极大螺旋微藻(分节螺旋属)在一六面体光合生物反应器中生物合成13C标识氨基酸和糖

This paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope ^13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreactor.The kinetic data of both batch and continuous cultures with characterization of the amino acids and sugars are shown. The continuous culture without nutrients deficiency is for biosynthesis of amino acids, with tyrosine as one of the principal constituents, and the batch culture with deficiency in nitrogen is for biosynthesis of labeled glucose that is uv to 64% versus dry mass of cells.     

孤立奇异性信号的分段脊寻踪*

现有的稀疏过完备表示的贪婪寻踪方法（如匹配寻踪、正交匹配寻踪等）的原子选取策略大多是针对一般性信号和字典的,对于一些具有特殊结构的信号和字典,其保稀疏性和收敛性较差。针对孤立奇异性信号和多尺度字典,基于分段正交匹配寻踪方法和小波变换的模极大理论,提出了分段脊寻踪方法。由于分段脊寻踪使用伪逆计算残差在局部字典下的最小2范数解,给出了最小2范数解是最小0范数解的充要条件。数值实验进一步表明了分段脊寻踪方法的保稀疏性、超分辨性和收敛性,在分析孤立奇异性信号时,优于现有方法。     

基于小波变换的信号重构

在信号分析中,奇异点和不规则性经常携带有重要的信息．文中利用小波变换模极大值对应的点来提取奇异点,并讨论了如何运用凸集上投影的方法来重构原始信号．     

Fully automatic brain tumor extraction and tissue segmentation from multimodal MRI brain images

Segmentation of Brain tumor from the magnetic resonance imaging (MRI) of head scans is an essential requirement for clinical diagnosis since manual segmentation is a fatigue and time‐consuming process. Recent computer‐aided diagnosis systems depend on the development of fully automatic methods to overcome these problems. In the present work, a fully automated algorithm is proposed to extract and segment tumor regions from multimodal magnetic resonance imaging (MMMRI) sequences. The algorithm has three phases: (a) tumor portion extraction, (b) tumor substructure segmentation, and (c) 3D postprocessing. First, the algorithm extracts tumor portion using a set of image processing operations from T2, fluid‐attenuated inversion recovery (FLAIR), and T1C images. Here, the proposed modified fuzzy c means clustering algorithm is used for enhancing the tumor portion extraction process. Then, the substructures of tumor such as edema, enhancing tumor, and necrotic regions are segmented from MMMRI sequences, T2, FLAIR, and T1C using region‐wise set operations in Phase II. Finally, 3D visualization of the segmented tumor and volume estimation is performed as postprocessing in Phase III. The proposed work was experimented on BraTS 2013 dataset. The quantitative analysis is performed using William's Index, Dice, sensitivity, specificity, and accuracy and is compared with 19 state‐of‐the‐art methods. The proposed method yields comparable results as 77%, 53%, and 59% of Dice for complete, core, and enhancing tumor regions, respectively.     

基于LabVIEW和小波分析的电力电缆故障定位方法

在分析行波法故障测距误差的基础上,根据小波变换模极大值在不同尺度下的特性,运用自相关分析提供的约束条件,基于LabVIEW平台,实现了对故障信号的准确识别和定位,准确测算出故障点的位置。大量的仿真测试表明,该方法故障测距精度较高,定位较为准确,同时具有界面友好、维护和升级方便、成本低廉、整个系统的功能可根据用户的具体要求实时调节等优良性能。     

LIR序关系的特征

讨论了广义TTT变换序与位置独立风险序之间的关系,证明了位置独立风险序关于简单随机样本和随机样本数目的极大值的反向保序性,并讨论了位置独立风险序关系的一些矩的不等式。     

带有极大值项的中立型差分方程的渐近性

考虑一类带有极大值项的中立型差分方程,得到了方程非振动解渐近性的若干结果,即方程的所|xn|=∞的充分条件,推广了已有文献中的相关结果.有非振动解{xn}满足limxn=0或limn→∞n→∞     

Insights into the structural characterisations,bioactivities and their correlations with water-soluble polysaccharides extracted from different pomelo (Citrus maxima Merr.) tissues

Pomelo (Citrus maxima Merr.), known as a famous fruit and folk medicine, is widely cultivated in China. Nonedible pomelo tissues contain peels, seeds, and segment membranes, which generally being discarded. Polysaccharides relationships among different pomelo tissues remain uncertain. Four water-soluble polysaccharides, PPPs, PSPs, FPPs and SMPs, were extracted from pomelo peels, seeds, pulps and segment membranes, respectively. Molecular structure and conformation were investigated by a combination of chemical and instrumental analyses. PPPs and FPPs were consisted of Ara, GalA, GlcA, Rha, Glc, Xyl and Gal, while PSPs and SMPs did not contain GalA and Gal. The average molecular weight (Mw) of PPPs, PSPs, FPPs and SMPs was 4.604 × 10⁵, 10.85 × 10⁵, 5.795 × 10⁵ and 16.06 × 10⁵ Da, respectively. PPPs, PSPs and SMPs all showed totally spherical structures, while FPPs primarily comprised linear chains. The structures–bioactivities correlations analysis revealed that low-Mw polysaccharides had strong DPPH•, OH• scavenging and HeLa cells inhibiting activities. These data revealed that the bioactivities of pomelo tissues polysaccharides were not a function of a single factor but a combination of various characteristics.     

Carotenoid composition and retinol equivalent in plants of nutritional and medicinal importance: Efficacy of β-carotene from Chenopodiumalbum in retinol-deficient rats

This study aimed to (1) quantify carotenoids in leafy vegetables and plants of nutritional and medicinal importance, (2) evaluate retinol equivalent (RE) of provitamin-A carotenoids and (3) determine efficacy of β-carotene from Chenopodium album and to compare with retinol formed on feeding to retinol-deficient rats for 3 weeks. β-Carotene and lutein contents (mg/100 g dry weight) ranged from 1.5 to 120 and 11.7 to 185 (leafy greens) and 0.4 to 34.7 and 11.8 to 679 (medicinal plants) whereas, α-carotene ranged from 0.3 to 35.6 (leafy greens) and 0.1 to 15.7 (medicinal plants). RE values (mg%) ranged from 0.4 to 20 and 0.42 to 5.8 in leafy greens and medicinal plants. Efficacy of β-carotene (2400 μg/kg diet) from C. album in retinol-deficient rats revealed a 93.6% rise in plasma retinol levels from 0.53 to 8.4 μM. The plants analysed are a good source of retinol precursors and biologically active lutein; therefore can be exploited to meet carotenoid requirements.