UTILITE ET EFFICACITE DU CATHETERISME SELECTIF DES VEINES SURRENALIENNES LORS D'UN HYPERALDOSTERONISME PRIMAIRE, REVUE DES 5 DERNIERES ANNEES AU CHUV

Contexte   L'hyperaldostéronisme primaire (HAP) est actuellement considéré comme la première cause d'hypertension artérielle secondaire. Son diagnostic est capital car il permet d'identifier des patients avec une cause potentiellement réversible d'hypertension. Cependant, le diagnostic et l'attitude thérapeutique (traitement médical vs. chirurgical) ne sont pas toujours évidents. Le cathétérisme sélectif des veines surrénaliennes (CVS) permet la détermination d'une latéralisation de la sécrétion d'aldostérone avec moins de risques de faux négatifs et de faux positifs que l'imagerie par scanner ou par IRM. Contrairement à d'autres pays européens, asiatiques ou américains, il n'existe pour le moment aucune donnée publiée sur le cathétérisme des veines surrénaliennes en Suisse.  Objectifs Déterminer le taux de succès du CVS ainsi que ses déterminants cliniques au cours des 5 dernières années au CHUV, ainsi que démontrer l'utilité d'un cathétérisme des veines surrénaliennes lorsqu'une surrénalectomie est envisagée dans le cadre d'un hyperaldostéronisme primaire  Méthodes Cette étude est rétrospective et monocentrique. La récolte de données s'est faite à partir de dossiers de 68 patients atteints d'hypertension artérielle (HTA) secondaire sur HAP biochimiquement confirmé et ayant eu un CVS au cours des 5 dernières années.  Résultats Au CHUV, le taux de succès du CVS (cathétérisme bilatéral des veines surrénaliennes) s'élève à 60% (41/68). Dans 53% des cas, il y a discordance entre les résultats de l'imagerie standard et ceux du CVS. Une attitude thérapeutique basée sur l'imagerie standard aurait entrainé des traitements inappropriés : 43% des patients auraient subi une chirurgie inadéquate, et 10% n'auraient pas été candidats à une sanction chirurgicale alors qu'elle aurait été indiquée sur la base du CVS.  Conclusions Le CVS doit être considéré comme l'étalon-or dans la prise en charge diagnostique de l'HAP lorsqu'une intervention chirurgicale est possible. En se basant uniquement sur l'imagerie, il en résulterait un taux élevé de traitement inapproprié. Aux vues des difficultés techniques associées à cet examen, de nouvelles procédures doivent être mises en place pour mener à une amélioration de son taux de succès et à l'interprétation des résultats

Beyond Binary Search: Parallel In-Place Construction of Implicit Search Tree Layouts.

M.S. Thesis. University of Hawaiʻi at Mānoa 2018

Interacting many-body systems in quantum wells: Evidence for exciton-trion-electron correlations

We report on the nonlinear optical dynamical properties of excitonic complexes in CdTe modulation-doped quantum wells, due to many-body interactions among excitons, trions and electrons. These were studied by time and spectrally resolved pump-probe experiments. The results reveal that the nonlinearities induced by trions differ from those induced by excitons, and in addition they are mutually correlated. We propose that the main source of these subtle differences comes from the Pauli exclusion-principle through phase-space filling and short-range fermion exchange.Comment: 5 pages, 4 figures. accepted for publications in Phys. Rev.

Light dressed-excitons in an incoherent-electron sea: Evidence for Mollow-triplet and Autler-Townes doublet

We demonstrate that the interaction between excitons and a sea of incoherent electrons does not preclude excitons dressing by light. We investigate the role of exciton-electron scattering in the light dressing by measuring the dynamical absorption spectrum of a modulation-doped CdTe quantum well, which shows a clear evidence for significant electron scattering of the excitonic states. We show the occurrence of dressed and correlated excitons by detecting quantum coherent interferences through excitonic Autler-Townes doublet and ac Stark splitting, which evolves to Mollow triplet with gain. We also evidence the partial inhibition of the electron-exciton scattering by exciton-light coupling

