• Economic and Environmental Geology
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• v.38 no.2 s.171
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• pp.135-142
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• 2005

In order to investigate the contamination level and seasonal variation of heavy metals and evaluate the bioavailability of toxic elements, environmental geochemical survey was undertaken at the Dogok Au-Ag-Cu mine area. The main pollution sources in the area were suggested as tailings, mine waste materials and mine water. Elevated levels of $140{\cal}mg/{\cal}kg{\;}As,{\;}107{\cal}mg/{\cal}kg{\;}Cd,{\;} 3017{\cal}mg/{\cal}kg{\;}Cu,{\;}12926{\cal}mg/{\cal}kg{\;}Pb,{\;}9094{\cal}mg/{\cal}kg$ Zn(before rainy season) were found in mine tailings. Concentrations of heavy metals in farmland soils exceeded normal level in nature soil (Bowen, 1979). The highest level of heavy metals was found in water samples near the mine tailing dumps regarded as a main pollution source of toxic elements in the area. These concentrations decreased to downstream due to the effect of dilution. From the results of sequential extraction analyses for tailings and soils, non-residual forms of heavy metals were found, which indicate the contamination to be progressing by continuing weathering and oxidation. Cadmium and Zn would be of the highest mobility in all samples. The bioavailability of Cd, Cu, Zn and As using SBET analysis from paddy soils was $53.3{\%},{\;}46.5{\%},{\;}41.0{\%}$ and $37.0\%$, respectively. The farmland soil sample(S3) showed the highest total concentration and bioavailability of heavy metals.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.127-132
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• 2009

In the working population, muscle fatigue and musculoskeletal discomfort are common, which, in the case of insufficient recovery may lead to musculoskeletal pain. Workers suffering from musculoskeletal pains need to be rehabilitated for recovery. Isokinetic testing has been used in physical strengthening, rehabilitation and post-operative orthopedic surgery. Frequency analysis of electromyography (EMG) signals using the mean frequency (MNF) has been widely used to characterize muscle fatigue. During isokinetic contractions, EMG signals present strong nonstationarities. Hilbert-Haung transform (HHT) and autoregressive (AR) model have been known more suitable than Fourier or wavelet transform for nonstationary signals. Moreover, several analyses have been performed within each active phase during isokinetic contractions. Thus, the aims of this study were i) to determine which one was better suitable for the analysis of MNF between HHT and AR model during repetitive maximum isokinetic extensions and ii) to investigate whether the analysis could be repeated for sequential fixed epoch lengths. Seven healthy volunteers (five males and two females) performed isokinetic knee extensions at $60^{\circ}/s$ and $240^{\circ}/s$ until 50% of the maximum peak torque was reached. Surface EMG signals were recorded from the rectus femoris of the right thigh. An algorithm detecting the onset and offset of EMG signals was applied to extract each active phase of the muscle. Following the results, slopes from the least-square error linear regression of MNF values showed that muscle fatigue of all subjects occurred. The AR model is better suited than HHT for estimating MNF from nonstationary EMG signals during isokinetic knee extensions. Moreover, the linear regression can be extracted from MNF values calculated by sequential fixed epoch lengths (p> 0.0I).

• Radiation Oncology Journal
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• v.13 no.3
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• pp.233-241
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• 1995

