两种寄生吸虫的染色体组型和繁殖方式

以精巢细胞染色体空气干燥标本制备技术,研究两种寄生吸虫的有丝分裂和减数分裂染色体,结果表明:片形吸虫体细胞染色体,2n=20,包括三对中着丝点、一对亚中着丝点、五对亚端着丝点、一对端着丝点染色体,这和前人报道的片形吸虫染色体形态有些差异。另外,群体中有65.3％的虫体细胞染色体为三倍体,3n=30。观察片形吸虫的配子形成,发现二倍体个体细胞减数分裂能正常进行,形成单倍体配子;三倍体个体细胞不进行减数分裂,也没有配子形成,推测二倍体虫体的生殖方式为有性繁殖,而三倍体虫体的生殖方式为孤雌生殖。并认为我国存在的两种片形吸虫:大片吸虫和肝片吸虫,有三倍体和二倍体两种,分别行无性繁殖和有性繁殖。     

几种寄生虫抗原组分的SDS-PAGE电泳比较分析

通过提取制备猪带绦虫、猪囊尾蚴虫体、猪囊虫囊液、多房型束球绦虫、肝片吸虫、细颈囊尾蚴、细颈囊尾蚴囊液和羊绦虫等8种寄生虫抗原，运用SDS－PAGE电泳法比较各种抗原的蛋白质的组成，不连续SDS－PAGE电泳结果显示猪带绦虫、猪囊尾蚴虫体、猪囊虫囊液、多房示绦虫、肝片吸虫、细颈囊尾蚴、细颈囊尾蚴囊液和羊绦虫等几种抗原的蛋白质在凝胶中分别有31，23，18，17，21，22，8和24条带，分子量在13kD-134kD之间，8种抗原的电泳带之间既有相似性又有特异性，其抗原的共同蛋白质亚基带的分子量为63kD,38kD和24kD。     

湘西三个乡耕牛片形吸虫病流行病学调查

<正>片形吸虫病是一种人畜共患寄生虫病,由片形科的肝片形吸虫和大片形吸虫引起,主要寄生于哺乳动物的肝脏胆道内,也可寄生于人体胆道中。片形吸虫对家畜牛、羊、猪等危害很大。对有关片形吸虫病,在家畜体内寄生和流行情况,我省迄今未见报道。我们于1985年8月,在永顺县对山、新寨和杉木三个乡,调查了耕牛553头,其中黄牛329头,水牛224头。在调查中发现,耕牛片形吸虫感染,以肝片形吸虫为主,仅数头耕牛有大片形吸虫感染。现将553头耕牛肝片形吸虫感染调查结果报告如下:     

肝片形吸虫种类鉴定PCR方法的建立

为了建立一种快速鉴定肝片吸虫种类的特异PCR方法,以肝片形吸虫基因组DNA为模板,以前后盘吸虫,胰阔盘吸虫,日本分体吸虫,牛弓首蛔虫、大片吸虫gDNA为对照,用肝片形吸虫特异性引物ITS-1、ITS-2进行PCR扩增,PCR产物经1.0%琼脂糖凝胶电泳,紫外透射仪观察;用核酸蛋白测定仪测定肝片形吸虫gDNA的浓度,然后将gDNA原液进行不同倍数的稀释,筛选最佳条件,进行敏感性检测.结果显示只有肝片吸虫样品有特异性条带,对照样品均呈阴性;可以检测到的最低DNA浓度分别为1.17 ng/μL、0.59 ng/μL.     

贝氏高原鳅不同组织原代培养的研究

采用胰酶半消化法,对贝氏高原鳅的吻端、肾脏和性腺组织的原代培养条件进行探究,使用MEM,RPMI1640,DMEM和DMEM/F12培养基进行培养;血清质量分数设置为10%,30%,50%和100%;分别置于37℃,26℃和室温(11～15℃)条件下培养,观察细胞在不同条件下的生长情况.初步确定了各组织原代培养的最佳条件是温度26℃、血清质量分数50%的条件下,吻端和肾脏组织在MEM培养基、精巢在DMEM培养基中生长情况最优.Giemsa染色显示各组织细胞结构完整,荧光染料Alexa fluor 488Phalloidin显示各组织细胞的微丝网络发达.     

