983 resultados para NOR


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用ACHT处理黑麦萌动种子,对修复前后材料的观察和分析结果表明:1. ACHT操作引起染色体数目变化和染色体断裂损失。在一定 条件和范围内,不同处理引起的这种变化具有显著差异,条件越剧烈,染色体数目变化的范围和频率愈大,断片发生的数量和频率 也愈高,同时修复前后染色体数目的变化范围和频率与断片发生的数量和频率以及它们的修复频率均表现明显的相关性。2. ACHT 操作引起染色体畸变的多样性。经ACHT处理后,胚根细胞染色体有4种断裂方式,包括着丝粒断裂、次溢痕断裂、长臂断裂和短臂 断裂等,其中着丝断裂频率最高;产生6种断片类型,包括有着丝粒和端粒的、有着丝粒而无端粒的、有部分着丝粒和端粒的、有 部分着丝粒而无端粒的、只有端粒的、既无着丝粒也无端粒的断片等。3. ACHT操作引起遗传结构重建的多样性。经ACHT处理后, 对修复24-72小时材料进行核型比较(按Stebbins 和 Levan 标准)和随体分析,处理细胞在染色体数目、大小、形态、位置等方面 均发生显著变化,说明ACHT处理使这些细胞的染色体结构和染色体组型发生了深刻变化。进一步通过Giemsa C— 带分析,观察到 多种重建染色体类型,包括易位型染色体、附加型染色体、无着丝粒染色体、化染色体、增加的m染色体以及某些带型特异的染色 体等。4. RAPD 分析从分子水平上验证了ACHT能有效地引起遗传结构的改变。所用10种引物对处理和对照材料基因组DNA的扩增产 物在条带数目、条带位置及带型特征等方面均有明显差异,其中4种引物出现条带减少,6种引物出现条带增加,后者还包括一个带 位移动。这说明两种材料的基因组DNA具有明显的RAPD反应多态性差异。This paper descripes some results draw on the basis of the observation and analysis on the rye before and after repaired through treating its budding seeds by ACHT in contrast to without ACHT: 1. ACHT manipulation caused the number variation and breakage damage of rye chromosome. Within certain conditions and timits, this phenomenon caused by different treats had signifcant difference: the more the treatment condition is drastie, the more the chageable range and frequence of rye chromosomae number, and so is the produced fragments. Meanwhile, there existed striking relationship among the changeable range and frequence of rye chromosome, the produced number and frequence of fragments and repairing frequence. 2. ACHT manipulafion engendered the diversify of rye chromosomal aberration. Four breakage patterns and six sorts of fragment were observed by watching the chromosome of the rye radicle treated by ACHT, including centric breakage (occuring in the highest frequence), secondary constriction breakage, long arm breakage and short arm breakage to the former, Comprising that with both centromere and telomere, that with centromere and without telomere, that with partial centromere and with telomere, that with partfial ceetromere and without telomere, that only with telomere and that neither with centromere nor with telomere, etc. 3. ACHT manipulation engendered the diversify or rye genetic structs reconstruction. Karureotype analysis(according to Stebbins and Levan) and satellite anaeysis were carried out to rye radicle through 24-72-hour-long recoverage after ACHT manipulation, which showed remarkable change happened on the rye chromosomal number、shape、arm ration and pattern, etc. and also on the satellite number、size、shape and location etc. Those indicated that ACHT manipulation engendered violent changes to rye chromatin structure and chromosome type. Further Giemsa C-banding analysis showed many types of reconstructed chromosome, such as translocation、addition、without centromere、st and other chromosome. 4. RAPD analysis checked the validity of ACHT on changing genetic structure of rye on the level of molecular biology. The treated and recovered rye has different amplifying band pattern by using IO valid arbitary primers selected from 40 comparing with the control.

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The high power EUV source is one of key issues in the development of EUV lithography which is considered to be the most promising technology among the next generation lithography. However neither DPP nor LPP seems to meet the requirements of the commercial high-volume product. Insufficiency of DPP and LPP motivate the investigation of other means to produce the EUV radiation required in lithography. ECR plasma seems to be one of the alternatives. In order to investigate the feasibility of ECR plasma as a EUV light source, the EUV power emitted by SECRAL was measured. A EUV power of 1.03W in 4 pi sr solid angle was obtained when 2000W 18GHz rf power was launched, and the corresponding CE was 0.5%. Considering that SECRAL is designed to produce very high charge state ions, this very preliminary result is inspiring. Room-temperature ECR plasma and Sn plasma are both in the planned schedule.

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We describe a low level of chromatid-type aberrations which included the relatively rare isochromatid/chromatid triradial in peripheral blood lymphocytes that were irradiated, ostensibly in GO, with accelerated heavy C-12 ions. These were produced only at the energies of 69 MeV/n (34.6 keV/ mu m), almost absent at the energy of either 58.6 McV/n (46.07 keV/mu m) or 19.3 MeV/n (97 keV/mu m), nor were they found after low-LET X-rays. Mechanisms potentially responsible for their formation are discussed.

