2,225 research outputs found

    How to unmask unique vulnerabilities in leukaemia

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    How to unmask unique vulnerabilities in leukaemia Acute myeloid leukaemia (AML) is a group of haematologic malignancies that have been traditionally difficult to classify and treat. Nucleophosmin (NPM1) mutations are the most frequent genetic alteration (about 30 per cent) in AML and NPM1-mutated AML is a new entity in the WHO classification of myeloid neoplasms. However, mechanisms of leukemogenesis and a specific therapy for this leukaemia are missing. The ContraNPM1AML project aims to unravel the complex network of molecular interactions that take place in this distinct genetic subtype and find their vulnerabilities to identify new targets for therapy. The expected discoveries will lead to novel therapeutic approaches and make clinical trials available to patients

    The use of India ink in tissue-simulating phantoms

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    The optical properties of India ink, an absorber often used in preparation of tissue simulating phantoms, have been investigated at visible and near infrared wavelengths. The extinction coefficient has been obtained from measurements of collimated transmittance and from spectrophotometric measurements, the absorption coefficient from multidistance measurements of fluence rate in a diffusive infinite medium with small concentrations of added ink. Measurements have been carried out on samples of India ink from five different brands, and for some brands also from different batches. As also reported in previously published papers the results we have obtained showed large inter-brand and inter-batch variations for both the absorption and the extinction coefficient. On the contrary, our results showed small variations for the ratio between the absorption and the extinction coefficient. The albedo is therefore similar for all samples: The values averaged over all samples investigated were 0.161, 0.115, and 0.115 at λ = 632.8, 751, and 833 nm respectively, with maximum deviations of 0.044, 0.019, and 0.035. These results indicate that, using the values we have obtained for the albedo, it should be possible to obtain with uncertainty smaller than about 4% the absorption coefficient of a sample of unknown ink from simple measurements of extinction coefficient. A similar accuracy is not easily obtained with the complicated procedures necessary for measurements of absorption coefficient

    Excitonic Effects in Quantum Wires

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    We review the effects of Coulomb correlation on the linear and non-linear optical properties of semiconductor quantum wires, with emphasis on recent results for the bound excitonic states. Our theoretical approach is based on generalized semiconductor Bloch equations, and allows full three-dimensional multisubband description of electron-hole correlation for arbitrary confinement profiles. In particular, we consider V- and T-shaped structures for which significant experimental advances were obtained recently. Above band gap, a very general result obtained by this approach is that electron-hole Coulomb correlation removes the inverse-square-root single-particle singularity in the optical spectra at band edge, in agreement with previous reports from purely one-dimensional models. Strong correlation effects on transitions in the continuum are found to persist also at high densities of photoexcited carriers. Below bandgap, we find that the same potential- (Coulomb) to kinetic-energy ratio holds for quite different wire cross sections and compositions. As a consequence, we identify a shape- and barrier-independent parameter that governs a universal scaling law for exciton binding energy with size. Previous indications that the shape of the wire cross-section may have important effects on exciton binding are discussed in the light of the present results.Comment: Proc. OECS-5 Conference, G\"ottingen, 1997 (To appear in Phys. Stat. Sol. (b)

    Educación artística: deconstruir, reconstruir, construir

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    La educación artística hoy en nuestro país y en el mundo está atravesada por variables que la complejizan. El contexto cultural que la comprende responde a desafíos pero además la enfrenta a cambios que se producen tanto en el arte como en las ciencias sociales ya que encara un nuevo estatus epistemológico. Parte también de diversos enfoques cognitivistas en psicología y responde a nuevas pedagogías tanto en el campo de la educación en general como en el específico y complejo campo de la educación artística. Muchas son las propuestas que en nuestra Universidad de Artes se presentan, a veces asociadas a diversos modelos, teorías y prácticas, algunas de ellas conviviendo con modelos nacidos hace ya muchos años y otras renovadoras que respiran relativismos estéticos y culturales que nos invitan a realizar propuestas pedagógicas reflexivas y críticas frente al impacto de la cultura visual en la que estamos inmersos desde hace ya varios años.Eje temático 1: Perspectivas teóricas y metodológicas.Facultad de Bellas Arte

    Educación artística: deconstruir, reconstruir, construir

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    La educación artística hoy en nuestro país y en el mundo está atravesada por variables que la complejizan. El contexto cultural que la comprende responde a desafíos pero además la enfrenta a cambios que se producen tanto en el arte como en las ciencias sociales ya que encara un nuevo estatus epistemológico. Parte también de diversos enfoques cognitivistas en psicología y responde a nuevas pedagogías tanto en el campo de la educación en general como en el específico y complejo campo de la educación artística. Muchas son las propuestas que en nuestra Universidad de Artes se presentan, a veces asociadas a diversos modelos, teorías y prácticas, algunas de ellas conviviendo con modelos nacidos hace ya muchos años y otras renovadoras que respiran relativismos estéticos y culturales que nos invitan a realizar propuestas pedagógicas reflexivas y críticas frente al impacto de la cultura visual en la que estamos inmersos desde hace ya varios años.Eje temático 1: Perspectivas teóricas y metodológicas.Facultad de Bellas Arte

