http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A New 2,3-Dimethyl Butenolide from the Brittle Star <i>Ophiomastix mixta</i>
Lee, Jinsoo,Wang, Weihong,Hong, Jongki,Lee, Chong-Ok,Shin, Sook,Im, Kwang Sik,Jung, Jee Hyung Pharmaceutical Society of Japan 2007 Chemical & pharmaceutical bulletin Vol.55 No.3
<P>A new butenolide (1) was isolated, along with a known acyclic polyhalogenated monoterpene (2), from the brittle star <I>Ophiomastix mixta</I>. The structures were defined by analysis and comparision of the spectral data with those in the literature. The 2,3-dimethyl butenolide (1) is uncommon and first encountered in a marine organism. The compounds were tested for cytotoxicity against a panel of five human solid tumor cell lines and displayed mild to significant activity.</P>
Lee, Sung Rae,Kim, Jongki,Lee, Sejin,Jung, Yongmin,Kim, Jun Ki,Oh, K. The Optical Society 2010 Optics express Vol.18 No.24
<P>A Bessel-like beam was generated in a novel all-fiber integrated structure. A concentric ring intensity pattern was achieved by the multimode interference along the coreless silica fiber, which was then focused by the integrated micro-lens to result in a Bessel-like beam. The average beam diameter of 7.5 관m maintained over 500 관m axial length for a continuous wave Yb-doped fiber laser input oscillating at the wavelength of 1.08 관m. The generated beam was successfully applied to two-dimension optical trapping and longitudinal transport of multiple dielectric particles confirming its unique non-diffracting and self-reconstructing nature. Physical principle of operation, fabrication, and experimental results are discussed.</P>
Lee, Jongki,Wi, Seunghwan,Yun, Beom Yeol,Yang, Sungwoong,Park, Ji Hun,Kim, Sumin Elsevier 2019 APPLIED ENERGY Vol.241 No.-
<P><B>Abstract</B></P> <P>The cost of energy use in buildings around the world is gradually increasing. To achieve energy saving in buildings, among the Thermal Energy Storage (TES) systems available, the use of Latent Heat Storage (LHS) is being actively studied. To effectively use an LHS system, Phase Change Materials (PCMs) are applied to buildings, and thus Shape-Stabilization PCMs (SSPCMs) must also be used. In this study, SSPCMs were manufactured using a large-capacity vacuum impregnation machine, and consisted of Exfoliated graphite nanoplatelets (xGnP) and n-octadecane. The SSPCMs were divided according to size (A, B, C, and D). SSPCMs were applied to a gypsum board (GB). Through a compressive strength test, a weight of 5% was applied to GB_A5, and the strength was reduced by 23.1% compared to GB and 50.1% for GB_A10. The thermal properties were analyzed based on a dynamic thermo-graphic analysis and dynamic heat flow analysis. From both analyses, it was confirmed that the GB with SSPCM showed a sufficient latent heat range and a corresponding exothermic range, compared to the reference GB. Based on EnergyPlus 8.5., a cooling energy reduction of approximately 3.4% was achieved through the addition of 10% SSPCMs to GB under the operating conditions. Therefore, it was proven that the application of SSPCMs to building materials is reasonable for achieving energy saving in buildings.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Shape-Stabilization Phase Change Material (SSPCM) was made n-octadecane with xGnP. </LI> <LI> SSPCM manufacturing process was conducted using novel vacuum impregnator. </LI> <LI> Thermally enhanced gypsum board was 1.91 °C higher in exothermic range than reference. </LI> <LI> Energy simulation results showed a saving of 11.39 kWh in performance. </LI> </UL> </P>
Lee, Wonwoong,Park, Na Hyun,Lee, Yong Chan,Kim, Ki-Hyun,Hong, Jongki Elsevier 2018 Trends in analytical chemistry Vol.106 No.-
