Study on charge transfer reactions at multilayers of polyoxometalates clusters and poly(allylamine hydrochloride) (Grotthuss-018)

Multilayers of anionic phosphotungstic acid (PTA) clusters and positively charged protonated poly(allylamine hydrochloride) (PAH) were assembled by layer-by-layer self-assembled method on Au electrode modified by 3-mercaptopropionic acid (3-MPA). The effect of the charge of the surface of the multilayer assembly on the kinetics of the charge transfer reaction was studied by using the redox probes [Fe(CN)(6)](3-)/(4-) [Ru(NH3)(6)](2+/3+). The cyclic voltammetry experiments showed that the peak currents and peak-to-peak potential differences changed after assembling different layers on the electrode surface indicating that the charge of the surface has a significant effect on the kinetics of the studied charge transfer reactions. These reactions were studied in more detail by electrochemical impedance spectroscopy. When [Fe(CN)(6)](3-/-) was used as the redox label, multilayers that terminated with negatively charged PTA showed a high charge transfer resistance but multilayers that terminated with positively charged PAH showed lower charge transfer resistance. With [Ru(NH3)(6)](2+/3+) as the redox label, the charge transfer resistance at multilayers that terminated with positively charged PAH was much higher than at the multilayer terminated by the negatively charged PTA.

Distributed measurement of birefringence dispersion in polarization-maintaining fibers

A new method to measure the birefringence dispersion in high-birefringence polarization-maintaining fibers is presented using white-light interferometry. By analyzing broadening of low-coherence interferograms obtained in a scanning Michelson interferometer, the birefringence dispersion and its variation along different fiber sections are acquired with high sensitivity and accuracy. Birefringence dispersions of two PANDA fibers at their operation wavelength are measured to be 0.011 ps/(km nm) and 0.018 ps/(km nm), respectively. Distributed measurement capability of the method is also verified experimentally. (c) 2006 Optical Society of America.

Characterization of birefringence dispersion in polarization-maintaining fibers by use of white-light interferometry

A new method for measuring the birefringence dispersion in polarization-maintaining fibers (PMFs) with high sensitivity and accuracy is presented. The method employs white-light interferences between two orthogonally polarized modes of PMFs. The group birefringence of the fiber is calibrated first. Then the birefringence dispersion and its variation along different fiber sections are acquired by analyzing the broadening of interferograms at different fiber lengths. The main sources of error are investigated. Bireffingence dispersions of two PANDA fibers at their operation wavelength are measured to be 0.011 ps/(km nm) and 0.018 ps/(km nm). A measurement repeatability of 0.001 ps/(km nm) is achieved. (C) 2007 Optical Society of America.

Bacillus pallidus sp nov., isolated from forest soil

A Gram-positive bacterium, designated strain CW 7(T), was isolated from forest soil in Anhui Province, south-east China. Cells were strictly aerobic, motile with peritrichous flagella and rod-shaped. The strain grew optimally at 30-37 degrees C and pH 7.0-8.0. The major fatty acids of strain CW 7(T) were anteiso-C-15:0, iso-C-15:0 and anteiso-C-17:0. The predominant menaquinone was MK-7. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The G + C content of the genomic DNA was 42.3 mol%. Phylogenetic analysis indicated that strain CW 7(T) belonged to a monophyletic cluster within the genus Bacillus and showed 16S rRNA gene sequence similarities of less than 96.5% to recognized species of the genus Bacillus. The results of the polyphasic taxonomic study, including phenotypic, chemotaxonomic and phylogenetic analyses, showed that strain CW 7(T) represents a novel species of the genus Bacillus, for which the name Bacillus pallidus sp. nov. is proposed. The type strain is CW 7(T) (=KCTC 13200(T)=CCTCC AB 207188(T)=LMG 24451(T)).

mtDNA Data Indicate a Single Origin for Dogs South of Yangtze River, Less Than 16,300 Years Ago, from Numerous Wolves

There is no generally accepted picture of where, when, and how the domestic dog originated. Previous studies of mitochondrial DNA (mtDNA) have failed to establish the time and precise place of origin because of lack of phylogenetic resolution in the so fa

Polymerase chain reaction based C4AQ0 and C4BQ0 genotyping: association with systemic lupus erythematosus in southwest Han Chinese