肝片形吸虫成虫及虫卵的扫描电镜观察

本文应用扫描电镜系统观察了肝片形吸虫的体表结构和虫卵.1.在口腔内壁上密市有细绒毛,其间还有很多小孔.2.肝片形吸虫的体棘在头锥部份排列整齐而有规则,共有60圈,每圈60～70个.在腹吸盘以后的体棘则规律不明显.3.本文将观察到的不同形态的体棘,按其发育过程分为初生期,早期,中期及后期体棘四类,它们的末端都呈锯齿状.体棘窝较浅.因此体棘较易脱落.4.在张开的生殖腔中,同时观察到了雌雄生殖系统的2个开口,并对伸出体外的阴茎进行了描述.5.肝片形吸虫卵的表面光滑,但在其外膜脱落后则有散在性的小凹陷;卵盖与卵壳连接处虽不很整齐,但并不呈锯齿状.约60%的虫卵后端也具有小结节.     

羊大片吸虫龙岩分离株ITS基因的克隆及序列分析

应用PCR方法扩增龙岩地区羊片形吸虫分离株ITS序列,经克隆、测序后获得ITS全长序列944bp,其中ITS-1为421bp,ITS-2为361bp;通过在肝片吸虫和大片吸虫ITS种间鉴别位点上的序列分析表明,从龙岩地区羊体内分离的片形吸虫虫种属大片吸虫(命名为FgLY)。与国内外大片吸虫的进化分析表明,FgLY与中国云南的2个分离株处在一个小分支,亲缘关系最近。该结果为羊大片吸虫的进一步生物学研究和片形吸虫病的预防奠定了基础。     

肝片形吸虫精子发生的染色体动态研究

采用常规细胞染色空气干燥标本制片技术制片及直接涂片,观察100个虫体的200张滴片,20个虫体的40张涂片,发现肝片形吸虫精子发生的染色体动态是:1.精原细胞,分为A型和B型。A型胞核内染色质细粒状,着色较深。B型胞核内染色质颗粒多沿核膜分布,着色较浅。在精原细胞增殖的有丝分裂中,其染色体中期相2n=20。2.初级精母细胞,核内染色质呈颗粒团,随后细胞进入第一次成熟分裂(减数分裂),其过程分为前期、中期、后期和末期,各期细胞染色体形状、大小相异。3.次级精母细胞,核内有大小不等的染色质颗粒团或染色痕迹。4.精细胞,染色体为单倍体(n=10)胞核由圆形迎渐为椭圆形、钉子形、V形、S形、弯梭形,最后由弯梭形的细胞分化产生精于。5.精子,头颈部螺旋状锥形,尾细长。     

肿瘤坏死因子对日本血吸虫雌虫产卵影响的体外试验研究

研究肿瘤坏死因子(TNF-α)对日本血吸虫雌虫产卵的影响。方法:日本血吸虫蚴尾感染家兔,收集50天龄雌虫,在含不同浓度的TNF-α的DMEM培养液中培养72h,观察其产卵情况。结果:TNF-α具有刺激雌虫产卵的作用,在10～40mg/ml范围内产卵量随TNF-α剂量增加而增高。当TNF-α为40mg/ml时,雌虫产卵量达高峰。当TNF-α为80mg/ml时,雌虫产卵量无继续增高趋势。结论:TNF-α可在一定范围内刺激日本血吸虫产卵。     

细菌XSJS3对松材线虫杀线活性的测定

细菌XSJS3是一种新发现的对松材线虫(Bursaphelenchus xylophilus)具有较高杀线活性的细菌,试验比较了细菌XSJS3培养液、细菌培养液滤液及含菌体水溶液对松材线虫的杀线活性,结果发现细菌菌体本身对松材线虫无杀线活性,杀线活性物质存在于细菌的培养液滤液中。通过对该细菌培养液滤液对松材线虫致死过程的观察发现:松材线虫接触该细菌培养液滤液30min后就表现为行动迟缓;在5h后所有虫体均不活动,针刺无反应;24h后部分僵直虫体出现局部膨大,且膨大部位出现体液外渗而虫体最终被消解。对不同培养时间的细菌XSJS3滤液杀线活性的比较试验表明:该细菌分泌的杀线物质在10d内随培养时间的延长而含量增加,杀线活性逐渐提高,不同培养时间下滤液的杀线活性差异明显;但培养15d后,稀释10倍的滤液对松材线虫杀线活性比培养10d时同样滤液的杀线活性则略有下降,但差异不明显,因此获得该细菌分泌的杀线物质较理想的培养时间为10d。将细菌XSJS3培养液滤液进行不同温度的热处理后测定对松材线虫的杀线活性,结果表明引起松材线虫死亡和消解的物质是两个不同物质,存在于培养液滤液中的对松材线虫有杀线活性的物质是热稳定的,而引起松材线虫虫体消解的物质是热不稳定的。     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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