ACTA (United States)

Carbon pellets (CPs) were prepared from the self-adhesive properties of date palm leaves (Phoenix dactylifera L.) and converted into pellets by applying (5 to 21) metric tons of pressure, before being carbonized at 1000 °C in a nitrogen environment using a multi-stipe heating profile. Characterizations of CPs produced were carried out in terms of Young's modulus (YM) and crystallite dimensions, specific surface area, and porosity. A microscopic cross-linking model based on crystallite dimensions (d002, Lc, and La) was also used to estimate YM, spring length (Sp) between two cubic granulars of the carbon microstructure structure, specific surface area, and porosity as a class of X-ray diffraction application, by assuming that the changes in YM for carbon pellets as a function of compression occur similarly as a function of heat treatment temperature. Results of the X-ray diffraction pattern show that the structure of the CPs is turbostatic, and its crystallite dimensions are improved by compressive pressure. The estimated YM from a microscopic cross-linking model was in good agreement with that measured by ultrasonic techniques, showing that the behavior of the YM is related to the crystallite dimensions. The results also found that the degree of stiffness as a function of compression pressure is equal to that of heat treatment temperature, proving that the changes in YM as a function of compression pressure occur similarly as a function of heat treatment temperature. The results also show that the data of specific surface area and porosity, estimated from microscopic cross-linking, are in good agreement with the measured data. The Sp is reduced with increasing compression pressure, and above 12 metric tons of pressure the CP observed the stress broadening behavior. These results can conclude that the crystal dimensions can play an essential role in the phenotypic and description of CP pellets, indicating the applicability of the microscopic cross-linking model to estimate the physical properties of carbon materials.

Cette première partie de l’ouvrage traite des situations de collaboration concernant l’école et la collaboration avec ses partenaires. Les deux premiers textes concernent l’adaptation partielle du travail scolaire au profit d’élèves ayant des difficultés ou des besoins particuliers, le troisième les enjeux de promotion de la santé et du développement des compétences psychosociales dans et hors l’école, enfin, le dernier texte porte lui une réflexion plus générale sur

More than a quarter of otherwise healthy six-year-old Swedish children may have metabolic risk factors that increase their risk for cardiovascular disease. This finding comes from a longitudinal study that was conducted in Halland, south-west Sweden, by Kjellberg et al. 1. They found that 26% of the 212 children in the study had abnormal metabolic profiles, including insulin resistance. Jan Gustafsson 2 comments on the findings. Caffeine has been widely used to treat apnoea of prematurity. This issue includes a systematic review by Brattström et al. 3 that compares high- versus low-dose caffeine. The authors concluded that the use of high-dose caffeine had no impact on mortality or bronchopulmonary dysplasia, but that it did result in fewer cases of extubation failure and shorter durations of mechanical ventilation. In another study, Huvanandana et al. 4 evaluated the cardiovascular impact of intravenous caffeine and found that caffeine was likely to increase the responsiveness of the autonomic nervous system. Meanwhile, Seppä-Moilanen et al. 5 report that caffeine and supplemental oxygen effectively suppressed periodic breathing in preterm infants, with only minor effects on the prevention of long episodes of apnoea. Ravichandran et al. 6 retrospectively determined the influence of cumulative dosing of caffeine citrate on the neurodevelopmental outcomes of 181 very low birthweight infants when they reached 18–22 months of age. They found that a higher average daily dose of caffeine citrate was associated with better neurodevelopmental outcomes. Meanwhile, Huvanandana et al. 7 observed a reduced correlation between mean arterial pressure and the tissue oxygenation index following caffeine administration in preterm infants. The results suggested an acute improvement in cerebral autoregulation following a loading dose of caffeine. The use of complementary and alternative medicines to treat a range of medical issues is becoming increasingly popular worldwide. Farrington et al. 8 conducted a literature review to explore the current use of alternative medicines in children and to highlight the possible risks associated with their use. Despite their perceived safety, adverse events have been documented following the use of these products and infants and children may be more susceptible to the harmful effects of these alternative approaches, due to their immature metabolism. Georgieva et al. 9 report that first-time urinary tract infections (UTIs) in girls were associated with low vitamin D levels, but not with low levels of antimicrobial peptides. In another study, Alberici et al. 10 evaluated the risk factors proposed by the Italian guidelines for the first febrile UTIs in children. They report that only the presence of pathogens other than Escheria coli significantly predicted reflux and that cystography could be postponed in children with no risk factors.

Voor u ziet u een bitewingopname gemaakt tijdens een periodiek mondonderzoek van een 33-jarige mannelijke patient (afbeelding 1). De patient heeft geen klachten en er zijn geen bijzonderheden in de medische anamnese. Er worden geen bijzonderheden opgemerkt tijdens het klinisch onderzoek.