Diesel spray velocity and break-up characterization with dense spray imaging

International audienceThis work presents analysis methods for categorizing breakup morphology in a diesel spray produced by a single-hole, plain orifice diesel injector issuing into ambient atmospheric conditions. Velocity data and images which include the near-nozzle region of a diesel spray were obtained using both time-gated ballistic imaging (BI) and high-resolution ultrafast shadow imaging (USI) measurements. The USI results provide high-resolution visualization of the spray edges and resolved droplets within the depth-of-field of the collection optics, while the BI results provide a view of the spray at a modified dynamic range which mitigates interferences from refracted light and multiple-scattering noise, revealing additional spatial information. Time-correlated image-pairs obtained by both techniques were filtered and cross-correlated on a variety of scales to produce velocity profile data and identifiable structures which can be exploited to differentiate the breakup modes observed in the diesel spray. In addition, a multi-scale analysis was applied to the image data, demonstrating an approach whereby physical parameters can be derived from the image data to quantify the degree of atomization exhibited by a diesel spray

A diaphragmatic electrical activity-based optimization strategy during pressure support ventilation improves synchronization but does not impact work of breathing.

Poor patient-ventilator synchronization is often observed during pressure support ventilation (PSV) and has been associated with prolonged duration of mechanical ventilation and poor outcome. Diaphragmatic electrical activity (Eadi) recorded using specialized nasogastric tubes is a surrogate of respiratory brain stem output. This study aimed at testing whether adapting ventilator settings during PSV using a protocolized Eadi-based optimization strategy, or Eadi-triggered and -cycled assisted pressure ventilation (or PSVN) could (1) improve patient-ventilator interaction and (2) reduce or normalize patient respiratory effort as estimated by the work of breathing (WOB) and the pressure time product (PTP). This was a prospective cross-over study. Patients with a known chronic pulmonary obstructive or restrictive disease, asynchronies or suspected intrinsic positive end-expiratory pressure (PEEP) who were ventilated using PSV were enrolled in the study. Four different ventilator settings were sequentially applied for 15 minutes (step 1: baseline PSV as set by the clinician, step 2: Eadi-optimized PSV to adjust PS level, inspiratory trigger, and cycling settings, step 3: step 2 + PEEP adjustment, step 4: PSVN). The same settings as step 3 were applied again after step 4 to rule out a potential effect of time. Breathing pattern, trigger delay (Td), inspiratory time in excess (Tiex), pressure-time product (PTP), and work of breathing (WOB) were measured at the end of each step. Eleven patients were enrolled in the study. Eadi-optimized PSV reduced Td without altering Tiex in comparison with baseline PSV. PSVN reduced Td and Tiex in comparison with baseline and Eadi-optimized PSV. Respiratory pattern did not change during the four steps. The improvement in patient-ventilator interaction did not lead to changes in WOB or PTP. Eadi-optimized PSV allows improving patient ventilator interaction but does not alter patient effort in patients with mild asynchrony. Clinicaltrials.gov identifier: NCT 02067403 . Registered 7 February 2014

Efficacy of Antenatal Corticosteroid Treatment on Neurodevelopmental Outcome according to Head Circumference at Birth

BACKGROUND: There are concerns about the efficacy of antenatal corticosteroid treatment (ACT) in the growth-restricted fetus. OBJECTIVE: To evaluate the effect of ACT on neurodevelopmental outcome at 2 years of corrected age according to the z score of birth head circumference (ZS HC) in a large prospective cohort of preterm infants. METHODS: This study was conducted as a population-based, prospective, multicenter study, including 4,965 infants born between 24 and 33 weeks\u27 gestation and whose status regarding ACT and the measurement of head circumference at birth were available. They were evaluated at 2 years of corrected age to assess neurological outcome. Three approaches were considered to estimate the effect of ACT on neurodevelopment: (i) logistic regression with adjustment on propensity score, (ii) weighted logistic regression using the inverse probability of treatment weighting method, and (iii) 1:1 matching of gestational age, ZS HC, and propensity score between treated and nontreated infants. RESULTS: ACT was documented in 60% of infants. Three groups of infants were considered according to their ZS HC: between -3 and -1 standard deviation (SD), -1 and +1 SD, and +1 and +3 SD, respectively. ACT was associated with a significant improvement of neurodevelopmental outcome only for infants with an ZS HC of between +1 and +3 SD (adjusted OR 1.72; 95% CI 1.06-2.79). Moreover, ORs estimated in the -3 to -1 and +1 to +3 categories were significantly different. CONCLUSION: We found beneficial effects of ACT on neurodevelopmental outcomes at 2 years of corrected age only in preterm infants with a ZS HC >1 SD

