• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5363-5368
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• 2014

This study examined contribution rate on the Soyangho Lake watershed based on the flow regime, and seasonal change was evaluated by calculating the delivery pollution load of the drainage area of Soyangho Lake watershed. According to the contribution rate of the drainage area by the flow regime change, Inbukcheon Creek watershed's SS and T-P entry have recorded abnormal Six month flow and a contribution rate of 46% and 51% during the Low-water flow period. At the same time, the T-P recorded a 49.5% contribution rate and a contribution rate of 48.5% during the Low-water flow period. In sequence, Inbukcheon creek's SS entry recorded a comparatively higher contribution rate than the other drainage area, which are 39.6% and 44.3% during the entire season and 53.8% for T-P, as a result of observing the contribution rate based on the seasonal changes. The T-N at the Naerincheon Creek watershed for the entire season recorded a contribution rate between 39.6% and 44.3%. Overall, Inbukcheon Creek watershed's SS and T-P entry and Naerincheon creek's T-N had a high contribution rate on contaminant spill.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.377-386
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• 1996

Austenitic stainless steel type 304L has been nitrided under the low pressure of high nitrogen environment for 5 hours by the square-wave-pulse-d.c. plasma as a function of temperature 400~$600^{\circ}C$ and of pulsation. At the temperature range lower than $500^{\circ}C$ and at the relatively high ratio of pulse duration to pulse period, nonstoichiometric stainless steel nitride has been developed in the form of a thin layer which has many cracks. At the temperature range higher than $500^{\circ}C$, with the increasing temperature or with the increasing ratio of the pulse duration to pulse period up to 50s/100s, the nitrided layer was composed mainly of CrN and Fe4N phases and became thick, uniform, columnar and nearly crack-free. The nitrided layer at $500^{\circ}C$ was mixed with the low-temperature layer and the high temperature layer and was very brittle.

• Journal of Ginseng Research
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• v.46 no.3
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• pp.464-472
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• 2022

Background: Gut microbiota influence the central nervous system through gut-brain-axis. They also affect the neurological disorders. Gut microbiota differs in patients with Alzheimer's disease (AD), as a potential factor that leads to progression of AD. Oral intake of Korean Red Ginseng (KRG) improves the cognitive functions. Therefore, it can be proposed that KRG affect the microbiota on the gut-brain-axis to the brain. Methods: Tg2576 were used for the experimental model of AD. They were divided into four groups: wild type (n = 6), AD mice (n = 6), AD mice with 30 mg/kg/day (n = 6) or 100 mg/kg/day (n = 6) of KRG. Following two weeks, changes in gut microbiota were analyzed by Illumina HiSeq4000 platform 16S gene sequencing. Microglial activation were evaluated by quantitative Western blot analyses of Iba-1 protein. Claudin-5, occludin, laminin and CD13 assay were conducted for Blood-brain barrier (BBB) integrity. Amyloid beta (Aβ) accumulation demonstrated through Aβ 42/40 ratio was accessed by ELISA, and cognition were monitored by Novel object location test. Results: KRG improved the cognitive behavior of mice (30 mg/kg/day p < 0.05; 100 mg/kg/day p < 0.01), and decreased Aβ 42/40 ratio (p < 0.01) indicating reduced Aβ accumulation. Increased Iba-1 (p < 0.001) for reduced microglial activation, and upregulation of Claudin-5 (p < 0.05) for decreased BBB permeability were shown. In particular, diversity of gut microbiota was altered (30 mg/kg/day q-value<0.05), showing increased population of Lactobacillus species. (30 mg/kg/day 411%; 100 mg/kg/day 1040%). Conclusions: KRG administration showed the Lactobacillus dominance in the gut microbiota. Improvement of AD pathology by KRG can be medicated through gut-brain axis in mice model of AD.

