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        검색결과 214

        63.
        2016.10 구독 인증기관·개인회원 무료
        Bombolitin is a venom peptide originally isolated from bumblebees and possesses various biological activities, including hemolytic activity. Bombolitins exhibit amphipathic α-helical structure in lipid-membrane-mimicking environments. To investigate their pharmacological and toxicological properties, anti-tumor, anti-microbial and cytotoxic activities of bombolitins from Bombus ardens and Bombus ussurensis were evaluated. Bombolitins of the two species exhibited extremely high anti-tumor activity against ovarian tumor cells SK-OV-3 and NIH; OVCAR-3 at 25-50 μM, which is 2-fold more potent than other wasp venom peptides studied to date (Yoon et al., 2015; Yoon et al., 2016). The two bombolitins showed significantly high antimicrobial activity. However, bombolotin of B. ussurensis showed no antimicrobial activity against Escherichia coli. In addition to their high levels of anti-tumor activity, bombolitins showed considerable levels of hemolytic activity. Thus, to utilize bombolitins as a potential candidate for anti-tumor peptide drugs, further studies for reducing cytotoxic properties of bombolitns is essential.
        64.
        2016.04 구독 인증기관·개인회원 무료
        The lesser paper wasp, Parapolybia varia, belongs to large subfamily Polistinae and is distributed in Middle East, the Indo-Papuan region and East Asia. P. varia is known to become aggressive when disturbed for defending their colonies, resulting in fatal envenomation. Vespid chemotactic peptide (VCP) and vespakinin have recently been determined to be the top two genes most abundantly transcribed in venom glands of P. varia. To investigate the pharmacological and toxicological properties of VCP and vespakinin, their antitumor, antimicrobial, and cytotoxic activities were evaluated. VCP exhibited a significantly high antitumor activity against ovarian tumor cell SK-OV-3 at 100 M. VCP also showed higher hemolytic activity than vespakinin. Antimicrobial activity was only observed with VCP against yeast Candida albicans at 1 mM. Since VCP showed a relatively low hemolytic activity but a considerable level of antitumor activity, it has further merits to be exploited as a potential antitumor agent with reduced side effects on normal cells.
        65.
        2016.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This experiment was designed to assess the physical and chemical properties of growing media substituted with a range of increasing concentrations of pretreated wood and to relate these properties to plant growth responses. For preparing the growing media, each material was combined with rural soil, peat, perlite and pretreated wood. Physicochemical properties studied were similar to ideal substrate ranges for plant growth on growing media, including pretreated wood. Physical properties were also well maintained over time. In comparison to plants growing in 100% rural soil, tall fescue(Festuca arundinacea) in the prepared growing media achieved better growth, especially when using the 50% rural soil + 50% PPW(peat + perlite + pretreated wood, 3:1:6(w/w/w)) and 30% rural soil + 70% PPW (peat + perlite + pretreated wood, 3:1:6(w/w/w)), and showed improved germination percentage. We confirmed the potential use of growing media, including pretreated wood. Furthermore, our results show a correlation among the physicochemical properties of tall fescue(Festuca arundinacea); physical properties were significantly influenced by germination and aerial parts. The root length of physicochemical properties was correlated with bulk density and organic compound (p<0.01).
        4,000원
        67.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An experiment was conducted to study the potential of thermal treated oak sawdust(steaming and steam explosion) as horticultural medium component in plug seedlings production of Chinese cabbage(Brassica campestris L.). This study involves the chemical, physical characterization and growth test of thermal treated oak sawdust(steaming and steam explosion) in order to evaluate their use as components of horticultural media. A commercial peat moss and oak sawdust were used as control. The total carbohydrate, C/N ratio, pH, phenolic compound, total porosity and water holding capacity were 45.1g/100g dry wt, 425.1, 4.4, 141.8mg/g wt, 82.5%, 47.1% in oak sawdust and 39.2g/100g dry wt, 300.3, 4.7, 131.7mg/g wt, 84.9% and 49.2% in steamed oak sawdust and 30.3g/100g dry wt, 247.8, 5.7, 40.8mg/g wt, 92.3% and 51.7% in steam exploded oak sawdust, respectively. The mixtures of the horticultural media were prepared using different substrate as peat moss, oak sawdust, steamed oak sawdust, steam exploded oak sawdust and perlite to grow Chinese cabbage in a greenhouse. The seed germination, stem height and leaf area were 68%, 2.2cm, 1.1cm2 in OSP(containing 90% oak sawdust and 10% perlite) and 69%, 2.5cm, 1.5cm2 in SMP(containing 90% steamed oak sawdust and 10% perlite) and 87%, 3.0cm, 2.2cm2 in SEP(containing 90% steam exploded oak sawdust and 10% perlite), respectively. The leaf area SEP(containing 90% steam exploded oak sawdust and 10% perlite) was higher than that of PP(containing 90% peat moss and 10% perlite). This research indicates that steam exploded oak sawdust may be utilized as a suitable replacement for peat moss in horticultural media component for Chinese cabbage.
