32 research outputs found

    The Learning of the subject Biology in a Master in Biomedical Physics

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    BIOLOGY is a dynamic and fascinating science. The study of this subject is an amazing trip for all the students that have a first contact with this subject. Here, we present the development of the study and learning experience of this subject belonging to an area of knowledge that is different to the training curriculum of students who have studied Physics during their degree period. We have taken a real example, the “Elements of Biology” subject, which is taught as part of the Official Biomedical Physics Master, at the Physics Faculty, of the Complutense University of Madrid, since the course 2006/07. Its main objective is to give to the student an understanding how the Physics can have numerous applications in the Biomedical Sciences area, giving the basic training to develop a professional, academic or research career. The results obtained when we use new virtual tools combined with the classical learning show that there is a clear increase in the number of persons that take and pass the final exam. On the other hand, this new learning strategy is well received by the students and this is translated to a higher participation and a decrease of the giving the subject u

    Estudio de la estabilidad térmica del ácido algínico y derivados en diversas atmósferas

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    El ácido algínico y sus sales están presentes en las algas marinas, como polisacáridos estructurales. Es un blocopolímero lineal de fórmula química (C6H806)n. peso molecular de 20.000 a 250.000 y de estructura compleja. Debido a su estructura polimérica forma con el agua soluciones coloidales que presentan una serie de propiedades fisicoquímicas, tales como: viscosidad elevada, poder espesante, formación de gel, formación de película y fibra, así como una moderada reactividad química debido a grupos carboxilicos libres. En base a dichas propiedades el ácido algínico y susderivados son ampliamente utilizados como aditivos en las Industrias, Alimentaria, Farmacéutica, Cosmética, Papelera, Textil; es utilizado también como material de inmovilización en Biotecnología; así como para la fabricación de lubricantes sólidos, composites, recubrimientos de electrodos, etc. En muchas de sus aplicaciones, en especial en la Industria Alimentaria, los productos que contienen estos aditivos deben someterse a tratamientos térmicos más o menos rigurosos, en los cuales puede producirse degradación térmica de los mismos, con la subsiguiente aparición de productos de degradación. Por ello se ha considerado interesante realizar un estudio comparativo de la estabilidad térmica del ácido algínico y sus derivados en diversas atmósferas. De la extensa bibliografía consultada no se han encontrado trabajos relativos a la estabilidad térmica del ácido algínico en atmósferas más o menos agresivas en que puedan ser utilizados. Por el contrario si se han encontrado referencias sobre la degradación térmica de sustancias relacionadas, tales como carbohidratos. También se han encontrado numerosos trabajos relativos a la determinación de la composición y estructura del ácido algínico y sus derivados. Las técnicas utilizadas son muy variadas y van desde la cromatografía de gases, a la Espectrofotometría de Resonancia Magnética Nuclear, pasando por la Espectrofotometría Infrarroja la Pirólisis y Espectrometría de Masas y la Cromatografía Líquida de Alta Resolución (HPLC). Otros autores estudian el grado de chstalinidad de estos compuestos mediante la técnica de Difracción de R-X llegando a la conclusión de que el ácido algínico presenta un grado de chstalinidad relativamente elevado. Por tanto la aportación original de esta tesis ha sido la aplicación de las Técnicas Térmicas: Termogravimetría (TG, TGD) y Análisis Térmico Diferencial (ATD) a la determinación de la estabilidad térmica del Acido Aigínico y de algunas de sus sales o ásteres de mayor aplicación tales como alginato sódico (ALGNa); amónico {ALGNH4); calcico (ALGCa) y de propilenglicol (ALGPG); en atmósfera de aire, oxigeno y nitrógeno. También se han evaluado los parámetros cinéticos: Energía de Activación y Factor de Frecuencia de la reacción de termodegradación para cada producto y en cada ambiente ensayado; cálculo que se ha llevado a cabo a partir de los datos extraídos de las curvas TG y TGD y mediante la aplicación del método cinético propuesto por BROIDO, A. (J. Polym Sci. A-2 1979, 176). Por último se ha realizado un estudio comparativo de la estabilidad térmica de dichos compuestos en las distintas atmósferas ensayadas. Los resultados obtenidos muestran la enorme complejidad del proceso particularmente en atmósfera de oxigeno. Por lo que se refiere a los parámetros cinéticos, energía de activación y factor de frecuencia, los valores obtenidos para cada peldaño varían dentro de una gama muy amplia dependiendo en gran medida de la naturaleza del compuesto y del tipo de atmósfera en que se degrada. degradativo de estos compuestos, presentando varias etapas o peldaños que solo se definen claramente en las curvas TGD. No obstante cada compuesto muestra características diferenciales en sus curvas gravimétricas. Para todos los compuestos la influencia del ambiente sobre su degradación es pequeña a temperaturas bajas (-100 ^C). Sin embargo a temperaturas más altas aumentan la influencia desfavorables del oxigeno y en menor grado del aire sobre la estabilidad térmica del compuesto. Del mismo modo aumenta notablemente las velocidades de degradació

