149 research outputs found

    Coupling Between Thermal Oscillations in the Surface of a Micro-Cylinder and Vortex Shedding

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    his article studies the coupling between prescribed thermal oscillations in the surface of a micro-cylinder and vortex shedding. We deal with the unsteady, laminar, compressible flow regime where the aerodynamics forces have a periodic behavior. It is shown that appropriate spatial and time-dependent temperature oscillations on the surface of the micro-cylinder create a resonance that controls the amplitude and frequency of both lift and drag coefficients. In practice, what we study is a mechanism to modulate the amplitude and frequency of mechanical loads of aerodynamics origin in a micro-structure by using surface temperature fluctuations as the control parameter

    A feature-rich transmission spectrum for WASP-127b

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    WASP-127b is one of the lowest density planets discovered to date. With a sub-Saturn mass (Mp=0.18±0.02MJM_{\rm p}=0.18 \pm 0.02 M_J) and super-Jupiter radius (Rp=1.37±0.04RJR_{\rm p}= 1.37 \pm 0.04 R_J), it orbits a bright G5 star, which is about to leave the main-sequence. We aim to explore WASP-127b's atmosphere in order to retrieve its main atmospheric components, and to find hints for its intriguing inflation and evolutionary history. We used the ALFOSC spectrograph at the NOT telescope to observe a low resolution (R330R\sim330, seeing limited) long-slit spectroscopic time series during a planetary transit, and present here the first transmission spectrum for WASP-127b. We find the presence of a strong Rayleigh slope at blue wavelengths and a hint of Na absorption, although the quality of the data does not allow us to claim a detection. At redder wavelengths the absorption features of TiO and VO are the best explanation to fit the data. Although higher signal-to-noise ratio observations are needed to conclusively confirm the absorption features, WASP-127b seems to posses a cloud-free atmosphere and is one of the best targets to perform further characterization studies in the near future.Comment: Accepted for Publication A&A Letters, May 22nd, 201

    Micro-Jet Test Facility for Aerospace Propulsion Engineering Education*

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    This paper describes the methodology that has been developed and implemented at the School of Aeronautics (ETSIA) of the Universidad Politecnica de Madrid (UPM) to familiarize aerospace engineering students with the operation of real complex jet engine systems. This methodology has a two-pronged approach: students carry out preparatory work by using, first, a gas turbine performance prediction numerical code; then they validate their assumptions and results on an experimental test rig. When looking at the educational aspects, we have taken care that, apart from being sufficiently robust and flexible, the experimental set-up is similar to real jet engine rigs, so the students are not constrained to exploring a much too limited parametric space. Also, because a facility like this is usually subject to extensive and somewhat rugged use, we have focused on a low cost design

    Single cell profiling of COVID-19 patients: an international data resource from multiple tissues

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    In late 2019 and through 2020, the COVID-19 pandemic swept the world, presenting both scientific and medical challenges associated with understanding and treating a previously unknown disease. To help address the need for great understanding of COVID-19, the scientific community mobilized and banded together rapidly to characterize SARS-CoV-2 infection, pathogenesis and its distinct disease trajectories. The urgency of COVID-19 provided a pressing use-case for leveraging relatively new tools, technologies, and nascent collaborative networks. Single-cell biology is one such example that has emerged over the last decade as a powerful approach that provides unprecedented resolution to the cellular and molecular underpinnings of biological processes. Early foundational work within the single-cell community, including the Human Cell Atlas, utilized published and unpublished data to characterize the putative target cells of SARS-CoV-2 sampled from diverse organs based on expression of the viral receptor ACE2 and associated entry factors TMPRSS2 and CTSL (Muus et al., 2020; Sungnak et al., 2020; Ziegler et al., 2020). This initial characterization of reference data provided an important foundation for framing infection and pathology in the airway as well as other organs. However, initial community analysis was limited to samples derived from uninfected donors and other previously-sampled disease indications. This report provides an overview of a single-cell data resource derived from samples from COVID-19 patients along with initial observations and guidance on data reuse and exploration

