The morphology and dynamic viscoelasticity for PPS/low-melting temperature glass hybrids prepared by melt blending

Polyphenylene sulfides(PPS) and low-melting temperature glasses(LMTG) were used to prepare a PPS/LMTG organicinorganic hybrid material by melt blending.The etched surfaces of the hybrids were observed by scanning electron microscope (SEM) and the images showed different dispersed phase morphologies compared to traditional filled composites,which maybe induced by shear.Advanced rheometric expanded system(ARES) was used to investigate the rheological behaviors of the hybrids and the results showed that the strain y dependence of dynamic storage modulus G’ for the hybrids with high contents of LMTG did not appear Payne effect.     

Cytotoxic terpenes from Abies sibirica

One new and 16 known compounds were isolated from Abies sibirica.Their structures were assigned mainly on the basis of NMR and MS spectroscopic data.In bioassay for anti-proliferative activity against four human tumor cells,compound 7 exhibited selective anti-proliferative activity against COLO-205 tumor cell with an IC₅₀ value of 0.9μg/mL.     

In vivo assessment of the permeability of the blood--brain barrier and blood-retinal barrier to fluorescent indoline derivatives in zebrafish

ABSTRACT: BACKGROUND: Successful delivery of compounds to the brain and retina is a challenge in the development of therapeutic drugs and imaging agents. This challenge arises because internalization of compounds into the brain and retina is restricted by the blood--brain barrier (BBB) and blood-retinal barrier (BRB), respectively. Simple and reliable in vivo assays are necessary to identify compounds that can easily cross the BBB and BRB. METHODS: We developed six fluorescent indoline derivatives (IDs) and examined their ability to cross the BBB and BRB in zebrafish by in vivo fluorescence imaging. These fluorescent IDs were administered to live zebrafish by immersing the zebrafish larvae at 7--8 days post fertilization in medium containing the ID, or by intracardiac injection. We also examined the effect of multidrug resistance proteins (MRPs) on the permeability of the BBB and BRB to the ID using MK571, a selective inhibitor of MRPs. RESULTS: The permeability of these barriers to fluorescent IDs administered by simple immersion was comparable to when administered by intracardiac injection. Thus, this finding supports the validity of drug administration by simple immersion for the assessment of BBB and BRB permeability to fluorescent IDs. Using this zebrafish model, we demonstrated that the length of the methylene chain in these fluorescent IDs significantly affected their ability to cross the BBB and BRB via MRPs. CONCLUSIONS: We demonstrated that in vivo assessment of the permeability of the BBB and BRB to fluorescent IDs could be simply and reliably performed using zebrafish. The structure of fluorescent IDs can be flexibly modified and, thus, the permeability of the BBB and BRB to a large number of IDs can be assessed using this zebrafish-based assay. The large amount of data acquired might be useful for in silico analysis to elucidate the precise mechanisms underlying the interactions between chemical structure and the efflux transporters at the BBB and BRB. In turn, understanding these mechanisms may lead to the efficient design of compounds targeting the brain and retina.     

Controlled synthesis of different morphologies of BaWO4 crystals via a surfactant-assisted method

BaWO₄ crystals with different morphologies, such as nanosheets, nanobelts, flower-like, quadrangled plates and sheaves of dendrite, have been successfully synthesized via PVP as templates. Our result shows that reaction parameters, such as the concentration of PVP aqueous solutions, pH value of the starting solution and molar ratio of [Ba²⁺]/[WO₄²⁻] played important roles in the formation of BaWO₄ crystal with different morphologies. It is obviously different between microwave irradiation heating and oil bath heating. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and electron diffraction.     

Integrated Solid-Phase Extraction,Ultra-High-Performance Liquid Chromatography–Quadrupole-Orbitrap High-Resolution Mass Spectrometry,and Multidimensional Data-Mining Techniques to Unravel the Metabolic Network of Dehydrocostus Lactone in Rats

Dehydrocostus lactone (DL) is among the representative ingredients of traditional Chinese medicine (TCM), with excellent anticancer, antibacterial, and anti-inflammatory activities. In this study, an advanced strategy based on ultra-high-performance liquid chromatography–quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC–Q-Orbitrap HRMS) was integrated to comprehensively explore the metabolic fate of DL in rats. First, prior to data collection, all biological samples (plasma, urine, and feces) were concentrated and purified using solid-phase extraction (SPE) pre-treatment technology. Then, during data collection, in the full-scan (FS) data-dependent acquisition mode, FS-ddMS² was intelligently combined with FS-parent ion list (PIL)-dynamic exclusion (DE) means for targeted monitoring and deeper capture of more low-abundance ions of interest. After data acquisition, data-mining techniques such as high-resolution extracted ion chromatograms (HREICs), multiple mass defect filters (MMDFs), diagnostic product ions (DPIs), and neutral loss fragments (NLFs) were incorporated to extensively screen and profile all the metabolites in multiple dimensions. As a result, a total of 71 metabolites of DL (parent drug included) were positively or tentatively identified. The results suggested that DL in vivo mainly underwent hydration, hydroxylation, dihydrodiolation, sulfonation, methylation, dehydrogenation, dehydration, N-acetylcysteine conjugation, cysteine conjugation, glutathione conjugation, glycine conjugation, taurine conjugation, etc. With these inferences, we successfully mapped the “stepwise radiation” metabolic network of DL in rats, where several drug metabolism clusters (DMCs) were discovered. In conclusion, not only did we provide a refined strategy for inhibiting matrix effects and fully screening major-to-trace metabolites, but also give substantial data reference for mechanism investigation, in vivo distribution visualization, and safety evaluation of DL.     

