• Asian-Australasian Journal of Animal Sciences
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• 제29권4호
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• pp.487-499
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• 2016

The aim of the present study was to examine the effects of testosterone (T) and estradiol-$17{\beta}$ ($E_2$) on the production of progesterone ($P_4$) by granulosa cells, and of the $E_2$ on the production of $P_4$ and T by theca internal cells. In the first experiment, granulosa cells isolated from the largest ($F_1$) and third largest ($F_3$) preovulatory follicle were incubated for 4 h in short-term culture system, $P_4$ production by granulosa cells of both $F_1$ and $F_3$ was increased in a dose-dependent manner by ovine luteinizing hormone (oLH), but not T or $E_2$. In the second experiment, $F_1$ and $F_3$ granulosa cells cultured for 48 h in the developed monolayer culture system were recultured for an additional 48 h with increasing doses of various physiological active substances existing in the ovary, including T and $E_2$. Basal $P_4$ production for 48 h during 48 to 96 h of the cultured was about nine fold greater by $F_1$ granulosa cells than by $F_3$ granulosa cells. In substances examined oLH, chicken vasoactive intestinal polypeptide (cVIP) and T, but not $E_2$, stimulated in a dose-dependent manner $P_4$ production in both $F_1$ and $F_3$ granulosa cells. In addition, when the time course of $P_4$ production by $F_1$ granulosa cells in response to oLH, cVIP, T and $E_2$ was examined for 48 h during 48 to 96 h of culture, although $E_2$ had no effect on $P_4$ production by granulosa cells of $F_1$ during the period from 48 to 96 h of culture, $P_4$ production with oLH was found to be increased at 4 h of the culture, with a maximal 9.14 fold level at 6 h. By contrast, $P_4$ production with cVIP and T increased significantly (p<0.05) from 8 and 12 h of the culture, respectively, with maximal 6.50 fold response at 12 h and 6, 48 fold responses at 36 h. Furthermore, when $F_1$ granulosa cells were precultured with $E_2$ for various times before 4 h culture with oLH at 96 h of culture, the increase in $P_4$ production in response to oLH with a dose-related manner was only found at a pretreatment time of more than 12 h. In the third experiment, theca internal cells of $F_1$, $F_2$ and the largest third to fifth preovulatory follicles ($F_{3-5}$) were incubated for 4 h in short-term culture system with increasing doses of $E_2$. The production of $P_4$ and T by theca internal cells were increased with the addition of $E_2$ of $10^{-6}M$. These increases were greater in smaller follicles. These results indicate that, in granulosa cells of the hen, T may have a direct stimulatory action in the long term on $P_4$ production, and on $E_2$ in long-term action which may enhance the sensitivity to LH for $P_4$ production, and thus, in theca internal cells, $E_2$ in short term action may stimulate the production of $P_4$ and T.

• 한국환경성돌연변이발암원학회지
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• 제19권1호
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• pp.34-38
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• 1999

Fumonisin B1 is a secondary metabolite of Fusarium moniliforme, a contaminant of corn and corn product. Fumonisin B1 has been shown to be responsible for major toxicological effects of the fungus in rats, horses, and pigs. Fumonisin B1 induced λ DNA fragmentation, which was increased with incubation time, reducing agent NADPH and metal ion (Cu2+). The DNA damage was inhibited by dimethyl sulfoxide (DMSO) or mannitol as radical scavenger for free radicals. DNA fragmentation, induced by fumonisin B1 in the presence of 1 mM NADPH and 0.1 mM CuCl2, was inhibited by 100 mM DMSO. By the in vitro reaction of fumonisin B1 with supercoiled plasmid pBR322 DNA, plasmid DNA was relaxed, eventually linearized in the agarose gel electrphoresis. From rifampicin sensitive E. coli CSH138 in bacterial mutagenesis system, the rifampicin resistant E. coli mutants were obtained by fumonisin B1. These results suggest that fumonisin B1 may be a possible environmental mutagen in bacterial mutagen assay system.

• ETRI Journal
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• 제32권4호
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• pp.520-529
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• 2010

In this paper, we present a low-voltage low-dropout voltage regulator (LDO) for a system-on-chip (SoC) application which, exploiting the multiplication of the Miller effect through the use of a current amplifier, is frequency compensated up to 1-nF capacitive load. The topology and the strategy adopted to design the LDO and the related compensation frequency network are described in detail. The LDO works with a supply voltage as low as 1.2 V and provides a maximum load current of 50 mA with a drop-out voltage of 200 mV: the total integrated compensation capacitance is about 40 pF. Measurement results as well as comparison with other SoC LDOs demonstrate the advantage of the proposed topology.

