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        검색결과 115

        23.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A eukaryotic marine microalga was isolated from Jungmun Saekdal Beach, Jeju Island, Korea and an integrated approach, including molecular phylogeny and morphology, was used to determine its taxonomical status. Molecular phylogenetic evidence inferred from the small subunit (SSU) 18S rRNA sequence and internal transcribed spacer (ITS) secondary structure analysis clearly showed that the isolate belonged to the recently described species, Jaagichlorella roystonensis. Distinctive morphological keys of the species were also observed by light microscopy and scanning/ transmission electron microscopy (S/TEM). In this study, a Korean marine J. roystonensis species was described for the first time and was subsequently added to the national culture collections in Korea.
        4,000원
        24.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Partheno Embryo's research is known to play a very important role in identifying the development of embryonic cells or analyzing the genetic mechanisms of embryonic development, but the information on apoptosis formed during the early stage of development on Partheno Embryo is very little. Therefore, this study analyzed whether the embryonic cell death of unit embryos can be inhibited by adding Scriptaid, one of HDACi, which plays a role in demethylation of histone proteins as a method of regulating the cell cycle in the early embryo development of Partheno Embryo. As a result, the differentiation rate was higher in the group that added Scriptaid and FBS, but the cellular development was higher in the group that added pregnant serum to Scriptaid. As a result of analyzing the expression of the gene through IF and PCR, the group with the addition of gestational serum increased the expression of BCL2 and PCNA, which affects the anti-Casp3 action in cell survival. In addition, it is interpreted that treatment of Scriptaid for 16 hours, rather than 24 h treatment lowers the expression of Casp-3, a representative factor of apoptosis, and also increases embryonic development, thus affecting early embryo development. Therefore, it is concluded that the 16-hour treatment of Scriptaid and the use of gestational serum will inhibit cell death in the early embryonic development and increase the development rate of the embryo.
        4,000원
        26.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In the early development of parthenogenetic embryo, cytoplasm and nucleic acid fragmentation may be a cause of lower embryo development. The purpose of this study was to evaluate whether embryonic development and apoptosis factors can be reduced by controlling the in-vitro culture environment by the addition of hormones, pregnancy serum and uterine milk. Our study showed that the activity of Casp-3 increased within the cytoplasm when artificially used hormones to induce the incubation environment, and PCNA's manifestation was low. However, the addition of pregnant serum appeared to lower the Casp-3 activity compared to the other groups. In addition, MMP-9 activity was increased and early embryo development and cytoplasmic fidelity were also increased. Therefore, the results of the present study showed that the use of gestational serum in the development of parthenogenetic embryo inhibit apoptosis and increases cytoplasmic reorganization by natural environmental control in in vitro culture.
        4,000원
        27.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A eukaryotic microalga was isolated from seawater in Janghang Harbor, Korea and its morphological, molecular, and physiological characteristics were investigated. Due to its simple morphology, no distinctive characters were found by morphological observation, such as light microscope or scanning/transmission electron microscopy (S/ TEM). However, molecular phylogenetic evidence inferred from the concatenated small subunit (SSU) 18S rRNA and internal transcribed spacer (ITS) sequence data indicated that the isolate belonged to the newly described Micractinium singularis. Furthermore, it was clustered with Antarctic Micractinium strains and it also showed a psychrotolerant property, surviving at temperatures as low as 5°C. However, its optimal growth temperatures range from 15°C to 25°C, indicating that this microalga is a mesophile. Additionally, gas chromatography-mass spectrometry (GC/MS) analysis showed that the isolate was rich in nutritionally important omega-3 polyunsaturated fatty acid, and high-performance liquid chromatography analysis (HPLC) revealed that the high-value antioxidant lutein was biosynthesized as an accessory pigment by this microalga, with glucose as the major monosaccharide. Therefore, in this study, a Korean marine M. singularis species was discovered, characterized, and described. It was subsequently added to the national culture collections.
        4,000원
        28.
        2020.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated whether infusion of colorectal cancer cell line and PMSG could increase endometrial cancer. As a result, our study confirmed that the injection of colorectal cancer can cause inflammation and cancer in the uterus and increase the VEGF gene in the uterus. The study also found that endometrial cancer was associated with PMSG.
