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991.
Photo‐ and pH‐Tunable Multicolor Fluorescent Nanoparticle‐Based Spiropyran‐ and BODIPY‐Conjugated Polymer with Graphene Oxide 下载免费PDF全文
Shazid Md. Sharker Chan Jin Jeong Sung Min Kim Jung‐Eun Lee Prof. Ji Hoon Jeong Prof. Insik In Prof. Haeshin Lee Prof. Sung Young Park 《化学:亚洲杂志》2014,9(10):2921-2927
We report a stimuli‐responsive fluorescent nanomaterial, based on graphene oxide coupled with a polymer conjugated with photochromic spiropyran (SP) dye and hydrophobic boron dipyrromethane (BODIPY) dye, for application in triggered target multicolor bioimaging. Graphene oxide (GO) was reduced by catechol‐conjugated polymers under mildly alkaline conditions, which enabled to formation of functionalized multicolor graphene nanoparticles that can be induced by irradiation with UV light and by changing the pH from acidic to neutral. Investigation of these nanoparticles by using AFM, fluorescence emission, and in vitro cell and in vivo imaging revealed that they show different tunable colors in bioimaging applications and, more specifically, in cancer‐cell detection. The stability, biocompatibility, and quenching efficacy of this nanocomposite open a different perspective for cell imaging in different independent colors, sequentially and simultaneously. 相似文献
992.
Flame Spray Pyrolysis for Finding Multicomponent Nanomaterials with Superior Electrochemical Properties in the CoOx‐FeOx System for Use in Lithium‐Ion Batteries 下载免费PDF全文
High‐temperature flame spray pyrolysis is employed for finding highly efficient nanomaterials for use in lithium‐ion batteries. CoOx‐FeOx nanopowders with various compositions are prepared by one‐pot high‐temperature flame spray pyrolysis. The Co and Fe components are uniformly distributed over the CoOx‐FeOx composite powders, irrespective of the Co/Fe mole ratio. The Co‐rich CoOx‐FeOx composite powders with Co/Fe mole ratios of 3:1 and 2:1 have mixed crystal structures with CoFe2O4 and Co3O4 phases. However, Co‐substituted magnetite composite powders prepared from spray solutions with Co and Fe components in mole ratios of 1:3, 1:2, and 1:1 have a single phase. Multicomponent CoOx‐FeOx powders with a Co/Fe mole ratio of 2:1 and a mixed crystal structure with Co3O4 and CoFe2O4 phases show high initial capacities and good cycling performance. The stable reversible discharge capacities of the composite powders with a Co/Fe mole ratio of 2:1 decrease from 1165 to 820 mA h g?1 as the current density is increased from 500 to 5000 mA g?1; however, the discharge capacity again increases to 1310 mA h g?1 as the current density is restored to 500 mA g?1. 相似文献
993.
Quantitative determination of enzalutamide,an anti‐prostate cancer drug,in rat plasma using liquid chromatography–tandem mass spectrometry,and its application to a pharmacokinetic study 下载免费PDF全文
Ji‐Hye Song Tae‐Heon Kim Jong‐Woo Jung Nakjeong Kim Sung Hoon Ahn Sung‐Ook Hwang Nam Sook Kang Sung‐Eun Yoo Tae‐Sung Koo 《Biomedical chromatography : BMC》2014,28(8):1112-1117
This report details a method using liquid chromatography–tandem mass spectrometry (LC‐MS/MS) that allows one to determine the concentration of an atypical anticancer drug, enzalutamide, in rat plasma. Specifically, this method involves the addition of an acetonitrile and bicalutamide (internal standard) solution to plasma samples. Following centrifugation of this mixture, an aliquot of the supernatant was directly injected into the LC‐MS/MS system. Separation was achieved using a column packed with octadecylsilica (5 µm, 2.1 × 50 mm) with 10 mM ammonium acetate in acetonitrile as the mobile phase; detection was accomplished using MS/MS by multiple‐reaction monitoring via an electrospray ionization source. This method demonstrated a linear standard curve (r = 0.997) over a concentration range of 0.001–1 µg/mL, as well as an intra‐ and inter‐assay precision of 2.7 and 5.1%, respectively, and an accuracy range from 100.8 to 105.6%. The lower limit of quantification was 1.0 ng/mL in 50 μL of rat plasma sample. We also demonstrated that this analytical method could be successfully applied to the pharmacokinetic study of enzalutamide in rats. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
994.
Dr. Jae‐Il Jung Dr. Hu Young Jeong Jang‐Soo Lee Dr. Min Gyu Kim Prof. Dr. Jaephil Cho 《Angewandte Chemie (International ed. in English)》2014,53(18):4582-4586
La0.3(Ba0.5Sr0.5)0.7Co0.8Fe0.2O3?δ is a promising bifunctional perovskite catalyst for the oxygen reduction reaction and the oxygen evolution reaction. This catalyst has circa 10 nm‐scale rhombohedral LaCoO3 cobaltite particles distributed on the surface. The dynamic microstructure phenomena are attributed to the charge imbalance from the replacement of A‐site cations with La3+ and local stress on Co‐site sub‐lattice with the cubic perovskite structure. 相似文献
995.