        4,200원
        68.
        2015.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Multi-walled carbon nanotube (MWCNT)/polycarbonate (PC) nanocomposite was prepared by direct melt mixing to investigate the effect of the shear rate on the surface resistivity of the nanocomposites. In this study, an experiment was carried out to observe the shear induced orientation of the MWCNT in the polymer matrix using a very simple melt flow indexer with various loads. The compression-molded, should be eliminated. MWCNT/PC nanocomposite sample exhibited lower percolation thresholds (at 0.8 vol%) and higher electrical conductivity values than those of samples extruded by capillary and injection molding. Shear induced orientation of MWCNT was observed via scanning electron microscopy, in the direction of flow in a PC matrix during the extrusion process. The surface resistivity rose with increasing shear rate, because of the breakdown of the network junctions between MWCNTs. For real applications such as injection molding and the extrusion process, the amount of the MWCNT in the composite should be carefully selected to adjust the electrical conductivity.
        4,000원
        69.
        2014.10 구독 인증기관·개인회원 무료
        The ectoparasitic honey bee mites was originally confined to the Asian honey bee(Apis cerana etc.), mites had become widely established in the world and have continued to cause extensive bee colony deaths. Mites attach to adults and developing brood, where they feed on their blood. If left untreated, mites can deform bees and eventually kill the colony. Varroa destructor and Tropilaelaps clareae has plagued European honey bees, Apis mellifera. Differences in mite tolerance are reported between two honey bee species A. mellifera and A. cerana. We were counted number of mites(V. destructor and T. clareae) form 20 colonies. V. destructor and T. clareae has very similar behavior in honeybee colony. When behaviorally close, two competing species may populational interfere, and thereby affect their population dynamics. We tested for populational interference (PI) between two populational competing honeybee mites, V. destructor and T. clareae, by investigating their population dynamics when they competed on the same colony.
        70.
        2014.10 구독 인증기관·개인회원 무료
        Porcine parvovirus (PPV), a member of the genus Parvovirus, family Parvoviridae, is a significant causative agent in porcine reproductive failure, causing serious economic losses in the swine industry. PPV is a non-enveloped virus and its capsid is assembled from three viral proteins (VP1, VP2, and VP3). The major capsid protein, VP2 is the main target for neutralizing antibodies in PPV. When VP2 was expressed in large amounts, it assembled into virus-like particles (VLPs) similar in size and morphology to the original virions. In this study, we generated the recombinant Bombyx mori nucleopolyhedrovirus (BmNPV) to express the VP2 protein. Expression of the VP2 protein was analyzed by SDS-PAGE and Western blot. The recombinant VP2 protein of approximately 64 kDa was detected by both analyses. The formation of VLP by recombinant VP2 was confirmed through transmission electron microscopy examination. The purified VP2 protein assembled into spherical particles with diameters ranging from 20 to 22 nm.
