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        검색결과 19

        1.
        2022.10 구독 인증기관·개인회원 무료
        The safe, efficient and cost-effective decommissioning and dismantling of radioactive facilities requires the accurate characterization of the radionuclide activities and dose rate environment. And it is critical across many nuclear industries to identify and locate sources of radiation accurately and quickly. One of the more challenging aspects of dealing with radiation is that you cannot see it directly, which can result in potential exposure when working in those environments. Generally, semiconductor detectors have better energy resolution than scintillation detectors, but the maximum achievable count rates are limited by long pulse signals. Whereas some high pure germanium detectors have been developed to operate at high count rates, and these HPGe detectors could obtain gamma-ray spectra at high count rates exceeding 1 Mcps. However, HPGe detectors require cooling devices to reduce the leak currents, which becomes disadvantageous when developing portable radiation detectors. Furthermore, chemicalcompound semiconductor detectors made of cadmium telluride and cadmium zinc telluride are popular, because they have good energy resolution and are available at room temperature. However, CdTe and CZT detectors develop irradiation-induced defects under intense gamma-ray fields. In this Review, we start with the fundamentals of gamma rays detection and review the recent developments in scintillators gamma-ray detectors. The key factors affecting the detector performance are summarized. We also give an outlook on the field, with emphasis on the challenges to be overcome.
        2.
        2020.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Runt related transcription factors (RUNX), a family of well-known transcription factors, play key regulatory roles in diverse biological processes, such as proliferation, differentiation, and DNA repair. Of RUNX family, RUNX3 is the least well characterized of the three family members. Nevertheless, the role of RUNX3 as a key regulator in essential biological pathways has been reported and inactivation of RUNX3 leads to a variety of disease, such as cancer, via regulation of Wnt signaling and K-ras mutations in many mammalian tissues. Recent studies using RUNX3-deficient cells and mice revealed an association with hematopoiesis and hypersensitivity to granulocytecolony stimulating factor. Nevertheless, protein dynamics associated with RUNX3 remain poorly understood. In the present study, we performed a large-scale protein study from Runx3 knockout (KO) mouse embryonic stem cells (mESC) using a stable isotope labeling by amino acids (SILAC)-based quantitative proteomics approach. The results showed that 67 proteins were significantly up and downregulated after Runx3 KO. Bioinformatic analyses that revealed that these proteins have diverse biological functions, such as substances transport and cellular structure. Thus, our results enhance our current understanding of the function of RUNX3 in mESCs and suggest potential roles for RUNX proteins in diverse diseases. Additionally, our results can be used as a database to help us understand the mechanism of action of RUNX3.
        4,000원
        4.
        2012.05 구독 인증기관·개인회원 무료
        Spider silks hold great potential as biomaterials with extraordinary properties. Here we report cloning and characterization of the major ampullate silk protein gene from the spider Araneus ventricosus. A cDNA coding for the partial major ampullate silk protein (AvMaSp) was cloned from A. ventricosus. Analysis of the cDNA sequence shows that AvMaSp consists of 240 amino acids of a repetitive region and 99 amino acids of a C-terminal non-repetitive domain. The peptide motifs found in spider major ampullate silk proteins, (A)n, (GA)n, and (GGX)n, were conserved in the repetitive region of AvMaSp. Phylogenetic analysis further confirmed that AvMaSp belongs to the spider major ampullate spidroin proteins. The AvMaSp-R cDNA, which contains sequences encoding for 240 amino acids of a repetitive domain, was expressed as a 22 kDa polypeptide of soluble form in baculovirus-infected insect cells. Recombinant AvMaSp-R was degraded abruptly by trypsin. However, AvMaSp-R was stable at 100 °C for at least 30 min. Additionally, the AvMaSp-R was stable at various pH values from 2 to 12 for at least 1 h. Taken together, our findings provide the molecular structure and biochemical property for A. ventricosus major ampullate silk protein as a biomaterial.
        6.
        2009.10 구독 인증기관·개인회원 무료
        We cloned and characterized two peroxiredoxins (Prxs), BiPrx1 (a 1-Cys Prx) and BiTPx1 (a 2-Cys Prx) from the bumblebee Bombus ignitus. The BiPrx1 gene consists of 5 exons, encoding 220 amino acid residues with one conserved cysteine residue. The BiTPx1 gene consists of three exons, encoding 195 amino acid residues with 2 conserved cysteine residues. Recombinant BiPrx1 (27 kDa) and BiTPx1 (25 kDa), expressed in baculovirus-infected insect Sf9 cells, reduced H2O2 in the presence of electrons donated by dithiothreitol. Unlike BiTPx1, however, BiPrx1 did not show reduction activity when thioredoxin was used as the electron donor. Both BiPrx1 and BiTPx1 protected super-coiled DNA from damage by metal-catalyzed oxidation (MCO) in vitro. Tissue distribution analyses showed the presence of BiPrx1 and BiTPx1 in the fat body, midgut, muscle and epidermis, but not in the hemolymph, suggesting that BiPrx1 and BiTPx1 are not secretable. When H2O2 was injected into B. ignitus bees, BiPrx1 and BiTPx1 transcripts were acutely up-regulated in the fat body tissues. We also demonstrated regulation of BiPrx1 and BiTPx1 expression via reduction of transcript levels in the fat body with RNA interference (RNAi). Under H2O2 overload, the RNAi-induced BiPrx1 knock-down B. ignitus worker bees showed up-regulated expression of BiTPx1. Reciprocally, BiTPx1 RNAi knockdowns showed up-regulated BiPrx1 expression in the fat body. These results indicate that loss of expression of BiPrx1 or BiTPx1 is compensated by up-regulation of expression of the other peroxidase in response to H2O2 overload.
