• Journal of Biomedical Engineering Research
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• v.16 no.2
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• pp.231-238
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• 1995

Tc-99m-MIBI (Sestamibi) myocardial SPECT along with TI-201 tomographic Imaging has demonstrated wide application and high image quality sufficient for the diagnosis of myocardial perfusion defect, which consequently reflects regional myocardial blood flow. The qualitative values of myocardial SPECT with Tc-99m-MIBI as well ds the quantitative cases depend in some degree on the reconstruction techniques of multiple projections. Filtered backprojection (FBP) Is the common standard method for reconstruction rather than the complicated and time-consuming arithmetic methods. In FBP it is known that the distribution of radioactivity in reconstructed transverse slices varies with the selected litter parameters such as cutoff frequencies and order (Butterworth case) The cutoff frequencies used in clinicAl practice partially remove and decrease the true radioactive distribution and alter the pixel counts, which lead to underestimation of true counts in specific myocardial regions. In this study, we have investigated the effect of cutoff frequencies of reconstruction filter on the artifactually induced perfusion defects, which are often demonstrated near inferior and/or inferoseptal cardiac walls due to the intense hepatic uptake of Tc-99m-MIBI. A computerized method for Identifying the relative degree of artifactual perfusion defect and for comparing those degrees along with the relative amount of hepatic uptake to myocardium was developed and patient images were studied to observe the quantitative degree of underestimation of myocardial perfusion, and to propose some reasonable threshold of cutoff frequency in the diagnosis of perfusion defect quantitatively. We concluded that from the quantitative viewpoint cutoff frequencies may be used as high as possible with the sacrifice of homogeneity of image quality, and those frequencies lower than the common 0.3 Wyquist frequency would reveal severe degradation of radioactive distribution near inferior and/or inferoseptal myocardium when applying Butterworth or low pass filter.

• Journal of Korean Academy of Nursing
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• v.26 no.2
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• pp.483-496
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• 1996

The purpose of this study was to describe how Korean nurses overcome the language barrier while working in the U.S. hospital settings. Twelve Korean nurses living in New York metropolitan area were asked open-ended, descriptive questions to collect the data. The interviews were done in Korean. All interviews were audiotaped under the permission of the participants and were transcribed verbatim. The data were analyzed using grounded theory analysis. The research process consisted of two phases. In the first phase 8 Korean nurses were interviewed and analyzed. In the second phase, further data were collected to verify categories and working hypotheses that were emerged from the first phase. The results of this study show that all Korean nurses experienced severe psychological stress such as confusion, anxiety, frustration, loss of self-confidence, embarrassment, guilt, depression, anger, and fear. Among the mode of communication such as listening, speaking, leading, and writing, they had the most difficulty in speaking. Speaking ability was especially important for them because of the emphasis of individualism and self-defense in the U.S. Among the verbal communication modes, non-face-to-face communications such as phone conversation and body language were the most difficu1t for them to overcome. It took at least 2 years for the participants to initially overcome the language barrier in U.S. hospitals. After 2-5 years they began to feel comfortable even in non-face-to-face communication. They could actively search for the better place to work after 5 years. They finally felt comfortable in English and in their job almost after 10 years. The factors that influenced the English improvement were ‘the years of clinical experience in Korea’, ‘the decade they came to the U.S.’ ‘coming to U.S. alone or with other Korean nurses’, ‘racial homogeneity or heterogeneity of the working unit’, and ‘the degree of social support’. The strategies Korean nurses used to overcome the language barrier included depending on the written communication, using ‘nunchi’, working and studying hard, and establishing good interpersonal relationships with co-workers. They also employed assertive behavior of the U.S., such as using more explicit verbal language and employing smiles and eye contact with others during the conversation. The results of the study may help Korean nurses and nursing students who try to work in U.S. hospital settings by understanding problems other Korean nurses faced, factors that influenced their English improvement, and strategies they used. They may also help U.S. nurses and administrators in developing and implementing efficient programs for newly employed Korean nurses by understanding major problems and feelings the Korean nurses experienced and strategies they used to overcome the language barriers.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.225-231
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• 2003

