蛋白质对测定水产品中氯苯类化合物的影响及消除

提出了气相色谱-质谱法测定水产品中1,3-二氯苯,1,2-二氯苯,1,2,4-三氯苯等3种氯苯类化合物含量的方法。采用荧光猝灭法研究了氯苯类化合物与蛋白质之间的结合作用,结果表明氯苯类化合物与鱼血清白蛋白之间存在较强的结合作用。水产品样品以丙酮-磷酸氢二钾-水双水相体系进行前处理。在气相色谱分离中用DB-WAX毛细管色谱柱为固定相,在质谱分析中采用选择离子监测模式。3种氯苯类化合物的质量浓度均在0.5~5.0mg·L-1范围内与其峰面积呈线性关系。以空白样品为基体进行加标回收试验,所得回收率在77.0%~116%之间,相对标准偏差(n=6)在2.6%~7.1%之间。     

微流控技术筛选酶抑制剂的研究进展

随着近年新合成或提取的化合物大量涌现,药物筛选朝着快速、高效、高通量方向发展。微流控分析技术具有的分析微型化、高通量化、可集成化和良好的生物相容性等特点,为药物的筛选提供了新的方法和技术平台。本文简要介绍了酶抑制剂筛选,重点评述基于微流控技术筛选酶抑制剂的研究进展。     

NMR波谱仪集中优化管理模式

论述了核磁中心采用的相对集中管理模式.集中管理模式主要体现在上样辅助、中央供气、数据集中上传与下载3个方面.另外,还提出了未来可以从集中供高纯N2和LN22个方面进一步改善中心的集中管理模式,从而能够更好的优化测试效率和工作环境.     

丙烯腈、己二腈和丙腈与水的二元体系液-液相平衡数据的测定和关联(英文)

采用平衡法测定了丙烯腈+水、己二腈+水、丙腈+水三个二元体系在不同温度(303.15、313.15、323.15、333.15K)下的液-液相平衡数据;并采用NRTL(α=0.2,α=0.3)模型和UNIQUAC模型对液-液平衡数据进行了关联.结果显示,NRTL和UNIQUAC模型对三个二元体系在不同温度下的互溶度关联的目标函数值均小于1×10-17,实验值与计算值吻合较好,绝对偏差小于0.009,关联精度较高.该研究结果可为丙烯腈、丙腈和水三元平衡溶解度数据的模拟和预测提供可靠的基础数据,并对电解二聚法生产己二腈中电解液的分离提纯工艺具有一定的指导意义.     

用自行设计的自动分析系统测定高含量SO3--对硫酸钡浊度测定法的改进

为了解决湿法磷酸生产中高含量SO3的测定,对硫酸钡浊度测定法的反应条件进行了改进,并自行设计制造了自动化的分析系统。测定时样品由蠕动泵(P)推入酸化盘管(AC)中进行酸化和稀释,由定量环(Sv)取样25μL,注入反应系统。在第一反应盘管(RC1)中,SO3与第一混合试剂中的BaCl2溶液反应生成BaSO4悬浊液,该溶液中的聚乙二醇-4000(PEG-4000)和乙醇通过协同作用避免了BaSO4颗粒的团聚,降低粒子间的相互作用,使BaSO4的生成减少,降低了测定的灵敏度,提高了稳定性。在第二反应盘管(RC2)中,BaSO4与第二混合试剂中的NH3·H2O/乙二胺四乙酸二钠(Na2EDTA)溶液发生络合反应同时被Na2EDTA包裹,进一步降低其灵敏度。最后反应溶液进入流通式光度检测器,在680.0nm波长处测试BaSO4悬浊液的吸光度。经优化试验条件,上述第一混合试剂中3种组分的质量分数或体积分数为:BaCl24%,PEG-4000 3%和乙醇2%;第二混合试剂中Na2EDTA的质量分数为6%,NH3·H2O的体积分数为6%。对实际按本方法及重量法分析进行测定,两种方法所得结果的相对偏差在±2%以内,且不受共存的高含量PO43-和F-的干扰。     

