• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.324-332
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• 2009

The purpose of this study was to investigate the effect of rigidity of post core systems on stress distribution by the theoretical technique, finite element stress-analysis method. Three-dimensional finite element models simulating an endodontically treated maxillary central incisor restored with a zirconia ceramic crown were prepared and 1.5 mm ferrule height was provided. Each model contained cortical bone, trabecular bone, periodontal ligament, 4 mm apical root canal filling, and post-and-core. Six combinations of three parallel type post (zirconia ceramic, glass fiber, and stainless steel) and two core (Paracore and Tetric ceram) materials were evaluated, respectively. A 50 N static occlusal load was applied to the palatal surface of the crown with a $60^{\circ}$angle to the long axis of the tooth. The differences in stress transfer characteristics of the models were analyzed. von Mises stresses were chosen for presentation of results and maximum displacement and hydrostatic pressure were also calculated. An increase of the elastic modulus of the post material increased the stress, but shifted the maximum stress location from the dentin surface to the post material. Buccal side of cervical region (junction of core and crown) of the glass fiber post restored tooth was subjected to the highest stress concentration. Maximum von Mises stress in the remaining radicular tooth structure for low elastic modulus resin core (29.21 MPa) was slightly higher than that for high elastic modulus resin core (29.14 MPa) in case of glass fiber post. Maximum displacement of glass fiber post restored tooth was higher than that of zirconia ceramic or stainless steel post restored tooth.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1172-1179
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• 2015

This study investigated optimal extraction conditions for application of Ulmus pumila L. as a natural antioxidant. U. pumila L. was extracted using ethanol (EtOH) at various concentrations (0, 40, and 80%) and extraction times (1, 2, and 3 h) at $70^{\circ}C$ and then evaluated for extraction yield, total phenolic contents, total flavonoid contents, as well as antioxidant activities [2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, reducing power, and oxygen radical absorbing capacity (ORAC)]. Antioxidant activities were correlated with total phenolic and flavonoid contents. Of the solvent conditions, 80% EtOH extracts for 3 h at $70^{\circ}C$ showed the highest total phenolic and flavonoid contents with strong antioxidant activities, although there were no significant time effects on DPPH and ABTS radical scavenging activities and reducing power. However, ORAC values of all EtOH extracts remarkably increased in a time-dependent manner. In addition, 80% EtOH extract for 3 h exhibited strong antioxidant effects on HDF and 3T3-L1 cells. Therefore, the antioxidant capacity of U. pumila L., may due to phenolic and flavonoid contents, and extraction conditions were 80% EtOH for 3 h at $70^{\circ}C$. This extract could be a good source for natural antioxidants.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.569-574
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• 2007

This study was performed to investigate the biological activities of roasted (RE) and non-roasted (NRE) hot water extract samples from Euonymus alatus leaf by measuring DPPH radical scavenging, total polyphenol content, hydroxyl radical scavenging, superoxide dismutase (SOD)-like activity, anti-inflammatory activity, and inhibitory effects on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ in vitro. The $IC_{50}$ values fur DPPH free radical scavenging activity of the NRE and RE hot water extracts were $19.1{\mu}g/mL$ and $21.9{\mu}g/mL$, respectively, and their total polyphenol contents were estimated as 9.6 mg/g for NRE and 10.6 mg/g for RE. Both NRE and RE scavenged the hydroxyl radical in a concentration-dependent manner, but their activities were lower than that of BHA. It was also shown that SOD-like activity was dependent on NRE and RE concentration, and the SOD-like activity of NRE was slightly higher than that of RE. The highest SOD-like activity obtained from NRE was 20% at a concentration of 3 mg/mL. Neither NRE nor RE seemed to have an effect on ${\alpha}-amylase$ and ${\alpha}-glucosidase$ inhibition. Finally, the hot water extracts of NRE and RE significantly decreased the concentration of LPS-induced NO in RAW 264.7 cells, indicating anti-inflammatory activity.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.145-156
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• 1988

This study was conducted to investigate the effect of embryo stage on bisection rates of embryos, on development of separated demi-embryos and on subsequent development to full term following transfer of demi-embryos to recipients. The results obtained in this study are summarized as follows. The 2-, 4-, 8-cell and morula embryos were mostly obtained at 36-42, 48-54, 62-66 and 72-78 hours after injection of hCG, respectively, and the average number of embryos recovered per head was 17.0. The bisection rate of 8-cell embryos was 83.6%, which was significantly higher than that of morula embryos, 65.5%. But the development of morula demi-embryos to blastocyst after in-vitro culture was better than that of 8-cell demi-embryos and the rate was 76.5% and 60.9%, respectively. When the 2, 10 and 15 cultured demi-embryos or intact embryos were transferred to each recipient mouse, respectively. the highest pregnancy rate was obtained when 15 embryos were transferred. And the overall offspring production rate of intact embryos was higher than that of demi-embryos.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.75-84
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• 2008