• 동력기계공학회지
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• 제15권3호
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• pp.31-37
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• 2011

직조 금속 스크린 리브(rib) 이 바닥에 설치된 사각 덕트에서 열전달과 유체유동의 압력강하를 측정하기 위해 실험적 연구를 수행하였다. 시험부의 치수는 200 mm(W) ${\times}$ 40 mm(H) ${\times}$ 712 mm(L)이고 수력직경은 66.6 mm이다. 입구영역에는 1.72m 길이의 가열되지 않은 동일한 치수의 채널을 설치하였다. 메쉬가 다른 4가지의 직조금속 스크린 리브에 대해 측정하였다. 그리고 비교를 위해 일체형 리브에 대해서도 측정하였다. 국부 열전달 계수의 측정에는 스테인레스 강제 포일(foil) 히터와 T형 열전대률 이용하였다. 레이놀즈 수는 23,000에서 58,000의 범위이다. 덕트의 수력직경($D_h$)에 대한 직조 금속 리브의 높이(e)의 비($e/D_h$)는 0.075 이고 리브 간격(p)과 높이의 비(p/e)는 10이다. 실험 결과 메쉬가 없는 일체형 리입에서 가장 누셀트 수와 마찰계수가 컷다.

• 에너지공학
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• 제12권2호
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• pp.93-100
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• 2003

An estimation methodology of the mass and energy (M/E) release due to the main steam line break (MSLB) has been developed with the RETRAN-3D code. In the case of equipment qualification (EQ), the over-estimated temperature would exceed the design limits of some cables or valves. In order to have a more flexible EQ profiles from the MSLB M/E release, the methodology with the best-estimated code was used. The major conditions affecting the MSLB M/E were found to be the initial SG level, heat transfer between primary and secondary sides, power level, operable protection system, main or auxiliary feedwater availability, and break conditions. The RETRAN-3D models were developed for the Kori unit 1 (KRN-1) which is typical two loop Westinghouse (WH) designed plant. Particularly, a detailed model of the steam generators was developed to estimate a more realistic two-phase heat transfer effect of the steam flow. After the modeling, the methodology has been developed through the sensitivity analyses. The M/E release data generated from the analyses have been used as the input to the inside containment pressure and temperature (P/T) analysis. According to the results at the point of view containment P/T, the Kori unit 1 can have more margin of 5∼15 ㎪ in pressure and 8∼15$^{\circ}C$ in temperature.

• Animal Bioscience
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• 제35권7호
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• pp.989-998
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• 2022

Objective: This study investigated the effects of intrauterine growth restriction (IUGR) during late pregnancy on the cell growth, proliferation, and differentiation in ovine fetal thymuses. Methods: Eighteen time-mated Mongolian ewes with singleton fetuses were allocated to three groups at d 90 of pregnancy: restricted group 1 (RG1, 0.18 MJ ME/body weight [BW]^0.75/d, n = 6), restricted group 2 (RG2, 0.33 MJ ME/BW^0.75/d, n = 6) and control group (CG, ad libitum, 0.67 MJ ME/BW^0.75/d, n = 6). Fetuses were recovered at slaughter on d 140. Results: The G0/G1 phase cell number in fetal thymus of the RG1 group was increased but the proliferation index and the expression of proliferating cell nuclear antigen (PCNA) were reduced compared with the CG group (p<0.05). Fetuses in the RG1 group exhibited decreased growth hormone receptor (GHR), insulin-like growth factor 2 receptor (IGF-2R), and their mRNA expressions (p<0.05). For the RG2 fetuses, there were no differences in the proliferation index and PCNA expression (p>0.05), but growth hormone (GH) and the mRNA expression of GHR were lower than those of the CG group (p<0.05). The thymic mRNA expressions of cyclin-dependent protein kinases (CDKs including CDK1, CDK2, and CDK4), CCNE, E2-factors (E2F1, E2F2, and E2F5) were reduced in the RG1 and RG2 groups (p<0.05), and decreased mRNA expressions of E2F4, CCNA, CCNB, and CCND were occurred in the RG1 fetuses (p<0.05). The decreased E-cadherin (E-cad) as a marker for epithelial-mesenchymal transition (EMT) was found in the RG1 and RG2 groups (p<0.05), but the OB-cadherin which is a marker for activated fibroblasts was increased in fetal thymus of the RG1 group (p<0.05). Conclusion: These results indicate that weakened GH/IGF signaling system repressed the cell cycle progression in G0/G1 phase in IUGR fetal thymus, but the switch from reduced E-cad to increased OB-cadherin suggests that transdifferentiation process of EMT associated with fibrogenesis was strengthened. The impaired cell growth, retarded proliferation and modified differentiation were responsible for impaired maturation of IUGR fetal thymus.

