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861.
In this study, we reported pH-responsive microparticles consisting of poly(D,L-lactide-co-glycolide) (PLGA), aminated hyaluronic acid (aHA) conjugated with 2,3-dimethylmaleic anhydride (DMA, as a pH-responsive cleavable molecule) (aHA-DMA), and doxorubicin (DOX, as an antitumor drug) for local tumor treatment. The DOX-loaded microparticles, denoted as PLGA(aHA-DMA)/DOX MPs, were fabricated using the W1/O/W2 multi-emulsification method. These PLGA(aHA-DMA)/DOX MPs (~10 μm in diameter) accelerated the rate of DOX release at pH 6.8 due to the acidic pH-responsive cleavage of the DMA moieties followed by electrostatic-repulsion between aHA and DOX. This event caused the structural destabilization and collapse of the MPs, leading to the rapid release of DOX. Consequently, the PLGA(aHA-DMA)/DOX MPs resulted in significant inhibition of tumor growth, demonstrating their ability for acidic tumor-specific treatment. 相似文献
862.
863.
Yong Un Jung Se-in Oh Sung-Hoon Choa Han-Ki Kim Seong Jun Kang 《Current Applied Physics》2013,13(7):1331-1334
We report a systematic study of the electromechanical properties of graphene films for flexible transparent conducting electrodes. The flexibility of graphene films, which were grown using a chemical vapor deposition (CVD) method and transfer process on polyethylene terephthalate (PET) substrates, was investigated using a lab-made inner/outer bending, twisting and stretching test system. The electromechanical properties as a function of the change of bending radius, twisting angle and strain distance were evaluated by measuring the change in resistance. The change in resistance during the inner bending test was less than 8% even when the bending radius was 3 mm. Additionally, the results of the inner bending fatigue test showed a constant resistance throughout 2000 bending cycles. However, in the outer bending test, the resistance increased substantially when the bending radius was smaller than 10 mm. Therefore, we can expect that more cracks form between the grains of graphene during the outer bending test. The twistability and stretchability of the graphene film were also investigated. Both twisting and stretching tests show gradually increasing resistances according to the twisting angle and stretching distance. These results provide useful information regarding the electromechanical properties of graphene transparent conducting films for the development of flexible electronics. 相似文献
864.
Dr. Nam‐Young Kang Dr. Sung‐Chan Lee Dr. Sung‐Jin Park Prof. Hyung‐Ho Ha Dr. Seong‐Wook Yun Dr. Elena Kostromina Dr. Natalia Gustavsson Dr. Yusuf Ali Yogeswari Chandran Dr. Hang‐Suk Chun Dr. MyungAe Bae Dr. Jin Hee Ahn Dr. Weiping Han Dr. George K. Radda Prof. Young‐Tae Chang 《Angewandte Chemie (International ed. in English)》2013,52(33):8557-8560
865.
866.
During alkylation of 2-(2-hydroxyaryl)-2-hydroxy-1,3-indanedione derivatives, O-alkylated benzo[b]indeno[2,1-d]furanone derivatives were formed in appreciable amounts. 相似文献
867.
868.
Woul Seong Park Mi Sik Shin Seung Kyu Kang Sang Dal Rhee Banda Narsaiah Hyae Gyeong Cheon Sung Soo Kim 《Journal of fluorine chemistry》2009,130(11):1001-1735
A series of triazepane derivatives such as (R)-3-amino-1-(1,2,5-triazepan-1-yl)-4-(2,4,5-trifluorophenyl)butan-1-ones (7, 13a-p) and (R)-3-amino-1-(1,2,5-triazepan-5-yl)-4-(2,4,5-trifluorophenyl)butan-1-ones (17a-e) was synthesized and evaluated for their ability to inhibit dipeptidyl peptidase IV (DPP-IV) enzyme. Compounds with the acid moiety were found to be potent inhibitors of DPP-IV without inhibiting CYP 3A4. Among them, compound 13p ((R)-4-[1-acetyl-2-{3-amino-4-(2,4,5-trifluorophenyl)butanoyl-1,2,5-triazepan-5-carbonyl}benzoic acid]) showed a good in vitro activity without inhibiting CYP. 相似文献
869.
Seong Yong Oh Fang Yu Yueh Jagdish P. Singh Connie C. Herman Kristine Zeigler 《Spectrochimica Acta Part B: Atomic Spectroscopy》2009
Laser-induced breakdown spectroscopy (LIBS) was applied to the analysis of simulant slurry samples used in the vitrification process of liquid radioactive wastes. A spectroscopic analysis was performed by two different detection systems: Czerny-Turner spectrometer coupled with intensified diode array detector (IDAD) and an Echelle spectrometer with intensified charge coupled device (ICCD). For the Czerny-Turner detection system, the normalized intensity method, which is the normalization of the atomic emission intensity by the released whole plasma emission area intensity, was employed to improve the reproducibility of LIBS signals. The Echelle detection system showed a high efficiency in simultaneous multi-element detection and determination of the physical quantities of the simulant. 相似文献
870.
Jung IH Lee YH Yoo JY Jeong SJ Sonn SK Park JG Ryu KH Lee BY Han HY Lee SY Kim DY Lee H Oh GT 《Experimental & molecular medicine》2012,44(5):311-318
In this study, the synergistic effect of 6-[4-(1-cyclohexyl- 1H-tetrazol-5-yl) butoxy]-3,4-dihydro-2(1H )-quinolinone (cilostazol) and Ginkgo biloba extract (GbE) was examined in apolipoprotein E (ApoE) null mice. Co-treatment with GbE and cilostazol synergistically decreased reactive oxygen species (ROS) production in ApoE null mice fed a high-fat diet. Co-treatment resulted in a significantly decreased atherosclerotic lesion area compared to untreated ApoE mice. The inflammatory cytokines and adhesion molecules such as monocyte chemoattractant-1 (MCP-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and VCAM-1 which can initiate atherosclerosis were significantly reduced by the co-treatment of cilostazol with GbE. Further, the infiltration of macrophages into the intima was decreased by co-treatment. These results suggest that co-treatment of GbE with cilostazol has a more potent anti-atherosclerotic effect than treatment with cilostazol alone in hyperlipidemic ApoE null mice and could be a valuable therapeutic strategy for the treatment of atherosclerosis. 相似文献