검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 288

        182.
        2014.04 구독 인증기관·개인회원 무료
        A long term monitoring was carried out to compare altitudinal effects on insect community structures on high mountains and evaluate responses the monitoring and changed of insect communities induced by the climate change. These mountains were choose for Mt. Jeombong for northern part, Mt. Ilwol for middle and Mt. Beakun for southern. Each mountain was divided into three altitudinal gradients. They were collected three times a season from spring to autumn, using pitfall traps for ground beetles and UV light trap for moths. The present study presents preliminary results of analysis for the first year monitoring. In total 41beetle species and 326 moths were collected from the monitoring sites in 2012. abundance of ground beetles and moths were the highest in Mt. Baekun followed by Mt. Ilwol and lowest in Mt. Jeombong. Analysis of variance (ANOVA) results showed statistically significant differences among sampling area, species evenness and Shannon’s diversity index with altitude in species abundance as a response variable. Also we found statistically significant differences to three species of ground beetle and six species of moths with altitude. Although we expected a distinct cluster with the difference of altitude at each study site. one of ordination analysis, nonmetric multidimensional scaling (NMS), showed distinct clusters with the ground beetles assemblage at some altitude and moths assemblage at sampling date.
        183.
        2013.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-coercive (Nd,Dy)-Fe-B magnets were fabricated via dysprosium coating on Nd-Fe-B powder. The sputtering coating process of Nd–Fe–B powder yielded samples with densities greater than 98%. (Nd,Dy)2Fe14B phases may have effectively penetrated into the boundaries between neighboring Nd2Fe14B grains during the sputtering coating process, thereby forming a (Nd,Dy)2Fe14B phase at the grain boundary. The maximum thickness of the Dy shell was approximately 70 nm. The maximum coercivity of the Dy sputter coated samples(sintered samples) increased from 1162.42 to 2020.70 kA/m. The microstructures of the (Nd,Dy)2Fe14B phases were effectively controlled, resulting in mproved magnetic properties. The increase in coercivity of the Nd-Fe-B sintered magnet is discussed from a micro- structural point of view.
        4,000원
        184.
        2013.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Most patients with chronic low back pain experience functional disability of trunk muscle, and limitations in physical activity. While there are many types of exercise programs available, in recent years sling exercise has been emerging as the exercise program for spinal stabilization. It has been supported by a great amount of research with positive findings on its effectiveness. This research studies the effects of bridging exercise, conducted on a sling, on pain level and trunk muscle activation in supine, sidelying, and prone positions during a 4 weeks period. 10 healthy people(normal group, n=10) and 28 patients with low back pain participated in this study. 28 patients were divided into two groups; one group participated in exercise with the sling(experimental group, n=14) and the other group exercised without the sling(control group, n=14). They were asked to use the Numerical Rating Scale(NRS) to answer to the level of their pain they felt (no pain: 0 point, severe pain: 10 points). During sling bridging exercises, the muscle activity level in each muscle measured in each position was standardized as three seconds of EMG signals during five seconds MVIC. In conclusion, the experimental group with four weeks of sling bridging exercise experienced a statistically significant reduction in the pain level(p<.05) and increase in the muscle activities of erector spinae when in supine position, internal oblique when in sidelying position, and rectus abdominis in prone position(p<.05). Regular sling bridging exercise reduces the low back pain and enhances other trunk muscle activation, thereby positively affect spinal stabilization.
        4,000원
        189.
        2012.06 구독 인증기관·개인회원 무료
        Ski protein is a nuclear transcription factor that does not bind DNA directly. Due to its unique binding properties with multiple factors, Ski could perform various roles in the regulation of both cellular proliferation and differentiation. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to examine whether the initiation of luteinization with luteinizing hormone (LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vitro models. RT-PCR and real time PCR analysis respectively revealed that LH had no effect on c-Ski mRNA expression in the cultured granulosa cells regardless of LH treatment. Though Ski protein isabsent in granulosa cells of preovulatory follicle, its mRNA(c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally. Moreover, expression of mRNA of Arkadia, an E3 ubiquitin ligases, in luteinizing granulosa cells in vivo was assessed by real time-PCR. The levels of Arkadia mRNA expression were unchanged during follicular growth and post ovulatory luteinization. These findings suggest that Ski protein level may be regulated during luteinization at translational and/or post-translational level but not by Arkadia.
        190.
