• Journal of the Korean Society of Safety
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• v.20 no.4 s.72
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• pp.34-39
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• 2005

To evaluate characteristics of explosion hazard of Methyl Ethyl Ketone Peroxide, MCPVT was used for this study. In result maximum explosion pressure and maximum explosion pressure rising velocity of MEK-PO were $12.1kgf/cm^2\;and\;106.81kgf/cm^2/s$. As a result or adding metal powder to estimate hazard of explosion, the maximum explosion pressure and maximum explosion pressure rising velocity according to adding Fe powder in MEK-PO increased. In opposite, those decreased resulting in adding Ca powder in MEK-PO.

• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.386-389
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• 2007

본 논문은 $TiO_2$(Degussa, P-25), 바인더(A-9540) 그리고 용제의 배합비율을 바꾸어 코팅액을 제조하여 금속판에 코팅한 후, 고농도의 IPA를 주입하여 분해효율을 고찰하였다. 고형분 함량 비율 변화에서는 $TiO_2$ 함량은 증가하고 바인더가 감소할수록 좋은 효율을 보였고, 용제는 ethanol과 MEK 두 가지 중에 MEK의 분해효율이 좋았다. 용제(MEK)함량 비율 변화에서는 일정량의 용제가 있을 경우 분해효율이 좋았고, 용제함량이 낮아질 경우 코팅액 점도가 높아지고 건조 후에는 표면이 갈라지는 현상을 보였다. 결국, 용제함량 비율 변화는 바인더 함량 실험에도 영향을 주어 1.75:0.25:10일 때 가장 좋은 분해효율을 보였다.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.195-198
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• 2006

Lethal toxin is a critical virulence factor of anthrax. It is composed two protein: protective antigen (PA) and lethal factor (LF). PA binds to specific cell surface receptors and, forms a membrane channel that mediates entry of LF into the cell. LF is a zinc-dependent metalloprotease, which cleaves MKKs [MAPK (mitogen-activated protein kinase) kinases] at peptide bonds very close to their N-termini. In this study, we suggest application of cell-based assays in the early phase of drug discovery, with a particular focus on the use of yeast cells. We constructed MEK1 expression system in yeast to determine LF activity and approached cell-based assay system to screen inhibitors, in which the results covering the construction of LF-substrate in yeast expression vector, expression, and LF-mediated proteolysis of substrate were described. These results could provided the basic steps in design of cell-based assay system with the high efficiency, rapidly and easy way to screening of inhibitors.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.277-285
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• 2007

The adsorption characteristics of multi-component solvent vapors including poorly-adsorbable chemicals such as toluene-xylene-MEK and toluene-MEK-IPA on the activated carbonaceous adsorbents were investigated in a stainless steel fixed bed of 10.2 cm ID and 50 cm in height in order to identify those carbons for eliminating and recovering solvent vapors from industrial emission sources. The used activated carbonaceous adsorbents were pelletized commercial activated carbons and activated carbon fiber. Breakthrough curves and adsorption capacity at atmospheric pressures were obtained. It has been found that non-polar and larger molecules have been adsorbed better than polar and smaller molecules. In special, alcohols and ketones were poorly adsorbed caused by competitive adsorbability in multi-component mixture system. However, it could be overcome by profitable employment of organization of cooperative system which was composed of different porosity activated carbonaceous adsorbents appropriately.

• The Korean Journal of Mycology
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• v.46 no.2
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• pp.161-176
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• 2018

Fungal ${\beta}$-glucan, known to have immunostimulatory and antitumor activities, can be recognized by host immune cells as one of the pathogen-associated molecular patterns (PAMPs). Although there are several reports on the diverse immunostimulatory activities of ${\beta}$-glucan, little is known about the intracellular signal transduction of ${\beta}$-glucan. Stimulation of RAW264.7 macrophage cells with ${\beta}$-glucan from Ganoderma lucidum induced the expressions of dectin-1, toll-like receptor 2 (TLR2), TLR4, and TLR6 at the transcription stage. Treatment with ${\beta}$-glucan also induced inflammatory mediators such as macrophage inflammatory proteins (MIP)-$1{\alpha}$, MIP-$1{\beta}$, MIP-$1{\gamma}$, interleukin (IL)-$1{\beta}$, and tumor necrosis factor (TNF)-${\alpha}$. Treatment of the cells with polymyxin B, an inhibitor of lipopolysaccharides (LPS), blocked the induction of inflammatory mediators in LPS- or ${\beta}$-glucan-stimulated systems. Pretreatment of the cells in our cell culture system with LY294002, a phosphoinositide 3-kinase (PI3K) inhibitor, or U0126, a mitogen-activated protein kinase/extracellular-signal-regulated kinase (MAPK/ERK) kinase (MEK)1/MEK2 inhibitor, led to a reduction in the induction of inflammatory mediators in a concentration-dependent manner. These results show that stimulation of the macrophage cells by ${\beta}$-glucan induced the expressions of both dectin-1 and TLRs. We also found that the PI3K/Akt and MEK pathways were involved in the induction of inflammatory mediators in macrophage cells during intracellular signal transduction of ${\beta}$-glucan.

