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        검색결과 143

        1.
        2021.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Because of depletion of fossil fuel from the earth curst and increase of environmental concerns, in search of an efficient alternative to the traditional carbon black (CB), a biochar known as rice husk carbon (RHC) has been examined here as a filler material to develop the EPDM composite. In this regard, the ball milled RHC was further treated with ultrasonic wave and used with or without its surface treatment by the silane coupling agent [i.e., 3-mercaptopropyl triethoxysilane (3-MPTMS)]. Among the RHC, ultrasonic treated RHC (UHC) and silane treated UHC (USHC), the EPDM composite of USHC showed nearly similar tensile strength to that of the CB (e.g., CB: 33.88 kgf/cm2, USHC: 31.38 kgf/cm2 at 20 wt% filler loading) with an enhanced elongation at break (e.g., CB: 206%, USHC: 342% at 20 wt% filler loading) and surprisingly much less compression set value (CB: 40.87%, USHC: 18.95% even after 40 wt% of filler loading). Compared to RHC, the UHC also showed its better performance next to the USHC. In addition to presence of both the carbon and silica in RHC and additional silica within the flexible aliphatic chain in USHC, the disintegration of RHC by ultrasonic treatment towards its narrow particle distribution, smaller particle size, and increased surface area is considered very much effective to develop the corresponding high performance EPDM composites. Thus, the use of waste material, i.e., rice husk through the ultrasonication of RHC followed by its surface treatment can be used as a potential filler material to prepare the environment friendly and cost effective high performing composites to be used in different efficient end products, and motivated further for industrial upscaling.
        4,000원
        2.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        『자서전』에서의 글은 어떤 의미에서 모두 자신의 제2의 자아이며 모든 문학적 근사치로서 (시적, 산문적) 정신의 과감한 깃털 펜으로써 가끔 답할 수 있거 나 흔히 답할 수 없는 것들이다.
        3,000원
        3.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        호프스태터와 예이츠는 인생의 신비함은 결코 틀리지 않으며, 신비하고, 매혹적이라는 점에 동의하는 것 같아 서로 연관성이 있어보여서 서로 비교하면서 읽게 되었다. 인생의 신비로움을 파헤치는 그들의 노력은 환상적이다. 그러나 읽으면 읽을수록 더 혼란스러워지는 것도 사실인 듯하다. 그러나 거의 따라가는 듯도 하며 책을 다 읽은 지금도 신비의 여운이 감돈다.
        4,000원
        7.
        2019.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        예이츠이 시극『그림자 어린 바다』에서 소유의 순간이 어떻게 꿈을 꾸는가? 본 논문은 꿈의 시작과 끝의 요호바적 전환부를 들여다본다. 즉 어떻게 성공적으로, 기교적으로 소유, 대리, 및 위치확정이라는 개념에 근거하여 잡아내기 어려운 불확정적 신비성을 들어내는지를 본다. 또 환각적 꿈꾸기의 중성적 특성을 위한 그의 창의성이 얼마나 유연하며 자연적인지도 본다. 그리고 마지막으로 환각적인 선상의 일련의 사건 들의 결말과 클라이맥스에 우리는 만족하는가? 이에 대한 문제도 검토한다.
        5,200원
        8.
        2019.04 구독 인증기관·개인회원 무료
        Methyl bromide (MB) has been still routinely used in quarantine fumigation on imported citrus, although there had been issuing chronic inhalation toxicity to fumigators and related workers as well as phytotoxic damages after fumigation. Ethyl formate (EF), is the only option to replace MB in terms of its safety for consumers (food additive and naturally occurred) and worker with higher threshold level limit (TLV = 100 ppm). Its application technology also provide cost effectiveness, good commercial practice in terms of application time (< 10 min) for 40 ft container. The replacement of MB with EF is recommended not to fumigate with hazardous and phasing-out MB on imported oranges.
