Molecular Cloning and Characterization of Three Novel Genes Related to Fatty Acid Degradation and Their Responses to Abiotic Stresses in Gossypium hirsutum L.

Fatty acid metabolism is responsible not only for oilseed metabolism but also for plant responses to abiotic stresses. In this study, three novel genes related to fatty acid degradation designated GhACX, Gh4CL, and GhMFP, respectively, were isolated from Gossypium hirsutum acc. TM-1. The phylogenetic analysis revealed that amino acid sequences of GhACXand GhMFP have the highest homology with those from Vitis vinifera, and Gh4CL has a closer genetic relationship with that from Camellia sinensis. Tissue- and organ-specific analysis showed that the three genes expressed widely in all the tested tissues, including ovules and fiber at different developing stages, with expressed preferentially in some organs. Among them, GhACX showed the most abundant transcripts in seeds at 25 d post anthesis （DPA）, however, GhMFP and Gh4CL have the strongest expression level in ovules on the day of anthesis. Based on real-time quantitative RT-PCR, the three genes were differentially regulated when induced under wounding, methyl jasmonate （MeJA）, cold, and abscisic acid （ABA） treatments. The characterization and expression pattern of three novel fatty acid degradation related genes will aid both to understand the roles of fatty acid degradation related genes as precursor in stress stimuli and to elucidate the physiological function in cotton oilseed metabolism.

Analysis of bacitracin and its related substances by liquid chromatography tandem mass spectrometry

A suitable liquid chromatography quadrupole time-of-flight mass spectrometric(LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was performed on Li Chrospher RP-18 column using methanol as mobile phase A and 0.2% ammonium acetate buffer solution as mobile phase B in gradient elution. A total of 12 related substances were detected through high resolution mass spectrometric determination in a positive electrospray ionization mode. They were identified as co-existing active components and degradation products of bacitracin through the analysis and elucidation of both the protonated parents and the product ions of all the related substances and their fragmentation pathways were also proposed.

Identification and characterization of related substances in EVT-401 by hyphenated LC–MS techniques

A sensitive and selective method was developed for the separation and characterization of related substances(RSs) in EVT-401 by hyphenated LC–MS techniques. Complete separation of the RSs was achieved with an Inertsil ODS-SP column(250 mm×4.6 mm, 5 μm) by linear gradient elution using a mobile phase consisting of 0.2% formic acid solution, methanol and acetonitrile. EVT-401 was found to be susceptible to acid, alkaline and oxidative stresses, while relatively stable under photolytic and thermal dry stress conditions. Fourteen RSs including six process-related substances and eight degradation products were detected and identified in EVT-401 with positive ESI high-resolution TOF-MS analysis of their parent ions and the corresponding product mass spectra elucidation, and some of them were further verified by chemical synthesis and NMR spectroscopy. The specific LC–MS method developed for separation, identification and characterization of RSs is valuable for EVT-401 manufacturing process optimization and quality control.

Experimental investigation on degradation mechanism of membrane electrode assembly at different humidity under automotive protocol

Humidity can affect the attenuation of MEA(membrane electrode assembly), however, the relationship between humidity and MEA decays is complex and ambiguous in realistic application. Herein, we design a simulating automotive protocol, performed on five single fuel cells under RH(relative humidity) 100%,RH 80%, RH 64%, and RH 40%, RH 10%, respectively, to study the relationship of MEA decays and humidity and suggest optimized humidity range to extend the durability. With the electrochemical impedance spectroscopy, cyclic voltammetry, X-ray fluorescence, X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, the four degradation mechanisms about catalyst layer, including Pt dissolution, Pt coarsening, carbon corrosion and ionomer degradation, are observed. Pt coarsening and carbon corrosion are accelerated by higher water content at high humidity. Ionomer degradation and Pt dissolution are enhanced in low humidity. With the linear sweep voltammetry, ion chromatography,nuclear magnetic resonance, tensile test and scan electron microscope, chemical and mechanical degradation in proton exchange membrane are all observed in these five fuels. Chemical degradation, characterized by membrane thinning and more fluoride loss, occurred markedly in RH 10%. Mechanical degradation, characterized by the non-uniformity thickness and bad mechanical properties, is more pronounced in RH 100%, RH 80%, RH 64%. These two degradations are in a moderate level in RH 40%. The research suggests that the RH range from 64% to 40% is conductive to mitigate the degradation of MEAs operated in automotive applications.

