The influence of the coconut fiber treated as reinforcement in PHB (polyhydroxybutyrate) composites

This study evaluated how the treatment of coconut fiber (CF) affected the fiber itself and the composites prepared with treated and in nature coconut fiber used as reinforcement in PHB (polyhydroxybutyrate) as a polymeric matrix. The coconut fiber in nature (CFi) underwent to a thermochemical treatment (CFt) with hot water (80 °C). The efficiency of treatment was evaluated by FT-IR analysis. The FT-IR and scanning electron microscope results showed partial removal of impurities such as waxes. The composites of (PHB/CFi or PHB/CFt) with weight rate of 90/10 and 80/20 were characterized by thermal and morphological properties. Thermogravimetric analysis showed that the presence of fiber in the PHB matrix improved thermal stability of the composite. The SEM analysis of the microstructure showed ta good interfacial adhesion between the PHB and coconut fiber especially when treated fiber was used

Parallel lives? Ethnic segregation in schools and neighbourhoods

We provide evidence on the extent of ethnic segregation experienced by children across secondary schools and neighbourhoods (wards). Using 2001 Schools Census and Population Census data we employ the indices of dissimilarity and isolation and compare patterns of segregation across nine ethnic groups, and across Local Education Authorities in England. Looking at both schools and neighbourhoods, we find high levels of segregation for the different groups, along with considerable variation across England. We find consistently higher segregation for South Asian pupils than for Black pupils. For most ethnic groups children are more segregated at school than in their neighbourhood. We analyse the relative degree of segregation and show that high population density is associated with high relative school segregation

Expression of Multiple Cytochrome P450 Enzymes and Multidrug Resistance-Associated Transport Proteins in Human Skin Keratinocytes

Cytochrome P450 enzymes metabolize various endogenous and exogenous small molecular weight compounds. Transport-associated proteins, such as P-glycoprotein, multidrug resistance-associated protein and lung resistance protein are overexpressed in drug-resistant cell lines, as well as in human tumors from various histologic origins, including malignant melanoma. Little is known about the expression and function of cytochrome enzymes and multidrug resistance-associated transport proteins in human skin; therefore, the aim of this study was to analyze the expression pattern of cytochrome enzymes and multidrug resistance-associated transport proteins in proliferating human epidermal keratinocytes under constitutive conditions and after induction with various inducers. Reverse transcription–polymerase chain reaction revealed constitutive expression of cytochromes 1A1, 1B1, 2B6, 2E1, and 3A5 in keratinocytes and showed expression of cytochrome 3A4 after incubation with dexamethasone. The expression of cytochrome 1A1 was enhanced on the mRNA level after induction with benzanthracene. Reverse transcription–polymerase chain reaction analysis of the multidrug resistance-associated transport proteins revealed constitutive expression of multidrug resistance-associated proteins 1 and 3–6, and lung resistance protein in human epithelial keratinocytes and was negative for multidrug resistance 1 and 2. Expression of 1 was seen after induction with dexamethasone. Reverse transcription–polymerase chain reaction results were confirmed by immunoblots which showed expression of cytochromes 1A1, 2B6, 2E1, and 3A, multidrug resistance-associated proteins 1, 3, and 5 as well as multidrug resistance 1 after induction with dexamethasone. Immunohistology showed positive immunofluorescence in skin specimens for cytochromes 1A1, 2B6, 2E1, and 3A and multidrug resistance-associated protein 1 and multidrug resistance 1. Constitutive activity of cytochrome 1A1, 2B, 2E1, and 3A enzymes was measured by catalytic assays. These results show that keratinocytes of the human skin express various transport-associated enzymes and detoxifying metabolic enzymes. Previous studies have revealed that cytochrome enzymes and transport-associated proteins play complementary parts in drug disposition by biotransformation (phase I) and anti-transport (phase III) and act synergistically as a drug bioavailability barrier