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        검색결과 533

        223.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        콩은 식물성 단백질 및 지방의 주요 공급원이고 콩 종실에는 기능성 성분이 많이 함유되어져 있어 소비 가 점차 증가하고 있지만 Lipoxygenase, Kunitz Trypsin inhibitor, 7S α′-subunit 단백질과 같은 성 분들이 존재하는데 이는 품질과 영양가치를 떨어뜨리고 섭취시 알러지를 일으키기도 한다. 콩에서 유전적 으로 이러한 성분이 결핍되어져 있는 유전자형의 선발은 품질이 우수한 콩 육종의 기초단계이다. “개척2 호”와 PI506876의 교배로부터 434개의 F2 종자를 얻어 F2 종자의 일부를 사용하여 SDS-PAGE로 각각 의 종자를 분석한 결과 Lipoxygenase와 Kunitz Trypsin inhibitor 및 7S의 α′-subunit 단백질이 모두 결핍되어져 있는 lx1lx1lx2lx2lx3lx3titicgy1cgy1 유전자형을 가진 종자를 선발하여 F2 식물체로 길러 성 숙 후 F3 종자를 수확하였다. F3 종자로부터 Lipoxygenase, Kunitz Trypsin inhibitor, 7S α′-subunit 단백질이 모두 결핍되어져 있음을 재확인하였으며 선발된 종자는 고품질 콩 품종 육성에 유용하게 활용될 것으로 기대된다.
        4,000원
        226.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 추출물 형태에 따른 파프리카 첨가 식이가 고콜레스테롤 식이 흰쥐의 혈청 지질과 α-tocopherol 농도에 미치는 영향을 알아보기 위해 Sprague-Dawley 수컷 25마리를 대조군(NC), 고콜레스테롤군(HC), 고콜레스테롤+동결 건조 파프리카 분말 섭취군(HC-FDP), 고콜레스테롤+파프리카 물 추출물 섭취군(HC-WEP), 고콜레스테롤+파프리카 에탄올 추출물 섭취군(HC-EEP)으로 나누어 실험 식이를 6주간 공급하였다. 6주 후 HC군과 파프리카 급여군에서 체중 증가는 각각 85.2%와 65.5~68.88%로 HC군에서 체중이 유의적으로 증가하였다. 그리고 내장지방 무게는 HC군보다 파프리카 급여군에서 감소하였으며, 파프리카 급여군의 중성지질, 총 콜레스테롤, LDL-콜레스테롤과 atherogenic index 역시 HC군보다 유의적으로 감소하였다(p<0.05). 그리고 파프리카 급여군들 중에서는 HC-EEP 군이 혈청지질 농도 감소 효과가 가장 큰 것으로 나타났다. 혈청 α-tocopherol 농도는 HC-EEP에서 30.5±0.6μMol/ℓ로 가장 높았고, 그 다음으로는 HC-WEP(30.0±0.8μMol/ℓ)>HC-FDP(29.1±0.5μMol/ℓ)>HC(27.7±0.3μMol/ℓ)이었다. 이는 고콜레스테롤 식이에 의한 산화적 스트레스를 감소시키기 위하여 혈청 α-tocopherol이 소모되는 것을 파프리카 급여로 절약 하는 효과를 나타낸 것으로 사료된다. 따라서 본 연구를 통해 파프리카는 혈중 지질 농도 저하 효과를 보였고, α-tocopherol 절약 작용을 통해 체내 항산화제로서 활용 가능성을 확인할 수 있었다.
        4,000원
        227.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A phytoremediation study has been conducted to see if some known aquatic plants can remove the pesticides, endosulfan-α, β and fenitrothion which are frequently used in the crop protection and golf course management, and are likely to exist as residual pollutants in the aquatic ecosystems. Among the five aquatic plants tested in the microcosms, water lily Nymphaea tetragona Georgi showed the highest degradation efficacies (85~95%) for the three pesticides as opposed to the control(13~26%). The efficacies for the other plants were in the range of 46~80% in the order of Pistia stratiotes, Cyperus helferi, Eichhornia crassipes, and Iris pseudoacorus. Fenitrothion, an organo-phosphorus pesticide, was much more vulnerable to the phytoremediation than the organo-chlorine pesticides, endosulfan-α and endosulfan-β. The kinetic rate constants (min-1) for removal of the three pesticides were more than 10 times higher than the control (non-planting) in case of Nymphaea tetragona Georgi. This aquatic plant showed kinetic rate constants about 2 times as much as the lower kinetic rate constants shown by Iris pseudoacorus. The reason for the highest degradation efficacy of water lily would be that the plant can live in the sediment and possess roots and broad leaves which could absorb or accumulate and degrade more pollutants in association with microbes. These results indicate that some of the selected aquatic plants planted near the agricultural lands and wetlands could contribute to remediation of pesticides present in these places, and could be applicable to protection of the aquatic ecosystems.
