肝气郁结和心脾两虚型抑郁伴焦虑患者前额叶白质的脑波谱研究

目的探讨肝气郁结和心脾两虚型抑郁伴焦虑患者前额叶白质氢质子波谱(1H-MRS)代谢产物的差异及特点,为抑郁伴焦虑患者的中医证型研究提供数据支持。方法运用汉密尔顿抑郁量表(Hamilton depression scale,HAMD)和汉密尔顿焦虑量表(Hamilton anxiety scale,HAMA)对40例抑郁焦虑共病患者(肝气郁结组20例,心脾两虚组20例)及19例健康者(对照组)进行测评,并应用1H-MRS技术对3组受试者的前额叶白质进行扫描,进而对N-乙酰天冬氨酸(NAA)、胆碱(Cho)、肌酐(Cr)、肌醇(MI)等指标进行检测分析。结果心脾两虚组的HAMD和HAMA的评分显著高于肝气郁结组(P<0.05);肝气郁结组的Cho/Cr值、心脾两虚组NAA/Cr值和Cho/Cr值均显著低于正常对照组(P<0.05),且心脾两虚组NAA/Cr值显著低于肝气郁结组(P<0.05),而3组MI/Cr差异无统计学意义。结论抑郁伴焦虑的发生可能与患者双侧前额叶白质NAA、Cho含量的减低有关,提示此类患者的抑郁焦虑症状可能较重且容易复发;心脾两虚型患者的抑郁焦虑症状及神经元功能损伤可能较肝气郁结患者更为严重。

电感耦合等离子体质谱法测定白酒中铅的前处理方法

目的探讨不同前处理方法对使用电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry,ICP-MS)测定白酒中铅含量检测结果准确性的影响。方法采用直接酸化稀释法、蒸干乙醇酸化稀释法和微波消解法分别对3份白酒样品及质控白酒样品进行前处理,使用10μg/L铋溶液作为在线内标,使用ICP-MS得到标准工作曲线后,测定白酒中的铅含量,并进行回收率实验。结果标准物质和加标回收率情况表明直接酸化稀释法处理的白酒样品铅平均含量偏低一些,但与其他2种方法相比差异不显著(P>0.05)。3种前处理方法对质控样品测定结果都在允许误差范围内。直接酸化稀释法存在一定的基体影响,蒸干乙醇酸化稀释法和微波消解法稳定性更好。结论蒸干乙醇酸化稀释法简化了白酒样品的前处理过程,减少了硝酸的用量,结果可靠,可在今后的检测工作中进行使用。

Genetic variation of yellow pigment and its components in foxtail millet(Setaria italica(L.) P.Beauv.) from different eco-regions in China

Kernel color is an important trait for assessing the commercial and nutritional quality of foxtail millet. Yellow pigment content （YPC） and carotenoid components （lutein and zeaxanthin） of 270 foxtail millet accessions, including 50 landraces and 220 improved cultivars, from four different eco-regions in China were surveyed using spectrophotometry and high performance liquid chromatography methods. Results indicated that YPC had rich variance, ranging from 1.91 to 28.54 mg kg-1, with an average value of 17.80 mg kg-1. The average YPC of improved cultivars （18.31 mg kg-1） was significantly higher than that of landraces （15.51 mg kg-l）. The YPC in cultivars from the Loess Plateau spring sowing region （LPSSR） was the highest （20.59 mg kg-~）, followed by the North China summer sowing region （NCSSR, 18.25 mg kg-1）, the northeast spring sowing region （NSSR, 17.25 mg kg-1）, and the Inner Mongolia Plateau spring sowing region （IMPSSR, 13.92 mg kg-1）. The variation coefficients of YPC in cultivars from NSSR, LPSSR, and IMPSSR were higher than that from NCSSR. A similar carotenoid profile was also obtained for 270 foxtail millet cultivars. Lutein and zeaxanthin accounted for approximately 55-65% of YPC in accessions. The lutein content was higher than zeaxanthin content in all cultivars. The ratio of lutein to zeaxanthin ranged from 1.51 to 6.06 with an average of 3.34. YPC was positively correlated with lutein （r=0.935, P〈0.01）, zeaxanthin （r=0.808, P〈0.01 ）, and growth duration （t=0.488, P〈0.01 ）, whereas it was negatively correlated with grain protein （t=-0.332, P〈0.01） and 1 000-kernel weight （t=-0.153, P〈0.05）. Our study is useful for screening and selecting cultivars with high levels of yellow pigment and for enhancing phytochemical concentrations in breeding programs.

