基于非靶向代谢组学的茄梨和红茄梨成熟期果皮代谢产物的差异分析

为了探究西洋梨品种茄梨及其红色芽变红茄梨成熟期果皮代谢产物差异,采用超高效液相色谱-质谱联用技术,对茄梨和红茄梨成熟期果皮进行非靶向代谢组学研究。通过主成分分析和正交偏最小二乘判别分析,构建了多变量统计分析模型,结合模型和变量重要性投影与最大差异倍数值,基于精确质量数、二级碎片以及同位素分布,使用PMDB(Plant Metabolome Database)数据库进行定性,筛选并鉴定出茄梨和红茄梨果皮中显著性变化(P<0.05, VIP(variable importance in project)≥1)的差异代谢物有83种,主要包括酚酸类、黄酮类和氨基酸类物质,涉及类黄酮代谢、氨基酸代谢、苯丙烷类代谢等代谢途径,其中53种物质含量上调,30种物质表达下调。通过KEGG(Kyoto Encyclopedia of Genes and Genomes)数据库进一步对差异代谢物质进行通路富集分析,差异代谢物主要分布在20条代谢途径中,P<0.05的代谢途径有6条,分别是类黄酮生物合成、黄酮和黄酮醇生物合成、苯丙烷生物合成、丁酸酯代谢、苯丙氨酸代谢、酪氨酸代谢。这些差异代谢物的变化可能是导致茄梨和红茄梨果皮色泽不同的原因。该研究从植物代谢组学角度初步揭示了茄梨和红茄梨成熟期果皮的代谢产物差异性。     

The regulation of biothiol-responsive performance and bioimaging application of benzo[c][1,2,5]oxadiazole dyes

The different oxidation states of sulphur atom play a significant role on functional materials. In this work, a aryl-thioether and its sulphone substituted benzo[c][1,2,5]oxadiazole dyes were synthesized and utilized to determine thiol-containing amino acids. The result of selectivity experiments showed they detected the cysteine and homocysteine under physiological condition with negligible interference from other amino acids. In comparison to the thioether dye, the sulphone-based dye exhibited much faster response time for Cys and Hcy. However, the sulphone restricted its thiol-reactivity and bioimaging performance in living cells. By reducing the oxidation state of sulphur atom, we amazedly found that the sulfoxide-based dye still maintained high selectivity ultrafast response time for Cys/Hcy under physiological condition. It was worth mentioning that it also had high reactivity and good bioimaging performance that sulfone compounds did not have.     

Cationic and temperature-sensitive liposomes loaded with eugenol for the application to silk

Silk has been widely used in the clothing industry due to their soft and smooth features, good biocompatibility, good heat dissipation, warmth and ultraviolet resistance. The application of fragrance to silk can significantly improve the performance of silk. However, there are two key scientific problems that need to be solved: slowing down the release rate of fragrances and increasing the scent lasting time of silk. In this study, cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol. These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner. The liposomes adhered to the silk through electrostatic adsorption interaction. The positive charge on the fragrance-loaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.     

天文/卫星组合点校捷联惯性导航系统算法研究

捷联式惯性导航系统通常采用卫星导航系统的位置、速度信息对惯导解算误差进行校正,但对于水下载体惯性导航系统而言,由于只能获得点位置信息,对惯导的校正精度以及校正参量有限。针对上述问题,提出了基于天文/卫星组合校正捷联式惯导技术,通过卫星精确定位信息和天文快速观测信息,全面修正惯导系统误差、提高导航精度。仿真结果表明,基于天文/卫星组合校正算法对惯导进行校正,相对于传统校正算法精度可提高约50%。     

Cycloaddition reactions of benzyne with olefins

Some novel cycloaddition reactions based on benzyne and olefins have been developed.These reactions were performed in the absence of a transition metal catalyst,and they displayed good yields.These cycloaddition reactions of benzyne with olefins provide effective routes for synthesizing benzocyclobutenes,biaryl compounds and 9,10-dihydrophenanthrene derivatives.     

