• Bulletin of the Korean Chemical Society
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• v.21 no.9
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• pp.882-890
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• 2000

Ab initio calculations are carried out on protonation equilibria of 5-memberedheteroaromatic aldehydes (5MHAs;heteroatom Y = NH, O, PH,and S and substituentZ = NH2, OCH3, SCH3, CH3, H, Cl, CHO, CN,NO2) at the $MP2}6-31G*$ level. Naturalbond orbital (NBO) analyses show that the optimal localized natural Lewis structures of the protonated aldehydes,(P), are ortho (C3) protonated (for Y = O, PH and S) and N-pro-tonated (for Y = NH) forms in contrast to the standard structural Lewis formula for aldehydes, (R). The delo-calizability of ${\pilone}-pairon$ the heteroatom $(n{\pi}(Y))$ is in the order Y = NH > O > S > PH. The transmission efficiency of (Z) substituent effects to the carbonyl moiety run parallel to the delocalizability of $n{\pi}(Y)$ for R,but is dominantly influenced by the cationic charge on $C{\alpha}(C{\alpha}+)$ for P, which is in the reverse order of thede-localizability of $n{\pi}(Y).$ The Hammett ${\rho}values$ for variation of Z in the protonation are determined by the dif-ference in the transmission efficiencies between Pand R stateat simple interpretation of their magnitude is not warranted. However,the magnitude of the gas-phase ${\rho}z+$ values decreases as the level ofcomputation is raised from RHF/3-21G* to RHF/6-31G* and to $MP2}6-31G*$ but increases again at the MP4SDQ/6-31G* level. Further decrease occurs when solvent effect (water) is accounted for by the SCRF method. Comparison of the SCRF ${\rho}z+values$ with those determined in the aqueous acid solution for Y = S and CHCH shows inadequacy of accounting for the solvent effects on the ${\rho}values$ by a continuum model. It is noteworthy that semiempirical calculations, especially theAM1 method, give even lower magnitude of the gas-phase ${\rho}values.

• YAKHAK HOEJI
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• v.57 no.1
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• pp.24-31
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• 2013

Although statins, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, have been shown to increase melanin synthesis, the exact mechanism of this action is not fully understood. In this study we investigated the possible involvement of intracellular $Ca^{2+}$ signal in the mechanism of stimulation of melanin synthesis induced by lovastatin in B16 cells. Lovastatin stimulated the production of melanin in a dose-dependent manner in the cells. Treatment with mevalonate, FPP and GGPP, precursors of cholesterol, did not significantly suppress the lovastatin-induced melanin production, suggesting that inhibition of cholesterol synthesis may not be involved in the mechanism of the action of lovastatin. In addition, lovastatin did not significantly alter the cAMP concentration and the stimulated production of melanin by lovastatin was not significantly changed by treatment with H89, a potent inhibitor of protein kinase A, which demonstrates that cAMP pathway may not be involved. However, lovastatin increased intracellular $Ca^{2+}$ concentration in a dose-related fashion. Treatment with EGTA, an extracellular $Ca^{2+}$ chelator did not significantly alter the lovastatin-induced intracellular $Ca^{2+}$ increase and melanin synthesis, whereas intracellular $Ca^{2+}$ reduction with BAPTA/AM and intracellular $Ca^{2+}$ release blockers (dantrolene and TMB-8) completely blunted these actions of lovastatin. Taken together, these results suggest that the intracellular $Ca^{2+}$ release may play an important role in the lovastatin-induced stimulation of melanin synthesis in B16 cells. These results further suggest that lovastatin may be useful for the treatment of hypopigmentation disorders, such as vitiligo.

• International Journal of Oral Biology
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• v.46 no.3
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• pp.105-110
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• 2021

The physicochemical properties of crystalline titanium dioxide nanoparticles (TiO₂ NPs) were investigated by comparing amorphous (amTiO₂), anatase (aTiO₂), metaphase of anatase-rutile (arTiO₂), and rutile (rTiO₂) NPs, which were prepared at various calcination temperatures (100℃, 400℃, 600℃, and 900℃). X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses confirmed that the phase-transformed TiO₂ had the characteristic features of crystallinity and average size. The surface chemical properties of the crystalline phases were different in the spectral analysis. As anatase transformed to the rutile phase, the band of the hydroxyl group at 3,600-3,100 cm^-1 decreased gradually, as assessed using Fourier transform infrared spectroscopy (FT-IR). For ultraviolet-visible (UV-Vis) spectra, the maximum absorbance of anatase TiO₂ NPs at 309 nm was blue-shifted to 290 nm at the rutile phase with reduced absorbance. Under the electric field of capillary electrophoresis (CE), TiO₂ NPs in anatase migrated and detected as a broaden peak, whereas the rutile NPs did not. In addition, anatase showed the highest photocatalytic activity in an UV-irradiated dye degradation assay in the following order: aTiO₂ > arTiO₂ > rTiO₂. Overall, the phases of TiO₂ NPs showed characteristic physicochemical properties regarding size, surface chemical properties, UV absorbance, CE migration, and photocatalytic activity.

