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        검색결과 457

        121.
        2014.10 구독 인증기관·개인회원 무료
        Double-stranded RNA(dsRNA) had been used to specitically suppress target gene expression at post-tanscription level. Injection of dsRNA to hemocoel is the most efficient to knockdown target mRNA. However, some insects have shown to be susceptible to feeding dsRNA. Spodoptera exigua was susceptible to dsRNA at oral treatment. Especially dsRNA specific to β-integrin was potent to survival of S.exigua larvae. This study advanced our dsRNA application technology by generating recombinant E.coli expressing dsRNA specific the β-integrin. A recombinant vector L4440 was constructed with a partial β-integrin gene under T7 RNA polymerase promoter. The recombinant vector was used to transform HT115 competent cells of E.coli. The transformed E.coli expressed the dsRNA. The production of dsRNA was proportional to the bacterial number. By feeding the recombinant E.coli, S.exigua underwent significant mortality. By adding E.coli expressing Cry1Ca Bt toxin to E.coli expressing dsRNA, S.exigua exhibited highly enhanced mortality. This study suggests a possibility to use a recombinant E.coli expressing dsRNA to control S.exigua.
        122.
        2014.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 남한지역 백두대간 마루금 일대의 고도별 식물 다양성 분포 패턴 및 기후인자, 면적, 기하학적 억제인자, 순일차 생산량이 고도별 식물 다양성 분포 패턴에 미치는 효과를 구명하기 위해 수행되었다. 백두대간 마루금 일대를 따라 위치한 1,100개의 조사구에 대한 식생조사 결과, 총 97과 342속 802종의 식물종이 관찰되었으며, 고도에 따른 식물종의 α 다양성을 나타내는 종풍부도와 Shannon-Wiener 지수는 단봉형 패턴을 나타내는 반면, β 다양성을 나타내는 Jaccard와 Chao-Jaccard 유사도 지수는 고도에 따라 일반적으로 증가하는 경향을 나타내었다. 또한, 이러한 분포 패턴을 제어하는 인자로서 기하학적 억제인자가 α 다양성을 설명하는 가장 중요한 인자로 나타났으며, β 다양성은 기후인자가 가장 높은 설명력을 가지는 인자로 나타났다. 본 연구는 동일한 분류군 내에서도 다양성 측정방법에 따라 상이한 고도별 분포 패턴 및 제어인자를 가진다는 것을 제시하며, 백두대간 마루금 일대의 식물 다양성을 제어하는 인자가 단순히 하나가 아닌 몇 가지 인자의 복합작용에 의해 나타나는 현상임을 의미한다.
        4,300원
        123.
        2014.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this research, a precipitation method was used to synthesize β-Ga2O3 powders with various particle morphologies and sizes under varying precipitation conditions, such as gallium nitrate concentration, pH, and aging temperature, using ammonium hydroxide and ammonium carbonate as precipitants. The obtained powders were characterized in detail by XRD, SEM, FT-IR, and TG-DSC. From the TG-DSC result, GaOOH phase was transformed to β-Ga2O3 at around 742˚C, and weight loss percent was about 14 % when NH4OH was used as a precipitant. Also, β-Ga2O3 formed at 749˚C and weight loss percent was about 15 % when (NH)2CO3 was used as a precipitant. XRD results showed that the obtained Ga2O3 had pure monoclinic phase in both cases. When (NH)2CO3 was used as a precipitant, the particle shape changed and became irregular. The range of particle size was about 500nm-4μm based on various concentrations of gallium nitrate solution with NH4OH. The particle size was increased from 1-2μm to 3-4μm and particle shape was changed from spherical to bar type by increasing aging temperature over 80˚C.
        4,000원
        124.