Objective: To investigate the association of complement C4 null genes (C4QO, including C4AQO and C4BQO) and C2 gene with systemic lupus erythematosus (SLE) in southwest Han Chinese; 136 patients with SLE and 174 matched controls were genotyped. Methods: C4 null genes were determined by a polymerase chain reaction (PCR) procedure with sequence specific primers (PCR-SSP). The 2 bp insertion in exon 29, which was previously identified in non-Chinese populations and caused defective C4A genes, was directly typed by sequencing the whole exon 29 using exon specific primers. The exon 6 of complement C2 was also sequenced in both the patients and controls. Results: The frequency of homozygous C4AQO allele was 12.5% (17/136) in patients with SLE compared with 1.1% (2/174) in controls (p<0.001, odds ratio (OR)=12.286, 95% confidence interval (95% CI) 2.786 to 54.170). There was no significant difference for homozygous C4BQO allele between patients with SLE and controls (p=0.699). Patients with the C4AQO gene had an increased risk of acquiring renal disorder, serositis, and anti-dsDNA antibodies compared with those without C4AQO (for renal disorder, p=0.018, OR=8.951, 95% Cl 1.132 to 70.804; for serositis, p=0.011, OR 4.891, 95% CI 1.574 to 15.198; for anti-dsDNA, p=0.004, OR 7.630, 95%Cl 1.636 to 35.584). None of the patients or controls had the 2 bp insertion in exon 29 of the C4 gene. The type I C2 deficiency was not detected in the 3 10 samples. Conclusion: It is suggested that deficiency of C4A (not due to a 2 bp insertion in exon 29), but not C4B or C2, may be a risk factor for acquiring SLE in south west Han Chinese; this results in increased risk of renal disorder, serositis, and anti-dsDNA antibodies in patients with SLE. Racial differences seem to be relevant in susceptibility to SLE.

Deep RNA sequencing at single base-pair resolution reveals high complexity of the rice transcriptome

Understanding the dynamics of eukaryotic transcriptome is essential for studying the complexity of transcriptional regulation and its impact on phenotype. However, comprehensive studies of transcriptomes at single base resolution are rare, even for modern organisms, and lacking for rice. Here, we present the first transcriptome atlas for eight organs of cultivated rice. Using high-throughput paired-end RNA-seq, we unambiguously detected transcripts expressing at an extremely low level, as well as a substantial number of novel transcripts, exons, and untranslated regions. An analysis of alternative splicing in the rice transcriptome revealed that alternative cis-splicing occurred in similar to 33% of all rice genes. This is far more than previously reported. In addition, we also identified 234 putative chimeric transcripts that seem to be produced by trans-splicing, indicating that transcript fusion events are more common than expected. In-depth analysis revealed a multitude of fusion transcripts that might be by-products of alternative splicing. Validation and chimeric transcript structural analysis provided evidence that some of these transcripts are likely to be functional in the cell. Taken together, our data provide extensive evidence that transcriptional regulation in rice is vastly more complex than previously believed.

藏獒群体遗传结构及遗传分化研究

采用不连续垂直板聚丙烯酰胺凝胶电泳技术,对河曲藏獒和青海藏獒2个群体86只犬的9个结构基因座(Tf、Po、Es-1、Es-2、Sα2、Hb、Alb、Pr、Amy)的遗传变异情况进行了检测,探讨了2个藏獒群体的遗传结构和遗传分化。结果表明,河曲藏獒群体内遗传变异较青海藏獒丰富,而2个藏獒群体间的遗传分化程度很低(GST=0.018 7);较大的基因流(Nm=14.543 7)是2个藏獒不同地理群体间遗传分化水平低的主要原因。

