• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.133-138
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• 2005

Automotive pulleys play a key role in driving the cooling pump, oil pump, air-conditioner and so on by using an engine power. Researches on design processes and technologies of the pulleys can be found in many literatures. On the other hand, the areas related to manufacturing processes of the pulleys have been treated negligently. Vast data extracted from various information systems are transformed, integrated, and summarized to become a special database for helping users make a decision. The database, namely the data warehouse has been popularly used in the marketing and customer management of enterprises and recently applied to improve the design and manufacturing processes. In this study the manufacturing process of pulleys were analyzed through the intensive investigation of shop-floors and the interviews with workers and managers. The defects generated during a manufacturing process were categorized in a few types and the causes of defects examined for extracting the dominant parameters in the setup process for producing pulleys. As the first step to construct the data warehouse for the manufacturing processes of pulleys, authors proposed its architecture focused on the reduction of defect rate during the setup process.

• Journal of Biomedical Engineering Research
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• v.34 no.3
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• pp.111-116
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• 2013

Finite element analysis(FEA) has been extensively applied in the analyses of biomechanical properties of stents. Geometrically, a closed-cell stent is an assembly of a number of repeated unit cells and exhibits periodicity in both longitudinal and circumferential directions. This study concentrates on various parameters of the FEA models for the analysis of drug-eluting biodegradable polymeric stents for application to the treatment of coronary artery disease. In order to determine the mechanical characteristics of biodegradable polymeric stents, FEA was used to model two different types of stents: tubular stents(TS) and helicoidal stents(HS). For this modeling, epigallocatechin-3-O-gallate (EGCG)-eluting poly[(L-lactide-co-${\varepsilon}$-caprolactone), PLCL] (E-PLCL) was chosen as drug-eluting stent materials. E-PLCL was prepared by blending PLCL with 5% EGCG as previously described. In addition, the effects of EGCG blending on the mechanical properties of PLCL were investigated for both types of stent models. EGCG did not affect tensile strength at break, but significantly increased elastic modulus of PLCL. It is suggested that FEA is a cost-effective method to improve the design of drug-eluting biodegradable polymeric stents.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.3
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• pp.381-387
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• 1999

Two experiments were conducted to subdivide threonine (exp. 1) and glycine (exp. 2) requirements of broilers into maintenance and growth requirements. Purified diets containing five graded levels of threonine (exp. 1) and glycine (exp. 2) were fed to growing chicks to estimate threonine (exp. 1) and glycine (exp. 2) requirements for growth and maintenance. A model developed to divide threonine requirement for maintenance from that for growth yielded a requirement for growth of 8.946 mg/g weight gain and 0.341 mg/mg N gain; the maintenance requirement was 0.033 or 0.030 mg per unit of metabolic body size $(Wg^{0.75})$. The plateau of plasma threonine concentration occurred at 279.4 mg threonine intake/day. The total threonine requirement was 289.1 mg/day or 0.69% of the diet, 294.1 mg/day or 0.71% of the diet based on weight gain and nitrogen gain responses, respectively. These estimates were in close agreement with previous estimates of threonine requirements. From the relationship of weight gain to N gain, 5.46% of the retained protein consisted of threonine; the reported threonine content of chick muscle was 4.02%. The glycine requirement for maintenance could not be determined due to failure to obtain data allowing extrapolation to zero response. However, ADG increased slightly up to 0.56% glycine.

• Journal of Korea Soil Environment Society
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• v.3 no.3
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• pp.75-86
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• 1998

This paper is going to show the way we can sample the landfill gases flowing out to the air through final cover soil by using an closed chamber in the field for a short time. In addition, we came to the following results through the application of model with actual measurements. 1) Analyzing changes of concentration in the chamber(H: 10-30cm) every 5 minutes, considering analysis time of gas chromatograph for an half hour. 2) The proportion of $CE_4$to $CO_2$changes rapidly near the surface of final cover soil by the influence of methane oxidation reaction. 3) When flux of landfill gas is F=$10^{-5}$mol/$\textrm{m}^2$.s), methane oxidation reaction has an influence on composition of gases, however there is little influence when F=$10^{-6}$ mol/($\textrm{m}^2$.s).

