• Journal of the Korea Convergence Society
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• v.11 no.2
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• pp.175-185
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• 2020

The purpose of this study was to investigate the effects of academic stress on academic burnout, the role of academic failure tolerance, and interpersonal stress among college students. The data were collected from 345 undergraduate students from a university in Seoul and were analyzed with a regression analysis and bootstrapping. The results found that first, academic stress affected academic burnout; the more academic stress, the more burnout students experienced. Second, academic stress caused a decreased academic failure tolerance, which then resulted in academic burnout. Third, the mediating effect of the academic failure tolerance on the academic stress and academic burnout was controlled by an interpersonal stress. The present study has significant implications for investigating how the students' personal and social aspects of stress affect academic burnout and suggests appropriate intervention methods.

• Natural Product Sciences
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• v.20 no.4
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• pp.274-280
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• 2014

Six compounds were isolated from the n-BuOH fraction of the aerial parts of Aruncus dioicus var. kamtschaticus including: sambunigrin (1), prunasin (2), aruncide A (3), aruncide C (4), 1-O-caffeoyl-${\beta}$-D-glucopyranose (5), and caffeic acid (6). Their structures were confirmed by comparing the spectral data with those reported in the literature. The isolated compounds (1 - 6) were then examined for their cytotoxic effects towards MCF-7, HL-60, and HeLa cancer cell lines, as well as their DPPH radical scavenging activity. The results indicated that compound 4 possessed the strongest inhibitory effect toward HeLa cell line with $IC_{50}$ value of $5.38{\pm}0.92{\mu}M$. Compound 3 possessed selective cytotoxic activity on HL-60 cells with $IC_{50}$ value of $6.27{\pm}0.17{\mu}M$, compound 5 was found as the best in inhibiting proliferation with $IC_{50}$ value of $2.25{\pm}0.09{\mu}M$, and the other compounds showed significant inhibition with $IC_{50}$ values ranging from 6.10 to $11.27{\mu}M$. Compound 5 also displayed the strongest cytotoxic effect toward MCF-7 cell line ($IC_{50}$ $4.32{\pm}0.15{\mu}M$). Both 5 and 6 demonstrated strong radical scavenging activity ($IC_{50}$ $6.87{\pm}0.03$ and $4.33{\pm}0.22{\mu}M$, respectively). Compounds 1 and 5 were isolated for the first time from this plant.

• The Journal of Korean Physical Therapy
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• v.30 no.5
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• pp.181-186
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• 2018

Purpose: This study investigated the effects of home-based exercise intensity on the aerobic capacity and 1 year re-hospitalization rate in patients with chronic heart failure (CHF). Methods: Forty seven patients with CHF (males 33, females 14, age $61.3{\pm}9.8years$) participated in this study. The patients were allocated randomly to 3 groups in accordance with home-based exercise intensity: no home based exercise (NHE, 40%, n=19), moderate intensity home-based exercise (MIHE, 43%, n=20), and high intensity home based exercise (HIHE, 17%, n=8). All patients completed the symptom-limited cardiopulmonary exercise (CPX) test safely at the cardiac rehabilitation hospital. Results: The NHE group significantly showed lower peak $VO_2$ and a higher $VE/VCO_2$ slope than the MIHE (p<0.05) and HIHE (p<0.01) groups. On the other hand, the NHE group did not show significant differences in the other hemodynamic responses, such as heart rate (HR) max, HR reserve, maximal systolic blood pressure (SBP), and SBP reserve. Nine out of 19 NHE patients (47%) were re-hospitalized related to heart disease and two out of 20 MIHE (10%) patients were re-hospitalized, but nobody in the HIHE group were re-hospitalized within 1 year from the CPX test. Conclusion: In patients with CHF, home-based self-exercise is one of the important factors for reducing the re-hospitalization rate. In addition, improved aerobic capacity is strongly associated with a lower re-hospitalization rate. In particular, re-hospitalized CHF patients showed significant differences in respiratory parameters and hemodynamic parameters compared to the non-re-hospitalized patients.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.16 no.2
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• pp.145-151
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• 2006