Regulating Gelation Time and Kinetics Analysis Based on the ARGET ATRP Mechanism

A novel activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) initiation system composing of an initiator sodium chloroacetate, a catalyst ferric chloride, and a reducing agent ascorbic acid was developed to improve the gelation time of the in situ crosslinked polymer system. The kinetics of polymerization of acrylamide showed features of a living/controlled process in which the concentrations of the growing radicals [P·] are kept constant throughout the polymerization process. Compared with conventional potassium persulfate initiators, the gelation time of the in situ crosslinked polymer system can be improved to 40 h or even longer using the ARGET ATRP initiation system at 80 °C due to the low radical concentration and slow polymerization reaction. Core flooding test showed that the ARGET ATRP initiating system developed could initiate the polymerization reaction of the in situ crosslinked polymer system in the core. However, the gelation time was extended in comparison to that of the result obtained in the bottle, resulting from the dilution and adsorption of ARGET ATRP components during the injection process. The research expands the application field of the ARGET ATRP principle and has a promising prospect on controlling the gelation time of the in situ crosslinked polymer system. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 519–527     

pH Tuning of Water-Soluble Arylazopyrazole Photoswitches

Arylazopyrazoles are an emerging class of photoswitches with redshifted switching wavelength, high photostationary states, long thermal half-lives and facile synthetic access. Understanding pathways for a simple modulation of the thermal half-lives, while keeping other parameters of interest constant, is an important aspect for out-of-equilibrium systems design and applications. Here, it is demonstrated that the thermal half-life of a water-soluble PEG-tethered arylazo-bis(o-methylated)pyrazole (AAP) can be tuned by more than five orders of magnitude using simple pH adjustment, which is beyond the tunability of azobenzenes. The mechanism of thermal relaxation is investigated by thorough spectroscopic analyses and density functional theory (DFT) calculations. Finally, the concepts of a tunable half-life are transferred from the molecular scale to the material scale. Based on the photochromic characteristics of E- and Z-AAP, transient information storage is showcased in form of light-written patterns inside films cast from different pH, which in turn leads to different times of storage. With respect to prospective precisely tunable materials and time-programmed out-of-equilibrium systems, an externally tunable half-life is likely advantageous over changing the entire system by the replacement of the photoswitch.     

基于离子液体的双水相体系的分离机理及应用

离子液体由于具有非挥发性、低毒、不易燃、热稳定性及化学稳定性高等优势,被认为是可替代传统有机溶剂的"绿色溶剂",在双水相体系构建方面得到了广泛应用。基于离子液体的双水相体系在生物大分子及有机化合物萃取分离方面具有独特优势,如萃取快速,操作简单,不需使用有害有机溶剂及复杂设备,易于规模化且生物兼容性好。该文综述了基于离子液体的双水相体系的两相分离机理及其在有机小分子及生物样品萃取纯化中的应用。并在此基础上讨论了离子液体双水相体系的优势、缺点以及未来发展趋势。     

Multivalent Aptamer-modified DNA Origami as Drug Delivery System for Targeted Cancer Therapy

In spite of great development in nanoparticle-based drug delivery systems(DDSs)for improved therapeutic efficacy,it remains challenging for effective delivery of chemotherapeutic drugs to targeted tumor cells.In this work,we report a triangle DNA origami as targeted DDS for cancer therapy.DNA origami shows excellent biocompatibility and stability in cell culture medium for 24 h.In addition,the DNA origami structures conjugated with multivalent aptamers enable for efficient delivery of anticancer drug doxorubicin(Dox)into targeted cancer cell due to their targeting function,reducing side effects associated with nonspecific distribution.Moreover,we also demonstrated that the multivalent aptamer-modified DNA origami loading Dox exhibits prominent therapeutic efficacy in vitro.Accordingly,this work provides a good paradigm for the development of DNA origami nanostructure-based targeted DDS for cancer therapy.     

Nanoarchitectonics beyond Self‐Assembly: Challenges to Create Bio‐Like Hierarchic Organization

Incorporation of non‐equilibrium actions in the sequence of self‐assembly processes would be an effective means to establish bio‐like high functionality hierarchical assemblies. As a novel methodology beyond self‐assembly, nanoarchitectonics, which has as its aim the fabrication of functional materials systems from nanoscopic units through the methodological fusion of nanotechnology with other scientific disciplines including organic synthesis, supramolecular chemistry, microfabrication, and bio‐process, has been applied to this strategy. The application of non‐equilibrium factors to conventional self‐assembly processes is discussed on the basis of examples of directed assembly, Langmuir–Blodgett assembly, and layer‐by‐layer assembly. In particular, examples of the fabrication of hierarchical functional structures using bio‐active components such as proteins or by the combination of bio‐components and two‐dimensional nanomaterials, are described. Methodologies described in this review article highlight possible approaches using the nanoarchitectonics concept beyond self‐assembly for creation of bio‐like higher functionalities and hierarchical structural organization.