• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.1
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• pp.79-86
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• 1990

A method to determine directly $J_{IC}$ from load-displacement curve without measuring crack growth amount is studied. A method to use key curve in determination of $J_{IC}$ is also considered. The values of $J_{IC}$ obtained from the above methods are compared with that obtained from the ASTM standard test method (E813). By performing experiments using both compact-tension specimen and three-point-bending specimen of a structural alloy steel SCM4, it is shown that the methods proposed here may be used in determination of $J_{IC}$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.709-716
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• 2004

In order to prevent the interface delamination of an plastic IC package in the infrared (IR) soldering process, we tried to reduce stress by parameterization, sensitivity analysis and unconstraint optimization. The design variables of dimensions and material properties are determined among all the possible variables from the parametric study. Their optimized values are determined by applying the unconstraint optimization to the parameterized IC package. The maximum von-Mises stress value decreases greatly by optimum design.

• Biomolecules & Therapeutics
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• v.21 no.3
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• pp.234-240
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• 2013

Monoamine oxidase inhibitors (MAOI) have been widely used as antidepressants. Recently, there has been renewed interest in MAO inhibitors. The activity-guided fractionation of extracts from Angelica keiskei Koidzumi (A. keiskei K.) led to the isolation of two prenylated chalcones, xanthoangelol and 4-hydroxyderricin and a flavonoid, cynaroside. These three isolated compounds are the major active ingredients of A. keiskei K. to inhibit the MAOs and DBH activities. Xanthoangelol is a nonselective MAO inhibitor, and a potent dopamine ${\beta}$-hydroxylase (DBH) inhibitor. $IC_{50}$ values of xanthoangelol to MAO-A and MAO-B were calculated to be 43.4 ${\mu}M$, and 43.9 ${\mu}M$. These values were very similar to iproniazid, which is a nonselective MAO inhibitor used as a drug against depression. The $IC_{50}$ values of iproniazid were 37 ${\mu}M$, and 42.5 ${\mu}M$ in our parallel examination. Moreover, $IC_{50}$ value of xanthoangelol to DBH was calculated 0.52 ${\mu}M$. 4-Hydroxyderricin is a potent selective MAO-B inhibitor and also mildly inhibits DBH activity. The $IC_{50}$ value of 4-hydroxyderricin to MAO-B was calculated to be 3.43 ${\mu}M$ and this value was higher than that of deprenyl (0.046 ${\mu}M$) used as a positive control for selective MAO-B inhibitor in our test. Cynaroside is a most potent DBH inhibitor. The $IC_{50}$ value of cynaroside to DBH was calculated at 0.0410 ${\mu}M$. Results of this study suggest that the two prenylated chalcones, xanthoangelol and 4-hydroxyderricin isolated from A. keiskei K., are expected for potent candidates for development of combined antidepressant drug. A. keiskei K. will be an excellent new bio-functional food material that has the combined antidepressant effect.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.3
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• pp.275-283
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• 2023

This study optimized the vegetable rice porridge preparation process with Israeli carp Cyprinus carpio (VRP-IC). The optimum heating period for Israeli carp paste (IC-P) in a retort was 120 min as per yield results. Response surface methodology was performed with IC-P/[rice (glutinous rice: non-glutinous rice=6:4) (Rice, RI)+vegetable (carrot: zucchini=1:1) (vegetable, VE)] (X₁) and RI/VE (X₂) as independent variables; viscosity (Y₁), hardness (Y₂), amino nitrogen (Y₃), and overall sensory acceptance (Y₄) as dependent variables. Optimum rates of IC-P, RI, and VE were 47.37%, 24.49%, and 28.15%, respectively; predicted multiple response optimum values for the dependent variables were 20,150 mPa·s, 2,002.9 N/m2, 193.1 mg/100 g, and a 6.4 score for Y₁, Y₂, Y₃, and Y₄, respectively. Under optimum conditions, experimental values for Y₁, Y₂, Y₃, and Y₄ were 20,359.8±191.9 mPa·s, 2,015.0±9.6 N/m2, 188.1±4.9 mg/100 g, and a 6.5±0.2 score, respectively, which were not significantly different from the predicted values (P < 0.05). Results of F0 value, viscosity, hardness, volatile odor intensity, and browning suggested that the optimum sterilization period was 25 min. VRP-IC prepared under the optimum conditions was superior to commercial vegetable rice porridges in sensory evaluations.

