• Title/Summary/Keyword: 결정분화

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Endless debates on the extant basal-most angiosperm (현생 기저 피자식물에 대한 끝나지 않는 논쟁)

  • Kim, Sangtae
    • Korean Journal of Plant Taxonomy
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    • v.40 no.1
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    • pp.1-15
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    • 2010
  • Recognizing a basal group in a taxon is one of the most important factors involved in understanding the evolutionary history of that group of life. Many botanists have suggested a sister to all other angiosperms to understand the origin and rapid diversification of angiosperms based on morphological and fossil evidence. Recent technical advances in molecular biology and the accumulation of molecular phylogenetic data have provided evidence of the extant basal-most angiosperm which is a sister to all other angiosperms. Although it is still arguable, most plant taxonomists agree that Amborella trichopoda Baill., a species (monotypic genus and monotypic family) distributed in New Caledonia, is a sister to all other extant angiosperms based on evidence from the following molecular approaches: 1) classical phylogenetic analyses based on multiple genes (or DNA regions), 2) analyses of a tree network of duplicated gene families, and 3) gene-structural evidence. As an alternative hypothesis with relatively minor evidence, some researchers have also suggested that Amborella and Nymphaeaceae form a clade that is a sister to all other angiosperms. Debate regarding the basal-most angiosperms is still ongoing and is currently one of the hot issues in plant evolutionary biology. We expect that sequencing of the whole genome of Amborella as an evolutionary model plant and subsequent studies based on this genome sequence will provide information regarding the origin and rapid diversification of angiosperms, which is Darwin's so called abominable mystery.

Effects of Country-of-Origin Dimensions on Product Evaluations: A Role of Motivational Focus (원산지 개념의 구성 차원이 소비자의 제품평가에 미치는 영향: 동기성향의 효과)

  • Shin, Sohyoun;Kim, Sanguk;Chaiy, Seoil
    • Asia Marketing Journal
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    • v.10 no.2
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    • pp.71-98
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    • 2008
  • Considerably many numbers of studies on country-of-origin(hereafter COO) effects have been presented in international business and marketing areas. Recent studies have been included the effects of COO of manufacture, parts, and design, as well as the effects of brand origin, reflected by the accelerating convergent manufacture circumstances and increasingly competitive environments. Moderating constructs such as knowledge of product category and involvement as individual variables, have been also introduced and researched in various angles. In addition, how the effects of COO occur as processes is also argued in previous studies. This research has attempted to explain business corporation's strategic decisions on choosing a domain of its product manufacturing for several critical reasons, for cost reduction or better image. We displayed two constructs of brand and manufacture in a positive and negative country image group to reconfirm the existence of the effects of COO. Additionally, the effects of respondents' regulatory fit between their motivational focus and the contents of product messages, have been declared. Furthermore the respondents' motivational focus moderates the main effect of COO on product evaluations in a positive 'made-in' combination, while, surprisingly, it does not statistically moderate in a negative, except attitude. Based on the results, implications and suggestions on how to plan and execute more effective marketing strategies regarding COO dimensions, especially COO of manufacture, are separately presented for each situations when it has already been determined and when it is to be.

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Effectiveness of Positron Emission Tomography in the Pre-operative Staging of Gastric Cancer (위암환자의 술 전 병기 결정에서 PET-CT의 유용성)

  • Park, Shin-Young;Bae, Jung-Min;Kim, Se-Won;Kim, Sang-Woon;Song, Sun-Kyo
    • Journal of Gastric Cancer
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    • v.9 no.3
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    • pp.110-116
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    • 2009
  • Purpose: The aim of this study was to examine the usefulness of positron emission tomography (PET)-computed tomography (CT) in the pre-operative staging of gastric cancer. Materials and Methods: Between February 2006 and August 2008, PET-CT and CT were performed on 70 patients diagnosed with gastric cancer by gastrofiberscopic biopsy. The sensitivities, specificities, Positive predictive value (PPV), and negative predictive value (NPV) of PET-CT and CT imaging for the detection of gastric cancer TNM staging were compared. Results: The detection rates for the primary tumor were as follows: PET-CT, 81.4% (57/70); and CT, 42.9% (30/70). For both early gastric cancer (EGC) and advanced gastric cancer (AGC), PET-CT was more accurate than CT in detecting the lesions. As the size of the tumor exceeded 3 cm, the detection rate increased. The sensitivities, specificities, PPV, and NPV of PET-CT for lymph node staging were 55.6%, 81%, 86.2%, and 45.9%, while the sensitivities, specificities, PPV, and NPV of CT were 40.0%, 85.7%, 85.7% and 40%, respectively. One case of multiple liver metastasis and two cases of dual primary cancer (rectal and pancreatic cancers) were detected by PET-CT. PET-CT also had a higher detection rate for all histologic types of primary tumors. PET-CT was more accurate than CT in detecting primary gastric cancer lesions. The detection of nodal metastasis by PET-CT was similar to CT; small-sized tumors or EGC detection rates were not high. However, PET-CT provided additional information to detect distant metastases and dual primary cancers and reduced unnecessary laparotomies to detect peritoneal seeding or carcinomatosis. Conclusion: It would be useful to make a pre-operative diagnosis of gastric cancer and determine treatment if PET-CT were added to other routine pre-operative studies.

