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        검색결과 127

        42.
        2017.10 구독 인증기관·개인회원 무료
        This study was carried out to investigate the management characteristics and techniques by comparing and analyzing the process of mixing, sterilization, cooling, inoculation and incubation for bag cultivation of L. edodes. The medium was sterilized after mixing it for 30 minutes, 1 and 2 hours respectively. The general moisture content of the sawdust substrate has been adjusted to 65%, while the case of the L. edodes substrate was 55%. Only 5% of wood chips of 5-8 mm in particle size were mixed to secure the space of the sawdust particles. As a result, mycelial growth was 1.4cm faster and the density was better(+++) than control(++). Wood chips are soaked in advance for a week during winter and 4 days during summer. There is an average number of 1.6x108 (cfu) of microorganisms in the sawdust that has been piled for six months outdoor. In summer, it has to be used immediately after mixing sawdust. High-pressure sterilization should be performed to use as a mushroom spawn, and to improve physical properties, it was great to sterilize the medium at a normal-pressure. There are height and width type for bags to be consumed for bagging. When the height was reduced into 17cm and the width was increased into 13cm, the browning period was shortened by 30 days and the period of mycelial growth was shortened by 25 days. The sterilized medium had an average of 4x103(cfu) of microorganisms at 25°C and 1.3×102 (cfu) at 15°C. After 25 days from inoculation in vitro, the growth condition of sawdust was the best with 13.2 cm, followed by grain spawn and liquid respectively. When inoculated with liquid spawn, the moisture content of substrate should be adjusted to 55% to 50% in advance.
        45.
        2017.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 오염된 점토 내 Cs을 제거하기 위하여, 계면활성제의 소수성 알킬사슬의 길이에 따른 Cs의 탈착특성을 연구 하였다. 양이온성 계면활성제로 Alkyl trimethyl ammonium bromide를 사용하였고, 소수성 알킬사슬은 octyl-, dodecyl-, cetyl- 으로 변화시켰다. 소수성 알킬사슬이 길어질수록 montmorillonite 내 계면활성제의 흡착량이 증가하였고, 계면활성제의 층간 흡착으로 층간거리가 증가하는 것으로 나타났다. Cs의 탈착률도 알킬사슬의 길이가 증가함에 따라 향상되었고 cetyl 그룹을 갖는 양이온성 계면활성제는 최대 99±2.9%의 Cs 제거율을 나타냈다.
        4,000원
        48.
        2014.04 구독 인증기관·개인회원 무료
        The Riptortus (stinkbug) has a specialized symbiotic organ, M4 midgut, to harboring symbiont Burkholderia. M4 midgut is located in abdomen and surrounded with insect hemolymph. Recently our group demonstrated that symbiotic Burkholderia showed different physiology after adapting in M4 gut compare with in vitro cultured Burkholderia. And population of symbiotic Burkholderia in the M4 midgut is regulated by special organ. However, the molecular mechanism to prevent spreading and migrating symbiont bacteria to other host tissues from symbiotic organ is not clear. Therefore, we assumed that symbiont Burkholderia are susceptible to host humoral immunity after established infection in M4 midgut to prevent spreading and migrating into the other host tissues through Riptortus hemolymph. To prove this assuming, we tested the susceptibility and survival rate of symbiont Burkholderia in hemolymph of Riptortus in vitro and in vivo. We also examined the susceptibility of symbiont Burkholderia using purified antimicrobial peptides (AMP), pyrrhocoricin-like, thanatin-like and defensin-like AMPs. Finally, we tested inducing ability for AMPs by systemic infection of symbiotic Burkholderia. Gene expression of purified AMPs was not different after systemic infection of both symbiont and in vitro cultured Burkholderia. Surprisingly, in vitro cultured Burkholderia resisted on bacteria injected hemolymph and purified AMPs but symbiont Burkholderia were highly susceptible in bacteria injected hemolymph and purified AMP. These results suggest that symbiont Burkholderia can't survive in the hemolymph after escaping symbiotic organ. Moreover, humoral immunity of host Riptortus is important to prevent spreading and migrating symbiont Burkholderia into the other host tissue or organ from symbiotic organ.
        49.
