• Journal of Life Science
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• v.33 no.7
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• pp.555-564
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• 2023

In this study, the anti-oxidant activity, elastase inhibitory activity, and skin moisturizing effect of mixed extracts of Acanthopanax senticosus and Citrus unshiu fermented with Bovista plumbea (B-MEAC) were evaluated to verify the availability as a material for inner beauty. The DPPH radical scavenging activity of B-MEAC was showed in a dose-dependent manner (SC₅₀=156.1±0.82 ㎍/ml). Also, B-MEAC inhibited the elastase activity in a concentration-dependent manner (p<0.001). To study the effect of B-MEAC on mouse skin hydration, skin moisture content and transepidermal water loss (TEWL) measured. As a result, skin moisture content increased (p<0.001) and TEWL decreased (p<0.01) compared to the dry-induced control group. The effect on the change of collagen fibers in the dry-induced mouse skin was examined through Masson's trichrome staining. In the group administered with B-MEAC, the amount of collagen relatively increased compared to the control group, and the intensity of blue color increased. The effect on the moisturizing function of the dry-induced mouse skin was examined by Western blot method. In the group administered with B-MEAC, the expression of matrix metalloproteinase-1 (MMP-1) protein decreased compared to the control group. In addition, the expression level of collagen1A1 (COL1A1), hyaluronan synthase-2 (HAS2), filaggrin, and aquaporin-3 (AQP3) recovered (p<0.001). Therefore, these results suggest the potential of B-MEAC as a skin hydration agent for inner beauty.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.10
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• pp.1454-1459
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• 2017

In spite of continuous increase of electric power demand and new generation plants, it is very difficult to install new transmission line. Therefore, it comes to be difficult to operate the power system stable, so it is required to find another way to get new transmission capacity. Because HVDC transmission system installation is the one of the best option for us, we have undertake the HVDC project in mainland. Buckdangjin-Goduck HVDC project(500kV, 3GW) is currently under construction and Eastern Power HVDC project(500kV, 8GW) is under the study for technical specification. Both of them have the Run-up SPS function for taking action of 765kV Transmission line fault. The Run-up SPS function increases the active power output of the HVDC rapidly when the transmission line between the power plant and network is tripped, thereby preventing the generator from overspeed and improving the power system stability. In this paper, we propose MEAC(Modified Equal Area Criteria) method based on traditional EAC method to quantitatively evaluate the effect of the HVDC run-up SPS function on the power system stability improvement.

• Korean Medical Education Review
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• v.20 no.1
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• pp.20-31
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• 2018

Good assessment is crucial for feedback on curriculum and to motivate students to learn. This study was conducted to perform item analysis on the Medical Education Assessment Consortium clinical knowledge mock examination (MEAC CKME) (2011-2016) and to evaluate several effects to improve item quality using both classical test theory and item response theory. The estimated difficulty index (P) and discrimination index (D) were calculated according to each course, item type, A (single best answer)/R (extended matching) type, and grading of item quality. The cut-off values used to evaluate P were: >0.8 (easy); 0.6-0.8 (moderate); and <0.6 (difficult). The cut-off value for D was 0.3. The proportion of appropriate items was defined as those with P between 0.25-0.75 and D ${\geq}0.25$. Cronbach ${\alpha}$ was used to assess the reliability and was compared with those of the Korean Medical Licensing Examination (KMLE). The results showed the recent mean difficulty and decimation index was 0.62 and 0.20 for the first MEAC CKME and 0.71 and 0.19 for the second MEAC CKME, respectively. Higher grade items evaluated by a self-checklist system had better D values than lower grade items and higher grade items gradually increased. The preview and editing process by experts revealed maintained P, decreased recall items, increased appropriate items with better D values, and higher reliability. In conclusion, the MEAC CKME (2011-2016) is deemed appropriate as an assessment to evaluate students' competence and prepare year four medical students for the KMLE. In addition, the self-checklist system for writing good items was useful in improving item quality.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.297-300
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• 1999

The protonation constants of the macrocyclic ligands, 1,4-dioxa-7,10,13,16-tetraaza-cyclooctadecane-N,N',N",N"'-tetra(acetic acid) [N-ac4[18]aneN402] and 1,4-dioxa-7,10,13,16-tetraazacyclooctadecane-1,4-dioxa-7,10,13,16-N,N',N",N"'-tetra(methylacetic acid) [N-meac4[18]aneN4O2] have been determined by using potentiometric method. The protonation constants of the N-ac4[18]aneN4O2 were 9.31 for logK1H, 8.94 for logK2H, 7.82 for logK3H, 4.48 for logK4H and 2.94 for logK5H. And the protonation constants of the N-meac4[18]aneN4O2 were 9.34 for logK1H, 9.13 for logK2H, 8.05 for logK3H, 5.86 for logK4H, and 3.55 for logK5H. The stability constants of complexes on the divalent transition ions (Co2+, Ni2+, Cu2+, and Zn2+) and tiivalent metal ions (Ce3+, Eu3+, Gd3+, and Yb3+) with ligands N-ac4[18]-aneN4O2 and N-meac4[18]aneN4O2 have been obtained from the potentiometric data with the aid of the BEST program. The three higher values of the protonation constants for synthesized macrocyclic ligands correspond to the protonation of nitrogen atoms, and the fourth and fifth values correspond to the protonation of the carboxylate groups for the N-ac4[18]aneN4O2 and N-meac4[18]aneN4O2. The meatal ion affinities of the two tetra-azamacrocyclic ligands with four pendant acetate donor groups or methylacetate donor groups are compared. The effects of the metal ions on the stabilities are discussed, and the trends in stability constants resulting from changing the macrocyclic ring with pendant donor groups and acidity of the metal ions.

• Journal of The Korean Dental Society of Anesthesiology
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• v.13 no.4
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• pp.167-178
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• 2013

Oxycodone is a semi-synthetic opioid synthesized from poppy-derived thebaine. It is a narcotic analgesic generally indicated for relief of moderate to severe pain. Although developed in an attempt to improve on the existing opioids, the adverse effects of oxycodone are those that are typically found in opioids. In recent years, the use of the opioid oxycodone has increased markedly and replacing morphine as the first line choice of opioid in several countries. There are formulations for oral immediate, oral extended release and intravenous use. In 2013, intravenous oxycodone was approved for marketing by Ministry of Food and Drug Safety (MFDS), with the indication of postoperative intravenous patient-controlled analgesia (IV PAC). Simulation study of oxycodone demonstrated that minimum effective analgesic concentration (MEAC) of oxycodone was most quickly reached with higher loading dose and IV PCA with background infusion, which may reduce the necessity of rescue analgesics during immediate postoperative period. Previous studies for postoperative pain management with intravenous oxycodone are limited in sample size, mostly less than 100 patients, which may not be large enough to assess safety of intravenous oxycodone. The effectiveness and tolerability of IV PCA with oxycodone should, therefore, be evaluated in large scale clinical trials in Korean populations.