• Investigative Magnetic Resonance Imaging
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• v.16 no.1
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• pp.16-24
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• 2012

Purpose : The purpose of this study was to determine whether there is a significant correlation between vertebral marrow fat fraction measured using Dixon quantitative chemical shift MRI (QCSI) and BMD on dual-energy X-ray absorptiometry (DXA). Materials and Methods: This retrospective study included 68 healthy individuals [mean age, 50.7 years; range, 25-76; male/female (M/F) = 36/32] who underwent DXA of the L-spine and whole body MRI including QCSI of the L-spine and chemical shift MRI of the liver. The enrolled individuals were divided into subgroups according to sex and T-score [i.e., normal bone density (M/F=27/23) and osteopenia (M/F=9/9)]. Vertebral marrow (Dixon QCSI, TR/TE 10.2/4.8 ms) and hepatic fat fractions (chemical shift technique, TR/TE 110/4.9 and 2.2 ms) were calculated on MRI. We evaluated whether there were significant differences in age, body mass index (BMI), vertebral marrow fat fraction, or hepatic fat fraction among the subgroups. Whether or not the participant had reached menopause was also evaluated in females. The correlations among variables (i.e., age, BMI, vertebral marrow and hepatic fat fractions, BMD) were evaluated using Spearman's correlation method. Results: There were no significant differences in age, BMI, or vertebral marrow and hepatic fat fractions between the two male subgroups (normal bone density vs. osteopenia). In female subjects, mean age in the osteopenic subgroup was greater than that in the normal subgroup (p=0.01). Presence of menopause was more common in the osteopenic subgroup [77.8% (7/9)] than the normal subgroup [26.1% (6/23), p<0.05]. The other variables showed no significant difference between female subgroups. The only significant correlation with marrow fat fraction after partial correlation analysis was that with age in the female subjects (r=0.43, p<0.05). Conclusion: The vertebral marrow fat fraction calculated using the Dixon QCSI does not precisely reflect the mild decrease in BMD for either sex.

• Journal of Life Science
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• v.23 no.6
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• pp.757-769
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• 2013

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater, identified as Bacillus velezensis by analyses of 16S rDNA and partial sequences of the gyrA, and designated as B. velezensis A-68. The optimal conditions for production of CMCase by B. velezensis A-68 were established using response surface methodology (RSM). The optimal concentrations of rice hulls and yeast extract, and initial pH of the medium for cell growth were 60.2 g/l, 7.38 g/l, and 7.18, respectively, whereas those for production of CMCase were 50.0 g/l, 5.00 g/l, and 7.30. The analysis of variance (ANOVA) implied that the most significant factor for cell growth as well as production of CMCase was yeast extract. The optimal concentrations of $K_2HPO_4$, NaCl, $MgSO_4{\cdot}7H_2O$, and $(NH_4)_2SO_4$ in the medium for cell growth were 7.50, 1.00, 0.10, and 0.80 g/l, respectively, which were the same as those for production of CMCase. The optimal temperatures for cell growth and production of CMCase were 30 and $35^{\circ}C$, respectively. The maximal production of CMCase under optimized conditions was 83.8 U/ml, which was 3.3 times higher than that before optimization. In this study, rice hulls, agro-byproduct, were developed as a substrate for production of CMCase and time for production of CMCase was reduced to 3 days using a newly isolated marine bacterium.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.539-551
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• 1996

