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        검색결과 551

        201.
        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).
        202.
        2012.06 구독 인증기관·개인회원 무료
        There are diverse methods of cryopreservation of mammalian embryos with variable degrees of success. Although cryopreservation technique of mammalian embryos has been advanced, freezing stress affect to cellular event such as apoptosis and autophage in embryos. The objective of the study is to investigate the affection of to survival, development, live offspring, apoptosis and autophagy on embryo. Mouse embryos were vitrified and thawed using normal straw and modified cut standard straw (M-CSS), then in vitro cultured until blastocyst stage and transferred to recipient. Recovery rates (100 vs 99.2%), survival rates (99.2 vs 78.6%), developmental rates (18.4 vs 10.7%), total cell numbers (45 vs 37), preganacy rates (34.5 vs 25%) and offspring numbers (10.1 vs 4.9 %) of M-CSS group are significantly higher than those of normal straw vitrified group. Also, rate of apoptosis in blastocysts developed using M-CSS (1.9%) was significantly lower than using normal straw vitrification (2.7%). Apoptosis-related gene, caspase 3, was expressed at the highest level in blastocysts derived from normal straw group. However, no differences of autophagy related gene, Atg6 and expression of LC3 between normal straw and M-CSS groups were observed. In conclusion, the standard vitrification procedure induces mitochondrial apoptosis in zygotes in an autophagy-independent manner, whereas the novel M-CSS procedure may improve embryo vitrification.
        203.
        2012.05 구독 인증기관·개인회원 무료
        We tested the identification ability of DNA barcodes comparing with morphological data using the Korean butterflies. The 921 samples (4.6 samples per species) for 202 resident Korean species except migratory species were used. The obtained samples were morphologically identified based on wing patterns. In a result, genetic divergence to the nearest-neighbouring taxon varied from 0 to 28.2%, with an average of 13.4 per cent. The neighbour joining (NJ) tree profile showed that sequence data for 185 of the 202 species formed distinct barcode clusters. Thus, our results indicated that 91.6 percent of the species were possible to allow the reliable identification using DNA barcoding. The rest 17 species (8.4%) consist of following four cases: clustering separated from each species by less than 1% branch length (two species pairs), paraphyletic clustering (two species pairs and one triple species pair), polyphyletic clustering with sharing barcodes (three species pairs), and clustering separated from existing species by the deep branch divergence (four clusters). However, it was not easy to interpret these ambiguous cases only using our current taxonomic evidences. Therefore, we are performing integrative taxonomy on these cases using other additional evidences such as examination on male genitalia and analysis of other gene regions.
        204.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to identify which width of the base of support(BOS) is safer and more effective in lifting by comparing muscle activations and body sways when lifting objects under the width variation of the BOS. A total of fifteen healthy adults participated in this study. For the width variation of the BOS, the participants changed the width between their feet into three different types(10cm, 32cm, 45cm) and lifted a 10kg four times in each type after going up on a force plate. In order to measure body sways according to the width variation of the BOS, a motion analysis system was used. In addition, in order to measure the muscle activations of lower extremities, including the erector spinae, gluteus maximus, rectus femoris, and tibialis anterior, an electromyogram(EMG) analysis was employed. In addition, the Borg's scale was drawn by quantifying the subjective discomfort levels felt from each width of the BOS. In conclusion, no statistically significant differences according to the width variation of the BOS were observed(p=.295, .308)(p>.05). However, a statistically significant difference was exhibited between the Borg's scale, which indicates the discomfort levels from lifting performances, and the width variation of the BOS (p=.000*).
        4,000원
        205.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to analyze lower limb muscle activity and 3D motion analysis according to change foot arch height during walking. We selected 9 young and healthy people who have been normal foot. And we selected 7 young and healthy people who have been flatfoot. So, people were divided into 2 groups and walked platform during 2 minutes twice for checked by 3D motion analysis. These data were characterized by EMG measurements of three muscles( tibialis anterior, medial and lateral gastrocnemius) while they were walking. The collected data were analyzed by Independent t test using the SPSS statistics program(Ver 12.0). In foot arch change, there were no significant difference in three muscles 3D motion analysis also found that there were no significant difference in joint angles. In this study was to analyze lower limb muscle activity and 3D motion analysis according to change foot arch, but there were no significant difference in 6 muscles neither joint angles.