        2014.04 구독 인증기관·개인회원 무료
        Integrin is a cell surface protein that is composed of α and β heterodimer and mediates cell interaction with extracellular matrix or other cells including microbial pathogens. A full length cDNA sequence (2,517 bp) of a integrin subunit β1 (HaITGβ1) was cloned from the oriental tobacco budworm, Helicoverpa assulta. Phylogenetic analysis showed that HaITGβ1 was clustered with other insect β integrin subunits with the highest amino acid sequence identity (61%) to β1 of other Noctuidae such as Spodoptera exigua and S. litura. Structural analysis of the HaITGβ1 possessed all functional domains known in other insect β1 integrins. RT-PCR analysis showed that HaITGβ1 was expressed in all developmental stages and all tested tissues of H. assulta. Injection of double-stranded HaITGβ1 RNA (dsHaITGβ1) into third instar of H. assulta suppressed HaITGβ1 expression and resulted in significant delay from last larval stage to pupal stage. The dsHaITGβ1 injection significantly impaired nodule formation of H. assulta in response to bacterial challenge and hemocyte adherence. These results suggest that HaITGβ1 plays crucial roles in cellular immune responses as well as development in H. assulta.
        125.
        2014.03 구독 인증기관 무료, 개인회원 유료
        Aggregatibacter actinomycetemcomitans is an important pathogen in the development of localized aggressive periodontitis. Lipopolysaccharide (LPS) is a virulent factor of periodontal pathogens that contributes to alveolar bone loss and connective tissue degradation in periodontal disease. Our present study was designed to investigate the cytokine expression and signaling pathways regulated by A. actinomycetemcomitans LPS (Aa LPS). Cytokine gene expression profiling in RAW 264.7 cells was performed by microarray analyses. The cytokine mRNA and protein levels and related signaling pathways induced by Aa LPS were measured by RT-PCR, ELISA and western blotting. Microarray results showed that Aa LPS strongly induced the expression of NF-κB, NF-κB-related genes, inflammatory cytokines, TNF-α and IL-1β in RAW 264.7 cells. NF-κB inhibitor pretreatment significantly reduced the levels of TNF-α and IL-1β mRNA and protein. In addition, the Aa LPS-induced TNF-α and IL-1β expression was inhibited by p38/JNK MAP kinase inhibitor pretreatment. These results show that Aa LPS stimulates TNF-α and IL-1β expression through NF-κB and p38/JNK activation in RAW 264.7 cells, suggesting the essential role of this pathway in the pathogenesis of localized aggressive periodontitis.
        4,000원
        126.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Inflammation mainly mediated by innate immune cells as the first line of host defense against pathogens is an acute response that limits tissue damage and eliminates pathogens in the body. In triggering inflammation, several pattern recognition receptors work together; membrane-associated Toll-like receptors, c-type lectin receptors, retinoic acid-inducible gene-like helicase receptors, absent in melanoma-like receptors, and cytosolic nucleotide-binding domain and leucine-rich repeat receptors. Among them, inflammasome is a newly trigger of inflammation in response to exogenous and endogenous stimuli and its activation leads to the assembly of multiprotein platforms composed of NLRP3 (NOD-like receptor family, pyrin domain containing 3), ASC (apoptosis associated speck-like protein containing a CARD), and procaspase 1. Thus, the activated inflammasome activates caspase 1, resulting in processing and secretion of interleukin (IL)-1β. Recent emerging data suggest that dysregulated metabolites, i.e., amyloids, ceramides, and cholesterol crystals, have been classified as inflammasome activators. In addition, IL-1β may play a critical role in the pathogenesis of chronic inflammation-induced disorders such as Alzheimer’s diseases, type 2 diabetes, and atheriosclerosis. This review introduces the basic concept of inflammasome activation and auto-inflammatory diseases. In addition, it discusses the updated signaling models of inflammasome activation that link metabolic dysfunction in order to outline future therapeutic approaches to inflammasome-mediating diseases.
        4,000원
        127.
