Climate indexes of phytoliths from Homo erectus'''' cave deposits in Nanjing

Many related papers have been published since the first report on the discovery of Nanjing hominid crania by Mu et al.[1]. Mu et al.[1], Xu et al.[2—4], the Tangshan Ar-chaeological Team[5] and Dong[6] have successively stud-ied the Nanjing Homo erectus?symbiotic faunas. Mu et al. and Xu et al. considered that the nature of the fauna in the Tangshan area belongs to the Oriental Realm,and this region was usually occupied by Ailuropoda-Tapirus fauna in the Pleistocene. However, the typica…     

Annual precipitation fields secular variation over global land areas for 1948—2000

In contrast to global temperature, fewer studies have been contributed to global precipitation. There are nu-merous efforts devoted to the problem, including Gruza[1], Diaz et al.[2], Bradley et al.[3], Vinnikov et al.[4] and Hulme[5], in which the global precipitation was addressed simply in the context of data in the 1980s, sometime be-fore that and the early 1990s[6—8]. More recently, studies have involved data around 1997 but on a local basis. Evi-dently, the problem of secular variatio…     

A novel comparative molecule/pseudo receptor interaction analysis

Quantitative structure-activity relationship (QSAR) becomes an important tool in the modern basic chemis- try. In the 1960s, Hansch et al.[1] proposed Hansch- Fujita method to express the relationships between ac- tivities and parameters. Free et al.[2] d…     

Conformational Changes in HL60 Cells during Differentiation and Apoptosis Induced by Genistein

IntroductionGenistein is a naturally occurring phytoestrogenpresent in a variety of plant foods,includingsoybean[1] .It is known to inhibit both tyrosineprotein kinases and DNA topoisomerase II.Akiyama et al.[2 ] described the ability of genisteinto specifically inhibit protein tyrosine kinase( PTKs) ,presumably at the level of the ATPbinding site.PTKs seem to play a key role intumorigenesis and are known to be associated withgrowth control receptors such as epidermal growthfactors[3] ,p…     

Numerical modelling of a turbulent bluff-body flow with Reynolds stress turbulent models

A bluff body stabilized flow has received specialattention recently[1—4]. In addition to its practical in terest, the bluff body flow is an excellent challengingtest case for turbulence model due to its simple andwell defined initial and boundary conditions with thecomplex recirculating flows.The bluff body stabilized flow investigated herewas studied experimentally by Dally et al.[1,2] As forits numerical simulation, Dally et al.[1] reported sim ulation results obtained using standard and …     

There is no micro-explosion in the diesel engines fueled with emulsified fuel

In 1965, Ivanov[1] observed the phenomenon of micro-explosion. Later on, Dryer[2], Lasheras[3], Chardra and Avedisiao[4], Mizomoto and Law et al.[5,6] also observed this phenomenon. The basic conditions for micro-explosion occurrence were developed as fol…     

Thermodynamic evolution of lithosphere of the North China craton： Records from lower crust and upper mantle xenoliths from Hannuoba

Lithospheric thinning in East China attracts much attention of geologists. In many cases where a lithospheric thinning is inferred, the trigger for instability is a preced-ing episode of crustal thickening by the continental colli-sion[1]. Lithospheric processes (e.g. lithospheric thinning) could be recorded by the thermal history of the lower crustal and upper mantle xenoliths. Xu et al.[2] suggested that the cooling (from >1200 to 850℃) recorded by spinel harzburgite from Northeast China …     

Response to“Discussion on the systematic position of the Early Cambrian priapulomorph worms”

Due to the combination of complex states of preser- vation and taphonomies in Chengjiang fossils, Huang et al.[1] expressed different opinions to those of Han et al.[2] on the morphology and systematic position of the fossil priapulomorph worms (Priapulom…     

Effect of Rating Scales and Test Parts of Body on the Evaluation Results of Fabric-evoked Prickle