Relative Abundance and the Relationships between Aniline,Phenol and Catechol Degraders in Fresh Water

Relative abundance and relationships between aniline, phenol and catechol degraders were investigated in unpolluted and polluted fresh waters in Osaka prefecture, Japan. Phenol and catechol degraders were found more frequently compared to aniline degraders. The results indicate that these degraders were more abundant in polluted waters than in unpolluted waters. Aniline degraders isolated from the Ina River water showed a higher capability of degrading catechol than phenol. Analysis on sequence homology among these three kinds of degraders indicated a possible relationship between aniline degraders and certain strains of both catechol and phenol degraders.

Characterization of alpine meadow surface crack and its correlation with root-soil properties

Quantifying surface cracks in alpine meadows is a prerequisite and a key aspect in the study of grassland crack development.Crack characterization indices are crucial for the quantitative characterization of complex cracks,serving as vital factors in assessing the degree of cracking and the development morphology.So far,research on evaluating the degree of grassland degradation through crack characterization indices is rare,especially the quantitative analysis of the development of surface cracks in alpine meadows is relatively scarce.Therefore,based on the phenomenon of surface cracking during the degradation of alpine meadows in some regions of the Qinghai-Tibet Plateau,we selected the alpine meadow in the Huangcheng Mongolian Township,Menyuan Hui Autonomous County,Qinghai Province,China as the study area,used unmanned aerial vehicle(UAV)sensing technology to acquire low-altitude images of alpine meadow surface cracks at different degrees of degradation(light,medium,and heavy degradation),and analyzed the representative metrics characterizing the degree of crack development by interpreting the crack length,length density,branch angle,and burrow(rat hole)distribution density and combining them with in situ crack width and depth measurements.Finally,the correlations between the crack characterization indices and the soil and root parameters of sample plots at different degrees of degradation in the study area were analyzed using the grey relation analysis.The results revealed that with the increase of degradation,the physical and chemical properties of soil and the mechanical properties of root-soil composite changed significantly,the vegetation coverage reduced,and the root system aggregated in the surface layer of alpine meadow.As the degree of degradation increased,the fracture morphology developed from"linear"to"dendritic",and eventually to a complex and irregular"polygonal"pattern.The crack length,width,depth,and length density were identified as the crack characterization indices via analysis of variance.The results of grey relation analysis also revealed that the crack length,width,depth,and length density were all highly correlated with root length density,and as the degradation of alpine meadows intensified,the underground biomass increased dramatically,forming a dense layer of grass felt,which has a significant impact on the formation and expansion of cracks.

转色期苯丙噻二唑处理对‘霞多丽’葡萄果实氨基酸构成及其降解代谢的影响

为探究苯丙噻二唑(benzothiadiazole,BTH)处理对葡萄生长过程中果实氨基酸积累及其降解代谢的影响,以‘霞多丽’葡萄为实验植株,果实转色期喷施50 mg/L BTH,花后60 d开始每10 d采集1次样品直至果实成熟(花后110 d),使用高效液相色谱法、氨基酸自动分析仪、固相微萃取联合气相色谱-质谱联用仪分别分析果实的葡萄糖、果糖、蔗糖、有机酸和氨基酸含量,以及氨基酸降解代谢相关酶活性和相应香气产物。结果表明:谷氨酸、精氨酸和脯氨酸是‘霞多丽’葡萄果实的主要氨基酸,BTH处理可促进果实氨基酸积累,抑制果实葡萄糖、果糖和蔗糖生成,提高成熟果实的酒石酸和柠檬酸含量,降低苹果酸含量;同时,BTH处理抑制了果实游离态支链脂肪族香气化合物的生成,增强了成熟葡萄的氨基酸转移酶(aminotransferase,AT)、醇酰基转移酶(alcohol acyltransferase,AAT)和丙酮酸脱羧酶活力,改变了氨基酸总量与乙醇脱氢酶活力的相关性及AT和AAT活力与单糖和有机酸含量的相关性,进而影响了氨基酸代谢香气物质的生成。研究结果可为BTH调控葡萄品质的应用提供理论指导及实践依据。

