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121.
Biooxidation of ferrous iron by immobilized Acidithiobacillus ferrooxidans in poly(vinyl alcohol) cryogel carriers 总被引:4,自引:0,他引:4
PVA-cryogels entrapping about 109 cells of Acidithiobacillus ferrooxidans per ml of gel were prepared by freezing-thawing procedure, and the biooxidation of Fe2+ by immobilized cells was investigated in a 0.365 l packed-bed bioreactor. Fe2+ oxidation fits a plug-flow reaction model well. A maximum oxidation rate of 3.1 g Fe2+ l–1 h–1 was achieved at the dilution rate of 0.4 h–1 or higher, while no obvious precipitate was determined at this time. In addition, cell-immobilized PVA-cryogels packed in bioreactor maintained their oxidative ability for more than two months under non-sterile conditions.
Nomenclature:
C
A0 – Concentration of Fe2+ in feed stream (g l–1) C
A – Concentration of Fe2 + in outlet stream (g l– 1) D – Dilution rate of the packed-bed bioreactor (h–1) F – Volumetric flow rate of iron solution (l h–1) F
A0 – Mass flow rate of Fe2+ in the feed stream (g h–1) K – Kinetic constant (l l–1 h–1) r
A – Oxidation rate of Fe2+ (g l–1 h–1) V – Volume of packed-bed bioreactor (l) X
A – Conversion ratio of Fe2+ (%) 相似文献
122.
Protein data, from sequence and structure to interaction, is being generated through many diverse methodologies; it is stored and reported in numerous forms and multiple places. The magnitude of the data limits researchers abilities to utilize all information generated. Effective integration of protein data can be accomplished through better data modeling. We demonstrate this through the MIPD project. 相似文献
123.
Li J Shao Y Chen Z Cong R Wang J Liu X 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2003,791(1-2):55-61
The suitability of membrane cartridges for the removal of endotoxin from both distilled water and interferon preparations was examined. The endotoxin concentrations were reduced to 4.0 and 7.3 EU/ml, respectively, when about 4000 ml of distilled water with 20 and 28 EU/ml were passed through the deoxycholate and chitosan immobilized membrane cartridges. When 200 ml of interferon preparation with endotoxin concentration more than 80 EU/ml and pH 3.9 were applied to a deoxycholate immobilized membrane cartridge at a flow-rate of 9 ml/min, the endotoxin concentration was reduced to less than 10 EU/ml. However, if an interferon preparation of 450 ml, with more than 80 EU/ml of endotoxin and pH 3.9 was applied to the chitosan immobilized membrane cartridge at a flow-rate of 18 ml/min, the endotoxin concentration was reduced to less than 10 EU/ml. 相似文献
124.
Cong Y Weaver CT Lazenby A Elson CO 《Journal of immunology (Baltimore, Md. : 1950)》2000,165(4):2173-2182
C3H/HeJBir is a mouse substrain that is highly susceptible to colitis. Their CD4+ T cells react to Ags of the commensal enteric bacteria, and the latter can mediate colitis when activated by these Ags and transferred to histocompatible scid recipients. In this study, multiple long-term C3H/HeJBir CD4+ T cell (Bir) lines reactive to commensal enteric bacterial Ags have been generated. All these were Ag specific, pauciclonal, and Th1 predominant; most induced colitis uniformly after transfer to scid recipients. Lesions were focal and marked by increased expression of IL-12p40 and IFN-gamma mRNA and protein. Pathogenic Bir T cell lines expressed CD40 ligand (CD40L) when cultured with Ag-pulsed APCs in vitro. Production of IL-12 was also increased in such cultures, an effect that was Ag- and T cell-dependent and required costimulation by CD40, but not by B7. The two Bir T cell lines that did not induce lesions after transfer failed to significantly express CD40L or increase IL-12 when cultured with Ag-pulsed APCs. Administration of anti-CD40L blocked disease expression induced by pathogenic T cells. We conclude that interactions in the colon mucosa between CD40L-expressing Bir Th1 cells with APCs endogenously loaded with commensal bacterial Ags are critical for sustained increases in local IL-12 production and progression to colitis. 相似文献
125.
