• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.313-324
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• 2009

We explore the effect of particle shape and size on 3-dimensional (3D) network and pore structure of porous earth materials composed of glass beads and silica gel using NMR micro-imaging in order to gain better insights into relationship between structure and the corresponding hydrologic and seismological properties. The 3D micro-imaging data for the model porous networks show that the specific surface area, porosity, and permeability range from 2.5 to $9.6\;mm^2/mm^3$, from 0.21 to 0.38, and from 11.6 to 892.3 D (Darcy), respectively, which are typical values for unconsolidated sands. The relationships among specific surface area, porosity, and permeability of the porous media are relatively well explained with the Kozeny equation. Cube counting fractal dimension analysis shows that fractal dimension increases from ~2.5－2.6 to 3.0 with increasing specific surface area from 2.5 to $9.6\;mm^2/mm^3$, with the data also suggesting the effect of porosity. Specific surface area, porosity, permeability, and cube counting fractal dimension for the natural mongolian sandstone are $0.33\;mm^2/mm^3$, 0.017, 30.9 mD, and 1.59, respectively. The current results highlight that NMR micro-imaging, together with detailed statistical analyses can be useful to characterize 3D pore structures of various porous earth materials and be potentially effective in accounting for transport properties and seismic wave velocity and attenuation of diverse porous media in earth crust and interiors.

• Tuberculosis and Respiratory Diseases
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• v.54 no.5
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• pp.495-509
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• 2003

Background : Neutrophil-mediated inflammation is usually self-limiting, because neutrophils have a remarkably short life span. Prolonged neutrophil survival, which is caused by decreased spontaneous apoptosis, leads to persistent inflammation in sepsis. Because many inflammatory cytokines, which generate signals that delay apoptosis, are regulated by nuclear factor-${\kappa}B$ transcription factor, we hypothesized that nuclear factor-${\kappa}B$ might be related to the reduced neutrophil apoptosis observed in sepsis. Methods : Neutrophils of healthy volunteers and sepsis patients were freshly isolated from venous blood. Neutrophil apoptosis was assayed with two approaches : by counting apoptotic cells under a microscope and by flow cytometry using Annexin V. The activity of nuclear factor-${\kappa}B$ was assessed by immunofluorescent staining or electrophoretic mobility shift assay. Expression of X-linked inhibitor of apoptosis was measured by western blot assay. Results : We confirmed reduced spontaneous neutrophil apoptosis in patients with sepsis. The number of apoptotic neutrophils in patients with sepsis increased to the level of that in healthy controls after cycloheximide treatment, suggesting that decreased spontaneous neutrophil apoptosis is dependent on de novo protein synthesis. In patients with sepsis, basal neutrophil nuclear factor-${\kappa}B$ was activated compared to the level in healthy controls. Moreover, a blockade of nuclear factor-${\kappa}B$ activity reversed the decreased spontaneous neutrophil apoptosis in sepsis patients. Meanwhile, X-linked inhibition of apoptosis expression, which is regulated by nuclear factor-${\kappa}B$, decreased 24 hours after incubation in healthy persons, but persisted for 24 hours in patients with sepsis. Conclusion : These observations suggest that the reduced spontaneous neutrophil apoptosis observed in patients with sepsis may be related to the induction of survival protein by nuclear factor-${\kappa}B$.

• Proceedings of the Korean Ceranic Society Conference
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• 2005.06a
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• pp.1-112
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• 2005

