Insight into Hydrolytic Stability and Tribological Properties of B-N Coordination Tung Oil-Based Lubricant Additive in Water

A tung oil-based boron-nitrogen coordination polymer(TWE-BN)was specially designed and synthesized as a highly efficient water-based lubricant additive,which has been beneficial to both energy conservation and conducive to environmental protection.Its hydrolysis stability and tribological properties in water were investigated.To better research the lubricating properties,and thus to understand the interaction between the surface and the lubricating additives.Herein,both experimental and theoretical computations based on density functional theory(DFT)were performed.The addition of TWE-BN reduces the water friction coefficient and wear scar diameter,and the maximum non-seizure load increased from 93 to 726 N.Moreover,the anti-corrosion ability on copper was classified as 1b level.The stainless-steel surface was analyzed using scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).In hydrolytic stability testing,TWE-BN was better than nitrogen-free tung oil-based lubricant additive(TWE-B)and remained non-hydrolyzed for at least 15 days,implying the feasibility of tung oil-based boron-nitrogen coordination as highly effective and hydrolytic stability lubricant additives.

内蒙古地区传统发酵酸马奶不同发酵时期乳清蛋白SDS-PAGE分析

[目的]探究内蒙古地区传统酸马奶发酵过程中乳清蛋白的变化情况。[方法]以从内蒙古锡林郭勒盟镶黄旗采集的马奶为原料制备传统发酵酸马奶,发酵温度为(22±2)℃,人工捣拌频率5次/d,每次300下;每隔12 h采集1次发酵0~96 h的酸马奶样品;离心提取酸马奶乳清蛋白样品,利用条件优化后的SDS-PAGE电泳技术分析酸马奶乳清蛋白在发酵过程中变化情况。[结果]优化后的SDS-PAGE电泳分析条件为:分离胶浓度12%,浓缩胶浓度5%,分离胶电泳电压180 V、电泳时间300 min,上样浓度0.5μg/μL,上样体积16μL,改良考马斯亮蓝法染色、脱色各12 h。在发酵0~12 h内,酸马奶乳清蛋白含量增加,在12 h时达到最高值(5.12μg/μL),之后随发酵时间延长呈下降趋势,发酵96 h时降低至3.92μg/μL。SDS-PAGE电泳图谱分析显示,在分子量10~70 kDa区间内共获得乳清蛋白有效条带13个。在发酵过程中,β-乳球蛋白、溶酶菌C和α-乳白蛋白3种蛋白质含量呈现不同程度的波动,发酵72 h时三者含量之和最高,占乳清蛋白总含量的85.73%,并且在发酵过程中始终保持较高水平,是传统发酵酸马奶发酵96 h内乳清蛋白的主要组分,其中,β-乳球蛋白含量最高,平均占乳清蛋白总含量的38.92%。分子量在20~40 kDa的酪蛋白含量在发酵24 h之后开始下降,至60 h时条带消失。分子量为10.33 kDa的蛋白质在发酵12 h内被消耗,60 h时再次出现且含量随发酵时间延长逐渐增加,在84 h时达到峰值,占乳清蛋白总含量的9.84%。分子量为49.80 kDa的蛋白质在发酵72 h之后开始出现,含量在96 h时达到乳清蛋白总含量的4.11%。与其他乳清蛋白组分相比,β-乳球蛋白和免疫球蛋白含量在发酵过程中变化较小。[结论]内蒙古地区传统发酵酸马奶在发酵96 h内,分子量为10~70 kDa的乳清蛋白含量表现出有规律的消长,主要被消化分解的蛋白质是酪蛋白。不同发酵阶段酸马奶乳清蛋白组成及含量存在一定差异,但原有主要组分β-乳球蛋白、溶酶菌C和α-乳白蛋白始终保持较高水平。自发酵中期开始,酸马奶乳清蛋白中相对分子质量较小的肽(10.33 kDa)所占比例逐渐升高,由此可见,传统发酵酸马奶中不仅保留马奶中乳清蛋白原有的营养价值,而且通过发酵还增添了易吸收的小分子量蛋白质。

SDS-PAGE凝胶电泳对驴皮胶及常见伪品胶中的蛋白分析研究

目的:研究驴皮胶及常见伪品胶马皮胶和牛皮胶的蛋白凝胶电泳行为。方法:自制3种皮胶,计算出胶率,BCA蛋白浓度测定试剂盒测定其蛋白含量,计算上样量,使上样量为20~30μg。垂直电泳仪进行SDS-PAGE凝胶电泳,采用考马斯亮蓝及银染法显色。结果:3种皮胶的凝胶电泳行为相似,蛋白成分主要集中在分子量大于25 kDa段上,银染法灵敏度更高,可显示较多条带。结论:3种皮胶分子量分布宽泛,具有共同的条带,进一步可用多肽蛋白质谱鉴定技术对各混合物组分进行更深入分析。

Effects of Lanthanum on Hydrolytic Enzyme Activities in Red Soil

The effects of La on some hydrolytic enzyme activities in red soil were studied in incubation and pot culture experiments. In the incubation experiment, La slightly stimulates the activities of urease and acidic phosphatase in soil and strongly stimulates sucrase activity in soil. In the pot culture experiment, La stimulates the activities of urease, acidic phosphatase and sucrase to different degrees. The stimulative effects of rare earth elements (REE) on hydrolytic enzyme activities in soil may result in increasing yield of crops.

