• Korean Journal of Veterinary Service
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• v.26 no.4
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• pp.329-337
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• 2003

The functional role of the cumulus cells on sperm penetration and polyspermy during in vitro fertilization was examined. The penetration rate was significantly higher(p<0.01) in oocytes with(61%) than without(25%) cumulus cells. No significant differences, however, was observed in polyspermy. When the hyaluronidase was supplemented to the fertilization medium with different concentrations, penetration rates in oocytes with cumulus cells were higher than oocytes without cumulus cells at 0(61 vs 34% ; p<0.05), 0.01(56 vs 35% ; p<0.05), 0.1(66 vs 30% ; p<0.05) and 1.0 mg/$m\ell$(39 vs 27%). On the other hand, the polyspermy rates were lower oocytes without than with cumulus cells, and had a tendency to decrease with high concentrations of hyaluronidase. In another experiment, the penetration and polyspermy rates had a tendency to increase as time of sperm-oocytes culture was prolonged. At 16 and 20hrs after insemination, the penetration rates were significantly higher(p<0.05) in oocytes with(48 and 62% for 16 and 20hrs) than without(25 and 31% for 16 and 20hrs) cumulus cells in medium with hyaluronidase. However, the polyspermy rates were significantly(p<0.05) lower in oocytes without(3 and 16%) than with(37 and 48%) cumulus cells at 16 and 20hrs after insemination. In cumulus-free oocytes inseminated in medium with or without hyaluronidase at different concentrations of cumulus cells, the penetration rates were significantly(p<0.05) higher in medium with than without hyaluronidase at different concentrations of cumulus cells. The proportions of polyspermy were lower in medium without than with hyaluronidase at 0 (10 vs 0%), 10$^2$(25 vs 0%), 10$^4$(24 vs 14%) and 10$\^$6/(29 vs 10% ; p<0.05) cumulus cells/ml. These results suggest the advantage of culture in medium with cumulus cells and denuded oocytes to inhibit polyspermy with no decrease in the penetration rates during the fertilization in vitro in the porcine.

• Journal of the Korean Geotechnical Society
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• v.23 no.12
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• pp.53-60
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• 2007

A program for predicting rate of penetration of sheet pile using cone penetration test results was developed. Especially, energy consumption occurring from lateral vibration of sheet pile was estimated quantitatively in order to overcome overprediction of rate of penetration for shallow depths of pile installation. Penetration rates of pile calculated from developed program were compared with those of field test. Predicted rates of pile penetration for the depths to 12m were $47%{\sim}120%$ of the measured values. As pile penetration depth decreases, the difference between the predicted rate of penetration and the measured rate of penetration decreases.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4022-4029
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• 2022

We investigated the possibility of using graphene for control of hydrogen isotopes by exploring adsorption, reflection, and penetration of hydrogen isotopes on graphene using molecular dynamics. Reflection is the dominant interaction when hydrogen isotopes have low incident energy. Adsorption rates increase with increasing incident energy until 5 eV is reached. After 5 eV, adsorption rates decrease as incident energy increases. At incident energies greater than 5 eV, adsorption rates increase with the number of graphene layers. At low incident energies (<1 eV), no isotopic effects on interactions are observed since the predominant interaction is derived from the force of π electrons. Between 1 eV and 50 eV, heavier isotopes exhibit higher adsorption rates and lower reflection rates than lighter isotopes, due to the greater momentum of heavier isotopes. Adsorption rates are consistently higher when the incident angle of the impacting atoms is smaller between 0.5 eV and 5 eV. At higher energies (>5 eV), larger incident angles lead to higher reflection and lower penetration rates. At high incident energies (>5 eV), crumpled graphene has higher adsorption and lower penetration rates than wrinkled or unwrinkled graphene. The results obtained in this research study will be used to develop novel nanomaterials that can be employed for tritium control.