    Nuclear Diacylglycerol Produced by Phosphoinositide-specific Phospholipase C Is Responsible for Nuclear Translocation of Protein Kinase C-α

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    It is well established that an independent inositide cycle is present within the nucleus, where it is involved in the control of cell proliferation and differentiation. Previous results have shown that when Swiss 3T3 cells are treated with insulin-like growth factor-I (IGF-I) a rapid and sustained increase in mass of diacylglycerol (DAG) occurs within the nuclei, accompanied by a decrease in the levels of both phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. However, it is unclear whether or not other lipids could contribute to this prolonged rise in DAG levels. We now report that the IGF-I-dependent increase in nuclear DAG production can be inhibited by the specific phosphatidylinositol phospholipase C inhibitor 1-O-octadeyl-2-O-methyl-sn-glycero-3-phosphocholine or by neomycin sulfate but not by the purported phosphatidylcholine-phospholipase C specific inhibitor D609 or by inhibitors of phospholipase D-mediated DAG generation. Treatment of cells with 1-O-octadeyl-2-O-methyl-sn-glycero-3-phosphocholine or neomycin sulfate inhibited translocation of protein kinase C-alpha to the nucleus. Moreover, exposure of cells to 1-O-octadeyl-2-O-methyl-sn-glycero-3-phosphocholine, but not to D609, dramatically reduced the number of cells entering S-phase upon stimulation with IGF-I. These results suggest that the only phospholipase responsible for generation of nuclear DAG after IGF-I stimulation of 3T3 cells is PI-PLC. When this activity is inhibited, neither DAG rise is seen nor PKC-alpha translocation to the nucleus occurs. Furthermore, this PI-PLC activity appears to be essential for the G0/G1 to S-phase transition

    Physico-Chemical Traits of Raw and Cooked Fillets of Rainbow Trout (Oncorhynchus Mykiss) from Different Strains and Farms

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    Fillets and cooking yields, water holding capacity, textural properties, colour, proximate composition, collagen and fatty acids of five strains (IT1, IT2, IT3, USA, UK) of rainbow trout, Oncorhynchus mykiss, reared in three farms (F1, F2, F3), were measured before and after cooking. Physico-chemical parameters of the strains greatly differed both in raw and cooked state. IT2 and USA recorded the highest yields. IT2 distinguished from the other strains, showing lowest values of hardness, chewiness, gumminess and springiness. It also had brighter and less pigmented flesh with low fat, mainly in the raw state. USA strain showed the most valuable traits in terms of texture and colour, and had higher fat and collagen content in flesh. The physico-chemical profile of each strain was differently modified by cooking. USA strain maintained a positive texture and colour profile after cooking and its quality was the best

    Bioremediation of Crude Oil by Haematococcus Pluvialis: A Preliminary Study

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    Nowadays, oil pollution is one of the main environmental problems. The current methods for recovering spills mainly involve chemical agents, but scientific research has focused on more natural and less harmful techniques for the environment, including a consortium of bacteria and microalgae to clean up water contaminated by hydrocarbons. The purpose of this preliminary study was to evaluate the ability of a microalga belonging to Chlorophyceae to grow in the presence of crude oil and remove the principal contaminants. H. pluvialis, which is usually used for nutraceutical purposes, thanks to the production of astaxanthin, was able to grow in anaerobic conditions, varying its metabolism from autotrophic to heterotrophic, exploiting the carbon present in the solution deriving from the presence of 1% of crude oil. Furthermore, the results of bioremediation showed a relevant reduction in chemical pollutants such as nitrate, fluoride, sulfate, and phosphate. The most important aspect of the study was the reduction after 160 days in the hydrocarbon concentration inside not only the culture medium (−32%) but also the algal biomass (−80.25%), demonstrating an optimized degradation rather than a simple absorption inside the alga

    Crude Oil Bioremediation: From Bacteria to Microalgae

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    Crude oil is one of the major pollutants present. Its extraction and processing generate processing waters contaminated by hydrocarbons which are harmful to both human health and the flora and fauna that come into contact with it. Hydrocarbon contamination can involve soil and water, and several technologies are used for recovery. The most used techniques for the recovery of spilt oil involve chemical-physical methods that can remove most of the pollutants. Among these, must consider the bioremediation by microorganisms, mostly bacterial capable of degrading many of the toxic compounds contained within the petroleum. Microalgae participate in bioremediation indirectly, supporting the growth of degrading bacteria, and directly acting on contaminants. Their direct contribution is based on the activation of various mechanisms ranging from the production of enzymes capable of degrading hydrocarbons, such as lipoxygenases, to the attack through the liberation of free radicals. The following review analyzed all the works published in the last ten years concerning the ability of microalgae to remove hydrocarbons, intending to identify in these microorganisms an alternative technology to the use of bacteria. The advantages of using microalgae concern not only their ability to remove toxic compounds and release oxygen into the atmosphere but their biomass could then be used in a circular economy process to produce biofuels
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