• Bulletin of the Korean Chemical Society
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• v.23 no.8
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• pp.1116-1119
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• 2002

Monoclonal antibodies have been generated against a generic hapten, ο,ο-diethyl ο-(5-carboxy-2-fluorophenyl) phosphorothioate, for the determination of organophosphorus (OP) pesticides in a class-specific manner. In an indirect competitive enzyme-linked immunosorbent assay (ELISA) format, employing a heterologous coating antigen, these monoclonal antibodies showed desirable properties for use in the class-specific determination, i.e., broad specificity and high sensitivity. The IC50 values of four commonly used ο,ο-diethyl OP pesticides were fairly uniform ranging from 0.1 to 0.3 ㎛/mL. The IC50 values of three ο,ο-dimethyl derivatives were between 0.3 and 1.4 ㎛/mL. These values, together with the limits of detection (LOD), were better, in terms of the specificity and sensitivity, compared with the values obtained previously with polyclonal antibodies.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.421-424
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• 2009

The $JHK_S$ magnitudes of the red giant branch tip (TRGB) and the distance moduli of the nearby dwarf irregular galaxy IC 1613 have been determined from the near-infrared luminosity functions (LFs) of the resolved stars in the galaxy. Applying a Savitzky-Golay filtering, we derived the second derivatives of the LFs, and estimated the apparent magnitudes of the TRGB as $m_J\;=\;19.1$, $m_H\;=\;18.4$, and $m_{Ks}\;=\;18.0$. The mean values of the theoretical absolute magnitudes of the TRGB were measured by using the Yonsei-Yale isochrones with a metallicity range of -2.1 < [Fe/H] < -0.5 and age of 12 Gyr. The derived values of near-infrared TRGB distance moduli for IC 1613 are (m - M) = $24.12{\pm}0.25$, $24.20{\pm}0.44$, and $24.00{\pm}0.52$ for J, H, and $K_S$ bands, respectively.

• Natural Product Sciences
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• v.24 no.2
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• pp.93-98
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• 2018

Medicinal plants are potential sources of anticancer agents screening. A large number of phytochemicals, including triterpenoids, have been reported to have significant cytotoxic effects on cancer cells. From the fruits of Ligustrum japonicum Thunb., thirteen triterpenoids (1 - 13) were isolated and evaluated for their cytotoxic activity against Hela and HL-60 cells. As results, 8 (oleanolic acid) showed significant effects on Hela with $IC_{50}$ values of $5.5{\mu}M$, and moderate effects on HL-60 cells with $IC_{50}$ values of $55.9{\mu}M$. Meanwhile, 10 (oleanderic acid) and 11 ($3{\beta}$-acetoxy-urs-12-en-28-oic acid) exhibited moderate inhibitory effects on Hela with $IC_{50}$ value of 55.0 and $68.8{\mu}M$, respectively. Moreover, 10 showed cytotoxic effect on HL-60 cell line with $IC_{50}$ value of $63.9{\mu}M$. To our knowledge, this is the first report that oleanderic acid was isolated from L. japonicum and investigated in cytotoxic effects on Hela and HL-60 cells.