        2013.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the changes of hormone levels of serum progesterone (P4) and estradiol-17 β (E2) in sows of Landrace (L), Yorkshire (Y) and F1 (L × Y) (respectively n=3) with excellent ability, and to provide a baseline data for improving reproductive performance. In this experiment, the sows at the age of 12 months or more were used. The sows were fed by two way methods, one is conventional methods and the other is 3 days-flushing feed before estrus. Each pig’s blood was collected in 3, 6, 9, 12, 15 and 18 days after the estrus for the analyses of P4 and E2. Serum was separated by centrifugation for 15 min. with 3,000 rpm. Progesterone and estradiol-17β were measured by immunochemical assay (ELIZA test). In conventional feeding, serum progesterone levels were significantly (p<0.01) higher in F1 than in L and Y. No significant differences in P4 concentrations were seen between the L and Y of sows. Serum E2 levels were similar the serum progesterone levels. In the case of flushing feed, the tendency of hormonal changes were similar to conventional methods. But almost of hormonal levels were a little higher than that of conventional methods. P4 level of L and Y in flushing feed were significantly different (p<0.01). Serum E2 level of Y in flushing feed was significantly different among the breeds (p<0.01). These results were similar to the tendency of hormonal changes in general sows and moreover, flushing feed is known to develop the swine production, these results proved the fact of the methods. And these results suggested that more studies about hormonal changes in sows according to seasonal and nutritional factors should be needed.
        3,000원
        129.
        2013.10 구독 인증기관·개인회원 무료
        A xylan-decomposing Gram-positive bacterium, Cellulosimicrobium cellulans DY-8, was isolated from the gut of a wood-feeding longicorn beetle, Moechotypa diphysis. To amplify a partial fragment of the GH 10 β-1,4- xylanase (XylC) gene of strain DY-8, two degenerated oligonucleotide primers were designed based on strictly conserved regions (WDVVNE and ITELLDV) in the GH family 10 xylanolytic enzymes. The full gene (1488-bp) of XylC, which was predicted to encode a protein consisting of 495 amino acids with a molecular mass of 52.0 kDa and a calculated pI of 6.49, was cloned by repeated DNA walking and nested PCR protocols. The results of a protein blast survey showed that XylC was a β -1,4-xylanase comprised of an N-terminal catalytic GH10 domain (from Ser48 to Leu338) and a C-terminal RICIN domain (from Tyr359 to Leu492). This overall structure of XylC was 57% identical to that of Actinoplanes sp. SE50/110 β -1,4-xylanase (Accession number: YP_006265966), which has not yet been biochemically characterized.
        130.
        2013.10 구독 인증기관·개인회원 무료
        A xylanolytic microorganism, strain DY-7, was isolated from the gut of the mole cricket, Gryllotalpa orientalis. The result of phylogenetic analysis based on its 16S rDNA sequence revealed that the isolate was a Gram-positive bacterium belonging to the genus Streptomyces. The cloned gene (1350-bp) encoding a GH family 10 β -1,4-xylanase (XylA) from Streptomyces sp. strain DY-7 was overexpressed in Escherichia coli BL21 and its gene products were characterized. The hydrolysis activities of rXylA and rXylAΔCBD II against xylosidic materials were maximum at pH 5.5 and 65oC. However, deletion of CBD II in the C-terminus region of XylA significantly increased the thermal stability of the enzyme at high temperatures above 50oC. The xylanolytic activity of rXylA was slightly enhanced in the presence of 1 mM Mn2+ and 5 mM sodium azide but it was completely inactivated by 1 mM Hg2+ and 5 mM N-bromosuccinimide. rXylA was capable of efficiently decomposing various xylosidic compounds, PNP-cellobioside, and PNP-xylopyranoside, whereas other hexose-based compounds were insensitive to the enzyme. The specific activities of rXylA toward oat spelts xylan and PNP-cellobioside were 649.8 U/mg and 328.1 U/mg, respectively. Enzymatic degradation of birchwood xylan and xylooligosaccharides (xylotriose to xylohexaose) resulted in the production of xylobiose (>75%) as the main hydrolysis product together with a small amount (4%<) of xylose as the final hydrolysis product.
