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        검색결과 52

        1.
        2022.10 구독 인증기관·개인회원 무료
        Boric acid-containing B-10 is used in a nuclear reactor as a coolant and absorbs thermal neutrons generated during nuclear fission in the primary circuit. Boron-containing coolant water waste is generated from maintenance, floor drain, decontamination, and reactor letdown flows. There are two options for aqueous solution waste of boric acid. One is recycling and discharge through filtration, ion exchange, and reverse osmosis. The other is immobilization after evaporation and crystallization processes. The dry powder of boric acid waste liquid can be immobilized by cement, polymer, etc. Before the mid-1990s, concentrated boric acid waste was solidified with a cement matrix. To overcome the disadvantage of low waste loading of cement waste form, a method of solidifying with paraffin was adopted. However, paraffin solids were insufficient to be disposed of as final waste. Paraffin is a kind of soft solidified material and has low compressive strength and poor leaching resistance. As a result, it was decided as an unsuitable form for disposal. In KOREA, paraffin waste form was adopted for boric acid waste treatment in the 1990s. A large amount of paraffin waste forms about 20,000 drums (200 l drum) were generated to treat boric acid waste and were stored in nuclear power sites without disposal. In this study, we want to obtain high-purity boric acid waste by oxidizing and decomposing solid paraffin waste form through a boric acid catalytic reaction. In this reaction, paraffin is separated in the form of various by-products, which can then be treated through a liquid waste treatment device or an exhaust gas treatment device. The proper temperature for sample decomposition during the catalytic reaction was set through TGA analysis. Compositions of by-products and residues generated at each stage of the reaction could be analyzed to determine the state during the reaction. Finally, the boric acid waste powder was perfectly separated from paraffin waste form with disposable products through this pyrolysis process.
        3.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이탈리안벌인 A, C, F계통과 코카시안벌인 D, V계통을 2005년부터 2007년까지 국내에서 수집하였다. 수집한 계통은 육종을 위해 격리 된 섬에서 근친교배를 통해 순계로 분리하였다. 이 연구는 꿀, 로열젤리 다수확계통 선발에 있어 개체군 선발과 육종 효율을 높이기 위해 수행되 었다. 23 개의 형태학적 특성을 평가하고 두 아종의 기존 데이터와 비교한 결과, 이탈리안벌 순계계통은 코카시안벌 순계 계통과 달리8개의 특성이 기존의 이탈리안벌과 유사해 더 많은 특성이 보존되고 있음을 알 수 있었다. 또한 국내에서 유지되고 있는 순계들은 타 지역의 동일 계통과 차 이를 보여 분리된 순계의 형태적인 특징이 확인되었다.
        4,300원
        5.
        2019.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        This study aimed to examine the effect of a mild elevation in serum cholesterol level in a porcine coronary overstretch restenosis model using a balloon angioplasty catheter or drug-eluting coronary stent. Pigs were divided into two groups and were fed a commercial normal diet (CND, n = 4) or a high-fat diet (HFD, n = 4) for 5 weeks. Coronary overstretch injury by balloon angioplasty or stent implantation was induced in the left anterior descending and left circumflex artery after 1 week of feeding. Histopathological analysis was performed at 4 weeks after coronary injury. During the experiment, the total cholesterol level in the HFD group increased by approximately 44.9% (from 65.9 ± 3.21 mg/dL at baseline to 95.5 ± 9.94 mg/dL at 5 weeks). The lumen area in the CND group was reduced in comparison with that in the HFD group after balloon angioplasty. After stent implantation, the injury score showed no significant difference. There were significant differences in the neointimal area (2.7 ± 0.33 mm2 in the CND group vs. 3.3 ± 0.34 mm2 in the HFD group, p<0.05), lumen area (2.6 ± 0.54 mm2 in the CND group vs. 2.0 ± 0.33 mm2 in the HFD group, p<0.05), and percent area stenosis (52.0 ± 7.96% in the CND group vs. 62.4 ± 5.15% in the HFD group, p<0.05). Body weight change was not different between the two groups. Increased serum cholesterol level activated vascular smooth muscle cell proliferation in the porcine coronary overstretch model.
