• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.173-192
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• 1999

The purpose of this study was to evaluate the effects of bioactive glass and natural coral on the human periodontal ligament fibroblast(HPLF) behaviors during the regeneration process of peridontium. To determine the cellular events occuring in the presence of the particles of bioactive glass and natural coral, HPLF were isolated from healthy premolar teeth extracted for orthodontic treatment. Cells were cultured in ${\alpha}$MEM at 37$^{\circ}C$, 5% $CO_2$, 95% humidity incubator. Bioactive glass and natural coral were powdered, and each particles(<40${\mu}$m) were placed on the cultured cells at the concentration of 0.3mg/ml, and 1,0mg/ml for experimental group. In control group no particles were added. And each group was evaluated by examining the cell morphology under phase-contrast micrograph at 4 day and transmission electron micrograph(TEM) and scanning electron micrograph(SEM) at 14 day, alkaline phosphatase activity at 5 and 9 day, protain synthesis at 4 day, DNA synthesis at 1, 2, 3 and 4 day, cell proliferation at 1, 3, 5,7 and 9 day and the formation of bone nodule at 30 day after culturing all groups in mineralizing supplemented mediun, No significant changes in cell morphology by adding these two matirials were found under phase contrast microscopy and TEM. HPLF phagocytocized each particles suggesting that HPLF is involved in the process of resorbing each particles and that bioactive glass were more biocompatible than natural coral. The ALPase activity of bioactive glass 0.3 mg/ml was similar with control groups and all the rests of control groups were significantly low(P<0.01) indicating a transient dedifferentiation of HPLF in the presence of bioactive glass and natural coral particles. There were no significant differences of protein synthesis between all groups. The DNA synthesis in experimental groups were significantly lower than control groups at 1, 2 and 3 day (P<0.01) but became similar to control groups at 4 day. Between control groups, the DNA synthesis in bioactive glass O.3mglml group was significantly higher than other groups(P<0.01). Cell proliferation in natural coral 1.0mg/ml and bioactive glass 1.0mglml groups were significantly lower than control group at 3 day(P<0.05) and there were no differences at 5, 7, 9 day. There were more bone nodule formation in experimental groups than in control groups. In conclusion, these results indicated that bioactive glass and natural coral have some effects of a transient dedifferentiation on HPLF and regeneration of periodontal tissues, however any significant cytotoxic effect on HPLF by these two particles were not found.

• Geophysics and Geophysical Exploration
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• v.2 no.1
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• pp.33-42
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• 1999

AVO and complex trace analyses mainly used to characterize natural gas reservoir were tested in this paper for a possible application to detection of major geological discontinuities such as fracture zones. The test data used in this study were calculated by utilizing a viscoelastic numerical program which was based on the generalized Maxwell body for a horizontal fracture model. In AVO analysis of a horizontal fracture zone, p-wave reflection appears to be variant depending upon the acoustic-impedence contrast and the offset distance. The fracture zone is also effectively clarified both in gradient stack and range-limited stack in which fracture zone reflection is attenuated with the increasing offset distance. In complex attribute plots (instantaneous amplitude, frequency, and phase), the top and bottom of the fracture Tone are characterized by a zone of strong amplitudes and an event of the same phase. Low frequency characteristics appear at the fracture zone and the underneath. Amplitude attenuation and waveform dispersion are dependent on Q-contrast between the fracture zone and the surrounding media. They were properly compensated by optimum inverse Q-filtering.

• Geophysics and Geophysical Exploration
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• v.4 no.4
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• pp.115-123
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• 2001

The bright spot is an indicator for natural gas on seismic stack sections, but it is also shown on layers where the acoustic impedance contrast is large. In order to distinguish sharply between gas and impedance contrast we need additional detailed data processing such as velocity analysis, AVO analysis and seismic complex analysis including measures of seismic amplitude, frequency, and phase. In this study, we performed detailed velocity analysis, complex analysis and DHI (Direct Hydrocarbon Indicator) analysis which is the result of amplitude variation according to the incident angles. The seismic complex analysis gives us the geological information which depends on geophysical properties at the interest layer. For the complex analysis, we computed several seismic attributes such as the instantaneous amplitude, the first and the second derivatives of the instantaneous amplitude, the instantaneous phase, the instantaneous frequency and weighted average instantaneous frequency. Then we applied these analysis techniques to a seismic data of Korea offshore which had been logged. From the result of this data analysis, it could be said that high possibility area for gas layer detection has amplitude anomalies in the instantaneous amplitude, the instantaneous frequency and the DHI section resulting from the AVO analysis. If there are not any other anomalies in detailed data processing, it will have low possibility for gas layer detection.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.138-144
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• 2011