IntroductionThe studies of Schneider and Holcombe[1]and Liet al .[2]demonstrated that s mooth and light-weightwool fabrics were able to enhance fabrics in the market-place the sensations of coolness when worn in war m andhumid environments due to wool s hygroscopicity . Thisis the principle underlying the development of “coolwool”.However ,someti mes wool products are complainedof prickle . In the study of Wang et al .[3],it was foundthat the main shortcoming in ter ms of comfort for light…     

Identification and mapping of quantitative trait loci controlling cold-tolerance of Chinese common wild rice (O. rufipogon Griff.) at booting to flowering stages

Cold injury is an important limitation of rice production. Therefore, screening for cold-tolerant genetic resources and the development of highly cold-tolerant cultivars is crucial for higher yield potential and stable yield of rice. There have been several reports on the genetic analysis and QTL mapping of the cold-tolerance at the booting stage. Toriyama et al.[1,2] and Futsuhara et al.[3,4] reported that 4 or more genes were involved in the cold-tolerance. Several QTLs at the booting sta…     

吡柔比星与DNA作用的光谱和电化学法研究

应用紫外、荧光、黏度、循环伏安等方法研究了吡柔比星与DNA的作用.结果发现:加入DNA后吡柔比星紫外光谱呈现减色效应,同时吡柔比星的加入使得EB-DNA荧光强度增强,黏度增大;循环伏安法表明DNA的加入使得吡柔比星的式量电位正移;Scatchard图表明吡柔比星对溴化乙锭(EB)与DNA的结合为竞争性抑制.综合以上实验结果,吡柔比星与DNA之间为嵌插作用;这些结果,可为合理改善药效,降低抗癌药物毒性和设计新药提供理论依据.     

3,5-二碘水杨醛缩-2-氨基苯并噻唑schiff碱过渡金属配合物的合成及与DNA的作用

合成3,5-二碘水杨醛缩-2-氨基苯并噻唑schiff碱及其过渡金属（Cu,Zn,Ni,Co）的配合物.用元素分析、UV和IR吸收光谱、TG-DTA分析和摩尔电导率方法表征了配合物的组成和基本性质;通过荧光发射光谱、黏度及其与溴化乙锭（EB）的竞争实验研究了配合物与CT DNA的作用情况.结果表明,该系列配合物的组成为M（NO3）L·H2O;配合物与CT DNA的作用方式为插入模式.另外,4种配合物对藤黄微球菌的抑菌作用明显高于配体.     

镓(Ⅲ)—水杨醛氨基酸Schiff碱配合物与DNA的相互作用研究

应用紫外-可见光谱、循环伏安法和粘度法研究了3个镓(Ⅲ)—水杨醛氨基酸Schiff碱配合物(GaL2,GaLbipyCl,GaLphenCl,L为水杨醛谷氨酸Schiff碱,bipy为2,2'-联吡啶,phen为1,10-邻菲啰啉)与DNA分子的键合作用.紫外-可见光谱表明配合物与DNA发生插入作用;循环伏安法表明GaLbipyCl与DNA的作用涉及沟槽或静电结合方式,GaL2和GaLphenCl与DNA发生嵌入作用;粘度法表明配合物与DNA以沟槽模式或部分插入的方式结合.综上所述,推测3个配合物以沟槽模式或部分插入的方式与DNA结合.     

O-季铵化硫脲壳寡糖的制备及与鲱鱼精DNA的相互作

以壳寡糖为原料, 制备O 季铵化硫脲壳寡糖, 并用红外光谱、 紫外 可见吸收光谱、 热重 差热分析法对合成的化合物进行表征. 以鲱鱼精DNA为靶点, 用紫外 可见吸收光谱、 循环伏安法和黏度法研究O-季铵化硫脲壳寡糖与鲱鱼精DNA的作用方式. 实验结果表明： O-季铵化硫脲壳寡糖在213.5,280.0 nm处出现吸收峰, 其热稳定性较差, 在180 ℃开始氧化分解; O-季铵化硫脲壳寡糖的紫外 可见吸收峰在加入DNA后发生变化; O-季铵化硫脲壳寡糖使铁氰化钾 DNA体系的氧化还原峰电流减小, 式量电位发生正移, 并使DNA的黏度增大, 即O 季铵化硫脲壳寡糖与鲱鱼精DNA之间存在嵌插结合作用.     