        4,000원
        32.
        2019.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Pitch precursors affording excellent spinnability, high-level oxidation-resistance, and good carbonization yields were prepared by bromination–dehydrobromination of various ratios of pyrolyzed fuel oil and coal tar pitch. The pitches exhibited spinnabilities that were much better than those of pitches prepared via simple distillation. A pitch prepared using a 1:2 ratio of fuel oil and coal tar pitch exhibited the best tensile strength. Pitch fibers of diameter 8.9 ± 0.1 μm were stabilized at 270 °C without soaking time after heating at a rate of 0.5 °C/min and carbonized at 1100 °C for 1 h after heating at 5 °C/min. The resulting carbon fibers exhibited a tensile strength, elongation, Young’s modulus, and average diameter of 1700 ± 170 MPa, 1.6 ± 0.1%, 106 ± 37 GPa, and 7.1 ± 0.2 μm, respectively.
        4,000원
        33.
        2019.04 구독 인증기관·개인회원 무료
        The pea aphid Acyrthosiphon pisum is a polyphagous, sap-sucking insect pest with a worldwide distribution. We investigated the developmental time and survivorship in nymphs and longevity and fecundity in adults of A. pisum at five different temperatures applying with following two programs, TWOSEX-MSChart and TIMING-MSChart. Regarding to thermal effect on A. pisum, in this presentation, we will discuss about a population projection and following population parameters calculated in this study: adult preoviposition period (APOP), total preoviposition period (TPOP), oviposition days, eggs per reproductive female, first age of survival rate <50%, proportion of male and female individuals, and life table parameters (net reproductive rate, intrinsic rate of increase, finite rate of increase, and mean generation time).
        34.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Excessive intake of red meat has been associated with colon carcinogenesis. The effect of hemin and zinc on colon carcinogenesis was investigated in male ICR mice. After acclimation for 1 week, five-week-old mice received three s.c. injections (0-2nd weeks of the experiment) of azoxymethane (AOM; 10 mg/kg b.w.) weekly and were treated by 2% dextran sodium sulfate (DSS) in drinking water for the next 1 week to induce aberrant crypt foci (ACF). Mice were fed on AIN-76A purified rodent diet for 6 weeks. There were three experimental groups; control, hemin, and hemin + zinc groups. The daily oral doses of hemin and zinc were 534 mg/kg and 55 mg/kg b.w., respectively. After staining colonic mucosa with 0.2% methylene blue, the ACF, aberrant crypts (AC), and polyps were counted. Lipid peroxidation in liver was evaluated by thiobarbituric acid-reactive substances (TBARS) assay. The numbers of AC, ACF, large ACF (i.e., ≥4 AC/ACF), and polyps in the hemin group were higher than those in the control group. In hemin + zinc group, the numbers of AC, ACF, large ACF were significantly lower compared to the hemin or control groups (p < 0.05), and the number of polyps was also significantly lower compared to that in the hemin group (p < 0.05). The TBARS level in the livers of the hemin + zinc group was significantly lower than that of the hemin group (p < 0.05). These results suggest that hemin enhances colon carcinogenesis and that co-treatment with zinc can protect against the induction of colon carcinogenesis.
        4,000원
        35.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Clostridium perfringens (C. perfringens) may cause diarrhea and enterotoxemia in adult and young livestock, leading to problems in the production and management of farms. Four hundred fecal samples were collected from 25 goat farms located in Gyeongsangbuk-do Province in the Republic of Korea. Sixteen C. perfringens strains were isolates from fecal samples, and the isolates were identified as type A (n=11) and type D (n=5). Additionally, α- and ε-toxin genes were detected in 16 and 5 strains by PCR, respectively, and the enterotoxin gene was presented in 2 strains. The antibiotic susceptibility test was performed using the disk diffusion method and E-test method. In the disk diffusion method, ampicillin (n=16) and chloramphenicol (n=15) were highly susceptible to 16 C. perfringens isolates. In the E-test method, ampicillin, amoxicillin, amoxicillin/clavulanic acid and meropenem were susceptible to more than 14 of 16 C. perfringens isolates. This study indicates that administration of antibiotics such as ampicillin, amoxicillin/clavulanic acid and meropenem can prevent and treat C. perfringens infections in goats.