Colored potatoes are an excellent source of dietary polyphenols including anthocyanins. Generally, anthocyanins from fruits and vegetables exhibit anti-carcinogenesis and anti-cancer properties in vitro test. This experiment was conducted to know the effects of colored potato extracts contained anthocyanins on antimutagenic activity and anticancer activity to six human cancer cell lines containing LNCaP (androgen-dependent) prostate cancer cells. Extracts of three colored potatoes ('Hongyoung', 'Jayoung' and 'Jasim') and the white potato ('Superior') cultivars were used in this study. The extracts of three colored potatoes inhibited the mutagenicities induced by direct mutagen such as 4-nitro-quinoline-1-oxide (4-NQO) and another indirect mutagens of bezo(a)pyrene (BaP). Also, the extracts of 'Hoyoung' and 'Jayoung' showed higher antimutagenic activity than 'Jasim' and 'Superior' against to direct or indirect mutagen on both strains of TA98 and TA100. The activity of growth-inhibitory of extract of four potato cultivars were screened by SRB (sulphorhodamine B) method on diverse human cancer cells representing different types of cancers. Among the extract of four potato cultivars, the extract of 'Jasim' showed moderate inhibition on proliferation of LNCaP, ACHN and MOLT-4F cells and did not inhibit the proliferation of other cancer cells. On the other hand, extract of 'Superior' did not inhibit the proliferation of any tested cancer cell lines. However, the extracts of 'Hongyoung and Jayoung' inhibited the proliferation of cancer cells with $GI_{50}$ values ranging from 2.5 to $30\;{\mu}g/mL$. On the basis of the $GI_{50}$ values, it is clear that LNCaP cells were more sensitive to extracts of colored potato cultivars than other cancer cells. The extract of 'Jayoung' at $30\;{\mu}g/mL$ were more active and inhibited cell proliferation, and induced apoptosis in LNCaP cells. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of antimutagenic and anticancer agent.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.159-168
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• 2003

With microtiter plate, the assay method was developed for detecting the fungicidal activity of new compounds against spore germination, spore adhesion and mycelial growth of Colletotrichum sp. JC24 cal1Sing red pepper anthracnose. Also, the effects of some commercialized fungicides on fungal development like above mentioned were investigated by measuring the optical density of mycelia grown into wells of microtiter plate. For the standardization of assay method, some factors, such as the treatment of MTT and/or propanol, inodulum density and incubation period, affecting on mycelial optical density were investigated. For obtaining precise and consistent mycelial optical density, it was necessary the treatment of MTT for 12 hrs and propanol for 1 hr. inoculum density adjusted to $1\times10^5$ spores/mL and incubation period for 36 hrs at $25^{\circ}C$. For fungicidal activities, 6 protective fungicides, 6 ones inhibiting sterol biosynthesis, and one inhibiting respiration were used in this study. While mancozeb, chlorothalonil and dithianon among 6 protective fungicides inhibited strongly spore germination, adhesion, and mycelial growth at $6.25{\mu}g/mL$, propineb, iminoctadine and fluazinam inhibited intermediately spore germination and mycelial growth at $100{\mu}g/mL$. Washing above 3 fungicides with new PD broth, their activity against spore adhesion decreased. With hexaconazole, tebuconazole and myclobutanil, the tendency of the activity against fungal differentiation of the early infection stage was similar to the latter group of protective fungicides, showing the decrease of the inhibitory activity against spore adhesion by washing 2 hrs after incubation. However, kresoxim-methyl inhibited spore adhesion distinctly, depending on the applied concentrations. Based on these results, it might be able to assess the fungicidal activity of many compounds against spore germination, adhesion and mycelial growth by the use of microtiter plate in vitro. Using the assay developed in this report, it was possible to investigate the inhibitory activity of some commercialized fungicides, too.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup2
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• pp.189-196
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• 2001

Objective : We tested the hypothesis that photodynamic therapy(PDT) with Photofrin inhibits tumor invasion of U87 human glioma cells using several in vitro assay to measure tumor invasiveness. The effects of PDT on cell growth, directional migration and cell invasion were investigated. Material and Method : Tumor cells were treated with Photofrin at various doses and at a fixed optical(632nm) dose of $100mJ/cm^2$. Cytotoxicity was tested using the MTT method. Invasion assays including the matrigelartificial basement membrane barrier migration and spheroid confrontation with confocal microscopic analysis were used to study the relationship between PDT and invasiveness. Result : U87 cells showed a dose dependent cytotoxic response to increasing Photofrin dose. Data from the matrigel artificial basement membrane assay indicate that PDT inhibits the U87 cell migration dose dependently. Low doses of subcytotoxic PDT treatment, such as 2.5ug/ml Photofrin dose, also appeared to significantly inhibit migration of U87 cells(p<0.05). In co-cultures between U87 cell spheroids and brain aggregates, progressive invasion with destruction of the brain aggregate occurs. The extent of tumor cell infiltration and proportion or intact brain aggregate remaining after 24h differs in Photofrin PDT treated versus Photofrin only control, with changes suggestive of a dose-response effect. Conclusion : our data indicate that PDT with Photofrin significantly inhibits the invasiveness of U87 cells, and this inhibition is dose dependent.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.1
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• pp.37-44
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• 2013

