• Preventive Nutrition and Food Science
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• v.5 no.4
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• pp.184-188
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• 2000

HMG-CoA reductase is th rate-limiting enzyme of cholesterol biosynthesis. As intracellular levels of cholesterol should be regulated elaborately in response to external stimuli an internal needs, the expression of the HMG-CoA reductase gene is regulated intricately at several different levels from transcription to post-translational modification. In this study, we investigated the regulatory mechanism of HMG-CoA reductase gene expression at the post-transcriptional/pre-translational levels in a baby hamster kidney cell line, C100. when 25-hydroxycholesterol was added to cells cultured in medium containing 5% delipidized fetal bovine serum and 25$\mu$M lovastatin, the levels of HMG-CoA reductase mRNA decreased rapidly, which seemed to be due to the increased degradation of reductase mRNA. These suppressive effects of 25-hydroxycholesterol on MG-CoA reductase mRNA levels were blocked by a translation inhibitor, cycloheximide. Similarly, actinomycin D and 5,6-dichloro-1-$\beta$-D-ribofuranosylbenzimidazole, transcription inhibitors, blocked the 25-hydroxycholesterol-mediated degradation of HMG-CoA reductase mRNA. These results indicate that new protein/RNA synthesis is required for the degradation of HMG-CoA reductase mRNA. In addition, data from the transfection experiments shows that cis-acting determinants, regulating the stability of reductase mRNA, were scattered in the sequence corresponding to 1766-4313 based on the sequence of Syrian hamster HMG-CoA reductase cDNA. Our data suggests that sterol-mediated destabilization of reductase mRNA might be one of the important regulatory mechanism of HMG-CoA reductase gene expression.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.731-739
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• 2014

Aluminum and boron co-doped zinc-oxide(AZOB) powders as transparent conducting oxide(TCO) were prepared by spray pyrolysis at $900^{\circ}C$. The micron-sized AZOB particles were prepared by spray pyrolysis from aqueous precursor solutions for aluminium, boron, and zinc. The micron-sized AZOB particle after the spray pyrloysis underwent post-heat treatment at $700^{\circ}C$ for 2 hours and it was changed fully to nano-sized AZOB particle by ball milling for 24 hours. The size of primary AZOB particle by Debye-Scherrer Equation and surface resistance of AZOB pellet were measured.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.108-111
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• 2005

A series of N-[4-cyano-2-fluoro-5-(2-pyrimidinyloxy, 2-benzyloxy or 2-pyridinyloxy)phenyl]-3,4,5,6-tetrahydrophthalimides was synthesized, and the herbicidal activities of those deivatives were evaluated through pre- and post-emergence application under upland conditions in a greenhouse. The results showed that most compounds resulted in stronger herbicidal activity on broadleaf weeds than on grass weeds and higher through post-emergence than pre-emergence application. The N-[(4-cyano-2-fluoro-5-(2-pyrimidinyloxy) phenyl]-3,4,5,6-tetrahydrophthalimide showed the best weed control efficacy and marginal corn safety at a rate of 60 g/ha through pre-emergence application.

• Structural Engineering and Mechanics
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• v.36 no.5
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• pp.643-667
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• 2010

The classical flexibility difference method detects damage by observing the difference of conventional deflection flexibility matrices between pre- and post-damaged states of a structure. This method is not able to identify multiple damage scenarios, and its criteria to identify damage depend upon the boundary conditions of structures. The key point behind the inability and dependence is revealed in this study. A more feasible flexibility for damage detection, the Angle-between-String-and-Horizon (ASH) flexibility, is proposed. The physical meaning of the new flexibility is given, and synthesis of the new flexibility matrix by modal frequencies and translational mode shapes is formulated. The damage indicators are extracted from the difference of ASH flexibility matrices between the pre- and post-damaged structures. One feature of the ASH flexibility is that the components in the ASH flexibility matrix are associated with elements instead of Nodes or DOFs. Therefore, the damage indicators based on the ASH flexibility are mapped to structural elements directly, and thus they can pinpoint the damaged elements, which is appealing to damage detection for complex structures. In addition, the change in the ASH flexibility caused by damage is not affected by boundary conditions, which simplifies the criteria to identify damage. Moreover, the proposed method can determine relatively the damage severity. Because the proposed damage indicator of an element mainly reflects the deflection change within the element itself, which significantly reduces the influence of the damage in one element on the damage indicators of other damaged elements, the proposed method can identify multiple damage locations. The viability of the proposed approach has been demonstrated by numerical examples and experimental tests on a cantilever beam and a simply supported beam.

