华南地区海水养殖鱼类主要弧菌病原的分离与鉴定

对海南、广东、广西等华南地区的主要海水养殖系统的斜带石斑鱼、红鳍笛鲷、褐点石斑鱼和珍珠龙胆(棕点石斑鱼♀×鞍带石斑鱼♂)等多种海水鱼类的弧菌病开展了流行病学调查,从病鱼体内共分离获得弧菌63株,人工感染试验结果表明,其中4株为强毒株,17株为弱毒株,42株为无毒株.经鉴定,哈维氏弧菌有43株(19株毒力株)、溶藻弧菌7株(1株毒力株)、副溶血弧菌5株、轮虫弧菌2株(1株毒力株)、需钠弧菌1株、无法确定的弧菌属其他细菌5株.     

广西北部湾大宗海水养殖鱼类卵形鲳鲹感染溶藻弧菌及其致病性研究

【目的】2016年广西钦州湾近海网箱养殖的卵形鲳鲹(Trachinotus ovatus)发生以体表皮肤溃烂、皮下出血、内脏器官病变为典型症状的细菌性疾病,通过对患病卵形鲳鲹中病原菌进行分离、鉴定与保存,为后续开展病原菌快速检测技术和防控技术等研究,以及控制相关病原菌在海水养殖中的暴发和流行奠定基础。【方法】利用LB平板和TCBS平板从患病卵形鲳鲹体表溃烂病灶、肾脏、肝脏组织中分离纯化疑似病原菌,并对其进行常规形态特征和生理生化反应的生物学检验,通过16SrDNA基因测序对疑似病原菌株进行分子生物学鉴定,在细胞和鱼体水平开展病原菌的致病性研究,同时进行人工感染的回接试验。【结果】分离得到4株疑似病原菌(TOQZ01,TOQZ02,TOQZ03,TOQZ04),基于其表型、分子生物学特征和进化关系,判定4株菌株均为弧菌属的溶藻弧菌(Vibrio alginolyticus),且细胞毒性试验和回归试验证实,分离得到的溶藻弧菌为此次卵形鲳鲹发病的病原菌。【结论】溶藻弧菌是引起广西沿海地区海水养殖鱼类发生细菌性鱼病的主要致病菌之一,未来将基于本研究中分离得到的溶藻弧菌开展病害快速检测技术和防控技术等现代海水生态健康养殖关键技术研究,以实现对广西海水养殖溶藻弧菌病的快速诊断、实时监控和有效预防。     

黄连水提物对卵形鲳鲹源溶藻弧菌的抑菌作用

卵形鲳鲹(Trachinotus ovatus)是一种生长快速且肉质鲜美的经济型海水养殖鱼类,但是近些年为满足人们的日常需求,在不断扩大养殖的同时病菌也逐渐泛滥。溶藻弧菌(Vibrio alginolyticus)是华南沿海地区海水养殖鱼类细菌性鱼病的主要致病菌之一,给水产养殖业带来巨大损失。本研究对黄连(Coptis chinensis Franch)的抗菌作用进行系统研究,目的是为由溶藻弧菌引起的爆发性细菌性鱼病的高效防治提供科学的用药依据。本研究采用二倍稀释法测定黄连水提物对卵形鲳鲹源溶藻弧菌的最低抑菌浓度(MIC)、最低杀菌浓度(MBC)和半数致死量(LD50),并使用BCA蛋白浓度测定试剂盒测定细菌超声破碎上清液中可溶性蛋白含量。结果表明,黄连水提物对溶藻弧菌具有明显的抑制作用,其对溶藻弧菌的MIC、MBC和LD50的值分别为7.800mg/mL、31.250mg/mL和15.625mg/mL。胞内可溶性蛋白含量变化的结果提示:黄连发挥抑菌作用的机制可能是通过损伤细菌的细胞壁导致细菌内容物的释放并引起菌体裂解死亡。黄连具有发展成为一种高效抗水产病害中草药制剂的潜力。     

海南地区养殖石斑鱼皮肤溃疡病病原的分离、鉴定、药敏分析及病理学研究

2016年,针对海南岛沿岸9个石斑鱼养殖场的石斑鱼皮肤溃疡病的调查发现,该疾病的发病面积广、死亡率高,对养殖产业的危害严重.从9个采样点3种患病石斑鱼样品的组织中分离得到了9株优势菌株,人工回感试验表明,其感染特征与自然病症一致,证明这9株菌均为皮肤溃疡病的致病原,在经过生理生化和16S r DNA序列分析后,这9株菌均被鉴定为哈维氏弧菌(Vibrio harveyi).人工回感试验证实,菌株SY-1对珍珠龙胆石斑鱼的毒力最强,其14天每克鱼体重的半致死剂量(LD50值)为7.18×10~4cfu;药敏实验的分析表明,这9株病原菌对34种抗菌药物的药敏谱基本一致,但对氟苯尼考、强力霉素、四环素等药物高度敏感;病理学的研究表明,患病鱼的鳃丝、皮肤、肌肉、肝脏、脾脏、肾脏、肠道和脑等组织器官都发生了不同程度的病理变化,因此认为该病为全身性感染.本研究表明,目前海南地区养殖石斑鱼皮肤溃疡病的致病原有较高的病原同一性,主要为哈维氏弧菌;而较早报道的溶藻弧菌、副溶血弧菌等致病菌的优势度大大降低了,其致病力有所下降,并且与海南地区养殖石斑鱼皮肤溃疡病的相关度不大.     