云南怒江高原鳅属鱼类一新种记述

2000 年7 月和2004 年7 月, 分别在云南省怒江傈僳族自治州和保山市怒江干流采集到一批高原鳅 标本。经鉴定, 为高原鳅属Triplophysa 一未经发表的新种。新种怒江高原鳅Triplophysa ( Triplophysa) nujiangen2 sa sp1nov1 在形态特征和食性方面与唐古拉高原鳅、斯氏高原鳅、粗唇高原鳅和细尾高原鳅较为相似。本新种 身体相对短圆, 头部近圆筒形, 吻端钝圆, 颊部正常, 吻部在鼻孔之前明显向下倾斜, 下颌铲状, 边缘锐利而 水平, 上唇缘无突起, 下唇中央中断, 后部无突起, 眼间隔稍隆起, 眼间距为尾柄高016～018 倍, 第一鳃弓内 侧鳃耙10～19 , 肠绕折3 个环, 前背长为体长7111 %～7712 % , 体长为头长416～515 倍, 偶鳍短圆, 背鳍分 枝鳍条8 根, 胸鳍分枝鳍条10～11 根, 腹鳍末端不达肛门, 尾鳍高度向尾鳍方向不明显降低, 尾柄起点处的宽 小于该处的高, 尾柄长为尾柄高116～218 倍, 胸鳍长为胸腹鳍起点间距4715 %～6315 % , 尾鳍内凹。本文列 出了中国高原鳅属5 种铲状下颌种类的检索表, 本新种可藉之与这些相似种相区别。

Population genetic structure of the parasitic nematode Camallanus cotti inferred from DNA sequences of ITS1 rDNA and the mitochondrial COI gene

The population genetic structure of fish parasitic nematode, Camallanus cotti, collected from the Yangtze River, Pearl River and Minjiang River in China was investigated. From these parasites, the similar to 730 bp of the first internal transcribed spacer of ribosomal DNA (ITS1 rDNA) and the 428 bp of mitochondrial cytochrome c oxidase subunit I (COI) gene were sequenced. For the ITS1 rDNA data set, highly significant Fst values and low rates of migration were detected between the Pearl River group and both the Yangtze River (Fst = 0.70, P < 0.00001; Nm = 0.21) and Minjiang River (Fst = 0.73, P < 0.00001; Nm = 0.18) groups, while low Fst value (Fst = 0.018, P > 0.05) and high rate of migration (Nm = 28.42) were found between the Minjiang and the Yangtze rivers. When different host/locality populations (subpopulations) within each river were considered, subpopulations between the Yangtze River and Minjiang River had low Fst values (<= 0.12) and high Nm values (>3.72), while Pearl River subpopulations were significantly different from the Yangtze River and Minjiang River subpopulations (Fst >= 0.59; Nm < 1). The COI gene data set revealed a similar genetic structure. Both phylogenetic analyses and a statistical parsimony network grouped the Pearl River haplotypes into one phylogroup, while the Yangtze River and Minjiang River haplotypes formed a second group. These results suggested that the Yangtze River and Minjiang River subpopulations constituted a single reproductive pool that was distinct from the Pearl River subpopulations. In addition, the present study did not find host-related genetic differentiation occurring in the same drainage. (C) 2009 Published by Elsevier B.V.

Genetic Stability of Progeny from an Artificial Allotetraploid Carp Using Sperm from Five Fish Species

Microsatellite markers and D-loop sequences of mtDNA from a female allotetraploid parent carp and her progenies of generations 1 and 2 induced by sperm of five distant fish species were analyzed. Eleven microsatellite markers were used to identify 48 alleles from the allotetraploid female. The same number of alleles (48) appeared in the first and second generations of the gynogenetic offspring, regardless of the source of the sperm used as an activator. The mtDNA D-loop analysis was performed on the female tetraploid parent, 25 gynogenetic offspring, and 5 sperm-donor species. Fourteen variable sites from the 1,018 bp sequences were observed in the offspring as compared to the female tetraploid parent. Results from D-loop sequence and microsatellite marker analysis showed exclusive maternal transmission, and no genetic information was derived from the father. Our study suggests that progenies of artificial tetraploid carp are genetically stable, which is important for genetic breeding of this tetraploid fish.

The picophytoplankton in three Chinese lakes of different trophic status and its relationship to fish populations

A year-round comparison was made of the picophytoplankton populations in three lakes of different trophic status (oligotrophic, mesotrophic, and hypereutrophic), as well as in experimental enclosures stocked with various densities of fish. Picophytoplankton abundance was significantly different between the hypereutrophic lake and the oligotrophic lake (P<0.018) and between the hypereutrophic lake and the mesotrophic lake (P<0.021), whereas the difference between the mesotrophic and oligotrophic lakes was not significant (P<0.745). The effect of total nitrogen:total phosphorus ratio on the abundance of picophytoplankton was demonstrated in the oligotrophic lake, but such effect did not manifest itself in the other lakes or in the experimental enclosures. The average annual picophytoplankton population sizes in the three lakes in 1995-1998 were correlated with estimated fish abundance (r=0.824, n=9, P=0.006). The results of enclosure experiments demonstrated that the abundance of picophytoplankton increased with the stocking density of fish (r=0.619, n=8, P=0.100).

