Prokaryotic Expression of Amphioxus BRA Protein and Preparation of the Polyclonal Antibody

Brachyury编码的转录调控因子BRA参与脊索动物脊索的分化形成,文昌鱼是最早具有真正脊索的后生动物类群,因此开展文昌鱼Brachyury基; 因功能研究,将有助于揭示脊索的起源与进化。文昌鱼具有2个Brachyury基因:Bra1和Bra2,二者编码的蛋白序列相似度高达93%,缺少有效; 区分二者的特异抗原表位,转录组数据分析表明Bra2表达量显著高于Bra1,进一步对BRA2蛋白序列特征分析发现其N端拥有丰富的潜在抗原决定簇,因; 此本研究选择了Bra2 N端696; bp基因序列所编码的蛋白片段作为制备抗体的抗原蛋白。将该段基因序列克隆重组入pET28a原核表达质粒,经诱导表达获分子量约31; ku的可溶性重组蛋白。通过Ni~(2+)亲和层析柱纯化,得到1.3 g/L高纯度抗原蛋白,用3只ICR小鼠(Mus; musculus)经4轮重组蛋白免疫[剂量50 mug/(只·次)]后获得最高效价(1︰256; 000)的多克隆抗体。Western印迹结果显示,本研究制备的鼠抗文昌鱼BRA多克隆抗体不仅可特异识别重组抗原蛋白,也可高效识别文昌鱼胚胎总蛋白; 中的BRA1和BRA2,为后续深入研究文昌鱼BRA在脊索发育调控中的作用提供了有力的分子工具。Homologues of the T-box gene Brachyury play an essential role in; notochord specification of early embryo development of chordates.; Amphioxuses, also called cephalochordates, represent the most basally; divergent lineage of chordates, being the sister group of urochordates; and vertebrates. It is now generally agreed that amphioxus is the first; animal group to evolve a real sense of notochord in all metazoans, hence; studying Brachyury in amphioxus would shed important insights into the; origin and evolution of notochord. In order to explore the function of; Brachyury in the developmental regulation network of amphioxus, we; generated a mouse anti-amphioxus BRA polyclonal antibody. Amphioxus; possesses two Brachyury homologues genes: Bra1 and Bra2, encoding two; proteins with a sequence similarity of 93% (Fig. 1a). It is very hard to; distinguish specific epitopes between them. The transcriptome data; showed that the expression level of Bra2 was much higher than that of; Bra1 (Fig. 1b). Further analysis of BRA2 sequence feature indicated that; ideal presume antigenic determinants located in the N-terminal of BRA2; (Fig. 1c). Therefore, a 696 bp gene segment was amplified by PCR from; Bra2 N-terminal (Fig. 2a) and inserted into prokaryotic expression; vector pET28a (Fig. 2b). The recombinant plasmid pET28a-Bra2-N was; transformed into Escherichia coli BL21 and induced to express the tagged; protein (Fig. 3a). We obtained a huge amount of soluble recombinant; protein with an expected size (31 ku) (Fig. 3b) and purified the tagged; protein using Ni~(2+) affinity chromatography (Fig. 3c). Three ICR mice; were immunized to generate polyclonal antibodies against amphioxus BRA2; with purified recombinant protein (1.3 g/L). The enzyme-linked; immunosorbent assay (ELISA) showed that the titer of mouse; anti-amphioxus BRA2 antibody was 1︰256 000, with a high sensitivity; (Fig. 4a). Western blot experiments showed that the polyclonal antibody; could not only effectively identify recombinant protein (Fig. 4b) but; also recognized amphioxus BRA1 and BRA2 (Fig. 4c, Fig. 5a, b). In; conclusion, we successfully generated the mouse anti-amphioxus BRA; polyclonal antibody that would be a powerful molecular tool for further; investigating the function of Brachyury in amphioxus.国家自然科学基金项

