630 research outputs found

    Expansivity and Shadowing in Linear Dynamics

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    In the early 1970's Eisenberg and Hedlund investigated relationships between expansivity and spectrum of operators on Banach spaces. In this paper we establish relationships between notions of expansivity and hypercyclicity, supercyclicity, Li-Yorke chaos and shadowing. In the case that the Banach space is c0c_0 or ℓp\ell_p (1≀p<∞1 \leq p < \infty), we give complete characterizations of weighted shifts which satisfy various notions of expansivity. We also establish new relationships between notions of expansivity and spectrum. Moreover, we study various notions of shadowing for operators on Banach spaces. In particular, we solve a basic problem in linear dynamics by proving the existence of nonhyperbolic invertible operators with the shadowing property. This also contrasts with the expected results for nonlinear dynamics on compact manifolds, illuminating the richness of dynamics of infinite dimensional linear operators

    Les fistules congenitales de la levre inferieure : a propos d’une observation

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    Objectifs : Les fistules congĂ©nitales de la lĂšvre infĂ©rieure sont rares pouvant ĂȘtre soit isolĂ©es soit associĂ©es Ă  d’autres malformations notamment les fentes vĂ©lopalatines. Le but de notre Ă©tude est de rappeler Ă  travers une observation les Ă©lĂ©ments Ă©pidĂ©miologiques, cliniques, Ă©tiopathogĂ©niques et les modalitĂ©s thĂ©rapeutiques de cette affection.MĂ©thode : Nous prĂ©sentons le cas d’une fillette ĂągĂ©e de 9 ans qui prĂ©sente une double fistule labiale infĂ©rieure sans autres malformations associĂ©es, mais l’enquĂȘte Ă©tiologique retrouve 10 cas similaires dans la famille.RĂ©sultats : une excision complĂšte du trajet fistuleux a Ă©tĂ© rĂ©alisĂ©e chez notre patiente avec un bon rĂ©sultat esthĂ©tique et une absence de rĂ©cidive aprĂšs un recul d’une annĂ©e.Conclusion : la dĂ©couverte de fistules labiales infĂ©rieures impose un bilan complet Ă  la recherche de malformations associĂ©es ainsi qu’une enquĂȘte familiale.Mots-clĂ©s : fistules labiales - malformations congĂ©nitalesPurpose of study: Congenital lower lip fistulae are rare and can be either isolated or associated with other malformations, namely soft palatal clefts. Our study aims at recalling through an observation the epidemiological, clinical etiopathogenic elements and the therapeutic courses of this disorder.Method: We present the case of a 9-year old little girl with a lower lip double fistula and no other accompanying malformation. The etiological study reveals 10 similar cases within the family.Results: A complete excision of the fistulous path has been carried out on our patient with a good esthetic result and the absence of a recurrence a year later.Conclusion: Finding out lower lip fistulae requires a thorough check up for associated malformations as well as a family inquiry.Key-words: lip fistulae- congenital malformation

    Synthesis of bridged aza-rebeccamycin analogues

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    The syntheses of rebeccamycin analogues possessing a 7-azaindole moiety instead of an indole unit, and with both indole and azaindole moieties linked to the carbohydrate are described. In these bridged aza compounds, the oxygen of the pyranose heterocycle is oriented towards either the indole, or the azaindole unit. In these series, compounds bearing a free imide nitrogen were synthesized by coupling the corresponding aglycones with a sugar pre-tosylated in 2-position via a Mitsunobu reaction. To obtain a precursor for bridged aza-rebeccamycin analogues substituted in 6-position on the sugar moiety, a 2,6-ditosylated sugar was use

    Synthesis of granulatimide bis-imide analogues

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    The synthesis of dipyrrolo[3,4-a:3,4-c]carbazole-1,3,4,6-tetraones, structurally related to granulatimide is reported. These compounds can be considered as granulatimide analogues in which a maleimide heterocycle replaces the imidazole moiety. The synthesis of pyridino[2,3-b]dipyrrolo[3,4-e:3,4-g]indole-1,3,4,6-tetraones is also reported. In these compounds, a 7-azaindole unit replaces the indole moiety present in the granulatimide and isogranulatimide structure

    NextMed, Augmented and Virtual Reality platform for 3D medical imaging visualization

