• Steel and Composite Structures
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• v.43 no.2
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• pp.241-256
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• 2022

In this article, an analytical procedure is presented for static analysis of composite cylinders with the geometrically nonlinear behavior, and non-uniform thickness profiles under different loading conditions by considering moderately large deformation. The composite cylinder includes two inner and outer isotropic layers and one honeycomb core layer with adjustable Poisson's ratio. The Mirsky-Herman theory in conjunction with the von-Karman nonlinear theory is employed to extract the governing equations which are a system of nonlinear differential equations with variable coefficients. The governing equations are solved analytically using the matched asymptotic expansion (MAE) method of the perturbation technique and the effects of moderately large deformations are studied. The presented method obtains the results with fast convergence and high accuracy even in the regions near the boundaries. Highlights: • An analytical procedure based on the matched asymptotic expansion method is proposed for the static nonlinear analysis of composite cylindrical shells with a honeycomb core layer and non-uniform thickness. • The effect of moderately large deformation has been considered in the kinematic relations by assuming the nonlinear von Karman theory. • By conducting a parametric study, the effect of the honeycomb structure on the results is studied. • By adjusting the Poisson ratio, the effect of auxetic behavior on the nonlinear results is investigated.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.8 no.1
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• pp.3-8
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• 2022

Alteration of the mGluR5 density is closely related to various brain diseases including schizophrenia, depression, Parkinson's disease, and Alzheimer's disease. Therefore, mGluR5 is considered as a valuable imaging biomarker for brain disease and many radiopharmaceuticals have been developed so far. Among them, [¹⁸F]FPEB has favorable pharmacokinetic characteristics, and this is the most frequently used radiopharmaceutical for preclinical and clinical studies. In the present study, we want to introduce the optimized radiosynthetic method for the routine production of [¹⁸F]FPEB using a GE TRACERlabTM FXFN pro module. In addition, the entire process was monitored with a webcam to solve the problems arising from the synthetic process. As a result, [¹⁸F]FPEB was prepared by nucleophilic substitution from its nitro- precursor at 120℃ for 20 min in dimethyl sulfoxide. Radiochemical yield was 13.7 ± 5.1% (decay-corrected, n = 91) with the molar activity of 84 ± 17 GBq/µmol at the end of synthesis. The radiochemical purity was determined to be above 96%. The manufactured [¹⁸F]FPEB injection for quality controls were carried out in accordance with an KIRAMS approved protocol, as per ICH and USP guidelines.

• Progress in Superconductivity and Cryogenics
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• v.10 no.1
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• pp.19-23
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• 2008

Spherical $MgB_2$ powders was synthesized with the ultrasonic spray pyrolysis(USP) process using aqueous solutions of boron and magnesium ion. The properties of synthesized $MgB_2$ powder were characterized by XRD, SEM and EDS. A small amount of MgO was detected as the secondary phase out of the synthesized powder and the ratios of $MgB_2$ to MgO increased with increasing furnace temperature. The particle size and morphology of $MgB_2$ powder were investigated with varying molar concentration of the boron and magnesium solution and furnace temperature between $600^{\circ}C$ and $1000^{\circ}C$ in $Ar/H_2$. The average particle size of $MgB_2$ showed narrow distribution ranging from 300nm to 400nm. The morphology of particles exhibited mostly spherical shapes and uniform distribution.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1745-1750
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• 2013

A novel green aqueous mobile phase modified with room temperature ionic liquids (RTILs) was employed in the absence of volatile organic solvents or ion-pairing reagents to analyze thiamine, a very polar compound, by reverse phase high performance liquid chromatography (RP-HPLC). Due to its strongly hydrophilic nature, thiamine was eluted near the column dead time ($t_0$) using a mobile phase without adding RTILs or ion-pairing reagents, even if a 100% aqueous mobile phase, which has weak elution power under reverse phase conditions, was used. Thus, 1-ethyl-3-methyl-imidazolium hexafluorophosphate ([EMIM][$PF_6$]), which has the strongest chaotropic effect, was selected as a mobile phase additive to improve retention and avoid baseline disturbances at $t_0$. Various mobile phase parameters such as cation moiety, chaotropic anion moiety, pH and concentration of RTILs were optimized to determine thiamine at the proper retention time. Method validation was performed to assess linearity, intra- and inter-day accuracy and precision, recovery and repeatability; all results were found to be satisfactory. The developed method was also compared to the current official United States Pharmacopoeia (USP) and Korean Pharmacopoeia (KP) methods using an organic mobile phase containing an ionpairing reagent by means of evaluating various chromatographic parameters such as the capacity factor, theoretical plate number, peak asymmetry and tailing factor. The results indicated that the proposed method exhibited better efficiency of thiamine analysis than the official methods, and it was successfully applied to quantify thiamine in pharmaceutical preparations.

