• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.1
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• pp.40-46
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• 2012

Cigarette smoking is known to be associated with various chronic pulmonary and cardiovascular diseases ranging from inflammation to cancer. Not only first-hand smoke but also second-hand smoke is suggested to be a factor of health risk. This study was to investigate whether Platycodi Radix extract administration would alter oxidative stress in lung leading to protection of cigarette smoke-induced lung damage. Sprague-Dawley rats were randomly divided into 3 groups; Intact, Smoke+PR and Smoke+Vehicle. In Smoke+PR and Smoke+Vehicle group, the exposure to cigarette smoke was performed for 15 min/day for 4 weeks in ventilated smoking chamber. The Platycodi Radix extract and saline were orally administrated to Smoke+PR and Smoke+Vehicle group each. The rats of Intact group were just kept in ventilated chamber without cigarette smoke. After the experiment for 4 weeks, the lung tissues were collected for histological observation and immunohistochemistry. In Results, airspace enlargement and goblet cell hyperplasia were observed after 4 weeks' exposure to cigarette smoke. Whereas, the oral administration of Platycodi Radix extract for 4 weeks reduced airspace enlargement and goblet cell hyperplasia. Moreover, the alterations of BAX/Bcl-2 proteins in lung tissues were observed. These results suggest that Platycodi Radix extract ameliorates lung damage in cigarette smoke-exposed rats and has protective effects on second-hand smoke injury.

• Preventive Nutrition and Food Science
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• v.2 no.2
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• pp.138-143
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• 1997

Crude catechin extracts were prepared using ethyl acetate from Korean Puerariae Radix (PR) and their biological effects on the alcoholic liver damage were investigated in male Sprague-Dawley rats (6 weeks old). Ethanol (5g ethanol/kg body weight/day) administration was performed for 8 weeks and after ethanol consuming rats were treated with one or two% catechin extracts of diet for 8 weeks. At the end of experimental period, lipid hydroperoxides in liver were analyzed using a chemiluminescence-high performance liquid chromatography (CL-HPLC) method. Compared with control animals, ethanol consumed rats showed lighter body weights, lower ratios of liver/body weight, higher activities of GOT and GPT, and increased lipid hydroperoxide amount in liver. With one or two% catechin extracts treatment, GOT and GPT activities returned to normal ranges. Lipid hydroperoxide contents in liver of on or two% PR treated rats lowered to 20% or 25% respectively, compared with the levels of those ethanol consumed animals without catechin extracts treatment. Therefore, we concluded that on or two% PR crude catechins treatment could be effective for alcoholic liver damage caused by lipid peroxidation.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.281-292
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• 1997

The objective of this study was to compare retrospectively the survival and pregnancy rates(PR) of cryopresered-thawed embryos obtained from intracytoplasmic sperm injection (ICSI) or conventional in vitro fertilization (IVF). Ninety-six cycles of cryopresered-thawed embryo transfer (ET) were performed in 79 patients from June, 1996 to September, 1997 and grouped as followings: 20 cycles (16 patients) inseminated by ICSI (ICSI Group) and 76 cycles (63 patients) by conventional IVF (IVF Group). Slow-freezing and rapid-thawing protocol was used with 1.5M propanediol (PROH) and 0.1M sucrose as cryoprotectant. All embryos were frozen-thawed at the two pronuclear (2 PN) stage excluding four cycles in which the early cleavage stage embryos were frozen, and allowed to cleave in vitro for one day before ET. The duration from freezing to thawing was comparable in both groups ($mean{\pm}SD$, $112.1{\pm}80.0$ vs. $124.8{\pm}140.1$ days). The age of female ($31.2{\pm}3.4$ vs. $32.6{\pm}3.3$ years) and the endometrial thickness prior to progesterone injection ($9.4{\pm}2.0$ vs. $9.3{\pm}1.8$ mm) were also comparable in both groups. There was no significant difference in the outcomes of cryopreserved-thawed ET between two groups: survival rate ($85.2{\pm}16.1%$ vs. $82.2{\pm}19.7%$), cleavage rate ($96.9{\pm}6.7%$ vs. $94.7{\pm}13.0%$), cumulative embryo score (CES, $54.5{\pm}31.1$ vs. $49.0{\pm}20.0$), preclinical loss rate (5.0% vs. 5.3%), clinical miscarriage rate (0% vs 29.4%), clinical PR per transfer (35.0% vs. 22.4%), implantation rate (9.9% vs. 5.6%), and multifetal PR (42.9% vs. 17.6%). In conclusion, human embryos resulting from ICSI can be cryopreserved-thawed and transferred successfully, and the survival rate and PR are comparable to conventional IVF.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.9 no.1
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• pp.16-26
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• 2002

