• Applied Biological Chemistry
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• 제40권4호
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• pp.307-312
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• 1997

유색미의 항암활성을 in vitro에서 조사하기 위한 기초실험으로서, 유색미 겨의 유기용매 추출물에 의한 DNA strand scission 및 발암 promotion의 억제효과를 조사하였다. 실험에는 유색미로 상해향혈나와 수원415호의 두 품종과 함께 대조구로 추청을 사용하였다. 품종별 변이원 억제활성은 70% 에탄올추출물 및 모든 유기용매 분획물에서 추청<상해향혈나<수원415호의 순서로 증가하였다. 그러나 DNA strand scission에 대한 억제활성은 70% 에탄올 추출물에서 상해향혈나<추청<수원415호의 순서로 증가하였다. 클로로포름 분획물에 대하여 조사한 결과, 상해향혈나에는 거의 DNA strand scission을 억제하는 활성이 없었으며, 예상과는 달리 추청은 오히려 상해향혈나보다 약간 활성이 높았다. 그리고 수원415호의 클로로포름분획물은 70%에탄올 추출물의 경우와 비슷한 수준의 강한 억제활성을 보였다(약 50% 억제). 발암 promotor에 의하여 유도된 Epstein-Barr 바이러스의 early diffusible antigen의 발현수준을 지표로 하여 70% 에탄올 추출물의 발암 promotion의 억제효과를 측정한 결과, 추청<상해향혈나< 수원415호의 순서로 억제활성이 높아짐을 알 수 있었다. 세 품종 모두의 클로로포름분획물에서 발암 promotion을 완전히 차단하는 효과가 발견되었지만, 세포독성이 동반되지 않은 promotion에 대한 억제효과는 수원415호에서만 유일하게 관찰되었다.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.1170-1176
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• 2015

Ginsenosides, the major active component of ginseng, are traditionally used to treat various diseases, including cancer, inflammation, and obesity. Among these, compound K (CK), an intestinal bacterial metabolite of the ginsenosides Rb₁, Rb₂, and Rc from Bacteroides JY-6, is reported to inhibit cancer cell growth by inducing cell-cycle arrest or cell death, including apoptosis and necrosis. However, the precise effect of CK on breast cancer cells remains unclear. MCF-7 cells were treated with CK ($0-70{\mu}M$) for 24 or 48 h. Cell proliferation and death were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry assays, respectively. Changes in downstream signaling molecules involved in cell death, including glycogen synthase kinase $3\beta$ ($GSK3\beta$), $GSK3\beta$, $\beta$-catenin, and cyclin D1, were analyzed by western blot assay. To block $GSK3\beta$ signaling, MCF-7 cells were pretreated with $GSK3\beta$ inhibitors 1 h prior to CK treatment. Cell death and the expression of $\beta$-catenin and cyclin D1 were then examined. CK dose- and time-dependently inhibited MCF-7 cell proliferation. Interestingly, CK induced programmed necrosis, but not apoptosis, via the $GSK3\beta$ signaling pathway in MCF-7 cells. CK inhibited $GSK3\beta$ phosphorylation, thereby suppressing the expression of $\beta$-catenin and cyclin D1. Our results suggest that CK induces programmed necrosis in MCF-7 breast cancer cells via the $GSK3\beta$ signaling pathway.

• 한국통신학회논문지
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• 제29권11A
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• pp.1263-1270
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• 2004

OFDM (Orthogonal Frequency Division Multiplexing) 기반의 무선 랜 모뎀에 사용되는 고속/저전력 64-점 FFT/IFFT 프로세서 코어를 설계하였다. Radix-2/4/8 DIF (Decimation-In-Frequency) FFT 알고리듬을 R2SDF (Radix-2 Single-path Delay Feedback) 구조에 적용하여 설계하였으며, 내부 데이터 흐름 특성에 대한 분석을 토대로 데이터 패스의 불필요한 switching activity를 제거함으로써 전력소모를 최소화하였다. 회로 레벨에서는 내부의 상수 곱셈기와 복소수 곱셈기를 절사형(truncated) 구조로 설계하여 칩 면적과 전력소모가 감소되도록 하였다. Verilog-HDL로 설계된 64점 FFT/IFFT 코어는 0.25-$\mu\textrm{m}$ CMOS 셀 라이브러리로 합성한 결과, 약 28,100 게이트로 합성되었으며, 추출된 게이트 레벨 netlist와 SDF를 이용한 타이밍 시뮬레이션 결과, 50-MHz＠2.5-V로 안전하게 동작하는 것으로 검증되어 64점 FFT/IFFT 연산에 1.3-${\mu}\textrm{s}$가 소요될 것으로 예상된다. 설계된 코어를 FPGA에 구현하여 다양한 테스트 벡터로 동작시킨 결과 정상 동작함을 확인하였으며, 50-dB 이상의 신호대잡음비(SNR) 성능과 50-MHz＠2.5-V 동작조건에서 약 69.3-mW의 평균 전력모소를 나타내었다.

