• Journal of Korean Society of Environmental Engineers
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• 제39권5호
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• pp.246-254
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• 2017

Microcystin-LR (MC-LR) is one of most abundant microcystins, and is derived from blue-green algae bloom. Advanced oxidation processes (AOPs) are effective process when high concentrations of MC-LR are released into a drinking water treatment system from surface water. In particular, UV-based AOPs such as UV, $UV/H_2O_2$, $UV/O_3$ and $UV/TiO_2$ have been studied for the removal of MC-LR. In this study, UV-LED was applied for the degradation of MC-LR because UV lamps have demonstrated some weaknesses, such as frequent replacements; that generate mercury waste and high heat loss. Degradation efficiencies of the MC-LR (initial conc. = $100{\mu}g/L$) were 30% and 95.9% using LED-L (280 nm, $0.024mW/cm^2$) and LED-H (280 nm, $2.18mW/cm^2$), respectively. Aromatic compounds of natural organic matter changed to aliphatic compounds under the LED-H irradiation by LC-OCD analysis. For application to raw water, the Nak-dong River was sampled during summer when blue-green algae were heavy bloom in 2016. The concentration of extracellular and total MC-LR, geosmin and 2-MIB slightly decreased by increasing the LED-L irradiation; however, the removal of MC-LR by UV-LED (${\lambda}=280nm$) was insufficient. Thus, advanced UV-LED technology or the addition of oxidants with UV-LED is required to obtain better degradation efficiency of MC-LR.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제35권6C호
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• pp.523-529
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• 2010

We propose a very low complexity lattice reduction (LR) algorithm for MIMO detection in time varying channels. The proposed scheme reduces the complexity by performing LR in a block-wise manner. The proposed scheme takes advantage of the temporal correlation of the channel matrices in a block and its impact on the unimodular matrices during LR process. From this, the proposed scheme can skip a number of redundant LR processes for consecutive channel matrices and performs a single LR in a block. The simulation results investigated in this letter reveal that the proposed detection scheme requires only 43.4% multiplications and 17.3% divisions of LLL-LR and only 50.2% multiplications and 68.2% divisions of the conventional adaptive LR with almost no performance degradation.

• Korean Journal of Acupuncture
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• 제22권3호
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• pp.1-15
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• 2005

Objectives: This research was performed to investigate the effect of invasive low level laser acupuncture therapy(LLLAT) at Yolgyol(LU7), Yogu(LR5) and Yolgyol+Yogu(LU7+LR5) on weight gain, food intake, food efficiency, lipid metabolism, atherogenic index, HTR(HDL-cholesterol to total cholesterol ratio) and liver function in hyperlipidemia rats. Methods : Experimental groups were divided into high fat diet group(Control group), high fat diet and LLLAT at LU7(LU7 group), high fat diet and LLLAT at LR5(LR5 group), LLLAT at LU7 and LR5(LU7+LR5 group). Animals was treated by the LLLAT at 30mW-5min once a 2day during 5 weeks. Results: Body weight was decreased significantly in LU7+LR5 group when compared with control group. Food intake was increased significantly in LU7, LR5, LU7+LR5 group when compared with control group. Food efficiency was decreased significantly in LU7, LR5, LU7+LR5 group when compared with control group. In the lipid metabolism, total cholesterol and HDL-cholesterol was decreased significantly in LU7+LR5 group, LDL-cholesterol and phospholipids were decreased significantly in LR5, LU7+LR5 group, triglyceride and fee fatty acid were decreased significantly in LU7 group when compared with control group. Atherogenic index was decreased significantly in LU7, LR5, LU7+LR5 group when compared with control group. HTR was increased significantly in LU7 group when compared with conool group. In the liver function, the significance was not showed in AST and ALT, ALP was decreased significantly in LU7+LR5 group when compared with control group. Conclusions: LLLAT at LU7 and LR5 maybe can manage hyperlipidemia by controlling body weight, food intake, food efficiency ratio and lipid metabolism.

