Fermentation process optimization of recombinant Saccharomyces cerevisiae for the production of human interferon-alpha2a

The effects of different culture conditions on the expression level of human interferon-alpha2a (IFN-alpha2a) by using recombinant yeast were investigated in a 2.6-L jar fermentor. Appropriate supplement of glucose and the maintenance of residual glucose at a low level resulted in the reduction of ethanol formation and enhancement of the bioactivity of IFN-alpha2a to 4.9 x 106 from 3.1 x 10(6) IU/mL. When adenine was added evenly for 10-20 h of fermentation into the basal culture medium at a speed of 2 microg/mL of medium/h, OD600 was greatly increased to 24, and the protein increased to 276 mg/L. The content of ethanol generated was also reduced tremendously during the process, and as a result, 1.3 x 10(7) IU/mL of biologic activity was achieved. In the expression phase, pH had an important impact on expression level, which should be controlled at 5.5.     

一种含三苯胺链段的PPV类交替共聚物的合成、表征及性能

合成了三苯胺二醛和1-甲氧基-4-辛氧基-2,5-二甲苯双(三苯基氯化)两种单体,通过Wittig反应制得了共轭聚合物,对共轭聚合物进行了表征和性能测试.这类共轭聚合物的氯仿溶液和膜在紫外光激发下能发出强的蓝绿光,与小分子三苯胺衍生物(TPD)相比,具有相对较高的热稳定性和良好的成膜性.电化学分析表明聚合物具有很好的空穴传输能力.同时对共轭聚合物的光致发光和电致发光性能进行了研究,结果表明,此聚合物与同类聚对亚苯基亚乙烯基(PPV)型聚合物相比具有较低的驱动电压和较高的发光亮度,是一种潜在的有机高分子电致发光材料.     

Panos-Fermented Extract-Mediated Nanoemulsion: Preparation,Characterization, and In Vitro Anti-Inflammatory Effects on RAW 264.7 Cells

This study focused on developing Panos nanoemulsion (P-NE) and enhancing the anti-inflammatory efficacy for the treatment of inflammation. The effects of P-NE were evaluated in terms of Nitric oxide (NO production) in Lipopolysaccharide (LPS), induced RAW 264.7 cells, Reactive oxygen species (ROS) generation using Human Keratinocyte cells (HaCaT), and quantitative polymerase chain reaction (qPCR) analysis. Sea buckthorn oil, Tween 80, and span 80 were used and optimize the process. Panos extract (P-Ext) was prepared using the fermentation process. Further high-energy ultra-sonication was used for the preparation of P-NE. The developed nanoemulsion (NE) was characterized using different analytical methods. Field emission transmission electron microscopy (FE-TEM) analyzed the spherical shape and morphology. In addition, stability was analyzed by Dynamic light scattering (DLS) analysis, where particle size was analyzed 83 nm, and Zeta potential −28.20 ± 2 (mV). Furthermore, 90 days of stability was tested using different temperatures conditions where excellent stability was observed. P-NE are non-toxic in (HaCaT), and RAW264.7 cells up to 100 µg/mL further showed effects on ROS and NO production of the cells at 50 µg/mL. The qPCR analysis demonstrated the suppression of pro-inflammatory mediators for (Cox 2, IL-6, IL-1β, and TNF-α, NF-κB, Ikkα, and iNOS) gene expression. The prepared NE exhibited anti-inflammatory effects, demonstrating its potential as a safe and non-toxic nanomedicine.     

与鱼类洄游相关的鱼类游泳特性研究进展

对鱼类游泳特性各评价指标进行了总结,介绍了目前国内外游泳特性的研究方法,从鱼类洄游角度综述了国内外鱼类游泳特性(包括运动代谢、游泳能力和生态行为)的评价模型,从不同影响因素(流速和温度,以及溶氧水平、盐度、鱼体重、年龄和摄食水平等)的角度探讨了鱼类游泳特性,可望为鱼道设计提供参考.     

单波长光照射下Co（OAc）_2催化溴代烃与CO的羰基化反应

对以Co（OAc）2为催化剂,在3种单波长（254、365、380nm）光照射下,溴代烃与CO的羰基化反应的研究结果表明,以溴代烷烃（溴代环己烷、1-溴己烷、1-溴辛烷）为底物,只有254nm的高能光对羰基化反应是有效的,碱性添加物对反应有明显的促进作用;以溴代环己烷为底物,加入NaOAc,环己基甲酸甲酯的产率可由34...     

