmentada permitio identifi car los hibridos: ʹExp A-1ʹ, ʹExp A-2ʹ, ʹExp A-3ʹ, ʹExp A -5ʹ, ʹExp B-1ʹ, ʹExp B-4ʹ, ʹPioneer 30F35ʹ y ʹDK-370ʹ como estables. Con ambos modelos el hibrido Exp A-1 fue identifi cado como estable y el Exp B-4 como adaptable a condiciones favorables. El modelo de regresion lineal bisegmentada fue mas discriminatorio que el indice de superioridad; por lo tanto, el primero de ellos fue mas efi ciente y adecuado para el analisis de adaptabilidad y estabilidad. Los hibridos Exp A-1 y Exp B-4 mostraron un buen comportamiento productivo en las diferentes localidades de evaluacion, lo cual deberia ser considerado para su liberacion como cultivares comerciales. EnglishThe phenotypic stability analysis provides detailed information on the behavior of each genotype against environmental variations, in this sense, the objective of this research was to detect the presence of genotype by environment interaction as well as to know the adaptability and phenotypic stability of eighteen maize hybrids (Zea mays L.), by using the models index of superiority and bilinear regression. Twelve experimental hybrids and six commercial controls were planted in seven locations of Venezuela, during 2012 rainy season, in a randomized complete block design with three replications. The trait of interest was grain yield (t ha-1). Combined analyses of variance showed that hybrids performance were inconsistent because of environmental variations. With the model of index of superiority the hybrids ʹDK 1596ʹ and ʹExp A-1ʹ were identifi ed as stable, while the model of bilinear regression allowed to identify the hybrids: ʹExp A-1ʹ, ʹExp A-2ʹ, ʹExp A-3ʹ, ʹExp A -5ʹ, ʹExp B-1ʹ, ʹExp B-4ʹ, ʹPioneer 30F35ʹ and ʹDK-370ʹ as stable. With both models the hybrid Exp A-1 was identifi ed as stable whereas Exp B-4 as adaptable to favorable conditions. The model of bilinear regression was more discriminatory than the index of superiority; therefore, the fi rst one was more effi cient and suitable for the analysis of both adaptability and stability. The hybrids Exp A-1 and Exp B-4 showed a good productive performance in the different localities of evaluation, which should be considered for their release as commercial cultivars.
Considering our interest in the use of peptides as potential target-specific drugs or as delivery... more Considering our interest in the use of peptides as potential target-specific drugs or as delivery vectors of metallodrugs for various biomedical applications, it is crucial to explore improved synthetic methodologies to accomplish the highest peptide crude purity in the shortest time possible. Therefore, we compared “classical” fluorenylmethoxycarbonyl (Fmoc)-solid phase peptide synthesis (SPPS) with ultrasound(US)-assisted SPPS based on the preparation of three peptides, namely the fibroblast growth factor receptor 3(FGFR3)-specific peptide Pep1 (VSPPLTLGQLLS-NH2) and the novel peptides Pep2 (RQMATADEA-NH2) and Pep3 (AAVALLPAVLLALLAPRQMATADEA-NH2), which are being developed aimed at interfering with the intracellular protein-protein interaction(PPI) RANK-TRAF6. Our results demonstrated that US-assisted SPPS led to a 14-fold (Pep1) and 4-fold time reduction (Pep2) in peptide assembly compared to the “classical” method. Interestingly, US-assisted SPPS yielded Pep1 in higher purity (8...
Bioconjugate Supramolecular Pd2+ Metallacages Penetrate the Blood Brain Barrier In Vitro and In Vivo
Bioconjugate Chemistry, 2021
The biomedical application of discrete supramolecular metal-based structures, specifically self-a... more The biomedical application of discrete supramolecular metal-based structures, specifically self-assembled metallacages, is still an emergent field of study. Capitalizing on the knowledge gained in recent years on the development of 3-dimensional (3D) metallacages as novel drug delivery systems and theranostic agents, we explore here the possibility to target [Pd2L4]4+ cages (L = 3,5-bis(3-ethynylpyridine)phenyl ligand) to the brain. In detail, a new water-soluble homoleptic cage (CPepH3) tethered to a blood brain barrier (BBB)-translocating peptide was synthesized by a combination of solid-phase peptide synthesis (SPPS) and self-assembly procedures. The cage translocation efficacy was assessed by inductively coupled mass spectrometry (ICP-MS) in a BBB cellular model in vitro. Biodistribution studies of the radiolabeled cage [[99mTcO4]- ⊂ CPepH3] in the CD1 mice model demonstrate its brain penetration properties in vivo. Further DFT studies were conducted to model the structure of the [[99mTcO4]- ⊂ cage] complex. Moreover, the encapsulation capabilities and stability of the cage were investigated using the [ReO4]- anion, the "cold" analogue of [99mTcO4]-, by 1H NMR spectroscopy. Overall, our study constitutes another proof-of-concept of the unique potential of supramolecular coordination complexes for modifying the physiochemical and biodistribution properties of diagnostic species.