Age-related white matter degradation rule of normal human brain： the evidence from diffusion tensor magnetic resonance imaging

Background Diffusion tensor imaging can evaluate white matter function in human brain.Fractional anisotropy is the most important parameter.This study aimed to find regional reduction of fractional anisotropy （FA） with aging in the whole brain and the changing rules of anisotropy with aging.Methods Fifty volunteers from 20 to 75 years old were divided into five consecutive age groups; a young group and four senior groups.FA values were calculated with diffusion tensor imaging （DTI） studio software.The difference of FA between the young group and the four senior groups were analyzed by analysis of voxel-level height threshold in Statistic Parametric Mapping （SPM）,and the regions with decreased FA were obtained.The FA values of these regions were then extracted using an in-house developed program,and a multiple linear regression model was built to assess the influence of age and sex on the FA values of these regions.Results Eight regions,including frontal lobe,postcentral gyrus,optic radiation,hippocampus,cerebella hemisphere,corona radiate,corpus callosum and internal capsule,were found to have decreased FA.There was a strong negative correlation between age and the FA in the frontal lobe,postcentral gyrus,optic radiation,hippocampus,and cerebella hemisphere,while a weaker negative correlation in the corona radiate,corpus callosum,and internal capsule was found.The FA reduction in the frontal lobe,postcentral gyrus,optic radiation,hippocampus and cerebella hemisphere were found earlier than in the corona radiate,corpus callosum and internal capsule.There was no correlation between sex and FA in these regions.Conclusions The FA in the subcortical white matter area reduces earlier than that in deep white matter.The areas with decreased FA continuously enlarge with aqing.The FAs in these regions have a strong negative correlation with age.

几种贮存寿命特征参数评估方法的比较研究

本文对T-检验、灰色关联分析和退化率计算从应用条件、执行所需工具等方面进行了全面分析,最后得出三种方法都能有效识别贮存寿命特征参数;T-检验应用条件严格、但应用时间长,易于接受,且有现成工具可用;灰色关联分析数据整理工作量大,但无应用前提条件,且可同时获得贮存寿命特征参数和最优影响因素,特别适合小样本量数据的分析;退化率计算既不需要前提条件,计算又简单,是一种较好的评估方法。

维格列汀原料药有关物质的合成

为更好地控制维格列汀原料药的质量,改进维格列汀杂质对照品合成方法,结合原料药生产工艺,合成了2个维格列汀原料药的工艺杂质。根据维格列汀原料药降解途径,合成了3个降解杂质。杂质合成无需柱层析,只需要通过简单的重结晶即可得到目标化合物。以核磁共振氢谱、碳谱和高分辨质谱对5个杂质进行了结构确证,通过高效液相测定,这5个杂质的纯度均高于95%,符合杂质定位和含量标定的要求,可以作为原料药检验用的杂质对照品。

宁夏退化草地恢复过程中植被与土壤变化及互馈关系

退化草地恢复是维护生态系统功能、防止土地沙漠化和水土流失、保护生物多样性、促进区域可持续发展的关键举措,深入理解植被与土壤的互馈关系对于指导宁夏退化草地的恢复工作具有重要意义。以宁夏13个典型围封的天然草地群落样地为研究对象,通过土壤样品采集和植被群落调查,开展宁夏退化草地恢复过程中植被与土壤变化及互馈关系研究。结果表明:①在退化草地恢复过程中,围栏内的植被生长状态和土壤质量优于围栏外,但0~10cm、10~20cm土壤理化性质间无显著差异;过长的围封年限不利于退化草地恢复,围栏内、外的最适宜草地恢复年限存在差异。②结构方程模型研究表明,植被盖度和土壤总氮含量直接影响植被地上生物量的变化。同时,地理纬度通过对土壤含水量和土壤pH值的间接影响对植被地上生物量起到调节作用。

Relative humidity and temperature dependence of mechanical degradation of natural fiber composites^(?)

