• The Korean Journal of Physiology and Pharmacology
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• v.5 no.4
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• pp.343-351
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• 2001

This study was undertaken to investigate the mechanism of lipopolysaccharide (LPS) and nitric oxide (NO) as a regulator of vascular smooth muscle cell (VSMC) proliferation. VSMC was primarily cultured from rat aorta and confirmed by the immunocytochemistry with anti-smooth muscle myosin antibody. The number of viable VSMCs were counted, and lactate dehydrogenase (LDH) activity was measured to assess the degree of cell death. Concentrations of nitrite in the culture medium were measured as an indicator of NO production. LPS was introduced into the medium to induce the inducible nitric oxide synthase (iNOS) in VSMC, and Western blot for iNOS protein and RT-PCR for iNOS mRNA were performed to confirm the presence of iNOS. Inhibitors of iNOS and soluble guanylate cyclase (sGC), sodium nitroprusside (SNP) and L-arginine were employed to observe the action of LPS on the iNOS-NO-cGMP signalling pathway. LPS and SNP decreased number of VSMCs and increased the nitrite concentration in the culture medium, but there was no significant change in LDH activity. A cell permeable cGMP derivative, 8-Bromo-cGMP, decreased the number of VSMCs with no significant change in LDH activity. L-arginine, an NO substrate, alone tended to reduce cell count without affecting nitrite concentration or LDH level. Aminoguanidine, an iNOS specific inhibitor, inhibited LPS-induced reduction of cell numbers and reduced the nitrite concentration in the culture medium. LY 83583, a guanylate cyclase inhibitor, suppressed the inhibitory actions of LPS and SNP on VSMC proliferation. LPS increased amounts of iNOS protein and iNOS mRNA in a concentration-dependent manner. These results suggest that LPS inhibits the VSMC proliferation via production of NO by inducing iNOS gene expression. The cGMP which is produced by subsequent activation of guanylate cyclase would be a major mediator in the inhibitory action of iNOS-NO signalling on VSMC proliferation.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.5
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• pp.533-541
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• 2007

The Zienkiewicz-Zhu(Z/Z) error estimate is slightly modified for the hierarchical p-refinement, and is then applied to L-shaped plates subjected to bending to demonstrate its effectiveness. An adaptive procedure in finite element analysis is presented by p-refinement of meshes in conjunction with a posteriori error estimator that is based on the superconvergent patch recovery(SPR) technique. The modified Z/Z error estimate p-refinement is different from the conventional approach because the high order shape functions based on integrals of Legendre polynomials are used to interpolate displacements within an element, on the other hand, the same order of basis function based on Pascal's triangle tree is also used to interpolate recovered stresses. The least-square method is used to fit a polynomial to the stresses computed at the sampling points. The strategy of finding a nearly optimal distribution of polynomial degrees on a fixed finite element mesh is discussed such that a particular element has to be refined automatically to obtain an acceptable level of accuracy by increasing p-levels non-uniformly or selectively. It is noted that the error decreases rapidly with an increase in the number of degrees of freedom and the sequences of p-distributions obtained by the proposed error indicator closely follow the optimal trajectory.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.3-11
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• 2015

Apartment developers consider the initial sales rate as an important indicator for their success of apartment development projects. They tried to achieve a secure level of initial sales rate. In spite of its importance, there is little research on the initial sales rate because of the difficulties in gathering proper data for analysis. This study, however, collects the data in initial sales rates in Su-won from various sources such as construction companies, marketing companies, sales companies and so on. By using this rare data, this study analyses the initial contract rate of apartment and estimates the initial contract rate by sales price. The result of this study shows that important of land area ratio, brand, and distance to park. It is expected that the proposed model will be used for apartment developers in sales planning phase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.8-16
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• 2013

We investigated the effect of red cabbage extract (RCE) on cell death in MDA-MB-231 human breast cancer cells. Cells were cultured in the presence 1.0, 1.5, and 2.0 mg/mL concentrations of RCE for 24 hours. MTT assays demonstrated that mitochondrial dehydrogenase activities decreased in a dose-dependent manner in cells (p<0.05). In contrast, the proportion of dual staining with Hoechst 33342/ethidium bromide (EtBr) for cell death increased in a dose-dependent manner in cells (p<0.05). Flow cytometry assays revealed that cell death caused by an apoptotic program increased in a dose-dependent (p<0.05). Also, increased ROS accumulation in cells, as revealed by DCF-DA staining, was observed in a dose-dependent fashion (p<0.05). The apoptosis suppressor gene Bcl-2 decreased significantly at the mRNA level. Pro-apoptotic genes Bax and caspase-3, genes that are related to the last stage of apoptosis significantly increased. The Bcl-2/Bax ratio which is an important indicator of apoptosis, was found to have significantly decreased dose dependence. These results taken together indicate that the effect of red cabbage extract induces cell death in MDA-MB-231 human breast cancer cells.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.280-285
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• 2011