Hydrolytic Degradation Study of Lansoprazole, Identification, Isolation and Characterisation of Base Degradation Product

Lansoprazole degradation is accelerated in both acidic and basic medium in water. The present investigation deals with the hydrolytic degradation of Lansoprazole. Acidic medium degradation show all known impurities and degradation products whereas basic degradation studies show new impurity which has higher molecular weight than Lansoprazole. New impurity was identified, isolated using mass based auto purification system and characterised by 1H NMR, 13C NMR, HMBC, HSQC, NOE, COSY and HRMS experiments. Isolated impurity was showing molecular weight of 467.10, molecular formula of C23H16F3N5OS and its name is 7-(3-Methyl-4-(2,2,2-trifluoroethoxy) pyridin-2-yl)-7H-benzo[4,5]imidazo[2,1-b]benzo[4,5]imidazo[2,1-d][1,3,5]thiadiazine.

Preliminary Study on the Performance and Interaction of Recycling Hydrolytic-Aerobic Combined Process of High Concentration Starch Wastewater

A new recycling hydrolytic-aerobic combined process was developed to treat the high concentration organic wastewater. Simulated wastewater containing 10 g·L^-1 starch with a CODcr value of 10000 mg·L^-1 wasused. At first, the hydrolytic degradation and aerobic degradation process were examined in two batch reactors, respectively. In the stand-alone hydrolytic process, starch in the wastewater almost disappeared after 11 h treatment, but CODCr remained as high as 5803mg·L^-1 after two days. In the aerobic process, the biodegradation rate of starch was much slower during the first 11 h than that in the hydrolytic process, although the CODCr removal efficiency reached 89.6% and more than 90% starch could be degraded after 37.5 h. To determine the interaction effects of the two processes, a series of hydrolytic-aerobic combinations were examined in details. Hydrolytic process played an important role in the whole recycle combination process as it could improve the biodegradability of the high concentration starch wastewater. However, from the other experiments, the negative effect of hydrolytic acidification was found in the hydrolytic-aerobic combination, which suggested that the aerobic microorganisms needed time to adapt themselves to the acidic environment. The effect of the degrading time, which was spent in the hydrolytic and aerobic unit, and the number of circulations, with which the wastewater went through the two units were investigated. It was found that a recycle combination of 6 h hydrolytic process with 12 h aerobic process was highly effective and potentially economical, in which the final removal efficiency of CODcr and efficiency of starch degradation reached 94.1% and 98.8%, respectively.

Studies of artificial Hydrolytic metalloenzymes The catalytic carboxyester hydrolysis by novel nucleophile containing phenolic pendant macrocyclic polyamines

Zinc(II) complexes of new macrocyclic tetraamines (cyclam derivatives) having a strategically appended phenolate group, have ben examined as catalyst for the hyd rolysis of 4nitrophenyl acetate(NA). It ovas proven that coordinated phenolate can serve as a good nucleophile that efficiently catalyze 4-nitrophenyl acetate(NA) hydrolysis.

Sponge-associated bacteria of Lakshadweep coral reefs, India: resource for extracellular hydrolytic enzymes

Sponges (Phylum: Porifera) is one of the major groups in the Lakshadweep coral reefs. These sponges harbor diverse bacteria with metabolic potentiality. From biodiversity to biotechnological prospecting, scientific investigations related to sponge associated microorganisms have expanded, but remain rather limited to few geographic locations. In this study, culturable bacteria associated with two demosponges viz Dysidea granulosa, Sigmadocia fibulata and the ambient water were screened for commercially important enzymes such as amylase, protease, gelatinase, lipase, deoxyribonucleic, phosphatase and urease. Amylase and phosphatase were the predominant enzymes produced by >80% of sponge-associated bacteria compared to the ambient water. Nearly 50% of the sponge-associated bacteria expressed multiple enzymatic activities (> 4) with variation in the percentage of expression of individual enzymes. More than 65% of the culturable heterotrophic bacteria associated with sponges were Gammaproteobacteria. The order Vibrionales was the main source for multiple enzyme production. Sponge associated bacteria formed more closely related clusters than the water isolates based upon their activity pattern. High recovery of sponge-associated bacteria with multiple enzymatic activities suggest that these versatile bacteria are yet unexploited potential for bioprospecting.