双核钌配合物的DNA键合及光断裂性能

合成了1个新型的双核钌配合物,并通过紫外-可见吸收光谱和荧光光谱滴定、热熔链、盐效应、黏度和凝胶电泳实验研究了其与小牛胸腺DNA(ct-DNA)之间的相互作用. 结果表明,由于主配体的位阻作用,该配合物通过部分插入模式与DNA键合,键合常数大于10⁶ L/mol;在365 nm紫外光照射下,该配合物能够断裂pBR322 DNA,是有效的DNA断裂试剂.     

锌(Ⅱ)配合物与DNA作用的研究

采用紫外可见光谱、荧光光谱等光谱方法研究了配离子[zn(phen)2]^2 (phen=邻菲咯啉)与小牛胸腺DNA的相互作用。在DNA存在下，配合物的紫外吸收光谱产生了明显的减色效应。DNA的碱变性曲线在配合物的存在下向pH值增大的方向移动，增色效应减小．荧光光谱表明EB(溴化乙锭)-DNA体系的荧光强度随[zn(phen)2]^2 的加入而迅速减弱，表明锌的邻菲咯啉配合物与DNA之间发生了插入作用。     

钌(Ⅱ)配合物合成、表征与DNA 相互作用及其抗氧化性研究

 设计合成一个新的钌(Ⅱ)多吡啶配合物［Ru(dip)₂(DBHIP)］(ClO₄)₂ {dip = 4,7-二苯基-1,10-邻菲咯啉;DBHIP = 2-(3,5-二溴-4-羟基苯)并咪唑［4,4-f］-(1,10-邻菲啰啉)},采用元素分析,质谱和1H NMR对其进行表征。用电子吸收光谱、黏度测试、Job plot荧光滴定法研究配合物与CT DNA作用,结果表明配合物以经典的插入模式与DNA键合。采用琼脂糖凝胶电泳实验研究配合物诱导pBR322DNA断裂。同时也研究配合物在高浓度情况下使pGL3 DNA缩合。     

含烷基链环多胺衍生物的合成及其与DNA作用研究

以1,4,7,10-四氮杂环十二烷(cyclen)为原料,合成了一系列具有不同长度烷基侧链的四氮十二杂环类化合物,并用氢谱、碳谱、高分辨质谱进行了结构表征.用DNA热变性分析和琼脂糖凝胶电泳实验分别研究了此系列化合物与小牛胸腺DNA(CT DNA)的结合能力和对超螺旋DNA(pBR322 DNA)的断裂作用.结果表明,在pH7.2 Tris-HCl缓冲液中,1,4,7,10-四(正辛基)-1,4,7,10-四氮杂环十二烷(h)与CT DNA的结合能力最强,CT DNA的熔点上升幅度最大(ΔTm=5.22℃),且存在明显的插入结合作用,但切割DNA的能力很弱.由此可见,亲脂性烷基侧链长度的增长有利于增加化合物与DNA的相互结合,但不能提高化合物切割DNA的活性.     

质粒pBR322DNA与内切酶EcoRI相互作用的研究

借助原子力显微镜(AFM)对DNA与内切酶的切割与结合作用进行研究.当缓冲液中有Mg2+存在时,内切酶EcoRI会在单一识别位点处切割pBR322DNA,如果缓冲液中的Mg2+用Ca2+代替,内切酶EcoRI则会与pBR322DNA在单一识别位点处结合,并且切割率与结合率都随着内切酶浓度的增加而增加.     

配合物[Ru（dmppd）_3]~（2＋）与DNA的相互作用

设计合成了含有三个插入配体的多吡啶钌（II）配合物,通过核磁共振、质谱、元素分析等一系列检测手段对所合成的配合物进行了表征。运用紫外光谱滴定、DNA热变性实验、粘度实验、EB竞争结合实验等手段,研究了配合物与DNA的插入作用。