• Tunnel and Underground Space
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• v.12 no.2
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• pp.115-119
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• 2002

Four tunnels have been planned to operate a large diameter shielded TBM in Gwangju urban subway construction site. No.1 tunnel has completely been excavated for 13 months operating. Net penetration rate and its relations with thrust farce of the shielded TBM are analysis in this report. This shallow depth tunnel of 536m length is located in soil layers at launching and in hard rocks at ending with 84 m length. The weekly net penetration rates haute dropped down as low as 20∼110 mm/hr in rock while 400∼800 mm/hr in soil. The actual penetration rates we proved to be high as the theoretical penetration rate which is analysis in consideration of conditions of machine and rock. And net penetration rate is investigated to increase linearly thrust force.

• Korean Journal of Animal Reproduction
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• v.9 no.2
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• pp.153-157
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• 1985

Ejaculated and epidiymal goat spermatozoa were preserved for 0, 6, 12 adn 18 h, and 0 and 18 h in a semi-aerobic condition at 20-$25^{\circ}C$, and preincubated for 5-6 h in a CO2 incubator in m-KRB solution. Then they were preincubated at different concentrations (3-5, 25-48 and 105-190$\times$107/ml), and ability of penetration into zona-free hamster eggs in vitro was examined. When ejaculated spermatozoa were preincubated in m-KRB solution after presservation for 12 and 18 h, 12 and 29% of zona-free eggs were penetrated, and only 4% of eggs were penetrated by epididymal spermatozoa which were preincubated after preservation for 18 h. When spermatozoa were preincubated at a low concentration, the penetration rates were very low. But when the sperm concentration during preincubation was 25-48 and 105-190$\times$107/ml, the penetration rates increased to about 30%.

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.237-242
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• 1995

Porcine follicular oocytes matured in culture were inseminated with frozen-thawed spermatozoa. When the oocytes were inseminated in the medium with oviductal epithelial cell monolayer, the penetration rates higher in those with (4.1, 31.7, 45.1, 54.5 and 69.4%) than without cells (0, 17.1, 34.8, 45.2 and 58.9%) at 4, 8, 12, 16 and 20 h after insemination. The proportions of polyspermy in penetrated oocytes in medium with or without cells increased with time of examine. In another experiment, the penetration rate was higher without (57.6%) than with (19.6~24.1%) preincubation of spermatozoa for 1~4 h in medium. However, when the oocytes were inseminated with spermatozoa preincubated for 1~2 h, the penetration rates significantly higher (P<0.05) in those with (65.6 and 55.9% for 1 and 2 h) than without (24.1 and 20.6% for 1 and 2 h) oviductal epithelial cell monolayer. On the other hand, the proportions of polyspermy decreased with time of spermatozoa preincubation. These results indicate the significant advantages of the spermatozoa preincubation with oviductal epithelial cell monolayer for 1 and 2 h to maintain penetration potential during in vitro fertilization in the porcine.

• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.63-69
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• 1996

Bovine immature oocytes cultured for various times in TC-199 medium were inseminated with frozne-thawed spermatozoa in TC-199 medium supplemented with caffeine(5mM) and heparin(10$\mu\textrm{g}$/ml). Sperm penetraton was possible in oocytes at any stage of maturation, but penetration rates were lower in oocytes inseminated 0~16h (60~76%) than 20h (98%) after culture. Formation of male and female pronuclei were first observed in oocytes inseminated 8h after cultrue. Formation of male and female pronuclei were first observed in oocytes inseminated 8h after culture. The proportions of polyspermy were high(50~76%) in oocytes inseminated at any stage of maturation. Sperm penetration into oocytes at the GV stage started at 8h after insemination and the penetration rates gradually increased as time after insemination proceeds. The proportion(35%) of oocytes matured beyond metaphase-II 20h after sperm-oocytes incubation was low. When oocytes were incubated without spermatozoa in TC-199 medium, maturation rates were significantly higher (P<0.001) in those without(45 and 84% for 16 and 20 h) than with (0 and 36% for 16 and 20 h) caffeine and heparin. These results indicate that TC-199 medium with caffeine and heparin is not suitable for maturation and fertilization of immature oocytes and may inhibit male pronuclear formation in the cytoplasm.

