• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.4
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• pp.348-354
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• 2011

Composite resin has been widely used for eroded enamel. But, as there have been many reports about the differences in physicochemical characteristics of eroded enamel compared with sound enamel, an additional effort was thought necessary to obtain the optimal bond strength. As a possible answer, we came to think about the application of infiltrant resin which is known to have an excellent penetration capacity into enamel. This study was performed for the purpose of comparing the bond strength of composite restoration with or without infiltrant resin under adhesives on the artificially eroded enamel. 60 extracted sound maxillary primary incisors were selected and divided into group 1, 2, 3 according to the number of artificial erosion cycling for 5 minute duration in 1% citric acid of pH 3.2 at $37^{\circ}C$. And the labial surfaces were divided into 3 areas; group A, only resin adhesive was used, group I, only infiltrant resin, group IA, infiltrant resin followed by resin adhesive. Afterwards, every specimen was restored with composite resin. Microtensile bond strength was measured and failure modes were observed. The obtained results were as follows: 1. In comparing the bond strength by the degree of enamel erosion, it was revealed the highest bond strength in group 1, followed by group 2 and 3, showing the lowest bond strength in most eroded group(p<0.05). 2. In comparing the bond strength by surface treatment methods, group IA and I showed higher value than group A(p<0.05), with unsignificant difference between group I and IA(p>0.05). 3. In observation of failure mode, it was shown higher frequency of cohesive failure in order of 1-2-3 and IA-I-A. Conclusively, it was shown decreasing tendency of bond strength as the enamel is more eroded, and infiltrant resin was thought helpful to replace or add to the resin adhesive for optimal bonding with eroded enamel.

• Tuberculosis and Respiratory Diseases
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• v.53 no.2
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• pp.113-126
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• 2002

Background : DNA repair plays a crucial role in protection from cancer-causing agents. Therefore, a reduced DNA repair capacity can increase the susceptibility to lung cancer. The XPC gene contains 15 exons and encodes a 940 amino acid protein that plays a central role in DNA damage recognition of the nucleotide excision repair pathway, which is a major DNA repair mechanisim removing the bulky-helix distorting DNA lesions caused by smoking. Recently several polymorphisms in the XPC gene were identified. In addition, it is possible that these polymorphisms may affect the DNA repair capacity, which modulate cancer susceptibility. The relationship between codon 499 and 939 polymorphisms, and a poly(AT) insertion/deletion polymorphism in the XPC gene, and the lung cancer risk were investigated. Materials and Methods : The genotypes were determined using either PCR or PCR-RFLP analysis in 219 male lung cancer patients and 150 healthy males controls. Results : The frequencies of the genotypes (Val499Ala, PAT and Lys939Gln) among the cases were not significantly different from those of the controls. There was no significant associantion between these polymorphi는 and the lung cancer risk when the analyses were stratified according to age, smoking status and the pack-years of smoking. Moreover, the genotypes had no apparent relationship with any of the histological types of lung cancer. There was a linkage disequilibrium among the Val499Ala, PAT and Lys939Gln polymorphisms. The PAT polymorphism had a strong linkage disequilibrium with the Lys939Gln polymorphism (kappa value=0.87). The XPC haplotypes showed no significant association with the lung cancer risk. Conclusion : These results suggest that XPC Val499Ala, PAT and Lys939Gln polymorphisms are not major contributors to the individual lung cancer susceptibility in Koreans.

• Food Science and Preservation
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• v.18 no.5
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• pp.786-794
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• 2011

