• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.341-348
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• 2013

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of -20 kPa and high temperatures over $30^{\circ}C$ was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension, even though somewhat lower tension values were obtained as compared to the target tension of -20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from -10 to -20 kPa with the required water estimation system.

• Korean Journal of Clinical Laboratory Science
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• v.49 no.1
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• pp.1-7
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• 2017

Zerumbone is a major component of the essential oil from Zingiber zerumbet Smith, which is a kind of wild ginger. In addition, various biological functions, such as liver protection, pain relief, atherosclerosis, and antimicrobial activity have been reported. It is also known to be effective in the proliferation of immune cells and the expression of cytokines. In this study, we investigated the effects of zerumbone on monocyte activation. First, it was confirmed that the proliferation of THP-1 cells was increased by zerumbone. The strongest increase in THP-1 proliferation after lipopolysaccharide treatment was observed at $5{\mu}M$ zerumbone treatment, and the increase of cell proliferation without lipopolysaccharide was the highest at $10{\mu}M$. Conversely, when treated with $50{\mu}M$ zerumbone, a rapid decrease of proliferation was observed regardless of the presence of lipopolysaccharide (LPS). The phosphorylation of signaling protein, Erk, induced by LPS was also increased by zerumbone. The strongest increase in phosphorylation was observed when treated with $50{\mu}M$ of zerumbone with reduced proliferation. The activity of transcription factor $NF-{\kappa}B$ was not significantly altered by zerumbone alone, but increased when treated with lipopolysaccharide. Furthermore, the transcription of the inflammatory cytokines $TNF-{\alpha}$ and IL-8, which are regulated by $NF-{\kappa}B$, is also increased by zerumbone. These results suggest that zerumbone can enhance the proliferation and activity of monocytes. Furthermore, it is believed that zerumbone can enhance rthe immune responses through increased monocyte activity in bacterial infections with LPS, thereby helping to treat effective bacteria.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.1
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• pp.1-7
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• 2003

Time domain reflectometry (TDR) is a newly developed method for measuring simultaneously solute concentrations and volumetric water content of soil. Bulk electrical conductivity ($EC_a$) of soil is obtained from TDR signal using several equations proposed, and electrical conductivity of soil solution ($EC_w$) can be calculated using the linear relationship $EC_a=EC_w\theta(a\theta+b)+EC_s$ between $EC_a$ and $EC_w$ at constant soil water content. The objectives of this study were to evaluate $EC_a$ proposed by several workers and to obtain the empirical constants (a, b, and $EC_s$) for $EC_w$ of the soils from A, Bl, and B2 horizon of an agricultural field (Coarse loamy, Fluvaquentic Eutrudepts). The $EC_a$ proposed by Yanuka et al. responded most sensitively to the KCl solute concentrations. The empirical constants of a, b, and $EC_s$ for $EC_w$ were -0.249, 1.358, and 0.054 for A horizon, -2.518, 2.708, and 0.097 for Bl horizon, and 2.490, -0.250, and 0.103 for B2 horizon, respectively. Therefore, the results of this study showed that Yanuka et al. equation was most useful one in determining $EC_a$, from TDR signal for agricultural soil with low salinity and that the empirical constants for the calculation of $EC_w$, from $EC_a$ can be obtained through a simple calibration experiment.

• Journal of Chest Surgery
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• v.38 no.10 s.255
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• pp.669-674
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• 2005

Background: There are several studies that report the relationship between leukocytosis and cardiovascular disease mortality. Most of these studies stand on the basis that atherosclerosis is mediated by inflammatory process. By the same token, preoperative white blood cell count is suggested as an independent predictable factor of postoperative mortality and morbidity in coronary artery bypass grafting. The purpose of this study is to define the influence of preoperative white blood cell count on postoperative morbidity and mortality after coronary artery bypass grafting. Material and Method: The medical records of the 133 patients who had undergone isolated coronary artery bypass grafting at Inha University Hospital from 1996 to 2003 were reviewed. Patients were evenly divided into four groups, and named as group A, B, C, and D respectively based on their preoperative white blood cell count in ascending order. The number of patients in each group were 33 with exception of 34 in group A. The range of white blood cell count were from $1.3\times10^3/{\mu}L\;to\;5.9\times10^3/{\mu}L\;in\;group\;A,\; from\;6.0\times10^3/{\mu}L\;to\;7.0\times10^3/{\mu}L\;in\;group\;B,\;from\;7.1\times10^3/{\mu}L\;to\;8.9\times10^3/{\mu}L$ in group C, and from $8.9\times10^3/{\mu}L\;to\;16.9\times10^3/{\mu}L$ in group D. Result: The number of patients with recent myocardial infarction was 0 in group A, $2(6.1\%)$ in group B, $4(12.1\%)$ in group C, and $8(24.3\%)$ in D group, showing proportional increase to the white blood cell count (p<0.01). There were six postoperative deaths; $1(2.9\%)$ in group A, $1(3.0\%)$ in group B, $2(2.6\%)$ in group C, and $2(6.1\%)$ in group D (p=0.44), showing no significant difference between the groups. Postoperative wound infection occurred in 3 patients; all 3 patients were in group D, showing that postoperative wound infection is closely related to the preoperative white blood cell count. Conclusion: The association between preoperative white blood cell count and postoperative mortality could not be defined. The incidence of postoperative wound infection was found to be proportional to the preoperative white blood cell counts.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.4
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• pp.438-446
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• 2006

