검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 72

        41.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Methanol as a carbon source in chemical vapor deposition (CVD) graphene has an advantage over methane and hydrogen in that we can avoid optimizing an etching reagent condition. Since methanol itself can easily decompose into hydrocarbon and water (an etching reagent) at high temperatures [1], the pressure and the temperature of methanol are the only parameters we have to handle. In this study, synthetic conditions for highly crystalline and large area graphene have been optimized by adjusting pressure and temperature; the effect of each parameter was analyzed systematically by Raman, scanning electron microscope, transmission electron microscope, atomic force microscope, four-point-probe measurement, and UV-Vis. Defect density of graphene, represented by D/G ratio in Raman, decreased with increasing temperature and decreasing pressure; it negatively affected electrical conductivity. From our process and various analyses, methanol CVD growth for graphene has been found to be a safe, cheap, easy, and simple method to produce high quality, large area, and continuous graphene films.
        4,000원
        43.
        2012.06 구독 인증기관·개인회원 무료
        Acteoside acts as an anti-oxidative activity and anti-apoptosis in the cells. But, it has been not studied on maturation and development of porcine oocytes. The aims of the present study were to examine the effects of acteoside on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. Oocytes were matured in tissue culture medium-199, supplemented with acteoside at various concentrations: 0 (control), 10, 30 and 50 μM. The oocytes maturation rates of groups supplemented with acteoside were no significantly different (81.13, 85.96, 82.95 and 83.68%, respectively). Level of ROS was significantly decreased in acteoside treated group. Furthermore, the parthenogenetic blastocyst rate was significantly improved in 10 μM acteoside treated group compared with control group (44.83 vs. 27.75%). And we investigated effect of acteoside on the oocytes condition represented by cytoplasmic maturation by homogeneous distribution and formation of cytoplasmic organelles and regulation of apoptosis-related genes. In the results. during IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with control oocytes. And reverse transcription polymerase chain reaction (RTPCR) of parthenogenetic blstocysts revealed that acteoside increased the anti-apoptotic genes (Mcl-1, Bcl-2 and Bcl-xL), whereas reduced the expression of pro-apoptotic genes (Bax and Bak). In conclusion, based on the results, the effect of acteoside on IVM was not attractive. However, in acteoside treated group, cytoplasmic maturation seemed to be improved with morphologically uniform distribution of cytoplasmic organelles. Furthermore, embryonic development in acteoside treated group was significantly highly increased than that of non-treated group. Our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes, providing a improved method for porcine oocytes in vitro. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        44.
        2011.05 구독 인증기관·개인회원 무료
        The Samia cynthia ricini (Lepidoptera: Saturniidae) is a commercial silk-producing insect belonging to an insect family Saturniidae in Bombycoidea. The species that has presumably been originated in India, is distributed in India, China, and Japan. Unlikely domestic silkworm the prime host plant for the species is a castor-oil plant (Ricinus communis in Euphorbiaceae). Recently, the eri-silkworm also is reared in Korea and is expected to be utilized for a diverse purpose. In this report, we present the complete mitochondrial genome of the species with the emphasis of a few major characteristics. The 15,384-bp long S. cynthia ricini (Lepidoptera: Saturniidae) mitochondrial genome was amplified into three long overlapping fragments (from COI ~ ND4, ND5 ~ lrRNA, and lrRNA ~ COI) and subsequent several short fragments using the long fragments as temperate. The primers for both long and short fragments were designed solely for lepidopteran genomes, without any species-specific primers. As a usual the genome is composed of 37 genes: 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes, and one large non-coding region termed the A+T-rich region. Arrangement of the genome is identical to those of other lepidopteran mitochondrial genome, but this differs from the common arrangement found in a diverse insect order, by the movement of tRNAMet to a position 5’- up stream of tRNAIle. Unlikely previous report on the start codon for COI gene in Lepidoptera S. cynthia ricini COI gene starts with typical ATT codon located between tRNATyr and the beginning region of COI gene. The 22 tRNAs that are interspersed throughout the mitogenome ranged in length from 62 to 71 bp. All tRNAs but tRNASer(AGN) were shown to be folded into the expected cloverleaf secondary structures. More detailed structural and phylogenetic analyses among Bombycidae and Saturniidae in connection with other families in the Bombycoidea will be performed soon
        45.
