• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.12 s.105
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• pp.1370-1377
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• 2005

The bottom structure of an instrumented capsule is a part which is joined at the receptacle of the flow tube in the reactor in-core. A geometrical change of the bottom structure has an effect on the pressure drop and the vibration of the capsule. The out-pile test to evaluate the structural integrity of the material capsule called 04M-17U was performed by using a single channel and a half core test loop. From the pressure drop test, the optimized diameter of the cone shape's bottom structure which satisfies HANARO's flow requirement (19.6 kg/s) is 71 mm. The maximum displacement of the capsule measured at the half core test loop is lower than 1.0 mm. From the analysis results, it is found that the test hole will not be interfered with near the flow tubes because its displacement due to the cooling water is very small at 0.072 mm. The fundamental frequency of the capsule under water is 9.64 Hz. It is expected that the resonance between the capsule and the fluid flow due to the cooling water in HANARO's in-core will not occur. Also, the new bottom structure of a solid cone shape with 71 mm in diameter will be applicable to the material and special capsules in the future.

• Earthquakes and Structures
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• v.11 no.1
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• pp.83-107
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• 2016

In this study, the response and behavior of machine foundations resting on dry and saturated sand was investigated experimentally. A physical model was manufactured to simulate steady state harmonic load applied on a footing resting on sandy soil at different operating frequencies. Total of (84) physical models were performed. The parameters that were taken into consideration include loading frequency, size of footing and different soil conditions. The footing parameters are related to the size of the rectangular footing and depth of embedment. Two sizes of rectangular steel model footing were used. The footings were tested by changing all parameters at the surface and at 50 mm depth below model surface. Meanwhile, the investigated parameters of the soil condition include dry and saturated sand for two relative densities; 30 % and 80 %. The dynamic loading was applied at different operating frequencies. The response of the footing was elaborated by measuring the amplitude of displacement using the vibration meter. The response of the soil to dynamic loading includes measuring the stresses inside soil media by using piezoelectric sensors. It was concluded that the final settlement (St) of the foundation increases with increasing the amplitude of dynamic force, operating frequency and degree of saturation. Meanwhile, it decreases with increasing the relative density of sand, modulus of elasticity and embedding inside soils. The maximum displacement amplitude exhibits its maximum value at the resonance frequency, which is found to be about 33.34 to 41.67 Hz. In general, embedment of footing in sandy soils leads to a beneficial reduction in dynamic response (displacement and excess pore water pressure) for all soil types in different percentages accompanied by an increase in soil strength.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.245-250
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• 2016

Background: Ginsenosides are the major effective ingredients responsible for the pharmacological effects of ginseng. Malonyl ginsenosides are natural ginsenosides that contain a malonyl group attached to a glucose unit of the corresponding neutral ginsenosides. Methods: Medium-pressure liquid chromatography and semipreparative high-performance liquid chromatography were used to isolate purified compounds and their structures determined by extensive one-dimensional- and two-dimensional nuclear magnetic resonance (NMR) experiments. Results: A new saponin, namely malonyl-ginsenoside Re, was isolated from the fresh flower buds of Panax ginseng, along with malonyl-ginsenosides Rb1, Rb2, Rc, Rd. Some assignments for previously published $^1H$- and $^{13}C$-NMR spectra were found to be inaccurate. Conclusion: This study reports the complete NMR assignment of malonyl-ginsenoside Re, $Rb_1$, $Rb_2$, Rc, and Rd for the first time.