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High-throughput screening is a promising new approach in analytical chemistry. Within the framework of an extended screening program (The German-Chinese Drug Screening Program), the enantioseparation of 86 drugs was investigated by capillary zone electrophoresis in the presence of the chiral solvating agent (CSA) octakis-(2,3,6-tri-O-methyl)-gamma-cyclodextrin (TM-gamma-CD). By this means, 15 drugs could be separated into enantiomeric pairs. Approximate measures for the degree of interaction (migration retardation factor, R-m) and for the degree of enantiomer recognition (migration separation factors, alpha(m)) revealed intriguing patterns that were compared with those found for native gamma-cyclodextrin (gamma-CD). Although there is a distinct influence of the analyte structure on the electrophoretic data, interpretation remains difficult. Most remarkably, permethylation of gamma-CD leads neither to a higher affinity nor to better chiral recognition, in contrast to the findings with alpha-CD.

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A method is presented for determining production and consumption rates of .OH radicals produced photochemically in natural surface waters. It is based on the determination of the kinetics by which the concentration of a specified trace compound decreases during irradiation. In samples from Lake Greifensee (Switzerland) low production rates for .OH limit its possible effects. In addition, fast consumptions by the natural dissolved organic solutes and by the bicarbonate protect organic micropollutants from oxidation by .OH. Neither direct nor indirect H2O2 photolysis was a significant source of .OH in the lakewater studied lacking iron, whereas nitrate photolysis could have been a source. Comparison with reaction kinetic formulations allows generalizations for other types of waters.

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I.四种猕猴属(Macaca)动物精母细胞联会复合体的比较研究 本工作采用去污剂微铺展--硝酸银染色技术比较研究了熊猴、平顶猴、藏酋猴、恒河猴及其亚种毛耳猴的精母细胞联会复合体(SC)核型和SC的结构、形态及其在减数分裂过程的行为。结果表明:1.这几种动物的SC核型及SC的发育过程基本一致。粗线期SC的相对长度和臂比与体细胞染色体的相对长度和臂比具有较好的吻合性。SC的形成开始于线期,成熟于粗线期,解体于双线期。2.在减数分裂前期,性染色体轴表现强烈的嗜银性,配对明显落后于常染色体。根据性染色体的形态和行为,可分为五种类型。此外,本文还对XY染色体的同源性和侧轴加粗等现象进行了讨论。II.食蟹猴(M.fascicularis)和熊猴(M.assamensis)杂种(F1)的细胞遗传学研究 本工作采用染色体显带、组织学观察以及低渗铺张--硝酸银染色等方法较为详细地研究了食蟹猴和熊猴种间杂种(F1)体细胞染色体的G带、C带、Ag-NOR、精母细胞联会复合体的结构、形态和行为以及精子发生。结果表明,①杂种亲本的染色体级具有高度的同源性;②杂种的精子发生过程完全正常;③食蟹猴和熊猴的种间生殖屏障可能主要是生态隔离。此外,本文还对食蟹猴和熊猴染色体高度同源的原因、二者的分类地位以及杂种细胞中Ag-NOR的多态性等问题进行了分析和讨论。

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Although colorless ionic liquids (ILs) are most desirable, as synthesized they frequently bear color, despite appearing pure by most analytical techniques. It leads to some uncertainties and limits for the fundamental research and applications of ILs, such as spectroscopy. Using 1-butyl-3-methylimidazolium bromide (BMIMBr), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) and 1-hexyl-3-methylimidazolium bromide (HMIMBr) as models, we demonstrated that following classic preparing method except that the water was added as solvent, colorless ILs could be facilely prepared. Neither critical pre-treatment of starting materials and pre-cautions during the reaction nor time-consuming and costly post-decolor-purification was needed, The effects of "on water" reaction conditions on preparing colorless IL and the reason why using water as solvent could produce colorless ILs were also preliminary investigated.

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The coordination reactions during the solvent extraction of cerium(IV) and fluorine(l) from mixed nitric acid and hydrofluoric acid solutions by di-(2-ethylhexyl)-2-ethylhexylphosphonate, L (DEHEHP) in heptane have been investigated. The extraction data have been analyzed by graphical methods taking into account all plausible species extracted into the organic phase. Different variables influencing the extraction of Ce(IV), such as the concentrations of nitrate ions, hydrofluroric acid, nitric acid, and extractant have been studied. The results demonstrate that DEHEHP can extract not only Ce(NO3)(4) as Ce(NO3)4.2L and HF as HF (.) H2O (.) L, but both together as Ce(HF)(NO3)(4) (.) L. The extraction equilibrium equations are determined according to slope analysis and IR spectra. The equilibrium constants of the extracted complexes have been calculated, taking into account complexation between the metal ion and inorganic ligands in the aqueous phase and all plausible complexes extracted into the organic phase. It is also shown that boric acid, which was added into the mixed solutions to complex with F(I) is not extracted by DEHEHP, and neither does it affect the extraction of cerium(IV) and HF, nor change the extraction mechanism.