• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.171-179
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• 2014

In this study, a novel method was proposed to test the integrity of water treatment system specifically equipped with membrane filtration process. We applied the silica particles coated with a fluorescent agent (rhodamine B isothiocyanate) as a surrogate to detect a membrane process integrity and evaluate the reliability of effluent quality in the system. Additionally, a series of experiments was conducted to evaluate the sensitivity of the method through the laboratory scale experiment. The laboratory scale experiments showed that the feasibility of application of proposed method to detect a breach or damaged part on the membrane surface. However, the sensitivity on predicting the area of a breach was significantly influenced by the testing conditions such as a concentration of surrogate, filtration flux, and detection time. The lowest error of predicting the area of breach was 3.5% at the testing condition of surrogate concentration of 80 mg/L injected with flux of $20L/m^2/hr$ for 10 minutes of detection time for the breach having the actual area of $7.069mm^2$. However, the error of estimation was increased at the small breach with area less than $0.785mm^2$. A future study will be conducted to estimate a damaged area with more accuracy and precision.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.7-15
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• 2007

To evaluate the durability of finger-jointed woods according to change of humidity conditions, four types of finger-jointed woods glued with different kinds of adhesives and finger pitches were made with Sitka spruce, and the effect of humidity conditions on creep performances was investigated. The shape of creep curves differed among humidity conditions, and the inclination of creep curves was greatest in 85%RH, and lowest in 65%RH. Their creep curves showed a linear behavior beyond approximately one hour, regardless of humidity conditions. The A values of the creep curves fitted to power law increased with increasing relative humidity, whereas the A' values were in order of 30 > 85 > 65%RH unlike the A values. The initial deformation increased with increasing relative humidity, whereas the creep deformation unlike the initial deformation was in order of 85 > 30 > 65%RH, and it was found that the creep deformation of finger-jointed woods indicated the smaller amount in air-dry moisture content rather than in a low moisture content less than 30%RH. Finger-jointed woods with 6.8 mm (L) pitch had the greater creep amount than in those with 4.4 mm (S) pitch in all humidity conditions. The difference of creep amount between both adhesives in all humidity conditions was small. Relative creep at 240 hr was greatest as 62.2~71.9% in 85%RH, and the values indicated 2.1~2.6 times that of 30%RH and 3.0~3.6 times that of 65%RH and were equal or slightly greater than that of solid spruce.

• The korean journal of orthodontics
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• v.51 no.2
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• pp.86-94
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• 2021

Objective: This study aimed to investigate the effect of micro-osteoperforations (MOPs) on external apical root resorption (EARR) during the initial orthodontic alignment phase of maxillary anterior crowding. Methods: Thirty patients (25 females, 5 males; mean age, 22.66 ± 3.27 years) who presented with moderate crowding of the upper labial segment and underwent extraction-based fixed appliance treatment were recruited. They were randomly allocated to receive adjunctive therapy with MOPs (n = 15) or treatment with fixed appliances only (control group; n = 15). EARR was measured from long-cone periapical radiographs taken at the start and the sixth month of treatment. A correction factor for the enlargement difference was used to calculate EARR. Data were analyzed with descriptive statistics and repeated-measures analysis of variance. Results: The mean root lengths of 168 teeth were measured and showed no statistically significant difference (p > 0.05) after six months of fixed appliance treatment in the MOP (mean difference [MD] = 0.13 mm; 95% confidence interval [CI] = -0.10-0.35) and control group (MD = 0.14 mm; 95% CI = -0.10-0.37). Most of the roots in the MOP and control groups (42.86% and 52.38%, respectively) showed only mild resorption. Less than 8% of the roots in both groups (7.14% in the MOP group and 4.76% in the control group) showed moderate resorption. Conclusions: Acceleration of orthodontic tooth movement with adjunctive MOPs therapy during the alignment phase does not exacerbate EARR in patients with moderate crowding of the upper labial segment in comparison with controls.

