牛心朴子的杀线虫机理

基于牛心朴子甲醇提取物具有显著的杀线虫活性,本研究测定了该提取物对线虫体内总糖、蛋白含量、保护酶活性、神经靶标酶及解毒酶活性等8项指标的影响.结果表明,牛心朴子甲醇提取物干扰了线虫体内糖和蛋白的代谢,抑制SOD、AChE和GST活性,破坏了线虫保护酶系统及神经系统.这一结果为利用牛心朴子研究和开发植物源杀线虫农药或先导化合物奠定了理论基础.     

薄荷提取物对提高秀丽线虫应激抵抗能力的影响

以秀丽线虫为模型,研究药食同源植物薄荷提取物对其应激抵抗能力的影响,并以紫外辐射为应激条件,进一步研究薄荷提取物抵抗紫外辐射的作用机制.结果表明:薄荷提取物可明显提高线虫抵抗紫外辐射、绿脓杆菌感染、35℃热应激和胡桃醌氧化的应激能力;薄荷提取物可明显降低紫外辐射后线虫体内活性氧(ROS)水平、提高超氧化物歧化酶(SOD...     

松材线虫拮抗细菌的筛选和鉴定

为了筛选对松材线虫(Bursaphelenchus xylophilus)具有较高杀线活性的拮抗细菌,从马尾松林中分离获得了230株细菌,并从中筛选出8株对松材线虫具有较高杀线活性的细菌,其中JK-JS3菌株对松材线虫的杀线活性最高.将该细菌培养滤液分别稀释2倍、4倍、10倍处理松材线虫,72h后线虫的死亡率均达到100%;线虫死亡后虫体消解,消解率分别为100%、97.8%、96.4%.测定了该细菌培养滤液对香蕉穿孔线虫(Radopholus similis)和水稻干尖线虫(Aphelenchoides besseyi)等植物线虫的杀线活性,结果表明对不同种的线虫杀线活性有差异.该菌株培养滤液对松材线虫和小杆线虫(Rhabditis sp.)的杀线活性最高,其余杀线活性从高到低依次为拟松材线虫(Bursaphelenchus mucronatus)、腐生线虫(Panagrellus redivivus)、香蕉穿孔线虫和水稻干尖线虫.形态特征和革兰氏染色观察,该细菌为革兰氏阳性菌、产芽孢、具有周生鞭毛;经Biolog细菌鉴定仪进一步鉴定该细菌为解淀粉芽孢杆菌(Bacillus amyloliquefaciens).     

四合木甲醇提取物中杀线虫物质的分离与活性鉴定

通过活性追踪，对四合木的甲醇提取物活性成分进行了初步分离，使用快速制备色谱（combiflash companion）对甲醇提取物的氯仿萃取相进行了进一步分离，得到18个较大的馏分，同时以松材线虫（Bursa phelenchus xylophilus）为供试对象，对各馏分杀线虫活性作了初步测定，结果表明：氯仿萃取相F4馏分有较强的杀线虫活性，具有进一步研究的价值．     

余甘子对秀丽隐杆线虫的抗衰老作用

以模式生物秀丽隐杆线虫(简称线虫)为模型,考察质量浓度分别为1.0,2.0,4.0mg/mL的余甘子提取物对线虫的抗氧化作用.实验结果表明:1.0 mg/mL的余甘子提取物能显著提高线虫产卵量,且对线虫的运动能力无显著影响,即在实验的质量浓度范围内,余甘子提取物具有低毒性;1.0mg/mL的余甘子提取物能显著延长线虫的寿命,并具有抗氧化压力作用;1.0mg/mL的余甘子提取物可显著提高线虫体内过氧化物酶活性,从而达到抗氧化的保护作用.     

葛根中黄酮提取工艺的优化及抗氧化作用

以时间、温度和料液比3个单因素进行正交实验,确定葛根中黄酮提取的最佳条件.结果表明,提取的最佳条件为:m(料)∶V(液)=(1∶40)g/mL,60℃浸提3h,葛根粗提率为82%,黄酮提取率最高为18.04%.以模式生物秀丽隐杆线虫(线虫)为模型,考察质量浓度分别为1,2,5 mg/mL黄酮提取物对线虫的抗氧化作用.结果表明,在35℃培养12h,1mg/mL黄酮提取物喂食线虫的存活率较对照组有显著提高,即黄酮提取物有明显的抗氧化作用.     

