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        검색결과 9,514

        6261.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        On the analysis of triacylglycerol (TG) from the kernels of Acanthopanax sessiliflorus by reversed phase-HPLC, it was separated into three main fractions of PN 44, 46 and 48, according to partition number (PN). On the contrary, it could be clearly classified into seven fractions of SMM, MMM, SMD, MMD, SDD, MDD and MDT by silver ion-HPLC by the number of double bond in the acyl chains of TG species. But resolution of so-called critical pairs of TG molecular species such as molecular pairs of PeLL [C18:1Ω12/(C18:2Ω6)2] and OLL [C18:1Ω9/(C18:2Ω6)2] and OOL [(C18:1Ω9)2/C18:2Ω6], and PePeL [(C18:2Ω12)2/C18:1Ω6] was not achieved (Pe; petroselinic acid, L; linoleic acid, O; oleic acid). On the other hand, TG extracted from Aralia continentalis kernels were also fractionated into seven groups of SSM, SMM, MMM, SMD, MMD, SDD and MDD (S; saturated acid, M; monoenoic acid, D; dienoic acid) by silver ion-HPLC, although it's were classified into three groups of PN 44, 46 and 48 by reversed phase-HPLC. The fractions of SMM, MMM, MMD and MDD were divided into two subfractions, respectively; the fractions of SMM, MMM, MMD and MDD were resolved into the subfraction of PPe/Pe and POO (critical pairs from each other), that of Pe/Pe/Pe and OOO, that of Pe/Pe/L and OOL, and that of Pe/L/L and OLL.
        4,000원
        6262.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Dinoflagellates were investigated from the coastal waters of Korea. The total 100 thecate dinoflagellates taxa, comprising of 93 species five varieties and two forms were identified, which were attributed to four orders nine families, 13 genera in Korean
        4,000원
        6263.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Potato (Solamum tuberosum 'Dejima') plantlets were investigated on culture type and initial quantity of inoculation in bioreactor and survival rate by hydroponics for mass production. rode stems (1 to 1.5cm in length) of potato plantlets multiplied in vitro were grown for 3 weeks in liquid Murashige and Skoog (MS) medium with sucrose 30 g L-1. When plantlets (80-node inoculation) were raised in 10L balloon type bubble (BB) bioreactor, the healthiest growth of plantlets was obtained from explants cultured in ebb & flow culture with medium supplied periodically 12 times per day. The suitable inoculation quantity of 20L BB bioreactor was 120 pieces of stem segments (mean 2.2g fresh weight) in ebb & flow culture. Number of nodal shoot was eight on the average. In controlled culture room, survival rate of plantlets at 7 days after stem cutting was above 70% when they were acclimatized by hydroponics grown in deep flow and solid medium culture. The highest survival rate of the stem cutting plantlets was in nutrient solution adjusted to EC 1.4dS·m-1. Stem cutting plantlets through one culture could be obtained 670~900, when plantlets were grown in ebb & flow culture during 3 weeks using a 20L bioreactor with initial 120 pieces of nodal segments. 11 is possible In do mass production of seedlings cultured in bioreactor and hydroponics.
        3,000원
        6264.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Silver impregnated activated carbon fibers were post-modified using hydrochloric acid. Adsorption behaviors, SEM morphologies, and functional groups for the silver impregnated ACFs were compared with those of post-modified ACFs. Adsorption isotherms were used to characterize SBET, the pore structure and volume of silver-activated carbon fibers (ACFs) before and after acid post-treatment. In order to the reveal the causes of the differences surface states after the samples were washed with hydrochloric acid, outer surface and pore structure were investigated by SEM. And the type and quality of various functional groups were studied from FT-IR spectra and Boehm titration method. Finally, the quantitative properties in silver contents were also examined by EDX spectra.
        4,000원
        6265.
        2005.12 구독 인증기관 무료, 개인회원 유료
        Methods for activation of reconstructed oocytes were examined for the production of nuclear transfer (NT) rat embryos using fetal neural stem cells as donor. Neural stem cells were isolated from Day 14.5 rat fetuses, and the oocytes for recipient cytoplasm were recovered from 4-week old Sprague Dawley rats. After enucleation and nuclear injection, the reconstructed oocytes were immediately exposed to activation medium consisting of 10 mM SrCl₂ for 4 h (immediate activation after injection; IAI), or cultured in vitro for 2~3 h before activation treatment (injection before activation; IBA). Pre-activated oocytes were also used for NT to test reprogramming potential of artificially activated oocytes. The oocytes were grouped as IIA (immediate injection after activation) and ABI (activation 2~3 h before injection). Following NT, the oocytes were cultured in vitro. Development of the NT embryos was monitored at 44 and 119 h after activation. The embryos in groups IAI, mA, and IIA were cleaved to the 2-cell stage at the rates of 36.6%(15/41), 39.5% (17/43) and 46.3% (25/54), respectively. However, in the ABI group, only one embryo (1.8%, 1/55) was cleaved after activation. After in vitro culture, two NT embryos from IAI group had developed to the morula stage (4.9%, 2/41). However, no morula or blastocyst was obtained in the other groups. These results suggest that immediate activation after injection (IAI) method may be used for the production of rat somatic cell NT embryos.
