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        검색결과 148

        61.
        2017.10 구독 인증기관·개인회원 무료
        The members of the genus Flavivirus are noteworthy, as they cause infectious diseases in humans, such as Zika, denguefever, yellow fever, West Nile, and Japanese encephalitis. Due to the increased awareness of the public health risk posedby flavivirus-infected mosquitoes, mosquito collections were performed in six urban parks of South Korea, as the parksare designated for human recreation but also provide suitable habitats for mosquitoes. We examined the diversity andabundance of mosquito species and conducted molecular diagnostics for the detection of flavivirus infections. Monthlycollections were carried out in each park from March to August in 2017. A total of 4,851 mosquitoes (5 genera and13 species) were collected using BG-sentinel traps and then investigated for flavivirus infections. Pathogenic flavivirusinfections causing human diseases were not observed in the field-collected mosquitoes. However, insect-specific flavivirus(ISF) infections were detected in several mosquito pools. ISF has been previously known to enhance or suppress the replicationof medically important flaviviruses in co-infected mosquito cells. In this study, partial sequences of ISF were analyzed.However, further studies are needed in order to determine its genetic characterization and biological function in vivo.
        62.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The organic light-emitting diodes are fabricated with six anthracene derivatives containing simple substituents such as phenyl or naphthyl group. The device structure is as in the following: Indium tin oxide (ITO) (180 nm)/4,4-4,4`,4``-tris[N-(1-naphthyl)-Nphenylamino] triphenylamine (2-TNATA) (30 nm)/4,4`-bis[N-(1-naphthyl)-N-phenyl-1-amino] biphenyl (NPB) (20 nm)/Emitting compound (30 nm)/2,2′,2"- (1,3,5-Benzinetriyl)-tris (1-phenyl-1-H–benz-imidazole) TPBi (40 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm). In the emitting layer the anthracene derivatives are used without any dopant. All the six devices show blue emissions. Among the tested diodes, the one with 9-(2-naphthyl)-10-(p-tolyl) anthracene (2-NTA) exhibited luminous efficiency, power and external quantum efficiencies of 3.26 cd/A, 0.98 lm/A, 2.8 % at 20 mA/cm .
        4,000원
        63.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Selecting an appropriate antigen with optimal immunogenicity and physicochemical properties is a pivotal factor to develop a protein based subunit vaccine. Despite rapid progress in modern molecular cloning and recombinant protein technology, there remains a huge challenge for purifying and using protein antigens rich in hydrophobic domains, such as membrane associated proteins. To overcome current limitations using hydrophobic proteins as vaccine antigens, we adopted in silico analyses which included bioinformatic prediction and sequence-based protein 3D structure modeling, to develop a novel periodontitis subunit vaccine against the outer membrane protein FomA of Fusobacterium nucleatum. To generate an optimal antigen candidate, we predicted hydrophilicity and B cell epitope parameter by querying to web-based databases, and designed a truncated FomA (tFomA) candidate with better solubility and preserved B cell epitopes. The truncated recombinant protein was engineered to expose epitopes on the surface through simulating amino acid sequence-based 3D folding in aqueous environment. The recombinant tFomA was further expressed and purified, and its immunological properties were evaluated. In the mice intranasal vaccination study, tFomA significantly induced antigen-specific IgG and sIgA responses in both systemic and oral-mucosal compartments, respectively. Our results testify that intelligent in silico designing of antigens provide amenable vaccine epitopes from hard-to-manufacture hydrophobic domain rich microbial antigens.
        4,000원
        64.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate the influence of a two-week English-language orientation program at a Korean university on first-year students’ perceptions of English. This quantitative study contributes to the local literature by documenting the changes on a preand post-course survey that measured participants’ willingness to communicate, foreign language anxiety, attitudes towards English, and perceptions of English as a global language. Key results of independent-samples t-tests indicated that student perceptions showed statistically significant changes on five of the six scales, and that the biggest influences of the program were on willingness to communicate and lessening student anxiety. The study also investigated the link between program satisfaction and experience of studying English abroad, finding that there was no relation between them. However, a one-way ANOVA and correlation analysis indicated that there was a relationship between program satisfaction and students’ self-rated proficiency, finding that the lower-proficiency students were slightly less satisfied than those rating themselves as “average” or “good” English speakers. The study concludes with recommendations for future studies and for planning English-language orientation programs in Korean universities.
        5,500원
        65.
