• Clinical and Experimental Pediatrics
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• v.49 no.9
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• pp.952-958
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• 2006

Purpose : The survival rate of infants weighing less than 1,000 g at birth(extremely low birth weight infants, ELBWI) has increased due to recent advances in perinatal and neonatal intensive care. The purpose of this study was to evaluate the survival rates of ELBWI born at Seoul National University Hospital during the last six years. Methods : A total of 99 infants were divided into three groups(period I: 2000 to 2001, period II: 2002 to 2003, period III : 2004 to 2005) based on date of birth. We compared the survival rate of ELBWI over the three periods, using CRIB II score for adjustment for clinical severity. Results : Overall survival rate of ELBWI was 74.7 percent. The survival rate of ELBWI increased over the three periods(period I: 60.7 percent, period II : 73.3 percent, period III : 85.3 percent). The threshold of viability(defined as survival of at least 50 percent of infants) was 25 weeks of gestation and 600 g at birth. The birth weight-specific survival rates increased considerably over the three periods for infants <750 g at birth(period I: 10 percent, period II: 46.2 percent, period III : 70.6 percent). The survival rates of ELBWI over the three periods increased much remarkably after adjustment for clinical severity by CRIB II score. Conclusion : In our institution, survival rates of ELBWI during the last six years continued to improve, particularly for infants weighing <750 g at birth. This increase in survival rates was not associated with the clinical severity of ELBWI.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.78-86
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• 2004

In order to reveal the relationship between the concentration of chlorophyll- a and the environmental factors affecting eutrophication, the present study was biweekly conducted at G stations in the lower part of the Han river during the period from Feb. 24,2001 to Feb. 9,2002. Water temperature was changed from $0.5^{\circ}C$ to $26.4^{\circ}C$, pH was 5.77${\sim}$8.99, DO 3.15${\sim}$14,36 mg $L^{-1}$, BOD 0.90${\sim}$7.45 mg $L^{-1}$, and COD 1.16${\sim}$9.13 mg $L^{-1}$. TN and TP were ranged from 1.68${\sim}$20.96 mg $L^{-1}$, and 0.02 ${\sim}$ 1.17 mg $L^{-1}$, respectively. $NH_4\;^+$-N, $NO_3\;^-$-N, and $PO_4\;^{3-}$-P were ranged from 0.56${\sim}$3.60 mg $L^{-1}$, 0.03${\sim}$7.29 mg $L^{-1}$, and 0.002${\sim}$0.754 mg $L^{-1}$. Chlorophyll- a was extensively changed from 2.29 ${\mu}g\;L^{-1}$ to 136.28 ${\mu}g\;L^{-1}$ by month and stations. Results of nutrients indicated the eutrophic level in this area and water quality was the gradual worsening in the lower stations than those of upper stations during the period studied. The Pearson correlation analysis between the concentration of chlorophyll- a and the environmental factors indicated that BOD, COD, pH, $NH_4\;^+$-N, TP, TN, conductivity and $PO_4\;^{3-}$-P were positive correlation, but $NO_3\;^-$-N was negative. The environmental factors investigated using the principal component method could be triparted. The first factor group included conductivity, BOD, COD, TN, TP, $NH_4\;^+$-N, $PO_4\;^{3-}$-P and SS, the second WT and DO, and the third pH and $NO_3\;^-$-N. Using the stepwise regression analysis, chlorophyll- a was under the influence of conductivity, $PO_4\;^{3-}$-P, $>NO_3\;^-$-N and $NH_4\;^+$-N Chlorophyll-a = 0.3661 ${\times}$ (Conductivity) - 0.3592 ${\times}$ ($PO_4\;^{3-}$-P) - 0.3449 ${\times}$ ($NO_3\;^-$-N)+0.4362 ${\times}$ ($NH_4\;^+$-N.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.280-286
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• 2012

