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排序方式: 共有1323条查询结果,搜索用时 15 毫秒
61.
Giseop Kwak Hong‐Qing Wang Kyu‐Han Choi Kyu‐Ho Song Soon‐Hak Kim Hyeok‐Soo Kim Sam‐Jong Lee Ho‐Young Cho Eon‐Ju Yu Hyo‐Jeong Lee Eun‐Jung Park Lee‐Soon Park 《Macromolecular rapid communications》2007,28(12):1317-1324
New poly(diphenylacetylene)s with alkoxy and fluoroalkyl groups as electron‐donating and electron‐withdrawing groups, respectively, were synthesized by using a WCl6‐n‐Ph4Sn catalyst. The polymer solutions emitted strong, bluish‐green lights when photo‐excited. The polymers that contained the electron‐donating alkoxy groups showed longer fluorescence‐maximum peaks when compared to the polymers that contained the electron‐withdrawing fluoroalkyl groups. However, such an effect of the substituent on the absorption property was not clearly seen. The emission bands of the solid films did not show any significant red shift, relative to that of the dilute solution.
62.
We calculated the potential of mean force (PMF) for the interaction between a model zwitterionic bilayer and a model charged bilayer. To understand the role of water, we separated the PMF into two components: one due to direct interaction and the other due to water-mediated interaction. In our calculations, we observed that water-mediated interaction is attractive at larger distances and repulsive at shorter. The calculation of the entropic and enthalpic contributions to the solvent-mediated components of the PMF showed that attraction is entropically dominant, while repulsion is dominated by the enthalpy. 相似文献
63.
64.
Limited environmental pollutants have only been investigated for the feasibility of light‐emitting diodes (LED) uses in photocatalytic decomposition (PD). The present study investigated the applicability of LEDs for annular photocatalytic reactors by comparing PD efficiencies of dimethyl sulfide (DMS), which has not been investigated with any LED‐PD system, between photocatalytic systems utilizing conventional and various LED lamps with different wavelengths. A conventional 8 W UV/TiO2 system exhibited a higher DMS PD efficiency as compared with UV‐LED/TiO2 system. Similarly, a conventional 8 W visible‐lamp/N‐enhanced TiO2 (NET) system exhibited a higher PD efficiency as compared with six visible‐LED/NET systems. However, the ratios of PD efficiency to the electric power consumption were rather high for the photocatalytic systems using UV‐ or visible‐LED lamps, except for two LED lamps (yellow‐ and red‐LED lamps), compared to the photocatalytic systems using conventional lamps. For the photocatalytic systems using LEDs, lower flow rates and input concentrations and shorter hydraulic diameters exhibited higher DMS PD efficiencies. An Fourier‐transformation infrared analysis suggested no significant absorption of byproducts on the catalyst surface. Consequently, it was suggested that LEDs can still be energy‐efficiently utilized as alternative light sources for the PD of DMS, under the operational conditions used in this study. 相似文献
65.
Supramolecular Phthalocyanine Assemblies for Improved Photoacoustic Imaging and Photothermal Therapy
Xingshu Li Eun‐Yeong Park Youngnam Kang Nahyun Kwon Mengyao Yang Seunghyun Lee Won Jong Kim Chulhong Kim Juyoung Yoon 《Angewandte Chemie (International ed. in English)》2020,59(22):8630-8634
Phototheranostic nanoplatforms are of particular interest for cancer diagnosis and imaging‐guided therapy. Herein, we develop a supramolecular approach to fabricate a nanostructured phototheranostic agent through the direct self‐assembly of two water‐soluble phthalocyanine derivatives, PcS4 and PcN4. The nature of the molecular recognition between PcS4 and PcN4 facilitates the formation of nanostructure (PcS4‐PcN4) and consequently enables the fabrication of PcS4‐PcN4 with completely quenched fluorescence and reduced singlet oxygen generation, leading to the high photoacoustic and photothermal activity of PcS4‐PcN4. In vivo evaluations suggest that PcS4‐PcN4 could not only efficiently visualize a tumor with high contrast through whole‐body photoacoustic imaging but also enable excellent photothermal therapy for cancer. 相似文献
66.
Da Eun Kim Jong Min Lee Christian D. Ahrberg Mohammed R. Shaker Ju‐Hyun Lee Woong Sun Bong Geun Chung 《Electrophoresis》2019,40(3):419-424
The inability of neurons to undergo mitosis renders damage to the central or peripheral nervous system. Neural stem cell therapy could provide a path for treating the neurodegenerative diseases. However, reliable and simple tools for the developing and testing neural stem cell therapy are still required. Here, we show the development of a micropillar‐based microfluidic device to trap the uniform‐sized neurospheres. The neurospheres trapped within micropillar arrays were largely differentiated into neuronal cells, and their neurite networks were observed in the microfluidic device. Compared to conventional cultures on glass slides, the neurite networks generated with this method have a higher reproducibility. Furthermore, we demonstrated the effect of thapsigargin on the neurite networks in the microfluidic device, demonstrating that neural networks exposed to thapsigargin were largely diminished and disconnected from each other. Therefore, this micropillar‐based microfluidic device could be a potential tool for screening of neurotoxins. 相似文献
67.