        4,000원
        228.
        2010.06 구독 인증기관 무료, 개인회원 유료
        Chronic inflammatory diseases such as Crohn′s disease and ulcerative colitis are associated with increased risk of colon adenocarcinoma. Apoptic induction of colon cancer cells by cytokines and death receptors is an important anti-cancer therapy. We observed that co-administration of TNFα and IFNγ in human colon cancer cell line, HCT116, resulted in cell death and expression of IL-32. Cleavage forms of caspase-3, caspase-9, and PARP were increased in TNFα / IFNγ-treated HCT116. mRNA expression of death receptors, including TNFR1 and Fas were not changed and NO generation was not induced by combination of TNFα and IFNγ. However, mRNA expression of IL-32α, β, and γ was increased in TNFα / IFNγ-treated HCT116. To determine the effect of IL-32 in HCT116 cell apoptosis by TNFα / IFNγ stimulation, IL-32 siRNA-transfected HCT116 cells were cultured with TNFα / IFNγ and cell proliferation was measured. IL-32 siRNA induced slight recovery of cell viability of TNFα / IFNγ-stimulated HCT116. These results suggest that IL-32 is not directly related to apoptosis of HCT116 by TNFα / IFNγ stimulation. However, IL-32 expression by TNFα or TNFα / IFNγ in a colon cancer cell line is very interesting because of the unknown effect of IL-32 in colon cancer. Our study will contribute to development of studies for IL-32 function in human colon cancer and anti-cancer therapies using cytokines.
        4,000원
        229.
        2010.06 구독 인증기관 무료, 개인회원 유료
        Enterococcus faecalis, a gram-positive bacterium, has been implicated in endodontic infections, particularly in chronic apical periodontitis. Proinflammatory cytokines, including tumor necrosis factor-α (TNF-α), are involved in the pathogenesis of these apical lesions. E. faecalis has been reported to stimulate macrophages to produce TNF-α. The present study investigated the mechanisms involved in TNF-α production by a murine macrophage cell line, RAW 264.7 in response to exposure to E. faecalis. Both live and heat-killed E. faecalis induced high levels of gene expression and protein release of TNF-α. Treatment of RAW 264.7 cells with cytochalasin D, an inhibitor of endocytosis, prevented the mRNA up-regulation of TNF-α by E. faecalis. In addition, antioxidant treatment reduced TNF-α production to baseline levels. Inhibition of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein (MAP) kinase also significantly attenuated E. faecalis-induced TNF-α expression by RAW 264.7 cells. Furthermore, activation of NF-κB and AP-1 in RAW 264.7 cells was also stimulated by E. faecalis. These results suggest that the phagocytic uptake of bacteria is necessary for the induction of TNF-α in E. faecalis-stimulated macrophages, and that the underlying intracellular signaling pathways involve reactive oxygen species, ERK, p38 MAP kinase, NF-κB, and AP-1.
        4,000원
        230.
        2010.05 구독 인증기관·개인회원 무료
        The phylogenetic relationships among true butterfly families (superfamily Papilionoidea) have been a matter of substantial controversy, and that debate has led to several competing hypotheses. Two of the most compelling of those hypotheses involve the relationships of (Nymphalidae + Lycaenidae) + (Pieridae + Papilionidae) and (((Nymphalidae + Lycaenidae) + Pieridae) + Papilionidae). In this study, approximately 3,500 nucleotide sequences from cytochrome oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA), and elongation factor-1 alpha (EF-1α) were sequenced from 83 species belonging to four true butterfly families, along with those of eight outgroup species belonging to the skipper family (superfamily Hesperioidea). These sequences were subjected to phylogenetic reconstruction via Bayesian Inference (BI), Maximum Likelihood (ML), and Maximum Parsimony (MP) algorithms. All phylogenetic analyses among the four true butterfly families strongly indicated a sister relationship between the Nymphalidae and Lycaenidae on one hand, and relatively strongly indicated a sister relationship between the Pieridae and Papilionidae on another hand, thus supporting the hypothesis: (Nymphalidae + Lycaenidae) + (Pieridae + Papilionidae).