    Stress compensation by gap monolayers for stacked InAs/GaAs quantum dots solar cells

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    In this work we report the stacking of 10 and 50 InAs quantum dots layers using 2 monolayers of GaP for stress compensation and a stack period of 18 nm on GaAs (001) substrates. Very good structural and optical quality is found in both samples. Vertical alignment of the dots is observed by transmission electron microscopy suggesting the existence of residual stress around them. Photocurrent measurements show light absorption up to 1.2 μm in the nanostructures together with a reduction in the blue response of the device. As a result of the phosphorus incorporation in the barriers, a very high thermal activation energy (431 meV) has also been obtained for the quantum dot emission

    InAs/AlGaAs quantum dot intermediate band solar cells with enlarged sub-bandgaps

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    In the last decade several prototypes of intermediate band solar cells (IBSCs) have been manufactured. So far, most of these prototypes have been based on InAs/GaAs quantum dots (QDs) in order to implement the IB material. The key operation principles of the IB theory are two photon sub-bandgap (SBG) photocurrent, and output voltage preservation, and both have been experimentally demonstrated at low temperature. At room temperature (RT), however, thermal escape/relaxation between the conduction band (CB) and the IB prevents voltage preservation. To improve this situation, we have produced and characterized the first reported InAs/AlGaAs QD-based IBSCs. For an Al content of 25% in the host material, we have measured an activation energy of 361 meV for the thermal carrier escape. This energy is about 250 meV higher than the energies found in the literature for InAs/GaAs QD, and almost 140 meV higher than the activation energy obtained in our previous InAs/GaAs QD-IBSC prototypes including a specifically designed QD capping layer. This high value is responsible for the suppression of the SBG quantum efficiency under monochromatic illumination at around 220 K. We suggest that, if the energy split between the CB and the IB is large enough, activation energies as high as to suppress thermal carrier escape at room temperature (RT) can be achieved. In this respect, the InAs/AlGaAs system offers new possibilities to overcome some of the problems encountered in InAs/GaAs and opens the path for QD-IBSC devices capable of achieving high efficiency at RT

    Phenolic diterpenes from Rosemary supercritical extract inhibit non-small cell lung cancer lipid metabolism and synergise with therapeutic drugs in the clinic

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    Lung cancer is one of the most deadly and common cancers in the world. The molecular features of patient’s tumours dictate the different therapeutic decisions, which combines targeted therapy, chemotherapy, and immunotherapy. Altered cellular metabolism is one of the hallmarks of cancer. Tumour cells reprogram their metabolism to adapt to their novel requirements of growth, proliferation, and survival. Together with the Warburg effect, the role of lipid metabolism alterations in cancer development and prognosis has been highlighted. Several lipid related genes have been shown to promote transformation and progression of cancer cells and have been proposed as biomarkers for prognosis. Nevertheless, the exact mechanisms of the regulation of lipid metabolism and the biological consequences in non-small cell lung cancer (NSCLC) have not been elucidated yet. There is an urgent necessity to develop multidisciplinary and complementary strategies to improve NSCLC patients´ well-being and treatment response. Nutrients can directly affect fundamental cellular processes and some diet-derived ingredients, bioactive natural compounds and natural extracts have been shown to inhibit the tumour growth in preclinical and clinical trials. Previously, we described a supercritical extract of rosemary (SFRE) (12 - 16% composition of phenolic diterpenes carnosic acid and carnosol) as a potential antitumoral agent in colon and breast cancer due to its effects on the inhibition of lipid metabolism and DNA synthesis, and in the reduction of resistance to 5-FluoroUracil (5-FU). Herein, we demonstrate SFRE inhibits NSCLC cell bioenergetics identifying several lipid metabolism implicated targets. Moreover, SFRE synergises with standard therapeutic drugs used in the clinic, such as cisplatin, pemetrexed and pembrolizumab to inhibit of cell viability of NSCLC cells. Importantly, the clinical relevance of SFRE as a complement in the treatment of NSCLC patients is suggested based on the results of a pilot clinical trial where SFRE formulated with bioactive lipids (PCT/ES2017/070263) diminishes metabolic and inflammatory targets in peripheral-blood mononuclear cells (PBMC), such as MAPK (p=0.04), NLRP3 (p=0.044), and SREBF1 (p=0.047), which may augment the immune antitumour function. Based on these results, SFRE merits further investigation as a co-adjuvant in the treatment of NSCLC.This research was funded by Regional Government of Community of Madrid (IND2017/BIO-7857; P2018/BAA-4343-ALIBIRD2020-CM), Ministerio de Ciencia e Innovación, Spain (PID2019-110183RB-C21); Ramon Areces Foundation (CIVP19A5937); EU Structural Funds and COST Action (CA17118); Synergistic Projects Community of Madrid (NUTRISION-CM/Y2020/BIO-6350) and REACT EU Program (Comunidad de Madrid and The European Regional Development Fund. ERDF. European Union- FACINGLCOVID-CM project). Adrián Bouzas has a predoctoral grant from the industrial predoctoral program of Community of Madrid (IND2017/BIO-7857).Peer reviewe