• Reproductive and Developmental Biology
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• v.34 no.1
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• pp.21-25
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• 2010

The purpose of this study was to investigate the effects of the collection time, co-culture and sperm penetration of canine oocytes on in vitro maturation and fertilization. The oocytes were cultured in TCM-199 media containing hormonal supplements (10% FCS, 10 IU/ml HCG, 10 IU/ml PMSG) at 5% $CO_2$, 95% air, $38^{\circ}C$. The in vitro maturation rate to MII stage of in vitro oocytes recovered from ovaries that collected at follicular, luteal and inactive phases of the reproductive phase for 44~72 hrs were 19.2%, 12.2%, and 6.0%, respectively. Follicular phases oocytes had a significantly higher in vitro maturation rate than oocytes collected at luteal and anestrus stage (p<0.05). The in vitro maturation rates to the MII stage of canine oocytes after 48 hrs of culture with glutathione, pyruvate, or glutathione + pyruvate were 12.5%, 10.7%, and 17.5%, respectively. This was higher than that in both alone or the combination of the two compared to the control group (19.0%). The sperm penetration rates of in vitro matured oocytes by fresh and frozen semen were 29/80 (36.3%) and 18/80 (22.5%), respectively. Although there are limited reports about canine oocytes co-culture and in vitro fertilization, our results on in vitro maturation is comparable to the results from other researches.

• Journal of Embryo Transfer
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• v.14 no.1
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• pp.9-15
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• 1999

This study was conducted to investigate the effect of $\alpha$-tocopherol and cysteamine with Whitten's medium in supporting the development on in vitro maturation(IVM), in vitro fertilization (IVF) and in culture(IVC) on porcine oocytes. When the immature oocytes were cultured of $\alpha$-tocopherol for 40h, the nuclear maturation rates were 39, 4, 52.5 and 54.1%, respectivley. The nuclear maturation rates of treat groups were signficantly (P<0.05) higher than those of non-treat groups. After matureation, the oocytes were inseminated in vitro in medium 199 with ejaculated spermatoza for examination of sperm penetration, polyspermy, male pronuclear(MPN) formation, and cleavage rate. Sperm penetration rates of treat higher than the control groups(P<0.05), and MPN formation rates were significantly(P<0.05) higher on treated groups (24.3~53.1%) than control groups(14.2~21.4%). After insemination, the cleavage rates at 120hr were groups higher than control groups(P<0.05).

• The Plant Pathology Journal
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• v.33 no.1
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• pp.66-74
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• 2017

This study was conducted to examine infectivity (penetration and gall and egg-mass formations) of the root-knot nematodes, Meloidogyne incognita and M. hapla, on carrots grown in soil conditions of 5 different soil textures consisting of bed-soil (b) and sand (s) mixtures (b-s mixtures) at the ratios of 10:0, 7:3, 5:5, 3:7, and 0:10. For M. incognita, the nematode penetration rates in b-s of 0:10 (100% sand) were significantly higher than in the other b-s mixtures, more greatly at 2 and 5 days after inoculation than at 10 DAI, while no significant differences in the penetration rates were mostly shown for M. hapla at the above DAI. However, for both nematodes, gall and egg-mass formations were remarkably increased in the b-s mixture of 0:10, compared to the other b-s mixtures, which is coincided with the general aspects of severe nematode infestations in sandy soils. This suggests the increased gall and egg-mass formations of M. incognita should be derived from the increased penetration rates in the sandy soil conditions, which provide a sufficient aeration due to coarse soil nature for the nematodes, leading to their mobility increased for the enhanced root penetration. For M. hapla, it is suggested that the sandy soil conditions affect positively on the healthy plant growth with little accumulation of the inhibitory materials and sufficient aeration, enhancing the nematode growth and feeding activities. All of these aspects provide information reliable for the development screening techniques efficient for the evaluation of the nematode resistance in the breeding programs.