• Analytical Science and Technology
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• v.36 no.4
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• pp.180-190
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• 2023

The presence of process related impurities in any drug or the drug product was associated with its safety, stability and efficacy. The overall literature survey proved that there is no method published on the assessment of process related impurities in brigatinib. In this study, a simple, reliable and stable HPLC qualitative method was reported for quantification of process related impurities with easy and quick extraction procedure. The impurities along with standard brigatinib was resolved on Lichrospher^® C18 (250 mm × 4.6 mm; 5 ㎛ particle size) column in room temperature using methanol, acetonitrile, pH 4.5 phosphate buffer in 55:25:20 (v/v) at 1.0 mL/min as mobile phase and UV detection at 261 nm. The method produces well resolved peaks at retention time of 4.60 min, 12.28 min, 3.37 min, 7.34 min and 8.39 min respectively for brigatinib, impurity A, B, C and D. The method produces a very sensitive detection limit of 0.0065 ㎍/mL, 0.0068 ㎍/mL, 0.0053 ㎍/mL and 0.0058 ㎍/mL for impurity A, B, C and D respectively with calibration curve linear in the concentration range of 22.5-135 ㎍/mL for brigatinib and 0.0225-0.135 ㎍/mL for impurities. The method produces all the validation parameters under the acceptable level and doesn't produces any considerable changes in peak area response while minor changes in the developed method conditions. The method can effectively resolve the unknown stress degradation products along with known impurities with less % degradation. The method can efficiently resolve and quantify the impurities in formulation and hence can suitable for the routine quality analysis of brigatinib in raw material and formulation.

• Clinical and Experimental Pediatrics
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• v.50 no.1
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• pp.47-51
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• 2007

Purpose : The early diagnosis of Kawasaki disease (KD) is difficult sometimes, especially in atypical or incomplete cases presenting 4 or less principal clinical features without coronary arterial lesions (coronary arterial ectasia or aneurysm). The authors investigated the incidence of echocardiographic abnormalities in patients with KD to discover whether abnormal echocardiographic findings might be helpful in the early diagnosis of KD. Methods : Echocardiography was done in the acute stage of 103 patients with KD (Kawasaki group) and 40 patients with other acute febrile illnesses (control group). Abnormal echocardiographic findings were classified into 4 categories and defined as follows; 1) significant pericardial effusion, 2) significant valvular dysfunctions, 3) left ventricular systolic dysfunction, 4) coronary arterial ectasia or aneurysm. Results : In the Kawasaki group, significant pericardial effusion was present in 24 patients (23.3 percent), significant valvular dysfunctions in 30 patients (29.1 percent), left ventricular systolic dysfunction in 10 patients (9.7 percent), and coronary arterial lesions in 27 patients (26.2 percent). In the control group, significant pericardial effusion was present in only one patient (2.5 percent). The number of patients with any one of echocardiographic abnormalities was 57 (55.3 percent) in Kawasaki group and one (2.5 percent) in control group. The sensitivity of echocardiography in the diagnosis of KD was 55.3 percent, the specificity 97.5 percent, the positive predictive value 98.3 percent, and the negative predictive value 45.9 percent. Conclusion : If abnormal echocardiographic findings, even if other than coronary arterial lesions, are confirmed in patients in whom KD is suspected, it seems desirable to inifiate specific treatment for KD.

• Journal of Chest Surgery
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• v.37 no.1
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• pp.35-42
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• 2004

Background: For the treatment of isolated left main coronary artery disease, twelve arterial revascularizations with Y-composite grafts using left internal thoracic artery and radial artery or right gastroepiploic artery were peformed. This study was performed to investigate whether V-composite graft can satisfy the blood flow required to make myocardium act properly or not. Borderline stenotic lesions on the left main coronary artery, which are very prone to remodel the bypassed vessels due to competitive flows, were also considered. Material and Method: Among 247 patients who underwent coronary artery bypass grafting from March 2000 to April 2003, 12 patients (4.7%) who had received total arterial revascularizations for the isolated left main coronary artery disease were studied retrospectively. Result: left anterior descending arteries were bypassed with left internal thoracic artery by off-pump technique in all patients, however, 2 cases of left obtuse marginal branches were bypassed under on-pump beating heart. Except for one patient, who did not have an obtuse marginal branch more than 1 mm in diameter, 11 patients had gone through complete arterial revascularizations by use of the Y shape arterial graft. Among five patients who had less than 75% stenosis, one patient showed string sign on left internal thoracic artery grafted to left anterior descending artery. However, two grafts to obtuse marginal blanches were completely obstructed and one showed slender sign. There were no graft-dominant flow in patients with stenotic lesion less than 75%. On the contrary to the result of patients with stenotic lesions less than 75%, all the patients with stenotic lesions more than 90% showed graft-dominant blood flow. Conclusion: In conclusion, it is assumed that, when stenotic lesions are over 90%, coronary artery bypass grafting with an Y shape arterial graft could possibly give enough help to the obstructed coronary arteries in blood supplying to myocardium, which needs massive quantity of blood to act well. However, when patients have borderline stenoses, through scrupulous examinations, more prudent and flexible decisions are required in choosing the treatment methods, such as, direct anastomosis of vein or artery to aorta, or adding supplementary treatment methods like percutaneous coronary intervention, rather than choosing a fixed treatment methods.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.420-427
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• 2000

