• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.189-198
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• 2000

The stochiometric mixture of evaporating materials for the $CuGaSe_2$single crystal thin films were prepared from horizontal furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal $CuGaSe_2$, it was found tetragonal structure whose lattice constant $a_0}$ and $c_0$ were 5.615 $\AA$ and 11.025 $\AA$, respectively. To obtains the single crystal thin films, $CuGaSe_2$mixed crystal was deposited on throughly etched GaAs(100) by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $610^{\circ}C$ and $450^{\circ}C$ respectively, and the growth rate of the single crystal thin films was about 0.5$\mu\textrm{m}$/h. The crystalline structure of single crystal thin films was investigated by the double crystal X-ray diffraction (DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility depending on temperature. From Hall data, the mobility was likely to be decreased by pizoelectric scattering in the temperature range 30 K to 150 K and by polar optical scattering in the temperature range 150 K to 293 K. The optical energy gaps were found to be 1.68 eV for CuGaSe$_2$sing1e crystal thin films at room temperature. The temperature dependence of the photocurrent peak energy is well explained by the Varshni equation then the constants in the Varshni equation are given by $\alpha$ = $9.615{\times}10^{-4}$eV/K, and $\beta$ = 335 K. From the photocurrent spectra by illumination of polarized light of the $CuGaSe_2$single crystal thin films. We have found that values of spin orbit coupling $\Delta$So and crystal field splitting $\Delta$Cr was 0.0900 eV and 0.2498 eV, respectively. From the PL spectra at 20 K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be 0.0626 eV and the dissipation energy of the acceptor-bound exciton and donor-bound exciton to be 0.0352 eV, 0.0932 eV, respectively.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.272-285
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• 2003

This study was conducted to observe the microscopic structures of cavities formed after ablation of primary teeth, permanent teeth, enamel and dentin in using a bur and cavities formed after ablation using laser and the following results were obtained after comparing the effects of ablation. Using a #330 bur and Er:YAG laser irradiated at 150 mJ, 200 mJ, 250 mJ and 300 mJ all at the frequency of 5 Hz, 1 mm enamel and dentin samples were ablated and the ablation time was measured. In order to measure the surfaces ablated, 5 each of primary teeth and permanent teeth were ablated using a #330 bur and Er:YAG laser at 150 mJ, 200 mJ, 250 mJ and 300 mJ for 1 sec and the cross section and vertical section were observed. The following results were obtained : 1. Cutting time of Er:YAG laser was longer than that of conventinal high-speed bur regardless of teeth type. 2. Cutting on enamel, Cutting time of conventional high-speed bur in deciduous teeth was longer than in permanent teeth(P<0.05). But Er:YAG laser was not showed any difference between the deciduous and permanent teeth(P>0.05). 3. Cutting on dentin, Cutting time of conventional high-speed bur in permanent teeth was longer than deciduous teeth. Er:YAG laser of 150 mJ, 5 Hz in permanent teeth was longer than in deciduous teeth(p<0.05). But laser of other power did not showed mean difference. 4. The cavity surface treated with the convetional high-speed bur revealed a relatively flat appearance, almost covered with a debris-like smear layer. Cavity wall showed striped appearance because of blade of bur. 5. The cavity surface treated by the Er:YAG laser system was irregular or rough surface with the absence charring, carbonization, or cracking of the dentin. In addition, there was an absence of a smear layer. Cavity floor was round and relatively smooth. According to these results, cutting time of Er:YAG laser was almostly same in permanent and deciduous teeth, but more effective in dentin than enamel. Cutting the sample, Er:YAG laser was needed more time than conventional bur. But SEM findings suggested that laser device produced favorable surface characteristic(i.e, no smear layer, irregular surface, cracking).

• Clinical and Experimental Pediatrics
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• v.50 no.2
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• pp.205-208
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• 2007

