• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.73-83
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• 1993

The purpose of this study was to evaluate the effect of various acid treatments on dentin bonding. Freshly extracted human teeth were uprightly embedded in self curing acrylic resin, and their occlusal surfaces were grinded to expose flat dentin surfaces. The specimens were divided into 4 groups. Specimens of one group were not treated so as to be a control and those of the other three groups were threated with 10% polyacrylic acid, 10% phosphoric acid, and 10-3 solution(10% citric acid/3% ferric chloride) respectively. Primer, bonding resin and composite resin were applied over the treated dentin surfaces sequentially. All specimens were stored in $37^{\circ}C$ distilled water for 24 hours, then the tensile bond strength was measured and the treated dentin surfaces and fracured dentin surfaces were examined under a scanning electron microscope. The results were as follows: Bond strengths of acid-treated groups were higher than those of the untreated group. In the acid-treated groups, bond strength was found to be the highest in the 10-3 solution group followed by the 10% phosphoric acid group and the 10% polyacrylic acid group(P<0.01). On SEM examination of dentin surfaces, the untreated dentin surface showed a remaining smear layer and closed dentinal tubules. Dentin surfaces treated with 10 % polyacrylic acid showed a clean dentin surface without the smear layer, but showed remaining smear plugs in dentinal tubules. A dentin surface treated with 10% phosphoric acid or 10-3 solution showed open dentinal tubules without the smear layer or smear plugs. On SEM observation of the fractured dentin-resin interface, the untreated group showed that failure occurred in the smear layer. The group treated with 10% polyacrylic acid showed no resin tag remained in the dentinal tubules, but resin tags in the dentinal tubules were observed in the group treated with the 10% phosphoric acid or the 10-3 solution. On the failure mode examination, the higher the bond strength of the group, the higher the frequency of cohesive failure. The coefficient between bond strength and cohesive failure rate was 0.71.

• Journal of Soil and Groundwater Environment
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• v.11 no.3
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• pp.31-42
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• 2006

Drought indices, such as PDSI (palmer Drought Severity Index), SWSI (Surface Water Supply Index) and SPI (Standardized Precipitation Index), have been developed to assess and forecast an intensity of drought. To find the applicability of groundwater level data to a drought assessment, a correlation analysis between SPI and groundwater levels was conducted for each time series at a drought season in 2001. The comparative results between SPI and groundwater levels of shallow wells of three national groundwater monitoring stations, Chungju Gageum, Yangpyung Gaegun, and Yeongju Munjeong, show that these two factors are highly correlated. In case of SPI with a duration of 1 month, cross-correlation coefficients between two factors are 0.843 at Chungju Gageum, 0.825 at Yangpyung Gaegun, and 0.737 at Yeongju Munjeong. The time lag between peak values of two factors is nearly zero in case of SPI with a duration of 1 month, which means that groundwater level fluctuation is similar to SPI values. Moreover, in case of SPI with a duration of 3 month, it is found that groundwater level can be a leading indicator to predict the SPI values I week later. Some of the national groundwater monitoring stations can be designated as DIW (Drought Index Well) based on the detailed survey of site characteristics and also new DIWs need to be drilled to assess and forecast the drought in this country.

• Radiation Oncology Journal
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• v.9 no.2
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• pp.215-219
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• 1991

To evaluate the effect of MVP chemotherapy and hyperfractionated radiotherapy in Stage III unresectable non small cell lung cancer (NSCLC), authors have conducted a prospective randomized study since January 1991, Stage IIIa or IIIb unresectable NSCLC patients were treated with hyperfractionated radiotherapy (120 cGy/fx BID) up to 6500 cGy following 3 cycles of induction MVP (Mitomycin C 6 mg/$m^2$, Vinblastine 6 mg/$m^2$, Cisplatin 60 mg/$m^2$) and randomized for either observation or 3 cycles of maintenance MVP chemotherapy. Until August 1991, 18 patients were registered to this study. 4 cases were stage IIIa and 14 were stage IIIb. Among 18 cases 2 were lost after 2 cycles of chemotherapy, and 46 were analyzed for this preliminary report. The response rate of induction chemotherapy was $62.5\%$ : partial response, $50\%$ and minimal response, $12.5\%$. Residual tumor of the one partial responder was completely disappeared after radiotherapy. Among 6 cases who were progressed during induction chemotherapy, 4 of them were also progressed after radiotherapy. All patients were tolerated BID radiotherapy without definite increase of acute complications, compared with conventional radiotherapy group. But at the time of this report, one patient expired in two month after the completion of the radiotherapy because of treatment related complication. Although the longer follow up is needed, authors are encouraged with higher response rate and acceptable toxicity of this treatment. Authors believe that this study is worthwhile to continue.