• Korean Journal of Biological Psychiatry
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• v.28 no.2
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• pp.58-69
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• 2021

Objectives The aim of this study was to examine the association between the sleep pattern, chronotype (midpoint of sleep on free days) and the depressive symptoms in adults aged 19 years and over in Korea. This study also investigated the mediating effect of perceived usual stress (PUS) and self-rated health (SRH) on the association between chronotype and depressive symptoms. Methods Among the subjects of the 7th Korea National Health and Nutrition Examination Survey (KNHANES) 2016 and 2018, 16142 adults aged 19 or over responded to the survey and finally 8604 were analyzed according to the exclusion conditions. Logistic regression analysis was conducted to see the risk of depressive symptoms, suicidal ideation over sleep pattern, chronotype. Finally, mediation analysis was performed in order to clarify how PUS and SRH are associated to chronoytpe and depression. Results After controlling for potential covariates, weekly sleep duration < 5 hours, ≥ 10 hours was associated with depressive symptoms. And late bed time sleeping after am 1:00 and later midpoints of sleep was associated with a higher level of depressive symptoms. Additionally, the PUS and SRH between chronotype and depressive symptoms showed a serial multiple mediation effect. Conclusions Short or long sleep duration, late bed time and later midpoints of sleep on free days are associated with depressive symptoms. Furthermore, the mechanism between chronotype and depressive symptoms needs to be further clarified by identifying the serial multiple mediation effects of PUS and SRH.

• Nutrition Research and Practice
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• v.13 no.2
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• pp.126-133
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• 2019

BACKGROUND/OBJECTIVES: The glycemic index (GI) is a measure of the postprandial glucose response (PPGR) to food items, and glycemic load (GL) is a measure of the PPGR to the diet. For those who need to maintain a healthy diet, it is beneficial to regulate appropriate levels of blood glucose. In reality, what influences the meal GI or GL depends on the macronutrient composition and the physical chemistry reactions in vivo. Thus, we investigated whether different macronutrients in a meal significantly affect the PPGR and the validity of calculated GI and GL values for mixed meals. SUBJECTS/METHODS: 12 healthy subjects (6 male, 6 female) were recruited at a campus setting, and subjects consumed a total of 6 test meals one by one, each morning between 8:00 and 8:30 am after 12 h of fasting. PPGR was measured after each consumed meal and serial finger pricks were performed at indicated times. Test meals included 1) 68 g oral glucose, 2) 210 g rice, 3) rice plus 170 g egg white (RE), 4) rice plus 200 g bean sprouts (RS), 5) rice plus 10 g oil (RO), and 6) rice plus, egg white, bean sprouts, and oil (RESO). The incremental area under the curve (iAUC) was calculated to assess the PPGR. Mixed meal GI and GL values were calculated based on the nutrients the subjects consumed in each of the test meals. RESULTS: The iAUC for all meals containing two macronutrients (RS, RO, or RE) were not significantly different from the rice iAUC, whereas, the RESO iAUC ($2,237.5{\pm}264.9$) was significantly lower (P < 0.05). The RESO meal's calculated GI and GL values were different from the actual GI and GL values measured from the study subjects (P < 0.05). CONCLUSIONS: The mixed meal containing three macronutrients (RESO) decreased the PPGR in healthy individuals, leading to significantly lower actual GI and GL values than those derived by nutrient-based calculations. Thus, consuming various macronutrient containing meals is beneficial in regulating PPGR.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.2
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• pp.1-10
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• 2019

Objectives : The objective of present study is to evaluate anti-inflammatory and anti-allergic effects of Perilla(Perilla frutescens; Labiatae, PF), the roots of Peucedanum praeruptorum(PP) and the root of Scutellaria baicalensis(SB) in vitro and anti-asthmatic effects of mixture of PF, PP and SB(PS) on ovalbumin (OVA)-induced asthma in BALB/c mice. Methods : Anti-inflammatory and anti-allergic effects were observed on the lipopolysaccharide(LPS) treated RAW 264.7 cells through Nitric Oxide(NO) production and RBL-2H3 cells through ${\beta}$-hexosaminidase. Anti-asthmatic effects were observed on the number of inflammatory cells in bronchoalveolar lavage fluid(BALF) and the level of IgE in serum on OVA-induced BALB/c mice. Results : The treatment of PF, PP and SB(12.5, 25, 50, $100{\mu}g/m{\ell}$) resulted in a significant inhibition of NO production in RAW 264.7 cells and mast cell degranulation in RBL-2H3 cells. Oral administration of PS(400mg/kg/day) resulted in a significant reduction in the numbers of eosinophils in BALF and level of IgE in serum. Conclusion : The oral administration of PS is effective in ameliorating the eosinophilic infiltration in vivo and thus can be a good therapeutic candidate for allergic asthma.

