苋菜红在银基汞膜电极上伏安特性的研究

本文讨论了不同条件下苋菜红在银基汞膜电极上的伏安行为.发现在 pH=4时,苋菜红在-0,24V 处有很灵敏的检出信号,在此条件下,汞膜电极有良好的再现性和使用寿命;在10-100ppb 范围内,还原电流与浓度呈良好的线性关系.     

大型煤电基地开发生态累积效应及定量分析方法研究

大型煤电基地(CEBs)是我国煤基能源和材料集中开发区域和国家能源战略安全重要支撑，合理评价CEBs开发生态影响是CEBs可持续协调开发、科学管理中的难点问题。研究将CEBs开发视为系统工程，与自然生态系统(NES)相关联，深入研究大型煤电基地生态系统(CEBES)的驱动行为、内在结构及主要关系、生态影响途径、生态累积过程和生态累积效应及阈值分析方法。基于CEBs空间和功能定位提出CEBs的概念、内涵和特点，融合构建的CEBES涵盖到自然资源、能源开发行为(煤、电等)、其他人类活动(农、牧、城)和大气、水、土壤及生物域；研究表明CEBES的生态累积状态受三种行为驱动和影响(自然行为、能源开发行为和其他人类活动),通过融合、传导和辐射耦合作用，表现为生态要素损伤、系统结构变化和系统状态失衡三级状态，生态累积具有影响多态性、空间多尺度和过程渐变性特点；明确了生态累积过程、累积效应和阈值及其相互关系，引入反映生态影响累积程度的生态损伤系数，提出四类生态阈值(生态要素、内部结构、系统状态和行为调控);基于系统性和实用性筛选反映生态累积相对状态的60项指标，构建具有“三力”驱动、分区要素耦合和系...     

Amplified Fragment Length Polymorphism (AFLP) Provides Molecular Markers for the Identification of Caladium bicolor Cultivars

Caladiums are popular ornamental plants that have not been wellstudied at the molecular level. Identification of species withinthe genus Caladium (Araceae) has been based primarily on morphology.However, the lack of comprehensive references makes identificationof Caladium cultivars extremely difficult. Amplified fragmentlength polymorphism (AFLP) analysis using 17 primer combinationswas carried out on two species of Caladium (C. bicolor and C.schomburgkii), including six cultivars of C. bicolor. Resultsshowed that AFLP can be used to distinguish these two speciesby their unique and different banding patterns. Unweighted PairGroup Method using Arithmetic Averages (UPGMA) permitted clusteranalysis of data from 17 selected primer combinations on sixcultivars of C. bicolor and one cultivar ofC. schomburgkii .It showed that closely related species can clearly be differentiatedand that genetic difference between cultivars can also be established.Unique AFLP molecular markers were detected for all the C. bicolorcultivars used. The use of AFLP has potential for preciselycharacterizing and identifying particular caladium cultivarsas well as for the registration of new cultivars. It will alsobe useful in future breeding programmes and systematics studies.Copyright 1999 Annals of Botany Company Araceae, Caladium species and cultivars, AFLP DNA fingerprinting, diversity, AFLP markers.     

Lectin Binding Assays for In-Process Monitoring of Sialylation in Protein Production

Many therapeutic proteins require appropriate glycosylation for their biological activities and plasma half life. Coagulation factor VIII (FVIII) is a glycoprotein which has extensive post-translational modification by N-linked glycosylation. The terminal sialic acid in the N-linked glycans of FVIII is required for maximal circulatory half life. The extent of FVIII sialylation can be determined by high pH anion-exchange chromatography coupled with a pulse electrochemical detector (HPAEC-PED), but this requires a large amount of purified protein. Using FVIII as a model, the objective of the present study was to develop assays that enable detection and prediction of sialylation deficiency at an early stage in the process and thus prevent downstream product quality excursions. Lectin ECA (Erythrina Cristagalli) binds to unsialylated Galβ1-4 GlcNAc and the ECA-binding level (i.e., terminal Gal(β1-4) exposure) is inversely proportional to the level of sialylation. By using ECA, a cell-based assay was developed to measure the global sialylation profile in FVIII producing cells. To examine the Galβ1-4 exposure on the FVIII molecule in bioreactor tissue culture fluid (TCF), an ELISA-based ECA-FVIII binding assay was developed. The ECA-binding specificity in both assays was assessed by ECA-specific sugar inhibitors and neuraminidase digestion. The ECA-binding specificity was also independently confirmed by a ST3GAL4 siRNA knockdown experiment. To establish the correlation between Galβ1-4 exposure and the HPAEC-PED determined FVIII sialylation value, the FVIII containing bioreactor TCF and the purified FVIII samples were tested with ECA ELISA binding assay. The results indicated an inverse correlation between ECA binding and the corresponding HPAEC-PED sialylation value. The ECA-binding assays are cost effective and can be rapidly performed, thereby making them effective for in-process monitoring of protein sialylation.     