Clean energy farming is the agricultural activity to improve an efficiency of agricultural energy use and to replace fossil fuels. This study was carried out to establish the clean energy farming system in the controlled cultivation of vegetable crop (cucumber) adopting the biogas production facility. In order to design the clean energy farming system, mass and energy balance was analyzed between the controlled cultivation system and the biogas production facility. Net yearly heating energy demands ($E_{YHED}$) of forcing and semi-forcing cultivation types were 48,697 and $13.536Mcal\;10^{-1}$ in the controlled cultivation of vegetable cucumber. To cover these $E_{YHED}$, the pig slurry of 511 and $142m^3\;10a^{-1}$ (biogas volume of 9,482 and $2,636Nm^3\;10a^{-1}$, respectively, as 60% methane content) were needed in forcing and semi-forcing cultivation types. The pig slurry of $511m^3\;10a^{-1}$ caused N 1,788, $P_2O_5$ $511kg\;10a^{-1}$ in the forcing cultivation type, and the pig slurry of $142m^3\;10a^{-1}$ caused N 497, $P_2O_5$ $142kg\;10a^{-1}$ in the semi-forcing cultivation type. The daily heating energy demand ($E_{i,DHED}$) by the time scale analysis showed the minimum $E_{i,DHED}$ of $7.7Mcal\;10a^{-1}\;day^{-1}$, the maximum $E_{i,DHED}$ of $515.1Mcal\;10a^{-1}\;day^{-1}$, and the mean $E_{i,DHED}$ of 310.2 in the forcing cultivation type. And the minimum $E_{i,DHED}$, the maximum $E_{i,DHED}$, and the mean $E_{i,DHED}$ were 5.3, 258.0, and $165.1Mcal\;10a^{-1}\;day^{-1}$ in the semi-forcing cultivation type, respectively. Input scale of biogas production facility designed from the mean $E_{i,DHED}$ were 3.3 and $1.7m^3\;day^{-1}$ in the forcing and the semi-forcing cultivation type. The maximum $E_{i,DHED}$ gave the input scale of 5.4 and $2.7m^3\;day^{-1}$ in the forcing and the semi-forcing cultivation type.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.83-87
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• 2011

Purpose: Recently in diagnostics area PET/CT is using a variety of areas including oncology, as well as in cardiology, neurology, etc. While increasing in the importance of PET/CT, there are various researches in the image quality related to reconstruction method. We compared and tested Iterative 2D Reconstruction Method with True X Reconstruction method by Siemens through phantom experiment, so we can see increasing of clinical usefulness of PET/CT. Materials and Methods: We measured contrast ratio and FWHM due to evaluating images on dose and experiment using Biograph 40 True Point PET/CT (Siemens, Germany). Getting a result of contrast ratio and FWHM, we used NEMA IEC PET body phantom (Data Spectrum Corp.) and capillary tube. We used the current TrueX and the previous Iterative 2D algorithm for all images which have 10 minutes long. Also, a clinical suitability of parameter for Iterative 2D and a recommended parameter by Siemens for True X are applied to the experiment. Results: We tested FWHM using capillary tube. As a result, TrueX was less than Iterative 2D. Also, the differences of FWHM get bigger in low dose. On the other hand, we tested contrasts ratio using NEMA IEC PET body phantom. As a result, TrueX was better aspect than Iterative 2D. However, there was no difference in dose. Conclusion: In this experiment, TrueX get higher results of contrast ratio and spatial resolution than Itertive 2D through experiment. Also, in the reconstruction result through TrueX, TrueX had better aspect of resolution than Iterative 2D in low dose. However, contrast ratio had no specific difference. In other words, TrueX reconstruction method in PET/CT had higher clinical value in use because TrueX can reduce exposure of patient and had a better quality of screen.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.146-153
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• 1997

Background : Chronic cough is commomly defined as a persistent or recurrent cough exceeding 3 week's duration. The prevalence of chroinc cough is reported to range from 14% to 23 % for nonsmoking adults. The post nasal drip syndrome has been determined to be the most common cause of chronic cough, followed by asthma, chronic bronchitis, gastroesophageal reflux and bronchiectasis. Cough can be the only manifestation of asthma. Bronchial provocation tests are useful in diagnosing cough variant asthma. We investigated the clinical or laboratory findings and the incidence of airway hyperresponsiveness and evaluated the etiology in patients with chronic cough. Method : We evaluated 46 patients with chronic cough. Methacholine challenge test were done. Results : The results were as follows : 1) Thirty - five percent(16/46) of the chronic cough patients and 44% of the post nasal drip syndrom(7/16) showed the positive responses to methacholine challenge test 2) The underlying causes of chronic cough were post nasal drip syndrome in 35%, bronchitis in 21.7%, cough-variant asthma in 17.4%, and unknown condition in 25.9%. 3) Airway hyperresponsiveness in chronic cough was not related to respiratory symptom, nasal symptom, post nasal drip, smoking, derangement of ventilatory function, atopy, or sinusitis. Conclusion : Airway hyperresponsivenss in patients with chronic cough increased in frequency when compaired with normal control, allergic rhinitis. Cough-variant asthma account for 17.4% of patients with chronic cough.