• Journal of Ginseng Research
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• v.34 no.4
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• pp.288-295
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• 2010

Ginsenosides are the principal components responsible for the pharmacological and biological activities of ginseng. Ginsenoside Rd was transformed into compound K using cell-free extracts of food microorganisms, with Lactobacillus pentosus DC101 isolated from kimchi (traditional Korean fermented food) used for this conversion. The optimum time for the conversion was about 72 h at a constant pH of 7.0 and an optimum temperature of about $30^{\circ}C$. The transformation products were identified by thin-layer chromatography and high-performance liquid chromatography, and their structures were assigned using nuclear magnetic resonance analysis. Generally, ginsenoside Rd was converted into ginsenoside F2 by 36 h post-reaction. Consequently, over 97% of ginsenoside Rd was decomposed and converted into compound K by 72 h post-reaction. The bioconversion pathway to produce compound K is as follows: ginsenoside Rd$\rightarrow$ginsenoside F2$\rightarrow$compound K.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.28-33
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• 2014

Background: Panax notoginseng has been used as a general tonic agent to invigorate human body for millennia in China and continued to be used until present. Methods: Some chromatographic methods were performed to isolate pure triterpenoids, and their structures were determined by nuclear magnetic resonance (NMR) experiments. Anti-diabetes activities of isolated compounds were evaluated through their inhibitory activity of protein tyrosine phosphatase 1B (PTP1B) enzyme. Results and Conclusion: Three new dammarane-type triterpenoids, notoginsenoside-LX (1), notoginsenoside-LY (2), and notoginsenoside-FZ (3) together with eighteen known compounds were isolated from the Panax notoginseng leaves. The structure-activity relationship of the compounds with dammaranetype triterpenoids and their PTP1B inhibitory activity were also reported. Results showed that compounds 2, 15, 20, and 21 can significantly inhibit the enzyme activity of PTP1B in a dose-dependent manner, with inhibitory concentration 50 ($IC_{50}$) values of $29.08{\mu}M$, $21.27{\mu}M$, $28.12{\mu}M$, and $26.59{\mu}M$, respectively. The results suggested that Panax notoginseng leaves might have potential as a new therapeutic agent for the treatment of diabetes.

• Korean Journal of Medicinal Crop Science
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• v.24 no.6
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• pp.437-443
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• 2016

Background: Previous phytochemical studies of whole Vernonia cinerea L. plants have identified sesquiterpene lactones, sterols, and triterpenes, which possess anticancer, antifeedant, and antimalarial activities. However, there are no reports of other types of bioactive metabolites. Therefore, the present study aimed to identify phenolic compounds with anti-inflammatory activity in the aerial parts of the plant. Methods and Results: Compounds were isolated from the aerial parts of V. cinerea using a silica and C-18 gel columns and semi-preparative HPLC instrument, and the structures of the compounds were determined using one- and two- dimension nuclear magnetic resonance spectroscopy and mass spectroscopy. The chloroform soluble extracts and isolated compounds were evaluated for their anti-inflammatory potential based on their ability to inhibit nitric oxide production and $TNF-{\alpha}$ induced $NF-{\kappa}B$ activity. Conclusions: Phytochemical study of the aerial parts of V. cinerea led to the isolation of six phenolic compounds. Compound 1 was a major metabolite, and to the best of our knowledge, compounds 2 - 6 were isolated from V.cinerea for the first time. Among the isolates, compounds 1 and 3 exhibited $TNF-{\alpha}$-induced $NF-{\kappa}B$ activity with $IC_{50}$ values of 7.5 and 11.5 M, respectively, and the inhibitory activity of phenyl propanoid compound 3 on $TNF-{\alpha}$-induced $NF-{\kappa}B$ was evaluated for the first time.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.2
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• pp.79-83
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• 2010

Musculoskeletal ultrasonography has been used as a convenient and simple tool for diagnosis of various conditions of orthopaedic diseases for many years. Generally magnetic resonance imaging (MRI) is thought to be the best method to search for anatomical structures or variations. However, for dynamic conditions such as dislocation or subluxation of tendons and nerves, MRI is not superior to ultrasonography, especially dynamic ultrasonography. So we present such a patient with an ulnar nerve subluxation at the elbow who has symtoms mimicking cubital tunnel syndrome diagnosed by dynamic ultrasonography and treated successfully by ulnar nerve anterior transposition and think that dynamic ultrasonography is a useful method for diagnosing dynamic condition such as ulnar nerve subluxation mimicking cubital tunnel syndrome.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.62-62
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• 2003

