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        검색결과 90

        2.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A facile and efficient method was developed to prepare highly stretchable and conductive graphene conductors with wrinkled structures by the mechanical stretching and shrinking of elastomeric substrates, in which graphene inks were printed on a prestretched elastomeric substrate. Stretchable and exfoliated graphene inks were prepared by mixing graphite and Ecoflex in a shear-assisted fluid dynamics reactor. The resultant graphene conductor exhibited excellent stretchability at 150% strain and high electrical conductivity of 64 ± 1.2 S m− 1. The resistance of the conductor did not change in bent, twisted, and stretched states. The resistance did not change during 10,000 cycles of stretching/releasing, with a maximum strain of 150%. Based on the graphene conductor, a stretchable conductometric sensor with a two-electrode configuration was fabricated to measure impedance changes at different concentrations of electrolyte ions. This sensor exhibited a good and linear sensitivity curve (298.61 Ω mM− 1, R2 = 0.999) in bent and stretched states.
        4,000원
        7.
        2018.10 구독 인증기관·개인회원 무료
        Royal jelly (RJ) is a well-known functional and medicinal food for human health promotion. Major royal jelly proteins (MRJPs), which are the major protein components in RJ, exhibit antimicrobial activities. However, the identities of the MRJPs of RJ responsible for its antioxidant effects have remained unclear. Here, we report that honeybee (Apis cerana) MRJP 2 (AcMRJP2) acts as an antimicrobial and antioxidant agent in RJ. Using recombinant AcMRJP2, which was produced in baculovirus-infected insect cells, we established the antimicrobial and antioxidant roles of MRJP 2. AcMRJP2 bound to the surfaces of bacteria, fungi, and yeast, which then induced structural damage in the microbial cell walls and led to a broad spectrum of antimicrobial activities. AcMRJP2 protected mammalian and insect cells via the direct shielding of the cell against oxidative stress, which led to reduced levels of caspase-3 activity and oxidative stress-induced cell apoptosis, followed by increased cell viability. Moreover, AcMRJP2 exhibited DNA protection activity against reactive oxygen species (ROS). Our data indicate that AcMRJP2 could play a crucial role as an antimicrobial agent and antioxidant in RJ, suggesting that MRJP 2 is a component responsible for the antimicrobial and antioxidant activities of RJ.
        8.
        2018.04 구독 인증기관·개인회원 무료
        Major royal jelly proteins (MRJPs), important protein components of bee royal jelly (RJ) and exclusive nourishments for queen, exhibit various biological and pharmacological activities. RJ is one of the most studied bee products, but the crucial roles for MRJP2 as an antimicrobial and antioxidant agents remain largely unknown. Here we demonstrated the antimicrobial and antioxidant functions of the Asiatic honeybee (Apis cerna) MRJP2 (AcMRJP2). Recombinant AcMRJP2 of approximately 53 kDa was expressed in baculovirus-infected insect cells, and it exhibited antimicrobial activity against bacteria, fungi, and yeast via binding to microbial surfaces and inducing structural damage in microbial cell walls. AcMRJP2 protected mammalian and insect cells against oxidative damage through shielding of cell membranes. Interestingly, AcMRJP2 exhibited DNA protection activity and DPPH radical-scavenging activity. Altogether, our data demonstrated that AcMRJP2 functions as antimicrobial and antioxidant agents.
        12.
        2010.10 구독 인증기관·개인회원 무료
        Pyrifluquinazon, as a quinazinalone chemical group, based on a new mode of biological activity. It is reported that mode of action is modifies insect behavior, rapidly stopping feeding such that insects starve to death. Time-release feature and mortality effect on M. persicae using different pyrifluquinazon nano type and non-nano type were compared. Pyrifluquinazon nano type was formulated with different molecular weight and density of used chitosan (CS 30000 0.1% and CS 3000 0.3%). In the CS 30,000 0.1%, the mortality was weakly occurred at early time, but steadily increased after 4days. Finally, we confirmed more than 70% mortality as a peak at 16days. In CS 3000 0.3%, the mortality showed about 70% until 18days as a effective controlled release. Also, We examine time-release feature and mortality effect on M. persicae according to the different pyrifluquinazon nano type(CS 30000 0.1% and CS 3000 0.3%) of concentrations. The CS 30000 0.1% bioassay results of different concentration were showed that the highest concentration(100ppm) was measured better mortality than other concentration at 0 day, but cannot confirm different effect about dissimilar concentration. However, increasing rates of M. persicae were low as treatment concentrate was high. In CS 3000 0.3% 100ppm concentration bioassay result, aphid mortality reached peak at 24 days and increasing rate also low. Additionally, for the comparing of bioassay and feeding behavior of M. persicae against pyrifluquinazon nano types and non-nano type, EPG technique was carried out. In case of non nano type, feeding inhibition efficacy was showed during 4 days after treatment, but appeared similar level with control after 10days. In CS 3000 0.3% 50ppm, residual efficacy was specially showed until 28days after treatment whereas treatments with CS 30000 0.1% were similar to the control after 22days. These result show that the change of feedinng behavior and motrality of M. persicae is correlated with the change of nano type or non nano type of pyrifluquinazon.