        231.
        2010.03 구독 인증기관 무료, 개인회원 유료
        Glycoprotein hormones have a common α-subunit that is involved in the signaling pathway together with G protein, adenylcyclase and cAMP induction; however, it is an unclear how this common structure is related to hormonal action. To determine the biological functions of the COOH-terminal amino acids in the α-subunit of these glycoprotein hormones, a tethered-molecule was constructed by fusing the NH2-terminus of the α-subunit to the COOH-terminus of the β-subunit of equine chorionic gonadotropin (eCG). The following deletion mutants were created by PCR; Ile was inserted at position 96 to form Δ96, Lys was substituted at position 95 to form Δ95, His was inserted at position 93 to form Δ93 and Tyr was substituted at position 87 to form Δ87. Each mutant was transfected into CHO-K1 cells. Tethered-wt eCG, and Δ96, Δ95, and Δ93 mutants were efficiently secreted into the medium but the Δ87 mutant was not secreted. Interestingly, the RT-PCR, real-time PCR, and northern blot analyses confirmed that the RNA was transcribed in the Δ87 mutant. However, the Δ87 mutant protein was not detected in the medium or the intracellular fraction of the cell lysates. The LH- and FSH-like activities of the recombinant proteins were assayed in terms of cAMP production using rat LH/CG and rat FSH receptors. The metabolic clearance rate (MCR) was determined by injecting rec-eCG (2 IU) into the tail vein. The Δ95 and Δ93 mutants were completely inactive in both the LH- and FSH-like activity assays. The Δ96 mutant showed slight activity in the LH-like activity assay. In comparison to the wild type, the activity of the Δ96 mutant in the FSH-like activity assay was the highest among all the mutants. The MCR assay in which rec-eCG was injected showed a peak at 10 min in all the treatment groups, which disappeared 4 h after injection. These results imply a direct interaction between the receptor and the COOH-terminal region of the α-subunit. The data also reveal a significant difference in the mechanism by which the eCG hormone interacts with the rLH and rFSH receptors. The COOH-terminal region of the α-subunit is very important for the secretion and functioning of this hormone.
        4,000원
        232.
        2010.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The unique features of spark plasma sintering process are the possibilities of a very fast heating rate and a short holding time to obtain fully dense materials. -SiC powder with 0, 2, 6, 10 wt% of -SiC particles (seeds) and 4 wt% of Al-B-C (sintering aids) were spark plasma sintered at for 10 min. The heating rate, applied pressure and sintering atmosphere were kept at , 40 MPa and a flowing Ar gas (500 CC/min). Microstructural development of SiC as function of seed content and temperature during spark plasma sintering was investigated quantitatively and statistically using image analysis. Quantitative image analyses on the sintered SiC ceramics were conducted on the grain size, aspect ratio and grain size distribution of SiC. The microstructure of SiC sintered up to consisted of equiaxed grains. In contrast, the growth of large elongated SiC grains in small matrix grains was shown in sintered bodies at and the plate-like grains interlocking microstructure had been developed by increasing sintering temperature. The introduction of -SiC seeds into -SiC accelerated the grain growth of elongated grains during sintering, resulting in the plate-like grains interlocking microstructure. In the -SiC seeds added in -SiC, the rate of grain growth decreased with -SiC seed content, however, bulk density and aspect ratio of grains in sintered body increased.
        4,000원
        233.
        2009.12 구독 인증기관 무료, 개인회원 유료
        The mechanisms underlying the actions of the antioxidants upon reactive oxygen species (ROS) generation by NADPH oxidase complex have remained uncertain. In this study, we investigated NADPH oxidase activity and the role of antioxidant enzymes upon the generation of ROS during hypoxic stress. ROS generation was found to increase in the mouse kidney under hypoxic stress in a time-dependent manner. Moreover, we found in MCT cells that hypoxia-induced hydrogen peroxide production was decreased by NAC pretreatment. We further analyzed HIF-1α, PHD2 and VHL expression in the NAC-pretreated MCT cells and assessed the response of antioxidant enzymes at the transcriptional and translational levels. SOD3 and Prdx2 were significantly increased during hypoxia in the mouse kidney. We also confirmed in hypoxic Prdx2-l- and SOD3 transgenic mice that erythropoietin (EPO) is transcriptionally regulated by HIF-1α. In addition, although EPO protein was found to be expressed in a HIF-1α independent manner in three mouse lines, its activity differed markedly between normal and Prdx2-l-/SOD3 transgenic mice during hypoxic stress. In conclusion, our current results indicate that NADPH oxidase-mediated ROS generation is associated with hypoxic stress in the mouse kidney and that SOD3 and Prdx2 cooperate to regulate cellular redox reactions during hypoxia.
