CD44-high neural crest stem-like cells are associated with tumour aggressiveness and poor survival in neuroblastoma tumours

BACKGROUND: Neuroblastoma is a paediatric tumour originated from sympathoadrenal precursors and characterized by its heterogeneity and poor outcome in advanced stages. Intra-tumoral cellular heterogeneity has emerged as an important feature in neuroblastoma, with a potential major impact on tumour aggressiveness and response to therapy. CD44 is an adhesion protein involved in tumour progression, metastasis and stemness in different cancers; however, there has been controversies about the significance of CD44 expression in neuroblastoma and its relationship with tumour progression. METHODS: We have performed transcriptomic analysis on patient tumour samples studying the outcome of patients with high CD44 expression. Adhesion, invasion and proliferation assays were performed in sorted CD44high neuroblastoma cells. Tumoursphere cultures have been used to enrich in undifferentiated stem-like cells and to asses self-renewal and differentiation potential. We have finally performed in vivo tumorigenic assays on cell line-derived or Patient-derived xenografts. FINDINGS: We show that high CD44 expression is associated with low survival in high-grade human neuroblastoma, independently of MYCN amplification. CD44 is expressed in a cell population with neural crest stem-like features, and with the capacity to generate multipotent, undifferentiated tumourspheres in culture. These cells are more invasive and proliferative in vitro. CD44 positive cells obtained from tumours are more tumorigenic and metastatic, giving rise to aggressive neuroblastic tumours at high frequency upon transplantation. INTERPRETATION: We describe an unexpected intra-tumoural heterogeneity within cellular entities expressing CD44 in neuroblastoma, and propose that CD44 has a role in neural crest stem-like undifferentiated cells, which can contribute to tumorigenesis and malignancy in this type of cancer. FUNDING: Research supported by grants from the "Asociación Española contra el Cáncer" (AECC), the Spanish Ministry of Science and Innovation SAF program (SAF2016-80412-P), and the European Research Council (ERC Starting Grant to RP).Spanish Ministry of Science and Innovation SAF program (SAF2016-80412-P

Desplazamiento epifisario en niños con insuficiencia renal crónica

Para buscar la prevalencia y factores clínicos-bioquímicos implicados en el desarrollo de epifisiolisis en niños con insuficiencia renal crónica, estudiamos 48 pacientes de 8,1+4,2 años, 28 en tratamiento conservador y 20 sometidos a diálisis crónica. Se analizó edad cronológica y de aparición de la insuficiencia renal, años de evolución y de diálisis y enfermedad fundamental y se practicó estudio del metabolismo fosfocálcico y mapa óseo. Cuatro enfermos presentaron epifisiolisis, lo que supone una prevalencia en nuestro medio del 8,3%. Los 4 seguían tratamiento dialítico y la insuficiencia renal se presentó durante la lactancia por una enfermedad renal congenita o de aparición en período neonatal precoz. Bioquímicamente tenían el grado más severo de hiperparal iroidismo con cifras inapropiadamente bajas de calcio y fósforo a pesar de instauración del tratamiento sustitutivo mediante diálisis crónica.Clinical, biochemical and roentgenological features of 48 children with chronic renal failure have been analysed. The prevalence and factors implicated with slipped epiphysis outlined. Four of 48 patients (8.3%) shown roentgenological dates of epiphysiolysis. In this cases, the underlying renal disease was congenital or neonatal, developping renal failure in infancy (average 0.6 months) and had the most severe hyperparathyroidism associated with low calcium and phosphorus level in spite of dialytic treatment

A knowledge management-based conceptual model to improve the level of utilization of ICTs in Mexican SMEs

The current commercial context for the Small and medium-sized enterprises (SMEs) is an ever-changing environment that is strongly influenced by the information and communication technologies (ICTs). This has led enterprises to implement these technologies as supportive tools for their business processes. Nevertheless, a vast number of SMEs have not obtained favorable results in implementing ICTs, since the lack of knowledge about the potential and application of these technologies has made this technological implementation activity prevail as an action oriented to the simple acquisition of equipment and informatic systems with a short-term vision without considering a business strategy. The aim of this paper is to perform a literature review that shows evidence of the low utilization of ICTs in SMEs, particularly in the Mexican environment, which leads to proposing a different approach where enterprises consider Knowledge Management (KM) in the implementation of the informatic technology, leading to a conceptual model to ensure human, organizational and relational capital provide the proper capabilities to complement a strategy that implies carrying out a correct acquisition and application of knowledge that contributes to improving the utilization of ICTs in the business processes