        2013.10 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are natural pathogens of insects and contribute to the regulation of host insect populations in the environment. Several these fungi produce a wide range of secreted enzymes, secreted protein toxins and secondary metabolites to overcome host defenses and ultimately kill the host, and to defend host resources against competing pathogens and saprophytes. Therefore, this study was performed to select the antimicrobial activity of entomopathogenic fungi form Korea soils against plant pathogenic bacteria Ralstonia solanacearum and plant pathogenic fungi Botrytis cinerea using dual culture technique on SDYA. In addition, we also performed to screening of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging activity compounds from liquid culture filtrates of entomopathogenic fungi and investigate to it’s anticancer activity. As results, 12 isolates, 6 isolates and 25 isolates showing of these fungal metabolites produced antibacterial, antifungal and radicals scavenging activity compounds, respectively. The preferential antimicrobial and radical scavenging activities give evidence that these entomopathogenic fungal metabolites might be useful as a source for plant pathogen control and pharmaceutical interests.
        51.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most patients with chronic low back pain experience functional disability of trunk muscle, and limitations in physical activity. While there are many types of exercise programs available, in recent years sling exercise has been emerging as the exercise program for spinal stabilization. It has been supported by a great amount of research with positive findings on its effectiveness. This research studies the effects of bridging exercise, conducted on a sling, on pain level and trunk muscle activation in supine, sidelying, and prone positions during a 4 weeks period. 10 healthy people(normal group, n=10) and 28 patients with low back pain participated in this study. 28 patients were divided into two groups; one group participated in exercise with the sling(experimental group, n=14) and the other group exercised without the sling(control group, n=14). They were asked to use the Numerical Rating Scale(NRS) to answer to the level of their pain they felt (no pain: 0 point, severe pain: 10 points). During sling bridging exercises, the muscle activity level in each muscle measured in each position was standardized as three seconds of EMG signals during five seconds MVIC. In conclusion, the experimental group with four weeks of sling bridging exercise experienced a statistically significant reduction in the pain level(p<.05) and increase in the muscle activities of erector spinae when in supine position, internal oblique when in sidelying position, and rectus abdominis in prone position(p<.05). Regular sling bridging exercise reduces the low back pain and enhances other trunk muscle activation, thereby positively affect spinal stabilization.
        4,000원
        52.
        2013.04 구독 인증기관·개인회원 무료
        The bulb mite (Rhizoglyphus echinopus) damages garlic, shallot and onion in the bulbs, corms and tubers. It has recently become a serious problem because of the continuous use of acaricides resulting in resistance among bulb mite population. Thus, there is need to find alternative control measures to suppress bulb mite population. Here, we report the screening result of pathogenic fungi for the control of R. echinopus. Initial screenings were performed using 352 isolates of entomopathogenic fungi from Korea soils. As results, 15 isolates of acaropathogenic fungi showed the pathogenicity to bulb mite supporting fungal conidiation. These isolates were identified as 3 isolates of Metarhizium flavoviride var. pemphigi and 12 isolates of Metarhizium pingshaense by microscopic examination and genetic sequencing of the ITS region and elongation factor-1 alpha. Selected 15 isolates were tested for their virulence against adult R. echinopus and the thermotolerance and the activity to UV-B irradiation of conidia. Additionally, the activities of chitinases and proteases produced by M. pingshaense were compared according to the medium. These acaropathogenic fungi would be considered promising for biological control of bulb mite.
        53.
        2013.04 구독 인증기관·개인회원 무료
        Entomopathogenic fungi are natural pathogens of insects and contribute to the regulation of host insect populations in the environment. Several these fungi produce a wide range of secreted enzymes, secreted protein toxins and secondary metabolites to overcome host defenses and ultimately kill the host, and to defend host resources against competing pathogens and saprophytes. This study was performed to evaluate the antimicrobial activity of 207 entomopathogenic fungi form Korea soils against plant pathogenic bacteria Ralstonia solanacearum and plant pathogenic fungi Botrytis cinerea using dual culture technique on SDYA. As results, twelve isolates (5.7%) and six isolates (2.8%) showing the greatest inhibition against R. solanacearum and B. cinerea, respectively. The culture supernatant of these selected isolates completely suppressed the growth of the pathogen, indicating that suppression was due to the presence of antimicrobial compound in the culture filtrate. The stability test of the culture filtrate showed that the antimicrobial component was heat stable and not protein. These entomopathogenic fungal metabolites may be a good feature to be used in the development of a new biocontrol method of R. solanacearum and B. cinerea.