As the plants grow in a fixed place, they can be a good indicator which reflects the level of environmental pollution. It is necessary for them to develop a strategy to cope with stress under unfavorable environmental conditions. In this study, spindle trees ($Euonymus$ $japonica$) were collected from a clean area (Kijang) as well as a heavily polluted area (Onsan) to check applicability of irradiation combined with plant bioassay to environmental monitoring. The leaves were irradiated with 0, 50 and 100 Gy of gamma rays, and then evaluated for antioxidative capacity with 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and superoxide dismutase (SOD) analysis. The result shows that there was no significant changes in SOD and EDA (Electron Donationg Ability) in the samples collected from a polluted area. In the meanwhile, SOD increased in the samples from a clean area until 6 to 10 hours after irradiation, then it decreased gradually until 24 hours after irradiation. In conclusion, the plants in the polluted area have developed higher resistance to oxidative stress induced by ionizing radiation than those in the relatively clean area. Irradiation combined with plant bioassay on enzymatic activities and free radical scavenging capacity has proven to be a possible tool for biomonitoring the environmental pollution.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.4
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• pp.284-291
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• 2017

There is no doubt that advances in UAV technology have improved military performance. However, these advances require humans to adapt to new and complex operational systems. UAV has been rapidly expanding to a variety of fields such as reconnaissance, transportation, communication and aerial photographing recently. Also, with the development of UAV automation technology, one operator is able to supervisory-control multiple-UAVs. However, as the number of assigned UAV increases, the amount of information increases and this results in the workload of the operator increasing and deterioration in controlling performance. Accordingly, there is a need for a model to determine the level of overload an operator may encounter with regard to multiple-UAV but nationally this kind of research is currently lacking. Therefore, this paper provides an experimental platform for evaluating workload index effectiveness integrating multiple-UAV operational environments, GCS, and eye-tracking system followed by a limited survey of domestic and international studies of multi-UAV overload studies.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.1
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• pp.15-24
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• 2006

This study was conducted to make a rapid and easy determination for the fertility of liquid pig manure as fertilizer by investigating the contents, and correlation coefficients of various nutrients. Samples were collected from 118 local pig farms in the western area of Jeju in Korea. Electrical conductivity(EC), dry matter(DM), $NH_4-N$ and minerals were determined and the relationships among them were examined. The collected liquid manure samples from 118 pig farms were classified according to the level of DM contents ;< 3% (92 farms), $3{\sim}6%$ (18 farms), $6{\sim}9%$ (5 farms) and>9% (3 farms), based on the collected data, most of the liquid manure coming from the local pig farms contain small amount of dry matter. The dry matter contents appeared highly correlated(p<0.01) with EC, $NH_4-N$, T-P, Ca, Mg and Na, except for K. In addition EC was proportional to $NH_4-N$, T-P, Ca, and Na except fer Mg. The fertilizer component ratio of $NH_4-N$, P and K in liquid pig manure were not constant, resulting in low efficiency for fertilizer. However, the toxic heavy metals of Cu etc. were below the criteria of organic fertilizer and soil contamination evaluation. Therefore, we concluded that both dry matter content and electrical conductivity could be used as an indicator for evaluating the fertility of liquid pig manure.

• Biomolecules & Therapeutics
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• v.18 no.3
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• pp.286-293
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• 2010