This report is results of a research on recent R&D trends in electroceramics, mainly focusing on the papers submitted to the organizing committee of the International Conference on Electroceramics 2005 (ICE-2005) which was held at Seoul on 12-15 June 2005. About 380 electroceramics researchers attended at the ICE-2005 from 17 countries including Korea, presenting and discussing their recent results. Therefore, we can easily understand the recent research trends in the field of electroceramics by analyses of the subject and contents of the submitted papers. In addition to the analyses of the papers submitted to the ICE-2005, we also collected some informations about domestic and international research trends to help readers understand this report easily. We analysed the R&D trends on the basis of four main categories, that is, informatics electroceramics, energy and environment ceramics, processing and characterization of electroceramics, and emerging fields of electroceramics. Each main category has several sub-categories again. The informatics ceramics category includes integrated dielectrics and ferroelectrics, oxide and nitride semiconductors, photonic and optoelectronic devices, multilayer electronic ceramics and devices, microwave dielectrics and high frequency devices, and piezoelectric and MEMS applications. The energy and environment ceramics category has four sub-categories, that is, rechargable battery, hydrogen storage, fuel cells, and advanced energy conversion concepts. In the processing and characterization category, there exist domain, strain, and epitaxial dynamics and engineering sub-category, innovative processing and synthesis sub-category, nanostructured materials and nanotechnology sub- category, single crystal growth and characterization sub-category, theory and modeling sub-category. Nanocrystalline electroceramics, electroceramics for smart sensors, and bioceramics sub-categories are included to the emerging fields category. We hope that this report give an opportunity to understand the international research trend, not only to Korean ceramics researchers but also to science and technology policy researchers.

• Development and Reproduction
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• v.10 no.3
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• pp.159-168
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• 2006

Rodents and many other mammals have two chemosensory systems that mediate responses to pheromones, the main and accessory olfactory system, MOS and AOS, respectively. The chemosensory neurons associated with the MOS are located in the main olfactory epithelium, while those associated with the AOS are located in the vomeronasal organ(VNO). Pheromonal odorants access the lumen of the VNO via canals in the roof of the mouth, and are largely thought to be nonvolatile. The main pheromone receptor proteins consist of two superfamilies, V1Rs and V2Rs, that are structurally distinct and unrelated to the olfactory receptors expressed in the main olfactory epithelium. These two type of receptors are seven transmembrane domain G-protein coupled proteins(V1R with $G_{{\alpha}i2}$, V2R with $G_{0\;{\alpha}}$). V2Rs are co-expressed with nonclassical MHC Ib genes(M10 and other 8 M1 family proteins). Other important molecular component of VNO neuron is a TrpC2, a cation channel protein of transient receptor potential(TRP) family and thought to have a crucial role in signal transduction. There are four types of pheromones in mammalian chemical communication - primers, signalers, modulators and releasers. Responses to these chemosignals can vary substantially within and between individuals. This variability can stem from the modulating effects of steroid hormones and/or non-steroid factors such as neurotransmitters on olfactory processing. Such modulation frequently augments or facilitates the effects that prevailing social and environmental conditions have on the reproductive axis. The best example is the pregnancy block effect(Bruce effect), caused by testosterone-dependent major urinary proteins(MUPs) in male mouse urine. Intriguingly, mouse GnRH neurons receive pheromone signals from both odor and pheromone relays in the brain and may also receive common odor signals. Though it is quite controversial, recent studies reveal a complex interplay between reproduction and other functions in which GnRH neurons appear to integrate information from multiple sources and modulate a variety of brain functions.

• Economic and Environmental Geology
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• v.50 no.3
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• pp.215-224
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• 2017

Arsenic (As) is known to be the most toxic element and frequently detected in groundwater environment. Inorganic As exists as arsenite [As(III)] and arsenate [As(V)] in reduced and oxidized environments, respectively. It has been reported that the toxicity of arsenite is much higher than that of arsenate and furthermore arsenite shows relatively higher mobility in aqueous environments. For this reason, there have been numerous researches on the process for oxidation of arsenite to arsenate to reduce the toxicity of arsenic. In particular, photooxidation has been considered to be simple, economical, and efficient to attain such goal. This study was conducted to evaluate the applicability of naturally-occurring goethite as a photocatalyst to substitute for $TiO_2$ which has been mostly used in the photooxidation processes so far. In addition, the effects of several factors on the overall performance of arsenite photocatalytic oxidation process were evaluated. The results show that the efficiency of the process was affected by total concentration of dissolved cations rather than by the kind of those cations and also the relatively higher pH conditions seemed to be more favorable to the process. In the case of coexistence of arsenite and arsenate, the removal tendency by adsorption onto goethite appeared to be different between arsenite and arsenate due to their different affinities with goethite, but any effect on the photocatalytic oxidation of arsenite was not observed. In terms of effect of humic acid on the process, it is likely that the higher concentration of humic acid reduced the overall performance of the arsenite photocatalytic oxidation as a result of competing interaction of activated oxygen species, such as hydroxyl and superoxide radicals, with arsenite and humic acid. In addition, it is revealed that the injection of oxygen gas improved the process because oxygen contributes to arsenite oxidation as an electron acceptor. Based on the results of the study, consequently, the photocatalytic oxidation of aqueous arsenite using goethite seems to be greatly feasible with the optimization of process.