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A Study on the Hull-dimension of 89 ton class Stow-net Vessel with Stern-fishing (89톤급 선미식 안강망어선의 선형치수에 관한 연구)

  • Park, Je-Ung;Lee, Hyeon-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.33 no.3
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    • pp.159-165
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    • 1997
  • This paper presents the optimum dimension of 89 ton class stow-net vessel with stern-fishing. The model of basic design is developed by using the optimization techniques referring to objective function and numerous constraints as follows; speed, fishing quantity, fishing days, catch per unit effort(CPUE), and weight/ratio of main dimensions, etc. Thus, the basic design of stow-net fishing vessel is built up by using the optimization of the design variables called the economic optimization criteria, and the objective function represents the criterion which is cost benefit ratio(CBR). The main conclusions are as follows. 1. S/W for decision of optimum hull size is developed in 89 ton class stow-net fishing vessel which is constructed with optimization of the design variables called the economic optimization criteria. 2. For optimum ship dimensions in 89 ton class stow-net fishing vessel, the hull dimensions can be obtained in the range of L= 27.3m, B = 6.6m, D = 2.80m, Cb = 0.695, T/D = 0.80, $\Delta$(displacement)=281.7ton with 10 knots.

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Mouse Embryonic Stem Cell Uptakes of Buforin 2 and pEP-1 Conjugated with EGFP (생쥐 배아 줄기세포의 Buforin 2 및 pEP-1에 결합된 EGFP의 세포 내 수송)

  • Jung, Su-Hyun;Park, Seong-Soon;Lim, Hyun-Jung;Cheon, Yong-Pil
    • Development and Reproduction
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    • v.11 no.2
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    • pp.111-119
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    • 2007
  • Differentiation of cells can be induced through modulation of endogenous regulators using exogenous factors. Useful transfection systems to transport a specific exogenous regulator into cell have been tried but still there are many obstacles to overcome. In this study, we examined the transfection efficiency of cell permeable peptides (CPPs) in mouse embryonic stem cell under the various conditions. To identify the CPP-mediated translocation of a protein, we employed recombinant CPP-enhanced green fluorescent protein (EGFP). Viability of R1 cells was different between experimental groups depending on the kind of CPP and the concentration of CPP-EGFP. Translocation of CPP-EGFPs into the R1 cells was not detected until 30 min after CPP-EGFPs treatment in all groups. After 1 hr, translocation of pEP-1-EGFP-N was detected, but it could not be detected in the other group. Transfection of pEP-1EGFP-N was independent on its concentration. The time course did not show saturation even after 24 hr in pEP-1-EGFP-N. These results showed that the permeability depended on the kind of CPP and the location of His-tag in the case of examined CPPs, and did not need biological energy. On summary, the efficiency of transfection of CPP-EGFP depends on the CPP sequences but the culture time is not a key factor in transfection for the mouse embryonic stem cell. For the future studies to improve the efficiency of translocation of protein into embryonic stem cells, it is needed to develop modified CPP or mediator. The studies would be very useful to induce the differentiation of embryonic stem cells.

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Cyanobacteria and Secondary Metabolites (시아노박테리아의 이차대사물질에 대한 연구)