        2017.05 구독 인증기관·개인회원 무료
        Generally, fate of spematogonial stem cells (SSCs) can be determined specifically by microenvironments enclosed with various extracellular matrix (ECM) components and integrins recognizing directly ECM proteins play an pivotal role in transporting ECM-derived signals into cytoplasm, resulting in inducing a variety of biological functions such as cell attachment, self-renewal and differentiation. However, to date, studies on type of integrins expressed on the undifferentiated SSCs remain unclear. Therefore, we tried to investigate systematically what kind of integrin subunits are expressed transcriptionally or translationally in the SSCs derived from testis of hybrid B6CBAF1 mouse. For these, isolation of SSCs from testis were conducted by magnetic activated cell sorting (MACS) using Thy1 antibody. Subsequently, transcriptional and translational level of integrin α and β subunits in the isolated SSCs were measured by real-time PCR and fluorescene immunoassay, respectively. As the results, transcriptional levels of genes encoding total 25 integrin subunits were quantified, and integrin α4, α6, α7, α9, αV, αL and αE and integrin β1, β5 showed higher expression levels than other subunits. By contrast, integrin α3, α5, α 10 and α11 and integrin β2, β3, β4, β7 were weakly transcribed. When translational levels of the integrin α subunits showing high transcription level (α4, α6, α7, α9, αV αL, and αE) were measured, integrin α6, α7, α9, αV and αL were higher than integrin α4 and αE. In case of integrin β subunit, β1 evaluated more expression than β5. From these results, we speculate that the undifferentiated SSCs derived from hybrid B6CBAF1 mouse may express integrin α4β1, α6β1, α7β1, α9β1, αVβ1 and/or αVβ5 on plasma membrane. Moreover, this information will greatly contribute to constructing non-cellular niche supporting self-renewal of SSCs in the future.
        66.
        2017.04 구독 인증기관·개인회원 무료
        Aedes albopictus is one species of mosquito transmitting flavivirus causing Dengue, Zika, and West Nile fever. Although it is an important disease vector, the genetic study of Ae. alpopictus populations has not been undertaken yet in South Korea. Here, we investigated the genetic variation of 99 Ae. albopictus individuals collected from 29 sites in nine provinces in 2016, through mitochondrial COI gene analysis. Haplotype analyses revealed seven haplogroups in South Korea. The main haplogroup, comprising 76 individuals (77.8%), was genetically identical to the one from Nagasaki. Two groups from Jeju Island (11) and the southern coast of South Korea (nine) were closely related to different Ae. albopictus strains from Kumamoto and Guangdong/Fujian, respectively. However, the others (four) were distinct from these two countries. No geographic divisions of populations were found in the study regions. The results suggest the possibility that the currently prevalent Ae. albopictus in South Korea, represents a part of the descendants that originated from nearby countries. However, more comprehensive investigations are needed to explain its movement routes.
        75.
        2016.04 구독 인증기관·개인회원 무료
        Pheromone biosynthesis activating neuropeptide (PBAN) produced in the subesophageal ganglion is known to stimulate pheromone production in the pheromone gland. A cDNA isolated from female adult heads of Maruca vitrata encodes 197 amino acids including PBAN, designated as Mvi-PBAN, and four other neuropeptides (NPs): diapause hormone (DH) homologue, α-NP, β-NP and γ-NP. All of the peptides are amidated in their C-termini and shared a conserved motif, FXPR(or K)L-NH2 structure. Mvi-PBAN consists of 35 amino acids as previously reported (Chang and Ramasamy, 2014). RT-PCR analysis revealed that Mvi-PBAN cDNA was expressed in all examined body parts. Nucleotide sequence analysis of RT-PCR products indicated the Mvi-PBAN sequence was identical in all examined body parts of both sexes. These results suggest that Mvi-PBAN expression is maintained in examined stages or tissues.
        76.
        2016.04 구독 인증기관·개인회원 무료
        Brachymystax lenok tsinlingensis (family Salmonidae), cold freshwater fish, is endemic to Asia. This species is currently distributed throughout Russia, Mongolia, China and the Korean Peninsula. B. lenok tsinlingensis in South Korea was severely affected by anthropogenic activities such as habitat destruction, agricultural run-off and water pollution, and hence this fish has recently been dramatically decreased in its population sizes and become now critically endangered. To recover the number of individuals of B. lenok tsinlingensis, stocking or translocation programs have been conducted continuously by local governments since 1970s. However, these programs made little effort to clarify populations that may have originated from stocked, translocated or introduced fish. An understanding of genetic characteristics of endangered populations is critical to develop effective conservation and restoration plans especially because genetic diversity ensues their future fate. Therefore, we assessed the “conservation status” of this species by estimating the level of genetic diversity and genetic structure among ten geographic populations including restored populations via reinforcement and supplementation. Also, we aimed to trace the genetic origins of the newly translocated population (Chiak) through a restoration practice program. Moreover, we inferred the phylogenetic relationships among Korean lenok populations as well as across the Northeast Asia. Two hundred eighteen individuals of B. lenok tsinlingensis were sampled from ten localities (Yanggu, Injae, Seorak, Bangtae and Hongcheon: North Han River basin; Pyeongchang, Chiak and Jeongseon: South Han River basin; Taebaek and Bonghwa: Nakdong River basin in South Korea). Based on mitochondrial DNA (mtDNA) control region and eight nuclear microsatellite loci, we found extremely low