• Journal of Oral Medicine and Pain
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• 제10권1호
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• pp.33-39
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• 1985

Changes of occlusal contacts after E.M.G. biofeedback therapy with D.D.S. (Self control system, EMG 220, Sandiago California) was investigated in 20 SNUH students and residents with normal occlusion. Treatment time was 30 minutes on every subject. Occlusal contacts of before biofeedback therapy were taken at 4: 00 P.M. and that of after biofeedback therapy were taken at 4:40 P.M. Author compared the occlusal contacts before biofeedback therapy with that of after biofeedback therapy. The obtained results were as follow : 1. The number of occlusal contacts was 23.9, before biofeedback therapy and, 26.3, after biofeedback therapy. 2. The percentage of accentuated contact to diffuse contact was 78.5%, before treatment and 38.8% after treatment. 3. 6 heaviest contacts were changed 4.3 teeth per one subject after biofeedback therapy.

• Journal of Animal Science and Technology
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• 제53권5호
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• pp.419-428
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• 2011

본 연구는 구멍갈파래 급여가 육계 혈액 내 항산화, 면역조절 효과에 미치는 영향을 구명하기 위해 실시 하였으며, 이를 위해 LPS로 염증반응이 유도된 육계에서 혈액 SOD 유사 활성, immunoglobulin 농도 및 비장 조직 내 cytokine mRNA 발현을 조사하였다. 공시계로는 1일령 Ross종 육계수컷 96수를 선별하여, 육계전기(0~3주), 육계후기(3~5주)의 5주 동안 사양시험을 실시하였다. 처리당 24수(3수${\times}$8반복)씩 4처리구에 총 96수를 임의배치 하여 실시하였다. 시험구 배치는 무첨가구(Negative Control ; NC), 시판 면역증강제 첨가구(Positive Control ; PC, ${\beta}$-glucan 25 ppm), 구멍갈파래 분말 3% 첨가구(Ulva pertusa kjellman Powder ; Ulva P) 및 구멍갈파래 추출물 0.3% 첨가구(Ulva pertusa kjellman Extract ; Ulva E)로 배치하였다. 혈액 내 SOD 유사 활성을 분석한 결과 구멍갈파래 첨가구 (Ulva P, Ulva E)는 무첨가구와 면역제제 첨가구보다 높은 항산화 활성을 가지는 것으로 나타났다(P<0.05). immunoglobulin 농도에서 IgA와 IgG 농도는 처리구간의 차이가 나타나지 않았지만 IgM농도에서 구멍갈파래 추출물 처리구가 무첨가구에 비해 유의적으로 낮은 수준을 나타냈다(P<0.05). 이는 구멍갈파래 추출물이 LPS에 대한 면역자극을 조절하여 과잉면역반응을 억제한 것으로 사료된다. 비장 조직 내 cytokine mRNA 발현량을 조사한 결과 IL-1, IL-2 및 IL-6에서 처리구별 공통적인 차이를 나타내었는데 구멍갈파래 처리구(Ulva P, Ulva E)의 mRNA 발현 비율이 무첨가구와 면역제제 처리구에 비해 낮았으며, 구멍갈파래 처리 간 비교에서 구멍갈파래 추출물이 분말보다 더 낮았다(P<0.05). iNOS의 경우 구멍갈파래 분말 첨가구는 무첨가구와 유의적인 차이가 없었지만 구멍갈파래 추출물 첨가구는 모든 처리구보다 iNOS의 발현이 낮았다(P<0.05). 구멍갈파래 분말과 추출물은 LPS 주입에 의한 염증 관련 사이토카인 mRNA 발현을 억제하는 경향을 나타내며, 특히 구멍갈파래 추출물이 발현억제 효과가 더 높은 것으로 확인되었다(P<0.05). 본 연구 결과 육계에서 구멍갈파래 급여는 염증, 질병의 원인인 활성산소 제거에 효과가 있다고 사료된다. 특히 구멍갈파래 추출물은 혈액 내 IgM의 농도를 조절하여 외부항원에 대한 과잉면역반응을 억제하고 염증 관련 cytokine mRNA 발현을 억제하여 육계 면역조절에 긍적적인 영향을 미치는 것으로 사료된다.

