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        검색결과 2,007

        1021.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Effective estrus detection and artificial insemination (AI) are necessary for profitable management of dairy herd. In current study, 45 crossbred lactating cows have been selected with the complaint of unobserved oestrus for more than sixty days postpartum. All cows had functional corpus luteum as examined by transrectal ultrasonography. Cows were treated with PGF2α analogue and AI was performed with observed oestrus and then single dose of GnRH was administered. Similar synchronization protocol has been repeated after 14 days in cows that did not repose to first treatment. Remaining cows received additional PGF2α after 14 days of second treatment and timed AI was performed following GnRH administration. Among 45 cows, 28.89% showed estrus after first treatment and 78.79% responded to second hormonal intervention. A higher conception rate (88.89% vs 26.66 and 72.72%) was observed in cows after triple administration of PGF2α and timed AI. We noticed a significant differences in body condition score (BCS, 1~5 scale), postpartum period, and daily milk production between cows that either responded of non-responded following first and second hormonal treatment. In addition, there was a significant positive correlation between daily milk production and BCS, age and postpartum days, milk production and estrus/BCS, and milk production/BCS/estrus and conception rate. Depending upon the findings we conclude that hormonal intervention with PGF2α and GnRH enhances postpartum ovarian cyclicity and help decreasing the days open of dairy herd. Therefore, this finding might provide an excellent guideline for target breeding system for profitable dairy herd management.
        4,000원
        1022.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyurethane (PU) nanofibers containing graphene oxide (GO) and Ag doped functionalized reduced graphene oxide (Ag-RGO) were successfully prepared via the electrospinning technique. The uniform distribution of GO sheets along with Ag nanoparticle in the nanofibers was investigated by scanning electron microscopy and the elemental mapping technique. X-ray diffraction and thermal gravimetric analysis verified the presence of GO and Ag in the bicomposite nanofibrous mats. Antibacterial tests against Escherichia coli demonstrated that the addition of GO and Ag-RGO to the PU nanofiber greatly enhanced bactericidal efficiency. Overall, these features of the synthesized nanofibers make them a promising candidate material in the biomedical field for applications such as tissue engineering, wound healing, and drug delivery systems.
        4,000원
        1023.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper introduces a nitrogen-doped ordered mesoporous carbon (NOMC) derived from glucosamine with hybrid capacitive behaviors, achieved by successfully combining electrical double-layer capacitance with pseudo-capacitance behaviors. The nitrogen doping content of the fabricated NOMC reached 7.4 at% while its specific surface area (SBET) and total pore volume reached 778 m2 g−1 and 1.17 cm3 g−1, respectively. A dual mesoporous structure with small mesopores centered at 3.6 nm and large mesopores centered at 9.9 nm was observed. The specific capacitance of the reported materials reached up to 328 F g−1, which was 2.1 times higher than that of pristine CMK-3. The capacitance retention rate was found to be higher than 87.9% after 1000 charge/discharge cycles. The supplementary pseudocapacitance as well as the enhanced wettability and conductivity due to the incorporation of nitrogen heteroatoms within the carbon matrixes were found to be responsible for the excellent capacitive performance of the reported NOMC materials.
        4,000원
        1027.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to classify the deficient abilities of seafarers into SRK (Skill, Rule, and Knowledge) and analyze and identify the SRK by the type of accident and ship. Experimental data used the SRK cumulative frequency for 1,606 marine accident records and two-way ANOVA and t-test were used for the analysis tools. The results of two-way ANOVA showed that it is possible to identify the deficient abilities by using the cumulative frequency of SRK in both accident and ship types. As a result of the t-test, the adoption of the null hypothesis (H=0) that the mean of two pairs is equal and the rejection of the null hypothesis (H=1) were 29.2 % and 70.8 %, respectively. For the ship type, H=0 is 33.3 % and H=1 is 66.7 %. Through this study, it was found that about 70 % of the deficient abilities of seafarers inherent in maritime accidents can be identified using the proposed method.