Comparative Analysis of Hydrolytic Amino Acids in Human and Cow Milk of Different Lactation Periods

In this study,the hydrolytic amino acids of Chinese human and Holstein cow milk of different lactation periods were analyzed by the advanced isobaric tags for relative and absolute quantitation(iTRAQ)combined with the high performance liquid chromatography-mass spectrometry(HPLC-MS/MS)approach.The total contents of the hydrolytic amino acids in cow colostrum,cow mature milk,human colostrum and human mature milk were 5.00,4.38,2.12 and 2.48 g·L^(-1),respectively.Among these,the contents of the hydrolytic amino acids in cow milk were higher than those in human milk,indicating a decreasing trend with the prolongation of lactation.Additionally,principal component and hierarchical cluster analyses were used to further screen the differentially expressed amino acids.These results enhanced the understanding of the hydrolytic amino acids in cow and human milk across different lactation periods,which could provide potential directions for newborn dairy powder and nutritious supplementary.

Optimization of the Production of Biogas in Anaerobic Digestion by the Addition of Hydrolytic Microorganisms

It is well known that fossil fuels are one of the major pollutants that contribute to climate change and there is a need to develop alternatives to their uses.One option is the use of a renewable fuel such as biogas obtained from the breaking down of organic matter in the anaerobic digestion process.When biogas is cleaned up to a certain quality,it can substitute the use of natural gas.However,this slow process requires optimization to increase the amount of gas.There are chemical,physical and biological treatments for organic matter to increase the amount and quality of biogas.In the former research,a biological treatment was tested by adding a selection of microorganisms that showed hydrolytic activity to an anaerobic digester for its optimization.First,a selection of microorganisms with the ability to grow in fresh sewage sludge as only nutrient was selected.Then,the lipolytic,cellulolytic and PA(Proteolytic Activity)of microorganisms was tested using selective growth media.Finally,10 samples with the greatest hydrolytic activity were used to evaluate their effects in the increasing of biogas production in the anaerobic process.The results showed that 83%of the microorganisms with the ability to grow in sewage sludge were proteolytic,while the percentage of lipolytic and cellulolytic microorganisms was smaller.Furthermore,it was found that proteolytic microorganisms are the ones that increase biogas yield in a maximum of 80%with a COD(Chemical Oxygen Demand)reduction of 58%.

Synthesis, Characterization and Crystal Structure of a New Schiff Base Ligand from a Bis(Thiazoline) Template and Hydrolytic Cleavage of the Imine Bond Induced by a Co(II) Cation

The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H2L (1). Characterization of the ligand was performed by FT-IR, 1H NMR, 13C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO3)2·6H2O and CuCl2·2H2O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.

A New Metallomicelle with Hydrolytic Metalloenzymatic Activity

A new metallomicelle, formed by Cu2+ Or Zn2+ ion and N-tetradecyl-2-(N-2-hydroxyethyl aminomethyl) imidazol in the presence of cetyltrimethylammonium bromide, was found to possess remarkable catalytic activity to the hydrolysis of p-nitrophenyl picolinate.

Effects of thermally modified green tea catechins on the oxidative and hydrolytic stability of butter

Green tea catechins are classified as (-)-epi-forms (2R, 3R) or (-)-forms (2S, 3R) with respect to stereoisomerism. The (-)-forms (2S, 3R) in catechin preparations obtained from green tea amounts to approximately 10% of total catechins, whereas the other 90% are (-)-epiforms (2R, 3R). High temperature induces the conversion of (-)-epiforms (2R, 3R) to (-)-forms (2S, 3R). This study investigated the effect of catechin prepa-rations containing 10, 20 and 30% (-)-forms (2S, 3R) on the oxidative and hydrolytic stability of butter. For comparison, butter with δ-tocopherol and BHT and butter without stabilizer were analysed. Butter stability was examined under conditions of refrigeration (8 oC) and freezing (-22 oC) and at temperature of 50 oC and 100 oC. Catechin preparations were more efficient butter stabilizers than BHT and δ-tocopherol. Thermal modification of catechins that led to the genera-tion of 20% of (-) forms (2S, 3R) improved their antioxidative efficacy, but longer treatment lead- ing to the formation of 30% of (-) forms (2S, 3R) decreased their antioxidative activity. The hy-drolytic stability of butter, however, increased as the amount of (-) forms (2S, 3R) increased.