Cytokine production is a sensitive indicator for monitoring perturbations of the immune system by xenobiotics in animals and humans. In the present study, we evaluated the changes in $IFN{\gamma}$, IL-5 and $TNF{\alpha}$ mRNA expression after atrazine (ATZ), perfluorooctanoic acid (PFOA) or zearalenone (ZEA) exposure in Jurkat cells. The IC50 (concentration for a 50% inhibition of cell proliferation) of PFOA and ZEA after 3 days culture were $226.6\;{\mu}M$ and $52.6\;{\mu}M$, respectively. The effects of ATZ on cytokine expression followed in increasing order of $IFN{\gamma}$>IL-5>$TNF{\alpha}$ at $3\;{\mu}M$ and at the lower concentrations the degree of effects on three cytokines were less clear between the cytokines when compared to control level. PFOA had marked increasing effect in order of $IFN{\gamma}$>$TNF{\alpha}$>IL-5 mRNA expression at IC50, and these patterns were continued at the lower concentrations, IC50/2 and IC50/4. ZEA caused the overexpression of cytokine mRNAs in order of IL-5>$IFN{\gamma}$>$TNF{\alpha}$ at both IC50 and IC50/2, and at IC50/4 the overexpression order was IL-5>$TNF{\alpha}$. On other hand, $IFN{\gamma}$ was less distinct compared to the control. These data indicate that ATZ, PFOA and ZEA caused the overtranscription of $IFN{\gamma}$, IL-5 and $TNF{\alpha}$ mRNA, and the overproduction of these cytokines may eventually lead to immune disorders.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.6
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• pp.415-418
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• 2008

The application of sludge wastes into agricultural fields has been increasing annually in Korea. In particular, sewage sludge application has been widely accepted in decades. Sewage sludge application aid in the recycling of essential nutrients and act as a source of organic matter improving the structure and water-holding properties of the soil. The efficient use of sludge wastes, however, requires an individual assessment of waste products. This study assessed the biological characteristics of organic waste-treated lysimeter soils and develop its indicator to assess the soil health of organic waste-treated lysimeter soils. Several analytical techniques more recently developed such as restriction fragment length polymorphism (RFLP), phospholipid fatty acid (PLFA), and community level substrate utilization (CLSU) fingerprints allow for detailed analyses of soil microbial communities. PLFA and RFLP was, therefore, used in the study to characterize the microbial communities in soil without the need to isolate individual fungi and bacteria. PLFA, RFLP and CLSU have been utilized to assess microbial characteristics of the lysimeter soils with four different sludge wastes for eight consecutive years. Each of these methods was analyzed for a different aspect of soil microbial characteristics. The study would disclose those methods yielded highly reproductive results for each soil and allow distinguishing the soils based on the structures of specific geneand PLFA-pools more than CLSU fingerprints. PLFA methods, especially, revealed the same relative similarities of the treated soils based on cluster analysis of the biological characteristics. Pig manure compost-treated soil, however, was only the same relative resemblance among the three methods. These results indicated that PLFA easily assessed the biological soil characterization.

• The Korean Journal of Nuclear Medicine
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• v.18 no.1
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• pp.1-8
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• 1984

To evaluate the clinical significance of serum tissue polypeptide antigen (TPA) levels in patients with malignancy, serum TP A levels were measured by radioimmunoassay in 49 normal controls, 9 patients of postoperative colon cancer without recurrence and 68 patients with various untreated malignancy, who visited Seoul National University Hospital from February, 1983 to September, 1983. The results were as follows; 1) Serum TPA levels in 49 normal controls were in the range of 22-135 U/L $(74{\pm}28U/L,\;mean{\pm}S.D.)$. There was no sex or age difference. Normal upper limit of serum TPA was defined as 130 U/L (mean+2S.D.). 2) Serum TPA levels in 68 patients with various untreated malignancy (stomach cancer 33 cases, colon cancer 11 cases, lung cancer 10 cases, primary liver cancer 9 cases and metastatic cancer of unknown primary site 5 cases) were in the range of 10-800 U/L $(189{\pm}170U/L,\;mean{\pm}S.D.)$ and significantly elevated, compared with those of normal controls (p<0.005). 3) The sensitivities of serum TPA in various untreated malignancy were 39% in stomach cancer, 55% in colon cancer, 50% in lung cancer, 67% in primary liver cancer and 80% in metastatic cancer of unknown primary site respectively. 4) The sensitivities of serum TPA related to resectability in stomach and colon cancer were 32% in resectable stomach cancer, 50% in unresectable stomach cancer, 29% in resectable colon cancer and 100% in unresectable colon cancer respectively. 5) The mean value of serum TPA levels in 9 patients of postoperative colon cancer without recurrence was $70{\pm}39U/L$ and significantly decreased, compared with that of untreated colon cancer, $180{\pm}150U/L$ U/L (p<0.05). 6) In patients with stomach or colon cancer, there was no significant correlation between serum TP A and serum CEA levels, but simultaneous measurement of serum TPA and serum CEA levels increased sensitivities. From above results, we concluded that serum TPA level is a useful indicator reflecting tumor activity and responses to anticancer treatment in patients with malignancy.