网湖似刺鳊Ju种群生长和死亡率研究

本文根据６６９尾标本,研究长江中游网湖小型经济鱼类似刺鳊Ｊｕ的种群生长和死亡率,从理论推导证明,鱼类的生长拐点与其临界年龄是一致的,并据以对网湖似刺鳊Ｊｕ等小型经济鱼类的合理渔业对策问题进行了初步分析讨论。     

傀儡湖似刺鳊种群生长特征及资源量评估研究

2013年4月至2014年12月,在昆山市傀儡湖开展了似刺鳊种群生长特征及资源量评估的研究.结果表明,傀儡湖似刺鳊种群共有6个年龄组,优势年龄组为1至2龄,占总数的72.18％;其次为3至4龄年龄组(22.59％);5至6龄年龄组仅占4.62％.全长与体重呈幂函数的增长关系:W=0.0037L3.3137(n=51...     

太湖似刺鳊(鱼句)年龄和生长的研究

本文较为详细地研究了太湖似刺鳊(鱼句)(Paracanthobrama guichenoti Bleeker)的年龄和生长,并对种的繁殖保护措施作了探讨。共积累756尾标本的生物学资料。     

长江中游鱼类单殖吸虫寄生于鯿鲌亚科的指环虫

鳊鲌亚科(Abramidinae)在我国分布广泛,是土著食用鱼类,颇有经济价值。自1961年以来,我们先后检查了产自湖北(武汉市郊野芷湖,武昌、咸宁、蒲圻、嘉鱼四县之间的西涼斧头湖,嘉鱼县三湖连江和所在的长江地段)的12种鳊鲌鱼类,共获指环虫44种。本文报告寄生于11种鳊鲌鱼类鳃上指环虫42种和一种鳊镰爪虫(寄生于似鱎鳃上的种类     

昆承湖优势种鱼类时空-营养生态位

为了解昆承湖优势种鱼类资源利用情况,首先利用生态位方法计算了时间、空间及营养三个资源维度的生态位宽度及重叠值,然后根据时空-营养生态位宽度值将优势种鱼类划分为广位种、中位种和窄位种,最后讨论了生态位宽度及重叠的可能原因。结果显示：刀鲚Coilia nasus、蒙古鲌Chanodichthys mongolicus、似鱎Toxabramis swinhonis、似鳊Pseudobrama simoni、鳙Hypophthalmichthys nobilis、鲢Hypophthalmichthys molitrix、花鱼骨Hemibarbus maculatus、似刺鳊鮈Paracanthobrama guichenoti、大鳍鱊Acheilognathus macropterus和鲫Carassius auratus为优势种。在时间维度：鲢的生态位宽度最大,似鳊的最小;生态位重叠具有显著意义的有24对,占总的53.33%。在空间维度,似刺鳊鮈最大,鲢最小;生态位重叠具有显著意义的有36对,占总的80%。在营养维度,最大的为鲫,最小的为花鱼骨;生态位重叠具有显著意义的有8对,占17.78%...     

长江河口潮间带鱼类群落的时空变化

根据2006年3-11月每月在长江口4个潮间带站点的36网次鱼类采样数据,分析了该水域鱼类群落组成的时空变化特征.结果表明：本次调查采获鱼类55种,隶属20科,其中,鲤科鱼类最多,有18种,占总种数的32.7%,虾虎鱼科其次,有8种,占14.5%,石首鱼科4种,占7.3%;调查水域潮间带鱼类群落可分为口内淡水区鱼类群落和河口咸淡水区鱼类群落2组,河口咸淡水区鱼类的物种多样性比口内淡水区略低,其中,口内淡水区以油似鳊和鳊等淡水鱼类为优势种,河口咸水区以斑尾刺虾虎鱼、鲻和棘头梅童等咸淡水鱼类为优势种;二组间鱼类种类组成的平均相异性为80.75%,23种鱼类对平均相异性的累积贡献率>90%,主要贡献来自油鲻、斑尾刺虾虎鱼、棘头梅童鱼、似鳊、红狼牙虾虎鱼、鲫、鳊和长蛇鮈等;春季的研究区鱼类群落丰度与夏、秋两季均存在一定程度的差异,而夏、秋两季间的差异相对较小.就单组鱼类群落丰度而言,水温对其季节变化的影响较盐度大,而盐度对整个河口鱼类群落的影响较水温大.     

