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        검색결과 244

        66.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Influenza A virus (IAV) causes respiratory disease in birds and mammals, including pigs and humans. Infection by IAV in pigs increases not only economic losses in the swine industry but also the emergence of novel IAV variants via gene reassortment, which is important due to the susceptibility of both birds and humans to IAV. This study provides serological data obtained during a study to detect IAV infections in pigs in the Republic of Korea during 2018 and 2019. A total of 1,559 samples were collected from 74 domestic pig farms. Hemagglutination inhibition (HI) assays were performed using the A/Swine/Korea/25-13(H1N1), A/Swine/Korea/E102 (H1N2), and A/Swine/Korea/Cy10/2007 (H3N2) viruses as antigens. The HI assay results showed that 266 of the 1,559 samples were seropositive (17.0%). Among these, H1N1, H1N2, and H3N2 comprised 7.3% (114), 6.0% (93), and 8.8% (137) of the 1,559 samples, respectively. Co-infections of H1N1/H1N2, H1N1/H3N2, H1N2/H3N2 and H1N1/H1N2/H3N2 were observed in 2.1% (31), 1.5% (23), 1.5% (24), and 0.8% (13) of the 1,559 samples, respectively. Interestingly, IAV infections were detected in all nine provinces of the country.
        3,000원
        69.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, nitrogen (N)-doped ultra-porous carbon derived from lignin is synthesized through hydrothermal carbonization, KOH activation, and post-doping process for CO2 adsorption. The specific surface areas of obtained N-doped porous carbons range from 247 to 3064 m2/g due to a successful KOH activation. N-containing groups of 0.62–1.17 wt% including pyridinic N, pyridone N, pyridine-N-oxide are found on the surface of porous carbon. N-doped porous carbon achieves the maximum CO2 adsorption capacity of 13.6 mmol/g at 25 °C up to 10 atm and high stability over 10 adsorption/desorption cycles. As confirmed by enthalpy calculation with the Clausius–Clapeyron equation, an adsorption heat of N-doped porous carbon is higher than non-doped porous carbon, indicating a role of N functionalities for enhanced CO2 adsorption capability. The overall results suggest that this carbon has high CO2 capture capacity and can be easily regenerated and reused without any clear loss of CO2 adsorption capacity.
        4,000원
        70.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Epoxy resin, which demonstrates a shape memory effect, is reinforced by chopped carbon fibers (CCFs) to improve the thermal and mechanical properties. The interfacial interactions between 2-mm-long CCFs and epoxy make an impact on not only molecular motion but also the physical behaviors of CCFs/epoxy composites. In particular, shape recovery ability of CCFs/epoxy composites is enhanced with an increase in thermal conductivity generated by crossing CCFs in the epoxy system, although CCFs/epoxy composites containing small amounts of CCFs, such as 1 or 3 phr (parts per hundred rubber), show slower recovery rates than those of raw epoxy specimens due to the difficulty of making heat bridges in composites. With these results, it is confirmed that for specific time-dependent purpose, the shape recovery vector of CCFs/epoxy can be controlled using the amount of CCFs.
        4,000원
        71.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to identify specific psychological and brain activation responses relating to the processing of negative emotions in patients with alcohol dependency. The authors hypothesized that patients with alcohol dependency would demonstrate the abnormal functioning of brain regions involved in negative emotions. Eleven male patients diagnosed with alcohol dependence in an inpatient alcohol treatment facility and 13 social drinkers with similar demographics were scanned using functional magnetic resonance imaging (fMRI) as they viewed film clips that evoked negative emotions. During exposure to negative emotional stimuli, the control group evinced significantly greater activity in the right anterior cingulate cortex (ACC) in comparison to patients with alcohol dependency. Correlation analyses demonstrated a negative association in the relationship between beta values from the right ACC and amygdala in participants classified in the control group. No statistically significant relationship was observed for blood oxygenation level-dependent (BOLD) changes between the two regions in the patient group during the elicitation of negative emotions. On the other hand, patients exhibited a greater activation of the amygdala as negative emotions were induced. These results suggest that alcoholism presents pathophysiology of brain activation that is distinct from the responses of healthy individuals functioning as controls.
        4,000원
        72.