• Journal of Mushroom
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• v.6 no.1
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• pp.13-19
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• 2008

This experiment was carried out to examine physiological and cultural characteristics of two strains ASI 19003, 'Poplar field-cap mushroom' Agrocybe cylindracea, and ASI 19016, 'Chaxingo' A. chaxingu, at the bottle cultivation which have very similar morphological characteristics in genus Agrocybe. There was significant difference between the physiological and cultural characteristics of ASI19003 and ASI19016. The optimal temperature for the hyphal growth was $28^{\circ}C$ in the strain ASI19003 and $30^{\circ}C$ in ASI19016. The optimal pH was not different in two strains and these strains grew well at pH 5.5~7.0. But the optimal pH in the submerged culture was 5.5 in ASI19003 and 5.0 in ASI19016. Especially, hyphal growth of the strain ASI19016 was very poor at pH 6.0~7.3. The optimal carbon source for the growth was lactose in the strain ASI19003 and fructose in ASI19016, and nitrate sources were asparagine, alanine, and glycine in the strain ASI19003, and ammonium tartrate, asparagine, glycine, and alanine in ASI19016, respectively. The periods of incubation and fruiting body formation in the bottle cultivation during the spring were 27 and 13 days in the strain ASI19003, 29 and 17 days in ASI19016. The yields of fruit body were 114 g per bottle (850 $m{\ell}$ volume) in the strain ASI19003 and 100 g in ASI19016. In the summer, the periods of hyphal incubation and fruiting body formation were 29 and 11 days in the strain ASI19003, 30 and 12 days in ASI19016. The color of the cap in the ASI19003 strain according to temperature increase during the fruit body development become more pale, but the strain ASI19016 kept dark color relative to ASI19003. The fruiting body formation of the strain ASI19016 was faster than that of ASI19003. Accordingly, the cultivation of A. cylindracea ASI19003 during the spring, fall and winter, and A. chaxingu ASI19016 during the summer can keep high quality and stable supply all year round of these mushrooms.

• Resources Recycling
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• v.28 no.6
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• pp.79-86
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• 2019

Recently, the use of lithium ion battery(LIB) has increased. As a result, the price of lithium and the amount spent lithium on ion battery has increased. For this reason, research on recycling lithium in waste LIBs has been conducted1). In this study, the effect of roasting for the selective lithium leaching from the spent LIBs is studied. Chemical transformation is required for selective lithium leaching in NCM LiNi_xCo_yMn_zO₂) of the spent LIBs. The carbon in the waste EV cell powder reacts with the oxygen of the oxide at high temperature. After roasting at 550 ~ 850 ℃ in the Air/N₂ atmosphere, the chemical transformation is analysed by XRD. The heat treated powders are leached at a ratio of 1:10 in D.I water for ICP analysis. As a result of XRD analysis, Li₂CO₃ peak is observed at 700 ℃. After the heat treatment at 850 ℃, a peak of Li₂O was confirmed because Li₂CO₃ is decomposed into Li₂O and CO₂ over 723 ℃. The produced Li₂O reacted with Al at high temperature to form LiAlO₂, which does not leach in D.I water, leading to a decrease in lithium leaching ratio. As a result of lithium leaching in water after heat treatment, lithium leaching ratio was the highest after heat treatment at 700 ℃. After the solid-liquid separation, over 45 % of lithium leaching was confirmed by ICP analysis. After evaporation of the leached solution, peak of Li₂CO₃ was detected by XRD.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.289-295
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• 2018