        4,000원
        37.
        2018.11 구독 인증기관·개인회원 무료
        The expression of MMPs in the development of the fertilized egg has a very important role in cell configuration. Objective To evaluate the clinical, the effect of differentially expressed MMPs on serum and serum - free medium on the maturation of blastocysts. The expression patterns of MMPs in serum and serum-free medium were compared at 6 h, 18 h and at the blastocyst stage using real-time PCR, ELISA and immunofluorescence. The results showed that the expression of MMPs was increased in the embryos of the serum medium, as a result of analysis of MMPs and TIMPs, MMP-2 was expressed in the cytoplasm of embryos in the serum-free medium, And it was found to be higher in expression than MMP-9. The serum medium was different from the bloodless badge: overall, TIMPs showed a higher expression in the ovarian cells than cyanosis, and TIMP-3 was more pronounced. Development rate of blastocyst according to in vitro culture method was higher than that of serum - free medium (61.22% 60/98) and serum - free medium (48.28% 28/58). Analysis of the protein release locations of MMPs and TIMPs showed that MMPs and TIMPs are highly expressed in serum mediums, focusing on the inner cell mass. However, very low expression appeared in the tropoblast. On the other hand, serum - free medium showed different expression from serum medium and TIMPs expression was generally low. Therefore, in the case of serum media, the expression of MMPs is highly expressed in the cytoplasm of the fertilized egg, increasing the reconstruction of cells.
        39.
        2018.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The major focus of this study is to analyze the expression of bovine MMPs and to monitor their activity during the estrus cycle and pregnancy. During pregnancy, MMP-2 expression was detectable around 30 days but became insignificant by 60 days, then started to increase again around 90 days and reached the maximum at 250 days. The activity of MMP-2 protein changed in accordance with its expression level. As expected, the level of TIMP-2 exhibited a reverse pattern. About MMP-9, high level expression was observed as early as 30 days and gradually increase until 90 days. Then started to decrease after 250 days. Again, the sites of MMP-9 expression were similar to those of MMP-2. On the other hand, expression of TIMP-3 remained low until 90 days but showed a small and temporal increase around 250 days. In summary, expression of different MMPs were differentially regulated during estrus cycle and pregnancy. While the expression of MMP-2 was high in estrus cycle, MMP-9 slowly takes over with the progression of pregnancy. These results indicated that the luteal tissue perform distinct functions during pregnancy and estrus. Perhaps the activity of MMP-2 is required for the structural remodeling of luteum, resulting the suppression of P4 inflow from blood. On the other hand, steady maintenance of MMP-9 throughout luteal development is important for the activation of cell proliferation, maturation and angiogenesis.
        4,000원
        40.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Red meats are important animal foods because of their nutritional aspects, but the over-consumption of red meat produces reactive oxygen species (ROS) caused by heme iron and induces colorectal cancer. The effect of orally administered hemin and calcium provided in drinking water for 6 weeks on colon carcinogenesis was observed in male ICR mice. After the mice were acclimated for 1 week, they received three subcutaneous azoxymethane (AOM, 10 mg/kg b.w.) injections weekly and were provided with 2% dextran sodium sulfate (DSS) via drinking water for the next week. The mice were divided into three groups: the control, hemin, and hemin + calcium groups. The orally administered daily dose of hemin was 2 g/kg b.w., and 0.05% calcium was provided daily via drinking water. Colonic mucosa samples were stained with methylene blue, and then, the numbers of aberrant crypt (AC) and aberrant crypt foci (ACF) were counted. Lipid peroxidation in feces was estimated by thiobarbituric acid-reactive substances (TBARS) assay. The total numbers of AC and ACF per colon in the hemin group were significantly higher than those in the control group. Calcium treatment significantly decreased the numbers of ACF and AC in the colon of mice. The TBARS value in the feces of the hemin + calcium group was significantly lower than that in the feces of the hemin group. These results showed that hemin enhances the formation of pre-neoplastic lesions in the colon of mice and that calcium decreases the risk of colon carcinogenesis.
        4,000원
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