        9.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The osmolarity of a medium that is commonly used for in vitro culture (IVC) of oocytes and embryos is lower than that of oviductal fluid in pigs. In vivo oocytes and embryos can resist high osmolarities to some extent due to the presence of organic osmolytes such as glycine and alanine. These amino acids act as a protective shield to maintain the shape and viability in high osmotic environments. The aim of this study was to determine the effects of glycine or/and alanine in medium with two different osmolarities (280 and 320 mOsm) during IVC on embryonic development after parthenogenesis (PA) and somatic cell nuclear transfer (SCNT) in pigs. To this end, IVC was divided into two stages; the 0-2 and 3-7 days of IVC. In each stage, embryos were cultured in medium with 280, 320, or 360 mOsm and their combinations with or without glycine or/and alanine according to the experimental design. Treatment groups were termed as, for example, "T(osmolarity of a medium used in 0-2 days of IVC)-(osmolarity of a medium used in 3-7 days of IVC)" T280-280 was served as control. When PA embryos were cultured in medium with various osmolarities, T320-280 showed a significantly higher blastocyst formation (29.0%) than control (22.2%) and T360-360 groups (6.9%). Glycine treatment in T320-280 significantly increased blastocyst formation (50.4%) compared to T320-280 only (36.5%) while no synergistic was observed after treatment with glycine and alanine together in T320-280 (45.7%). In contrast to PA embryonic development, the stimulating effect by the culture in T320-280 was not observed in SCNT blastocyst development (27.6% and 23.7% in T280-280 and T320-280, respectively) whereas the number of inner cell mass cells was significantly increased in T320-280 (6.1 cells vs. 9.6 cells). Glycine treatment significantly improved blastocyst formation of SCNT embryos in both T280-280 (27.6% vs. 38.0%) and T320-280 (23.7% vs. 35.3%). Our results demonstrate that IVC in T320-280 and treatment with glycine improves blastocyst formation of PA and SCNT embryos in pigs.
        4,000원
        10.
        2018.10 구독 인증기관·개인회원 무료
        Insect peptides have been extensively studied due to beneficial effects in the treatment of infectious diseases. Melittin, a fundamental component of honeybee venom produced by European honeybee Apis mellifera, has applied to prevent various inflammatory disease and bacterial infections in human. However, the therapeutic application of melittin is limited due to its low stability, hemolytic activity and expensive manufacturing costs. In this study, we aimed to discovery unknown peptides from the Apis mellifera and evaluate its antibacterial activity against Escherichia coli KACC 10005. A total 15,853 peptide sequences were diciphered using Illumina HiSeq 2500 next-generation sequencing (NGS) platform and analyzed based on the Apis mellifera official Gene Set Version 3.2 (amel_OGSv3.2) and the Collection of Anti-Microbial Peptides (CAMPR3) database. All the peptide sequences and annotation data sets were combined and sorted by physicochemical features of antimicrobial peptides (AMPs), such as short peptide length <=50, positive charge, isoelectric point (8.0<=pl<=12), and aggregation propensity (in-vitro: <=500, in-vivo: –40<= Na4vSS <=60). Among the screened peptides, four unknown peptide candidates, named AMP1-4, were chemically synthesized and tested for antimicrobial activity in comparison with a reference peptide, melittin. Inhibition of bacterial growth was observed in the AMP4 treated group from 6 hours to 48 hours post-treatment against E. coli. These results suggest that honeybee-derived peptide sequences can be applied as natural resources to acquire novel AMPs and the peptide sequences derived parameters are enough to recognize antibacterial peptides. In addition, the selected novel peptide candidate, AMP4, has antibacterial activity.
        11.
        2018.10 구독 인증기관·개인회원 무료
        The hypopharyngeal gland (HPG) of the honeybee worker produces royal jelly (RJ) and has a developmental cycle closely related to the division of labor. In this study, we investigated to compare the HPG acini diameter of differently aged worker bees with high royal jelly producing colony (HRC) or less producing colony (LRC). Additionally, we also evaluated whether the fresh weight of the head is a reliable indicator of the developmental status of HPG. The HRC showed a significantly higher RJ production about two-times as compared with those of the LRC. We measured the HG-diameters on days 1, 3, 6, 9, 12, 15. The microscopic analysis revealed that the acini size of the HRC was significantly larger than the LRC. In addition, the acini diameter of HRC was 15% longer than the LRC on the first day after emerging. It was shown that the fastest development during 3 days which is preparing for nurse the brood. The HPG acini diameters increased in both colonies in a similar fashion until day 12 and then decreased. We also compared the fresh head weight of the experimental colonies, differences were similar to the development of HPG. Therefore, high royal jelly production may have a positive correlation between HPG acini size and the fresh head weight.