Study on production of liquid hydrocarbon fuels from sorbitol and mannitol

在温和条件下研究了氢碘酸还原生物质基多元醇制备液体燃料的过程,使用气相色谱质谱仪(GC-MS)和红外光谱仪(FT-IR)分析了产物组成。结果表明,山梨醇和甘露醇为原料制备的液体产物中主要成分是C_(12)H_(16)、C_(12)H_(18)、C_(12)H_(20)、C_(12)H_(22)和C_(18)H_(26)等烃类物质。通过与碱的醇溶液反应将副产物碘代烷转化为烃,经旋转蒸发和减压蒸馏获得纯净的高碳烃产品。山梨醇、甘露醇以及二者混合物制备出的高碳烃的产率分别是81.1%、73.2%和77.3%。本研究获得的高碳烃产品是一种有前景的液体燃料,其含水量为0.1%,密度为0.83~0.84 g·mL~(-1),含氧量为2.0%~2.2%,热值均高于42 MJ·kg~(-1)。This paper describes the process of sorbitol and mannitol conversion to liquid heavier hydrocarbons via reduction with hydroiodic acid under mild reaction conditions. The compositions of the obtained products were analyzed using gas chromatography mass spectrometer( GC-MS) and Fourier transform infrared spectrometer( FT-IR). It is found that the products obtained from C6 polyols were mainly C_(12)H_(16),C_(12)H_(18),C_(12)H_(20),C_(12)H_(22) and C_(18)H_(26). The yields of heavier hydrocarbons from sorbitol,mannitol,and the mixture of sorbitol and mannitol were 81. 1%,73. 2%,and 77. 3%,respectively.To obtain pure hydrocarbon fuels,the obtained crude oil was treated with potassium hydroxide in an alcohol solution followed by rotary evaporation and vacuum distillation. The final liquid hydrocarbons obtained have a water content of 0. 1%,densities of 0. 83 ~ 0. 84 g·mL~(-1),oxygen content of 2. 0% ~2. 2%,and heating values > 42 MJ·kg~(-1) at room temperature,which is potentially a good transportation fuel for diesel replacement.国家自然科学基金项目(21276214

Study of Properties of Multi-Walled Carbon Nanotubes (MWCNTs) as Gas Chroma tographic Column Packing Material

将甲烷催化裂解法生产的经过纯化的多壁碳纳米管 (PMWCNTs)、活性炭、石墨化碳黑 (CarbopackB)分别填装成气相色谱填充柱 ,比较它们分离烷烃、芳香烃、卤代烃、醇、酮、醚、酯类的性能 .分别在PMWCNTs和CarbopackB上涂渍 5 % (w/w)的Carbowax 2 0M ,填装成气相色谱填充柱后 ,比较它们分离醇、酮、醚、酯、有机酸类的性能 .结果表明 ,PMWCNTs是一种性能优异的气相色谱固定相 .与相同比表面积的CarbopackB石墨化碳黑相比较 ,它有更强的保留能力 ,适合于分析沸点相对较低的化合物 ;具有更均匀的表面 ,表现为极性化合物亦可得到对称的峰形 ;理论塔板数较小 .此外 ,和CarbopackB一样 ,PMWCNTs涂渍 5 % (w/w)Carbowax 2 0M后可用来分离极性化合物 ,甚至是强极性的小分子有机酸The purified MWCNTs (PMWCNTs), prepared by catalytic decomposition of methane, activated carbon and graphitized carbon black (Carbop ack B) were used as gas chromatographic column packing materials. Their characte ristics of separation of aromatic hydrocarbons, alkanes, halogenated hydrocarbon s, ketones, ethers, esters and alcohols were compared. PMWCNTs and Carbopack B m odified with 5%(w/w) Carbowax 20M were also used as gas chromatographic col umn packing materials to separate ketones, ethers, esters, alcohols and organic acids for comparison of their separation properties. The results show that PMWCN Ts are excellent packing materials. Comparing to Carbopack B with the same surfa ce area, PMWCNTs has the following characteristics: having stronger retention ab ility, suitable for the separation of compounds with relatively low boiling poin ts, showing symmetric peaks for polar compounds due to its more homogeneous surf ace, having lower theoretical plate number. Similar to Carbopack B, PMWCNTs modi fied with 5%(w/w) Carbowax 20M can be used to separate polar compounds, even lower organic acids

单域抗体的研究和应用进展

传统IgG抗体分子一般由轻链和重链组成,轻链包含1个可变区(VL)和1个恒定区(CL),重链包含1个可变区(VH)和3个恒定区(CH1,CH2,CH3)。单域抗体(Single domain antibody,sdAb),是指缺失抗体轻链而只有重链可变区的一类抗体,因其分子量小,也被称为纳米抗体(Nanobody)。20世纪90年代,单域抗体最早在骆驼科动物中被发现,之后在护士鲨、大星鲨和鳐鱼等软骨鱼纲动物中也发现了类似的抗体。单域抗体虽然结构简单,但仍然可以达到与传统抗体相当甚至更高的与特异抗原结合的亲和力。相比于传统抗体,单域抗体具有分子量小、稳定性强、易于重组表达等优点。近年来在生物学基础研究和医学临床应用方面均备受关注并被广泛应用。文中将从单域抗体的结构特征、理化性质、筛选方法及其在生物医学领域的重要应用进展进行综述。国家自然科学基金(No.81672023)资助~

