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        검색결과 745

        201.
        2012.06 구독 인증기관·개인회원 무료
        Semen can be divided into two parts. One is cellular part which contains sperms the other is liquid part which is called by seminal plasma. The seminal plasma is a nutritive and protective medium for the sperms. Fructose, which is major energy source, is supplied to sperms swim to female oocyte. Alkalic property protects sperms from hostile environment of female reproductive organ. Also, seminal plasma induces tolerance to preexisted immune cells, and changes intra‐uterine environment to better conditions for fertilized embryos to implant. However, the effects of seminal plasma in in vitro culture of fertilized embryos are unclear. Second fraction of fresh semen was obtained from a normal farm pig. The semen was centrifuged to remove sperms, and then supernatant was filtrated. The filtered seminal plasma was stored in — 30℃. In this study, electrically activated and chemically activated porcine embryos were employed to investigate the developmental rate after 2 hours treatment of none, 0.1%, 0.5%, and 1% seminal plasma in culture media by two days of activation. Both electrically and chemically activated embryos, cleavage rate and cell numbers of blastocysts were not significant difference within four groups. Blastocyst formation rate of electrically activated embryos also did not show significant difference within any groups. However 0.1% seminal plasma treatment group showed significantly increase of blastocyst formation rate in chemically activated group (None; 24.8%, 0.1%; 31.7%, 0.5%; 19.4, and 1%; 16.5%, respectively. p<0.05).
        202.
        2012.06 구독 인증기관·개인회원 무료
        Cryopreservation of canine spermatozoa affords potential exchange of genetic material, and thus may lead to improvement in the breeding management. However, canine spermatozoa undergo many damages such as, cold shock, ice crystal formation, oxidative stress during cryopreservation. In this study used the CASA for investigating the effect of various trehalose concentrations and thawing temperatures on the sperm viability. In addition, the efficacy of the most optimal of the tested cryopreservation protocols in this study was verified by AI as the in vivo test. Also, this study evaluates the variation of frozen- thawed canine spermatozoa during different incubation condition. The addition of trehalose 25 mM was optimal concentration and frozen-thawed semen quality was significantly higher better than control (Glucose) and other concentration groups. In effect of thawing temperature on frozen-thawed sperm movement and intact acrosome evaluations, which result enhance the sperm motility and movement value depending on increase temperature condition at 36, 54 and 72℃. Also, in the effect of different incubation condition on frozen-thawed sperm after thawing at 36℃ for 60 sec, that the results trehalose 25 mM was significantly better (p<0.05) than glucose in general as well as, the post-thawed sperm motility and intact acrosome was reduced depending on increase the incubation time. Especially, incubation at 4 to 8 hour was rapidly depreciation of movement value and the rate of intact acrosome was dropped similar tendency. Thus, incubation 17℃ was better than other incubation groups on sperm motility and acrosome integrity. For the in vivo evaluate of spermatozoa survival and is the most definitive test of sperm function, we performed artificial insemination in estrous bitch. The semen was prepared for intrauterine insemination using the 25 mM trehalose freezing extender and thawing at 36℃, and 2 bitches were inseminated with 1×106 motile spermatozoa by surgical method. The results of AI, the pregnancy rates, mean litter size and oocyte fertilization rate were 16.6% (1/6), and 50% (2/4), respectively. In conclusion, based on the results of these experiments, the effect of addition of trehalose on extender improves the movement and intact acrosome of frozen-thawed semen. In particular, trehalose 25 mM groups was higher than other different concentration group on movement value and acrosome integrity of frozen-thawed sperm. Also, through incubation condition, this study identify the optimal incubation temperature after thawing was 17℃. Furthermore, the information will be contributed to develop the canine ART including AI, IVF and canine ICSI. * This research was supported by iPET (Grants 110056-3), Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea.
        204.
        2012.04 구독 인증기관·개인회원 무료
        207.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate the post-thawed characteristics of leopard cat semen. In this experiment, semen was collected from two leopard cats (A and B) at wild animal center in Seoul Grand Park in Korea. After collection, the sperms were washed with D-PBS and diluted by the freezing medium (Irvine science, USA) and stored in liquid nitrogen. The post-thawed concentration was for A and for B. The viability of post-thawed sperm from A and B individual was 24.0% and 19.0%, respectively. Pre-freezing motility of A and B individual semen was 68.54% and 56.65. Leopard cat A had more normal sperm than that of B (69.5% vs. 54.5%). Acrosome integrity analysis detected live (14.5% vs. 9.0%), damage (39.0% vs. 44.0%) and dead (46.0% vs. 47.0%) in leopard cat A and B, respectively. The present results concluded that leopard cat semen can be collected successfully by electro-ejaculation method and cryopreserved successfullyfor future use in different assisted reproductive technologies. The cryopreservation protocol needs to be modified for increasing post-thawed viability of leopard cat spermatozoa.
        4,000원
        208.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbon nanotubes (CNTs) have developed into one of the most competitively researched nano-materials of this decade because of their structural uniqueness and excellent physical properties such as nanoscale one dimensionality, high aspect ratio, high mechanical strength, thermal conductivity and excellent electrical conductivity. Mass production and structure control of CNTs are key factors for a feasible CNT industry. Water and ethanol vapor enhance the catalytic activity for massive growth of vertically aligned CNTs. A shower system for gas flow improves the growth of vertically aligned single walled CNTs (SWCNTs) by controlling the gas flow direction. Delivery of gases from the top of the nanotubes enables direct and precise supply of carbon source and water vapor to the catalysts. High quality vertically aligned SWCNTs synthesized using plasma enhance the chemical vapor deposition technique on substrate with suitable metal catalyst particles. This review provides an introduction to the concept of the growth of vertically aligned SWCNTs and covers advanced topics on the controlled synthesis of vertically aligned SWCNTs.
