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Search Results: 1 - 10 of 22468 matches for " Ha Hyung Kim "
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Kwang Ha,Joon Heo,Hyung Jin Kim
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809048892
Abstract: In the title compound, C27H23N3, the dihedral angles between the central pyridine ring and the two outer benzene rings are 32.6 (1) and 52.0 (1)°. The compound displays intermolecular π–π interactions between adjacent six-membered rings, the shortest centroid–centroid distance being 3.981 (3) .
Kwang Ha,Hyun Sub Lim,Hyung Jin Kim
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810034872
Abstract: The title compound, C14H15ClN2O, contains an eight-membered 5,5-fused bicycle with two substituents. The dihedral angle between the nearly planar eight-membered ring [maximum deviation = 0.033 (2) ] and the benzene ring is 25.0 (1)°. In the crystal structure, molecules are stacked in columns along the b axis and C—H...π interactions are observed between the columns.
Kwang Ha,Sae Byul Park,Hyung Jin Kim
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536810051044
Abstract: The title compound, C29H29NO3, the nearly planar nine-membered indanedione ring [maximum deviation = 0.027 (2) ] is located approximately parallel to its carrier pyridine ring [maximum deviation = 0.021 (2) ] with a dihedral angle of 1.8 (1)° between the planes. However, because of steric hindrance, the benzene ring [maximum deviation = 0.006 (2) ] is not parallel to the pyridine ring [dihedral angle = 37.29 (8)°]. The molecules display numerous intermolecular π–π interactions between the five- and six-membered rings, the shortest centroid–centroid distance being 3.796 (2) . There are inter- and intramolecular O—H...O and C—H...O hydrogen bonds.
Observation and Numerical Simulations with Radar and Surface Data Assimilation for Heavy Rainfall over Central Korea

Ji-Hyun HA,Hyung-Woo KIM,Dong-Kyou LEE,

大气科学进展 , 2011,
Abstract: This study investigated the impact of multiple-Doppler radar data and surface data assimilation on forecasts of heavy rainfall over the central Korean Peninsula; the Weather Research and Forecasting (WRF) model and its three-dimensional variational data assimilation system (3DVAR) were used for this purpose. During data assimilation, the WRF 3DVAR cycling mode with incremental analysis updates (IAU) was used. A maximum rainfall of 335.0 mm occurred during a 12-h period from 2100 UTC 11 July 2006 to 0900 UTC 12 July 2006. Doppler radar data showed that the heavy rainfall was due to the back-building formation of mesoscale convective systems (MCSs). New convective cells were continuously formed in the upstream region, which was characterized by a strong southwesterly low-level jet (LLJ). The LLJ also facilitated strong convergence due to horizontal wind shear, which resulted in maintenance of the storms. The assimilation of both multiple-Doppler radar and surface data improved the accuracy of precipitation forecasts and had a more positive impact on quantitative forecasting (QPF) than the assimilation of either radar data or surface data only. The back-building characteristic was successfully forecasted when the multiple-Doppler radar data and surface data were assimilated. In data assimilation experiments, the radar data helped forecast the development of convective storms responsible for heavy rainfall, and the surface data contributed to the occurrence of intensified low-level winds. The surface data played a significant role in enhancing the thermal gradient and modulating the planetary boundary layer of the model, which resulted in favorable conditions for convection.
Kwang Ha,Sae Byul Park,Young Ju Lee,Hyung Jin Kim
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810028813
Abstract: The title compound, C24H20Br2N2O4, is an 18-membered tricycle including two isoxazole rings. The asymmetric unit contains one half of the formula unit; a centre of inversion is located at the centroid of the compound. The dihedral angle between adjacent isoxazole and benzene rings is 84.0 (2)°. The compound displays intra- and intermolecular π–π stacking interactions between the isoxazole rings, the shortest centroid–centroid distances being 3.837 (3) and 3.634 (3) , respectively. The molecules are stacked in columns along the a axis with short Br...Br contacts [3.508 (1) ].