Purpose : Vascular endothelial cell damage and alteration of a fibrinolytic system was suggested to play a role in the development of coronary artery abnormalities in Kawasaki disease (KD). D-dimer is one of the markers of endothelial damage and fibrinolysis. We evaluated the clinical usefulness of D-dimer to differentiate KD from other febrile diseases and predict coronary artery abnormalities in KD. Methods : Sixty eight patients diagnosed as KD and twenty eight patients presented with acute febrile illnesses other than KD from September 2005 to July 2006 were included. Blood levels of D-dimer and various inflammatory markers were measured before treatment and the clinical course of KD was followed. Serial echocardiography was performed at the onset of disease and thereafter at a monthly interval for at least 2 months. Results : KD patients showed a higher D-dimer level than febrile controls, but the difference was not significant ($1.21{\pm}0.77{\mu}g/mL$ vs $0.92{\pm}0.71{\mu}g/mL$, P=0.083). Neither was the difference between KD patients who had coronary artery abnormalities and those who had not ($1.49{\pm}0.98{\mu}g/mL$ vs $1.15{\pm}0.71{\mu}g/mL$, P=0.169). D-dimer was significantly correlated with other inflammatory markers, such as C-reactive protein and erythrocyte sedimentation rate in both KD patients and febrile controls. Conclusion : D-dimer was not specific for KD. But it may be useful as an inflammatory marker to assess the severity of KD.

• Journal of fish pathology
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• v.22 no.3
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• pp.293-303
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• 2009

Effects of stress on the low salinity stress were examined in the pacific abalone Haliotis discus discus. Changes in survival rate, hemolymph count, antioxidant enzyme activities (catalase: CAT and superoxide dismutase: SOD), respiratory burst activity, phenoloxidase activity, lysozyme activity and expression of heat shock protein 70 (HSP70) mRNA were measured 0, 3, 6, 12, 24 or 48hours after low salinity treatment with 25, 30, 33 and 35 psu. Survival rates of pacific abalone were 100% at 33 and 35 psu, but 93 and 97% at 25 and 30 psu for 48 hours, respectively. Hemolymph counts decreased in the time elapsed-dependent way at all of the experimental groups. At low salinity, 25 and 30 psu, SOD and CAT activity increased compared to the experimental group of 33 psu. Moreover, respiratory burst activities of the pacific abalone seemed to have no effect on low salinity stress at any experimental group. However, phenoloxidase activity is an important component of the defence against pathogen that was decreased in a reduction of salinity dependent way. Lysozyme activity also immediately reduced at 25 psu experimental group for 48 h. The HSP70 mRNA was weakly expressed at 33 psu, but strongly detectable at 25 psu experimental group. The HSP 70 mRNA expression in gill increased in the time elapsed-dependent way at 25 psu experimental group and then recovered at 48 h. These results suggest that low salinity stress give rise to inhibitory action of immune system as a result of the decrease of phenoloxidase and lysozyme activity in the pacific abalone, especially.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.236-244
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• 2001

Background : Most current research using prognostic scoring systems in critically ill patients have focused on prediction using the first intensive care unit (ICU) day data or daily updated data. Usually the mean ICU length of stay in Korea is longer than in the western world. Consequently, a more cost-effective and practical prognostic parameter is required. The principal aim of this study was to assess the prognostic value of the seventh day(7th day : the average mean ICU length of stay) APACHE III score in a medical intensive care unit. Methods : 241 medical ICU patients from July 1997 to April 1998 were enrolled. The 1st and 7th scores were measured by using the APACHE III scoring system and compared between survivors and non-survivors. Logistic regression analysis was performed to determine the relationship between the $1^{st}$ and $7^{th}$ APACHE III scores and the mortality risk. Results : 1 )The mean length of stay in the ICU was $10.3{\pm}13.8$ days. 2)The mean $1^{st}$ and $7^{th}$ day APACHE III scores were $59.7{\pm}30.9$ and $37.9{\pm}27.7$. 3) The mean $1^{st}$ day APACHE III score was significantly lower in survivors than in non- survivors($49.9{\pm}23.8$ vs $86.3{\pm}32.3$, P<0.0001). 4)The mean $7^{th}$ day APACHE III score was significantly lower in survivors than in non- survivors($30.1{\pm}18.5$ vs $80.1{\pm}30.4$, P<0.0001). 5)The odds ratios among the $1^{st}$ and $7^{th}$ day APACHE III scores and the mortality rate were 1.0507 and 1.0779 respectively. Conclusion : These results suggest that the seventh day APACHE III score is as useful in predicting the outcome as is such like the first day APACHE III score. Therefore, in comparison to the daily APACHE III score, measuring the $1^{st}$ and $7^{th}$ day APACHE III scores are also useful for predicting the prognosis of critically ill patients in terms of cost-effectiveness. It is suggested that the $7^{th}$ day APACHE III score is useful for predicting the clinical outcome.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.667-673
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• 2005