<P><B>Abstract</B></P> <P>Neurochemicals are mainly distributed in the central nervous system, and related to various neurological functions and disorders. Because neurochemicals are biosynthesized and metabolized through multiple pathways, it is difficult to understand the overall nervous system or to diagnose neurological disorders based on certain neurochemical levels. Therefore, to learn more about the nervous system and neurological disorders, metabolomics approaches should be used to profile the metabolic pathways of neurochemicals. To date, the neurochemical profiling has been pursued by various methods, especially including mass spectrometry (MS) coupled with conventional chromatographic techniques, which can sensitively and selectively determine numerous neurochemicals in biological samples. Nevertheless, the development of chromatographic MS-based analytical platforms to profile neurochemicals in biological samples has faced several challenges. This review was organized to help characterize neurochemicals using descriptions of the basic procedures (sample preparation and chromatographic MS detection). Moreover, we describe clinical applications and performance evaluation of these techniques.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Advances and challenges in neurochemical profiling of biological samples are discussed. </LI> <LI> Recent trends of biological sample preparation methods are presented. </LI> <LI> Clinical applications of neurochemical profiling techniques are summarized. </LI> <LI> Analytical performance of advanced mass spectrometry-separation methods is discussed. </LI> </UL> </P>
Lee, Won-Woong,Lee, Sun-Young,Yu, Se Mi,Hong, Jongki Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.11
An analytical method has been developed for the rapid determination of perfluorinated compounds (PFCs) in human serum samples. The extraction and purification of PFCs from human serum were performed by the modified method of previous report. Ten PFCs were rapidly separated within 3.3 min by C18-monolithic column liquid chromatography (LC) and detected by electrospray ionization (ESI) tandem mass spectrometry (MS/MS) in negative ion mode. The runtime of PFCs on monolithic column LC was up to 4-fold faster than that on conventional column LC. The effect of triethylamine (TEA) to the mobile phase has investigated on the overall MS detection sensitivity of PFCs in ESI ionization. Quantification was performed by LC-MS/MS in multiple-ion reaction monitoring (MRM) mode, using $^{13}C$-labeled internal standards. Method validation was performed to determine recovery, linearity, precision, and limits of quantification, followed by, the analysis of a standard reference material (SRM 1957 from NIST). The overall recoveries ranged between 81.5 and 106.3% with RSDs of 3.4 to 16.2% for the entire procedure. The calibration range extended from 0.33 to 50 $ng\;mL^{-1}$, with a correlation coefficient ($R^2$) greater than 0.995 and the limits of quantification with 0.08 to 0.46 $ng\;mL^{-1}$. This approach can be used for rapid and sensitive quantitative analysis of 10 PFCs in human serum with high performance and accuracy.
Lee, Sun Young,Lee, Seonjeong,Park, Sung Bum,Kim, Ki Young,Hong, Jongki,Kang, Dukjin Elsevier 2018 Journal of chromatography. B, Analytical technolog Vol.1100 No.-
<P><B>Abstract</B></P> <P>We introduce a simple online <SUP>18</SUP>O-labeling protocol for protein samples that uses a parallelizing microbore hollow fiber enzyme reactor (mHFER) as an alternative tool for online proteolytic digestion. Online <SUP>18</SUP>O-labeling is performed by separately attaching two mHFERs in parallel to a 10-port switching valve with a high-pressure syringe pump and two syringes containing <SUP>16</SUP>O- or <SUP>18</SUP>O-water. <SUP>16</SUP>O-/<SUP>18</SUP>O-labeled peptides are formed in this manner and simultaneously analyzed online using nanoflow liquid chromatography-tandem mass spectrometry (nLC-MS/MS) without any residual trypsin activity. The usefulness of a parallel mHFER platform (P-mHFER) in <SUP>18</SUP>O-labeling was tested using both cytochrome C and alpha-1-acid-glycoprotein to verify the incorporation level of two <SUP>18</SUP>O atoms into tryptic peptides and to provide a quantitative assessment with varied mixing ratios. Additionally, our <SUP>18</SUP>O-labeling approach was used to study the serum <I>N</I>-glycoproteome from lung cancer patients and controls to evaluate the applicability of lectin-based quantitative <I>N</I>-glycoproteomics. We successfully quantified 76 peptides (from 62 <I>N</I>-glycoproteins). Nineteen of these peptides from lung cancer serum were up-/down-regulated at least 2.5-fold compared to controls. As a result, the P-mHFER-based online <SUP>18</SUP>O-labeling platform presented here can be a simple and reproducible way to allow quantitative proteomic analysis of diverse proteome samples.