In this study, a number of distance-dependent competition indices on tree-level which incorporate the tree sizes and distances to competitors, and traditional stand-level density measures were estimated from the data compiled with position-dependent survey in a Pinus densiflora stand. The performance of the estimated competition indices was examined by comparing the relationship with the diameter growth, and a dbh growth function, in which the competition index is considered as a one of influence factors, are developed. In the searching method of competing trees, the competition index estimated with $30^{\circ}$ competition interrupting angle showed the highest correlation with the annual dbh growth, while the expanding the competing zone distance had no significant effect on the performance of competition index in estimating annual dbh growth. The most of the examined stand-level competition indices, based on distance-dependent single-tree competition indices, were evaluated to describe similarly the stand competition status. As a result of partial correlation analysis in which the effect of age and site index are eliminated, Alemdag's mean competition index and relative spacing index were determined to have the highest correlation with dbh. The relative spacing index, which can be easily measured in field without measuring the position of individual trees, was considered to be a better suited one for estimating mean dbh of a stand. Among distance-dependent competition indices on tree-level, Hegyi's competition index showed the best performance in their correlation with annual dbh growth, if eliminated the effect of site index and dbh. This enabled to derive the following annual dbh growth function of individual trees which incorporate age, dominant height, dbh and Hegyi's competition index as influence factors : $$dbh^{\prime}=3.975362676{\cdot}age^{-1.099274613}{\cdot}ho^{0.199893990}{\cdot}dbh^{0.269430865}{\cdot}HgCI^{-0.353643587}$$ This function is coincided to the growth principle in which site index has a positive effect on the annual dbh growth, while high age or competition causes to reduce the annual dbh growth, and can be used as a function in single tree growth model.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.776-784
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• 1997

Background : Various combinations of treatment modalities have been reported in stage III non-small cell lung cancer (NSCLC). however, the standard treatment modality has not established yet. Recently, the efficacy of concurrent chemotherapy and radiation therapy has been reported in locally advanced lung cancer. We evaluate the response rate, toxicity, and survival of concurrent chemotherapy with etoposide and cisplatin(EP) and radiation therapy for unresectable stage III NSCLC. Method : Between October 1995 and December 1996, 32 patients with histologically proven unresectable stage III NSCLC without malignant pleural effusion were entered into this study. Twenty-nine patients were eligible for the response, survival, and toxicity analysis. Induction was two cycles of chemotherapy with etoposide and cisplatin plus concurrent chest RT to 4500cGy. Resection was attempted if the clinical response offered surgical resectability. Boost radiation therapy upto 5940cGy and one cycle of EP were performed if the disease were stable or responsive but still unresectable. Results : Of 29 eligible patients, 22(75.9%) showed partial response(PR). The progression free interval was 6.3months(range 1.1 to 19.5months). Surgical resection was performed in one patient. The median survival was 12.1months and one-year survival rate was 50.6%. The major toxicity was leukopenia($\geq$ grade 3, 46%). Thrombocytopenia over grade 3 was found in 11%. Radiation pneumonitis occurred in 13 patients(46%). Conclusion : Concurrent chemotherapy(EP) plus radiotherapy was effective and tolerable in the treatment of unresectable stage III NSCLC.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.366-375
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• 2006

Background: Hypomagnesemia is a common complication after cardiac surgery with cardiopulmonary bypass. The purpose of this study was to assess the clinical beneficial effect of administration of magnesium sulfate in cardiac surgery. Material and Method: Thirty five patients scheduled for elective cardiac surgery were randomly assigned to magnesium group (n=20) which received magnesium sulfate in priming solution (1 g) and cardioplegic solution (1 g) or control group (n=15) which did not receive it. Arterial blood samples were drawn for measuring $Mg^{++}$ and electrolytes contents, blood gas analysis, CBC, total protein, albumin, blood urea nitrogen (BUN), creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, tumor necrosis factor-${\alpha}$ $(TNF-{\alpha})$, interleukin-6 (IL-6), interleukin-10 (IL-10), creatine phosphokinase (CpK), creatine kinase-MB (CK-MB), lactate dehydrogenase(LDH), troponin-1 (TNI), prothrombin time (PT) and activated pratial thromboplastin time level (aPTT). Venous blood samples were drawn before and after the operation for measuring activated clotting time level (ACT). Result: $Mg^{++}$ levels in magensium group were higher than those of control group at intraoperative and post-operative periods (p<0.05). dysrhythmias were lower in magnesium group (8 cases out of 17 patients, 46.4%) than in control group (10 cases out of 10, 100%, p=0.050). Conclusion: These results showed that administration of low dose magnesium sulfate during cardiac surgery prevented hypomagnesemia and lowered incidence of dysrhythmia.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.485-494
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• 2000

