Assessing the potential uses as industrial mineral, bauxite from Débélé, Guinea, has been characterised by chemical and mineralogical analyses, the determination of the amorphous content, the rate of po...Assessing the potential uses as industrial mineral, bauxite from Débélé, Guinea, has been characterised by chemical and mineralogical analyses, the determination of the amorphous content, the rate of portlandite consumption in an aqueous solution, the strength activity index, and the thermal behaviour up to 1200<span style="white-space:nowrap;">°</span>C. It was evidenced that the raw sample is gibbsite-rich type bauxite with about 45.06 wt% of alumina, 23.80 wt% of iron oxide, and 1.74 wt% of silica. It meets the chemical composition required for bauxites used for refractory cement. During heating, the raw bauxite undergoes high densification with low linear shrinkage, motivating a potential use in dense ceramic compositions with high thermal stability. Also, the heating at only 600<span style="white-space:nowrap;">°</span>C gives a significant pozzolanic activity in combination with Portland cement. The correlation between the pozzolanicity, the amorphous phase content, and the specific surface area indicated that the raw and the calcined materials present an interesting reactivity for using them in alternative cement formulations.展开更多
Ciprofloxacin (CFX) was loaded on Bana clay (Cameroon) and CFX loaded-clays have been evaluated as drug delivery system. Raw clays and CFX loaded compounds have been characterized by some physico-chemicals methods. &l...Ciprofloxacin (CFX) was loaded on Bana clay (Cameroon) and CFX loaded-clays have been evaluated as drug delivery system. Raw clays and CFX loaded compounds have been characterized by some physico-chemicals methods. <i>In vitro</i> release studies have been done in gastric and phosphate buffer experimental mediums;bacteriological studies have been made up on <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>. X-ray diffractometry patterns of loaded compounds show a basal spacing increasing due to CFX intercalation. On Fourier-Transformed Infrared spectrometry spectra, appearance of CFX characteristic bands and shifting of certain bands already presents on clay confirmed CFX intercalation. After 96 h of CFX released from release mediums, prolonged and continue profiles have been observed. Diffusion tests displayed an inhibition radius of ~2 cm on gelose seeded with <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> due to CFX. The overall results show a modified release of ciprofloxacin with an effective antibacterial activity, giving the way for a new ciprofloxacin drug delivery system using Bana clay as carrier.展开更多
文摘Assessing the potential uses as industrial mineral, bauxite from Débélé, Guinea, has been characterised by chemical and mineralogical analyses, the determination of the amorphous content, the rate of portlandite consumption in an aqueous solution, the strength activity index, and the thermal behaviour up to 1200<span style="white-space:nowrap;">°</span>C. It was evidenced that the raw sample is gibbsite-rich type bauxite with about 45.06 wt% of alumina, 23.80 wt% of iron oxide, and 1.74 wt% of silica. It meets the chemical composition required for bauxites used for refractory cement. During heating, the raw bauxite undergoes high densification with low linear shrinkage, motivating a potential use in dense ceramic compositions with high thermal stability. Also, the heating at only 600<span style="white-space:nowrap;">°</span>C gives a significant pozzolanic activity in combination with Portland cement. The correlation between the pozzolanicity, the amorphous phase content, and the specific surface area indicated that the raw and the calcined materials present an interesting reactivity for using them in alternative cement formulations.
文摘Ciprofloxacin (CFX) was loaded on Bana clay (Cameroon) and CFX loaded-clays have been evaluated as drug delivery system. Raw clays and CFX loaded compounds have been characterized by some physico-chemicals methods. <i>In vitro</i> release studies have been done in gastric and phosphate buffer experimental mediums;bacteriological studies have been made up on <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>. X-ray diffractometry patterns of loaded compounds show a basal spacing increasing due to CFX intercalation. On Fourier-Transformed Infrared spectrometry spectra, appearance of CFX characteristic bands and shifting of certain bands already presents on clay confirmed CFX intercalation. After 96 h of CFX released from release mediums, prolonged and continue profiles have been observed. Diffusion tests displayed an inhibition radius of ~2 cm on gelose seeded with <i>Escherichia coli</i> and <i>Staphylococcus aureus</i> due to CFX. The overall results show a modified release of ciprofloxacin with an effective antibacterial activity, giving the way for a new ciprofloxacin drug delivery system using Bana clay as carrier.