        12.
        2018.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        예이츠 시의 생사의 신비에 대한 비전 내용을 선불교적 명상을 통해서 시적 공감력을 높인 후, 그의 영생에 대한 영적 문학성을 현대 실험 표현장르인 “서정 에세이(Lyric Essay)” 양식을 빌려서 시적 산문 창작을 해보았다. 명상 대상시는 “재림,” “죽음을 예견한 아이랜드 비행사,” “서커스 동물 탈주,” “레다 여신과 백조”를 중심했다.
        5,700원
        17.
        2016.10 구독 인증기관·개인회원 무료
        In mature oocytes, maturation promoting factor (MPF) activity is playing important roles in arrest at M-phase and its continuous phenomenon, oocyte aging. In most mammals, metaphase II oocytes show high MPF activity and have been used as ooplasts in somatic cell nuclear transfer (SCNT). Caffeine has been found to regulate MPF activity in mammalian oocytes. Caffeine inhibits p34cdc2 phosphorylation and increases MPF activity. The present study investigated the effects of caffeine treatment during last 4 hours of in vitro maturation (IVM) on oocyte maturation and embryonic development after parthenogenesis (PA) and SCNT. The IVM medium was medium-199, 10% (v/v) PFF, cysteine, pyruvate, epidermal growth factor, kanamycin, insulin, and hormones. Immature oocytes were matured in IVM medium without or with 2.5 mM caffeine during the last 4 hours of IVM. The in vitro culture medium for embryonic development was porcine zygote medium-3 containing 0.3% (w/v) bovine serum albumin. Nuclear maturation (83.6–87.2%) and intraoocyte glutathione contents (0.9–1.0 pixels/oocyte) of oocytes were not influenced by the caffeine treatment. The membrane fusion of cell-cytoplast couplets (75.5–76.5%) and cleavage (85.4–86.2%) were also not altered by the caffeine treatment. However, caffeine-treated oocytes showed higher (P<0.05) blastocyst formation after SCNT (47.5 vs. 34.3%) than untreated oocytes. Our results demonstrate that caffeine treatment during last 4 hour of IVM improves the developmental competence of SCNT embryos probably by influencing MPF activity.
        19.
        2015.05 구독 인증기관 무료, 개인회원 유료
        The oocyte undergoes various events during maturation and requires many substances for the maturation process. Various intracellular organelles are also involved in maturation of the oocyte. During the process glucose is essential for nuclear and cytoplasmic maturation, and adenosine triphosphate is needed for reorganization of the organelles and cytoskeleton. If mitochondrial function is lost, several developmental defects in meiotic chromosome segregation and maturation cause fertilization failure. The endoplasmic reticulum, a store for Ca2+, releases Ca2+ into the cytoplasm in response to various cellular signaling molecules. This event stimulates secretion of hormones, growth factors and antioxidants in oocyte during maturation. Also, oocyte nuclear maturation is stimulated by growth factors such as epidermal growth factor. This review summarizes roles of organelles with focus on the Golgi apparatus during maturation in oocyte.
        4,000원
        20.
        2015.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of the present study is to provide exercises, together with music, that are helpful for elderly people’s balancing ability, and to determine their effects in order to provide data for the promotion of elderly persons’health. Thirty elderly persons were randomly assigned to a balance training group(BTG) of 15 subjects, or a music and balance training group (music therapy + balance training [MTBTG]) of 15 subjects; intervention was implemented three times per week for six weeks. To measure the changes in their balancing ability before and after the experiment, the limit of stability, the“Timed Up and Go”(TUG) test, and the Berg Balance Scale (BBS) were measured. Changes in the limit of stability before and after the experiment were shown to be significant in both the BTG and the MTBTG. Changes in the limit of stability of the right side before and after the experiment showed statistically significant differences between the BTG and the MTBTG. Changes in the TUG test and the BBS before and after the experiment were shown to be statistically significant in both the BTG and the MTBTG. The application of music during balance training thus is considered to have a positive effect on elderly persons’balancing ability.
        4,000원
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