A lab-scale batch test was conducted to develop capping materials to reduce the sediment phosphorus in the stagnant water zone of Gyeongancheon in Paldang Lake. The mean grain size(Mz) of sediment in the investigated area was 7.7 ${\phi}$, which is very fine, and the contents of organic carbon($C_{org}$) was 2.4%, which is very high. For the phosphorous release experiment to select the optimal capping material, sand layer, powder-gypsum($CaSO_4{\cdot}2H_2O$), granule-gypsum, complex layer(gypsum+sand) and the control were compared and evaluated in the 150 L reactor for 45 days. In case of the capping with the sand, it was found that the phosphorous from the sediment could be reduced by around 50%. However, it was found that this caused the reduction of the dissolved oxygen in the water column(by less than 3 mg/L) due to the resuspension of sediment and the organic matter decomposition that comes from the generation of $CH_4$ gas in the 1 cm of the sand layer. Therefore, it is likely that the sand layer has to be thickener in case of the sand capping. Powder-gypsum and granule-Gypsum reduced phosphorous release by more than 80%. However, the concentration of ${SO_4}^{2-}$ in the water column increased, making it difficult to apply it to the drinking water protection zone. We developed Fe-Gypsum and $SiO_2$-gypsum materials to reduce the solubility of ${SO_4}^{2-}$. Powder-Gypsum creates the interception film that does not have any aperture on the sediment layer when it is combined with the water. However phosphorous release caused by the generation of $CH_4$ gas may happen at a time when the gypsum layer has the crack. Capping through the complex layer(granule-Gypsum+sand(1 cm)) found to be suitable for the drinking water protection zone because it was effective to prevent phosphorus release. Moreover, this leads to the lower solubility from the concentration of ${SO_4}^{2-}$ into the water column than the powder-Gypsum and granule-Gypsum. The addition of gypsum($CaSO_4{\cdot}2H_2O$) into the sediment can reduce the progress of methanogensis because fast early diagenesis and sufficient supply of ${SO_4}^{2-}$ to the sediment, stimulate the SRB(sulfate reducing bacteria) highly.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1093-1099
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• 2006

Purpose : Homocysteine is a strong and independent risk factor for cardiovascular disease. The deleterious effects of homocysteine included endothelial dysfunction, arterial intimal-medial thickening, wall stiffness and procoagulant activity. However, the precise mechanism responsible for homocysteine release in children with coronary artery disease is still unknown. The purpose of this study was to investigate serum homocysteine and tumor necrosis $factor(TNF)-{\alpha}$ levels and identify whether these levels had any association with the development of coronary artery lesions in Kawasaki disease(KD). Methods : Serum homocysteine and $TNF-{\alpha}$ levels were measured in 24 KD patients(group 1, eight patients with normal coronary artery; group 2, 16 patients with coronary artery lesions) and 21 controls(group 3, 10 afebrile controls; group 4, 11 febrile controls). Blood samples were drawn from each study group before and after intravenous immunoglobulin(IVIG) therapy and in the convalescent stage. Results : The homocysteine levels before IVIG therapy were significantly higher in group 1 than in group 3, and in group 2 than in group 3 and 4. The $TNF-{\alpha}$ levels before IVIG therapy were significantly higher in group 2 than group 3 and 4. Serum homocysteine and $TNF-{\alpha}$ levels were highest in group 2 before IVIG therapy. In the acute KD patients, serum homocysteine levels correlated significantly with $TNF-{\alpha}$ levels. Conclusion : The increased serum homocysteine levels in the acute stage increase the susceptibility to coronary arterial lesions in KD. $TNF-{\alpha}$ may also play an important role in the formation of coronary arterial lesions in KD.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.1
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• pp.5-10
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• 2012

In general, the fabrications of the LEDs with mesa structure are performed grown by MOCVD method. In order to etch and separate each chips, the LEDs are passed the RIE and scribing processes. The RIE process using plasma dry etching occur some problems such as defects, dislocations and the formation of dangling bond in surface result in decline of device characteristic. The SAG method has attracted considerable interest for the growth of high quality GaN epi layer on the sapphire substrate. In this paper, the SAG method was introduced for simplification and fabrication of the high quality epi layer. And we report that the size of selective area do not affect the characteristics of original LED. The diameter of SAG circle patterns were choose as 2500, 1000, 350, and 200 ${\mu}m$. The SAG-LEDs were measured to obtain the device characteristics using by SEM, EL and I-V. The main emission peaks of 2500, 1000, 350, and 200 ${\mu}m$ were 485, 480, 450, and 445 nm respectively. The chips of 350, 200 ${\mu}m$ diameter were observed non-uniform surface and resistance was higher than original LED, however, the chips of 2500, 1000 ${\mu}m$ diameter had uniform surface and current-voltage characteristics were better than small sizes. Therefore, we suggest that the suitable diameter which do not affect the characteristic of original LED is more than 1000 ${\mu}m$.