        4,000원
        6266.
        2005.12 구독 인증기관 무료, 개인회원 유료
        Education in Indonesia is facing some major problems related to access and quality. Only about half of the eligible children are enrolled in school at the junior secondary level and only one-third at the senior secondary level. Regarding quality, large proportions of students fail to meet the cutoff scores in various subjects at all levels in school completion examinations. ICT is viewed as a potential contributor to solutions for these problems. In terms of government policy for ICT, Telematika which refers to the utilization of ICT in various sectors and aspects of life, was established based on a presidential decree, and Telematika Pendidikan (utilization of ICT in education) has been developed, and a five-year action plan was implemented in the years 2001 to 2005. The success of Telematika depends on the availability of appropriate infrastructure. Currently, Indonesia has 8 million Internet users (about 3% of the population); other statistics show that the ICT infrastructure is less extensive compared with neighboring countries such as Singapore, Malaysia, and Thailand. In addition, Internet access costs are still prohibitive in Indonesia. The implementation of E-Learning in Indonesian education can be viewed as a supplement, a complement, or a substitute for the traditional teaching-learning process. To date some subjects of the senior secondary school and vocational school curriculum have been developed in the form of E-Learning as a substitute for face-to-face instruction. In the near future this will be expanded to some subjects of the junior secondary school curriculum. At the tertiary education level, there are some universities that have implemented E-Learning, especially as a supplement for their regular teaching-learning process. In regard to extending access into schools, the Ministry of National Education has been piloting Open Senior Secondary School in seven districts of six provinces by implementing E-Learning.
        4,000원
        6267.
        2005.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 고준위 방사성폐기물 심지층 처분시설의 규모 및 layout설정에 필요한 요소인 처분터널 및 처분공 간격에 대한 분석을 수행하였다. 이를 위하여, 기준 처분개념과 공학적 방벽 개념을 바탕으로 다양한 조건의 처분터널 및 처분공 단면을 설정하고, 단층 배치 및 복층 배치 개념 에 따른 처분동굴의 구조적, 열적 안정성을 분석하였다. 분석 결과를 바탕으로 설계에 있어서 주요한 고려인자 중의 하나인 굴착량을 감소시킬 수 있는 처분동굴 및 처분공 간격을 제안하였다. 본 연구의 결과는 심지층 처분시설 설계시 활용될 것이며, 향후, 부지에 대한 불확실성을 줄이기 위하여 정확한 부지특성 자료를 통한 상세한 분석이 필요하다.
        4,000원
        6268.
        2005.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Single-pass flow-through (SPFW) 방법에 의한 유리고화체의 용해율 측정에서 정밀도를 구하기 위하여 연구소간 실험프로그램의 하나로서 붕규산유리고화체의 정용해율을 구하였는데, 이 SPFT 방법은 American Society for Testing and Materials (ASTM)에서 표준화를 위하여 작성되었다. 이를 위해 100/200 mesh 크기의 모의 저방사능 유리고화체 분말시료를 , 알곤 분위기에서 SPFT 방법으로 리튬 완충용액 (pH=10)을 이용하여 용해실험을 시도하였다. 얻어진 용출액 중 규소와 붕소의 농도에 따라 용해율의 변화를 구한 결과, 유리의 정용해율이 부근으로 나타났다.
        4,000원
        6269.
        2005.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Type 304 stainless steel 시편에 느슨하게 붙어있는 분말에 대한 초음파 제염 거동을 조사하였다. 매질을 물, PFC 및 의 음이온 계면활성제를 함유한 PFC 용액으로 변화시킴에 따라 제염계수는 20, 50 및 200으로 증가하였다. 제염계수에 차이가 생기는 이유를 초음파 매질의 표면장력 및 양으로 하전된 산화물 표면과 음이온 계면활성제 사이의 상호작용에 기인한 것으로 설명할 수 있었다. 음이온 계면활성제를 함유한 PFC 용액 내에서 분말로 오염된 평면 시편, 파이프 시편, 틈새 시편 및 용접 시편에 대한 초음파 제염 효과를 관찰하였다. 연구된 모든 시편에 대해, 대부분의 오염물이 완벽하게 제거되는 것으로 나타났다. 길이가 6cm인 파이프 시편에 대해서는 오염물의 가 제거되었다.
