Determination of Veterinary Drug Residues in Animal-derived Foods by Liquid Chromatography-Mass Spectrometry

[Objectives]This study was conducted to establish a rapid and effective method for simultaneous extraction of 54 kinds of veterinary drug residues in animal-derived food, including sulfonamides, quinolones, tetracyclines, malachite greens, penicillins, nitroimidazoles, tranquilizers and macrolides, by HPLC-MS. [Methods] The samples were extracted with 80% acetonitrile water(containing 0.1% formic acid), combined with QuEChERS extraction technology and C18 and PSA purification, analyzed by high performance liquid chromatography-mass spectrometry, and quantified by external standard method. The target substances were analyzed on ZORBAX Eclipse C18 chromatographic column using 0.2% formic acid water and 0.2% methanol as mobile phases. The gradient elution mode was used for chromatographic separation and multiple reaction detection. [Results] In the linear range of 0.5-50.0 ng/ml, the linear relationship of the 54 kinds of veterinary drug residues was good, with correlation coefficients(r~2) greater than 0.995, and the detection limits ranged from 0.30 to 1.00 μg/kg. The results showed that the recovery ranged from 75.4% to 118.2% when different matrixes were added for recovery. [Conclusions] This method is simple, efficient, accurate, stable, and highly operable. It is applicable to simultaneous batch screening of veterinary drug residues in animal-derived food, and has high practical application value.

Evaluation of Uncertainty in Determination of Ethyl Maltol in Vegetable Oil by Ultra-high Performance Liquid Chromatograph-Mass Spectrometer(UPLC-MS)

[Objectives]This study was conducted to establish an uncertainty evaluation method for the determination of ethyl maltol by ultra-high performance liquid chromatograph-mass spectrometer(UPLC-MS).[Methods]A mathematical model of uncertainty was established by analyzing the method for determining ethyl maltol using UPLC-MS.The sources of uncertainty were analyzed,and the components of uncertainty were calculated to evaluate the expanded uncertainty of the method.[Results]When the content of ethyl maltol in edible vegetable oil was 1657μg/kg,the expanded uncertainty was 22.4μg/kg(K=2,P=95%).[Conclusions]The uncertainty in this evaluation model mainly came from standard solution preparation,sample weighing,dilution of sample to constant volume,standard curve fitting,and repeated measurement.

Chemical Components of Achyranthes bidentata Leaves by Ultra High Performance Liquid Chromatography-Mass Spectrometry

[Objectives] To study the chemical components and relative content of Achyranthes bidentata leaves and provide a scientific basis for further development and utilization of A. bidentata leaves.[Methods] The chemical components of A. bidentata leaves were rapidly analyzed using the ultra high performance liquid chromatography-time of flight-high resolution mass spectrometry (UHPLC-TOF-MS).[Results] Thirty eight chemical compounds were identified in samples of A. bidentata leaves collected from Wen County of Henan Province, in which seven chemical compounds had the relative content higher than 5%, linoleic acid reached 25.7% and inokosterone A reached 13.8%.[Conclusions] A. bidentata leaves contain many kinds of chemical compounds. This study is expected to provide a certain basis for further extraction of linoleic acid and inokosterone A.

A Validated Liquid Chromatography-Mass Spectrometry Method for the Detection and Quantification of Oxidative Metabolites of 2,2',4,4'-Tetrabromodiphenyl Ether in Rat Hepatic Microsomes

In the present study, we developed and validated an analytical method using ultra performance liquid chromatography-mass spectrometry (UPLC/MS) for the quantitative determination of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) metabolism by rat hepatic microsomes. BDE-47 is a brominated flame retardant that was widely used in a variety of consumer products and has subsequently been identified as a ubiquitous environmental contaminant. Hydroxy-bromodiphenyl ethers (OH-BDEs) were isolated from rat hepatic microsomes by liquid-liquid extraction. Chromatographic separation was achieved by UPLC on a C18 column with gradient elution using a mobile phase consisting of methanol and water, each containing 0.1% formic acid, at a flow rate of 0.2 mL/min. Detection and quantification were performed using a mass spectrometer in single ion recording mode with negative electrospray ionization. The UPLC/MS method was validated for linearity, limit of quantification (LOQ), accuracy, precision and recovery. The weighted calibration curves (1/X2) were linear over a concentration range of 5 - 250 nM with LOQ values between 5 nM and 50 nM for the individual OH-BDEs. Intra- and inter- day accuracy (%DEV) and precision (%RSD) values ranged from –11.7% to 9.5% and 5.9% to 16.5%, respectively. Recovery values of 70% to 90% were obtained for all OH-BDEs. The validated method allowed us to successfully analyze metabolite formation following incubation of BDE-47 with hepatic microsomes prepared from phenobarbital-treated rats. Results demonstrate that the UPLC/MS method has sufficient sensitivity and reproducibility to fully characterize the in vitro metabolism of BDE-47 and possibly other PBDEs.