        2012.06 구독 인증기관·개인회원 무료
        Sloan-Kettering virus gene product of a cellular pro-oncogene c-Ski is an unique nuclear pro-onco protein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. Ski protein is implicated in proliferation/differentiation in a variety of cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of this study was, by means of immunohistochemical methods, to locate Ski protein in the rat ovaries during ovulation and corpora lutea(CL) formation to predict the possible involvement of Ski in luteinization. In addition, to examine whether the initiation of luteinization with luteinizing hormone(LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vivo models. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone(LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum(CL). These results indicate that Ski is profoundly expressed in the luteinized granulosa cells and luteal cells of CL during luteinization, and suggest that Ski may play a role in luteinization of granulosa cells.
        191.
        2012.06 구독 인증기관·개인회원 무료
        For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at — 7℃ to — 35℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen- thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5 ml, and 43.6 % frozen at 20embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).
        192.
        2012.06 구독 인증기관·개인회원 무료
        The objective of this study was to investigate the effects of NEAA and leptin supplemented to in vitro culture medium on the developmental competence of porcine embryos after intracytoplasmic sperm injection (ICSI), and to modify the culture condition to improve the quality and the development of ICSI-derived porcine embryos in vitro. After ICSI, the putative zygotes were then cultured in PZM-3 medium with/without NEAA or leptin. The proportion of embryos that developed to the blastocyst stage significantly increased when 1% NEAA (24.62%) was added to the medium compared with 2% NEAA and no NEAA group (17.24% and 20.24%, respectively, p<0.05). The effect of different concentration of leptin (0, 10, 100, 500 ng/ml) was evaluated on the development of porcine ICSI embryos cultured in vitro. In case of blastocyst formation, 100 ng/ml group (27.05%) showed significantly higher rate than 10, 500 ng/ml, and control group (23.45%, 17.99%, and 19.68%, respectively, p<0.05). We also evaluated the effects of different NEAA and leptin treatment time on the development of porcine embryos after ICSI. Among groups of embryos cultured in the presence of NEAA or leptin for whole 7 days (D 1-7), first 4 days (D 1-4), the subsequent 3 days (D 5-7), both NEAA (27.13%, 21.17 %, and 17.56%, respectively, p<0.05) and leptin (25.60%, 20.61%, and 16.53%, respectively, p<0.05) showed that supplementation for whole 7 days significantly increased the blastocyst formation rate compared with the other groups of D1-4 and D5-7. We further evaluated the combination effect of 1% NEAA and 100 ng/ml leptin compared with the effect of each supplementation with 1% NEAA or 100 ng/ml leptin or no supplementation on development of embryos. For blastocyst formation, combination group of NEAA and leptin (24.78%) showed significantly higher rate than other three groups (18.37%, 20.44 %, and 13.27%, respectively, p<0.05). We further evaluated the expression of proapoptosis genes such as BAX and BAK and anti-apoptosis genes, BCL-XL and BCL-2 in blastocysts cultured in the presence of 100 ng/ml leptin. RT-PCR analysis revealed that leptin supplementation significantly decreased the expression of pro-apoptosis genes as well as increased the expression of anti-apoptosis genes. These results of present study demonstrate that NEAA and leptin could improve the in vitro development of ICSI- derived porcine embryos with optimal concentration of each reagent. Furthermore, the optimal culture condition could increase the quality of ICSI-derived embryos in vitro.
        193.
        2012.06 구독 인증기관·개인회원 무료
        True hermaphrodites are animals of equivocal sex in which both male and female gonads develop simultaneously. The frequency of true hermaphroditism is higher in pigs than in other domestic animals. Two Korean pigs were diagnosed with true hermaphroditism showing ovotestes, epididymes, penes, and uteri. Histomorphologically, the testicular tissues consisted of Sertoli cells that were devoid of spermatogenic germ cells and showed proliferation of interstitial cells. However, the uteri were of normal architecture and had well-developed uterine endometrial glands. The samples were 38, XX female karyotype without the sex-determining region Y (SRY) gene. The findings of this study could contribute to the understanding of true hermaphroditism in the Korean pig industry. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        194.