2,3,7-三羟基-9-[3,5-二溴-4-(2,4-二羟基)苯偶氮]苯基荧光酮的合成及与锆(Ⅵ)的显色反应

介绍了新试剂2,3,7三羟基-9-[3,5-二溴-4-（2,4二羟基）苯偶氮]苯基荧光酮（DBARPF）的合成。通过元素分析、红外光谱和紫外光谱等方法测试,确定了该试剂的组成和结构。研究了试剂与一些金属离子显色反应的光度性质,建立了光度法测定微量锆（Ⅳ）的新方法。在0．6mol/L盐酸介质中,阳离子表面活性剂CTMAB存在下,锆（Ⅳ）与DBARP形成稳定的1：4水溶性络合物,λmax＝538nm,λ538nm为1．78×105L·mol-1·cm-1。锆（Ⅳ）含量在0～400μg/L范围服从比尔定律。拟定方法用于铝合金样品中微量锆（Ⅳ）的测定,获得满意的结果。     

用计算机进行多组份混合物的多体系分光光度分析

讨论了用计算机进行多组份同时分析中影响结果可靠性的诸因素与分析结果间的定量关系;提出了结果可靠性的经验判别式;编制了选择最佳测定点及其个数的程序;讨论了多体系方法的优缺点,对该方法作出初步评价并指出了可能的改善途径。     

Synthesis of a π-Extended Double [9]Helicene

Double helicenes are appealing chiral frameworks. Their π-extension is desirable to achieve (chir)optical response in the visible and near-infrared (NIR) region, but access to higher double [n]helicenes (n≥8) has remained challenging. Herein, we report an unprecedented π-extended double [9]helicene ( D9H ), unambiguously revealing its structure by single-crystal X-ray diffraction. D9H shows remarkable NIR emission from 750 to 1100 nm with a high photoluminescence quantum yield of 18 %. In addition, optically pure D9H exhibits panchromatic circular dichroism with a notable dissymmetry factor (g_CD) of 0.019 at 590 nm, which is among the highest in the visible region for reported helicenes.     

苯甲酸、对甲苯胺、乙酰苯胺三组分分离实验教学设计

分离提纯是有机合成中关键的实验步骤,反应后处理这部分的工作内容要占到90%的工作量。为提高学生从混合物中分离目标化合物的实验技能,进一步锻炼学生综合运用萃取、蒸馏、重结晶等纯化实验操作,中南大学化学化工学院有机化学教学组在有机化学实验教学中安排了"三组分混合物分离"实验,面向的学生为医学临床五年制和八年制、化学化工学院的制药工程及应用化学专业。本文详细探讨了该实验的酸、碱分离两种教学方案,对先加酸分离得到的三个组分进行了1H NMR测试。从两个方案的实验教学效果来看,先加酸或先加碱对实验结果没有影响。     

Hydrophilic interaction chromatography separation mechanisms of tetracyclines on amino-bonded silica column

Effects of mobile-phase variations on the chromatographic separation on amino-bonded silica column in hydrophilic interaction chromatography (HILIC) were investigated for four zwitterionic tetracyclines (TCs): oxytetracycline, doxycycline, chlortetracycline, and tetracycline. A mixed-mode retention mechanism composed of partitioning, adsorption, and ion exchange interactions was proposed for the amino HILIC retention process. Buffer type and pH significantly influenced the retention of TCs, but showed similar separation selectivity for the tested analytes. Experiments varying buffer salt concentration and pH demonstrated the presence of ion exchange interactions in TCs retention. The type and concentration of organic modifier also affected the retention and selectivity of the analytes, providing direct evidence supporting the Alpert retention model for HILIC. The retention time of the analytes increased in the following order of organic modifiers: tetrahydrofuran < methanol < isopropanol < acetonitrile. The linear relationships of logk' versus %water (v/v) curve and logk' versus logarithm of %water (v/v) in the mobile phase indicated that TCs separation on the amino phase was controlled by partitioning and adsorption. The developed method was successfully utilized in the detection of TCs in both river water and wastewater samples using solid-phase extraction (SPE) for sample cleanup.