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        검색결과 32

        1.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.
        4,000원
        4.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 중소기업의 임원보수, 기업성과, 국제화에 대한 소유구조의 역할을 고찰한다. 소유와 경영의 엄격한 분리를 상정한 기존 문헌과 달리 소유와 경영이 중첩되는 임원의 주식소유에 주목한다. 임원 소유지분을 지배주주 소유지분과 분리․취급함으로써 임원보수, 기업성과, 국제화에 미치는 소유지분의 순효과를 임원과 지배주주의 몫으로 분해하여 측정할 수 있다. 이에 2014~2018년 기간 비금융산업에 속하는 국내 상장 중소기업의 공시정보를 활용하여 소유지분 및 임원보수가 기업성과와 국제화에 각각 어떠한 효과를 가져오는지를 주로 분석하였다. 주요 분석 결과는 다음과 같다: (1) 임원보수는 기업성과와 국제화에 직접 영향을 미치는 요인이며, (2) 임원 지분소유는 임 원보수와 양의 상관관계를 통해 간접 경로로 기업성과와 국제화에 영향을 주고 있으나, (3) 지배주주 지분소유은 기업성과 및 국제화에 직․간접 관계가 있다고 판단하기 어렵다. 이 결과를 통해 소 유와 경영의 일치가 기업성과와 국제화에 직․간접적으로 중요한 요소라는 점을 확인할 수 있다.
        6,700원
        5.
        2017.10 구독 인증기관·개인회원 무료
        An increased use of organic phosphorous based chemical pesticides in domestic and overseas agriculture has resultedin emergence of tolerant strains of insect pests. These pests have spread throughout South Korea and are responsible forsignificant reduction in crop yields. Furthermore, as yet there is no effective way of controlling these insects or the damageresulting from pest infestation. To this end, we are attempting to develop biological control based methods to protectcrop plants against insect pests. A screen for biocontrol agents conducted in five farms that were heavily infested bynematodes in 2015-2016 identified Aspergillus niger F22 strain that was very effective against root-knot nematode. Afour-time treatment with A. niger F22 at an internal of ten days was able to reduce nematode population by 70-90%compared to untreated controls. The biocontrol agent was also more effective compared to ograno-phosphorus based pesticide,which caused a 30% reduction in nematode population. Notably, the extract (suspension concentrate) prepared from A.niger culture was equally effective in controlling the root-knot nematode and is currently being developed as a marketableproduct under the brand name “NAMAFREE”.
        6.
        2017.10 구독 인증기관·개인회원 무료
        Oyster mushrooms are one of the most famous mushrooms for foods in Korea. ‘Santari’ developed on this study is P. pulmonarius of oyster mushroom species. ‘Santari’ is a new variety of oyster mushroom for the bottle culture. It was bred by mating with monokaryons isolated from ‘GMPO20404’ and ‘Hosan’. The optimum temperature for the mycelial growth was 26~29°C on PDA medium and that for the primordia formation and the growth of fruiting body of ‘Santari’ was 22°C and 20°C on sawdust media. It took 34 days to finish spawn running, 3 days to finish primordia formation, 3 days to finish fruitbody growth in the bottle culture. In the characteristics of fruit body, pilei were round type and brownish, stipe color was white and stipe shape was long and thick. The yield per bottle was 172g/1,100ml and was 43% higher than that of control variety(Hosan). As results of the physical properties of fruit body, springness, cohesive, gumminess and brittleness of stipe tissue were 87%, 82%, 193g and 16kg, respectively. The values of them are lower than those of control except cohesive.
        7.
        2017.10 구독 인증기관·개인회원 무료
        Oyster mushrooms are one of the most famous mushrooms for foods in Korea. ‘Santari’ developed on this study is P. pulmonarius of oyster mushroom species. ‘Santari’ is a new variety of oyster mushroom for the bottle culture. It was bred by mating with monokaryons isolated from ‘GMPO20404’ and ‘Hosan’. The optimum temperature for the mycelial growth was 26~29°C on PDA medium and that for the primordia formation and the growth of fruiting body of ‘Santari’ was 22°C and 20°C on sawdust media. It took 34 days to finish spawn running, 3 days to finish primordia formation, 3 days to finish fruitbody growth in the bottle culture. In the characteristics of fruit body, pilei were round type and brownish, stipe color was white and stipe shape was long and thick. The yield per bottle was 172g/1,100ml and was 43% higher than that of control variety (Hosan). As results of the physical properties of fruit body, springness, cohesive, gumminess and brittleness of stipe tissue were 87%, 82%, 193g and 16kg, respectively. The values of them are lower than those of control except cohesive.
        8.