Purpose : To analyse clinical outcome and prognostic factors according to treatment modality, this paper report our experience of retrospective study of patients with esophageal cancer Materials and Methods : One hundred and ten patients with primary esophageal cancer who were treated in Presbyterian Medical Center from May 1985 to December 1992. We analysed these patients retrospectively with median follow up time of 28 months, one hundred and four patients($95{\%}$) were followed up from 15 to 69 months. In methods, twenty-eight patients were treated with median radiation dose irradiated 54.3Gy only. Fifty-six patients were treated with combined chemoradiotherapy. Sixteen cases of these patients were treated with concurrent chemoradiation and the other patients(forty cases) were treated sequential chemoradiotherapy. In concurrent chemoradiotherapy group, patients received 5-FU continuous IV infusion for 4 days. Cisplatin IV bolus. and concurrent esophageal irradiation to 30 Gy. After that patients received 5-FU continuous IV, Cisplatin bolus injection and Mitomycin-C bolus IV, Bleomycin continuous IV, and irradiation to 20 Gy. In sequential chemoradiotherapy group, the chemotherapy consisted of 5-FU 1,000mg/$m^2$ administered as a continuous 24 hour intravenous infusion during five days and Cisplatin 80-100mg/$m^2$ bolus injected, or Bleomycin, Vinblastine, Cisplatin, Methotrexate were used of 1 or 2 cycles. After preoperative concurrentm chemoradiation twenty-six patients underwent radical esophagectomy. Results : Ninety-three patients could be examined for response assessment, By treatment modality, response rates were $85.1{\%}$ for radiation alone group and $86.3{\%}$ for combined chemoradiation group. But in operation group, after one cycle of concurrent chemoradiation treatment, response rate was $61.9{\%}$. The pathologic complete response were $15.4{\%}$ in operation group. Overall median survival was II months and actuarial 5-year survival rate was $8{\%}$. The median survival interval was 6 months for radiation alone group, 11 months for combined chemoradiation group and 19 months for operation group. And also median survival was 19 months for complete responder group that 8 months for noncomplete responder group. In univariative analysis, statistically significant prognostic factors were tumor size, clinical stage, tumor response, and operation. In multivariative analysis, significantly better survival was associated with clinical stage, tumor response, radiation dose, and operation. Conclusion : Compared with radiotherapy alone, combined multimodality may improve the median survival in patients with localized carcinoma of the esophagus and toxicity is acceptable.

• Geophysics and Geophysical Exploration
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• v.19 no.4
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• pp.187-199
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• 2016

In order to delineate the soft ground distribution, an integrated geostatistical analysis was performed using the MASW (Multichannel Analysis of Surface Wave) which has the information of overall region and CPTu (Piezo Cone Penetration Test) which provides the direct information of the measuring point of the ground. MASW results were known to have close relationship with the ground stiffness. This correlation was confirmed through the comparison of MASW data obtained from two survey lines to the laboratory test with extracted soil samples. 3D physical property distribution in the study area was acquired by geostatistical integrated analysis with the data of tip resistance ($q_c$) and pore pressure (u) from the CPTu obtained at 6 points within the study area. The integrated analysis was conducted by applying the COSGSIM (Sequential Gaussian Co-Simulation) technology which can carry out the simulation in accordance with the spatial correlation between the MASW results and both tip resistance and pore pressure. Besides the locations of CPTu, borehole investigations were also conducted at two different positions. As a result, the N value of SPT and borehole log could be secured, so these data were used for the analysis of the geotechnical engineering accuracy of the integrated analysis result. For the verification of reliability of the 3D distribution of tip resistance and pore pressure secured through integrated analysis, the geotechnical information gained from the two drilling areas was compared, and the result showed extremely high correlation.

• Investigative Magnetic Resonance Imaging
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• v.21 no.3
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• pp.125-130
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• 2017

Purpose: To evaluate the clinical significance of T1 high signal intensity on the globus pallidus as a predictor of severe hepatic encephalopathy in patients with acute-on-chronic liver failure (ACLF), which is a distinct syndrome characterized by multi-organ dysfunction including cerebral failure. Materials and Methods: From January 2002 to April 2014, we retrospectively reviewed the magnetic resonance imaging (MRI) findings and clinical and magnetic resonance (MR) features of 74 consecutive patients (44 men and 30 women; mean age, 59.5 years) with liver cirrhosis. The chronic liver failure-sequential organ failure assessment score was used to diagnose ACLF. The pallidal index (PI), calculated by dividing the mean signal intensity of the globus pallidus by that of the subcortical frontal white matter were compared according to ACLF. The PI was compared with the Model for End-Stage Liver Disease (MELD) score in predicting the development of ACLF. Results: Fifteen patients who were diagnosed with ACLF had higher hepatic encephalopathy grades (initial, P = 0.024; follow-up, P = 0.002), MELD scores (P < 0.001), and PI (P = 0.048). In the ACLF group, the mean PI in patients with cerebral failure was significantly higher than that in the patients without cerebral failure (1.33 vs. 1.20, P = 0.039). In patients with ACLF, the area under the curve (AUC) for PI was 0.680 (95% confidence intervals [CI], 0.52-0.85), which was significantly lower than that for the MELD score (AUC, 0.88; 95% CI, 0.77-0.99) (P = 0.04). Conclusion: The PI can be an ancillary biomarker for predicting the development of ACLF and severe hepatic encephalopathy.