• Toxicological Research
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• v.30 no.3
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• pp.199-204
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• 2014

The aim of this research was to improve our understanding of human toxicity due to exposure to DMF, MEK, or TOL individually as compared to exposure to DMF-MEK or DMF-TOL mixtures, by comparing $EC_{50}$ values as well as the morphological changes in HepG2 cells treated with these substances. We found that there was marked cell necrosis in the groups treated with mixtures than in those treated with the compounds alone, and that the amount of cell death and the $EC_{50}$ value were more dependent on MEK and TOL than on DMF. Moreover, analysis of the changes in effective concentration curves revealed that MEK had an antagonistic effect on the human toxicity of DMF, whereas TOL had a synergistic effect. Accordingly, these results suggest that in workplaces involved in the manufacture of synthetic leather, mixtures of DMF and TOL should be avoided as much as possible in order to minimize environmental toxicity and protect the health of the workers.

• Advances in Traditional Medicine
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• v.10 no.4
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• pp.254-262
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• 2010

Artemisia capillaris (A. capillaries) is known to play roles in many cellular events, such as cell proliferation, differentiation, and apoptosis. We investigated the antifibrogenic efficacy of A. capillaris in the immortalized human hepatic stellate cell line LX2. Cell proliferation was determined by the MTT assay. Cell cycle was analyzed by the flow cytometry. Apoptotic cells were measured using a cell death detection ELISA. Caspase activity was detected by a colorimetric assay. The mRNA level of Bcl-2 and Bax mRNA were measured by real-time PCR. MEK and ERK protein were detected by Western blot analysis. We provide evidence that A. capillaris induces cell cycle arrest, apoptosis, and potently inhibits the mitogen-activated protein kinase pathway. A. capillaris inhibited cell proliferation of LX2 cells in a dose- and time-dependent manner, increased the apoptosis fraction at cell cycle analysis with an accompanying DNA fragmentation, and resulted in a significant decrease in Bcl-2 mRNA levels and an increase in Bax expression. Exposure of LX2 cells to A. capillaris induced caspase-3 activation, but co-treatment of A. capillaris with the pan-caspase inhibitor Z-VAD-FMK, and the caspase-3 inhibitor Z-DEVE-FMK, blocked apoptosis. A. capillaris down-regulated Mcl-1 protein levels and inhibited phosphorylation of MEK/ERK, suggesting that it mediates cell death in LX2 cells through the down-regulation of Mcl-1 protein via a MEK/ERK-independent pathway.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.2
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• pp.135-144
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• 2001

This study was performed to measure airborne dimethylformamide(DMF), methyl ethyl ketone(MEK) and toluene and their urinary metabolites concentrations and to determine the relationship between airborne and urinary concentration. Airborne samples and their urinary metabolites were measured 98 male workers who work for 8 synthetic leather factories in a portion of Kyoung-In area. Urine samples were collected at end-of-shift to estimate the exposure levels. 1. The concentration of airborne DMF by process was 8.81 ppm for wet-mixing, 15.05 ppm for wet-coating, 6.03 ppm for dry-mixing, 5.58 ppm for dry-coating, 5.37 ppm for printing, and 9.03 ppm for total. There was statistically significant difference by process. Urinary NMF concentrations of wet-mixing, wet-coating, dry-mixing, dry-coating and printing were $90.55mg/{\ell}$, $79.80mg/{\ell}$, $39.86mg/{\ell}$, $25.23mg/{\ell}$, and $38.15mg/{\ell}$, respectively, and total geometric mean was $56.24mg/{\ell}$. There was significant difference by process. 2. The concentration of airborne MEK by process was 1.89 ppm for wet-mixing, 1.96 ppm for wet-coating, 10.33 ppm for dry-mixing, 29.24 ppm for dry-coating, 14.98 ppm for printing, and 4.87 ppm for total. There was statistically significant difference by process. Urinary MEK concentrations of wetmixing, wet-coating, dry-mixing, dry-coating and printing were $0.93mg/{\ell}$, $0.70mg/{\ell}$, $3.29mg/{\ell}$, $3.29mg/{\ell}$, and $1.06mg/{\ell}$, respectively, and total geometric mean was $1.25mg/{\ell}$. There was statistically significant difference by process. Urinary MEK 3. The concentration of airborne toluene by process was 0.35ppm for wet-mixing, 0.42ppm for wet-coating, 2.95ppm for dry-mixing, 11.67ppm for dry-coating, 4.88ppm for printing, 1.24ppm for total. There was statistically significant difference by process. Urinary hippuric acid concentrations of wet-mixing, wet-coating, dry-mixing, dry-coating and printing were 0.24g/g creatinine, 0.21g/g creatinine, 0.34g/g creatinine, 0.52g/g creatinine, and 0.29g/g creatinine, respctively and total geometric mean was 0.28g/g creatinine. There was statistically significant difference by process. 4. No. of exceeded KPEL was 40 workers(40.8%) for DMF(10ppm), 1 worker(1.0%) for MEK(200ppm), and no worker for toluene(100ppm). No. of exceeded KBEI was 62 workers(63.3%) for urinary NMF($40mg/{\ell}$), 29 workers(29.6%) for urinary MEK, 1 worker(1.0%) for urinary hippuric acid. 5. The regression equations were Log(NMF)=0.4094*Log(DMF)+1.3587(r=0.4516) for DMF, Log(MEKU)=0.1859*Log(MEK)-0.0324(r=0.3303) for MEK, Log(HA)=0.2106*Log(Toluene)-0.5685(r=0.4497) for toluene. Synthetic leather factory workers expose to 3 kinds of organic solvents which are DMF, MEK and toluene. Their urinary NMF and MEK levels were higher than their concentration levels through respiratory. It seems that the urinary levels were affected skin absorption for working habit and alcohol intake.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.491-498
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• 2009