There is an urgent need for the development of new anti-HIV drugs that can complement existing me... more There is an urgent need for the development of new anti-HIV drugs that can complement existing medicines to be used against resistant strains. Here, we report the anti-HIV-1 peptide pepRF1, a human serum-resistant peptide derived from the Dengue virus capsid protein. In vitro, pepRF1 shows a 50% inhibitory concentration of 1.5 nM with a potential therapeutic window higher than 53 000. This peptide is specific for CXCR4-tropic strains, preventing viral entry into target cells by binding to the viral coreceptor CXCR4, acting as an antagonist of this receptor. pepRF1 is more effective than T20, the only peptide-based HIV-1 entry inhibitor approved, and excels in inhibiting a HIV-1 strain resistant to T20. Potentially, pepRF1 can be used alone or in combination with other anti-HIV drugs. Furthermore, one can also envisage its use as a novel therapeutic strategy for other CXCR4-related diseases.
La energía geotérmica se ha venido diseminando por todo el mundo como una excelente opción para g... more La energía geotérmica se ha venido diseminando por todo el mundo como una excelente opción para generar electricidad de manera limpia y eiciente [1], con una capacidad instalada de 8884,8 MW en todo el globo [2], de tal manera que en lugares como Islandia representa el 26.2% de toda la energía generada [3] y según el MIT (Massachusetts Institute of Technology) de Estados Unidos, actualmente hay disponibles en el planeta alrededor de 13000 ZJ de energía geotérmica, de los cuales son aprovechables, con las tecnologías actuales, 2000 ZJ siendo el consumo mundial al año de electricidad 0.5 ZJ [4], por lo tanto, si se profundizara más en este campo, se supliría la demanda energética, sin tener que utilizar otros medios aparte de la geotermia. Al analizar el ámbito local se observa un gran potencial geotérmico, debido a la ubicación de Colombia sobre el Cinturón de Fuego del Paciico, lo que ha impulsado el estudio de las siguientes zonas del territorio nacional [5]: Proyecto Chiles-Tuiño Cerro Negro (frontera colombo-ecuatoriana), Proyecto Azufral (departamento de Nariño), Proyecto de Paipa (departamento de Boyacá), Proyecto Macizo Volcánico del Ruiz (departamentos de Caldas, Tolima y Risaralda). A pesar de los datos satisfactorios, que han arrojado los diferentes estudios, hasta ahora no se ha construido ninguna planta de energía geotérmica en Colombia. MATERIALES Y MÉTODOS Para la realización de los cálculos termodinámicos de la planta [6], se estudiaron las diferentes tecnologías que se usan para la construcción de centrales de energía geotérmica (las cuales se basan en ciclo Rankine) [1], para de esta manera escoger el sistema que mas se ajuste a las propiedades de la zona seleccionada en el territorio colombiano. Luego, se establecieron los costos de inversión de esta clase de proyectos y los parámetros de venta de electricidad en Colombia, con el objetivo de realizar una proyección económica, aplicando las formulas del Valor Presente Neto, Tasa Interna de Retorno y Punto de Equilibrio.