        71.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 양념 닭 가슴살의 양념 액에 귤 껍질 추출물(CPE, 2%), 양파 껍질 추출물(OPE, 2%), calcium lactate(2%), 난황 유래 phosvitin(0.1%)과 CPE, OPE 및 calcium lactate 복합처리를 첨가하였을 때 서로 다른 저장온도와 저장기간에 따른 항균 효과 및 품질 변화를 확인하고자 수행되었다. 모든 저장온도와 저장기간에서 CPE, OPE 및 복합 처리군의 총 호기성 세균 수는 대조구에 비해 유의적으로 낮게 확인되었으며, 가장 높은 미생물 생장 억제 효과가 있었던 처리군은 CPE 처리군이었다. 하지만, calcium lactate와 phosvitin 처리군의 미생물의 성장 억제 효과는 나타나지 않았다. pH의 경우, calcium lactate와 OPE 처리군은 모든 저장온도의 저장 0일차에서 대조구에 비해 유의적으로 낮은 값을 나타내었다. OPE 처리군은 모든 저장온도와 저장기간에서 다른 처리구들에 비해 유의적으로 높은 적색도를 나타내었고, CPE와 함께 저장온도에 따른 유의적 차이를 나타내지 않았다. 하지만 이러한 OPE 처리군은 풍미, 맛 및 종합적 기호도에서 다른 처리구들에 비해 유의적으로 낮은 값을 보였으며, calcium lactate와 phosvitin 처리군의 종합적 기호도는 대조구와 유의적 차이가 나타나지 않았다. 결론적으로, 양념 닭가슴살의 CPE, OPE 및 복합처리군에서 저장온도를 달리한 저장기간에 따른 미생물 억제 효과를 확인할 수 있었으나, 관능적 특성을 개선하는 방법의 개발이 필요하다고 판단된다.
        4,200원
        72.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The 304 stainless steel powders were prepared by high energy ball milling and subsequently sintered byspark plasma sintering, and the microstructural characteristics and micro-hardness were investigated. The initial size ofthe irregular shaped 304 stainless steel powders was approximately 42 µm. After high energy ball milling at 800 rpmfor 5h, the powders became spherical with a size of approximately 2 µm, and without formation of reaction compounds.From TEM analysis, it was confirmed that the as-milled powders consisted of the aggregates of the nano-sized particles.As the sintering temperature increased from 1073K to 1573K, the relative density and micro-hardness of sintered sampleincreased. The sample sintered at 1573K showed the highest relative density of approximately 95% and a micro-hard-ness of 550 Hv.
        4,000원
        73.
        2013.10 구독 인증기관·개인회원 무료
        Apolipophorin III (apoLp-III) is a well-known hemolymph protein having a functional role in lipid transport and immune response of insects. We cloned full-length cDNA encoding putative apoLp-III from larvae of the coleopteran beetle, Tenebrio molitor (TmapoLp-III), by identification of clones corresponding to the partial sequence of TmapoLp-III, subsequently followed with full length sequencing by a clone-by-clone primer walking method. The complete cDNA consists of 890 nucleotides, including an ORF encoding 196 amino acid residues. Excluding a putative signal peptide of the first 20 amino acid residues, the 176-residue mature apoLp-III has a calculated molecular mass of 19,146 Da. Genomic sequence analysis with respect to its cDNA showed that TmapoLp-III was organized into four exons interrupted by three introns. Several immune-related transcription factor binding sites were discovered in the putative 5’-flanking region. BLAST and phylogenetic analysis reveals that TmapoLp-III has high sequence identity (88%) with Tribolium castaneum apoLp-III but shares little sequence homologies (<26%) with other apoLp-IIIs. Homology modeling of Tm apoLp-III shows a bundle of five amphipathic helices, including a short helix 3’. The ‘helix-short helix-helix’ motif was predicted to be implicated in lipid binding interactions, through reversible conformational changes and accommodating the hydrophobic residues to the exterior for stability. Highest level of TmapoLp-III mRNA was detected at late pupal stages, albeit it is expressed in the larval and adult stages at lower levels. The tissue specific expression of the transcripts showed significantly higher numbers in larval fat body and adult integument. In addition, TmapoLp-III mRNA was found to be highly up-regulated in late stages of L. monocytogenes or E. coli challenge. These results indicate that TmapoLp-III may play an important role in innate immune responses against bacterial pathogens in T. molitor.
        74.