        2017.10 구독 인증기관·개인회원 무료
        Hericium erinaceus (HE) is an edible mushroom to exhibit several biological activities, such as antioxidant, anti-inflammation and anti-cancer effects. This study focuses on the antioxidant potential of HE as extraction solvents. HE was extracted with ethanol (HEE) and water (HEW) in order to observe the change of the extraction amount of the active ingredient. Total polyphenol content (TPC) analyses were performed to decide the active ingredient contents of HEE and HEW. Moreover, 2,2-diphenyl-picrylhydrazyl hydrate (DPPH) and 1,2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities were conducted to compare the antioxidant activities of HEE and HEW extracts. As a result, TPC (7.08 ± 0.08 g GAE/kg extract) of HEE was found significantly higher as compared to HEW (4.94 ± 0.02 g GAE/kg extract). The IC50 values based on the ABTS for HEE (471.47 ± 20.38 μg/ml) was generally stronger showing potential antioxidant properties compared to HEW (606.97 ± 1.04 μg/ml). On the other hand, DPPH radical scavenging activity showed no significant change in HEE and HEW extracts. These results demonstrated that ethanol extracts from HE could be useful as an antioxidative functional ingredients.
        9.
        2016.06 구독 인증기관·개인회원 무료
        ‘Mantari’ is a new variety of oyster mushroom for the bottle culture. It was bred by mating with monokaryons isolated from ‘DM11732’ and ‘Chunchu-2ho’. The optimum temperature for the mycelial growth was 26~29°C on PDA medium and that for the primordia formation and the growth of fruiting body of ‘Mantari’ was 18°C and 16°C on sawdust media. It took 32 days to finish spawn running, 4 days to finish primordia formation, 3 days to finish fruitbody growth in the bottle culture. In the characteristics of fruit body, pilei were round type and dark grayish, stipe color was gray-white color and stipe shape was long and thin. The yield per bottle was 179g/900ml and was 5% higher than that of control veriety(Chunchu-2ho). As results of the physical properties of fruit body, springness, cohesive, gumminess and brittleness of stipe tissue were 96%, 76%, 160g and 15kg, respectively.
        11.
        2015.10 구독 인증기관·개인회원 무료
        To clarify the geographical distribution of scrub typhus vectors in Korea, the first survey of chigger mites was conducted from 2005 to 2007 by collecting wild small mammals twice a year (spring and autumn) at 24 sites nationwide. The two predominant mite species were Leptotrombidium pallidum (52.6%) and L. scutellare (27.1%). However, the proportions of L. scutellare in southern areas, including endemic provinces such as Chungcheongnam-Do, Jeollabuk-Do, Jeollanam-Do, and Gyeongsangnam-Do, were relatively higher than in central Korean regions where L. pallidum was predominant. In autumn, the ratio of L. scutellare increased to 42% while the ratio of L. pallidum decreased. The geographical distribution map of the L. scutellare chigger index was identical to the incidence pattern of scrub typhus, whereas those of overall mites and L. pallidum showed no relationship with case incidence patterns. Distribution mapping analysis shows an identical geographical distribution of L. scutellare and epidemic incidence of scrub typhus in South Korea. The second periodical survey was performed from 2011 to 2013. The result suggests that the distribution of L. scutellare has not been changed remarkably in comparison to the first survey.
        12.
        2011.05 구독 인증기관·개인회원 무료
        Field research was undertaken for recovering mosquito larval mermithid parasite, Romanomermis species in rice fields in 54 different areas in period of May through October, 2009. Of 54 area rice fields surveyed, Romanomermis sp. recoveries were made from 4 areas. 32 Anopheles mosquito larvae, malaria disease vector were infected and died from samples collected in Pochon area, and a total of 10 Culex mosquito larvae, house frequenting mosquito were infected to death in 3 different areas, Gimpo, Sangju and Gurae, respectively. On the basis of positive natural infection record, an intensive host-parasite occurrences and/or population study was surveyed in foci area of Pochon in small pond (P) and Rice paddies (A and B) during 5 months till end of October. The natural mermithid infection was continuously occurred from June through October in weekly samples, however the rate of infection was appeared higher in June-July, thereafter the rate gradually decreased in progress of the season. The highest natural infection rate was observed from the Pond 9.1% followed by Rice paddy "A" 5.2%, Rice paddy "B" 2.4%, respectively. Including 2 other Rice paddies "C" and "D", a total mosquito larvae collected was 3,270, an overall average natural infection rate was recorded as 3.7% (121 Anopheles mosquito larvae infected).
        13.