The aim of this study was to develop and validate an analytical method for determining the presence of wogonin, quercetin, and quercetin-3-O-glucuronide in extracts of Nelumbo nucifera, Morus alba L., and Raphanus sativus mixtures. We evaluated the specificity, linearity, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) of analytical methods for wogonin, quercetin, and quercetin-3-O-glucuronide using high performance liquid chromatography. Our result showed that the correlation coefficients of the calibration curve for wogonin, quercetin, and quercetin-3-O-glucuronide were 0.9999. The LOD for wogonin, quercetin, and quercetin-3-O-glucuronide ranged from 0.09 to 0.16 and those for the LOQ ranged from 0.26 to $0.48{\mu}g/mL$. The inter-day and intra-day precision values of wogonin, quercetin, and quercetin-3-O-glucuronide ranged from 0.74 to 1.87 and from 0.28 to 1.12%, respectively. The inter-day and intra-day accuracies were 99.96~115.88% and 99.73~114.81%, respectively. Therefore, the analytical method was validated for the detection of wogonin, quercetin, and quercetin-3-O-glucuronide in extracts of Nelumbo nucifera, Morus alba L., and Raphanus sativus mixtures.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.188-197
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• 2015

Purpose: To investigate the patterns of care for patients with nasopharyngeal carcinoma (NPC) in South Korea. Materials and Methods: A multi-institutional retrospective study was performed (Korean Radiation Oncology Group [KROG] 11-06) on a total of 1,445 patients from 15 institutions. Results: Of the 1,445 patients, more than half were stages III (39.9%) and IV (35.8%). In addition to patterns of care, we also investigated trends over time with the periods 1988-1993, 1994-2002, and 2003-2011. The frequencies of magnetic resonance imaging and positron emission tomography-computed tomography were markedly increased in the third period compared to previous 2 periods. Concurrent chemoradiation (CCRT) was performed on 894 patients (61.9%), neoadjuvant chemotherapy on 468 patients (32.4%), and adjuvant chemotherapy on 366 patients (25.3%). Of stage II-IV patients, CCRT performed on 78.8% in 2003-2011 compared to 15.0% in 1988-1993. For patients treated with CCRT, cisplatin was the most commonly used agent in 81.3% of patients. Over the periods of time, commonly used radiotherapy (RT) techniques were changed from 2-dimensional RT (1988-1993, 92.5%) to 3-dimensional RT (2003-2011, 35.5%) or intensity-modulated RT (IMRT; 2003-2011, 56.5%). Median RT doses given to primary tumors, high-risk lymphatics, and low-risk lymphatics were 70.0 Gy, 58.1 Gy, and 48.0 Gy, respectively. Adoption of IMRT increased the dose per fraction and escalated total radiation dose. Conclusion: Assessment of the patterns of care for NPC patients in South Korea demonstrated that management for NPC including diagnostic imaging, treatment regimen, RT techniques and dose schedule, advanced in accordance with the international guidelines.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.822-828
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• 1998

Binary system of water and polyoxyethylene dodecyl ether, $C_{12}H_{25}(OCH_2CH_2)nOH$, have been studied by $^1H$ NMR techniques. For n=5($C_{12}EO_5$) and n=8($C_{12}EO_8$), the self-diffusion coefficients of nonionic surfactants in the isotropic phase($L_1$) have been measured by using pulsed field gradient technique for a range of temperature and concentrations. In addition the line widths of the different proton signals have been monitored, and samples of some liquid crystalline characteristic were also studied. Dramatic Broadening of the methylene signals of the alkyl($C_{12}H_{25}$) chain is observed as the hexagonal liquid crystalline phase is approached in the $C_{12}EO_5-$water system, while only small broadening is observed in the $C_{12}EO_8-$water system. It was shown that there was a growth of $C_{12}EO_5$ micelles to rods with increasing concentrations, while the $C_{12}EO_8-$ micelles at low temperature remain small in the concentration range. The self-diffusion coefficients of the surfactants decrease rapidly with increasing concentration until a minimum is reached after which there is slow increase. The location of the minimum point occurs at lower concentrations the temperature is close to the cloud point, where the system separate into two isotropic phase. In the line width studies, broadening is found at a certain temperature interval when the concentration is increased in the $C_{12}EO_5$ system. The results indicate that the surfactant aggregates grow in size at the cloud point is approached. The aggregates seem to be flexible and probably not to be of a definite shape close to the cloud point. In the $C_{12}EO_8$ system, the micelles are much less affected by an increase in temperature and micellar growth can't be unambiguously established. The methylene signals of the ethylene oxide moieties consistantly show narrower $^1H$ signals, showing that in the aggregates they are less ordered than the chain methylenes. The various changes in aggregate size and shape are correlated with the stability ranges of the isotropic and liquid crystalline phases according to phase diagrams from the literature. Both aggregate size and phase structure are in qualitative agreement with concentration based on the effective shape of the molecules at different temperature and concentration.