    The hydrodynamic efficiency of laser-target acceleration

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    The acceleration of a thin foil using a laser pulse is studied. It is shown that the acceleration efficiency eta H is heavily dependent on the behaviour of the corona ejected by the foil: there is no universal relation eta H( Delta M/M0),M0 and Delta M being initial foil mass and ablated mass, respectively. Known results on the coronal flow are used to check the theory against experimental data available in the literature; effects due to both a non-planar corona, and the time-dependence of the laser irradiance, are considered. The agreement with experiments is substantially better than that for previous analyses. Acceleration of thin spherical shells is also discussed

    Surface and Temporal Biosignatures

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    Recent discoveries of potentially habitable exoplanets have ignited the prospect of spectroscopic investigations of exoplanet surfaces and atmospheres for signs of life. This chapter provides an overview of potential surface and temporal exoplanet biosignatures, reviewing Earth analogues and proposed applications based on observations and models. The vegetation red-edge (VRE) remains the most well-studied surface biosignature. Extensions of the VRE, spectral "edges" produced in part by photosynthetic or nonphotosynthetic pigments, may likewise present potential evidence of life. Polarization signatures have the capacity to discriminate between biotic and abiotic "edge" features in the face of false positives from band-gap generating material. Temporal biosignatures -- modulations in measurable quantities such as gas abundances (e.g., CO2), surface features, or emission of light (e.g., fluorescence, bioluminescence) that can be directly linked to the actions of a biosphere -- are in general less well studied than surface or gaseous biosignatures. However, remote observations of Earth's biosphere nonetheless provide proofs of concept for these techniques and are reviewed here. Surface and temporal biosignatures provide complementary information to gaseous biosignatures, and while likely more challenging to observe, would contribute information inaccessible from study of the time-averaged atmospheric composition alone.Comment: 26 pages, 9 figures, review to appear in Handbook of Exoplanets. Fixed figure conversion error

    Evolución del riesgo cardiometabólico en pacientes supervivientes de leucemia aguda infantil

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    Introducción: los supervivientes de leucemia aguda (LA) infantil presentan un riesgo incrementado de alteraciones metabólicas y cardiovasculares que aumentan su morbimortalidad a largo plazo.Objetivo: estimar la prevalencia de obesidad, resistencia a la insulina, dislipemia e hipertensión arterial como factores de riesgo cardiometabólico (FRCM) en un grupo de supervivientes de LA infantil, y analizar las posibles causas asociadas a su desarrollo.Material y métodos: estudio observacional retrospectivo en 47 supervivientes de LA tratados en un periodo de 4 años, que recibieron seguimiento durante 10 años.Resultados: el 40% de los participantes presentaron al menos un FRCM durante el seguimiento, siendo la dislipemia (aumento LDL) el más frecuente (38, 3%), seguido de obesidad/sobrepeso (31, 9%) y HTA sistólica (23, 4%). El sexo femenino se estableció como factor de riesgo parael desarrollo de todos ellos (RR 1, 6; RR 3, 16; RR 1, 69; p < 0, 05). Ningún superviviente desarrolló diabetes mellitus, pero sí resistencia a la insulina el 19, 4%. Los pacientes con leucemias de peor pronóstico presentaron mayor riesgo de desarrollar obesidad, resistencia a la insulina y aumento de LDL (RR 3, 56; RR 4, 08; RR 2, 53; p < 0, 05). Los pacientes tratados con trasplante de progenitores hematopoyéticos presentaron mayor riesgo de obesidad, aumento de LDL e HTA sistólica (RR 2, 86; RR 2, 39; RR 3, 12; p<0, 05). La radioterapia se asoció de igual modo con un incremento de resistencia a la insulina e hipertensión arterial sistólica (RR 2, 47; RR 2, 53; p < 0, 05).Conclusiones: existe un aumento en la prevalencia de obesidad/sobrepeso, dislipemia, resistencia a la insulina y alteración de la tensión arterial sistólica en supervivientes de leucemia aguda infantil a lo largo del tiempo, especialmente en aquellos con enfermedades y tratamientos más agresivos. Background: Survivors of childhood acute leukemia (AL) face an increased risk of metabolic and cardiovascular late effects which increase their long-term morbimotality. Objective: To assess the prevalence of obesity, insulinresistance, dyslipidemia and hypertension as cardiometabolic risk factors in survivors of a childhood AL, and also to determine possible causes for these adverse cardiometabolic traits. Material and methods: A retrospective cohort study of 47 pediatric acute leukemia survivors diagnosed between 0-15 years, with a ten years follow-up. Results: Forty percent of participants had at least one cardiometabolic risk factor. Dyslipidemia (increased LDL cholesterol) was the most frequent (38.3%), secondly overweight/obese (31.9%), followed by systolic hypertension (23.4%). Females in contrast to males had an increased risk of developing all three risk factors (RR 1.6; RR 3.16; RR 1.69; p < 0.05). Only 19.4% of participants developed insulin resistance, while none were diagnosed with diabetes mellitus. High risk acute leukemia survivors were significantly more likely than low risk leukemia survivors to manifest multiple cardiometabolic traits like overweight/obesity, insulin resitance and dyslipidemia (RR 3.56; RR 2.39; RR 2.53; p < 0.05). Also, those who received hematopoietic cell trasplantation had an increased prevalence of overweight/obesity, increased LDL-cholesterol and systolic hypertension. Radiotherapy treatment was also associated with insulin resitance and systolic hypertension (RR 2.47; RR 2.53; p < 0.05). Conclusions: There is an increased risk of overweight/obesity, dyslipidemia, insulin resistance and systolic blood pressure modification in childhood acute leukemia survivors, specially in those who were diagnosed as a high risk acute leukemia and those treated with more aggressive treatments