        8.
        2008.10 구독 인증기관·개인회원 무료
        Metamorphosis is a development process involving the programmed cell death of obsolete larval organs. Aspartic proteinase cathepsin D (BmCatD) is involved in the silkworm Bombyx mori metamorphosis. Here we show a novel functional role of cysteine proteinase cathepsin B during B. mori metamorphosis. The B. mori cathepsin B (BmCatB) was expressed in the fat body, epidermis, ovary, testis, and hemocyte of the larval and pupal stages. The BmCatB was ecdysoneinduced, expressed in the fat body of the molting, the final larval instar and pupal stages, and its expression led to programmed cell death. RNA interference (RNAi)-mediated BmCatB knock-down inhibited the programmed cell death of larval and pupal fat body, resulting in the arrest of larval-pupal transformation. BmCatB RNAi is up-regulated the expression of BmCatD. Based on these results we concluded that BmCatB is critically involved in the histolysis of the larval and pupal fat body, indicating that BmCatB and BmCatD are mutally regulated during silkworm metamorphosis.
        10.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        This study investigated the effect of leaf form or phenotype and light intensity on the toluene, xylene, and ethylbenzene removal of three foliage plants. Green and variegated forms of Ardisia pusilla, Scindapsus aureus, and Hedera helix plants were grown under 10 and 20 μmol・m-2・s-1 light intensities for 8 months and were tested for their volatile organic compound (VOC) removal efficiency for 15 h. In general, variegated forms of the plant species have higher VOC removal after 15 h of VOC exposure than green plants, particularly when grown in 10 μmol・m-2・s-1. This is more evident in A. pusilla and S. aureus than in H. helix. The highest rate of toluene, m-, p-, and o-xylene removal per hour by plants grown under 10 μmol・m-2・s-1 was achieved by variegated A. pusilla, while for ethylbenzene, variegated A. pusilla and variegated H. helix had the highest removal rate per hour. In plants grown in 20 μmol・m-2・s-1 light intensity, variegated and green H. helix have the highest removal rate per hour of toluene and m-, p-, and o-xylene. For ethylbenzene, variegated A. pusilla and green and variegated H. helix had the highest removal rates per hour. The plant with the lowest removal rate per hour for all five VOCs was green S. aureus grown under both light intensities. The percentage VOC removal rate of variegated over green plants was 22% higher at a lower light intensity
        11.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study on the variations of bioactive compounds in ginseng according to the cultivation of soil and the applied fertilizer types (or amount). Therefore, this study aims to examine the variations of 37 fatty acids (FA) and 8 vitamin E (Vit-E) vitamers in 6-year-old ginseng root cultivated in different soil types with different fertilizers regimes. Methods and Results : The profiling of 37 FAs and 8 Vit-E vitamers in 6-year-old ginseng roots was measured by gas chromatography coupled with a flame ionization detector, and then these results were statistically analyzed with chemometrics. The FA and Vit-E content in ginseng roots varied significantly with respect to soil cultivation conditions due to organic fertilizer types and amounts used. Unsaturated FA in ginseng is approximately 2.7 fold higher than the saturated FA. Linoleic, palmitic, and oleic acids were the most abundant FAs found in the ginseng roots. Also, the major Vit-E vitamer found in ginseng root is α -tocopherol. In particular, the application of rice straw compost or food waste fertilizer was increased to create nutritionally-desirable FAs and bioactive Vit-E in ginseng root. In addition, phytonutrient profiling coupled with chemometrics can be used to discriminate the cultivation conditions of ginseng. Conclusion : This preliminary study extends our understanding about the variations of FA and Vit-E in ginseng root depending on cultivation conditions. Hence, these results can be useful as basic information for reliable ginseng production containing high amounts of phytonutrients in a paddy-converted field.
        12.
