The glucagon-like peptide-1 (GLP-1) is a peptide with incretin activity and plays an important role in glycemic control as well as the improvement of insulin resistance in type 2 diabetes mellitus (T2DM). However, the short half-life of the native GLP-1 in circulation poses difficulties for clinical practice. To improve the proteolytic stability and delivery properties of GLP-1, a protease-resistant modified GLP-1 (mGLP-1) was constructed with added arginine to ensure the structural integrity of the released mGLP-1 in vivo. The model probiotic Lactobacillus plantarum WCFS1 was chosen as the oral delivery vehicle with controllable endogenous genetic tools driven for mGLP-1 secretory constitutive expression. The feasibility of our design was explored in db/db mice which showed an improvement in diabetic symptoms related to decreased pancreatic glucagon, elevated pancreatic β-cell proportion, and increased insulin sensitivity. In conclusion, this study provides a novel strategy for the oral delivery of mGLP-1 and further probiotic transformation.

Self-sorting, as an effective strategy to construct well-defined supramolecular assemblies, has attracted much research attention, but it remains a challenge to achieve particular functions and applications based on the unique characteristics. Herein, we report a supramolecular polymer network (SPN) prepared on the basis of a polymer blend, in which two kinds of polymers are connected by host-guest self-sorting recognitions. The supramolecular self-sorting is able to improve the interfacial binding force and compatibility between the two polymers, and thus results in a microphase-separated structure in the SPN. The resultant structure across multiple length scales in the SPN could work synergistically with each other to endow the SPN with remarkable mechanical properties. In nanoscale, the hard phase could reinforce the strength of the network, whose size could be regulated by adjusting the annealing time, thus imparting tunable mechanical properties to the SPN. In molecular scale, the host-guest self-sorting recognitions not only lead to the micmphase-separated structure but also act as sacrificial bonds to dissipate energy and toughen the SPN. Our work represents a step forward in preparing elastomeric materials with microphase-separated structure, and would also promote the development and application of supramolecular self-sorting.

中华中医药源远流长,在农业生产中也越来越引起重视,尤其是由于长期大量施用化学农药防治农业病虫害,导致农业环境和农产品受到污染,已经严重危害了人们的健康.综述了植物源中草药防治农业病虫害的研究进展,为推动减施化学农药,绿色生产提供依据.

Asymmetric hydrogenation is one of the most powerful methods for the preparation of single enantiomer compounds. However, the chemo- and enantioselective hydrogenation of the relatively inert unsaturated group in substrates possessing multiple unsaturated bonds remains a challenge. We herein report a protocol for the highly chemo- and enantioselective hydrogenation of conjugated enynes while keeping the alkynyl bond intact. Mechanism studies indicate that the accompanying Zn2+ generated from zinc reduction of the CoII complex plays a critical role to initiate a plausible CoI /CoIII catalytic cycle. This approach allows for the highly efficient generation of chiral propargylamines (up to 99.9 % ee and 2000 S/C) and further useful chemical transformations.

以植物油基多元醇蓖麻油(CO)、多元醇2010A、三羟甲基丙烷(TMP)和1,4-丁二醇(BDO)为A胶羟基基团基本原料,PM200为B胶异氰酸酯基团基本原料,制备得到透水路面用无溶剂双组分聚氨酯胶粘剂,并对胶粘剂的力学性能和耐紫外老化性能进行了测试.研究结果证明:保持A胶中扩链剂的羟基物质的量总量不变,当TMP与BDO的羟基物质的量之比为1:1时,聚氨酯胶粘剂的拉伸强度和断裂伸长率可达15.53 MPa和56.59％;在保证韧性基础上另添加0.15％气相Si02时,胶粘剂的拉伸强度提高至19.53 MPa.耐紫外老化性能表明,采用多元醇2010A制得的胶粘剂相比初始拉伸强度提高14％,断裂伸长率下降30％;相对于聚酯多元醇两个配方(XCPA和耐水解2010A),其力学性能较为稳定.

概述了传统的溶剂型涂料与环保型水性涂料在使用要求、基本性能、功能等方面的差异,重点对近年来水性无机富锌涂料、水性环氧涂料、水性丙烯酸涂料、水性聚氨酯涂料的主要成份、特点及最新研究进展进行分析,并介绍了 4类涂料的优、缺点及其应用前景;阐述了环保型水性涂料在汽车、铁路车辆、集装箱及重防腐中的应用现状及进展;对当前环保型水性涂料的研究做出了展望.