In this paper,the mechanical degradation of natural fiber composites is studied with the consideration of the relative humidity and the temperature.A nonlinear constitutive model is established,which employs an internal variable to describe the mechanical degradation related to the energy dissipation during moisture absorption.The existing experimental researches demonstrated that the mechanical degradation is an irreversible thermodynamic process induced by the degradation of fibers and the damages of interfaces between fiber and matrix,both of which depend on the variation of the relative humidity or the temperature.The evolution of the mechanical degradation is obtained through the determination of dissipation rates as a function of the relative humidity and the temperature.The theoretically predicted mechanical degradations are compared with experimental results of sisal fiber reinforced composites subject to different relative humidity and temperatures,and a good agreement is found.

高掺氢比高钢级管材环焊缝材料轴向本构关系研究

为了研究氢环境下管道环焊缝材料轴向本构关系,开展了典型掺氢环境(掺氢比20%)与空气环境下高压力(10 MPa)、高钢级(X80)管道环焊缝材料含缺口试样慢应变速率拉伸对比试验研究,提出了一种基于有限元模型与优化算法的反演掺氢环境下高钢级管道环焊缝材料本构关系的新方法,并利用核极限学习机(KELM)与改进灰狼优化算法(I-GWO)获得了掺氢环境下环焊缝材料真实应力应变本构关系。该方法具有较好的准确性,与试验数据相比,相对均方根误差(RMSE)小于3×10^(-4)。本研究建立的适用于高掺氢比、高压力、高钢级管道环焊缝材料的应力应变本构关系可为掺氢管道环焊缝完整性评价模型提供重要的数据支撑。

长春西汀注射液杂质谱研究

目的优化长春西汀注射液中有关物质的测定方法,并研究其杂质谱,明确杂质来源及其与生产工艺间的关系。方法采用HPLC法,色谱柱为ACE Excel C_(18)柱(4.6 mm×250 mm,5μm),以乙腈-0.2 mol·L^(-1)乙酸铵溶液为流动相,梯度洗脱,流速1.0 mL·min^(-1),柱温35℃,检测波长280 nm,测定7家企业生产的79批次长春西汀注射液中有关物质,采用UHPLC-Q-TOF对最大未知杂质结构进行推测,结合酸、碱、氧化、高温和氧化破坏试验及工艺分析和模拟灭菌工艺,确定检出杂质,归属杂质来源。结果优化后的检测方法,可对长春西汀杂质A、B、C、D、F及长春胺、苯甲醛和糠醛等8个已知杂质进行有效分离和测定。7家企业生产的长春西汀注射液均检出3~6种已知杂质和1~3种未知杂质,杂质A是最大已知杂质,结果中位数为0.22%~0.31%,最大未知杂质为长春西汀结构类似物,结果中位数为0.034%~0.082%,杂质总量结果中位数为0.53%~0.73%。不同厂家的杂质谱不尽相同。结论本法适用于长春西汀注射液中有关物质的测定和质量控制,工艺处方分析结果表明,糠醛和苯甲醛为辅料维生素C和苯甲醇氧化降解引入的杂质,杂质A、B、C、D、F和长春胺为工艺杂质,其中杂质A、F也是降解杂质。

丁酸氢化可的松乳膏有关物质的研究

目的:建立测定丁酸氢化可的松乳膏有关物质的方法,并对丁酸氢化可的松在不同pH值下的降解动力学及主要降解产物进行研究。方法:采用反相高效液相色谱法测定,色谱柱为Phenomenex Luna C18(250 mm×4.6 mm,5μm),流动相为水-乙腈-冰醋酸(55∶45∶0.5),流速为1.0 ml/min,柱温为30℃,检测波长为240 nm,进样体积为20μl。结果:该色谱条件下主成分与杂质能完全分离,丁酸氢化可的松的检测质量浓度线性范围为0.10~2.95μg/ml(r=1.0000);平均回收率为100.3%,RSD为1.1%(n=6);定量限和检测限分别为2.0 ng和1.0 ng;在pH值为1.0~8.0的范围内,丁酸氢化可的松在24 h内相对稳定。结论:建立的方法简便、灵敏度高,可用于丁酸氢化可的松乳膏的有关物质含量的测定。

