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        검색결과 36

        8.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Photosynthetic characteristics and growth responses of Phalaenopsis Queen Beer ‘Mantefon’ orchid were determined in plants exposed to variable carbon dioxide (CO2) concentrations at 2-, 24-, and 36-weeks age (i.e., corresponding to juvenile, young, and mature vegetative growth stages, respectively). Plants were grown at 400 (control), 800, or 1,600 μmol・mol-1 CO2 for 6 hours during the nighttime for 32 weeks. Phalaenopsis ‘Mantefon’ in 2- and 24-week-old plants grown at 1,600 μmol・mol-1 CO2 had increased leaf number and net CO2 uptake compared with the plants grown at 400 μmol・mol-1 CO2. In 36-week-old of Phalaenopsis ‘Mantefon’, leaf number was significantly greater in plant grown at 800 and 1,600 μmol・mol-1 conditions compared with plants grown at 400 μmol・mol-1 CO2. Leaves that emerged after the start of the CO2 treatment were initially longer in the plants grown at 1,600 μmol・mol-1 CO2 than at 400 μmol·mol-1 C O2, but the final leaf length was shortest in the plants grown at 1,600 μmol・mol-1 CO2 condition. Plants showed crassulancean acid metabolism characteristic of nighttime CO2 uptake regardless plant growth stages. We found that growers may be able to promote leaf growth with increasing leaf number and reducing time to leaf initiation in the 36-week-old (i.e., mature stage) plants with 800 – 1,600 μmol·mol-1 CO2 and 2- and 24-week-old (i.e., juvenile and young stages) plants with 1,600 μmol·mol-1 C O2 for Phalaenopsis ‘Mantefon’.
        4,000원
        9.
        2018.11 구독 인증기관·개인회원 무료
        This study was conducted to investigate effect of feeding beet pulp on reproductive performance, colostrum composition and microbiological characteristics in sows. A total of 12 sows(Landrace×Yorkshire) were randomly allotted three dietary treatments at gestating 90 days. The diets were prepared by adding 0, 5 and 10% of the beet pulp in basal diets. The pigs fed 5% beet pulp showed higher litter size than the 0 and 10% beet pulp treatments, although there was not significant among the treatments. Similarly, birth and 21days weight in piglet were not different among the treatments. In colostrum fat, protein, lactose, citric acid, solid, ffa, true protein were ranged to reference values, but not difference among the treatments. E.coli of feces was lower(P<0.01) in the 5% beet pulp than the 0 and 10% beet pulp treatments. But no effect was observed on Lactobacilli of feces among dietary treatments. These our results indicate the beet pulp has no significant effect of reproductive performance and colostrum composition in sows. But, 5% level beet pulp is effective for reduction of intestinal pathogenic microorganisms.
        10.
        2018.10 구독 인증기관·개인회원 무료
        기후변화, 외래병해충발생, 밀원수 감소 등 여러 요인으로 인해 우리 나라의 양봉농가는 벌꿀생산량 및 농가소득이 감소하는 추세이다. 또한 밀원이 없는 시기에 가축용 사료가 아닌 고가의 식용설탕을 꿀벌의 인공사료로 급여하고 있어 농가는 ‘생산비 상승’과 ‘밀원수 부족’을 국내양봉업이 직면한 가장 큰 문제점으로 지적하고 있다. 이에 따른 양봉농가의 생산비를 절감하고 꿀벌의 생리·생태의 개선효과를 가지는 저가형 당액사료개발을 위해 농산부산물에서 추출한 천연당을 봉군에 적용시험을 추진하였다. 양파(OS-1, OS-2), 양배추(CS-1, CS-2), 바나나(Banana)부산물에서 추출한 천연당의 봉군당 평균먹이소모량(mL)은 설탕당액(대조구) 처리구와 비교시 바나나추출당액 급여구에서 5500.00±0.00, 5133.33±404.15로 유사하였다. 그러나 꿀벌의 봉세발달은 대조구에 비해 21006.7±2137, 17403.3±2257마리로 조사되어 낮은 경향을 나타내었고 수명조사 결과는 큰 차이가 없었다. 농산부산물을 이용한 천연당은 우선 꿀벌의 기호도 향상을 우선으로 개선시켜야 할 것으로 보인다.
        11.
