HPLC-MS/MS法同时测定大鼠血浆中3种蟾皮主要活性成分

建立大鼠血浆中3种蟾皮提取物的HPLC-MS/MS测定方法,并用于大鼠体内的药代动力学研究.采用静脉给药和动脉取血的方式,甲醇直接沉淀蛋白的方法快速制备样品;分析柱为Agilent Zorbax Eclipse XDB-C18(150mm×4.6mm,5μm),流动相为乙腈/水(体积比65∶35),流速为1.0mL/min;质谱条件为ESI(+)电离方式,扫描方式为定量的多反应监测(MRM).结果表明,3种提取物分析方法的线性范围均为5～50 000ng/mL(r>0.999),样品的检出限均为5ng/mL,日内和日间精密度的相对标准偏差(RSD)≤4.02%,方法的回收率均在78%以上;经此方法测得的药代动力学数据表明,3种提取物在大鼠体内有相似的药代动力学行为.本方法样品预处理快速简便,检测专一灵敏,适合于3种蟾皮提取物的药代动力学研究

田间密植诱导抽穗期玉米叶片衰老时的光合作用机制

为理解田间密植是否诱导抽穗期玉米叶片衰老以及衰老叶片的光合作用规律和机制,本研究以玉米"先玉335"为材料研究了抽穗期栽培密度对穗位叶和穗下第4叶的光环境、比叶重、氮素含量、叶绿素含量、气体交换以及叶绿素荧光诱导动力学的影响。结果表明,随着密度的增加玉米冠层内的光强大幅降低,尤其穗下第4叶;穗位叶和穗下第4叶的比叶重降低。同时,穗位叶和穗下第4叶的氮素含量和叶绿素含量均随栽培密度增加而下降。不同栽培密度下穗位叶荧光诱导动力学曲线(OJIP)未发生明显改变,而高密度下穗下第4叶OJIP的J和I相的相对荧光产量较低密度有提高趋势。高密度下,穗位叶和穗下第4叶叶片的光合速率、气孔导度和蒸腾速率均降低;不过,穗位叶胞间CO2浓度降低,穗下第4叶胞间CO2浓度增加。我们认为,田间密植条件下异质性光环境可以迅速诱导抽穗期玉米冠层下部叶片(如穗下第4叶)衰老;该过程中,光合作用的限制因素不是光能吸收和电子传递,而可能是碳同化

Two-dimensional countercurrent chromatography x high performance liquid chromatography for preparative isolation of toad venom

National Natural Science Foundation of China [81102333, 81273400]; Fundamental Research Funds for the Central Universities [2010121108]; Fujian Natural Science Foundation for Distinguished Young Scholars [2012106020]; Natural Science Foundation of Fujian Province of China [2011J05101]In this work, a new on-line two-dimensional chromatography coupling of flow programming countercurrent chromatography and high-performance liquid chromatography (2D CCC x HPLC) was developed for preparative separation of complicated natural products. The CCC column was used as the first dimensional isolation and a preparative ODS column operated in reversed-phase (RP) mode as the second dimension. The CCC was operated at a controlled flow rate to ensure that each fraction eluted within one hour, corresponding to the isolation time of the 2nd dimensional preparative HPLC. The eluent from the 1st dimensional CCC was diluted using a makeup pump and trapped onto holding column, before been eluted and transferred to the 2nd dimensional HPLC. The performance of the holding column was evaluated, in terms of column size, dilution ratio and diameter-height ratio, as well as system pressure, for the solution to the issue of online trapping of low pressure eluent from a CCC column. Satisfactory trapping efficiency and tolerable CCC pressure can be achieved using a commercially available 15 mm x 30 mm i.d. ODS pre-column. The present integrated system was successfully applied in a one-step preparative separation of 12 compounds, from the crude methanol extract of venom of Bufo bufo gargarizans. Compounds 1-12 were isolated in overall yield of 1.0%, 0.8%, 2.0%, 13%, 2.0%, 1.5%, 1.9%, 3.6%, 6.1%, 4.8%, 3.5% and 4.1%, with HPLC purity of 99.9%, 99.7%, 90.6%, 99.9%, 77.0%, 99.9%, 90.4%, 99.9%, 52.0%, 99.9%, 99.3%, and 85.0%, respectively. All the results demonstrate that the flow programming CCC x HPLC method is an efficient and convenient way for the separation of compounds from toad venom and it can also be applied to isolate other complex multi-component natural products. (C) 2014 Elsevier B.V. All rights reserved