According to the worldwide interest in controlling $CO_2$ which contributes to green house effect. new techniques of reducing $CO_2$ are under development. We have developed new technique for reducing $CO_2$. In low $CO_2$ concentration. the chemical absorption method is useful. In this study. the kinetics of the reaction between $CO_2$ and the sterically hindered amine solution with piperazine. have been investigated from measurements of the rate of absorption of $CO_2$ in the stirred vessel that has a horizontal liquid-gas interface, in the temperature range $30{\sim}70^{\circ}C$. The experiments were carried out in the range 10.130~20.260 kPa of partial pressure of $CO_2$, and in aqueous $2.0kmol/m^3$ AMP solution with $0{\sim}0.4kmol/m^3$ piperazine The experimental results are as follows: 1) The absorption rate of $CO_2$ into aqueous AMP + piperazine solution is gett ng faster than that of aqueous AMP absorbents with temperature. Because the activation energy of piperazine 57.147 kJ/mol is higher than that of AMP 41.7kJ/mol. therefore the effect of piperazine on absorption rate increases with temperature. 2) Compared with aqueous AMP solution. the absorption rate of $CO_2$ into AMP + piperazine solution increases from 6.33% at $30^{\circ}C$ to 12% at $70^{\circ}C$, so AMP + piperazine solution is thought to be a better than AMP solution, 3) The reaction rate constants of piprazine in aqueous AMP solution with $CO_2$ have been determined as 217.21, 420.46, 707.00 and $3162.167m^3/kmol{\cdot}s$ respectively at 30, 40, 50 and $70^{\circ}C$ but these results are higher than those of Xu which were 186.7. 367.32. 693.01. $2207.65m^3/kmol{\cdot}s$ at 30, 40, 55, $70^{\circ}C$in aqueous MDEA solution. So the regression analysis of the data has led to the following equation In $k_p$ =28.324-6934.7/T.

• Journal of Chest Surgery
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• v.37 no.10
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• pp.827-832
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• 2004

Background: The significance of MIDCAB is emerging topics recently as OPCAB is going to be universalized, and long-term outcome of bypass graft surgery was proved to be more excellent than balloon dilation or stent insertion. We report our MIDCAB results in 73 patients in the last three years. Material and Method: Retrospective analysis of medical records was done from November 1, 2000 through November 31, 2003. There were 47 males and 26 females ranging in age from 31 years to 79 years (average $61.3\pm9.8$ years). Observation periods after operative procedures were 10 to 1238 days (average $763\pm319.8$ days). Left longitudinal parasternal incision as a standard procedure was done to approach the heart after dissection of the left internal thoracic artery by partial or total resection of 3rd to 5th ribs. Result: Of those patients, 46 patients were transferred to ICU after extubation at operation room and 58 patients were extubated within 3 hours after operation. Average ICU staying periods was $26.8\pm11.5$ hours. Follow-up angiography during admission was done in 36 patients and showed 100% patency. Only one patient died on the 10$^{th}$ post operative day because of sudden CVA. Complications included wound problems in 4 patients, and constructing pericardial window using thoracoscopy due to continuous pericardial effusion in 1. Permanent pacemaker was inserted in one patient owing to sick sinus syndrome. In one patient with recurrence of angina 8 months after operation, stenosis at anastomic site was found and improved with balloon dilatation. Conclusion: We were satisfied with our results of MIDCAB in single and multi-vessel coronary artery disease. These results have made the cardiologists tried to operate positively and we expect widening operative indications including hybrid revascularization.

