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991.
Beom Soo Shin Tae Hwan Kim Soo Heui Paik Yong Ha Chi Joo Han Lee Hyun Kwang Tan Yohan Choi Minki Kim Sun Dong Yoo 《Biomedical chromatography : BMC》2011,25(11):1208-1214
Fimasartan, 2‐butyl‐5‐dimethylaminothiocarbonylmethyl‐6‐methyl‐3‐[[2'‐(1H tetrazol ‐5‐yl)biphenyl‐4‐yl]methyl]pyrimidin‐4(3H)‐one (BR‐A‐657), is a novel angiotensin II receptor blocker exhibiting potent and selective AT1 receptor blocking activity. This study reports the liquid chromatography–tandem mass spectrometry assay for the simultaneous determination of fimasartan and its active metabolite, BR‐A‐557, in rat plasma. The assay was validated to demonstrate the specificity, linearity, recovery, lower limit of quantification, accuracy, precision and stability. The multiple reaction monitoring was based on the transition of m/z 502.1 → 207.1 for fimasartan, 486.2 → 207.1 for BR‐A‐557 and 526.1 → 207.1 for BR‐A‐563 (internal standard). The assay utilized a simple precipitation procedure with acetonitrile and isocratic elution. The LLOQ was 0.2 ng/mL for fimasartan and BR‐A‐557 using 50 μL plasma samples. The assay was linear over a concentration range from 0.2 to 500 ng/mL for fimasartan and BR‐A‐557, with correlation coefficients >0.9995. The intra‐ and inter‐day assay accuracies were 93.6–108.0 and 90.8–101.4% for fimasartan and 102.2–107.1 and 99.6–103.3% for BR‐A‐557, respectively. The intra‐ and inter‐day precision were 2.4–4.4 and 3.0–13.4% for fimasartan and 3.1–5.2 and 2.8–9.8% for BR‐A‐557, respectively. The developed assay may be used to study the metabolism and mechanistic pharmacokinetics of fimasartan in future studies. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
992.
993.
Hyun‐Woo Shim Ah‐Hyeon Lim Jae‐Chan Kim Gwang‐Hee Lee Prof. Dong‐Wan Kim 《化学:亚洲杂志》2013,8(11):2851-2858
A phase‐pure MnWO4‐based nanocomposite, MnWO4@MWCNTs (MWCNTs=multiwalled carbon nanotubes), was successfully synthesized through a simple hydrothermal reaction at 180 °C by adjusting the pH of the precursor medium. The resulting nanocomposite maintains the original flowerlike morphology of MnWO4 with hierarchical structures composed of numerous single‐crystalline nanorods that drive growth preferentially along the [001] direction. The growth mechanism for the flowerlike formations is also discussed. In addition, the Li electroactivity of pure MnWO4 and MnWO4@MWCNTs electrodes was investigated. As an anode for Li‐ion batteries, the MnWO4@MWCNTs nanocomposite showed enhanced electrochemical performance in reversible Li storage relative to that shown by bare MnWO4 electrodes, including a high capacity of 425 mAh g?1 and superior rate performance. This performance can be attributed to the synergistic effect of the nanocomposite combined with the MWCNTs, which provide efficient electron transport in their role as a conductor. 相似文献
994.
995.
Mickhail V. Ryzhkov Alexei Mirmelstein Sung‐Woo Yu Brandon W. Chung James G. Tobin 《International journal of quantum chemistry》2013,113(16):1957-1965
Calculations of the electronic structure of clusters of plutonium have been performed, within the framework of the relativistic discrete‐variational method. These theoretical results and those calculated earlier for related systems have been compared to spectroscopic data produced in the experimental investigations of bulk systems, including photoelectron spectroscopy. Observation of the changes in the Pu electronic structure as a function of size provides powerful insight for aspects of bulk Pu electronic structure. © 2013 Wiley Periodicals, Inc. 相似文献
996.
