电生理诊断中实时数字滤波器的设计与实现

根据视觉电生理信号的特点，采用计算机软件方法实现了一种消除人体５０Ｈｚ工频干扰的实时带阻滤波器．     

芽殖酵母细胞周期过程不同时期的定量观测

在芽殖酵母中构建CDC10-mCherry和SPC42-mCherry荧光蛋白, 作为酵母细胞周期不同时期的报告系统。根据酵母细胞中芽环(CDC10-mCherry)的产生和消失以及纺锤体极体(SPC42-mCherry)的复制和分离,可以测量细胞周期中 G1期、S期、Early M期和Late M期的时间长度。在此报告系统的基础上, 分别构建S期细胞周期蛋白CLB5-GFP和M 期细胞周期蛋白CLB2-GFP菌株, 实现单细胞观测, 检验报告系统工作的稳定性和准确性。该报告系统可作为研究酵母细胞周期不同时期时间长度等定量生物学问题的背景菌株。     

A novel pattern of fast calcium oscillations points to calcium and electrical activity cross-talk in rat chromaffin cells

Slow oscillations of cytosolic calcium ion concentration – – typically originate from release by intracellular stores, but in some cell types can be triggered and sustained by Ca²⁺ influx as well. In this study we simultaneously monitored changes in and in the electrical activity of the cell membrane by combining indo-1 and patch-clamp measurements in single rat chromaffin cells. By this approach we observed a novel type of spontaneous oscillations, much faster than those previously described in these cells. These oscillations are triggered and sustained by complex electrical activity (slow action potentials and spike bursts), require Ca²⁺ influx and do not involve release from intracellular stores. The possible physiological implications of this new pathway of intracellular signalling are discussed.Received 30 July 2004; received after revision 14 October 2004; accepted 1 November 2004     

微生物油脂花生四烯酸产生菌离子束诱变和发酵调控

某些微生物是高质量油脂的生产者.微生物油脂不仅有益健康,而且是生物柴油潜在的油脂来源.中国是个油脂资源缺乏的国家,开发微生物源油脂具有重要的意义.本文以产油微生物——高山被孢霉菌为出发菌,以单细胞油脂多不饱和脂肪酸产率为筛选目标,采用二步离子束诱变-筛选的策略,获得了高产菌株.研究了高产菌株的营养需求,创建了重复利用提油后的残体(菌粕)合成微生物油脂的技术.针对丝状真菌高密度发酵的传能和传质问题,研制了6×50和4×200m3大容量专用反应器组,单位发酵容积生物量达38.2g/L(发酵液)、油脂20.67g/L.其中具有重要生理活性的花生四烯酸产率最高达9.89g/L,平均为8.97g/L.花生四烯酸提取和精炼后的残油转化为生物柴油,主要指标达到国家生物柴油标准.     

基于生物信息学构建前列腺癌单细胞层面lncRNA-miRNA-mRNA调控网络

利用生物信息学筛选差异表达基因(Differentially Expressed Genes, DEGs),构建前列腺癌(Prostate Cancer, PCa)单细胞层面lncRNA-miRNA-mRNA调控网络,在分子水平上研究前列腺癌的发生发展过程及预后指标。首先从基因表达综合数据库(GEO)和癌症基因组图谱(TCGA)数据库分别下载单细胞RNA测序数据GSE157703和转录组测序数据TCGA-PRAD,通过R语言筛选差异表达信使RNA(DEmRNA)和差异表达长非编码RNA(DElncRNA),利用相关软件预测并构建lncRNA-miRNA-mRNA调控网络;然后使用R语言进行基因本体论(Gene Ontology, GO)和京都基因与基因百科全书(Kyoto Encyclopedia of Genes and Genomes, KEGG)分析,运用STRING数据库、Cytoscape软件建立蛋白相互作用网络,同时对单细胞RNA测序数据进行质控、降维、聚类和分群,构建单细胞层面的lncRNA-miRNA-mRNA调控网络;最后进行生存分析,通过人类蛋白质图谱进行验证。结果...     

