饲料添加剂硒和谷胱甘肽对微囊藻毒素胁迫下罗非鱼肝脏去毒相关基因诱导表达的影响

为从分子水平探讨饲料添加剂硒(Se)和谷胱甘肽(GSH)对淡水养殖鱼类肝脏微囊藻毒素胁迫下去毒分子机理的影响,实验杂交罗非鱼一组喂食含0.15 mg/kg Se的富硒酵母粉饲料,一组喂食含普通酵母粉的饲料,喂食一个月以上;实验尼罗罗非鱼一组喂食含1 g/kg GSH的饲料,一组喂食普通饲料,两组均饱食10 d.所有实验组再均分两组,一组腹腔注射磷酸缓冲液(PBS),一组按体质量注射腹腔注射50μg/kg微囊藻毒素-LR(MC-LR),24 h后分离肝脏组织.以β-肌动蛋白作为外参照,采用半定量RT-PCR方法研究Se和GSH分别对罗非鱼肝脏去毒相关基因转录水平的诱导改变.结果表明,未喂食Se的实验组,杂交罗非鱼肝脏alpho-可溶性谷胱甘肽S-转移酶(sGSTA)和谷胱甘肽过氧化物酶(GPX)基因mRNA表达水平在腹腔注射50μg/kg MC-LR 24 h后,均较PBS组有诱导趋势;Se+MC-LR组sGSTA和GPX基因mRNA表达水平,均较Se+PBS组略低,可能与添加剂的低剂量添加相关.喂食GSH的实验组,尼罗罗非鱼腹腔注射MC-LR组,肝脏sGSTA基因mRNA表达水平较PBS组有诱导趋势;Se+MC-LR组GPX基因mRNA表达水平,较Se+PBS组有升高趋势,而sGSTA和rho-可溶性谷胱甘肽S-转移酶(sGSTR)基因mRNA表达水平则轻微降低.本实验首次从基因表达水平比较研究了Se和GSH对罗非鱼微囊藻毒素压力情况下,肝脏去毒酶基因表达的影响变化,为Se和GSH饲料添加剂在鱼类饲料中的合理添加提供分子水平的理论依据.     

复方苦豆子制剂的急性毒性研究

通过评价复方苦豆子急性毒性,为临床安全使用提供依据和资料。对小白鼠灌胃最大耐受量及腹腔注射的半数致死量(LD50)进行测定。结果表明:小白鼠灌胃最大耐受量为成人临床拟日用剂量的184倍,腹腔注射LD50为(79.75±9.09)g/kg,该制剂无急性毒性反应,有较大的开发利用价值。     

青龙衣毒性作用及体内抗肿瘤作用的实验研究

采用常规小鼠急性毒性试验方法对青龙衣提取物及其分离成分的体内抗肿瘤作用的实验研究．除小鼠腹腔注射青龙衣氯仿萃取物LD50为575．38mg/kg和青龙衣乙酸乙酯萃取物为1303．59mg/kg,青龙衣总提取物和青龙衣石油醚萃取物、正丁醇萃取物和水萃取物小鼠口服及腹腔注射LD50均大于5g/kg．在试验剂量下,青龙衣氯仿萃取物和乙酸乙酯萃取物对腋下移植性实体型肉瘤S180及移植性腹水型肿瘤H22有一定的抑制作用,与阴性对照组比较具有显著差异．青龙衣氯仿提取物和乙酸乙酯提取物具有一定的抗肿瘤作用．     

WHPI经腹腔注射和静脉注射对小鼠的急性毒性研究

目的 考察WHPI经腹腔注射和静脉注射对小鼠的急性毒性作用。方法 按中药新药毒理学研究指南的要 求与方法,用SPF级昆明小鼠以腹腔注射、尾静脉注射两种给药途径进行了WHPI的急性毒性试验,用Bliss法计 算其半数致死量( Lethal Dose 50,LD50)。结果 受试物腹腔注射给药对昆明小鼠的LD50为30.08 mg/kg;尾静脉注 射给药对昆明小鼠的LD50为71.45 mg/kg。结论 WHPI腹腔注射对昆明小鼠的毒性比静脉注射的毒性高。这可 能是WHPI经肝代谢后的产物毒性比静脉注射时高,提示临床上宜采用静脉注射途径。     

阿霉素对昆明种小白鼠腹腔给药的半致死剂量研究

目的:研究阿霉素对小白鼠经腹腔给药途径的半致死剂量.方法:通过预实验得到近似的最大致死剂量(Dm)和最小致死剂量(Dn),在正式实验中,将70只小鼠随机分为7组,每组10只,雌雄各半.给药途径为腹腔注射,给药次数1次,给药剂量为对照组给生理盐水,其余六组的剂量分别是13.4 mg/kg、19.2 mg/kg、27.4 mg/kg、39.2 mg/kg、56 mg/kg、80 mg/kg.给药后观察时间为14 d,统计小鼠的死亡情况.结果:除对照组和最小剂量(13.4 mg/kg)外,其他剂量组在7 d内均有数量不等的动物死亡,并且死亡率随着阿霉素浓度的增加而递增.经Bliss软件计算,其LD50值为24.941 mg/kg,95%的可信限为21.241～29.271 mg/kg.     