        2013.08 서비스 종료(열람 제한)
        Cleft palates with or without cleft lip is one of the most common congenital craniofacial defects in dogs. It has been reported that monogenic autosomal recessive inheritance caused this defect in this species. However, here, we aimed to report cleft palate in a cloned dog. A fibroblast cell line was established from skin tissues of an eight-year-old German shepherd dog. Blood was collected from oocyte donor dogs, and serum progesterone concentration was measured by chemiluminescence enzyme immunoassay method. Ovulation was determined when serum progesterone results reached 5-10 ng/ml, and in vivo matured oocytes were collected surgically about 72 hr after ovulation. Donor cells were cultured with Dulbecco’s modified Eagle medium supplemented with 10% (v/v) fetal bovine serum until confluence. An in vivo matured oocyte was enucleated, and a donor cell was injected into the perivitelline space. The oocyte-cell couplet was electrically fused, and chemically activated. Reconstructed embryos were transferred to an oviduct of a recipient. Pregnancy diagnosis was performed 27 days after the embryo transfer, and ultrasonography of fetal heart beat, and rectal temperature and serum progesterone value of recipient was monitored until the day of delivery. Microsatellite analysis was performed using genomic DNA of cell donor, clones, and oocyte donors. As results, a total of 74 cloned embryos were transferred to five recipients, and one recipient diagnosed as pregnant with two fetuses by ultrasonography and radiology. Caesarean section was performed on day 58 after embryo transfer due to a decreased heart beat of a fetus, which was lower than 180. Two cloned puppies with 640g and 320g of birth weight were delivered safety, but the small one was born with a cleft palate. Microsatellite analysis results of both clones were identical with the cell donor. Cleft palate of the clone was surgically corrected on day 40 after birth. To our knowledge, there has been no report about cleft palate in cloned dogs, and also, no report about clones with different phenotype of cleft palate in dogs. Therefore, this study can give a clue of cleft palate in dogs, which might not be a genetic cause. Further studies about aberrant epigenetic reprogramming in those clones are needed.
        13.
        2012.07 서비스 종료(열람 제한)
        Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetables and widely cultivated in Asia countries including Korea and China. Recently, whole genome sequence and full-length cDNA information of this species became available, which are encouraging genetic studies of this species to characterize agricultural important traits. Orange-colored (Or) cultivar of Chinese cabbage has inner leaves in orange, whereas other cultivars generally cultivated have yellow (Ye)- or white-colored inner leaves. In this study, we investigated phenotypes and carotenoid biosynthesis genes related to color variation in the Or cultivar. Firstly we compared the carotenoid content and composition between the Or and Ye cultivars by HPLC analysis. The inner leaves of Or cultivar contained approximately 9-fold high β-carotene content, whereas content of both lutein and violaxanthin was decreased to less than 30%, compared to Ye cultivar. Or cultivar was segregated with ratio of 3:1 in F2 population derived from crossing between Or and Ye inbred lines, indicating that Or phenotype is controlled by single recessive gene. To identify this gene, we investigated the expression of several genes involved in carotenoid biosynthesis by RT-PCR analysis. Among genes tested, two encoding putative carotenoid isomerase (CRTISO) and phytoene desaturase (PDS) were identified to show different expression between Or and Ye cultivars. Through further analysis of genomic DNA regions of these two genes, we could expect that several mutations such as InDel and base-substitution occurred and then affected expression of these genes in Or cultivar. In this presentation, I will introduce more detailed results for Or cultivars.
        15.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        A new cultivar ofDianthus caryophyUus "Dreambyul" was selected from the progenies ofa cross "Zenga" and "Euge-nia" in 1999 at the National Horticultural Research Institute, Rural Development Administration. It was fmally selected in 2002after the investig
        16.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        A new cultivar of Dianthus caryophyHus "Orion" was selected from the progenies of a cross "Rossini" and "Tropicshort node of upper shoot. Optimum temperature for its growth are over 8"C at night and under 25"C at day in summer. The cul- tivar was applied
        19.
        2000.06 KCI 등재 서비스 종료(열람 제한)
        An extensive investigation has been made for the possible utilization of polypropylene spunbonded fabrics in rice seedling nursery. Considering the cropping systems available in southern part of Korea, sowing dates were fixed at April 5 and April 20 for single cropping and May 6 and May 26 for double cropping. Nursery period was fixed to 35 days for each sowing date. Four different thickness of polypropylene spunbonded fabrics, 40, 60, 80, 100 g/m2 , were tested in rice seedling nursery. The temperature and light intensity were not significantly different among the thickness of polypropylene spunbonded fabrics. Light intensity was significantly reduced in polypropylene spunbonded fabric (72.2 Klux) compared with polyethylene mm (85.5 Klux), however, the reduced light intensity was enough for seedling growth. The temperature in the polypropylene spunbonded fabric covering during low air temperature was higher than that in polyethylene mm tunnel. At transplanting, the rice seedlings grown in polypropylene spunbonded fabric condition was shorter (17cm) but healthier than those in polyethylene mm (23cm). The estimated possible nursery periods using the polypropylene spunbonded fabric covering may start from April 1 at Chinju (plain area in Southern Korea, 20m altitude) and April 15 at Susang (mountainous area, 430m altitude). Labour hours and cost were reduced by about 28% and 48%, respectively.