The purposes of this study were 1) to analyze the preference of leadership style among ${\lceil}$Transformational leadership$\rfloor$ and ${\lceil}$Service leadership$\rfloor$, 2) to examine the differences of the job satisfaction between the high level of service leadership group and low level of the service leadership group and 3) to testify the hypothesis that the service leadership and its 4 elements (belief, attitude, ability, insight) affect the job satisfaction. The questionnaires were developed to measure the service leadership, the preference of leadership style (transfer-mational leadership and service leadership) and Job satisfaction. The surveys were distributed to 120 managers and employees in the family restaurant in Korea, and 104 questionnaires were responded (response rate: $86.7\%$). The SPSS 12.0 package program was used to conduct the descriptive analysis, correlation analysis, t-test and multiple regression analysis. The result of leadership style preference showed the followers preferred the service leadership $(75.0\%)$ to the transformational leadership $(25.0\%)$. Comparing the job satisfaction of high level of service leadership group and that of low level of service leadership group, the job satisfaction of high level of service leadership group was significantly (p<0.001) higher than that of low level of service leadership group (high level of service leadership group: 4.03, low service leadership group: 3.27, measured on a 5-point likert scale). All three factors of job satisfaction (human factor, service system and company image) in high level of leadership group were significantly (p<0.001) higher than those of lower level of service leadership group. The result of multiple regression analysis presented that the service leadership and it's 4 elements (concept, mind, skill, insight) have significant (p=0.000) effects on the job satisfaction. As a conclusion, we examined theoretical framework of service leadership model and testified the applicability in the field of family restaurants. But the service leadership was the new conceptual theory, so there should be the more empirical studies on managers and employees in the service industry.

• Journal of Acupuncture Research
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• v.22 no.1
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• pp.131-144
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• 2005

Objective : The aim of this study is to observe the effect of Herbal-acupuncture(HA) with Luffae Fructus Retinervus Herbal-Acupuncture Solution(LFR-HAS) at ST36(Joksamni) on Collagen Ⅱ -induced arthritis(CIA) in mice. Methods : DBA1/J mice were immunized with bovine type Ⅱ collagen(CⅡ) on days 0 and 21 to induce an arthritis. The mice were divided into 5 groups. They were Normal group(wild type), Control group(CIA), Saline group(CIA +saline injection), Needle Prick group(CIA +single Prick with an injection needle) and LFR-HA group(CIA +LFR-HA treatment). The saline injection, needle prick and LFR-HA were made on the right ST36(Joksamni) of mice for 5 weeks, 3 times a week beginning 4 weeks after the booster immunization. Results : 1. The highest synovial rate of lung fibroblasts was measured in the 1% LFR-HAS. 2. TNF-${\alpha}$ expression of survival cells from CIA mouse joint was significantly reduced in the 1% LFR-HAS. 3. The incidence of arthritis and the spleen weight of CIA mouse were significantly reduced by the Luffae Fructus Retinervus Herbal-Acupuncture (LFR-HA) at ST36. 4. The concentrations of IL-6, INF-${\alpha}$, INF-${\alpha}$, IgG, IgM, and anti-collagen Ⅱ in the CIA mouse serum were significantly reduced by the LFR-HA at ST36. 5. The histological examination showed that, in the LFR-HA group, the cartilage destruction and the synoviocyte proliferation in the CIA mouse joint were not significant compared to the control group, and the collagen fiber was similarly expressed as the normal group. 6. In the LFR-HA group, the ratio of CD3e+ to CD19+ cell, and the ratio of CD4+ to CD8+ cell in the lymph node were similarly maintained as those of the normal group. 7. CD69+/CD3e+ and CD11a+/CD19+ cells in the CIA mouse lymph node were significantly reduced by the LFR-HA at ST36. 8. CD11b+/Gr-1+ cells in the CIA mouse joint were significantly reduced by the LFR-HA at ST36. Conclusions : These results indicate that Luffae Fructus Retinervus Herbal-Acupuncture (LFR-HA) at ST36 may regulate the immune system and have a therapeutic effect on Collagen-induced arthritis(CIA) in mice.

