ABSTRACT
Understanding the true nature of extra-terrestrial water and organic matter that were present at the birth of our solar system, and their subsequent evolution, necessitates the study of pristine astromaterials. In this study, we have studied both the water and organic contents from a dust particle recovered from the surface of near-Earth asteroid 25143 Itokawa by the Hayabusa mission, which was the first mission that brought pristine asteroidal materials to Earth's astromaterial collection. The organic matter is presented as both nanocrystalline graphite and disordered polyaromatic carbon with high D/H and 15N/14N ratios (δD = + 4868 ± 2288; δ15N = + 344 ± 20) signifying an explicit extra-terrestrial origin. The contrasting organic feature (graphitic and disordered) substantiates the rubble-pile asteroid model of Itokawa, and offers support for material mixing in the asteroid belt that occurred in scales from small dust infall to catastrophic impacts of large asteroidal parent bodies. Our analysis of Itokawa water indicates that the asteroid has incorporated D-poor water ice at the abundance on par with inner solar system bodies. The asteroid was metamorphosed and dehydrated on the formerly large asteroid, and was subsequently evolved via late-stage hydration, modified by D-enriched exogenous organics and water derived from a carbonaceous parent body.
ABSTRACT
UNLABELLED: The aim of this paper was to report the vital and neurological outcome of 249 preterm infants of less than 29 weeks born between 1990 and 1996, and included in a prospective study until two years of age. RESULTS: The initial mortality rate was 19%. This was related to gestational age and severe transfontanellar ultrasonographically (TFU) detected abnormalities. The rate of follow-up at two years of age was 98%. Neurological sequelae amounted to 12.8%, including four cases of deafness. The possibility of survival without neurological sequelae increased from 52% at 24-25 weeks to 72% at 26-28 weeks of gestational age (p < 0.005). The presence of sequelae was significantly related to severe cranial ultrasonographically-detected abnormalities, to parental social level, and to early neonatal anemia. Normal TFU and/or isolated periventricular hyperechogenicity could not exclude the presence of neurological sequelae which, however, appeared to be less severe than at the onset. CONCLUSION: Gestational age, severe TFU abnormalities and neonatal anemia play a major role in the rate of mortality and in the neurological sequelae in preterm infants, and can influence the decisions concerning the treatment of this pediatric population.
Subject(s)
Developmental Disabilities/etiology , Developmental Disabilities/mortality , Gestational Age , Infant, Premature , Age Factors , Anemia/complications , Apgar Score , Developmental Disabilities/prevention & control , Female , France/epidemiology , Global Health , Humans , Infant Mortality , Infant, Newborn , Intensive Care, Neonatal/standards , Male , Predictive Value of Tests , Prognosis , Prospective Studies , Risk Factors , Treatment OutcomeABSTRACT
Delivery room management of neonatal respiratory disorders must be adapted to gestational age, etiology and clinical status at birth. Depending on these factors, management will require pharyngeal or tracheal aspiration, mask or mechanical ventilation, continuous positive pressure or oxygen alone. Its aim is to prevent or correct airway obstruction and inadequate oxygenation, and secondary metabolic disorders, prior to the transfer of the neonate in neonatal unit.