126.
中国株丙型肝炎病毒(HCV)结构区蛋白在昆虫细胞中的表达及加工 总被引:4,自引:1,他引:3
利用杆状病毒表达系统在昆虫细胞中表达了完整的中国河北株丙丙型肝炎病毒结构蛋白。免疫印迹实验结果显示,表达产物中有一系列分子量不同、可以与HCV抗体阳性病人血清反应的蛋白,表明结构蛋白被宿主细胞蛋白酶切割与加工,相应分别为20kD的核心蛋白、32kD糖基化的E1蛋白40kD的未糖化的E2蛋白和70kD糖基化的E2蛋白,另有80kD及100kD的两组前体蛋白。利用表达产物检测慢性HCV感染者血清,发现 相似文献
127.
基因扩增产物的固相杂交-酶联显色方法的建立 总被引:3,自引:0,他引:3
建立基于基因扩增技术的简便、快速的病毒核酸定量检测方法.将标记有生物素的寡核苷酸引物所扩增的病毒基因产物,与通过共价键结合在微孔反应板上的特异性探针进行快速杂交,然后通过辣根过氧化物酶标记的抗生物素进行酶联显色,读取光密度值.应用本方法对血清中乙型、丙型肝炎病毒核酸定量检测,灵敏度分别可达1-5拷贝/反应.此方法简便、快速、特异性好、敏感性高、半定量指标客观,可广泛应用于肝炎病毒感染的临床诊断和疗效评价. 相似文献
128.
129.
The global invasion of Tephritidae (fruit flies) attracts a great deal of attention in the field of plant quarantine and invasion biology because of their economic importance. Predicting which one in hundreds of potential invasive fruit fly species is most likely to establish in a region presents a significant challenge, but can be facilitated using a self organising map (SOM), which is able to analyse species associations to rank large numbers of species simultaneously with an index of establishment. A global presence/absence dataset including 180 economically significant fruit fly species in 118 countries was analysed using a SOM. We compare and contrast ranked lists from six countries selected from each continent, and also show that those countries geographically close were clustered together by the SOM analysis because they have similar fruit fly assemblages. These closely clustered countries therefore represent greater threats to each other as sources of invasive fruit fly species. Finally, we indicate how this SOM method could be utilized as an initial screen to support prioritizing fruit fly species for further research into their potential to invade a region. 相似文献
130.
Xiaoyu Yu Dandan Zhang Bisheng Shi Guangxu Ren Xiuhua Peng Zhong Fang Maya Kozlowski Xiaohui Zhou Xiaonan Zhang Min Wu Cong Wang Zhenghong Yuan 《PloS one》2015,10(4)
Hepatitis B virus (HBV) persistent infection is associated with ineffective immune response for the clearance of virus. Immunomodulators represent an important class of therapeutics, which potentially could be beneficial for the treatment of HBV infection. The particulate yeast-derived glucan (PYDG) has been shown to enhance the innate and adaptive immune responses. We therefore, assessed the efficacy of PYDG in enhancing HBV specific immune responses by employing the hydrodynamic injection-based (HDI) HBV transfection mouse model. Mice were intragatric administered PYDG daily for 9 weeks post pAAV/HBV1.2 hydrodynamic injection. PYDG treatment significantly promoted HBV DNA clearance and production of HBsAb compared to control mice. PYDG treatment resulted in recruitment of macrophages, dendritic cells (DCs) and effector T cells to the liver microenvironment, accompanied by a significantly augmented DCs maturation and HBV-specific IFN-γ and TNF-α production by T cell. In addition, enhanced production of Th1 cytokines in liver tissue interstitial fluid (TIF) was associated with PYDG administration. Live imaging showed the accumulation of PYDG in the mouse liver. Our results demonstrate that PYDG treatment significantly enhances HBV-specific Th1 immune responses, accompanied by clearance of HBV DNA, and therefore holds promise for further development of therapeutics against chronic hepatitis B. 相似文献