91 research outputs found

    Self-Assembly of Polyhedral Hybrid Colloidal Particles

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    We have developed a new method to produce hybrid particles with polyhedral shapes in very high yield (liter quantities at up to 70% purity) using a combination of emulsion polymerization and inorganic surface chemistry. The procedure has been generalized to create complex geometries, including hybrid line segments, triangles, tetrahedra, octahedra, and more. The optical properties of these particles are tailored for studying their dynamics and self-assembly. For example, we produce systems that consist of index-matched spheres allowing us to define the position of each elementary particle in three-dimensional space. We present some preliminary studies on the self-assembly of these complex shaped systems based on electron and optical microscopy.Engineering and Applied SciencesPhysic

    Regulatory T-cells in chronic lymphocytic leukemia: actor or innocent bystander?

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    Abstract: Regulatory T (Treg) cells are now under extensive investigation in chronic lymphocytic leukemia (CLL). This small subset of T-cells has been, in fact, considered to be involved in the pathogenesis and progression of CLL. However, whether Treg dysregulation in CLL plays a key role or it rather represents a simple epiphenomenon is still matter of debate. In the former case, Treg cells could be appealing for targeting therapies. Finally, Treg cells have also been proposed as a prognostic indicator of the disease clinical course

    The DNA Damage Response Pathway Contributes to the Stability of Chromosome III Derivatives Lacking Efficient Replicators

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    In eukaryotic chromosomes, DNA replication initiates at multiple origins. Large inter-origin gaps arise when several adjacent origins fail to fire. Little is known about how cells cope with this situation. We created a derivative of Saccharomyces cerevisiae chromosome III lacking all efficient origins, the 5ORIΔ-ΔR fragment, as a model for chromosomes with large inter-origin gaps. We used this construct in a modified synthetic genetic array screen to identify genes whose products facilitate replication of long inter-origin gaps. Genes identified are enriched in components of the DNA damage and replication stress signaling pathways. Mrc1p is activated by replication stress and mediates transduction of the replication stress signal to downstream proteins; however, the response-defective mrc1AQ allele did not affect 5ORIΔ-ΔR fragment maintenance, indicating that this pathway does not contribute to its stability. Deletions of genes encoding the DNA-damage-specific mediator, Rad9p, and several components shared between the two signaling pathways preferentially destabilized the 5ORIΔ-ΔR fragment, implicating the DNA damage response pathway in its maintenance. We found unexpected differences between contributions of components of the DNA damage response pathway to maintenance of ORIΔ chromosome derivatives and their contributions to DNA repair. Of the effector kinases encoded by RAD53 and CHK1, Chk1p appears to be more important in wild-type cells for reducing chromosomal instability caused by origin depletion, while Rad53p becomes important in the absence of Chk1p. In contrast, RAD53 plays a more important role than CHK1 in cell survival and replication fork stability following treatment with DNA damaging agents and hydroxyurea. Maintenance of ORIΔ chromosomes does not depend on homologous recombination. These observations suggest that a DNA-damage-independent mechanism enhances ORIΔ chromosome stability. Thus, components of the DNA damage response pathway contribute to genome stability, not simply by detecting and responding to DNA template damage, but also by facilitating replication of large inter-origin gaps

    Orientare al tirocinio e alle professioni: L’università incontra le aziende

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    In questo volume si presentano i risultati di un lavoro di ricerca, di durata triennale, che ha avuto come obiettivo l’analisi di due profili professionali formati dai Corsi di laurea in Scienze dell’Educazione della Sapienza: l’Educatore e l’Educatore nei servizi per l’infanzia. Nello specifico, sono state realizzate delle Giornate di studio su queste due figure professionali con la partecipazione di alcune aziende ospitanti i tirocinanti. Finalità dell’incontro tra università e il mondo del lavoro è stata quella di contribuire all’aggiornamento dell’offerta formativa del Corsi di laurea, di migliorare l’orientamento degli studenti (in entrata e in uscita) e di rivedere il modello di tirocinio in modo da perfezionare l’integrazione degli apprendimenti teorici – peculiari del contesto accademico – con quanto acquisito, in modo implicito ed esplicito, nel contesto lavorativo in cui si sperimenta la pratica
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