6,466 research outputs found
Asporin is a stromally expressed marker associated with prostate cancer progression.
BACKGROUND: Prostate cancer shows considerable heterogeneity in disease progression and we propose that markers expressed in tumour stroma may be reliable predictors of aggressive tumour subtypes. METHODS: We have used Kaplan-Meier, univariate and multivariate analysis to correlate the expression of Asporin (ASPN) mRNA and protein with prostate cancer progression in independent cohorts. We used immunohistochemistry and H scoring to document stromal localisation of ASPN in a tissue microarray and mouse prostate cancer model, and correlated expression with reactive stroma, defined using Masson Trichrome staining. We used cell cultures of primary prostate cancer fibroblasts treated with serum-free conditioned media from prostate cancer cell lines to examine regulation of ASPN mRNA in tumour stromal cells. RESULTS: We observed increased expression of ASPN mRNA in a data set derived from benign vs tumour microdissected tissue, and a correlation with biochemical recurrence using Kaplan-Meier and Cox proportional hazard analysis. ASPN protein localised to tumour stroma and elevated expression of ASPN was correlated with decreased time to biochemical recurrence, in a cohort of 326 patients with a median follow up of 9.6 years. Univariate and multivariate analysis demonstrated that ASPN was correlated with progression, as were Gleason score, and clinical stage. Additionally, ASPN expression correlated with the presence of reactive stroma, suggesting that it may be a stromal marker expressed in response to the presence of tumour cells and particularly with aggressive tumour subtypes. We observed expression of ASPN in the stroma of tumours induced by p53 inhibition in a mouse model of prostate cancer, and correlation with neuroendocrine marker expression. Finally, we demonstrated that ASPN transcript expression in normal and cancer fibroblasts was regulated by conditioned media derived from the PC3, but not LNCaP, prostate cancer cell lines. CONCLUSIONS: Our results suggest that ASPN is a stromally expressed biomarker that correlates with disease progression, and is observed in reactive stroma. ASPN expression in stroma may be part of a stromal response to aggressive tumour subtypes.British Journal of Cancer advance online publication, 2 February 2017; doi:10.1038/bjc.2017.15 www.bjcancer.com
Características clínicas e histopatológicas asociadas a pacientes con Cáncer de Mama Triple Negativo en un Hospital de Referencia peruano, 2012- 2018: Clinical and histopathological characteristics associated with patients with triple-negative Breast cancer at a national reference hospital, 2012 - 2018
Objective: To determine the clinical and histopathological characteristics associated to patients with triple negative breast cancer of the Hipolito Unanue National Hospital between June 2012 to June 2018. Methods: Cross-sectional analytical study. Results: 134 patients were included, out of which 36 (26.9%) were TN and 98 No TN. Of the histopathological characteristics, the most frequent CD was III and II for the two groups. The histological type that predominated was the infiltrating ductal type in both groups. The high histological grade was characteristic in NT (58%) unlike non TN. The NTs were larger 5.75 cm in contrast to the TNs with 3 cm, and the Ki 67 was higher in the TN 35% in contrast to the NON TN with 15%. In the bivariate analysis the size (RP: 1.4, CI: 1.17-1.68, p = 0.0001), Ki 67 (RP: 1.05, CI: 1.03-1.07, p = 0.001), BMI ≥25 kg/m2 ( RP: 1.14, CI: 1.23-6.22, p = 0.014), Histological Grade 3 (RP: 3.87, CI: 1.74-8.63, p = 0.001), size ≥5 cm (RP: 2.94, CI: 1.33-6.48, p = 0.008) were significant. In the multivariate analysis it was found that grade 3 (PR: 1.74, CI: 1.01-3, p = 0.0046) and Ki 67 (RP: 1.02, CI: 1.01-1.03, p = 0.0001) were histopathological characteristics associated with CMTN. Conclusion: There are histopathological characteristics associated with triple negative breast cancer particularly high histological grade and Ki67 value.Objetivo:Determinar las características clínicas e histopatológicas asociadas a las pacientes con cáncer de mama triple negativo (CMTN) en un Hospital peruano de referencia. Métodos: Estudio transversal, analítico. Se revisaron las historias clínicas de todas las pacientes atendidas en el Hospital Nacional Hipóito Unanue durante el periodo de junio del 2012 a junio del 2018. Resultados: Se incluyeron 134 pacientes de los cuales 36 (26.9%) correspondieron a CMTN. el estadío clínico más frecuente fue el III y II para los dos grupos. El tipo histológico que más predomino fue el tipo ductal infiltrante en ambos grupos. El grado histológico elevado fue característico en los casos de CMTN (58%) a diferencia de los No TN. Los CMTN fueron de mayor tamaño (5.75 cm vs 3cm en no TN), y el Ki 67 fue más elevado en el TN (35% en comparación con el No TN con 15%). Se determinó en el análisis bivariado que el tamaño (RP: 1.4, IC: 1.17-1.68, p= 0.0001), Ki 67 (RP: 1.05, IC: 1.03-1.07, p= 0.001), IMC ≥25 kg/m2 (RP: 1.14, IC: 1.23-6.22, p= 0.014) y el Grado Histológico 3 (RP:3.87, IC: 1.74-8.63, p= 0.001) se asociaron significativamente a la presencia de CMTN. En el análisis multivariado se encontró que el grado 3 (RP: 1.74, IC: 1.01-3. p= 0.0046) y el Ki 67 (RP: 1.02, IC: 1.01-1.03, p= 0.0001) fueron las características histopatológicas asociados al CMTN. Conclusión: Las características más consistentemente asociadas al cáncer de mama triple negativo en fueron el elevado grado histológico y mayor valor de Ki67