似刺鳊鮈外周血细胞显微结构和血清生化指标的初步研究

似刺鳊(鮈)(Paracanthobrama guichenoti)外周血细胞可分为红血细胞、嗜中性粒细胞、单核细胞及大、小淋巴细胞和血栓细胞,未发现嗜酸性和嗜碱性粒细胞.外周血液中可观察到少量未成熟的及正在分裂的红血细胞.白细胞中,血栓细胞体积最小,嗜中性粒细胞体积最大;数量上,血栓细胞最多,而大淋巴细胞则最少.似刺鳊(鮈)血清生化指标测定结果显示,谷丙转氨酶(ALT)、胆固醇(CHOL)和总蛋白(TP)变化范围较大,且谷草转氨酶(AST)的水平较高,似刺鳊(鮈)雄鱼的血液生化指标相应值均显著低于雌鱼(P<0.05).     

生石灰、巴豆、茶粕清塘比较试验（附石灰带水清塘法）

我国池塘养鱼专业有着悠久的历史,饲养的种类有鲩（草鱼）,青,鲢,鳙,鲤,鳊,鲮等,通常称为“家鱼”,而生长在池塘里的其他鱼类如刺鳅（Mastacembelus aeuleatus),黄鳝（Monopterus albus),鳗鲡（Anguilla japonica),鲫（Carassius auratus),     

基于水声学探测的香溪河鱼类资源时空分布特征评估

为了掌握三峡水库香溪河鱼类资源时空分布特征, 2013 年5 月和11 月运用Simrad EY60 型分裂波束回声探测仪在香溪河进行了水声学探测, 辅以常规渔获物分析方法。渔获物调查共发现鱼类7 科41 种, 其中似鳊、贝氏、、银和蛇等小型鱼类在数量上占据优势地位。水声学探测结果表明, 香溪河春季鱼类密度显著高于秋季, 采用加权平均法求得2013 年5 月和11 月探测的鱼类密度分别为53.4 和15.4 ind./1000 m3。鱼类资源在空间上不均匀分布, 从高岚河至香溪河口鱼类密度逐渐降低;在垂直方向上, 春季和秋季水声学探测的鱼类密度显示出相同的趋势, 即表层 中层 底层。在运用鱼类生物操纵改善水质途径方面, 建议通过壮大肉食性鱼类种群来控制小型鱼类资源量, 同时通过增殖放流鲢、鳙以加强对浮游植物的滤食作用。       

岷江眉山段四川华鳊年龄与生长

为了解我国长江上游特有鱼类四川华鳊Sinibrama taeniatus种群资源现状,于2013年3月至2014年1月在长江一级支流岷江眉山段采集了580尾四川华鳊样本,以鳞片作为鉴定材料,对其年龄和生长特征进行了研究。结果显示:四川华鳊鳞片年轮特征明显,表现为普通疏密型,为一年一个周期。研究样品的年龄由0~+~3~+(1~4龄)4个年龄组组成,其中以1~+~2~+龄(2~3龄)为主,占样品总量的96.07%。体长(L,m)和鳞径(R,mm)具有显著相关性雌、雄鱼差异无统计学意义(P0.05)表达式为L=25.45R+65.73。体质量(W,g)与体长呈幂函数相关,雌、雄鱼差异无统计学意义(P0.05),属等速增长,表达式为W=2.4×10~(-5)L~(2.94)(R~2=0.25)。Von Bertalanffy生长方程分别为:L_t=139.57×[1-e~(-0.15(t+3.16))],W_t=47.97×[1-e~(-0.15(t+3.16))]~(2.94),生长系数为0.15,拐点年龄为4.09龄,对应的体长和体质量分别为L_i=92.06mm,W_i=14.13g。岷江眉山段四川华鳊属于生长相对较快型鱼类。建议依法取缔非法捕捞工具,减少水电工程建设,这些措施对于保护四川华鳊种质资源有重要作用。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8⁺ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8⁺ T cells are involved in the pathogenesis of RE.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans.