反相色谱法分离十二烷基硫酸钠溶液中的蛋白质

探讨了十二烷基硫酸钠(SDS)溶液溶解的牛血清白蛋白(BSA)及溶菌酶(Lys)在反相色谱(RPC)上的保留行为及分离效果.结果表明:蛋白质在反相色谱上的分离明显受到样品液中的SDS浓度及蛋白质自身理化性质的影响,但通过改变流动相条件能够去除蛋白质溶液中的SDS,实现蛋白质在反相色谱上的分离.该方法为分离纯化SDS处理的蛋白质提供了新的途径,有较大的应用价值.     

超氧化物歧化酶吸附分离-化学修饰的耦合过程

以超氧化物歧化酶(supcroxide dismutase,SOD)为模板蛋白,将其分离纯化过程和修饰过程耦合起来,从而获得比活更高、稳定性更好的修饰SOD.将SOD选择性地吸附在DEAE-52层析柱和铜离子螯合葡聚糖凝胶柱上,先不经洗脱分离,直接用活化的聚乙二醇(PEG)5000对吸附在柱上的SOD进行化学修饰,再通过特异性洗脱分离获得PEG-SOD,使SOD分离纯化和修饰过程同步完成.SOD通过离子交换吸附层析-PEG修饰耦合过程和金属螯合层析-PEG修饰耦合过程,所得的PEG-SOD比活力分别为9638.0 U/mg和9067.8 U/mg,纯化倍数分别为1.87倍和1.755倍,氨基修饰率分别为35.3%和40.9%.结果表明SOD的分离纯化-化学修饰耦合过程是可行的,且金属螫合层析-修饰耦合过程的效果要优于离子交换吸附层析-修饰耦合过程.     

L-精氨酸/L-赖氨酸改性大豆分离蛋白乳化性

在质量浓度为20 g/L大豆分离蛋白(SPI)中分别加入终质量浓度分别为1、3 g/L的L-精氨酸(L-Arg)和L-赖氨酸(L-Lys),以不加氨基酸、仅调节与上述溶液对应相同pH的样品为处理对照,制备水包油型(O/W)乳状液.通过物化手段及光谱技术表征SPI结构、溶液的物化性质和乳化性能以及乳状液的微观结构.结果表...     

石榴叶超氧化物歧化酶的纯化及性质研究

利用有机溶剂分级沉淀法从石榴叶中分离出超氧化歧化酶(SOD),研究了分离纯化的最佳工艺条件,并对其性质进行了探讨。结果表明,当石榴叶(g)与磷酸缓冲液(mL)之比为1∶2,磷酸缓冲液pH值为7.6,提取时间为1.5 h。氯仿-乙醇混合物量为提取液的0.25倍,丙酮量为粗酶液的1倍时,分离效果最佳。温度0~60℃,pH 4~9范围内酶的活性稳定。过氧化氢和乙醇-氯仿试验表明,该酶属Cu.Zn-SOD。研究结果为SOD提供了新的酶源。     

表面活性剂与耐热超氧化物歧化酶混合溶液的储存稳定性

通过考察表面活性剂-耐热超氧化物歧化酶TcSOD混合溶液在不同储存时间、不同复配组合、不同储存温度、不同质量分数、不同pH条件下的SOD保留活性,研究了表面活性剂对TcSOD储存稳定性的影响。90 d储存的结果表明,无论是30还是45℃,单一表面活性剂鲸蜡硬脂醇聚氧乙烯(25)醚(A25)、单硬脂酸甘油酯(GMS)、椰油酰胺丙基二甲基甜菜碱(CAB)以及复配表面活性剂脂肪醇聚氧乙烯醚硫酸钠(AES)或十二烷基硫酸钠(K12)+GMS,AES或K12+N-月桂酰谷氨酸钠(SG)对混合溶液SOD保留活性的影响最小;高温储存是加速多数混合溶液TcSOD失活的协助因素;与离子型表面活性剂相比,混合溶液的SOD保留活性随非离子型表面活性剂质量分数增加而显著下降;非离子型表面活性剂-TcSOD混合溶液SOD保留活性峰值出现在pH=6,阴离子型和两性离子型表面活性剂-TcSOD混合溶液SOD保留活性在pH=6～8时较高。     

加压精馏分离乙二醇二甲醚/异丙醇工艺研究

在制药工业药物合成的工艺路线中产生了含水的乙二醇二甲醚(DMEN)-异丙醇混合溶液,环保和工艺均要求对其进行分离。从热力学原理分析了DME和异丙醇的性质,通过化工模拟软件PROII对分离含水的DMEN-异丙醇混合液的加压精馏进行了模拟研究。分析各个因素对分离效果的影响,得到了含水(1.0%)的DMEN-异丙醇混合液的加压精馏优化工艺条件:精馏塔的理论塔板数为50,原料进料位置为第30块理论板,回流比为4,操作压力为6 atm。在该工艺条件下,分离得到的DME质量分数可达到98.53%,异丙醇的质量分数可达到97.52%。同时,对生产过程混合溶液中水含量的不同对DMEN-异丙醇分离的影响进行了研究。     

极端酸碱pH偏移改善白果蛋白溶解性和乳化性

以白果种子为原料提取蛋白,研究其分离蛋白经历极端酸性(pH 2.0、3.0、4.0)和极端碱性(pH 10.0、11.0、12.0)偏移处理2 h后、再将pH恢复至中性后的溶解性和乳化性.基于0.5 mol/L NaCl溶液体系,采用物理化学分析、光谱技术及电泳技术等手段表征白果分离蛋白的水化性质、分子组分和结构修饰以...     