        4,000원
        1028.
        2017.05 구독 인증기관·개인회원 무료
        Embryo development is very important in reproductive physiology of domestic animal experiments. Therefore, in the above experiment, we want to provide a lot of important information with regard to fertilization breeding by looking at the expression of transcription factor by early embryo development. It is known that mice affect early embryonic development of many transcription factors, many experiments are underway. Different types of mammals showed different expression patterns, thus, we used pigs, which are known to be the most similar to humans, to observe the expression of transcription factors in early embryonic development. Transcription factors were observed using CDX2, OCT4 and E-CADHERIN. CDX2 was expressed in 2 cells, OCT4 and E-CADHERIN were expressed in blastocyst. OCT4 was expressed specifically in ICM (inner cell mass) in blastocyst, and E-CADHERIN was expressed in cell wall and junction of blastocyst. These results show that CDX2, OCT4 and E-CADHERIN play an important role in early embryonic development in pigs.
        1029.
        2017.05 구독 인증기관·개인회원 무료
        Oocyte is the central factor in the bi-directional communication axis in the ovarian follicles. It controls the cumulus or granulosa cells to perform functions which are beneficial for its own development via secreting paracrine growth factors, including GDF9 and BMP15. The aim of this study was to investigate whether the recombinant GDF9 and BMP15 are able to promote meiotic resumption and cumulus expansion of canine COCs during IVM, as well as to demonstrate the actions of GDF9 and BMP15 in regulating the expression of connexin transcripts in the ovarian granulosa cells. As results, GDF9 and BMP15 significantly improved the meiotic resumption rate and cumulus expansion by activating ERK1/2 signaling. Treatments with GDF9 significantly improved the expression of CyclinB1 but inhibited the expression of Cx43 transcripts. In addition, cumulus expansion genes (MAPK1, Ptgs2, Tnfaip6 and Ptx3) were differentially improved by GDF9 and BMP15. In the ovarian granulosa cells, GDF9 suppressed the expression of Cx43 transcripts by binding ALK4/5/7 receptors and activation Smad2/3 signaling, whereas, BMP15 stimulated the expression of Cx43 transcripts by binding ALK2/3/6 receptors and activating Smad1/5/8 signaling. In conclusion, by regulating functions of granulosa/cumulus cells, oocyte has the potential to enhance the growth and maturation of itself.
        1030.
        2017.05 구독 인증기관 무료, 개인회원 유료
        Oocyte is the central factor in the bi-directional communication axis in the ovarian follicles. It controls the cumulus or granulosa cells to perform functions which are beneficial for its own development via secreting paracrine growth factors, including GDF9 and BMP15. The aim of this study was to investigate whether the recombinant GDF9 and BMP15 are able to promote meiotic resumption and cumulus expansion of canine COCs during IVM, as well as to demonstrate the actions of GDF9 and BMP15 in regulating the expression of connexin transcripts in the ovarian granulosa cells. As results, GDF9 and BMP15 significantly improved the meiotic resumption rate and cumulus expansion by activating ERK1/2 signaling. Treatments with GDF9 significantly improved the expression of CyclinB1 but inhibited the expression of Cx43 transcripts. In addition, cumulus expansion genes (MAPK1, Ptgs2, Tnfaip6 and Ptx3) were differentially improved by GDF9 and BMP15. In the ovarian granulosa cells, GDF9 suppressed the expression of Cx43 transcripts by binding ALK4/5/7 receptors and activation Smad2/3 signaling, whereas, BMP15 stimulated the expression of Cx43 transcripts by binding ALK2/3/6 receptors and activating Smad1/5/8 signaling. In conclusion, by regulating functions of granulosa/cumulus cells, oocyte has the potential to enhance the growth and maturation of itself.