• Korean Chemical Engineering Research
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• v.56 no.1
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• pp.42-48
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• 2018

Silicon has attracted extensive attention due to its high theoretical capacity, low discharge potential and non-toxicity as anode material for lithium ion batteries. In this study, Si-CNT-C composites were fabricated for use as a high-efficiency anode material in a lithium ion battery. Aerosol self-assembly and post-heat treatment processes were employed to fabricate the composites. The morphology of the Si-CNT-C composites was spherical and an average particle size was $2.72{\mu}m$. The size of the composite increased as concentration of Si and CNT increased in the precursor solution. In the Si-CNT-C composites, CNT and C carbonized from glucose were attached to the surface of Si particles. Electrochemical measurement showed that the cycle performance of Si-CNT-C composites was better than that of silicon particles.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.4
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• pp.1-11
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• 2001

The purpose of this study is to re-interpretate the meaning of place from the perspective view of events. In the realm of events, time, process, and evolution are emerging as more important elements for better places rather than space or fixed physical elements. First, this study reviews the phenomenological contribution to the meaning of place by discussing differences between positivism and phenomenology. The phenomenological approach has strengths that can perceive individual experiences and idiosyncraises through a holistic approach and qualitative methods. However, it has weaknesses such as unpredictability, subjectivity and ambiguity. In order to overcome these weaknesses, the notion of singularities(pure events) on the metaphysical plane existing between nature and culture is explored via Deleuzean concepts(Post-structuralism); singularities become events(simulacre) through ´becoming´ and these events have meaning through this process in the particular place. By this process, the subject an feed a sense of place through this meaning. Events unexpectedly create a series of events and have impact in the future. Creating various events in the particular place requires many contextural settings where the embodied perceptions could take place. Describing the potentiality of embodied perceptions demands ´smooth space´ rather than ´striated space´. Smooth space refers to the space where orientations and linkages are in continuous variation. Recent architectural and landscape architectural design projects reveal that the emphasis is placed on the open-ended set of various events unfolding over time rather than the physical settings of the place. For better landscape design, new concepts need to be introduced and implemented. These new concepts should focus on creating a series of events and considering the evolution of the place over time through multi-contextural and rhizomatical synthesis rather than rigid and static master plan of SAD(survey-analysis-design) methodology.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.1 no.2
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• pp.137-144
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• 2015

Hypoxia is an important adverse prognostic factor for tumor progression and is a major cause of failure of radiation therapy. In case of short-term hypoxia, the metabolism can recover to normal, but if hypoxia persists, it causes irreversible cell damage and finally leads to death. So a hypoxia marker would be very useful in oncology. In particular, 2-nitroimidazole can be reduced to form a reactive chemical species, which can bind irreversibly to cell components in the absence of sufficient oxygen, thus, the development of radiolabeled nitroimidazole derivatives for the imaging of hypoxia remains an active field of research to improve cancer therapy result. 2-nitroimidazole based hypoxia marker, [$^{18}F$]FMISO holds promise for the evaluation of tumor hypoxia by Positron emission tomography (PET), at both global and local levels. In the present study, [$^{18}F$]FMISO was synthesized using an automatic synthesis module with high radiochemical purity (>99%) in 60 min. Immunohistochemical analysis using pimonidazole confirmed the presence of hypoxia in xenografted CT-26 tumor tissue. A biodistribution study in CT-26 xenografted mice showed that the increased tumor-to-muscle ratio and tumor-to-blood ratios from 10 to 120 min post-injection. In the PET study, [$^{18}F$]FMISO also showed increased tumor-to-muscle ratios from 10 to 120 min post-injection. In conclusion, this study demonstrates the feasibility and utility of [$^{18}F$]FMISO for imaging hypoxiain mouse colon cancer model using small animal PET.