        4,000원
        234.
        2009.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cellulose triacetate (CTA) was prepared from cotton linter and pulps which contain various contents of α-cellulose. CTA which contains 2.8 of degree of substitution (DS) and 222 of degree of polymerization (DP) was obtained from V-81 pulp under the heterogeneous system. The DS was measured by the titration method, and the DP was obtained by measurement of viscosity. FT-IR spectometer (FT-IR 6300, JASCO) was used to analyze the chemical structure of raw materials and cellulose triacetate, and X-ray diffractometer (X-pert MPD PW3040, Philips) was used to confirm the crystal structure and to calculate the relative crystallinity index (RCI). As α-cellulose content in pulp increased, the acetylation yield increased. Besides with a kind of pulp, it contains insoluble residue which was mainly formed due to the formation of glucomannan triacetate and xylan diacetate during the esterification.
        4,000원
        235.
        2009.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Epigallocatechin-3-gallate (EGCG) and theaflavins (TF) are polyphenols included in green and black teas, respectively. Both green and black teas have been studied for their potential health benefits for cancer. Hypoxia-inducible factor (HIF) has been implicated multiple physiological and pathophysiological pathways, particularly, oncogenesis. But, the molecular pathways that govern the cell response to EGCG are not fully elucidated. The present study investigated the intracellular mechanism in oral squamous cell carcinoma (OSCC) cells treated with EGCG, focusing on HIF-1 expression and its effect on epithelial phenotype. EGCG decreased phosphorylated Raf-1 protein in YD 8 OSCC cell, but B-raf protein was not affected at all by EGCG and TF. In addition, we here found that EGCG regulated HIF-1α expression independent of Raf-1 protein. Taken together with our previous result, the result imply that EGCG is attributed to the HIF-1α expression via Raf/MEK/ERK pathway, and the HIF-1α expression is associated with the change of epithelial phenotype in OSCC cell.
        4,000원
        236.
        2009.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        인간과 가축의 영양을 위한 식물성 단백질의 주요 공급원은 콩이며 콩 단백질은 영양 및 기능성면에서 우수하여 소비가 점차 증가하고 있다. 그러나 콩 단백질에는 알러지를 일으키고 영양가치를 떨어뜨리는 성분도 포함되어져 있다. 7S 및 11S 글로블린은 콩 저장단백질의 대부분을 차지하며 7S는 영양가치가 떨어지고 7S의 함량을 줄어든 콩 계통 육성에 대한 관심이 높아지고 있다. 7S 성분중의 하나인 α′-subunit의 유전양상을 파악하기 위하여 진품콩2호와 PI506876의 교배로부터 98개의 F2 종자가 얻어졌다. SDS-PAGE로 각각의 종자를 분석한 결과 α′-subunit을 가진 종자가 70개였고 결핍된 종자가 28개였다. 이러한 유전양상은 단인자 유전원칙 (χ2 = 0.667, P=0.414)과 일치하여 콩 종자에서 7S의 α′-subunit 단백질은 한 개의 유전자에 의해서 좌우되었다. 이 결과는 7S 단백질 함량이 줄어든 콩 계통 선발에 유용하게 활용될 것으로 기대된다.
        3,000원
        237.