• Radiation Oncology Journal
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• v.28 no.2
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• pp.71-78
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• 2010

Purpose: To evaluate the result of neoadjuvant chemotherapy, surgery, and radiation therapy in locally advanced breast cancer as well as analyze the prognostic factors affecting survival. Materials and Methods: One hundred fifty-nine patients with breast cancer were treated by neoadjuvant chemotherapy between April 1995 and November 2006 at the Samsung Medical Center. Among these patients, we retrospectively reviewed 105 patients treated with neoadjuvant chemotherapy followed by surgery and radiation therapy for a cure with an initial tumor size >5 cm or clinically positive lymph nodes. All patients received anthracycline based chemotherapy except for 2 patients. According to clinical tumor stage, 3 patients (3%) were cT1, 26 (25%) were cT2, 39 (37%) were T3 and 37 (35%) were T4. Initially, 98 patients (93%) showed axillary lymph node metastasis. The follow-up periods ranged from 7~142 months (median, 41 months) after the beginning of neoadjuvant chemotherapy. Results: Locoregional failure free survival rate and distant metastasis free survival rate at 5 years were 82.1% and 69.9%, respectively. Disease free survival rate and overall survival rate at 5 years were 66.1% and 77.1%, respectively. The results of a univariate analysis indicate that clinical tumor stage, pathologic tumor stage, pathologic nodal stage and pathologic TNM stage were statistically significant factors for disease free survival rate and overall survival rate. Whereas, a multivariate analysis indicated that only hormone therapy was a statistically significant factor for survival. Conclusion: The current study results were comparable to other published studies for neoadjuvant chemotherapy for breast cancer. Hormone therapy was a statistically significant prognostic factor. The patients with early clinical or pathologic stage had a tendency to improve their survival rate.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.257-269
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• 2010

To investigate the possibility of discrimination between organic and non-organic rice using stable isotope nitrogen of natural abundance, organic rice of 17 samples and non-organic rice of 13 samples grown at adjoining organic rice field were collected in 2008. Rice was grinded into brown rice, milled rice and hull, and samples were analysed for nitrogen and $\delta^{15}N$ at NICEM. Authors also made inquiries about N source for both farmers who conduct organic- and non-organic rice cultivation. In order to know whether the $\delta^{15}N$ can be used in discrimination between organic and non-organic rice, discriminant analysis were made with SPSS and logistic method. 1. Organic farmers used manure, rice bran, used mushroom culture, fermented fertilizer (company products), and oil cake, but non-organic farmers applied compound fertilizer. Rice straws were remained in organic rice field while moved out in non-organic field. 2. There were difference in $\delta^{15}N$ among organic rice and its byproduct(7.760????% in hull, 6.720????% in rice), but significant difference was not found between them. And the trend was same between province. Non-organic rice showed similar results. 3. Significant difference of $\delta^{15}N$ were found between organic rice and non-organic rice (p<0.01) and between hull of organic rice and that of non-organic rice hull (p<0.05). $\delta^{15}N$ seemed to be useful criteria for discrimination of organic and non-organic rice. 4. When applied discrimination analysis of SPSS and logistic, there were significant difference between organic rice, non-organic rice and its byproducts except brown rice and hull in SPSS method. Hull can be used as the most useful component for unknown sample prediction with 83.3% probability.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.200-211
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• 2009

A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and non-point sources in watershed scale.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.466-473
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• 2016

This study was performed to investigate the reduction in bitter taste and quality characteristics by pretreatments (brining; 1, 5% and blanching; 1, 3 min) in pickled bitter melon, respectively. We prepared picked bitter melon samples at 1%-1 min, 1%-3 min, 5%-1 min, 5%-3 min. Total polyphenol and total flavonoid contents were found to be the highest in 5%-1 min at $14.23{\pm}0.40mg\;CE/g$ (dry) and $4.46{\pm}0.10mg\;RE/g$ (dry), respectively. L-ascorbic acid level was the highest in control samples. Arginine and glutamic acid were increased by brining and blanching. ABTS and DPPH radical scavenging activity were found to be the highest at $43.60{\pm}0.40$ and $44.88{\pm}0.20%$ at 5%-1 min, respectively. ${\alpha}-glucosidase$ inhibitory activity was the highest at 5%-1 min. The a value was statistically different, whereas L and b values were similar among different pretreatments. Hardness in pretreated samples was decreased as compared to that in the control. Among sensory evaluations, 'color' did not indicate any statistical difference, while 'texture', 'bitterness preference' and 'overall preference' increased with pretreatments, and 'bitter intensity' decreased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.432-438
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• 2016