• Advances in Traditional Medicine
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• v.8 no.1
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• pp.86-92
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• 2008

The aim of the study was to evaluate in vitro antioxidant and cytotoxic activities of the methanolic extracts of leaves of Solanum sisymbrifolium, Solanum anguivi multiflora, Solanum barbisetum and Solanum jasminoides. In the in vitro antioxidant screening using ABTS [2,2'-azino-bis (3-ethylbenzo-thiazoline-6-sulphonic acid) diammonium salt] method, the methanol extracts of Solanum jasminoides, Solanum barbisetum and Solanum anguivi multiflora exhibited potent antioxidant activity with $IC_{50}$ values 31.25 $\pm$ 0.35, 40.33 $\pm$ 0.57 and 54.33 $\pm$ 0.57 ${\mu}g$/ml, respectively. Solanum barbisetum also showed potent activity in DPPH [1,1-diphenyl-2-picryl hydrazyl] method with an $IC_{50}$ value of 55.33 $\pm$ 1.66 ${\mu}g/ml. In the cytotoxicity studies, the methanol extract of Solanum barbisetum exhibited moderate activity against Vero, HEp-2, HeLa and A-549 cell lines with $IC_{50}$ values in the range of 83.30 - 127.30 ${\mu}g$/ml. Solanum anguivi multiflora extract also showed moderate activity against Hep-2 cell line with $IC_{50}$ value of 80.13 ${\mu}g$/ml. Solanum barbisetum possessing both the activities requires further investigation.

• Proceedings of the Ginseng society Conference
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• 1998.06a
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• pp.216-223
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• 1998

Cyclic nucleotide phosphodiesterases (PDEs) represent the unique enzymatic system degrddinf cAMP and cGMP which play a major role in the regulation of cell physiology. To investigate a possible molecular mechanism of ginsenosides, their activities were evaluated on PDEs which are recently described is new therapeutic targets. PDEs are classified into 7 families according to their genes (PDEI to PDE7) and are differently distributed in tissues. The IC50 values of ginsenosides were determined on PDEI to PDE 5 chromatographically isolatetl from bovine aorta. The results show that total ginseng saponin extract preferentially inhibits PDE 1 and PDE4 at concentrations nearby 200 ug/ml. Protopanaxadiol (PPD) fraction acts preferentially on PDE4 with and IC50 value of 100 nlml and inhibits also PDEI and PDE5 at 14 to 2 fold higher concentrations, respectively. Protopanaxatriol (PPT) fraction preferentially inhibits PDE 1 with and IC50 value of 170 ug/ml. Compound Rgl, originated from PPT fraction, and RC3 (5) represent the most active compounds towards PDE 1 with IC50 values around 80 UM. However Rg3 (R), epimer of Rgl (5) has no effect on the various PDEs tested, excepted on PDE3 rich is sligthly sensitive Compound Rbl, originated from PPD, acts on both PDEI and PDE4. It if two fold less active than Rgl and Rg3 (5) on PDEI. Taken together, these results mainly suggest that PDEI and PDE4 inhibitions could be a molecular mechanism which would participate in ginsenoside mechanisms, especially the effect of PPD on blood vessel and on CNS.

• Archives of Pharmacal Research
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• v.28 no.2
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• pp.190-194
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• 2005

In our search for monoamine oxidase (MAO) inhibitors from natural resources, we found that the methanol extract of the roots of Sophora flavescens showed an inhibitory effect on mouse brain monoamine oxidase (MAO). Bioactivity-guided isolation of the extract yielded two known flavonoids, formononetin (1) and kushenol F (2), as active compounds along with three inactive compounds, oxymatrine (3), trifolirhizin (4), and ${\beta}$-sitosterol (5). Formononetin (1) and kushenol F (2) showed significant inhibitory effects on MAO in a dose-dependent manner with $IC_{50}$ values of 13.2 and $69.9\;{\mu}M$, respectively. Formononetin (1) showed a slightly more potent inhibitory effect against MAO-B ($IC_{50}:\;11.0\;{\mu}M$) than MAO-A ($IC_{50}:\;21.2\;{\mu}M$). Kushenol F (2) also preferentially inhibited the MAO-B activity than MAO-A activity with the $IC_{50}$ values of 63.1 and $103.7\;{\mu}M$, respectively.