• Clinical and Experimental Reproductive Medicine
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• v.46 no.2
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• pp.67-75
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• 2019

Objective: Sperm cryopreservation has been widely used in assisted reproductive technology, as it offers great potential for the treatment of some types of male infertility. However, cryopreservation may result in changes in membrane lipid composition and acrosome status, as well as reductions in sperm motility and viability. This study aimed to evaluate sperm DNA fragmentation damage caused by conventional freezing using the sperm chromatin dispersion test. Methods: In total, 120 fresh human semen samples were frozen by conventional methods, using SpermFreeze Solution as a cryoprotectant. Routine semen analysis and a Halosperm test (using the Halosperm kit) were performed on each sample before freezing and after thawing. Semen parameters and sperm DNA fragmentation were compared between these groups. Results: There was a significant decrease in sperm progressive motility, viability, and normal morphology after conventional freezing (32.78%, 79.58%, and 3.87% vs. 16%, 55.99%, and 2.55%, respectively). The sperm head, midpiece, and tail defect rate increased slightly after freezing. Furthermore, the DNA fragmentation index (DFI) was significantly higher after thawing than before freezing (19.21% prior to freezing vs. 22.23% after thawing). Significant increases in the DFI after cryopreservation were observed in samples with both normal and abnormal motility and morphology, as well as in those with normal viability. Conclusion: Conventional freezing seems to damage some sperm parameters, in particular causing a reduction in sperm DNA integrity.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.3
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• pp.343-349
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• 2009

This study was designed to simplify a cryopreservation program for embryonic stem cells (ESCs) by selection of cooling method and cryoprotectant. Commercially available mouse E14 embryonic stem cells (ESCs) were cryopreserved with various protocols, and morphology and viability of the frozen-thawed ESCs and their reactive oxygen species (ROS) production were subsequently monitored. Post-thaw colony-formation of ESCs was detected only after a slow freezing using dimethyl sulfoxide (DMSO) by stepwise placement of a freezing container into a $-80^{\circ}C$ deep freezer and subsequently into -$196^{\circ}C$ liquid nitrogen, while no proliferation was detected after vitrification. When the simplified protocol was employed, the replacement of DMSO with a mixture of DMSO and ethylene glycol (EG) further improved the post-thaw survival. ROS generation in ESCs frozen-thawed with the optimized protocol was not increased compared with non-frozen ESCs. The use of fresh mouse embryonic fibroblasts as feeder cells for post-thaw subculture did not further increase post-thaw cell viability. In conclusion, a simplified slow-freezing program without employing programmable freezer but using DMSO and EG was developed which maintains cell viability and colony-forming activity of ESCs during post-thaw subculture.

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.203-208
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• 1995

This study was carried out to efficiently use the ultrarapid freezing method in the cryopreservation of mouse ova. For this, the effects of dehydration method, oval vigour and $0^{\circ}C$ controlling method on post-thawing viability were investigated. Fresh mouse ova were dehydrated in mPBS with 3.5M DMSO and /or 0.25M sucrose, and directly immersed in L$N_2$ for ultrarapidly freezing. The frozen ova were thawed at 37$^{\circ}C$, rehydrated in mPBS with 0.25M sucrose, and then repeatedly washed in HAM's Fl0 before evaluating the morphological normality of frozen-thawed ova. The results obtained showed that there was difference between treatments in a experiment. 1) The post-thawing viability of ova dehydrated in multi-step (48.4$\pm$13.8%) was higher than that of ova in two-step (40.9$\pm$14.0%). 2) The post-thawing viability of fertilized ova (87$\pm$14.0%) was significantly(p<0.0l) higher than that of unfertilized ova (5.4$\pm$5.4%). 3) The post-thawing viability of ova dehydrated and rehydrated using a cooling machine (95.8$\pm$4.2%) was significantly(p<0.05) higher than that on ice(84.1$\pm$9.9). In conclusion, in order to efficiently cryopreserve ova in vitro with ultrarapidly freezing method, highly viable embryos should be selected, heavy osmotic shock to the dehydrating ova should be avoided, and embryos in high osmotic condition were dehydrated and rehydrated in a constantly low temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.3_4
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• pp.101-111
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• 1973