Background : Isolated leukopenia is rare, but it has important clinical implications during antituberculosis treatment. Inadvertent discontinuation of short-course regimen drugs for fear of leukopenia inevitably will extend the duration of treatment, and the completion of treatment will be delayed. However no guidelines concerning proper management for leukopenia during antituberculosis treatment have been presented. Therefore, this study was performed to evaluate the possibility of continuing the same short-course regimen if a mild-to-moderate degree of isolated leukopenia was to develop during antituberculosis treatment. Method : Thirty-six patients who had been prescribed a short-course antituberculosis regimen between January 1997 and August 1999, had newly developed, mild-to-moderate degree, isolated leukopenia during medication, and had continued the same drug regimen despite leukopenia were enrolled. One patient was not available for the follow-up, so the remaining thirty-five (twenty-five prospectively and ten retrospectively) patients were analyzed. Patients who had other known causes of leukopenia were excluded. A mild-to-moderate degree of isolated leukopenia was arbitrarily defined as having a peripheral blood leukocyte count between 2,000 and $3,499/mm^3$ and no evidence of coexisting hematologic abnormalities. Results : 1) All thirty-five patients were able to complete short-course anti-tuberculosis treatment without complication or further decrease of leukocytes count to less than $2,000/mm^3$ despite continuous treatment with the same regimen. 2) The mean duration from start of antitituberculosis medication to detection of leukopenia was $64{\pm}65$ days. 3) The mean leukocyte count was $5,035{\pm}1,583/mm^3$ before treatment, and the its lowest count was $2,908{\pm}390/mm^3$ during treatment. Leukopenia recovered after completion of treatment ($4,283{\pm}1,269/mm^3$). 4) The main component of leukopenia was the decrease in neutrophil count ($3,361{\pm}1,732$ vs. $1,512{\pm}423/mm^3$, p<0.05). Conclusion : For mild-to-moderate degree of isolated leukopenia ($2,000/mm^3{\leq}$ WBC < $3,500/mm^3$), developing during short-course antituberculosis treatment, the short-course antituberculosis regimen may be continued without complications.

• Tuberculosis and Respiratory Diseases
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• v.45 no.1
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• pp.140-152
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• 1998

Background: Prone position improves oxygenation in patients with ARDS probably by reducing shunt Reduction of shunt in prone position is thought to be effected by lowering of the critical opening pressure (COP) of the dorsal lung because the pleural pressure becomes less positive in prone position compared to supine position. It can then be assumed that prone position would bring about greater improvement in oxygenation when PEEP applied in supine position is just beneath COP than when PEEP is above COP. Hemodynamically, prone position is expected to attenuate the lifting of cardiac fossa induced by PEEP. Based on these backgrounds, we investigated whether the effect of prone position on oxygenation differs in magnitude according to the level of PEEP applied in supine position, and whether impaired cardiac output in supine position by PEEP can be restored in prone position. Methods: In seven mongrel dogs, $PaO_2/F_1O_2$(P/F) was measured in supine position and at prone position 30 min. Cardiac output (CO), stroke volume (SV), pulse rate (PR), and pulmonary artery occlusion pressure (PAOP) were measured in supine position, at prone position 5 min, and at prone position 30 min. After ARDS was established with warmed saline lavage(P/F ratio $134{\pm}72$ mm Hg), inflection point was measured by constant flow method($6.6{\pm}1.4cm$ $H_2O$), and the above variables were measured in supine and prone positions under the application of Low PEEP($5.0{\pm}1.2cm$ $H_2O$), and Optimal PEEP($9.0{\pm}1.2cm$ $H_2O$)(2 cm $H_2O$ below and above the inflection point, respectively) consecutively. Results : P/F ratio in supine position was $195{\pm}112$ mm Hg at Low PEEP and $466{\pm}63$ mm Hg at Optimal PEEP(p=0.003). Net increase of P/F ratio at prone position 30 min, however, was far greater at Low PEEP($205{\pm}90$ mm Hg) than at Optimal PEEP($33{\pm}33$ mm Hg)(p=0.009). Compared to CO in supine position at Optimal PEEP($2.4{\pm}0.5$ L/min), CO in prone improved to $3.4{\pm}0.6$ L/min at prone position 5 min (p=0.0180) and $3.6{\pm}0.7$ L/min at prone position 30 min (p=0.0180). Improvement in CO was attributable to the increase in SV: $14{\pm}2$ ml in supine position, $20{\pm}2$ ml at prone position 5 min (p=0.0180), and $21{\pm}2$ ml at prone position 30 min (p=0.0180), but not to change in PR or PAOP. When the dogs were turned to supine position again, MAP ($92{\pm}23$ mm Hg, p=0.009), CO ($2.4{\pm}0.5$ L/min, p=0.0277) and SV ($14{\pm}1$ ml, p=0.0277) were all decreased compared to prone position 30 min. Conclusion: Prone position in a dog with saline-lavaged acute lung injury appeared to augment the effect of relatively low PEEP on oxygenation, and also attenuate the adverse hemodynamic effect of relatively high PEEP. These findings suggest that a PEEP lower than Optimal PEEP can be adopted in prone position to achieve the goal of alveolar recruitment in ARDS avoiding the hemodynamic complications of a higher PEEP at the same time.