CO₂Absorption Solvent Degradation Compound Identification Using Liquid Chromatography-Mass Spectrometry Quadrapole-Time of Flight (LCMSQTOF)

The degradation of the alkanolamine solvent used in the removal of acid gases from natural gas streams due to exposure to contaminants, thermal degradation and presence of oxygen or oxygen containing compounds will change the solvent properties, such as heat transfer coefficient, diffusion coefficient, and mass transfer coefficient of the solvent. Therefore, characterization and quantification of amine degradation product becomes one of the important analyses to determine alkanolamine solvent’s health. In order to identify degradation products of alkanolamine solvent, analytical strategies by using mass spectrometry (MS) as detector have been studied extensively. In this work, due to the low concentration of the amine degradation product, a method was developed for identification of alkanolamine degradation products using LCMS-QTOF technique. A strategy for identification of trace degradation products has been identified. Six (6) alkanolamine degradation products had been identified by using LCMS-QTOF targeted analysis in the blended alkanolamine solvent used in natural gas processing plant. Another fifteen (15) molecular formulas having similarity in chemical structure to alkanolamine degradation products were identified using untargeted analysis strategy, as possible compounds related to degradation products. Using LCMS-QTOF via targeted and untargeted analysis strategy, without tedious column separation and reference standard, enables laboratory to provide a quick and indicative information for alkanolamine solvent’s organic degradation compounds identification in CO2 adsorption, within reasonable analysis time.

Liquid Chromatography-mass Spectrometry Analysis on Effect of Roughage Types on Liver Metabolic in Dairy Cows

The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,metabolomic methods based on ultra performance liquid chromatography-mass spectrometry(LC-MS)were used to study the liver metabolites of dairy cows fed on corn straw diet or mixed diet.Ten healthy Chinese Holstein cows were randomly assigned to two groups,under the same management condition,fed different diets respectively,corn straw group(CS)or a mixture of alfalfa hay and Chinese wild rye hay mixed forage group(MF).All the cows were fed for 8 weeks and recorded body weight,dry matter intake,body condition score,fat,protein,lactose,milk yield and the total solids.Livers were sampled from each cow through a liver puncture needle for analysis of a significant difference in small molecule metabolites in cow liver samples from the two different diets.The results suggested that different diet types had significant effects on liver metabolism and milk components in dairy cows.The contents of milk fat,the total solids,milk protein,lactose,dry matter intake(DMI),milk yield,milk protein(%),lactose(%)and milk fat(%)of the corn straw group were significantly lower than those of the mixed forage group(p<0.05);the contents of phosphatidylcholine(PC),histidine,hypoxanthine and mridine in liver tissues of the corn straw group were significantly lower than those in the mixed forage group(p<0.05);acetylcarnitine,uric acid,triacylglycerol(TG),acetal phosphatidylcholine(plasmenyl-PC),acetalphosphatidylethanolamine(plasmenyl-PE)and sphingomyelin(SM)of the corn straw group were significantly higher than those in the mixed forage group(p<0.05).In summary,cows fed on mixed forage diet significantly improved milk yield and lactation performance clearly.