EFFECT OF MESQUITE SEED GUM ON THE RHEOLOGICAL PROPERTIES OF MIXTURES WITH ARABIC AND GELLAN GUMS
ABSTRACT The mesquite seed gum (Prosopis sp.) represents an alternative application in the food industry, due to its structural likeness with other galactomannans used at the moment. The information about the properties of mesquite seed gum is scarce, for this is important to known the rheological properties of this biopolymer and its interactions with other polymers for seeing future applications. The aim of this work was study the rheological behavior of mesquite seed gum and their effects in arabic and gellan gum mixtures. They were prepared aqueous dispersions according to a Simplex-Centroid design, being obtained gum combinations of total concentration of 1% from mesquite-arabic, mesquite-gellan, arabic-gellan and mesquitearabic-gellan, the pH from the dispersions were adjusted to 4, 5 and 6. The mixtures as well as the individual biopolymers were dispersed to ambient temperature, and later heated during 20 minutes at 90 °C and cooling at 25 °C. The rheological studies were made using an Haake RV2 viscometer. The statistical analysis showed differences (a = 0.05) among the rheologic value for mixtures at different pH. The mixtures showed a nonNewtonian behavior, type pseudoplastic flow (shear thinning) and showed high viscosities to low shears rates (100 s l) in all the cases. The tendency of mixtures with two or three components showed an antagonistic effect in the viscosity. Particularly the mesquite seed gum suffers an antagonistic effect in the viscosity when it was mixed with the arabic and gellan gums, being observed decreases from a 8 until 45%, below the control
The seasonality of tuberculosis, sunlight, vitamin D, and household crowding.
BACKGROUND: Unlike other respiratory infections, tuberculosis diagnoses increase in summer. We performed an ecological analysis of this paradoxical seasonality in a Peruvian shantytown over 4 years. METHODS: Tuberculosis symptom-onset and diagnosis dates were recorded for 852 patients. Their tuberculosis-exposed cohabitants were tested for tuberculosis infection with the tuberculin skin test (n = 1389) and QuantiFERON assay (n = 576) and vitamin D concentrations (n = 195) quantified from randomly selected cohabitants. Crowding was calculated for all tuberculosis-affected households and daily sunlight records obtained. RESULTS: Fifty-seven percent of vitamin D measurements revealed deficiency (<50 nmol/L). Risk of deficiency was increased 2.0-fold by female sex (P < .001) and 1.4-fold by winter (P < .05). During the weeks following peak crowding and trough sunlight, there was a midwinter peak in vitamin D deficiency (P < .02). Peak vitamin D deficiency was followed 6 weeks later by a late-winter peak in tuberculin skin test positivity and 12 weeks after that by an early-summer peak in QuantiFERON positivity (both P < .04). Twelve weeks after peak QuantiFERON positivity, there was a midsummer peak in tuberculosis symptom onset (P < .05) followed after 3 weeks by a late-summer peak in tuberculosis diagnoses (P < .001). CONCLUSIONS: The intervals from midwinter peak crowding and trough sunlight to sequential peaks in vitamin D deficiency, tuberculosis infection, symptom onset, and diagnosis may explain the enigmatic late-summer peak in tuberculosis
Subharmonic ripple analysis of an interleaved buck converter based on the Filippov method
El diseño de convertidores conmutados en gran parte de la literatura científica está realizado desde el modelo promediado, debido a la facilidad de obtener las funciones de transferencia lineales. Asimismo, la conmutación en los convertidores de potencia causa un rizado en las variables de estado que no es considerado en el modelo promediado. El componente de frecuencia de una de las variables de estado está compuesto por un espectro de potencia con un único pico de nivel DC (valor promedio), un único pico a la frecuencia de conmutación (componente de rizado) y en un número finito de picos en cada sub-armónico (inestabilidades). El método de Filippov es utilizado para la predicción de inestabilidades debidas a las dinámicas rápidas, este método predice el rango de los parámetros que evitan la primera bifurcación en las dinámicas rápidas. En el presente artículo se presenta una predicción de un espacio de parámetros estables para el controlador PI (), estimados por el método de Filippov para un convertidor buck de dos fases con regulación de voltaje. Finalmente, los resultados presentados son validados mediante simulaciones de Matlab y Psim.In many papers, the averaged model of power switching converters is used to design the control system due to its simple manipulation, which can be approximated by linear transfer functions. Therefore, the power converter commutation causes a state variable ripple that is not considered on the averaged model. The component frequency of the state variables is composed by a power spectrum with a unique peak at the DC level (average variable), a unique peak at the switching frequency (ripple component) and a finite number of peaks in each sub-harmonic (instabilities). The Filippov method is used for instability predictions due to fast dynamics, this method predicts the parameters range that avoids the first bifurcation of the fast dynamics. In this paper a stable space of parameters (Kp, Ti) for a PI controller is presented, it estimated with the Filippov method, for a buck converter with voltage regulation. Finally, the presented results are validated using both Matlab and Psim simulations