• Clean Technology
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• v.16 no.2
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• pp.95-102
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• 2010

Sulfonic acid (-SO3H) functionalized mesoporous silica containing HMS, SBA 15(S15), MCM 41(M41) were synthesized by post-synthesis and co-condensation method. Their catalytic performance is tested by dehydration reaction of D-xylose to furfural. As a result, good conversion and selectivity was obtained using water as an environmentally friendly solvent. Additionally, increased amounts of sulfuric acid in catalysts resulted in improved conversion of D-xylose. All of the acid-functionalized mesoporous silica showed higher selectivity than other solid acids such as ${\gamma}-Al_{2}O_{3}$ and zeolite.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.371-378
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• 2004

The $SrGa_2S_4:Eu^{2+}$ green emitting phosphor has been studied as a luminous device for CRT (Cathode Ray Tube) or FED (Field Emission Display) and EL (Electroluminescence). This phosphor, also, is under noticed for LED (Lighting Emitting Diode) phosphor, which makes use of excitation characteristics of long wavelength region. The $SrGa_2S_4:Eu^{2+}$ phosphor was prepared generally conventional synthesis method using flux. However, this method needs high heat-treated temperature, long reaction time, complex process and harmful $H_2S$or $CS_2$ gas. In this works, therefore, we have synthesized $SrGa_2S_4:Eu^{2+}$ using SrS, $Ga_2S_3$, and EuS as starting materials, and the mixture gas of 5% H2/95% N2 was used to avoid the $H_2S$or $CS_2$. We investigated the luminescence characteristic of $SrGa_2S_4:Eu^{2+}$ phosphor prepared in various synthesis conditions, performed post-treatment and sieving process for application to LED.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2001.11a
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• pp.43-56
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• 2001

Colostrum contains various kinds of cytokines including TGF-${\beta}$ which is known to be multifunctional in immune response and act as an anti-inflammatory agent. First, we measured the amount of TGF-${\beta}$ in bovine and human colostrum. Expression pattern of TGF-${\beta}$ isotypes was dramatically different between human and bovine colostrial samples. Bovine colostrum collected on day 1 post-delivery retained $41.79{\pm}16.96ng/ml$ of TGF-${\beta}$ 1 and $108.4{\pm}78.65ng/ml$ of TGF-${\beta}$ 2 while in human, $284{\pm}124.75ng/ml$ of TGF-${\beta}$ 1 and $29.75{\pm}6.73ng/ml$ of TGF-${\beta}$ 2. Thus, TGF-${\beta}$ is the predominant TGF-${\beta}$ isotype in bovine colostrum and vice versa in human colostrum. Both TGF-${\beta}$ isotypes diminished significantly in human and bovine colostrum with time. Next, biological activity of colostrial samples was examined in vitro. Both human and bovine colostrum increased IgA synthesis by LPS-activated mouse spleen B cells, which is a typical effect of TGF-${\beta}$ on the mouse B cell differentiation. Futhermore, we found that anti-proliferative activity in MV1LU cells by colostrum samples disappeared by addition of anti-TGF-${\beta}$ 1 and anti-TGF-${\beta}$ 2 antibody. In conclusion, there are substantial amounts of biologically active TGF-${\beta}$ 1 and TGF-${\beta}$ 2 in bovine and human colostrum. The results that the colostrum can increase IgA expression has important implications since IgA is the major Ig class produced in the gastrointestinal tract. We have previously shown that the stimulatory effect of Bifidobacteria bifidum on spllen B cells was quite similar to that of LPS which is a well-known polyclonal activator for murine B cells. In the present study, we further asked whether B. bifidum regulate the synthesis of IgA by mucosal lymphoid cells present in Peyers patches (PP) and mesenteric lymph nodes (MLN). B. bifidum alone, but not C. perfringens, significantly induced overall IgA and IgM synthesis by both MLN and PP cells. This observation indicates that B. bifidum possesses a modulatory effect on the mucosal antibody production in vivo. We, therefore, investigated the mucosal antibody prodduction following peroral administration of B. bifidum to mice. Ingested B. bifidum significantly increased the numbers of Ig (IgM, IgG, and IgA) secreting cells in the culture of both MLN and spleen cells, indicating that peroally introduced B. bifidum enhances mucosal and systemic antibody response. Importantly, however, B. bifidum itself does not induce the own specific antibody responses, implying that B. bifidum do not incite any unwanted immune reaction. Subsequently, it was found that excapsulation of B. bifidum further augments the total IgA production by increasing the number of IgA-secreting cells in the culture of both MLN and spleen cells. Finally, we found that the immuno-stimulating activity of B. bifidum is due to its cell wall components but not due to any actively secreting component(s) from bacteria. Thus our data reveal that peroral administration of B. bifidum can enhance intestinal IgA production and that encapsulation of B. bifidum further reinforces the IgA production.