• Childhood Kidney Diseases
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• v.11 no.1
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• pp.59-64
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• 2007

Purpose : Suprapubic aspiration(SPA) has been considered the "gold standard" for obtaining urine in non-toilet trained infants. Ultrasound(US)-guided SPA improves the success rate of the procedure and reduces the complications. However, many physicians perceive SPA as invasive and prefer the use of urethral catheterization (Ucat). We compared the success rate, complications and accuracy of US-guided SPA and Ucat. Methods : 121 infants who visited Ewha Womans University Mokdong Hospital with suspected urinary tract infection(UTI) were investigated. For the first study, the study infants were randomly assigned to either the US-guided SPA(n=32) or Ucat(n=32) groups. The success rate and complications of both procedures were compared. For the second study, US-guided SPA and Ucat were performed simultaneously(n=57). The accuracy of urethral catheterization was subsequently analyzed. The criteria for success was defined as the collection of more than 0.5 mL of urine. UTI was diagnosed by the presence of uropathogens over 105 colony-forming units (CFU)/mL. Results : The overall success rate of the US-guided SPA was 96.9%(71.9% in first attempts, 25.0% in second attempts) which was not significantly different compared to 96.9%(90.6% in first attempts, 6.3% in second attempts) in the Ucat(P>0.05) group. The aspirated urine volume was $7.4{\pm}3.7mL$ in the US-guided SPA group, which was not significantly different to $4.5{\pm}2.6mL$ in the Ucat(P>0.05) group. The accuracy of Ucat in comparison to the US guided SPA was low with sensitivity 59.5%, specificity 86.6%, false-positive rate 13.3% and false-negative rate 40.5%. Conclusion : US-guided SPA should be encouraged as the best method to collect the urine in non-toilet trained infants with UTI.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.1 no.1
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• pp.21-32
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• 1981

Recent trends in design standards development in some European countries and U.S.A. have encouraged the use of probabilistic limit sate design concepts. Reliability based design criteria such as LSD, LRFD, PBLSD, adopted in those advanced countries have the potentials that they afford for symplifying the design process and placing it on a consistent reliability bases for various construction materials. A reliability based design criteria for RC flexural members are proposed in this study. Lind-Hasofer's invariant second-moment reliability theory is used in the derivation of an algorithmic reliability analysis method as well as an iterative determination of load and resistance factors. In addition, Cornell's Mean First-Order Second Moment Method is employed as a practical tool for the approximate reliability analysis and the derivation of design criteria. Uncertainty measures for flexural resistance and load effects are based on the Ellingwood's approach for the evaluation of uncertainties of loads and resistances. The implied relative safety levels of RC flexural members designed by the strength design provisions of the current standard code were evaluated using the second moment reliability analysis method proposed in this study. And then, resistance and load factors corresponding to the target reliability index(${\beta}=4$) which is considered to be appropriate level of reliability considering our practices are calculated by using the proposed methods. These reliability based factors were compared to those specified by our current ultimate strength design provisions. It was found that the reliability levels of flexural members designed by current code are not appropriate, and the code specified resistance and load factors were considerably different from the reliability based resistance and load factors proposed in this study.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.133-140
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• 1994

Recently, there are many considerations and studies on biological effects of radiations in radiation workers, as well as in accidentally or therapeutically irradiated persons. The most practical and reliable method of dosimetry for radiation accidents is the scoring of gross chromosomal aberrations in human lymphocytes (Ydr) as a biological dosimetry. By the way, although usual doses of $^{131}I$ administered therapeutically for thyroid cancer are ranging from 100 mCi to 200 mCi, there are differences of absorbed doses and Ydr, ranging from 0.004 to 0.04, on equally administered $^{131}I$ due to variations in metabolic characteristics, stage of tumors and physical status of subjects. In this study, We exert to obtain the dose-response relationships of $^{131}I$, as a good guide to evaluating acute effects of accidental irradiations and radiation induced leukemia or solid tumor, by in vitro induction of chromosomal aberrations. we studied the relationship between radiation dose (D) and the frequency of chromosomal aberrations (Ydr) obserbed in peripheral lymphocytes that were irradiated in vitro with $^{131}I$ at doses ranging from 0.05 to 6.00 Gy. By scoring cells with unstable chromosomal aberrations (dicentric chromosomes and ring chromosomes) we obtained this linear-quadratic dose response equation Ydr=0.064351 $D^2$-0.13143 D+0.045684 This dose-response relationship may be useful for evaluating acute and chronic $^{131}I$ induced biological effects.