基于单体4-苯基醚-1,3-二胺制备了一种新型乙炔基封端热固性聚酰亚胺.利用傅里叶变换红外光谱仪、核磁共振氢谱仪和X射线衍射仪对其结构进行表征,其结果表明制备得到了相应结构的预聚体.利用差示扫描量热仪测得预聚体的玻璃化转变温度(Tg)仅为155℃.预聚体在有机溶剂中具有高的溶解性,常温下在N-甲基吡咯烷酮中的溶解度高于50％.熔体黏度测试表明,预聚体的最低熔体黏度在237℃时为47.5 Pa·s.动态力学热分析仪测试表明,交联固化后树脂的Tg值高达335℃,具有非常高的耐温性.热失重曲线表明,该种热固性聚酰亚胺树脂具有高的热分解稳定性,在空气中5％热失重温度为535℃,氮气中800℃的残炭率为57％.

在影响科技创新诸要素中,区域成果转移转化政策对科创企业的培育起到引导、促进和保障的重要作用.上海应从强化科技创新的策源能力出发,改变混同策略,分类制定转移和转化政策;强化匹配和评估,疏通服务企业科创大动脉;优化投资政策,提升科创企业技术创新能力.从而着力优化科技成果转移转化政策,提高科技成果转移转化成效,促进科创企业高质量发展.

以正硅酸乙酯为硅源,通过溶胶-凝胶法反应制得SiO2包覆的铝颜料,然后通过沉淀剂BaCl2?2H2O分别将有机颜料酞菁蓝或偶氮红沉淀在SiO2包覆层的表面,制得具有金属光泽的有机颜料/SiO2双层包覆蓝色铝颜料和红色铝颜料.采用FE-SEM、接触角和耐碱性测试对制备的SiO2包覆铝颜料和有机颜料/SiO2双层包覆彩色铝颜料的性能进行表征.结果 表明,SiO2首先在铝颜料表面形成一层均匀致密的亲水性包覆层,继续包覆酞菁蓝或偶氮红有机颜料层后得到的双层包覆彩色铝颜料与水的接触角由SiO2包覆铝颜料的23.2°增加至80.0°左右,疏水性增加;在40℃、pH=9的弱碱性环境下,SiO2包覆铝颜料48 h内氢气释放量小于6 mL,有机颜料/SiO2双层包覆彩色铝颜料氢气释放量小于30 mL,之后二者均趋于平稳;色卡对比和多角度色差分析仪结果表明,制备的有机颜料/SiO2双层包覆彩色铝颜料具有明显的"随角异色"性,红色铝颜料的色彩饱和度大于蓝色铝颜料,且随着酞菁蓝原料的增加,蓝色铝颜料的颜色饱和度增加,但对明度的影响不大.

A reactive diluent (ODA-PEPA) and a flexible phenylethynyl-terminated imide oligomer (PEI-PEPA) were designed and synthesized based on the 2,3,3’,4’-diphenyl ether tetracarboxylic acid dianhydride (a-ODPA), 3,4’-oxydianiline (3,4’-ODA), and 4-phenylethynylphthalic anhydride (PEPA). Solution blended systems with the addition of 5, 10, and 15 wt% ODA-PEPA to PEI-PEPA oligomer and their cured resin systems were prepared. Results showed that ODA-PEPA is semi-crystalline in nature. The Tg values of cured resins were improved from 273 °C to 280 °C by the addition of ODA-PEPA, due to the higher crosslink densities. In addition, rheological properties of blends showed lower melt viscosity and wider processing window, revealing improved melt processabilities for potential application in making advanced composites. The isothermal viscosity in 280 °C of PEI-PEPA containing 15 wt% ODA-PEPA reactive diluent decreased by two thirds, due to the low molecular weight of ODA-PEPA. The cured blends demonstrated high thermal stability and heat resistance. 5 wt% thermal decomposition temperatures (Td5) of the cured blends were above 549 °C and 547 °C in N2 and air atmosphere, respectively. The char yield reported at 800 °C in N2 atmosphere increased from 58.8% to 63.7 % with the addition of ODAPEPA. Meanwhile, the cured polyimides blends possessed good bond strength (> 9.3 MPa).

