多肽配基亲和吸附介质的配基密度控制规律

以谷胱甘肽为配基,琼脂糖微球为骨架,探索将谷胱甘肽通过共价键偶联到琼脂糖微球骨架上,制备可以分离谷胱甘肽S转移酶(Glutathione S-transferase, GST)及以其为标签的融合蛋白的亲和吸附介质.采用正交实验方法考察了谷胱甘肽加入量、偶联缓冲液的pH值和反应温度对亲和介质配基密度的影响.结果发现,该反应过程中的pH值对配基密度影响最大,其次为谷胱甘肽的加入量.用所制备的亲和吸附介质纯化GST(大鼠肝脏谷胱甘肽S转移酶),发现GST的吸附量随配基密度增加而增加,但GST活性却随配基密度的增加而下降,较好的干胶配基密度为260 μmol/g.大鼠肝匀浆液经过离子交换和亲和层析两个步骤,获得了电泳纯的GST,比活力为12.08 U/mg,总活性回收率为40%以上.     

高温氢气处理对活性炭及钯炭催化剂性能的影响

采用高温氢气对不同活性炭进行处理,并分别采用比表面分析仪(BET)、红外光谱(IR)、氩气-程序升温脱附实验(Ar-TPD)和热重分析(TGA)对高温氢气处理前后的活性炭进行表征.结果表明,高温氢气处理对活性炭的孔结构和比表面影响较小,高温氢气处理后活性炭表面含氧官能团含量降低.以高温氢气处理后的活性炭为载体制备钯炭催化剂,催化剂上的钯的分散度降低,在粗对苯二甲酸精制反应中的初活性下降.     

Linear adsorption of nonionic organic compounds from water onto hydrophilic minerals: silica and alumina

To characterize the linear adsorption phenomena in aqueous nonionic organic solute-mineral systems, the adsorption isotherms of some low-molecular-weight nonpolar nonionic solutes (1,2,3-trichlorobenzene, lindane, phenanthrene, and pyrene) and polar nonionic solutes (1,3-dinitrobenzene and 2,4-dinitrotoluene) from single- and binary-solute solutions on hydrophilic silica and alumina were established. Toward this objective, the influences of temperature, ionic strength, and pH on adsorption were also determined. It is found that linear adsorption exhibits low exothermic heats and practically no adsorptive competition. The solute-solid configuration and the adsorptive force consistent with these effects were hypothesized. For nonpolar solutes, the adsorption occurs presumably by London (dispersion) forces onto a water film above the mineral surface. For polar solutes, the adsorption is also assisted by polar-group interactions. The reduced adsorptive forces of solutes with hydrophilic minerals due to physical separation by the water film and the low fractions of the water-film surface covered by solutes offer a theoretical basis for linear solute adsorption, low exothermic heats, and no adsorptive competition. The postulated adsorptive forces are supported by observations that ionic strength or pH poses no effect on the adsorption of nonpolar solutes while it exhibits a significant effect on the uptake of polar solutes.     

An effective and green method for the extraction and purification of aglycone isoflavones from soybean

In this paper, an effective and green strategy was developed to obtain aglycone isoflavones from soybean through the extraction, hydrolysis, and purification steps. Firstly, a novel ethanol-alkaline extraction method was designed and optimized. The high extraction yield (94.34%) of isoflavones was achieved under the optimal extraction conditions of pH 9.0, 70°C, 60 min, ethanol concentration of 65%, and 1:15 of the solid to liquid ratio. Then, the cellulase (GC-220) was used instead of traditional β-glucosidase to hydrolyze the glycoside isoflavones into aglycone isoflavones which gave an excellent conversion of 95%. Finally, the crude aglycone isoflavones have been purified by an environmental-friendly procedure comprised of ethanol precipitation, ethyl acetate extraction, and water rinse. The final amount of aglycone isoflavones obtained was 1.279 mg for every gram of defatted soybean by this strategy, and the final recovery, and purity of aglycone isoflavones could achieve 80.38 and 87.21%, respectively.     

明清山东盐业史的一部力作——评纪丽真博士的《明清山东盐业研究》

<正>山东省是我国东部沿海省市之一,拥有丰富的海洋资源,自古及今,颇享渔盐之利。在山东的历史发展中,尤其是明清两代,留下了丰富的盐业文     

1 株水开菲尔粒中植物乳杆菌的鉴定及产细菌素基因分析

目的：对从水开菲尔粒中分离得到1 株能产生抑菌物质的菌株QF01进行菌种鉴定,并对其产细菌素进行实验、鉴定和基因序列分析。方法：通过牛津杯法测定抑菌能力,采用聚合酶链式反应（polymerase chain reaction,PCR）扩增16S rDNA和细菌素相关基因并测序,利用ProParam tool、TMHMM 2.0、InterProScan、SOPM和SWISS-MODEL在线软件对基因编码产物进行分析。结果：该菌株产的细菌素对大肠杆菌（Escherichia coli JM109）有明显的抑制作用,通过16S rDNA序列分析初步确定该菌株属于植物乳杆菌（Lactobacillus plantarum）。该菌株含有plnD、plnEF、plnV、plnR四种基因,其中plnV基因编码产物有跨膜螺旋结构,其结构存在信号肽特征。此外,从三级结构的模型预测得到4?种基因的编码产物均存在α-螺旋、β-转角、伸展链和无规则卷曲。结论：从水开菲尔粒分离得到的L. plantarum QF01菌株,含有plnD、plnEF、plnV、plnR细菌素基因,对大肠杆菌有很好的抑制作用。     

直接苛化的超高浓黑液气化工艺

汤姆林逊(Tomlinson)回收炉应用于硫酸盐浆厂化学品的回收已有很多年的历史.该工艺经过多年的发展革新后仍然有一些明显的缺点,其一是存在熔融物与水接触发生爆炸的危险,其二是由于化学上的原因,硫化物和碳酸钠总是按一定的比例从燃烧炉以熔融物的形式排出.     

0癌症进展Oncology Progress5R-5E0546E

ieved in the study of gynecological cancers,early diagnosis,early treatment and valid recognition of precancerous stage are still the priority of therapy.The standardization of treatment on gynecological cancers remains to be generalized and the surgeries are prone to be humanize and individuate.The technique of clinical treatment should be based on evidence-based medicine and cooperation of multi-ceneri和L.hilgardii无法加以区分,但是仍有助于将未知杆菌归入这一群。     

软包装榨菜的超高压杀菌工艺研究

采用正交试验设计研究了超高压处理对榨菜杀菌效果以及理化指标的影响。结果表明,超高压工艺对榨菜的脆度影响很小,杀菌的优化工艺条件为:压力300 MPa,保压时间为20 min,中盐(8.5%)可以有效杀灭微生物,防止胖袋并且大肠菌群小于30个。     

英《糖业文摘》主题词表、作者索引和引用中国期刊的研究

对英国出版的《糖业文摘》（ＳｕｇａｒＩｎｄｕｓｔｒｙＡｂｓｔｒａｃｔｓ）的主题词表、作者索引和引用中国期刊做了初步的研究,介绍了它们的编排特点,提出了我国科技期刊尤其是糖业期刊要创造条件争取进入该刊检索范围的建议