• Polymer(Korea)
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• v.30 no.6
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• pp.498-504
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• 2006

A suspension polymerization of styrene In aqueous phase was employed to study if polystyrene particles ranging from 1 to $20{\mu}m$ can be produced. Hydrophobic silica was selected as a stabilizer and azo-bisisobutyronitrile (AIBN) as an initiator. Polymerization reaction was carried out at a selected temperature in the range of $65{\sim}95^{\circ}C$. Stabilizer concentration was varied from 0.17 to 3.33 wt% compared to the water while the concentration of the initiator was raised from 0.13 to 6.0 wt% compared to the monomer. Dispersion of hydrophobic silica into the water phase was achieved by precise control of pH. Optimum dispersion of silica was obtained at pH 10. Average particle diameter decreased with increasing amounts of stabilizer concentration initially, exhibiting the minimum average diameter at 1.67 wt% of stabilizer concentration, after which it started to Increase. It is speculated that an excessive presence of stabilizer encouraged a secondary reaction in the reaction medium, which led to particle agglomeration, and as a result an increase in average particle diameter. Molecular weight was found to be independent of stabilizer concentration between 0.13 and 1.00 wt% whereas, it increased when stabilizer concentration exceeded 1.67 wt%. Variation of molecular weight was probably caused by the reduced activity and efficiency of initiator due to the high concentration of silica, and the secondary reaction in the reaction medium, as well. An increase in the Initiator concentration and/or reaction temperature resulted in an increase in both reaction rate and particle diameter. Consequently, we have confirmed that spherical polystyrene particles with $1{\sim}20{\mu}m$ in diameter can be prepared by careful selection of the concentration of stabilizer, initiator, pH and reaction temperature.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.7
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• pp.667-678
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• 2002

In this paper, a new radiating structure with a multi-layered two-dimensional metallic disk array was proposed for shaping the flat-topped element pattern. It is an infinite periodic planar array structure with metallic disks finitely stacked above the radiating circular waveguide apertures. The theoretical analysis was in detail performed using rigid full-wave analysis, and was based on modal representations for the fields in the partial regions of the array structure and for the currents on the metallic disks. The final system of linear algebraic equations was derived using the orthogonal property of vector wave functions, mode-matching method, boundary conditions and Galerkin's method, and also their unknown modal coefficients needed for calculation of the array characteristics were determined by Gauss elimination method. The application of the algorithm was demonstrated in an array design for shaping the flat-topped element patterns of $\pm$20$^{\circ}$ beam width in Ka-band. The optimal design parameters normalized by a wavelength for general applications are presented, which are obtained through optimization process on the basis of simulation and design experience. A Ka-band experimental breadboard with symmetric nineteen elements was fabricated to compare simulation results with experimental results. The metallic disks array structure stacked above the radiating circular waveguide apertures was realized using ion-beam deposition method on thin polymer films. It was shown that the calculated and measured element patterns of the breadboard were in very close agreement within the beam scanning range. The result analysis for side lobe and grating lobe was done, and also a blindness phenomenon was discussed, which may cause by multi-layered metallic disk structure at the broadside. Input VSWR of the breadboard was less than 1.14, and its gains measured at 29.0 GHz. 29.5 GHz and 30 GHz were 10.2 dB, 10.0 dB and 10.7 dB, respectively. The experimental and simulation results showed that the proposed multi-layered metallic disk array structure could shape the efficient flat-topped element pattern.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.12-18
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• 2021

The in vitro antioxidant activity of oregano seed fractions, fractionizing with 80% ethanol, n-hexane, ethyl acetate, n-butanol, and water, was evaluated, and their effects on edible oils were determined in corn oil at 180℃. The ethyl acetate fraction had the highest radical-scavenging activity. The ferric reducing antioxidant power activity and total phenol content of the ethyl acetate fraction were determined as 6,130 µmol ascorbic acid equivalents/g extract and 770 µmol tannic acid equivalents/g extract, respectively, which were significantly higher than those of the other fractions (p<0.05). Primary and secondary oxidation products in corn oil added with the ethyl acetate fraction of oregano seed significantly decreased by 1.5 and 1.26 times, respectively, compared with those in the control groups. The major volatile ingredients in the ethyl acetate fraction of oregano seeds were determined to be carvacrol, thymoquinone, and 3-cyclopentylcyl-cyclopentan-1-one. Ethyl acetate is a suitable solvent for extracting antioxidant compounds from oregano seeds and can be used as a natural antioxidant.

• Journal of the Korean Chemical Society
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• v.67 no.2
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• pp.81-88
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• 2023

The contribution of hydrophobic residues to the protein folding reaction was studied by using HubWA variant proteins with I and L to V mutation. Folding kinetics of all V variant proteins was observed to be satisfied by a three-state on-pathway mechanism, U ⇌ I ⇌ N, where U, I, and N represent unfolded, intermediate, and native state, respectively. Three-state folding reaction was quantitatively analyzed and the free energy of folding of each elementary reactions and overall folding reaction, ΔG^o_UI, ΔG^o_IN, and ΔG^o_UN, were obtained. From the ratio of free energy difference between the variant protein and HubWA, ΔΔG^o_UI/ΔΔG^o_UN (ΔΔG^o_UI = ΔG^o_UI (variant protein) - ΔG^o_UI (HubWA) and ΔΔG^o_UN = ΔG^o_UN (variant protein) - ΔG^o_UN(HubWA)), the contribution of hydrophobic residues to HubWA folding was analyzed. The residues which are located in the hydrophobic core between α-helix and β-sheet, I3, I13, L15, I30, L43, I61 and L67, showed ΔΔG^o_UI/ΔΔG^o_UN value of ~0.5 when each of these residues was mutated to V, indicating that these residues form relatively solid hydrophobic core in the intermediate state. Residues located at the end of secondary structures and loop, I23, L69 and I36 showed ΔΔG^o_UI/ΔΔG^o_UN value below 0.4 when each of these residues was mutated to V, indicating that the region containing these residues are loosely formed in the intermediate state. V17A, L50V and L56V showed fairly high ΔΔG^o_UI/ΔΔG^o_UN value of ~0.8. Since L50 and L56 are located in the region containing long loop (residue 46 to 62), it is suggested that the high ΔΔG^o_UI/ΔΔG^o_UN value of these residues prevents the formation of aggregate at the early stage of folding reaction.