Utilizing a chiral bicyclic imidazole organocatalyst and adopting a continuous injection process, an alternative route has been developed for the efficient synthesis of chiral phthalidyl ester prodrugs via dynamic kinetic resolution of 3-hydroxyphthalides through enantioselective acylation (up to 99 % ee). The computational studies suggest a general base catalytic mechanism differing from the widely accepted nucleophilic catalytic mechanism. The structure analysis of the key transition states shows that the CH-π interactions and not the previously considered cation/π-π interactions between the catalyst and substrate is the dominant factor giving rise to the observed stereocontrol.

研究了正硅酸乙酯(TEOS)在片状铝颜料表面水解缩聚形成SiO2包覆膜制备Al颜料的反应过程,重点探讨了两阶段升温变化对包覆性能的影响.FE-SEM和刮板试验结果表明:第一阶段温度50℃,第二阶段80℃时,能在片状铝颜料表面形成一层均匀、致密且遮盖性高、光泽高的SiO2薄膜;EDS和粒径分布测试结果表明:与未包覆的铝颜料相比,SiO2包覆的Al颜料表面硅元素含量增加了1.48％,氧元素含量由1.81％增加到4.60％,SiO2包覆的Al颜料的D50增大了约15％,表明在铝颜料表面形成的SiO2包覆膜非常薄;在pH为9的弱碱性溶液中,220 h后析出的H2体积仅为未包覆铝颜料的2.2％,具有良好的耐弱碱性.

为了提高铝颜料在水性涂料中的耐腐蚀性能,以正硅酸乙酯(TEOS)为前驱物,通过溶胶-凝胶反应在铝颜料表面形成了一层致密的二氧化硅包覆薄膜,通过优化固含量、溶剂种类及TEOS的用量,提高铝颜料的耐碱性.利用扫描电镜、刮板试验、接触角测试、析氢实验进行表征,结果表明:以无水乙醇为溶剂,铝金属颜料固含量为10％,升温至50℃后,逐滴加入6 g TEOS,再升温至80℃,该条件下制备的SiO2膜包覆后的铝颜料具有优异的耐碱性,同时表面性能由疏水性转变成亲水性,对铝颜料起到了很好的保护作用.

An asymmetric hydrogenation of aroylacrylic acids catalyzed by RuPHOX-Ru catalyst has been developed, affording the corresponding chiral γ-lactones in high yields and with up to 93% ee. The methodology has the advantage of utilizing easily accessible substrates and has therefore expand the scope of the resulting chiral γ-lactones. Furthermore, high catalytic efficiency was achieved in that the reduction of both the CC and CO double bonds was achieved in one step. The current work provides an alternative and convenient pathway for the synthesis of a wide range of chiral γ-lactones.

AbstractAn efficient cobalt‐catalyzed asymmetric hydrogenation of C=N bonds has been realized. Chiral hydrazines were obtained in high yields and with excellent enantioselectivities (95–98 % ee). The hydrogenation went smoothly at up to 2000 substrate/catalyst and on a gram scale. The success of this reaction relies on the presence of an NHBz group in the substrates, with the reactivity and enantioselectivity improved by an assisted coordination to the cobalt atom and a nonbonding interaction with the ligand. Furthermore, this reaction has practical applications for the synthesis of several useful chiral nitrogen‐containing compounds.

A RuPHOX-Ru catalyzed selective asymmetric hydrogenation of exocyclic α,β-unsaturated ketones has been developed, furnishing the corresponding chiral exocyclic allylic alcohols in high yields and with up to >99.5% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C) without any loss in reaction activity and enantioselectivity. The resulting hydrogenated products could be easily transformed to several biologically active compounds with high asymmetric performance. The asymmetric protocol provides an efficient methodology for the synthesis of chiral exocyclic allylic alcohols.