    Strain balanced quantum posts for intermediate band solar cells

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    In this work we present strain balanced InAs quantum post of exceptional length in the context of photovoltaics. We discuss the general properties of these nanostructures and their impact in the practical implementation of an intermediate band solar cell. We have studied the photocurrent generated by strain balanced quantum posts embedded in a GaAs single crystal, and compared our results with quantum dot based devices. The incorporation of phosphorous in the matrix to partially compensate the accumulated stress enables a significant increase of the quantum post maximum length. The relative importance of tunneling and thermal escape processes is found to depend strongly on the geometry of the nanostructures. tunneling and thermal escape processes is found to depend strongly on the geometry of the nanostructures

    Un estudio de estereotipos de género en alumnado de secundaria en el marco de Proyecto Meitner

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    [ES] Este artículo presenta Proyecto Meitner como una acción de divulgación científica diseñada para abordar, entre otras cuestiones, la problemática de las mujeres en Física a través de las artes escénicas. Se presenta, también, un estudio de sesgos y estereotipos de género en ciencia realizado al alumnado de los centros de secundaria de la Comunitat Valenciana que participaron en dos sesiones matinales de la obra de teatro Proyecto Meitner. Se utilizó un cuestionario que rellenaron 134 estudiantes estudiantes antes de las funciones. Las respuestas revelan una perpetuación de los estereotipos asociados al personal científico, definido principalmente como muy inteligente, culto, occidental, hombre, mayor, solitario y con bata. Además, el alumnado encuestado cree que los chicos tienen mejores aptitudes que las chicas para las carreras universitarias aun cuando las capacidades en ambos casos son las mismas

    Artificial intelligence within the interplay between natural and artificial computation:Advances in data science, trends and applications

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    Artificial intelligence and all its supporting tools, e.g. machine and deep learning in computational intelligence-based systems, are rebuilding our society (economy, education, life-style, etc.) and promising a new era for the social welfare state. In this paper we summarize recent advances in data science and artificial intelligence within the interplay between natural and artificial computation. A review of recent works published in the latter field and the state the art are summarized in a comprehensive and self-contained way to provide a baseline framework for the international community in artificial intelligence. Moreover, this paper aims to provide a complete analysis and some relevant discussions of the current trends and insights within several theoretical and application fields covered in the essay, from theoretical models in artificial intelligence and machine learning to the most prospective applications in robotics, neuroscience, brain computer interfaces, medicine and society, in general.BMS - Pfizer(U01 AG024904). Spanish Ministry of Science, projects: TIN2017-85827-P, RTI2018-098913-B-I00, PSI2015-65848-R, PGC2018-098813-B-C31, PGC2018-098813-B-C32, RTI2018-101114-B-I, TIN2017-90135-R, RTI2018-098743-B-I00 and RTI2018-094645-B-I00; the FPU program (FPU15/06512, FPU17/04154) and Juan de la Cierva (FJCI-2017–33022). Autonomous Government of Andalusia (Spain) projects: UMA18-FEDERJA-084. Consellería de Cultura, Educación e Ordenación Universitaria of Galicia: ED431C2017/12, accreditation 2016–2019, ED431G/08, ED431C2018/29, Comunidad de Madrid, Y2018/EMT-5062 and grant ED431F2018/02. PPMI – a public – private partnership – is funded by The Michael J. Fox Foundation for Parkinson’s Research and funding partners, including Abbott, Biogen Idec, F. Hoffman-La Roche Ltd., GE Healthcare, Genentech and Pfizer Inc
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