• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.624-628
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• 2014

Reverse electrodialysis (RED) is a technique to produce electricity from two feed water that has different salinity. Recently, RED has been considered the attractive technology because this new process has large global potential and possibility to generate energy from abundant but largely unused resources. To make RED an economically attractive technology, the optimization of operation condition should be developed. In this study, we investigate the relation of internal resistance to power density of RED. And the effect of sea water and fresh water flow rate on power density was confirmed. To minimize the internal resistance and to increase power density of RED, the ratio of sea water and fresh water flow rate was optimized. Experimental result show the best performance with $1.30W/m^2$ of power density at 1.7 flow ratio of seawater/freshwater.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.6
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• pp.485-489
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• 2015

Diabetic nephropathy (DN) is the leading cause of end-stage failure of the kidney, but the efficacy of currently available strategies for the prevention of DN remains unsatisfactory. In this study, we investigated the effects of free anthraquinones (FARs) extract, which was extracted from the rhubarb and purified by macroporous resin DM130 with gradient mixtures of ethanol/water as the lelution solvents, in high glucose-cultured glomerular mesangial cells (MCs). The cell proliferation was determined by CCK-8 assay, the levels of TGF-${\beta}1$, CTGF, ColIV and FN proteins in the supernatant of MCs were measured by ELISA assays, and the mRNA levels of these four genes were detected by RT-PCR. The results showed that the increased proliferation of MCs, the mRNA levels and protein expression of TGF-${\beta}1$, CTGF, ColIV and FN induced by high glucose were inhibited after the treatment with the FARs extract. This indicated that FARs extract could inhibit cell proliferation and the expression of main extracellular matrix induced by high glucose in MCs. The FARs extract exhibited potential values for prophylaxis and therapy of DN.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.333-333
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• 2006

We synthesized two novel polynorbornene derivatives, chiral poly(norbornene acid methyl ester) (C-PNME) and racemic poly(norbornene acid n-butyl ester) (R-PNME), which are potential low dielectric constant materials for applications in advanced microelectronic and display devices. Thin films of these polymers deposited on substrates were investigated by structural analyses using synchrotron grazing incidence X-ray scattering, specular reflectivity and ellipsometry. These analyses provided important information on the structure, electron density gradient across film thickness, chain orientation, refractive index and thermal expansion of the polymers in substrate-supported thin films. The structural characteristics and properties of the thin films were first dependent on the polymer chain' tacticity and further influenced by film thickness and thermal annealing.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.309-314
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• 2013

Aim: Brain tumors almost universally have fatal outcomes; new therapeutics are desperately needed and will only come from improved understandins of glioma biology. Methods: Exosomes are endosomally derived 30~100 nm membranous vesicles released from many cell types. Examples from GL26 cells were here purified using density gradient ultracentrifugation and monitored for effects on GL26 tumor growth in C57BL/6j mice (H-2b). Lactate dehydrogenase release assays were used to detect the cytotoxic activity of CD8+T and NK cells. Percentages of immune cells producing intracellular cytokines were analyzed by FACS. Results: In this study, exosomes from murine-derived GL26 cells significantly promoted in vivo tumor growth in GL26-bearing B6 mice. Then we further analyzed the effects of the GL26 cells-derived exosomes on immune cells including CD8+T, CD4+T and NK cells. Inhibition of CD8+T cell cytotoxic activity was demonstrated by CD8+T cell depletion assays in vivo and LDH release assays in vitro. The treatment of mice with exosomes also led to a reduction in the percentages of CD8+T cells in splenocytes as determined by FACS analysis. Key features of CD8+T cell activity were inhibited, including release of IFN-gamma and granzyme B. There were no effects of exosomes on CD4+T cells and NK cells. Conclusion: Based on our data, for the first time we demonstrated that exosomes from murine derived GL26 cells promote the tumor growth by inhibition of CD8+T cells in vivo and thus may be a potential therapeutic target.