Improvement of Ge self-organized quantum dots by use of Sb surfactant

A Sb-mediated growth technique is developed to deposit Ge quantum dots (QDs) of small size, high density, and foe of dislocations. These QDs were grown at low growth temperature by molecular beam epitaxy. The photoluminescence and absorption properties of these Ge QDs suggest an indirect-to-direct conversion, which is in good agreement with a theoretical calculation. (C) 1998 American Institute of Physics. [S0003-6951(98)00420-3].

黄土丘陵区纸坊沟流域“退耕还林”工程实施后生态足迹变化分析

以黄土丘陵区纸坊沟流域所辖3个自然村农户的调查资料为依据,利用生态足迹理论及模型对该流域生态足迹与生态承载力进行了测算。结果表明,纸坊沟流域退耕还林工程实施前(1999年)生态足迹0.9910 hm2/cap,生态承载力0.8926 hm2/cap,生态赤字0.0984 hm2/cap;退耕还林工程一期结束后(2007年)生态足迹1.0188 hm2/cap,生态承载力1.2703 hm2/cap,生态盈余0.2515 hm2/cap,说明退耕还林工程的实施已见成效;同时退耕还林一期工程实施前后3个自然村生态足迹顺序并未发生变化,这与其区位特征一致。根据该流域及其3个自然村的发展特点,为实现其可持续发展,应发展商品型生态农业,强化产业与资源的耦合。

