45 research outputs found

    Prevalence and sociodemographic correlates of stunting, underweight, and overweight among Palestinian school adolescents (13-15 years) in two major governorates in the West Bank

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    <p>Abstract</p> <p>Background</p> <p>There is little information about height and weight status of Palestinian adolescents. The objective of this paper was to assess the prevalence of stunting, underweight, and overweight/obesity among Palestinian school adolescents (13-15 years) and associated sociodemographic factors in 2 major governorates in the West Bank.</p> <p>Methods</p> <p>A Cross-sectional survey was conducted in 2005 comprising 1942 students in 65 schools in Ramallah and Hebron governorates. Data was collected through self-administered questionnaires from students and parents. Weights and heights were measured. Overweight and obesity were assessed using the 2000 Centers for Disease Control and Prevention (CDC) reference and the International Obesity Task Force (IOTF) criteria. Stunting and underweight were assessed using the 2000 CDC reference.</p> <p>Results</p> <p>Overweight/obesity was more prevalent in Ramallah than in Hebron and affected more girls than boys. Using the 2000 CDC reference, the prevalence of overweight and obesity in Ramallah among boys was 9.6% and 8.2%, respectively versus 15.6% and 6.0% among girls (P < 0.01). In Hebron, the corresponding figures were 8.5% and 4.9% for boys and 13.5% and 3.4% for girls (P < 0.01). Using the IOTF criteria, the prevalence of overweight and obesity among boys in Ramallah was 13.3% and 5.2%, respectively versus 18.9% and 3.3% for girls. The prevalence of overweight and obesity among boys in Hebron was 10.9% and 2.2%, respectively versus 14.9% and 2.0% for girls. Overweight/obesity was associated with high standard of living (STL) among boys and with the onset of puberty among girls. More boys were underweight than girls, and the prevalence was higher in Hebron (12.9% and 6.0% in boys and girls, respectively (P < 0.01)) than in Ramallah (9.7% and 3.1% in boys and girls, respectively (p < 0.01)). The prevalence of stunting was similar in both governorates, and was higher among boys (9.2% and 9.4% in Ramallah and Hebron, respectively) than among girls (5.9% and 4.2% in Ramallah and Hebron, respectively). Stunting was negatively associated with father's education among boys and with urban residence, medium STL and onset of puberty among girls.</p> <p>Conclusion</p> <p>Under- and overnutrition co-exist among Palestinian adolescents, with differences between sexes. Region, residence, STL, and onset of puberty were associated factors.</p

    Review on catalytic cleavage of C-C inter-unit linkages in lignin model compounds: Towards lignin depolymerisation

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    Lignin depolymerisation has received considerable attention recently due to the pressing need to find sustainable alternatives to fossil fuel feedstock to produce chemicals and fuels. Two types of interunit linkages (C–C and C–O linkages) link several aromatic units in the structure of lignin. Between these two inter-unit linkages, the bond energies of C–C linkages are higher than that of C–O linkages, making them harder to break. However, for an efficient lignin depolymerisation, both types of inter-unit linkages have to be broken. This is more relevant because of the fact that many delignification processes tend to result in the formation of additional C–C inter-unit bonds. Here we review the strategies reported for the cleavage of C–C inter-unit linkages in lignin model compounds and lignin. Although a number of articles are available on the cleavage of C–O inter-unit linkages, reports on the selective cleavage of C–C inter-unit linkages are relatively less. Oxidative cleavage, hydrogenolysis, two-step redox-neutral process, microwave assisted cleavage, biocatalytic and photocatalytic methods have been reported for the breaking of C–C inter-unit linkages in lignin. Here we review all these methods in detail, focused only on the breaking of C–C linkages. The objective of this review is to motivate researchers to design new strategies to break this strong C–C inter-unit bonds to valorise lignins, technical lignins in particular

    Biotribocorrosion (tribo-electrochemical) characterization of anodized titanium biomaterial containing calcium and phosphorus before and after osteoblastic cell culture

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    International audienceThe purpose of this study was to investigate the relationship between the osteoblastic cells behavior and biotribocorrosion phenomena on bioactive titanium (Ti). Ti substrates submitted to bioactive anodic oxidation and etching treatments were cultured up to 28 days with MG63 osteoblast-like cells. Important parameters of in vitro bone-like tissue formation were assessed. Although no major differences were observed between the surfaces topography (both rough) and wettability (both hydrophobic), a significant increase in cell attachment and differentiation was detected on the anodized substrates as product of favorable surface morphology and chemical composition. Alkaline phosphatase production has increased (≈20 nmol/min/mg of protein) on the anodized materials, while phosphate concentration has reached the double of the etched material and calcium production increased (over 20 µg/mL). The mechanical and biological stability of the anodic surfaces were also put to test through biotribocorrosion sliding solicitations, putting in evidence the resistance of the anodic layer and the cells capacity of regeneration after implant degradation. The Ti osteointegration abilities were also confirmed by the development of strong cell–biomaterial bonds at the interface, on both substrates. By combining the biological and mechanical results, the anodized Ti can be considered a viable option for dentistry
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