• Advances in Traditional Medicine
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• v.9 no.1
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• pp.20-38
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• 2009

The objectives of this study were to determine the effect of herb formula HDDM, a modification of Huangdan decoction that has been shown to be effective in the treatment of glomerulonephritis and chronic renal failure, on the blood glucose levels in multiple low doses (MLD; 50 mg/kg for five consecutive days) of streptozotocin (STZ)-treated female B6C3F1 mice. Initial studies were performed to compare diabetes induction in five strains (e.g., B6C3F1, NOD, CD-1, C3H/HeN and C57BL/6) of mice by MLD-STZ, and immune changes following the treatment. The results suggested that the order of susceptibility to diabetes induction was NOD $\approx$ CD-1 > B6C3F1 $\approx$ C3H > C57BL/6. Furthermore, STZ modulation of T cell development, differentiation and activation might play a role in diabetes induction by MLD-STZ treatment. MLD-STZ-induced diabetes in female B6C3F1 mice was moderate, which allowed the evaluation of drug-induced protection or exacerbation of diabetes to be performed. As such, modulation of blood glucose by HDDM, which consisted of Da Huang (Radix Et Rhizoma Rhei), Huang Qi (Radix Astragali Seu Hedysari), Dan Shen (Radix Salviae Miltiorrhizae), Yin Yang Huo (Herba Epimedii), Yi Yi Ren (Semen Coicis or Coix lacryma-jobi), Mai Dong (Radix Ophiopogonis) and Shan Zhu Yu (Fructus Corni), was evaluated in MLD-STZ-treated female B6C3F1 mice. The results suggested that HDDM could lower the blood glucose levels, but it had no immunomodulatory activities. Additionally, HDDM-treated mice exhibited improved glucose tolerance. In conclusion, these studies have suggested that MLD-STZ-induced diabetes in female B6C3F1 mice is a useful model to evaluate drug modulation of diabetes, and that the herb formula HDDM possesses anti-diabetic effects.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3817-3825
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• 2015

Background: The human protein methyl-transferase DOT1L catalyzes the methylation of histone H3 on lysine 79 (H3K79) at homeobox genes and is also involved in a number of significant processes ranging from gene expression to DNA-damage response and cell cycle progression. Inhibition of DOT1L activity by shRNA or small-molecule inhibitors has been established to prevent proliferation of various MLL-rearranged leukemia cells in vitro, establishing DOT1L an attractive therapeutic target for mixed lineage leukemia (MLL). Most of the drugs currently in use for the MLL treatment are reported to have low efficacy, hence this study focused on various natural compounds which exhibit minimal toxic effects and high efficacy for the target receptor. Materials and Methods: Structures of human protein methyl-transferase DOT1L and natural compound databases were downloaded from various sources. Virtual screening, molecular docking, dynamics simulation and drug likeness studies were performed for those natural compounds to evaluate and analyze their anti-cancer activity. Results: The top five screened compounds possessing good binding affinity were identified as potential high affinity inhibitors against DOT1L's active site. The top ranking molecule amongst the screened ligands had a Glide g-score of -10.940 kcal/mol and Glide e-model score of -86.011 with 5 hydrogen bonds and 12 hydrophobic contacts. This ligand's behaviour also showed consistency during the simulation of protein-ligand complex for 20000 ps, which is indicative of its stability in the receptor pocket. Conclusions: The ligand obtained out of this screening study can be considered as a potential inhibitor for DOT1L and further can be treated as a lead for the drug designing pipeline.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.13
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• pp.5265-5271
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• 2015

Background: The effects of plant products on cancer cells has become a field of major importance. Many substancesmay induce apoptosis in anti-cancer treatment. Pectins, a family of complex polysaccharides, and their degradation products may for exasmple exert apoptotic effects in cancer cells. Apples and citrus fruits are the main sources of pectin which can be applied for anti-cancer research. The present study concerned an intact form of pectic-oligoshaccharide named pectic acid (poly galactronic acid). Materials and Methods: Inhibition of cell proliferation assays (MTT), light microscopy, fluorescence microscopy (acridin orange/ethidium bromide), DNA fragmentation tests, cell cycle analysis, annexin PI and Western blotting methods were applied to evaluate apoptosis. Results: The results indicated that pectic acid inhibited cell growth and reduced cell attachment after 24h incubation. This did not appear to be due to necrosis, since morphological features of apoptosis were detected with AO/EB staining and cell cycling was blocked in the sub-G1 phase. Annexin/PI and DNA fragmentation findings indicated that apoptosis frequency increased after 24h incubation with pectic acid. In addition, the data showed pectic acid induced caspase-dependent apoptosis. Conclusions: These data indicate that apple pectic acid without any modification could trigger apoptosis in MDA-MB-231 human breast cancer cells and has potential to improve cancer treatment as a natural product.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.271-272
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• 1998