        4,000원
        206.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Cytokines are known to function as regulatory molecules that can be produced by virtually every nucleated cell type in the body, including lymphocytes, monocytes/macrophages, epithelial cells, fibroblasts, and many others. Cytokines include lymphocyte-derived factors (lymphokines), monocyte-derived factors (monokines), hematopoietic factors (colony-stimulating factors), connective tissue/ growth factors, and chemotactic chemokines. Cytokines released in response to infection can affect tumor development in different ways. When exposed to infectious agents, cytokines are secreted by sentinel cells, such as macrophages and dendritic cells. These cytokines include interleukin 1 (IL-1) and tumor necrosis factor-α, as well as others, such as IL-6, IL-12, and IL-18. When released in sufficient quantities, these molecules can cause inflammation. Chronic inflammation is highly associated with tumor initiation, promotion, and progression. In this article, we review the roles and mechanisms of cytokines in tumor development.
        4,300원
        207.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 환경스트레스 저항성이 증진된 페튜니아를 개발하기 위하여 NDPK2유전자 도입 형질전환 계통 NDPK2-7-1와 SOD2 유전자 도입 형질전환 계통 SOD2- 2-1-1-35간의 교잡에 의해 획득된 후대들의 비생물적 스트레스 저항성을 조사하기 위해 수행되었다. 비 생물적 스트레스 유발원인 메틸바이올로젠(methyl viologen, MV) 100 μM과 200 μM 처리에서 교잡후대들은 그들의 교배 모본 SOD2 유전자나 NDPK2 유전자가 단독으로 도 입된 형질전환 계통이나 비형질전환체 보다 메틸바이 올로젠에 의한 피해를 적게 받았다. 이는 SOD2 유전 자나 NDPK2 유전자가 단독으로 도입된 형질전환 계 통간 교잡에 의해 획득된 후대들이 그들의 교배모본 (SOD2 유전자나 NDPK2 유전자가 단독으로 도입된 형질전환 계통)이나 비형질전환체 보다 산화적 스트레 스에 대한 저항성이 증진되었음을 증명해 준다고 할 수 있다. 이들 교잡후대들은 초장 등 11종류의 양적형질의 특성이 비형질전환체에 비해 약간 길거나 짧긴 하였지 만 비형질전환체와 거의 유사하였으며, 꽃 색갈이나 모양 또한 그들의 교배모본 (SOD2 유전자나 NDPK2 유전 자가 단독으로 도입된 형질전환 계통)이나 비형질전환 체와 차이가 없었다.
        4,000원
        208.
        2011.12 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to determine the effect of macrophages on growth of human colon cancer cells. The results showed that co-culture of colon cancer cells with macrophages inhibited the growth of colon cancer cells (HCT116 and SW620) depending on the number of macrophages, RAW 264.7 cells, and activated THP-1 cells accompanied by down regulation of pSTAT3 in cancer cells. We also found that expression and release of cancer cell growth inhibitory cytokines, IL-1 receptor antagonist (IL-1ra) and IL-10, was increased in macrophages. Blocking of the STAT3 pathway with specific inhibitor and siRNA of STAT3 abolished the growth of colon cancer cells and expression of IL-1ra and IL-10. In addition, neutralization of IL-1ra and IL-10 with antibodies resulted in reversal of macrophage-induced inhibition of cancer cell growth. These data showed that IL-1ra and IL-10 released from macrophages inhibit growth of colon cancer cells through inhibition of the STAT3 pathway.
        4,500원
        209.