塔克拉玛干沙漠腹地生物固沙绿化试验研究

在寸草不长的塔克拉玛干沙漠腹地流沙上，在极端干旱、风沙肆虐，酷热剧冷变化无常的恶劣环境里，就地利用地下咸水灌溉，建立人工绿地３８亩，简易温棚一座。抗逆性植物种选择技术研究。引进耐风沙压埋、耐旱、耐盐等抗逆植物１６０种，试验成功１００种，并筛选出１７种适宜沙漠腹地环境的优良固沙植物;盐水利用技术。使用矿化度４．５－５．０克／升高矿化水，对不同植物种的不同生长发育阶段采取不同灌溉方式，植物生长良好，地表不积盐;沙地简易温室和露地栽培技术。单产超过南疆地区绿洲的产量;沙漠腹地固沙植物育苗繁殖和珍惜濒危植物保护。繁育固沙植物３０万株，对地区特有种和濒危植物如：塔干柽柳、大颖三芒草、沙蔗茅、塔干冬青的繁育营救了这些种;草坪、花坛、绿篱建植技术。为开发利用沙漠高矿化水进行生物防沙和在恶劣生境建设人工绿洲提供了科学依据。有５位中共中央政治局委员参观了沙漠腹地生物防沙绿化基地，邹家华副总理亲自植树予以支持，并批示农业部、水利部、林业部总结经验，李铁映同志题词“沙漠绿化，伟大的创举”。该成果已在塔中全面推广。现已建成防沙林带６条、苗木基地６０亩、蔬菜温室４亩、草坪６亩及绿篱、行道树等。人工绿地总面积２５０亩

Static analysis and neural network based software failure prediction technique construction method

本发明提供一种基于静态分析和神经网络的软件故障预测技术的构建方法,步骤如下：1、搜集被诊断软件的有效故障，加入到创建的故障案例库；2、统计软件各历史版本的有效故障的次数；3、使用静态分析工具扫描软件源代码，输出复杂度度量值；4、进行相关性分析，计算故障次数与度量值的显著性水平；5、选出与故障次数具有显著相关性的复杂度度量值；6、构建网络训练输入输出矩阵和预测输入矩阵；7、构建BP神经网络；8、完成网络训练，构建故障预测系统；9、神经网络预测，预测新版本的故障数量。通过上述步骤，可以完成对基于静态分析和BP神经网络的软件故障预测技术的构建。本发明能帮助开发者预测可能发生的软件故障，具有实用价值

Using positive-ion electrospray ionization mass spectrometry and H/D exchange study phosphoryl group transfer reactions involved in amino acid ester isopropyl phosphoramidates of Brefeldin A

As mini-chemical models, amino acid ester isopropyl phosphoramidates of Brefeldin A (compounds 2a-2d) were synthesized and investigated by electrospray ionization tandem mass spectrometry in combination with H/D exchange. To further confirm the fragments's structures, off-line Fourier transform resonance tandem mass spectrometry (FT-ICR-MS/MS) was also performed. The fragmentation rules of compounds 2a-2d have been summarized and the plausible schemes for the fragmentation pathways were proposed. In this study, one dephosphorylated ion and two phosphorylated ions were observed in ESI-MS2 spectra of [M+Na]+ ions for compounds 2a-2d. The possible mechanisms about phosphorylation and dephosphorylation were proposed and confirmed by H/D exchange. For the "dephosphorylation" rearrangement, a nitrogen atom was migrated from the phosphoryl group to the carbon atom of Brefeldin A's backbone with losing a molecule of C3H7PO3 (122Da). For the "phosphorylation" rearrangement, an oxygen atom of one phosphoryl group attacked the sideward phosphorus atom to form a nine-member ring intermediate, then two steps of CH covalent bond cleavage with consecutive migration of hydrogen atom to lose a molecule of C16H20O2 (244Da). The two proposed rearrangement mechanisms about phosphoryl group transfer might be valuable for the structure analysis of other analogs and provide insights into elucidating the dynamic process of the phosphorylation-dephosphorylation of proteins. ? 2014 Elsevier B.V

塔里木沙漠腹地油田基地环境观测与防沙绿先导试验

塔克拉码干沙漠腹地的塔中四油田为亿吨级油田。开发沙漠油田对贯彻石油“稳定东部、发展西部”方针至关重要。项目紧紧围绕沙漠油田开发中遇到的环境问题，通过先导试验，在塔里木沙漠腹地石油基地建立防沙人工绿化带积累环境要素资料，为油田开发和地面建设提供科学依据，建设防沙人工绿化带提供示范样板。主要内容有：沙漠腹地油田基地环境要素监测研究；高抗性植物种选择试验；油田基地防沙及环境绿化防护系统研究；高矿化水灌溉新技术研究；沙地简易温棚栽培试验；新技术新材料配套应用研究。项目组在塔中沙漠腹地建立一套环境监测系统，取得风沙运动、地下水、灌溉土壤、动植物和人对环境反应的完整资料；建成绿地２．５公顷，引种固沙植物５０余种；筛选出适用于沙漠环境的灌木１７种、草本植物４种；培育乔灌苗木３０万株；利用沙漠腹地咸水（矿化度４．５￣５．０克／升），培育温室和露地蔬菜２０多种，至１９９６年６月收获鲜菜３０００公斤，单产达到中国先进水平，开展太阳能淡化水、盐水灌溉、盐水固沙、保水剂、新型微肥等配套技术应用研究