Advances in Power and Energy Systems
Processing electrical energy is one of the most important research fields in our society. So far, tremendous efforts have been made to improve the efficiency of each step in electrical systems: generation systems have been enhanced by introducing renewable energy sources and new control systems for conventional generators, losses have been reduced, the power quality of distribution and transmission systems has been increased, the life-time and state-of-health of energy storage devices have been extended, and sections of the power grid have been isolated for intelligent energy management
Dimensioning of Photovoltaic Generation Systems Located in Medellin City
Los sistemas fotovoltaicos son una de las soluciones más eficientes a la creciente crisis energética de las últimas décadas. La implementación de estos sistemas será viable económicamente en la mayoría de los casos, debido a extensa cantidad de ventajas que estos exhiben, sin embargo, en aras de un mejor rendimiento económico, se generan diferentes estrategias para el manejo de estos. El presente artículo muestra una estrategia de optimización basada en la redistribución de energía generada, que busca dejar de consumirla conforme se produce, para aprovecharla en aquellos momentos en los cuales las tarifas de energía son mayores, haciendo uso de un sistema de almacenamiento. Se presentan los pasos para el diseño de un sistema fotovoltaico con dichos criterios y un análisis económico que dicte las condiciones para la viabilidad del mismo.Photovoltaic systems are one of the most efficient solutions to the energy crisis of the last decades. The implementation of these systems will be economically feasible in most cases, due to extensive number of advantages that they exhibit. However, for the sake of better economic performance, it is important to generate different strategies for their management. This paper presents an optimization strategy based on the redistribution of power generated, which seeks to stop spending as it is produced to take advantage of those times when energy rates are higher, making use of a storage system. The steps for the photovoltaic system design with these criteria and economic analysis will be presented
Gestión de resultado de investigación en Instituciones de Educación Superior
"El presente libro se deriva del proyecto de investigación «La introducción de resultados de las investigaciones científicas "" tecnológicas en Instituciones de Educación Superior»: un análisis explicativo de sus alcances en la solución de problemas sociales, empresariales y académicos en tres instituciones de la ciudad de Medellín: Instituto Tecnológico Metropolitano, Politécnico Colombiano Jaime Isaza Cadavid y la Facultad de Ciencias Humanas y Sociales de la Universidad de Antioquia. Se propone como objetivo dar cuenta de los componentes necesarios a tener presente en la configuración de un modelo para la gestión de los resultados de la investigación en Ciencia, Tecnología e Innovación en las Instituciones de Educación Superior. Con este estudio se espera lograr una contribución a la gestión del conocimiento que dé cuenta de las posibles estrategias, para avanzar de la producción de la ciencia, la tecnología y la innovación, hacia la introducción, generalización y validación de sus resultados en los diversos contextos, donde se hacen necesarios para lograr metas coherentes con los procesos de construcción de una sociedad del conocimiento.""""This book is derived from the research project """"The introduction of results from scientific-technological research in Higher Education Institutions"""": a comprehensive analysis of their scope in the solution of social, business and academic problems in three institutions from Medellín: Instituto Tecnológico Metropolitano, Politécnico Colombiano Jaime Isaza Cadavid and the Faculty of Human and Social Sciences of the Universidad de Antioquia. The book aims at presenting the necessary components that must be present in the configuration of a model for the management of research results in Science, Technology and Innovation in Higher Education Institutions. This study is expected to be a contribution to knowledge management that presents the potential strategies for progress in the production of science, technology and innovation, aiming at the introduction, generalization and validation of the results in the various contexts in which they are needed to achieve goals consistent with the process of building a knowledge society.""