PVA/PVP共混交联膜对2-甲基四氢呋喃溶液渗透汽化脱水的研究

利用共混交联法将马来酸酐(MAH)加入聚乙烯醇(PVA)和聚乙烯吡咯烷酮(PVP)混合溶液中制备PVA/PVP膜.考察了膜的组成、料液中水质量分数和温度对渗透汽化分离性能的影响.结果表明,在V(PVA):V(PVP)= 8:2、水质量分数为3.9％的2-甲基四氢呋喃(2-MeTHF)溶液和最佳温度为68℃条件下,渗透通...     

硫酸铵-碘化钾-十二烷基三甲基溴化铵-水体系浮选分离镉(Ⅱ)的研究

研究了硫酸铵一碘化钾-十二烷基三甲基溴化铵-水体系浮选分离镉(Ⅱ)的行为及其与常见离子分离的条件.结果表明,当固体(NH4)2SO4用量为1.0g,0.10mol/L碘化钾溶液和5.0×10-3mol/L十二烷基三甲基溴化铵(DTAB)溶液的用量均为1.0mL时,体系中形成的不溶于水的三元缔合物(DTAB)2(Cdl4)可浮于盐水相上形成界面清晰的两相,从而Cd2 被定量浮选,而Zn2 、Mn2 、Ni2 、Co2 、Fe2 、Al3 等在此条件下不被浮选,实现了Cd3 与这些离子的定量分离,据此建立了浮选分离镉(Ⅱ)的方法.该方法对合成水样中微量镉进行了定量浮选分离,浮选率为97.1%～103.0%.     

己酰酯化羧甲基淀粉的制备及粘度性质研究

以羧甲基淀粉(CMS)为原料,己酰氯为酯化试剂,二甲基亚砜(DMSO)为溶剂,吡啶为有机碱合成了己酰酯化羧甲基淀粉(HCMS)。研究了反应温度、反应时间、催化剂用量、溶剂用量对己酰酯化取代度(DS)和反应效率(RE)的影响,确定了最佳反应条件为:5 g CMS,40 mL DMSO,反应温度为50℃,反应时间为30 min,有机碱用量为1.0 g。通过IR、流变仪对产物进行了结构及溶液黏度性质研究。通过对不同质量分数和己酰酯化取代度(DShexyl)的羧甲基淀粉溶液黏度性质(剪切速率0～500 s-1)的研究表明,达到临界聚集质量分数2.0%时,适当己酰基取代度(DShexyl=0.3)的HCMS,可以使羧甲基淀粉溶液的黏度由420 mPa.s提高到34 000 mPa.s(γ=5 s-1)。     

黑泥对小鼠皮肤胶原蛋白和毛发生长的影响

研究黑泥对小鼠皮肤和毛发生长的作用。将黑泥涂抹于小鼠脱毛皮肤部位,观察涂抹部位毛发生长情况,35d后取涂抹部位皮肤,测定SOD活性、胶原蛋白和丙二醛量,扫描电镜观察毛发表面结构。结果表明：黑泥能明显增加小鼠皮肤中胶原蛋白的量,提高皮肤中SOD的活性,有降低皮肤中丙二醛量的趋势,促进毛发生长,增加毛发表面光滑度。黑泥具有延缓皮肤衰老、促进毛发生长和提高毛发质量的作用。     

Sensitive and molecular size-selective detection of proteins using a chip-based and heteroliganded gold nanoisland by localized surface plasmon resonance spectroscopy

A highly sensitive and molecular size-selective method for the detection of proteins using heteroliganded gold nanoislands and localized surface plasmon resonance (LSPR) is described. Two different heteroligands with different chain lengths (3-mercaptopionicacid and decanethiol) were used in fabricating nanoholes for the size-dependent separation of a protein in comparison with its aggregate. Their ratios on gold nanoisland were optimized for the sensitive detection of superoxide dismutase (SOD1). This protein has been implicated in the pathology of amyotrophic lateral sclerosis (ALS). Upon exposure of the optimized gold nanoisland to a solution of SOD1 and aggregates thereof, changes in the LSPR spectra were observed which are attributed to the size-selective and covalent chemical binding of SOD1 to the nanoholes. With a lower detection limit of 1.0 ng/ml, the method can be used to selectively detect SOD1 in the presence of aggregates at the molecular level.     

