基于多特征算法选择的太赫兹时域光谱用于水稻种子掺假研究

该文提出了一种基于太赫兹时域光谱的水稻种子模式识别方法。实验以10种不同品牌混合掺假的水稻种子为样本,基于采集的样本太赫兹时域光谱数据,通过建立Relief、随机森林（RF）、支持向量机递归特征消除（SVM-RFE）和最大相关最小冗余（mRMR）模型分别对样本光谱波长进行特征选择,最后设计分类器对4种特征选择方法处理后的样本进行分类识别。结果表明,基于布谷鸟算法（CS）优化的极限学习机模型对经RF特征选择算法提取后的样本光谱数据具有最佳识别效果,其准确率可达100%,实验对于法庭科学领域内种子的掺假鉴定具有一定的借鉴意义。     

Purification of monoclonal antibody from tobacco extract using membrane-based bioseparation techniques

Transgenic plants offer a promising system for large-scale production of therapeutic proteins such as monoclonal antibodies (mAbs). This paper describes a membrane-based process suitable for purification of a humanized mAb expressed in tobacco. Most monoclonal antibody purification schemes rely on the use of Protein A as the affinity ligand for antibody capture. The main objective of our work was to develop non-Protein A-based purification methods to avoid some of the problems and limitations associated with this ligand, e.g. cost, immunotoxicity, and antibody aggregation during elution. Ion exchange membrane chromatography (IEMC) was used for primary capture and preliminary purification of the mAb from tobacco juice. Hydrophobic interaction membrane chromatography (HIMC) was then used for high-resolution purification, followed by ultrafiltration for polishing, desalting and buffer exchange. Using this scheme, both high mAb purity (single peak in size exclusion chromatogram, i.e., ca. 100% purity) and high recovery (77% of mAb spiked into the tobacco extract) were achieved. Membrane chromatography is generally considered unsuitable for resolving bound proteins by gradient elution and is therefore commonly used in the bind and elute mode with a single-step change of mobile phase. We show that the gradient elution process in the HIMC step can be optimized to increase the resolution and thereby obtain product of high purity.     

Physical Stability and the Droplet Distribution of Rice Oil–in–Water Emulsion

The objective of the current study was to evaluate long-term stability of emulsions with rice oil by assessing their physical properties. For this purpose, six emulsions were prepared, their stability was examined empirically, and the most correctly formulated emulsion composition was determined using a computer simulation. Variable parameters (oil and thickener content) were indicated with optimization software based on Kleeman's method. Synthesized emulsions were studied by numerous techniques involving determination of particle size and distribution of emulsion, optical microscopy, viscosity, and novelty analysis—Turbiscan test.

The emulsion containing 50 g of oil and 1.2 g of thickener had the highest stability. Empirically determined parameters proved to be consistent with the results obtained using the computer software. The computer simulation showed that the most stable emulsion should contain from 35.93 to 50 g of oil and 0.94 to 1.19 g of thickener. The computer software based on Kleeman's method proved to be useful for fast optimization of the composition and providing parameters of stable emulsion systems. Forming emulsions based on rice oil is a chance to introduce a new, interesting representative of functional food as well as a cosmetic product.     

发芽糙米微量元素锌的生物强化

目的发芽糙米的锌生物强化培育及对人体补锌的适用性探讨。方法选取3个品种(吉梗81号、博优209号、黑糯米)的糙米为材料,用不同质量浓度锌培养液(0~250μg·m L-1)浸种24 h(28℃)并发芽36 h(30℃),在萌发过程中实行锌的生物强化,培育富锌发芽糙米。通过测定不同锌含量条件下发芽糙米的萌发参数(吸水率、发芽率),以及锌、Vc和矿物质(Fe、Mn、Mg)含量,探明培养液锌的适宜含量条件和富锌发米糙米的补锌适用性。结果对吉梗81号、博优209号、黑糯米等3个品种,富锌发芽糙米培育的锌培养液适宜质量浓度均为75~150μg·m L-1,最佳质量浓度为100μg·m L-1。3个品种发芽糙米对锌的富集能力由强到弱顺序为:吉梗81号,博优209号,黑糯米。与对照处理(CK)相比,富锌发芽糙米Vc、GABA含量较高,而矿质元素(Fe、Mn、Mg)渗漏损失略低。富锌发芽糙米每10 g(DW)的锌积累量,对吉梗81号、博优209号及黑糯米等3个品种可提供锌占中国成人RNI百分数分别是:53.8%(男性)和89.7%(女性),45.6%(男性)和76.0%(女性),以及41.1%(男性)和68.5%(女性)。结论发芽糙米可能是进行锌生物强化的优良载体,预计富锌发芽糙米适用于人体补锌。     

基于太赫兹时域光谱技术与PCA-BPN网络的转基因大豆鉴别

基于太赫兹波段内的光谱分析技术以及主成分特性分析与反向前馈神经网络建模,提出了一种转基因大豆鉴别方法.从光谱数据中提取累计方差贡献率达到97.582％的前8种主成分因子,并将其作为输入源导入神经网络模型,通过剔除冗余数据、降低数据维数,所建立的神经网络模型能准确识别校验集.该方法可以实现转基因大豆的快速、无损检测,在农业安全领域有广泛的应用前景.     