        2018.11 구독 인증기관·개인회원 무료
        The Jeju Black Cattle (JBC) are a type of traditional Korean native cattle with a characteristic black fur that covers the entire body. Semen analysis is the most commonly used procedure to evaluate male fertility potential. This study was to evaluate the quality of 10 JBC bulls belonging to Jeju Special Self-Governing Province Promotion Institute. [JBC A∼J grade]. The freezing medium (20% egg yolk plus 20% triladyl) was added in semen sample to a final concentration of 100×106 sperm/ml. For sperm cooling, diluted semen was filled in 0.5 ml plastic straws and then kept in refrigerator at 4°C for 2 h. They were placed in 7 cm over liquid nitrogen (LN2) vapor for 10 min and then directly plunged into LN2 for storage. Thawing was done by transferring the frozen straws into water bath at 37°C for 30 sec for analysis. The sperm motility, vitality and morphology in each group was assessed using the Sperm Analysis Imaging System (SAIS Plus; Medical Supply Co, Ltd., Korea), eosin-nigrosin stain and diff-quik kit. There was no difference in the motility of the fresh groups (87.4 ~ 100%), while it was difference in the frozen-thawed groups (42.8 ~ 98.6%) (p<0.05). The best motility was shown in JBC-B (100/fresh and 98.6%/frozen-thawed). There was significant difference in the vitality of the fresh group (19.8 ~ 59.2%) and frozen-thawed group (21.2 ~ 49.8%)(p<0.05). The highest vitality was also shown in JBC-B (59.2/fresh and 49.8%/frozen-thawed). Morphologically, in fresh semen the highest normal ratio was indicated in JBC-E (90.9%) and in frozen-thawed group the highest was in JBC-C (90.2%). These results demonstrated that the analysis including motility, vitality and morphology of fresh or frozen-thawed semen is valuable to select the high quality sperm using for reproduction.
        73.
        2018.11 구독 인증기관·개인회원 무료
        Light Mineral Oil is a material generally used as an overlay covering microdrops of culture medium in petri dishes. Although Light Mineral Oil can protect the damage by oxidation in air, it can't completely protect the damage by evaporation and alteration of pH and osmolality in culture medium. To minimize the damage by evaporation and alteration of pH and osmolality, we assumed that Heavy Mineral Oil could be used as an alternative. Heavy Mineral Oil is high purity paraffin oil which has more viscosity and density than Light Mineral Oil, so it can prevent evaporation and maintain stable osmolality and pH in culture medium more than Light Mineral Oil. The objective of this study was to examine whether the effect of Heavy Mineral Oil is superior to the effect of Light Mineral Oil during in vitro cultivation of porcine oocytes. According to the data of repeated six experiments, survival and cleavage rate of porcine oocytes, and cell number of blastocysts were not significantly different between two groups. However, the in vitro development rate of porcine parthenogenetic embryo was significantly higher in Heavy Mineral Oil group than in Light Mineral Oil group (Light, 36.6% ± 3.9%; and Heavy, 52.1% ± 6.4%, p < 0.05). Thus, these results indicated that the treatment of Heavy Mineral Oil can improve the in vitro developmental capacity of porcine parthenogenetic embryos compared to Light Mineral Oil.
        74.
        2018.11 구독 인증기관·개인회원 무료
        Preimplantation embryonic production in vitro is important in human assisted reproductive technology and animal embryo engineering. Icariin (ICA) is one type of flavonoids and a main component isolated from the stem leaf of Epimedium brevicornum. Flavonoids, which are among the best well-studied natural antioxidants, have been demonstrated to be active in clearing reactive oxygen species (ROS). The purpose of this study was to investigate the effects of ICA treatment during porcine oocyte in vitro aging and their in vitro developmental competency after parthenogenetic activation (PA). Porcine oocytes were matured in vitro for 44 h (control) and for an additional 24 h in the presence of 0, 5 μM ICA (aging, ICA-5), respectively. This study investigated the effects of ICA on nuclear maturation, ROS level, apoptosis index, and the developmental capacity of aged porcine oocytes. Oocyte survival was not different in aging group compared to control or ICA-5 group. The increased ROS level during in vitro aging was prevented in ICA-5 group, while GSH level was not decreased. The decrease of normal spindle formation during in vitro aging was prevented in ICA-5 group. After PA, although the cleavage rate was not different among treatment groups, the blastocyst formation was significantly higher in control and ICA-5 group than in aging group. However, there was significantly difference in the apoptotic index of the ICA-5 group, while it was no difference in the total cell number of the ICA-5 group. (p<0.05). Therefore, this result demonstrated that the ICA is an effective agent to prevent the deterioration during in vitro aging of porcine oocytes.
        75.