Young Jin Cho Seung Hwan Lee Jong Woo Bae Sung Hoon Kim Sam Rok Keum Cheol Min Yoon 《合成通讯》2013,43(12):2205-2211
The 7-acetoxyspiropyrans (4a and 4b) have been prepared by the reaction of Fischer's bases (3) with 2,4-diacetoxybenzaldehyde in refluxing ethanol in moderate yields. The acetyl group of 7-acetoxy-spiropyran 4a was easily removed to give a 7-hydroxyspiropyran 6 in high yield under the basic condition. 相似文献
997.
Effect of Glass Transition Temperature of Pressure Sensitive Adhesives on Light Leakage in LCD Panel
Pressure-sensitive adhesives (PSA), which mainly are made of acrylic polymers, have been used to fix optical films to liquid crystal display (LCD) cells to prevent contraction or expansion of the optical film under high temperature and high humidity conditions, while residual stress on the polarizing film is generated and light-leakage results from it in the peripheral area of an LCD panel. In this work, we prepared two different kinds of PSAs and tested light leakage with respect to Tg, verifying that Tg would have an effect on light leakage. We calculated their Tg values using the Fox equation and investigated them by DSC. Rheological properties of the PSAs were also acquired by a rotational rheometer which confirm the relation between Tg and dynamic moduli (G′ and G″). It was found that the higher the Tg, the less is an amount of light leaked. 相似文献
998.
Heung Soo Baek Byung Woo Yoo Sam Rok Keum Cheol Min Yoon Sung Hoon Kim Joong Hyup Kim 《合成通讯》2013,43(1):31-38
α-Haloketones reacted with acyl cyanides to form 1,3-diketones in the presence of samarium diiodide. The reaction was assumed to proceed via a mechanism involving samarium enolates formed in situ from α-haloketones. 相似文献
999.
Sung Yong Park Jae Woo Chung Rodney D. Priestley Seung-Yeop Kwak 《Cellulose (London, England)》2012,19(6):2141-2151
We develop an antimicrobial active robust metal-cellulose nanohybrid by covalent assembly of metal nanoparticles on cellulose fabric using a simple impregnation of thiol-modified cellulose fabric in colloidal silver (Ag) or palladium (Pd) nanoparticle solutions. The combined results of high resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDXS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) reveal that the nanoparticles are highly loaded and dispersed in the thiol-modified cellulose fabric, and X-ray photoelectron spectroscopy (XPS) analysis reveals that the nanoparticles are immobilized in the fabric by a strong and stable covalent bond with thiol functional group. This robust covalent linkage between the nanoparticles and the fabric leads to a remarkable suppression of the release of metal nanoparticles from the fabric. In addition, the metal-cellulose nanohybrids show high antimicrobial activity in excess of 99.9 % growth inhibition of the microorganism. Thus, we anticipate that our metal-cellulose nanohybrid may not only protect cell damage caused by penetration and fixation of metal nanoparticles into the human body but also act as a sustainable biomedical textile. 相似文献
1000.
l-Cysteine molecules dramatically enhance the photoluminescence of colloidal CdSe/ZnSe quantum dots (i.e., CTAB/TOPOQD). Based on our spectroscopic studies of temporal variations in QD quantum yields as well as the in situ infrared spectral features of QDs, we propose that adsorption and rearrangement of l-cysteine molecules at the QD–water interface induces the observed unusual enhancement of the photoluminescence quantum yield. Upon addition of l-cysteine to the CTAB/TOPOQD solution, the adsorption of l-cysteine to the CTAB/TOPOQD colloidal particles is driven by the formation of a kinetically favorable intermediate species, which is formed by the coordination of thiol groups to the QD surface Cd atoms. The above species then reacts further to form a thermodynamically stable QD species, which probably involves coordination of both the amine and thiol groups of l-cysteine on the QD surface. Additional comparison studies using MPAQD and other small ligands (i.e., l-alanine, l-serine, and MPA) confirmed our proposed mechanism of l-cysteine adsorption at the CTAB/TOPOQD–water interfaces. In addition to these adsorption structures, we also propose that the dramatic enhancement of QY observed in this study is probably induced by the rearrangement and structural organization of l-cysteine and CTAB molecules at the QD–water interface, which improves the homogeneity and self-organization of the interfacial molecules. 相似文献