        131.
        2013.10 구독 인증기관·개인회원 무료
        The aim of this study is to analyze the functional activity of an endo-β-1, 4-glucanase from the wood dwelling lower termite Coptotermes gestroi. Full length cDNA sequences of the endo-β-1,4-glucanase were obtained by primer walking in conjunction with Rapid Amplification cDNA Ends. With the obtained full length sequences, primers for amplifying open reading frame (ORF) excluding the signal peptide and glycophosphatidylinositol anchor were designed. Amplified endo-β-1,4-glucanase fragment was cloned and expressed using pET30(+) expression vector in BL21 E.coli strain. Expression of endo-β-1,4-glucanase was confirmed by Western blotting and the result revealed that only full ORF was expressed. The cellulase activity of protein preparations from the induced and non-induced cells was analyzed with Congo Red assay with the cellulase from Aspergillus niger (Sigma Aldrich) as a positive control. The activity of C. gestroi endo-β-1,4-glucanase was significantly higher than those observed in the positive control and the enzyme preparation from non-induced cells. Therefore, this study confirmed that C. gestroi endo-β-1,4-glucanase had a function of cellulose hydrolysis.
        132.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        알칼리 가수분해에 따른 보리 β-glucan의 이화학적 특성변화를 살펴보기 위하여 새쌀보리, 새찰쌀보리 및 흰찰쌀보리에 0.2~1.0 N NaOH를 처리하였으며, 총 및 수용성 β-glucan의 함량 및 순도, 수용성 β-glcuan의 분자량, 점도 및 재용해율을 살펴보았다. 3품종 보리의 총 β-glucan 함량은 7.77~8.40% 범위이었으며, 알칼리 가수분해 농도가 증가함에따라 6.89~7.54% 범위로 감소하였다. 수용성 β-glucan의 함량은 무처리의 4.16~4.80% 범위에서 알칼리 가수분해 농도가 증가함에 따라 4.30~4.82% 범위로 유의적인 차이가 없었다. 수용성 β-glucan의 순도는 3품종 모두 30.91~35.79% 범위이었으나, 알칼리 가수분해에 의해 74.02~81.41%까지 증가하였다. 분자량은 메성보리보다 찰성보리가 더 컸으며, 알칼리 가수분해 농도가 증가함에 따라서 크게 감소하였다. β-Glucan 수용액의 점도는 알칼리 가수분해 농도가 증가함에 따라 감소하였으며, 메성보리보다 찰성보리가 높았고, 흰찰쌀보리보다 새찰쌀보리가 높았다. 재용해율은 무처리의 50~55% 범위에서 알칼리 가수분해 농도가 증가함에 따라 증가하여 1.0 N NaOH 처리구에서 80.00~87.66% 범위로 증가하였다.
        4,000원
        133.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Prostate cancer is a leading cause of death among the aging men. Surgical or radio therapy is effective when the cancer is confined to the prostate gland but once the cancer spreads beyond the pelvis, even chemotherapy and hormonal ablation therapy fails in curing this disease. Our previous studies have shown that β-glucan induces apoptosis in prostate cancer cells. Cellular viability of these cells treated with β-glucan was measured by MTT assay. β-glucan induced dose- and time-dependent inhibition of cell viability in LNCaP cancer cells. In flow cytometry analysis, β-glucan induced dose- and timedependent apoptotic activities in LNCaP cancer cells. In addition, increased of expression caspase-3, caspase-9, Bax, and cytochrome C but decreased of expression Bcl-2 was observed in LNCaP cells treated with β-glucan. These results suggest that β-glucan induces apoptosis in LNCaP human prostate cancer cells mediated mainly through the increased of expression caspase-3, -9, Bax, cytochrome C and decreased of expression Bcl-2.
