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        검색결과 490

        181.
        2016.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Even though klotho deficiency in mice exhibits multiple aging-like phenotypes, studies using large animal models such as pigs, which have many similarities to humans, have been limited due to the absence of cell lines or animal models. The objective of this study was to generate homozygous klotho knockout porcine cell lines and cloned embryos. A CRISPR sgRNA specific for the klotho gene was designed and sgRNA (targeting exon 3 of klotho) and Cas9 RNPs were transfected into porcine fibroblasts. The transfected fibroblasts were then used for single cell colony formation and 9 single cell–derived colonies were established. In a T7 endonuclease I mutation assay, 5 colonies (#3, #4, #5, #7 and #9) were confirmed as mutated. These 5 colonies were subsequently analyzed by deep sequencing for determination of homozygous mutated colonies and 4 (#3, #4, #5 and #9) from 5 colonies contained homozygous modifications. Somatic cell nuclear transfer was performed to generate homozygous klotho knockout cloned embryos by using one homozygous mutation colony (#9); the cleavage and blastocyst formation rates were 72.0% and 8.3%, respectively. Two cloned embryos derived from a homozygous klotho knockout cell line (#9) were subjected to deep sequencing and they showed the same mutation pattern as the donor cell line. In conclusion, we produced homozygous klotho knockout porcine embryos cloned from genome-edited porcine fibroblasts.
        4,000원
        182.
        2016.07 구독 인증기관·개인회원 무료
        With the rapid development of digital technologies and the Internet, the boundaries between countries are shrinking and markets are becoming global (Oh et al., 2016). Simultaneously, cross-border online shopping is another trend that has spread across the world, and global e-commerce has now become a reality (Johnson et al., 2003; Moore, 2015). However, in prior studies related to eWOM, the national culture has received little attention among the numerous factors that could adjust the effect of eWOM (Christodoulides et al., 2012). In addition, in the real world, although individuals are frequently exposed to combined eWOM messages containing both positive and negative information about the same product, most previous studies on eWOM have focused on the one-sided eWOM valence. There are not many empirical studies on the influence of the two-sided eWOM valence on consumers’ persuasions. Thus, Study I examines the attitude effect of the two-sided eWOM valence from a cross-cultural perspective, particularly on the basis of the differences in thinking styles between the Easterners and Westerners. For this, we use a 2[Valence: positive/negative, negative/positive] x 2[Culture: East (South Korea), West (United States)] factorial design. To classify the culture, the thinking style was measured as a within-group variable. As a result, the interaction effect between valence and culture (nation) was significant. Specifically, in the East (South Korea), no significant difference existed in the changes in brand attitude depending on the two-sided eWOM valence, whereas brand attitude changes from a negative/positive presentation order in the West (United States) were significantly larger than the positive/negative presentation order. Study II demonstrates the mediated moderation effect of perceived cognition congruency in a cross-cultural setting for explaining the underlying mechanism. Drawing on the cognitive fit theory, we present a two-sided eWOM-consumers’ perceived cognition congruency proposition: the two-sided eWOM valence that matches the information processing order consumers habitually have would facilitate the favorable comprehension (reflected by perceived cognition congruency) and assessment (reflected by changes in brand attitude) of the reviews. As a result, the two-sided eWOM valence indirectly affects brand attitude changes by mediating perceived cognition congruency. This valence directly affects the brand attitude changes in the Westerner (United States) group, which has an analytical thinking style. However, the direct and indirect effects of two-sided eWOM valence on brand attitude changes are not significant in the Easterner (South Korea) group, which has a holistic thinking style. This examination might explain why differences in the changes in brand attitude between the Easterners and Westerners were revealed through the twosided eWOM valence, thus providing in-depth insights into consumer responses for the valence. This study expands the diversity of studies conducted on the characteristics of the two-sided eWOM. Furthermore, it is expected to provide a strategic direction and practical implications for two-sided eWOM-driven information management by organizations.
        186.