Purpose: This study was done to investigate the effect of foot reflexology on vital signs, general fatigue, mood and foot fatigue in cancer patients receiving chemotherapy. Method: Data were collected from a convenience sample of 11 patients who were admitted at S and E University Hospital. Changes in systolic blood pressure (SBP), diastolic blood pressure(DBP), pulse rate(PR), general fatigue, mood status, and foot fatigue between pre and post foot reflexology were analyzed using Wilcoxon signed rank test and Friedman test at 0.05 level of significance. Results: There were significant differences in the SBP(p= .009), DBP(p=.014), PR(p=.015), general fatigue (p=.015) mood status(p=.007), and foot fatigue(p= .007) between pre and post foot reflexology. Conclusion: Foot reflexology can improve vital signs, general/foot fatigue and mood status, therefore we recommend to use foot reflexology as an effective nursing intervention in cancer patients receiving chemotherapy.

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.207-211
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• 1993

The CO substitution reactions in the complex, $Cp(S-C_5H_7)CrCO$ with $PR_3(PR_3=PMePh_2,\;P(OCH_3)_3,\;PMe_2Ph)$ were investigated spectrophotometrically at various temperatures. From the reaction rates, it was suggested that the CO substitution reaction takes place by first-order (dissociative) pathway. Activation parameters in decaline are ${\Delta}H^{\neq}\;=\;24.58\;kcal\;{\cdot}\;mol^{-1},\;{\Delta}S^{\neq}\;=\;3.05 cal\;{\cdot}\;mol^{-1}{\cdot}K^{-1}$. Unusually low value of ${\Delta}S^{\neq}$ suggests an ${\eta}^5-S\;{\to}\;{\eta}^5-U$ conversion of the pentadienyl ligand. This was confirmed by the extended-Huckel molecular orbital (EHMO) calculations, which revealed that the total energy Of $Cp(S-C_5H_7)CrCO$ is about 6.84 kcal/mol more stable than that of $Cp(U-C_5H_7)CrCO$ and the energy of $[Cp(U-C_5H_7)CrCO^{\neq}$ transition state is about 4.25 kcal/mol lower than that of $[Cp(S-C_5H_7)Cr]^{\neq}$ transition state.

• Journal of Periodontal and Implant Science
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• v.42 no.3
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• pp.88-94
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• 2012

Purpose: The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. Methods: Thirty-seven identical disks (5 mm in diameter) were investigated in this study. The specimens were divided into eight groups according to the types of instrumentation and the angle of application. Ultrasonic scaling systems were applied on a titanium disk to simulate standard clinical conditions. The equipment included a piezoelectric ultrasonic scaler with a newly developed metallic tip (NS group), a piezoelectric ultrasonic scaler with a conventional tip (CS group), a piezoelectric root planer ultrasonic scaler with a conventional tip (PR group), and a plastic hand curette (PH group). In addition, the sites treated using piezoelectric ultrasonic scaler systems were divided two sub-groups: 15 and 45 degrees. The treated titanium surfaces were observed by scanning electron microscopy (SEM), and the average surface roughness (Ra) and mean roughness profile depth (Rz) were measured with a profilometer. Results: SEM no significant changes in the titanium surfaces in the NS group, regardless of the angle of application. The PH group also showed no marked changes to the titanium surface, although some smoothening was observed. All CS and PR sites lost their original texture and showed irregular surfaces in SEM analysis. The profilometer analysis demonstrated that the roughness values (Ra and Rz) of the titanium surfaces increased in all, except the PH and NS groups, which showed roughness decreases relative to the untreated control group. The Ra value differed significantly between the NS and PR groups (P<0.05). Conclusions: The results of this study indicated that changes in or damage to titanium surfaces might be more affected by the hardness of the scaler tip than by the application method. Within the limitations of this study, the newly developed metallic scaler tip might be especially suitable for peri-implant surface decontamination, due to its limited effects on the titanium surface.

