• Animal Bioscience
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• v.34 no.6
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• pp.985-992
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• 2021

Objective: Artificial insemination plays an important role in genetic improvement in the goat farming system. The aim of this study was to investigate the effect of cervical application of hyaluronan (HA) on the fertility in goats after cervical artificial insemination using frozen-thawed (F-T) semen. Methods: After oestrous synchronisation with progesterone sponges and pregnant mare serum gonadotropin injection, both nulli- and multi-parous goats, were randomly allocated to 2 groups, and were inseminated with 0.25 mL of F-T semen (150×106 spermatozoa) twice at 52 h and 56 h after sponge removal. Prior to the insemination, goats in Group 1 only were given topical cervical HA application at 48 h after sponge removal. Site of insemination was recorded as os-cervix or intra-cervix or intra-uterus. Pregnancy was tested ultrasonographically 42 days after insemination. The data on pregnancy rates and percentage of animals according to the site of semen deposition were compared by Chi-square analysis. Results: The overall pregnancy rate was significantly (p<0.004) higher in goats with prior application to the cervix with HA (63.3%) than without (36.0%). Same pattern was observed in the pregnancy rates of nulli- and multi-parous goats in both the groups. Percentage of nulliparous goats according to the site of insemination in the HA group did not differ between first and the second insemination. However, in multiparous goats the percentage of animals inseminated intra-cervically was significantly increased (p≤0.05) between the first and the second inseminations. Conclusion: The results suggest that significantly higher fertility rate in the "HA goats" compared to the "without HA" group was because of deeper insemination facilitated by topical cervical application of HA. The deeper insemination into the cervical canal increase the rate of fertilisation when the cervical artificial insemination is performed.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.117-126
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• 2022

Objective: This study examined whether the addition of triple antioxidants (3A)-10 µM acetyl-L-carnitine, 10 µM N-acetyl-L-cysteine, and 5 µM α-lipoic acid-in freezing-thawing medium during human sperm cryopreservation using the sucrose vitrification (SuV) and liquid nitrogen vapor (Vapor) techniques could improve post-thaw survival of spermatozoa. Methods: We analyzed 30 samples from healthy human sperm donors. Each sample was allocated into one of five groups: fresh control, SuV, SuV+3A, Vapor, and Vapor+3A. The sperm motility, morphology, viability, intracellular and extracellular reactive oxygen species (ROS) levels, and sperm DNA fragmentation (SDF) were evaluated. Results: The cryopreserved spermatozoa had significantly reduced percentages of motility (p<0.05) and viability (p<0.05). Antioxidant supplementation non-significantly improved these parameters (p>0.05). No significant differences were found in sperm morphology between the fresh and frozen-thawed groups (p>0.05). After freezing, the extracellular ROS levels in the frozen-thawed groups were significantly higher (p<0.05) than in the fresh group. However, we did not find any differences in intracellular ROS parameters among these groups (p>0.05). The SDF was higher in the SuV and Vapor groups than in the fresh group, but without statistical significance (p=0.075 and p=0.077, respectively). Conclusion: Cryopreservation had detrimental effects on sperm motility, viability, and extracellular ROS levels, without changing the morphology or intracellular ROS levels. Antioxidant supplementation was slightly effective in preventing SDF in frozen-thawed spermatozoa.

• Journal of the Korean GEO-environmental Society
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• v.25 no.7
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• pp.21-27
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• 2024

Frost heave, a significant engineering aspect of frozen ground, leads to various damages in Korea during the winter. Both the United States and Japan, encompassing regions with frozen ground, have actively researched frost heave and possess standardized experimental methods. Particularly, the Japanese Geotechnical Society (JGS) has introduced a frost heave standard testing method, offering the advantage of relatively simple specimen preparation and experimental procedures. However, issues persist regarding the ambiguous engineering interpretation of frost heave test results and the lack of clear criteria for frost heave susceptibility assessment. This paper presents laboratory testing results following the JGS testing method on sand and silt mixtures using a triaxial temperature-controllable cell, and thoroughly analyzes the frost heave rate calculation process. Furthermore, it evaluates the applicability of frost heave susceptibility criteria proposed in the United States to frost heave rates based on the JGS testing method.