• 한국도로학회논문집
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• 제17권2호
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• pp.55-62
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• 2015

Cracking is an inevitable fact of asphalt concrete pavements and plays a major role in pavement deterioration. Pavement cracking is one of the main factors determining the frequency and method of repair. Cracks can be treated with a number of preventative maintenance actions, including overlay surface treatments such as slurry sealing, crack sealing, or crack filling. Pavement cracks can show up as one or all of the following types: transverse, longitudinal, fatigue, block, reflective, edge, and slippage. Crack sealing is a frequently used pavement maintenance treatment because it significantly extends the pavement service life. However, crack sealant often fails prematurely due to a loss of adhesion. Because current test methods are mostly empirical and only provide a qualitative measure of the bond strength, they cannot accurately predict the adhesive failure of the sealant. This study introduces a laboratory test aimed at assessing the bonding of hot-poured crack sealant to the walls of pavement cracks. A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the bonding strength of the hot-poured crack sealant as a function of the curing time and temperature. Based on a limited number of test results, the hot-poured crack sealants have very different bonding performances. Therefore, this test method can be proposed as part of a newly developed performance-based standard specification for hot-poured crack sealants for use in the future. PURPOSES : The purpose of this study was to evaluate both the adhesion and failure performance of a crack sealant as a function of its curing time and curing temperature. METHODS: A pneumatic adhesion tensile testing instrument (PATTI) was adopted to measure the adhesion performance of a crack sealant as a function of the curing time and curing temperature. RESULTS: With changes in the curing time, curing temperature, and sealant type, the bond strengths were found to be significantly different. Also, higher bond strengths were measured at lower temperatures. Different sealant types produced completely different bond strengths and failure behaviors. CONCLUSIONS: The bonding strength of an evaluated crack sealant was shown to differ depending on various factors. Two sealant types, which were composed of different raw materials, were shown to perform differently. The newly proposed test offers the possibility of evaluating and differentiating between different crack sealants. Based on alimited number of test results, this test method can be proposed as part of a newly developed performance-based standard specification for crack sealants or as part of a guideline for the selection of hot-poured crack sealant in the future.

• 한국임상수의학회지
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• 제33권4호
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• pp.234-236
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• 2016

A 14 kg, 9-year-old, spayed female, Cocker Spaniel was presented to the Veterinary Medical Teaching Hospital of Seoul National University with a history of head tilt and circling. Otitis externa and media were diagnosed by computerized tomography, and total ear canal ablation was performed. In preanesthetic evaluation, systemic hypertension and second-degree atrioventricular block were observed, but there was no regurgitation through the heart valves. Systemic hypertension was managed with amlodipine (0.1 mg/kg, PO, BID) for the anesthesia. The dog was premedicated with cefazolin (22 mg/kg, IV) and midazolam (0.2 mg/kg, IV). Anesthesia was induced with alfaxalone (2 mg/kg, IV) and maintained with isoflurane and 100% oxygen following intubation. During surgery, vital signs (heart rate, respiratory rate, blood pressure, end tidal carbon dioxide partial pressure and body temperature) were maintained within normal ranges, but bradycardia was observed and corrected with glycopyrrolate (5 ug/kg IV, twice). During subcuticular suture, electrohemostasis was applied at the incision line, which was close to the trigeminal nerve. In no time at all, heart rate dramatically decreased from 110 to 60 beats per minute. No additional treatment was done because mean blood pressure was maintained above 70 mmHg. The heart rate recovered according to the decrease of end tidal isoflurane concentration and there were no complications associated with the anesthesia and surgery. Sudden bradycardia after electrical stimulation around the trigeminal nerve was considered as trigeminocardiac reflex (TCR). It is recommended to be careful of bradycardia from TCR when electrocautery is used in the craniofacial area during surgery.