Recommended from our members
Loss of hSef promotes metastasis through upregulation of EMT in prostate cancer
We have previously reported that the negative signaling regulator Similar Expression to FGF (hSef) is downregulated in prostate cancer and its loss is associated with clinical metastasis. Here, we explored the mechanistic basis of this finding. We first confirmed our clinical observation by testing hSef manipulation in an metastasis model. hSef stable expressing cells (PC3M-hSef) or empty vector controls (PC3M-EV) were injected subcutaneously into the lateral thoracic walls of NOD-SCID gamma mice and lungs were harvested at autopsy. In this model, 6/7 PC3M-EV xenografts had definitive lung micro-metastasis whilst only 1/6 PC3M-hSef xenografts exhibited metastasis recapitulating the clinical scenario ( = 0.03). Gene expression studies revealed key perturbations in genes involved in cell motility and epithelial to mesenchymal transition (EMT) along with alterations in cognate signaling pathways. These results were validated in an EMT specific PCR array whereby hSef over-expression and silencing reciprocally altered E-Cadherin expression ( = <0.001) amongst other EMT markers. Immunohistochemistry of excised tumors from the xenografts also confirmed the effect of hSef in suppressing E-Cadherin expression at the protein level. Phosphokinase arrays further demonstrated a role for hSef in attenuating signaling of not only ERK-MAPK but also the JNK and p38 pathways as well. Taken together, these data suggest evidence that loss of hSef may be a critical event facilitating tumor dissemination of prostate cancer through alteration of EMT. Detection of downregulated hSef, along with other negative regulators, may therefore be a useful biomarker heralding a transition to a metastatic phenotype and warrants further exploration in this context.Grant sponsor: Medical Research Council/The Prostate Cancer Charity Clinical Research Training Fellowship (S.H.); Grant number: G1001961; Grant sponsor: The Royal College of Surgeons Surgical Research Fellowship (S.H.), Addenbrooke’s Charitable Trust Oncology Research Fellowship (S.H.) and the University of Cambridge Raymond and Beverly Sackler Studentship (S.H.) DOI: 10.1002/ijc.30604
Technical-economic feasibility analysis of micro grids integrating fuel cells in non-interconnected zones in Colombia
La necesidad de proveer soluciones energéticas sostenibles para las zonas no interconectadas de Colombia, dependiendo de los recursos renovables disponibles en cada zona, supone un desafío respecto al análisis de viabilidad técnico-económica de las alternativas de solución a través de las microrredes. Este documento tiene como objetivo analizar el impacto técnico-económico de introducir celdas de combustible en la reducción de costos a lo largo del tiempo de vida de una microrred para zonas no interconectadas, empleando el software HOMER. Dicho impacto se evalúa tanto en el diseño técnico de la microrred como en el Valor Presente Neto y en el Costo nivelado de Energía (/kWh). The analysis considers the calculation of the demand of a generic village, the size and cost of the technologies that constitute the micro grid to satisfy the demand, and the availability of solar and wind power in two areas located at different latitudes in Colombia. In addition, the effect of introducing fuel cells into the energy mix was examined. Finally, the advantages were highlighted by comparing each case with traditional generation alternatives based on diesel consumption
- …