        4,000원
        134.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Abstract This manuscript reports on compared color evolution about phase transformation of α-FeOOH@SiO2 and β-FeOOH@SiO2 pigments. Prepared α-FeOOH and β-FeOOH were coated with silica for enhancing thermal properties and coloration of both samples. To study phase and color of α-FeOOH and β-FeOOH, we prepared nano sized iron oxide hydroxide pigments which were coated with SiO2 using tetraethylorthosilicate and cetyltrimethyl-ammonium bro- mide as a surface modifier. The silica-coated both samples were calcined at high temperatures (300, 700 and 1000°C) and characterized by scanning electron microscopy, CIE L*a*b* color parameter measurements, transmission electron microscopy and UV-vis spectroscopy. The yellow α-FeOOH and β-FeOOH was transformed to α-Fe2O3 with red, brown at 300, 700°C, respectively.
        4,000원
        135.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This manuscript reports on compared color evolution about phase transformation of α-FeOOH@SiO2 and β-FeOOH@SiO2 pigments. Prepared α-FeOOH and β-FeOOH were coated with silica for enhancing thermal properties and coloration of both samples. To study phase and color of α-FeOOH and β-FeOOH, we prepared nano sized iron oxide hydroxide pigments which were coated with SiO2 using tetraethylorthosilicate and cetyltrimethyl-ammonium bro- mide as a surface modifier. The silica-coated both samples were calcined at high temperatures (300, 700 and 1000°C) and characterized by scanning electron microscopy, CIE L*a*b* color parameter measurements, transmission electron microscopy and UV-vis spectroscopy. The yellow α-FeOOH and β-FeOOH was transformed to α-Fe2O3 with red, brown at 300, 700°C, respectively.
        4,000원
        137.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sephadex G-100 column chromatography에 의해 Xylogone sphaerospora 유래 β-mannanase의 정제를 수행하여 비활성 8.24 units/mL 정제배율 58.86배를 나타내었다. SDS-PAGE에 의한 단일밴드를 확인하였고, 분자량은 42 kDa으로 결정되었다. 정제효소에 의해 Picea abies Galactosyl glucomannan을 가수분해하여 activated carbon column chromatography에 의해 당가수분해물을 분리 회수하여 TLC와 FACE법 및 Timell's method에 의해 중합도 7, 8, 12 and 13으로 결정되었으며, Penicillum purpurogenum 유래 정제 β-mannanase와 α-galactosidase를 이용한 enzymatic sequential action에 의해 4가지 가수분해산물 모두 hetero type galactosyl glucomannooligosaccharides로 확인되었다. B. longum, B. bifidum, B. infantis, B. animalis, B. breve, B. adolessentis, B. auglutum의 생육활성에 대한 중합도 7, 8, 12 and 13의 영향을 검토하기 위하여 modified-MRS 배지상에 탄소원으로 중합도 7, 8, 12 and 13을 대체하여 생육활성을 비교한 결과 B. longum에서는 D.P. 7 galactosyl glucomanno-oligosaccharide를 탄소원으로 대체한 경우 표준 MRS배지와 비교하여 10.8배, D.P. 8에서 12.5배, D.P. 12에서 10.2배 D.P. 13에서 9.2배의 상대활성을 나타내어 가장 우수한 생육활성을 나타내었으며, B. bifidum의 경우에서도 D.P. 7에서 3.0배, D.P. 8에서 3.3배, D.P. 12에서 3.7배 D.P. 13에서 5.7배의 활성을 보였다.
        4,000원
        138.
