Circulating exosome‐derived bona fide long non‐coding RNAs predicting the occurrence and metastasis of hepatocellular carcinoma

Although the diagnosis and therapy approach developed, techniques for the early diagnosis of HCC remain insufficient which results in poor prognosis of patients. The traditional biomarker AFP, however, has been proved with low specificity. Circulating exosomal ncRNAs revealed different profiles reflecting the characteristics of tumour. In this study, we mainly focused on circulating exosomal ncRNAs which might be the fingerprint for HCC, especially for the diagnosis or metastasis prediction. A high throughput lncRNA microarray in exosomes extracted from cell‐free plasma was applied. The risk score analysis was employed to screen the potential exosome‐derived lncRNAs in two independent sets based on different clinical parameters in 200 paired HCC patients. After a multi‐stage validation, we finally revealed three lncRNAs, ENSG00000248932.1, ENST00000440688.1 and ENST00000457302.2, increased in HCC comparing with the both chronic hepatitis (CH) patients and cancer‐free controls. ROC curve revealed a higher sensitivity and specificity in predicting the occurrence of HCC from cancer‐free controls and CH patients with the area under curve (AUC) of 0.905 and 0.879 by combining AFP. The three lncRNA panel combined with AFP also indicted a fingerprint function in predicting the metastasis of HCC with the AUC of 0.870. In conclusion, ENSG00000248932.1, ENST00000440688.1 and ENST00000457302.2 might be the potential biomarker for the tumorigenesis prediction from CH patients or healthy controls and may also be applied for dynamic monitoring the metastasis of HCC.     

Identification and evaluation of a potential biocontrol agent,Bacillus subtilis,against Fusarium sp. in apple seedlings

To find a potential biocontrol agent against Fusarium sp. in apple seedlings, an endophytic bacterium strain was isolated from apple tree tissues. The inhibitive efficiency of the isolated strain against the hyphal growth of Fusarium sp. and Rhizoctonia solani was tested. Strain Y-1 showed significant inhibitory effects against Fusarium oxysporum, F. moniliforme, F. proliferatum, F. solani and R. solani. Its antifungal activity against F. oxysporum was the highest, reaching up to 64.90 %. In vivo tests indicated that strain Y-1 effectively protects apple from F. oxysporum infections. The control effect reached 92.26 % when bacterial inoculation was performed 3 days prior to pathogen inoculation. Strain Y-1 could colonize the rhizosphere and tissues within 30 days. It was also able to induce systemic resistance in apple seedlings as shown by the activities of SOD and POD. Strain Y-1 significantly increased the root length, root wet and dry weights, and plant height of the apple seedlings compared with the control group. The homology analysis of the 16S rRNA sequence, together with morphological, physical, and biochemical analyses, revealed that strain Y-1 is Bacillus subtilis.     

城市公园春季声景观与植被结构的关系

城市公园是城市生态系统的重要组成部分和城市生物多样性热点地区,具有丰富的声景观资源。由于声景观及声学方法具有信息量大,成本低,低侵入的特点,因此其研究和应用对生态系统健康及监测具有较高价值。声景观研究通过总结生物声的活动或多样性来衡量生物多样性。记录了北京20个城市公园的春季声景观,使用定量方法描述了声景观特征与变化;测试三种了已被证明与生物多样性相关并被广泛使用的声学指数（BIO、ADI、NDSI）与植被群落关系,完成了城市环境中声景观与环境关系的初步探究。研究结果表明：（1）声学指数能够有效表征城市公园声景观信息,具有显著的时间动态特性,能准确反映鸟类黎明合唱等重要生物生态活动;（2）声学强度指数也具有显著的时间动态变化和沿频率梯度的变化,不同的频率区间反映了不同声学群落的活动信息;（3）植被结构尤其是垂直结构对声景观起着重要作用,垂直异质性越大,声学多样性越高。发现支持声景观作为公园植被状况的度量,强调了其作为生物多样性和生态系统健康状况监测方法,用于城市管理和可持续发展的巨大潜力。     

青海祁连棱果沙棘自然杂交带三种沙棘 光合特性日变化分析

杂交带是研究物种形成及进化的天然实验室。为探究棱果沙棘自然杂交带三种沙棘的生理生态适应性,该研究在光照充足的7月中旬分别测定了该区域三种沙棘雌、雄株的光合特性及相关环境因子的日变化。结果表明:(1)同种沙棘雌、雄株间光合日变化规律基本一致,不同沙棘光合特性的日变化规律存在较大差异。中国沙棘(Hippophae rhamnoides ssp. sinensis)净光合速率(Pn)日变化呈明显的双峰曲线,峰值出现在光合有效辐射(PAR)和空气温度(Ta)相对较高的10:00和14:00,最高达到(19.53±5.35)μmol·m~(-2)·s~(-1);棱果沙棘(Hippophae goniocarpa)和肋果沙棘(H. neurocarpa ssp. neurocarpa) Pn日变化均呈近双峰曲线,在PAR和Ta相对较低的8:00和16:00有较高的值,最高值分别为(13.43±3.43)和(15.27±2.43)μmol·m~(-2)·s~(-1)。(2)三种沙棘水分利用效率(WUE)与Pn的日变化规律一致,但中国沙棘具有最高的WUE,达到(6.72±0.95)μmol·mmol~(-1),棱果沙棘和肋果沙棘的WUE日变化最高分别为(4.03±1.08)和(4.93±0.86)μmol·mmol~(-1)。(3)三种沙棘蒸腾速率(Tr)、气孔导度(Gs)、胞间二氧化碳浓度(Ci)和气孔限制值(Ls)的日变化规律相似,其中Gs均在10:00后一致下降,在12:00左右均出现不同程度的气孔关闭现象,这是其发生光合午休的主要原因之一。杂交带三种沙棘光合特性日变化差异主要表现在中国沙棘和其他两种沙棘之间,而杂交种棱果沙棘与亲本种肋果沙棘的变化规律基本一致,其Pn与WUE可能受到了Ta、PAR和空气相对湿度(RH)等环境因子的影响。     

浅谈间歇式活性污泥法

为了防止水体污染的加重,水处理技术得到了深入研究和迅速发展,从而促进了水质净化新工艺的不断出现和广泛应用。间歇式活性污泥法工艺能满足排放要求、处理效果好、运行费用低,作为一种污水处理新技术、新工艺发展迅速。本文从SBR工艺的基本原理出发,介绍了几种SBR的改良工艺,并突出其工艺特征。     

明永冰川融水中一株裂解性低温噬菌体的分离及特征

【目的】高山冰川是一类独特的生态系统,本研究探索从明永冰川地区分离和培养低温菌噬菌体,并对其特征进行研究。【方法】利用已分离的低温菌为宿主,采用"双层平板法"从明永冰川融水中分离纯化低温菌噬菌体;对噬菌体及其宿主进行电镜形态观察,并进行噬菌体基因组限制性酶切片段长度多态性分析、衣壳蛋白组成分析及噬菌体生理特征研究。【结果】从明永冰川融水中分离获得一株裂解性低温噬菌体,命名为MYSP03(Mingyong Flavobacterium Siphoviridae Bacteriophage),其宿主菌MYB03鉴定为Flavobacterium菌株。噬菌体MYSP03为长尾型,无囊膜,头部具典型的正多面体立体对称结构,直径约72 nm;尾管长约240 nm,直径约10 nm;4℃时具侵染活性,在4℃-20℃范围内均可产生边缘清晰、透明的噬菌斑,最适感染温度约10℃,pH耐受范围较广,最适感染pH约9.4,对氯仿不敏感,基因组为双链DNA,大小约66 kb。