        2016.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was designed to develop and to qualify a coffee alternative beverage using a mixture of coffee beans and roasted black beans (Rhynchosia nulubilis). Therefore, the total isoflavone content (TIC), total phenol content (TPC), antioxidant activity, anti-inflammatory activity, NFATc1 (Nuclear factor of activated T-cells c1) expression in RANKL (receptor activator of nuclear factor kappa-B ligand)-stimulated RAW264.7 cells and sensory evaluation were measured for 5 different Cb (coffee bean)-RoS (roasted seomoktae) mixture extracts (Cb100RoS0, Cb75RoS25, Cb50RoS50, Cb25RoS75, and Cb0RoS100). Cb0RoS100 had the highest TIC (516.83±36.61 mg/100 g) and TPC (18.11±1.77 mg TAE/100 g) along with the highest antioxidant activity as measured by DPPH radical scavenging activity (73.55±8.11%) and ABTS radical scavenging activity (63.27±7.27%). Also, Cb0RoS100 showed the highest anti-inflammatory activity as measured by NO production (13.57±2.21 μM) and PGE2 production (3.25±0.21 ng/mL). The more the RoS ratio was increased in the mixtures of Cb-RoS, the more the NFATc1 protein expression was decreased in RANKL-stimulated RAW264.7 cells. In case of sensory evaluation, Cb50RoS50 had the highest scores for flavor, delicate flavor and overall quality, which were similar to those in Cb alone (Cb100RoS0). We suggest that the use of RoS replacement instead of Cb in/as a coffee alternative beverage may help to reduce the risk of caffeine-related bone loss and/or bone disease by effectively blocking NFATc1 expression in RANKLstimulated RAW264.7 cells compared with Cb alone.
        4,000원
        187.
        2016.04 구독 인증기관·개인회원 무료
        Recently, many studies have shown that propolis has diverse health beneficial effects such as anti-cancer, anti-bacterial, anti-inflammation, and anti-oxidant activities. Water-insolubility of propolis has made it extremely difficult in manufacturing health beneficial beverages containing propolis. In this study, the solubility of propolis was dramatically improved by entrapping with beta-cyclodextrin and the prebiotics effect of water-soluble propolis on the yogurt fermentation was investigated. Lactobacillus pentosus SC60 was selected as a starter for the yogurt fermentation due to its high DPPH radical scavenging activity. Low-fat milk which was supplemented with different concentrations of propolis (0.01, 0.05, 0.1, or 0.5% (w/v)) was fermented with L. pentosus SC60 for 30 h and the viable cell number, pH, and titratable acidity were checked. The rates of decrease in pH and increase in titratable acidity of yogurt after 12 h of fermentation were the highest when 0.5% (w/v) propolis were supplemented. Meanwhile pH and titratable acidity of yogurt without propolis reached 4.54 and 0.73%, respectively, most slowly after 30 hoffer mentation when compared with other yogurts supple mented with propolis. The viable cell number of L. pentosus SC60 in yogurt with 0.5% (w/v) propolis increased with highest rate and it exceeded 9 log CFU/mL at 8 h of fermentation, but that of yogurt with no propolis was only 8.54 log CFU/mL at 30 h of fermentation. This results showed that L. pentosus SC60 grew very well in the presence of water-soluble propolis and it is proposed that propolis acts as prebiotics
        188.
        2016.04 구독 인증기관·개인회원 무료
        Various insect pests and plant disease can outbreak in a field. For the effective control of pests and plant diseases during crop cultivation, farmers simultaneously or sequentially spray various eco-friendly agricultural materials (EFAM), chemical pesticides and microbial control agents on the same fields. It was reported that many agrochemicals are harmful to entomopathogenic fungi, especially some fungicides with broad spectrum activity that are routinely applied for the control of plant diseases. In addition, some pesticides may antagonize the potential insecticidal activity and efficiency of entomopathogenic fungi. Therefore, sometimes the utilization of fungal entomopathogen in forestry and agricultural production is limited because of the undesirable interference from some fungicides and pesticides. There is little research that examines the compatibility of these EFAMs with entomopathogenic fungi and the influence of EFAMs on the control efficacy of mycopesticides. We conducted a study of influence of pretreated eco-friendly agricultural materials on control efficacy of Isaria javanica isolate against sweet potato whitefly.