吡唑醚菌酯在小麦上的残留分析及安全性评价研究

目的建立超高效液相色谱-串联质谱法(ultra performance liquid chromatography/tandem mass spectrometry,UPLC-MS/MS)测定小麦中吡唑醚菌酯的含量,研究其在小麦籽粒和秸秆中的残留状况及消解规律,评估吡唑醚菌酯的膳食风险。方法实验样品经乙腈提取、净化后,经Waters Acquity UPLC BEH C18柱(50 mm×2.1 mm,1.7μm)分离,以0.1%甲酸水-甲醇为流动相进行梯度洗脱;流速为0.3 mL/min,多反应监测模式监测。结果吡唑醚菌酯在0.0005-0.20 mg/mL的范围内线性关系良好,相关系数大于0.999,小麦籽粒、小麦秸秆不同添加水平下的平均回收率范围为66%~97%、88%~98%,相对标准偏差分别为1.9%~5.5%、1.2%~12.4%,定量限为0.01 mg/kg。吡唑醚菌酯在小麦籽粒中的残留消解符合一级动力学方程,其消解半衰期为2.74~5.82 d;用药后小麦籽粒中吡唑醚菌酯的最终残留未检出~0.10 mg/kg;膳食风险评估表明,末次施药21 d后吡唑醚菌酯的国家估算每日摄入量是1.0874 mg,风险概率为57.53%。结论吡唑醚菌酯在小麦中的消解速度较快,虽不能在小麦中完全降解,但通过膳食评估发现长期膳食摄入对人体健康不会产生不可接受的风险。

Fast determination of multi-mycotoxins in corn by dispersive solid-phase extraction coupled with ultra-performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry

A fast analytical method for the simultaneous determination of 9 mycotoxins, including alfatoxins （B1, B2, G1, and G2）, fumonisins （B1, B2 and B3）, zearalenone, and deoxynivalenol in corn using dispersive solid-phase extraction method and ultra-performance liquid chromatography coupled to tandem quadrupole time-of-lfight mass spectrometry （UPLC-Q-TOF-MS） was developed and validated. Samples were extracted with acetonitrile-water （84：16, v：v, containing 1% acetic acid） using ultrasonic extraction. The extracts were puriifed with a dispersive SPE method using C18 as a cleaning agent. The ifnal clear extracts were dried by nitrogen blowing and subsequently redissolved in methanol-water （5：5, v：v）. The samples were then analyzed by UPLC-Q-TOF-MS with 0.1% formic acid in ammonium acetate-methanol as mobile phase. The mean recoveries were ranged from 68.0 to 120.0%, and the relative standard deviation （RSD） ranged from 0.18 to 6.29%. Limits of detections ranged from 0.05 to 50 μg kg？1, and limits of quantiifcation ranged from 0.1 to 200 μg kg？1, which were below the legal limits set by the European Union for the legislated mycotoxins. The developed method was applied to 130 corn samples. Among the mycotoxins studied, alfatoxins B1 and fumonisins B1, B2 and B3 were the most predominant mycotoxins, and their concentrations were 0–593.12, 0–2.01×104, 0–6.94×103 and 0–3.05×103 μg kg–1, respectively.

