Box-Behnken设计法优化大肠杆菌重组DsBA蛋自纯化工艺(英文)

Disulfide bond formation protein A (DsbA) is one of the important helper proteins for folding in protein synthesis in vivo. In this study, purification of recombinant DsbA was investigated by examining four important factors with Box-Behnken design method, a statistic-based design of experiments. The optimal operation conditions were obtained by adopting the effectiveness coefficient method on the multi-objective problem, which takes the protein recovery, purification efficiency and throughput of ion-exchange chromatography into account. After the optimization, protein recovery of 96.8% and purity higher than 95% DsbA was achieved, and the productivity was (377.9±1.7)mg soluble DsbA per liter broth. The purified protein was identified by peptide mass fingerprinting matching the record of gi|2624856, a mutant of DsbA. The DsbA was preliminarily applied to the refolding of denatured lysozyme in vitro.     

利用响应面法优化双歧杆菌冻干保护剂的配比

目的优化双歧杆菌冻干保护剂的配比。方法应用单因素试验、析因试验、最速上升试验和响应面分析法,对双歧杆菌冻干保护剂的配比进行优化。以优化的最佳配比进行3次重复冻干试验,计算菌体存活率。结果冻干保护剂的最佳配方为海藻糖浓度18%、甘油浓度6%、维生素C浓度0.1%、明胶浓度0.1%,以优化的最佳配比进行的3次重复冻干试验,菌体平均存活率可达86.7%。结论优化的冻干保护剂适用于双歧杆菌菌体保存。     

响应面法优化碳热还原合成LiFePO4/C的工艺参数（英文）

A statistically based optimization strategy is used to optimize the carbothermal reduction technology for the synthesis of LiFePO4/C using LiOH,FePO4 and sucrose as raw materials.The experimental data for fitting the response are collected by the central composite rotatable design(CCD).A second order model for the discharge ca-pacity of LiFePO4/C is expressed as a function of sintering temperature,sintering time and carbon content.The ef-fects of individual variables and their interactions are studied by a statistical analysis(ANOVA).The results show that the linear effects and the quadratic effects of sintering temperature,carbon content and the interactions among these variables are statistically significant,while those effects of sintering time are insignificant.Response surface plots for spatial representation of the model illustrate that the discharge capacity depends on sintering temperature and carbon content more than sintering time.The model obtained gives the optimized reaction parameters of sinter-ing temperature at 652.0 ℃,carbon content of 34.33 g?mol-1 and 8.48 h sintering time,corresponding to a dis-charge capacity of 150.8 mA·h·g-1.The confirmatory test with these optimum parameters gives the discharge ca-pacity of 147.2 and 105.1 mA·h·g-1 at 0.5 and 5 C,respectively.     

冻干人用狂犬病疫苗(Vero细胞)冻干保护剂的筛选

目的筛选适用于冻干人用狂犬病疫苗(Vero细胞)的冻干保护剂。方法用同一批冻干人用狂犬病疫苗(Vero细胞)原液在同一冻干条件下,改变右旋糖酐40、海藻糖及人血白蛋白3种保护剂主要成分的含量,组合成6种保护剂配方,分别制备成半成品。冻干后检测成品外观、疫苗效力及热稳定性,确定最佳冻干保护剂配方。以最佳保护剂配方制备6批成品进行适用性验证,并选择3批成品进行长期稳定性验证。结果确定最佳冻干保护剂的配方为4%海藻糖、3%右旋糖酐40、1%蔗糖、0.5%甘露醇、2%人血白蛋白。以该配方制备的6批成品的各项检测指标均符合《中国药典》三部(2010版)的要求,其中3批成品经2~8℃保存12个月后的效价较稳定。结论筛选获得了最佳冻干人用狂犬病疫苗(Vero细胞)的冻干保护剂,且具有良好的稳定性。     

由竹脚手架制备的活性炭经化学修饰后的表征(英文)

In this study,bamboo scaffolding was used to produce activated carbon by carbonization at 600 ℃ and 900 ℃ with the purge of nitrogen.The 600 ℃ char was then further modified chemically by acids and alkalis by reflux for 6 hours.The produced chars were then characterized by nitrogen adsorption isotherm,He pyncometry,pH,elemental analysis and Boehm titration.For most of the chemically modified carbons,the micropore surface areas and volumes have increased compared with the 600 ℃ char,while the mesopore surface areas and volumes slightly decreased,which may have been due to the dissolving of some of the permeated inorganic matter and oxidizing deposited carbon that blocks the pore openings.For the acidic modified carbons,larger amounts of acidic groups were present in the carbons after being activated by phosphoric acid,phosphoric acid further treated with 2 mol·L-1 nitric acid,and calcium hydroxide.Although carbon treated with 2 mol·L-1 and 5 mol·L-1 nitric acid also produced high acidity,the surface areas and pore volumes were relatively low,due to the destruction of pores by nitric acid oxidation.The reduction of porosity may impair the adsorption capacity.     