• Journal of Chest Surgery
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• v.51 no.2
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• pp.109-113
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• 2018

Background: Low cardiac output syndrome (LCOS) after cardiac surgery usually requires inotropes. In this setting, critical illness-related corticosteroid insufficiency (CIRCI) may develop. We aimed to investigate the clinical features of CIRCI in the presence of LCOS and to assess the efficacy of steroid treatment. Methods: We reviewed 28 patients who underwent a rapid adrenocorticotropic hormone (ACTH) test due to the suspicion of CIRCI between February 2010 and September 2014. CIRCI was diagnosed by a change in serum cortisol of <$9{\mu}g/dL$ after the ACTH test or a random cortisol level of <$10{\mu}g/dL$. Results: Twenty of the 28 patients met the diagnostic criteria. The patients with CIRCI showed higher Sequential Organ Failure Assessment (SOFA) scores than those without CIRCI ($16.1{\pm}2.3$ vs. $11.4{\pm}3.5$, p=0.001). Six of the patients with CIRCI (30%) received glucocorticoids. With an average elevation of the mean blood pressure by $22.2{\pm}8.7mm\;Hg$ after steroid therapy, the duration of inotropic support was shorter in the steroid group than in the non-steroid group ($14.1{\pm}2.3days$ versus $30{\pm}22.8days$, p=0.001). Three infections (15%) developed in the non-steroid group, but this was not a significant between-group difference. Conclusion: CIRCI should be suspected in patients with LCOS after cardiac surgery, especially in patients with a high SOFA score. Glucocorticoid replacement therapy may be considered to reduce the use of inotropes without posing an additional risk of infection.

• Journal of Trauma and Injury
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• v.28 no.3
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• pp.104-107
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• 2015

Purpose: Nitric oxide (NO) is a vasodilator and inhaled NO (iNO) is used in acute respiratory distress syndrome (ARDS) to improve alveolocapillary gas exchange. The mechanism to improve oxygenation is likely to redistribute blood flow from unventilated areas to ventilated areas. Though improvement of oxygenation, iNO therapy has not been shown to improve mortality and considered as only rescue therapy in severe hypoxemia. We conducted the study to investigate an efficacy of iNO in trauma patients with severe hypoxemia. Methods: We reviewed the trauma patients who underwent iNO therapy retrospectively from 2010 to 2014. Degree of hypoxemia was represented as $PaO_2/FiO_2$ ratio (PFR) and the severity of patient was represented with sequential organ failure assessment (SOFA) score. Patients were divided into the survivor group and non-survivor group according to the 28-day mortality. Results: A total of 20 patients were enrolled. The mortality of 28-day was 40%. There were no significant differences between survivor and non-survivor group in age, sex, severity of injury, PFR and SOFA score. There was significant difference in initiation time of iNO after injury (p=0.047). Maximum combinations of sensitivity and specificity for timing of iNO therapy were observed using cut-off of 3-day after injury with a sensitivity of 88% and specificity of 75%. Conclusion: Though iNO therapy does not influence the mortality, iNO therapy may decrease the mortality caused by respiratory failure in the early phase of trauma.