Analysis of 13 kinds of steroid hormones in raw milk using modified QuEChERS method combined with UPLC-QTOF-MS

Thirteen kinds of steroid hormones in raw milk（cow, goat and buffalo milk） were analyzed with ultra performance liquid chromatography-quadrupole time of flight mass spectrometry（UPLC-QTOF-MS） after extraction and cleanup with the modified Qu ECh ERS method. These steroid hormones included 17β-estradiol, estriol, estrone, diethylstilbestrol, progesterone, melengestrol acetate, megestrol acetate, chlormadinone acetate, 19-nortestosterone, metandienone, boldenone, epitestosterone, and testosterone. The limits of detection for the raw milk basing on 3 times the signal to noise ratios（S/N=3） was in range of 0.07-0.51 μg kg^–1, and the limits of quantification（basing on S/N=10 method） covered the ranges from 0.23 to 1.7 μg kg^–1. With matrix external standard method, the substances presented recoveries over the range 74.2–99.7%. Qualitative analysis was also done in the mass/mass spectrum（MS/MS） mode and each debris structure of 13 kinds of steroid hormones was achieved. The methodology was then applied in real raw milk samples which were collected in several areas of China and the progesterone was detected with high level.

喷丸强化对20CrMoH渗碳齿轮表层组织和性能的影响

利用主减速齿轮20CrMoH渗碳淬火材料进行强力喷丸试验,结合蔡司光学显微镜、显微硬度计、TimeSurf粗糙度仪和X射线应力分析仪对喷丸后齿轮材料的性能进行了分析,系统地研究了喷丸强化对齿轮显微组织、硬度、表面粗糙度和齿轮表面及不同层深残余应力的影响规律,对比了复合喷丸与单一喷丸的强化效果。结果表明:喷丸强化能够显著细化表面和微区的晶粒组织,提高材料的表面硬度和表面及微区的残余压应力,降低齿轮表面粗糙度;复合喷丸的强化作用要显著大于单一强化喷丸。

强射流对堰塞湖冲击引流的特性研究

为避免堰塞湖传统引流泄洪应急处置措施导致次生灾害的发生,提出了强射流冲击引流的新方法,简析了强射流的特性和影响因素,计算了射流冲击力的理论数值,通过大量实地试验和数据分析对比,验证了采用强射流冲击引流技术在堰塞湖坝体上快速冲击形成一定规模的引流泄洪槽具有一定的可行性。强射流冲击引流技术对迅速、有效、安全地进行堰塞湖引流泄洪,减少人员伤亡和经济损失具有非常重要的现实意义。

AUT凝胶电泳在牛胰核糖核酸酶折叠研究中的应用

目的:牛胰核糖核酸酶是一种用于蛋白折叠研究的经典模式蛋白,在折叠研究过程中主要使用高效液相色谱用于分离检测不同阶段的蛋白折叠中间体。高效液相色谱具有自动化、分离效果好、样品可回收等优点,同时也存在检测通量较低、仪器设备较为昂贵等不足。AUT凝胶电泳简便、快捷、检测通量较高,本文尝试将其应用于牛胰核糖核酸酶的折叠研究。方法:使用AUT凝胶电泳、酶活性检测、质谱对牛胰核糖核酸酶还原变性过程及产生的折叠中间体进行检测;通过高效液相色谱和质谱对折叠中间单体进行分离检测,并分别进行AUT凝胶电泳检测以解析各折叠中间单体在电泳中的条带位置;通过AUT凝胶电泳和酶切后质谱鉴定各折叠中间单体的二硫键配对方式。结果:AUT凝胶电泳可以有效区分不同条件下的牛胰核糖核酸酶还原变性过程,检测结果与酶活性、质谱结果相符,并可以很好地区分牛胰核糖核酸酶还原变性过程折叠中间体。高效液相色谱将牛胰核糖核酸酶还原变性过程折叠中间体分离为13个色谱峰,并与AUT凝胶电泳中的11个条带位置进行匹配。确认牛胰核糖核酸酶还原变性过程折叠中间单体的二硫键配对方式,并与AUT凝胶电泳条带进行匹配,Cys58-Cys110和Cys26-Cys84构象熵减作用强于Cys40-Cys95和Cys65-Cys72。结论:AUT凝胶电泳适用于检测牛胰核糖核酸酶折叠中间体,可以与高效液相色谱、质谱等检测技术相互补充,共同应用于牛胰核糖核酸酶的折叠研究。