Hydroxylamine sulfate （HAS） and sodium nitrite are used as the accelerators for zinc phos- phate coating on high carbon steel. Phase evolution of phosphate coating was investigated by X-ray diffraction. It is found ...Hydroxylamine sulfate （HAS） and sodium nitrite are used as the accelerators for zinc phos- phate coating on high carbon steel. Phase evolution of phosphate coating was investigated by X-ray diffraction. It is found that the phosphating coatings are mainly composed of hopeite Zn3Fe（PO4）2.4H2O and phosphophyllite Zn2Fe（PO4）2.4H2O. The microstructural changes of the phosphate coating, as a function of phosphating time, were evaluated by scanning elec- tron microscopy. Four-ball friction experiments reveal that hydroxylamine sulfate instead of sodium nitrite can effectively reduce the friction coefficient of lubricated phosphating coat- ing. Therefore, it may be expected that HAS will be widely used as a fast and ECO-friendly accelerator in phosphate industry.展开更多
Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange ...Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.展开更多
目的探讨富血小板血浆(PRP)联合透明质酸(HA)关节内注射与PRP单独注射相比的疗效和安全性,为膝骨性关节炎(KOA)的治疗提供循证策略。方法查阅PubMed、Web of Science、中国知网(CNKI)、万方数据库,检索建库初到2021年10月公开发表的文...目的探讨富血小板血浆(PRP)联合透明质酸(HA)关节内注射与PRP单独注射相比的疗效和安全性,为膝骨性关节炎(KOA)的治疗提供循证策略。方法查阅PubMed、Web of Science、中国知网(CNKI)、万方数据库,检索建库初到2021年10月公开发表的文献。纳入已发表的随机对照实验(RCT)或队列研究。研究对象为KOA患者,实验组为PRP联合HA关节内注射,对照组为PRP或HA关节内注射。对纳入RCT研究使用Cochrane手册风险评估工具进行质量评价,队列研究使用Newcastle-Ottawa Scale进行质量评价,用RevMan5.3软件对结局指标进行Meta分析。结果纳入10篇文献,共1110例患者,其中PRP组467例,PRP+HA组450例,HA组193例。Meta分析结果显示,PRP+HA组在治疗6个月后视觉模拟评分(VAS,MD:-0.31;95%CI(-0.60~-0.03);P=0.03)、西大略和麦克马斯特大学骨关节炎指数(WOMAC)评分(MD:-2.81;95%CI(-4.48~-1.13);P=0.001)、Lequesne指数(MD:-1.46;95%CI(-2.01~-0.90);P<0.00001)均显著优于PRP组;两组并发症发生率无统计学意义(RD:0.00;95%CI(-0.03~0.04);P=0.97)。结论PRP联合HA治疗KOA具有良好的临床治疗效果。基于此Meta分析,与单纯关节内注射PRP相比,PRP联合HA可提高治疗6个月后的WOMAC评分、VAS评分和Lequesne指数评分。在并发症发生率方面,两种治疗方案的安全性相似。展开更多
基金This work was supported by the Bengbu Yucheng New Materials Science and Technology Ltd. （No.2012QTXM0375） and the Natural Science Foundation of Anhui Province （No.1208085QE99）.
文摘Hydroxylamine sulfate （HAS） and sodium nitrite are used as the accelerators for zinc phos- phate coating on high carbon steel. Phase evolution of phosphate coating was investigated by X-ray diffraction. It is found that the phosphating coatings are mainly composed of hopeite Zn3Fe（PO4）2.4H2O and phosphophyllite Zn2Fe（PO4）2.4H2O. The microstructural changes of the phosphate coating, as a function of phosphating time, were evaluated by scanning elec- tron microscopy. Four-ball friction experiments reveal that hydroxylamine sulfate instead of sodium nitrite can effectively reduce the friction coefficient of lubricated phosphating coat- ing. Therefore, it may be expected that HAS will be widely used as a fast and ECO-friendly accelerator in phosphate industry.
基金supported by grants from National Natural Science Foundation of China(51078106)Heilongjiang Provincial Science Foundation for Distinguished Youth Scholar(JC200708)Heilongjiang Provincial Finance Foundation for Basic Sciences(CZ12BZSM06)
文摘Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.
文摘目的探讨富血小板血浆(PRP)联合透明质酸(HA)关节内注射与PRP单独注射相比的疗效和安全性,为膝骨性关节炎(KOA)的治疗提供循证策略。方法查阅PubMed、Web of Science、中国知网(CNKI)、万方数据库,检索建库初到2021年10月公开发表的文献。纳入已发表的随机对照实验(RCT)或队列研究。研究对象为KOA患者,实验组为PRP联合HA关节内注射,对照组为PRP或HA关节内注射。对纳入RCT研究使用Cochrane手册风险评估工具进行质量评价,队列研究使用Newcastle-Ottawa Scale进行质量评价,用RevMan5.3软件对结局指标进行Meta分析。结果纳入10篇文献,共1110例患者,其中PRP组467例,PRP+HA组450例,HA组193例。Meta分析结果显示,PRP+HA组在治疗6个月后视觉模拟评分(VAS,MD:-0.31;95%CI(-0.60~-0.03);P=0.03)、西大略和麦克马斯特大学骨关节炎指数(WOMAC)评分(MD:-2.81;95%CI(-4.48~-1.13);P=0.001)、Lequesne指数(MD:-1.46;95%CI(-2.01~-0.90);P<0.00001)均显著优于PRP组;两组并发症发生率无统计学意义(RD:0.00;95%CI(-0.03~0.04);P=0.97)。结论PRP联合HA治疗KOA具有良好的临床治疗效果。基于此Meta分析,与单纯关节内注射PRP相比,PRP联合HA可提高治疗6个月后的WOMAC评分、VAS评分和Lequesne指数评分。在并发症发生率方面,两种治疗方案的安全性相似。