• Journal of the Korean GEO-environmental Society
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• v.3 no.1
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• pp.27-36
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• 2002

This study is about the applicability of copper slag as the ground improvement material. By the geo-technical characteristics of the copper slag and by the effect of consolidation and under drainage condition, it is proved that the copper slag can be used for ground improvement material as substitution for sand. As a result of laboratory tests, it was shown that the permeability of the copper slag was similar to that of sands under the vertical drainage condition. In addition, the copper slag showed higher critical hydraulic gradient than that of sand under up-ward vertical flow state. The copper slag has potential safety against piping and it has internal stability of particles. The conclusion is that the copper slag is suitable for drainage and filter material.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.68-73
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• 1995

This study of culturing testicular cell types in vitro has potential to be an invaluable tool for assessing the mechanisms of testicular toxicity, especially those of intragonadal interaction and spermatogenesis. Combined with the Sertoli/germ cell cultures, Leydig cells provide comprehensive and detailed information on the action of testicular toxicants at the level of the testis. Sertoli/germ cell were isolated and incubated well in vitro from 20~30 g rats and Leydig cells from 250~300 g rats. The Sertoli cells isolated from the testis of the SD rats grew into monolayer on about the 2nd~3rd day of culture, an appreciable cell increment being observed between the 4th~5th day. The Leydig cells isolated from the testis of the SD rats grew into a monolayer on about the 3rd-4th day of culture, an appreciable cell increment being observed between the 5th-7th day. These results suggest that Sertoli and Leydig cells can be cultured as a male fertility evaluation method alternative to the in vivo/conventional fertility test method and further study for the physio-chemical determination is needed.

• Herbal Formula Science
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• v.21 no.1
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• pp.177-185
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• 2013

Objectives : Leejung-tang (Lizhong-tang) has been used for treatment of gastrointestinal disorders in Korea. In this study, we performed quantification analysis of five marker components, liquiritin, ginsenoside Rb1, ginsenoside Rg1, glycyrrhizin, and 6-gingerol in Leejung-tang using a ultra performance liquid chromatography- electrospray ionization-mass spectrometer (UPLC-ESI-MS). In addition, we evaluated antioxidant activity of Leejung- tang. Methods : The column for separation of five constituents used a UPLC BEH C18 ($100{\times}2.1mm$, $1.7{\mu}m$) maintained at $45^{\circ}C$. The mobile phase consisted of two solvent systems, 0.1% (v/v) formic acid in H2O (A) and CH3CN (B) by gradient flow. The flow rate was 0.3 mL/min with detection at mass spectrometer. The antioxidative activities conduct an experiment on 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of Leejung-tang. Results : Calibration curves of five marker compounds were acquired with r2 values > 0.99. The amount of the five compounds in Leejung-tang were 0.07 - 0.84 mg/g. The concentration required for 50% reduction (RC50) against ABTS radical was 119.02 ug/mL. In addition, the scavenging against DPPH radical of Leejung-tang was 11.4%, 14.5%, 19.8%, 29.6%, and 49.2% at 25 ug/mL, $50{\mu}g/mL$, $100{\mu}g/mL$, $200{\mu}g/mL$, and $400{\mu}g/mL$, respectively. Conclusions : The established LC-MS/MS method will be helpful to improve quality control of Leejung-tang. In addition, Leejung-tang is a potential antioxidant therapeutic agent.

• The Journal of Korean Medicine
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• v.32 no.3
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• pp.25-34
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• 2011

