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921.
Leukocyte adhesion to adhesion molecules on endothelial cells is important in immune function, cancer metastasis and inflammation. This cell-cell binding is mediated via cell adhesion molecules such as E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) found on endothelial cells. Because these adhesion molecules on endothelial cells vary significantly across several disease conditions such as autoimmune diseases, inflammation or cancer metastasis, investigations of therapeutic agents that down-regulate leukocyte-endothelial interactions have been based on in vitro models using endothelial cell lines. Here we report a new model, an inflammatory mimetic microfluidic chip, which emulates leukocyte binding to cell adhesion molecules (CAM) by controlling the types and ratio of adhesion molecules. In our model, E-selectin was essential for the synergic binding of Jurkat T cells. Immunosuppressive drugs, such as tacrolimus (FK506) and cyclosporine A (CsA), were used to inhibit T cell interactions under the physiologic model of T cell migration at a ratio of 5?:?4.3?:?3.9 (E-selectin?:?ICAM-1?:?VCAM-1). Our results support the potential usefulness of the inflammatory mimetic microfluidic chip as a T cell adhesion assay tool with modified adhesion molecules for applications such as immunosuppressive drug screening. The inflammatory mimetic microfluidic chip can also be used as a biosensor in clinical diagnostics, drug efficacy tests and high throughput drug screening due to the dynamic monitoring capability of the microfluidic chip. 相似文献
922.
Yoo Young Bum Park Jee Ho Song Kie Moon Lee Se Jong Baik Hong Koo 《Journal of Sol-Gel Science and Technology》2012,64(1):257-263
Journal of Sol-Gel Science and Technology - Solution-processed oxide thin films have many attractive features for various electronic applications as like a next generation display and flexible... 相似文献
923.
Young Mi Ha Yohei Uehara Daeui Park Hyoung Oh Jeong Ji Young Park Yun Jung Park Ji Yeon Lee Hye Jin Lee Yu Min Song Hyung Ryong Moon Hae Young Chung 《Applied biochemistry and biotechnology》2012,168(6):1416-1433
We describe the design, synthesis, and biological activities of 5-chloro-2-(substituted phenyl)benzo[d]thiazole derivatives as novel tyrosinase inhibitors. Among them, 4-(5-chloro-2,3-dihydrobenzo[d]thiazol-2-yl)-2,6-dimethoxyphenol (MHY884) and 2-bromo-4-(5-chloro-benzo[d]thiazol-2-yl)phenol (MHY966) showed inhibitory activity higher than or similar to kojic acid, against mushroom tyrosinase. Therefore, we carried out kinetic studies on the two compounds with potent tyrosinase inhibitory effects. Kinetic analysis of tyrosinase inhibition revealed that all of these compounds are competitive inhibitors. MHY884 and MHY966 effectively inhibited tyrosinase activity and reduced melanin levels in B16 cells treated with ??-melanocyte stimulating hormone (??-MSH). These data strongly suggest that the newly synthesized compounds MHY884 and MHY966 could suppress production of melanin via inhibition of tyrosinase activity. 相似文献
924.
Chen J Su H Song F Moon WJ Kim YS Zhang D 《Journal of colloid and interface science》2012,370(1):117-123
The reticular hierarchical structure of butterfly wings (Papilio Paris) is introduced as template for Au/TiO(2) photocatalyst by depositing the Au nanoparticles on TiO(2) matrix, which is carried out by a water-ethanol sol-gel procedure combined with subsequent calcination. The obtained Au/TiO(2) nanocomposites present the reticular hierarchical structure of butterfly wings, and Au nanoparticles with an average size of 7 nm are homogeneously dispersed in TiO(2) substrate. Benefiting from such unique reticular hierarchical structure and composition, the biomorphic Au/TiO(2) exhibits high-harvesting capability and presents superior photocatalytic activity. Especially, the biomorphic Au/TiO(2) at the nominal content of gold to titanium of 8 wt% shows the highest photocatalytic activity and can completely decompose methyl orange within 80 min, which is obviously higher than that of commercial Degussa P25 powders. 相似文献
925.
Beaujuge PM Tsao HN Hansen MR Amb CM Risko C Subbiah J Choudhury KR Mavrinskiy A Pisula W Brédas JL So F Müllen K Reynolds JR 《Journal of the American Chemical Society》2012,134(21):8944-8957
Given the fundamental differences in carrier generation and device operation in organic thin-film transistors (OTFTs) and organic photovoltaic (OPV) devices, the material design principles to apply may be expected to differ. In this respect, designing organic semiconductors that perform effectively in multiple device configurations remains a challenge. Following "donor-acceptor" principles, we designed and synthesized an analogous series of solution-processable π-conjugated polymers that combine the electron-rich dithienosilole (DTS) moiety, unsubstituted thiophene spacers, and the electron-deficient core 2,1,3-benzothiadiazole (BTD). Insights into backbone geometry and wave function delocalization as a function of molecular structure are provided by density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level. Using a combination of X-ray techniques (2D-WAXS and XRD) supported by solid-state NMR (SS-NMR) and atomic force microscopy (AFM), we demonstrate fundamental correlations between the polymer repeat-unit structure, molecular weight distribution, nature of the solubilizing side-chains appended to the backbones, and extent of structural order attainable in p-channel OTFTs. In particular, it is shown that the degree of microstructural order achievable in the self-assembled organic semiconductors increases largely with (i) increasing molecular weight and (ii) appropriate solubilizing-group substitution. The corresponding field-effect hole mobilities are enhanced by several orders of magnitude, reaching up to 0.1 cm(2) V(-1) s(-1) with the highest molecular weight fraction of the branched alkyl-substituted polymer derivative in this series. This trend is reflected in conventional bulk-heterojunction OPV devices using PC(71)BM, whereby the active layers exhibit space-charge-limited (SCL) hole mobilities approaching 10(-3) cm(2) V(-1) s(-1), and yield improved power conversion efficiencies on the order of 4.6% under AM1.5G solar illumination. Beyond structure-performance correlations, we observe a large dependence of the ionization potentials of the polymers estimated by electrochemical methods on polymer packing, and expect that these empirical results may have important consequences on future material study and device applications. 相似文献
926.