• Journal of Korean Society on Water Environment
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• v.28 no.4
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• pp.595-600
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• 2012

This study is to assess the application of SWAT-CUP(Soil and Water Assessment Tool-Calibration Uncertainty Programs) and to extend daily flow data from 8-day interval flow data which has been measured by Korean Ministry of Environment(MOE). Model sensitivity analysis and calibration were performed with sequential uncertainty fitting(SUIF-2), which is one of the programs interfaced with SWAT, in the package SWAT-CUP. The most sensitive parameters were SOL_K.sol, CH_N2.rte, CN2.mgt, SOL_BD.sol, ALPHA_BF.gw, ALPHA_BNK.rte, SOL_AWC.sol, CH_K2.rte, SFTMP.bsn, GW_DELAY.gw. Following the sensitivity analysis, SWAT-CUP calibration was carried out using 8-day interval flow data from January 2008 to December 2010. The results were then assessed based on the visual agreement and simulated flow plots and the performance statistics generated $R^2$ and NSE which are 0.71 and 0.61 respectively. Results of these statistics indicated that there was a good agreement between the observed and simulated flow. To extend daily flow data from 8-day interval flow data, parameters, which were estimated by SWAT-CUP, re-entered for SWAT model. As a result, the observed flow data were found to reflect the trend of simulated flow data. From these results, it is thought that this method could be used to provide daily flow data using 8-day interval flow data.

• Journal of Chest Surgery
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• v.32 no.11
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• pp.971-977
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• 1999

Background: Immunologic and inflammatory responses of cardiopulmonary bypass(CPB) influence postoperative mortality and morbidity with multiple organ injury. It has been reported that ischemia/reperfusion induced-myocardial injury during CPB is causative of release of inflammatory cytokines such as interleukin-6(IL-6) and tumor necrosis factor-$\alpha$ (TNF-$\alpha$). The purpose of this study was to detect the time course of the activated cytokine and troponin-T(TnT), and to examine the correlation between such parameters during CPB. Material and Method: The serial samples were collected from arterial blood via radial arterial catheter in 23 patients who are underwent open heart surgery (OHS) with CPB, the IL-6, TNF-$\alpha$ and TnT were checked. Result: \circled1 IL-6, TNF$\alpha$- and TnT concentration increased significantly during CPB with a peaking level of CPB-off (p 0.05). \circled2 IL-6 had highly positive correlation with aortic cross clamping time and total bypass time(r=0.80, 0.78; p 0.05, respectively). \circled3 There was no correlation among IL-6, TNF-$\alpha$ and TnT. Conclusion: In conclusion, these data showed that elevated production of serum IL-6 during CPB was attributable to ischemia/reperfusion induced-myocardial damage. IL-6 will become a new and sensitive biological marker in assessment of myocardial damage during OHS with CPB. However, further studies will be needed to apply IL-6 in more patient population.

• Journal of Ecology and Environment
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• v.35 no.4
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• pp.323-329
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• 2012

The Standardized Precipitation Index (SPI) is a widely used drought index to provide good estimations of the intensity, magnitude and spatial extent of droughts. The objective of this study was to analyze the spatial pattern of drought by SPI index. In this paper, the patterns of drought hazard in Iran are evaluated according to the data of 40 weather stations during 1967-2009. The influenced zone of each station was specified by the Thiessen method. It was attempted to make a new model of drought hazard using GIS. Three criteria for drought were studied and considered to define areas of vulnerability. Drought hazard criteria used in the present model included: maximum severity of drought in the period, trend of drought, and the maximum number of sequential arid years. Each of the vulnerability indicators were mapped and these as well as a final hazard map were classified into 5 hazard classes of drought: one, slight, moderate, severe and very severe. The final drought vulnerability map was prepared by overlaying three criteria maps in a GIS, and the final hazard classes were defined on the basis of hazard scores, which were determined according to the means of the main indicators. The final vulnerability map shows that severe hazard areas (43% of the country) which are observed in the west and eastern parts of country are much more widespread than areas under other hazard classes. Overall, approximately half of the country was determined to be under severe and very severe hazard classes for drought.