Preliminary study of patients with chronic mountain sickness by GC-TOF-MS based serum metabolomics analysis

AIM: To evaluate specific metabolomics profiles in the serum of patients with chronic mountain sickness (CMS) and to explore the potential metabolic biomarkers in the native Tibetans living on the Qinghai-Tibet Pla-teau.METHODS: A gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) approach as a metabolomics technique was used to evaluate metabolic differences. The native Tibetan CMS patients (n=10) and healthy Tibetan controls (n=10) were enrolled from YuShu in Qinghai province in this study. The serum samples were collected and analyzed by GC-TOF-MS coupled with a series of multivariate statistical analyses such as principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA).RESULTS: The intergroup differences between CMS patients and control subjects have been observed. A list of differential metabolites and several top altered metabolic pathways have been identified. The levels of fumaric acid, an intermediate in the tricarboxylic acid (TCA) cycle, and inosine were highly upregulated in the CMS patients, suggesting a greater effort to hypoxic adaptation in high elevation area. Other differential metabolites, such as methyl phosphate, 2-ketoadipate, lyxose and phytanic acid were also identified. Importantly, the differential metabolites possessed higher area under the ROC curve (AUC) values, indicating an excellent clinical ability for the prediction of CMS. Increased levels of amino acids (isoleucine, glycine, serine, L-cysteine, citrulline and trimethyllysine) were detected in CMS group, yet significantly decreased levels of sulfuric acid, oxamic acid, lyxose and glutamine were also detected in CMS group than those in control group. At the same time, the levels of ribose and glucose-1-phosphate were markedly elevated in CMS group (P<0.05).CONCLUSION: The metabolic activities are significantly altered in the serum of CMS patients. High altitude hypoxia may act on the disturbed glucose metabolism and amino acid metabolism in part of the Tibetan triggered by CMS.     

基质分散萃取-高效液相色谱法对菠菜中噻虫胺残留的检测

研究确立了乙腈为分散萃取溶剂,以羧基化双壁碳纳米管(DWCNTs-COOH)和石墨化碳黑(GCB)为基质分散材料的菠菜(Spinacia oleracea L.)样品中噻虫胺残留基质分散萃取前处理方法,建立并优化了乙腈等度洗脱的HPLC残留样品外标定量方法。结果表明,优化色谱条件下,噻虫胺标准样品的色谱保留时间为6.258 min,在0.05~100 mg/L范围内与对应色谱峰积分面积线性响应良好,回归方程为y=4.948 2x-1.316 9(R~2=0.999 7),噻虫胺在菠菜样品中0.1、0.5和5.0 mg/kg 3个水平的添加回收率均在85%以上,各添加水平的相对标准偏差均小于7%,该色谱条件下仪器检出限为0.052 7μg/L,方法的最低检测量为0.015 mg/kg。表明该残留样本前处理方法和样品检测方法简便、高效、经济、可靠,可满足噻虫胺在菠菜中的残留定量检测要求。     

潮州6种蔬菜汤中F~-·Cl~-·NO_2~-·NO_3~-的同时测定

[目的]同时测定潮州蔬菜汤中F-、Cl-、NO2-和NO3-的含量。[方法]利用WICⅡ-型离子色谱仪,测定潮州不同鲜度6种蔬菜汤中F-、Cl-、NO2-和NO3-的的含量。[结果]菜汤中NO3-的含量较高;菜汤中有适宜的F-、Cl-含量。[结论]保鲜处理放置的蔬菜中,NO2-、NO3-含量增加。     

反相高效液相色谱法测定瘤胃液中的生物胺

本文旨在应用反相高效液相色谱法建立瘤胃液中生物胺的测定方法.样品经0.5 mol/L盐酸提取后,用丹磺酰氯柱前衍生,流动相为乙腈和0.1 mol/L乙酸铵溶液；采用梯度洗脱,流速为1.0 mL/min；紫外检测器波长254 nm,柱温30℃.应用该方法,研究高精料和低精料饲粮条件下瘤胃液中5种生物胺浓度的差异.结果表明...     