Discrimination of transgenic tomatoes based on visible/near-infrared spectra

VIS-NIR spectroscopy combined with multivariate analysis after the appropriate spectral data pre-treatment has been proved to be a very powerful tool for judgment of the relative pattern of the objects that have very similar properties. In this study, seventy transgenic tomatoes with antisense LeETR2 and 94 of their parents, non-transgenic ones were measured in VIS-NIR diffuse reflectance mode. Principal component analysis (PCA), discriminant analysis (DA) and partial least-squares discriminant analysis (PLSDA) were applied to classify tomatoes with different genes into two groups. Calibrations were developed using PLS regression with the leave-one-out cross-validation technique. The results show that differences between transgenic and non-transgenic tomatoes do exist and excellent classification can be obtained after optimizing spectral pre-treatment. The correct classifications for transgenic and non-transgenic tomatoes were both 100% using PLSDA after derivative spectral pre-treatment. The raw spectra with PLSDA model after the second derivative pre-treatment had the best satisfactory calibration and prediction abilities, with r_c = 0.97964, root mean square error of calibration (RMSEC) = 0.099, r_cv = 0.97963, root mean square error of cross-validation (RMSECV) = 0.0993 and a factor. The results in the present study show VIS-NIR spectroscopy together with chemometrics techniques could be used to differentiate transgenic tomato, which offers the benefit of avoiding time-consuming, costly and laborious chemical and sensory analysis.     

Transgenic Artemisia dubia WALL showed altered phytochemistry and pharmacology

The rol genes have been shown to enhance the production of secondary metabolites in plants. This report examines the effect of trans-genes (rol ABC) on possible high production of biologically important phytochemicals and enhanced pharmacological activities. Three transgenic lines (1, 2 and 3) of Artemisia dubia WALL (transformed with Agrobacterium tumefaciens harboring rol ABC genes) were subjected to phytochemical analysis and pharmacological studies. A great variation in phytochemistry and the pharmacological activities was observed not only between the transgenic and non-transgenic control plants but also among the transgenic lines itself. Comparative chemical profile obtained via HPLC, TLC and spectrophotometry showed high degree of variations in the quantity of phytochemicals. An increased production of total flavonoids (71.1% in transgenic line 2) and total phenolics (110.8% in transgenic line 1), increase in caffeic acid and catechin and a decrease in gallic acid content in the extracts of transformed plants compared to the untransformed control plants was decreased. In case of pharmacological activities, moderate to high level increase in antimicrobial (antibacterial and antifungal) activities, cytotoxicity (14.1%), antitumor (29%) and antioxidant activities (23.9%) was observed (in transgenic line 2). In general all the three transgenic lines under study showed improvement in their pharmacological activities in the order of transgenic line 2 > 1 > 3 > control. The implication of these findings will help to meet the increasing demand of pharmacologically important compounds.     

Antioxidant Effects of Anthocyanin-Rich Riceberry™ Rice Flour Prepared Using Dielectric Barrier Discharge Plasma Technology on Iron-Induced Oxidative Stress in Mice

Redox-active iron generates reactive oxygen species that can cause oxidative organ dysfunction. Thus, the anti-oxidative systems in the body and certain dietary antioxidants, such as anthocyanins, are needed to control oxidative stress. We aimed to investigate the effects of dielectric barrier discharge (DBD) plasma technology in the preparation of Riceberry™ rice flour (PRBF) on iron-induced oxidative stress in mice. PRBF using plasma technology was rich in anthocyanins, mainly cyanidine-3-glucoside and peonidine-3-glucoside. PRBF (5 mg AE/mg) lowered WBC numbers in iron dextran (FeDex)-loaded mice and served as evidence of the reversal of erythrocyte superoxide dismutase activity, plasma total antioxidant capacity, and plasma and liver thiobarbituric acid-reactive substances in the loading mice. Consequently, the PRBF treatment was observed to be more effective than NAC treatment. PRBF would be a powerful supplementary and therapeutic antioxidant product that is understood to be more potent than NAC in ameliorating the effects of iron-induced oxidative stress.     

光程变化对基于近红外光谱的黄酒品质检测的影响

以绍兴酒为研究对象,利用近红外光谱分析技术和化学计量学分析方法,开展了光程变化对基于近红外光谱的黄酒品质检测影响的研究,建立了黄酒酒精度、糖度和pH值3个品质指标的分析模型.通过比较0.5,1,1.5,2,2.5和3 mm 6个不同光程,并比较原始光谱、一阶微分光谱和二阶微分光谱三种光谱预处理方式对模型性能的影响,确定了这3个指标的最佳检测方式.黄酒酒精度和pH的最佳检测方式为:光程2 mm,采用偏最小二乘回归结合原始光谱;糖度的最佳检测方式为光程1mm,采用偏最小二乘回归结合原始光谱.这一研究表明光程变化对基于近红外光谱的黄酒品质检测有影响,选择合适的光程能够有效地提高检测精度.     

生物质秸秆热重分析及几种动力学模型结果比较

利用热重分析在不同升温速率和氮气气氛下对两种生物质（玉米秸秆和稻秆）的热失重行为进行了研究。根据热重实验数据，采用四种利用热分析获取动力学参数的方法（Coats-Redfern法，Doyle法，最大速率法和分布活化能模型(DAEM)），计算生物质秸秆热分解反应活化能E、反应级数n及频率因子A，并进行比较。结果表明，采用不同的处理方法，得出的热分解动力学参数不同。利用Coats-Redfern法，玉米秸秆和稻秆在热解主要阶段（失重约5 w%～80 w%时）可由一段一级反应过程描述，升温速率10 K/min时活化能值分别为68.8 kJ/mol和70.0 kJ/mol。Doyle法和DAEM模型得到的结果较为接近，可以得到生物质热解过程中的活化能随失重率的变化曲线。生物质秸秆热解包含分子键能断裂的一系列复杂、连续反应过程。