        2012.06 구독 인증기관·개인회원 무료
        Cryopreservation of avian semen is a useful tool to preserve genetic resource for aim of preventing extinction induced by infectious disease like avian influenza. Unlike those of mammals, data from chicken cryopreserved semen has not been showed feasible results. So, various cryoprotectants and diluents have been examined in many methods. In this report, as a major ingredient of avian seminal plasm, glutamine was substituted by alanyl glutamine to enhance physiological stability of chicken semen during freezing. We studied effect of glycerol and Dimethylacetamide(DMA) on motility and progressive motility of spermatozoa using glutamine diluent(EK-G) or alanyl glutamine diluent(EK-A) condition. The semen of Ogye was collected twice a week by the dorso-abdominimal massage method and diluted with same volume of EK-G or EK-A at 25℃ and stored for 10 min at 4℃ in cold chamber. Glycerol or DMA was added to diluted semen to reached 7% of final concentration at 4℃. After 3min of equilibration, the diluted semen was packed into 0.25ml straws and subjected to cryopreservation used freezing equipment. The packed straw were placed on height 5 cm above surface of liquid nitrogen(LN2) and held for 10min. After preserved for 2 weeks, the straw was thawed onto the 4℃ cooling bath. The images of motility and progressive motility spermatozoa were recorded by digital image recorder and analyzed by manual. The results showed 68.5% motility and 34.1% progressive motility in DMA/EKA diluent, 31.45% and 17.6% in glycerol/EKA, 45.4% and 8.6% in DMA/EKG, and 9.7% and 6.4% in glycerol/EKG. With these results, the alanyl glutamine and DMA could be used as a main composition of diluent and cryoprotectant for cryopreservation of chicken semen.
        195.
        2012.06 구독 인증기관·개인회원 무료
        There are diverse methods of cryopreservation of mammalian embryos with variable degrees of success. Although cryopreservation technique of mammalian embryos has been advanced, freezing stress affect to cellular event such as apoptosis and autophage in embryos. The objective of the study is to investigate the affection of to survival, development, live offspring, apoptosis and autophagy on embryo. Mouse embryos were vitrified and thawed using normal straw and modified cut standard straw (M-CSS), then in vitro cultured until blastocyst stage and transferred to recipient. Recovery rates (100 vs 99.2%), survival rates (99.2 vs 78.6%), developmental rates (18.4 vs 10.7%), total cell numbers (45 vs 37), preganacy rates (34.5 vs 25%) and offspring numbers (10.1 vs 4.9 %) of M-CSS group are significantly higher than those of normal straw vitrified group. Also, rate of apoptosis in blastocysts developed using M-CSS (1.9%) was significantly lower than using normal straw vitrification (2.7%). Apoptosis-related gene, caspase 3, was expressed at the highest level in blastocysts derived from normal straw group. However, no differences of autophagy related gene, Atg6 and expression of LC3 between normal straw and M-CSS groups were observed. In conclusion, the standard vitrification procedure induces mitochondrial apoptosis in zygotes in an autophagy-independent manner, whereas the novel M-CSS procedure may improve embryo vitrification.
        196.
        2012.06 구독 인증기관·개인회원 무료
        The aim of this study was to examine the effect of acteoside (the cyclin-dependent kinase inhibitor) on the SCNT efficiency with adult fibroblasts in dog. Canine adult fibroblasts were obtained from muscle and cell cycle of fibroblasts was synchronized by culturing to confluency, serum starvation and treating with 30 μM acteoside for 48 h. Cell cycle stages, cell cytotoxicity (apoptosis) and, prduction of reactive oxygen species (ROS) were analyzed using flow cytometry. The canine cells, prepared by confluent-cell culture or treating with 30 μM acteoside for 48 h, were injected into enucleated in vivo matured oocytes, the couplets were electrical fused and activated by calcium ionomycin. SCNT embryos using acteoside-treated fibroblasts were surgically transferred into oviducts of estrus cycle synchronized recipient dogs. In cell cycle synchronization (G0/G1), there was no significant difference between serum starvations (83.9%) and acteoside treated groups (81.3%) that were higher than confluent group (78.5%). In production of apoptosis, confluent and acteoside treated groups (4.3 and 4.5%, respectively) were generated less than serum starvation group (21.8%). In case of ROS, serum starvation group was induced a significantly higher than other groups. After synchronization of the donor cell cycle, either confluent or acteoside treated, cells were placed with enucleated in vivo-matured dog oocytes, fused by electric stimulation, activated, and transferred into naturally estrus-synchronized surrogates. Fusion and cleavage rate of acteoside treated group were 64.1 and 41.5%, which were higher than those of confluent group (53.9 and 20.6%, respectively). The reconstructed embryo development rates to 4-cell and 8-cell in acteoside treated group were 29.5 and 14.8%, respectively, while confluent group showed 11.1 and 3.2%, respectively. Total 54 SCNT embryos using acteoside-treated fibroblasts were transferred into oviducts of 2 recipient dogs and one recipient finally delivered one puppy, whereas din`t detected pregnancy on transfer of cloned embryos reconstructed with confluent cells in 6 surrogate dogs. In conclusion, the results of the current study demonstrated that canine fibroblasts could be successfully arrested at the G0/G1 stage with reduced the formation of ROS and apoptosis after acteoside treatment. This results may contribute to improve the effi-ciency of canine SCNT. * This research was supported by iPET (Grants 110056-3), Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        197.