高活性织物柔软剂的配方(英文)

自从开发出洗衣剂用的合成表面活性剂以来 ,衣服柔顺剂就成为家庭洗衣用品中的重要一员。人工合成的表面活性剂尽管是非常有效的清洁剂 ,但通常也会令洗后的衣物变得粗糙硬挺。因此 ,人们会使用衣服柔顺剂以便衣物回复原先的松软弹性。到目前为止 ,最通用的衣服柔顺剂是专为在洗衣程序的最后一道漂洗步骤中设计加入的阳离子季铵化合物     

一种新型成核剂对聚乳酸等温结晶行为的影响(英文)

The effect of a novel active nucleating agent(TBC8-eb) on the isothermal crystallization of poly(L-lactic acid) (PLLA) was studied by differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FTIR) . The analysis on kinetics demonstrates that TBC8-eb can not only accelerate the crystallization rate but also transform most of the original spherulite crystals of PLLA into sheaf-like crystals. Furthermore,the free energy of folding(σe) of PLLA and PLLA with TBC8-eb is 0.15 and 0.06 J·m-2,respectively,which suggests that the addition of TBC8-eb favors the regular folding of molecule chains in the crystallization of PLLA,improv-ing its crystallization rate. The FTIR results show that TBC8-eb can accelerate the conformational ordering of PLLA in the isothermal crystallization. The conformational ordering of PLLA nucleated with TBC8-eb begins with the interchain interaction of CH3,and then a short helix emerges where a couple of CH3 groups interact.     

聚乙烯-碳纳米管串晶的高效制备(英文)

We report a novel method to prepare nanohybrid shish-kebab (NHSK) structure of polyethylene (PE) and carbon nanotube (CNT). Pristine CNTs without surface modification with high concentration was effectively dispersed in xylene solution by a simple shearing method, which induces the quick crystallization of PE in xylene to form a novel NHSK structure with more dense and smaller PE kebab on CNT axis. The flocculated NHSK product was transferred quickly from the xylene solution to the ethanol solution, in order to shorten the preparation time. The freeze-drying method was used in vacuum instead of high-temperature drying to avoid the aggregation of NHSK product. These improvements allow the formation of NHSK with an absolute yield of 200 mg·h-1 , which is 2000 folds of that reported previously. It is favorable to apply this structured material in high performance nanocomposite, by improving the compatibility of CNTs in polymer and the interfacial force between CNTs and polymer.     

硝酸浓度对橄榄石基活性炭特性的影响(英文)

In this work we investigated the effect of nitric acid concentration on the pore structure, surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents. Chemicals and textural characterization show that the increase of HNO3 concentration increases considerably the total acidic groups but decreases specific surface area and pore volume. The study of adsorption in aqueous solutions of two organics, phenol and methylene blue, on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO3 concentrations less or equal to 2 mol·L 1, while it has a negative effect on phenol adsorption.     

表面活性剂在气/液界面上扩散控制的吸附动力学(英文)

For the diffusion-controlled adsorption, the expression of dynamic surface adsorption P（t） was ob- tained by solving the diffusion equation. Two cases, i.e. the short and long time limits, were mainly discussed in this paper. From the measured dynamic surface tension of aqueous surfactant sodium dodecyl sulfate （SDS） solutions at 25 ℃, the adsorption kinetics of SDS at air/solution interface was studied. It was proved that for both of the short and long time limits, the adsorption process of SDS was controlled by diffusion.     

高特异性长双歧杆菌多克隆抗体的制备

目的制备高特异性长双歧杆菌多克隆抗体,为长双歧杆菌的免疫学检测提供参考。方法以破碎的长双歧杆菌细胞碎片为抗原免疫小鼠,制备抗血清;利用偶联相同抗原的磁珠,分离纯化长双歧杆菌多抗,分别采用间接ELISA、SDS-PAGE和点杂交法检测纯化多抗的效价、纯度和交叉反应性。结果所制备的纯化多抗效价约为1∶1500,回收率约为80%,纯度可达83%。纯化的多抗有效消除了与金黄葡萄球菌的非特异性交叉反应。结论已制备出高特异性的长双歧杆菌多克隆抗体,可用于长双歧杆菌制剂的菌体检测。     

A Model for Optimizing Glass Batch Compositions

A model is presented for finding the cheapest and least-sensitive batch composition that meets a set of specified physical properties of a glass. The model is tested on two glasses reported in the literature and is shown to be a useful tool for simulating the consequences of a change either in the desired properties of a glass or in the composition and/or set of batch materials.     