        54.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present an analysis of the papers published in the journals Nature and Science in the years from 2006 to 2010. During this period, 7788 papers in total were published in the two journals. This includes 544 astronomy papers that correspond to 7.0% of the papers in 'all' research fields and 18.9% of those in the field of 'physical sciences'. The sub-fields of research of the astronomy papers are distributed, in a descending order of the number of papers, in Solar System, stellar astronomy, galaxies and the universe, the Milky Way Galaxy, and exoplanets. The observational facilities used for the studies are mainly ground-based telescopes (31.1%), spacecrafts (27.0%), and space telescopes (22.8%), while 16.0% of papers did not use any noticeable facilities and 1.7% used other facilities. Korean scientists have published 86 papers (33 in Nature and 53 in Science), which is 1.10% of all the papers (N = 7788) in the two journals. The share of papers by Korean astronomers among the scientific papers by Koreans is 8.14%, slightly higher than the contribution of astronomy papers (7.0%) in both journals.
        4,300원
        55.
        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).
        56.
        2012.03 구독 인증기관 무료, 개인회원 유료
        For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at —7 ℃ to —35 ℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen-thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5ml, and 43.6 % frozen at 20 embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).
        4,000원
        57.
        2011.11 구독 인증기관 무료, 개인회원 유료
        바다에 기름오염 사고가 발생하면 여러 가지 방제 방법 중 물리적 회수 방법을 우선적으로 사용하고 유처리제는 최후 수단으로 고려하는 경향이 있다. 유처리제는 수중으로 기름이 신속히 분산되도록 하여 해수면으로부터 제거하는 방법이다. 해수면으로부터 신속히 기름을 제거하는데 대한 유처리제의 효용성은 널리 증명되어 왔으나 아직도 대부분의 국가들은 해양환경에 미치는 독성을 우려하여 적극적인 사용을 하지 않고 있는 실정이다. 보고된 자료에 의하면 유처리제 사용 후 수중생물에 대한 독성은 발견되지 않았으며, 유처리제와 혼합된 기름이 기 름 그 자체보다 독성이 더 크게 나타나지 않았다. 멕시코만 기름유출 사고 시 미국 정부와 BP사는 최대한 해안에 기름이 도달하지 않는데 중 점을 두고 해수면뿐만 아니라 수중의 기름에 대해서도 유처리제를 사용하였다.
        3,000원
        58.
        2011.10 구독 인증기관·개인회원 무료
        Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinization to predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally.
        59.
        2011.10 구독 인증기관·개인회원 무료
        Sloan-Kettering virus gene product of a cellular protooncogene c-Ski is an unique nuclear pro-oncoprotein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. The aim of the present study was to locate Ski protein in rat ovaries in order to predict the possible involvement of Ski in follicular development and atresia. First, expression of c-Ski mRNA in the ovaries of adult female rats was confirmed by RT-PCR. Then, ovaries obtained on the day of estrus were subjected to immunohistochemical analysis for Ski and proliferating cell nuclear antigen (PCNA) in combination with terminal deoxynucleotidyl transferase- mediated dUTP nick end-labeling (TUNEL). Ski was expressed in granulosa cells that were positive for TUNEL, but negative for PCNA, regardless of the shape and size of follicles. Expression of Ski in TUNEL-positive granulosa cells, but not in PCNA-positive granulosa cells, was also verified in immature hypophysectomized rats having a single generation of developing and atretic follicles by treatment with equine chorionic gonadotropin (eCG). These results indicate that Ski is profoundly expressed in the granulosa cells of atretic follicles, but not in growing follicles, and suggest that Ski plays a role in apoptosis of granulosa cells during follicular atresia.
        60.
        2011.10 구독 인증기관·개인회원 무료
        The green peach aphid, Myzus persicae Sulzer, is one of the most important pests affecting protected and open-grown crops, because they cause direct damage by feeding on crops and indirect damage as virus vectors. It has recently become a serious problem because of the continuous use of insecticide resulting in resistance among green peach aphid population. Thus, the development of entomopathogenic fungi as aphid biocontrol agents has received increasing interest as part of integrated control strategies. In this study, we report the screening result of pathogenic fungi for the control of green peach aphid. Initial screenings were performed using 347 isolates of putative pathogenic fungi from Korea soils. As results, 20 isolates of entomopathogenic fungi were isolated from cadavers of green peach aphid supporting fungal conidiation. These isolates were identified as three strains of Lecanicillium attenuatum, nine strains of Beauveria bassiana, one strain of Metarhizium anisopliae, one strain of Metarhizium flavoviride, five strains of Paecilomyces lilacinus, one strain of Aspergillus sp. by microscopic examination, genetic sequencing of the ITS region and Universally Primed PCR (UP-PCR). Based on the screening results, twenty isolates were tested for their pathogenicity against adult green peach aphid. All fungal isolates were pathogenic to green peach aphid but mortality varied with isolates. These entomopathogenic fungi may be useful to develop eco-friendly insecticide to control green peach aphid.
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