Contrast-enhanced CT has an important role in the assessment of liver lesions. However, the optimal protocol to get most effective result is not clear. The main principle for deciding injection protocol is to optimize lesion detectability by rapid scanning when lesion-to-liver contrast is maximum. For this purpose, we developed a physiological model of contrast medium enhancement based on the compartment modeling and pharmacokinetics. Blood supply to liver was modeled in two paths. This dual supply character distinguishes the CT enhancement of liver from that of the other organs. The first path is by hepatic artery and the second is by portal vein. It is assumed that only hepatic artery can supply blood to hepatocellular carcinoma (HCC) compartment. It is known that this causes the difference of contrast enhancement between normal liver tissue and hepatic tumor. By solving differential equations for each compartment simultaneously using computer program Matlab, CT contrast-enhancement curves were simulated. Simulated enhancement curves for aortic, hepatic, portal vein, and HCC compartments were compared with mean enhancement curves from 24 patients exposed to the same protocols as simulation. These enhancement curves were in a good agreement. Furthermore, we simulated lesion-to-liver curves for various injection protocols, and analyzed the effects. These may help to optimize the scanning protocols for good diagnosis.

• Journal of Mushroom
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• v.18 no.1
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• pp.10-19
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• 2020

Light is an important factor for cordycepin production in Cordyceps militaris. We investigated the effects of different light-emitting diode (LED) conditions including various LED wavelengths and their combinations on cordycepin production in Cordyceps militaris cultivated in submerged culture. The results of our study showed that the combinations of LED wavelengths were more beneficial than single LED sources for cordycepin production. Among the three tested wavelength combinations, the greatest effects for cordycepin production were observed for the red:blue light combination at the wavelength ratio of 5:5 or 3:7. The optimal culture conditions were 19.2278 h/day of illumination time; 9.19497 g/50 mL of glucose content in the media; and 53.112 h of cultivation time. Our model predicted a maximum yield of 2860.01 ㎍/mL cordycepin. Finally, to verify the calculated maximum, we performed experiments in the culture media representing the obtained optimum combination and the cordycepin yield of 2412.5 ㎍/mL.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.80-86
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• 2017

BACKGROUND: Pesticides is exposed in an aquatic environment and effected to benthic animals. Especially, sediment-associated pesticides is required for determination of sediment toxicity on aquatic organisms. This study was conducted to evaluate the impact of six pesticides (chlorfluazuron, difenoconazole, dithianon, flufenoxuron, flutianil, pendimethalin) on Chironomus riparius in aquatic ecosystems. METHODS AND RESULTS: Chlorfluazuron, difenoconazole, dithianon, flufenoxuron, flutianil and pendimethalin were used as a model compounds, which have a sediment-associated potential ($K_{oc}$>3). Acute and chronic toxicity tests on Chironomus riparius were performed at six concentrations of each pesticide with four replicates of each based on OECD test guideline 235 and 218. The calculated 48-h $EC_{50}$ values of chlorfluazuron, flutianil, pendimethalin, difenoconazole, dithianon and flufenoxuron were 6.72, 2.55, 2.27, 0.77, 0.30 and 0.11 mg/L, respectively. Flufenoxuron was the lowest 48-h $EC_{50}$ value in this study. The No Observed Effective Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC) of flufenoxuron for Chironomus riparius in 28-days test were 30 and $60{\mu}g/kg$, respectively. CONCLUSION: Pesticides of the sediment-associated have the potential effect for Chironomus riparius in aquatic ecosystems. Therefore, sediment toxicity assessment of these pesticides should be further investigated to evaluate the impact to benthic organisms.