The native form of serpin (serine protease inhibitor) is kinetically trapped in metastable state. Metastability in these proteins is critical to their biological function. Serpins inhibit target proteases by forming a stable covalent complex in which the cleaved reactive site loop of the serpin is inserted into $\beta$-sheet A of the serpin with concomitant translocation of the protease to the opposite of the initial binding site. Despite recent determination of the crystal structures of a Michaelis protease-serpin complex as well as a stable covalent complex, details on the kinetic mechanism remain unsolved. In this study we constructed several $\alpha$$_1$-antitrypsin variants and examined their kinetic mechanism of loop translocation and formation of protease-serpin complex by stopped-flow experiments of fluorescence resonance energy transfer as well as quenched-flow experiment. We report here the relationship of serpin's conformational switch mechanism with Inhibitory activity. There is little direct correlation between loop insertion rate and inhibitory activity. Rather, disrupting a salt bridge between R196 and E354 accelerates loop translocation even though it impairs the inhibitory activity. Moreover, the serpin's reactive site loop is translocated, at least partially, prior to loop cleavage.

• Journal of Ginseng Research
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• v.41 no.4
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• pp.602-607
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• 2017

Background: Panax ginseng is a traditional herb used for medicinal purposes in eastern Asia. P. ginseng contains various ginsenosides with pharmacological effects. In this study, floralginsenoside A (FGA), ginsenoside Rd (GRD), and ginsenoside Re (GRE) were purified from P. ginseng berry. Methods: Chemical structures of FGA, GRD, and GRE were determined based on spectroscopic methods, including fast atom bombardment mass spectroscopy, ID-nuclear magnetic resonance, and infrared spectroscopy. Inhibitory activities of these compounds on melanogenesis were studied by measuring the expression of protein and melanin content in the melan-a cell line. This inhibitory activity was confirmed by observing pigmentation and tyrosinase activities of zebrafish. Results: GRD, GRE, and FGA were not cytotoxic at concentrations less than $20{\mu}M$, $80{\mu}M$, and $160{\mu}M$ in melan-a cells, respectively. GRD, GRE, and FGA inhibited melanin biosynthesis in melan-a cells by 15.2%, 22.9%, and 23.9% at $20{\mu}M$, $80{\mu}M$, and $160{\mu}M$, respectively. FGA was observed to display the most potent inhibitory effect. In addition, FGA decreased microphthalmia-associated transcription factor protein expression in a dose-dependent manner. Moreover, FGA induced extracellular signal-regulated kinase phosphorylation level in melan-a cells. In addition, melanin pigment content and tyrosinase activity in zebrafish treated with FGA at $160{\mu}M$ were reduced. Conclusion: FGA showed the most potent inhibition of melanogenesis in both in vitro and in vivo studies. This study suggests that FGA purified from P. ginseng may be an effective melanogenesis inhibitor.

• Journal of the Korean Society for Railway
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• v.15 no.2
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• pp.147-153
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• 2012

Precise estimation f a structure's dynamic characteristics is indispensable for ensuring stable dynamic response during life time especially for the structures which can experience resonance such as railway bridges. Especially, concrete track can change the modal properties of the railway bridge, through the contribution of stiffness as well as mass effects, generally only the mass effect is considered in dynamic analysis of the railway bridge. In this paper, static and dynamic behaviors of railway bridge with concrete track were investigated through experimental study. Also, numerical analysis was performed about considering only mass of concrete track and together with stiffness and mass of concrete track. These were compared with experiment value. Numerical analysis value considering together with stiffness and mass of concrete track was similar experiment value. Therefore, when dynamic analysis of railway bridge with concrete track is performed, the contribution of stiffness as well as mass effects for concrete track is considered.