• 한국토양비료학회지
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• 제45권2호
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• pp.280-286
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• 2012

본 연구는 바이오가스 생산시설과 연계하는 시설채소 오이의 청정에너지 농업 시스템 구축을 위하여 물질 및 에너지 수지 분석하였으며, 물질 및 에너지 수지 분석을 통해 시설채소 청정에너지 시스템의 도입 방안을 검토하였다. 시설 채소 오이 재배지의 연간 가온용 순에너지요구량 ($E_{YHED}$)을 충족시키는 바이오가스양은 촉성과 반촉성 재배에서 각각 9,482, $2,636Nm^3\;10a^{-1}$ (60% 메탄함량을 기준)이었으며, 바이오가스 생산을 위해서 각각 양돈슬러리 511, $142m^3\;10a^{-1}$가 요구되었다. 해당 양돈슬러리에서 발생하는 질소(N)와 인산 ($P_2O_5$)은 촉성재배에서 1,788, $511kg\;10a^{-1}$, 반촉성 재배에서 497, $142kg\;10a^{-1}$이었으며, 비료성분의 농지환원을 위해서는 촉성 재배의 경우 질소시비 기준 7.5 ha, 반촉성 재배의 경우 질소시비 기준 2.1 ha의 오이재배 면적이 요구되었다. 가온기간 중 촉성 재배에서 일일 가온에너지 요구량 ($E_{i,DHED}$)은 최소 7.7, 최대 515.1, 평균 $310.2Mcal\;10a^{-1}\;day^{-1}$을 나타냈으며, 반촉성 재배에서 일일 가온에너지 요구량 ($E_{i,DHED}$)은 최소 5.3, 최대 258.0, 평균 $165.1Mcal\;10a^{-1}\;day^{-1}$을 나타났다. 촉성 및 반촉성 재배에서 일일 가온에너지 요구량 ($E_{i,DHED}$)의 평균치를 기준으로 산출한 바이오가스 생산 시설의 양돈슬러리 유입용량은 각각 3.3, $1.7m^3\;day^{-1}$이었으며, 일일 가온에너지 요구량 ($E_{i,DHED}$)의 최대값을 기준으로 한 유입용량은 각각 5.4, $2.7m^3\;day^{-1}$로 나타났다. 또한 소화액의 처리측면에서 지역특성에 따라 액비이용을 고려한 바이오가스 생산시설 용량설계와 하절기의 잉여 바이오가스 활용 방안의 모색이 필요하였다.

• Journal of Nutrition and Health
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• 제50권3호
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• pp.236-245
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• 2017

본 연구에서는 난소절제 흰쥐에 구아바잎 추출물을 8주 동안 경구투여한 결과 난소절제 대조군인 OVX군과 비교시 체중 증가량 및 혈중 유리지방산이 유의적으로 감소된 것을 확인하였다. 또한 간 내 중성지방 농도가 $OVX{\cdot}GL$군과 $OVX{\cdot}GH$군에서 모두 유의적으로 감소하였으며 혈중 항산화 효소인 GPx 농도가 유의적으로 증가하였다. 간 내 항산화 효소 및 eNOS의 mRNA 발현 정도를 측정한 결과 OVX군에 비해 구아바잎 추출물 급여군인 $OVX{\cdot}GL$군과 $OVX{\cdot}GH$군에서 모두 Nrf2 및 CAT의 mRNA 발현 정도가 유의적으로 증가하였으며 eNOS또한 $OVX{\cdot}GH$군에서 유의적으로 증가함을 확인할 수 있었다. 따라서 본 연구의 결과를 종합해 볼 때 구아바잎 추출물 경구투여는 항산화 효소의 활성을 증가시키고 혈관내피세포의 기능을 향상시킴으로써 폐경 후 나타날 수 있는 혈관질환과 산화스트레스로 인한 대사적 장애 개선에 도움이 될 것으로 사료된다.