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排序方式: 共有1502条查询结果,搜索用时 46 毫秒
81.
Xuan Thang Cao Ali Md Showkat Chan Park Yeong Soon Gal 《Molecular Crystals and Liquid Crystals》2015,618(1):103-110
Poly(?-caprolactone) grafted poly(2-hydroxyethyl methacrylate) functionalized hydroxyapatite (HAP@PHEMA-g-PCL) nanocomposites were synthesized by the combination of reversible addition fragmentation chain transfer (RAFT) polymerization and ring-opening polymerization (ROP). The RAFT agent was anchored on the surface of hydroxyapatite nanocrystals (HAPs) through the silane condensation process of 3-chloropropyltrimethoxysilane followed by reaction with potassium xanthogenate. Poly(2-hydroxyethyl methacrylate) (PHEMA) was covalently functionalized on the surface of HAPs by RAFT polymerization. Then, poly(?-caprolactone) (PCL) was grafted on HAPs by ROP based on the hydroxyl groups of PHEMA to afford HAP@PHEMA-g-PCL. The structure and composition of HAP@PHEMA-g-PCL nanocomposites were characterized by FT-IR, XRD, and TGA analyses. The morphology and formation of the polymer encapsulating HAPs were demonstrated from SEM and TEM images, while the 1H MNR analysis of the cleaved PHEMA-g-PCL confirmed the grafting. 相似文献
82.
Hyun-Shik Yun Hongkyun Lee Young-Tae Park Min-Kyu Ji Akhil N. Kabra Chung Jeon Byong-Hun Jeon Jaeyoung Choi 《Applied biochemistry and biotechnology》2014,173(8):2054-2064
Microalgae were selected and isolated from acid mine drainage in order to find microalgae species which could be cultivated in low pH condition. In the present investigation, 30 microalgae were isolated from ten locations of acid mine drainage in South Korea. Four microalgae were selected based on their growth rate, morphology, and identified as strains of KGE1, KGE3, KGE4, and KGE7. The dry biomass of microalgae species ranged between 1 and 2 g L?1 after 21 days of cultivation. The growth kinetics of microalgae was well described by logistic growth model. Among these, KGE7 has the highest biomass production (2.05?±?0.35 g L?1), lipid productivity (0.82?±?0.14 g L?1), and C16–C18 fatty acid contents (97.6 %). These results suggest that Scenedesmus sp. KGE 7 can be utilized for biodiesel production based on its high biomass and lipid productivity. 相似文献
83.
Jinwon Jeon Dr. Yu-Tao He Sanghoon Shin Prof. Dr. Sungwoo Hong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(1):287-291
The photocatalyzed ortho-selective migration on a pyridyl ring has been achieved for the site-selective trifluoromethylative pyridylation of unactivated alkenes. The overall process is initiated by the selective addition of a CF3 radical to the alkene to provide a nucleophilic alkyl radical intermediate, which enables an intramolecular endo addition exclusively to the ortho-position of the pyridinium salt. Both secondary and tertiary alkyl radicals are well-suited for addition to the C2-position of pyridinium salts to ultimately provide synthetically valuable C2-fluoroalkyl functionalized pyridines. Moreover, the method was successfully applied to the reaction with P-centered radicals. The utility of this transformation was further demonstrated by the late-stage functionalization of complex bioactive molecules. 相似文献
84.
Jinny Claire Lee Hye Yun Kim Sejin Lee Jisu Shin Hyunjin Vincent Kim Kyeonghwan Kim Seungyeop Baek Donghee Lee Hanna Jeon DaWon Kim Seung‐Hoon Yang Gyoonhee Han Keunwan Park Jaeho Choi Jinwoo Park Jason A. Moss Kim D. Janda YoungSoo Kim 《Angewandte Chemie (International ed. in English)》2020,59(28):11491-11500
Amyloid‐β (Aβ) oligomers are implicated in Alzheimer disease (AD). However, their unstable nature and heterogeneous state disrupts elucidation of their explicit role in AD progression, impeding the development of tools targeting soluble Aβ oligomers. Herein parallel and anti‐parallel variants of Aβ(1–40) dimers were designed and synthesized, and their pathogenic properties in AD models characterized. Anti‐parallel dimers induced cognitive impairments with increased amyloidogenesis and cytotoxicity, and this dimer was then used in a screening platform. Through screening, two FDA‐approved drugs, Oxytetracycline and Sunitinib, were identified to dissociate Aβ oligomers and plaques to monomers in 5XFAD transgenic mice. In addition, fluorescent Astrophloxine was shown to detect aggregated Aβ in brain tissue and cerebrospinal fluid samples of AD mice. This screening platform provides a stable and homogeneous environment for observing Aβ interactions with dimer‐specific molecules. 相似文献
85.
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
86.
Min Ku Jeon Kweon Ho Kang Geun Il Park Young Soon Lee 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):513-517
Chlorination reaction behavior of Zircaloy-4 (Zry-4) cladding hulls was demonstrated by using a quartz reactor system. By
reacting at 380 °C for 3 h, mass of the Zry-4 hulls decreased by 65.8 wt% with Cl2 utilization of 87.1 mol%. Composition of collected product was analyzed and it was revealed that concentration of Zr was
higher than 99.97 wt%. The purity of Zr in the experimental result was higher than expectation when considering Sn (1.31 wt%)
and Fe (0.25 wt%) contents which can produce gaseous SnCl4 and FeCl3 at the experimental condition. Theoretical calculations were performed to clarify the high purity of Zr by using the HSC
code. The simulation results revealed that formation of ZrCl4 is more preferred than SnCl4, FeCl3, and CrCl3. The preference of chloride formation was confirmed by the theoretical calculation, and it was suggested that the major constituents
of Zry-4 might react with Cl2 to produce chlorides in an order of ZrCl4 > CrCl3 > SnCl4 > FeCl3. It was also suggested that continuous removal of ZrCl4 and sufficient supply of Zr source during the chlorination reaction might have contributed to the high purity of Zr. 相似文献
87.
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89.
Kumar Sunil Jeon H. C. Kang T. W. Kalia Rajesh Sharma J. K. Panwar Sanjay Kalia Sapna Sharma Vandana Choubey R. K. 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2017,91(13):2666-2670
Russian Journal of Physical Chemistry A - In the present work, the effect of temperature and moisture has been studied on nano-porous polycarbonate membranes of size 15, 50, and 80 nm, respectively... 相似文献
90.