Biochemical Characterization and Complete Conversion of Coenzyme Specificity of Isocitrate Dehydrogenase from Bifidobacterium longum

Bifidobacterium longum is a very important gram-positive non-pathogenic bacterium in the human gastrointestinal tract for keeping the digestive and immune system healthy. Isocitrate dehydrogenase (IDH) from B. longum (BlIDH), a novel member in Type II subfamily, was overexpressed, purified and biochemically characterized in detail. The active form of BlIDH was an 83-kDa homodimer. Kinetic analysis showed BlIDH was a NADP⁺-dependent IDH (NADP-IDH), with a 567- and 193-fold preference for NADP⁺ over NAD⁺ in the presence of Mg²⁺ and Mn²⁺, respectively. The maximal activity for BlIDH occurred at 60 °C (with Mn²⁺) and 65 °C (with Mg²⁺), and pH 7.5 (with Mn²⁺) and pH 8.0 (with Mg²⁺). Heat-inactivation profiles revealed that BlIDH retained 50% of maximal activity after incubation at 45 °C for 20 min with either Mn²⁺ or Mg²⁺. Furthermore, the coenzyme specificity of BlIDH can be completely reversed from NADP⁺ to NAD⁺ by a factor of 2387 by replacing six residues. This current work, the first report on the coenzyme specificity conversion of Type II NADP-IDHs, would provide better insight into the evolution of NADP⁺ use by the IDH family.     

淋病奈瑟氏菌培养基和保护剂的研究

本文报告了淋病奈瑟氏菌生长培养基、糖发酵生化培养基、保存培养基和真空干燥保护剂的研究。应用27株淋病奈瑟氏菌进行试验表明,全部菌株在特殊蛋白胨血琼脂和多种蛋白胨血琼脂上24小时生长良好;26株菌在NGCM-1生化培养基中发酵葡萄糖产酸(96.3％),保存培养基在27℃可保存菌种30天左右,10％脱脂奶粉作为保护剂真空干燥菌种可保存20个月以上。     

The Effect of Proline on the Freeze-Drying Survival Rate of Bifidobacterium longum CCFM 1029 and Its Inherent Mechanism

Amino acids, which are important compatible solutes, play a significant role in probiotic lyophilization. However, studies on the functions of Bifidobacterium during freeze-drying are limited. Therefore, in this study, we compared the freeze-drying survival rate of Bifidobacterium longum CCFM 1029 cultivated in different media containing different kinds of compatible solutes. We found that the addition of 21 g/L proline to the culture media substantially improved the freeze-drying survival rate of B. longum CCFM 1029 from 18.61 ± 0.42% to 38.74 ± 1.58%. Interestingly, this change has only been observed when the osmotic pressure of the external culture environment is increased. Under these conditions, we found that proline accumulation in this strain increased significantly. This change also helped the strain to maintain its membrane integrity and the activity of some key enzymes during freeze-drying. Overall, these results show that the addition of proline can help the strain resist a tough environment during lyophilization. The findings of this study provide preliminary data for producers of probiotics who wish to achieve higher freeze-drying survival rates during industrial production.     

化工制药工艺优化

化工制药在社会生产发展、减缓疾病、保障人体身心健康等层面存在显著效用。对化工制药工艺不断优化改进,是促进社会生产进一步发展的关键力量。在社会大众生活质量大幅改善、社会生产所需愈加严格的背景下,化工制药不但需确保品质、生产效率,还需优化工艺,以此为化工制药企业更好的发展予以支撑,确保药品生产更具安全可靠性。首先对化工制药工艺优化的必要性、化工制药行业现状进行了阐述,而后分析了化工制药工艺相关问题,并提出了具体的化工制药工艺优化策略。     

9-芴甲氧羰基氨基保护试剂的合成与分析

研究了9 芴甲基氯甲酸酯(Fmoc Cl)、9 芴甲基叠氮甲酸酯(Fmoc N3)和9 芴甲基琥珀酰亚胺碳酸酯(Fmoc OSu)这3种氨基保护试剂的合成方法。用碳酸二(三氯甲酯)代替光气与芴甲醇反应得到Fmoc Cl;Fmoc Cl可分别与叠氮化钠及N 羟基琥珀酰亚胺反应得到9 芴甲基叠氮甲酸酯(Fmoc N3)以及9 芴甲基琥珀酰亚胺碳酸酯(Fmoc OSu),收率分别为87 9%和86 9%。上述Fmoc保护试剂在碱性条件下分别与甘氨酸反应进行氨基保护得到产品Fmoc 甘氨酸,收率分别为83 1%、73 3%及93 9%,用毛细管电泳仪分析其摩尔分数分别为97 7%、99 5%及大于99 9%,结果表明,Fmoc OSu是甘氨酸Fmoc氨基保护的最佳试剂。     

注射用尼可地尔的冻干工艺研究

研究了注射用尼可地尔的处方及冻干生产工艺.采用单因素实验方法,以冻干粉针剂的性状、pH、含量及有关物质等为考察指标,对处方中赋形剂的类型、用量、pH范围及冻干工艺参数进行筛选及优化.获得了优化处方及冻干工艺:制备规格为12 mg的注射用尼可地尔,甘露醇作为赋形剂,加入量为18 mg,pH范围为6.5 ～7.5,选择2次退火,退火温度为-15℃,退火保持时间为2h,制备的冻干粉针剂成型性好、易复溶.该制剂处方工艺设计合理,工艺路线可行,为注射用尼可地尔的处方及工艺筛选提供借鉴.     

轻化工程专业实践教学体系的优化

本文结合轻化工程专业特色,分析了构建轻化工程专业实践教学体系的基本原则,讨论了加强实践教学体系的措施,阐述了实践教学体系的内容。