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Developing MW sorting-based parallel mHFER (P-mHFER) for <SUP>18</SUP>O-labeling of protein(s) </LI> <LI> P-mHFER allows to form <SUP>18</SUP>O<SUB>2</SUB>-labeled peptides online in a short time (~30 min). </LI> <LI> MW sorting-based P-mHFER lowers the back-exchange caused by trypsin activity. </LI> <LI> P-mHFER has the potential in proteolytic <SUP>18</SUP>O-labeling for quantitative proteomics. </LI> </UL> </P>
Lee, Myoung Eun,Ko, Keon-hee,Park, Na-Hyun,Lee, Wonwoong,Yoo, Hye Hyun,Lee, Jeongmi,Choi, Yong Seok,Hong, Jongki Elsevier 2018 Microchemical Journal Vol.143 No.-
<P><B>Abstract</B></P> <P>Analysis of marine biotoxins in high-lipid bivalves has several limitations due to the coexistence of lipid matrices, low biotoxin concentrations, and the different physiochemical properties of the various biotoxins. In this study, a sensitive and reliable method to simultaneously determine six diarrhetic shellfish poisoning (DSP) toxins (five acidic and one neutral biotoxins) in oysters and mussels was developed based on UHPLC-MS/MS-multiple ion reaction monitoring (MRM) using time segment polarity switching. For effective sample pretreatment, three protocols including syringe filtration, Strata™-X solid phase extraction (SPE), and freezing lipid filtration combined with SPE (FLF + SPE) were evaluated, and FLF + SPE method was shown to be the most effective with high lipid removal efficiency. Aging effects of the UHPLC mobile phase on MS detection sensitivity and retention time shift of DSP toxins were carefully examined. The developed method provided good recoveries ranging from 81.0 to 119.6%, showing no significant matrix effect and assay was linear with coefficients of determination above R<SUP>2</SUP> > 0.99 for all analytes. Validation tests using a certified reference material (CRM) and spiking DSP toxins (OA and DTX-1 at 1.07 μg/g, and DTX-2 at 0.86 μg/g) showed this method to be acceptable, with a relative standard deviation of <0.17% and recovery ranging from 87.29 to 109.97%. Finally, the established method was successfully applied to quantify DSP toxins in 40 oyster and mussel samples collected from Korean fishery markets, ensuring sea food safety.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three extraction protocols were examined for determining lipophilic DSP toxins in high-lipid bivalves </LI> <LI> SPE combined with FLF was shown the best analytical performance in terms of cleanup efficiency, matrix effect, and sensitivity of DSP toxins. </LI> <LI> Simultaneously determined different polarity DSP toxins in a single run using time segment polarity switching mode </LI> <LI> Validated quantification of trace DSP toxins through CRM analysis and spiking experiments </LI> <LI> Successful monitoring the levels of DSP toxins in high-lipid bivalves </LI> </UL> </P>
Lee, Jongki,Wi, Seunghwan,Yun, Beom Yeol,Chang, Seong Jin,Kim, Sumin Elsevier 2019 Journal of industrial and engineering chemistry Vol.70 No.-
<P><B>Abstract</B></P> <P>This study was conducted to energy saving in buildings, with TES system. The manufacturing method of Shape-Stabilized Phase Change Materials (SSPCMs) was developed as the advanced vacuum impregnation. The validation was conducted using Activated Carbon (AC), Expanded Graphite (EG) and Exfoliated graphite (xGnP) as supporting materials and <I>n</I>-octadecnae was used as Phase Change Materials (PCMs). Through various experiments, the feasibility when it applied to in building, and thermal performance of this novel manufacturing method have been confirmed. Also, through the energy simulation, only 1mm thickness of SSPCMs was applied as wall, reduced building energy up to 255.44kWh.</P>