        2018.10 구독 인증기관·개인회원 무료
        농촌진흥청 개발 품종인 토종벌 신품종(질병저항성 우수계통)에 대해 전남지역에서의 형질특성(봉세발달, 마리당 수밀력, 청소력 등)을 조사하였다. 질병저항성 계통(RS)으로 육성된 토종벌의 유밀기 마리당 수밀력은 들어오는 일벌의 무게가 80.89±8.95mg, 나가는 일벌의 무게가 63.56±8.90mg으로 조사되었고, 비저항성계통(NRS)은 각각 83.22±1.39, 66.67±1.20mg으로 조사되어 RS에서 그 무게차가 0.7mg 더 높았으나 통계적 유의차는 없었다. Pin killed test에 의한 사충제거능력(청소력)은 제거하지 못한 유충잔존율이 RS에서 12시간과 24시간 경과시 14.00±10.39와 7.00±3.46으로, NRS에서는 20.33±14.29, 13.33±10.41%로 조사되었으며, 특히 RS와 NRS의 사충 비제거율이 24시간 경과하였을 때 4.67±2.08, 8.33±7.77%로 RS가 우수한 특성을 보였다. 신규여왕벌 입식 후 봉군세력발달은 NRS에 비하여 RS의 일벌수, 번데기 및 유충수의 발달율이 안정적이고 다소 빠르게 증가하였다.
        12.
        2018.10 구독 인증기관·개인회원 무료
        Japanese pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is considered as a serious pest in pine trees. To develop an eco-friendly strategy to manage this forest insect, we collected entomopathogenic fungi from Korean soil and assessed their virulence against the adults of the insect in laboratory conditions. As a result, two isolates with conidial suspension (1.0×107conidia/ml), showed 87% and 90% mortality 12 days after fungal treatment, respectively. We assessed the potential of the fungi-derived destruxin and protease as additives to the fungal isolates, and they showed insecticidal activity via feeding and spraying treatments. Finally, we produced fungal conidia in massive solid cultures and formulated wettable powders, and now studying optimal conditions of oil-based formulation with two isolates. Based on these results, we are evaluating the control efficacy of the fungal agents against M. alternatus in field conditions.
        13.
        2017.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the properties of the pitches. As the hydrogen pressure increased, the C/H ratio decreased, and the solubility in n-hexane increased. The mesophase pitch with entirely anisotropic domains of flow texture exhibited good meltspinnability. The mesophase carbon fibers obtained from the catalytically hydrogenated petroleum residue showed moderate mechanical properties.
        4,000원
        14.
        2017.09 구독 인증기관 무료, 개인회원 유료
        Xenotransplantation is proposed as a solution to the problem of organ shortage. However, transplantation of xenogeneic organs induces an antigen-antibody reaction in α-1,3-gal structure that are not present in humans and primates, and thus complement is also activated and organs die within minutes or hours. In this study, we used FasL gene, which is involved in the immune response of NK cell, and US11, which suppresses MHC Class I cell membrane surface expression, to inhibit cell mediated rejection in the interspecific immunity rejection, and also hDAF(CD55) was introduced to confirm the response to C3 complement. These genes were tranfeced into Korean native pig fetal fibroblasts using pCAGGS vector. And cytotoxicity of NK cell and human complement was confirmed in each cell line. The US11 inhibited the cytotoxicity of NK cell and, in addition, the simultaneous expression of US11 and Fas ligand showed excellent suppress to T-lymphocyte cytotoxicity, hDAF showed weak resistance to cytotoxicity of natural killer cell but not in CD8+ CTLs. Cytotoxicity study with human complement showed that hDAF was effective for reducing complement reaction. In this studies have demonstrated that each gene is effective in reducing immune rejection.
        4,000원
        15.
        2012.06 구독 인증기관·개인회원 무료
        Pluripotent stem cells can be derived from both pre- and post-implantation embryos. Embryonic stem cells (ES cells), derived from inner cell mass (ICM) of blastocyst are naïve pluripotent and epiblast stem cells (EpiSCs) derived from post-implantation epiblast are primed pluripotent. The phenotypes and gene expression patterns of the two pluripotent stem cells are different each other and EpiSCs thought to be in a more advanced pluripotent (primed pluripotent state) than mouse ES cells (naïve pluripotent state). Therefore, we questioned whether EpiSCs are less potential to be differentiated into specialized cell types in vitro. EpiSCs were isolated from 5.5~6.5 day post coitum mouse embryos of the post-implantation epiblast. The EpiSCs could differentiate into all tree germ layers in vivo, and expressed pluripotency markers (Oct4, Nanog). Interestingly, EpiSCs also were able to efficiently differentiate into neural stem cells (NSCs). The NSCs differentiated from EpiSCs (EpiSC-NSCs) expressed NSC markers (Nestin, Sox2, and Musasi), self-renewed over passage 20, and could differentiate into two neural subtypes, neurons, astrocytes and oligodendrocytes. Next, we compared global gene expression patterns of EpiSC-NSCs with that of NSCs differentiated from ES cells and brain tissue. Gene expression pattern of brain tissue derived NSCs were closer to ES cell-derived NSCs than EpiSC-NSCs, indicating that the pluripotent stem cell-derived somatic cells could have different characteristics depending on the origin of pluripotent stem cell types. * This work was supported by the Next Generation Bio-Green 21 Program funded by the Rural Development Administration (Grant PJ 008009).