• Journal of The Korean Society of Emergency Medicine
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• v.29 no.6
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• pp.603-615
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• 2018

Objective: We analyzed the association between regional weather and temporal changes on the daily occurrence of trauma emergencies and their severity. Methods: In this cross-sectional prospective study, we investigated daily atmospheric patterns in trauma episodes in 1,344 patients in Cheongju city, South Korea, from January 2016 to December 2016 and analyzed the association of trauma occurrence and Injury Severity Scores (ISS) with weather conditions on a daily scale. Results: The mean age of trauma patients was $53.0{\pm}23.8years$ and average ISS was $9.0{\pm}2.0$. Incidence of trauma was positively correlated with average temperature (r=0.512, P<0.001) and atmospheric pressure (r=0.332, P=0.010) and negatively correlated with air pollutants (particulate matter less than $2.5{\mu}m^3$ [PM2.5], r=-0.629, P<0.001; particulate matter less than $10{\mu}m^3$ [PM10], r=-0.679, P<0.001). ISS was not significantly correlated with climate parameters and air pollutants, and variability was observed in the frequency and severity of trauma by time of day (highest occurrence, 16-20 pm; highest ISS, 4-8 am), day of the week (highest occurrence and highest ISS, Saturday), month of the year (highest occurrence, July; highest ISS, November), and season (highest incidence, summer; highest ISS, autumn). Conclusion: The study shows a positive relationship between trauma occurrence and specific weather conditions, such as atmospheric temperature and pressure. There was a negative relationship between concentrations of PM2.5 or PM10, and trauma occurrence. However, no correlation was observed between weather conditions or the concentrations of air pollutants and ISS. In addition, seasonal, circaseptan, and circadian variations exist in trauma occurrence and severity. Thus, we suggest that evaluation of a larger, population-based data set is needed to further investigate and confirm these relationships.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.34 no.2
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• pp.91-98
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• 2021

Objective : The purpose of this study is to report a case of lacquer allergy improved by Korean medicine treatment. Methods : The patient visited our hospital complaining of rash, and pruritus which lasted for 10days after eating lacquer chicken. Considering that patient's symptoms occurred due to food allergen, we prescribed Injinho-tang(Yinchenhao-tang) and acupuncture at Daejang-Junggyeok for 7days. Results : On the 4th day of treatment, pruritus decreased to less than half of the initial treatment, and skin symptoms also improved to a mild level. About a week later, most of the skin symptoms disappeared (Total Objective Symptom score decreased 10 to 3), and subjective symptoms such as pruritus improved to about 30% of the time of the first visit (Total Subjective Symptom score decreased 12 to 3). Conclusions : After 7days of Korean medicine treatment, lacquer tree allergy with skin lesions and pruritus has improved considerably.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.3
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• pp.412-419
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• 2020

The strategic unit communication infrastructure for military command, communications requires a dualized network structure of various communication methods, considering the direction of development, strategic unit and line characteristic. It has been pointed out that MicroWave, which is typical of wireless systems, is inefficient because it operates only with existing technologies. Therefore, it is necessary to analyze the structure, efficiency of the MW transmission system and its effects. It is difficult to transfer efficiently considering wireless environment due to a fixed type of access structure in the existing MW transmission system. Adaptive modulation allows improvement, but with traditional access structures and fixed bandwidth, there is a limit. Following the transmission performance improvement technique considering availability and link distance in the previous study, this paper presented improved packetized MW transmission system structure and variable bandwidth transmission in consideration of adaptive modulation based variable transmission waveform, bandwidth and distance, and performed the analysis in view of the strategic unit and command control circuit.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.9-17
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• 2020

COVID19 is causing many fundamental phenomena all over the world. Since January 2020, the number of confirmed medical examinations has increased significantly worldwide, and the medical systems in each country have become paralyzed. South Korea has taken a proactive approach and is doing well, befitting the name K-Peace Prevention. However, it can be said that there is still a lack of awareness of legal and administrative limits. In this study examines the shortcomings and limitations of the laws relevant to the current infectious disease prevention and management systems from the perspective of criminal policy based on the "Infectious Disease Control and Prevention Act," and comparatively analyzes the laws in advanced countries to propose effective and practical criminal policy response measures for the prevention and control of infectious diseases.