Because of the limitations of maximal load tests for $VO_2max$, submaximal tests using cycle ergometer are used for field study in general. This study was conducted to evaluate validity of various submaximal tests using cycle ergometer. This study had been conducted during May to June 2005, which subjects were 15 males and 15 females in twenties. Experiment was performed with restrictive conditions which regulated ambient temperature, noise, and entrance restriction. Submaximal load test protocols including YMCA Protocol (YP), ${\AA}strand$-Rhyming Protocol (ARP), Relative heart ratio Protocol (RP), and Ramp test Protocol (RP) were compared with maximal load test which used gas mask analyser using Bruce Protocol. All submaximal load tests were highly related with maximal load test (Spearman's correlation coefficient > 0.60) with statistical significancy. The highest correlation coefficient with maximal test was found in RP. Three submaximal test results except RP were significantly different with maximal test results (Wilcoxon rank test). All submaximal tests had high validity. The reason why RP had highest validity might be that it represents Korean physical strength and individual differences better than the others. RP using cycle ergometer would make easy to study for physical capacity evaluation and field workload estimation.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.470-477
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• 2014

The purpose of this study was to investigate the association of homocysteine and antioxidant nutrients with obesity in Korean middle aged women. The study subjects included were middle-aged obese women (n=36) whose body mass index (BMI) was greater than $25kg/m^2$. A total of 36 participants were randomly divided into two groups. They were assigned to either the Nutritional Management and Exercise (NME) program or the Exercise Management (EM) program, which were both conducted for 3 months. We measured serum homocysteine, total cholesterol and HDL cholesterol levels of the participant. We also measured the dietary intakes of antioxidant nutrient, cholesterol, body weight, body mass index, blood pressure, and $VO_2$. At the end of both programs, please confirm this change. It was unclear when these measurements were shown to have decreased. The body weight and BMI of NME group were decreased compared to those of EM group. The serum total cholesterol levels of the participants in NME group were significantly decreased, in contrast to EM group. Also, serum homocysteine levels of NME group participants were decreased compared to EM group, but the difference was not statistically significant. In the NME group, there were significant differences in the change of dietary cholesterol and vitamin C intake. These results showed that participating NME program will continuously promote the healthy status of the middle aged obese women, compared to participating only in the EM program.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.481-491
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• 1995

Endovaginal and endorectal receiver only surface coils were designed for MR imaging (MRI) and $^1H$ MR spectroscopy (MRS) for the uterine cervix and the prostate. The shape of endovaginal coil wire was rectangular with round corner. Size of the coil wire was empirically determined for 7cm and 4cm along the long and short axis, respectively. The coil wire loop was supported by acryl handle and bent about $150^{\circ}$ at one side of the loop considering the average angle of the cervix to the vagina. We called this as a "spoon-type endovaginal coil". The wire of the endorectal coil was made of the flexible materials so that the wire loop became long elliptic shape by pushing the acryl handle into the plastic tube for the comfort of patients when the coil was inserted into the cervix. Then, the shape was maintained to be circle by popping out handle. Conventional spin echo (SE) and fast spin echo (FSE) sequences were used as 71 and 72 weighted imaging sequences, respectively. Matrix size was 128~$256{\times}256$. FOVs for surface coil and body coil were 14cm and 24cm, respectively. 3D volume localized in vivo $^1H$ MR spectroscopy of the human cervix and prostate was performed using PRESS or STEAM localization method with the following parameters . TR=3 sec, TE=135 msec for PRESS or 30 msec for STEAM, NEX=2, NS=48, Sl=2048, and SW=2500 Hz. Using home-built endovaginal and endorectal coils, excellent T1- and T2-images were obtained to visualize early cervical and prostate tumors. 3D volume localized in vivo IH MRS was useful to differentiate the cancerous tissue from the normal tissue.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.696-705
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• 2007

Statement of problem: In the Protar articulator, the models are almost parallel with the Camper's plane. The ultrasonic-based ARCUSdigma system is basis for the determination of dynamic function parameters with so-called "articulator related registration". Purpose: The purpose of this study was to compare the sagittal condylar guidance angles found by use of the wax protrusive records in a semi-adjustable articulator(KaVo Protar 7) with those found by use of the Axiograph (ARCUSdigma). 83 volunteers with intact dentition participated in this study after obtainment of informed consent. Material and method: The sagittal condylar guidance angles were measured and estimated statistically by semi-articulator and Axiograph. All the readings were in degrees. No control was used in this project. To test whether there was a significant difference between the 2 independent samples, paired t-test and Kruskal-Wallis test were carried out(p=.05). Results: 1. The mean results for the wax protrusive records were as follow: right side (32.65 degrees, SD 16.48); left side (33.27 degrees, SD 17.49). 2. The mean results for the Axiograph were as follow: right side (32.26 degrees, SD 7.00); left side (33.07 degrees, SD 7.58). 3. There was no statistical difference on the wax protrusive records and Axiograph(p>0.05). Conclusion: Both methods of wax protrusive records and Axiograph are clinically acceptable for measuring the sagittal condylar guidance angles in semi-adjustable articulators.