A new access control unit for GANIL and SPIRAL 2

International audienceFor the GANIL safety revaluation and the new project of accelerator SPIRAL 2, it was decided to replace theexisting access control system for radiological controlled areas. These areas are all cyclotron rooms and experimental areas. The existing system is centralized around VME cards. Updating is becoming very problematic. The new UGA (access control unit) will becomposed of a pair of PLC to ensure the safety of each room. It will be supplemented by a system UGB (radiological control unit) that will assure the radiological monitoring of the area concerned

Usefulness of Parent-Completed ASQ for Neurodevelopmental Screening of Preterm Children at Five Years of Age.

International audienceINTRODUCTION: Preterm children are at greater risk of developmental impairment and require close follow-up for early and optimal medical care. Our goal was to examine use of the parent-completed Ages and Stages Questionnaire (ASQ) as a screening tool for neurodevelopmental disabilities in preterm infants at five years of age.PATIENTS AND METHODS: A total of 648 preterm children (285 were not distinctive for mild delay or normal development. In children with developmental delay, no difference was found when ASQ scores according to maternal education levels were analyzed.CONCLUSIONS: ASQ at five years is a simple and cost-effective tool that can detect severe developmental delay in preterm children regardless of maternal education level, while its capacity to identify children with mild delay appears to be more limited

Severe bronchiolitis in infants born very preterm and neurodevelopmental outcome at 2 years

Preterm infants are at greater risk of bronchopulmonary dysplasia, which is associated with neurodevelopmental impairment. These infants are also more likely to develop severe bronchiolitis, which can contribute to neurodevelopmental impairment. The aim of this study was to determine whether severe bronchiolitis in very preterm infants (born before 33 weeks of gestation) was associated with an increased risk of neurodevelopmental impairment at 2 years of age. We analyzed a population-based cohort of infants (the Loire Infant Follow-up Team cohort) born between 1 January 2003 and 31 December 2009. Severe bronchiolitis was defined as hospitalization due to bronchiolitis during the first year of life. Neurodevelopmental outcome was assessed at 2 years of corrected age. A total of 2,405 infants were included in this analysis and categorized based on neonatal respiratory status: 1,308 (54.4 %) received no respiratory assistance, 864(35.9 %) received oxygen for <28 days, and 167 (6.9 %) had mild and 66 (2.7) moderate or severe bronchopulmonary dysplasia. At 2 years, 502 children displayed non-optimal neurodevelopmental outcome (20.9 %). Moderate or severe bronchopulmonary dysplasia was significantly associated with non-optimal neurodevelopmental outcome at 2 years (adjusted odds ratios (OR) = 2.3 [95 % confidence interval (CI): 1.3–3.9], p = 0.003). In the first year, 318 infants acquired severe bronchiolitis (13.2 %), which was not associated with non-optimal neurodevelopmental outcome (adjusted OR = 1.0 [95 % CI: 0.8–1.4]; p = 0.88). In conclusion, respiratory status in the neonatal period was significantly associated with non-optimal neurodevelopmental outcome at 2 years, while severe bronchiolitis was not

The Global School Adaptation score: a new neurodevelopmental assessment tool for very preterm children at five years of age