        4,000원
        7.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pigs are considered as optimal donor animal for the successful xenotransplantation. To increase the possibility of clinical application, genetic modification to increase compatibility with human is an important and essential process. Genetic modification technique has been developed and improved to produce genetically modified pigs rapidly. CRISPR/Cas9 system is widely used in various fields including the production of transgenic animals and also can be enable multiple gene modifications. In this study, we developed new gene targeting vector and enrichment system for the rapid and efficient selection of genetically modified cells. We conducted co-transfection with two targeting vectors for simultaneous inactivation of two genes and enrichment of the genetically modified cells using MACS. After this efficient enrichment, genotypic analysis of each colony showed that colonies which have genetic modifications on both genes were confirmed with high efficiency. Somatic cell nuclear transfer was conducted with established donor cells and genetically modified pigs were successfully produced. Genotypic and phenotypic analysis of generated pigs showed identical genotypes with donor cells and no surface expression of α-Gal and HD antigens. Furthermore, functional analysis using pooled human serum revealed dramatically reduction of human natural antibody (IgG and IgM) binding level and natural antibody-mediated cytotoxicity. In conclusion, the constructed vector and enrichment system using MACS used in this study is efficient and useful to generate genetically modified donor cells with multiple genetic alterations and lead to an efficient production of genetically modified pigs.
        4,000원
        8.
        2016.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        경주 방사성폐기물 처분시설은 향후 80만 포장물을 처분할 계획이며 다양한 처분방식 및 관리형태를 가진 복합계가 될 것 이다. 본 논문에서는 전체부지 처분용량(80만 포장물) 처분시설의 단계별 개발에 따른 영향을 평가하기 위하여 처분시설 종 합개발계획(안)에 따른 예비안전성평가를 수행하였다. 각 시나리오에 대한 안전성평가결과 처분시설의 성능목표치를 만족 하였다. 다만, 전체처분시설의 안전성 평가결과에 중준위 방사성폐기물로 인하여 1단계 동굴 처분시설이 가장 크게 영향을 미치므로 처분시설의 안전성 향상을 위하여 처분방사능량제한 설정 등 관리방안이 필요하다. Safety Case 단계별 구축을 통 하여 중·저준위 방사성폐기물 처분시설 종합개발 과정에서 인지된 불확실성을 저감하여 안전성을 증진 시킬 수 있을 것으 로 판단된다.
        6,400원
        9.
        2009.09 구독 인증기관 무료, 개인회원 유료
        Effects of Vegemil® containing soybean proteins and isoflavones on the growth and bone density of broiler chickens were investigated. One-week-old male and female Arbor Acres broiler chickens were fed on Vegemil® A containing 3% soybean proteins and 162 ppm isoflavones, instead of water, for 30 days and their growth indices (body weight, leg weight and femur length) and bone density were analyzed. The body weight gains in male and female chickens were increased by 15.6% and 31.7%, respectively, following feeding Vegemil® A compared to normal water. Vegemil® A increased leg weight as well as femur length of females by 22.9% and 15.0%, respectively. In addition, Vegemil® A feeding enhanced femoral bone density by 21.3% in comparison with water feeding. Therefore, it is suggested that Vegemil® A not only facilitates body growth, but also strengthens bone density of normal chickens, and that it could be a promising candidate for the improvement of infant growth and for the prevention of menopausal osteoporosis.
        4,000원
        13.
        1994.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Slow seedling growth rate and nodulation failure of white clover (Trifolium repens L.) has been limited its good establishment to pastures. The experiment was done to determine the effect of removal of cotyledon and unifoliolate on the shoot, root growth,
        4,000원
        14.
