• Radiation Oncology Journal
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• v.20 no.2
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• pp.186-192
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• 2002

Purpose : Measurement of transmission dose is useful for in vivo dosimetry. In this study, previous algorithm for estimation of transmission dose was modified for use in cases with tissue deficit. Materials and Methods : The beam data was measured with flat solid phantom in various conditions of tissue deficit. New algorithm for correction of transmission dose for tissue deficit was developed by physical reasoning. The algorithm was tested in experimental settings with irregular contours mimicking breast cancer patients using multiple sheets of solid phantoms. Results : The correction algorithm for tissue deficit could accurately reflect the effect of tissue deficit with errors within ${\pm}1.0\%$ in most situations and within ${\pm}3.0\%$ in experimental settings with irregular contours mimicking breast cancer treatment set-up. Conclusion : Developed algorithm could accurately reflect the effect of tissue deficit and irregularly shaped body contour on transmission dosimetry.

• Journal of the Korean Arthroscopy Society
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• v.7 no.2
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• pp.196-200
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• 2003

Purpose : To evaluate clinical outcomes after anterior cruciate ligament (ACL) reconstruction in middle-aged patients and determine the factors affecting the outcome. Subjects and Methods : Clinical results obtained from 60 cases (60 patients) older than 40 years of age at the time of surgery and 58 cases (58 patients) younger than 40 years of age who underwent ACL reconstruction between August 1988 to January 2002, return to sports activity, and stress radiographs using Telos instrument were compared. Results : The Lysholm knee score was improved from the preoperative score of 54.0 points to the postoperative score of 92.9 in patients older than 40 years of age and was improved from 56.2 points to 92.2 points in patients younger than 40 years of age. Clinical outcome was excellent in 51 cases $(85\%)$ and good in 9 cases $(15\%)$ in patients olde. than 40 years of age and was excellent in 47 cases $(81.0\%)$ and good in 11 cases $(19.0\%)$ in patients younger than 40 years of age. There was a significant difference in the rate of returning to preoperative sports activity between patients older than 40 years of age ($60\%$, 36 cases) and younger than 40 years ($82.8\%$, 48 cases). According to Telos stress radiography, the preoperative difference of 11.2 mm was decreased to the postoperative difference of 3.1 mm in patients older than 40 years of age and the preoperative difference of 10.7 mm was decreased to the postoperative difference of 2.9 mm in patients younger than 40 years of age. Clinical outcome did not show significant correlation with age, gender, surgery method, the presence of additional injury, and the rate of return to sports activity before receiving injury (p>0.05). Conclusion : Age didn't have a significant influence on the final outcome of ACL reconstruction and good results could be obtained with ACL reconstruction even in middle-aged patients.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.10 no.6
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• pp.1-13
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• 2015

There are various performance factors for SMEs in order to survive in the rapid changing market and it is discussing the importance of entrepreneurs' entrepreneurial orientation based on many researches. Thus, it is worth to analyze factors of seize new opportunity and firm's performance to build sustainable competitive advantages, which provide the directions to SMEs. This study investigates through exploratory research that the important factors of entrepreneurial orientation and the influence factors on firm's performance confirmed by empirical study. This study was conducted to explore the relationship between entrepreneurial orientation of SME CEO, learning orientation and corporate performance was verified following section. First, entrepreneurial orientation (pro-activeness, competitive aggressiveness, risk taking, innovativeness) was to examine the effect of learning orientation; Second, entrepreneurial orientation was to examine the impact on firm's performance; and in the last, validated learning orientation affect factors that are mediated between entrepreneurship orientation and firm's performance through empirical research. The results of this study, each SME have shown that they have a different impact on firm's performance based on a variety of entrepreneurial orientation. This result shows that the need for a separate independent study on entrepreneurial orientation of SMEs. In conclusion, this study implicates that entrepreneurial orientation is important role for firm's performance, entrepreneurs of SMEs are innovative rather than competitive aggressive, and risk taking activities positively affect firm's activity. The conclusions of this study would be utilized to develop the entrepreneurial orientation when necessary for entrepreneurs of SMEs.

• Journal of Life Science
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• v.25 no.12
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• pp.1354-1361
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• 2015

This study was aimed to investigate the distribution status and phylogenetic relationship of Myotis aurascens in Jeju Ialnd, which has not clearly confirmed until now. We found three groups of M. aurascens from three different cave enforcements (CEs). The bat population of Jeju Island had smaller levels of HBL and Hfcu, but greater levels of TL, EL, FAL, and Tra than those of the Korean Peninsula population. Jeju bats had wide range in the lengths of FAL and Hfcu comparing to those of European bats. From the bimonthly monitoring to each finding site, we have actually failed to observe those again, estimating that they use those CEs as the daily-roosting place in activating seasons. The sequences of CYTB and COI genes showed identical sequences among Jeju bats tested, indicating that they are maternally related. The results from molecular phylogeny showed that the sequences of these bats located on the same branch with those for M. aurascens in the phylogenetic trees. Besides, the nucleotide sequences of the Jeju bats showed the closest relation with that of Korean Peninsula. Consequently, these findings indicate that the bats of M. aurascens, verified the natural distribution in Jeju Island, have originated from a single maternal origin and differences in morphological and genetic backgrounds form those of Korean Peninsula and the other countries, and had probably immigrated via Korean Peninsula. These findings will contribute as basic information for understanding the migration history and biogeographic relationship of mammals on Jeju Island in East Asia.