Novelties Filtration Theory of Liquid Chromatography-Mass Spectrometry in Volume Nanotube of Cotton Filament of Layers Woven Fabrics

Objectives of the research to present a modern theory of water purification for multiple purposes entitled “a novelties filtration theory of liquid chromatography-mass spectrometry” is an exceedingly sensitive and specific analytical technique in volume layers woven fabrics that can precisely determine the identities and quantities of compounds within volume Nanotube of cotton filament of layers woven fabrics. The problems are that the filters in the local and international markets have increased complications in configuration, installation and cost without reaching the efficiency that humanity hopes. Throw materials and methods the chromatography-mass spectrometry in layers woven fabrics, and throw the nanotube of cotton filament for purification of water dyes and smells. Industry, in which mass spectrometry is a convenient, versatile method for characterization and identification of process throw the Nanotube of cotton filament for purification of water dyes and smells. Results came up with a theme “innovations in textiles”, and also, for characterization of fibers and contaminants of the fabrics. Additive manufacturing in layers woven fabrics, are the processes used to synthesize a volume object under computer control with successive material layers that have been used and highlighted. The conclusions has included chromatography-mass spectrometry drop, physico-chemical, biological, combined physical-biological and chemical-biological treatment processes recently being developed to meet Jet-filtration, the strict discharging limits set by ASTM standards. Some important aspects of both qualitative and quantitative data analysis have been described and the power of using mass profiles to enhance selectivity and sensitivity has been demonstrated.

Determination of penehyclidine hydrochloride in beagle dog plasma by liquid chromatography-electrospray ionization mass spectrometry and the pharmacokinetic study

To develop a fast and sensitive liquid chromatography-mass spectrometry method for the determination of penehyclidine hydrochloride （PH） in beagle dog plasma. PH and diphenhydramine hydrochloride （internal standard, IS） were extracted with a solvent mixture of petroleum ether-ethyl ether （7：3）. Chromatographic separation was achieved on a reversed-phase Eclipse XDB-C18 column （4.6 mm × 150 mm, 5 um） using the eluent of methanol-water （5 mmol/L ammonium acetate） （90：10, v/v, pH 5.8） as mobile phase. The electrospray ionization source was set at the positive multiple reaction monitoring （MRM） mode. This method involved the use of the [M＋H]^＋ ions of PH and diphenhydramine hydrochloride at m/z 316.4- 128.2 and m/z 256.4-167.2. The calibration curve was linear in the range of 1-1000 ng/mL with a correlation coefficient of 0.9988. The lower limit of quantification was 0.05 ng/mL. The precision, accuracy and recovery of the method were acceptable. Following intravenous injection admires＇ tration at doses of 0.5, 1 and 5 mg/kg PH, the main pharmacokinetic parameters were as the followings, t1/2a 0.33 h, t1/2β 2.44 1% tmax 0.058 1% AUC and Cmax exhibited a linear increase along with the increase of dose. The two-compartment model fit the three dose groups. This method was sensitive, accurate and fast for the determination of concentration of PH in beagle dog plasma. It could be used in pharmacokinetic studies of PH.

Determination of brominated diphenyl ethers in atmospheric particulate matter using selective pressurized liquid extraction and gas chromatography–mass spectrometry with a negative chemical ionization

This study describes the development and validation of a sensitive and reliable method for determination of polybrominated diphenyl ethers（PBDEs）in atmospheric particulate matter using selective pressurized liquid extraction（SPLE）and gas chromatography–mass spectrometry with a negative chemical ionization（GC-NCI-MS）.Extraction and clean-up were performed using PLE with 2 g florisil and 3 g silica placed in the extraction cells.Under optimal conditions,14 PBDEs were extracted at 70℃ using hexane/dichloromethane（50：50,v/v）as solvent.Validation of SPLE returned excellent recoveries for most analytes,with relative standard deviations mostly below20%.Method detection limits ranged from 0.13 to15.38 ng·mL^-1 for the GC-MS analyses.The method was successfully applied to atmospheric particulate matter of Beijing,where analytes were detected in the range of182.79 to 468.99 pg·m^-3.

