Production of monoclonal antibodies against hop-derived (Humulus lupulus L.) prenylflavonoids and the development of immunoassays

Monoclonal antibodies against the hop-derived prenylated chalcone xanthohumol (X) and the prenylated flavonoids isoxanthohumol (IX) and 8-prenylnaringenin (8-PN) were developed. Carboxylic acid haptens of X, IX and 8-PN were synthesized by linking a spacer to their C4′-OH group followed by subsequent coupling to bovine serum albumin (BSA) to form conjugates that were employed as immunogens in BALB/c mice to raise antibodies. The monoclonal antibodies that were secreted from the established hybridoma cell lines proved, in cross-reactivity studies, to possess highly specific binding capacities in an optimized competitive indirect ELISA. The immunoassays make use of immunogen-coated microtiterplates and a peroxidase-labeled anti-mouse IgG₁ secondary antibody with ABTS as a chromogenic substrate. For X the IC₅₀ value derived from the standard curve was 62.91 ng mL⁻¹, and for both IX and 8-PN 37.15 ng mL⁻¹. The assay was validated for the quantitative analysis of X, IX and 8-PN in urine and serum. A simple sample pretreatment procedure using a diethyl ether extraction was optimized and the recoveries and matrix effects were assessed. The validity of the established assay was tested and mean inter- and intra-assay variations in urine were 2.32% and 1.91%, respectively for X, 6.24% and 2.39%, respectively for IX and 7.18% and 0.74%, respectively for 8-PN. In serum, the mean inter- and intra-assay variations were 8.90% and 1.37%, respectively for X, 6.13% and 1.57%, respectively for IX and 6.13% and 2.43%, respectively for 8-PN. Furthermore, the method demonstrated excellent accuracy and significant correlation with measurements by an established and validated HPLC-MS method.     

Acrylamide/2-acrylamido-2-methylpropane sulfonic acid and associated sodium salt superabsorbent copolymer nanocomposites with mica as fire retardants

Acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS-H⁺) or its sodium salt (AMPS-Na⁺) were copolymerised by free-radical crosslinking polymerization to obtain poly(AM-co-AMPS-H⁺) and poly(AM-co-AMPS-Na⁺) superabsorbent polymers (SAPs). A maximum water absorbency in deionised water of 1200 g g⁻¹ was achieved for poly(AM-co-AMPS-Na⁺) at a 85% mol of AMPS-Na⁺. The inclusion of mica at 5-30% (w w⁻¹) into the preparation of poly(AM-co-AMPS-Na⁺) SAP leads to an intercalated structure, as detected by XRD and TEM analyses. Poly(AM-co-AMPS-Na⁺)/30% (w w⁻¹) mica SAP nanocomposite showed a tap water absorbency of 593 g g⁻¹ with a better thermal stability, compared to the pure SAP. Cone calorimetric analyses revealed that the wood specimens coated with the prepared poly(AM-co-AMPS-Na⁺) SAP or its 30% (w w⁻¹) mica nanocomposite provided excellent protection in delaying the ignition time after exposure to an open flame when compared to that observed with the uncoated specimen. The maximum reduction in the peak heat release rate and the greatest extension of time at peak heat release rate were observed with the nanocomposite-coated surface, but the total heat release rate was increased. The delayed burning mechanism is brought by the intercalating structure of mica in the SAP nanocomposites, which provided a better shielding effect against external heat sources, and the capability of the SAP nanocomposite in holding a large amount of water.     

Intrinsic viscosities of polyelectrolytes: determination and modeling of the effects of extra salt

Based on early measurements of J. J. Hermans and co-workers (D. T. F. Pals, J. J. Hermans, Recl. Trav. Chim. Pays-Bas 1952, 71, 513-520; D. T. F. Pals, J. J. Hermans, J. Polym. Sci. 1950, 5, 733-734; D. T. F. Pals, J. J. Hermans, J. Polym. Sci. 1948, 3, 897-898), the present contribution demonstrates how primary data should be evaluated in order to obtain reliable intrinsic viscosities. This procedure yields detailed information on the changes of the intrinsic viscosities and of the corresponding viscometric interaction parameters caused by an increasing salinity of water. Both quantities decline from a maximum value in the pure solvent to a minimum value, which is approached in the limit of sufficiently high salt concentrations, and can be modeled quantitatively by means of a Boltzmann sigmoid. Particular attention is paid to the significance of results obtained by means of the method of isoionic dilution, proposed by J. J. Hermans and co-workers.     

Expanding Mg-Zn hybrid chemistry: inorganic salt effects in addition reactions of organozinc reagents to trifluoroacetophenone and the implications for a synergistic lithium-magnesium-zinc activation

Numerous organic transformations rely on organozinc compounds made through salt-metathesis (exchange) reactions from organolithium or Grignard reagents with a suitable zinc precursor. By combining X-ray crystallography, NMR spectroscopy and DFT calculations, this study sheds new light on the constitution of the organometallic species involved in this important synthetic tool. Investigations into the metathesis reactions of equimolar amounts of Grignard reagents (RMgX) and ZnCl(2) in THF led to the isolation of novel magnesium-zinc hybrids, [{(thf)(2)Mg(μ-Cl)(3)ZnR}(2)] (R=Et, tBu, nBu or o-OMe-C(6)H(4)), which exhibit an unprecedented structural motif in mixed magnesium-zinc chemistry. Furthermore, theoretical modelling of the reaction of EtMgCl with ZnCl(2) reveals that formation of the mixed-metal compound is thermodynamically preferred to that of the expected homometallic products, RZnCl and MgCl(2). This study also assesses the alkylating ability of hybrid 3 towards the sensitive ketone trifluoroacetophenone, revealing a dramatic increase in the chemoselectivity of the reaction when LiCl is introduced as an additive. This observation, combined with recent related breakthroughs in synthesis, points towards the existence of a trilateral Li/Mg/Zn synergistic effect.     

