• Journal of the Korea Institute of Building Construction
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• 제19권6호
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• pp.539-547
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• 2019

Recently, the international community signed a climate change agreement to prevent global warming. Yet currently, the fossil fuels have been widely used in to supply building energy for cooling and heating. The Green Building certification (G-SEED), an energy efficiency rating for new or existing buildings requires that buildings meet certain conditions. Insulation is used as a building material to reduce the energy supply to buildings and to improve the thermal insulation, and it accounts for more than 90% of the total heat resistance provided by the building surface components that meet the energy-saving design standards of new buildings. In this investigation, a performance evaluation study was conducted through an experimental study by directly extracting the foam polystyrene insulation on-site during the remodeling of a building that was in the range of 22~38 years old. Through tests, it was found that the thermal conductivity of the extrusion method insulation (XPS) was reduced by 48% and the compressive strength of XPS decreased by 36% compared to KS M 3808, which is the initial quality standard. For bead method insulation (EPS) with a thickness of 50mm, the thermal conductivity, the compressive strength, and flexural failure load were similar to the initial quality standard. Therefore, in the calculation of the primary energy requirement per unit area per year, the performance of bead method insulation can be estimated simply by considering the thickness of the insulation, while a correction factor that considers its performance deterioration should be applied when extrusion method insulation is used.

• Neonatal Medicine
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• 제18권2호
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• pp.272-279
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• 2011

Purpose: The incidence of nosocomial infection caused by Gram-negative bacilli (GNB) has increased in neonatal intensive care units (NICU). This study identified the progression of sepsis caused by GNB colonization and analyzed the risk factors associated with using periodic stool culture surveillance. Methods: We included 86 newborns admitted to the NICU, Kosin University Gospel Hospital from October 2007 to May 2008. Three stool specimens were collected right after birth and two more were collected at 2 week intervals. The risk factors related to GNB colonization were established from each medical record and related references. Results: The incidence of colonization by GNB was 22 (25.6%) per 86 neonates but none had culture-proven sepsis. The three most commonly isolated GNB were Pseudomonas aeruginosa, Enterobacter cloacae, and Citrobacter freundii. Approximately 89% (32/36) of isolated GNB were susceptible to amikacin. The probability of GNB colonization increased in infants who were fed a small volume during enteral feeding. In contrast, delayed enteral feeding resulted in a decreased probability for GNB colonization. Conclusion: Colonized GNB in the intestine was confirmed by enteric surveillance culture of newborns admitted to the NICU. However, we found no evidence of culture-proven GNB sepsis. As lower feeding volume on the colonization day is a risk factor for GNB colonization, the chance for GNB colonization should be considered when feeding intolerance is present.

• Journal of Life Science
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• 제24권5호
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• pp.588-593
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• 2014

Tumor angiogenesis is important in tumorigenesis and therapeutic interventions in cancer. To know inhibitor and effector of tumor angiogenesis in cancer, the specific gene of tumor and angiogenesis may develop the mechanisms of cancer suppression and therapy. Recently, we described the role of RalA-binding protein 1 (RLIP76) in tumor angiogenesis. Tumor vascular volumes were diminished, and vessels were fewer in number, shorter, and narrower in RLIP76 knockout mice than in wild-type mice. Moreover, angiogenesis in basement membrane matrix plugs was blunted in the knockout mice in the absence of tumor cells, with endothelial cells isolated from the lungs of these animals exhibiting defects in migration, proliferation, and cord formation in vitro. RLIP76 is expressed in most human tissues and is overexpressed in many tumor types. In addition, the protein regulates tumorigenesis and angiogenesis in vivo and in vitro. As the export of chemotherapy agents is a prominent cellular function of RLIP76, it is a major factor in mechanisms of drug resistance. Moreover, RLIP76 acts as a selective effector of the small GTPase, R-Ras, and regulates R-Ras signaling, leading to cell spreading and migration. Furthermore, in skin carcinogenesis, RLIP76 knockout mice are resistant, with tumors that form showing diminished angiogenesis. Thus, RLIP76 is required for efficient endothelial cell function and angiogenesis in solid tumors.