        2013.10 구독 인증기관·개인회원 무료
        We carried out DNA barcoding of five Korean Lymantria species to establish identification references library for quarantine inspection. Total of 118 samples including 34 samples obtained through quarantine inspection, two from USDA, and one collected from Philiphine were used for this study. And 30 sequences of 10 species from GenBank of NCBI were used as reference sequences. In a result of DNA barcoding of the Korean Lymantria species, sequence divergence of 148 DNA barcodes ranged from null to 17.0%, intraspecific divergence from null to 1.0%, and interspecific divergence from 5.1 to 17.0%. In NJ tree, L. dispar contained three clusters, which were identified as L. dispar asiatica, L. albescens, and L. xylina, respectively. L. xylina was collected through quarantine inspection on a foreign merchant ship in Yeosu port, and L. albescens was obtained by pheromone trap on L. dispar installed in Busan port. And L. monacha known as single species in Korea was revealed as species complex with three species, L. monacha, L. minomonis, and L. sugii. In subspecies level, L. dispar dispar (EGM) built single cluster, but L. d. asiatica (AGM) and L. d. japonica showed as multiple cluster. Therefore, DNA barcoding lead to rapid and accurate identification in species level, but in subspecies level, only a taxon showing geographically far distance was discriminated from the others. And the results could provide a taxonomic outline of the Korean Lymantria fauna and might be used as identification reference for Lymantria species in quarantine inspection.
        75.
        2013.10 구독 인증기관·개인회원 무료
        A taxonomic review on the Korean Lymantria Hübner, 1819 was conducted. In a result, a total of nine species under four subgenera including two new recorded species were detected as followings: L. dispar asiatica Vnukovskij, 1926, L. xylina Swinhoe, 1903, L. monacha (Linnaeus, 1758), L. minomonis Matsumura, 1933, L. sugii Kishida, 1986, L. lucescens (Butler, 1881), L. mathura Moore, 1865, L. fumida Butler, 1877, and L. bantaizana Matsumura, 1933. Of the two unrecorded species, L. minomonis was found only in Is. Bogildo of Jeollanam-do, the southern part of Korea, and the other one, L. sugii was collected in the middle part of Korea. On the two species, L. xylina and L. fumida, the Korean specimens could not be examined through this study. Therefore, we considered that the two species might be excluded from the Korean Lymantria fauna. Each species was identified on the basis of wing pattern and genitalia of male/female adult. We provided diagnosis, male/female adult habitus photos, male genitalia photos, and female ovipositor photos.
        76.
        2013.04 구독 인증기관·개인회원 무료
        Mealworms, Tenebrio molitor (L.) is used as an important animal feed additive for growth promotion and health management, but potentially exposes to fungal infection. In this work, virulence of two species of entomopathogenic fungi against the insect, and the relationship between abiotic features and virulence were investigated. Secondly our consideration was also given to the effect of chemical fungicides on conidial germination for risk control. Between Beauveria bassiana (Bb) and Metarhizium roberstii (Mr) (previously M. anisopliae), Bb isolates had much higher virulence (~100% mortality in 3~4 days after the treatment), rather than Mr isolates in laboratory assays. Next, fungus-treated mealworms were kept at wheat bran at 20, 25, 30 and 35℃ with 3, 6, 9 times of water spray to the feeds for set-up of different humidity conditions. Inoculation of fungi to mealworms was conducted by fungal spray and feeding methods, which resulted in higher virulence in feeding method. In the feeding method, all temperature treatments except 35℃ showed high virulence against mealworms, but any significant relationship between virulence and humidity was not observed. In the chemical fungicide screening, fluazinam (CAS No. 79622-59-6) and mancozeb (8018-01-7) significantly inhibited the germination of Bb and Mr conidia. This work suggest that contamination of wheat bran with fungal pathogens, particularly B. bassiana may induce mycosis of mealworms, but introduction of effective fungicides possibly reduce fungal infection.
        77.