网箱养殖石斑鱼暴发性溃疡病病原菌分离、鉴定及致病性研究

调查了1996～1998年海南省各地网箱养殖石斑鱼暴发性溃疡病的病症、流行特点,通过细菌学常规鉴定和人工感染以及重复感染试验,初步确认病原菌为溶藻弧菌(Vibrioalginolyticus),并研究其生理生化特性．     

闽南地区紫石斑(Epinephelus lanceolatus)幼鱼爆发性传染病的病原学研究

应用RT-PCR技术．检测了福建南部石斑鱼育苗场患病紫石斑鱼的病原．结果检出神经坏死病毒；对该病毒的RT-PCR产物进行了核酸测序和序列分析．与基因库中马拉巴斑和紫石斑神经坏死病毒编码病毒核衣壳蛋白的基因片段序列的同源性大于97％．病原菌分离鉴定结果．有2菌株分别是溶藻弧菌和豚鼠气单胞菌．对实验动物有一定的毒力．药敏试验表明这些菌株对常用抗生素表现耐药．临床症状和实验结果都表明．神经坏死病毒感染是导致石斑鱼大批死亡的主要原因．而溶藻弧菌和豚鼠气单胞菌应为继发感染．加重了病情．使更多的石斑鱼死亡．     

五种常用药物对鲑点石斑鱼鱼种的毒性试验

鲑点石斑鱼 Epinephelus fario,俗称芝麻斑。其生长快,肉质细嫩,肉味鲜美,是一种经济价值很高的海水鱼类,并可摄食人工配合饲料,在南方的市场广大,价格高,现已成为南方海水网箱养殖的主要品种之一。为使该鱼养殖能健康发展,防治疾病是一项重要的研究内容。为此,笔者进行了鲑点石斑鱼鱼种对五种常用鱼药的毒性试验,以便能正确掌握各种药物的使用及剂量,为此鱼在养殖过程中的病害防治工作提供一些科学的依据和参考。 1材料与方法 1.1试验鱼 　　试验鱼种为从新加坡万丰渔场引进的鱼种,平均体长 8.65 cm,平均体重 27.86 g。试验…     

中国南方沿海13种石斑鱼类的分子系统进化关系分析

石斑鱼类(Groupers)是世界性海洋经济鱼类,也是中国南方沿海省份重要的海水增养殖对象,其种类繁多,由于缺乏明显的种间外部形态区别特征,石斑鱼的分类一直是鱼类系统分类学的一个难题,存在着较多的争议和混淆。为了从分子水平揭示石斑鱼类的系统进化关系,应用线粒体细胞色素b基因(Cyt b)及两个核糖体RNA基因(16S和12S)序列联合构建系统进化树对中国近海石斑鱼亚科3属13种进行种类鉴定及亲缘关系分析,探讨了石斑鱼类的分子系统进化。结果表明:①线粒体基因序列在石斑鱼类种间存在较大的变异,种内变异极小,是进行石斑鱼类种类鉴定较为适宜的分子标记;②所研究的3属13种石斑鱼类中,石斑鱼属与九棘鲈属的亲缘关系较近,与鳃棘鲈属的较远;③赤点石斑鱼和青石斑鱼、蜂巢石斑鱼与鲑点石斑鱼、斜带石斑鱼与棕斑石斑鱼两两间具有较近的亲缘关系。     

小熊猫源大肠杆菌病的病理诊断与病原鉴定

大肠埃希氏菌的致病性血清型菌株可引起幼龄动物严重的腹泻与败血症。采用常规病理学方法,剖检死亡小熊猫(Ailurus fulgens)并取肠道和实质器官做组织学观察,发现其病变特征为坏死性肠炎及败血症。从肝、脾、肾中无菌分离培养出致病菌,经革兰氏染色及16S rDNA测序鉴定为大肠杆菌。经小鼠毒力实验测得该菌半数致死量LD_(50)为6. 5×10~7CFU,并且从攻毒小鼠脏器分离得到了相同的大肠杆菌。结论:该小熊猫致死原因为致病性大肠杆菌感染。     

一株海洋蛭弧菌类生物对海水细菌的生物控制和水质的影响

 研究了一株海洋蛭弧菌类生物(Bdellovibrio-and-like organisms,BALOs) DA5与溶藻弧菌（Vibrio alginolyticus）在海水中共培养时的相互作用;并研究了DA5对添加营养的自然海水中细菌的生物控制效果及对水体pH、化学需氧量(COD)、氨氮(NH₃-N)和亚硝酸氮(NO₂-N)含量的影响。结果表明DA5在振荡培养条件下对溶藻弧菌具有明显的裂解作用,较高的感染比有助于快速减少寄主菌,但长时间的共培养也不能完全清除溶藻弧菌。DA5对自然海水中异养细菌和弧菌均有一定的清除作用,且对弧菌的消减作用更明显,但对水体pH、COD、NH₃-N和NO₂-N含量均无显著影响,且BALOs含量总体上与细菌或弧菌的含量呈正相关。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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