• Tuberculosis and Respiratory Diseases
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• v.53 no.3
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• pp.309-318
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• 2002

Background : Usual interstitial pneumonia (UIP) is a fatal progressive fibrotic disorder of the lung with unknown etiology and characterized by a poor response to conventional immunosuppressive therapy. The histologic hallmark of UIP is parchy distribution of subpleural fibrosis and fibroblastic foci(FBF) with interposed normal appearing lung. Because FBF is a collection of actively proliferating myofibroblasts, it can be a marker of activity and prognosis of UIP. However, there were contradictory reports about the correlation between the degree of FBF and survival. Therefore we performed this study to investigate the value of FBF as prognostic marker of UIP. Methods : This was a retrospective study on the 46 patients(M:F=33:13, mean age:$59{\pm}12$ years) with UIP diagnosed by the surgical lung biopsy at the Asan Medical Center, Seoul, Korea between 1990 and 2000 and had follow-up of more than a year. All the biopsy specimens were reevaluated and diagnosed as UIP according to the ATS/ERS classification. Semiquantitative grading of FBF(absent, 0; mild 1; moderate 2; marked 3) by the experienced pathologists who did not know the clinical findings were compared to the clinical data and the follow up course. Results : Thirteen patients(28.2%) died of UIP progression during the study period. The median survival time of all the subjects was 26 months after the biopsy. At the univariate analysis, FVC, $D_Lco$, smoking history and the grade of FBF were significantly related to the survial. The survival was longer in subjects with lesser degrees of FBF, higher DLco, higher FVC and history of smoking. However the multivariate analysis with Cox regression test showed the extent of FBF was the only independent prognostic marker of UIP. Conclusion : These data suggested that the extent of FBF on the surgical lung biopsy can be used as a prognostic marker of UIP.

• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.15-21
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• 2003

Background : There are many risk factors for osteoporosis in patients with chronic obstructive pulmonary disease(COPD). These include smoking, a low body mass index, insufficient exercise, and the use of glucocortcoids. However, there is lack of data on the incidence of osteoporosis according to the different glucocorticoid administration methods in patients with COPD. This study compared the incidence of osteoporosis according to the different administration methods of glucocorticoid. Methods : A matched case-controlled study (gender, age, cumulative steroid dose and pack-years of smoking) was conducted. Forty-five patients with documented COPD for at least a 3 year duration and a cumulative glucocorticoid dose above 1,000 mg were enrolled in study. The patients were classified into the following three groups. First, fifteen patients received continuous inhaled glucocorticoid with intermittent oral steroids but had no admission history due to an acute exacerbation(Group I). Secondly, fifteen patients received a multiple course of oral steroids with additional inhaled glucocorticoid but had no admission history due to their acute exacerbation(Group II). Lastly, fifteen patients received intermittent oral or inhaled glucocorticoids and had an admission history due to the acute exacerbation with intravenous steroid treatment for at least 2 weeks per year(Group III). The enrolled patients had apulmonary function test and bone densitometry performed at the lumbar spine and femoral neck. Results : The patients from Group III had significantly high incidence of osteoporosis in the lumbar and femoral neck compared to Group I and Group II (p<0.01). Conclusion : The incidence of osteoporosis in patients with COPD appears to be strongly affected by the method of steroid administration. This result suggests that intravenous steroid administration is strongly associated with the risk of osteoporosis.

• Journal of Life Science
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• v.28 no.10
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• pp.1186-1192
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• 2018

The purpose of this study was to compare the effects of either aerobic exercise or polyphenols supplementation on mRNA expression of endoplasmic reticulum stress in skeletal muscle of high fat diet-induced obese mice. In the study, mice were divided into five groups: (1) NC (normal diet for 16 weeks as a control, n=10), (2) HC (high fat diet for 16 weeks as a control, n=10), (3) H-Re (high fat diet with resveratrol 25 mg/kg supplementation for 16 weeks, n=10), (4) H-Ch (high fat diet with chrysin 50 mg/kg supplementation for 16 weeks, n=10), and (5) HE (high fat diet with aerobic exercise for 16 weeks, n=10). Aerobic exercise was performed on a treadmill for 40~60 min/day at 10~14 m/min, 0% grade, four days/week for 16 weeks. Endoplasmic reticulum stress related genes were measured by real-time polymerase chain reaction. ATF6, PERK, $IRE1{\alpha}$, and BIP/GRP78 mRNA were significantly decreased in HE compared with those in HC (p<0.05). Also, ATF6, $IRE1{\alpha}$, and BIP/GRP78 mRNA were significantly decreased in H-Re compared with those in HC (p<0.05). ATF6 mRNA was significantly decreased in H-Ch compared with that in HC (p<0.05). These findings suggest that aerobic exercise, resveratrol, and chrysin supplementation changed ER stress markers. However, aerobic exercise was most effective on ameliorating the high fat diet induced ER stress markers. Thus, it seems that aerobic exercise might have a more positive effect on skeletal muscle endoplasmic reticulum stress compared with polyphenol supplementation in high fat diet-induced obese mice.