Untargeted and targeted mass spectrometry reveal the effects of theanine on the central and peripheral metabolomics of chronic unpredictable mild stress-induced depression in juvenile rats

L-theanine has been shown to have a therapeutic effect on depression.However,whether L-theanine has an excellent preventive effect on depression in children and adolescents and what its mechanism is have not been well explained.Given the complexity of the pathogenesis of depression,this study investigated the preventive effect and mechanism of L-theanine on depression in juvenile rats by combining serum and hippocampal metabolomic strategies.Behavioral tests,hippocampal tissue sections,and serum and hippocampal biochemical indexes were studied,and the results confirmed the preventive effect of Ltheanine.Untargeted reversed-phase liquid chromatography-quadrupole-time-of-flight mass spectrometry and targeted hydrophilic interaction liquid chromatography-triple quadrupole mass spectrometry were developed to analyze the metabolism changes in the serum and hippocampus to screen for potential biomarkers related to L-theanine treatment.The results suggested that 28 abnormal metabolites in the serum and hippocampus that were considered as potential biomarkers returned to nearnormal levels after L-theanine administration.These biomarkers were involved in various metabolic pathways,mainly including amino acid metabolism and lipid metabolism.The levels of amino acids and neurotransmitters in the phenylalanine,tryptophan,and glutamic acid pathways were significantly reduced after L-theanine administration compared with chronic unpredictable mild stress-induced rats.In summary,L-theanine had a significant preventive effect on depression and achieved its preventive results on depression by regulating various aspects of the body,such as amino acids,lipids,and inflammation.This research systematically analyzed the mechanism of L-theanine in preventing depression and laid the foundation for applying L-theanine to prevent depression in children and adolescents.

Application of Mass Spectrometry (MS)-coupled Techniques in Pesticide Residue Detection

Pesticide residue detection is an important work to ensure the quality safety of agricultural products.In the process of agricultural production,in order to prevent and control agricultural diseases and pests,a certain amount of pesticides need to be used.However,if pesticides are used excessively,there will be certain pesticide residues in crops and related products.Therefore,it is necessary to do a good job in pesticide residue detection.The gas chromatography-mass spectrometry(GC-MS)and liquid chromatography-mass spectrometry(LC-MS)detection methods have good results and can effectively detect pesticide residues in related products.This paper reviewed and analyzed the application of GC-MS and LC-MS in pesticide residue detection,and proposed optimization measures based on practical experience,hoping to provide reference for relevant scholars.

液液萃取-气相色谱质谱法测定水质中的环氧氯丙烷

比较了不同前处理方法进行水质中环氧氯丙烷的测试,其中液液萃取的前处理方法简单可靠,方便易行,适合复杂基质水样的测定。同时比较了气相色谱仪不同检测器对环氧氯丙烷(ECH)的响应值,其中质谱检测器对ECH的响应值最高。液液萃取-气相色谱质谱法测定水质中的环氧氯丙烷,该方法的检出限为0.6μg/L,测定下限为2.4μg/L。对海水、地表水、工业污水样品加标浓度为0.001 mg/L、0.02 mg/L、0.2 mg/L进行平行6次测定,结果的相对标准偏差分别为6.9%、2.7%和6.3%,加标回收率分别为93.5%、99.0%和99.6%,非常适合各类水质ECH的监测。

不同干燥方式八角果实挥发性化合物代谢组分析

【目的】探明不同干燥方式对八角果实挥发性成分的影响,筛选出适宜八角果实干燥的处理方式,为八角后期深加工、保存及应用提供参考。【方法】以新鲜八角果实为材料,采用自然晾晒、40℃、50℃、60℃、70℃、80℃和90℃烘干7种处理方式进行干燥,通过液相色谱-质谱(LC-MS)技术检测分析八角果实代谢产物,阐明八角果实不同温度干燥与自然晾晒处理的代谢物差异。【结果】与自然晾晒相比,八角果实40℃干燥差异代谢产物有11类17种,其中,萜类、醇类和醛类3类代谢物上调;50℃干燥差异代谢物有10类25种,其中,上调代谢物6类(萜类、醇类、酯类、酮类、卤代烃类、酚类);60℃干燥差异代谢物有8类13种,其中,醇类和烃类代谢物上调;70℃干燥差异代谢物为13类40种,其中,醇类、萜类和酯类3类代谢物上调;80℃干燥差异代谢物有13类38种,仅醇类代谢物上调;90℃干燥差异代谢物有13类52种,其中,上调代谢物4类(萜类、醇类、酮类、卤代烃类)。40℃、50℃和60℃干燥的八角果实与自然晾晒差异代谢物较少,上调代谢物主要是苯甲醛、醋酸植物醇、茴香脑、6-异羟基樟脑、乙酸异丁香酚酯和甲基丁香酚等挥发性化合物,提升了八角浓厚的香味。70℃、80℃和90℃干燥的八角果实与自然晾晒差异代谢物较多,且与八角香味相关的许多代谢物下调表达,主要有香芹酮、茴香脑、E-氧化玫瑰、4-蒈烯、对薄荷脑1,5,8-三烯、苯甲醛、芳樟醇、3-甲基苯并噻吩、2-甲基-2-四氢呋喃和2-乙酰基-5-甲基呋喃等挥发性化合物,减弱了八角香味。【结论】不同干燥处理八角果实的挥发性化合物种类均存在一定差异。40℃、50℃和60℃干燥八角果实,苯甲醛、醋酸植物醇和茴香脑等上调表达的挥发性化合物提升了八角香味。八角果实经50℃干燥后,上调表达的代谢物有萜类、醇类、酯类、酮类、卤代烃类和酚类6类,果实独特香气保持最好,宜在生产上推广应用。