We studied to develop high-efficiency removal system of odor and VOCs(Volatile Organic Compounds) from environmental infrastructure facilities and oil refineries, painting facilities and so on. It can replace RTO and RCO. We tried an removal experiment for VOCs (toluene, xylene, benzene, MEK(methyl ethyl ketone), ethanol, formalin etc. and odor compounds (hydrogen sulfide, etc.). In process, as pre-treatment we used the scrubber with vortex flow (Multi-scrone) to remove the hydrophilic VOCs and as post-treatment, used fibrous bio-filter to remove the hydrophobic VOCs. This hybrid system remove with high efficiency both the hydrophilic VOCs and hydrophobic VOCs. And we tried to make this system to be compact. In experiment using Multi-scrone, contact time is 2~3 seconds and absorption scrubbing water is diaphragm-type electrolysis water. hydrophilic VOCs like ethanol and relatively hydrophilic odor compounds like hydrogen sulfide is excellent, these substances has been removed almost completely, respectively 95~99%, 93~97%. And for MEK, formalin also Showed a high removal efficiency, respectively 78~90%, 72~85%. But in experiment using Multi-scrone, the hydrophobic VOCs like BTX showed a low removal efficiency, respectively 16~22%, 12~18%, 8~16%. In hydrophobic VOCs, toluene removal experiment using fibrous bio-filter, early efficiency was low but after 10days, adaptation period showed high efficiency 85~95%. but in the mixed phase, toluene and MEK efficiency reduced 5~10%. this show microorganism treat first MEK easy to remove. The removal efficiency for MEK using the fibrous biofilter was stable, 80~92%. This hybrid system is also high economical efficiency for RTO. This system reduce more than 50% the cost of equipment and maintenance. As a result, we expect this technology is in the limelight as high efficiency treatment of VOCs in mid-low price.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.15 no.1
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• pp.1-28
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• 2011

Objectives: A study on the importance and consistency of pulse-daignosis in the Dongeuibogam Methods: We used Deyeuk Dongeuibogam of Dongeuibogam publishing company from original photographic edition. Results: The frequency of 27 mek (pulse condition) in Dongeuibogam is as in the following. Bumek (Floating pulse) appeared 120(8.9%) times, wanmek (moderate pulse) appeared 28(2%) times, chokmek (running pulse) appeared 7 (0.5%) times, gyumek (hollow pulse) appeared 19 (1.4%) times, saekmek (uneven pulse) appeared 33 (2.4%) times, sapmek (uneven pulse) appeared 51 (3.8%) times, kyulmek (knotted pulse) appeared 18 (1.3%) times, whalmek (slippery pulse) appeared 69 (5.1%) times, chimek (slow pulse) appeared 43 (3.2%) times, demek (intermittent pulse) appeared 13 (1%) times, silmek (replete pulse) appeared 45 (3.3%) times, bokmek (deep-sited pulse) appeared 29 (2.1%) times, neomek (firm pulse) appeared 4 (0.3%) times, hyunmek (taut pulse) appeared 110 (8.1%) times, yumek (soft pulse) appeared 20 (1.5%) times, dongmek (short and rapid pulse) appeared 16 (1.2%) times, kinmek (tense pulse) appeared 67 (5%) times, yakmek (weak pulse) appeared 46 (3.4%) times, semek (thready pulse) appeared 62 (4.6%) times, hongmek (full pulse) appeared 50 (3.7%) times, jangmek (long pulse) appeared 14 (1%) times, sakmek (rapid pulse) appeared 103 (7.6%) times, mimek (indistinctive pulse) appeared 65 (4.8%) times, danmek (short pulse) appeared 16 (1.2%) times, demek (large pulse) appeared 106 (7.9%) times, chimmek (deep pulse) appeared 112 (8.3%) times, heomek appeared 70 (5.2%) times, sanmek (scattered pulse) appeared 14(1%)times. Conclusions: We can know Donguibogam is given on the basis 27mek (pulse condition), because the frequency of 27mek (pulse condition) is high. But there are another expressions. So we can not say that Donguibogam is consistent in expressing mekbub(the way of pulse-diagnosis).