在辉光放电中八氟环丁烷聚合的研究

I 理论部分：对未知结构聚合物的ESCA谱进行表征，一是利用已知结构小分子化合物的ESCA谱中结合能值进行标定，二是运用电荷电位模型经量子化学计算对谱峰进行归属。由于所处化学环境不同，用小分子化合物的ESCA谱峰位对象合物标定不够准确，量子化学计算又太复杂。本工作提出了电负性经验公式，可计算ESCA谱中C_(1S)结合能位移值，与实测值作对照即可判断聚合物结构，方法简便，准确可靠。电负性经验公式表达如下：聚合物分子链上某碳原子1S电子结合能位移ΔEc可看作该碳原子与相邻基团间电负性差值和的函数，即ΔEc = K_c ∑ from i=1 to 4 1/(n_i) (X_i - 2.5) + b。聚合物分子链上各碳原子的实际电负性为X_c = (∑ form j=1 to 4 1/(n_j) X_j/∑ form j=1 to 4 1/(n_j) + 2.5)/2运用电负性经验公式计算了九个模型化合物中C_(1S)的ΔEc，推导出F作为α、β、γ位碳上的取代基的对α位碳上1s电子结合能位移影响产生的效应值，即，对于ΔEc = aα + bβ + cγ，有α = 3.018 (±0.007)，β = 0.2513 (±0.0007) γ = 0.0176 (±0.003)。此结果与ESCA谱实测值相符。本工作设计了十六种化合物模型，模型中具有含氟等离子体聚合物中可能存在的大部分基团，通过电负性经验公式计算求得化学环境不同的C_(1S)结合能位移值，把ESCA谱的实测值和计算值进行对照，可对象合物的求知结构作出大致判断。II 在辉光放电中八氟环丁烷的聚合与刻蚀反应：在碳氧化合物的辉光放电中同时存在聚合与刻蚀两种相反的过程，聚合与刻蚀竞争的结果对聚合速率，产物结构都有很大影响。本工作通过测定聚合速率、IR谱、ESCA谱研究了反应条件对八氟环丁烷等离子体聚合与刻蚀的影响，得到了一致的和半定量的结果。实验证实，随着功率的增大或压力的减小，刻蚀有增强的趋势，不同的等离子气体对聚合与刻蚀的竞争过程有不同的影响，刻蚀强弱的顺序为Ar>N_2>H_2>He，增加等离子气体对单体的比率，引起刻蚀增加。聚合速率不随功率的改变而变化的状态是由聚合与刻蚀间的平衡引起的。随着功率增大或压力减少，聚合产物支化程度增加，线性程度减小，F/C比相应减小。同样随等离子气体种类不同，聚合物支化程度大小的顺序是Ar>N_2>H_2>He，F/C比相应变化。总之，聚合产物支化程度的变化和聚合与刻蚀的竞争结果相一致。对等离子体聚合与刻蚀竞争过程的定量描述未见文献报导。III 八氟环丁烷等离子体聚合物的结构和表征：用IR和ESR谱测得OFCB等离子体聚合物中存在五种元素：C、F、O、N、Si，并对可能存在于结构中的基因作了分析。通过NaHSO_3的亲核双键加成反应，用IR和ESR谱证实了等离子体聚合物中存在的双键及其类型。类似工作未见文献报导。用CuSO_4·5H_2作标样，测出PPOFCB中的自由基浓度为10~(19)自旋数/克。在80、100、120、140 ℃考察PPOFCB中俘获自由基的衰减过程，证实此过程涉及两类不同的反应，一是自由基的复合反应，二是自由基的氧气的终止反应。对上述两类反应进行动力学处理，求出了自由基复合反应在不同温度时的速度常数，并得到反应治化能为374焦耳/摩尔或8.869千卡/摩尔。氧和自由基的终止反应中，氧气的扩散过程是决定反应速度的步骤，反应速度常数就是扩散速度常数，K = 5.3 * 10~(-23)自旋数~(-1)、克分~(-1)。根据VPO测出的PPOFCB的分子量和自由基浓度，算出每4.5个分子中有一个自由基。类似工作未见文献报导。PPOFCB的分子量随反应条件不同而变化，用VPO测出，在80W和40W功率，在Ar存在下制备的OFCB等离子体聚合物的分子量分别为2736和2003。用~(19)F-NMR谱对PPOFCB中的基团进行定量计算，得出在一个90W，He气中制备的聚合物分子中，CF_3-CF_2为6.1，CF_2为13.5，CF_3-CF为7.9，CF为17.5，CF_3-C为6.1，C为13.5。在用上述方法进行结构表征的基础上，提出了OFCB等离子体聚合物的结构模型。IV 八氟环丁烷等离子体聚合的反应历程：以Ar、N_2、H_2、He为等离子气体，分别对OFCB等离子体聚合的气体冷凝物进行GC-Mg、~(19)F-NMR和ESR测试，观察到在气相中，OFCB经历了等离子态反应。单体被打断的程度，和高能电子浓度有关。体系中电子浓度依赖于气体的第一电离势和气相内的化学反应类型。初级粒子二氟卡宾：CF_2和中间体六氟丙烯是气相中的主要产物。~(19)F-NMR证实气相中存在支化产物，表明聚合物在气相中发生了重排。ESR谱测得，在气相产物中存在高浓度的由二种以上组分混合而成的自由基，自由基间的复合反应是生成聚合物的主要增长过程，气相产物的分子量随放电功率的升高而增大。根据聚合物中存在的高含量CF_3基团，分析了CF_3基团对聚合过程的影响。CF_3基团产生了屏蔽效应，它既保护了聚合物不致被降解，也限制了生成高分子量产物。实验证实，CF_3基团的生长来自F的重排，同时未自支化气相产物的非均相增长。OFCB等离子体聚合物中俘获自由基主要是由高能电子轰击聚合物表面产生的，同时来自被固相吸附的带有自由基的气相产物。在碳氟化合物的等离子体聚合中，吸附是和聚合同样重要的过程，气相产物被吸附后，可继续再引发、增长、刻蚀等反应过程、直到成为固相内层分子为止。ESR谱证实，高能粒子的轰击在辉光放电中起主导作用，紫外辐射对含氟聚合物引发和脱氟作用微弱。在气相和表面反应历程讨论的基础上，提出了OFCB等离子体聚合的反应历程模型，解释了碳氢和碳氟两个等离子体象合体系遵循不同反应历程的原因。本部分工作的实验和反应历程解释基本未见文献报导。