• 한국식품과학회지
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• 제50권1호
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• pp.92-97
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• 2018

말차 첨가 코코넛밀크 스프레드의 항산화 활성과 품질특성을 측정하였다. 본 실험의 스프레드 제조 시 말차 첨가량은 각각 S1(0 g), S2 (4 g), S3 (8 g), S4 (12 g), S5 (16 g)으로 하였다. 품질특성 결과 수분, L값, a값, pH의 경우 말차 첨가량이 증가할수록 측정값은 감소하였다. 반면 점도, b값의 경우 말차 첨가량이 증가할수록 측정값은 증가하였다. 동량의 설탕을 첨가한 각 군의 당도 범위는 모든 군이 $2.70-3.27^{\circ}Bx$ 사이에 속하였다. 관능검사는 색, 맛(단맛, 쓴맛), 조직감(부착성, 발림성), 전반적인 기호도 항목을 평가하였다. 그 결과, 8 g의 말차를 첨가한 S3 스프레드가 가장 선호도가 높았다. 말차 분말의 항산화 활성에서 총 폴리페놀 함량과 총 플라보노이드 함량은 각각 226 mg GAE/g, 809.42 mg QE/g이였다. 또한 DPPH 라디칼 소거능과 환원력은 $5.76{\mu}g/mL$ ($IC_{50}$), 2.26 O.D.으로 측정되었다. 말차 첨가 코코넛밀크 스프레드의 항산화 활성은 말차 첨가량이 높을수록 증가함을 알 수 있다.

• 생명과학회지
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• 제17권8호통권88호
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• pp.1100-1103
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• 2007

합성항산화제 3종과 17종의 식물 추출물을 이용하여 양성자 빔을 1,000, 5,000, 10,000 Gray 수준으로 처리하여 에너지양에 따른 항산화 활성에 미치는 영향을 탐색 하고자 DPPH radical 소거능 과 ABTS cation radical 소거능의 활성에 대하여 조사하였다. 이중 6종류의 시료는 양성자 빔을 조사한 결과 활성이 감소하였으며, 2종류의 시료는 활성변화가 없었으며, 12종류의 시료는 활성이 증가하였다. DPPH radical 소거 효과는 1,000 Gray 에서 마황은 60%, 괄루인은 5,000 Gray 에서 77.8%로 활성이 증가하는 경향을 나타내었다. ABTS cation radical 소거효과에서 토천궁은 1,000 Gray의 양성자 빔을 조사한 결과 38.5% 활성이 감소하였으며, 합성 항산화제는 활성변화가 거의 없으나, 뼝쑥 추출물은 5,000 Gray에서 $IC_{50}$값이 2.4 ${\mu}g/ml$로 BHT의 $IC_{50}$값 2.3 ${\mu}g/ml$과 유사하였다.

• The Plant Pathology Journal
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• 제35권3호
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• pp.243-256
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• 2019

Field surveys for Plum pox virus (PPV) infection were conducted in stone fruit orchards all over Bulgaria. In total, 1168 out of 3020 leaf samples from cultivated Prunus spp. and wildly growing P. cerasifera trees reacted positive for PPV in DASI-ELISA with the universal monoclonal antibody (MAb) 5B. Further ELISA analyses showed that 987 and 127 isolates belonged to PPV-M and PPV-D serotypes, respectively. The plum and P. cerasifera showed 82.0% and 50.5% levels of infection, respectively followed by the peach (40.0%) and the apricot (32.0%). Five hundred fifty one PPV isolates were further typed by IC-RT-PCR with PPV-Rec, -M and -D-specific primers, targeting (Cter)NIb-(Nter) CP genome region, as 125 isolates were sequenced. The results revealed the presence of PPV-Rec, PPV-M and PPV-D and mixed infections of these strains. PPV-Rec was the most prevalent strain (49.0%), followed by PPV-M (40.1%), while PPV-D was the less spread strain (8.2%). PPV-Rec was the most common strain in plums, including the eight "old-aged" trees from the region of the first Sharka discovery. PPV-M was the most prevalent strain in peach and apricot. Phylogenetic analyses on (Cter)NIb-(Nter)CP of the isolates were performed. PPV-Rec isolates formed a homogeneous group, while PPV-M isolates split into PPV-Ma and PPV-Mb subgroups. Five separated clades were formed by the analyzed PPV-D isolates. Nucleotide sequences of the partial CP coding region of the analyzed isolates revealed a slightly higher intra-strain genetic variability in PPV-Rec and PPV-M isolates, while that of PPV-D strain isolates was higher from the reported for these strains.