Objectives: We performed simultaneous determination of five constituents by HPLC in Samul-tang (SMT). Additionally, we investigated the immune-stimulatory potential of SMT on specific cellular and humoral immune responses in ovalbumin (OVA)-immunized mice. Methods: Reverse-phase chromatography using a Gemini C18 column operating at $40^{\circ}C$, and photodiode array (PDA) detection at 190-400 nm, were used for quantification of the five components of SMT. Mobile phase using a gradient flow consisted of two solvent systems. Solvent A was 1.0% (v/v) aqueous acetic acid and solvent B was acetonitrile with 1.0% (v/v) acetic acid. C57BL/6 mice were immunized intraperitoneally with OVA/alum ($100{\mu}g/200{\mu}g$) on days 1, 8, and 15. The extract of SMT (1000 mg/kg) was given to mice orally for 21 days (from day 1 to day 21). At day 22, OVA-, lipopolysaccharide (LPS)- and concanavalin A (Con A)-stimulated splenocyte proliferation and OVA-specific and total antibodies were measured in plasma. Results: Calibration curves were acquired with $r^2$>0.9999, and the relative standard deviation (RSD, %) for intra- and inter-day precision were both less than 3.5%. The recovery was in the range of 95.69-115.12%, with an RSD less than 6.0%. The contents of five components in SMT were 1.08-15.30 mg/g. SMT significantly enhanced Con A-induced splenocyte proliferation in OVA-immunized mice (p<0.01). Also, SMT significantly enhanced OVAspecific IgG, IgG1 and total IgM levels in plasma compared with the OVA-immunized group. Conclusions: The established method will be applied for the quantification of major components and immunestimulating activity in OVA-immunized mouse model of SMT.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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• pp.73-80
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• 2009

Purpose: In order to examine difference in the activity of potential of spinal neurons and cortical neurons according to muscle contraction type in post stroke hemiplegic subjects and healthy subjects, the present study conducted an experiment as follows. Methods: The subjects in the experimental group were 17 left-side hemiplegic subjects (9 female, 8 male; mean age, 63.41$\pm$9.86 years) with the right hand as the dominant hand selected among post stroke hemiplegic subjects, and 17 age matched healthy control subjects (10 female, 7 male; mean age, 64.12$\pm$12.07 years). Movement-related cortical potentials (MRCPs) were measured using surface electromyography and electroencephalography while concentric and eccentric movements were made alternately. Results: As to the pattern of the activity of MRCP, which indicates the activity of motor cortical neurons, we found that the amplitude is high (p<0.01), the length of excitement is short (p<0.01) and the ascending gradient of amplitude to the peak increases (p<0.05) in post stroke hemiplegic subjects' lesion sites different from healthy subjects. Conclusion: The activity of cortical neurons was no difference in activity according to contraction type was observed in post stroke hemiplegic subjects' lesion sites. This suggests that there is no distinction in the activity of cortical neurons between concentric contraction and eccentric contraction. Accordingly, if post stroke hemiplegic subjects' activity of motor cortex is analyzed by measuring MRCPs, it is considered useful in research on neural plasticity or as a ground of clinical effects in the area of physical therapy for the central nervous system.

• Tuberculosis and Respiratory Diseases
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• v.81 no.3
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• pp.198-215
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• 2018

Bronchodilators provide improvements in lung function and reductions in symptoms and exacerbations, and are the mainstay of pharmacological management of chronic obstructive pulmonary disease (COPD). The Global Initiative for Chronic Obstructive Lung Disease strategy recommends the use of a combination of long-acting ${\beta}_2-agonist$/long-acting muscarinic antagonists (LABA/LAMA) as the first-line treatment option in the majority of symptomatic patients with COPD. This review provides an indirect comparison of available LABA/LAMA fixed-dose combinations (FDCs) through discussion of important efficacy and safety data from the key literature, with the objective of providing physicians with a framework for informed decision-making. LABA/LAMA FDCs provided greater benefits compared with placebo and similar or greater benefits compared with tiotropium and salmeterol/fluticasone in improving lung function, dyspnea, health-related quality of life, reducing rescue medication use and preventing exacerbations, although with some variability in efficacy between individual FDCs; further, tolerability profiles were comparable among LABA/LAMA FDCs. However, there is a disparity in the amount of evidence generated for different LABA/LAMA FDCs. Thus, this review shows that all LABA/LAMA FDCs may not be the same and that care should be taken when extrapolating individual treatment outcomes to the entire drug class. It is important that physicians consider the efficacy gradient that exists among LABA/LAMA FDCs, and factors such as inhaler devices and potential biomarkers, when choosing the optimal bronchodilator treatment for long-term management of patients with COPD.