        2016.10 서비스 종료(열람 제한)
        Background : Perilla frutescens L. is valuable as a medicinal plant as well as a natural medicine and functional food. Limonene perilla collected from various places showed 60% limonene compounds. However biological activity of these accession has not been reported before. Therefore, this study was conducted to investigate the biological activity of limonene perilla. Methods and Results : Fractional solvent extracts were obtained by using organic solvents such as n-hexane, chloroform, ethyl acetate, n-BuOH, and aqueous solvent from different parts of limonene perilla extracted initially in 70% EtOH. We investigated the effects of limonene perilla on total phenol and flavonoid contents, FRAP (Ferric Reducing Antioxidant Power), total saponin contents and tyrosinase inhibition activity. Leaves of limonene perilla produced the highest total phenolic contents (29.88 mg·CAE/g), flavonoid (8.39 mg·QE/g) and saponin contents (47.77 mg·GIE/g) than stems and roots of limonene perilla. FRAP of leaves was 823.00±3.58 μM·FeSO4·E/mg. Tyrosinase inhibition activity rate was 40.31% in 70% ethanol extracts from leaves of limonene perilla. Conclusion : This results suggest that leaf of limonene perilla fractions has significant antioxidant activity. Also, limonene perilla could be used as a functional biomaterial in developing cosmetics and functional foods.
        15.
        2016.10 서비스 종료(열람 제한)
        Background : Plants are the rich source of antioxidants, which plays a very important role in maintaining human health. Their antioxidant property protects cells of different organs of human beings against free radicals and free radical mediated diseases. Even though, there is lack of knowledge on the antioxidant effect of lutein present in plants. In the present study, lutein was isolated from the GreenTea leaves (Camellia sinensis) which is used as a dietary source. Methods and Results : The procedure adopted for the isolation and purification of lutein using acetone extraction and preparative high performance liquid chromatography (HPLC) is simple and less time consuming. Free radicals scavenging activity of isolated lutein from acetone extract of GreenTea was assessed by DPPH radical scavenging assay and reducing power. The isolated lutein scavenged 79% of DPPH radicals at 20 ㎍/㎖ and two fold lower concentration compared to the standard antioxidants (α-tocopherol). No significant differences were found between the reducing power of the lutein and BHT when their concentrations were high. However, significant differences were observed at relatively low concentrations, the reducing power of lutein was isolated from the GreenTea leaves was stronger than those of their acetone extract and standard antioxidants (BHA). Both electron spin resonance (ESR) and in vitro assay confirmed that lutein was isolated from the GreenTea leaves, exhibited a greater capacity for scavenging superoxide (O2 •-) and hydroxyl (OH •) radicals than standard antioxidants β-carotene and α-tocopherol respectively. Conclusion : The results proven that lutein isolated from GreenTea leaves has an efficient antioxidant ability, it could serve as an antioxidant to scavenge reactive oxygen species.
        16.
        2016.10 서비스 종료(열람 제한)
        Background : Lutein, a xanthophyll, consists of chains with 8 conjugated double bounds containing closed rings on each end of the chain. This carotenoid is found in fruits and vegetables, especially dark green leafy vegetables such as green tea. In this study, we investigated the anticancer effects of purified lutein from green tea on human cancer cell lines containing prostate carcinoma cancer cells (LNCaP). Methods and Results : Prostate carcinoma cancer cells (LNCaP) were cultured and evaluated the inhibitory effect of lutein isolated from green tea compared other carotenoids (β-carotene and lycopene) on cell proliferation. Cyclin D1 and PCNA were evaluated as cell differentiation. In results, PCNA/cyclin regulates the initiation of cell proliferation by mediating DNA polymerase. Under cultural conditions, lycopene remarkably suppressed the PCNA expression prostate cancer cell line LNCaP in higher doses (20 μM - 100 μM) statistically. However, β-carotene and lutein presented the less inhibitory effects on PCNA expression. Determination of PCNA expression in control and treated cells demonstrates that lycopene did affect proliferation in LNCaP cancer cells in dose-dependent manner. However, β-carotene and lutein suppressed the cyclin D1 expression in dose-dependent manner but no in lycopene group. These results indicate that differ carotenoids presented the various suppressive ability of PCNA and cyclin D1 expression in cell proliferation. Conclusion : In conclusion, lutein suppressed the carcinogenesis of induced prostate cancer cell line by acting as a suppressor for inhibiting the expression of cyclin D.
        17.