• 대한전자공학회논문지SD
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• 제47권12호
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• pp.75-82
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• 2010

본 논문은 다중대역 송수신기 CMOS RFIC 단일 칩을 위한 광대역 델타시그마 분수분주형 주파수합성기에 관한 것이다. 광대역 VCO의 LC Tank에 6-bit Switched Capacitor Array Bank를 작용하여 2340~3940 MHz의 출력주파수 범위를 가지도록 하였으며, 위상동기 전 Capacitor Bank Code를 선택하기위한 VCO Frequency Calibration 회로는 전체 주파수대역에서 $2{\mu}s$이하로 보정을 마치는 뛰어난 성능을 보여준다. 광대역 VCO로부터 T-DMB/DAB/FM Radio의 LO 신호를 생성하기 위해 선택 가능한 다중분주비 ${\div}2$, ${\div}16$, ${\div}32$를 가지는 LO 신호 발생기는 L-Band (1173 ~ 1973 MHz), VHF-III (147 ~ 246 MHz), VFH-II (74~123 MHz)에서 I/Q신호를 생성한다. Integrated Phase Noise는 전체 대역에서 0.8 degree RMS 이하로 측정되어 매우 낮은 위상잡음을 보여주었다. 또한, VCO Frequency Calibration 시간을 포함하는 주파수합성기의 전체 동기시간은 $50{\mu}s$ 이하로 측정되었다. 이 광대역 델타시그마 분수분주형 주파수합성기는 $0.13{\mu}m$ CMOS공정으로 제작되었으며, 1.2 V 전원전압에서 15.8 mA의 전류를 소모한다.

• 한국인터넷방송통신학회논문지
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• 제17권6호
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• pp.69-78
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• 2017

5G 스마트폰의 샤논과 신호처리의 푸리에가 표본화정리(최고 주파수의 2배분1 즉, $\frac{1}{2f_n}=T$)에서 만난다. 본 논문에서는 초기 샤논 정리가 Point-to-Point에서 샤논 용량을 구했지만 5G는 Multi point MIMO로 기술이 발전했음을 Relay 채널에서 보인다. 푸리에 변환은 고정매개변수로 신호처리를 했는데, 멀티미디어 시대에 2N-1 다변수인 푸리에-Jacket 변환을 제안해서 성능을 분석했다. 이 연구에서 저자는 시간 계산 측면에서 프리 코딩 / 디코딩 복잡성을 줄이기위한 Jacket 기반의 빠른 방법을 제안함으로써 신호 처리의 복잡성 문제를 해결한다. 재킷 변환은 신호 처리 및 코딩 이론에서 응용 프로그램을 찾는 것으로 나타냈다. 재킷 변환은 속성 $AA^{\dot{+}}=nl_n$이 있는 필드 F에 대해 $n{\times}n$ 행렬 $A=(a_{jk})$로 정의되며, 여기서 $A^{\dot{+}}$는 A의 원소 역행렬의 전치 행렬, 즉 $A^{\dot{+}}=(a^{-1}_{kj})$이며, 이는 변환을 일반화하고 중심 가중 변환, 특히 재킷 변환 특성을 이용하여, 저자는 전송 기반의 중계 기반 DF 협동 무선 네트워크에서 분산 다중 입력 다중 출력 채널의 프리 코딩 및 디코딩에 적용하여 새로운 고유치 분해 (EVD : eigenvalue decomposition) 방법을 제안한다. 단일 심볼 디코딩 가능한 시공간 블록 코드를 사용한다. 본 논문은은 제안 된 Jacket 기반 EVD 방법이 기존의 EVD 방법에 비해 계산 시간이 현저히 단축되었다. 계산 시간 단축과 관련된 성능은 수학적 분석 및 수치결과를 통해 정량적으로 평가했다.

• Molecules and Cells
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• 제38권7호
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• pp.663-668
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• 2015

hBMSCs are multipotent cells that are useful for tissue regeneration to treat degenerative diseases and others for their differentiation ability into chondrocytes, osteoblasts, adipocytes, hepatocytes and neuronal cells. In this study, biodegradable elastic hydrogels consisting of hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly(${\varepsilon}$-caprolactone) (PCL) scaffolds were evaluated for tissue engineering because of its biocompatibility and the ability to control the release of bioactive peptides. The primary cultured cells from human bone marrow are confirmed as hBMSC by immunohistochemical analysis. Mesenchymal stem cell markers (collagen type I, fibronectin, CD54, $integrin1{\beta}$, and Hu protein) were shown to be positive, while hematopoietic stem cell markers (CD14 and CD45) were shown to be negative. Three different hydrogel scaffolds with different block compositions (PEG:PCL=6:14 and 14:6 by weight) were fabricated using the salt leaching method. The hBMSCs were expanded, seeded on the scaffolds, and cultured up to 8 days under static conditions in Iscove's Modified Dulbecco's Media (IMDM). The growth of MSCs cultured on the hydrogel with PEG/PCL= 6/14 was faster than that of the others. In addition, the morphology of MSCs seemed to be normal and no cytotoxicity was found. The coating of the vascular endothelial growth factor (VEGF) containing scaffold with Matrigel slowed down the release of VEGF in vitro and promoted the angiogenesis when transplanted into BALB/c nude mice. These results suggest that hBMSCs can be supported by a biode gradable hydrogel scaffold for effective cell growth, and enhance the angiogenesis by Matrigel coating.