Concept of Formation Length in Radiation Theory

The features of electromagnetic processes are considered which connected with finite size of space region in which final particles (photon, electron-positron pair) are formed. The longitudinal dimension of the region is known as the formation length. If some external agent is acting on an electron while traveling this distance the emission process can be disrupted. There are different agents: multiple scattering of projectile, polarization of a medium, action of external fields, etc. The theory of radiation under influence of the multiple scattering, the Landau-Pomeranchuk-Migdal (LPM) effect, is presented. The probability of radiation is calculated with an accuracy up to "next to leading logarithm" and with the Coulomb corrections taken into account. The integral characteristics of bremsstrahlung are given, it is shown that the effective radiation length increases due to the LPM effect at high energy. The LPM effect for pair creation is also presented. The multiple scattering influences also on radiative corrections in a medium (and an external field too) including the anomalous magnetic moment of an electron and the polarization tensor as well as coherent scattering of a photon in a Coulomb field. The polarization of a medium alters the radiation probability in soft part of spectrum. Specific features of radiation from a target of finite thickness include: the boundary photon emission, interference effects for thin target, multi-photon radiation. The experimental study of LPM effect is described. For electron-positron colliding beams following items are discussed: the separation of coherent and incoherent mechanisms of radiation, the beam-size effect in bremsstrahlung, coherent radiation and mechanisms of electron-positron creation.Comment: Revised review paper, 96 pages, 28 figures. Description of SLAC E-146 experiment removed, discussion of CERN SPS experiment adde

Direct measure of the exciton formation in quantum wells from time resolved interband luminescence

We present the results of a detailed time resolved luminescence study carried out on a very high quality InGaAs quantum well sample where the contributions at the energy of the exciton and at the band edge can be clearly separated. We perform this experiment with a spectral resolution and a sensitivity of the set-up allowing to keep the observation of these two separate contributions over a broad range of times and densities. This allows us to directly evidence the exciton formation time, which depends on the density as expected from theory. We also evidence the dominant contribution of a minority of excitons to the luminescence signal, and the absence of thermodynamical equilibrium at low densities

Study protocol for the ETMED-L project: longitudinal study of mental health and interpersonal competence of medical students in a Swiss university using a comprehensive framework of empathy.

Physician interpersonal competence is crucial for patient care. How interpersonal competence develops during undergraduate medical education is thus a key issue. Literature on the topic consists predominantly of studies on empathy showing a trend of decline over the course of medical school. However, most existing studies have focused on narrow measures of empathy. The first aim of this project is to study medical students' interpersonal competence with a comprehensive framework of empathy that includes self-reported cognitive and affective empathy, performance-based assessments of emotion recognition accuracy, and a behavioural dimension of empathy. The second aim of the present project is to investigate the evolution of mental health during medical school and its putative link to the studied components of interpersonal competence. Indeed, studies documented a high prevalence of mental health issues among medical students that could potentially impact their interpersonal competence. Finally, this project will enable to test the impact of mental health and interpersonal competence on clinical skills as evaluated by experts and simulated patients. This project consists of an observational longitudinal study with an open cohort design. Each year during the four consecutive years of the project, every medical student (curriculum years 1-6) of the University of Lausanne in Switzerland will be asked to complete an online questionnaire including several interpersonal competence and mental health measures. Clinical skills assessments from examinations and training courses with simulated patients will also be included. Linear mixed models will be used to explore the longitudinal evolutions of the studied components of interpersonal competence and mental health as well as their reciprocal relationship and their link to clinical skills. The project has received ethical approval from the competent authorities. Findings will be disseminated through internal, regional, national and international conferences, news and peer-reviewed journals

Clinical determinants of adrenal vein sampling success

Background: Primary aldosteronism (PA) is one of the most prevalent forms of secondary hypertension, which may be cured by unilateral adrenalectomy. Adrenal vein sampling (AVS) is considered the gold-standard procedure for distinction between bilateral and unilateral aldosterone hypersecretion. However, the procedure is viewed as a technical challenge. The objectives of this study were to define the success rate of AVS, and its clinical determinants, and to compare the accuracy of high-resolution adrenal computed tomography (CT) with AVS. Methods: In this single-centre retrospective study, patients with biologically proven PA who were referred for AVS between 2009 and 2014 were included. Adrenal vein catheterisation was considered selective if the selectivity index (adrenal vein / inferior vena cava cortisol) was ≥2. Results: Data from 68 patients (48% women) were available. The success rate of catheterisation in bilateral AVS was 60% (41/68). The significant clinical determinants of success were male sex (r = 0.35, p = 0.004), a higher body mass index (BMI) (r = 0.54, p = 0.001) and plasma creatinine (r = 0.25, p = 0.048) in univariate analysis. In multivariate linear regression analysis, only BMI was associated with success (coefficient = 0.049, p = 0.004). CT was discordant with AVS in 53% of patients, and would have resulted in inappropriate adrenalectomy in 43% of the patients and inappropriate exclusion from surgery in 10% of the cases. Conclusion: Clinical characteristics such as BMI and sex may influence the success rate of AVS. The inaccuracy of CT may result in inappropriate treatment proposals if the indication for surgical intervention is based on CT only