• Investigative Magnetic Resonance Imaging
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• 제25권3호
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• pp.172-182
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• 2021

Purpose: We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. Materials and Methods: We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). Results: PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). Conclusion: In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

• The Korean Journal of Ecology
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• 제24권3호
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• pp.141-147
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• 2001

Soil respiration and some environmental factors which affect soil respiration were studied in an oak forest, Kongju, Korea. Soil respiration was measured at midday of the 15th and 30th day at every month in control(Con), artificial forest gap (Gap) and litter removed area (Lr) with portable CO₂ Analyzer equipped soil respiration chamber. In July, maximum soil respiration in Con, Cap and Lr was 15.6, 11.2 and 7.7 CO₂μmol·m/sup -2/·s/sup -1/, respectively. Respiration in Gap and Lr decreased by 28.6% and 50.6%, respectively, compared with that in Con. Annual amount of soil CO₂ evolution from Con, Gap and Lr was 6.86, 5.84, 3.81 kg·m/sup -2/·yr/sup -1/, respectively. Annual amount of CO₂ evolution in Gap and Lr decreased by 14.8% and 44.5%, respectively, compared with that in Con. Soil respiration rates exponentially increased with temperature. Temperature of soil surface and at 5 cm depth was strongly related to soil respiration rates in Con (r₂＝0.87, 0.93), Gap (r₂=0.81, 0.88) and Lr (r/sub 2/=0.89).

• Journal of Korean Academy of Nursing
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• 제43권2호
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• pp.154-164
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• 2013

Purpose: The purpose of this article is twofold: 1) introducing logistic regression (LR), a multivariable method for modeling the relationship between multiple independent variables and a categorical dependent variable, and 2) examining use and reporting of LR in the nursing literature. Methods: Text books on LR and research articles employing LR as main statistical analysis were reviewed. Twenty-three articles published between 2010 and 2011 in the Journal of Korean Academy of Nursing were analyzed for proper use and reporting of LR models. Results: Logistic regression from basic concepts such as odds, odds ratio, logit transformation and logistic curve, assumption, fitting, reporting and interpreting to cautions were presented. Substantial shortcomings were found in both use of LR and reporting of results. For many studies, sample size was not sufficiently large to call into question the accuracy of the regression model. Additionally, only one study reported validation analysis. Conclusion: Nursing researchers need to pay greater attention to guidelines concerning the use and reporting of LR models.

• Journal of Nutrition and Health
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• 제51권4호
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• pp.316-322
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• 2018

Purpose: The Glycyrrhiza uralensis species (Leguminosae) as a medicinal biocompound, and one of its root components, isoliquritigenin (ISL), which is a flavonoid, has been reported to have anti-tumor activity in vitro and in vivo. However, its function in bone formation has not been studied yet. In this study, we tested the effect of Glycyrrhiza uralensis (ErLR) and baked Glycyrrhiza uralensis (EdLR) extracts on osteoblast proliferation, alkaline phosphatase (ALP) activity, and bone-related gene expression in osteoblastic MC3T3-E1 cells. Methods: MC3T3-E1 cells were cultured in various levels of ErLR (0, 5, 10, 15, $20{\mu}g/mL$), EdLR (0, 5, 10, 15, $20{\mu}g/mL$), or ISL (0, 5, 10, 15, $20{\mu}M$) in time sequences (1, 5, and 20 days). Also, isoliquritigenin (ISL) was tested for comparison to those two biocompound extracts. Results: MTT assay results showed that all three compounds (ErLR, EdLR, and ISL) increased osteoblastic-cell proliferation in a concentration-dependent manner for one day. In addition, both ErLR and EdLR compounds elevated the osteoblast proliferation for 5 or 20 days. Extracellular ALP activity was also increased as ErLR, EdLR, and ISL concentration increased at 20 days, which implies the positive effect of Glycyrrhiza species on osteoblast mineralization. The bone-related marker mRNAs were upregulated in the ErLR-treated osteoblastic MC3T3-E1 cells for 20 days. Bone-specific transcription factor Runx2 gene expression was also elevated in the ErLR- and EdLR-treated osteoblastic MC3T3-E1 cells for 20 days. Conclusion: These results demonstrated that Glycyrrhiza uralensis extracts may be useful for preventing osteoporosis by increasing cell proliferation, ALP activity, and bone-marker gene expression in osteoblastic cells.