        189.
        2016.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungus is a useful control agent to sucking type insect such as whitefly and aphid. The fungi are influenced by some environmental factors such as relative humidity, temperature and UV and cause slow and fluctuation in pest control efficacy. Especially, UV kills conidia or spores of entomopathogenic fungi and a mycopesticide using fungi has short control period in field. UV intensity changes from season to season. Survival rate of entomopathognic fungi treated may differ from seasons and will show different control efficacy. Therefore, we conducted a study to estimate the persistence of an Isaria javanica isolate, which was already reported as sweet potato whitefly control agent, in potted greenhouse soil planted different crops. The number of survival spore decreased gradually and differ from seasons.
        190.
        2016.04 구독 인증기관·개인회원 무료
        As ubiquitous organisms entomopathogenic fungi may natually occur within environment including phylloplanes and soil or deposite and survive for a while after spraying a fungal suspension to control insect pest. The existence of pathogenic fungi is a threat to arthropods foraging for food and oviposition sites. The detection and avoidance of pathogens is important for host survival, longevity and ultimate fitness. Although entomopathogenic fungi are ubiquitous worldwide and act as common natural enemies of many invertebrate species, very few studies have conducted abiut the detection and avoidance of pathogenic fungi by insect pest. We have studied that an insect pest can recognize a high virulence fungi on crop surface, avoid oviposition and don’t enter the field treated their pathogen.
        191.
        2016.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are natural enemies of insect pests and contribute to the natural regulation of their host populations. These fungal group are often used as active ingredients for microbial insect pest control. In addition, the potential antimicrobial effect by entomopathogenic fungi including Beauveria bassiana, Lecanicillium spp., and Isaria fumosorosea have recently been reported against fungal plant pathogens. Dual microbial control effects with entomopathogenic fungi against both aphids and cucumber powdery mildew had reported in Canada. In our previous studies we conducted bioassay with entomopathogenic fungi to develop dual microbial control agent which can control both aphid and fungal plant disease. We selected an Beauveria bassiana isolate which has high dual control effects against both cotton aphid, Aphis gossypii and sclerotinia rot, Sclerotinia sclerotiorum. In this study, we have tested the dual control efficacy of the B. bassiana isolate against cotton aphid and sclerotinia rot on whole potted cucumber plants. We found that the B. bassiana isolate protected the plant from cotton aphid and sclerotinia rot under laboratory condition.
        192.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to investigate effects of Maitland orthopedic manipulative physiotherapy and stretching on pain, cervical range of motion, and muscle tone of adults with forward neck posture. A total 40 subjects were divided into a Maitland OMPT group(n=20) and a stretching group(n=20), performing joint mobilization exercise and stretching three times per week for six weeks. As for changes in pain, statistically significant decrease were found before and after the exercise within group comparison( p<.01), while no statistically significant difference was observed between-group comparison. In changes in cervical range of motion before and after the exercise, the Maitland OMPT group showed statistically significant increase(p<.01) in flexion, (left lateral flexion(p<.05), extension, left rotation, right rotation, and right lateral flexion, while the stretching group showed statistically significant increase(p<.05) in extension(p<.01), left rotation, left lateral flexion, right rotation, and right lateral flexion. However, no significant differences in between group comparison in flexion, extension, right rotation, left rotation, right lateral flexion and left lateral flexion. The results of measuring muscle tone changes showed that the Maitland OMPT group and the stretching group did not show significance in within and between group comparison(p<.05). In conclusion, the Maitland OMPT and stretching were effective on improving pain and range of motion.
