Biofouling is an important problem for reverse osmosis (RO) membrane manufacturers. Bacteria are mainly involved in generating fouling and obturating RO membranes. Insights into biofilm bacteria composition could help...Biofouling is an important problem for reverse osmosis (RO) membrane manufacturers. Bacteria are mainly involved in generating fouling and obturating RO membranes. Insights into biofilm bacteria composition could help prevent biofouling, reduce the cost of using RO-fouling membranes and guarantee safe water. Culture-dependent and independent techniques were then performed in order to identify bacteria associated with RO membranes. Bacteria cultures described the presence of six pure colonies, four of which were identified through API testing. Based on 16s rRNA gene analysis, a predominant bacterium was identified and annotated as Sphingomonas sp. The 16s rRNA gene clone library, on the other hand, showed that the bacterium, Pseudomonas marincola, accounted for nearly 30% of the clone library, while the rest of bacteria were chimeras (62%) and non-representative species (3%). In conclusion, culture-dependent and independent approaches showed that two dominant bacteria were commonly observed in RO desalination membranes.展开更多
Aim: To develop a simple and sensitive high-performance liquid chromatography method to determine plasmatic levels of trimethoprim/sulfamethoxazole in paediatric population. Method: Chromatographic separation was carr...Aim: To develop a simple and sensitive high-performance liquid chromatography method to determine plasmatic levels of trimethoprim/sulfamethoxazole in paediatric population. Method: Chromatographic separation was carried out using a reverse phase column with detection ultraviolet at a wavelength of 225 nm. The mobile phase consists of phosphate buffer 0.1 M, acetonitrile and methanol, (65:20:15) with a flow of 1.0 ml/min. Results: Calibration curve was linear over the concentration range for trimethoprim of 0.25 to 5 μg/ml and 5 to 100 μg/ml for sulfamethoxazole. Precision were found to be within 15% for both compounds. The detection limits and quantifications for trimethoprim/sulfamethoxazole were 0.2 - 0.25 μg/ml and 3 - 5 μg/ml respectively. Conclusions: The developed method was applied for the quantification of both compounds in plasma samples of two patients resulting concentrations within the therapeutic ranges. The method is convenient for pharmacokinetic studies.展开更多
文摘Biofouling is an important problem for reverse osmosis (RO) membrane manufacturers. Bacteria are mainly involved in generating fouling and obturating RO membranes. Insights into biofilm bacteria composition could help prevent biofouling, reduce the cost of using RO-fouling membranes and guarantee safe water. Culture-dependent and independent techniques were then performed in order to identify bacteria associated with RO membranes. Bacteria cultures described the presence of six pure colonies, four of which were identified through API testing. Based on 16s rRNA gene analysis, a predominant bacterium was identified and annotated as Sphingomonas sp. The 16s rRNA gene clone library, on the other hand, showed that the bacterium, Pseudomonas marincola, accounted for nearly 30% of the clone library, while the rest of bacteria were chimeras (62%) and non-representative species (3%). In conclusion, culture-dependent and independent approaches showed that two dominant bacteria were commonly observed in RO desalination membranes.
文摘Aim: To develop a simple and sensitive high-performance liquid chromatography method to determine plasmatic levels of trimethoprim/sulfamethoxazole in paediatric population. Method: Chromatographic separation was carried out using a reverse phase column with detection ultraviolet at a wavelength of 225 nm. The mobile phase consists of phosphate buffer 0.1 M, acetonitrile and methanol, (65:20:15) with a flow of 1.0 ml/min. Results: Calibration curve was linear over the concentration range for trimethoprim of 0.25 to 5 μg/ml and 5 to 100 μg/ml for sulfamethoxazole. Precision were found to be within 15% for both compounds. The detection limits and quantifications for trimethoprim/sulfamethoxazole were 0.2 - 0.25 μg/ml and 3 - 5 μg/ml respectively. Conclusions: The developed method was applied for the quantification of both compounds in plasma samples of two patients resulting concentrations within the therapeutic ranges. The method is convenient for pharmacokinetic studies.