Resumen El objetivo de la investigación fue analizar el comportamiento ambiental y las potenciali... more Resumen El objetivo de la investigación fue analizar el comportamiento ambiental y las potencialidades de aplicación de mecanismos de producción más limpios (PML) en una granja dedicada a la cría de cerdos en la Amazonía ecuatoriana. El estudio se realizó durante un ciclo completo de cría y constó de tres fases: reconocimiento, diagnóstico y formulación de alternativas de producción más limpia. Las herramientas empleadas fueron la revisión ambiental inicial, los ecomapas, los análisis de flujos y análisis de costos e ingresos, a partir de las cuales se definieron las medidas de PML aplicables a las condiciones del lugar. Se evaluaron cinco opciones de mejora relacionadas con la alimentación y el manejo del estiércol y efluentes. Las alternativas de manejo de estiércol presentaron los mejores resultados desde el punto de vista económico y ambiental. Asimismo, la opción 2 (incorporación de un sistema de lombricompostaje) presentó el mayor valor actual neto (VAN) (USD 5696,94 en 5 años) y tasa de interés de retorno (TIR) de 76,22%, superior a la tasa de interés de entidades bancarias (12%). En conclusión, la aplicación de prácticas y tecnologías enmarcadas en sistemas de PML puede mejorar en gran medida la eficiencia de utilización de las materias primas y la reducción de los contaminantes sólidos y líquidos. Sin embargo, aún existen muchos desafíos en las pequeñas y medianas empresas en Ecuador y es necesario la continua búsqueda de estrategias factibles que potencien las actividades de los pequeños productores e impulsen el desarrollo sostenible de la región. Palabras clave: manejo ambiental; impacto ambiental; estiércol, cría porcina; producción más limpia.
Frontiers in Bioengineering and Biotechnology, 2020
The characterization of biologically active peptides relies heavily on the study of their efficac... more The characterization of biologically active peptides relies heavily on the study of their efficacy, toxicity, mechanism of action, cellular uptake, or intracellular location, using both in vitro and in vivo studies. These studies frequently depend on the use of fluorescence-based techniques. Since most peptides are not intrinsically fluorescent, they are conjugated to a fluorophore. The conjugation may interfere with peptide properties, thus biasing the results. The selection of the most suitable fluorophore is highly relevant. Here, a comprehensive study with blood-brain barrier (BBB) peptide shuttles (PepH3 and PepNeg) and antimicrobial peptides (AMPs) (vCPP2319 and Ctn[15-34]), tested as anticancer peptides (ACPs), having different fluorophores, namely 5(6)-carboxyfluorescein (CF), rhodamine B (RhB), quasar 570 (Q570), or tide fluor 3 (TF3) attached is presented. The goal is the evaluation of the impact of the selected fluorophores on peptide performance, applying routinely used techniques to assess cytotoxicity/toxicity, secondary structure, BBB translocation, and cellular internalization. Our results show that some fluorophores significantly modulate peptide activity when compared with unlabeled peptides, being more noticeable in hydrophobic and charged fluorophores. This study highlights the need for a careful experimental design for fluorescently labeled molecules, such as peptides.
Replications in psychological science sometimes fail to reproduce prior findings. If replications... more Replications in psychological science sometimes fail to reproduce prior findings. If replications use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replications from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) in which the original authors had expressed concerns about the replication designs before data collection and only one of which was “statistically significant” (p < .05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate (Gilbert et al., 2016). We revised the replication protocols and received formal peer review prior to conducting new replications....
The purpose of the study. Running speed represents a global marker of individual performance and ... more The purpose of the study. Running speed represents a global marker of individual performance and provides a simple method of objective measurement of motor performance for use in clinical and research environments. Speed is most often at relatively short distances at normal or fast pace, using methods of obtaining manual time (e.g., stopwatch) or automated (e.g., photocells). Materials and methods. The sample consisted of 25 students, 12 males and 13 females, all 13 years old and walked a course 20 meters away, we used to obtain the time elapsed the time, and the method by photocells. The agreement was examined using Bland and Altman graphs and linear regression. Results. There are significant and strong differences between the evaluation methods (T =14,205; p<0,001) and there is a significant and strong correlation between the variables (r = 0.902; p<0.001). Conclusions. This study suggests that for measurement in research context or in sports aimed at high yield it is advisa...
This research presents an approach based on artificial intelligence techniques for wheel polygoni... more This research presents an approach based on artificial intelligence techniques for wheel polygonization detection. The proposed methodology is tested with dynamic responses induced on the track by passing a Laagrss-type rail vehicle. The dynamic response is attained considering the application of a train-track interaction model that simulates the passage of the train over a set of accelerometers installed on the rail and sleepers. This study, which considers an unsupervised methodology, aims to compare the performance of two feature extraction techniques, namely the Autoregressive Exogenous (ARX) model and Continuous Wavelets Transform (CWT). The extracted features are then submitted to data normalization considering the Principal Component Analysis (PCA) applied to suppress environmental and operational effects. Next to data normalization, data fusion using Mahalanobis distance is performed to enhance the sensitivity to the recognition of defective wheels. Finally, an outlier analy...