Hao Tang Zhuo Li Yu‐Hong Yang Ying Zhao Su‐Qin Wan Hui‐Ling Liu Xu‐Ri Huang 《Journal of computational chemistry》2012,33(16):1448-1457
A general comparison of fundamental distinctions between the FeO2+ and FeS2+ complexes in an identical cyanide or isocyanide ligand environment for methane hydroxylation has been probed computationally in this work in a series of hypothetical [FeIV(X)(CN)5]3?, [FeIV(X)(NC)5]3?, (X = O, S) complexes. We have detailed an analysis of the geometric and electronic structures using density functional theory calculations. In addition, their σ‐ and π‐mechanisms in C? H bond activation process have been described with the aid of the schematic molecular orbital diagram. From our theoretical results, it is shown that (a) the iron(IV)‐sulfido complex apparently is able to hydroxylate C? H bond of methane as good as the iron(IV)‐oxo species, (b) the O? CN, S? CN complexes have an inherent preference for the low‐spin state, while for the case of O? NC and S? NC in which S = 1 and S = 2 states are relatively close in energy, (c) each of the d block electron orbital plays an important role, which is not just spectator electron, and (d) in comparison to the cyanide and isocyanide ligand environment, we can see that the FeS2+ species prefer the cyanide ligand environment, while the FeO2+ species favor the isocyanide ligand environment. In addition, a remarkably good correlation of the σ‐/π‐mechanism for hydrogen abstraction from methane with the gap between the Fe‐dz2 (α) and C? H (α) pair as well as the Fe‐dxz/yz (β) and C? H (β) pair has been found. © 2012 Wiley Periodicals, Inc. 相似文献
927.
A simple LC‐MS/MS method has been developed and validated for the quantification of endogenous myo‐ and chiro‐inositol in human urine. myo‐ and chiro‐Inositol were completely resolved from other carbohydrates and there were no interference peaks in human urine. The correlation coefficient (n = 3) was greater than 0.9991 over the range 0.05–25.0 µg/mL with the weighted (1/C2) least square method. Precision (%RSD) and accuracy (%RE) were 0–10.0% and 0–6.0% for the intra‐day assay (n = 5) and 0–14.3% and 0–10.0% for the inter‐day assay (n = 5). myo‐ and chiro‐Inositol have been shown to be stable in human urine stored at room temperature and for three freeze–thaw cycles. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
928.
Song Ju Park Jung Min Cho Won‐Bae Byun Jong‐Cheol Lee Won Suk Shin In‐Nam Kang Sang‐Jin Moon Sang Kyu Lee 《Journal of polymer science. Part A, Polymer chemistry》2011,49(20):4416-4424
Polymer solar cells (PSCs) were fabricated using a ternary blend film consisting two conjugated polymers and a soluble fullerene derivative as the donor and acceptor materials, respectively. And, to compare ternary blend system, the single‐component copolymers consisting of the repeating units of each of the copolymers, used in ternary blend solar cells, were designed and synthesized for use as the electron donor materials in binary blend solar cells. We systematically investigated the field‐effect carrier mobilities and the optical, electrochemical, and photovoltaic properties of the copolymers. Under optimized conditions, the binary blend polymer systems showed power conversion efficiencies (PCEs) for the PSCs in the range 3.87–4.16% under AM 1.5 illumination (100 mW cm?2). All polymers exhibited similar PCEs that did not depend on the ratio of repeating units. The binary blend solar cell containing a single‐component copolymer as the electron donor material performed better than the ternary blend solar cell in this work. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
929.
930.
Dr. Sang A Han Hamzeh Qutaish Prof. Min-Sik Park Prof. Janghyuk Moon Prof. Jung Ho Kim 《化学:亚洲杂志》2021,16(24):4010-4017
Utilization of lithium (Li) metal anode is highly desirable for achieving high energy density batteries. Even so, the unavoidable features of Li dendritic growth and inactive Li are still the main factors that hinder its practical application. During plating and stripping, the solid electrolyte interphase (SEI) layer can provide passivation, playing an important role in preventing direct contact between the electrolyte and the electrode in Li metal batteries. Because of complexities of the electrolyte chemical and electrochemical reactions, the various formation mechanisms for the SEI are still not well understood. What we do know is that a strategic artificial SEI achieved through additives electrolyte can suppress the Li dendrites. Otherwise, the dendrites keep generating an abundance of irreversible Li, resulting in severe capacity loss, internal short-circuiting, and cell failure. In this minireview, we focus on the phenomenon of dendritic Li-growth and provide a brief overview of SEI formation. We finally provide some clear insights and perspectives toward practical application of Li metal batteries. 相似文献