碳酸二甲酯腹腔注射染毒小鼠急性毒性实验研究

研究碳酸二甲酯腹腔注射染毒对小鼠急性毒性的影响.小鼠腹腔注射给予3707.40、4521.22、5513.68、6724.00、8200.00 mg/kg碳酸二甲酯,给药后记录小鼠进食量、体重、心电图,计算半数致死量(LD50).实验结束后,检测血液学、血液cTnI和生化指标,计算脑、心、肝、脾、肺、肾、卵巢、睾丸、附...     

鸡腹腔注射盐酸普萘洛尔急性毒性试验

将40日龄健康艾维因肉仔鸡25只随机分成5组,按a=4 mg/kg,r=1.5,分别腹腔注射4.0,6.0,9.0,13.5,20.25mg/kg的盐酸普萘洛尔,进行急性毒性试验.结果5个试验组肉仔鸡死亡率分别为0,0.2,0.4,0.8和1.0.经过数据处理,LD50为9.396,标准误为0.058 9,95%可信限为9.334～9.450 mg/kg.     

探索一种蛙类成蛙的给药方式

目的探索一种对成蛙给药的新方式。方法采用90日龄虎纹蛙（Ranarugulosa）成蛙为实验动物,人工灌胃添加苏云金芽孢杆菌（Bacillusthuringiensis,Bt）菌剂的饲料,实验分组为1个空白对照组和5个剂量组,其剂量分别为1000、2150、4640、10000和21500mg／kg,每组4个重复,每个重复有5只成蛙,通过计算农药的LD,。及14d的体质量增加,评价采用灌胃给药开展成蛙急性毒性实验的可行性。结果人工灌胃饲料可使虎纹蛙获得营养支持,使其体质量增加;通过强饲添加不同剂量的Bt菌剂饲料,可以引起成蛙不同的毒性反应及不同的死亡率,且死亡率随Bt剂量增加而增大。Bt菌剂的LD,。为6691mg／kg,95％的置信区间为（5564,8329）mg／kg。结论对成蛙可以采用灌胃方式给药或者补给营养,以进行成蛙相关的毒性实验。     

大、小鼠口服腰痛宁胶囊的急性毒性研究

目的 观察大鼠和小鼠口服腰痛宁胶囊(含有马钱子、土鳖虫和全蝎等中药)的急性毒性作用。方法 以SD和Wistar种大鼠，昆明种和BALB／c小鼠为受试对象，采用Bliss法测定口服腰痛宁胶囊的LD50。结果 雄性SD大鼠口服腰痛宁胶囊的LD50为6158．95mg／kg，而雌性大鼠的LD50为803．85mg／kg；雄性Wistar大鼠口服腰痛宁胶囊的LD50为5807．57mg／kg，而雌性大鼠的LD50为861．94mg／kg；昆明种小鼠口服腰痛宁胶囊的LD50为640．44mg／kg；BALB／C小鼠的LD50为448．34mg／kg。结论 不同性别的大鼠对腰痛宁胶囊的急性毒性反应有非常著性差异，SD大鼠雄性LD50比雌性高7．66倍，Wistar大鼠雄性LD50比雌性高6．74倍。小鼠LD50几乎没有性别差异。     

醋酸铅对小鼠受精能力及受精卵发育毒性研究

目的研究醋酸铅对公鼠精子受精能力及受精卵发育的毒性,为进一步研究提供依据。方法采用腹腔注射染毒法将体重为(18±2)g的性成熟期公鼠随机分为高剂量(1/10 LD50)、中剂量(1/50 LD50)、低剂量(1/250 LD50)染毒组和对照组。染毒组公鼠于试验的0,3,6,9 d和12 d分别腹腔注射1.2,0.24,0.048 mg/mL的Pb(CH3COO)2.3H2O溶液,注射量0.01 mL/g,对照组注射相应体积的灭菌蒸馏水。染毒30 d后用各组公鼠与未染毒超排母鼠配种。结果回收胚胎中受精并卵裂的胚胎比例随染毒剂量的增加而显著下降,未受精卵比例相应上升。在受精卵地进一步发育中,随着染毒剂量的增加,退化胚比例显著上升,发育到囊胚~孵化胚的比率则显著降低。结论醋酸铅能明显影响小鼠精子的受精能力,并影响受精卵的进一步发育。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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