        2018.11 구독 인증기관·개인회원 무료
        In general, the shape of cumulus-oocyte-complexes (COCs) at germinal vesicle (GV) stage is important roles on meiotic maturation of porcine oocyte during in vitro maturation (IVM). Then, mitochondria produce reactive oxygen species (ROS) such as superoxide from electron transport system during oocyte maturation. ROS levels on oocytes are regulated by various antioxidant enzymes in cumulus cells (CCs). However, the effect of mitochondria derived superoxide production from CCs during IVM of porcine oocyte has not been reported. Firstly, we divided groups according to large number of CCs (Grade 1: G1) and small number of CCs (Grade 2: G2). Then, we counted cumulus cells of G1 and G2 oocyte by using haemocytometer. The oocyte maturation rate was significant decreased (p < 0.05) in G2 oocytes than that of G1 oocytes. We measured mitochondria derived superoxide in G1 and G2 COCs by using Mito-SOX staining. Mitochondrial superoxide was higher in G2 COCs than G1 COCs. Then, the mRNA expression levels of antioxidant enzymes (SOD1, SOD2 and PRDX3) in G2 COCs were decreased compared to G1 COCs. To reduce mitochondria derived superoxide, we used Mito-TEMPO as mitochondrial superoxide scavenger. Oocyte maturation rates in both G1 and G2 groups treated with Mito-TEMPO were increased than that of non-treated groups. Mitochondrial superoxide was lower in G1 and G2 groups treated with Mito-TEMPO than that of non-treatment groups. The mRNA expression levels of antioxidant enzymes in G1 and G2 COCs treated with Mito-TEMPO were increased compared to non-treated groups. Based on these findings, we suggest that reduction of mitochondria derived superoxide by Mito-TEMPO assists maturation competence in porcine oocytes.
        76.
        2018.11 구독 인증기관·개인회원 무료
        The citrus flavonoid hesperetin has various pharmacological actions, including antioxidant, anti-inflammatory, and anticancer activities. The purpose of this study is to confirm whether the treatment of hesperetin can protect the oocyte from in vitro aging. Porcine oocytes were matured in vitro for 44 h (control) and for an additional 24 h in the presence of 0, 1, 10, 100, and 250 μM hesperetin (aging, H-1, H-10, H-100 and H-250, respectively). This study investigated the effect of different concentration of hesperetin on maturation, and reactive oxygen species (ROS) level, apoptosis index, and the developmental capacity of aging porcine oocytes. In the results, the percentage of cleaved oocytes that reached to the blastocyst stage of H-100 group (37.9 ± 1.1%) was similar to control (38.1 ± 0.8%), and also significantly higher than other aging groups (23.2 ± 0.8%; H-1, 19.7 ± 1.3%; H-10, 26.7 ± 0.6%; and H-250, 18.4 ± 1.6%.)(p<0.05). The H-100 group was significantly decreased ROS activity, and increased the level of glutathione (GSH) and expression of the antioxidant genes (PRDX5, NFE2L, SOD1 and SOD2) compared to the aging group. The H-100 groups prevented aberrant spindle organization and chromosomal misalignment, blocked the decrease in the level of phosphorylated-p44/42 mitogen-activated protein kinase (MAPK), and increased the mRNA expression of cytoplasmic maturation factor genes (GDF9, CCNB1, BMP15 and MOS). Also, it was confirmed that the H-100 group expressed higher level of estrogen receptor than the aging group. Therefore, this result indicated that hesperetin is an effective agent to protect from the oxidative stress during in vitro aging of porcine oocytes.
        77.
        2018.11 구독 인증기관·개인회원 무료
        The national natural monument of Korea, Jeju Black Cattle (JBC), it is a native species with unique blood line. This cattle breed needs mass production and industrialization to further improve and preserve their characteristics. This study was to examine whether there were differences in in vitro developmental rates according to body weight (<300, 300 ~ 350, 350 ~ 400 and >400 kg) and grade (1++, 1+, 1, 2 and 3), and oocyte donors or non-donors. As a method of IVM, groups of ten cumulus oocyte complexes (COCs) were cultured in 50 μl droplets of maturation medium (TCM199 supplemented with 10% FBS, 0.2 mM sodium pyruvate, 1 μg/ml follicle-stimulating hormone, 1 μg/ml estradiol-17β) under mineral oil at 38.8℃ in an incubator with a 5% CO2 atmosphere for 22 to 24 h. For IVF, 44 ul IVF drop contained 10 oocytes with sperm concentration of 1 × 106 cells/ml, and then 2 μl heparin and 2 μl PHE (20 μM peicillamine, 10 μM hypotaurine, 2 μM epinephrine) were added. For IVC, after 44±2 h of incubation, cleaved embryos were incubated in CR1aa medium containing 3 mg/ml FAF-BSA until day 4 at 38.8℃ in a 5% CO2 incubator. Embryos were then cultured in CR1aa medium containing 10% FBS until day 8. As a result, in vitro development rates were the highest in 350 ~ 400 kg body weight group and in 1++ grade group than other groups (p<0.05). However, there was no difference in in vitro developmental capacity of classified donor and non-donor oocyte groups. This result demonstrated that the better in vitro developmental capacity was obtained in high level originated oocyte groups (350 ~ 400kg, 1++ grade) than in others, while there was no different in donor types.