Competitive foam separation of rare earth elements from aqueous solutions using a cationic collector

ABSTRACT

Competitive foam separation of two rare earth elements (REEs), Eu(III) and Tb(III), are investigated in this study in presence of ethylenediaminetetraacetic acid (edta) using cetylpyridinium chloride (CPC). The effects of pH, [edta]/Σ[REEs] and [CPC]/[edta] molar ratio, frother concentration, ionic strength and air-flow rate on the foam separation efficiency are also evaluated. At the optimal experimental condition, Eu(III)/Tb(III) separation factor of 141.56 is obtained. The kinetic data obtained at all the studied parameters are analyzed by the flotation first-order and second-order kinetic models. Eventually, a schematic flow-sheet for Eu(III)/Tb(III) separation is proposed.     

Mn-SOD的纯化方法研究

以嗜热芽孢杆菌B．S110—2所产Mn—SOD为研究对象,对其纯化方法进行了研究,用碱处理的方法替代了传统的硫酸铵分级沉淀蛋白的方法;通过对金属螯合层析中二价金属离子的选择及洗脱液pH的选择,初步建立了一套适合分离纯化Mn-SOD的金属螯合层析体系,为实际生物产品的分离奠定了基础。     

Floe Foam Flotation of Chromium(VI) with Polyelectrolytes

Abstract

The separation efficiency of the floe foam flotation of chromium(VI) with Fe(II) from aqueous solutions with high ionic strength can be improved by adding a very small amount of polyelectrolyte (either cationic or anionic polymer) as an activator. The possible mechanisms by which flotation is affected by polyelectrolytes are discussed. The effects of the order of the addition of the reagents (polyelectrolyte and base) on flotation and sedimentation are also studied. It was found that effective separation of chromium(VI) by floe foam flotation with Fe(II) can be achieved for a rather wide range of initial chromium(VI) levels by using the same treatment parameters.     

Separation characteristics of acetic acid–water mixtures using poly(vinyl alcohol‐g‐4‐vinyl pyridine) membranes by pervaporation and temperature difference evapomeation techniques

The separation of acetic acid–water mixtures was carried out using pervaporation (PV) and temperature difference evapomeation (TDEV) methods. For the separation process, 4‐vinyl pyridine was grafted on poly(vinyl alcohol). Membranes were prepared from the graft‐copolymer by casting method and crosslinked by heat treatment. The effects of feed composition on the separation characteristics were studied and the performances of the separation methods were compared. Permeation rates were found to be high in PV whereas separation factors were high in TDEV method. Membranes gave permeation rates of 0.1–3.0 kg/m²h and separation factors of 2.0–61.0 depending on the composition of the feed mixture and the method. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1385–1394, 2006     

多元素专用肥对油松幼苗几种酶活性影响的研究

对3年生油松幼苗4种不同施肥处理下超氧化物歧化酶活性、过氧化物酶活性和多酚氧化酶活性的动态变化进行了测定,探讨了施肥对上述3种酶活性的影响及其机理。结果表明,多元素油松专用肥明显提高超氧化物歧化酶活性和过氧化物酶活性,对增强油松的抗性有重要作用;而对多酚氧化酶活性影响则不甚明显。     

A Comparative Study on the Separation of Different‐Shape Particles Using a Mini‐Hydrocyclone

The separation efficiency from water of different‐shape particles was studied experimentally using a mini‐hydrocyclone. Spherical and flaky (plate‐like) aluminum particles with the same particle size distributions were employed. Also, the effects of the feed flow rate and the temperature on the separation performance were studied. The results were investigated in terms of slurry recovery, total efficiency, and partition curves. The separation efficiency of the spherical particles increased with increasing particle size, temperature, and feed flow rate, as expected. The fishhook effect, as a noticeable phenomenon, was observed for the spherical particles. In case of the flaky particles, the separation showed an unusual behavior: The separation efficiency decreased with increasing particle size in the largest particle fraction, which has so far not been reported and addressed in this way.     

Effect of filler concentration on the phase separation in poly(vinyl acetate)-poly(methyl methacrylate) mixtures

The temperatures and kinetics of phase separation have been studied as a function of filler concentration in a polymer mixture of poly(vinyl acetate)-poly(methyl methacrylate). The filler was shown to have a marked effect on the cloud point position and the phase separation kinetics at various temperatures. The effects observed are dependent upon the component ratio.     

Sodalites as ultramicroporous frameworks for hydrogen separation at elevated temperatures: thermal stability, template removal, and hydrogen accessibility

Sodalite (SOD) is a highly promising porous structure for hydrogen separation from larger gas molecules due to the presence of small (～2.8 Å) six-membered ring openings of the sodalite cages. Thermal stability, template removal, and the release of encapsulated hydrogen were studied for low-silica (Si/Al = 1), high-silica (Si/Al = 5) and pure-silica (Si/Al = ∞) sodalites. The release of encapsulated hydrogen from sodalite cages was observed at 380, 550, and 480 °C for low-silica, high-silica and pure-silica sodalites, respectively, suggesting the operating temperatures for hydrogen separation employing these sodalite structures.