• Journal of Ginseng Research
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• v.42 no.4
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• pp.485-495
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• 2018

Background: The geographical origin of Panax ginseng Meyer, a valuable medicinal plant, is important to both ginseng producers and consumers in the context of economic profit and human health benefits. We, therefore, aimed to discriminate between the cultivation regions of ginseng using the stable isotope ratios of C, N, O, and S, which are abundant bioelements in living organisms. Methods: Six Korean ginseng cultivars (3-yr-old roots) were collected from five different regions in Korea. The C, N, O, and S stable isotope ratios in ginseng roots were measured by isotope ratio mass spectrometry, and then these isotope ratio profiles were statistically analyzed using chemometrics. Results: The various isotope ratios found in P. ginseng roots were significantly influenced by region, cultivar, and the interactions between these two factors ($p{\leq}0.001$). The variation in ${\delta}^{15}N$ and ${\delta}^{13}C$ in ginseng roots was significant for discriminating between different ginseng cultivation regions, and ${\delta}^{18}O$ and ${\delta}^{34}S$ were also affected by both altitude and proximity to coastal areas. Chemometric model results tested in this study provided discrimination between the majority of different cultivation regions. Based on the external validation, this chemometric model also showed good model performance ($R^2=0.853$ and $Q^2=0.738$). Conclusion: Our case study elucidates the variation of C, N, O, and S stable isotope ratios in ginseng root depending on cultivation region. Hence, the analysis of stable isotope ratios is a suitable tool for discrimination between the regional origins of ginseng samples from Korea, with potential application to other countries.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.158-162
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• 2005

Purpose: In order to clarify the carcinogenesis mechanism from chronic atrophic gastritis toward gastric cancer, we measured the pepsinogen I and II and compared their ratio with several clinical findings. Materials and Methods: We measured the preoperative serum pepsinogen I and II by using a radio-immunoassay and compared their ratio with several clinical findings, such as tumor size, mucinous vs non-mucinous tumor, cell differentiation, tumor location, depth of invasion, lymph-node status, Lauren's classification, and peritumoral atrophy in 103 consecutive patients with gastric adenocarcinomas who had received resections at Bundang CHA Hospital during the period from July 2003 to February 2005. Results: There were significant differences in the serum pepsinogen I/II ratio between patients with mucinous vs non-mucinous tumors (n=4 vs 9 and mean pep I/II=1.29 vs. 2.99, p=0.0288), with tumor size more than and less than $10cm^2$ (n=55 vs. 48 and mean pep I/II=2.64 vs. 3.24, p=0.0491), and with or without peritumoral atrophy (n=94 vs. 9 and mean pep I/II=2.83 vs. 3.89, p=0.0466). In patients with peritomoral atrophy, the pepsinogen I/II ratio was also lower in larger tumors (n=48 vs. 46 and mean pep I/II=2.44 vs. 3.23, p=0.0083). Well-differentiated carcinomas showed significantly lower serum pep I/II ratios than signet-ring-ceil types. There was no correlation between serum pep I/II ratio and tumor location, depth of invasion, lymph-node status, or Lauren's classification Conclusion: We proved the existence of a correlation between serum pepsinogen level and musosal atrophy, but these results are not sufficient for clinical application of serum pepsinogen level as a screening tool for gastric cancer.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.677-681
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• 2009

$In_xGa_{1-x}N$ alloys with 20-nm-thickness were deposited onto Mg:GaN/AlN/SiC substrates by MOCVD at $800\;^{\circ}C$. TMGa, TMIn and $NH_3$ were used as the precursor of gallium, indium and nitrogen, respectively. The mole ratio of indium in $In_xGa_{1-x}N$ films varied between 0 and 0.2. The energy-band-gaps of the films were obtained from the photoluminescence and cathodoluminescence peaks. The mole ratios of $In_xGa_{1-x}N$ films were calculated by applying Vegard's law to XRD results. The energy-band-gap versus indium composition plot for $In_xGa_{1-x}N$ alloys were well fit with a bowing parameter of 2.27.

• Journal of Astronomy and Space Sciences
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• v.35 no.1
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• pp.7-18
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• 2018

We have investigated the intensities and full width at half maximum (FWHM) of the high dispersion spectroscopic N III emission lines of AG Peg, observed with the Hamilton Echelle Spectrograph (HES) in three different epochs at Mt. Hamilton's Lick Observatory. The earlier theoretical Bowen line study assumed the continuum fluorescence effect, presenting a large discrepancy with the present data. Hence, we analyzed the observed N III lines assuming line fluorescence as the only suitable source: (1) The O III and N III resonance line profiles near ${\lambda}$ 374 were decomposed, using the Gaussian function, and the contributions from various O III line components were determined. (2) Based on the theoretical resonant N III intensities, the expected N III Bowen intensities were obtained to fit the observed values. Our study shows that the incoming line photon number ratio must be considered to balance at each N III Bowen line level in the ultraviolet radiation according to the observed lines in the optical zone. We also found that the average FWHM of the N III Bowen lines was about $5km{\cdot}s^{-1}$ greater than that of the O III Bowen lines, perhaps due to the inherently different kinematic characteristics of their emission zones.

