• Korean Journal of Biological Psychiatry
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• v.10 no.1
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• pp.70-79
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• 2003

Object : Currently, the alteration of cytokine system has been known to play an important role in regard to depressive symptom. We focused on the relationship between immunological parameters and clinical improvement in major depressive disorder. Method : Data were collected on 26 patients with major depressive disorder using a 8-week prospective follow-up design. After 8-week treatment period with fluoxetine, patients were classified into a response group and a non-response group according to their psychopathological outcome as evaluated by Hamilton Depression Rating Scale. The differences of the immunological parameters between pre-treatment phase and post-treatment phase were compared among patients. The difference of those was also compared within each phase among them. The relationship between socio-demographic variables, depression, cytokine, mononuclear cells was examined by correlation analysis. Multiple regression analyses were performed to explore the predictors of clinical improvement of major depressive disorder. Result : Pre-treatment levels of IL-$1{\beta}$ in the response group were significantly higher than those in the non-response group. Pre-treatment levels of IL-$1{\beta}$ of all patients and in the response group were positively correlated with pre-treatment monocyte counts. Patients with subsequent remission showed significantly lower IL-6 values at baseline than those with non-response. Post-treatment values of IL-6 did not differ significantly among the patients. The correlation test showed more frequent relations among cytokines and mononuclear cells in the response group than in the non-responder group. Especially, serum level of IL-6 in pre-treatment phase was only significantly correlated with HAMD score after 8-week treatement phase, while other cytokines and mononuclear cells were not. Pretreatment level of IL-6 was of paramount importance in predicting clinical improvement of depressive symptom. Conclusion : The immune system of major depressive disorder patients might dichotomize the patients into subsequent responders and non-responders. Immune system might be of great influence on the clinical improvement of major depressive disorder. The mode of interaction between depression and cellular immune function and the mediators responsible for the cytokine production need to be studied further.

• The Korean Journal of Ceramics
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• v.7 no.2
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• pp.70-73
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• 2001

Phase transformation of TiSi$_2$ confined in sub-micron area of which the size is around or smaller than the grain size of C49 TiSi$_2$ phase is studied. It has been known that the C49 to C54 phase change is massive transformation that occurs abruptly starting from C54 nuclei located at triple point grain boundaries of C49 phase. When the C49 phase is confined in sub-micron area, however, the massive phase transformation is observed to be hindered due to the lack of the triple point grain boundaries of C49 phase. Heat treatment at higher temperatures starts to decompose the C49 phase, and the resulting decomposed Ti atoms diffuse to, and react with, the underneath Si material to form C54 phase that exhibits spherical interface with silicon. The newly formed C54 grains can also trigger the massive phase transformation to convert the remaining undecomposed C49 grains to C54 grains by serving as nuclei like conventional C54 nuclei located at triple point grain boundaries.

• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.87-92
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• 2009

The effect of aging on the precipitation of the $\sigma$ phase and the corrosion resistance in tungsten substituted super duplex stainless steels was investigated. The volume fraction of the $\sigma$ phase and the current density increased with aging at temperatures up to $750^{\circ}C$ and then decreased. With an increase in aging time, the volume fraction of the $\sigma$ phase and the current density also increased. The $\sigma$ phase hardly influenced the corrosion resistance. With the substitution of tungsten for molybdenum in super duplex stainless steel, the volume fraction of the $\sigma$ phase and the current density decreased remarkably.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.262-264
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• 2005