• The Korean Journal of Pharmacology
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• v.31 no.2
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• pp.251-259
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• 1995

Pharmacokinetics and pharmacodynamics of metoprolol, a selective beta-l blocker, were examined for 360 minutes after intravenous bolus administration of metoprolol to 6 dogs. Plasma concentration and excreted amount in the urine metoprolol were measured by liquid chromatography with fluorescence detection. PR interval and heart rate were measured by ECG monitoring. Blood pressure was monitored through intraarterial catheter in femoral artery and cardiac output by thermodilution method using Swan-Ganz catheter. To analyze the effect site concentration-response relationship, plasma concentration and pharmacological effects were simultaneously fitted to a two pharmacokinetic compartment linked to pharmacodynamic model with NONLIN program. Results are as follows. 1) The plasma concentration of metoprolol after intrvenous injection decreased biexponentially. The terminal half-life estimated was $1.33{\pm}0.40$ hours and the volume of distribution at steady state (Vdss) and the total body clearance were $1.04{\pm}0.4\;L/kg,\;6.55{\pm}2.21\;L/hr$, respectively. The central compartment volume of distribution and peripheral compartment volume of distribution were $0.35{\pm}0.14L/kg\;and\;0.69{\pm}0.34L/kg$. The renal clearance and intercompartment clearance were $0.53{\pm}0.25\;L/min\;and\;0.35{\pm}0.19\;L/min$. 2) Simulated biophase concentration-response curve shows hyperbolic relationship and the estimated concentration-effect relationship was best explained by Emax model when the prolongation of PR interval and the reduction of the heart rate were used as pharmacodynamic parameters. Emax and EC50 were estimated to be $26.3{\pm}4.7\;msec\;and\;88.8{\pm}82.3\;g/ml$ for PR interval, and $48.7{\pm}18.8\;beats/min\;and\;113.5{\pm}78.7\;ng/ml$ for heart rate, respectively. 3) The changes of cardiac output-effect site concentration relationship was best fitted by a linear model and the slope of the relationship was $0.005{\pm}0.003$. Diastolic blood pressure-effect site concentration relationship was also explained by the linear model and the slope of the relationship was $0.038{\pm}0.034$.

• Solar Energy
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• v.13 no.2_3
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• pp.120-132
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• 1993

The purpose of this research is to study the characteristics of heat transfer in composite rotary heat pipe as modeled turbine rotating by a finite element analysis and experiment. Nu number, Re number, Pr number and dimensionless condensate layer thickness by thermal input and revolutions per minute were given as analysis factors. The comparison between calculated and experimental data showed similar tendency. Therefore the analysis method may be useful to predict the performance of composite heat pipe. The resistance on heat pipe showed the best effect of heat transfer by film condensation, by decreasing film condensation, the heat transfer rate from condenser was increased rapidly. The dimensionless condensate layer thickness according to Re number at given Pr number showed constant values, the dimensionless condensate layer thickness is proportionate to the square root of inverse of revolution number per minute. In this study Nu=A$({\delta}({\omega}/v)^{-1/2}Re^B)$ is used to the convection heat transfer coefficient and A=0.963, B=0.5025 were obtained as analysis predicts.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.236-243
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• 2015

Objectives: This study sought to examine the association between long working hours and depressive symptoms among interns and residents in South Korea. Methods: We analyzed a cross-sectional survey of 1,661 interns and residents from the 2014 Korean Interns & Residents Survey. Total working hours during the preceding week was assessed and classified into five categories(i.e. less than 60 hours, 60-79 hours, 80-99 hours, 100-119 hours, and 120-168 hours). Depressive symptoms during the previous week were measured by using ten items from the Center for Epidemiologic Studies Depression Scale questionnaire. Multivariate negative binomial regression was applied to examine the association between long working hours and depressive symptoms after adjusting for potential confounders, including medical specialty and training year. All analyses were performed using STATA/SE version 13.0. Results: 86%(N=1,429) of interns and residents worked 60 hours or more per week. Compared to the "less than 60 hours" group, long working hours for interns and residents were significantly associated with depressive symptoms: "60-79 hours"(PR: 1.56, 95% CI: 1.05, 2.32), "80-99 hours"(PR: 2.27, 95% CI: 1.54, 3.33), "100-119 hours"(PR: 2.62, 95% CI: 1.76, 3.89), and "120-168 hours"(PR: 3.28, 95% CI: 2.21, 4.86). Conclusions: This study found that long working hours were prevalent among interns and residents in South Korea, and it was associated with depressive symptoms.

• The Journal of the Convergence on Culture Technology
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• v.6 no.2
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• pp.207-215
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• 2020

The purpose of this study is to examine the effectiveness of PBL in a college AD/PR class. This class was run under the theme of 'Sinchon Regeneration Project' in the 'Seodaemun-gu & University Collaborative Project Program'. As a result of the pre-post surveys, the authors found a significant increase in the place attachment to Sinchon, which was considered as a critical variable in this program. This research is an important study with high practicality in the area of cultural content production education PBL. The PBL teaching method can contribute to enhancing the class satisfaction and strengthening the competitiveness of students in cultural content related majors.