• Journal of Digital Convergence
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• v.16 no.8
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• pp.161-167
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• 2018

The purpose of this study is to investigate how the advertising campaign is spreading in social networks, and how the advertising model plays an important role in advertisement diffusion. In order to grasp the diffusion patterns of advertising, a text mining and social network analysis were conducted using the beer brand 'Kloud' as a collection keyword. After analyzing the social data for two months since the on-air of 'Good Body' advertisement, which was the first ad that "Sulhyun" appeared in. After the launch of the ad, Kloud has been mainly associated with keywords such as 'yavis & trendy style', 'beer brand', 'beer matching food', 'luxury beer drinking place', 'leisure trend', and 'SNS activity', etc. In addition, "Sul Hyun" also showed that an advertising model contributes to the spread of advertisement on social media in terms of image transition as well as brand's name and unique selling point.

• Analytical Science and Technology
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• v.31 no.4
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• pp.143-148
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• 2018

Currently, the Korean Pharmacopoeia (KP XI) recommends HPLC and potentiometric titration (which is less specific than HPLC) for the determination of triflusal content in capsules and raw materials, respectively. Additionally, the British Pharmacopoeia (BP 2017) and European Pharmacopoeia (EP 8.0), which include a monograph for triflusal in raw materials only, describe a titration method for the assay. The latest version of the United States Pharmacopoeia (USP 39) and Japanese Pharmacopoeia (JP 17) still have not published monographs for triflusal and its preparations. To improve the specificity and efficacy of the assay, we present an HPLC method to determine triflusal content in both raw materials and capsules. The proposed method was validated in accordance with the requirements of the International Conference on Harmonization. A good linear relationship was achieved for triflusal in the range of $200-1250{\mu}g/mL$ with a coefficient of determination of approximately 0.9996. The relative standard deviations (RSDs) of inter- and intraday precision were 0.73-1.12 % and 0.34-0.51 %, respectively. The recovery percentage of triflusal was in the range of 98.80-101.31 %. Because its system suitability, intermediate precision, and robustness were satisfactory, this method could be suitable for determining triflusal content in raw materials and capsules.

• BMB Reports
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• v.40 no.4
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• pp.501-510
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• 2007

Sex-related genes expressed in vitellogenic ovaries of the giant tiger shrimp, Penaeus monodon, were identified by an EST approach. A total of 1051 clones were unidirectionally sequenced from the 5 terminus. Nucleotide sequences of 743 EST (70.7%) significantly matched known genes previously deposited in the GenBank (E-value <$10^{-4}$) whereas 308 ESTs (29.3%) were regarded as newly unidentified transcripts (E-value >$10^{-4}$). A total of 559 transcripts (87 contigs and 472 singletons) were obtained. Thrombospondin (TSP) and peritrophin (79 and 87 clones accounting for 7.5 and 8.3% of clones sequenced, respectively) predominated among characterized transcripts. everal full length transcripts (e.g. cyclophilin, profillin and thioredoxin peroxidase) were also isolated. A gene homologue encoding chromobox protein (PMCBX, ORF of 567 nucleotides encoding a protein of 188 amino acids) which is recognized as a new member of the HP1 family was identified. Expression patterns of 14 of 25 sex-related gene homologues in ovaries and testes of P. monodon broodstock were examined by RT-PCR. Female sterile and ovarian lipoprotein receptor homologues were only expressed in ovaries whereas the remaining transcripts except disulfide isomerase related P5 precursor and adenine nucleotide translocator 2 were higher expressed in ovaries than testes of P. monodon broodstock. A homologue of ubiquitin specific proteinase 9, X chromosome (Usp9X) revealed a preferential expression level in ovaries than testes of broodstock-sized P. monodon (N = 13 and 11, P<0.05) but was only expressed in ovaries of 4-month-old shrimp (N = 5 for each sex).