• The Journal of Advanced Prosthodontics
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• v.8 no.6
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• pp.479-488
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• 2016

PURPOSE. The aim of this study was to test the modulus of elasticity (E) across the interfaces of yttria stabilized zirconia (YTZP) / veneer multilayers using nanoindentation. MATERIALS AND METHODS. YTZP core material (KaVo-Everest, Germany) specimens were either coated with a liner (IPS e.max ZirLiner, Ivoclar-Vivadent) (Type-1) or left as-sintered (Type-2) and subsequently veneered with a pressable glass-ceramic (IPS e.max ZirPress, Ivoclar-Vivadent). A $5{\mu}m$ (nominal tip diameter) spherical indenter was used with a UMIS CSIRO 2000 (ASI, Canberra, Australia) nanoindenter system to test E across the exposed and polished interfaces of both specimen types. The multiple point load - partial unload method was used for E determination. All materials used were characterized using Scanning Electron Microscopy (SEM) and X - ray powder diffraction (XRD). E mappings of the areas tested were produced from the nanoindentation data. RESULTS. A significantly (P<.05) lower E value between Type-1 and Type-2 specimens at a distance of $40{\mu}m$ in the veneer material was associated with the liner. XRD and SEM characterization of the zirconia sample showed a fine grained bulk tetragonal phase. IPS e-max ZirPress and IPS e-max ZirLiner materials were characterized as amorphous. CONCLUSION. The liner between the YTZP core and the heat pressed veneer may act as a weak link in this dental multilayer due to its significantly (P<.05) lower E. The present study has shown nanoindentation using spherical indentation and the multiple point load - partial unload method to be reliable predictors of E and useful evaluation tools for layered dental ceramic interfaces.

• Proceedings of the Safety Management and Science Conference
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• 2009.11a
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• pp.15-24
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• 2009

Cycling that transform human energy into mechanical energy is one of the man-machine systems out of sports fields. Benchmarking means " improving ourselves by learning from others ", therefore benchmarking toward dominant cyclist is necessary on field. the goals of this study were to provide important factors on multi-disciplines (kinematics, physiology, power, psychology) for a tailored-training program that is suitable to individual characteristics. Two cyclist participated in this study and gave consent to the experimental procedure. one was dominant cyclist (years:21 yrs, height:177 cm, mass:70 kg), and the other was non-dominant cyclist(years:21, height:176, mass:70). Kinematic data were recorded using six infrared cameras (240Hz) and QTM (software). Physiological data (VO2max, AT) were acquired according to graded exercising test with cycle ergometer and power with Wingate test used by Bar-Or et. al ( 1977) and to evaluate muscle function with Cybex. Psychological data were collected with competitive state anxiety inventory (CSAI-2) that were devised by Martens et. al (1990) and with athletes' self-management questionnaire (ASMQ) of Huh (2003). It appears that the dominant's CV(coefficient of variability) was higher than non-dominant's CV in Sports Biomechanics domain, that the dominant's values for all factors ware higher than non-dominant's values in physical, and physiological domain, and their values between cognitive anxiety and somatic anxiety were contrary to each other in psychology. Further research on multi-disciplines may lead to the development of tailored-optimal training programs applicable with key factors to enhance athletic performance by means of research including athlete, coach and parents.

• Journal of Korean Medicine for Obesity Research
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• v.4 no.1
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• pp.95-123
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• 2004

Objects: This study was aimed to find out correlation between life style and cardiopulmonary function and body fat. Methods: We divided two groups by the score of behavior modification therapy questionnaire. Westudied tendency of change of cardiopulmonary function and body fat for medication of Mahuang capsule by ergogenic aids and placebo with circuit training. We got the results for Exercise stress test and Segmental Bioelectrical Impedence Analysis. Results: 1. High Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of Lean Body Mass, Body Fat, Waist Circumference and not significantly elevation of Body Weight, But Basal Metabolic Rate was declined. Low Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of Waist Circumference and not significantly elevation of Body Weight and Body Fat, Lean Body Mass but decline of Basal Metabolic Rate, Waist to Hip Ratio 2. High Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of $VO_{2max}$ and not significantly elevation of the rest. Low Score Group in Behavior Modification Therapy Questionnaire significantly(p<.05) showed elevation of rest Heart Rate, Diastolic Blood Pressure, and not significantly elevation of the rest except for METs Conclusion: High score group in Behavior Modification Therapy Questionnaire showed significantly elevation of body composition, but had no relationship with Cardiopulmonary function