        4,000원
        193.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 인적자원관행의 보편적 접근법을 토대로 하여 인적자원관행이 기업성과에 미치는 영향과 IMF 이후 비정규직비율이 급격하게 증가하면서 고용불안을 야기하는 현 상황에서 달라진 고용형태, 즉 비정규직 비중이 인적자원관행과 기업성과 간 관계에 미치는 조절효과를 분석하는데 초점을 두고 있다. 분석 결과, 성과배분보상과 고용안정협약은 주관적 재무성과와 유의한 관계를 미치는 것으로 나타났다. 그러나 고용안정협약은 가설과 달리 주관적 재무성과에 부정적 영향을 미치는 것으로 나타났다. 노동생산성에 대해서는 성과배분보상, 직무분석 실시와 종업원 참여가 유의한 정(+)의 영향을 미치는 것으로 나타났다 인적자원관행과 기업성과에 대한 비정규직비율의 조절효과를 실증 분석한 결과, 비정규직 비율 이 높을 경우 공식훈련제도, 직무분석, 종업원 참여와 같은 전략적 인적자원관행의 중요성이 더욱 크다는 것을 알 수 있었다. 즉, 비정규직비율이 높을 경우 종업원에 대한 공식훈련이 더욱 필요하고 직무분석 실 시와 종업원의 경영계획에 대한 의견을 반영하는 노력이 기업성과에 긍정적인 효과를 주는 것으로 확인 되었다. 본 연구는 보편적인 인적자원관행이라고 여겨졌으나 기업을 둘러싸고 있는 여러 상황이 변화함 에 따라 모범사례(best practice)라고 여겼던 일부 인적자원관행이 현 기업 상황에 맞지 않을 수 있다는 점과 비정규직 비율이 높을 경우 보편적인 인적자원관행(human resource practices)의 실시는 더욱 더 중요한 시스템이라는 점을 시사하고 있다. 연구 결과를 토대로 연구의 한계점과 향후 연구방향에 대해 논의하였다.
        6,300원
        194.
        2015.12 구독 인증기관 무료, 개인회원 유료
        DNA methylation is the most common and well-characterized epigenetic change in human cancer. Recently, the association between GATA-binding protein 5 (GATA5) methylation and carcinogenesis of various types of tumors was investigated. The aim of the present study was to evaluate the effect of GATA5 methylation status on clinicopathological features and prognosis in primary non-muscle invasive bladder cancer (NMIBC) patients with a long-term follow-up period. The GATA5 methylation status was determined for 171 human bladder specimens (eight normal controls [NCs] and 163 primary NMIBC patients) using quantitative pyrosequencing analysis. The primary NMIBC tissues were obtained from patients who underwent transurethral resection (TUR) for histologically diagnosed transitional cell carcinomas between 1995 and 2012 at Chungbuk National University Hospital. GATA5 methylation was significantly higher in NMIBC patients than in NCs and was significantly associated with higher grade and more advanced stage of cancer. Kaplan-Meier estimates showed significant differences in tumor recurrence and progression according to GATA5 methylation status (each p<0.05). Our results show that increased methylation of GATA5 was significantly associated with not only aggressive characteristics but also poor prognosis in primary NMIBC patients. Alteration of GATA5 methylation might be used as a biomarker for prognosis of NMIBC patients. However, prospective and functional investigations are necessary to clarify the role of GATA5 methylation in future clinical management of patients with NMIBC.
        4,000원
        197.
        2015.10 구독 인증기관·개인회원 무료
        We investigated the distribution of ixodid ticks in severe fever with thrombocytopenia syndrome (SFTS) case reported areas using flagging method from May to November 2014 in Korea. We collected 13,471 ixodid ticks with 2 genera and 3 species. Among them, Genus Haemaphysalis and Ixodes accounted for 99.9% (13,455) and 0.1% (16), respectively. Genus Haemaphysalis consisted of 2 species, H. longicornis (96.2%) and H. flava (3.7%). I. nipponensis was only collected in Genus Ixodes. H. longicornis was the dominant species (over 90%) in most study areas. Ixodid ticks were evenly distributed at various environmental sites, such as residences, hills, grassfields, fields, graves, copses, other sites. The further study on SFTSV infection in ixodid ticks will be needed.
        198.
