化學

磁共振對比劑標記的聚合物傳輸siRNA抑制基因表達

王衛(wèi)娟，肖洪，程度，等

二乙烯三胺（DETA）修飾生物可降解的聚乙二醇（PEG）-聚天冬氨酸（PAsp）兩嵌段聚合物PEG-PAsp，并通過配體交換將PEG-PAsp（DETA）修飾到磁共振（MR）對比劑SPIO表面，陽離子嵌段PAsp（DETA）可負載核酸分子siRNA，從而獲得兼具MR顯像和核酸傳輸功能的生物可降解載體.細胞毒性研究證實該載體聚合物具有較好的生物安全性，可被腫瘤細胞高效吸收，且使轉基因細胞株A549-Luc（恒定表達螢火蟲熒光素酶）中熒光素酶的活性下調60%.MR成像也證實，SPIO經載體負載后，其橫場弛豫率比游離的水溶性SPIO（WSPIO）提高了3倍以上，達到147 Fe（mmol/L）-1s-1，顯著提高了磁共振的顯像效果.

核酸傳輸載體；聯(lián)合輸送；siRNA；磁共振對比劑

來源出版物：高分子學報，2015，（4）: 484-492聯(lián)系郵箱：程度，chengdu@mail.sysu.edu.cn

Non-aqueous Suspension Polycondensation in NMP-CaCl2/Paraffin System —A New Approach for the Preparation of Poly（p-phenylene terephthalamide）

Pei-jian Wang，Kai Wang，Ji-song Zhang，et al.

來源出版物：Chinese Journal of Polymer Science，2015，33（4）: 564-575聯(lián)系郵箱：Guang-sheng Luo，gsluo@tsinghua.edu.cn

有機催化蒽酮與β-硝基烯烴的不對稱Michael加成反應

張?zhí)煲?，年文霞，金?/p>

將金雞納生物堿衍生物用于催化蒽酮和 β-硝基芳基乙烯的不對稱 Michael加成反應.考察了溶劑、溫度及催化劑用量對反應催化性能的影響.結果表明，最佳條件為 5%（摩爾分數(shù)）催化劑1 b、甲苯為溶劑、0℃反應，得到了91%～99%的化學產率和最高達95%ee的對映體選擇性.

金雞納生物堿衍生物；有機催化；不對稱Michael加成反應；蒽酮；β-硝基烯烴

來源出版物：應用化學，2015，32（4）: 422-427

聯(lián)系郵箱：金瑛，jinying1021@sina.com

來源出版物：SCIENCE CHINA Chemistry，2015，58（4）: 553-564聯(lián)系郵箱：Xiaoming Cao，xmcao@ecust.edu

A non-aqueous suspension polycondensation method was proposed to proceed the reaction of p-phenylenediamine and terephthaloyl chloride for the preparation of poly（pphenylene terephthalamide）（PPTA）. The system was operated with NMP-CaCl2solution as the dispersed phase and inert liquid paraffin as the continuous phase. Each of NMP-CaCl2solution microdroplet suspended in paraffin served as a microreactor where the polycondensation took place. According to the results of TGA，XRD，IR，SEM and EA，PPTA with good quality was obtained through this novel method，and a number of main factors influencing this process were investigated to determine the optimum condition for the preparation of PPTA. Besides，this twophase polycondensation system brings many unique advantages compared to the conventional solution polycondensation method，including a sealed reaction environment keeping the reactants away from oxygen and water，easy removal of HCl to promote the reaction，well-controlled temperature and low viscosity which means less energy cost.

Poly（p-phenylene terephthalamide）； Non-aqueous suspension polycondensation； Weight-average molecular weight； Microreactor； Microdroplets

封面介紹：The chemical reduction of carbon dioxide CO2which is the primary greenhouse gas in the atmosphere is thought to be responsible for increasingly global warming leading to numerous ecological problems. Industrial synthesis of methanol utilizing copper-based catalysts is a commonly used process for CO2hydrogenation. The selectivities of CO2electroreduction at copper electrode could mainly be towards carbon monoxide（CO），formic acid（HCOOH），methane（CH4）or ethylene（C2H4），which depends on the chemical potentials of hydrogen controlled by the applied potential. Interestingly，methanol could hardly be produced electrochemically despite utilizing metallic copper as catalysts in both processes. Hence，in this work，a critical review is provided concentrated on the present proposals of reaction mechanisms of copper catalyzing CO2reduction in industrial methanol synthesis and electrochemical environment in terms of density functional theory（DFT）calculations，respectively. Furthermore，the influence from the simulation method of solvation and electrochemical model at liquid-solid interface on the reaction mechanism to explore the possible roles of different operation environments involving water and potential in the different selectivities of these two processesare investigated，to achieve a better understanding of the possible reaction mechanisms（see the review by Xitong Sun，Xiaoming Cao & P. Hu on page 553-564）.

Theoretical insight into the selectivities of copper-catalyzing heterogeneous reduction of carbon dioxide

Xitong Sun，Xiaoming Cao，P. Hu

The chemical reduction of carbon dioxide（CO2）has always drawn intensive attentions as it can not only remove CO2which is the primary greenhouse gas but also produce useful fuels. Industrial synthesis of methanol utilizing copper-based catalysts is a commonly used process for CO2hydrogenation. Despite extensive efforts on improving its reaction mechanism by identifying the active sites and optimizing the operating temperature and pressure，it is still remains completely unveiled. The selectivities of CO2electroreduction at copper electrode could mainly be towards carbon monoxide（CO），formic acid（HCOOH），methane（CH4）or ethylene（C2H4），which depends on the chemical potentials of hydrogen controlled by the applied potential. Interestingly，methanol could hardly be produced electrochemically despite utilizing metallic copper as catalysts in both processes. Moreover，the mechanistic researches have also been performed aiming to achieve the higher selectivity towards more desirable higher hydrocarbons. In this work，we review the present proposals of reaction mechanisms of copper catalyzing CO2reduction in industrial methanol synthesis and electrochemical environment in terms of density functional theory（DFT）calculations，respectively. In addition，the influences of the simulation methods of solvation and electrochemical model at liquid-solid interface on the selectivity are discussed and compared.

methanol synthesis； electrocatalytic reduction of CO2； CO2hydrogenation； selectivity