        4,000원
        6277.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        Hereditary dentin defects consists of dentin dysplasia(DD) and denti nogenesis imperfecta(Dr) ‘ The Dl associated with osteogenesis imperfecta has been classified as DI type 1. whereas isolated inherited defects have been categori zed as DI types II and III , However‘ whether DI type III should be considered a distinct phenotype 01' a variation of DI type 1I is debatable , Recent genetic findings have focused attention on the role of the dentin sialo phosphoprotein(DSPP) gene in the etiology of inherited defects of tooth dentin, We have identified novel mlltation( c,727G - > A, p,D243N) at the 243th codon of exon 4 of the DSPP gene in a Korean patient with DI type III The radiographic and histologic features of the patient revealed the classic phenotype of shell teeth These findings sllggest that DI type II and III are not separate diseases bllt rather the phenotypic variation 01' a s ingle disease
        6278.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        1'0 determine Lhe ll1echanism of cell c1eath incluced by iron chelators. we explored the pathways of the three structurally relatecl ll1 itogen-activatecl protein(MAP) kinase subfami li esduring iron cbelator- inclucecl apoptosis ancl differentiation of oral precancerous ancl cancel‘ cells. The iron chelator c1 eferoxamine(DFO) exertecl potent timeancl c1ose-c1epenclent inhi bitory effects on the growth of IHOK and HN4 cells The major mechanism of growth inhibition following DFO treatment was fOllncl to be apoptosis incluction. as assessecl by annexin V-FITC staining. cell cycle analysis‘ DNA lacldering, a ncl Hoechst staining. We report that DF'O s trongly activates the p38 MAP kinase and extracell ular signal- regu lated kinase(ERK). but c10es not activate the c-Jun N-terminal kin ase/ stl않s-activaLecl protein kinase(JNK/8APK) . Of the three MAP kinase blockers usecl‘ the selective p38 MAP kinase inhibitor 8ß203580 ancl ERK inhibitor PD98059 protected oral premaIignant ancl malignant cells againsL iron chelator- nclllced cell death. which incl icates that the p38 MAP kinase serves as a major mecliator 01' apoptos is induced by this iron chelator DFO also evoked the release of cytochrome c from mitochondria, and incluced the activation of caspase-3 ancl caspase-8 in oral cancer cells, which suggests that apoptosis occurs via the mi tochoncl ri on - mecl iaLed pathway. DFO enhanced the expression of Bax in IHOK ancl HN4 cells. consistent witll thei r p53 status Moreover. DFO downregulatecl the expression 01' Bcl-2 in oral cancer cells. which suggests that DFO- incluced apoptos is 01' oraJ cancer and precancerous cells may be mediatecl by an increase in the ratio of pro-apoptotic to anti-apoptotic proteins. ln terestingJy, trcatmcnt 01' IHOK ancl HN4 cel ls with 8B203580 abolishecl cytochrome c release‘ as wel l as the activation of caspase-3 and caspase-8. DFO suppressecl the expression of epithelial di ffe rentiation markers, such as involucrin, t ransglutaminase II. CK6. and CK19. ancl this suppression was blockecl by p38 ancl ERK MAP kinase ll1hlbltors The oral premalignant(IHOK) ancl malignant cell s(I-lN4) showed differential responses to DFO with respect to the expression of cel l cycle regulatory proteins. cell growth. ancl apoptosis. Coll ectively. the current study reveals that p38 MAP kinase plays an ill1 portant role in iron chela tor-mecliatecl cel l cleath and in the suppression of differentiation of oral premalignantandmalignanLcell s.by activating a c10wnstream apoptotic cascade that executes the ceIl c1eath pathway
        6279.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        A novel indil‘ubin analog‘ 5’ nitro-indirubinoxime(Ol1) inhibits cell proliferation and induces apoptosis again st variolls hllman cancer cell s. ln this stlldy, we performed the microarray analysis to identify genes diffel'enti ally expressed in the KB oral sqllamollS carcinoma cells after treatment with 011 Of the 10‘ 800 genes a nalyzed , 1700 genes(15.7%) showed di fferent expression level in the 011-treated cells with respect to untreated control cel1s Arnong those‘ 263 genes(15, 5%) were down -reg띠 ated and 220 genes(12, 9%) were IIp-regulated more than 2-fold, Functionally related gene clllsters inclllde genes associated with signal transdllction(18, 1%) , especially genes re lated with a poptosis(3, 5%) and cell cycle reglllation(5. 8%) . Our application of microarray ar뻐ysis on 01l-treated 01'외 cancer cells al lows the identifi cati on of candidate genes for providing novel insights into the 011-mediated anti -tllmor actl Vl ty ,