• Archives of design research
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• v.17 no.1
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• pp.89-98
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• 2004

A systemic approach to behavior on the basis of human psychology is needed for behavior-centered space design. Also, the recognition that human and environment, in all, have complementarity is needed- human and space shall be understood as a general phenomenon, supposing interaction. Design of behavior-oriented space means configuration and coordination of physical subjects as well as understanding, analysis and reflection of psychological and behavioral phenomena. It is analysis of a private individual as well as understanding of interaction between human groups, as well. In respect of space recognition, analysis not on material movement but on energy circulation and variable is important. It means that the understanding of user's behavior and psychology does not orient reasonable purpose just for convenience. That is, such understanding intends to understand behavioral patterns and psychological phenomena between space and human beyond the decomposition of structure of human and space into physical elements and the design based on standardized data. Thereby, more human-oriented space design might be implemented by the understanding of behavioral essence. Also, a user-centered design process from another viewpoint might be created, and the general amenity among man, space and environment - better environmental quality - might be produced. For this, the consciousness of human activity that is, activity system shall be ahead of it, and the approaches for design shall be implemented into a process not in predictive ideas but in semi-scientific system. On the basis of the above view, this study was attempted to investigate the orientation of design to recognize space as another life, and explore a process where it is drawn into a design language on the basis of human behavior. If the essence of space behavior and the activity system are analyzed through user observation and it is reflected upon a space design program and then developed into a formative language, a new design process on human and environment might be produced. In conclusion, the reflection of user's behavior and psychology into design, contrary to existing public space design based on physical data, can orient quality improvement of human life and ultimately be helpful to the proposition, 'humanization of space'.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.281-287
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• 2011

BACKGROUND: According to Korean regulations, bottled waters (BWs) can not be treated with chemical disinfectants like chlorine, so UV and ozone disinfection is applied. During the past several years, chemicals were detected in some BWs, and the public was concerned about the safety of BWs. METHODS AND RESULTS: Mineral waters were stored for 180 days at $25^{\circ}C$ and $50^{\circ}C$, tested acetaldehyde and formaldehyde by HPLC. When mineral waters were put in a PET bottles, the formaldehyde level ranged from 5 to $66{\mu}g/L$ during 180 days at $50^{\circ}C$. While the acetaldehyde level ranged from 31 to $221{\mu}g/L$, it was low than $16{\mu}g/L$ in glass bottle. CONCLUSION(s): This result showed that formaldehyde and acetaldehyde were detected higher in PET bottles than glass bottles, these also increased depending on the time of storage. Concentration of formaldehyde and acetaldehyde could be significantly influenced by the time of storage and temperature.

• The Korean Journal of Nuclear Medicine
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• v.34 no.4
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• pp.336-343
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• 2000