Nanostructured liquid crystalline particle assisted delivery of 2,4-dichlorophenoxyacetic acid to weeds,crops and model plants

Routine agricultural practices are heavily dependent on the use of surfactants, many of which are toxic to humans and detrimental to the environment. In proof of concept work we have previously shown the potential of nanostructured liquid crystalline particles (NLCP) to safely interact with plant leaf cuticular surfaces with minimal impact on epicuticular waxes. Here we demonstrate the use of NLCP to effectively deliver the auxin herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) to plant leaves in laboratory and field studies. In the laboratory, the physiological stress responses of lupin, Lupinus angustifolius (L.) (Fabaceae) towards NLCP spray applications were shown to be much reduced in comparison with application of two common surfactants. Phytotoxicity assays of 2,4-D loaded NLCP were used to validate the herbicidal effects on Arabidopsis thaliana (L.) Heynth. (Brassicaceae) and established a similarity with that of surfactant assisted 2,4-D delivery when tested at a concentration of 0.1%. Field trials were conducted to test the efficacy of NLCP-assisted delivery of 2,4-D in comparison with commercial surfactants for the control of the invasive weed wild radish, Raphanus raphanistrum (L.) (Brassicaceae), in wheat, Triticum aestivum (L.) (Poaceae) crop fields. Compared against Estercide 800, a commercially available 2,4-D formulation, NLCP assisted delivery of 2,4-D was effective at low concentrations of 0.03% and 0.06%. The crop yield remained similar for all the tested concentrations and formulations of 2,4-D loaded NLCP and Estercide 800. This is the first report to directly show that, as an alternative to conventional methods, NLCP can be used under both laboratory and field conditions to successfully delivery an agrochemical.     

高效液相色谱-串联质谱法检测水产品中三聚氰胺残留的比较研究

该研究利用高效液相色谱．串联质谱法（LC—MS／MS）检测水产品中的三聚氰胺，分别比较C18柱、氰基柱（CN）和强阳离子交换与反相C18混合填料柱（CR）3种色谱柱及其相对应的流动相对三聚氰胺的保留和分离效果。结果显示，以甲醇和5mmol的挥发性离子对试剂全氟庚酸作为流动相，采用梯度洗脱，三聚氰胺在C18柱中能得到较好地保留和分离。该研究拓宽了C18柱在药物残留分析中的应用范围。方法成本低、灵敏度高、稳定性和重现性良好，适用于水产品中三聚氰胺的残留检测。     

液体立式自动包装机主要结构设计

目前,我国包装机械不断发展壮大,其市场前景非常可观,包装机械的技术要求也在不断的提高。现在市场上大多包装机械结构复杂、造价高,多适用于大型的包装企业,一般中小型企业难以承受。为此,对液体立式自动包装机进行了结构设计并确定了主要技术参数。该机具有体积小、结构简单、造价低、出现故障易排查等特点。     

滴灌灌水器流道设计理论研究若干问题的综述

灌水器是滴灌系统最关键的部件之一,其结构与水力性能的优劣对滴灌系统的灌水均匀性、抗堵塞能力以及寿命影响很大。在简要论述国内外滴灌灌水器流道发展现状的基础上,从灌水器流量压力关系、流道内流体流动机理、流道堵塞与防治三个方面详细阐述了灌水器流道设计理论的研究进展,最后提出了滴灌灌水器流道的发展趋势以及国内在灌水器流道设计理论研究中急需解决的问题。     

印度Leh地区沙棘籽油中脂肪酸测定

本文分析了印度Leh地区沙棘籽油中脂肪酸各成分的含量,结果显示沙棘种子含油量为17.61%,籽油富含油酸(23.012%)和亚油酸(30.162%).     

膨胀颗粒污泥床（EGSB）反应器处理高浓度自配水的试验研究

本文对EGSB反应器处理高浓度自配有机废水进行了较系统地研究，研究表明中温条件下(31～35℃)，进水COD浓度为8200～9000mg