        2015.10 구독 인증기관·개인회원 무료
        A surveillance of chigger mites was performed to monitor the incidence of scrub typhus vectors at 4 environmental collection points of 6 locations from September to November 2014 in Korea. During the survey period, 420 chigger mites were collected and the dominant species was Leptotrombidium scutellare (42.6%). The first appearance of chigger mite was at 37th week (9.3.-9.10.) and the collected numbers of chigger mites was the highest at 43rd week (10.17.-10.23.). In Goryeong-gun, 299 chigger mites were collected, whereas 5 chigger mites were collected In Yesan-gun. The high environmental collecting rates were recorded at rice field (56%) and waterway (20%). The annually collected numbers (2012-2014) of chigger mites were compared with the average temperatures in August. This result suggests that the average temperature in August might be related with the annual incidence of scrub typhus vectors in Korea. However, the relationship between climate factors and the density of chigger mites needs to be studied by long-term periodical surveillance.
        199.
        2015.06 구독 인증기관 무료, 개인회원 유료
        Osteoclasts originated from hematopoietic stem cells are multi-nucleated cells that can resorb the bone matrix. Receptor activator of nuclear factor kappa-B (RANK)/RANK ligand (RANKL) signaling pathway is crucial for the differentiation and activation of osteoclasts. In this study, we investigated for the first time whether or not RANKL induced mitogen- and stress-activated kinase 1 (MSK1) phosphorylation at Ser 376. Activation of MSK1 was detected as soon as 5 min after RANKL stimulation and sparsely detected at 30 min after stimulation. RANKL-induced MSK1 phosphorylation occurred in a dose-dependent manner. MSK1 is known as a downstream signaling molecule of cAMP-dependent protein kinase (PKA). Treatment with the PKA inhibitor H89 significantly suppressed c-Fos and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1) induction upon RANKL stimulation. In addition, cAMP response element-binding protein (CREB) phosphorylation was extremely inhibited by H89 treatment. Mitogen-activated protein kinases (MAPKs) have been investigated for induction of MSK1 phosphorylation. Specific signaling pathway inhibitors for p38 and extracellular signal-regulated kinases (ERKs) significantly blocked RANKL-induced MSK1 activation. Finally, as a downstream effector of the p38-MSK1 pathway, c-Fos transcriptional activity was determined. RANKL-mediated elevation of c-Fos transcriptional activity was significantly suppressed by p38 inhibitor. Moreover, a dominant negative form of CREB suppressed activation of NFATc1. In conclusion, RANKL-stimulated MSK1 phosphorylation could play a role in induction of NFATc1 through CREB and c-Fos activation as a downstream molecule of p38, ERK MAPKs, and PKA. Our results support basic information for the development of osteoclast specific inhibitors.
        4,000원
        200.
        2015.04 구독 인증기관·개인회원 무료
        This study is the first report about the toxicity of pesticides to the mycophagous predator, I. koebelei, of powdery mildew of agricultural crops. Pesticides we tested are composed of synthetic and environmental-friendly products and being used conventionally for the control of insect or microbial pests on cucumber in Korea. our study was conducted to determine the relative toxicities of several pesticides used in Korea cucumber production to mycophagous natural enemy, I. koebelei and to provide a background for implementation of integrated powdery mildew management programs. Based on IOBC classification, three insecticides, bifenthrin + imidacloprid, acetamiprid + indoxacarb, acetamiprid + etopheprox are classified as having a Class 4 (harmful). Spiromesifen showed the low toxicity to the survival and the fecundity of I. koebelei when this chemical had been exposed to 3rd larva or newly emerged adult via feeding with cucumber powdery mildew. However, pyriproxyfen not only decreased the fecundity of female adult but also strongly prohibited from pupation. Many commercial biological or botanical pesticides can restrict the population of I. koebelei. However, Q pact (a.i. Ampelomyces quisqualis 94013), Top seed (a.i. Paenibacillus polymyxa AC-1), BT one (Bacillus thuringiensis) and Solbitchae (insecticidal microorganism) had no toxicity to I. koebelei when this chemical had been exposed to 3rd larva or newly emerged adult feeding with cucumber powdery mildew.