室内装饰材料中甲醛的致突变作用研究

对不同浓度气态甲醛诱导昆明种小鼠骨髓嗜多染红细胞微核率进行了统计分析.将40只小鼠随机分成对照组和4,12,36 mg/m3剂量组,采用静式呼吸道染毒,连续染毒4d,每天6h,染毒结束后将小鼠处死,测定微核率.结果表明,中、高剂量组的小鼠骨髓微核率与阴性对照组比较有显著性差异(P<0.05);不同剂量组微核率经方差分析有显著性差异(P<0.01);经F检验,受试物剂量组之间无显著性差异(P>0.05),且雌雄两性微核率无显著性差异(P>0.05);环磷酰胺组(40 mg/kg Bw)微核率与阴性对照组同性别微核率相比,有显著性差异(P<0.01),且雌、雄两性微核率均无显著性差异.认为气态甲醛对小鼠有致突变作用.     

五氯酚钠的遗传毒性效应研究

五氯酚钠属有机氯农药,在世界范围内广泛使用,为了研究其对生态安全特别是水环境安全的潜在危害,采用小鼠骨髓细胞微核试验、蚕豆根尖微核试验和斑马鱼胚胎发育试验,评价了五氯酚钠的毒性效应.微核试验结果表明:对于小鼠骨髓细胞,50 mg/kg和100 mg/kg剂量组均能不同程度增加其微核率,和阴性对照组相比存在显著性差异(.P<0.05),并存在一定的剂量-效应关系;对于蚕豆根尖细胞,各个剂量组均能不同程度增加其微核率,最高剂量组5.0 mg/L和阴性对照组相比存在显著性差异(P<0.01),并存在一定的剂量-效应关系.斑马鱼胚胎发育试验结果表明:25℃时,五氯酚钠对斑马鱼胚胎发育有明显的致畸作用,72 hEC50为515.31 μg/L,可以看出胚胎异常率随暴露时间的延长和暴露剂量的增加呈现出增大趋势.微核试验和斑马鱼胚胎发育试验表明五氯酚钠具有一定的致突变性.     

聚天冬氨酸钙的毒性及血清半衰期初探

目的:对聚天冬氨酸钙进行初步毒理生物利用度的检测.方法:通过灌胃造成急性毒性确定半数致死量(LD50),并对小鼠蓄积毒性、骨髓嗜多染红细胞(PCE)微核试验和血清半衰期进行了研究.结果:受试物对小鼠的LD50大于5 000 mg/kg,属于无毒.以蓄积毒性剂量500 mg/kg连续灌胃给药20 d后,小鼠的体重和心、肝、脾、肺、肾、肠胃等器官在形状、大小、颜色等指标上与阴性组对照无明显差异.分别以500、800、1 000 mg/kg的剂量对小鼠连续灌胃2 d,PCE微核率分别为4.8±0.87‰、5.4±0.99‰、5.6±1.05‰,与阴性对照组比较无显著性差异.相同剂量灌胃后小鼠血清中药峰值出现时间为120、140和150 min,血清半衰期时间分别为:160、200和220 min,长于天冬氨酸钙的药峰值时间(20、30和40 min)和半衰期(均为50 min).结论:聚天冬氨酸钙属于无毒,其吸收和代谢相对缓慢,药效持续时间较长.     

绿茶提取物(TP—91)对小鼠致突变作用的观察

绿茶提取物是我室从湖北绿茶中提取的有色聚合物.本文Amos试验表明,绿茶提取物600μg、120μg、2.4μg剂量无致基因突变作用.在小鼠骨髓嗜多染红细胞(PCE)微核试验中,一次给小鼠25g/kg,12.5g/kg绿茶提取物,6小时后观察微核发生率,用药组与正常组比较无显著差异(P>0.05),说明对小鼠体细胞染色体无损伤作用     

重组人酸性成纤维细胞生长因子的遗传毒性

目的:了解重组人酸性成纤维细胞生长因子(rhaFGF)皮肤外用的遗传毒性。方法:用CHL细胞染色体畸变试验、小鼠骨髓PCE微核试验和Am es试验方法对rhaFGF进行遗传毒性研究。结果:rhaFGF各剂量组和阴性对照组在加或不加S9情况下,其CHL染色体畸变率均<5%;各剂量组的骨髓细胞微核细胞率与阴性对照组比较均差异无显著性(P>0.05);rhaFGF各剂量组(0.5~5 000μg/皿)对TA97、TA98、TA100、TA102菌珠在加或不加S9混合液条件下均无致突变作用。结论:在所选试验和剂量范围内未见到rhaFGF具有遗传毒性。     