New approaches aimed at identifying patient-specific drug targets and addressing unmet clinical n... more New approaches aimed at identifying patient-specific drug targets and addressing unmet clinical needs in the framework of precision medicine are a strong motivation for researchers worldwide. As scientists learn more about proteins that drive known diseases, they are better able to design promising therapeutic approaches to target those proteins. The field of nanotechnology has been extensively explored in the past years, and nanoparticles (NPs) have emerged as promising systems for target-specific delivery of drugs. Virus-like particles (VLPs) arise as auspicious NPs due to their intrinsic properties. The lack of viral genetic material and the inability to replicate, together with tropism conservation and antigenicity characteristic of the native virus prompted extensive interest in their use as vaccines or as delivery systems for therapeutic and/or imaging agents. Owing to its simplicity and non-complex structure, one of the viruses currently under study for the construction of VL...
Anais do X Workshop de Visualização, Evolução e Manutenção de Software (VEM 2022)
Continuous Integration (CI) is a powerful tool to leverage software development in a safe, reliab... more Continuous Integration (CI) is a powerful tool to leverage software development in a safe, reliable, and efficient way. However, in day-to-day of software development, bad habits can arise in working with CI, which can make CI not reach its full potential in projects. These bad habits we call CI bad practices. This paper presented an exploratory study on closed-source projects to investigate how CI bad practices can affect software quality. We observe (1) the impact on the quality internal attributes after the implantation of CI, (2) the evolution of software quality indicators over time, and (3) the bad practices considered most harmful to the software quality by the development teams. Our results mean that projects affected by CI bad practices will not necessarily have their quality impaired. However, this does not mean that quality will be maintained or improved over time. Our analysis of the quality indicators has allowed us to observe that, generally, they have remained stable,...
Numa primeira fase é analisada a evolução do luxo ao longo da história, até à atualidade. Será an... more Numa primeira fase é analisada a evolução do luxo ao longo da história, até à atualidade. Será analisado o comportamento do consumidor e os seu motivos de compra que são essencialmente emocionais e não racionais. Será importante perceber como as marcas estimulam os seus clientes de modo a oferecer propostas que ultrapassam o seu valor estético, proporcionando ao consumidor uma experiência ou um legado numa peça carregada de emoção e simbolismo. Serão comparadas várias marcas deste segmento, analisando as suas propostas de valor, o que as distingue e como se posicionam no mercado. O tipo de materiais utilizados, técnicas de fabrico, comunicação que é usada neste setor também será abordada, de modo a definir um "produto de luxo". Uma definição que poderá ser subjetiva, mas que foi suportada através de diversos pontos de vista de vários autores, procurando uma análise que se enquadra dentro do tipo de mobiliário de luxo que as marcas, Muranti e Alma de Luce, apresentam nas su...
Revista Interdisciplinar de Pesquisa em Engenharia - RIPE, Feb 16, 2017
Resumo. O presente artigo descreve a calibração experimental dos modelos numéricos de duas pontes... more Resumo. O presente artigo descreve a calibração experimental dos modelos numéricos de duas pontes ferroviárias em alvenaria de pedra localizadas na rede ferroviária Portuguesa, a ponte do Côa e a ponte de Durrães. Os modelos numéricos tridimensionais desenvolvidos baseiam-se no método dos elementos finitos, com uma representação realística dos componentes estruturais das pontes e dos respetivos materiais. Os ensaios dinâmicos envolveram a realização de ensaios de vibração ambiental, tendo em vista a caraterização dos parâmetros modais, em particular, as frequências, os modos de vibração e os coeficientes de amortecimento. A metodologia de calibração automática baseou-se na utilização de um algoritmo genético que permitiu estimar e atualizar os parâmetros do modelo numérico, particularmente as propriedades elásticas de materiais. Os resultados da calibração evidenciaram uma muito boa concordância entre as respostas modais numéricas e experimentais e uma melhoria significativa em relação aos modelos numéricos antes da calibração.
