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        검색결과 73

        3.
        2018.11 구독 인증기관·개인회원 무료
        To preserve the superior genetic resources and restore the endangered species, Somatic cell nuclear transfer (SCNT) has been used widely. In Korea, the research of dog cloning has made outstanding achievements including the production of the world`s first cloned dog. Sapsaree (Sapsalgae), the representative dog of Gyeongsan-si was designated as a Korea natural monument (No. 368). This male dog used in this study has azoospermia due to unknown cause. In this study, the aim was to confirm the cause of infertility in the cell donor dog and to evaluate the reproduction potential of dog cloning using infertile male dog by SCNT. First, to confirm the infertility of the cell donor dog, the reproductive history and the testis were evaluated. The breeding histology was not recorded in individual document. In histopathology, the Sertoli cell tumor was confirmed in biopsy of the cell donor dog after death. But, these tumors are predominantly in older dogs. Second, we produced the cloned dogs with the somatic cells of the infertile dog and the appearance was similar with the cell donor dog. Also, microsatellite analysis confirmed the genetic relationship between the cell donor and clone dogs. Third, the potential breeding capacity of the cloned dog was confirmed. In T4 assay, the normal dog (same age with cloned dogs), cell donor dog, and cloned dogs was investigated. The cell donor dog with azoospermia had very low T4 level, and cloned dogs showed higher level of T4 than normal dogs. In CASA, There was no significant difference in sperm motor ability between normal dogs and cloned dogs. As a result, cloned dogs produced by SCNT had no problem regarding the reproductive function of the testis. In AI experiment, the semen of clone dogs was used to fertilize a natural female bitch and was diagnosed pregnancy by ultrasonography. In total, 7 puppies were born by normal delivery (male: 3, female: 4). In conclusion, this study confirmed that the reproduction problem of non-genetic infertility can generate a normal descendant by SCNT. Also, the first successful research to restore infertile dogs was completed. Furthermore, SCNT would be useful for the restoration of endangered species and application of superior traits.
        11.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fe-TiC composite powders are fabricated by planetary ball mill processing. Two kinds of powder mixtures are prepared from the starting materials of (a) (Fe, TiC) powders and (b) (Fe, TiH2, Carbon) powders. Milling speed (300, 500 and 700 rpm) and time (1, 2, and 3 h) are varied. For (Fe, TiH2, Carbon) powders, an in situ reaction synthesis of TiC after the planetary ball mill processing is added to obtain a homogeneous distribution of ultrafine TiC particulates in Fe matrix. Powder characteristics such as particle size, size distribution, shape, and mixing homogeneity are investigated. In case of (Fe, TiC) powder many coarse TiC particulates with size of several μm are unevenly distributed in Fe-matrix. The composite powder prepared from (Fe, TiH2, C) powder mixture showed a homogeneous dispersion of ulatrafine TiC particulates.
        4,000원
        12.
        2013.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present a multi-dimensional reduction method of the surveyed cube database obtained using a single- dish radio telescope in Taeduk Radio Astronomy Observatory (TRAO). The multibeam receiver system installed at the 14 m telescope in TRAO was not optimized at the initial stage, though it became more stabilized in the following season. We conducted a Galactic Plane survey using the multibeam receiver system. We show that the noise level of the first part of the survey was higher than expected, and a special reduction process seemed to be definitely required. Along with a brief review of classical methods, a multi-dimensional method of reduction is introduced; It is found that the ‘background’ task within IRAF (Image Reduction and Analysis Facility) can be applied to all three directions of the cube database. Various statistics of reduction results is tested using several IRAF tasks. The rms value of raw survey data is 0.241 K, and after primitive baseline subtraction and elimination of bad channel sections, the rms value turned out to be 0.210 K. After the one-dimensional reduction using ‘background’ task, the rms value is estimated to be 0.176 K. The average rms of the final reduced image is 0.137 K. Thus, the image quality is found to be improved about 43% using the new reduction method.
        4,000원
        14.
