Synthesis and characterization of network liquid crystal elastomers and thermosets

A new series of network liquid crystal polymers were synthesized by graft copolymerization of the difunctional mesogenic monomer 4-allyloxy-benzoyloxy-4'-allyloxybiphenyl (M) upon polymethylhydrosiloxane (PMHS). Monomer M acted not only as a mesogenic unit but also as a crosslinker for the network polymers. The chemical structures of the polymers were confirmed by IR spectroscopy. DSC, TGA, and X-ray scattering were used to measure their thermal properties and mesogenic properties. The glass transition temperature (T-g) of these network liquid crystal polymers was increased when the monomer was increased, and T-d (temperature of 5% weight loss) at first went up and reached a maximum at P, then went down. The slightly crosslinked polymers (P, P,) show rubber-like elasticity, so it was called liquid-crystal elastomer. Network polymers will lose elasticity property with a highly crosslinked degree, and turn into thermosetting polymers (P-4, P-5). All polymers exhibited a smectic texture by X-ray scattering.

流动注射示差动力学分析法提高测定的选择性

本文归纳了流动注射示差动力学分析法所基于的化学反应和常用的流路,评述了流动注射示差动力学分析法在单一组分的高选择性测定和多组分的连续或同时测定中的应用。

Identification and characterization of a myeloid differentiation factor 88 (MyD88) cDNA from Zhikong scallop Chlamys farreri

Myeloid differentiation factor 88 (MyD88) is a universal and essential adapter for the TLR/IL-1R family. In this report, the first mollusk Myd88 ortholog (named as CfMyd88) was cloned from Zhikong scallop (Chlamys farreri). The full-length cDNA of CfMyd88 was of 1554 bp, including a 5 '-terminal untranslated region (UTR) of 427 bp, a polyA tail, and an open reading frame (ORF) of 1104 bp encoding a polypeptide of 367 amino acids containing the typical TLR and IL-1R-related (TIR) domain and death domain (DD). Homology analysis revealed that the predicted amino acid sequence of CfMyd88 was homologous to a variety of previously identified Myd88s with more than 30% identity. The temporal expressions of CfMyd88 mRNA in the mixed primary cultured haemocytes stimulated by lipopolysaccharide (LPS) and peptidoglycans (PGN) were measured by real-time RT-PCR system. The mRNA expression of CfMyd88 decreased after stimulation with both LPS and PGN, and the lowest level was about 1/3 times (at 6 h) and 1/10 times (at 9 h) to that in the control group, respectively. The expression then recovered and was upregulated to two-fold at 9 h after LPS stimulation or to the original level at 12 It after PGN stimulation. The results suggest that the MyD88-dependent signaling pathway exists in scallop and was involved in the defense system. (c) 2007 Elsevier Ltd. All rights reserved.

海藻中植物生长素的提取、纯化及测定

生长素是一类重要的内源植物激素。它广泛存在于水生和陆生植物中，对其它生长发育起着至关重要的作用。国内外对海藻生长的相关研究报道较少，迄今尚未以对提取、纯化海藻中生长素的方法进行系统研究的报道，海藻生长系的定量分析也处在起步阶段，只有少量文献报道了个别海藻中生长素的含量。本论文通过较系统的实验，首次确定了一整套海藻生长素的提取、纯化及测定方法，并运用该方法首次测定和报道了我国有代表性的部分海藻中生长素的含量及组成。在分析比较现有方法的基础上，确定了以有机溶剂提取法提取海藻中的生长素，以萃取法和柱层析法对其进行分离纯化的初步方案，通过一系列实验对该方案中各关键步骤（包括前处理、提取、脱色、萃取纯化、碱液洗涤及柱层析纯化等）的具体操作条件进行了优选，从而建立了一种操作简便、提取率较高且重复性较好的海藻生长素的提取和纯化方法。运用已确定的提取、纯化及测定方法，对我国青岛海区的红、绿、褐三大类共16种有代表性海藻的生长素含量进行了测定。其生长素IAA含量为1.1～46.9ng/g FW，其中褐藻绳藻中生长素的含量在16种海藻中最高，为46.9 ng/g FW，是海藻肥的较佳资源种；鼠尾藻的含量最小，只有1.1 ng/g （鲜重）。运用TLC方法对所有海藻提取样品中生长素的组成进行了分析。大多数样品只有1个IAA显色点，其Rf值在0.43～0.48之间；鼠尾藻、海黍子和孔石莼样品未检出生长素；海带、蜈蚣藻和小珊瑚样品中除有IAA显色点外，还有1～2个其它斑点，这些斑咪的显色牲与吲哚类物质相同，是吲哚类生长素。

低氧对大鼠体液免疫的抑制作用

本实验以模拟高原低氧的方法，探讨了低氧对大鼠体液免疫的作用，并与高原鼠免比较，体液免疫以溶血亲和IgG产生为指标。实验结果：与对照组相比，大鼠低氧10d，5km海拔抑制溶血素形成10．3％，7km海拔抑制溶血素形成21．9％；经再次免疫后又低氧10d，5km海拔抑制溶血素形成4．2％，7km海拔抑制溶血素形成4．6％，高原土著动物高原鼠兔（Ochotona curzoniae）则不表现上述的抑制现象；大鼠经SRBC腹腔致敏2d后低氧5d和8d，未表现低氧抑制溶血素形成的作用；大鼠侧脑室给予外源性CRF（1μg／rat），可抑制溶血素形成和IgG产生，溶血素形成抑制8.6％，IgG产生抑制14．0％；7km低氧大鼠侧脑室给予CRF受体阻断剂（α-helicalCRF(9-41)）50μg对低氧抑制溶血素形成一定的阻断作用，可部分阻断低氧抑制IgG产生，使IgG产生的抑制率由24.2%提高到12.1%；大鼠腹腔注射1μgCRF对溶血素形成和IgG产生无影响；与假手术组比，大鼠在摘除双侧肾上腺后，低氧对溶血素形成仍抑制6.6%。因而，本研究认为低氧对初次和再次体液免疫均产生抑制作用，而且抑制作用发生在体液免疫的起始阶段，其抑制作用与中枢CRF升高有关。