Objective To determine the usefulness of a neurodevelopmental assessment tool consisting of a questionnaire administered to teachers to measure the Global School Adaptation (GSA) scores of very preterm children at the age of 5 years. Study design A sample of 445 very preterm children (<35 weeks of gestation) was assessed at 5 years of age using GSA and IQ scores. According to the consistency between the scores, children were determined to be well classified, intermediately classified, or misclassified. The differences between groups were assessed through univariate and multivariate logistic regression. Results The GSA score was highly or intermediately consistent with the IQ score for 89.2% of the children, and 10.8% were considered misclassified. Children with a higher GSA than IQ score had more autonomy and self-confidence (P < .01), and those with a lower GSA than IQ score had more behavioral problems (P < .01). Analysis by logistic regression showed that sex and gestational age significantly affected the consistency between the 2 scores. Thus, girls were less likely to have a lower GSA than IQ score (aOR = 0.45; 95% CI: 0.24-0.84; P = .01), and a lower gestational age significantly increased the likelihood of having a higher GSA than IQ score (for children born between 24 and 28 weeks of gestation: aOR = 2.70; 95% CI: 1.23-5.92; P = .01). Conclusions The GSA score is a simple, inexpensive, and reliable screening tool for assessing neurodevelopment in very preterm children at 5 years of age

A Small but Efficient Collaboration for the Spiral2 Control System Development

http://accelconf.web.cern.ch/AccelConf/ICALEPCS2013/papers/tucobab01.pdfThe Spiral2 radioactive ion beam facility to be commissioned in 2014 at Ganil (Caen) is built within international collaborations. This also concerns the control system development shared by three laboratories: Ganil has to coordinate the control and automated systems work packages, CEA/IRFU is in charge of the "injector" (sources and low energy beam lines) and the LLRF, CNRS/IPHC provides the emittancemeters and a beam diagnostics platform. Besides the technology Epics based, this collaboration, although being handled with a few people, nevertheless requires an appropriate and tight organization to reach the objectives given by the project. This contribution describes how, started in 2006, the collaboration for controls has been managed both from the technological point of view and the organizational one, taking into account not only the previous experience, technical background or skill of each partner, but also their existing working practices and "cultural" approaches. A first feedback comes from successful beam tests carried out at Saclay and Grenoble; a next challenge is the migration to operation, Ganil having to run Spiral2 as the other members are moving to new projects

Respiratory support by neurally adjusted ventilatory assist (NAVA) in severe RSV-related bronchiolitis: a case series report

<p>Abstract</p> <p>Background</p> <p>Neurally adjusted ventilatory assist (NAVA) is a new mode of mechanical ventilation controlled by diaphragmatic electrical signals. The electrical signals allow synchronization of ventilation to spontaneous breathing efforts of a child, as well as permitting pressure assistance proportional to the electrical signal. NAVA provides equally fine synchronization of respiratory support and pressure assistance varying with the needs of the child. NAVA has mainly been studied in children who underwent cardiac surgery during the period of weaning from a respirator.</p> <p>Case presentation</p> <p>We report here a series of 3 children (1 month, 3 years, and 28 days old) with severe respiratory distress due to RSV-related bronchiolitis requiring invasive mechanical ventilation with a high level of oxygen (FiO₂≥50%) for whom NAVA facilitated respiratory support. One of these children had diagnosis criteria for acute lung injury, another for acute respiratory distress syndrome.</p> <p>Establishment of NAVA provided synchronization of mechanical ventilatory support with the breathing efforts of the children. Respiratory rate and inspiratory pressure became extremely variable, varying at each cycle, while children were breathing easily and smoothly. All three children demonstrated less oxygen requirements after introducing NAVA (57 ± 6% to 42 ± 18%). This improvement was observed while peak airway pressure decreased (28 ± 3 to 15 ± 5 cm H₂O). In one child, NAVA facilitated the management of acute respiratory distress syndrome with extensive subcutaneous emphysema.</p> <p>Conclusions</p> <p>Our findings highlight the feasibility and benefit of NAVA in children with severe RSV-related bronchiolitis. NAVA provides a less aggressive ventilation requiring lower inspiratory pressures with good results for oxygenation and more comfort for the children.</p