        4,000원
        209.
        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.
        210.
        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.
        211.
        2011.10 구독 인증기관·개인회원 무료
        The necessity of conditional gene expression in pigs for transgenic models is raised. Thus, in this study, Cre-loxP conditional expression in porcine fetal fibroblasts was investigated and the transformed fibroblasts were reprogrammed in enucleated oocytes for further early embryonic development. Fetal fibroblasts from miniature pigs were used for transfection with pCALNL-DsRed including floxed neomycin resistant gene and selected with 750 ug/mL neomycin for two weeks. The transfected cells did not express DsRed under fluorescence microscope. After transient transfection of plasmid DNA expressing Cre, the fibroblasts began to express DsRed. The cells expressing Ds- Red were employed into somatic cell nuclear transfer (SCNT). A total of 121 oocytes were used for SCNT and 76 cloned embryos (62.8%)were cleaved. Six blastocysts were grown up after SCNT and expressed DsRed. Deletion of floxed neomycin resistant gene was confirmed by RT-PCR in cloned blastocysts. Taken together, this study demonstrated that Cre-loxP recombination in miniature pig fibroblasts were successfully worked and those sequential transformed cells were developed into pre-implantation stage via SCNT.
        212.
        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.
        217.
        2011.05 구독 인증기관·개인회원 무료
        The sweetpotato whitefly, Bemisia tabaci, acts as a vector of more than 100 plant viruses. B. tabaci is known to harbor a primary endosymbiont (Portiera) and 6 secondary endosymbionts (Arsenophonus, Cardinium, Fritschea, Hamiltonella, Rickettsia and Wolbachia). These endosymbionts play important roles in the acquisition and transmission of plant viruses. Using PCR analysis, we identified endosymbiotic bacteria in various B. tabaci populations collected from different places of Korea. Distribution of endosymbionts was different according to the biotype of B. tabaci. Subsequently, their relative densities of endosymbionts were compared between TYLCV-viruliferous and non-viruliferous populations of the Q biotype using quantitative realtime PCR. We found that the densities of Portiera, Cardinium and Hamiltonella are higher in viruliferous than non-viruliferous whiteflies. Our results suggest the role of endosymbiont for the TYLCV transmission of whiteflies.
        218.
        2011.05 구독 인증기관·개인회원 무료
        The sweetpotato whitefly, Bemisia tabaci, is a vector of more than 100 plantdiseased viruses as well as a serious pest to various horticultural crops. Virus acquisition affects the vector’s development and reproduction, but its mechanism is largely unknown. Here we compared the temperature responses between non-viruliferous and TYLCV-viruliferous Q biotype of B. tabaci. When both non-viruliferous and viruliferous whiteflies were exposed for 1 and 3 h at 4, 25, and 35°C, the mortality rate of viruliferous whiteflies is higher than nonviruliferous after exposure at 4°C and 35°C, but no differences at 25°C between them. Analysis of the expression levels of heat shock protein (hsp) genes using the quantitative realtime PCR showed that viruliferous whiteflies has higher expression in hsp70, and hsp90 at both 4°C and 35°C, but no differences at 25°C. The results suggest that vector insects may not be durable to unfavorable temperature conditions when they acquisite plant viruses.
        219.
        2011.05 구독 인증기관·개인회원 무료
        The green peach aphid(Myzus persicae) and sweet-potato whitefly(Bemisia tabaci) biotype Q are serious pests in hot pepper and cucumber. To optimize the formulation type of Clothianidin 1.8% granule, coated and extruded granule formulation types were tested against green peach aphid in hot pepper and sweetpotato whitefly in cucumber. Clothianidin 1.8% granules were incorporated in soil before transplant of hot pepper and cucumber. At recommend dose(540g ai/ha), the efficacy of Clothianidin 1.8% coated and extruded granules were 83.3% and 94.4% and continued until 50 days and 70 days against green peach aphid, respectively. Against sweet-potato whitefly, the efficacy of Clothianidin 1.8% coated and extruded granules were 65.7% and 96.3% at 32 days in cucumber, respectively. Clothianidin 1.8% extruded granule was safe on crops (hot pepper, cucumber, melon, cabbage etc.) at 540g ai/ha (recommend dose) and 1080g ai/ha. The results suggested that Clothianidin 1.8% extruded granule is promising as a best insecticide against green peach aphid and sweet-potato whitefly, because of the high efficacy and low phytotoxicity.
        220.
        2011.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        UBV I CCD photometry of NGC 2353 is performed as a part of the "Sejong Open cluster Survey" (SOS). Using photometric membership criteria we select probable members of the cluster. We derive the reddening and distance to the cluster, i.e., E(B - V ) = 0.10 ± 0.02 mag and 1.17 ± 0.04 kpc, respectively. We find that the projected distribution of the probable members on the sky is elliptical in shape rather than circular. The age of the cluster is estimated to be log(age)=8.1 ± 0.1 in years, older than what was found in previous studies. The minimum value of binary fraction is estimated to be about 48 ± 5 percent from a Gaussian function fit to the distribution of the distance moduli of the photometric members. Finally, we also obtain the luminosity function and the initial mass function (IMF) of the probable cluster members. The slope of the IMF is Γ = -1.3 ± 0.2.
        4,000원