• Journal of Life Science
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• 제28권6호
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• pp.733-737
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• 2018

Cucurbitacin-I, a natural triterpenoid derived from Cucurbitaceae family plants, exhibits a number of potentially useful pharmacological and biological activities. Indeed, the previous study demonstrated that cucurbitacin-I reduced the proliferation of colon cancer cells by enhancing apoptosis and causing cell cycle arrest at the G2/M phase. CD44, a type I transmembrane protein with the function of adhering to cells, mediates between the extracellular matrix and other cells through hyaluronic acid. Recent studies have demonstrated that an overexpression of the CD44 membrane receptor results in tumor initiation and growth, specific behaviors of cancer stem cells, the development of drug resistance, and metastasis. The aim was to examine the effect of cucurbitacin-I on CD44 expression human ovarian cancer cells because the effect of cucurbitacin-I on CD44 expression has not been reported. The expressions of CD44 mRNA and protein were detected using a quantitative real-time reverse-transcription polymerase chain reaction and a Western blot analysis, respectively. Treatment with cucurbitacin-I inhibited the expression of CD44 mRNA and protein. A subsequent analysis revealed that cucurbitacin-I blocked the phosphorylation of activator protein-1 (AP-1) and nuclear factor kappa-B ($NF-{\kappa}B$), which are key regulators of CD44 expression. Taken together, the data demonstrate that cucurbitacin-I regulates the AP-1 and $NF-{\kappa}B$ signaling pathways, leading to decreased CD44 expression.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제38권1호
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• pp.31-37
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• 1993

To analyze and classify the varietal variation of alkali digestibility in detail, which is closely connected with the gelatinization temperature and physical characteristics of cooked rice, the patterns of alkali decomposition changed along the alkali concentration were investigated for thirty three Korean leading rice cultivars and new breeding lines(japonica : 25, Tongil-type:8) including five glutinous rice. Principal component analysis was used to condense the information and to classify rice materials according to decomposed reaction pattern at several levels of potassium hydroxide(KOH) concentration. Thirty three rice varieties were classified largely into four groups by the distribution on the plane of upper two principal component scores which contained above 92% of total informations. Group I was consisted of one variety, Dobongbyeo, which owned almost same strong resistance to alkali digestion at the range of 0.8% to 1.6% KOH solutions. Group II included three japonica and Tongil-type glutinous rice varieties, which revealed medium alkali digestion value(ADV) at 1.4% KOH solution and intermediate change in ADV from 0.8% to 1.6% KOH solutions. Most of Tongil-type and early-maturity japonica rice, which exhibited medium-high ADV at 1.4% of KOH concentration and large ADV difference between low and high alkali solutions, were contained in Group III. Group N included most of medium or medium-late-maturity japonica, which showed high ADV at 1.4% KOH and medium or intermediate-high ADV change between low and high alkali solutions. The 1st principal component indicated the average index of ADV through 0.8-1.6% KOH solutions and the 2nd principal component pointed out the factor related with ADV difference between low and high alkali solutions or regression coefficients of ADV change along with the KOH concentrations.

• International Journal of Highway Engineering
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• 제2권3호
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• pp.129-144
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• 2000

This paper presents the characteristics of viscoelastic properties and fatigue performance of SBS modified asphalt mixtures depending on the aggregate gradation. Dynamic shear rheometer (DSR) and uniaxial tensile creep tests are performed to analyze the thermomechanical behavior of asphalt binders and mixtures, respectively. Uniaxial tensile fatigue tests for seven different asphalt mixtures are conducted to evaluate the effects of aggregate gradations and SBS modifier on the fatigue performance of the mixtures. DSR and uniaxial tensile creep tests results show that the SBS modified asphalt mixtures have better rutting resistance than the unmodified mixtures at high temperatures regardless of the aggregate gradations used. Fatigue factor $G^*sin\delta$ in Superpave binder specification may not be adequate for evaluating the fatigue Performance of asphalt mixtures. It is observed from uniaxial tensile fatigue tests that SBS modified asphalt mixtures compared to unmodified mixtures have ten times longer fatigue lives regardless of the aggregate gradations(dense, SMA, and Superpave gradations) used in the mixtures. The better fatigue performance of the SBS modified mixtures is observed even after long-term aging process. The effect of aggregate gradations on the fatigue performance is not as significant as the SBS modifier. The cellulose fiber added in the SMA mixture has negligible effects on the viscoelastic Properties and fatigue performance of the mixture, but is effective in reducing draindown. Although the SBS modified asphalt binder is used, it may be necessary to add the cellulose fiber into the SMA mixture to prevent the draindown.

• Korean Journal of Materials Research
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• 제20권4호
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• pp.210-216
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• 2010

This paper investigates the dependence of a-Si:H/c-Si passivation and heterojunction solar cell performances on various cleaning processes of silicon wafers. It is observed that the passivation quality of a-Si:H thin-films on c-Si wafers depends highly on the initial H-termination properties of the wafer surface. The effective minority carrier lifetime (MCLT) of highly H-terminated wafer is beneficial for obtaining high quality passivation of a-Si:H/c-Si. The wafers passivated by p(n)-doped a-Si:H layers have low MCLT regardless of the initial H-termination quality. On the other hand, the MCLT of wafers incorporating intrinsic (i) a-Si:H as a passivation layer shows sensitive variation with initial cleaning and H-termination schemes. By applying the improved cleaning processes, we can obtain an MCLT of $100{\mu}sec$ after H-termination and above $600{\mu}sec$ after i a-Si:H thin film deposition. By adapting improved cleaning processes and by improving passivation and doped layers, we can fabricate a-Si:H/c-Si heterojunction solar cells with an active area conversion efficiency of 18.42%, which cells have an open circuit voltage of 0.670V, short circuit current of $37.31\;mA/cm^2$ and fill factor of 0.7374. These cells show more than 20% pseudo efficiency measured by Suns-$V_{oc}$ with an elimination of series resistance.