        16.
        2012.06 구독 인증기관·개인회원 무료
        Neural stem cells (NSCs) are self-renewing tripotent cell populations and have capacity of neuronal (neurons) and glial (astrocytes and oligodendrocytes) differentiation. Many researchers have reported that NSCs have therapeutic effects in neurological disease by transplantation. However, it is not easy to obtain NSCs in vitro. Recently, Yamanaka and colleagues showed that somatic cells could be reprogrammed into pluripotent state by enforcing reprogramming factors. Induced pluripotent stem (iPS) cells undergo unlimited self-renewal and have differentiation potential into various types of cells like embryonic stem cells. Direct differentiation into a specialized cell types from iPS cells hold considerable promise for regenerative medicine as well as basic research. Here, we induced differentiation of iPS cells into NSCs in vitro and in vivo, which were compared with embryonic stem (ES) cell-derived NSCs and brain derived NSCs. NSCs from ES and iPS cells were morphologically indistinguishable from brain derived NSCs and stained positive for NSCs markers Nestin and Sox2. ES cells derived NSCs were transcriptionally distinguishable from brain derived NSCs. However, global gene expression pattern were similar but distinct between iPS derived NSCs and brain derived NSCs. Moreover, iPS derived NSCs were spontaneously aggregated upon passaging, formed ES cell like colonies, and finally reactivated Oct4-GFP. The spontaneously reverted GFP-positive cells (iPS-NSC-iPS) expressed similar levels of pluripotency markers (Oct4,Nanog) to ES and iPS cells, and could form germ line chimera. One possible explanation for this phenomenon is that spontaneously re-reprogramming was associated with transgene re-activation when iPS cells were differentiated into NSCs. However, NSCs from dox-inducible iPScells could not be reprogrammed into pluripotent state without doxycycline. Taken together, iPS derived NSCs were morphologically and similar to brain derived NSCs, but differ in gene expression pattern and maintenance. * This work was supported by the Next Generation Bio-Green21 Program funded by the Rural Development Administration (Grant PJ008009).
        19.
        2010.10 구독 인증기관·개인회원 무료
        Bee venom contains a variety of peptides and enzymes, including serine proteases. While the presence of serine proteases in bee venom has been demonstrated, the role of these proteins in bee venom has not been elucidated. Furthermore, there is currently no information available regarding the melanization response or the fibrin(ogen)olytic activity of bee venom serine protease, and the molecular mechanism of its action remains unknown. Here we show that bee venom serine protease (Bi-VSP) is a multifunctional enzyme. In insects, Bi-VSP acts as an arthropod prophenoloxidase (proPO)-activating factor (PPAF), thereby triggering the phenoloxidase (PO) cascade. Bi-VSP injected through the stinger induces a lethal melanization response in target insects by modulating the innate immune response. In mammals, Bi-VSP acts similarly to snake venom serine protease, which exhibits fibrin(ogen)olytic activity. Bi-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products, defining roles forBi-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings provide a novel view of the mechanism of bee venom in which the bee venom serine protease kills target insects via a melanization strategy and exhibits fibrin(ogen)olytic activity.
        20.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The HMG box containing protein (HBP) has a high mobility group domain and involved in the regulation of proliferation and differentiation of tissues. We screened HBP2 in glioblastoma using Suppression Subtractive Hybridization (SSH) and isolated human spermatogonial stem cell‐like cells (hSSC‐like cells) derived from patients of nonobstructive azoospermia (NOA). Expression of HBP2 was analyzed by RT‐PCR in undifferentiated stem cells (human Embryonic Stem Cells, hSSC‐like cells 2P) and spontaneous differentiated stem cells (hSSC‐like cells 4P). It was overexpressed in hESC and hSSC‐like cells 2P but not in hSSC‐like cells 4P. Also, the expression level of HBP2 was downregulated in colon tumor tissues compared to normal tissues. Specifically in synchronized WI‐38 cells, HBP2 was highly upregulated until the G1 phase of the cell cycle and gradually decreased during the S phase. Our results suggest that HBP2 was downregulated during the spontaneous differentiation of hSSC‐like cells. HBP2 was differently expressed in colon tissues and was related to G1‐progression in WI‐38 cells. It may play a role in the maintenance of an undifferentiated hSSC‐like cell state and transits from G1 to S in WI‐38 cells. This research was important that it identified a biomarker for an undifferentiated state of hSSC‐like cells and characterized its involvement to arrest during cell cycle in colon cancer.
        4,000원
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