630 research outputs found
Expansivity and Shadowing in Linear Dynamics
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 or (), 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 dâune observation
Objectifs : Les fistules congĂ©nitales de la lĂšvre infĂ©rieure sont rares pouvant ĂȘtre soit isolĂ©es soit associĂ©es Ă dâautres 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 dâune fillette ĂągĂ©e de 9 ans qui prĂ©sente une double fistule labiale infĂ©rieure sans autres malformations associĂ©es, mais lâenquĂȘte 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 dâune annĂ©e.Conclusion : la dĂ©couverte de fistules labiales infĂ©rieures impose un bilan complet Ă la recherche de malformations associĂ©es ainsi quâune 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
Global nonexistence of solutions for nonlinear coupled viscoelastic wave equations with damping and source terms
Synthesis of bridged aza-rebeccamycin analogues
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
Effective control of chronic c-herpesvirus infection by unconventional MHC class Iaâindependent CD8 T cells
Synthesis of granulatimide bis-imide analogues
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
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 Îł-Herpesvirus Infection by Unconventional MHC Class IaâIndependent CD8 T Cells
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 Iaâdependent 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(bâ/â)xD(bâ/â) 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)-mâdependent, but Class Iaâindependent, unconventional CD8 T cells can efficiently control chronic virus infection, implicating a role for ÎČ(2)-nâdependent 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 Iaârestricted T cells
Impact of thoracoabdominal imaging on diagnosis and management in patients with suspected infective endocarditis.
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 <sup>18</sup> 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 >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 >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
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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