Da Hyeon Choi Jiwon Park Ju Kwang Choi Kyeong Eun Lee Won Hee Lee Jinho Yang Ju Yeon Lee Yoon Jeong Park Chan Oh Ho-Ryun Won Bon Seok Koo Jae Won Chang Yoon Shin Park 《Experimental & molecular medicine》2020,52(9):1564
Oral microbes have the capacity to spread throughout the gastrointestinal system and are strongly associated with multiple diseases. Given that tonsils are located between the oral cavity and the laryngopharynx at the gateway of the alimentary and respiratory tracts, tonsillar tissue may also be affected by microbiota from both the oral cavity (saliva) and the alimentary tract. Here, we analyzed the distribution and association of the microbial communities in the saliva and tonsils of Korean children subjected to tonsillectomy because of tonsil hyperplasia (n = 29). The microbiome profiles of saliva and tonsils were established via 16S rRNA gene sequencing. Based on the alpha diversity indices, the microbial communities of the two groups showed high similarities. According to Spearman’s ranking correlation analysis, the distribution of Treponema, the causative bacterium of periodontitis, in saliva and tonsils was found to have a significant positive correlation. Two representative microbes, Prevotella in saliva and Alloprevotella in tonsils, were negatively correlated, while Treponema 2 showed a strong positive correlation between saliva and tonsils. Taken together, strong similarities in the microbial communities of the tonsils and saliva are evident in terms of diversity and composition. The saliva microbiome is expected to significantly affect the tonsil microbiome. Furthermore, we suggest that our study creates an opportunity for tonsillar microbiome research to facilitate the development of novel microbiome-based therapeutic strategies.Subject terms: Comparative genomics, Metagenomics 相似文献
68.
A dye‐sensitized solar cell (DSSC) containing a TiO2 film treated with COOH‐functionalized germanium nanoparticles (Ge COOH Nps) exhibited a higher short‐circuit photocurrent density (Jsc; 15.4 mA cm−2) compared to the corresponding untreated DSSC (13.4 mA cm−2) using N719 and a 12 μm thick TiO2 film at 100 mW cm−2. The amount of N719 attached to the treated TiO2 film was 21 % greater than that attached to the untreated TiO2 film. Enhancement of the Jsc value by 15 % was attributed mostly to an intramolecular charge transfer from N719 attached to the Ge COOH Nps to the TiO2 conduction band through the Ge COOH Nps. 相似文献
69.
Wang‐Eun Lee Dong‐Cheul Han Dong‐Hee Han Heung‐Jin Choi Toshikazu Sakaguchi Chang‐Lyoul Lee Giseop Kwak 《Macromolecular rapid communications》2011,32(14):1047-1051
Fluorescence (FL) emission properties, microporous structures, energy‐minimized chain conformations, and lamellar layer structures of the silicon‐containing poly(diphenylacetylene) derivative of p‐PTMSDPA before and after desilylation were investigated. The nitrogen‐adsorption isotherms of p‐PTMSDPA film before and after desilylation were typical of type I, indicating microporous structures. The BET surface area and pore volume of the p‐PTMSDPA film were significantly reduced after the desilylation reaction, simultaneously, its FL emission intensity remarkably decreased. The theoretical calculation on both model compounds of p‐PTMSDPA and its desilylated polymer, PDPA, showed a remarkable difference in chain conformation: The side phenyl rings of p‐PTMSDPA are discontinuously arranged in a zig‐zag pattern, while the PDPA is continuously coiled in a helical manner. The lamellar layer distance (LLD) in the p‐PTMSDPA film significantly decreased after the desilylation reaction.
70.
Biman B. Mandal Eun Seok Gil Bruce Panilaitis David L. Kaplan 《Macromolecular bioscience》2013,13(1):1-1
Front Cover: Highly aligned 3D silk scaffolds using directional freezing in a custom designed chamber was demonstrated. The method is versatile and holds potential to produce complex, multicomponent aligned structures for various tissue engineering and biomedical applications, needing immediate cell alignment to mimic native tissue hierarchy and function. Further details can be found in the article by B. B. Mandal, E. S. Gil, B. Panilaitis, and D. L. Kaplan* on page 48 .