固相萃取-超高效液相色谱-三重四极杆/线性离子阱质谱法检测水中大环内酯类抗生素

采用固相萃取-超高效液相色谱-三重四极杆线性离子阱质谱技术(SPE-UPLC-QTRAP MS)建立了环境水样中阿奇霉素、林可霉素、克林霉素、红霉素及替米考星5种大环内酯类抗生素的检测方法。调节水样pH为10后经HLB固相萃取柱净化、富集,然后用Kinetex F5色谱柱进行分离,用0.1%甲酸水溶液和0.1%甲酸乙腈溶液进行洗脱,采用电喷雾正离子源(ESI+),多反应监测(MRM)-信息依赖采集(IDA)-增强子离子(EPI)扫描模式对样品进行检测,用多反应监测(MRM)进行定量,增强子离子(EPI)谱图库辅助定性。结果表明:5种大环内酯类抗生素线性关系良好,相关系数均大于0.9992;检出限为0.01~0.30μg·L^(-1),定量限为0.10~0.50μg·L^(-1);3种不同浓度的水样加标回收率为71.60%~111.05%,相对标准偏差均在10%以内,EPI谱库比对纯度值均大于90%。该方法将传统的MRM扫描模式结合EPI谱图库检索,实现了同时定性和定量分析,对未知物准确定性定量检测提供了重要参考。

Characterization of mulberry leaf instant tea and evaluation of its hypolipidemia effect via regulation of intestinal microbiota

The purpose of this study was to characterize mulberry leaf instant tea(MLIT)powder prepared from the'Longsang No.1'(Morus abla L.cv.Longsang 1)mulberry leaves in Heilongjiang Province(China)and assess its obesity-preventing/relieving effects.A total of 174 compounds including quercetin,chlorogenic acid,1-deoxyecomycin(1-DNJ)related to antihyperlipidemia effects were identified from the MLIT powder.MLIT treatment reversed the Lee's index,fat coefficient,and serum biochemical parameters in both the obesity relieving and obesity preventing mice fed with high-fat diet.In the obesity relieving experiment,the relative abundance of Desulfovibrio in mouse feces decreased after both 0.5%and 1%MLIT treatments.In obesity preventing experiments,mouse with different amount of MLIT treatments showed increased relative abundance of Akkermansia,Bifidobacterium and Lactobacillus,while Deferribacteres,Desulfobacterota decreased.The beneficial bacteria in the intestinal tract of mice treated with MLIT increased.This study proved that MLIT had antihyperlipidemia potential via modulating intestinal microbiota in mice.

基于液相色谱-三重四级杆质谱仪的栀子及水栀子中萜类物质鉴定及成分差异研究

目的建立栀子中萜类物质的高通量分析方法,并将其应用于栀子与水栀子的成分差异研究。方法结合液相色谱-三重四级杆质谱仪中的全扫描、子离子扫描、母离子监测、中性丢失离子扫描、多反应离子监测、动态多反应离子监测等多种技术提出栀子中萜类物质的定性、定量分析策略,进一步应用主成分分析和正交偏最小二乘判别分析等多元变量分析方法研究栀子与水栀子的成分差异。结果共鉴定出并相对定量81种萜类物质,发现栀子与水栀子间萜类物质含量差异显著,其中13种物质可作为鉴别栀子与水栀子的差异标志物。结论所建立的方法操作便捷,结果准确,为栀子药材鉴别及质量评价提供了新思路,并为栀子资源的合理开发利用提供了参考依据。