        2011.10 구독 인증기관·개인회원 무료
        The entomopathogenic fungi were an important natural pathogenic of insects that has been developed as potential biological control agents for many important agricultural, forest and medical pests. Several these fungi produce a wide range of secondary metabolites with high therapeutic value as antibiotics, cytotoxic substances, insecticides, compounds that promote or inhibit growth, attractor and repellent. Therefore, this study was performed to select the antibacterial activity of liquid culture filtrates of 347 entomopathogenic fungi form Korea soils against two pathogenic bacteria including Ralstonia solanacearum and Escherichia coli using novel method which represents a quick and easily applicable tool obtaining large number of samples. As results, eight-five strains (24%) and seventy-six strains (22%) of these fungal metabolites produced anti-R. solanacearum and anti-E. coli compounds, respectively. The preferential antibacterial activity against R. solanacearum and E. coli gives evidence that these entomopathogenic fungal metabolites might be useful as an agent for bacteria control and the technique was simple to operate and allowed a large number of samples to be handled concurrently.
        210.
        2011.09 구독 인증기관 무료, 개인회원 유료
        This study was undertaken to evaluate the relationship between in vitro maturation and plasminogen activators (PAs) activity on porcine cumulus-oocytes complexes (COCs) exposed to oxidative stress. When COCs were cultured in maturation medium with hydrogen peroxide (H2O2), the proportion of the germinal vesicle breakdown (GVBD) and oocytes maturation were decreased with addition of H2O2, and were significantly (p<0.05) lower in medium with 0.1 mM H2O2 than control group. Also, the rate of degenerated oocytes was increased in as H2O2 concentration increased. When COCs were cultured for 48 h, three plasminogen-dependent lytic bands were observed: tissue-type PA (tPA); urokinase-type PA (uPA); and tPA-PA inhibitor (tPA-PAI). PA activity was quantified using SDS-PAGE and zymography. When H2O2 concentration was increased, tPA and tPA-PAI activities also increased in porcine oocytes cultured for 48 h, but not uPA. In other experiment, embryos were divided into three groups and cultured in (1) control medium, (2) control medium with 1.0 mM H2O2 and (3) control medium with 1.0 mM H2O2 along with catalase in concentrations of 0.01, 0.1, and 1.0 mg/ml, respectively. H2O2 decreased the rate of GVBD and maturation in porcine COCs but catalase revealed protective activity against oxidative stress caused by H2O2. In this experiment, tPA and tPA-PAI activities were higher in media with 1.0 mM H2O2 alone. Increasing concentration of catalase decreased tPA and tPA-PAI activities in porcine oocytes. These results indicate that the exposure of porcine follicular oocytes to ROS inhibits oocytes maturation to metaphase-II stage and increase the oocytes degeneration. Also, we speculated that increased ROS level may trigger tPA and tPA-PAI activities in porcine oocytes matured in vitro.
        4,000원
        211.
        2011.06 구독 인증기관 무료, 개인회원 유료
        Naturalness assessment can be utilized as a criterion to evaluate performance of preferred color corrections and to compare naturalness of images reproduced by displays. This paper presents a new model to assess naturalness based on three dimensional color space. Experimental results indicate that the proposed model outperforms three previous models proposed for the naturalness assessment.
        4,000원
        213.
        2011.05 구독 인증기관·개인회원 무료
        The two-spotted spider mite, Tetranychus urticae Koch, is an economically important pest of crops of plant grown in the field or greenhouse worldwide. It has recently become a serious problem because of the continuous use of acaricides resulting in resistance among spider mite population. Thus, there is a need to find alternative control measures to suppress spider mite populations. In this study, we report the screening result of pathogenic fungi for the control of spider mite. Initial screenings were performed using 352 isolates of putative pathogenic fungi from Korea soils. As results, 11 strains of acaropathogenic fungi were isolated from 8 cadavers of spider mite supporting fungal conidiation. These isolated were identified as four isolates of Beauveria bassiana (6, 2R-3-3-1, 2R-4-5, 2R-4-7), two isolates of Metarhizium anisopliae (4-2, 2-2), one isolate of Clonostachys rosea 5-2, one isolate of Lecanicillium attenuatum 4-1, one isolate of Pochonia suchlasporia 2R-3-1, one isolate of Aspergillus flavus 7 and one isolate of Isaria lilacinus 2R-4-6 by microscopic examination and genetic sequencing of the ITS region. Based on the screening results, eleven isolates were tested for their virulence against adult spider mites. All fungal isolates were pathogenic to spider mite but mortality varied with isolates. These acaropathogenic fungi may be useful to develop eco-friendly acaricide to control two-spotted spider mite.