Up-front irradiation technique as 3-dimensional conformation, or intensity modulation has kept large proportion of brain tumors from being complicated with acute radiation reactions in the normal tissue during or shortly after radiotherapy. For years, we've cannot help but counting on 2-D vertex beam technique to reduce acute reactions in the brain tumor patients because we're not equipped with 3-dimensional planning system. We analyzed its advantages and limitations in the clinical application. From 1998 to 2001, vertex or oblique vertex beams were applied to 35 patients with primary brain tumor and 25 among them were eligible for this analysis. Vertex(V) plans were optimized on the reconstructed coronal planes. As the control, we took the bilateral opposed techniques(BL) otherwise being applied. We compared the volumes included in 105% to 50% isodose lines of each plan. We also measured the radiation dose at various extracranial sites with TLD. With vertex techniques, we reduced the irradiated volumes of contralateral hemisphere and prevented middle ear effusion at contralateral side. But the low dose volume increased outside 100%; the ratio of V to BL in irradiated volume included in 100%, 80%, 50% was 0.55+/-0.10, 0.61+/-0.10, and 1.22+/-0.21, respectively. The hot area within 100% isodose line almost disappeared with vertex plan; the ratio of V to BL in irradiated volume included in 103%, 105%, 108% was 0.14+/-0.14, 0.05./-0.17, 0.00, respectively. The dose distribution within 100% isodose line became more homogeneous; the ratio of volume included in 103% and 105% to 100% was 0.62+/-0.14 and 0.26+/-0.16 in BL whereas was 0.16+/-0.16 and 0.02+/-0.04 in V. With the vertex techniques, extracranial dose increased up to $1{\sim}3%$ of maximum dose in the head and neck region except submandibular area where dose ranged 1 to 21%. From this data, vertex beam technique was quite effective in reduction of unnecessary irradiation to the contralateral hemispheres, integral dose, obtaining dose homogeneity in the clinical target. But it was associated with volume increment of low dose area in the brain and irradiation toward the head and neck region otherwise being not irradiated at all. Thus, this 2-D vertex technique can be a useful quasi-conformal method before getting 3-D apparatus.

• Korean Journal of Childcare and Education
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• v.3 no.1
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• pp.17-37
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• 2007

An abundant emotional experience in childhood can be a basis of success of their life. In this research, I set up a hypothesis as follows to see if a group plastic activities are effective for the improvement of children's emotional intelligence and self-emotion awareness ability, self-emotion management ability, self-motivation ability, other's emotion awareness ability and personal relationship skill ability. The research subjects were 40 children of 5 years old(experimental Group: 20, controlled group: 20) in Y kindergarten located in Ulsan. In pretest, we confirmed homogeneity between experiment and control group using child emotional checklist and then applied small group plastic artistic activities to the experiment group. Data analysis was performed with population, percentage, t-test and Cronbach a. The findings of this study were: First, the group plastic artistic activities was effective for the emotional intelligence of children. Second, the small group plastic activities was effective for the self-emotion awareness, self-emotion control and self motivation ability of children. Third, the small group plastic activities was effective for the awareness ability about other's emotion and personal relationship skill ability. The result of this study implies that the small group plastic artistic activities are effective children's emotion and we need to develop the various activity program and practice for children's emotion development.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.307-316
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• 2003

Fish assemblage structure in a sheltered shallow water in the Southern Coast of Korea was examined monthly. Sampling was conducted in Doam Bay using a beam trawl between March 2001 and February 2001. A total of 53 fish species from 33 families were caught. Pinkgray goby (Chaeturichthys hexanema), ponyfish (Leiognathus nuchalis) and yellowfin goby (Acanthogobius favimanus) were the most frequent species, comprised 67.4％ of the total numbers captured. Snailfish (Liparis tanakai), yellowfin goby (Acanthogobius flavimanus) and pinkgray goby (Chaeturichthys hexanema) represented 50.8％ of the total biomass. While total abundance (number of individuals) and biomass were high in autumn and winter, species richness (number of species) and diversity were high in spring. Cluster analysis, based on monthly abundance data of the 14 most frequent species, showed that the species were separated into three different groups. Group A composed of pinkgray goby, yellowfin goby, robust tonguefish (Cynoglossus robustus) and scaly hairfin anchovy (Setipinna taty), which were year-round residents, and devil flathead (Onigocia spinosa), Red dragonet (Repomucenus lunatus) and ponyfish, which were abundant in autumn, group B surmullet (Upeneus japonicus), hairtail (Trichiurus lepturus) and gaff-topsail goby (Cryptocentrus filifer), which were abundant in summer, and group C grassfish (Liparis tanakai), spotted velvefish (Erisphex pottii), chameleon goby (Tridentiger trigonocephalus) and Richardson dragonet (Repomucenus richardsonii), which were abundant in winter and spring. A seasonal homogeneity of fish assemblage indicates that overall fish assemblage in Dom Bay is largely controlled by year-round residents.

• Journal of the Korean Ceramic Society
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• v.42 no.4
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• pp.260-268
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• 2005

A heat-resisting diatomite protection tube, using diatomite as a main component, was manufactured through an extrusion molding of ceramic slurry in different component ratios. And its mechanical strength, carbon analysis and microstructural non-homogeneity were investigated. After fixing $60wt\%$ of porous diatomite whose particle size was $50\~100\;{\mu}m$, the optimum mixture ratio with composition variables by changing $1\;wt\%$ of each component that was silica sol$(4.3\~7.3\;wt\%)$ as an inorganic binder, CMC (Sodium CarboxyMethyl Cellulose $(6\~9\;wt\%)$) as an organic binder and paper powder$(4.7\~7.7\;wt\%)$ was obtained. As a result of the investigation on a composition containing $60\;wt\%$ diatomite, $5.3\;wt\%$ silica sol, and $7\;wt\%$ CMC, a heat-resisting protection tube that could be used as a molten steel probe for measuring the temperature and components of molten steel was developed. The bending strength, compressive strength, and elastic modulus of the protection tube developed, that contained $\le2.3\;wt\%$ carbon, were 7.1 MPa, 7.5 MPa, and 1090 MPa, respectively.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.216-223
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• 2003