• Asia pacific journal of information systems
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• v.22 no.4
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• pp.7-29
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• 2012

Smartphone and its applications (i.e. apps) are increasingly penetrating consumer markets. According to a recent report from Korea Communications Commission, nearly 50% of mobile subscribers in South Korea are smartphone users that accounts for over 25 million people. In particular, the importance of smartphone has risen as a geospatially-aware device that provides various location-based services (LBS) equipped with GPS capability. The popular LBS include map and navigation, traffic and transportation updates, shopping and coupon services, and location-sensitive social network services. Overall, the emerging location-based smartphone apps (LBA) offer significant value by providing greater connectivity, personalization, and information and entertainment in a location-specific context. Conversely, the rapid growth of LBA and their benefits have been accompanied by concerns over the collection and dissemination of individual users' personal information through ongoing tracking of their location, identity, preferences, and social behaviors. The majority of LBA users tend to agree and consent to the LBA provider's terms and privacy policy on use of location data to get the immediate services. This tendency further increases the potential risks of unprotected exposure of personal information and serious invasion and breaches of individual privacy. To address the complex issues surrounding LBA particularly from the user's behavioral perspective, this study applied the privacy calculus model (PCM) to explore the factors that influence the adoption of LBA. According to PCM, consumers are engaged in a dynamic adjustment process in which privacy risks are weighted against benefits of information disclosure. Consistent with the principal notion of PCM, we investigated how individual users make a risk-benefit assessment under which personalized service and locatability act as benefit-side factors and information privacy risks act as a risk-side factor accompanying LBA adoption. In addition, we consider the moderating role of trust on the service providers in the prohibiting effects of privacy risks on user intention to adopt LBA. Further we include perceived ease of use and usefulness as additional constructs to examine whether the technology acceptance model (TAM) can be applied in the context of LBA adoption. The research model with ten (10) hypotheses was tested using data gathered from 98 respondents through a quasi-experimental survey method. During the survey, each participant was asked to navigate the website where the experimental simulation of a LBA allows the participant to purchase time-and-location sensitive discounted tickets for nearby stores. Structural equations modeling using partial least square validated the instrument and the proposed model. The results showed that six (6) out of ten (10) hypotheses were supported. On the subject of the core PCM, H2 (locatability ${\rightarrow}$ intention to use LBA) and H3 (privacy risks ${\rightarrow}$ intention to use LBA) were supported, while H1 (personalization ${\rightarrow}$ intention to use LBA) was not supported. Further, we could not any interaction effects (personalization X privacy risks, H4 & locatability X privacy risks, H5) on the intention to use LBA. In terms of privacy risks and trust, as mentioned above we found the significant negative influence from privacy risks on intention to use (H3), but positive influence from trust, which supported H6 (trust ${\rightarrow}$ intention to use LBA). The moderating effect of trust on the negative relationship between privacy risks and intention to use LBA was tested and confirmed by supporting H7 (privacy risks X trust ${\rightarrow}$ intention to use LBA). The two hypotheses regarding to the TAM, including H8 (perceived ease of use ${\rightarrow}$ perceived usefulness) and H9 (perceived ease of use ${\rightarrow}$ intention to use LBA) were supported; however, H10 (perceived effectiveness ${\rightarrow}$ intention to use LBA) was not supported. Results of this study offer the following key findings and implications. First the application of PCM was found to be a good analysis framework in the context of LBA adoption. Many of the hypotheses in the model were confirmed and the high value of $R^2$ (i.,e., 51%) indicated a good fit of the model. In particular, locatability and privacy risks are found to be the appropriate PCM-based antecedent variables. Second, the existence of moderating effect of trust on service provider suggests that the same marginal change in the level of privacy risks may differentially influence the intention to use LBA. That is, while the privacy risks increasingly become important social issues and will negatively influence the intention to use LBA, it is critical for LBA providers to build consumer trust and confidence to successfully mitigate this negative impact. Lastly, we could not find sufficient evidence that the intention to use LBA is influenced by perceived usefulness, which has been very well supported in most previous TAM research. This may suggest that more future research should examine the validity of applying TAM and further extend or modify it in the context of LBA or other similar smartphone apps.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.328-333
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• 2002