基于金属有机骨架材料的磁固相萃取与高效液相色谱-紫外检测法分析饮料和方便面中4种防腐剂

通过简单的搅拌共混方式制备了磁性氨基功能化的金属有机骨架化合物(MOFs)材料,得到的复合材料磁性和热稳定性良好,比表面积大,被用于不同极性防腐剂(苯甲酸、山梨酸、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯)的萃取。优化磁固相萃取及解吸条件后,将解吸液引入高效液相色谱-紫外检测分析仪器,采用Purospher^? STAR LP C18色谱柱(250 mm×4.6 mm, 5μm)分离,以甲醇-10 mmol/L醋酸铵水溶液(50∶50, v/v)为流动相进行梯度洗脱。结果表明,目标防腐剂的检出限为0.51～1.89μg/L;苏打水、维生素饮料和方便面面饼中目标防腐剂的加标回收率为72.2%～109%。该方法简单快速,准确可靠,适用于饮料和食品中不同极性防腐剂的分析,为食品安全及质量监控提供了有效的技术有段。     

一个新的可积广义超孤子族及其自相容源、守恒律

该文利用Lie超代数B(0,1)导出一个新的广义超孤子族,借助超迹恒等式将广义超孤子族写成超双-Hamilton结构形式.其次,建立了广义超孤子族的自相容源.最后,给出了广义超孤子族的无穷守恒律.     

Synthesis of P123-Templated and DVB-Cross-linked Meso-macroporous Poly (ionic liquids) with High-Performance Alkylation

Meso-macroporous poly (ionic liquids) (MPILs) were successfully synthesized through a novel strategy with P123 (PEO₂₀PPO₇₀PEO₂₀) as the pore-forming agent and divinylbenzene as crosslinker. Then effects of reaction temperature and the molar ratio of ionic liquid to divinylbenzene (IL to DVB) were systematically investigated together with the morphology and structure of MPILs. It was found the MPILs owned a meso-macroporous channel-like structure, large surface area (up to 732 m²/g), large pore volume (1.42 cm³/g) and high thermal stability. Meanwhile, the Brunauer–Emmett–Teller surface of MPILs could be fabricated by adjusting the reaction temperature and especially the IL to DVB molar ratio. In the probe reaction of alkylation of styrene and o-xylene, a 100% conversion of styrene and 96.4% PXE yield was acquired, and this is more expert than common commercial liquid acid catalyst. This work might develop a novel way for synthesizing porous heterogeneous polymer catalysts in the future and owning a promising future applied in other acidic catalytic reactions.     

High Catalytic Performance of Mesoporous Dual Brønsted Acidic Ternary Poly (Ionic Liquids) for Friedel‐Crafts Alkylation

A newfangled cross‐linked dual Brønsted acidic ternary mesoporous poly (ionic liquids)(MPILs) with mesoporous structure was successfully synthesized with divinylbenzene as cross linker, 1‐vinyl‐3‐butyl imidazole bromide and sodium p‐styrene sulfonate as functional group through an ordinary post‐modification method and anion exchange process. A sponge‐like mesoporous tunnel structure was observed and the obtained P (BVS‐SO₃H)‐SO₃CF₃ sample appeared a relatively high thermal stability, a large surface area (up to 286.8 m²/g) and great pore volume (0.73 cm³/g). The abundant dual acidic group of sulfonic acid and trifluoromethanesulfonic acid of the composite in the polymer framework impart Brønsted acidity. For the sake of demonstrating our claims, the sample has been used as a novel solid acid catalyst for the reaction of alkylation of o‐xylene with styrene to 1‐diphenylethane (PXE). Under optimal reaction conditions (reaction under 120 °C for 3 hr, catalyst amount was 0.5 wt% of the reaction system, and the mass ratio of o‐xylene/styrene was 7.5:1, a 100% conversion of styrene and 93.7% PXE yield was acquired. After four times recycle, the yield remains 53.3%. Comparing with the commercial liquid acid catalyst, it processing a higher catalytic property and recyclability. Moreover, this fresh dual acidic heterogeneous catalyst owning a promising future applied in other acidic catalytic reactions and provide a new method to modify catalyst.     

Synthesis and characterization of trans-di(nitrobenzo)- and di(aminobenzo)-18-crown-6 derivatives with high selectivity

The dibenzo-18-crown-6 derivatives such as di(nitrobenzo)-18-crown-6 and di(aminobenzo)-18-crown-6 were synthesized by nitration reaction and catalytic hydrogenation with high selectivity. The chemical structures were determined by FTIR, ¹H NMR, ¹³C NMR, and UV. Regarding the mixture of Ac₂O and HNO₃ as nitrating agent, the reaction exhibited commendable trans-isomer selectivity. Effects of nitrating agent ratio, reaction temperature and reaction time on yield of trans-di(nitrobenzo)-18-crown-6 were investigated. The yield of trans-di(nitrobenzo)-18-crown-6 was 62.9% for nitrating agent ratio of 1/1, reaction temperature of 50?°C and reaction time of 5?h. Moreover, effect of reaction time on trans-di(aminobenzo)-18-crown-6 was also studied.