To investigate the sanitary-quality level of commercial kimchi in South Korea, the pH, acidity, and microbial-flora changes in the kimchi were determined. Samples of kimchi produced by three different manufacturers (a small grocery store, a small/medium-sized enterprise, and a large food company) were collected. Freshly made kimchi was purchased and fermented at $10^{\circ}C$ for 10 days. The pH of the commercial kimchi on the purchased day was approximately pH 5.8, and that on the $10^{th}$ day of fermentation was ${\simeq}pH$ 4.1. The kimchi purchased from a large company showed a more rapid decline in pH level during fermentation. The saltiness of the kimchi purchased from a medium-sized company was slightly higher than those of the other commercial kimchi samples. The saccharinity index of the kimchi produced by a small grocery store was higher than those of the other samples, and its value deviation was also higher than those of the other commercial kimchi samples. A higher total viable-cell count and a higher lactic-acid bacteria (LAB) count were detected in the kimchi from the large food company at the beginning of fermentation compared to the samples of the two other kimchi manufacturers. The highest cell numbers of gram-positive bacteria (except LAB) and coliform bacteria were detected from the small-grocery-store kimchi, but the coliform bacteria count gradually decreased during fermentation although such bacteria were still detected until the $10^{th}$ day of fermentation. In contrast, coliform bacteria were not detected in the samples from the medium-sized and large food companies. Yeast, which is detected in over-ripened kimchi, was detected in the unfermented kimchi from the small grocery store, which had a below-0.36% acidity level. The gram-positive bacteria (except LAB) that were detected in all the tested commercial kimchi samples were determined to be Bacillus spp., and the gram-negative bacteria were determined to be Escherichia coli, Enterobacter spp., Sphingomonase spp., and Strenophomonas spp. The proportions of all the aforementioned bacteria in the kimchi samples, however, were different depending on the samples that were taken. These results indicate that a more sanitary kimchi production process and a more systematic kimchi production manual should be developed to industrialize and globalize kimchi.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.533-538
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• 2013

Potatoes were first introduced outside the Andes region four centuries ago, and have become an integral part of much of the world's food. Potatoes were first introduced into Europe in the 16th century and Korea in the early 19th century. In the nutritional aspects, potatoes contain abundant vitamins and minerals, as well as an assortment of phytochemicals such as carotenoids and natural phenols. Chlorogenic acid constitutes up to 90% of potato natural phenols. Due to the high content of potato functional compounds, it has known that potatoes are effective in the prevention of various human diseases. Recently, color-fleshed potatoes 'Hongyoung' and 'Jayoung' were developed by RDA, and it has reported that they have high content of anthocyanin. Additionally they show higher radical scavenging activity compared to white or yellow fleshed potatoes. So it will be expected that the consumption of color-fleshed potatoes grandually increase by pre-peeled potatoes and color potato chips. This study was conducted to enhance the peel of color-fleshed potatoes utilization and to determine the biological activity of peel of color-fleshed potatoes extract. The anti-inflammatory effects on ethanol extract and its solvent fraction were also evaluated. The anti-inflammatory activities of $CHCl_3$ fraction was evaluated for inhibitory activities against lipopolysacchride(LPS) induced nitric oxide(NO) and prostaglandin $E_2(PGE_2)$ production as well as inducible nitric oxide synthase(iNOS) and cyclo oxygenase-2(COX-2) protein expressions in RAW264.7 cell lines. The fraction inhibitory activity for both tests with $IC_{50}$ values showed in the ranges of $25{\sim}50{\mu}g/ml$. This result revealed that $CHCl_3$ fraction of Jayoung's peel is expected to be good candidate for development into source of anti-inflammatory agent.

• Journal of Life Science
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• v.30 no.11
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• pp.965-972
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• 2020

Sambucus sieboldiana var. miquelii (Nakai) Hara is distributed in Korea, China, and Japan, and has been used as an anti-rheumatic in folk medicine in oriental countries. The present study aims to investigate the potential use of this species in health functional foods, cosmetics, and food preservatives. Methanol extracts of leaves and branches from this plant were prepared to quantitatively analyze the total phenol and flavonoid contents, and to investigate the antioxidative and enzyme inhibitory activities, and the inhibition of nitric oxide (NO) production activity. The results showed that the total polyphenol and flavonoid contents of the crude extract were 1.52±0.1 mg/g and 1.73±0.1 mg/g, respectively. S. sieboldiana polyphenols exhibited potent scavenging activity shown by 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and 2, 2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation assay. The crude extract also exhibited significant α-glucosidase and tyrosinase inhibitory activity with IC₅₀ values of 183.5 ㎍/ml and 323.9 ㎍/ ml, respectively. Additionally, the crude extract exhibited strong anti-inflammatory activity determined through the nitric oxide inhibition assay in a dose-dependent manner with an IC₅₀ value of 36.7 ㎍/ml and no cytotoxic effect on the macrophages. Therefore, we demonstrated that the leaves and branches of S. sieboldiana extract possess antioxidant, anti-diabetic, depigmentation potential, and NO production inhibitory activities. According to recent research, S. sieboldiana has great potential as a source of the bioactive compound which could be used as food, cosmetics, and pharmaceutical agents.