Function and application of surrogate and internal standard in environmental sample analysis

环境样品分析结果的准确与否关系到环境质量分析的准确度 ,没有可靠的数据质量控制方法 ,数据的可靠性就无从得到保证。国际上近年来广泛应用一种适用于环境样品中有机污染物分析的数据质量控制方法 ,其关键部分是替代物和内标物的使用。分析者能够准确地进行定量 ,并清楚地知道自己的分析数据是否符合要求。本文作者从实际工作出发 ,经过大量的验证 ,确定了计算公式 ,探讨了替代物和内标物的关系、它们的作用和应用。The accuracy of environmental quality analysis depends on the accuracy of analytical data. Lack of quality control method leads to unreliable data. The core part of data quality control in advanced laboratories is the application of surrogate and internal standard. Quality control is especially suitable for trace organic analysis of environmental samples. With quality control samples the analysts can determine the target analytes accurately and make sure the data reliability. The relative equations have been derived and explained in this paper. The relationship between surrogate and internal standard has been discussed. Research examples are given to show the function and application of these quality control samples

慢性乙型肝炎潜在治疗靶点和新药研发进展

尽管预防性疫苗显著减少了乙型肝炎病毒(hepatitis B virus,HBV)新发感染,但目前全球仍有超过2.4亿慢性HBV感染者,其中每年因HBV感染相关的终末肝病和肝癌引起的死亡人数高达68万。目前用于慢性乙型肝炎(chronic hepatitis B,CHB)治疗的抗病毒药物包括干扰素和核苷/核苷酸类似物两大类,但均难以实现理想的临床治疗终点,即乙肝表面抗原(HBsAg)阴转或血清学转换。针对CHB患者尚未被满足的巨大医疗需求,国内外团队正在针对HBV生活周期的各个关键步骤以及潜在的宿主因子,尝试研发更为有效的CHB治疗药物,本文简要综述了当前处于临床开发阶段以及部分临床前阶段的CHB候选药物研发进展

Progress on development and application of coagulants and flocculent in water and wastewater treatment

分三部分论述了 90年代以来国内外混凝剂和絮凝剂研究的主要进展 :1 )混凝、絮凝的微观机理及其行为的研究成果和实验研究手段 ;2 )混凝剂和絮凝剂的开发 ;3)混凝和絮凝方法在废水处理中的净化效率的提高、条件优化和在线监控等。s:The recent development of coagulants and flocculent was reviewed.Three topics were discussed:(1)Mechanisms of coagulants and flocculent,and the experimental methods of process study;(2)Development of coagulants and flocculent;(3)Researches on improvement of coagulants and flocculent efficiency,process optimization and on line monitoring and controlling as well.厦门市科委夕阳红基金会资

Preparation of inorganic coagulants from waste stone powder and its effects of turbidity removal

利用废石粉渣制备无机混凝剂，并研究所得初产品对硅藻土悬浮液和受污湖水样品进行处理的适宜操 作条件以及除浊净水效果。结果表明，利用某些废石粉值制备的混凝剂有较好效果，但制备工艺有待改善。In order to recover coagulation-effective substances from waste stone powder, some inorganic coagulants were prepared from waste stone powder.Then the effects of the prepared coagulants on turbidity removal from polluted lake water and diatomile suspended solution were tested, some parameters, such as dosage and pH, were also studied.The results showed that the coagulants had good effects on turbidity removal.厦门市夕阳红科学基

Research progress in separation of bio-oils by extraction methods

综述了国内外采用萃取技术分离生物油的研究进展,包括水萃取、有机溶剂萃取、络合萃取、超临界萃取、柱层析萃取等,总结了这些萃取方法的优点和缺点。指出可通过对生物质热解过程本身进行改进,如对原料进行预处理、引入催化剂进行催化热解、对热解蒸汽进行分级冷凝等,以获得富含目的产物组成的生物油,为萃取分离提供便利。最后,建议尝试一些新的萃取分离方法,如微波萃取和超声波萃取等,考察对生物油萃取分离的有效性。The recent progress in separation of bio-oils by extraction worldwide was reviewed,and specifically,the extraction with water,extraction with organic solvents,reactive extraction,supercritical extraction,and extraction-column chromatography were discussed.The advantages and drawbacks of aforementioned extraction methods were summarized.Improvements in biomass fast pyrolysis itself,such as pre-treatment of feedstocks,pryolysis with catalysts,or multi-stage condensation of pyrolysis-vapor should be attempted to obtain bio-oils rich in target components to facilitate separation of bio-oils by extraction.New extraction methods,such as microwave extraction and ultrasonic extraction may be investigated to examine their effectiveness for bio-oils separation