• Food Science and Biotechnology
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• 제15권4호
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• pp.564-571
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• 2006

In order to improve the quality and preservation of nabakkimchi, omija was added as an ingredient to determine its effect on the physicochemical characteristics of kimchi during fermentation, as well as the optimum level of omija extract. Omija extract was prepared from omija seeds by extraction with water for 9 hr at room temperature in concentrations (w/v) of 0.5, 1.0, 1.5, and 2.0% for use as an ingredient in nabakkimchi. The physicochemical characteristics of nabakkimchi containing omija extract were analyzed during fermentation of the product for up to 25 days. Delayed fermentation was observed, particularly in the early stage of fermentation, and was dependent on the concentration of the omija extract, as shown by stabilization of pH decreases and increases in the total acidity. An increased concentration of omija extract also raised the initial total vitamin C content and the reducing sugar content, which both then stabilized thereafter. Delayed development of turbidity within the optimum fermentation period of 16 days, increased redness and total color difference, and an electron-donor effect were also promoted by the omija extract. However, the omija extract also triggered extra tannin production, which leads to an astringent taste, especially at the 1.5 and 2.0% treatment levels.

• Safety and Health at Work
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• 제11권4호
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• pp.500-508
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• 2020

Background: Research on the status of many chemicals used in the semiconductor industry is needed. The purpose of this study was to describe the overall status of chemical use in the semiconductor industry in Korea and to examine it from a health perspective. Methods: Data on the status of chemical use and safety data sheets at 11 of 12 major semiconductor workplaces in Korea were collected. The number of chemical products and chemical constituents, quantities of chemicals, and trade secret ingredients used, as well as the health hazards were examined. Results: On average, 210 chemical products and 135 chemical constituents were used at the surveyed workplaces. Among all chemical products, 33% (range: 16-56%) contained at least one trade secret ingredient. Most of the trade secret ingredients were used in the photolithography process. Several carcinogens, including sulfuric acid, chromic acid, ethylene oxide, crystalline silica, potassium dichromate, and formaldehyde were also used. Only 29% (39 of 135) of the chemical constituents had occupational exposure limits, and more than 60% had no National Fire Protection Association health, safety, and reactivity ratings. Based on the aforementioned results, this study revealed the following. First, many chemical products and constituents are being used in the semiconductor industry and many products contained trade secret ingredients. Second, many products contained significant amounts of carcinogenic, mutagenic, and reproductive toxicant materials. Conclusion: We conclude that protecting workers in the semiconductor industry against harm from chemical substances will be difficult, due to widespread use of trade secret ingredients and a lack of hazard information. The findings of the status of chemical use and the health and safety risks in semiconductor industry will contribute to epidemiological studies, safe workplace, and worker health protection.

• 대한화학회지
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• 제55권3호
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• pp.400-404
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• 2011

홍화는 예로부터 '사람의 건강에 도움이 된다'고 해서 '잇꽃'으로 불려져 왔으며 동의보감에서는 꽃잎이 홍색을 나타내기 때문에 홍화(紅花)로 소개되어 있다. 예로부터 홍화는 꽃잎을 압착후 정제된 색소를 이용하여 옷감에 천연색소를 입히는 염료와 연지의 재료로 사용되기도 하였다. 현대에 와서는 홍화의 주성분인 폴리페놀 화합물(Polyphenol cocktail) 성분이 건강식품업계에서 항노화 및 항산화물질로 알려지면서 관심의 대상이 되고 있다. 금번연구에서는 홍화의 주성분인 폴리페놀 화합물이 청소년기 혹은 장년기에서도 고민거리가 되고 있는 여드름균의 생성을 억제시킬 수 있는 항균, 항염효능이 있음을 DDT(Disk Diffusion Test) assay, MTT assay, NF-${\kappa}$B Luciferase activity inhibition assay의 in vitro법으로 확인하고 더불어 인체안면에 대한 임상시험에 사용할 세안화장품 제형의 화장비누 시제품을 제조하여 여드름피부의 개선 효과가 있음을 시험하고자 한다. 또한 이번 연구는 여드름용 화장비누 개발에 진일보하여 약용화장품 산업의 발전에 기여할 것임을 확신한다.

• 공업화학
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• 제17권4호
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• pp.397-402
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• 2006

TFT-LCD TV용 백라이트 유니트(BLU)의 각 구성성분이 최종 광확산필름의 물리적, 전기적, 열적, 광학적 특성에 미치는 영향에 관하여 고찰하였다. 블로킹 방지층에 있어서는 $6{\mu}m$의 아크릴 비드를 0.5~1.5 wt%로 첨가했을 때 블로킹 방지성이 우수하였고, 4급 암모니움 염을 0.8 wt%로 첨가하였을 경우 Decay-Time 및 수분에 대한 안정성이 가장 우수한 결과를 나타내었다. 광확산층에 있어서는 아크릴 폴리올을 바인더 수지로서 사용하고, 무황변 타입의 HDI계 경화제를 바인더 수지에 대해 30~35 wt%로 첨가하였을 경우가 PET 필름 표면상에의 접착력, 경화속도 및 유연성 측면에서 가장 우수한 결과를 보였다. 또한 $20{\mu}m$의 다분산형 폴리스티렌($20{\mu}m$ PS) 및 폴리메틸메타크릴레이트($20{\mu}m$ PMMA) 비드를 바인더 수지 대비 250 wt%로 첨가하였을 경우에 가장 높은 법선휘도값을 얻을 수 있었으며, PS 입자를 사용했을 경우보다는 PMMA 입자를 사용했을 경우가 투과율 차이로 인해 더 높은 법선휘도값을 나타내었다.