The Prognostic Significance of Cancer-Associated Fibroblasts in Esophageal Squamous Cell Carcinoma
Sang Yun Ha, So-Young Yeo, Yan-hiua Xuan, Seok-Hyung Kim
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0099955
Abstract: Background Cancer-associated fibroblasts (CAF) are activated fibroblasts in the cancer stroma and play an important role in cancer progression. Some reports have indicated the correlation between the expression of CAF markers and adverse prognosis in several cancers. However, no reports have studied CAF phenotype and its clinical relevance in esophageal squamous cell carcinoma (ESCC). Methods We investigated CAF phenotype of ESCC based on histology and immunohistochemical expressions of five CAF markers such as fibroblast activation protein (FAP), smooth muscle actin (SMA), fibroblast-specific protein-1 (FSP1), platelet-derived growth factor receptor (PDGFRα), and PDGFRβ in 116 ESCC tissue samples. Besides, we also examined the correlation of the CAF phenotype with clinical relevance as well as other cancer-microenvironment related factors. Results Histologically immature CAF phenotype was correlated with poor prognosis (p<0.001) and associated with increased microvessel density, increased tumor associated macrophages, and epithelial to mesenchymal transition. CAF markers were characteristically expressed in stromal fibroblast close to tumor cells and the expression pattern of 5 CAF markers was highly heterogeneous in every individual cases. Of five CAF markers, SMA, FSP1, and PDGFRα were unfavorable prognostic indicators of ESCC. The number of positive CAF markers was greater in ESCC with immature CAFs than in those with mature ones. Conclusions Our results demonstrate that histologic classification of CAF phenotype is a reliable and significant prognostic predictor in ESCC. CAF markers have the potential to be diagnostic and therapeutic targets in ESCC.
Antiobesity and lipid-lowering effects of Bifidobacterium spp. in high fat diet-induced obese rats
Hyang An, Shin Park, Do Lee, Jung Kim, Min Cha, Si Lee, Hyung Lim, Kyung Kim, Nam Ha
Lipids in Health and Disease , 2011, DOI: 10.1186/1476-511x-10-116
Abstract: Thirty-six male Sprague-Dawley rats were divided into three groups as follows: (1) SD group, fed standard diet; (2) HFD group, fed high fat diet; and (3) HFD-LAB group, fed high fat diet supplemented with LAB supplement (B. pseudocatenulatum SPM 1204, B. longum SPM 1205, and B. longum SPM 1207; 108 ~ 109 CFU). After 7 weeks, the body, organ, and fat weights, food intake, blood serum levels, fecal LAB counts, and harmful enzyme activities were measured.Administration of LAB reduced body and fat weights, blood serum levels (TC, HDL-C, LDL-C, triglyceride, glucose, leptin, AST, ALT, and lipase levels), and harmful enzyme activities (β-glucosidase, β-glucuronidase, and tryptophanase), and significantly increased fecal LAB counts.These data suggest that Bifidobacterium spp. used in this study may have beneficial antiobesity effects.Obesity, a condition in which an abnormally large amount of fat is stored in the adipose tissue, resulting in an increase in body weight, is one of the major public health problems in the United States and other developed countries. In general, it is accepted that obesity results from disequilibrium between energy intake and expenditure [1], and this condition has a great impact on several metabolic and chronic ailments including heart disease, cancer, arthritis, obstructive sleep apnea, hypertension, hyperlipidemia, and type 2 diabetes associated with insulin resistance [2]. To date, pharmacological treatments do not appear to be effective in producing sustained long-term weight loss [3]. Therefore, further research is needed to discover new drug therapies that can be used to reduce the prevalence of obesity.Probiotics are defined as viable microbial dietary supplements that exert beneficial effects on host health [4]. Probiotics have attracted public attention because of their potential effectiveness for both the prevention and the treatment of immune diseases [5]. In addition, recent experimental studies have demonstrated the preventive eff
High Yield Production and Refolding of the Double-Knot Toxin, an Activator of TRPV1 Channels
Chanhyung Bae, Jeet Kalia, Inhye Song, JeongHeon Yu, Ha Hyung Kim, Kenton J. Swartz, Jae Il Kim
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0051516
Abstract: A unique peptide toxin, named double-knot toxin (DkTx), was recently purified from the venom of the tarantula Ornithoctonus huwena and was found to stably activate TRPV1 channels by targeting the outer pore domain. DkTx has been shown to consist of two inhibitory cysteine-knot (ICK) motifs, referred to as K1 and K2, each containing six cysteine residues. Beyond this initial characterization, however, the structural and functional details about DkTx remains elusive in large part due to the lack of a high yielding methodology for the synthesis and folding of this cysteine-rich peptide. Here, we overcome this obstacle by generating pure DkTx in quantities sufficient for structural and functional analyses. Our methodology entails expression of DkTx in E. coli followed by oxidative folding of the isolated linear peptide. Upon screening of various oxidative conditions for optimizing the folding yield of the toxin, we observed that detergents were required for efficient folding of the linear peptide. Our synthetic DkTx co-eluted with the native toxin on HPLC, and irreversibly activated TRPV1 in a manner identical to native DkTx. Interestingly, we find that DkTx has two interconvertible conformations present in a 1:6 ratio at equilibrium. Kinetic analysis of DkTx folding suggests that the K1 and K2 domains influence each other during the folding process. Moreover, the CD spectra of the toxins shows that the secondary structures of K1 and K2 remains intact even after separating the two knots. These findings provide a starting point for detailed studies on the structural and functional characterization of DkTx and utilization of this toxin as a tool to explore the elusive mechanisms underlying the polymodal gating of TRPV1.