• Journal of the Korean Vacuum Society
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• v.16 no.4
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• pp.298-304
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• 2007

We have studied the effect of $N_2$ flow rate on the structural and optical properties of GaN nanorods grown on (111) Si substrates by radio-frequency plasma-assisted molecular-beam epitaxy. The hexagonal shape nanorods with lateral diameters from 80 to 190 nm with increasing $N_2$ flow rate from 1.1 to 2.0 sccm are obtained. However, the ratio of length (thickness) and compact region increases with increasing $N_2$ flow rate up to 1.7 sccm and then saturate. From the photoluminescence, free exciton transition is clearly observed for GaN nanorods with low $N_2$ flow rate. And the PL peak energies are blue-shifted with decreasing diameter of the GaN nanorods due to size effect. Temperature-dependent photoluminescence spectra for the nanorods with $N_2$ flow rate of 1.7 sccm show an abnormal behavior like "S-shape" with increasing temperature.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.397-402
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• 2009

In Korea, salt stress is one of the major problems limiting crop production and eco-environmental quality in greenhouse soil. The objective of this study was to evaluate the effectiveness of organic residues (Chinese milk vetch, maize stalk, rice straw, and rye straw) for reducing salt activity in greenhouse soil. Organic residues was incorporated with salt-accumulated soil (EC, 3.0 dS $m^{-1}$) at the rate of 5% (wt $wt^{-1}$) and the changes of electrical conductivity (EC) was determined weekly for 8 weeks under incubation condition at $30^{\circ}C$. The EC, microbial biomass carbon (MBC), and water soluble ions in soil was strongly affected by C/N ratio of organic residues. After 8 weeks incubation, the concentration of water soluble $NO_3{^-},\;Ca^{2+}$, and $Mg^{2+}$ was significantly decreased in organic residues having high C/N ratio (maize stalk, rice straw, and rye straw) incorporated soil compared to organic residues having lower C/N ratio (Chinese milk vetch) incorporated soil. The EC value in Chinese milk vetch incorporated soil was higher than control treatment. In contrast, maize stalk, rice straw, and rye straw amended soil was highly decreased the EC value compared to control and Chinese milk vetch applied soil after 4 weeks incubation. Our results indicated that incorporation of organic residues having high C/N ratio (>30) could reduce salt activity resulting from reducing concentration of water soluble ions.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.2
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• pp.129-143
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• 2010

Objectives : This study examined search on how the obesity indices, that are largely used in clinics such as waist circumference(WC), body mass index(BMI) and waist-hip ratio(WHR), are related to the visceral fat that was measured from abdominal computed tomography(CT) and the ratio of visceral fat/subcutaneous fat. Then, two groups ware compared in order to find out which characteristics of ordinary adults relationship with the abdominal obesity. Two groups are divided as follows; ones who are obese based on the measurement of WC and the others who are obese based on the level of BMI. Methods : A group of 63 test subjects that were gathered in the oriental medical hospital of Kyung-Won university is divided into two groups; ones (n=51, general obesity; group A) who have $BMI{\geq}25$ and $WC{\geq}85$, and the others (n=12, abdominal obesity; group B) who have BMI<25 and $WC{\geq}85$. Then, each group's obesity indices, abdominal CT, lipid level, glucose, adiponectin, leptin and C-reactive protein(CRP) are compared. In addition, subjects are again divided into two to examine the characteristics; ones (n=14, visceral obesity; group C) with visceral obesity based on the ratio between visceral fat and subcutaneous fat measured through abdominal CT, and the others (n=38, non-visceral obesity; group D) who are obese but not viscerally obese. Results & Conclusions : As a measurement that applies abdominal visceral fat and subcutaneous fat, BMI and WC can be considered as an appropriate obesity index while WHR cannot appropriately apply the abdominal fat amount. Moreover, the study indicates that abdominal obesity group based on the ratio of visceral fat/subcutaneous fat has more significant difference than the abdominal obesity group based on the WC in case of blood lipid index.