• Korean Journal of Environment and Ecology
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• v.33 no.6
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• pp.677-685
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• 2019

We investigated the ecological characteristics of kumgang fat minnow (Rhynchocypris kumgangensis) in the Eocheon stream from October 2017 to September 2018. The water temperature was 10.2- 14.3℃ and remained below 15℃ during the year. The fishes in cohabitation with kumgang fat minnow were Cottus koreanus (16.62%), Phoxinus phoxinus (10.74%), Rhynchocypris oxycephalus (1.55%), Oncorhynchus mykiss (0.56%), Zacco koreanus (0.28%), and Iksookimia koreensis (0.14%%). The ratio of females to males was 1:0.91 and did not vary widely. The frequency analysis of total length indicated that the fishes with less than 40 mm in total length were one year old, those with 40 - 69 mm were two years old, those with 70 - 84 mm were three years old, and those with 85 mm or more were four years old for individuals collected in May through June. The sexually mature fishes were over two years old. The spawning season was from late May to late August, and the water temperature was 12.5~14.5℃ during the period. The prosperous spawning season was from June to July, and the water temperature was 13.6 - 14.5℃ during the spawning period. The average number of eggs in the ovaries was 1,006 (664 - 1,666) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 1.34±0.17 mm. The length-weight correlation of R. kumgangensis was BW = 0.00003TL^2.77 with the constant a as 0.00003, b as 2.77, the average condition factor (K) as 1.04(0.65~1.48), and the slope as -0.0012. The kumgang fat minnows inhabiting in the spring water had a longer spawning period, a fewer number of eggs in ovaries, and the lower condition factor (K) than those inhabiting other areas.

• The Journal of Natural Sciences
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• v.14 no.1
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• pp.139-149
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• 2004

It was aimed to find out an efficient method of drying hot pepper, of which powder is used as one of the main ingredients in Korean dish preparation including Kimchi. Before sun or heat drying fruits harvested were horizontally cut into three pieces punched with an auger of 4 mm in diameter, or used as the whole fruit. Various drying methods were used including sun drying, drying under a plastic house, sun drying after heat drying for 5 hours at $70^{\circ}C$, $80^{\circ}C$, or $90^{\circ}C$, heat drying only at $50^{\circ}C$, $60^{\circ}C$, or $70^{\circ}C$, and changing temperature of $70^{\circ}C$, $5hours+60^{\circ}C$ until coplete dry, $80^{\circ}C+60^{\circ}C$, or $90^{\circ}C+60^{\circ}C$. The results are summarized as follows. With sun drying of the whole fruit, in required about 10days to reach the satisfactory level of dryness as indicated by its moisture content of below 10% in general. In case of heat drying combined with sun drying, it required 5 to 7 days. For cut fruits, it required 1 or 2 days less than for whole or pinholed fruits until drying. Under heat of alternation temperature drying, cut fruits also dried 15-20 hours earlier compared with whole of pinholed fruits. There were not significant differences for the recovery rate of the fruit with various drying methods. The occurrence of white fruits, which are caused by one of physiological disorders during drying, and rotten fruits was reduced with the cut fruit drying. The damages were very high with the PE house drying, but very little with the heat drying.