• Geomechanics and Engineering
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• v.34 no.5
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• pp.507-527
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• 2023

Accurately estimation of the geo-mechanical parameters in Artificial Ground Freezing (AGF) is a most important scientific topic in soil improvement and geotechnical engineering. In order for this, one way is using classical and conventional constitutive models based on different theories like critical state theory, Hooke's law, and so on, which are time-consuming, costly, and troublous. The others are the application of artificial intelligence (AI) techniques to predict considered parameters and behaviors accurately. This study presents a comprehensive data-mining-based model for predicting the Young's Modulus of frozen sand under the triaxial test. For this aim, several single and hybrid models were considered including additive regression, bagging, M5-Rules, M5P, random forests (RF), support vector regression (SVR), locally weighted linear (LWL), gaussian process regression (GPR), and multi-layered perceptron neural network (MLP). In the present study, cell pressure, strain rate, temperature, time, and strain were considered as the input variables, where the Young's Modulus was recognized as target. The results showed that all selected single and hybrid predicting models have acceptable agreement with measured experimental results. Especially, hybrid Additive Regression-Gaussian Process Regression and Bagging-Gaussian Process Regression have the best accuracy based on Model performance assessment criteria.

• Clinical and Experimental Reproductive Medicine
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• v.16 no.1
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• pp.9-14
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• 1989

For the cryopreservation of human embryos this study was accomplished as a preliminary experiment. The purpose of this study is to obtain optimal cryoprotectant, addition and dilution method of cryoprotectant and cooling rate for raising survival of frozon and thawed 2-cell mouse embryos. Seeding was done at $-7^{\circ}C$ and the straw contained embryos was plunged at $-30^{\circ}C$ when the slow cooling was ended. Embryos those developed normally to blastocyst after in vitro culture for over 96 hours were regarded as survival ones. The survival was the rate of number of survival embryos against the recovered embryos. The results are followed : 1. The survivals were 6.3, 71.2 and 67.4% respectively, when Glycerol, DMSO and 1,2-Propanediol were used as cryoprotectant. 2. When sucrose was added in freezing solution, the survival was 69.0%. That was higher than the survival of embryos frozen without sucrose in freezing solution. The difference was not significant. 3. Addition and dilution of cryoprotectant by 4 stepwise raised the survival than by direct, but that was not significant. 4. When embryos were frozen by -0.3, -0.5 and $-1^{\circ}C/min$ before plunged into $LN_2$, the survivals were 67.9, 78.0 and 37.0% respectively. The differnce was significant.

• Korean Journal of Animal Reproduction
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• v.14 no.1
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• pp.50-56
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• 1990

Bovine oocytes obtained from follicles(2~5mm) of ovaries after slaughter were cultured in TCM 199 medium with 10~20% heat-inactivated estrus cow serum(ECS) for 25~27 hr, at 39$^{\circ}C$ under 5% CO2 in air. At the end of culture period, some oocytes were stained with 1% acetoorcein and examined for the evidence of oocyte maturation. The remainder were used to assess the potential of in vitro fertilization(IVF) with frozen-thawed spermatozoa and subsequent development in media with or without bovine oviduct epithelial cell (BOEC) co-culture. The results obtained were summarized as follows ; 1. The maturation rate of oocyte in vitro in TCM 199 medium with 15% ECS group(76.3) was superior to 10% ECS group(68.3%) and 20% ECS group(64.5%). 2. The IVF rates of oocytes matured in vitro, and formation rate of male and female pronuclei were 63.6%(77/121) and 93.5%(72/77), respectively. The incidence of polyspermy was very low(2.4%). 3. Of 73 oocytes fertilized in vitro and cultured in TCM 199 medium with 10% fetal calf serum for 7 days, 41(56.3%) were cleaved over 2-cell and only 1(2.4%) was developed beyond the 16-cell stage. 4. Of 76 oocytes co-cultured with BOEC, 58(76.3%) were cleavaged and 23(39.7%) were developed to morula and blastocyst stage. The results of this study indicate that co-culture with BOEC deserved a positive effect on the IVF oocyte development through the 16-cell block.

• Journal of Embryo Transfer
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• v.6 no.1
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• pp.25-32
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• 1991

The present study was performed to investigate the effects of co-culture with granulosa cells on in vitro fertilization and cleavage of early bovine embryo development. Bovine oocytes were matured for 20-24 hrs in vitro with granulosa cells or without and then fertilized in vitro using frozen-thawed spermatozoa treated with BO-caffeine, BO-BSA(2OmM heparin added). At l8hrs after insemination, oocytes were fixed and examined or further cultured in TCM 199 for 48hrs. The fertilization rates between the control(70.4%) and the groups of co-cultured with granulosa cell(2.5$\times$106 cells/ml; 71.6%, 5.0$\times$ 106/ml; 71.9%, l.0$\times$ 107/ml; 71.1%) did not differ significantly. The cleavage rates in the groups co-cultured with granulosa cell(2.5$\times$ 106 cells/mi; 43.6%, 5.0$\times$ 106/ml; 46.8%. l.0$\times$ 107/ml; 45.0%)were significantly higher than that of without granulosa cell, respectively(P<0.05). However there were no significant differences between the groups co-cultured with granulosa cells. The result indicated that co-culture with granulosa cell was effective means to cleavage of bovine follicular oocytes but did not affect the in vitro fertilization.