        2015.07 서비스 종료(열람 제한)
        Zinc finger nucleases (ZFNs) have been used for targeted mutagenesis in eukaryotic cells. Custom-designed ZFNs can induce double-strand breaks (DSBs) at a specific locus. Our custom ZFN dimer was designed 3-finger of left and 4-finger of right with 2 kb size using 2A. A Ti-plasmid vector, pTA7002 containing the target site of SSS4A gene for a ZFN pair, that was shown to be active in yeast, was integrated in the rice genome. This promising technique for genome engineering was induced into 4 exon region of SSS4A gene in rice genome using Agrobacterium-mediated transformation. The SSS4A full-length cDNA was 5,070 bp consisting of a 318 bp 5′-untranslated region (UTR), a complete ORF of 2,928 bp encoding a polypeptide of 975 amino acids and a 3′-UTR of 1,824 bp. The vector is based on glucocorticoid receptor inducible gene expression system. Thus, SSS4A::ZFN expression was tightly controlled and the phenotype in low concentrations 10uM of the glucocorticoid hormone dexamethasone (DEX). In plant cells, transient ZFN expression is achieved by direct gene transfer into the target cells. For an alternative, ZFN delivery and production of mutant plants using a tobacco transient expression system for indirect transient delivery of ZFNs into a variety of tissues and cells of plants. ZFN activity was determined by PCR and sequence analysis of the target site. ZFN induced plants were obtained in up to 2% of the PCR products, consisting of deletions ranging between 1and 100 bp and insertions ranging between 1 and 10 bp. Our results describe an alternative to direct gene transfer for ZFN delivery and for the production of mutated rice.
        18.
        2015.07 서비스 종료(열람 제한)
        UDP-glucose 4-epimerase (UGE; EC 5.1.3.2) is an enzyme that plays an essential role in the interconverts UDP-D-glucose (UDP-Glc) and UDP-Dgalactose (UDP-Gal). Five members of the Chinese cabbage (Brassica rapa) UDP-glucose 4-epimerase gene family, designated BrUGE1 to BrUGE5, have been cloned and characterized. Quantitative PCR shows that the BrUGE1and BrUGE4 mRNA are most abundant among other BrUGE genes, accounting for more than 55% of total BrUGE transcripts in most of the tissues examined. All genes showed organ specific expression pattern, two of which (BrUGE1 and 4) actively responded after Pectobacterium carotovorum subsp. carotovorum infection, while four genes (BrUGE-1, -3, -4 and -5)were shown to respond considerably against salt, drought and abscisic acid (ABA) treatments. To better understand the function of the UGE gene, we constructed a recombinant pART vector carrying the BrUGE1 gene under the control of the CaMV 35S promoter and nos terminator and transformed using Agrobacterium tumefaciens. We then investigated BrUGE1 overexpressing rice lines at the physiological and molecular levels under biotic and abiotic stress conditions. Bioassay of T3 progeny lines of the transgenic plants in Yoshida solution containing 120 mM Nacl for 2 weeks, confirmed that the BrUGE1 enhances salt tolerance to transgenic rice plants. Also T3 progeny lines of the transgenic plants, when exposed to infection caused by Xanthomonas oryzae pv oryzae, showed tolerance to bacterial blight. These results showed that BrUGE1 can be used as potential genetic resource for engineering Brassica with multiple stress resistance.
        19.
        2012.07 서비스 종료(열람 제한)
        The antimicrobial peptide possesses defence system to virus, fungi and bacteria. To study antibiotic in plant, antimicrobial peptides were obtained by PCR analysis by primers designed from antimicrobial peptides (Gene bank accession no. NM-004345), cloned in pET28 expression vector and the vector transformed into E. coli. And this gene was inserted into Ti-plasmid VB2 vector, which contained the pGD1 promoter. The expression construction was transformed into Agrobacterium EHA105 and then plant tissues of rice (Oryza sativa). Seeds from transgenic plants (T0) were germinated on selective media containing spectinomycin 50 mg/L. Selected plants and wild type were analyzed by PCR and RT-PCR with pGD1 promoter region and transgene specific primer set. All transgenic plants showed expression pattern of similar levels. We showed that the chromobody is effective in binding GFPand antimicrobial peptide gene in tobacco leaf. Most interestingly, this can be applied to interfere with the function of GFP fusion protein and to mislocalize (trap) GFP fusions to the plant cytoplasm in order to alter the phenotype mediated by the targeted proteins. Bacterial blight disease was enhanced resistance in transgenic lines. These results showed that antibiotic peptides might show a broad-spectrum antimicrobial activity.
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