The aim of this study was to design porous matrix beads for floating drug delivery using enteric polymer, Eudragit~? L and various amounts of waxes(0, 0.1, 0.5, 1, 2 and 3% w/w). In this study, wax containing cetyl al...The aim of this study was to design porous matrix beads for floating drug delivery using enteric polymer, Eudragit~? L and various amounts of waxes(0, 0.1, 0.5, 1, 2 and 3% w/w). In this study, wax containing cetyl alcohol and white petrolatum was utilized to produce pores using a wax removal technique. To prepare the beads, Eudragit~? L, metronidazole and wax were dissolved in acetone and then extruded into dichloromethane. The effect of the amount of wax on the floating and drug release behavior of the Eudragit~? L beads was determined.After the extruded product was immersed in dichloromethane, wax dissolved out from the formed beads, resulting in a porous structure. The prepared beads could float in simulated gastric fluid for more than 10 hours. Different amounts of wax had an effect on the drug release. We found that when the percentage of wax increased, the drug release was higher while the beads remained floating. The results suggest that Eudragit~? L beads could be used as a carrier for an intragastric floating drug delivery system.展开更多
A phosphate-accumulating bacteria strain PAO3-1 was isolated from biological phosphorus removal sludge supplied with sodium acetate as carbon source under stable performance. This strain has good enhanced biological p...A phosphate-accumulating bacteria strain PAO3-1 was isolated from biological phosphorus removal sludge supplied with sodium acetate as carbon source under stable performance. This strain has good enhanced biological phosphorus removal effect on normal activated sludge system. Phosphorus removal ratio was raised form 44% with no added strain to more than 82% with strain strengthening biological phosphorus removal. It is identified to be Alcaligenes sp. according to its morphology, biochemical characteristics and 16S rDNA sequence analysis. The cell of strain PAO3-1 is straight bacilli form, 0.4×1.1μm, no flagellum, gram negative and special aerobiotic. The optimal temperature and pH for growth are 32℃-37℃ and 5.5-9.5, respectively. The shape of slant clone is feathery. The phosphate accumulating rate of strain PAO3-1 was 8.1mgP/g cell·h, and 14.3 mgP/g cell·h when in phosphate-starving situation, which was 76.5% higher than that in non-starving situation. Its phosphate release rate of log course in anaerobic phase and in culture without phosphorus was 7.6mgP/g cell·h, while in stable course the rate was 6.1mgP/g cell·h. The rate in stable course was 19.7% lower than that in log course.展开更多
Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal we...Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal were investigated in a 50 ml flask incubated in a thermostatic cultivation cabinet. The optimized conditions were: temperature 40 ℃, shaking at 170 r·min-1, acid/alcohol molar ratio 1:0.9, lipase dosage in 10% (by mass) of oleic acid, and open reaction for water removal. As a result, the conversion rate reached 98% for reaction of 8 h. The volume of reactor was scaled up to 1 L three-neck flask. The optimized parameters were: 200 r·min-1 agitation speed, 2.5% (by mass) lipase dosage, others were the same as the parameters described above. The conversion rate reached 95% for reaction of 24 h. The lipase retained 46% conversion rate after reuse for 6, 7 batches. The products were purified by removing remained cetyl alcohol and fatty acids with ethanol and saturated sodium carbonate so-lution, respectively. The purity of the wax ester, cetyl oleate, was 96%. The physical and chemical properties of cetyl oleate were tested and compared with those of jojoba oil. The results show that the product cetyl oleate has great potential to use as the substitute of natural jojoba oil.展开更多
Bacillus velezensis M3-1 strain isolated from the sediment of Myriophyllum aquatium con-structedwetlandswas found to efficiently convert NO_(3)^(-)-N to NO_(2)^(−)-N,and the requirements for carbon source additionwere...Bacillus velezensis M3-1 strain isolated from the sediment of Myriophyllum aquatium con-structedwetlandswas found to efficiently convert NO_(3)^(-)-N to NO_(2)^(−)-N,and the requirements for carbon source additionwere not very rigorous.Thiswork demonstrates,for the first time,the feasibility of using the synergy of anammox and Bacillus velezensis M3-1 microorganisms for nitrogen removal.In this study,the possibility of M3-1 that converted NO_(3)^(−)-N produced by anammox to NO_(2)^(−)-N was verified in an anaerobic reactor.The NO_(3)^(−)-N reduction ability of M3-1 and denitrifying bacteria in coupling system was investigated under different C/N conditions,and it was found that M3-1 used carbon sources preferentially over denitrifying bacteria.By adjusting the ratio of NH4+-N to NO_(2)^(−)-N,it was found that the NO_(2)^(−)-N con-verted from NO_(3)^(−)-N by M3-1 participated in the original anammox.The nitrogen removal efficacy(NRE)of the coupled system was increased by 12.1%,compared to the control group anammox system at C/N=2:1.Functional gene indicated that itmight be a nitrate reducing bacterium.This study shows that the nitrate reduction rate achieved by the Bacillus velezensis M3-1 can be high enough for removing nitrate produced by anammox process,which would enable improve nitrogen removal from wastewater.展开更多
基金the Faculty of Pharmacy, Silpakorn University for financial support
文摘The aim of this study was to design porous matrix beads for floating drug delivery using enteric polymer, Eudragit~? L and various amounts of waxes(0, 0.1, 0.5, 1, 2 and 3% w/w). In this study, wax containing cetyl alcohol and white petrolatum was utilized to produce pores using a wax removal technique. To prepare the beads, Eudragit~? L, metronidazole and wax were dissolved in acetone and then extruded into dichloromethane. The effect of the amount of wax on the floating and drug release behavior of the Eudragit~? L beads was determined.After the extruded product was immersed in dichloromethane, wax dissolved out from the formed beads, resulting in a porous structure. The prepared beads could float in simulated gastric fluid for more than 10 hours. Different amounts of wax had an effect on the drug release. We found that when the percentage of wax increased, the drug release was higher while the beads remained floating. The results suggest that Eudragit~? L beads could be used as a carrier for an intragastric floating drug delivery system.