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.185-194
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• 2000

Rapid Prototyping(RP) techniques have their unique characteristics according to the working principles: stair-stepped surface of parts due to layer-by-layer stacking, low build speed caused by line-by-line solidification to build one layer, and additional post processing to improve surface roughness, so it is required very high cost to introduce and to maintain of RP apparatus. The objective of this study is to develop a new RP process, Variable Lamination Manufacturing using linear hotwire cutting technique and expandable polystyrene foam sheet as part material(VLM-S), and to investigate characteristics of part material, cutting characteristics by using linear hotwire cutting system and bonding. Experiments were carried out to investigate mechanical properties of part material such as anisotropy and directional tensile strength. In order to obtain optimal dimensional accuracy, surface roughness, and reduced cutting time, addition experiments were performed to find the relationship between cutting speed and cutting offset of hotwire, and heat generation of hotwire per unit length. So, adhesion strength tests according to ASTM test procedure showed that delamination did not occur at bonded area. Based on the data, a clover-shape was fabricated using unit shape part(USP) it is generated hotwire cutting. The results of present study have been reflected on the enhancement of the VLM-S process and apparatus.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.2
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• pp.41-52
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• 2016

PURPOSE: This study was conducted to compare the levels of usage of the superficial neck muscles during head rotation in forward head posture and in multimodal postures for improvement of cervical rotation movement impairment. METHODS: To acquire electromyography (EMG) signals from the sternocleidomastoid (SCM-M), upper trapezius (UPT-M), and the splenius capitis (SPC-M) muscles, 11 subjects practiced right rotation of the head in forward head postures (FHP), upright sitting postures (USP), upright sitting postures with supported arms (SUP), standing postures with the arms leaning against the wall (WSP), and four feet postures (FFP), respectively. RESULTS: The left SCM-M was used significantly more in the FFP compared to the FHP, but not in other postures (p<0.01). The left UPT-M was used significantly more in all postures other than the FHP. The right SPC-M was used significantly more in the FFP (p<0.001) and significantly less (p<0.05) in the SUP compared to the FHP. CONCLUSION: During the rotation of the head, although the usage of the SPC-M significantly decreased in SUP compared to FHP but the usage of the SCM-M and UPT-M did not decrease significantly in other postures compared to FHP. Further research is necessary to prove the hypothesis that special postures may reduce the activity of the superficial neck muscles during head rotation.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.239-247
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• 2011

Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. Simvastatin has good permeability, but it also has low solubility (BCS class II), which reduces its bioavailability. To overcome this problem, a solid dispersion is formed using a spray-dryer with polymeric material carrier to potentially enhance the dissolution rate and extend drug absorption. As carriers for solid dispersion, Gelucire$^{(R)}$44/14 and Gelucire$^{(R)}$ 50/13 are semisolid excipients that greatly improve the bioavailability of poorly-soluble drugs. To avoid any toxic effects of an organic solvent, we used aqueous medium to melt Tween$^{(R)}$ 80 and distilled water. The structural behaviors of the raw materials and the solid dispersion were analyzed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The DSC and PXRD data indicated that the crystalline structure of simvastatin was transformed to an amorphous structure through solid dispersion. Then, solid dispersion-based tablets containing 20 mg simvastatin were prepared with excipients. Dissolution tests were performed in distilled water and artificial intestinal fluid using the USP paddle II method. Compared with that of the commercial tablet (Zocor$^{(R)}$ 20 mg), the release of simvastatin from solid dispersion based-tablet was more efficient. Although the stability study is not complete, this solid dispersion system is expected to deliver poorly water-soluble drugs with enhanced bioavailability and less toxicity.