levels of within-population genetic diversity, which suggests small effective population sizes (Ne) within populations. For mtDNA control region, each population housed one, or at most, two haplotypes that are restricted to the respective localities, meaning that these ‘genetically unique’ lineages will be lost permanently if the local populations undergo extinction. The overall values of haplotype diversity (h) and nucleotide diversity (π) for the entire Korean population were 0.703 ± 0.024 and 0.021 ± 0.010, respectively. In the case of microsatellites, average number of alleles across the eight loci for the entire population was 9.1 and allelic richness (AR) per population ranged from 2.375 to 4.144 (mean = 3.104). The values of observed heterozygosity (HO) and expected heterozygosity (HE) were similar to each other [HO: 0.400 ~ 0.590 (mean = 0.518); HE: 0.407 ~ 0.608 (mean = 0.504)]. The inbreeding coefficient (FIS) values were generally low, ranging from 0.048 to 0.279. Consequently, the majority of the populations (except Yanggu and Pyeongchang) were not significantly deviated from Hardy-Weinberg equilibrium (HWE), suggesting random mating at these loci tested. In addition, we found that Korean lenok populations were significantly genetically isolated from each other, with private mtDNA haplotypes and microsatellite alleles, indicating limited gene flow among populations, strong effects of genetic drift due to small Ne, or a combination of both. The Mantel test of microsatellites revealed a significant correlation (r = 0.414, P = 0.04) between genetic and geographic distances for pairwise comparisons among the ten populations, while that of mtDNA showed a lack of correlation. Given the shared identical mtDNA haplotype and similar microsatellite allelic distributions between Chiak and Hongcheon populations, we suggest that the restored (introduced) Chiak population would be inferred to be genetically originated from Hongcheon population. Phylogenetic relationships among Northeast Asian populations showed that South Korean lineages have more recently diverged from China (Yellow River), than between North Korea and Russia. Although the phylogenetic relationship would be expected to be associated with geography, South-North Korea and China populations with a similar latitude was more phylogenetically closely related. These findings may suggest a possible scenario for the historical movements of B. lenok tsinlingensis in Northeast Asia during Last Glacial Maximum (LGM). It would be supported by the line of evidence that most lenok populations migrated to southward from Northern Asia such as Russia and Mongolia during LGM because the Korean Peninsula was landlocked as inland epoch and functioned as a southern shelter with Yellow River. For this reason, the Korean Peninsula is suggested to be an important geographical region for better understanding phylogenetic relationships and evolutionary histories of B. lenok tsinlingensis across the Northeast Asia. Despite large efforts made to develop several restoration programs in South Korea for B. lenok tsinlingensis, it is still unknown whether these past restoration efforts were successful or fruitless, mainly because of little attention paid to post-restoration monitoring research. Hence, there was a lack of their published official records. In the future, conservation and restoration projects of the Korean lenok populations should consider the genetic data for a better understanding of their ecological and evolutionary trajectories. And finally, we hope that our findings here can help inform on the future effective conservation and restoration plans for B. lenok tsinlingensis populatio ns in South Korea.
        77.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to investigate the effects of core strengthening training on baseball throwing. A total of 14 subjects were recruited from among middle school baseball players. The main outcome measures were as follows: speed guns were used to measure the velocity of baseballs thrown; scored targets were used to measure throwing accuracy; and 50m measuring tapes were used to measure throwing distances. It was found that core strengthening training improved the velocity of baseballs thrown and throwing accuracy and distance. Thus, core strengthening training is effective for improving the throwing ability of baseball players.
        4,000원
        78.
        2016.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to investigate the immunomodulatory effects mixed with Weissella cibaria JW15 strain and black soybean (Glycine max (L.) Merr.). In this experiment, JW15 was cultured in De Man Rogosa and Sharpe (MRS) broth at 37% for 17 hr, and the cells were washed twice with sterile phosphate buffered saline (PBS) (pH 7.2). And black soybean was extracted by ethanol or hot boiling water. The immuno-modulatory effects of mixed JW15 and black soybean extract were investigated by measuring the production of nitric oxide (NO), nuclear factor κB (NF-κB) and cytokine (Interleukin-1β and Tumor necrosis factor-α) in RAW 264.7 macrophage cells or RAW blue cells. The 0.1 % ethanol and hot water extract of black soybean increased NO, NF-κB, and cytokine production in a concentration dependent manner. The NF-κB activation by JW15 mixed with 0.1 % hot water extract of black soybean (0.26 ± 0.02) was significantly higher than JW15 alone (0.20 ± 0.02). Also, combination of JW15 and 0.1% hot water extract of black soybean triggered IL-1β production of 110.19 ± 4.38 pg/mL, which was significantly greater than the JW15 alone (12.06 ± 7.58 pg/mL). The results of this study indicate that combination of Weissella cibaria JW15 and black soybean extract may have an ability to activate innate immune response synergistically. According to these results, the mixture of JW15 and black soybean extract could hold great promise for use in probiotics.
        4,000원
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