        2013.05 구독 인증기관·개인회원 무료
        민주름버섯목의 구멍장이버섯과에 속하는 영지(Ganoderma lucidum)는 정신안정, 심장병 및 고혈암 예방 효과가 있으며, 복분자(Rubus coreanus)는 항염증작용과 항산화 작용이 보고 되어 있다. 영지버섯 균사체를 활용하여 생약초 발효 식품을 개발하고자, 현미에 복분자 부산 물 20%첨가한 후, 영지균사체로 배양하여, 동결건조한 후, 시료로 사용하였다. 본 연구에서는 생약초 발효 식품 개발의 일환으로 구성아미노산과 기능성 물질인 β-glucan의 함량을 분석하 였다. β-Glucan은 다당류의 일종으로 면역증강작용을 가지고 있어, 인간정상세포의 면역기능 을 활성화시켜 암세포의 증식과 재발을 억제시키는 물질로 알려져 있다. 영지의 구성아미노산 의 함량은 3,054.35 mg%로 나타났으며 그 중 필수아미노산의 함량은 1,514.76 mg%로 나타났 고, β-glucan 함량은 18.25%로 나타났다. 현미에 복분자 부산물 20%를 첨가하여 표고 균사체 를 배양한 배양미의 구성아미노산의 함량은 6,489.02 mg%로 나타났으며 그 중 필수아미노산 의 함량은 2,439.34 mg%로 나타났고, 배양미의 β-glucan 함량은 9.90%로 나타났다. 이상의 결과는 복분자, 영지 및 현미의 배합으로 필수아미노산 함량이 높아짐을 보여, 아미노산 함유 가공식품 개발에 효율적일 것으로 보인다. 사 사 : 본 연구는 산업통산자원부 지역특화기술융복합연구지원사업으로 수행되었으며, 이에 감사드립니다.
        139.
        2013.03 구독 인증기관 무료, 개인회원 유료
        In this study, we observed anti-diabetic effects of acid hydrolyzed silk peptides, where the amount of peptides in the total amino acid mixture was strictly regulated. Using in vitro diabetes models, silk peptide-containing amino acid mixtures of 5.60% (G5), 11.30% (G10), 14.50% (G15), and 20.50% (G20) were examined separately in order to determine whether they have biological activities. According to our results, a cytoprotective effect was observed following treatment of interleukin-1β in RINm5f pancreas β-cells. As a consequence, Bax, a pro-apoptotic gene, was down-regulated, while Bcl-2, a pro-survival gene, was retained at normal level. Results of the 4’,6-diamidino-2-phentylindole (DAPI) staining assay confirmed that G20 has a better cytoprotective effect. Insulin release from RINm5f cells showed a significant increase following treatment with G5-G20, suggesting that silk peptide effectively regulated and induced insulin production. Single treatment with G5-G20 resulted in enhanced glucose uptake in L6 skeletal muscle cells. In addition, a higher amount of each group inhibited the activity of α-glucosidase. In summary, these data suggest that silk peptide may have an anti-diabetic effect through protection of pancreas β-cells and enhancement of insulin release, which showed a close association with Type 1 diabetes mellitus (DM), and can improve glucose uptake, which was the major target for therapy of Type 2 diabetes. Taken together, we concluded that acid hydrolyzed silk peptides can be used effectively for control of blood sugar metabolism via improvement of the problematic indices of Type 1 and Type 2 DM.
        4,000원
        140.
        2013.03 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate immunopotentiating activities of β-glucan derived from Saccharomyces (S.) cerevisiae and to select new strains having possibility as an immune-enhancing substance. We examined SB20 strains derived from commercial product as a control, and extracted β-glucans from the four strains of S. cerevisiae. RAW264.7 macrophages were treated with heat-killed yeasts, β-glucans, and lipopolysaccharide (LPS). The production of nitric oxide (NO) and cytokines such as TNF-α and IL-1β were then quantified. When macrophages were induced directly by in vitro addition of β-glucan, little production of NO and IL-1β was observed. When pretreated with strong stimulants, i.e., LPS, most yeasts showed down-modulation of NO and IL-1β production. However, TNF-α secretion was triggered by β-glucans and even more increased by the mixture effect of LPS and β-glucans. In particular, S6 strain induced TNF-α secretion more than other strains. Therefore, we can conclude that the S6 strain has possibility as an immune-enhancing substance.
        4,000원