        2013.04 구독 인증기관·개인회원 무료
        The cotton aphid, Aphis gossypii (Glover), is one of the most serious pests in various vegetable crops. In Korea, some field populations of A. gossypii especially in greenhouse showed high resistance against neonicotinoids. The imidaclopridresistant strain (IR) selected from one of the greenhouse strains was found to be about 3,800 folds more resistant to imidacloprid, compared to the susceptible strain (S), as judged by LC50 values. To identify differentially expressed genes in IR, an isogenic strain, reverse susceptible strain (IRS) was generated from IR and comparative transcriptome analyses based on GS-FLX were conducted using total RNAs extracted from both IR and IRS. Also we confirmed protein expression patterns by 2DE and detoxification enzyme over-expression by synergist test. However there was no significant variation among IR, IRS and S. Comparison of the nucleotide sequence of seven nicotinic acetylcholine receptor (nAChR) subunit (alpha 1-5,7 and beta 1) genes from S and IR strain revealed a point mutation causing an arginine to threonine substitution (R81T) in the loop D region of the nAChR beta 1 subunit of the IR. These mechanisms were also reported in M. persicae and this amino acid change confers a vertebrate-like character to the insect nAChR and results in reduced sensitivity to neonicotinoids. Moreover an extra point mutation, L80S (leucine to serine substitution) was also detected nearby R81T mutation in nAChR beta 1 subunit variant. These mutations can be an additive factor in imidacloprid resistance in A. gossypii. This is the first report of imidacloprid resistance mechanism in A.gossypii. Further, this would be helpful in managing A. gossypii resistant populations in field.
        79.
        2012.10 구독 인증기관·개인회원 무료
        We investigated the molecular and kinetic properties of two acetylcholinesterases (AmAChE1 and AmAChE2) from the Western honey bee, Apis mellifera. Western blot analysis revealed that AmAChE2 has most of catalytic activity rather than AmAChE1, further suggesting that AmAChE2 is responsible for synaptic transmission in A. mellifera, in contrast to most other insects. AmAChE2 was predominately expressed in the ganglia and head containing the central nervous system (CNS), while AmAChE1 was abundantly observed not only in the CNS but also in the peripheral nervous system/non-neuronal tissues. Both AmAChEs exist as homodimers; the monomers are covalently connected via a disulfide bond under native conditions. However, AmAChE2 was associated with the cell membrane via the glycophosphatidylinositol anchor, while AmAChE1 was present as a soluble form. The two AmAChEs were functionally expressed with a baculovirus system. Kinetic analysis revealed that AmAChE2 has approximately 2,500-fold greater catalytic efficiency toward acetylthiocholine and butyrylthiocholine than AmAChE1, supporting the synaptic function of AmAChE2. In addition, AmAChE2 likely serves as the main target of the organophosphate (OP) and carbamate (CB) insecticides as judged by the lower IC50 values against AmAChE2 than against AmAChE1. When OP and CB insecticides were pre-incubated with a mixture of AmAChE1 and AmAChE2, asignificant reduction in the inhibition of AmAChE2 was observed, suggesting a protective role of AmAChE1 against xenobiotics. Taken together, based on their tissue distribution pattern, molecular and kinetic properties, AmAChE2 plays a major role in synaptic transmission, while AmAChE1 has non-neuronal functions, including chemical defense.
        80.
        2012.09 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to assess the efficacy of photodynamic therapy (PDT) using erythrosine and a halogen light source to treat a biofilm formed on a machined surface titanium disk in vivo. Ten volunteers carried an acrylic appliance containing six machined surface titanium disks on the upper jaw over a period of five days. After the five days of biofilm formation period, the disks were removed. PDT using 20 μM erythrosine and halogen light was then applied to the biofilms formed on the disks. Experimental samples were divided into a negative control group (no erythrosine and no irradiation), E0 group (erythrosine 60s + no irradiation), E30 group (erythrosine 60s + halogen light 30s), and E60 group (erythrosine 60s + halogen light 60s). Following PDT, the bacteria in the biofilm were found to be detached from each disk. Each suspension with detached bacteria were diluted and cultivated on a blood-agar plate for five days under anaerobic conditions. The cultivated bacterial counts in the E60 group were significantly lower than the control group (86.4%) or E0 group (76.7%). In the experimental groups also, the light exposure time and bacterial counts showed a negative correlation. In conclusion, PDT using erythrosine and halogen light has bactericidal effects on biofilms formed on a titanium disk in vivo. Notably, applying 20 μM erythrosine and 60 seconds of halogen light irradiation had a significantly potent effect.
        4,000원
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