Operation of the Four 12 kW at 4.5 K Refrigerators for LEP

In 1998 the first energy upgrade of the LEP Electron/Positron collider, LEP2, was completed at CERN. Sixty-eight superconducting modules supplied by four 12 kW @ 4.5 K equivalent power refrigerators have been operated allowing a colliding beam energy of 94.5 GeV. Meanwhile, the operation and maintenance responsibilities were transferred to an industrial firm on the basis of a result-oriented contract. After a short description of the operational organization, we report on the operation of the LEP2 cryogenic system over the past three years. Particular attention is given to power availability, failure statistics and recovery time after interruptions. The most relevant problems and their solutions are exposed. Finally, we review the interactions between the cryogenic system and the particle beams, which are limiting the ultimate performance of the LEP collider

Aspects Thérapeutiques du Décollement de la Rétine chez les Évacués Sanitaires de Horns, Bénin, de 2015 à 2020

L’objectif de cette étude est de décrire les aspects thérapeutiques du décollement de la rétine chez les évacués sanitaires hors Bénin de 2015 à 2020. Nous avons réalisé une étude observationnelle transversale descriptive à visée analytique avec collecte rétrospective des données. Elle s’est déroulée à la Direction Générale de la Médecine Hospitalière et des Explorations Diagnostiques et dans des centres d’Ophtalmologie publics et privés. La durée moyenne entre le diagnostic et la chirurgie était de 81,67 ±23,05 jours avec des extrêmes de 2 et 400 jours.  Une chirurgie de DR par voie endoculaire était réalisée sur 28 yeux (60,87%). Notons que des 28 yeux ayant subi une chirurgie endoculaire, 19 ont eu un tamponnement par huile de silicone et les 9 restants, un tamponnement par gaz. Sur les 46 yeux, 25 (54,35%) présentaient des complications postopératoires dont 15 cataractes et 9 récidives du DR. En préopératoire, 28 yeux sur 46 (60,87%) avaient une AV<1/20 et 5 yeux (10,87%) avaient une AV>3/10. En postopératoire, 34 yeux (73,91%) avaient une AV≥1/20 dont 32 (69,57%) une AV >1/20 et 17 (36,96%) une AV>3/10. L’AV était réduite pour 7 yeux (15,22%), stationnaire pour 10 yeux (21,74%) et 29 yeux (63,04%) ont eu un gain d’AV. En préopératoire, 6 yeux (13,04%) avaient une AV<1/20 et 2 yeux (4,35%) avaient une AV>3/10. En postopératoire, 4 yeux (8,70%) avaient une AV<1/20 et 4 yeux (8,70%) avaient une AV>3/10. Chez les 2 sujets opérés dans un délai ≤ 7 jrs (4,35%), l'AV était améliorée et le gain supérieur à 6 lignes. Le décollement de la rétine est une pathologie oculaire grave pouvant causer la cécité. Toutefois, de bonnes pratiques thérapeutiques donnent généralement un bon gain visuel.   The objective of this study is to describe the therapeutic aspects of retinal detachment in medical evacuees outside Benin from 2015 to 2020. We conducted an observational cross-sectional descriptive study with an analytical purpose and retrospective data collection. The study took place at the General Directorate of Hospital Medicine and Diagnostic Explorations and in public and private Ophthalmology centers. The average duration between diagnosis and surgery was 81.67 ± 23.05 days, ranging from 2 to 400 days. Endocular surgery for retinal detachment was performed on 28 eyes (60.87%). Of these 28 eyes undergoing endocular surgery, 19 had tamponade with silicone oil, and the remaining 9 had tamponade with gas. Among the 46 eyes, 25 (54.35%) had postoperative complications, including 15 cataracts and 9 retinal detachment recurrences. Preoperatively, 28 eyes out of 46 (60.87%) had visual acuity (VA) <1/20, and 5 eyes (10.87%) had VA >3/10. Postoperatively, 34 eyes (73.91%) had VA ≥1/20, with 32 (69.57%) having VA >1/20 and 17 (36.96%) having VA >3/10. VA was reduced for 7 eyes (15.22%), remained stationary for 10 eyes (21.74%), and 29 eyes (63.04%) showed a gain in VA. Preoperatively, 6 eyes (13.04%) had VA <1/20, and 2 eyes (4.35%) had VA >3/10. Postoperatively, 4 eyes (8.70%) had VA <1/20, and 4 eyes (8.70%) had VA >3/10. Among the 2 subjects operated within ≤ 7 days (4.35%), VA improved, and the gain was greater than 6 lines. Retinal detachment is a serious ocular condition that can lead to blindness. However, proper therapeutic practices generally result in significant visual improvement

Aspects Therapeutiques du Decolement de Retine chez les Evacues Sanitares Hors Benin de 2015 a 2020