        4,000원
        1034.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two dimensional finite element method with quadrilateral basis functions was applied to the spherical high order filter on the spherical surface limited area domain. The basis function consists of four shape functions which are defined on separate four grid boxes sharing the same gridpoint. With the basis functions, the first order derivative was expressed as an algebraic equation associated with nine point stencil. As the theory depicts, the convergence rate of the error for the spherical Laplacian operator was found to be fourth order, while it was the second order for the spherical Laplacian operator. The accuracy of the new high order filter was shown to be almost the same as those of Fourier finite element high order filter. The two-dimension finite element high order filter was incorporated in the weather research and forecasting (WRF) model as a hyper viscosity. The effect of the high order filter was compared with the built-in viscosity scheme of the WRF model. It was revealed that the high order filter performed better than the built in viscosity scheme did in providing a sharper cutoff of small scale disturbances without affecting the large scale field. Simulation of the tropical cyclone track and intensity with the high order filter showed a forecast performance comparable to the built in viscosity scheme. However, the predicted amount and spatial distribution of the rainfall for the simulation with the high order filter was closer to the observed values than the case of built in viscosity scheme.
        4,000원
        1037.
        2017.04 구독 인증기관·개인회원 무료
        Frankliniella intonsa (Trybom) (Thysanoptera: Thripididae) is an important pest of field and greenhouse crops such as pepper and strawberry. Chemical attractants are commonly used for monitoring thrips, but few are available for F. intonsa. Thus, we evaluated three attractants of Frankliniella occidentalis known from literatures for their attraction of F. intonsa in Y-tube olfactometer. Fed unmated adult females of F. intonsa showed higher initial response to (S)-(−)-verbenone than other attractants, i.e. aggregation pheromone of F. occidentalis and methyl isonicotinate. Unfed mated adult females of F. intonsa showed similar initial response. These results suggest that (S)-(−)-verbenone also can be used for monitoring and further in behavioral control tactics of F. intonsa.
        1038.
        2017.04 구독 인증기관·개인회원 무료
        Filixungulia, a small genus within the subfamily Allantinae (Symphyta: Tenthredinidae), consists of three species distributed only in Northern China: F. alboclypea Wei, 1997; F. crassitarsata Wei, 1997; F. cylindrica Wei, 2003. It is close to Asiemphytus Malaise and Macremphytus MacGillivray but is separated by the following characteristics: claws simple and very slender; basal lobe and inner tooth absent. Up to date, Filixungulia has not yet been recorded out of China. As a result of the present study, the genus Filixungulia is newly recognized from South Korea with two species, F. alboclypea and F. cylindrica. This discovery extends the range of the genus Filixungulia, which was previously known as a Chinese endemic genus. Also, a key, diagnosis and photographs of each species are provided.
        1039.
        2017.04 구독 인증기관·개인회원 무료
        One species of the genus Coleopius (Hymenoptera: Braconidae: opiinae) are reported in this study. The genus Coleopius is a small braconid group distributed in the Palaearctic and Oriental regions, which has three species in the korea in current. In this study, Coleopioides postpectalis Li and van Achterberg is recognized for the first time in South Korea, which had been recently recorded from China. Descriptions, diagnosis distribution and illustration are provided
        1040.
        2017.04 구독 인증기관·개인회원 무료
        Aphidiinae in Braconidae includes more than 400 species within approximately 60 genera worldwide. Species of Aphidiinae are mostly known as solitary koinobiont endoparasitoids specifically associated with aphid hosts, and some of them are used for biological control. In the present study, two aphiniine species are newly recognized from South Korea based on morphological and molecular study: Aphidius rhopalosiphi de Stefani-Perez 1902 and A. uzbekistanicus Luzhetzki 1960. Although It was very difficult to discriminate two species morphologically, we cleary identified them by using COI (cytochrome c oxidase subunit I) DNA Barcode sequences. Here we present their morphological descriptions, illustrations and barcoding results.