Photoinduced Copper‐Catalyzed Regioselective Synthesis of Indoles: Three‐Component Coupling of Arylamines,Terminal Alkynes,and Quinones 下载免费PDF全文
Dr. Arunachalam Sagadevan Ayyakkannu Ragupathi Prof. Kuo Chu Hwang 《Angewandte Chemie (International ed. in English)》2015,54(47):13896-13901
The first successful example of a visible‐light‐induced copper‐catalyzed process for C? H annulation of arylamines with terminal alkynes and benzoquinone is described. This three‐component reaction allows use of a variety of commercial terminal alkynes as coupling partners for the one‐step regioselective synthesis of functionalized indoles. Moreover, the current process represents a sustainable and atom‐economical approach for the preparation of complex indoles from easily accessible starting materials under visible‐light irradiation, without the need for expensive metals and harsh reaction conditions. 相似文献
996.
Annika Höhn Petra Hartmann Veronika Gebhart Johanna Sonntag Tilman Grune Tobias Jung 《Photochemistry and photobiology》2015,91(4):887-894
In this study, the athermal effects of water‐filtered infrared A (wIRA)‐irradiation (780–1400 nm) on human dermal fibroblasts were investigated. For this purpose, cells were exposed to wIRA‐irradiation (178 mW cm?2 for 1 h), while a sophisticated experimental setup prevented warming of the samples exceeding 0.1°C. The investigated parameters were the formation of reactive oxygen species (ROS), mitochondrial membrane potential and superoxide release, protein oxidation, proliferation rate, as well as intracellular Ca2+‐release in single cells, most of them quantified via fluorescence microscopy and fluorimetric techniques. The existence of actual athermal wIRA‐effects is still intensively discussed, since their detection requires a careful experimental setup and both efficient and powerful temperature regulation of the exposed samples. Here, we can definitively show that some of the supposed athermal wIRA‐effects may be rather artifacts, since wIRA did not reveal any impact on the above mentioned parameters—as long as the temperature of the exposed cells was carefully maintained. Though, we were able to identify an athermal DNA‐protective wIRA‐effect, since the induced DNA damage (quantified via 8‐Oxo‐G‐formation) was significantly decreased after a subsequent UVB‐exposure. These results suggest that many of the supposed athermal wIRA‐effects can be induced by pure warming of the samples, independent from any wIRA‐irradiation. 相似文献
997.
Surface and Structural Investigation of a MnOx Birnessite‐Type Water Oxidation Catalyst Formed under Photocatalytic Conditions 下载免费PDF全文
Benjamin J. Deibert Jingming Zhang Paul F. Smith Dr. Karena W. Chapman Dr. Sylvie Rangan Debasis Banerjee Kui Tan Hao Wang Nicholas Pasquale Prof. Feng Chen Prof. Ki‐Bum Lee Prof. G. Charles Dismukes Prof. Yves J. Chabal Prof. Jing Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14218-14228
Catalytically active MnOx species have been reported to form in situ from various Mn‐complexes during electrocatalytic and solution‐based water oxidation when employing cerium(IV) ammonium ammonium nitrate (CAN) oxidant as a sacrificial reagent. The full structural characterization of these oxides may be complicated by the presence of support material and lack of a pure bulk phase. For the first time, we show that highly active MnOx catalysts form without supports in situ under photocatalytic conditions. Our most active 4MnOx catalyst (~0.84 mmol O2 mol Mn?1 s?1) forms from a Mn4O4 bearing a metal–organic framework. 4MnOx is characterized by pair distribution function analysis (PDF), Raman spectroscopy, and HR‐TEM as a disordered, layered Mn‐oxide with high surface area (216 m2g?1) and small regions of crystallinity and layer flexibility. In contrast, the SMnOx formed from Mn2+ salt gives an amorphous species of lower surface area (80 m2g?1) and lower activity (~0.15 mmol O2 mol Mn?1 s?1). We compare these catalysts to crystalline hexagonal birnessite, which activates under the same conditions. Full deconvolution of the XPS Mn2p3/2 core levels detects enriched Mn3+ and Mn2+ content on the surfaces, which indicates possible disproportionation/comproportionation surface equilibria. 相似文献
998.
Targeted Delivery of Vaccine to Dendritic Cells by Chitosan Nanoparticles Conjugated with a Targeting Peptide Ligand Selected by Phage Display Technique 下载免费PDF全文
999.
Lee KY Kim M Hahn J Suh JS Lee I Kim K Han SW 《Langmuir : the ACS journal of surfaces and colloids》2006,22(4):1817-1821
Carbon nanotubes (CNTs)-mediated self-assembly of metal (Au and Ag) nanoparticles at the liquid/liquid interface in the form of a stable nanocomposite film is reported. The metallic luster results from the electronic coupling of nanoparticles, suggesting the formation of closely packed nanoparticle thin films. The interfacial film could be transferred to mica substrates and carbon-coated transmission electron microscopy (TEM) grids. The transferred films were very stable for a prolonged time. The samples were characterized by UV-vis spectroscopy, scanning electron microscopy (SEM), TEM, and X-ray photoelectron spectroscopy (XPS). SEM and TEM results show that the films formed at the liquid/liquid interface are indeed composite materials consisting of CNTs and nanoparticles. XPS measurements further indicate the presence of the interaction between nanoparticles and CNTs. 相似文献
1000.