        78.
        2018.11 구독 인증기관·개인회원 무료
        Successful cryopreservation of bovine oocytes is a very important technology for research and commercial applications. However, the survival and development rate of vitrified-thawed oocytes is lower than non-vitrified oocytes. Hydroxypropyl Cellulose supplementation (HPCs) has extremely high viscosity, which permits transitions to a glassy state at low temperatures. This characteristics of HPCs have been reported to help the survival of human oocytes. In this study, we investigated the survival rate, fertilization rate and ROS levels to confirm the effect of cryoprotectant solutions with HPC for oocyte vitrification in bovine. For vitrification, bovine MII oocytes were pretreated with EG10 (added 0, 10, 50 and 100 ㎍/㎖ HPC) for 5 min, exposed to EG30 (added 0, 10, 50 and 100 ㎍/㎖ HPC) for 30 sec, and then directly plunged into LN2. Thawing was taken by 4-step procedures [1 M sucrose and 10% FBS added D-PBS (SFD) -> 0.5 M SFD -> 0.25 M SFD -> 0.125 M SFD] for 1 min, respectively. After thawing, oocytes were washed with TL-HEPES, incubated in a droplet of previous cultured IVM medium for 1 h to recover. IVF drop (44 ㎕) contained 10 vitrified-thawed oocytes with sperm concentration of 1 × 106 cells ㎖, and then 2 ㎕ heparin and 2 ㎕ PHE were added. At 2 days after IVF, cleaved embryos were cultured in CR1aa + 3 mg/mL FAF-BSA for 48 h and cultured in CR1aa + 10% FBS for 4 days. In the results, in vitro survival rate of bovine vitrified-thawed MII oocyte was significantly higher in 50 (85.5%) and 100 ㎍/㎖ (80.2%) HPC groups than 0 (71.2%) and 10 ㎍/㎖ (71.3%) groups (p<0.05). The ROS level was lower in 50 ㎍/㎖ HPC group than in control group. After in vitro fertilization, cleavage rate and blastocyst development rate were not significantly different among treatment groups. Therefore, these results indicated that HPC treatment has a positive effect on the survival of vitrified-thawed bovine oocytes.
        80.
        2018.10 구독 인증기관·개인회원 무료
        The organism evaluation equipment (OEE) was developed to determine the insecticidal effect of atmospheric-pressure plasma jets (APPJ). The equipment consisted of a plasma-generating acrylic chamber (PGAC) equipped with a plasma generator, a plasma-maintaining acrylic chamber (PMAC), and plasma efficacy evaluation container (PEEC). The amount of reactive oxygen species (ROS) directly exposed to PEEC in the PMAC was measured using an ozone calculator. The ROS concentration in the PGAC and PEEC increased over time, and the optimum position for the PEEC was selected showing the lowest variance of ROS concentration. Based on the established equipment, five major insect pests (Aphis gossypii, Bemisia tabaci, Helicoverpa armigera, Tetranychus kanzawai, and Thrips palmi) were tested, and their knockdown time, recovery time, and median lethal time (LT50) were determined. As a result, B. tabaci showed the fastest knockdown in respond to the plasma, but the remaining insect pests were knock downed within 2-3 min. Recovery was the fastest in T. palmi and T. kanzawai and slowest in B. tabaci. The LT50 were determined as 13 and 16 min in B. tabaci and T. palmi, respectively. However, the LT50 of other insect pests showed over 21 min. In conclusion, the OEE system can be used to measure the optimum exposure time of plasma against various insect pests, and the plasma might be used as an alternative tools for pest control in the future.
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