$Bi_{2}Sr_{2}CaCu_{2}O_{x}$(Bi-2212) and $Bi_{2}Sr_{2}Ca_{2}Cu_{3}O_{y}$(Bi-2223) high-$T_{c}$ superconductor(HTS) coating have been prepared by plasma spraying and heaat treatment. The Bi-2212 HTS coating later is synthesized through the peritectic reaction between Sr-Ca-Cu oxide coating layer and Bi-Cu oxide coating later, and $Bi_{2}Sr_{2}CaCu_{2}O_{y}$(Bi-2212) superconducting phase grow by partial melting process. The superconducting characteristic depends strongly on the conditions of the partial melting process. the Bi-2212 HTS layer consists of the whiskers grown in the diffusion direction. Above the 2212 layer, Bi-2223 phase and secondary phase was observed. The secondary phase is distributed uniformly over the whole surface. This is caused to the microcrack on the coatings surface. Despite everything, the film shows superconducting with an onset $T_{c}$ of about 115K. There are two changes steps. One changes (1step) at 115K is due to the diamagnetism of the Bi-2223 phase and the other changes (2step) at 78K is due to the diamagnetism of the Bi-2212 phase.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.219-225
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• 1996

This study was performed to investigate the inhibition mechanism of cancer cell proof iferation caused by the petroleum-ether extract of ginseng against human rectum (HRT-18), colon (HT-29), llepatoma (Hep G2) and prostate (LNCaP) cancer cells and monkey kidney cells (Vero 76). Cells were treated with the petroleum-ether extract of ginseng (50 to 200 $\mu\textrm{g}$/ml) in G1 or S phase of the cell cycle, and proliferation and protein kinase C activity were measured. The petroleum-eth or extract of ginseng inhibited proliferation of HRT-18, HT-29, Hep G2 and LNCaP when treated in Gl phase, but not in S phase. This result shows that the ginseng extract arrests the cell cycle in G1 phase, resulting in the inhibition of cell proliferation. At the same concentrations, treatment of the ginseng extract in G1 phase decreased protein kinase C activity, while the treatment in S phase had no effect. This reault suggests that protein kinase C might be involved in the inhibition of the cell cycle and proliferation of cancer cells caused by the petroleum-ether extract of ginseng.

• Korean Journal of Metals and Materials
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• v.49 no.6
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• pp.440-447
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• 2011

To improving the mechanical properties of Mg alloys at high temperature, we investigated the mechanical properties at high temperature and the change of microstructure of Mg-6 wt%Zn-0.4 wt%Mn and Mg-6 wt%Zn-0.4 wt%Mn-1 wt%Ag alloys on age treatment that have a stable MgZn phase at high temperature and $AgMg_4$ improving yield stress. In order to predict thermodynamic data of Mg alloys, a phase diagram and precipitation phase were calculated using a thermodynamic program, and it was confirmed that the MgZn and $AgMg_4$ phase existed as main precipitation in this alloys. The experimental data examined using DSC and XRD were comparable with the calculated data for reliability. In order to analysis the microstructure and precipitate phase during aging treatment, it was measured by SEM/EDS and TEM. Lastly, mechanical properties of the MgZn and $AgMg_4$ phase were measured by a tensile test at high temperature.

• Land and Housing Review
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• v.2 no.1
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• pp.87-92
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• 2011

The anaerobic digestion of food waste effluent through single- and two-phase process was estimated and compared in this study. The treatment efficiencies for total solid(TS), volatile solid(VS), tCOD(total COD) and sCOD(soluble COD) were invariably higher in the single-phase process, which was accounted for by the fact that the treatment efficiency of organic wastes usually showed an inverse relationship with organic loading rate in the anaerobic digestion. In fact, the organic loading rate was lower for single-phase process. The concentration of tCOD were significantly lower in two-phase process but much more biogas was produced, compared to single-phase anaerobic digestion process, which might be explained partly by the relatively higher stability of two-phase process resulting from the separation of acid phase from methane phase.