基金Fok Ying Tung Education Foundation ( No.94004)Shanghai Natural ScienceFoundation(No.04ZR14010)Young Teacher Foundation of Donghua University (No.113-10-0044065)
文摘A phosphate-accumulating bacteria strain PAO3-1 was isolated from biological phosphorus removal sludge supplied with sodium acetate as carbon source under stable performance. This strain has good enhanced biological phosphorus removal effect on normal activated sludge system. Phosphorus removal ratio was raised form 44% with no added strain to more than 82% with strain strengthening biological phosphorus removal. It is identified to be Alcaligenes sp. according to its morphology, biochemical characteristics and 16S rDNA sequence analysis. The cell of strain PAO3-1 is straight bacilli form, 0.4×1.1μm, no flagellum, gram negative and special aerobiotic. The optimal temperature and pH for growth are 32℃-37℃ and 5.5-9.5, respectively. The shape of slant clone is feathery. The phosphate accumulating rate of strain PAO3-1 was 8.1mgP/g cell·h, and 14.3 mgP/g cell·h when in phosphate-starving situation, which was 76.5% higher than that in non-starving situation. Its phosphate release rate of log course in anaerobic phase and in culture without phosphorus was 7.6mgP/g cell·h, while in stable course the rate was 6.1mgP/g cell·h. The rate in stable course was 19.7% lower than that in log course.
基金Supported by the National＇High Technology Research and Development Program of China （2009AA02Z207）, the National Natural Science Foundation of China （20876012） and the Hi-Tech Research and Development Program of China （2009AA03Z232, 2010AA101601）.
文摘Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal were investigated in a 50 ml flask incubated in a thermostatic cultivation cabinet. The optimized conditions were: temperature 40 ℃, shaking at 170 r·min-1, acid/alcohol molar ratio 1:0.9, lipase dosage in 10% (by mass) of oleic acid, and open reaction for water removal. As a result, the conversion rate reached 98% for reaction of 8 h. The volume of reactor was scaled up to 1 L three-neck flask. The optimized parameters were: 200 r·min-1 agitation speed, 2.5% (by mass) lipase dosage, others were the same as the parameters described above. The conversion rate reached 95% for reaction of 24 h. The lipase retained 46% conversion rate after reuse for 6, 7 batches. The products were purified by removing remained cetyl alcohol and fatty acids with ethanol and saturated sodium carbonate so-lution, respectively. The purity of the wax ester, cetyl oleate, was 96%. The physical and chemical properties of cetyl oleate were tested and compared with those of jojoba oil. The results show that the product cetyl oleate has great potential to use as the substitute of natural jojoba oil.
基金supported by the National Natural Sci-ence Foundation of China(Nos.42177099,91951108,and 21976197)the Knowledge Innovation Program of Shenzhen(No.JSGG20191129112812329),and the CAS International Part-nership Program(No.121311KYSB20200017)the special fund of State Key Joint Laboratory of Environment Simula-tion and Pollution Control(No.21Z02ESPCR).
文摘Bacillus velezensis M3-1 strain isolated from the sediment of Myriophyllum aquatium con-structedwetlandswas found to efficiently convert NO_(3)^(-)-N to NO_(2)^(−)-N,and the requirements for carbon source additionwere not very rigorous.Thiswork demonstrates,for the first time,the feasibility of using the synergy of anammox and Bacillus velezensis M3-1 microorganisms for nitrogen removal.In this study,the possibility of M3-1 that converted NO_(3)^(−)-N produced by anammox to NO_(2)^(−)-N was verified in an anaerobic reactor.The NO_(3)^(−)-N reduction ability of M3-1 and denitrifying bacteria in coupling system was investigated under different C/N conditions,and it was found that M3-1 used carbon sources preferentially over denitrifying bacteria.By adjusting the ratio of NH4+-N to NO_(2)^(−)-N,it was found that the NO_(2)^(−)-N con-verted from NO_(3)^(−)-N by M3-1 participated in the original anammox.The nitrogen removal efficacy(NRE)of the coupled system was increased by 12.1%,compared to the control group anammox system at C/N=2:1.Functional gene indicated that itmight be a nitrate reducing bacterium.This study shows that the nitrate reduction rate achieved by the Bacillus velezensis M3-1 can be high enough for removing nitrate produced by anammox process,which would enable improve nitrogen removal from wastewater.