• Composites Research
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• v.14 no.3
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• pp.18-31
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• 2001

Interfacial and microfailure properties of the modified steel, carbon and glass fibers/cement composites were investigated using electro-pullout test under tensile and compressive tests with acoustic emission (AE). The hand-sanded steel composite exhibited higher interfacial shear strength (IFSS) than the untreated and even neoalkoxy zirconate (Zr) treated steel fiber composites. This might be due to the enhanced mechanical interlocking, compared to possible hydrogen or covalent bonds. During curing process, the contact resistivity decreased rapidly at the initial stage and then showed a level-off. Comparing to the untreated case, the contact resistivity of either Zr-treated or hand-sanded steel fiber composites increased to the infinity at latter stage. The number of AE signals of hand-sanded steel fiber composite was much more than those of the untreated and Zr-treated cases due to many interlayer failure signals. AE waveforms for pullout and frictional signals of the hand-sanded composite are larger than those of the untreated case. For dual matrix composite (DMC), AE energy and waveform under compressive loading were much higher and larger than those under tensile loading, due to brittle but well-enduring ceramic nature against compressive stress. Vertical multicrack exhibits fur glass fiber composite under tensile test, whereas buckling failure appeared under compressive loading. Electro-micromechanical technique with AE can be used as an efficient nondestructive (NDT) method to evaluate the interfacial and microfailure mechanisms for conductive fibers/brittle and nontransparent cement composites.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.27-34
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• 1999

Purpose: This study was designed to investigate the changes in soluble interleukin-2 receptor (sIL-2R) level in sera and urines of children with primary nephrotic syndrome, eliminating the confounding effects of age, proteinuria, and steroid treatment. Methods: Soluble IL-2R was measured by ELISA in sera and urines from patients with minimal change nephrotic syndrome or focal segmental glomerulosclerosis as well as from healthy controls. The serum levels and urinary sIL-2R/creatinine ratios were compared between control group and the 12 patient groups divided by their ages (0-1, 2-4, over 5 years), and presence or absence of proteinuria and/or steroid treatment (PU+Tx-, PU+Tx+, PU-Tx+, PU-Tx-). Results: Though the differences were not statistically significant probably because of the small numbers, serum sIL-2R levels seemed to be higher in younger age groups both in patients and control group. Nephrotic children did not show higher serum levels than normal children. Among the patients, proteinuric condition seemed to raise and steroid treatment tended to suppress the serum sIL-2R levels. Urinary sIL-2R/creatinine ratios were higher in younger age groups, more significantly in patients (P<0.001). Proteinuria and steroid treatment affected the urinary sIL-2R/creatinine ratios by the same way as the serum sIL-2R levels. Serum sIL-2R levels and urinary sIL-2R/creatinine ratios were not different between groups of different histologic findings or steroid responsiveness (P>0.05). Conclusion: Serum sIL-2R levels and the urinary sIL-2R/creatinine ratios were higher in younger age, and they were not higher in nephrotic patients compared to control group. The patients in relapse showed higher levels, while the levels were suppressed with steroid treatment. In proteinuric state, urinary sIL-2R/creatinine ratios reflected serum sIL-2R levels.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1370-1377
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• 2005

Purpose : Delineation of serum lipid and lipoprotein values in children after Kawasaki disease(KD) is important because of the predilection of this disease for the coronary arteries. Methods : The KD group was composed of 51 patients who were hospitalized from Jan. 2002 to Dec. 2003. Control was 25 patients with non-KD febrile illness. The levels of total lipid, phospholipid, triglyceride, HDL-cholesterol(HDL-C), LDL-cholesterol, total cholesterol, apolipoprotein A1(apo A1), apolipoprotein B, and Lipoprotein(a) were measured and compared with Echocardiographic findings. Measurements were obtained in four time periods: acute febrile, subacute, convalescent phase and 1 year after KD. Results : HDL-C($33.64{\pm}7.49mg/dL$ vs $50.43{\pm}14.41mg/dL$, P<0.01) and apo A1($99.75{\pm}6.39mg/dL$ vs $113.34{\pm}11.35mg/dL$, P<0.05) were decreased more in the acute febrile period of KD than in the control, but these changes were not correlated with cardiac complications. All lipid profiles were markedly elevated in the subacute stage and normalized in the convalescent stage; there were no changes until 1-year follow up. There were no significant differences in the changes of lipid profiles, including Lp(a) and coronary dilatation, in any time periods. Conclusion : KD is associated with important abnormalities in lipid metabolism, but these changes were transient and appear to be due to the disease itself. These data lead us to infer that KD dose not cause such permanent changes in lipid abnormalities as to be considered a risk factor for atherosclerosis, beyond that caused by the disease itself.