Polymer biodegradation: mechanisms and estimation techniques.

Within the frame of the sustainable development, new materials are being conceived in order to increase their biodegradability properties. Biodegradation is considered to take place throughout three stages: biodeterioration, biofragmentation and assimilation, without neglect the participation of abiotic factors. However, most of the techniques used by researchers in this area are inadequate to provide evidence of the final stage: assimilation.

[Outcome of 404 premature infants born before 32 weeks of gestation in 1978-1980].

The outcome of 404 prematures born before 32 weeks of gestation and admitted on the first day of life to the Institut de Puériculture (IP) in 1978-1980 was studied with respect to post-menstrual age and birth weight: 83 (20,5%) died during the hospitalization. Of the 321 still alive after the neonatal hospitalization, 71% were followed until at least 2 years of age; 3,1% died unexpectedly at home. There was a 8% handicap rate (9 with cerebral palsy and 9 with psychomotor deficiency) in the survivors.

[Bronchopulmonary dysplasia].

A retrospective study of 2 125 preterm infants, who were ventilated at the Institut de Puériculture in Paris over 9 years (1974-1982) for respiratory distress at birth, showed that 45 (2%) developed clinical and radiological bronchopulmonary dysplasia (BPD): 8 minimal forms, 23 moderate forms and 14 severe forms, 30 of these patients survived (66%). The pathogenesis of this chronic respiratory disease is multifactorial: oxygen + pressure + duration + endotracheal intubation. Efforts should be made to limit the damaging effect of each of these factors, which should be kept down to the minimum values compatible with adequate oxygenation.

[Prolonged Q-T interval with functional A-V block in neonates and young infants (author's transl)].

A prolonged Q-T interval (0.56 to 0.70 s.