        2012.06 구독 인증기관·개인회원 무료
        The reactive oxygen species (ROS) generated during the somatic cell transfer nuclear (SCNT) procedures may cause the mitochondrial dysfunction and DNA damage, which may result in restricts the reprogramming of SCNT embryos and play a key direct role in apoptosis. The present study was conducted to investigate the effect of antioxidant treatment during the SCNT procedures on the inhibition of mitochondria and DNA damages in bovine SCNT embryos. The reconstituted oocytes were treated with antioxidants of 25 μM β-mercaptoethanol (β-ME) or 50 μM vitamin C (Vit. C) during the SCNT procedures. In vitro fertilization (IVF) was performed for controls. Mitochondrial morphology and membrane potential (ΔΨ) were evaluated by staining the embryos with MitoTracker Red or JC-1. Apoptosis was analyzed by Caspase-3 activity assay and TUNEL assay, and DNA fragmentation was measured by comet assay at the zygote stage. Mitochondrial morphology of non-treated SCNT embryos was diffused within cytoplasm without forming clumps, while the IVF embryos and antioxidant treated SCNT embryos were formed clumps. The ΔΨ of β-ME (1.3±0.1, red/green) and Vit. C-treated (1.4±0.2, red/green) SCNT embryos were significantly higher (p<0.05) than that of non-treated SCNT embryos (0.9±0.1, red/ green), which similar to that of IVF embryos (1.3±0.1, red/green). Caspase-3 activity was not difference among the groups. TUNEL assay also revealed that little apoptosis was occurred in SCNT embryos as well as IVF embryos regardless of antioxidant treatment. Comet tail lengths of β-ME and Vit. C-treated SCNT embryos (337.8±23.5 μm and 318.7 ±27.0 μm, respectively) were shorter than that of non-treated SCNT embryos (397.4± 21.4 μm) and similar to IVF embryos (323.3±10.6 μm). These results suggest that antioxidant treatment during SCNT procedures can inhibit the mitochondrial and DNA damages of bovine SCNT embryos.
        15.
        2012.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this work, the silver nanoparticles have been synthesized by electrical explosion of wire in three liquid mediums: deionized water (DIW), polyvinylpyrrolidone (PVP) and sodium dodecyl benzene sulfonate (SDBS) solutions. Absorption in the UV-visible region of these suspensions was measured in the range of 300-800 nm. A surface plasmon peak was observed at ~400 nm in all suspensions in measured wavelength range. Particle size was analyzed by transmission electron microscope. It showed that the particles had nearly spherical shape in all samples. The average particle sizes prepared in DIW, PVP and SDBS solution were 37, 31 and 27 nm, respectively. Stability of the suspensions was estimated by multiple light scattering method. The presence of PVP and SDBS surfactants in the exploding medium resulted in enhanced stability of the silver suspensions.
        4,000원
        16.
        2011.10 구독 인증기관·개인회원 무료
        Cell transplantation therapy using adult stem cells has recently been identified as a potential treatment for spinal cord injury (SCI). But, recovery after traumatic SCI is very limited. As dogs are physiologically much more similar to human compared with other traditional mammalian models in disease presentation and clinical responses, a number of researches demonstrated canis familiaris is a suitable model for human diseases. This study investigated the effect of transplantation of canine Mesenchymal Stem Cells (cMSC) and neural-induced cMSC (nMSC) to understand how these cells improve neurological function in canine SCI model. The differentiation of cMSC into neural precursor cells was induced in dulbecco’s modified eagle’s medium supplemented with N2-supplement, dibutyryl cyclic adenosine monophosphate, and butylated hydroxyanisole. SCI was induced between T1 and T2 by surgical hemi-section in adult dogs, and then assigned to two groups according to the applied cell types (cMSC vs nMSC). Pelleted cMSC or nMSC were transplanted directly into the injured site after SCI, respectively. Analysis of motor function after transplantation was evaluated by modified Olby score. Magnetic resonance imaging (MRI), histological and immunohistichemical analysis were also performed. Functional recovery in group of cMSC was increasing gradually after transplantation and was higher than nMSC. In MRI, we could not confirm any difference between the cMSC and nMSC experimental groups. Immunohistochemically, beta3-tubuline and nestin were observed in injury site of two experimental groups with the expression level close to non-injured groups. Transplantation of mesenchymal stem cells could promote neuronal reconstruction and repair motor function in SCI. These showed mesenchymal stem cells could be a great candidate as a therapeutic tools in degeneration disease, and dogs could be used to explore human regenerative medicine as a promising animal model. This research was supported by iPET (Grants 110056032CG000), Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        17.