Estabilidad Fenotípica De Híbridos De Maíz en Venezuela Utilizando El Índice De Superioridad y La Regresión Lineal Bisegmentada
espanolEl analisis de estabilidad fenotipica proporciona informacion detallada del comportamiento... more espanolEl analisis de estabilidad fenotipica proporciona informacion detallada del comportamiento de cada genotipo frente a variaciones ambientales; en tal sentido, el objetivo de esta investigacion fue detectar la presencia de interaccion genotipo por ambiente y conocer la adaptabilidad y estabilidad fenotipica de 18 hibridos de maiz (Zea mays L.), utilizando los modelos: indice de superioridad y regresion lineal bisegmentada. Doce hibridos experimentales y seis testigos comerciales fueron sembrados en siete localidades de Venezuela durante la estacion lluviosa del ano 2012, en un diseno de bloques completamente aleatorizados con tres repeticiones. El caracter evaluado fue rendimiento de grano (t ha-1). El analisis de varianza combinado mostro que el comportamiento de los hibridos fue inconsistente debido a las variaciones ambientales. Con el modelo indice de superioridad, los hibridos ʹDK 1596ʹ y ʹExp A-1ʹ fueron identifi cados como estables, mientras que el modelo de la regresion lineal bisegmentada permitio identifi car los hibridos: ʹExp A-1ʹ, ʹExp A-2ʹ, ʹExp A-3ʹ, ʹExp A -5ʹ, ʹExp B-1ʹ, ʹExp B-4ʹ, ʹPioneer 30F35ʹ y ʹDK-370ʹ como estables. Con ambos modelos el hibrido Exp A-1 fue identifi cado como estable y el Exp B-4 como adaptable a condiciones favorables. El modelo de regresion lineal bisegmentada fue mas discriminatorio que el indice de superioridad; por lo tanto, el primero de ellos fue mas efi ciente y adecuado para el analisis de adaptabilidad y estabilidad. Los hibridos Exp A-1 y Exp B-4 mostraron un buen comportamiento productivo en las diferentes localidades de evaluacion, lo cual deberia ser considerado para su liberacion como cultivares comerciales. EnglishThe phenotypic stability analysis provides detailed information on the behavior of each genotype against environmental variations, in this sense, the objective of this research was to detect the presence of genotype by environment interaction as well as to know the adaptability and phenotypic stability of eighteen maize hybrids (Zea mays L.), by using the models index of superiority and bilinear regression. Twelve experimental hybrids and six commercial controls were planted in seven locations of Venezuela, during 2012 rainy season, in a randomized complete block design with three replications. The trait of interest was grain yield (t ha-1). Combined analyses of variance showed that hybrids performance were inconsistent because of environmental variations. With the model of index of superiority the hybrids ʹDK 1596ʹ and ʹExp A-1ʹ were identifi ed as stable, while the model of bilinear regression allowed to identify the hybrids: ʹExp A-1ʹ, ʹExp A-2ʹ, ʹExp A-3ʹ, ʹExp A -5ʹ, ʹExp B-1ʹ, ʹExp B-4ʹ, ʹPioneer 30F35ʹ and ʹDK-370ʹ as stable. With both models the hybrid Exp A-1 was identifi ed as stable whereas Exp B-4 as adaptable to favorable conditions. The model of bilinear regression was more discriminatory than the index of superiority; therefore, the fi rst one was more effi cient and suitable for the analysis of both adaptability and stability. The hybrids Exp A-1 and Exp B-4 showed a good productive performance in the different localities of evaluation, which should be considered for their release as commercial cultivars.
Considering our interest in the use of peptides as potential target-specific drugs or as delivery... more Considering our interest in the use of peptides as potential target-specific drugs or as delivery vectors of metallodrugs for various biomedical applications, it is crucial to explore improved synthetic methodologies to accomplish the highest peptide crude purity in the shortest time possible. Therefore, we compared “classical” fluorenylmethoxycarbonyl (Fmoc)-solid phase peptide synthesis (SPPS) with ultrasound(US)-assisted SPPS based on the preparation of three peptides, namely the fibroblast growth factor receptor 3(FGFR3)-specific peptide Pep1 (VSPPLTLGQLLS-NH2) and the novel peptides Pep2 (RQMATADEA-NH2) and Pep3 (AAVALLPAVLLALLAPRQMATADEA-NH2), which are being developed aimed at interfering with the intracellular protein-protein interaction(PPI) RANK-TRAF6. Our results demonstrated that US-assisted SPPS led to a 14-fold (Pep1) and 4-fold time reduction (Pep2) in peptide assembly compared to the “classical” method. Interestingly, US-assisted SPPS yielded Pep1 in higher purity (8...