L’objectif de cette étude est de décrire les aspects thérapeutiques du décollement de la rétine (DR) chez les évacués sanitaires hors Bénin de 2015 à 2020. Nous avons réalisé une étude observationnelle transversale descriptive à visée analytique avec collecte rétrospective des données. Elle s’est déroulée à la Direction Générale de la Médecine Hospitalière et des Explorations Diagnostiques et dans des centres d’Ophtalmologie publics et privés. La durée moyenne entre le diagnostic et la chirurgie était de 81,67 ±23,05 jours avec des extrêmes de 2 et 400 jours.  46 yeux de 42 patients ont été inclus dans l’étude. Une chirurgie de DR était réalisée par voie endoculaire sur 28 yeux (60,87%), par voie externe sur 4 yeux (8,70%) et technique chirurgicale non précisée sur 14 yeux (30,43%).  Notons que des 28 yeux ayant subi une chirurgie endoculaire, 19 ont eu un tamponnement par huile de silicone et les 9 restants, un t amponnement par gaz. Sur les 46 yeux, 25 (54,35%) présentaient des complications postopératoires dont 15 cataractes et 9 récidives du DR. En préopératoire, 28 yeux sur 46 (60,87%) avaient une AV<1/20 et 5 yeux (10,87%) avaient une AV>3/10. En postopératoire, 34 yeux (73,91%) avaient une AV≥1/20 et 17 (36,96%) une AV>3/10. L’AV était réduite pour 7 yeux (15,22%), stationnaire pour 10 yeux (21,74%) et 29 yeux (63,04%) ont eu un gain moyen d’AV de 3 lignes. Chez les 2 sujets opérés dans un délai ≤ 7 jours (4,35%), l'AV était améliorée et le gain supérieur à 6 lignes. Le décollement de la rétine est une pathologie oculaire grave pouvant causer la cécité. Toutefois, de bonnes pratiques thérapeutiques donnent généralement un bon gain visuel. The objective of this study is to describe the therapeutic aspects of retinal detachment in medical evacuees outside Benin from 2015 to 2020. We conducted an observational cross-sectional descriptive study with an analytical purpose and retrospective data collection. The study took place at the General Directorate of Hospital Medicine and Diagnostic Explorations and in public and private Ophthalmology centers. The average duration between diagnosis and surgery was 81.67 ± 23.05 days, ranging from 2 to 400 days. Endocular surgery for retinal detachment was performed on 28 eyes (60.87%), externally in 4 eyes (8,70%) and unspecified surgical technique in 14 eyes (30,43%). Of these 28 eyes undergoing endocular surgery, 19 had tamponade with silicone oil, and the remaining 9 had tamponade with gas. Among the 46 eyes, 25 (54.35%) had postoperative complications, including 15 cataracts and 9 retinal detachment recurrences. Preoperatively, 28 eyes out of 46 (60.87%) had visual acuity (VA) <1/20, and 5 eyes (10.87%) had VA >3/10. Postoperatively, 34 eyes (73.91%) had VA ≥1/20, with 17 (36.96%) having VA >3/10. VA was reduced for 7 eyes (15.22%), remained stationary for 10 eyes (21.74%), and 29 eyes (63.04%) showed a gain in VA. Among the 2 subjects operated within ≤ 7 days (4.35%), VA improved, and the gain was greater than 6 lines. Retinal detachment is a serious ocular condition that can lead to blindness. However, proper therapeutic practices generally result in significant visual improvement

Reverse micelle-loaded lipid nanocarriers: A novel drug delivery system for the sustained release of doxorubicin hydrochloride

In this study, we are pioneering new nanotechnology for the encapsulation of anticancer drugs (doxorubicin (DOX) and/or docetaxel (DOCE)), whatever their solubility and water affinity. The purpose of this study is to highlight the potential of this recently patented technology, by carrying out a thorough physicochemical characterisation of these multiscaled nanocarriers, followed by the study of an encapsulation and release model of hydrophilic anticancer drug. The formulation process is based on a low-energy nano-emulsification method and allows the generation of a structure composed of oil-based nanocarriers loaded with reverse micelles. Thanks to this, hydrophilic contents can be solubilised in the oily core of this kind of nano-emulsion along with lipophilic content. The results emphasise some original structure particularities due to the multistep formulation process, and the diffusion-based behaviour revealed for the DOX release profile that is shown to be intimately linked to the morphology of the particles

Quasi-spherical ice in convective clouds

Homogeneous freezing of supercooled droplets occurs in convective systems in low and midlatitudes. This droplet-freezing process leads to the formation of a large amount of small ice particles, so-called frozen droplets, that are transported to the upper parts of anvil outflows, where they can influence the cloud radiative properties. However, the detailed microphysics and, thus, the scattering properties of these small ice particles are highly uncertain. Here, the link between the microphysical and optical properties of frozen droplets is investigated in cloud chamber experiments, where the frozen droplets were formed, grown, and sublimated under controlled conditions. It was found that frozen droplets developed a high degree of small-scale complexity after their initial formation and subsequent growth. During sublimation, the small-scale complexity disappeared, releasing a smooth and near-spherical ice particle. Angular light scattering and depolarization measurements confirmed that these sublimating frozen droplets scattered light similar to spherical particles: that is, they had angular light-scattering properties similar to water droplets. The knowledge gained from this laboratory study was applied to two case studies of aircraft measurements in midlatitude and tropical convective systems. The in situ aircraft measurements confirmed that the microphysics of frozen droplets is dependent on the humidity conditions they are exposed to (growth or sublimation). The existence of optically spherical frozen droplets can be important for the radiative properties of detraining convective outflows.Peer reviewe

A matter of availability: sharper tuning for memorized than for perceived stimulus features

Our visual environment is relatively stable over time. An optimized visual system could capitalize on this by devoting less representational resources to objects that are physically present. The vividness of subjective experience, however, suggests that externally available (perceived) information is more strongly represented in neural signals than memorized information. To distinguish between these opposing predictions, we use EEG multivariate pattern analysis to quantify the representational strength of task-relevant features in anticipation of a change-detection task. Perceptual availability was manipulated between experimental blocks by either keeping the stimulus available on the screen during a 2-s delay period (perception) or removing it shortly after its initial presentation (memory). We find that task-relevant (attended) memorized features are more strongly represented than irrelevant (unattended) features. More importantly, we find that task-relevant features evoke significantly weaker representations when they are perceptually available compared with when they are unavailable. These findings demonstrate that, contrary to what subjective experience suggests, vividly perceived stimuli elicit weaker neural representations (in terms of detectable multivariate information) than the same stimuli maintained in visual working memory. We hypothesize that an efficient visual system spends little of its limited resources on the internal representation of information that is externally available anyway