  • Kim, Gi-Eun;Kwon, Jong-Hee
    • KSBB Journal
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    • v.22 no.5
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    • pp.356-361
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    • 2007
  • Cyanobacteria are a very old group of prokaryotic organisms that produce very diverse secondary metabolites, especially non-ribosomal peptide and polyketide structures. Although some cyanobacteria produce lethal toxins such as microcystins and anatoxins, some may be useful either for development into commercial drugs or as biochemical tools. Detection of unknown secondary metabolites was carried in the present study by a screening of 98 cyanobacterial strains from Cyanobiotech GmbH in order to establish a screening process, isolate pure substances and determine their bioactivities. A degenerated polymerase chain reaction technique as molecular approaches has been used for general screening of NRPS gene and PKS gene in cyanobacteria. A putative PKS gene was detected by DKF/DKR primer in 38 strains (38.8%) and PCR amplicons resulted from a presence of NRPS gene were showed by MTF2/MTR2 primer in 30 strains (30.6%), respectively. A screening of interesting strains was performed by comparing PCR screening results with HPLC analyses of extracts. HPLC analysis for a detection of natural products was performed in extracts from biomass. 5 strains were screened for further scale-up processing. 7 pure substances were isolated from the scale-up cultures and tested for bioactivities under consideration to purity, amount and molecular weight of substances. One substance isolated from CBT 635 showed cytotoxic activity. This substance may be regarded as Microcystin LR.

Overwintering Conditions of the Diamondback Moth and Genetic Variation of Overwintering Populations (배추좀나방 월동 조건과 야외 월동집단의 유전적 변이)

  • Kim, Eunseong;Choi, Bongki;Park, Youngjin;Cha, Ookhyun;Jung, Chungryel;Lee, Daeweon;Kim, Kwangho;Kim, Yonggyun
    • Korean journal of applied entomology
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    • v.53 no.4
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    • pp.355-365
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    • 2014
  • It has been unclear whether the diamondback moth, Plutella xylostella can overwinter in Korean field conditions. This study determined overwintering conditions of P. xylostella by conducting field exposure tests based on its cold tolerance and monitoring overwintering populations by direct examination of overwintering larval habitats and capturing adults with sex pheromone traps. In addition, the overwintering populations were analyzed using polymorphic genetic markers to trace their sources. When all immature stages of P. xylostella were exposed to $-5^{\circ}C$, which was the temperature much above their supercooling points, they significantly suffered with direct cold injuries, where larval stage was most tolerant to the cold injury. However, the exposure to $5^{\circ}C$ for a long period (4 weeks) did not give any significant cold injury to nonfeeding stages, while this treatment gave lethality to larval stage without diet. When all developmental stages of P. xylostella were exposed to open field conditions during winter, they exhibited significant decreases of survival rates. However, some protected and indoor conditions reduced the cold injuries and the diet provision significantly increased larval survival rates. Adult monitoring with sex pheromone during winter period indicated that the first captures were observed at similar periods at different locations (${\approx}260$ Km apart). The overwintering adults were captured until early April. Genetic variation of these overwintering populations was analyzed with polymorphic molecular markers, indicating significant genetic divergences among the overwintering populations. This study indicates that P. xylostella can overwinter in southern Korean fields or some protected greenhouses with host plants.

Changes in Dormant Phase and Bud Development of 'Fuji' Apple Trees in the Chungju Area of Korea (충주지역에서 '후지' 사과나무의 휴면단계 변화 및 눈 발달)

  • Lee, ByulHaNa;Park, YoSup;Park, Hee-Seung
    • Horticultural Science & Technology
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    • v.33 no.4
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    • pp.501-510
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    • 2015
  • In this study, we investigated the onset and release of endo-dormancy under natural conditions by observing bud break characteristics in 'Fuji' apple trees using water cuttings. Through examinations of bud break rate and days to bud break, we found that the endo-dormancy of 'Fuji' apple tree continues for 70 d from 165 to 255 d after full bloom (DAFB), from late October to early January of the following year. In addition, within 20 d of first bud break, based on a final bud break rate of 60% or more, we able to identify the timing of the changeover from para-dormancy to endo-dormancy, and endo-dormancy to eco-dormancy. Analysis of the chilling requirement during the endo-dormancy period revealed that chilling accumulation up to 255 DAFB to release endo-dormancy amounted to 666 and 517 h based on the CH and Utah models, respectively. Observation of internal changes in the bud during endo-dormancy showed that flower bud differentiation begins from mid-July, and t ime of inflorescence o f the disk f lower is a vailable to f ind. The f lower buds subsequently developed slowly but steadily during endo-dormancy and in the following year in February, the developmental stage of each organ had progressed. Moreover, the flower buds of 'Fuji' apples were mostly healthy during the dormancy period, but some exhibited necrosis of flower primordium, due partial cell damage from the formation of ice crystals rather than a direct effect of the low temperature. Flower buds were formed in both the axillary buds of bourse shoots and terminal buds of spurs, but lower bud differentiation was observed for the terminal buds of spurs at rate of about 65% of total buds, which was directly related to the bud size and shoot diameter.