• Sleep Medicine and Psychophysiology
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• v.8 no.1
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• pp.45-51
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• 2001

Objectives: The experience of traffic accident is a kind of the psychosocial stressors to person. The traffic accident-related patients may show the psychophysiologic hyperarousal. So we examined the differences of psychophysiologic response between patients with and without the memory of experienceing a traffic accident. Methods: Twenty-four traffic accident-related patients were divided into two groups according to ther memory of a traffic accident. In psychological assessment, levels of anxiety and depression were evaluated by State-Trait Anxiety Inventory, Beck's Depression Inventory, and Hamilton Rating Scales For Anxiety and Depression. Heart rate, electrodermal response (EDR), and electromyographic activity (EMG) were measured by biofeedback system, and systolic and diastolic blood pressure by automated vital sign monitor during baseline, task, and rest periods. We utilized script-driven imagery technique as a stressful task. The patients listened to the script describing their own traffic accident experience and were instructed to imagine the event during the task period. Statistically analytic data were obtained from the differences of psychological and psychophysiologic data between two groups. Results: The memory group did not show significantly higher EDR than the none memory group, but showed higher tendency during baseline, imagery, and rest periods. The memory group showed significantly lower EMG than the none memory group during rest period. However, there were no differences in other psychophysiologic reponses between the two groups. Conclusion: Our results showed that the memory group had higher tendency in autonomic arousal level such as electrodermal response than the none memory group. We suggest that physicians need to minimize repetitive imagery of traffic accident (reexperience), and decrease the autonomic hyperarousal in the treatment of traffic accident-related patients.

• Progress in Medical Physics
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• v.17 no.1
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• pp.24-31
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• 2006

Automated analysis software was developed to measure the magnitude of the intrafractional and interfractional errors during breast radiation treatments. Error analysis results are important for determining suitable planning target volumes (PTV) prior to Implementing breast-conserving 3-D conformal radiation treatment (CRT). The electrical portal imaging device (EPID) used for this study was a Portal Vision LC250 liquid-filled ionization detector (fast frame-averaging mode, 1.4 frames per second, 256X256 pixels). Twelve patients were imaged for a minimum of 7 treatment days. During each treatment day, an average of 8 to 9 images per field were acquired (dose rate of 400 MU/minute). We developed automated image analysis software to quantitatively analyze 2,931 images (encompassing 720 measurements). Standard deviations ($\sigma$) of intrafractional (breathing motion) and intefractional (setup uncertainty) errors were calculated. The PTV margin to include the clinical target volume (CTV) with 95% confidence level was calculated as $2\;(1.96\;{\sigma})$. To compensate for intra-fractional error (mainly due to breathing motion) the required PTV margin ranged from 2 mm to 4 mm. However, PTV margins compensating for intefractional error ranged from 7 mm to 31 mm. The total average error observed for 12 patients was 17 mm. The intefractional setup error ranged from 2 to 15 times larger than intrafractional errors associated with breathing motion. Prior to 3-D conformal radiation treatment or IMRT breast treatment, the magnitude of setup errors must be measured and properly incorporated into the PTV. To reduce large PTVs for breast IMRT or 3-D CRT, an image-guided system would be extremely valuable, if not required. EPID systems should incorporate automated analysis software as described in this report to process and take advantage of the large numbers of EPID images available for error analysis which will help Individual clinics arrive at an appropriate PTV for their practice. Such systems can also provide valuable patient monitoring information with minimal effort.

• Progress in Medical Physics
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• v.26 no.2
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• pp.87-92
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• 2015

The gated RapidArc may produce a dosimetric error due to the stop-and-go motion of heavy gantry which can misalign the gantry restart position and reduce the accuracy of important factors in RapidArc delivery such as MLC movement and gantry speed. In this study, the effect of stop-and-go motion in gated RapidArc was analyzed with varying gating window time, which determines the total number of stop-and-go motions. Total 10 RapidArc plans for treatment of liver cancer were prepared. The RPM gating system and the moving phantom were used to set up the accurate gating window time. Two different delivery quality assurance (DQA) plans were created for each RapidArc plan. One is the portal dosimetry plan and the other is MapCHECK2 plan. The respiratory cycle was set to 4 sec and DQA plans were delivered with three different gating conditions: no gating, 1-sec gating window, and 2-sec gating window. The error between calculated dose and measured dose was evaluated based on the pass rate calculated using the gamma evaluation method with 3%/3 mm criteria. The average pass rates in the portal dosimetry plans were $98.72{\pm}0.82%$, $94.91{\pm}1.64%$, and $98.23{\pm}0.97%$ for no gating, 1-sec gating, and 2-sec gating, respectively. The average pass rates in MapCHECK2 plans were $97.80{\pm}0.91%$, $95.38{\pm}1.31%$, and $97.50{\pm}0.96%$ for no gating, 1-sec gating, and 2-sec gating, respectively. We verified that the dosimetric accuracy of gated RapidArc increases as gating window time increases and efforts should be made to increase gating window time during the RapidArc treatment process.