Study of the nanocrystalline bulk Al alloys synthesized by high energy mechanical milling followed by room temperature high pressing consolidation

AbstractIn the present study high energy mechanical milling followed by high-pressing consolidation has been used to obtain bulk nanocrystalline Al-Fe-Si alloy. Quantitative XRD analysis and scanning electron microscopy were used to characterize the material evolution during thermal treatments in the temperature range 25–500∘C. The cold-worked structure have been synthesized with microstructure showing a mixture of a significant low size of crystallite (70 nm) and a high level of lattice strains (0.85%). Starting from the nanocrystalline specimens, isochronal experiments were carried out to monitor the reserve microstructure and transformations. The high temperature annealing is required for ameliorating the quality of room temperature consolidated materials by removing all porosity and obtaining good interparticle bonding. The thermal conductivity and the thermal diffusivity are investigated with the Photothermal deflection technique. These thermal parameters increase with the annealing temperatures. This behavior is attributed to the increase in the rate of diffusion coefficient of added elements inside the aluminum matrix

Early abolition of cough reflex predicts mortality in deeply sedated brain-injured patients

Background: Deep sedation may hamper the detection of neurological deterioration in brain-injured patients. Impaired brainstem reflexes within the first 24 h of deep sedation are associated with increased mortality in non-brain-injured patients. Our objective was to confirm this association in brain-injured patients. Methods: This was an observational prospective multicenter cohort study involving four neuro-intensive care units. We included acute brain-injured patients requiring deep sedation, defined by a Richmond Assessment Sedation Scale (RASS) < -3. Neurological assessment was performed at day 1 and included pupillary diameter, pupillary light, corneal and cough reflexes, and grimace and motor response to noxious stimuli. Pre-sedation Glasgow Coma Scale (GCS) and Simplified Acute Physiology Score (SAPS-II) were collected, as well as the cause of death in the Intensive Care Unit (ICU). Results: A total of 137 brain-injured patients were recruited, including 70 (51%) traumatic brain-injured patients, 40 (29%) vascular (subarachnoid hemorrhage or intracerebral hemorrhage). Thirty patients (22%) died in the ICU. At day 1, the corneal (OR 2.69, p = 0.034) and cough reflexes (OR 5.12, p = 0.0003) were more frequently abolished in patients that died in the ICU. In a multivariate analysis, abolished cough reflex was associated with ICU mortality after adjustment to pre-sedation GCS, SAPS-II, RASS (OR: 5.19, 95% CI [1.92-14.1], p = 0.001) or dose of sedatives (OR: 8.89, 95% CI [2.64-30.0], p = 0.0004). Conclusion: Early (day 1) cough reflex abolition is an independent predictor of mortality in deeply sedated brain-injured patients. Abolished cough reflex likely reflects a brainstem dysfunction that might result from the combination of primary and secondary neuro-inflammatory cerebral insults revealed and/or worsened by sedation

Faire face à la menace infectieuse en réanimation: de la veille épidémiologique à l'innovation. Actes du séminaire de recherche translationnelle de la Société de réanimation de langue française (5 décembre 2017)

The annual seminar of the Translational Research Committee of the French Intensive Care Society is aimed at bringing together physicians and scientists to answer relevant research questions in the field of intensive care medicine. The fourth edition of the meeting was related to infectious diseases, and focused on various concerns in critically ill patients, including host-pathogen relationships, the potential role of pathogens in diseases classically viewed as non-infectious, emerging infectious threats, technological advances in the molecular diagnosis of infections, and the development of alternative anti-bacterial strategies besides classical antibiotic chemotherapy.SCOPUS: cp.jinfo:eu-repo/semantics/publishe

Insuffisances rénales aiguës : actes du 5^e Séminaire de recherche translationnelle de la Société de réanimation de langue française (Paris, 4 décembre 2018)

Le séminaire annuel de la commission de recherche translationnelle de la SRLF a eu lieu à Paris le 4 décembre 2018. Ce séminaire a pour but de réunir des cliniciens et scientifiques autour de grandes thématiques de recherche en médecine intensive et réanimation. La cinquième édition a porté sur l’insuffisance rénale aiguë, problématique quotidienne importante des réanimateurs. Les interventions se sont intéressées à la physiopathologie des diverses formes d’insuffisance rénale aiguë, à la récupération rénale, aux modèles expérimentaux, à l’hémodynamique régionale ou encore aux innovations technologiques en épuration extrarénale.</jats:p

Intraoperative neurophysiologic monitoring in spine surgery. Developments and state of the art in France in 2011

SummaryIntraoperative spinal cord monitoring consists in a subcontinuous evaluation of spinal cord sensory-motor functions and allows the reduction the incidence of neurological complications resulting from spinal surgery. A combination of techniques is used: somatosensory evoked potentials (SSEP), motor evoked potentials (MEP), neurogenic motor evoked potentials (NMEP), D waves, and pedicular screw testing. In absence of intraoperative neurophysiological testing, the intraoperative wake-up test is a true form of monitoring even if its latency long and its precision variable. A 2011 survey of 117 French spinal surgeons showed that only 36% had neurophysiological monitoring available (public healthcare facilities, 42%; private facilities, 27%). Monitoring can be performed by a neurophysiologist in the operating room, remotely using a network, or directly by the surgeon. Intraoperative alerts allow real-time diagnosis of impending neurological injury. Use of spinal electrodes, moved along the medullary canal, can determine the lesion level (NMEP, D waves). The response to a monitoring alert should take into account the phase of the surgical intervention and does not systematically lead to interruption of the intervention. Multimodal intraoperative monitoring, in presence of a neurophysiologist, in collaboration with the anesthesiologist, is the most reliable technique available. However, no monitoring technique can predict a delayed-onset paraplegia that appears after the end of surgery. In cases of preexisting neurological deficit, monitoring contributes little. Monitoring of the L1–L4 spinal roots also shows low reliability. Therefore, monitoring has no indication in discal and degenerative surgery of the spinal surgery. However, testing pedicular screws can be useful. All in all, thoracic and thoracolumbar vertebral deviations, with normal preoperative neurological examination are currently the essential indication for spinal cord monitoring. Its absence in this indication is a lost opportunity for the patient. If neurophysiological means are not available, intraoperative wake-up test is a minimal obligation