利用食线虫真菌防治植物寄生线虫的研究进展

植物寄生线虫每年给农业、林业造成的损失十分巨大,食线虫真菌是植物寄生线虫生物防治中极其有用的生物资源.综述在利用这类真菌研发线虫生防菌剂中涉及的应用基础研究进展,包括食线虫真菌资源,食线虫真菌侵染线虫的分子机制,生物防治现状,杀线虫毒素概况,以及线虫生防中需要解决的生态学问题.     

杀植物线虫的Bt菌Cry蛋白研究进展

植物寄生线虫（Plant parasitic nematodes）对农林业生产造成了巨大的经济损失,为减少环境污染,发展绿色农业,生物防治愈发受到关注。Bt菌（Bacillus thuringiensis, Bt）作为一种重要的生防细菌,对鳞翅目、鞘翅目、双翅目和线虫具有特异性的杀虫活性,对人类和非靶标昆虫无害。文章对已报道的Bt菌及其杀植物线虫Cry蛋白种类、结构特征和杀虫机制等方面研究进展进行了简要综述。     

喜旱莲子草与乌蔹莓等植物提取物对松材线虫的毒杀活性研究

【目的】松材线虫病是当前我国林业生产上危害最严重的森林病害。尽管投入了大量的人力、物力和财力,但松材线虫病防控形势依然严峻。化学杀线剂具有环境局限性,研发高效植物源杀灭松材线虫的药剂对控制松材线虫病疫情,同时降低环境化学污染具有重要意义。【方法】采用乙醇浸渍提取法制备喜旱莲子草(Alternanthera philoxeroides)、乌蔹莓(Cayratia japonica)、迷迭香(Rosmarinus officinalis)等30种植物的提取物,测定其对松材线虫的毒杀活性。利用液液萃取法,用乙醇、石油醚、乙酸乙酯、正丁醇和水等有机溶剂对两种植物中的活性成分进行分步提取,得到药液的质量浓度梯度为10.000、5.000、2.500、1.250和0.625 g/L,并分别测定其对松材线虫的毒杀活性。虫卵悬浮液在25 ℃恒温保湿培养箱内培养,24 h后开始观察,32 h后结束观察。通过镜检统计线虫卵数,并计算相应的线虫卵累计孵化率和孵化抑制率。【结果】采用质量浓度为10 g/L的喜旱莲子草、乌蔹莓乙醇提取物分别处理松材线虫,72 h后线虫校正死亡率均为 100%。喜旱莲子草的乙酸乙酯萃取物和乌蔹莓的水层萃取物中存在主要的杀线活性物质,两种植物萃取物处理松材线虫72 h后的半致死剂量(LC₅₀)分别为0.588 8和0.969 3 g/L。在离体虫卵孵化试验中,喜旱莲子草的乙酸乙酯萃取物对线虫的卵孵化抑制率最大,为79.77%,其次为乌蔹莓的水层萃取物,为46.51%。【结论】可见,喜旱莲子草和乌蔹莓对松材线虫成虫和虫卵均具有较强的生物毒杀活性,可作为新型植物杀线虫剂加以开发利用。     

5种药食同源植物的抗氧化作用

以刺梨、 干姜、 肉桂、 山药、 葡萄籽5种药食同源植物为原料, 利用水提法提取有效成分. 以模式生物秀丽隐杆线虫(线虫)为模型, 通过线虫寿命测定实验、 体外氧化压力测定实验和体内自由基清除实验评估5种药食同源植物的抗氧化作用. 实验结果表明: 2 mg/mL的刺梨水提物和2 mg/mL的葡萄籽水提物均能显著延长受试线虫寿命; 5种不同质量浓度的植物水提物均对受试线虫有显著的氧化损伤修复能力及一定的清除体内自由基能力, 其中刺梨[KG*8]和葡萄籽水提物的清除自由基能力效果明显.     

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     

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