• Journal of Dairy Science and Biotechnology
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• v.33 no.2
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• pp.111-118
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• 2015

Probiotic, prebiotic, and synbiotic substances as well as microorganisms were added to infant formula in an attempt to influence the intestinal microflora with an aim to stimulate the growth of lactic acid bacteria, especially bifidobacteria and lactobacilli. Over the last 10 years, new synbiotic infant formulas containing probiotics and prebiotics have been proposed in order to simulate the effect of breast-feeding on the intestinal microflora. Owing to their synergistic effect, the new synbiotics are expected to be more helpful than using probiotics and prebiotics individually. Maintenance of the viability of the probiotics during food processing and the passage through the gastrointestinal tract should be the most important consideration, since a sufficient number of bacteria ($10^8cfu/g$) should reach the intended location to have a positive effect on the host. Storage conditions and the processing technology used for the manufacture of products such as infant formula adversely affect the viability of the probiotics. When an appropriate and cost-effective microencapsulation methodology using the generally recognized as safe (GRAS) status and substances with high biological value are developed, the quality of infant formulas would improve. The effect of probiotics may be called a double-effect, where one is an immunomodulatory effect, induced by live probiotics that advantageously alter the gastrointestinal microflora, and the other comprises anti-inflammatory responses elicited by dead cells. At present, a new terminology is required to define the dead microorganisms or crude microbial fractions that positively affect health. The term "paraprobiotics" (or ghost probiotics) has been proposed to define dead microbial cells (not damaged or broken) or crude cell extracts (i.e., cell extracts with complex chemical composition) that are beneficial to humans and animals when a sufficient amount is orally or topically administered. The fecal microflora of bottle-fed infants is altered when the milk-based infant formula is supplemented with probiotics or prebiotics. Thus, by increasing the proportion of beneficial bacteria such as bifidobacteria and lactobacilli, prebiotics modify the fecal microbial composition and accordingly regulate the activity of the immune system. Therefore, considerable attention has been focused on the improvement of infant formula quality such that its beneficial effects are comparable to those of human milk, using prebiotics such as inulin and oligosaccharides and potential specific probiotics such as bifidobacteria, which selectively stimulate the proliferation of beneficial bacteria in the microflora and the indigenous intestinal metabolic activity of the microflora.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1158-1164
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• 1998

Aluminium sulfate solution was prepared by sulfuric acid treatment from gibbsite. Aluminium sulfate hydrate [$Al_2(SO_4)_3$ · $nH_2O$] was precipitated from aluminium sulfate solution by adding it into ethylalcohol. From XRD analysis as-prepared $Al_2(SO_4)_3$ · $nH_2O$ was confirmed to have mixed-crystalization water(n=18, 16, 12, 6). The average water of crystalization calculated from thermogravimetry(TG) was 14.7. Aluminium sulfate hydrate [$Al_2(SO_4)_3$ · $nH_2O$] was thermally decomposed and converted to $Al_2(SO_4)_3$ at $800^{\circ}C$, $\gamma-Al_2O_3$ at $900-1000^{\circ}C$, and $\alpha-Al_2O_3$ at $1200^{\circ}C$. Ni-doped $\gamma-Al_2O_3$, was synthesized from the slurry of as-prepared $\gamma-Al_2O_3$, with the ratio of [Ni]/[Al]=0.5. The reaction conditions of synthesis were determined as initial pH 9.0 and temperature $80^{\circ}C$ The basicity(pH) of slurry was controlled by using urea and $NH_4OH$ solution. Urea was also used for deposition-precipitation. For determining termination of reaction, the data acquisition was performed by oxidation reduction potential(ORP), conductivity and pH value in the process of reaction. Termination of the reaction was decided by observing the reaction steps and rapid decrease in conductivity. On the other hand, BET(Brunauer, Emmett and Teller) and thermal diffusity of Ni- doped $\gamma-Al_2O_3$, with various content of Ni were measured and compared. Thermal stability of Ni- doped $\gamma-Al_2O_3$ at $1250^{\circ}C$ was confirmed from BET and XRD analysis. The surface state of Ni-doped $\gamma-Al_2O_3$ was investigated by X-ray photoelectron spectroscopy(XPS). The binding energy at $Ni2P_{3/2}$ increased with increasing the formation of $NiAl_2O_4$ phase.