Modification of polyetherimide membranes with ZIFs fillers for CO2 separation

[EN] Flat hybrid membranes composed of polyetherimide (PEI) as matrix and zeolitic imidazolate frameworks (ZIFs) as fillers at concentrations of 10 and 20 wt% were prepared. Apparent permeability coefficient and apparent diffusivity coefficient of gases (CO2 and N-2) for these hybrid membranes (PZIFs) were determined by the "timelag" method. The experimental conditions used were from 25 degrees C to 55 degrees C with pressures of 2, 3 and 5 bar. The PZIFs with fillers of ZIF-8 (PZ-Zn) and ZIF-67 (PZ-Co) showed apparent selectivities (alpha(pa(CO2)/pa(N2))) of 39.6 and 27.5, respectively, higher than the alpha(pa(CO2)/pa(N2)) of the reference membrane PEI, while the membrane with filler of ZIF-Mix (PZ-Zn/Co) showed the lowest alpha(pa(CO2)()/pa(N2)) selectivity of 10.3 in the membrane series (under conditions of 25 degrees C and 2 bar). It is proposed that the selectivity of the membrane series can be attributed to two critical factors: the particle size/distribution ratio in the polymer base and sorption of CO2 at local sites of the bimetallic mixture. On the other hand, gas permeation studies (O-2, CO2 and CH4, and CO2/CH(4 )and CO2/C2H4 mixtures), were carried out in the series of PZIFs membranes. Permeability data were obtained by an isostatic method based on a permeation cell connected in series to a gas chromatograph where the rate of permeated gases was analyzed until a stationary state was reached. The complementary characterization techniques were: scanning electron microscopy, thermogravimetric analysis, and powder X-ray diffraction, which support the existence of the amorphous/crystalline phases of the PZIFs.This research has been supported by the ENE/2015-69203-R project, granted by the Ministerio de Economia y Competitividad (MINECO), Spain; Also authors are grateful to UNAM-DGAPA-PAPIIT projects IG-100185, and IG-114818. This study was partially supported by the CONACyT (Mexico) projects 2013-05-231461 and CB -2014-01-235840.Vega, J.; Andrio, A.; Lemus, A.; Díaz, J.; Del Castillo, L.; Gavara, R.; Compañ Moreno, V. (2019). Modification of polyetherimide membranes with ZIFs fillers for CO2 separation. Separation and Purification Technology. 212:474-482. https://doi.org/10.1016/j.seppur.2018.11.033S47448221

Phosphorylation-dependent regulation of the NOTCH1 intracellular domain by dual-specificity tyrosine-regulated kinase 2

NOTCH proteins constitute a receptor family with a widely conserved role in cell cycle, growing and development regulation. NOTCH1, the best characterised member of this family, regulates the expression of key genes in cell growth and angiogenesis, playing an essential role in cancer development. These observations provide a relevant rationale to propose the inhibition of the intracellular domain of NOTCH1 (Notch1-IC) as a strategy for treating various types of cancer. Notch1-IC stability is mainly controlled by post-translational modifications. FBXW7 ubiquitin E3 ligase-mediated degradation is considered one of the most relevant, being the previous phosphorylation at Thr-2512 residue required. In the present study, we describe for the first time a new regulation mechanism of the NOTCH1 signalling pathway mediated by DYRK2. We demonstrate that DYRK2 phosphorylates Notch1-IC in response to chemotherapeutic agents and facilitates its proteasomal degradation by FBXW7 ubiquitin ligase through a Thr-2512 phosphorylation-dependent mechanism. We show that DYRK2 regulation by chemotherapeutic agents has a relevant effect on the viability, motility and invasion capacity of cancer cells expressing NOTCH1. In summary, we reveal a novel mechanism of regulation for NOTCH1 which might help us to better understand its role in cancer biology