• Journal of Periodontal and Implant Science
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• v.36 no.1
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• pp.69-84
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• 2006

Reports on the comparison of clinical effect between non-surgical and surgical therapy, and the change of the clinical parameters during maintenance phase have been rarely presented in Korea. This study was to observe the clinical changes during maintenance phase of 6 months in patients with chronic periodontitis treated by non-surgical or surgical therapy in Department of Periodontics, Chonnam National University Hospital. Among the systemically healthy and non-smoking patients with moderate to severe chronic periodontitis, twenty eight patients (mean age: 47.5 years) treated by non-surgical therapy (scaling and root planning) and nineteen patients (mean age: 47.3 years) treated by surgical therapy (flap surgery) were included in this study. The periodontal supportive therapy including recall check and oral hygiene reinforcement was started as maintenance phase since 1 month of healing after treatment. Probing depth, gingival recession. clinical attachment level and tooth mobility were recorded at initial, baseline and 1, 2, 3 and 6 month of maintenance phase. The clinical parameters were compared between the non-surgical and surgical therapies using Student t-test and repeated measure ANOVA by initial probing depth and surfaces. Surgical therapy resulted in greater change in clinical parameters than non-surgical therapy. During the maintenance phase of 6 months, the clinical effects after treatment had been changed in different pattern according to initial probing depth and tooth surface. During maintenance phase, probing depth increased more and gingival recession increased less after surgical therapy, compared to non-surgical therapy. The sites of initial probing depth less than 3 mm lost more clinical attachment level, and the sites of initial probing depth more than 7 mm gained clinical attachment level during maintenance phase after non-surgical therapy, compared to surgical therapy. Non-surgical therapy resulted in greater reduction of tooth mobility than surgical therapy during maintenance phase. These results indicate that the clinical effects of non-surgical or surgical therapy may be different and may change during the maintenance phase.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.225-234
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• 2014

This study was carried out to investigate the sustainable agriculture of no-tillage technique including recycling of the ridge and the furrow of a field for following crops in Korea. No-tillage systems affect soil physical properties such as three phase (solid, liquid, and air phase) and distribution of soil granular. Solid ratio of subsoil in 3-year of no-tillage (NT) treatment was remarkably lower than that in conventional (CT, 2-year of no-tillage + 1-year of tillage) treatment, while air ratio of subsoil in NT remarkably increased. Bulk density of subsoil in NT remarkably decreased. Porosity of subsoil in NT remarkably increased. Deviation of air phase, bulk density, and porosity of top soil and subsoil in NT remarkably decreased in NT compared with CT. Solid phase ratio and liquid phase ratio in NT and CT had positive (+) correlation. Solid phase ratio and air phase ratio in NT and CT had negative (-) correlation, also liquid phase ratio and air ratio had negative (-) correlation. Bulk density and liquid ratio in soil had positive (+) correlation at top soil and subsoil in NT. Bulk density and air ratio in soil had negative (-) correlation in NT and CT. Porosity and liquid phase ratio had negative (-) correlation, r =1), the significant value was lower in NT than in CT. Porosity and air phase ratio had positive (+) correlation (r =1).

• Journal of the Korean Society for Heat Treatment
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• v.11 no.2
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• pp.99-110
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• 1998

The effects of pre-heat treatment(Q/T) on microstructure and hardness of SCM435 structural steel nitrided by micro-pulse plasma was investigated. The quenching and tempering temperatures for obtaining matrix hardness of SCM435 steel on range of HRC30 to HRC40 desired for machine parts were about $860^{\circ}C$ and $500^{\circ}C$ respectively. The case depth of SCM435 nitrided at $480^{\circ}C$ for 5 hours was independent of pre-heat treatment condition and was approximately $150{\mu}m$. However, hardness and compactness of nitrified layer on Q/T treated specimen were more heigher than annealed specimen. The case depth increased linearly with the increase of nitriding temperature, however, the hardness of nitrified layer decreased with the temperature. Phase mixture of ${\gamma}^{\prime}$-phase($Fe_4N$) and ${\varepsilon}$-phase($Fe_3N$) were detected by XRD analysis in the nitrified layer formed at optimum nitriding condition, and only single ${\gamma}^{\prime}$-phase was detected in the nitrified layer formed at higher nitriding temperature such as $540^{\circ}C$. The optimum nitriding temperature was approximately $480^{\circ}C$ which is lower than tempering temperature for preventing softening behavior of SCM435 matrix during nitriding process and the surface hardness of nitrified layer obtained by optimum preheat treatment condition was about Hv930.