        214.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was to examine on the respiratory variables, heart rate and muscle activity between the static recovery and dynamic recovery after progressive resistance exercise to maximal point. Subjects were 15 students enrolled in N University. All were tested two times (static recovery and dynamic recovery) and were requested to perform a walking on a treadmill after progressive resistance exercise to maximal point. Electromyography(EMG) was used to monitor the muscle activity(TA: Tibialis Anterior, MG: Medial Gastrocnemius) during gait. CPEX-1 was used to measure the respiratory variables and heart rate. The dynamic recovery group was shown the significant lower heart rate than that of static recovery group at during gait. Respiratory rate showed statistically a significant difference. Electromyography(RMS, root mean square) showed a non-significant difference. But the dynamic recovery group of muscle activity was found highly in TA and MG. This study indicated that the dynamic recovery method evidenced more faster than the static recovery method. And this type of dynamic rest by walking can be a help of recovery after exercise.
        4,000원
        215.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        With comparison of maximum vertical reaction force and lower limb on drop landing between normal and flat foot group, this study is to provide fundamental data of the prevention of injury and the treatment of exercise which are frequently occurred on flat foot group's drop landing. The surface electrodes were sticked on lateral gastrocnemius muscle, medial gastrocnemius muscle, tibialis anterior and the drop landing on a force plate of 40cm was performed with a normal group who had no musculoskeletal disease and a flat foot group of 9 people who had feet examinations. Vertical reaction force were significantly statistically different between two groups(p<.001). Muscle activity of lower limbs in all three parts were not statistically different but showed high tendency on average in the flat foot group. The flat foot group had difficulties in diversification of impact burden and high muscle activity. Therefore, it was suggested that muscular strengthening of knee joints and plantar flexions of foot joints which were highly affected in impact absorption will be required.
        4,000원
        216.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Purpose: The purpose of this study was to estimate the effects of subliminal music with balance imagery training on balance and concentration. Methods: The participants were 45 seniors in an undergraduate school in Korea. The subliminal music with balance imagery training intervention was carried out for 20 minutes. Other interventions were also carried out for 20 minutes. 12 seniors(Group A) listened to subliminal music with balance imagery training, 12 seniors(Group B) listened to subliminal music, 11 seniors(Group C) received balance imagery training, and 10 seniors(Group D) had no intervention(Control group). The grid test is related to measured levels of concentration intensity. Romberg one legged standing test was carried out for 30 seconds. The collected data was analyzed by one-paired t test and one way ANOVA using the SPSS Windows 12 ver. program. Results: The major findings of this study were as follows: Concentration levels of Group A and C improved, and balance levels of Group C and D improved. There was a statistically significant decrease in concentration between Group A and B, Group A and C after intervention. Conclusion: These findings suggest that listening to subliminal music with balance imagery training may be useful in managing concentration in seniors. So it provides basic information for further concentration on improving education on music with balance imagery training.
        4,000원
        217.
        2010.10 구독 인증기관·개인회원 무료
        In agricultural fields, the entomopathogenic fungal species have been investigated for their potential as the biological control agents due to their role of natural enemies for insects. To address the requirements of a potential South Korea based biocontrol effort using entomopathogenic fungi, we investigated the occurrence of various entomopathogenic fungi in 1080 soil samples representing from various area and locations in South Korea. Entomopathogenic fungi were isolated from soils using semiselective medium SDA-D50 contained saboraund dextrose agar, 50 ug/ml dodine, 100 ug/ml chloramphenicol and 50 ug/ml streptomycin. The isolated putative fungi were identified by the determination of internal transcribed spacer (ITS) region sequences of the nuclear ribosomal analysis. As a result, entomopathogenic fungi were found to occur in 30.8% of the soil samples studied. The most abundant species were Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae (Metschn.) Sorok. Isolates of B. brongniartii, Cordyceps sp., Lecanicillium sp., Isaria sp. and Tolypocladium cylindrosporum were also found. The occurrence of entomopathogenic fungi was analyzed by the area and soil types. These positive entomopathogenic fungi may have potential against variety pests in agriculture and forest
        218.