Sleep quality and sleep deprivation: relationship with academic performance in university students during examination period

The beginning of the university brings together maturational, psychosocial and academic changes that make university students more prone to suffer from insufficient or poor quality sleep, which can negatively influence their academic performance. The period of taking exams is a key part of the academic year. However, there are few studies that analyze sleep during this period of time. Our aim is to study the association of sleep quality and sleep deprivation with academic performance during the examination period. A descriptive, cross-sectional and correlational study was carried out with the participation of 640 subjects in the first three years of five faculties belonging to the Universidad Autónoma de Madrid. The instrument used consisted of a questionnaire that included sociodemographic and academic data, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and information about the academic performance. During the examination period, a positive association was found between sleep quality and academic performance. University students slept less than desired, both on weekdays and weekends, and the sleep debt during the week was associated with a worse students’ perception of their academic performance. In total, 61.3% of the students believed that their performance would improve by getting more sleep. In addition, low drowsiness and napping were also found. In conclusion, during periods of greater academic demand, an insufficient sleep and poor quality is commonly observed, affecting negatively to their academic performance. Actually, about 2/3 of our subjects believed that their performance would improve by getting more slee

Self-dual Ginzburg-Landau vortices in a disk

We study the properties of the Ginzburg-Laundau model in the self-dual point for a two-dimensional finite system . By a numerical calculation we analyze the solutions of the Euler-Lagrange equations for a cylindrically symmetric ansatz. We also study the self-dual equations for this case. We find that the minimal energy configurations are not given by the Bogomol'nyi equations but by solutions to the Euler Lagrange ones. With a simple approximation scheme we reproduce the result of the numerical calculation.Comment: 8 pages, 4 figures, RevTex macro

Simulación de un enfriador híbrido alimentado por energía solar térmica

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: En este trabajo se presenta la modelación y simulación de un enfriador híbrido compresión/absorción alimentado por un concentrador solar de disco parabólico. El enfriamiento producido por este sistema se utiliza para aire acondicionado de una vivienda. El estudio fue realizado mediante balances de energía y de masa, en cada componente de los sistemas de refrigeración y del sistema solar. La transferencia de calor por convección y por radiación también fueron considerados. Los resultados muestran que la carga proporcionada por el sistema de compresión es 20% mayor que el alimentado por el sistema de absorción. Aunque el sistema de absorción opera al 40% de la carga total requerida en el espacio a condicionar, requiere en torno a 40% más energía térmica que el sistema de compresión. Pueden obtenerse temperaturas cercanas a 1050 °C y 400 °C con relación de concentración de 20 y radiación solar de 600W/m2 respectivamente. La eficiencia del colector solar es 0.4 (40%) cuando la temperatura exterior es 35 °C a baja radiación de 200 W/m2.RESUMO: This paper presents the modeling and simulation of a compression/absorption hybrid chiller driven by a solar dish collector. The cooling produced by this system is used for air conditioning in a home. The study was carried out using energy and mass balances in each component of the cooling systems and the solar system. Convection and radiation heat transfer were also considered. The results show that the load provided by the compression system is 20% greater than that fed by the absorption system. Although the absorption system operates at 40% of the total load required in the space to be conditioned, it requires around 40% more thermal energy than the compression system. Temperatures close to 1050 °C and 400 °C can be obtained in concentration ratio of 20 and solar radiation of 600W/m2 respectively. Efficiency of the solar collector is 0.4 (40%) when the outdoor temperature is 35 °C at a low radiation of 200 W/m2.info:eu-repo/semantics/publishedVersio

Non BPS noncommutative vortices

We construct exact vortex solutions to the equations of motion of the Abelian Higgs model defined in non commutative space, analyzing in detail the properties of these solutions beyond the BPS point. We show that our solutions behave as smooth deformations of vortices in ordinary space time except for parity symmetry breaking effects induced by the non commutative parameter $\theta$.Comment: 17 pages, 5 figure