This study was conducted to investigate the effects of Lespedeza caneata extract on the livers of alcohol-administered mice. The study subjects were divided into a control (Con), alcohol administration (AL), alcohol and Lespedeza Caneata extract 200 mg/kg administration (AL-LC 200), and alcohol and Lespedeza caneata extract400 mg/kg administration (AL-LC 400) group. Distilled water was administrated orally to control and alcohol groups for ten days, while Lespedeza caneata extract was administered orally to alcohol and Lespedeza caneata extract groups for ten days. All experimental groups were fasted for twelve hours seven days after the oral administration, after which distilled water was administered orally to Con five times at twelve-hour intervals. At the same time, 50% ethanol (MERCK, USA) at 10 g/kg concentration was administered orally to AL and AL-LC groups five times at 12-hour intervals. The AST, ALT enzyme activation in blood and histology of the liver were then evaluated. AST and ALT in AL-LC groups were lower than in the AL group. Particularly, the AL-LC 200 and AL-LC 400 groups had significantly lower AST activation than the AL group. Histological results showed that most of the subjects in the AL group had necrosis and deformation in their livers, while fat droplets were accumulated in hepatic cells around the central vein. AL-LC 200 group revealed that a portion of the central vein was swollen, liver cells were expanded, and small fat droplets were accumulated. In the AL-CL 400 group, the central vein was normal and small fat droplets were accumulated in some liver cells. However, most of the liver cells appeared normal in the AL-CL 400 group. These results suggest that the extracts of Lespedeza caneata prevented alcohol induced liver damage in mice and have great potential for use as natural health products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1139-1145
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• 2006

In this study, antioxidant activities of enzymatic and methanolic extracts from E. cava stem and leave were evaluated by measuring the scavenging activities on 1,1 diphenyl 2 picrylhydrazyl (DPPH), hydroxyl radical, hydrogen peroxide and the inhibitory effects on DNA damage induced by oxidative stress of cells. Enzymatic extracts were prepared by enzymatic hydrolysis of both stem and leave using food grade five different carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme, Alcalase). The enzymatic extracts were lower than methanolic extracts in polyphenol contents, but higher in extraction yield by approximately 30%. The enzymatic extracts were superior to methanolic extracts in DPPH and H2O2 scavenging activities and DNA damage protective effect. There were no significant antioxidant activity difference between stem and leave, but the extracts of leave were relatively better than those of stem. In this study it is suggested that E. cava stem as well as its leave would be a good raw materials for antioxidants compound extraction and enzymatic hydrolysis would be a good strategy to prepare antioxidant extracts from seaweeds.

• Korean Journal of Remote Sensing
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• v.37 no.5_3
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• pp.1447-1460
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• 2021

Urbanization increases the amount of impervious surface and artificial heat emission, resulting in urban heat island (UHI) effect. Local climate zones (LCZ) are a classification scheme for urban areas considering urban land cover characteristics and the geometry and structure of buildings, which can be used for analyzing urban heat island effect in detail. This study aimed to examine the UHI effect by urban structure in Suwon and Daegu using the LCZ scheme. First, the LCZ maps were generated using Landsat 8 images and convolutional neural network (CNN) deep learning over the two cities. Then, Surface UHI (SUHI), which indicates the land surface temperature (LST) difference between urban and rural areas, was analyzed by LCZ class. The results showed that the overall accuracies of the CNN models for LCZ classification were relatively high 87.9% and 81.7% for Suwon and Daegu, respectively. In general, Daegu had higher LST for all LCZ classes than Suwon. For both cities, LST tended to increase with increasing building density with relatively low building height. For both cities, the intensity of SUHI was very high in summer regardless of LCZ classes and was also relatively high except for a few classes in spring and fall. In winter the SUHI intensity was low, resulting in negative values for many LCZ classes. This implies that UHI is very strong in summer, and some urban areas often are colder than rural areas in winter. The research findings demonstrated the applicability of the LCZ data for SUHI analysis and can provide a basis for establishing timely strategies to respond urban on-going climate change over urban areas.