• Journal of agriculture & life science
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• v.46 no.2
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• pp.115-127
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• 2012

Antioxidant and neuronal cell protective effects of aqueous extract from lotus (Nelumbo nucifera) leaf tea (LLTE) were investigated. The 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging effect, ferric reducing antioxidant power, and malondialdehyde inhibition of LLTE were increased in a dose dependent manner. Intracellular reactive oxygen species accumulation resulting from hydrogen peroxide ($H_2O_2$) treatment was significantly reduced when LLTE were present in the media compared to PC12 cells treated with $H_2O_2$ only. In neuronal cell viability assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT), LLTE showed protective effect against $H_2O_2$-induced neurotoxicity. In addition, lactate dehydrogenase release into medium was also inhibited by LLTE (7.13-43.89%). Total phenolics of LLTE were 33.16 mg/g and a quercetin was identified as major phenolics (105.93 mg/100g). Therefore, above these data suggest that LLTE including quercetin may be useful in the natural antioxidant substance, and may reduce the risk of neurodegenerative disease.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.2
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• pp.133-147
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• 2005

Objectives: This study was carried out to establish human embryonic stem cells derived from frozen-thawed embryos using mouse embryonic fibroblasts (mEFs), human fetal skin and muscle fibroblasts as feeder cells, and to identify the characteristic of embryonic stem cells. Methods: When primary mEFs, human fetal skin and muscle fibroblasts were prepared, passaging on 4 days from replating could have effective trypsinization and clear feeder layers. Eight of 23 frozenthawed 4~8 cell stage embryos donated from consenting couples developed to blastocysts. Inner cell mass (ICM) was isolated by immunosurgery. ICM was co-cultured on mEFs, human fetal skin or muscle fibroblasts. The ICM colonies grown on mEFs, human fetal skin or muscle fibroblasts were tested the expression of stage specific embryonic antigen-3, -4 (SSEA-3, -4), octamer binding transcription factor-4 mRNA (Oct-4) and alkaline phosphatase surface marker. Results: We obtained 1 ICM colony from 2 ICM co-cultured on mEFs as feeder cells and did not obtain any ICM colony from 6 ICM clumps co-cultured on human fetal skin or muscle fibroblasts. The colony formed on mEFs could be passaged 30 times every 5 days with sustaining undifferentiated colony appearance. When the colonies cultured on mEFs were grown on human fetal skin or muscle fibroblasts, the colonies could be passaged 15 times every 9 days with sustaining undifferentiated colony appearance. The colonies grown on mEFs and human fetal fibroblasts expressed SSEA-4 and alkaline phosphatase surface markers and positive for the expression of Oct-4 by reverse transcription-polymerase chain reaction (RT-PCR). The produced embryoid body differentiated spontaneously to neural progenitorlike cells, neuron-like cells and beating cardiomyocyte-like cells, and frozen-thawed embryonic stem cells displayed normal 46,XX karyotype. Conclusions: The human embryonic stem cells can be established by using mEFs and human fetal fibroblasts produced in laboratory as feeder cells.

• Archives of Craniofacial Surgery
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• v.16 no.2
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• pp.92-95
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• 2015

A keratoacanthoma is a rapidly growing cutaneous tumor that spontaneously involutes in most instances. A giant keratoacanthoma is a rare variant and are characterized by lesions larger than 20 mm in diameter. We report a 56-year-old man with a rapidly growing tumor of the right cheek, which was diagnosed as keratoacanthoma. The mass was excised completely under general anesthesia, followed by Limberg flap for reconstruction. Intraoperative frozen section histology suggested the lesion to be a well-differentiated squamous cell carcinoma, whereas final histopathology was consistent with keratoacanthoma. We herein report the first case of a giant keratoacanthoma treated with surgical excision in Korea and discuss the clinical and histopathological features of keratoacanthoma, with a review of the literature.