        2010.05 구독 인증기관·개인회원 무료
        Five field-collected populations (TR-CP, UR-CP, JR-CP, GR-CP, and BR-CP colonies) of northern house mosquito, Culex pipiens pallens, identified by polymer chain reaction (PCR) were tested for susceptibility to 10 different insecticides by direct-contact mortality bioassay in comparison with an insecticide-susceptible KS-CP strain. Marked regional variations of insecticide susceptibility were observed. Extremely high to high levels of resistance were obtained: bifenthrin, resistance ratio (RR) = 1–520; β-cyfluthrin, RR = 16–397; α -cypermethrin, RR = 9–343; deltamethrin, RR = 1–40; etofenprox, RR = 2–42; permethrin, RR = 2–12; chlorpyrifos, RR = 2–675; fenitrothion, RR = 0.5–364; and fenthion, RR = 2–360. All of the colonies were susceptible to one or more of the insecticides examined. These results indicate that careful selection and rotational use of these insecticides should result in continued satisfactory control against field populations of northern house mosquito.
        14.
        2010.05 구독 인증기관·개인회원 무료
        Density of malaria vector mosquito was monitored at 24 sites in Korea to estimate malaria epidemic from 2004 to 2009. Twenty four locations include six in Gwangwon province and nine in Kyonggi province and nine in Incheon metropolitan city. Mosquitoes collected by public health centers in 24 sites were sent to each RIPHE(Research Institute of Public Health & Environment) then the RIPHE identified the malaria vector mosquitoes. KCDC analysed the results. Number of malaria vector mosquito collected in 2009 shapely decreased over 33 % when compared with number of mosquito collected from 2004 to 2009. In 2009, malaria vector mosquitoes firstly were collected at Injegun on 2nd week of April (6-13, April) and the highest peak of collected mosquito was demonstrated on 3rd week of August. Number of collected mosquito sharply decreased below 10 at 3rd week of september and None of mosquito was collected 2nd week October. Decrease of number of malaria vector mosquito collected in 2009 seem to be related with lowest temperature around midnight and precipitation days per month.
        15.
        2009.10 구독 인증기관·개인회원 무료
        Monochamus alternatus and M. saltuarius were reported as the vectors of Bursaphelenchus xylophilus, pine wood nematode in Korea. According to Kwon et al. (2006), each of 2 species has occupied their own regional distribution : M. saltuarius in southern part including Jeju island and M. alternatus in mid-northern part of Korean peninsula. We measured the supercooling point (SCP) of 2 species (laboratory-reared populations) by each of developmental stages. The SCPs of 2nd, 3rd and 5th instar larvae of M. saltuarius were -7.68±0.19℃, -7.02±0.69℃, -4.93±1.34℃ each of stages. On the other hand, the SCPs of 3rd, 4th, 5th instar larvae and pupae of M. alternatus. were -4.46±1.12℃, -5.94±1.33℃, -7.83±1.44℃, -9.53±1.78℃ each of stages. The SCPs of M. saltuarius larvae generally was lower than that of M. alternatus. The pupae of M. alternatus and 2nd instar larvae of M. saltuarius had the lowest SCP among measured samples. On the other hand, the highest SCP were recorded in 2nd and 5th instar larvae, each. This result shows that regional distribution of 2 beetles may be associated with the adaptation capacity to low temperature represented by the SCP as well as the developmental temperature. However, beetles experimented were not collected from pine forest fields. In further study, we are planning experiments with field populations and all developmental stages.
        16.
        2008.10 구독 인증기관·개인회원 무료
        Sclerodermus harmandi populations were collected from 6 Korean regions (Seoul, Gangwon, Chungcheong, Jeolla, Gyeonasang and Jeju provinces), 1 Chinese region (Nanjing) and 1 Japanese region (Tokyo). Above all was identified as the same species based on morphological characteristics. In present study, we compared the intra-specific characteristics of regional isolated populations of S. harmandi based on nucleotide and amino acid sequences of variant genomic and mitochondrial loci: the full length of internal transcribed spacer 1 and 2 (ITS1 & ITS2), the complete cytochrome oxidase subunit I and II (COI & COII) and tRNA genes for aspartate and lysine and 5'end of ATPase 8 genes. There were no significant differences among the analysed 9 populations regardless of regional segregation. The nucleotide and translated amino acid sequences similarities were significantly high, despite some sequence differences were found in same loci. This result support the report based on the morphological characteristics. However, we are conducting further study to identify whether sequence differences in specific loci are the characteristics of individual level in population or population level and to analyse the full sequences of mitochondrial DNA by regional segregation.
        17.