Purpose: Thallous-201 chloride produced at Korea Cancer Center Hospital(KCCH) is used in detecting cardiovascular disease and cancer. Thallium impurity can cause emesis, catharsis and nausea, so the presence of thallium and other metal impurities should be determined. According to USP and KP, their amounts must be less than 2 ppm in thallium and 5 ppm in total. In this study, the detection method of trace amounts of metal impurities in $[^{201}Tl]$TICI injection with polarography was optimized without environmental contamination. Materials and Methods: For the detection of metal impurities, Osteryoung Square Wave Stripping Voltammetry method was used in Bio-Analytical System (BAS) 50W polarograph. The voltammetry was composed of Dropping Mercury Electrode (DME) as a working electrode, Ag/AgCl as a reference electrode and Pt wire as a counter electrode. Square wave stripping method, which makes use of formation and deformation of amalgam, was adopted to determine the metal impurities, and pH 7 phosphate buffer was used as supporting electrolyte. Results: Tl, Cu and Pb in thallous-201 chloride solution were detected by scanning from 300 mV to -800 mV Calibration curves were made by using $TINO_3,\;CuSO_4\;and\;Pb(NO_3){_2}$ as standard solutions. Tl was confirmed at -450 mV peak potential and Cu at -50 mV Less than 2 ppm of Tl and Cu was detected and Pb was not detected in KCCH-produced thallous-201 chloride injection. Conclusion: Detection limit of thallium and copper is approximately 50 ppb with this method. As a result of this experiment, thallium and other metal impurities in thallous-201 chloride injection, produced at Korea Cancer Center Hospital, are in the regulation of USP and KP Polarograph could be applied for the determination of metal impurities in the quality control of radiopharmaceuticals conveniently without environmental contamination.

• Journal of Food Hygiene and Safety
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• v.19 no.1
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• pp.12-18
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• 2004

Ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin in chicken muscle were seperated by liquid extraction and determined with high performance liquid chromatography (HPLC) with fluorescence detector. Analysis was carried out using following conditions; Cl8 column (250${\times}$4.6 mm i.d. 5 ${\mu}{\textrm}{m}$ particle size), mobile phase composed of D.W. (containing 0.4% triethylamine and phospholic acid): methanol : acetonitrile (800:100:100, v/v/v), isocratic pump at a flow rate of 1.0 $m\ell$/min and 50 ${mu}ell$ of injection volume, fluorescence detector with EX278 nm/EM.456 nm. The calibration curves of four fluoroquinolones showed linearity (${\gamma}$$^2$$\geq$0.999) at concenration range of 0.025-0.6 $\mu\textrm{g}$/ml. The recoveries in fortified chicken muscle represented more than 80% with low coefficient of variation (〈10%) for concentration range of four fluoroquinolones. The detection limits for ofloxacin, norfloxacin, ciprofloxacin, and enrofloxacin were 23.5, 3.4, 3.0 and 2.5 ng/g in chicken muscle, respectively. We also monitored fluoroquinolones residue in muscle of chickens (broiler 1:227, Korean native chicken 219, laying chicken 77) using EEC-4-plate screening and HPLC conformation methods. Ten(broiler 5, Korean native chicken 5) out of the fifteen samples which were positively detected by EEC-plate screening method from 1,523 chicken meat were confirmed with ciprofloxacin and enrofloxacin by HPLC. The ranges of residual concentration were 0-0.12 ppm for ciprofloxacin and 0.01-6.79 ppm for enrofloxacin. In conclusion, our method could be applied effectively to determine four fluoroquinolones residues in chicken meat, and further survey for fluoroquinolones residue in chicken meat are needed for more effective control of fluoroquinolones used in livestock.

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.641-644
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• 2001

This study was performed for development of new analytical method of monascus pigments in foods. In this method, analysis of monascus pigment in foods has been carried out by detection of monascin and ankaflavin of the main color component of monascus pigment as indicator compounds. Monascin and ankaflavin were isolated and identified by TLC, HPLC, Prep. HPLC, $^{1}H-NMR$ and Mass spectrophotometer. The analysis of monascin and ankaflavin in foods such as massal, sausage, mixed press ham, mixed fish sausage, semi-dried sausage and syrup was performed by using reverse phase high performance liquid chromatograph with Capcell Pak C18 column at wave length 390 nm. The quantitative results of monascin were as follows : $0.01{\sim}3.31\;{\mu}g/g$ item in massal, $0.05{\sim}0.10\;{\mu}g/g$ in mixed fish sausage, and $0.34{\sim}0.35\;{\mu}g/g$ in semi-dried sausage. But the quantitative results of ankaflavin were as follows: $0.02{\sim}0.89\;{\mu}g/g$ in massal, ankaflavin were not founded in other samples.