Purpose: The purpose of this study was to evaluate the cleansing effect of recently developed alkaline ionized water, e-WASH, on microorganisms of the denture surface. Materials and methods: Removable partial and complete dentures were randomly assigned to the experimental group of 41 dentures, and the control group of 26. The denture was immersed in the e-WASH solution (experimental group), or tap water (control group) for 5 minutes. The plaque was collected from the denture surface before and after immersion, and smeared on the slide glass. Amount and motility of microorganisms were compared according to the morphology and strain of microorganisms, using the phase contrast microscope. Statistical analysis was accomplished with paired t-test and independent t-test at 95% confidence level (P<.05). Results: 1. The amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were decreased after denture cleansing with the alkaline ionized water, e-WASH (P<.05). But in the control group, only the amount of cocci showed a significant difference (P<.05), but no difference from the others. There were no differences in other analysis. 2. In the experimental group, the amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were smaller and more inactive compared to the control group (P<.05). Conclusion: These results indicated that the alkaline ionized water, e-WASH could effectively reduce the amount and motility of the experimented microorganisms on the denture surface, and that e-WASH could be recommended as an effective denture cleanser.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.47.1-47.12
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• 2024

Importance: Staphylococcus aureus and Escherichia coli contribute to global health challenges by forming biofilms, a key virulence element implicated in the pathogenesis of several infections. Objective: The study examined the efficacy of various generations of cephalosporins against biofilms developed by pathogenic S. aureus and E. coli. Methods: The development of biofilms by both bacteria was assessed using petri-plate and microplate methods. Biofilm hydrolysis and inhibition were tested using first to fourth generations of cephalosporins, and the effects were analyzed by crystal violet staining and phase contrast microscopy. Results: Both bacterial strains exhibited well-developed biofilms in petri-plate and microplate assays. Cefradine (first generation) showed 76.78% hydrolysis of S. aureus biofilm, while significant hydrolysis (59.86%) of E. coli biofilm was observed by cefipime (fourth generation). Similarly, cefuroxime, cefadroxil, cefepime, and cefradine caused 78.8%, 71.63%, 70.63%, and 70.51% inhibition of the S. aureus biofilms, respectively. In the case of E. coli, maximum biofilm inhibition (66.47%) was again shown by cefepime. All generations of cephalosporins were more effective against S. aureus than E. coli, which was confirmed by phase contrast microscopy. Conclusions and Relevance: Cephalosporins exhibit dual capabilities of hydrolyzing and inhibiting S. aureus and E. coli biofilms. First-generation cephalosporins exhibited the highest inhibitory activity against S. aureus, while the third and fourth generations significantly inhibited E. coli biofilms. This study highlights the importance of tailored antibiotic strategies based on the biofilm characteristics of specific bacterial strains.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.154-201
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• 2016