Effects of Li+ Codoping on the Optical Properties of SrAl2O4 Long Afterglow Ceramic Phosphors
Timur Sh. Atabaev,Hong Ha Thi Vu,Mac Kim,Yong Suk Yang,Hyung-Kook Kim,Yoon-Hwae Hwang
Advances in Optics , 2014, DOI: 10.1155/2014/459065
Abstract: Rare-earths codoped long afterglow strontium aluminate phosphors with high brightness were synthesized via a facile combustion synthesis method using urea as a fuel. The resulted phosphor particles were analyzed by using X-ray diffraction and field emission scanning electron microscope, whereas their optical properties were monitored by photoluminescence spectroscopy. The prepared SrAl2O4:Eu2+, Dy3+, Li+ samples showed a broad green-yellowish emission, peaking at 512?nm when excited by 348?nm. Compared to traditional SrAl2O4:Eu2+, Dy3+ phosphor, the initial luminescence brightness of SrAl2O4:Eu2+, Dy3+, codoped with Li+ improved from 1.89?cd/m2 to 2.71?cd/m2 and the afterglow decay time was prolonged from 103 to 121?min. The possible mechanism of SrAl2O4:Eu2+, Dy3+, Li+ phosphorescence enhancement has been discussed. 1. Introduction Long afterglow phosphor is a kind of energy-storing material, which can absorb the light photons, store the energy, and then release the energy as visible light. Alkaline aluminates based phosphor materials generally generate more defect-related traps when they are doped with rare-earths RE. The luminescence emission of these RE-doped alkaline aluminates is strongly dependent on the host lattice and can occur from the ultraviolet to the red region. For example, CaAl4O7:Eu2+, Dy3+ phosphors exhibited a broad blue emission band with the main peak at 445?nm [1]. The emission colour of MgAl4O7:Eu2+, Dy3+ nanoparticles shifts from bluish (700°C) to reddish (900°C) with increasing calcination temperature [2]. Recently, strontium aluminates activated with rare-earths have attracted a lot of attention since they exhibit excellent properties such as long afterglow time, high quantum efficiency, good phase stability, and bright emitting color [3], when compared with known sulfide long afterglow phosphors. Since the lifetime greatly exceeds that of any other material, this offers an unexpectedly large field of applications for the use of these aluminates [4, 5]. Although many studies have examined the optical properties of RE-doped alkaline aluminates, only a few have investigated the codoping of three or more different ions in the same host material. It is also known that optical properties of phosphorescent materials are strongly influenced by the incorporation of auxiliary activators. Among them, smaller cationic radius of Li+ ions are favored for their movement and site occupation in the host matrix and these advantages make them attractive for tailoring the crystal field of host lattice [6]. There are many reports on significant
Associated factors for a hyperechogenic pancreas on endoscopic ultrasound
Cheol Woong Choi, Gwang Ha Kim, Dae Hwan Kang, Hyung Wook Kim, Dong Uk Kim, Jeong Heo, Geun Am Song, Do Youn Park, Suk Kim
World Journal of Gastroenterology , 2010,
Abstract: AIM: To identify the associated risk factors for hyperechogenic pancreas (HP) which may be observed on endoscopic ultrasound (EUS) and to assess the relationship between HP and obesity.METHODS: From January 2007 to December 2007, we prospectively enrolled 524 consecutive adults who were scheduled to undergo EUS. Patients with a history of pancreatic disease or with hepatobiliary or advanced gastrointestinal cancer were excluded. Finally, 284 patients were included in the analyses. We further analyzed the risk of HP according to the categories of visceral adipose tissue (VAT) and subcutaneous adipose tissue in 132 patients who underwent abdominal computed tomography scans.RESULTS: On univariate analysis, age older than 60 years, obesity (body mass index > 25 kg/m2), fatty liver, diabetes mellitus, hypertension and hypercholesterolemia were identified as risk factors associated with HP (P < 0.05). On multivariate analysis, fatty liver [P = 0.008, odds ratio (OR) = 2.219], male gender (P = 0.013, OR = 2.636), age older than 60 years (P = 0.001, OR = 2.874) and hypertension (P = 0.044, OR = 2.037) were significantly associated with HP. In the subgroup analysis, VAT was a statistically significant risk factor for HP (P = 0.010, OR = 5.665, lowest quartile vs highest quartile).CONCLUSION: HP observed on EUS was associated with fatty liver, male gender, age older than 60 years, hypertension and VAT.
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