• The Korean Journal of Food And Nutrition
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• v.29 no.3
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• pp.438-447
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• 2016

This study was conducted in order to investigate the physiochemical properties and antioxidative activity of red ginseng manufactured using the high temperature high pressure (HTHP) process, which is faster and simpler than the conventional process. According to increasing the steaming temperature, pressure and time, the content of minor non-polar ginsenosides, such as Rg3, Rk3, Rh4, Rk1 and Rg5 gradually increased. Also, the contents of acidic polysaccharide, total phenolic compounds and maltol gradually increased. Based on the results of the physiochemical properties and appearance quality, the optimum conditions of HTHP process were estimated as $140^{\circ}C$, $3kg/cm^2$ in 20 min. The total phenolic compounds and maltol contents of the HTHP process red ginseng (1.0% and 2.49 mg%, respectively) were higher than those of conventional red ginseng (0.23% and 0.60 mg%, respectively). In addition, the antioxidative activity was investigated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-aziono-bis(3-ethylbenzthiazoline-6-sulfonic acid)) radical scavenging activity. DPPH and ABTS radical scavenging activities of HTHP process red ginseng increased by 3.4 and 3.6 folds, respectively, compared with conventional red ginseng. In addition, total phenolic compounds and maltol contents, as well as the antioxidant activity of the HTHP process red ginseng were similar to black ginseng. The present results suggest that the HTHP process is available for the development of value-added red ginseng products.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.483-489
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• 2001

The objective of this study was to investigate the effect of ripening on the quality of kimchi or freeze-dried/rehydrated kimchi. Kimchi stored/ripened at 0$\^{C}$ for 120 days was taken at an interval of 10 days and freeze-dried/rehydrated with water. The number of lactic acid bacteria(LAB), shearing force and sensory properties of kimchi ripened (Raw sample) or kimchi ripened/freeze-dried/rehydrated (F/D sample) were observed. The results were as follows: (1) The number of LAB of Raw and F/D samples decreased slightly during ripening for 120 days, while the pH of both samples decreased. The number of LAB in kimchi decreased up to 6∼16% of the original value by freeze-drying. (2) Ripening for 120 days did not affect shearing force of kimchi while freeze-drying increased markedly its shearing force. (3) Although overall acceptability and taste of Raw and F/D samples decreased gradually, the degree of change between two samples was different. The odor of Raw and F/D samples decreased slightly during ripening for 120 days while the degree of change between two samples was similar after 70 days of ripening. Moistness of Raw and F/D samples was maintained relatively stable during ripening. Chewiness of Raw sample decreased during ripening for 120 days while that of F/D sample was not affected by ripening. Color of Raw and F/D sample was changed during ripening while the degree of change between two samples was not significant. It can be concluded that the change of some sensory properties between Raw sample and F/D sample was affected by ripening for 120 days while the change in the number of LAB, pH and shearing force between both samples was not affected markedly by ripening.

• Microbiology and Biotechnology Letters
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• v.35 no.2
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• pp.163-172
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• 2007

This study was designed to investigate that inorganic germanium $(GeO_2)$ did not exist in germanium-fortified yeast or obtained to non-detectable value by current analytical methods and equipments. For this purpose, we achieved $GeO_2$ qualitative analysis protocol which could be the scientific basis of the study. Since reddish brown precipitate was formed from the reaction of $GeO_2$ with 1 equiv $NaBH_4$, and dark brown precipitate was also formed from the reaction of $GeO_2$ with 2 equiv $NaBH_4$, $GeO_2$ was qualitatively analyzed by observing these particular colored-precipitates. Because no color change was showed from the reaction between $NaBH_4$ and $SiO_2$, the color change could be caused by charge transfer transition on Ge-O and B binding properties. The reaction between $NaBH_4$ and germanium-fortified yeast did not show any color change and precipitate formation which meant no $GeO_2$ existed in germanium-fortified yeast. The reaction between $NaBH_4$ and supernatant specimen collected from the outside of dialysis membrane (MWCO 1,200 dalton) did not show any color change and precipitate formation. Therefore, we considered that the both germaniums in and outside of the dialysis membrane were organic germaniums. Germanium-fortified yeast which was biosynthesized organic germanium can be applied not only as a new functional material for improving health, prevention and treatment of chronic degenerative diseases including cancers, and the regulation of immune system, but also as a new materials.