圈养非洲白犀牛初乳蛋白组分及5种酶活性测定

为了积累圈养非洲白犀牛初乳蛋白组分和酶活性的基础数据,本研究对非洲圈养白犀牛分娩后1-5天的初乳成分进行分析。用考马斯亮蓝法对白犀牛初乳蛋白质含量进行测定,以SDS-聚丙烯酰胺凝胶电泳不连续垂直板状电泳分离乳蛋白各组分,并用分光光度法测定淀粉酶(AMS)、乳过氧化物酶(LP)、N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)、碱性磷酸酶(ALP)和γ-谷氨酰胺转移酶(γ-GT)等5种酶活性。结果显示:白犀牛初乳中蛋白质浓度第1天最高为150.33±4.2 mg/mL,后呈下降趋势,约为荷斯坦牛乳蛋白质浓度的5倍。白犀牛初乳中Igs含量最为丰富,第1天最高为38.59%,后呈下降趋势;荷斯坦牛乳以CN为含量最丰富的蛋白质,为49.41%。AMS、LP和ALP的活性第2天最高为46.27±0.42 U/100 mL、299.33±15.5 U/mL和193.22±1.63 U/100 mL,后逐渐下降,其中各天LP活性均高于荷斯坦牛乳;NAGase活性第1天最高为48.22±1.15 U/L后逐渐下降,各天活性均高于荷斯坦牛乳;γ-GT活性呈上升趋势,第5天最高为1053.85±6.78 U/100 mL,高于荷斯坦牛乳。

多倍体麦类作物Wx蛋白检测的SDS-PAGE方法

本文通过对小麦蜡质蛋白的实验和研究 ,详细论述了蜡质蛋白的特性、提取原理、电泳原理和检验原理。对多倍体麦类作物Wx蛋白亚基的检测 ,提出了应用效果良好的电泳系统 ,并就提取方法、凝胶配方和操作步骤进行了描述。本文还列出了部分麦类作物蜡质蛋白亚基基本模式示意图和实验例证 ,具有很好的参考价值。

白果蛋白质提取及SDS-PAGE分析

以白果为原料,采用不同的原料处理及蛋白质提取方法,运用单因素和正交设计的方法,以料液比、提取时间、提取液浓度、提取液pH值为考察因素,研究白果蛋白质提取的最佳工艺条件,并对提取的白果蛋白进行SDS-PAGE凝胶电泳分析。结果表明:经过冷冻干燥处理的白果采用Tris-HCl提取法获得的白果蛋白含量较高;Tris-HCl法提取白果蛋白的最佳工艺为pH8.5、0.15mol/L Tris-HCl溶液、料液比1:20(g/mL)、提取时间4h,白果蛋白质的提取率达到75.01%。白果蛋白SDS-PAGE分析表明,白果蛋白中约含13条亚基,主要为21kD和32kD的两种亚基,白果蛋白的亚基主要集中在31～100kD,占亚基总数的77%。

凝胶成像系统SDS-PAGE法测定乳及乳制品中乳铁蛋白

为了建立一种检测市场上乳及乳制品中的乳铁蛋白含量的简便方法——SDS-PAGE法,采集了10种液态奶、4种奶酪、3种乳清蛋白粉、4种酸奶和4种奶粉,利用SDS-PAGE法分离乳铁蛋白,并优化了分离胶的浓度、电压、上样量和染色方法。经优化的SDS-PAGE法的操作条件为:分离胶浓度为12%,浓缩胶电压为120V,分离胶电压为200V,改良的考马斯亮蓝染色,乳铁蛋白标准品的点样浓度为0.1111mg/mL,点样量为12μL。采用此电泳条件分离不同乳及乳制品中的乳铁蛋白,运用凝胶成像系统测得乳铁蛋白含量的相对标准偏差小于10%,且测得的含量均高于其检出限和定量限。同一样品同一块胶,同一样品不同凝胶乳铁蛋白的含量相对标准偏差小于10%,说明利用本方法得到的实验结果准确度高,重复性好。

新风胶囊中水溶性蛋白的SDS-PAGE分析方法研究

目的:建立新风胶囊中水溶性蛋白SDS-PAGE的分析方法。方法:采用SDS-PAGE电泳方法,根据分子量大小不同,分离新风胶囊中水溶性蛋白;电泳条件:1.0 mm×25齿试样格,浓缩胶浓度为4.5%,分离胶浓度为12.5%,分离电压100 V,上样量5μL,染色2 h,脱色4 h。结果:新风胶囊中水溶性蛋白成分含量不均,其中主带有2条,分子量为16.38、17.07 kDa左右。结论:SDS-PAGE电泳方法可以用于新风胶囊中水溶性蛋白成分测定,为建立该制剂电泳特征图谱提供依据。

小麦高分子量麦谷蛋白亚基的SDS-PAGE方法

小麦高分子量麦谷蛋白亚基(HMW-GS)与小麦面粉的加工品质密切相关,SDS-PAGE是其常用分离方法。在前人工作的基础上摸索了一套适于分析HMW-GS的SDS-PAGE方法,具有简便、快速、微量、不影响种子萌发出苗、分辨率好、制成干板清晰、不皱缩、易保存等优点,以供有关工作者参考。