• 대한화학회지
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• 제54권6호
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• pp.707-710
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• 2010

우리나라 서남단의 지리산에는 천연야생에서 자생하는 한방약초의 보고라고 할 수 있다. 현재 약초로 분류되는 식물로는 1200여종이 자생 혹은 재배되고 있다. 최근들어 이들 중 현대인의 피부노화억제와 관련하여 관심을 끌고 있는 약초로 홍화에 관한 연구가 활발히 연구되고 있는데 금번연구에서는 홍화의 주성분인 폴리페놀 화합물(Polyphenol cocktail)이 30 - 40대 중년기의 여성에게 주름생성을 억제시켜 피부노화에 대한 지연효과를 줄 수 있는 천연물질임을 확인하고자 한다. 본 연구에서는 1차적으로 in vitro법으로 DPPH assay로 항산화효과를 확인하고 더불어 인체에 대한 임상시험을 통해 얼굴피부의 주름발생에 대한 억제 혹은 개선효과가 있음을 입증하고자 한다. 또한 홍화추출물을 주성분으로 하는 항노화 마스크팩 시제품의 개발로 진일보하여 기능성화장품 산업의 발전에 기여할 것임을 확신한다.

• Fisheries and Aquatic Sciences
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• 제25권7호
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• pp.390-402
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• 2022

In this study we investigate physical and chemical characteristics of immature and mature skipjack tuna (Katsuwonus pelamis) roes in fresh and dried forms. Fresh roes were studied for histological structure and also dried by three methods: hot air drying (HD), vacuum drying (VD) and freeze drying (FD). The obtained roe powders were analysed for proximate composition, color value, fatty acid composition, amino acid profile, equivalent umami concentration (EUC) and protein pattern. Unyolked oocytes were more common in immature roes, while fully yolked oocytes were more common in mature roes. All dried tuna roes contained high content of protein and lipid (69.31%-70.55% and 11.14%-16.02%, respectively). The powders obtained by FD provided the highest lightness value (L^*). The main fatty acid found in all roe powders was docosahexaenoic acid (DHA) (23.49%-27.02%). Glutamic acid, leucine, and aspartic acid were the three most abundant amino acids found in the powders (13.58-14.61, 8.06-8.42, and 7.81-8.39 g/100 g of protein, respectively). The mature roe powder obtained from HD provided the highest EUC value (73.09 g monosodium glutamate/100 g of samples). The protein band at molecular weight of 97 kDa (vitelline) represented the major protein. Therefore, dried tuna roe could be a functional ingredient source of protein and lipid rich in DHA and it also has potential to be used as taste enhancer with umami compound.

• Carbon letters
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• 제11권3호
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• pp.211-215
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• 2010

Multi-walled carbon nanotube (MWCNT)/poly(vinyl alcohol) (PVA) nanocomposite hydrogels were prepared by freezingthawing method for the electro-responsive transdermal drug delivery. MWCNTs were used as the functional ingredient to improve both mechanical and electrical properties of MWCNT/PVA nanocomposite hydrogels. The morphology of nanocomposites revealed the uniform distribution of MWCNTs and the good interfacial contact. The compression moduli of hydrogel matrices increased greatly from 40 to 1500 kPa by forming MWCNT/PVA nanocomposites. The swelling ratio of MWCNT/PVA nanocomposites decreased as the content of MWCNTs increased under no electric voltage applied. However, the swelling ratio of MWCNT/PVA nanocomposites increased as the content of MWCNTs increased under electric voltage applied and the applied electric voltage increased. The drug was released in the electro-responsive manner through the skin due to the electro-sensitive swelling characteristics of MWCNT/PVA nanocomposite hydrogels.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.100-104
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• 2006

In this study, we investigated the relationship between the morphology and the rheological properties of Penicillium citrinum to improve the production of neo-fructosyltransferase (neo-FTase). In a 2.5 L bioreactor culture of P. citrinum, it was observed that agitation speed and aeration rate had significant effects on the production of neo-FTase and that maximum cell mass and neo-FTase production obtained at 500 rpm and 1.5vvm were 8.14 g/L and $53.2{\times}10^{-3} U/mL$, respectively. Cell mass and neo-FTase production increased to 91.53 and 25.17%, respectively. In the morphology and rheology studies, P. citrinum showed a typical pellet morphology that was explained by a shaving mechanism; this phenomenon was significantly affected by carbon sources. The rheology of neo-FTase fermentation by P. citrinum was dependent on cell growth and fungal morphology.

• 대한화학회지
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• 제19권4호
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• pp.213-217
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• 1975

N,N-디에틸-m-톨루아미드 분자는 malaria 모기에 대한 방충제로서의 효력이 있지만 메틸기가 오르토나 파라 위치에 있는 이성질체들은 그러한 효능이 없다. 반 실험적 양자역학 이론인 확장 Huckel 이론을 사용하여 이들 분자들의 형태를 계산하고 상기의 차이점을 이론적으로 설명하고 실험결과와 비교하였다.

• KSBB Journal
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• 제27권2호
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• pp.131-135
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• 2012

To develop potential cosmetic ingredients with antimicrobial and antioxidant activities of 4 Korean bamboo species (P. bambusoides, P. nigra var. henonis, P. pubescens and Sasa coreana) using three different extraction methods-water, ethanol and supercritical fluid extraction. Antimicrobial activities and DPPH assay have been examined. Among the antimicrobial activities against two test strains, Escherichia coli and Staphylococcus aureus, ethanol extracts of 3 bamboo trees, P. bambusoides, P. nigra var. henonis, and P. pubescens, showed stronger than those of supercritical extracts. However, 4 bamboo supercritical extracts showed dose-dependent increase in antioxidant activity by DPPH assay. These results suggest that water fraction of bamboo extracts may be useful for the cosmetic ingredient with low cytotoxicity.