相对分子质量对烷基芳基磺酸盐复配体系固液吸附性能的影响

测定了5种平均相对分子质量和相对分子质量(以下简称分子量)分布不同的烷基芳基磺酸盐复配体系的吸附等温线,分别考察了分子量、分子量分布、温度和无机盐对复配体系在油砂/石英砂表面的吸附量的影响。 结果表明,对5种分子量分布复配体系吸附量依次降低的顺序为递增分布、正态分布、反正态分布、递减分布和均匀分布;复配体系在油砂表面的吸附量随着磺酸盐的平均分子量的增大而增大,随温度的升高而降低,随NaCl浓度的增加而增加。另外,在低浓度时,MgCl2、CaCl2和Na2SO4比NaCl对吸附的影响显著。 NaCl对复配体系在油砂表面的吸附影响比对石英砂表面吸附的影响略大。     

二季戊四醇磷酸酯三聚氰胺盐的合成及阻燃性能测试

以磷酸、季戊四醇、三聚氰胺为原料,通过酸醇直接酯化和烘焙中和两步反应合成膨胀型阻燃剂二季戊四醇磷酸酯三聚氰胺盐,并对烘焙中和反应条件及其在聚乙烯中的阻燃性能进行了研究.确定最佳合成条件:n (二季戊四醇磷酸酯):n (三聚氰胺)=1:1;反应温度130-140℃;反应时间3-4h.将此阻燃剂添加到聚乙烯中,样品重量35...     

碳化作用下不同氯盐掺量水泥浆体的微结构研究

通过加速碳化试验方法, 研究了碳化与氯盐复合作用下水泥浆体的微观结构, 分析了氯盐掺量对水泥基材料的抗碳化性能的影响. 同时, 利用X射线衍射分析了碳化前后样品的物相组成、水化产物类型和微观结构特征. 结果表明, 碳化养护更有利于浆体裂缝的愈合, 但碳化后大孔占比增加; 碳化作用下掺加氯盐会减缓水泥浆碳化速度; 碳化后产生单硫型水化硫铝酸钙和碳酸盐类物质, 钙矾石消失, 浆体的孔隙总体积减少, 孔隙结构得到了细化.     

Preparation and Performances of Room Molten Salt as Electrolyte in Carbon-carbon Capacitor Based on LiPFe and Trifluoroacetamide

利用LiPF6和三氟乙酰胺为前驱物,制备了低共熔温度约为-62℃的室温熔盐,并测试了该熔盐作为碳-碳电化学电容器（EDLCs）电解液时的性能。其中,使用差示扫描量热法（DSC）和红外光谱法（FTIR）分析了不同LiPF6和三氟乙酰胺配比熔盐的热稳定性,拟制了该二元组分的共熔相图,认为LiPF6和三氟乙酰胺极性基团间的氢键作用促成了室温熔盐的形成。循环伏安（CV）、交流阻抗（EIS）和电导等测定结果表明,所制备的LiPF6/三氟乙酰胺电解液的室温电导率为1.30mS/cm,电化学窗口大于5.6V,大于60℃的使用温度,作为电解液可满足碳-碳EDLCs的使用要求。     

以活性炭为基材负载季鏻盐多孔碳材料的制备与表征

以市售普通活性炭为碳源,先对其进行强碱活化处理制得多孔碳材料,再经硝酸氧化后,通过水热溶剂法将季鏻阳离子负载于多孔碳上,得到功能化的多孔碳材料。通过比表面积(BET)、热重分析(TGA)、X射线衍射(XRD)、高分辨透射电镜(HRTEM)以及ζ电位对其形貌和结构进行分析,并对其抗菌活性进行表征。结果表明,该方法成功合成了功能化多孔碳材料,该碳材料在水溶液中具有较好的分散性、稳定性和荷电性,并对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)具有良好的抗菌活性。     

季铵盐、季膦盐类高分子抗菌剂的研究进展

综述了季铵盐、季膦盐类高分子抗菌剂的研究进展,包括该类抗菌剂的合成、性能及抗菌机理。现有的研究结果表明,含有多种杀菌基团高分子抗菌剂的抗菌作用可能与杀菌基团的种类、杀菌基团的固载量、载体与杀菌基的结合位置、杀菌基团的分布、载体的表面亲水性能、聚合物的交联度、链结构等有关。若能在分子结构中同时有序引入季铵盐或季膦盐、海因类杀菌基团,有可能存在杀菌基团的协同效应,并且可能形成一个新的高分子抗菌材料的研究分支。