阿特拉津降解菌ADH-2的分离、鉴定及其特性研究

从长期施用阿特拉津的玉米地中采集土样,通过富集培养的方法分离出一株能以阿特拉津为唯一碳、氮源生长的细菌ADH-2,结合生理生化特性及16S rRNA基因的相似性分析将其初步鉴定为节杆菌属(Arthrobacter sp.)。该菌在10h内对100mg.L-1阿特拉津的降解率为99.9%。外加氮源能促进菌株的生长,但对阿特拉津的降解有轻微的抑制作用。外加蔗糖和葡萄糖能显著促进菌株的生长,但对阿特拉津的降解表现出显著的抑制。而淀粉既能促进菌株的生长又能促进阿特拉津的降解。对其降解基因的初步研究显示,该菌含有trzN、atzB和atzC3个阿特拉津降解相关基因。通过与本实验室另外两株阿特拉津降解菌比较,菌株ADH-2具有更好的应用潜力。

船舶柴油机润滑油衰变监测信息关联性分析

以船用柴油机润滑油FT-IR光谱和理化指标等衰变监测数据为对象,应用改进生成的加权灰关联矩阵模型进行了关联分析.以获取的典型故障油样为例,对能够表征润滑油衰变故障的特征信息进行了分析.研究表明:正常衰变情况下,加权灰关联矩阵能有效揭示润滑油FT-IR光谱指标与常规理化指标、FT-IR光谱指标间的关联规则,氧化是润滑油衰变的主导因素;在润滑油存在水和燃油污染时,FT-IR光谱的水分和燃油量两项指标分别与常规理化指标的水分和黏度、闪点能很好地对应;FT-IR光谱信息能够有效的间接表征理化指标并监测润滑油衰变.根据研究结果,为消除信息冗余,开展了FT-IR光谱分析监测润滑油衰变的研究,优化了润滑油监测流程.

不同耐贮性粉果番茄贮藏期间果实软化相关酶活性的研究

以不同耐贮性的粉果番茄品种"欧盾"、"津粉207"为试材,研究在低温(10±0.2)℃贮藏期间果实硬度、乙烯释放量、细胞壁降解酶活、膜脂过氧化以及抗氧化酶活性的变化。结果表明:随着贮藏时间的延长,耐贮性强的"欧盾"品种番茄果实硬度下降较慢,乙烯释放量低,细胞壁降解酶活性、丙二醛含量、脂氧合酶(LOX)和抗氧化相关酶活性偏低;而"津粉207"品种番茄比"欧盾"品种番茄硬度下降快,乙烯释放量和丙二醛含量高,细胞壁降解酶活性、LOX和抗氧化相关酶的活性较高。

基于多尺度形态分解谱熵的电机轴承预测特征提取及退化状态评估

由于预测特征提取与退化状态评估直接关系故障预测可信性,结合数学形态学与信息熵理论,针对电机滚动轴承,提出基于多尺度形态分解谱熵的预测特征提取方法,用灰色关联分析对退化状态进行评估。对不同损伤程度轴承振动信号进行多尺度形态分解,分别计算其在不同尺度域内的复杂性度量能谱熵、奇异谱熵,以其作为预测特征向量。建立标准退化模式矩阵,对待检测样本信号特征向量与标准模式进行灰色关联分析,据关联度大小对样本信号退化状态进行评估。并仿真与实例数据验证该方法对电机轴承退化状态评估的有效性。

夏萝卜中有机磷农药残留消解动态及影响因素

利用酶抑制快速检测法对有机磷农药在夏萝卜中的消解动态变化进行了研究 ,结果表明 :敌敌畏、辛硫磷降解较快 ,敌百虫最慢 ,每种农药都有随浓度的增大残留量增加的趋势 ;从农药的残留量的影响因素来看 ,农药的残留量与植株叶绿素含量呈正相关 ,与植株鲜重呈负相关。