        2009.10 구독 인증기관·개인회원 무료
        There has been a substantial controversy on the phylogenetic relationships among butterfly families and several competing phylogenetic hypothesis have been suggested. Among them the relationships of (((Nymphalidae + Lycaenidae) + Pieridae) + Papilionidae) has been further widely accepted. In this study, we sequenced EF1-α, COI, and 16S rRNA from 62 species belonging to four true butterfly families, Papilionoidea. Phylogenetic analyses using BI, ML, and MP showed that the traditionally recognizable families were strongly supported as monophyletic groups, with the exception of Nymphalidae, wherein the singly included species of Danainae was placed as basal lineage of the Nymphalidae + Lycaenidae group. Phylogenetic relationships among families supported the sister group relationship of Nymphalidae and Lycaenidae strongly by all analyses and placed Papilionidae as the most basal lineage of the Papilionoidea. On the other hand, the relationships of Nymphalidae and Lycaenidae group to Pieridae were either unresolved, revealing trichotomy, or the relationships of (((Nymphalidae + Lycaenidae) + Pieridae) + Papilionidae) as previously supported by several morphological and molecular works supported. Detailed within-family relationships among some genera also are shown in the presentation.
        238.
        2009.05 구독 인증기관·개인회원 무료
        α-cypermethrin은 합성피레스로이드계 살충제로, 진딧물류 해충에 대해 접촉 독 및 소화중독을 일으켜 살충효과를 나타내는 약제이다. 진딧물은 성충, 약 충이 어린잎이나 잎의 뒷면에 떼를 지어 흡즙하여 식물체 잎을 위축, 퇴색하 게 하고 생육저해를 일으킨다. 이러한 진딧물류의 방제를 위해 살포된 살충제 에 의한 환경오염을 최소화하고, 적은 양으로도 최대의 살충효과를 지속적으 로 나타낼 수 있는 서방형제형의 키토산 캐리어화한 나노형 α-cypermethrin을 개발하여 복숭아혹진딧물(Myzus persicae Sϋlzer) 방제 실용화가능성을 검토하 였다. 키토산 캐리어의 분자량과 키토산 함량차이에 따른(Nano M.W. 3,000과 30,000) 두 가지 제형을 가지고 처리 당일부터 처리 후 14일까지의 경과일에 따른 고추의 복숭아혹진딧물의 살충효과와 개체군 증가율비교를 통한 방제효 과를 확인하였다. 처리 후 10일차의 나노타입에 대한 비교결과, 예상과는 다 르게, 3,000제형에서 개체군증가율 0.001로 30,000(개체군증가율 0.346)제형보 다 낮게 나타나 방제효과의 지속성을 확인할 수 있었다. 그러나 무처리구에서 의 개체군증가율(0.235)보다 높게 나타나 나노 30,000제형의 경우 방제효과구 명이 어려워, 나노캐리어 살충제 처리 후 식물체 표면과 복숭아혹진딧물의 충 체표면(구기, 복부, 등판)에서의 부착정도를 확인하기 위해 주사전자현미경을 통해 관찰하였다. 그 결과, 처리 후 시간이 경과할수록 두 시료 모두 나노캐 리어화된 α-cypermethrin의 입자의 부착밀도가 낮은 것을 확인할 수 있어 서방 형제형의 형태가 안정되지 않음을 알 수 있었다
        239.
        2009.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        1997년 9월부터 2007년 12월까지 동해의 SeaWiFS 자료를 이용하여 SeaWiFS 클로로필-α 농도가 가지는 스펙클 오차의 특성을 분석하고 그 원인을 조사하였다. 비정상적으로 큰 농도를 가진 스펙클들은 산발적으로 분포하였으며, 주변 화소들과 비교하였을 때 10mg/m3 이상의 현저하게 큰 편차를 보였다. 이 스펙클들은 겨울철에 자주 나타나는 경향이 있었으며, 이는 구름 분포와 관련이 있을 수 있다. 10년 평균된 겨울철 운량은 동해 북서쪽보다 스펙클이 자주 출현하는 남동쪽에서 더 크게 나타났다. 통계적 분석 결과는 운량이 증가할수록 스펙클의 수가 증가하는 것을 보여주었다. 스펙클 화소의 정규화 된 수출광량은 단파장 영역(443, 490, 510nm)에서 상당히 낮았으나 555nm 파장대는 정상적이었다. 이러한 낮은 관측치들은 클로로필-α 산출 식에서 비정상적으로 큰 농도를 생산하였다. 본 연구는 동해의 SeaWiFS 클로로필-α 농도자료가 지니는 스펙클 오차에 대한 문제점을 제기하였으며, 적절한 해색 원격탐사 기술을 활용한 좀 더 신뢰도 있는 클로로필-α 자료를 해양 응용 연구에 사용해야 함을 제시하였다.
        4,500원