        2011.10 구독 인증기관·개인회원 무료
        Bacterial contamination reduces the semen quality, semen preservation, and cause of disease spread as well. Sperm fertility is essential factor of reproductive performance in swine. Sperm fertility is affected by semen quality such as sperm motility, abnormality, morphology, and rate of bacterial contamination. This study was conducted to determine the relationship between elapsed time after semen preservation on the changes of bacteria and semen quality. Semen was diluted with BTS extender without antibiotic for 7 days and sperm parameter and fertility were measured. Sperm motility was measured by CASA and total bacteria number was counted after 22 24 hr incubation from counting agar plate in which sperm dilute to 10 106 in 0.9% saline solution and inoculate to agar. Acrosomal integrity was measured by Chlortetracycline (CTC) staining. CTC patterns were uniform fluorescence over the whole head (pattern A), characteristic of uncapacitated acrosome-intact spermatozoa; fluorescence-free band in the post-acrosomal region (pattern B), characteristic of capacitated acrosome-intact spermatozoa; and almost no fluorescence over the whole head except for a thin band in the equatorial segment (pattern C), characteristic of acrosome reacted spermatozoa. Total number of bacteria was significantly increased (p<0.0001) 3 days after preservation. Sperm motility, viability, and morphological abnormality on elapsed time after preservation were lower from 5 (77.24±6.47, p<0.001) and 7 days (77.24±6.47, p< 0.001) after preservation compared to 1 (15.71±7.18) and 3 days(18.39±7.22) after preservation, respectively. Sperm viability was significantly lower (53.25±35.03, p<0.0001) at 7 days after preservation. Mohological abnormality of sperm was lower (p<0.001) at 1 (15.71±7.18) and 3 (18.39±7.22) days compared to (5 21.84±7.91) and 7 (22.59± 9.93) days after preservation. Acrosomal integrity and capacitation rate (pattern A) were significantly lower (p<0.001) from 5 days after preservation.
        18.
        2011.10 구독 인증기관·개인회원 무료
        Acteoside (verbascoside) is a typical phenylethanoid glycoside, extracted from various plants. It has various biological functions such as anti-oxidant, anti-inflammation, and anti-hypertension. Specially, it was powerful anti-oxidants either by direct scavenging of reactive oxygen and nitrogen species, or by acting as chain-breaking peroxyl radical scavengers. We examined the role of acteoside in IVM medium on the morphological progress of meiosis, developmental competence, and ROS in porcine oocytes. 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. The selected COCs were cultured in TCM-199 with various concentration of acteoside: 0 (control), 10, 30, and 50 μM. After 22 h of maturation with hormones, the oocytes were washed twice in a fresh maturation medium before being cultured in hormone-free medium for additional 22 h. The oocytes maturation rates of supplemented with acteoside were no significantly different compared with control group (71.13, 75.96, 72.95 and 73.68%, 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 (40.03 vs. 22.95%). During IVM, 10 μM acteoside treated oocytes showed that the mitochondria and lipid droplet were smaller and homogeneous distribution in cytoplasm compare with non-treated control oocytes. And reverse transcription polymerase chain reaction (RT-PCR) witarthenogenetic blstocysts revealed that acteoside increased the anti-apoptoticgenes, otherwise reibued pro-apoptotic genes. In conclusion, our results represents that addition of acteoside to the IVM medium has a beneficial effect in physiology of porcine oocytes such as viability and activation, providing a improved method for porcine oocytes in vitro.
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