        2009.10 구독 인증기관·개인회원 무료
        The devastating insect pests of the tomato (Lycopersicon esculentum) were surveyed in environmentally friendly (no-pesticide and organic) greenhouses located in the provinces of Gyeonggi, Gyeongsang, Gangwon, Chungcheong and Jeju. Whitefly, leaf miner, aphid and moth were recorded as the major pests in these surveys. Among them, whitefly was the most serious pest of greenhouse cultivated tomato and major species was Trialeurodes vaporariorum. The population densities of T. vaporariorum was 0~36 nymph per leaf. Population of moths Spodoptera litura were the highest in summer season. Population of the whitefly was considered to be influenced by the previous cultural methods. Farmers in organic cultivation, used insect natural enemy, commercial EFAM (Environment Friendly Agricultural Material), yellow sticky trap or home made pesticides. Commercial microbial pesticides were applied to evaluate their insecticidal activities against whitefly. The results revealed that microbial pesticides exhibited 65.3 to 100% whitefly nymph mortality. Further, pesticidal activities of Cooking Oil and Yolk (COY), plant extracts and neem oil were evaluated against other tomato pests as well.
        46.
        2009.08 구독 인증기관·개인회원 무료
        The main nutritional problem of sorghum×sudangrass (sudangrass) silage is low quality and dry matter (DM) contents. This experiment was conducted to evaluate whether agricultural byproducts addition of sorghum×sudangrass silage increases DM content and forage quality of the silage. Sorghum×sudangrass silage with added byproducts had low pH values, however sorghum×sudangrass silage (control) had a high pH value because of its high moisture content. Silage added with byproduct had lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents than control silages, while its non-fiber carbohydrate (NFC), and total digestible nutrients (TDN) and lactic acid contents showed the opposite results. Silages added with crushed rice and green grain of rice were higher in lactic acid content than othor treatments as well as high DM, NFC, and TDN contents. Silage added with crushed rice and green grain of rice can be recommended as the most effective treatment for increasing forage quality and DM content of sorghum×sudangrass silage.
        47.
        2005.06 구독 인증기관 무료, 개인회원 유료
        Cloned calves derived from somatic cell nuclear transfer (SCNT) have been frequently lost by sudden death at 1 to 3 month following healthy birth. To address whether placental anomalies are responsible for the sudden death of cloned calves, we compared protein patterns of 2 placentae derived from SCNT of Korean Native calves died suddenly at two months after birth and those of 2 normal placentae obtained from AI fetuses. Placental proteins were separated using 2-Dimensional gel electrophoresis. Approximately 800 spots were detected in placental 2-D gel stained with coomassie-blue. Then, image analysis of Malanie III (Swiss Institute for Bioinformatics) was performed to detect variations in protein spots between normal and SCNT placentae. In the comparison of normal and SCNT samples, 8 spots were identified to be up-regulated proteins and 24 spots to be down-regulated proteins in SCNT placentae, among which proteins were high mobility group protein HMG1, apolipoprotein A-1 precursor, bactenecin 1, tropomyosin beta chain, H+-transporting ATPase, carbonic anhydrase II, peroxiredoxin 2, tyrosine-rich acidic matrix protein, serum albumin precursor and cathepsin D. These results suggested that the sudden death of cloned calves might be related to abnormal protein expression in placenta.
        4,000원
        48.
        1998.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        청둥오리의 압란유의 기능성 특성을 알아보기 위하여 흰쥐를 모델로 하여 streptozotocin(STZ)을 투여하여 당뇨병을 유발시킨 다음, 혈액 중의 당 농도, 지질의 변화 및 동맥경화 지표와의 상관관계를 검토하였고, 또한 Sarcoma-180을 쥐에 이식하여 이에 대한 항암 효과를 실험하였다. STZ로 당뇨병을 유발시킨 흰쥐를 청둥오리의 압란유를 15일간 투여하였던 바 혈중의 당 농도는 정상상태로 유지되었고 phospholipid 및 triglyceride의 함량은 STZ를 처리한 압란유의 경우에는 증가하였으나, STZ 처리군에 압란유를 투여하였을 때 감소되었다. 혈중 total cholesterol, LDL+VLDL의 cholesterol 및 동맥경화의 지표는 STZ 처리군에서는 증가하였으나, 시료를 150㎎/㎏ 투여시에는 감소하였다. 한편 Sarcoma-180에 대한 성장억제율은 압란유를 150㎎/㎏ 투여시 63.89%로 나타났고 수명연장 실험에서는 압란유의 경우 15.4%로 나타났다.