    Intra- and Inter-cellular Rewiring of the Human Colon during Ulcerative Colitis

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    Genome-wide association studies (GWAS) have revealed risk alleles for ulcerative colitis (UC). To understand their cell type specificities and pathways of action, we generate an atlas of 366,650 cells from the colon mucosa of 18 UC patients and 12 healthy individuals, revealing 51 epithelial, stromal, and immune cell subsets, including BEST4(+) enterocytes, microfold-like cells, and IL13RA2(+)IL11(+) inflammatory fibroblasts, which we associate with resistance to anti-TNF treatment. Inflammatory fibroblasts, inflammatory monocytes, microfold-like cells, and T cells that co-express CD8 and IL-17 expand with disease, forming intercellular interaction hubs. Many UC risk genes are cell type specific and coregulated within relatively few gene modules, suggesting convergence onto limited sets of cell types and pathways. Using this observation, we nominate and infer functions for specific risk genes across GWAS loci. Our work provides a framework for interrogating complex human diseases and mapping risk variants to cell types and pathways.Peer reviewe

    In Situ Compatibilization of Biopolymer Ternary Blends by Reactive Extrusion with Low-Functionality Epoxy-Based Styrene Acrylic Oligomer

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    [EN] The present study reports on the use of low-functionality epoxy-based styrene¿acrylic oligomer (ESAO) to compatibilize immiscible ternary blends made of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polylactide (PLA), and poly(butylene adipate-co-terephthalate) (PBAT). The addition during melt processing of low-functionality ESAO at two parts per hundred resin (phr) of biopolymer successfully changed the soften inclusion phase in the blend system to a thinner morphology, yielding biopolymer ternary blends with higher mechanical ductility and also improved oxygen barrier performance. The compatibilization achieved was ascribed to the in situ formation of a newly block terpolymer, i.e. PHBVb- PLA-b-PBAT, which was produced at the blend interface by the reaction of the multiple epoxy groups present in ESAO with the functional terminal groups of the biopolymers. This chemical reaction was mainly linear due to the inherently low functionality of ESAO and the more favorable reactivity of the epoxy groups with the carboxyl groups of the biopolymers, which avoided the formation of highly branched and/or cross-linked structures and thus facilitated the films processability. Therefore, the reactive blending of biopolymers at different mixing ratios with low-functionality ESAO represents a straightforward methodology to prepare sustainable plastics at industrial scale with different physical