• 한국전자파학회논문지
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• 제15권10호
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• pp.1011-1017
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• 2004

UWB(Ultra Wideband) 기술은 초고속통신, 고정밀의 위치정보시스템 등을 구현하기 위하여 500 MHz 이상의 광대역 주파수 자원이 요구되고 있다. UWB 신호의 에너지는 DC로부터 수 GHz까지 광대역 특성을 갖기 때문에, 현재 사용되고 있는 통신시스템들과의 간섭에 대한 분석이 필수적이라고 할 수 있지만 아직까지 국내에서 UWB 신호와 Cellular CDMA(Code Division Mutiple Access) 이동통신과 WCDMA(Wideband CDMA)와 간섭에 대한 연구가 이루어지고 있지 않다. 본 논문에서는 임펄스 방식과 DS-CDMA(Direct Sequence-CDMA) 방식의 UWB 신호원과 국내 이동통신 서비스중 Cellular CDMA와 WCDMA의 간섭에 관하여 측정을 하고 분석하였다. 본 논문의 결과로부터, 임펄스 방식에 비해 DS-CDMA방식의 UWB 신호는 이동통신시스템에 간섭효과가 크지 않다는 사실을 얻었다.

• Journal of Microbiology and Biotechnology
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• 제28권9호
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• pp.1426-1432
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• 2018

Staphylococcus aureus causes a broad variety of diseases. The spread of multidrug-resistant S. aureus highlights the need to develop new ways to combat S. aureus infections. Sortase A (SrtA) can anchor proteins containing LPXTG binding motifs to the bacteria surface and plays a key role in S. aureus infections, making it a promising antivirulence target. In the present study, we used a SrtA activity inhibition assay to discover that isovitexin, a Chinese herbal product, can inhibit SrtA activity with an $IC_{50}$ of $28.98{\mu}g/ml$. Using a fibrinogen-binding assay and a biofilm formation assay, we indirectly proved the SrtA inhibitory activity of isovitexin. Additionally, isovitexin treatment decreased the amount of staphylococcal protein A (SpA) on the surface of the cells. These data suggest that isovitexin has the potential to be an anti-infective drug against S. aureus via the inhibition of sortase activity.

• 한국세라믹학회지
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• 제48권6호
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• pp.510-515
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• 2011

In this study, as a material used to replace silica fumes for high strength concrete, nano-silica compound with organic functional group for dispersion and with inorganic silica group that can cause a pozzolan reaction is synthesized, These nano silica compound is divided into IC, which is nano size $SiO_2$ with irregularly combined hydroxyl group and carboxyl group, and RC, which is nano size $SiO_2$ with regularly combined hydroxyl group and carboxyl group. The effects of these nano silica compound on the hydration of cement are reviewed. As a result, all of synthesized nano-silica compounds have excellent dispersion on the cement flow, we think that dispersion property is the effect of air entraining by synthesized nano-silica compounds. The result of the microstructure observation showed that the particle size of the synthesized nano-silica is smaller than silica fume and spread evenly among the cement particles. In initial The phenomenon of strength decreasing occurred due to delayed hydration reaction by the synthesized nano-silica with carboxyl(-COOH) and hydroxyl(-OH) functional group.

• 한국정밀공학회지
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• 제27권2호
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• pp.13-19
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• 2010

Due to the rapid spread of mobile handheld devices, industrial demands for micro-scale holes with a diameter of even smaller than $10{\mu}m$ in sapphire/silicon wafers have been increasing. Holes in sapphire wafers are for heat dissipation from LEDs; and those in silicon wafers for interlayer communication in three-dimensional integrated circuit (IC). We have developed a sapphire wafer driller equipped with a 532nm laser in which a cooling chuck is employed to minimize local heat accumulation in wafer. Through the optimization of process parameters (pulse energy, repetition rate, number of pulses), quality holes with a diameter of $30{\mu}m$ and a depth of $100{\mu}m$ can be drilled at a rate of 30holes/sec. We also have developed a silicon wafer driller equipped with a 355nm laser. It is able to drill quality through-holes of $15{\mu}m$ in diameter and $150{\mu}m$ in depth at a rate of 100holes/sec.