Purpose : To analyze the treatment results of concurrent chemoradiation with oral 5-FU plus Gemcitabine or Paclitaxel for unresectable pancreatic cancer. Materials & Methods : The patients, who were diagnosed by imaging modalities or by explo-laparotomy, were treated with concurrent chemoradiation. Radiotherapy was delivered to primary tumor and regional lymph nodes, and the total dose was 45 Gy. Patients received Gemcitabine $1,000\;mg/m^2$ or Paclitaxel $50\;mg/m^2$ weekly and oral 5-FU daily The total number of cycles of chemotherapy ranged from 1 to 39 (median, 11 cycles). The follow-up period ranged from 6 to 36 months, Survival was analyzed using the Kaplan-Meier method. Results : Fifty-four patients between Jan. 1999 to Nov. 2001 were included in this study. Forty-two patients who completed the planned treatment were included in this analysis. The patients' age ranged from 37 to 73 years (median, 50 years) and the male to female ratio was 30:12. Treatment was interrupted for 12 patients due to: disease progression for 6 $(50\%)$, poor performance status for 4 $(33.3\%)$, intercurrent disease for 1 $(8.3\%)$, and refusal for 1 $(8.3\%)$. Response evaluation was possible for 40 patients. One patient gained complete remission and 24 patients gained partial remission, hence the response rate was $59\%$. The survival rates were $46.7\%\;and\;17.0\%$ at 1 year and 2 years, respectively with a median survival time of 12 months. Patients treated with Paclitaxel showed superior outcomes compared to those patients treated with Gemcitabine, in terms of both response rate and survival rate although this difference was not statistically significant. Grade III or IV hematologic toxicity was shown in 8 patients $(19\%)$, while grade III or IV non-hematologic toxicity was shown in 5 patients $(12\%)$. Conclusion : Concurrent chemoradiation with oral 5-FU and Gemcitabine or Paclitaxel improves both the response rate and survival rate in patients with unresectable pancreatic cancer. A prospective study should be investigated in order to improve both the patient selection and the treatment outcome as well as to reduce the toxicity.

• Journal of Chest Surgery
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• v.35 no.3
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• pp.177-181
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• 2002

Background: Follow-up studies have shown that although outcomes have improved substantially over time, results of the Fontan operation and its modifications remain suboptimal. In this study, we reviewed our experience with the extracardiac conduit Fontan operation, with a focus early and midterm change of internal diameter of PTFE conduit. Material and Method: Between April 1997 and July 2000 were reviewed. Twelve patients (M:6, F:6, mean age 42.04 $\pm$ 12.43months, mean body weight 13.80$\pm$ 1.94kg) underwent extracardiac conduit Fontan operation with expanded PTFE graft. Mean cardiopulmonary bypass time was 109.7$\pm$26.99minute and mean operation time was 455$\pm$89.51minute. Intraoperative fenestration was performed in 10 patients. The aortic cross clamping was not performed in all patients. Result: There was no early deaths and no postoperative dysrhythmia. Postoperative protein losing enteropathy and prolonged pleural effusion occurred in 1(8.3%) and 4 patients(33.3%). Conduit patency was evaluated by magnetic resonance imaging studies. A 9.84$\pm$3.84% mean reduction in conduit internal diameter and there was no statistical correlation between the change of internal diameter of conduit and the postoperative duration after partial correlation analysis(r=0.019, p=0.955). Conclusion: These results demonstrate that the extracardiac conduit Fontan operation provies good early and midterm results and may reduce the prevalence of late arrhythmia. And there is no correlation between the change of internal diameter of conduit and the postoperative duration after extracardiac conduit Fontan operation with the expanded PTFE graft conduit.