复硝酚钠的致突变性研究

检测复硝酚钠有无致突变作用,为其安全生产和使用提供依据.采用鼠伤寒沙门氏菌回复突变试验(Ames试验),用TA97,TA98,TA100,TA102菌株,加与不加S9,剂量设为:0,250,500,1 000,2 000 μg/皿;小鼠骨髓多染红细胞微核试验,剂量设为雄、雌性小鼠给药剂量均为:15.8,31.6,63.2 mg/kg;小鼠睾丸精母细胞染色体畸变试验,剂量设为:15.8,31.6,63.2 mg/kg检测有无致突变作用.结果为Ames试验中各测试浓度的诱发回变菌落数均未超过自发回变菌落数的2倍;小鼠骨髓多染红细胞微核试验和小鼠睾丸精母细胞染色体畸变试验,各剂量组和溶剂对照组的微核率进行统计学处理,未见有显着性差异(P＞0.05),表明各项试验结果均为阴性.因此在本试验条件下,复硝酚钠无致突变作用.     

亚硝酸异丁酯遗传毒性效应的研究

摘要:探讨亚硝酸异丁酯致突变作用,根据《化学品毒性鉴定技术规范》 ,采用鼠伤寒沙门氏菌回复突变实验( Ames实验)和小鼠骨髓嗜多染红细胞( PCE)微核实验,进行亚硝酸异丁酯的遗传毒性研究。 Ames 实验使用的菌株为鼠 伤寒沙门氏菌( Salmonella typhimurium) 组氨酸缺陷型( his-) 菌株 TA97a、TA98、TA100 及 TA102,实验共设 10 个剂 量组,剂量区间在 250 ~ 5 000 μg / 皿,同时设阴性对照组和阳性对照组,采用平板掺入法,观察每皿回变菌落数;微核实验设 11 mg / kg、41 mg / kg 及 103 mg / kg 三个剂量组,设阴性对照组和阳性对照组,检测骨髓嗜多染红细胞微核率。 结果提示亚硝酸异丁酯在 Ames 实验中未呈现致突变作用,但在微核实验中 103 mg / kg 时对小鼠有致突变作用。     

五指毛桃拮抗环磷酰胺诱发的遗传损伤效应

目的探讨五指毛桃对环磷酰胺所致小鼠遗传物质损伤的拮抗效应.方法 30只SPF级昆明种雄性小鼠,随机分为阴性对照组、阳性对照组及五指毛桃高（20g/kg）、中（10g/kg）、低（5g/kg）3个抗突变组.抗突变组用五指毛桃水提液灌胃,阴性对照组、阳性对照组灌以等量生理盐水,1次/d,连续15d.于第14 d,除阴性对照组外,各组小鼠腹腔注射环磷酰胺40mg/kg,24h后重复注射一次.用微核试验,检测五指毛桃水提液对环磷酰胺诱发小鼠骨髓嗜多染红细胞和睾丸生精细胞微核发生率的影响.结果抗突变组的骨髓嗜多染红细胞和睾丸生精细胞微核率均明显降低,与阳性对照组比较有统计学意义（P〈0.01）,并且随着五指毛桃液浓度的增高,微核率逐渐降低.结论五指毛桃可以拮抗环磷酰胺诱发的小鼠遗传物质损伤,提示五指毛桃有一定的抗突变作用.     

小鼠腹腔注射阿霉素诱导骨髓细胞微核率的最佳时间—剂量效应分析

目的：寻找一次染毒条件下,腹腔注射阿霉素诱导小鼠骨髓细胞微核率出现峰值的时间-剂量条件。方法：将150只小鼠随机分为5组,每组30只,雌雄各半。腹腔注射,1次给药,对照组给生理盐水,处理组的阿霉素剂量分别是2.5 mg/kg、5 mg/kg、10 mg/kg和20 mg/kg。染毒18 h、24 h、30 h、48 h和72 h后取小鼠骨髓进行微核分析,评价阿霉素对小鼠的遗传毒性作用。结果：理想的腹腔注射诱导的小鼠骨髓细胞微核率峰值的条件就是：一次染毒,阿霉素剂量在10%LD50即2.5 mg/kg至80%LD50即20 mg/kg的范围内剂量越大微核率越高,取样时间在30~48 h间微核率最高。     

芜菁块根汁对环磷酰胺致小鼠损伤的拮抗效应

以清洁级ICR小鼠为实验动物,研究芜菁块根汁对环磷酰胺（Cyclophospamide,CP)引起遗传物质损伤的拮抗效应。采用小鼠骨髓嗜多染红细胞（PCE）的微核试验,小鼠骨髓染色体畸变试验等方法,结果显示灌胃（ig)不同剂量芜菁块根汁均使小鼠骨髓PCE微核率,骨髓细胞染色体畸变率有所下降,且具有明显的剂量效应。结论：芜菁块根汁对环磷酰胺引起小鼠的损伤具有明显的拮抗作用。     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Jane Eyre——A Feminist In The 19th Century

In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.     

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-