• 천문학회보
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• 제44권2호
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• pp.72.3-72.3
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• 2019

OB associations are young stellar systems on a few tens to a hundred parsec scale, and many of them are composed of multiple substructures. It is suggested that some hints about their formation process are probably imprinted on structural features and internal kinematics. In this context, we study the massive star forming region W4 in the Cassiopeia OB6 association using the Gaia proper motion data and high-resolution optical spectra taken from Hectochelle on MMT. We probe the structure and internal kinematics of W4 to trance its formation process. Several nonmembers with different kinematic properties are excluded in our sample. Some of them may be young stellar population spread over a large area of the Perseus spiral arm given their wide spatial distribution over 50 parsecs. W4 is composed of an central open cluster (IC 1805) and an extended stellar component. Their global expansion patterns are detected in stellar proper motion. In this presentation, we will further discuss the formation process of W4, based on the velocity dispersions of stars comprising these substructure.

• 한국식품영양학회지
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• 제30권3호
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• pp.501-509
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• 2017

This study investigated the quality characteristics and antioxidant activities of gluten-free cookies containing teff flour. By substituting 0% (control), 25% (TF25), 50% (TF50), 75% (TF75), and 100% (TF100) of wheat flour with teff flour, five samples were produced. Baking loss rate was the highest in TF25 at 13.76% and the lowest in TF75 at 4.03%. Spread factor was significantly higher in cookies made with teff flour (83.00~85.00) than in the control (81.33) (p<0.05). There was no significant difference in density among the samples at 1.17~1.25 g/mL (p<0.05); however, pH significantly decreased at 6.42~6.04 (p<0.05). While the L-value and b-value significantly decreased with the amount of teff flour, the a-value significantly increased (p<0.05). The ${\Delta}E$ value was the highest in the control at 31.31 and the lowest in TF100 at 58.69. Hardness was the highest in the control at 42.04 N than in cookies containing teff flour. The content of polyphenols was the highest in TF100 at $3.37{\mu}g\;GAE/mg$ and the lowest in the control at $1.32{\mu}g\;GAE/mg$. The content of flavonoids was the highest in TF100 at $3.66{\mu}g\;QE/mg$ and the lowest in controls at $0.45{\mu}g\;QE/mg$. The value of DPPH $IC_{50}$ was the highest in the control at $3,723.00{\mu}g/mL$ and the lowest in TF 100 at $405.27{\mu}g/mL$. The value of ABTS $IC_{50}$ was the highest in the control at $1,822.32{\mu}g/mL$ and the lowest in TF100 at $529.30{\mu}g/mL$. In sensory evaluation, while control, TF75, and TF100 had a higher score in appearance at 5.52~5.60, all samples had no significant differences in flavor, sweetness, savory taste, chewiness, and overall acceptability (p<0.05). These results showed that the gluten-free cookies containing teff flour can improve the quality characteristics and antioxidant activities of a cookie. We concluded that gluten-free cookies containing 100% teff flour are desirable.

• 한국식품조리과학회지
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• 제33권2호
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• pp.127-136
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• 2017

Purpose: This study examined the effect of different gluten-free flours on the properties of cookies. Methods: Each gluten-free cookie was made from wheat, brown rice, buckwheat, corn, sorghum, teff, or black rice. Results: Baking loss was highest on sorghum (18.85%) and the lowest on teff (12.73%). The spread factor was highest on brown rice (8.20) and lowest on corn (7.60). The density was similar in all samples (1 g/mL). pH was the highest on buckwheat (6.45) and lowest on wheat (5.96). While L-value, a-value and b-value were lowest on black rice, the ${\Delta}E-value$ was the highest on black rice (35.57). The hardness was highest on wheat (30.28 N) and lowest on teff (14.87 N). The polyphenol and flavonoid content was the highest on buckwheat ($25.97{\mu}g\;GAE/mg$) and the flavonoid content was the highest on black rice ($24.33{\mu}g\;QE/mg$). The DPPH IC50 value was highest on wheat ($352.41{\mu}g/mL$) and lowest on black rice ($33.59{\mu}g/mL$). The ABTS $IC_{50}$ value was highest on wheat ($349.30{\mu}g/mL$) and lowest on black rice ($57.72{\mu}g/mL$). The results of the sensory properties revealed color to be highest on corn (7.33). The top grain was similar in all the samples (5.43-6.57). Flavor was highest on black rice and teff (6.43-6.48). The softness was the highest on wheat, sorghum, teff, and black rice (6.48-7.05). Sweetness was highest on sorghum, teff, and black rice (6.19-6.71). The overall preference also was highest on sorghum, teff, and black rice (6.14-6.48). Conclusion: Gluten-free flours can improve the quality characteristics and antioxidant activities of cookies.