• Journal of Korean Philosophical Society
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• v.152
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• pp.59-79
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• 2019

The main purpose of this paper is to critically examine the intractable problems of Peirce's notion of 'symbol' as a higher and perfect mode of sign, and present a more appropriate account of the higher status of symbol from an experientialist perspective. Peirce distinguished between icon, index, and symbol, and suggested symbol to be a higher mode of sign, in that it additionally requires "interpretation." Within Peirce's picture, the matter of interpretation is to be explained in terms of "interpretant," while icon or index are not. However, Peirce's conception of "interpretant" itself remains fraught with intractable opacities, thereby leaving the nature of symbol in a misty conundrum. Drawing largely on the experientialist account of the nature and structure of symbolic experience, I try to explicate the complexity of symbol in terms of "the symbolic mapping." According to experientialism, our experience consists of two levels, i.e., physical and symbolic. Physical experience can be extended to symbolic level largely by means of "symbolic mapping," and yet is strongly constrained by physical experience. Symbolic mapping is the way in which we map part of certain physical experience onto some other area, thereby understanding the other area in terms of the mapped part of the physical experience. According to this account, all the signs, icon, index, and symbol a la Peirce, are constructed by way of symbolic mapping. While icon and index are constructed by mapping physical level experience onto some signifier(i.e. Peirce's "representamen"), symbol is constructed by mapping abstract level experience onto some signifier. Considering the experientialist account that abstract level of experience is constructed by way of symbolic mapping of physical level of experience, the symbolic mapping of abstract level of experience onto some other area is a secondary one. Thus, symbol, being constructed by way of secondary or more times mapping, becomes a higher level sign. This analysis is based on the idea that explaining the nature of sign is a matter of explaining that symbolic experience, leaving behind Peirce's realist conception of sign as a matter of an event or state of affairs out there. In conclusion, I suggest that this analysis will open up new possibilities for a more appropriate account of the nature of signs, beyond Peirce's complicated riddles.

• Journal of Life Science
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• v.25 no.7
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• pp.826-832
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• 2015

This study describes the effects of activated charcoal on the removal of salts, detergents, and pigments from protein extracts of ginseng leaves and roots. Incubation of protein extracts with 5% (w/v) activated charcoal (100-400 mesh) for 30 min at 4℃ almost removed the salts and detergents including NP-40 as can be observed on SDS-PAGE. In addition, analysis of chlorophyll content showed significant depletion of chlorophyll (~33%) after activated charcoal treatment, suggesting potential effect of activated charcoal on removal of pigments too along with the salts and detergents. 2-DE analysis of activated charcoal treated protein samples showed better resolution of proteins, further indicating the efficacy of activated charcoal in clearing of protein samples. In case of root proteins, although not major differences were observed on SDS-PAGE, 2-DE gels showed better resolution of spots after charcoal treatment. In addition, both Hierarchical clustering (HCL) and Principle component analysis (PCA) clearly separated acetone sample from rest of the samples. Phenol and AC-phenol samples almost overlapped each other suggesting no major differences between these samples. Overall, these results showed that activated charcoal can be used in a simple manner to remove the salts, detergents and pigments from the protein extracts of various plant tissues.

• Journal of the Mineralogical Society of Korea
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• v.22 no.4
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• pp.395-405
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• 2009

The maturity of amber matrix and inclusion was studied to explore the effect of heat treatment on the formation of the sun spangle in the transparent Baltic amber from Gdansk, Poland. Optical microscope revealed two types of inclusions in the original amber samples. The inclusions in the amber which had sun spangle were dramatically expanded by the heat treatment, comparing to those without sun spangle which contains fissure and shows different refractive index. The amber sample which didn't show sun spangle after the heat treatment showed a strong carbon related peak in TOF-SIMS spectra and weak oxygen related peak. it means that the maturity of this amber sample is comparatively higher than the one with spangle. The two amber samples show similar IR spectra before the heat treatment. However, the amber which had sun spangle exhibited an additional 1019 $cm^{-1}$ absorption peak and a more intense 887 $cm^{-1}$ peak. The different chemical compositions between the two types of amber is believed to be due to the different absorption spectra between 1000~600 $cm^{-1}$. According to the study of DSC analysis, the two samples show different DSC profiles. Although they have the same geological origin, their geological ages are different and have different chemical compositions. Thus, they exhibited different behavior after the heat treatment. The formation of sun spangle seemed to depend on the difference in the heat expansion rate of amber matrix with different maturity and chemical compositions.