To study the effect of freezing rate on the duality of frozen abalone(Haliotis gigantea, GMELIN) liquid nitrogen spray freezing, air blast freezing, semi-air blast freezing, and still air freezing were carried out. The rheological change, protein denaturation, and free water content of frozen and thawed abalone were examined at the period of 0, 1, 2, and 3 month during cold Storage at $-20^{\circ}C$. The results are summarized as follows : 1. The onset and duration of rigor mortis of fresh abalone was faster and shorter as compared to that of fishes. 2. There was no difference in compression value and shear value between freezing methods but they varied with a slight decrease in storage period. 3. Gradual decrease in extractibility of salt soluble protein was observed in all samples except those frozen with liquid nitrogen. 4. The free water of the foot muscle remained constant during the storage while that of the adductor muscle tended to increase. 5. A significant correlation was observed among the changes of panel texture and free water (P< 0.01), protein denaturation (P<0.05), and compression value (P<0.01).

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.221-224
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• 2004

Several factors of concrete durability decline factor are acted as complex deterioration and is happened not that happen by simplicity deterioration. Specially, in case of sea construction, as complex salt damage, carbonation and freezing & thawing, concrete surface and pore structure is deteriorated. Therefore, analyzing concrete carbonation and pore structure after freezing and thawing test by fresh water and sea water in this research, we wish to study about acceleration of decline of durability and complex deterioration by concrete surface deterioration in sea environment.

• Korean Journal of Agricultural Science
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• v.33 no.2
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• pp.129-140
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• 2006

There are need to develop of merchandise of value added fresh ginseng because of high consciousness level of consumer and enlarge of markets for high quality products. The fresh ginseng after harvest was distributed to farmer partually but in general, it was to market by consigner or wholsaler directly after harvest. There were a high difference on storage period of fresh ginseng in different harvesting seasons. The reduction of value of commodities of fresh ginseng for storage period was caused by decomposition and tender of tissue. The storage temperature was under the freezing point and the packing method was sealing tightly by plastic film. As the quality of fresh ginseng was defined by naked eye, it was difficult to sort the quality of ginseng directly harvest.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.527-532
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• 2003

When fresh concrete is exposed to sufficiently low temperature, the free water in the concrete is cooled below its freezing point and transforms into ice, which causes decrease in compressive strength of concrete. Of the many influencing factors on the loss of compressive strength, the age of concrete at the beginning of freezing, water-cement ratio, and cement-type are significantly important. The objective of this study is to examine how the these factors affect the compressive strength of concrete frozen at early ages. The results from the tests showed that as age at the beginning of freezing is delayed and water-cement ratio is low, the loss of compressive strength decreases. In addition, concrete made with high-early-strength cement is less susceptible to frost damage than concrete made with ordinary portland cement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.32-33
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• 2013

This study was a result of laboratory test to confirm the porperties of concrete containing the domestic artificial lightweight aggregate. The domestic artificial lightweight aggregate is made with bottom ash which waste material in the thermal power plant. In the experimental result air contents of fresh concrete was measured lower than other artificial lightweight aggregate. This air contents is important for retaining the resistance of freezing and thawing. Therefore air contents of concrete will be considered for retaining the resistance of freezing and thawing when manufacture the concrete containing the domestic artificial aggregate.

• 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.

• Food Science of Animal Resources
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• v.24 no.2
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• pp.151-155
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• 2004

This study was performed to develop the method of differentiation fresh and frozen meat by using the measurement of mitochondrial malate dehydrogenase. The principle of this experiment is based on the fact the enzyme proteins associated with mitochondria membrane could be released by freezing. The methods were studied by measurements of protein concentration of meat press juice, WHC (water-holding capacity), drip loss and mitochondrial malate dehydrogenase enzyme activity. Samples were stored at 4$^{\circ}C$ and -18$^{\circ}C$ during storage period, respectively. Protein concentration of meat press juice was ranged from 8.5 mg/mL to 12.7 mg/mL and increased by freezing below at -18$^{\circ}C$(p<0.05). The WHC was not significantly different between fresh meat and frozen chicken meat (p＞0.05). The amount of drip loss of fresh and frozen chicken meat at 4$^{\circ}C$ and -18$^{\circ}C$ was not significantly different (p＞0.05). Mitochondrial malate dehydrogenase activity of frozen meat (-18$^{\circ}C$) was significantly higher (p＜0.05) than that of fresh meat. Also, enzyme activity of frozen meat was maintained at the same level after 3 minutes reaction. But fresh meat had not this reaction. From these results, it suggests that mitochondrial malate dehydrogenase can be used as a promising enzyme to differentiate between fresh and frozen meat.