Role of extracellular matrix molecules in the development of the sodium current in quail mesencephalic neural crest cells

The occurrence of the voltage-dependent sodium current has been studied in developing neurons from quail mesencephalic neural crest on different substrates, using the whole-cell patch clamp technique. Explants from 9–12 somite embryos were cultured on dishes coated with type I collagen, fibronectin, laminin or on plastic dishes in a chemically defined medium. After 18 h of culture the sodium current was observed in 70% of the neurons tested, and at 24 h some of these neurons were able to generate an action potential. After 18–25 h cells grown on fibronectinor collagen I-coated dishes showed a significantly higher occurrence of the sodium current (83% and 84% respectively) as compared to cells grown on uncoated plastic dishes (51%). Moreover, in the presence of fibronectin, the current density of the sodium current was more than doubled in comparison with cells grown on other substrates.     

Oviposition-deterring pheromone inRhagoletis cerasi L.: Purification and determination of the chemical constitution

Summary An oviposition-deterring pheromone (ODP) of the European cherry fruit flyRhagoletis cerasi L. was isolated from faeces using cellulose and several reverse phase TLC and HPLC procedures. The biological activity was evaluated by means of behavior tests and by electrophysiological recordings from tarsal contact chemoreceptors. The compound was structurally characterized as a N[15(-glucopyranosyl)oxy-8-hydroxypalmitoyl]-taurine by spectroscopic means. The configurations of C-8 and C-15 of the fatty acid constituent remain to be established by synthetic work.     

新型临床用视网膜电图和视觉诱发电位两用仪的研制

介绍了以单板机为基础的ERG(Electroretinegran)和VEP(Visual EvokedPotential)检测仪器。采用平面发光管产生弱光刺激,以皮肤电极检测电信号,并用迭加和滤波方法对信号进行处理,得到视网膜电图和视觉诱发电位。     

营养条件对水华蓝藻铜绿微囊藻的胞外多糖产生的影响

当自然条件下的群体微囊藻转入实验室培养后,它们的胶被多糖往往急剧下降,形态由群体解聚为单细胞。M icrocystis aeruginosaDCA(群体)和M.aeruginosaDCS(单细胞)是同源而形态不同的两株微囊藻,对它们的研究在一定程度上可展示微囊藻群体解聚机制。研究显示两株微囊藻在正常培养基中的生长和EPS产量差异很大,单细胞微囊藻生长快但EPS产量少,群体微囊藻正相反。以单细胞微囊藻为材料研究N,P,S,Fe和EDTA等营养元素对EPS产生的影响,实验浓度为正常培养基中营养元素的5倍和1/5。结果显示,在N缺乏条件下,单细胞微囊藻生长很慢,大约在第6天停止生长,其他营养条件的改变对单细胞微囊藻的生长没有明显的影响,在N缺乏条件下单细胞微囊藻的EPS含量在第3天达到最高,然后急剧下降;5倍的N条件显著刺激EPS的产生,P丰富的条件也轻微刺激EPS的产生。其他营养条件的改变对生长和EPS产生的影响都不明显。我们的结果与一般规律显著不同,即在某些产生EPS的微藻,N缺乏刺激多糖合成。     

Non-invasive scanning ion-selective electrode technique and its applications to the research of higher plants

The process of various ions and molecules getting into and out of cells is critical for plant survival. The non-invasive scanning ion-selective electrode technique (SIET) is a non-invasive method to obtain the information of ions/molecules across membranes in plant. This technique can measure the absolute concentration of ions and molecules, and also their fluxes and directions of movement. The samples to be analyzed can be a single cell, a piece of tissue, a whole organ and even an intact seedling. This article reviews the recent progress made in plant physiology by using this technique and discusses its potentials in future studies on plant physiology.