Monitoring the microbial community succession and diversity of Liangzhou fumigated vinegar during solid-state fermentation with next-generation sequencing

This study reveals the microbial community succession and diversity during the whole solid-fermentation processes of naturally fermented Liangzhou fumigated vinegar (LZFV). Dynamics and diversity of microbial community succession in “Daqu” starter and other fermentation stages (starch saccharification, alcoholic fermentation, and acetic acid fermentation) were monitored using a metagenomic approach involving high-throughput sequencing. Meanwhile, dynamic changes of characteristic flavor compounds of vinegar were determined by gas chromatograph (GC) analysis. The result showed that the microbiota composition exhibited rich diversity. Twenty-five bacterial and 18 fungal genera were found in the whole fermentation process where Lactobacillus, Acetobacter, Aspergillus, Saccharomyces, and Alternaria were the predominant microorganisms. Alpha diversity metrics showed that bacterial diversity in Daqu was greater than that in AF and AAF. By contrast, fungal diversity increased from Daqu to AF and decreased in the initial stage (5–8 days) of AAF then remained relatively steady. Hence, these results could help understand dynamics of microbial community succession in continuous fermentation of traditional Chinese vinegars. The LZFV fermentation is a continuous process with spontaneous growth that affects the dynamics of microbial communities. Continuous changes of micro-environment conditions in substrate affect the diversity and structure of microbiota. Microbial growth and metabolism were closely related to the changes in the physicochemical characteristics of the cultures. The microbial flora composition showed rich diversity, and with the increase in brewing time and the change in micro-ecological environmental conditions; the microbial community showed a complex dynamic changes.

     

蝉虫草样品的分级萃取与化学成分分析

利用索氏萃取技术,依次采用石油醚、乙酸乙酯、丙酮、无水乙醇和甲醇等5种溶剂对蝉虫草纯粉进行分级萃取,运用傅里叶变换红外光谱分析法和气相色谱-质谱联用技术对5级萃取物进行分析鉴定。傅里叶变换红外光谱分析显示萃取物中含有与烯烃类、羧酸类、酯类、醇类和酮类等化合物相关的C-H、C=O、C-O和C=C等官能团。气相色谱-质谱联用技术共鉴定出有机小分子化合物34种,以酯类和脂肪酸类为主,多为碳链长度为15-20的长链脂肪酸及对应的酯,其中十八碳不饱和脂肪酸相对含量高达28.95%;分别存在于两种或以上萃取物中的有机化合物共有11种;仅存于石油醚萃取物中的化合物6种,乙酸乙酯萃取物中3种,丙酮萃取物中2种,无水乙醇萃取物中6种,甲醇萃取物中6种。在一定极性范围内,利用溶剂的极性梯度变化,可实现蝉虫草中活性物质的按极性梯度分离;采用分级萃取技术可有效分离蝉虫草中部分化学成分。鉴定结果充实了蝉虫草中化合物的种类资源,为蝉虫草中活性物质谱图库的完善、构效关系的建立及蝉虫草产品的利用开发提供支撑。     