• Archives of Pharmacal Research
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• 제28권9호
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• pp.1002-1012
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• 2005

5-Substituted 4-oxo-2-thioxo-1,,2,3,4-tetrahydropyrimidine were synthesized by interaction of 4­oxo-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-sulfonylhydrazide with some aldehydes to give the corresponding Schiff-bases, which after cyclization gave corresponding thiazolidinones. For some of the thiazolidinones, Mannich bases reaction was carried out. All the derivatives were tested for their possible inhibitory effect on Schistosoma mansoni cercarial elastase (CE). Only, N'-(4-methylbenzyledine)-4-oxo-2-thioxo-1,2 ,3,4-tetrahydropyrimidine-5-sulfonylhydrazide was found to have potent inhibitory effect on the CE activity with $IC_{50} = 264{\mu}M.$ Upon its use as a paint for mice tails before infection with S. mansoni cercariae, the compound formulated in jojoba oil caused a significant reduction ($93\%$; P-value = 0.0002) in the worm burden. IgG & IgM in mice sera were measured by using several S. mansoni antigens by ELISA. Sera from treated infected mice (TIM) 2, 4, and 6 weeks (W) post infection (PI) showed 1.2 folds lower, 1.2 folds higher, 1.7 folds lower IgM reactivity against soluble cercarial antigenic preparation (CAP), respectively, when compared with sera collected from infected untreated mice (IUM). Sera from TIM 2, 4, and 6WPI showed 1.3, 1.6, and 1.7 folds higher IgG reactivity, respectively against CAP than the IgG reactivity from IUM. Sera from TIM 2, 4 and 6WPI showed 1.5, 1.2 folds lower and 1.4 folds higher IgM reactivity, respectively against soluble worm antigenic preparation (SWAP) when compared with sera collected from IUM. Sera from TIM 2, 4, and 6WPI showed 1.4, 1 folds lower and 1 fold higher IgG reactivity, respectivley to SWAP when compared with sera from IUM. Sera from TIM 2, 4, and 6WPI had generaly lower IgM and IgG reactivities against soluble egg antigen (SEA) when compared with sera from IUM.

• 건축역사연구
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• 제21권1호
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• pp.7-26
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• 2012

Nakseonjae in Changdeokgung Palace was established at The King Hunjong's 13rd year (1847), the mid-19th century. It was constructed for own rests of King Hunjong and the residence of Kyungbin (king's concubines), and is showing features of upper-class houses from several points such as rustic architectural types by getting out of authoritative aspects as king's shelter space within the palace, block and floor distribution that separated spaces for men and women, simplicity in structures and styles, and non-colorful painting etc. This study aims at tracing on which architectural types did the upper-class houses within Hanyang (modern Seoul) at late Joseon Dynasty have and what was characteristics of Nakseonjae. The resemblance between Nakseonjae and the upper-class houses was very little differences from scale aspects, and floor plan shapes of Anchae (women's quarters) and Sarangchae (men's quarters) were followed basic common styles. Also, resemblance could be confirmed in the structural styles too. Characteristics of Nakseonjae are showing apparent differences from clearance compositions such as hall configuration etc. Nakseonjae was king's dwelling place, and spaces for house's collateral functions such as kitchen, stable, and warehouse etc together with shrine were unnecessary, and such places were substituted into servants' quarters for assisting the Royal family. In detailed structural styles, column's size was larger 3cm or more than the upper-class houses, and its height was higher to the degree of 30~60cm. Besides, formality as king's shelter space was raised more in decorating aspects, and Nakseonjae was implemented by getting architectural influences from Qing Dynasty of China. This study induced features of Hanyang's upper-class houses at the 19th century by supplementing distribution and space configurations at existing cases of Seoul and Gyeonggi area together with house diagrams having been collected by Gaokdohyung (site and floor plan) of Jangseogak Library, and confirmed resemblances and differences with Nakseonjae, that is, features of Nakseonjae. Through the result, this study judges a fact that architecture of Nakseonjae seemed to be affected from conveniences of upper-class houses within Hanseong, and also architectural styles and distribution types of Nakseonje would give influences to the upper-class houses.