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991.
Experimental Mechanics - Compressive stress-strain response of porcine muscle was experimentally determined at intermediate strain rates (100/s-102/s) in this study. A hydraulically driven... 相似文献
992.
993.
Min Sun Yan Gao Chenyu Guo Fengliang Cao Zhimei Song Yanwei Xi Aihua Yu Aiguo Li Guangxi Zhai 《Journal of nanoparticle research》2010,12(8):3111-3122
Curcumin, a widely used coloring agent and spice in food, has a potential in blocking brain tumor formation and curing Alzheimer’s disease. Due to the specific properties of blood–brain barrier (BBB), only traces of curcumin were transported across BBB. The aim of the present study was to design and characterize curcumin loaded polybutylcyanoacrylate nanoparticles (PBCN) coated with polysorbate 80, and to evaluate the effect of PBCN as a delivery system on carrying curcumin across BBB. Curcumin loaded nanoparticles were prepared by an anionic polymerization method, and they presented in a core–shell spherical shape under transmission electron microscopy, with an average diameter of 152.0 nm. The average drug loading was 21.1%. Physicochemical status of curcumin in the nanoparticles was confirmed with differential scanning colorimetry and Fourier transform infrared spectroscopy. The in vitro release behavior of drug from the nanoparticles was fitted to a double phase kinetics model. The studies of pharmacokinetic and bio-distribution to brain were conducted in mice after intravenous administration of the nanoparticle formulation at the dose of 5 mg/kg and curcumin solution at the dose of 10 mg/kg via the tail vein. The results showed that in plasma, the area under concentration–time curve (AUC0–∞) for curcumin loaded nanoparticles was greater than that for the control solution, moreover, the mean residence time of curcumin loaded nanoparticles was 14-fold that of the control solution. In brain, AUC0–∞ for curcumin loaded nanoparticles was 2.53-fold that for the control solution. In conclusion, the present study demonstrated that PBCN could enhance the transport of curcumin to brain and have a potential as a delivery system to cross the BBB. 相似文献
994.
Yaogong Li Yaqin Zhang Dong Yang Chun Feng Sujuan Zhai Jianhua Hu Guolin Lu Xiaoyu Huang 《Journal of polymer science. Part A, Polymer chemistry》2009,47(22):6032-6043
A series of well‐defined amphiphilic graft copolymers containing hydrophilic poly(acrylic acid) (PAA) backbone and hydrophobic poly(vinyl acetate) (PVAc) side chains were synthesized via sequential reversible addition‐fragmentation chain transfer (RAFT) polymerization followed by selective hydrolysis of poly(tert‐butyl acrylate) backbone. A new Br‐containing acrylate monomer, tert‐butyl 2‐((2‐bromopropanoyloxy)methyl) acrylate, was first prepared, which can be polymerized via RAFT in a controlled way to obtain a well‐defined homopolymer with narrow molecular weight distribution (Mw/Mn = 1.08). This homopolymer was transformed into xanthate‐functionalized macromolecular chain transfer agent by reacting with o‐ethyl xanthic acid potassium salt. Grafting‐from strategy was employed to synthesize PtBA‐g‐PVAc well‐defined graft copolymers with narrow molecular weight distributions (Mw/Mn < 1.40) via RAFT of vinyl acetate using macromolecular chain transfer agent. The final PAA‐g‐PVAc amphiphilic graft copolymers were obtained by selective acidic hydrolysis of PtBA backbone in acidic environment without affecting the side chains. The critical micelle concentrations in aqueous media were determined by fluorescence probe technique. The micelle morphologies were found to be spheres. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6032–6043, 2009 相似文献
995.
996.
Wentao Zhai Hongying Wang Jian Yu Jinyong Dong Jiasong He 《Journal of Polymer Science.Polymer Physics》2008,46(16):1641-1651
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 相似文献
997.
Koichi Mikami Tatsushi Murase Lili Zhai Yoshimitsu Itoh Shigekazu Ito 《Tetrahedron: Asymmetry》2010,21(9-10):1158-1161
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. 相似文献
998.
Wenshan Qu Yunhui Zhai Shuangming Meng Yueqin Fan Qiang Zhao 《Mikrochimica acta》2008,163(3-4):277-282
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. 相似文献
999.
B Zhang Y Zhao X Zhai L Wang J Yang Z Tan P Gong 《Chemical & pharmaceutical bulletin》2012,60(8):1046-1054
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. 相似文献
1000.
Jiang N Zhai X Chen Z Liang C Sun C Han J Gong P 《Chemical & pharmaceutical bulletin》2012,60(5):659-664
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. 相似文献