独活寄生汤加减治疗对风寒湿痹型腰椎间盘突出症患者生活质量、自由基代谢及睡眠质量的影响

目的:探讨独活寄生汤加减治疗对风寒湿痹型腰椎间盘突出症(LIDP)患者生活质量、自由基代谢及睡眠质量的影响。方法:选取2012年1月～2017年12月期间海南省中医院骨一科收治的风寒湿痹型LIDP患者286例。采用随机数字表法将患者分为对照组(n=143)和研究组(n=143),对照组给予常规治疗,研究组在对照组基础上联合独活寄生汤加减治疗,比较两组临床疗效,比较两组治疗前、治疗30 d后生活质量、自由基代谢及睡眠质量情况,记录两组治疗期间不良反应情况。结果:研究组临床总有效率为93.71%,显著高于对照组的66.43%(P0.05)。治疗30 d后,两组患者超氧化物歧化酶(SOD)水平升高,且研究组高于对照组(P0.05),丙二醛(MDA)水平降低,且研究组低于对照组(P0.05)。两组患者治疗前、治疗30d后活力(VT)、社会功能(SF)评分比较无差异(P0.05),两组患者治疗30d后躯体功能(PF)、躯体疼痛(BP)、躯体角色(RP)、心理健康(MH)、总体健康(GH)以及情感角色(RE)评分均较治疗前升高,且研究组较对照组升高(P0.05)。两组患者治疗30 d后匹兹堡睡眠质量指数(PSQI)评分均较治疗前降低,且研究组低于对照组(P0.05)。两组患者治疗期间不良反应发生率比较无统计学差异(P0.05)。结论:独活寄生汤加减治疗风寒湿痹型LIDP患者疗效确切,其可有效改善患者生活质量、自由基代谢及睡眠质量,且安全性较好,具有一定的临床应用价值。     

DELAYED HEADING DATE1 interacts with OsHAP5C/D,delays flowering time and enhances yield in rice

Heading date is an important agronomic trait affecting crop yield. The GRAS protein family is a plant‐specific super family extensively involved in plant growth and signal transduction. However, GRAS proteins are rarely reported have a role in regulating rice heading date. Here, we report a GRAS protein DHD1 (Delayed Heading Date1) delays heading and enhances yield in rice. Biochemical assays showed DHD1 physically interacts with OsHAP5C/D both in vitro and in vivo. DHD1 and OsHAP5C/D located in the nucleus and showed that rhythmic expression. Both DHD1 and OsHAP5C/D affect heading date by regulating expression of Ehd1. We propose that DHD1 interacts with OsHAP5C/D to delay heading date by inhibiting expression of Ehd1.     

Inhibition of circular RNA CDR1as increases chemosensitivity of 5‐FU‐resistant BC cells through up‐regulating miR‐7

This study aims to explore the mechanism of Circular RNA CDR1as implicating in regulating 5‐fluorouracil (5‐FU) chemosensitivity in breast cancer (BC) by competitively inhibiting miR‐7 to regulate CCNE1. Expressions of CDR1as and miR‐7 in 5‐FU‐resistant BC cells were determined by RT‐PCR. CCK‐8, colony formation assay and flow cytometry were applied to measure half maximal inhibitory concentration (IC50), 5‐Fu chemosensitivity and cell apoptosis. Western blot was used to detect the expressions of apoptosis‐related factors. CDR1as was elevated while miR‐7 was inhibited in 5‐FU‐resistant BC cells. Cells transfected with si‐CDR1as or miR‐7 mimic had decreased IC50 and colony formation rate, increased expressions of Bax/Bcl2 and cleaved‐Caspase‐3/Caspase‐3, indicating inhibition of CDR1as and overexpression of miR‐7 enhances the chemosensitity of 5‐FU‐resistant BC cells. Targetscan software indicates a binding site of CDR1as and miR‐7 and that CCNE1 is a target gene of miR‐7. miR‐7 can gather CDR1as in BC cells and can inhibit CCNE1. In comparison to si‐CDR1as group, CCNE1 was increased and chemosensitivity to 5‐Fu was suppressed in si‐CDR1as + miR‐7 inhibitor group. When compared with miR‐7 mimic group, CDR1as + miR‐7 mimic group had increased CCNE1 and decreased chemosensitivity to 5‐Fu. Nude mouse model of BC demonstrated that the growth of xenotransplanted tumour in si‐CDR1as + miR‐7 inhibitor group was faster than that in si‐CDR1as group. The tumour growth in CDR1as + miR‐7 mimic group was faster than that in miR‐7 mimic group. CDR1as may regulate chemosensitivity of 5‐FU‐resistant BC cells by inhibiting miR‐7 to regulate CCNE1.