Foaming behavior of polypropylene/polystyrene blends enhanced by improved interfacial compatibility

A series of polypropylene (PP)/polystyrene (PS) blends were prepared by solvent blending with PS‐grafted PP copolymers (PP‐g‐PS) having different PS graft chain length as compatibilizers. The interfacial compatibility was significantly improved with increasing PS graft chain length until the interface was saturated at PS graft chain length being 3.29 × 10³ g/mol. The blends were foamed by using pressure‐quenching process and supercritical CO₂ as the blowing agent. The cell preferentially formed at compatibilized interface because of low energy barrier for nucleation. Combining with the increased interfacial area, the compatibilized interface lead to the foams with increased cell density compared to the uncompatibilized one. The increase in interfacial compatibility also decreased the escape of gas, held more gas for cell growth, and facilitated the increase in expansion ratio of PP/PS blend foams. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1641–1651, 2008     

Highly enantioselective synthesis of α-(perfluoroalkyl)amines via hydrogenation of enamide precursors in the presence of chiraphos-rhodium catalyst

Highly (up to 99% ee) enantio-enriched perfluoroalkyl amines can be synthesized by the perfluoroalkylation of nitriles with Lewis acidic perfluoroalkyl titanate reagents and catalytic asymmetric hydrogenation with the chiraphos-Rh catalyst of the resultant perfluoroalkyl enamides via base-mediated tautomerization.     

Selective solid phase extraction and preconcentration of trace mercury(II) with poly-allylthiourea packed columns

A new method for selective solid-phase extraction and preconcentration of trace mercury(II) from aqueous solution was developed by using poly-allylthiourea as a new extractant. The procedure is based on the retention of analyte in the form of thiourea complex on a mini column of polymer resin. The effects of pH, eluent type, eluent concentration, sample volume, sample flow rate, and foreign ions on the recovery of the analyte were investigated using model solutions. At optimal pH value, the extraction capacity of the new sorbent was 1.13 mmol g^?1. The adsorption behavior of mercury(II) on the sorbent can be described by a Langmuir adsorption isotherm equation. The method was validated by analyzing a certified reference material with the results being in agreement with those quoted by manufacturers. The method was applied to the determination of trace inorganic mercury(II) in natural water samples and vegetables with satisfactory results.     

Design, Synthesis and Anticancer Activities of Diaryl Urea Derivatives Bearing <i>N</i>-Acylhydrazone Moiety

A new series of diaryl urea derivatives bearing N-acylhydrazone moiety were designed and synthesized. All the target compounds were evaluated for their cytotoxic activities in vitro against human lung adenocarcinoma epithelial cell line (A549), human breast cancer cell line (MDA-MB-231) and human leukemia cell line (HL-60) by standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Several compounds (1a, 1f and 1h) were further evaluated against human embryonic fibroblast, lung-derived cell line (WI38). The pharmacological results indicated that some compounds exhibited promising anticancer activities. In particular, compound 1f showed the most potent cytotoxicity against the tested three cell lines with IC50 values of 0.41?μM, 0.24?μM and 0.23?μM, respectively.     

Design, synthesis and cytotoxicity of novel 2-arylvinyl-4-aminoquinoline derivatives

With an aim to develop promising anti-tumor agents, a novel series of 2-arylvinyl-4-aminoquinoline derivatives were designed, synthesized and evaluated for their cytotoxicity against H-460, HT-29, HepG2 and SGC-7901 cell lines in vitro. The pharmacological results indicated that most compounds were more potent than the positive controls, especially compounds 8, 14 and 16 with IC(50) values ranging from 0.05 to 0.85 μM against all tested cell lines respectively, which were 5.7- to 112-fold better than Iressa. The most active compound 14 (IC(50) values of 0.05, 0.25, 0.16, 0.68 μM), bearing 4-fluorostyryl at C-2 position and 3-(dimethylamino)-1-propylamino at C-4 position, showed great promise as a lead for the development of more effective quinoline analogues.     