        4,000원
        49.
        1996.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        배관을 구속시키기 위한 원동형 배관 지지대 (Trunnion Pipe Support) 까 부착된 uß 간의 응-딱해석플 위하 여 유한요소해석을 사용하였다. 해석션파로 부터 얻어진 응역은 두께에 대한 평칸(막응역) 넷 선행 응→박( ""," 힘응력) 으로 분류 되었므며, 분류된 응벽값은 암략에 악한 언차응략겨l 수 (B 1 ) 와 이자응역겨l 수 (C 1 ) , 보멘트에 의한 일차응력계수 (B" , Bιr) 와 이차응략셰수 (C객, C!T) 플- 추성하시 위하여 ASME Code 에 성의뭔것파 일치 하게 해석되었다 무차원의 함수로써 응력 세수에 대한 경험식 얀 새만히기 위하여 여서 ~i~ l;'l 의 해삭 2~ 수행하 였다.
        4,000원
        50.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        최근 기후변화와 도시화로 인한 수재해 문제가 증가하고 있으며, 이에 대응방안인 저영향개발(Low-Impact Development, LID) 기법에 관한 연구가 확대되고 있다. LID 기법은 도시 내의 우수유출수를 저감시켜 다양한 수재해 문제를 친환경적으로 제어하고, 도시 개발 이전의 물순환 체계로 회복시키는 기술이다. 하지만 LID 기법에 관한 정량적 데이터가 부족한 실정이다. 따라서 본 연구에서는 저류형 LID 기술인 식생화분(Planter Box)의 Curve Number (CN)값을 산정하여, 물순환(침투, 유출, 월류수) 분석을 실시하였다. Planter Box의 물순환 분석에 관한 강우강도 시나리오(60.4 mm/hr, 83.1 mm/hr, 97.4 mm/hr, 108.2 mm/hr)는 부산시 확률강우강도표(2010)를 이용하여 선정하였다. 실험 결과는 건물화분3 (BPB-3)과 거리화분3(SPB-3)에서 우수저류율이 각각 43.5%∼52.9%, 33.4%∼39.0%로 나타났다. 또한 BPB-3에서 CN값은 평균 83이 산출되었고, Horton 침투능 곡선식 적용에 따른 우수유출효과는 17%∼96%로 나타났다.
        51.
        2018.04 KCI 등재 서비스 종료(열람 제한)
        흡연 유무의 남성을 대상으로 뇌 회백질의 손상 유무를 파악 할 수 있는 확산텐서영상을 검사하여 영상을 획득 한 후 Tract-Based Spatial Statics(TBSS)방법으로 뇌 회백질 부위의 기저핵 신경섬유로의 비등방도 FA(fractional anisotropy)값을 측정 분석한 결과 모든 영역에서 흡연자가 비흡연자보다 비등방성 측정값이 낮게 관찰되었으며 FA값은 통계적으로 유의하였다. 본 연구의 측정한 FA결과 값으로 추측하자면 즉, 흡연이 뇌 회백질 기저핵의 모든 해부학적 미세 구조성 변화에 크게 영향을 미치며 신경 섬유로를 손상시키고 이와 관련된 기능적 이상에 영향을 준다고 할 수 있다.
        52.
        2013.12 서비스 종료(열람 제한)
        Retroperitoneal liposarcoma is an infrequent malignancy in adulthood arising from mesenchymal tissues. It is often diagnosed when the tumor becomes too large, suppressing adjacent organs and causing symptoms. We report on a case of giant liposarcoma found in a 77-year-old female undergoing surgical resection.
        1 2 3 4