During the Incipient and Early Silla phases, which witnessed the establishment and development of the ancient Silla state, the Wolseong North Burial Ground functioned as not only the central burial ground in the Gyeongju region of the capital of Silla but also as the central burial ground of the whole Silla state. Wolseong North Burial Ground is where transformations in Silla funerary architecture first occurred. As such, an empirical study of the tombs constructed at this burial ground can be regarded as a starting point from which an understanding of the development of the tomb culture of the Silla state may be achieved. This paper therefore aims to examine the changing nature of the tomb culture of the Early Silla phase through the burial data of Wolseong North Burial Ground and the Gyeongju region. Wooden chamber tombs were constructed from the late phase of Saroguk. At Wolseong North Burial Ground, which eventually developed into the central burial ground of the Gyeongju region, wooden chamber tombs embellished with stone packing emerged during the Incipient Silla phase; wooden chamber tombs with stone mounds, on the other hand, first appeared in the Early Silla phase and eventually became established as the central tomb type. A key difference between the wooden chamber tomb embellished with stone packing and the wooden chamber tomb with stone mound is that, in the case of the latter, stones were packed not only around sides of the wooden structure that acted as the burial chamber but also on top of this structure. The addition of a high earthen mound surrounded by protective ring of stones is another distinctive feature of the latter, presenting a contrast to the low mound of the former. During the Early Silla phase, two types of wooden chamber tombs with stone mounds were constructed at Wolseong North Burial Ground: those with burial chambers located above ground and those with subterranean burial chambers. Also constructed during this phase were the wooden chamber tomb embellished with packed stones, the wooden chamber tomb embellished with packed clay, simple earth cut burials, which had been used since the Incipient Silla phase, as well as the stone-lined burials with vertical entrance which first appeared in the Early Silla phase. However, of these different types of burials, it was only the wooden chamber tomb with stone mound that was covered with a 'high mound.' Differentiation between the different tomb types can also be observed in terms of location, type of burial chamber used, construction method, and tomb size. It is therefore possible to surmise that stratification between the different tomb types, which first emerged in the Incipient Silla phase, became intensified during the Early Silla phase.

• Journal of Yeungnam Medical Science
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• v.26 no.1
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• pp.30-37
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• 2009

Purpose : To radiologically differentiate renal oncocytoma from other renal solid tumors, we analyzed and characterized, retrogradely, radiologic findings of renal oncocytomas. Materials and Methods : Radiologic findings of pathologically proven renal oncocytoma were analyzed in 9 patients. CT was performed in all patients, ultrasonography in 4 patients and MRI in 3 patients.(51) Results : On ultrasonography, the echogenicity of the mass was slightly more hyperechoic than normal renal parenchyma in all 4 cases. Two cases were homogeneous and the remaining two cases were relatively homogeneous. On CT, all 8 cases showed iso-density to slightly low density compared to normal renal parenchyma and 5 cases were homogeneous but the central portion of the mass was of a slightly lower density than the peripheral portion in 3 cases. All six cases had an arterial phase scan and were heterogeneously enhanced. An irregular, lower-enhancing portion was found in the central portion of the mass. Segmental inversion of contrast enhancement was found in 5 of 6 cases that had a dynamic enhancement study. On MR T1-weighted imaging, the mass was of iso-signal intensity to normal renal parenchyma and the central portion of the mass had a slightly hypo-signal intensity than the peripheral portion. On T2-weighted imaging, 2 cases were heterogeneous; the peripheral portion was of low signal intensity and central portion was of higher signal intensity than normal renal parenchyma. One case was relatively homogeneous and showed a slightly lower signal intensity than that of normal parenchyma, except for a central small portion showing high signal intensity. For 2 cases that had a dynamic study, a segmental inversion of contrast enhancement was noted. Conclusion : Renal oncocytoma is seen as a well-marginated solid mass lesion. On enhanced scans it is heterogeneously enhanced and segmental inversion of contrast enhancement may be seen. The possibility of oncocytoma can be suggested in cases showing these radiologic findings.

• Ocean and Polar Research
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• v.33 no.3
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• pp.309-319
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• 2011