聚乙二醇改性壳聚糖作为小分子药物载体的研究进展

壳聚糖具有抗菌、抗氧化、增强胶凝特性以及可作为生物活性分子的微型或纳米载体等优点,因此其化学改性和应用近年来受到广泛关注。然而,壳聚糖既不溶于有机溶剂也不溶于水,极大地限制了它的应用。在改性的壳聚糖中,聚乙二醇化壳聚糖不仅能保持壳聚糖的优点,还能提高水溶性,并能有效运输生物活性分子。因此,本文总结了2008-2012年聚乙二醇化壳聚糖作为紫杉醇、阿霉素、5-氟尿嘧啶等小分子载体的最新进展,为今后聚乙二醇化壳聚糖的研究提供有益参考和理论依据。     

BiPO4/石墨烯光电极的制备及其光电催化性能（英文）

光电催化(PEC)氧化法是一种使用半导体电极材料在光和电的共同作用下处理水中有机污染的有效方法.在PEC工艺中,施加偏压不仅可以利用电催化对有机污染物进行降解,而且在偏压作用下,光生电子-空穴对能够得到有效的分离和传输,从而大大提高了机物污染物的去除速率.尽管PEC技术已经取得了许多重要的突破,但是能量转换效率仍然无法满足实际应用.因此,开发具有优异性能,良好稳定性和低成本的光电极材料是一项具有挑战性的研究工作.本文采用两步电沉积法制备了BiPO4纳米棒/还原氧化石墨烯/FTO复合光电极(BiPO4/r GO/FTO).电镜结果表明,电沉积制得的纳米棒状磷酸铋均匀负载在石墨烯纳米片层表面.采用甲基橙为模型体系,考察了复合光电极的光电催化活性.BiPO4/r GO/FTO复合电极的光电催化降解速率是BiPO4/FTO光电极的2.8倍,显示出优良的光电催化活性.实验进一步研究了工作电压和BiPO4沉积时间对甲基橙光电降解性能的影响.最佳的BiPO4沉积时间为45 min,最佳工作电压为1.2 V.捕获实验和ESR实验表明羟基自由基(·OH)和超氧化物自由基(·O2-)是该电极的主要活性物种.BiPO4/r GO/FTO复合电极经过四次循环实验后其降解甲基橙效率保持不变,显示出高稳定性,采用光电流,交流阻抗及其荧光测试对其光催化机理进行推测.结果表明该复合光电极具有高PEC活性的主要原因是:石墨烯的引入加快了BiPO4的电子空穴的分离,拓宽了石墨烯的可见光吸收范围;同时,石墨烯诱导产生的BiPO4混合相也进一步促进了光生电子空穴的分离,提高了光电降解活性.     

Palladium‐Catalyzed Asymmetric [4+3]‐Cyclization Reaction of Fused 1‐Azadienes with Amino‐trimethylenemethanes: Highly Stereoselective Construction of Chiral Fused Azepines

Summary of main observation and conclusion A Pd-catalyzed asymmetric aromative[4+3]-cyclization reaction of amino-trimethylenemethanes(TMM,1d,ip3-oles)with fused 1-azadienes has been developed.This method enables access to the synthetically importance and biologically active benzofuran fused azepines and indeno-azepines in excellent efficiency and stereoselectivity(up to 95%yield,99%ee,>19:1 dr).     

Progress on intelligent hydrogels based on RAFT polymerization: Design strategy,fabrication and the applications for controlled drug delivery

Although intelligent hydrogels have shown bright potential application in biomedical fields,they were prepared by conventional methods and still face many serious challenges,such as uncontrollable stimulus-response and low response sensitivity.Recently,RAFT polymerization provides a versatile strategy for the fabrication of intelligent hydrogels with improved stimulus-response properties,owing to the ability to efficiently construct hydrogel precursors with well-defined structure,such as block copolymer,graft copolymer,star copolymer.In this review,we summarized the recent progress on intelligent hydrogels based on RAFT polymerization with emphasis on their fabrication strategies and applications for controlled drug delivery.     

High-refractive index acrylate polymers for applications in nanoimprint lithography

The development of polymeric optical materials with a higher refractive index,transparency in the visible spectrum region and easier processability is increasingly desirable for advanced optical applications such as microlenses,image sensors,and organic light-emitting diodes.Most acrylates have a low refractive index(around 1.50)which does not meet the high perfo rmance requirements of advanced optical materials.In this research,three novel acrylates were synthesized via a facile one-step approach and used to fabricate optical transparent polymers.All of the polymers reveal good optical properties including high transparency(≥90%)in the visible spectrum region and high refractive index values(1.6363)at 550 nm.Moreover,nanostructures of these acrylate polymers with various feature sizes including nanogratings and photonic crystals were successfully fabricated using nanoimprint lithography.These results indicate that these acrylates can be used in a wide range of optical and optoelectronic devices where nanopatterned films with high refractive index and transparency are required.