        13.
        2010.09 구독 인증기관 무료, 개인회원 유료
        We examined the effect of Bulnesia sarmienti (BS) water extract on hyperlipidemia induced by a high-fat diet. ICR mice were fed a high-fat diet ad libitum for four weeks. Simultaneously, BS water extract was administered intragastrically at 0 mg/kg (control), 30 mg/kg, or 300 mg/kg once daily for four weeks. Male ICR mice were divided into four groups; normal control group (NC), high-fat diet+vehicle treatment group (HF), high-fat diet+BS of 30 mg/kg treatment group (HF+BS30), and high-fat diet+BS of 300 mg/kg treatment group (HF+BS300). The levels of serum biochemical parameters and histological appearances were evaluated. After four weeks, body weight gain and serum levels of triglycerides, total cholesterol, and Low-density lipoprotein (LDL)-cholesterol were significantly higher in the HF group than in the normal control group. Together, serum High-density lipoprotein (HDL)-cholesterol level in the HF group was lower than that in the normal control group. However, treatment with BS resulted in significantly reduced body weight gain and levels of serum triglycerides, total cholesterol, and LDL-choleterol. In addition, serum HDL-cholesterol level in the BS treatment group was significantly elevated, compared to that of the HF group. Histopathological evaluation of the liver showed fat accumulation and swelling of hepatocytes in the high-fat diet group; these abnormalities were ameliorated by treatment with BS. These results suggest that treatment with BS water extract resulted in dose-dependent prevention and mitigation of high-fat diet-induced hyperlipidemia.
        4,000원
        14.
        2010.05 구독 인증기관·개인회원 무료
        The porcine reproductive and respiratory syndrome virus (PRRSV) has three major structural proteins which designated as GP4, GP5, and M. They have been considered very important to arouse the humoral and cellular immune responses against PRRSV infection and proposed to be the excellent candidate proteins in the design of PRRS bioengineering vaccine. However, the PRRSV structural proteins are produced in low levels in the infected cells because it forms insoluble protein and possesses several transmembrane regions. To overcome this problem, we fused the GP4, GP5, and M with SUMO (Small ubiquitin-related modifier), and expressed the fused gene in Bm5 cells and silkworm larvae. Expression of the proteins were analyzed by 12% SDS-PAGE and western blotting using 6xHis tag and porcine anti-PRRSV antibodies. In results, SUMO fused proteins were expressed at a high level in Bm5 cells. The levels of protein using the silkworm larvae is higher than that using Bm5 cells. The fused protein was purified by Ni-NTA affinity chromatography. This study demonstrated that SUMO, when fused with PRRSV structural proteins, was able to promote its soluble expression. This may be a better method to produce PRRSV structural proteins for vaccine development.
        15.
        2010.05 구독 인증기관·개인회원 무료
        The multicolored Asian ladybird beetle, Harmonia axyridis, is a generalist predator of aphids also, shows a high level of phenotype polymorphism in color pattern of elytra. Although, it is not sure about genetic information of color polymorphism, it has been confirmed that this phenomenon comes from their genetic traits. The color of H. axyridis elytra is mainly composed of black and red pigment. Phenoloxidase (PO) plays an important role in many insect physiological functions, i.e. sclerotization and pigmentation of cuticle and melanization of parasites. Following activation, PO catalyses the hydroxylation of tyrosine and subsequent oxidation of phenolic substance into quinines, which are further converted to melanin. However, the molecular bases of H. axyridis color pattern formation are almost unknown but it may be that the different pro-POs have different expression. In this study, total RNA samples from four each color pattern individuals, for example, succinea 1, succinea 2, conspicua and spectabilis was extracted. A cDNA enconding pro-PO was molecular cloned from each color pattern of H. axyridis and its putative amino acid sequence shared homology with pro-PO of other insects. We are pursuing to elucidate that their pro-PO sequence will be similar with those other insect PPO sequence. There are also regions of high sequence similarity, including putative activation site and two copper binding sites.