Bioconjugate Supramolecular Pd2+ Metallacages Penetrate the Blood Brain Barrier In Vitro and In Vivo
Bioconjugate Chemistry, 2021
The biomedical application of discrete supramolecular metal-based structures, specifically self-a... more The biomedical application of discrete supramolecular metal-based structures, specifically self-assembled metallacages, is still an emergent field of study. Capitalizing on the knowledge gained in recent years on the development of 3-dimensional (3D) metallacages as novel drug delivery systems and theranostic agents, we explore here the possibility to target [Pd2L4]4+ cages (L = 3,5-bis(3-ethynylpyridine)phenyl ligand) to the brain. In detail, a new water-soluble homoleptic cage (CPepH3) tethered to a blood brain barrier (BBB)-translocating peptide was synthesized by a combination of solid-phase peptide synthesis (SPPS) and self-assembly procedures. The cage translocation efficacy was assessed by inductively coupled mass spectrometry (ICP-MS) in a BBB cellular model in vitro. Biodistribution studies of the radiolabeled cage [[99mTcO4]- ⊂ CPepH3] in the CD1 mice model demonstrate its brain penetration properties in vivo. Further DFT studies were conducted to model the structure of the [[99mTcO4]- ⊂ cage] complex. Moreover, the encapsulation capabilities and stability of the cage were investigated using the [ReO4]- anion, the "cold" analogue of [99mTcO4]-, by 1H NMR spectroscopy. Overall, our study constitutes another proof-of-concept of the unique potential of supramolecular coordination complexes for modifying the physiochemical and biodistribution properties of diagnostic species.
There is an urgent need for the development of new anti-HIV drugs that can complement existing me... more There is an urgent need for the development of new anti-HIV drugs that can complement existing medicines to be used against resistant strains. Here, we report the anti-HIV-1 peptide pepRF1, a human serum-resistant peptide derived from the Dengue virus capsid protein. In vitro, pepRF1 shows a 50% inhibitory concentration of 1.5 nM with a potential therapeutic window higher than 53 000. This peptide is specific for CXCR4-tropic strains, preventing viral entry into target cells by binding to the viral coreceptor CXCR4, acting as an antagonist of this receptor. pepRF1 is more effective than T20, the only peptide-based HIV-1 entry inhibitor approved, and excels in inhibiting a HIV-1 strain resistant to T20. Potentially, pepRF1 can be used alone or in combination with other anti-HIV drugs. Furthermore, one can also envisage its use as a novel therapeutic strategy for other CXCR4-related diseases.
La energía geotérmica se ha venido diseminando por todo el mundo como una excelente opción para g... more La energía geotérmica se ha venido diseminando por todo el mundo como una excelente opción para generar electricidad de manera limpia y eiciente [1], con una capacidad instalada de 8884,8 MW en todo el globo [2], de tal manera que en lugares como Islandia representa el 26.2% de toda la energía generada [3] y según el MIT (Massachusetts Institute of Technology) de Estados Unidos, actualmente hay disponibles en el planeta alrededor de 13000 ZJ de energía geotérmica, de los cuales son aprovechables, con las tecnologías actuales, 2000 ZJ siendo el consumo mundial al año de electricidad 0.5 ZJ [4], por lo tanto, si se profundizara más en este campo, se supliría la demanda energética, sin tener que utilizar otros medios aparte de la geotermia. Al analizar el ámbito local se observa un gran potencial geotérmico, debido a la ubicación de Colombia sobre el Cinturón de Fuego del Paciico, lo que ha impulsado el estudio de las siguientes zonas del territorio nacional [5]: Proyecto Chiles-Tuiño Cerro Negro (frontera colombo-ecuatoriana), Proyecto Azufral (departamento de Nariño), Proyecto de Paipa (departamento de Boyacá), Proyecto Macizo Volcánico del Ruiz (departamentos de Caldas, Tolima y Risaralda). A pesar de los datos satisfactorios, que han arrojado los diferentes estudios, hasta ahora no se ha construido ninguna planta de energía geotérmica en Colombia. MATERIALES Y MÉTODOS Para la realización de los cálculos termodinámicos de la planta [6], se estudiaron las diferentes tecnologías que se usan para la construcción de centrales de energía geotérmica (las cuales se basan en ciclo Rankine) [1], para de esta manera escoger el sistema que mas se ajuste a las propiedades de la zona seleccionada en el territorio colombiano. Luego, se establecieron los costos de inversión de esta clase de proyectos y los parámetros de venta de electricidad en Colombia, con el objetivo de realizar una proyección económica, aplicando las formulas del Valor Presente Neto, Tasa Interna de Retorno y Punto de Equilibrio.