氧诱导视网膜病变模型小鼠肾组织代谢组学研究

目的探讨高氧环境对氧诱导视网膜病变(OIR)模型小鼠肾脏代谢物的影响,了解病理性视网膜血管新生和肾损伤之间的潜在机制。方法采用随机数字表法将16只健康SPF级C57/B6J新生小鼠随机分为OIR组与正常对照组,每组8只。小鼠自出生后标准饲养至第7天(P7),OIR组小鼠和母鼠置于(75±2)%的高氧箱中饲养至P12,然后正常饲养;正常对照组一直在正常环境下饲养。各组小鼠在饲养P17时采用二氧化碳安乐死,取视网膜组织铺片并行血管异凝集素(IB4)染色,观察视网膜血管形态、中央无灌注区及病理性新生血管情况;另取小鼠肾组织进行液相色谱-质谱分析,取其对应小鼠的全血进行抗凝处理,通过离心沉淀,获得不含细胞成分的血浆,对血浆进行靶向代谢组学分析。使用代谢组学数据处理软件Progenesis QI v2.3对质谱信息进行解析,用无监督的主成分分析及正交偏最小二乘法分析(OPLS-DA)来区分各组间代谢轮廓的总体差异,比较2个组间代谢物的倍数变化。以变量权重值>1且P<0.05为条件筛选出差异代谢物。基于KEGG数据库对差异代谢物进行代谢通路富集分析。结果视网膜铺片IB4染色结果显示,P17时正常对照组小鼠视网膜血管分布均匀;OIR组小鼠视网膜周边血管迂曲、紊乱,中央可见大面积无灌注区域形成,在视网膜无灌注区和血管区交界处形成大量新生血管簇,呈强荧光染色。OIR组小鼠视网膜无灌注区相对面积为(25.16±3.50)%,明显大于正常对照组的(0.63±0.30)%,差异有统计学意义(t=12.07,P<0.001)。OPLS-DA模型参数R2X cum、解释率R2Y cum、和预测率Q2 cum分别为0.578、0.978和0.857,表明OPLS-DA模型具有较好的预测能力。共筛选鉴定到26个主要的差异代谢物,其中上调表达17个,下调表达9个,包括甘油磷脂类化合物[PC 20∶4(5Z,8Z,11Z,14Z)/0∶0、PC 22∶6(4Z,7Z,10Z,13Z,16Z,19Z)/0∶0、PC 14∶1(9Z)/20∶2(11Z,14Z)、PE P-18∶0/20∶4(6E,8Z,11Z,14Z)(5OH[S])]、氨基酸类代谢物(精氨酸、鸟氨酸、哌可酸和羟基赖氨酸)、嘌呤类(鸟嘌呤、次黄嘌呤、羟嘌醇)和脂肪酸类(15-棕榈酸甲酯、2,6,8,12-Tetramethyl-2,4-tridecadien-1-ol)等。差异代谢物主要富集于ABC转运蛋白(L-精氨酸、牛磺酸、肌醇、腺苷、N-乙酰基-D-氨基葡萄糖、L-谷氨酰胺)、氨酰-tRNA生物合成(L-异亮氨酸、L-脯氨酸、L-精氨酸、L-组氨酸、L-谷氨酰胺)、精氨酸生物合成(L-精氨酸、L-鸟氨酸、L-谷氨酰胺)等代谢通路。血浆的靶向代谢组学结果显示,差异的氨基酸类代谢产物主要富集于氨酰-tRNA生物合成、精氨酸生物合成代谢以及ABC转运蛋白等代谢通路。结论OIR小鼠的ABC转运蛋白、氨酰-tRNA生物合成、精氨酸生物合成代谢通路可能参与了肾损伤及早产儿视网膜病变新生血管形成的病理变化过程。