properties that can be of interest in, for instance, food packaging applications.This research was funded by the EU H2020 project YPACK (Reference number 773872) and by the Spanish Ministry of Science, Innovation, and Universities (MICIU) with project numbers MAT2017-84909-C2-2-R and AGL2015-63855-C2-1-R. L. Quiles-Carrillo wants to thank the Spanish Ministry of Education, Culture, and Sports (MECD) for financial support through his FPU Grant Number FPU15/03812. Torres-Giner also acknowledges the MICIU for his Juan de la Cierva contract (IJCI-2016-29675).Quiles-Carrillo, L.; Montanes, N.; Lagaron, J.; Balart, R.; Torres-Giner, S. (2019). In Situ Compatibilization of Biopolymer Ternary Blends by Reactive Extrusion with Low-Functionality Epoxy-Based Styrene Acrylic Oligomer. Journal of Polymers and the Environment. 27(1):84-96. https://doi.org/10.1007/s10924-018-1324-2S8496271Babu RP, O’Connor K, Seeram R (2013) Prog Biomater 2:8Torres-Giner S, Torres A, Ferrándiz M, Fombuena V, Balart R (2017) J Food Saf 37:e12348Quiles-Carrillo L, Montanes N, Boronat T, Balart R, Torres-Giner S (2017) Polym Test 61:421Zakharova E, Alla A, Martínez A, De Ilarduya S, Muñoz-Guerra (2015) RSC Adv 5:46395Steinbüchel A, Valentin HE (1995) FEMS Microbiol Lett 128:219McChalicher CWJ, Srienc F (2007) J Biotechnol 132:296Reis KC, Pereira J, Smith AC, Carvalho CWP, Wellner N, Yakimets I (2008) J Food Eng 89:361Vink ETH, Davies S (2015) Ind Biotechnol 11:167John RP, Nampoothiri KM, Pandey A (2006) Process Biochem 41:759Madhavan Nampoothiri K, Nair NR, John RP (2010) Biores Technol 101:8493Garlotta D (2001) J Polym Environ 9:63Lim LT, Auras R, Rubino M (2008) Prog Polym Sci 33:820Quiles-Carrillo L, Montanes N, Sammon C, Balart R, Torres-Giner S (2018) Ind Crops Prod 111:878Quiles-Carrillo L, Blanes-Martínez MM, Montanes N, Fenollar O, Torres-Giner S, Balart R (2018) Eur Polym J 98:402Witt U, Müller R-J, Deckwer W-D (1997) J Environ Polym Degrad 5:81Siegenthaler KO, Künkel A, Skupin G, Yamamoto M (2012) Ecoflex® and Ecovio®: biodegradable, performance-enabling plastics. In: Rieger B, Künkel A, Coates GW, Reichardt R, Dinjus E, Zevaco TA (eds) Synthetic biodegradable polymers. Springer, Berlin Heidelberg, p 91Jiang L, Wolcott MP, Zhang J (2006) Biomacromol 7:199Brandelero RPH, Yamashita F, Grossmann MVE (2010) Carbohyd Polym 82:1102Muthuraj R, Misra M, Mohanty AK (2014) J Polym Environ 22:336Porter RS, Wang L-H (1992) Polymer 33(10): 2019Koning C, Van Duin M, Pagnoulle C, Jerome R (1998) Prog Polym Sci 23:707Muthuraj R, Misra M, Mohanty AK (2017) J Appl Polym Sci 135:45726Ryan AJ (2002) Nat Mater 1:8Wu D, Zhang Y, Yuan L, Zhang M, Zhou W (2010) J Polym Sci Part B 48:756Kim CH, Cho KY, Choi EJ, Park JK (2000) J Appl Polym Sci 77:226Supthanyakul R, Kaabbuathong N, Chirachanchai S (2016) Polymer 105:1Na