        2010.10 구독 인증기관·개인회원 무료
        This study was conducted to investigate the altitudinal distribution of the ground beetle community in a mountain area during 2007 to 2009, and to examine what habitat characters are most relevant to the distribution of mountain ground beetle species, and finally to identify potential biological indicators for monitoring in forest. The study area was Mt. Sobaeksan National Park (1439 m elevation), in Punggi-up, Gyeongsangbuk-do, Korea. Ground beetles were collected by pitfall traps, which were installed along the altitudinal gradient 437, 757, 1100 and 1420 m. In total, 3,259 individuals were identified as 32 species in 18 genera. The dominant species were Synuchus cycloderus (29.4%), Eucarabus sternbergi sobaeksanensis (15.4%) and Pterostichus orientalis (9.7%) in order. Overall, the ground beetle community structure was different along the altitude (similarity 65.2%) by NMDS ordination, but also were clustered into 2 groups, 437 and 757 m, and 1100 and 1420 m (similarity 57.9%). Therefore, the ground beetle assemblage could provide basic information for forest management. In this study, some ground beetle species were suggested to potential biological indicators along altitudinal gradient.
        219.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        원자전달 라디칼 중합을 이용하여 poly(epichlorohydrine) (PECH)를 주사슬로 한 양친성 가지형 공중합체를 합성하였다. PECH로부터 poly(methyl methacrylate)(PMMA) 및 poly(butyl methacrylate)(PBMA)의 가지형 중합이 성공적임을 1H NMR과 FT-IR분석을 통해 확인하였다. 합성한 가지형 공중합체에 KI나 LiI 염을 도입하였을 때, ether 신축진동 피크가 낮은 wavenumber영역으로 이동하였으며, 이는 배위결합 상호작용 때문이다. PECH-g-PBMA 복합체의 이온 전도도는 PECH-g-PMMA 복합체에 비해 항상 높게 나타났는데, 이는 고무상인 PBMA 사슬의 높은 이동성으로부터 기인한 것으로 확인되었다. 최고 이온전도도 값은 질량비 10 wt%의 KI가 도입된 PECH-g-PBMA 전해질체에서 2.7 × 10 -5 S/cm로 나타났다.
        4,000원
        220.
        2010.06 구독 인증기관 무료, 개인회원 유료
        Chronic inflammatory diseases such as Crohn′s disease and ulcerative colitis are associated with increased risk of colon adenocarcinoma. Apoptic induction of colon cancer cells by cytokines and death receptors is an important anti-cancer therapy. We observed that co-administration of TNFα and IFNγ in human colon cancer cell line, HCT116, resulted in cell death and expression of IL-32. Cleavage forms of caspase-3, caspase-9, and PARP were increased in TNFα / IFNγ-treated HCT116. mRNA expression of death receptors, including TNFR1 and Fas were not changed and NO generation was not induced by combination of TNFα and IFNγ. However, mRNA expression of IL-32α, β, and γ was increased in TNFα / IFNγ-treated HCT116. To determine the effect of IL-32 in HCT116 cell apoptosis by TNFα / IFNγ stimulation, IL-32 siRNA-transfected HCT116 cells were cultured with TNFα / IFNγ and cell proliferation was measured. IL-32 siRNA induced slight recovery of cell viability of TNFα / IFNγ-stimulated HCT116. These results suggest that IL-32 is not directly related to apoptosis of HCT116 by TNFα / IFNγ stimulation. However, IL-32 expression by TNFα or TNFα / IFNγ in a colon cancer cell line is very interesting because of the unknown effect of IL-32 in colon cancer. Our study will contribute to development of studies for IL-32 function in human colon cancer and anti-cancer therapies using cytokines.
        4,000원