Novel asymmetric bismaleimide (BMI) oligomers with different molecular weights and dianhydrides were designed and synthesized by 3,4′‐oxydianiline (3,4′‐ODA), 2,3,3′,4′‐oxydiphthalic dianhydride (a‐ODPA), and 2,3,3′,4′‐biphenyltetracarboxylic dianhydride (a‐BPDA). The chemical structures of BMI oligomers were confirmed by Fourier transform infrared spectrometry (FTIR) and gel permeation chromatography (GPC). X‐ray diffraction (XRD) exhibited broad peaks, suggesting amorphous structures. Heat flow curves of oligomers measured by differential scanning calorimeter (DSC) displayed wide processing window due to low glass transition temperatures (Tg). BMI oligomers exhibited high solubility in common organic solvents. Particularly, the OD‐BMI‐1 oligomer exhibited excellent solubility of more than 50 wt% in DMAc solvent. Tg value and minimum complex viscosity of OD‐BMI‐1 oligomer were only 121 °C and 8.1 Pa · s, respectively. The cured BMI resins possess high thermal and thermal‐oxidative stability. The Tg and the temperature of 5% weight loss in nitrogen were above 256 and 449 °C, respectively, and the residual weight percentages at 800 °C were all >49%. Moreover, films made of BMI resins exhibited excellent mechanical properties flexibility, as confirmed by photograph and DMA results of films. The elongation at break of the prepared films was found to be high (almost >9.6%). POLYM. ENG. SCI., 59:2265–2272, 2019. © 2019 Society of Plastics Engineers

Functionalized N -carbonylmethylene-2-pyridones are some of the most important structural motifs and exist in many natural products and bioactive compounds. Thus, the efficient construction of such skeletons has attracted much atten-tion. Generally, the synthesis of N -carbonylmethylene-2-pyridones is realized via an intermolecular nucleophilic substitution of 2-hydroxypyridines and appropriate electrophiles. However, the above reactions often suffer from low yields caused by poor O/N chemoselectivities due to the dual nucleophilicity of the 2-hydroxypyridines. As far as the structure is concerned, N -carbonylmethylene-2-pyridones can be divided into three sections: a pyridone, a carbonylmethyl group and a side chain. When the side chain is a H atom, the N -substituted pyridones can be constructed conveniently via a reaction of 2-hydroxypyridines and primary α -bromocarbonyl compounds in high yields with excellent chemoselectivities. However, when the side chain is not a H atom, for example an alkyl group, only limited examples have been reported and only moder-ate yields of the desired N -substituted pyridine products are obtained by a combination of 2-hydroxypyridines and bulky secondary α -bromocarbonyl compounds, mainly due to the poor O/N chemoselectivities. To achieve a general synthetic pathway for the latter, the following practical strategy was designed. 2-Hydroxypyridines were first treated with primary α -bromocarbonyl compounds to generate the unique N -substituted intermediates in situ , which then reacted with the side chain electrophiles to give only the N -alkylated final products. Thus, a Pd-catalyzed three-component chemospecific allylic substitution cascade has been developed for the synthesis of N -carbonylmethylene-2-pyridone derivatives, with the desired products being obtained in up to 98% yield. No O -alkylated by-product was observed. The results suggested that the N -carbonylmethylene-2-pyridones are constructed via a cascade reaction consisting of a nucleophilic substitution followed by an allylic alkylation. The reaction was performed on a gram scale and the corresponding alkylated product was conveniently converted to a pyridone-containing unnatural amino acid. This methodology allows for the highly chemoselective synthesis of biologically important N -carbonylmethylene-2-pyridone derivatives.

A new chiral nucleophilic organocatalyst bearing a 5,6,7,8-tetrahydroimidazo[1,2-a]pyridine skeleton has been developed.

采用低温水热法制备了TiO 2/PSR(Perfluorosulfonated Resin,全氟磺酸树脂)复合型纳米杂化薄膜,并采用XRD、AFM和FT-IR等测试方法对该薄膜的晶型、粒径、表面形态进行表征,结合TiO 2与PSR两相间协同作用,对杂化薄膜的性能进行了分析.在此基础上,通过降解甲基橙溶液评价了TiO 2/PSR杂化薄膜的光催化活性及其影响因素.结果表明:采用低温水热法制备的TiO 2/PSR杂化薄膜晶型由无定型转变锐钛矿;同时,PSR中的-SO 3 H与Ti-OH存在化学键和氢键的作用有利于体系的稳定共存以及光催化活性的提高.