This is a preliminary study of the feasibility of obtaining reliable tidal current harmonic constants, using one month of current observations, to verify the accuracy of a tidal model. An inference method is commonly used to separate out the tidal harmonic constituents when the available data spans less than a synodic period. In contrast to tidal constituents, studies of the separation of tidal-current harmonics are rare, basically due to a dearth of the long-term observation data needed for such experiments. We conducted concurrent and monthly harmonic analyses for tidal current velocities and heights, using 2 years (2006 and 2007) of current and sea-level records obtained from the Tidal Current Signal Station located in the narrow waterway in front of Incheon Lock, Korea. Firstly, the l-year harmonic analyses showed that, with the exception of $M_2$ and $S_2$ semidiurnal constituents, the major constituents were different for the tidal currents and heights. $K_1$, for instance, was found to be the 4th major tidal constituent but not an important tidal current constituent. Secondly, we examined monthly variation in the amplitudes and phase-lags of the $S_2$ and $K_1$ current-velocity and tide constituents over a 23-month period. The resultant patterns of variation in the amplitudes and phase-lags of the $S_2$ tidal currents and tides were similar, exhibiting a sine curve form with a 6-month period. Similarly, variation in the $K_1$ tidal constant and tidal current-velocity phase lags showed a sine curve pattern with a 6-month period. However, that of the $K_1$ tidal current-velocity amplitude showed a somewhat irregular sine curve pattern. Lastly, we investigated and tested the inference methods available for separating the $K_2$ and $S_2$ current-velocity constituents via monthly harmonic analysis. We compared the effects of reduction in monthly variability in tidal harmonic constants of the $S_2$ current-velocity constituent using three different inference methods and that of Schureman (1976). Specifically, to separate out the two constituents ($S_2$ and $K_2$), we used three different inference parameter (i.e. amplitude ratio and phase-lag diggerence) values derived from the 1-year harmonic analyses of current-velocities and tidal heights at (near) the short-term observation station and from tidal potential (TP), together with Schureman's (1976) inference (SI). Results from these four different methods reveal that TP and SI are satisfactorily applicable where results of long-term harmonic analysis are not available. We also discussed how to further reduce the monthly variability in $S_2$ tidal current-velocity constants.

• Journal of Conservation Science
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• v.35 no.6
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• pp.664-669
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• 2019

Yeonpyo-beob is a method of manufacturing pigments using bamboo trunk and glue solution. Glue solutions of concentrations 1, 5, and 10% were employed to manufacture pigments, and the characteristics of pigment manufacturing were analyzed according to these concentrations. The pigment manufacturing process can be divided into holding and drying phases. The holding phase involves the sedimentation of relatively large particles, whereas the drying phase involves the sedimentation of small particles. The layers formed during the drying phase have almost similar forms regardless of the concentration of the glue solution. If the concentration of the glue solution is low in the holding phase, the particles are mixed and the formation of a layer is difficult. In contrast, when the concentration of the glue solution is higher, the layer of the pigment is more distinct. These results confirmed that the differences in viscosity due to the variation in the concentration of the glue solution affect the sedimentation velocity of the pigment particles, thereby affecting the formation of the layer of the pigment and the pigment manufacture. Consequently, applying 10% glue solution to reduce the sediment velocity is deemed suitable for the stratification of the pigment particles and the manufacture of pigments.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4571-4576
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• 2015

Background: To investigate the inhibitory effect and the underlying mechanism of triptolide on cultured human endometrial carcinoma HEC-1B cells and corresponding xenograft. Materials and Methods: For in vitro studies, the inhibition effect of proliferation on HEC-1B cell by triptolide was determined by MTT assay; cell cycle and apoptosis of the triptolide-treated and untreated cells were detected by flow cytometry. For in vivo studies, a xenograft tumor model of human endometrial carcinoma was established using HEC-1B cells, then the tumor-bearing mice were treated with high, medium, and low-dose ($8{\mu}g$, $4{\mu}g$ and $2{\mu}g/day$) triptolide or cisplatin at $40{\mu}g/day$ or normal saline as control. The mice were treated for 10-15 days, during which body weight of the mice and volume of the xenograft were weighted. Then expression of Bcl-2 and vascular endothelial growth factor (VEGF) was analyzed by SABC immunohistochemistry. Results: Cell growth was significantly inhibited by triptolide as observed by an inverted phase contrast microscope; the results of MTT assay indicated that triptolide inhibits HEC-1B cell proliferation in a dose and time-dependent manner; flow cytometry showed that low concentration (5 ng/ml) of triptolide induces cell cycle arrest of HEC-1B cells mainly at S phase, while higher concentration (40 or 80 ng/ml) induced cell cycle arrest of HEC-1B cells mainly at G2/M phase, and apoptosis of the cells was also induced. High-dose triptolide showed a similar tumor-inhibitory effect as cisplatin (-50%); high-dose triptolide significantly inhibited Bcl-2 and VEGF expression in the xenograft model compared to normal saline control (P<0.05). Conclusions: triptolide inhibits HEC-1B cell growth both in vitro and in mouse xenograft model. Cell cycle of the tumor cells was arrested at S and G2/M phase, and the mechanism may involve induction of tumor cell apoptosis and inhibition of tumor angiogenesis.