Matrix solid-phase dispersion extraction of sulfonamides from blood

Matrix solid-phase dispersion extraction was applied to the extraction of sulfadiazine, sulfamerazine, and sulfamethazine from human and animal bloods. The separation and determination of the analytes were carried out by high-performance liquid chromatography. The effects of the types of the dispersion adsorbents and elution solvents were investigated, and the highest recovery was obtained when diatomaceous earth was used as the dispersion adsorbent, while acetone was used as the elution solvent. Under the optimal conditions, the linear range for determining the sulfonamides in blood samples was 0.020-10.0 μg/mL, and the average recoveries of the three sulfonamides were higher than 87.5%.     

Biomimetic semisynthesis of arglabin from parthenolide

The semisynthesis of arglabin, an anticancer drug in clinical application, is developed from abundant natural product parthenolide via three steps. Each step in this sequence is highly stereoselective, and the substrate-dependent stereoselectivity in the epoxidation step can be explained by computational calculations. The success of chemical semisynthesis of arglabin suggests that the biosynthesis of arglabin might proceed in a similar pathway.     

Electrochemical sensor for lead(II) ion using a carbon ionic-liquid electrode modified with a composite consisting of mesoporous carbon, an ionic liquid, and chitosan

A novel electrode was prepared that enables sensing of lead(II) ion. A suspension composed of ordered mesoporous carbon (OMC), an ionic liquid (IL), and chitosan was deposited on the highly conductive surface of a carbon ionic-liquid electrode (CILE). The surface of the sensing electrode was characterized by scanning electron microscopy and cyclic voltammetry. The new electrode can be used to determine lead(II) ion because the hydrophobic ionic liquid of the CILE can extract Pb(II), while the OMC accelerates the electron transfer rate between the electrode and Pb(II) and also strongly adsorbs Pb(II). The resulting electrode displays excellent and synergistic response to Pb(II) which is linear in the range from 0.05 to 1.4?μM, with a correlation coefficient of 0.997 and a detection limit of 25 nM.

The improvement of solar photocatalytic activity of ZnO by doping with Er3+:Y3Al5O12 during dye degradation

The Er³⁺:Y₃Al₅O₁₂, an upconversion luminescence agent, which is able to transform the visible light to ultraviolet light, was synthesized by nitrate-citric acid method. And then, a novel photocatalyst, Er³⁺:Y₃Al₅O₁₂/ZnO composites, was prepared by ultrasonic dispersing and liquid boil method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structural morphology and surface properties of the Er³⁺:Y₃Al₅O₁₂/ZnO. Azo Fuchsine dye was selected as target organic pollutant to inspect the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/ZnO. The key parameters affecting the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/ZnO, such as Er³⁺:Y₃Al₅O₁₂ content, heat-treatment temperature and heat-treatment time, were studied. In addition, the effects of dye initial concentration, Er³⁺:Y₃Al₅O₁₂/ZnO amount and solar light irradiation time were also reviewed, as well as the photocatalytic activity in degradation of other organic dyes were compared. It was found that the photocatalytic activity of Er³⁺:Y₃Al₅O₁₂/ZnO was much superior to pure ZnO under the same conditions. Thus, the Er³⁺:Y₃Al₅O₁₂/ZnO is a useful photocatalyst for the wastewater treatment because it can efficiently utilize solar light by converting visible light into ultraviolet light.     

Eucalyptals D and E,new cytotoxic phloroglucinols from the fruits of Eucalyptus globulus and assignment of absolute configuration

Two new phloroglucinols, named eucalyptals D (1) and E (2), along with a related known compound (euglobal-In-3, 3) were isolated from the fruits of Eucalyptus globulus. Their structures were established on the basis of extensive spectroscopic studies, revealing that they share a common 3,5-diformyl-isopentyl phloroglucinol unit, but each is instead coupled to a different sesquiterpenoid skeleton (aromadendrene in 1, cadinene in 2, and a spirosesquiterpene in 3). Compound 1 possessed an unusual seven-membered D ring with an ether bridge between C-2 of the aromadendrene moiety and C-2′ of the aromatic unit. The absolute configuration of the isolates was defined by the comparison of experimental and calculated electronic circular dichroism (ECD) spectra. Compounds 1–3 exhibited significant in vitro cytotoxicities against a few human cancer cell lines (Huh-7, Jurkat, BGC-823, and KE-97) using the CellTiter-Glo^TM luminescent cell viability assay method.