肝细胞癌中UBE2S互作蛋白的筛选及预后模型构建

目的:筛选泛素结合酶E2S (UBE2S)互作蛋白并构建肝细胞癌(HCC)基于UBE2S互作蛋白的预后模型(UIPM),分析UIPM评估HCC患者预后的价值。方法:采用免疫共沉淀(Co-IP)技术筛选与Flag-UBE2S结合的蛋白复合体,经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(SDSPAGE)和Western blotting法验证后,采用液相色谱-质谱联用仪(LC-MS)分析鉴定UBE2S互作蛋白,并对互作蛋白进行基因本体论(GO)功能和京都基因与基因组百科全书(KEGG)信号通路富集分析。采用R软件survival包筛选癌症基因组图谱(TGGA)中HCC预后相关蛋白与UBE2S互作蛋白取交集,通过LASSO回归分析从交集蛋白中获取关键蛋白构建UIPM,并建立预后模型风险评分公式,按照风险评分的中位值将TGGA中HCC患者分为高风险组和低风险组,通过受试者工作特征曲线(ROC)评估UIPM的预测准确性,并采用国际癌症基因组联盟(ICGC)数据库对UIPM预测准确性进行再次验证。采用单因素和多因素Cox回归分析评估UIPM风险评分是否为HCC的预后独立危险因素,并进一步构建列线图模型。结果:Co-IP联合LC-MS分析得到97个UBE2S互作蛋白。GO功能和KEGG信号通路富集分析,互作蛋白主要与半胱氨酸型内肽酶活性、氧化应激和细胞死亡有密切关联。TCGA筛选出5 163个HCC预后相关蛋白,与UBE2S互作蛋白取交集,获得40个预后相关互作蛋白,LASSO回归分析得到7个关键蛋白,包括UBE2S、热休克蛋白家族A成员8(HSPA8)、异质性胞核核糖核蛋白H1(HNRNPH1)、含TCP1伴侣蛋白亚基3 (CCT3)、真核翻译起始因子2亚基1 (EIF2S1)、活化蛋白C激酶1受体(RACK1)和肌动蛋白相关蛋白2/3复合体亚基4(ARPC4),并构建了UIPM,高和低风险组HCC患者生存率存比较差异有统计学意义(P<0.05)。ROC曲线,UIPM预测HCC患者1、2和3年UIPM风险评分的ROC曲线下面积(AUC)值均大于0.7,表明预测模型准确度较高。ICGC数据库数据也证实UIPM预测准确度较高。单因素和多因素Cox回归分析,UIPM风险评分是HCC患者的独立预后危险因素(P<0.05)。列线图预测HCC患者生存率与实际生存率之间有较好的一致性。结论:97个互作蛋白与UBE2S相互作用,可能通过氧化应激和铁死亡相关通路的失调促进HCC发生发展。UIPM风险评分是HCC预后的独立危险因素,可以用于预测HCC患者预后。而UBE2S、HSPA8、HNRNPH1、CCT3、EIF2S1、RACK1和ARPC4有望成为HCC新的生物标志物和治疗靶点。

液相质谱仪示教实验的虚拟仿真设计制作

以液相质谱仪(LC-MS)示教实验的虚拟仿真设计开发为例,介绍本项目团队成员自主设计的虚拟仿真场景应用于我校大型仪器分析示教实验制作过程。项目组运用开源软件Blender构建LC-MS仪器模型;运用虚幻引擎软件构建实验室教学场景,以此加深学生对分析仪器的内部结构和相关原理的理解,提升教学效果并延展教学评价体系。经过团队成员近三年摸索实践,虚拟仿真设计制作范围已涉及到我校多学科多个实验内容,希望以此累积逐步构建拟仿真在高校实践类教学实验中应用,也为相关高校提供借鉴参考意义。

扫描电镜/能谱法对粉底液的检测分类研究

为建立一种将扫描电镜/能谱法与多元统计学结合检测粉底液物证的方法。对收集到的50个粉底液样本进行前处理,利用扫描电镜/能谱仪对样本进行分析测试,将50个样本大致分成2大类;结合K-Means聚类对实验数据进行处理,将2大类样本细化分为4类;最后利用随机森林算法搭建分类模型,40个样本作为训练集,10个样本作为测试集,测试集的预测正确率达到86.6%,预测效果良好,可实现样本分类自动化。此方法操作简单,可实现无损检材、分类效果良好,可直接用于公安机关侦查破案,在法庭科学领域有广阔的应用前景。