        16.
        2009.10 구독 인증기관·개인회원 무료
        The Classical Swine Fever Virus (CSFV) is a member of the Pestivirus genus of the Flaviviridae. The genome of CSFV is a positive single-stranded RNA molecule 12.3 kb and contains a single large open reading frame (ORF). The polyprotein composed of eight nonstructural and four structural proteins (nucleocapsid protein C and three envelope glycoprotein E0, E1 and E2). E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. To determine the characteristics of the CSFV, LOM strain, we investigated the nucleotide sequence of the glycoprotein E0, E1 and E2. Comparison of the LOM with the other strains revealed nucleotide sequence identity ranging from 97 to 98%. Expression of the glycoprotein E2 was identified by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies in Sf21 cells. The expression levels of glycoprotein E2 were observed from day 3 and 5 days maximum. In addition, its expression efficiency by media and cell line was investigated. The result showed that High-Five cells and Grace’s insect media for Sf21 were the best conditions for the expression of the glycoprotein E2.
        17.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The early diagnosis of bovine pregnancy is an essential component of successful reproductive planning on farms, because lack of bovine pregnancy over the long term results in reproductive failure and low milk yield‐the latter of which is a special concern on dairy farms. This study was designed to identify early pregnancy‐specific whey proteins in bovine, by comparing milk samples collected from cattle during pregnancy (Days 30 and 50) and from non‐pregnant cattle. In this study, differentially expressed proteins in five pregnant and five non‐pregnant Holstein dairy cattle were investigated and compared, using proteomics analysis. The first dimension was applied to a pH 3.0~10.0 strip, by loading a 2‐mg milk protein sample. After the second‐dimension separation was performed, the gels were stained with colloidal Coomassie brilliant blue. The stained gels were scanned and the images were analyzed, to detect variations in protein spots between non‐pregnant and pregnant cattle milk protein spots, using ImageMaster; this was followed by analysis with MALDI TOF‐MS. Analysis of the 2‐DE gel image resulted in a total of approximately 500~600 protein spots, of which 12 spots were differentially expressed, six spots were up‐regulated, and four spots were downregulated; two spots were identified as pregnancy‐specific proteins. These proteins were identified as lactoferrin, NADH dehydrogenase subunit 2, albumin, serum albumin precursor and transferrin. Our results via 2‐D PAGE analysis revealed composite profiles of several milk proteins related to early bovine pregnancy, implying the possible use of these milk proteins in the early detection of bovine pregnancy.
        4,000원
        18.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Interspecies somatic cell nuclear transfer (iSCNT) is a valuable tool for studying the interactions between an oocyte and somatic nucleus. The object of this study was to investigate the developmental competence of in vitro‐matured porcine oocytes after transfer of the somatic cell nuclei of 2 different species (goat and rabbit). Porcine cumulus oocytes were obtained from the follicles of ovaries and matured in TCM‐199. The reconstructed embryos were electrically fused with 2 DC pulses of 1.1 kV/cm for 30 μs in 0.3 M mannitol medium. The activated cloned embryos were cultured in porcine zygote medium‐3 (PZM‐3), mSOF or RDH medium for 7 days. The blastocyst formation rate of the embryos reconstructed from goat or rabbit fetal fibroblasts was significantly lower than that of the embryos reconstructed from porcine fetal fibroblast cells. However, a significantly higher number of embryos reconstructed from goat or rabbit fetal fibroblasts cultured in mSOF or RDH, respectively, developed to the morular stage than those cultured in PZM‐3. These results suggest that goat and bovine fetal fibroblasts were less efficacious than porcine‐porcine cloned embryos and that culture condition could be an important factor in iSCNT. The lower developmental potential of goat‐porcine and porcine‐bovine cloned embryos may be due to incompatibility between the porcine oocyte cytoplasm and goat and bovine somatic nuclei.
        4,000원
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