• Clinical and Experimental Pediatrics
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• v.45 no.5
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• pp.629-636
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• 2002

Purpose : Our study was aimed to investigate the characteristics of seizures as well as to determine whether the expression of neuronal nitric oxide synthase expression(nNOS) of hippocampus has an affect in the hyperthermic seizure in developing rat. Methods : Hyperthermic seizures were repeatedly induced twice a week for four weeks in 20-day old Spraque-Dowley rats. Fifty two rats were used as a hyperthermic group and 30 rats used as a normothermic control group. Hyperthermic seizures were induced in a water bath at $45^{\circ}C{\pm}1$ for 4 min. The characteristics of seizures were recorded. Using western blot, hippocampal nNOS expression was measured in normothermic control, hyperthermic non-seizure, and hyperthermic seizure groups, respectively. Results : Eighty seven percent of hyperthermia exposed rats showed generalized tonic-clonic seizure most frequently. The duration of seizure was ranged from 12 to 145 sec(mean 55 sec) and the latency to seizure ranged from 158 to 240 sec(mean 204 sec). The duration of seizure was prolonged but there was no significant difference in the seizure latency as the rat exposed more number of hyperthermia. Interestingly, the expression level of hippocampal nNOS in hyperthermic seizure and hyperthermic non-seizure groups was not different from each other, however, the expression in these groups was lower than that of the control group. Conclusion : Our results indicate that nNOS do not have an affect in this repeated hyperthermic seizures. Further studies are required to clarify a role of nNOS in hyperthermic seizure.

• Tuberculosis and Respiratory Diseases
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• v.51 no.6
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• pp.570-578
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• 2001

Background: With cases of chronic obstructive pulmonary disease(COPD), weight loss and low body weight have been found to correlate with increased mortality and poor prognosis. Therefore, nutritional aspects are an important part of the treatment in cases of COPD. In Korea, there is only limited data available for the changes of resting pulmonary function in relation to nutritional status. This study was carried out to investigate the differences of resting pulmonary function in relation to the nutritional status of patients with COPD. Method : 83 stable patients, with moderate to severe COPD, were clinically assessed for their nutritional status and resting pulmonary function. The patients' nutritional status was evaluated by body weight and fat-free mass (FFM), which was assessed by bioelectrical impedance analysis. According to their nutritional status, the 83 patients were divided into two groups, designated as the depleted, and non-depleted, groups. Result : Of the 83 patients, 31% were characterized by body weight loss and depletion of FFM, whereas 28% had either weight loss or depleted FFM. In the depleted group, significantly lower peak expiratory flow rate(p<0.05) and Kco(p<0.01), but significantly higher airway resistance(Raw, p<0.05) were noted. There was no difference for the non-depleted group in forced expiratory volume at one second, residual volume, inspiratory vital capacity, or total lung capacity. Maximal inspiratory pressure($P_{Imax}$) was also significantly lower in the depleted group(p<0.05). Conclusion : We conclude, from our clinical studies, that nutritional depletion is significantly associated with the change in resting pulmonary function for patients with moderate to severe COPD.

• Economic and Environmental Geology
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• v.44 no.6
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• pp.463-474
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• 2011

The Haenam epithermal mineralized zone is located in the southwestern part of South Korea, and hosts low sulfidation epithermal Au-Ag deposit (Eunsan-Moisan) and clay quarries (Okmaesan, Seongsan, and Chunsan). Epithermal deposits and accompanying hydrothermal alteration related to Cretaceous volcanism caused large zoned assemblages of hydrothermal alteration minerals. Advanced argillic-altered rocks with mineral assemblages of alunite-quartz, alunite-dickite-quartz, and dickite-kaolinite-quartz exposed on the Okmaesan, Seongsan, and Chunsan area. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), with three visible and near infrared bands, six shortwave infrared bands, and five thermal infrared bands, was used to identify advanced argillic-altered rocks within the Haenam epithermal mineralized zone. The distinct spectral features of hydrothermal minerals allow discrimination of advanced argillic-altered rocks from non-altered rocks within the study area. Because alunite, dickite, and kaolinite, consisting of advanced argillic-altered rocks within the study area are characterized by Al-O-H-bearing minerals, these acid hydrothermal minerals have a strong absorption feature at $2.20{\mu}m$. The band combination and band ratio transformation cause increasing differences of DN values between advanced argillic-altered rock and non-altered rock. The alunite and dickite-kaolinite of advanced argillic-altered rocks from the Okmaesan, Seongsan, and Chunsan have average DN values of 1.523 and 1.737, respectively. These values are much higher than those (1.211 and 1.308, respectively) of non-altered area. ASTER images can remotely provide the distribution of hydrothermal minerals on the surface. In this way good relation between ASTER spectra analysis and field data suggests that ASTER spectral analysis can be useful tool in the initial steps of mineral exploration.