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    The visualization of the radiological results with more advanced techniques than the current ones, such as Augmented Reality and Virtual Reality technologies, represent a great advance for medical professionals, by eliminating their imagination capacity as an indispensable requirement for the understanding of medical images. The problem is that for its application it is necessary to segment the anatomical areas of interest, and this currently involves the intervention of the human being. The Nextmed project is presented as a complete solution that includes DICOM images import, automatic segmentation of certain anatomical structures, 3D mesh generation of the segmented area, visualization engine with Augmented Reality and Virtual Reality, all thanks to different software platforms that have been implemented and detailed, including results obtained from real patients. We will focus on the visualization platform using both Augmented and Virtual Reality technologies to allow medical professionals to work with 3d model representation of medical images in a different way taking advantage of new technologies

    Effective Control of Chronic γ-Herpesvirus Infection by Unconventional MHC Class Ia–Independent CD8 T Cells

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    Control of virus infection is mediated in part by major histocompatibility complex (MHC) Class Ia presentation of viral peptides to conventional CD8 T cells. Although important, the absolute requirement for MHC Class Ia–dependent CD8 T cells for control of chronic virus infection has not been formally demonstrated. We show here that mice lacking MHC Class Ia molecules (K(b−/−)xD(b−/−) mice) effectively control chronic Îł-herpesvirus 68 (ÎłHV68) infection via a robust expansion of ÎČ(2)-microglobulin (ÎČ(2)-m)-dependent, but CD1d-independent, unconventional CD8 T cells. These unconventional CD8 T cells expressed: (1) CD8αÎČ and CD3, (2) cell surface molecules associated with conventional effector/memory CD8 T cells, (3) TCRαÎČ with a significant VÎČ4, VÎČ3, and VÎČ10 bias, and (4) the key effector cytokine interferon-Îł (IFNÎł). Unconventional CD8 T cells utilized a diverse TCR repertoire, and CDR3 analysis suggests that some of that repertoire may be utilized even in the presence of conventional CD8 T cells. This is the first demonstration to our knowledge that ÎČ(2)-m–dependent, but Class Ia–independent, unconventional CD8 T cells can efficiently control chronic virus infection, implicating a role for ÎČ(2)-n–dependent non-classical MHC molecules in control of chronic viral infection. We speculate that similar unconventional CD8 T cells may be able to control of other chronic viral infections, especially when viruses evade immunity by inhibiting generation of Class Ia–restricted T cells

    Impact of thoracoabdominal imaging on diagnosis and management in patients with suspected infective endocarditis.

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    Embolic events (EEs) are a common complication of infective endocarditis (IE) and their presence can impact diagnosis and modify the therapeutic plan. The present study aimed to describe the role of thoracoabdominal imaging, either thoracoabdominal-pelvic Computed Tomography or &lt;sup&gt;18&lt;/sup&gt; F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography, on diagnosis and management of patients with suspected IE. This study was conducted at a university hospital, from January 2014 to June 2022. EEs and IE were defined according to modified Duke criteria. Among 966 episodes with suspected IE and thoracoabdominal imaging, 528 (55%) patients were asymptomatic. At least one EE was found in 205 (21%) episodes. Based on thoracoabdominal imaging findings, the diagnosis was reclassified from rejected to possible or from possible to definite IE in 6 (1%) and 10 (1%) episodes, respectively. Among the 413 patients with IE, at least one EE was found on thoracoabdominal imaging in 143 (35%) episodes. Together with the presence of left-side valvular vegetation &gt;10 mm, the results of thoracoabdominal imaging established a surgical indication (prevention of embolism) in 15 (4%) episodes, 7 of which were asymptomatic. Thoracoabdominal imaging performed in asymptomatic patients with suspected IE improved the diagnosis in only a small proportion of patients. Thoracoabdominal imaging led to a new surgical indication (in association with left-side valvular vegetation &gt;10 mm) in only a small percentage of patients

    Synthesis and cytotoxicities of 7-aza rebeccamycin analogues bearing various substituents on the sugar moiety, on the imide nitrogen and on the carbazole framework

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    The synthesis of a family of rebeccamycin analogues in which one indole unit has been replaced by a 7-azaindole moiety is described. Substitutions have been carried out on the imide nitrogen, on the carbazole framework and on the sugar part. Compounds with a lactam upper heterocycle have also been prepared. The cytotoxicities of the newly synthesized compounds toward four tumor cell lines, one murine leukemia (L1210) and three human tumor cell lines (prostate carcinoma DU145, colon carcinoma HT29, and non-small cell lung carcinoma A549) have been evaluated and compared to those of rebeccamycin and parent non-aza and aza compound
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