• Food Science and Biotechnology
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• 제17권2호
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• pp.438-441
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• 2008

A novel lactobacilli replicon from plasmids of Lactobacillus reuteri KCTC 3678 was isolated. Eight L. reuteri strains from Korean Collection for Type Cultures (KCTC) and Korea Food Research Institute (KFRI) were screened for cryptic plasmids and most strains harbored 1 or 2 plasm ids. Particularly, L. reuteri KCTC 3678 contained 6 plasm ids which all were used for screening of lactobacilli replicon. EcoRI digests of the plasmid DNA prep from L. reuteri KCTC 3678 were ligated with pUC19 and the recombinant DNAs were serially named from pLR1 to pLR7. A cat (chloramphenicol acetyltransferase; $Cm^r$) gene originated from pC194 was introduced into pLR1-7, resulting in pLR1cat-pLR7cat, respectively. The recombinant plasmids were introduced into L. reuteri KCTC 3679, and only transformants harboring pLR5cat were obtained, indicating that the insert in pLR5 functioned as a lactobacilli replicon.

• Microbiology and Biotechnology Letters
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• 제50권1호
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• pp.51-62
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• 2022

Lactobacillus rhamnosus SKG34 (LrSKG34), a potential probiotic strain, was successfully isolated from Sumbawa Mare's milk. Our previous studies showed that the strain is resistant to gastrointestinal conditions, possesses antioxidant activity, and lowers blood cholesterol levels. Further clarification of the potential probiotic characteristics and safety assessment are necessary. This study aimed to evaluate the adhesion of LrSKG34 to Caco-2 cell monolayers and its effect on mucosal integrity in vitro. We also examined the LrSKG34 safety profile based on antimicrobial susceptibility testing, haemolytic activity determination, Caco-2 cell monolayer translocation evaluation, and in vivo investigation of the effect of LrSKG34 on the physiology, biochemical markers, and histopathological appearance of major organs in an animal model. LrSKG34 attached to Caco-2 cell monolayers and maintained mucosal integrity in vitro. The typical resistance of lactobacilli to ciprofloxacin, gentamicin, vancomycin, trimethoprim-sulfamethoxazole, and metronidazole was confirmed for LrSKG34. No haemolytic activity was observed on blood agar plates, and no LrSKG34 translocation was observed in Caco-2 cell monolayers. Administration of LrSKG34 to Sprague-Dawley rats did not adversely affect body weight. No abnormalities in hematological parameters, serum biochemistry levels, or histopathological structures of major organs were observed in LrSKG34-treated rats. Collectively, the results implicate LrSKG34 as a promising and potentially safe probiotic candidate for further development.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.321-326
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• 2016

The porcine major histocompatibility complex (MHC) is called swine leukocyte antigen (SLA), which controls immune responses and transplantation reactions. The SLA is mapped on pig chromosome 7 (SSC7) near the centromere. In this study, 3 class I (SLA-1, SLA-3, and SLA-2) and 3 class II (DRB1, DQB1, and DQA) genes were used for investigation of SLA haplotypes in Yucatan miniature pigs in Korea. This pig breed is a well-known model organism for biomedical research worldwide. The current study indicated that Korean Yucatan pig population had 3 Class I haplotypes (Lr-4.0, Lr-6.0, and Lr-25.0) and 3 class II haplotypes (Lr-0.5, Lr-0.7, and Lr-0.25). The combinations of SLA class I and II haplotype together, 2 homozygous (Lr-4.5/4.5 and Lr-6.7/6.7) and 3 heterozygous (Lr-4.5/6.7, Lr-4.5/25.25, and Lr-6.7/25.25) haplotypes were identified, including previously unidentified new heterozygous haplotypes (Lr-4.5/4.7). In addition, a new SLA allele typing method using Agilent 2100 bioanalyzer was developed that permitted more rapid identification of SLA haplotypes. These results will facilitate the breeding of SLA homozygous Yucatan pigs and will expedite the possible use of these pigs for the biomedical research, especially xenotransplantation research.