Genetic diversity and historical population structure of Schizopygopsis pylzovi (Teleostei : Cyprinidae) in the Qinghai-Tibetan Plateau

1. Complete sequences of 1140 base pair of the cytochrome b gene from 133 specimens were obtained from nine localities including the inflow drainage system, isolated lakes and outflow drainage system in Qinghai-Tibetan Plateau to assess genetic diversity and to infer population histories of the freshwater fish Schizopygopsis pylzovi.2. Nucleotide diversities (pi) were moderate (0.0024-0.0045) in populations from the outflow drainage system and Tuosuo Lake, but low (0.0018-0.0021) in populations from Qiadam Basin. It is probable that the low intra-population variability is related with the paleoenvironmental fluctuation in Qiadam Basin, suggesting that the populations from Qiadam Basin have experienced severe bottleneck events in history.3. Phylogenetic tree topologies indicate that the individuals from different populations did not form reciprocal monophyly, but the populations from the adjacent drainages cluster geographically. Most population pairwise F-ST tests were significant, with non-significant pairwise tests between Tuosu Lake and Tuosuo Lake in the north-west of the Qinghai-Tibetan Plateau. Analysis of molecular variance (AMOVA) indicates that the significant genetic variation was explained at the levels of catchments within and among, not among specific boundaries or inflow and outflow drainage systems.4. The nested clade phylogeographical analysis indicates that historical processes are very important in the observed geographical structuring of S. pylzovi, and the contemporary population structure and differentiation of S. pylzovi may be consistent with the historical tectonic events occurred in the course of uplifts of the Qinghai-Tibetan Plateau. Fluctuations of the ecogeographical environment and major hydrographic formation might have promoted contiguous range expansion of freshwater fish populations, whereas the geological barriers among drainages have resulted in the fragmentation of population and restricted the gene flow among populations.5. The significantly large negative F-s-value (-24.91, P < 0.01) of Fu's F-s-test and the unimodal mismatch distribution indicate that the species S. pylzovi underwent a sudden population expansion after the historical tectonic event of the Gonghe Movement.6. The results of this study indicate that each population from the Qinghai-Tibetan Plateau should be managed and conserved separately and that efforts should be directed towards preserving the genetic integrity of each group.

Rubisco small subunit, chlorophyll a/b-binding protein and sucrose : fructan-6-fructosyl transferase gene expression and sugar status in single barley leaf cells in situ. Cell type specificity and induction by light

Chungui Lu, Olga A. Koroleva, John F. Farrar, Joe Gallagher, Chris J. Pollock, and A. Deri Tomos (2002). Rubisco small subunit, chlorophyll a/b-binding protein and sucrose : fructan-6-fructosyl transferase gene expression and sugar status in single barley leaf cells in situ. Cell type specificity and induction by light. Plant Physiology, 130 (3) pp.1335-1348 Sponsorship: BBSRC RAE2008

Ethylene rapidly up-regulates the activities of both monomeric GTP-binding proteins and protein kinase(s) in epicotyls of pea

Igor E. Moshkov, Galina V. Novikova, Luis A.J. Mur, Aileen R. Smith, and Michael A. Hall. (2003). Ethylene rapidly up-regulates the activities of both monomeric GTP-binding proteins and protein kinase(s) in epicotyls of pea. Plant Physiology, 131(4), 1718-1726 RAE2008

Salicylate accumulation inhibits growth at chilling temperature in Arabidopsis

Ian M. Scott, Shannon M. Clarke, Jacqueline E. Wood and Luis A.J. Mur (2004). Salicylate accumulation inhibits growth at chilling temperature in Arabidopsis. Plant Physiology, 135(2), 1040-1049. RAE2008

Laser photoacoustic detection allows in planta detection of nitric oxide in tobacco following challenge with avirulent and virulent pseudomonas syringae pathovars

Luis A.J. Mur, I. Edi Santosa, Lucas J.J. Laarhoven, Nicholas J. Holton, Frans J.M. Harren and Aileen R. Smith (2005). Laser photoacoustic detection allows in planta detection of nitric oxide in tobacco following challenge with avirulent and virulent pseudomonas syringae pathovars. Plant Physiology, 138(3), 1247-1258. Sponsorship: BBSRC / EU RAE2008

Legacy of unresolved legal issues on mental health

ANALYSIS The time has come for a fundamental review of the Mental Health Act 2001.

Reflexiones críticas sobre modelos matemáticos en la clase: ¿sueño o realidad?

Sobre la base de dos casos de modelos matemáticos aplicados a problemas auténticos, sugeriré algunas consecuencias de usar las matemáticas. Para ver si las reflexiones sobre estos asuntos se pueden introducir en el aula observé algunos cursos de modelado en escuelas danesas de educación superior. Encontré que las reflexiones eran realizadas en unas pocas circunstancias aisladas, y que generalmente estaban separadas de la actividad de modelaje de los estudiantes. Sin embargo, observé algunas diferencias interesantes entre dos de los cursos. En uno, las experiencias a partir del modelaje estaban en alguna medida influyendo las reflexiones que los estudiantes adelantaban. En el otro, las reflexiones sobre modelos eran claramente opuestas tanto al modelaje como a la actividad matemática de los estudiantes -opuesta en contenido lo mismo que como tipo de discurso.