        2012.06 구독 인증기관·개인회원 무료
        Acteoside acts as an anti-oxidative activity and anti-apoptosis in the cells. But, it has been not studied on maturation and development of porcine oocytes. The aims of the present study were to examine the effects of acteoside on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. Oocytes were matured in tissue culture medium-199, supplemented with acteoside at various concentrations: 0 (control), 10, 30 and 50 μM. The oocytes maturation rates of groups supplemented with acteoside were no significantly different (81.13, 85.96, 82.95 and 83.68%, respectively). Level of ROS was significantly decreased in acteoside treated group. Furthermore, the parthenogenetic blastocyst rate was significantly improved in 10 μM acteoside treated group compared with control group (44.83 vs. 27.75%). And we investigated effect of acteoside on the oocytes condition represented by cytoplasmic maturation by homogeneous distribution and formation of cytoplasmic organelles and regulation of apoptosis-related genes. In the results. during IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with control oocytes. And reverse transcription polymerase chain reaction (RTPCR) of parthenogenetic blstocysts revealed that acteoside increased the anti-apoptotic genes (Mcl-1, Bcl-2 and Bcl-xL), whereas reduced the expression of pro-apoptotic genes (Bax and Bak). In conclusion, based on the results, the effect of acteoside on IVM was not attractive. However, in acteoside treated group, cytoplasmic maturation seemed to be improved with morphologically uniform distribution of cytoplasmic organelles. Furthermore, embryonic development in acteoside treated group was significantly highly increased than that of non-treated group. Our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes, providing a improved method for porcine oocytes in vitro. * This work was supported by a grant (Code# PJ008148) from BioGreen21 Program, Rural Development Administration, Republic of Korea.
        198.
        2012.06 구독 인증기관·개인회원 무료
        The objective of the current study was to describe in vitro embryo production in Hanwoo, analyzing oocytes yield and embryo production. The effects of oocytes production and the number of OPU procedures per animal on embryo production were also evaluated. OPU was done every 3~4 days during experimental period and collected oocytes were fertilized in vitro in both OPU and needle puncture groups. First, we compared the recovery rate of oocytes based on OPU session (Experiment 1). The average of collected oocytes was calculated from every 10 session. The average number of total oocytes recovered per animalonsessionwas 5.16 (mean). Second, we compared the recovery rate base on collection period of OPU (Experiment 2). The following results show the difference of the number of recovered oocytes in every month during the procedure between the months of session. Every animal shows the constant number of recovered oocytes for the first 5 months. However, the recovery rate of oocytes was decreased from month 6 to 8. Third, we compared the developmental rate to blastocyst in two groups (Experiment 3). Oocytes by needle puncture were fertilized with frozen-thawing semen; the cleavage rate 24~48 h after in vitro fertilization (IVF) was 75.8% and blastocyst development rate was 18.8% in needle puncture group. Even though there is lower cleavage rate after IVF in OPU group (61.1%), blastocyst development rate was higher compared with needle puncture group (28.4%). In conclusion, Blastocyst developmental rate could be increased by OPU than classical method of needle puncture. Improvement of bio- technique in collecting oocytes could be applied to understand the reproductive physiology in cattle, expecially Hanwoo. Therefore, further investigation should be done to clarify the efficiency and advantage of OPU involved in reproduction in animals and human being.
        199.
        2012.05 구독 인증기관·개인회원 무료
        The genus Pratylenchus is considered as one of the most important plant-parasitic nematodes around the world because of its broad spectrum host ranges and worldwide distribution. 72 species of root-lesion nematodes have already been described from various parts of the globe. Among all of them, only 5 species are regulated as a target species in quarantine inspection. As the importation of target items inspecting nematodes are surely increasing every year, detection rate of nematodes in quarantine also increased. However, the rate of species identification has been decreased due to lack of related information. The species belonging to genus Pratylenchus are shown very low identification rate because we have specimens and information about only 10 domestic species and 5 regulated species. In this study, we identified the species in the genus Pratylenchus and obtained related information for application in the quarantine field. Species identification was performed with extracted nematodes from plants obtained in the recent quarantine inspection. Newly identified species were 5 species including Pratylenchus crenatus, P. fallax, P. kumamotoensis, P. panamaensis and P. penetrans. The photos, measured value and morphological characters of each species are provided.
        200.
        2012.03 구독 인증기관 무료, 개인회원 유료
        For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at —7 ℃ to —35 ℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen-thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5ml, and 43.6 % frozen at 20 embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).
        4,000원