A 1.3-kb of chitosanase gene (choA) encoding 45-kDa polypeptide was cloned, expressed, and characterized from a newly isolated Bacillus cereus H-1. The chitosanase protein (ChoA) of B. cereus H-l was purified to homogeneity by ammonium sulfate precipitation and CM-sephadex column chromatography. Optimum pH was around 7, and stable pH range in the incubation at 50 C was 4-11. Optimum temperature was around 50 C, and enzyme activity was relatively stable below 45 C. ChoA showed the activities toward carboxymethyl cellulose (CMC) in addition to soluble or glycol chitosan. Based on MALDI-TOF MS analysis of purified ChoA, the entire amino acid sequence of ChoA was interpreted by database searching of previously known Bacillus chitosanases. A 1.6 kb of PCR product of corresponding chitosanase gene was obtained and its DNA sequence was determined. The deduced amino acid of choA revealed that ChoA have a 98% homology with those of Bacillus sp. No.7-M strain and Bacillus sp. KCTC0377BP. The recombinant ChoA protein was expressed in E. coli DH5$\alpha$. Deduced amino acid comparison of choA with other chitosanases suggested that it belongs to family 8 microbial endo-chitosanase with chitosanase-cellulase activity.

• Journal of Pharmaceutical Investigation
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• v.39 no.1
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• pp.29-36
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• 2009

Since the quality of final products is significantly affected by the homogeneity of powder mixture, the powder blending process has been regarded as one of the critical pharmaceutical unit processes, especially for solid dosage forms. Accordingly, the monitoring to determine a blending process' end-point based on a faster and more accurate in-line/on-line analysis has attracted enormous attentions recently. Among various analytical tools, NIR (near-infrared) spectroscopy has been extensively studied for PAT (process analytical technology) system due to its many advantages. In this study, NIR spectroscopy was employed with an optical fiber probe for the in-line monitoring of fluid-bed blending process. The position of the probe, the ratio of binary powder mixture, the powder size differential and the back-flush period of the shaking bag were examined as principal process parameters. During the blending process of lactose and mannitol powders, NIR spectra were collected, corrected, calibrated and analyzed using MSC and PLS method, respectively. The probe position was optimized. A reasonable end-point was predicted as 1,500 seconds based on 5% RSD value. As a consequence, it was demonstrated that the blending process using a fluid-bed processor has several advantages over other methods, and the application of NIRS with an optical fiber probe as PAT system for a fluid-bed blending process could be high feasible.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.165-171
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• 1998

The $Y_1Ba_2Cu_3O_{7-x}$(123) superconductor powders were prepared by pyrophoric synthesis method(PSM) using $Y_2O_3$(99.9%), $BaCO_3$(99.9%), and CuO(99.9%) powders. The phase formation and reaction kinetics of 123 superconductor manufactured with powders prepared in various pHs of pyrophoric synthetic solution have been studied through the experiments at various heat treatment temperatures and times. Inductively coupled plasma(ICP) spectroscopy and scanning electron microscopy(SEM) measurements were performed to examine the composition and morphology of the sample. X-ray diffraction(XRD) analysis was done to determine phase formation and conversion ratio of Y-Ba-Cu-O systems. The 123 powder prepared at pH 7(${\pm}0.3$) yields the best result in terms of purity, homogeneity, and reactivity. The activation energies(${\Delta}E_a$) of 123 phase formation were found to be 191 kJ/mol and 230kJ/mol in solid state reaction method and pyrophoric synthesis method, respectively.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.47-52
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• 1998

3-Hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the conversion of HMG-CoA to mevalonic acid, the first intermediate of isoprenoid biosynthetic pathway in plants. The enzyme was solubilized with 0.4% Brij (polyoxyethylene ether) W-1 from a microsomal fraction of etiolated rice seedlings (Oryza sativa L.) in which its maximal activity was observed on the fourth day after germination. HMGR was purified to near homogeneity by employing $(NH_4)_2SO_4$ fractionation plus chromatographic procedures including DEAE-Sephadex A-50 and HMG-CoA-hexane-agarose affinity column. The size of the purified enzyme was estimated to be 55 kDa when judged by SDS-PAGE analysis with silver staining method. The apparent $K_m$ and $V_{max}$ values for HMG-CoA were determined to be $180\;{\mu}M$ and 107 pmol/min/mg, and those for NADPH were $810\;{\mu}M$ and 32.1 pmol/min/mg, respectively.