        2004.12 구독 인증기관 무료, 개인회원 유료
        Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo. Human ES cells have the capacity to differentiate into various types of cells in the body. Human ES cells are indefinite source of cells for cell therapy in various degenerative disorders including neuronal disorders. Directed differentiation of human ES cells is a prerequisite for their clinical application. The objective of this study is to develop the culture condition for the derivation of neural precursor cells from human ES cells. Neural precursor cells were derived from human ES cells in a stepwise culture condition. Neural precursor cells in the form of neural rosette structures developed into neurospheres when cultured in suspension. Suspension culture of neurospheres has been maintained over 4 months. Expressions of nestin, soxl, sox2, pax3 and pax6 transcripts were upregulated during differentiation into neural precursor cells by RT-PCR analysis. In contrast, expression of oct4 was dramatically downregulated in neural precursor cells. Immunocytochemical analyses of neural precursor cells demonstrated expression of nestin and SOX1. When induced to differentiate on an adhesive substrate, neuro-spheres were able to differentiate into three lineages of neural systems, including neurons, astrocytes and oligo-dendrocytes. Transcripts of sox1 and pax6 were downregulated during differentiation of neural precursor cells into neurons. In contrast, expression of map2ab was elevated in the differentiated cells, relative to those in neural precursor cells. Neurons derived from neural precursor cells expressed NCAM, Tuj1, MAP2ab, NeuN and NF200 in immunocytochemical analyses. Presence of astrocytes was confirmed by expression of GFAP immuno-cytochemically. Oligodendrocytes were also observed by positive immuno-reactivities against oligodendrocyte marker O1. Results of this study demonstrate that a stepwise culture condition is developed for the derivation of neural precursor cells from human ES cells.
        4,000원
        18.
        2015.07 서비스 종료(열람 제한)
        MicroRNAs (miRNAs) are a class of non-coding RNAs approximately 21-nt in length which play important roles in regulating gene expression in plants. Although many miRNA studies have focused on a few model plants, miRNAs and their target genes remain largely unknown in hot pepper (Capsicum annuum), one of the most important crops cultivated worldwide. We here employed high-throughput small-RNA and degradome sequencing to comprehensively identify small-RNAs and their targets in pepper. From these, we identified several novel targets of miRNAs, including the major de novo methylation enzyme involved in RNA-directed DNA methylation in plants. Furthermore, we identified several highly abundant 22-nt miRNA families that target conserved domains in NB-LRRs and trigger the production of phased secondary siRNAs. We showed that transient co-expression of can-miR482 with Rpi-blb1, one of the potato NB-LRRs, resulted in the attenuation of the hypersenstive responses in Nicotiana benthamiana, suggesting that interaction between miR-482 family and disease resistance proteins is likely to serve as a conserved trigger for defense mechanism in Solanaceae. This work provides the first reliable draft of the pepper small RNA transcriptome that offers an expanded picture of miRNAs in relation to NB-LRR regulation, providing a basis for understanding the functional roles of miRNAs in disease resistance pepper.
        19.
        2015.07 서비스 종료(열람 제한)
        MicroRNAs (miRNAs) are a class of non-coding RNAs approximately 21-nt in length which play important roles in regulating gene expression in plants. Although many miRNA studies have focused on a few model plants, miRNAs and their target genes remain largely unknown in hot pepper (Capsicum annuum), one of the most important crops cultivated worldwide. We here employed high-throughput sequencing to comprehensively identify small RNAs and their targets in pepper. From these, we identified several novel targets of miRNAs, including the major de novo methylation enzyme involved in RNA-directed DNA methylation in plants. Furthermore, we identified several highly abundant 22-nt miRNA families that target conserved domains in NB-LRRs. We showed that transient co-expression of the miRNA with NB-LRRs, resulted in the attenuation of the hypersenstive responses in Nicotiana benthamiana, suggesting that interaction between miRNA family and disease resistance proteins is likely to serve as a conserved trigger for defense mechanism in Solanaceae. This work provides the first reliable draft of the small RNA transcriptome in pepper that offers an expanded picture of miRNAs in relation to NB-LRR regulation, providing a basis for understanding the functional roles of miRNAs in disease resistance.
        20.
        2015.06 서비스 종료(열람 제한)
        Diffuse involvement of the right pulmonary artery (PA) associated with fistula between the PA and coronary artery is report-ed in a woman with Takayasu’s arteritis. Both the subclavian arteries were totally occluded and drained by the meanderinged artery arising from both common carotid arteries. Lung perfusion scan revealed perfusion defect of right lung. Two fistulas were identified. A large fistula was between the right PA and left circumflex artery. A small fistula was between the right PA and left anterior descending artery. This is a rare case of Takayasu’s arteritis presenting with a coronary – pulmonary artery fistula that is secondary to a diffuse unilateral involvement of PA.
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