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101.
重组人白细胞介素-10在大肠杆菌中的表达及生物学活性分析 总被引:1,自引:0,他引:1
目的在大肠杆菌中表达重组人白细胞介素-10(Interleukin-10,IL-10),并检测其生物学活性。方法将IL-10基因重组到质粒pET11c中,转化BL21(DE),提取质粒,经酶切鉴定和测序分析;在25℃用低浓度的IPTG诱导表达,对包涵体IL-10稀释复性;经ELISA检测其含量,MC/9细胞增殖法检测其生物学活性。结果工程菌IL-10/pET11c/BL21诱导表达的目的蛋白以可溶性和包涵体两种形式存在,Westernblot鉴定证实为IL-10蛋白,两种形式的IL-10均具有一定的生物学活性。结论已成功地在大肠杆菌中表达了IL-10,为进一步纯化和制备IL-10的基因工程药物打下了基础。 相似文献
102.
用RAP法(reactivo atmosphere process)处理KCl熔体,在不改变生长气氛和RAP继续处理的情况下,提拉生长KCl晶体,以解决高纯、大尺寸、生长速度快、成品率高和有较大经济效益的问题。 相似文献
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104.
Consequences of different cutting regimes on regrowth and nutrient stoichiometry of Sparganium erectum L. and Potamogeton natans L.
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Aquatic vegetation forms an essential component in freshwater ecosystems but due to changed environmental and anthropogenic conditions often needs management to reduce nuisance for human land‐use. In this paper, the authors looked at the regrowth of two macrophyte species (Potamogeton natans and Sparganium erectum) in two lowland rivers under different cutting treatments. After an initial cross‐sectional transect was manually removed from bank to bank at the beginning of the growth season, a monthly repetitive removal of biomass in plots on that transect was done during the rest of the growth season (testing frequency of mowing). Additional new transects were also cut in subsequent months (testing timing of mowing). Finally, biomass was repetitively removed in plots in those additional transects too (testing frequency of mowing × timing of mowing). The biomass at the end of the growth season was analysed for C, N, P, and Si. It was demonstrated that timing and frequency of vegetation cutting has an important effect on the capacity and rate of species' recovery and therefore on the efficiency of the applied management. Nutrient stoichiometry of the regrown biomass was directly affected by cutting. Caused by differences in the applied timing and frequency of the cutting, C/N and N/P ratios and BSi concentrations were highly variable. Yet, overall, there was a clear tendency towards a higher C/N ratio and BSi concentration and lower N/P ratio in biomass that recovered after cutting. This human impact on the quantity and quality of autochthonous organic matter may have knock‐on effects on the decomposers food web and mineralization process. 相似文献
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The selective oxidation of n-butane to maleic anhydride(MA) on a vanadium-phosphorus oxide (VPO) catalyst was studied using on-line gas-chromatography combined with mass spectrometry(GC-MS) and transient response technique.The reaction intermediates,butene and furan,were found in the reaction effuent under near industrial feed condition (3% butane 15% O2),while dihydrofuran was detected at high butane concentration (12% butane,5%O2).Some intermediates of MA decomposition were also identified.Detection of these intermediates shows that the vanadium phosphorus oxides are able to dehydrogenate butane to butene,and butene further to form MA.Based on these observations,a modified scheme of reaction network is proposed.The transient experiments show that butane in the gas phase may directly react with oxygen both on the surface and from the metal oxide lattice,without a proceeding adsorption step.Gas phase oxygen can be adsorbed and transformed to surface lattice oxygen but it can not participate in selective oxidation.Adsorbed oxygen leads to deep oxidation,while lattice oxygen leads to selective oxidation. 相似文献
108.
Phosphorus modification of ZSM-5 leads to extra framework P5+ and probably incorporation of +3 valence state of P in the framework. The resulting system has increased Brønsted acidity. Theoretical calculations also favour the postulate that phosphorus in +3 valence state can be incorporated into the lattice. 相似文献
109.
In this paper, the optimal policies for bulk polymerization of n‐butyl methacrylate (BMA) are determined in a nonisothermal batch reactor. Four objectives are realized for BMA polymerization based on a detailed process model. The objectives are: (i) maximization of monomer conversion in a specified operation time, (ii) minimization of operation time for a specified, final monomer conversion, (iii) maximization of monomer conversion for a specified, final number average polymer molecular weight, and (iv) maximization of monomer conversion for a specified, final weight average polymer molecular weight. For each objective, the optimal temperature policy of heat‐exchange fluid inside reactor jacket is determined. The temperature of the heat‐exchange fluid is considered as a function of a specified variable. Necessary equations are provided to suitably transform the process model in terms of a specified variable other than time, and to evaluate the elements of Jacobian to help in the accurate solution of the process model. A genetic algorithm‐based optimal control method is applied to realize the objectives. The resulting optimal policies of this application reveal considerable improvements in the batch production of poly(BMA). © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 2799–2809, 2006 相似文献
110.
净化黄磷尾气合成甲酸甲酯研究 总被引:4,自引:0,他引:4
用净化黄磷尾气为原料与甲醇液相合成甲酸甲酯 ,并对影响一氧化碳及甲醇转化率、甲酸甲酯时空收率等的因素进行了研究。研究结果表明 ,随着主催化剂浓度或反应压力的增大 ,一氧化碳转化率及甲醇转化率均提高 ;助剂的加入可以大大提高甲酸甲酯时空收率和延长催化剂的寿命。优化的反应条件为 :主催化剂 (甲醇钠 )浓度 0 .4mol L ;助催化剂吡啶浓度 1.74mol L ;温度 80℃ ;时间 160min ;压力 4MPa。在此条件下 ,黄磷尾气中一氧化碳及甲醇转化率可分别达到 95 .5 %和 43%。 相似文献