• Journal of Food Hygiene and Safety
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• 제15권3호
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• pp.241-247
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• 2000

The incidence of verotoxin-producing Escherichia coli(VTEC) was surveyed in domestic foods including hamburger, raw meats and vegetables from 1997 to 1999. The molecular biological characteristics of the isolates were analyzed. Three VTEC strain were isolated from 1,700 samples. Serotypes of those isolates were 0157 : H7, 026 H4, and 056 : Hl2, respectively. Serotype O26 : H4 produced VT I and VT II, and 055 Hl2 isolate produced VT I, however the 60 MDa plasmid DNA and eae gene were not found from both strains. One 0157 : H7 isolate produced VT II and harbour 60 MDa plasmid DNA, however eae gene was not found in the strain. Although they produced VT, it seemed that the virulence of two strains were relatively weak because of the lack of the eae gene. In addition, the serotype O157 : H7 isolate resistant to ampicillin and streptomycin, while isolates of serotype O26 : H4 and O55 : Hl2 were multi-resistant to antibiotics including ampicillin, carbenicillin , cephalothin, trimethoprim/sulfamethoxazole and tetracycline. Supernatants of cultures of all three isolates were showed cytotoxic effect to vero and HeLa cell

• Journal of Nutrition and Health
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• 제53권2호
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• pp.99-110
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• 2020

Purpose: The rice germ fraction is a better source of protein, lipid, and fiber than the rice endosperm. Furthermore, the rice germ is rich in bioactive phytochemicals such as γ-aminobutyric acid, tocopherols, tocotrienols, phytic acid, and so on. In this study, the phytosterol content and antioxidant activity of Keunnunjami germ (KG) or normal rice germ supplement were investigated in healthy adult rats. Methods: In vitro, quantitative assessment of phytosterols, including β-sitosterol, campesterol, cycloartenol, and stigmasterol, was performed. Comparative antioxidant activities of 2 rice germs were measured based on DPPH radical scavenging activity, reducing power, and ABTS radical scavenging capacity. In vivo, male Spraque-Dawley rats (30-weeks-old) were randomly assigned a diet of normal control (NC, AIN-93M diet), AIN-93M diet supplemented with normal rice germ 3% (NG3), or AIN-93M diet supplemented with KG 3% (KG3) and fed for 8 weeks. Results: KG contained significantly higher campesterol and stigmasterol contents and antioxidant activity than normal rice germ. The KG3 group exhibited significantly lower body weight gain as well as inguinal and total white adipose tissue weights. There were no significant differences in plasma glucose, insulin, C-peptide, or homeostasis model assessment of insulin resistance level among the 3 groups. The plasma tumor necrosis factor-α concentration was significantly lower while leptin, advanced oxidation protein products, and interleukin-6 showed downward trends in the KG3 group. In addition, the superoxide dismutase level of the KG3 group was significantly higher compared to the NC and NG3 groups. Conclusion: This study indicates that KG can be considered as a valuable source of phytosterol components. Lastly, KG has strong antioxidant properties and may have potential to ameliorate elevation of proinflammatory cytokine production with age.

• Korea and Global Affairs
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• 제1권1호
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• pp.7-30
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• 2017

The conspiracy theories of political events are occurring in every country and society. In Korean society, conspiracy theories about political events are constantly happening. Conspiracy refers to the phenomenon of a particular individual or group who oppose the official causes of social phenomena. Conspiracy is a resistance to the credibility of the state and the government. In Korean society, conspiracy occurs mainly in political events. The conspiracy theories of political events appear in the form of conservatism and progressivism, which seeks to replace political power and political power to stabilize political power. The conspiracy theory about Jang Jun-Ha's death occurred in the process of seeking justification for a person who is resisting the ruling forces. Also, the conspiracy theory of the Gwangju Democratization Movement and the Cheonan Warship Sinking may be a drag on the justification for the justification for the takeover of the new military government and the justification for the Disconnection of inter-Korean relations. In Korean politics, Conspiracy theory is a factor that confuses Korean society regardless of whether it is true or not.