444 research outputs found

    AB≠BA : an investigation into the historical roots of noncommutative algebra

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    Includes bibliographical references.Abstract Algebra is a branch of mathematics in which a large amount of research is currently taking place. This research includes the investigation into different types of algebraic structures such as fields, rings, groups, and their properties. The history of algebra is as rich as the science itself. It is my intention to investigate a crucial step in the development of algebra: the beginning of noncommutative algebra.B.S. (Bachelor of Science

    Is combining ACE inhibitors and ARBs helpful or harmful?

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    The combination of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) has been studied for treatment of heart failure, hypertension, and proteinuric renal disease. Combination therapy with an ACE inhibitor and an ARB decreases symptoms in heart failure patients, but does not appear to have an impact on overall mortality (strength of recommendation [SOR]: A). Preliminary data from small trials indicate that combination therapy may be more effective than monotherapy with an ACE inhibitor or an ARB for lowering blood pressure (SOR: B), although morbidity and mortality data for the combination are not currently available. Additionally, in trials involving diabetic and nondiabetic proteinuric renal disease, the combination of ACE inhibitors and ARBs delays progression of renal disease to a greater extent than monotherapy; however, mortality data are also unavailable (SOR: A)

    Hydrocéphalie du nouveau-né et du nourrisson au Centre Hospitalier National de Nouakchott

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    LÂŽhydrocĂ©phalie du nouveau-nĂ© et du nourrisson constitue un facteur important de mortalitĂ© et de morbiditĂ© dans les pays en voie de dĂ©veloppement avec des moyens diagnostiques et thĂ©rapeutiques limitĂ©s. Cette Ă©tude avait pour objectif de rapporter notre expĂ©rience dans la prise en charge de cette pathologie en Mauritanie. Il sÂŽagissait dÂŽune Ă©tude rĂ©trospective portant sur 126 dossiers dÂŽenfants dÂŽĂąge compris entre 0 et 24 mois, pris en charge pour hydrocĂ©phalie dans le service de neurochirurgie du CHN de Nouakchott, de juin 2014 au juin 2018. Le dĂ©lai moyen de suivi Ă©tait de 15 mois (9-27 mois). LÂŽĂąge moyen au diagnostic Ă©tait de 5 mois (2 jours Ă  20 mois). On notait une prĂ©dominance fĂ©minine (sex-ratio de 0,77). La sĂ©rie Ă©tait composĂ©e de 45 nouveau-nĂ©s (35,7%) et de 81 nourrissons (64,3%). Un antĂ©cĂ©dent infectieux de la grossesse avait Ă©tĂ© retrouvĂ© dans 19,8% et une infection nĂ©onatale dans 23,8%. Sur le plan clinique, 87,3% avaient une macrocĂ©phalie, 35,7% un retard du dĂ©veloppement psychomoteur et 15,8% un refus de tĂ©ter. La principale Ă©tiologie Ă©tait reprĂ©sentĂ©e par les myĂ©lomĂ©ningoceles (23,8%), suivie de la mĂ©ningite (15,8%). La dĂ©rivation ventriculo-pĂ©ritonĂ©ale (DVP) Ă©tait le principal traitement chez le nouveau-nĂ© (68,8%), tandis que la ventriculocisternostomie endoscopique (VCE) Ă©tait prĂ©fĂ©rĂ©e chez le nourrisson (74,1%). Le taux global de complications Ă©tait de 26,1% (57,6% pour les DVP et 4,1% pour la VCE). LÂŽhydrocĂ©phalie est la principale pathologie de la neurochirurgie pĂ©diatrique en Afrique. Sa prise en charge reste tardive, dÂŽoĂč lÂŽimportance de la prĂ©vention surtout des anomalies du tube neural et des infections

    Patterning porous networks through self-assembly of programmed biomacromolecules

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    Two‐dimensional (2D) porous networks are of great interest for the fabrication of complex organized functional materials for potential applications in nanotechnologies and nanoelectronics. This review aims at providing an overview of bottom‐up approaches towards the engineering of 2D porous networks by using biomacromolecules, with a particular focus on nucleic acids and proteins. The first part illustrates how the advancements in DNA nanotechnology allowed for the attainment of complex ordered porous two‐dimensional DNA nanostructures, thanks to a biomimetic approach based on DNA molecules self‐assembly through specific hydrogen‐bond base pairing. The second part focuses the attention on how polypeptides and proteins structural properties could be used to engineer organized networks templating the formation of multifunctional materials. The structural organization of all examples is discussed as revealed by scanning probe microscopy or transmission electron microscopy imaging techniques
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