Sodium hypochlorite and ethylene diamine tetra acetic acid are substances usually used during endodontic treatment. Several studies found that the bonding was negated with certain irrigants and some of the used irrigants have demineralizing and chealating effects, so it was advocated to omit the etching step in etch and rinse adhesive systems. The purpose of this in vitro study was to evaluate the influence of NaOCl & EDTA on the bonding strength of ethanol wet bonding. Thirty human molars were selected and mesiodistally sectioned into halves, thus providing sixty specimens. The specimens were randomly assigned to 4 groups(n=15) according to the irrigant regimen used : (1) irrigated with distilled water for 10min (control); (2) irrigated with 5.25% NaOCl(10min), flushed with 5.25% NaOCl(1min) (3) irrigated with 5.25% NaOCl, flushed with 17% EDTA (4) irrigated with 5.25% NaOCl, flushed with 17% EDTA. Each group was acid-etched with 37% phosphoric acid(except group 4) and had their dentin surfaces dehydrated with ethanol solutions : 50%, 70%, 80%, 95%, 3x100%, 30s for each application. After dehydration, a primer( 50% all bond 3 resin + 50% ethanol) was used, followed by the adhesive(ALL-BOND 3 RESIN) application. Resin composite build-ups were then prepared using an incremental technique. Specimens were sectioned into beams and submitted to a tensile load using a Micro Tensile Tester(Bisco Inc.). The data were statistically analyzed using one-way ANOVA and Tukey HSD at p<0.5 level. There was no significant difference on G1(control) and G2(irrigated with NaOCl only ). (p>0.05). G3(flushed with EDTA) showed significantly high tensile bonding strength compared to the G2 (p<0.05). G4( treated with EDTA but no acid-etching) was significantly lower value than G3. (p<0.05) Although there was no significant difference, 5.25% NaOCl seemed to have an adverse effect on the bonding strength of ethanol wet bonding. The flushing with EDTA after NaOCl irrigation prevents the decrease of bonding strength. The use of 17% EDTA as a final flush can enhance the bonding strength but EDTA flushing can't substitute for a acid-etching.

• Journal of the Korean Geographical Society
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• v.36 no.2
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• pp.111-125
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• 2001

An estuary is semi-inclosed inlets, located between terrestrial and marine environment. Since many estuaries along south-western coasts of Korean peninsula were affected by human settlements and activities, significant changes in sedimentation environments have been observed. The research area is divided into three distinct morpho-stratigraphic units: fluvial dominated area(Area1), mixed area(Area 2), tide-dominated area(Area3). The landform of this area has been changed by reclamation and river channel change. Temporal variations affected by dam construction, periodic freshet was iterrupted. Sediments began to continuously accmulate on estuary banks by tide. Meanwhile, because of the continuous but reduced discharge of fresh water, the salinity of estuarine sediments was declined. That processes made vegetated area( Phregmites lonivalvis and Suaeda japonica) to be expanded. It indicates that the magnitude and frequency of geomorphic processes has been significantly changed.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.4 no.1
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• pp.37-53
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• 1998

The sprig of Jinryungtang Gagambang has been used for curing as a traditional medicine without any experimental evidence to support the rational basis for their clinical use. This experiment was carried out to evaluate the possible therapeutic or antitumoral effects of Jinryungtang Gagambang extract against cancer, and to study some mechanisms responsible for its effect. The cytotoxic and antitumor effects were evaluated on human cell liens (A549, hep3B, Caki-1, Sarcoma 180) after exposure to Jinryungtang Gagambang extract using in ILS, colony forming efficency and SRB assay which were regarded as a valuable method for cytotoxic and antitumor effects of unknown compound on tumor cell lines. The results obtained in this studies were as follows. 1. As a result of exposure to Jinryungtang Gagambang extract, the proliferation of A549, hep3B, Caki-1, good correlations were shown from the results of SRB assay and those of clogenetic assay. 2. The oral administration of Jinryungtang Gagambang extract showed significant effects of increase of MST(mean survival time) and ILS(increased life span) depending on the increasing concentration. 3. Against squamous cell carcinoma induced by MCA, Jinryungtang Gagambang decreased not only the frequency of tumor production but also the number and weight of tumors per tumor bearing mice(TBM). Jinryungtang Gagambang also significantly suppressed the development of 3LL cell-implanted tumors by frequency and their size, and some developed tumors were regressed by the continuous treatment of Jinryungtang Gagambang extract into TBM. 4. Jinryungtang Gagambang extract also increased NK cell activities. According to the above results, it could be suggested that Jinryungtang Gagambang extract has prominent antiutmor effect.