Identification of Matrix Mineralization-Related Genes in Human Periodontal Ligament Cells Using cDNA Microarray (cDNA microarray에 의한 치주인대세포의 광물화 결절형성에 관여하는 유전자들의 분석)

  • Shin, Jae-Hee;Park, Jin-Woo;Yeo, Shin-Il;Noh, Woo-Chang;Kim, Moon-Kyu;Kim, Jung-Chul;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.37 no.sup2
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    • pp.447-463
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    • 2007
  • Periodontal ligament (PDL) cells have been known as multipotential cells, and as playing an important rolesin periodontal regeneration. The PDL cells are composed of heterogeneous cell populations which have the capacity to differentiate into either cementoblasts or osteoblasts, depending on needs and conditions. Therefore, PDL cells have the capacity to produce mineralized nodules in vitro in mineralization medium which include ascorbic acid, ${\beta}$-glycerophosphate and dexamethasone. In spite of these well-known osteoblast like properties of PDL cells, very little is known about the molecules involved in the formation of the mineralized nodules in the PDL cells. In the present study, we analysed gene-expression profiles during the mineralization process of cultured PDL cells by means of a cDNA microarray consisting of 3063 genes. Nodules of mineralized matrix were strongly stained with alizarin red S on the PDL cells cultured in the media with mineralization supplements. Among 3,063 genes analyzed, 35 were up-regulated more than two-fold at one or more time points in cells that developed matrix mineralization nodules, and 38 were down-regulated to less than half their normal level of expression. In accord with the morphological change we observed, several genes related to calcium-related or mineral metabolism were induced in PDL cells during osteogenesis, such as IGF-II and IGFBP-2. Proteogycan 1, fibulin-5, keratin 5, ,${\beta}$-actin, ${\alpha}$-smooth muscle actin and capping protein, and cytoskeleton and extracellular matrix proteins were up-regulated during mineralization. Several genes encoding proteins related to apoptosis weredifferentially expressed in PDL cells cultured in the medium containing mineralization supplements. Dkk-I and Nip3, which are apoptosis-inducing agents, were up-regulated, and Btf and TAXlBP1, which have an anti-apoptosis activity, were down-regulated during mineralization. Also periostin and S100 calciumbinding protein A4 were down-regulated during mineralization.

Immunohistochemical Study of NSE in Small Cell Lung Cancer (SCLC) Combined with Serum Assay (소세포폐암에서 Neuron Specific Enolase의 면역조직 화학염색과 혈청농도에 관한 연구)

  • Kwak, Seung-Min;Kim, Hyung-Jung;Shin, Dong-Hwan;Jang, Joong-Hyun;Lee, Hong-Lyeol;Kim, Se-Kyu;Ahn, Chul-Min;Kim, Sung-Kyu;Lee, Won-Young;Lee, Kyi-Beom
    • Tuberculosis and Respiratory Diseases
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    • v.39 no.6
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    • pp.502-510
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    • 1992
  • Background: Neuron specific enolase (NSE) is a neuronal form of the glycolytic enzyme enolase which was first found in extracts of brain tissue, and later in a variety of APUD cells and neurons of the diffuse endocrine system. SCLC shares many APUD properties with normal neuroendocrine cells. NSE immunostaining and serum NSE measurement may be a useful marker of neuroendocrine differentiation in lung tumors and diagnosis of small cell carcinoma. Methods: NSE immunohistochemical staining was done and at the same time serum NSE levels were measured in 22 small cell lung cancer and 21 non small cell lung cancer which were confirmed histologically. Results: 1) NSE immunoreactivity was detected in 9 of the 18 (50%) small cell lung cancer, in 5 of the 16 non small cell lung cancer. 2) Whereas the mean value in non-small cell lung cancer group was $11.79{\pm}4.47\;ng/ml$, the mean level of serum NSE in small cell lung cancer increased up to $59.3{\pm}77.8\;ng/ml$. In small cell lung cancer patients, mean value of limited disease group was $20.19{\pm}12.91\;ng/ml$, while mean value of extended disease group was $91.9{\pm}94.2\;ng/ml$ showing statistically significant difference. If serum levels above 20 ng/ml were tentatively defined as positive, 16 of 22 (73%) patients with SCLC had positive serum NSE level, but only one patient with NSCLC did. There was no correlation between serum NSE level and immunoreactivity of NSE. Conclusion: These studies indicate that serum NSE measurement may be a useful marker for the diagnosis and disease extent and NSE immunostaining can be used to demonstrate the neuroendocrine components of lung tumor.

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