Y-H, He Y, Shuai X, Kikkawa Y, Doi Y, Inoue Y (2002) Biomacromolecules 3:1179Zeng J-B, Li K-A, Du A-K (2015) RSC Adv 5:32546Xanthos M, Dagli SS (1991) Polym Eng Sci 31:929Sundararaj U, Macosko CW (1995) Macromolecules 28:2647Milner ST, Xi H (1996) J Rheol 40:663Villalobos M, Awojulu A, Greeley T, Turco G, Deeter G (2006) Energy 31:3227Torres-Giner S, Montanes N, Boronat T, Quiles-Carrillo L, Balart R (2016) Eur Polym J 84:693Lehermeier HJ, Dorgan JR (2001) Polym Eng Sci 41:2172Liu B, Xu Q (2013) J Mater Sci Chem Eng 1:9Eslami H, Kamal MR (2013) J Appl Polym Sci 129:2418Loontjens T, Pauwels K, Derks F, Neilen M, Sham CK, Serné M (1997) J Appl Polym Sci 65:1813Ojijo V, Ray SS (2015) Polymer 80:1Frenz V, Scherzer D, Villalobos M, Awojulu AA, Edison M, Van Der Meer R (2008) Multifunctional polymers as chain extenders and compatibilizers for polycondensates and biopolymers. In: Technical papers, regional technical conference—society of plastics engineers, p. 3/1678Utracki LA (2002) Can J Chem Eng 80:1008Al-Itry R, Lamnawar K, Maazouz A (2012) Polym Degrad Stab 97:1898Lin S, Guo W, Chen C, Ma J, Wang B (2012) Mater Des (1980–2015) 36: 604Arruda LC, Magaton M, Bretas RES, Ueki MM (2015) Polym Test 43:27Wang Y, Fu C, Luo Y, Ruan C, Zhang Y, Fu Y (2010) J Wuhan Univ Technol Mater Sci Ed 25:774Wei D, Wang H, Xiao H, Zheng A, Yang Y (2015) Carbohyd Polym 123:275Abdelwahab MA, Taylor S, Misra M, Mohanty AK (2015) Macromol Mater Eng 300:299Sun Q, Mekonnen T, Misra M, Mohanty AK (2016) J Polym Environ 24:23Torres-Giner S, Gimeno-Alcañiz JV, Ocio MJ, Lagaron JM (2011) J Appl Polym Sci 122:914Miyata T, Masuko T (1998) Polymer 39:5515Muthuraj R, Misra M, Mohanty AK (2015) J Appl Polym Sci 132:42189Ren J, Fu H, Ren T, Yuan W (2009) Carbohyd Polym 77:576Torres-Giner S, Montanes N, Fenollar O, García-Sanoguera D, Balart R (2016) Mater Des 108:648Jamshidian M, Tehrany EA, Imran M, Jacquot M, Desobry S (2010) Compr Rev Food Sci Food Saf 9:552Savenkova L, Gercberga Z, Nikolaeva V, Dzene A, Bibers I, Kalnin M (2000) Process Biochem 35:573Costa ARM, Almeida TG, Silva SML, Carvalho LH, Canedo EL (2015) Polym Test 42:115Zhang K, Mohanty AK, Misra M (2012) ACS Appl Mater Interfaces 4:3091Zhang N, Wang Q, Ren J, Wang L (2009) J Mater Sci 44:250Chinsirikul W, Rojsatean J, Hararak B, Kerddonfag N, Aontee A, Jaieau K, Kumsang P, Sripethdee C (2015) Packag Technol Sci 28:741Auras R, Harte B, Selke S (2004) J Appl Polym Sci 92:1790Sanchez-Garcia MD, Gimenez E, Lagaron JM (2008) Carbohyd Polym 71:235Sanchez-Garcia MD, Gimenez E, Lagaron JM (2007) J Plast Film Sheeting 23:133Lagaron JM (2011) Multifunctional and nanoreinforced polymers for food packaging. In: Multifunctional and nanoreinforced polymers for food packaging. Woodhead Publishing, Cambridge, p 
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