Resumen El objetivo de la investigación fue analizar el comportamiento ambiental y las potenciali... more Resumen El objetivo de la investigación fue analizar el comportamiento ambiental y las potencialidades de aplicación de mecanismos de producción más limpios (PML) en una granja dedicada a la cría de cerdos en la Amazonía ecuatoriana. El estudio se realizó durante un ciclo completo de cría y constó de tres fases: reconocimiento, diagnóstico y formulación de alternativas de producción más limpia. Las herramientas empleadas fueron la revisión ambiental inicial, los ecomapas, los análisis de flujos y análisis de costos e ingresos, a partir de las cuales se definieron las medidas de PML aplicables a las condiciones del lugar. Se evaluaron cinco opciones de mejora relacionadas con la alimentación y el manejo del estiércol y efluentes. Las alternativas de manejo de estiércol presentaron los mejores resultados desde el punto de vista económico y ambiental. Asimismo, la opción 2 (incorporación de un sistema de lombricompostaje) presentó el mayor valor actual neto (VAN) (USD 5696,94 en 5 años) y tasa de interés de retorno (TIR) de 76,22%, superior a la tasa de interés de entidades bancarias (12%). En conclusión, la aplicación de prácticas y tecnologías enmarcadas en sistemas de PML puede mejorar en gran medida la eficiencia de utilización de las materias primas y la reducción de los contaminantes sólidos y líquidos. Sin embargo, aún existen muchos desafíos en las pequeñas y medianas empresas en Ecuador y es necesario la continua búsqueda de estrategias factibles que potencien las actividades de los pequeños productores e impulsen el desarrollo sostenible de la región. Palabras clave: manejo ambiental; impacto ambiental; estiércol, cría porcina; producción más limpia.
Frontiers in Bioengineering and Biotechnology, 2020
The characterization of biologically active peptides relies heavily on the study of their efficac... more The characterization of biologically active peptides relies heavily on the study of their efficacy, toxicity, mechanism of action, cellular uptake, or intracellular location, using both in vitro and in vivo studies. These studies frequently depend on the use of fluorescence-based techniques. Since most peptides are not intrinsically fluorescent, they are conjugated to a fluorophore. The conjugation may interfere with peptide properties, thus biasing the results. The selection of the most suitable fluorophore is highly relevant. Here, a comprehensive study with blood-brain barrier (BBB) peptide shuttles (PepH3 and PepNeg) and antimicrobial peptides (AMPs) (vCPP2319 and Ctn[15-34]), tested as anticancer peptides (ACPs), having different fluorophores, namely 5(6)-carboxyfluorescein (CF), rhodamine B (RhB), quasar 570 (Q570), or tide fluor 3 (TF3) attached is presented. The goal is the evaluation of the impact of the selected fluorophores on peptide performance, applying routinely used techniques to assess cytotoxicity/toxicity, secondary structure, BBB translocation, and cellular internalization. Our results show that some fluorophores significantly modulate peptide activity when compared with unlabeled peptides, being more noticeable in hydrophobic and charged fluorophores. This study highlights the need for a careful experimental design for fluorescently labeled molecules, such as peptides.
Replications in psychological science sometimes fail to reproduce prior findings. If replications... more Replications in psychological science sometimes fail to reproduce prior findings. If replications use methods that are unfaithful to the original study or ineffective in eliciting the phenomenon of interest, then a failure to replicate may be a failure of the protocol rather than a challenge to the original finding. Formal pre-data collection peer review by experts may address shortcomings and increase replicability rates. We selected 10 replications from the Reproducibility Project: Psychology (RP:P; Open Science Collaboration, 2015) in which the original authors had expressed concerns about the replication designs before data collection and only one of which was “statistically significant” (p < .05). Commenters suggested that lack of adherence to expert review and low-powered tests were the reasons that most of these RP:P studies failed to replicate (Gilbert et al., 2016). We revised the replication protocols and received formal peer review prior to conducting new replications....
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