Assessment of refrigerant mixtures performance with thermal glide for cold climate air-source heat pumps

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.Heat pumps are currently considered as one of the most promising means for meeting low energy consumption requirements in buildings. However conventional air source heat pumps suffer from severe limitations in terms of performance at low ambient temperatures, while new designs such as multi-stage compression or ground source heat pumps are still very costly. The main challenge is to improve on the air-source heat pumps low efficiency in cold climates at a reasonable cost. The use of mixtures of refrigerants with the aim of increasing heat pumps performance (COP and/or heating capacity) by taking advantage of the thermal glide has been so far, little studied for the heating and cooling of buildings. In this paper, the goal is to assess the performance of refrigerant mixtures with thermal glide for cold climate air-source heat pumps. A simple theoretical and an extended model have been developed and used for refrigerant mixtures performance evaluation. It is shown that a good potential exists in refrigerant mixtures with moderate glide to improve the performance of cold climate air-source heat pumps.cf201

MRI in active surveillance: a critical review

INTRODUCTION: Recent technological advancements and the introduction of modern anatomical and functional sequences have led to a growing role for multiparametric magnetic resonance imaging (mpMRI) in the detection, risk assessment and monitoring of early prostate cancer. This includes men who have been diagnosed with lower-risk prostate cancer and are looking at the option of active surveillance (AS). The purpose of this paper is to review the recent evidence supporting the use of mpMRI at different time points in AS, as well as to discuss some of its potential pitfalls. METHODS: A combination of electronic and manual searching methods were used to identify recent, important papers investigating the role of mpMRI in AS. RESULTS: The high negative predictive value of mpMRI can be exploited for the selection of AS candidates. In addition, mpMRI can be efficiently used to detect higher risk disease in patients already on surveillance. CONCLUSION: Although there is an ongoing debate regarding the precise nature of its optimal implementation, mpMRI is a promising risk stratification tool and should be considered for men on AS

Rôle de l’IRM prostatique dans le cancer de la prostate en 2016: mise au point et perspectives d’avenir

Le diagnostic du cancer de la prostate est le plus souvent porté à l’occasion d’un dosage élevé de PSA, fait dans le cadre du dépistage individuel, et repose sur la réalisation de «biopsies systématisées» par voie transrectale avec guidage échographique. Cette stratégie classique entraîne un risque de sur-diagnostic de cancers cliniquement non significatifs [microfoyers], ainsi qu’une non-détection de certains cancers cliniquement significatifs situés en dehors des zones prélevées. La réalisation d’une IRM prostatique avant les biopsies a tout changé. Elle augmente la détection des cancers de volume significatif grâce aux «biopsies ciblées» sur les anomalies vues à l’IRM. Elle améliore l’estimation de leur grade, de leur taille et permet de préciser leur localisation et contour. Elle permettrait aussi de diminuer la détection des cancers non significatifs, si les biopsies systématisées n’étaient plus faites en cas d’IRM sans cible suspecte. Les applications thérapeutiques de l’IRM sont déterminantes pour l’essor des options récentes de prise en charge comme la sélection des patients pour la surveillance active ainsi que pour l’indication de traitement focal. Les modalités de réalisation et d’interprétation de l’IRM ont été publiées en 2016 sous forme d’une mise à jour du score PI-RADS [Prostate Imaging Reporting and Data System version 2]. Cette standardisation aide les radiologues à proposer aux cliniciens urologues et radiothérapeutes les éléments nécessaires pour le diagnostic et le traitement des cancers de la prostate

Focal therapy as primary treatment for localized prostate cancer: definition, needs and future.

Focal therapy (FT) may offer a promising treatment option in the field of low to intermediate risk localized prostate cancer. The aim of this concept is to combine minimal morbidity with cancer control as well as maintain the possibility of retreatment. Recent advances in MRI and targeted biopsy has improved the diagnostic pathway of prostate cancer and increased the interest in FT. However, before implementation of FT in routine clinical practice, several challenges are still to overcome including patient selection, treatment planning, post-therapy monitoring and definition of oncologic outcome surrogates. In this article, relevant questions regarding the key steps of FT are critically discussed and the main available energy modalities are analyzed taking into account their advantages and unmet needs

Nodules testiculaires de l’homme infertile et échographie de contraste : étude préliminaire

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