• Korean Journal of Agricultural Science
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• v.47 no.3
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• pp.657-665
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• 2020

The objective of this study was to investigate whether supplementation of pentoxifylline (PTX; phosphodiesterase inhibitor) to thawed boar semen improves the post-thaw motility of sperm and affects the efficiency of artificial insemination (AI) and further development. To determine the concentration of PTX for AI, frozen-thawed semen was incubated with 0, 5, 10, and 20 mM PTX in an extender freezing medium, respectively, after thawing. Kinematic properties of sperm were examined with a computer-assisted semen analysis (CASA) system. In addition, viability and mitochondrial activity were also tested by LIVE/DEAD and a MitoTracker kit. There were no significant differences in the kinetic parameters of thawed sperm between control and treatment groups, but overall assessment parameters such as motility and rapid progressive were higher in the 10 mM PTX group. In the viability and mitochondrial assay, there were no significant differences observed in the PTX treatment, compared to the control. For further analysis, artificial inseminations were performed using frozen semen and 10 mM PTX treated cryopreserved semen, respectively. There were no differences in pregnancy rates and fetus weights among the groups until 30 and 40 days, but litter size was reduced and relatively low-birth weight was observed in the PTX group. In summary, our findings suggest that enhancement of in vitro sperm quality or non-toxicity supplemented by PTX may have detrimental effects on fetus development.

• Geomechanics and Engineering
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• v.36 no.2
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• pp.145-156
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• 2024

The mechanical properties of the concrete-frozen soil interface play a significant role in the stability and service performance of construction projects in cold regions. Current research mainly focuses on the precast concrete-frozen soil interface, with limited consideration for the more realistic cast-in-place concrete-frozen soil interface. The two construction methods result in completely different contact surface morphologies and exhibit significant differences in mechanical properties. Therefore, this study selects silty clay as the research object and conducts direct shear tests on the concrete-frozen soil interface under conditions of initial water content ranging from 12% to 24%, normal stress from 50 kPa to 300 kPa, and freezing temperature of -3℃. The results indicate that (1) both interface shear stress-displacement curves can be divided into three stages: rapid growth of shear stress, softening of shear stress after peak, and residual stability; (2) the peak strength of both interfaces increases initially and then decreases with an increase in water content, while residual strength is relatively less affected by water content; (3) peak strength and residual strength are linearly positively correlated with normal stress, and the strength of ice bonding is less affected by normal stress; (4) the mechanical properties of the cast-in-place concrete-frozen soil interface are significantly better than those of the precast concrete-frozen soil interface. However, when the water content is high, the former's mechanical performance deteriorates much more than the latter, leading to severe strength loss. Therefore, in practical engineering, cast-in-place concrete construction is preferred in cases of higher negative temperatures and lower water content, while precast concrete construction is considered in cases of lower negative temperatures and higher water content. This study provides reference for the construction of frozen soil-structure interface in cold regions and basic data support for improving the stability and service performance of cold region engineering.

• Journal of Food Hygiene and Safety
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• v.24 no.3
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• pp.217-225
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• 2009

The study was conducted to evaluate the effect of drying, curing and freezing on the quality of beef. Three types of dried (without salt = $T_1$, with salt = $T_2$ and salt + spices = $T_3$); three types of cured (salt curing = $T_4$, sugar curing = $T_5$ and brine curing = $T_6$) and three types of frozen beef ($0^{\circ}C=T_7^{\circ}C$, $-10^{\circ}C=T_8$ and $-20^{\circ}C=T_9$) were analyzed at different time intervals up to the period of 180 d. Parameters studied were protein, fat, ash, color and cooking loss of beef. All the chemical constituents (protein, fat and ash) were decreased gradually up to 120 d. The decreasing trend was observed rapid after 120 d up to 180 d of preservation. Highest protein loss was found in $T_7$ (11.1 %) and the lowest protein loss was found in $T_6$ (3.85%) in 180 d preservation and significant (p < 0.01) differences were observed among the different preservation methods. Highest fat loss was observed in $T_6$ (7.62%) and the lowest fat loss was observed in $T_2$ (3.18%) and the differences were also significant (p < 0.05) among different methods during the experimental period. Spices dried beef showed a brighter color than others and cured beef showed brown color and the intensity of color was reduced gradually with the increasing of storage period. $T_9$ showed the lowest cooking loss among 3 treatments of frozen beef and the differences also significant (p < 0.01) up to 180 d. It might be stated that sugar curing ($T_5$) and spices drying ($T_3$) would be the useful technique of meat preservation in rural areas and freezing ($T_9$) would be used in large scale preservation at urban areas.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.229-234
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• 2002

This study was carried out to investigate the general characteristics such as concentration sperm motility and abnormality of sperm on the whole epididymal semen(EWS), RSP-S(removed seminal plasma by saline) and RSP-T(removed seminal plasma by tris-buffer) semen and survival rates after freezing on motility of whole and RSP-S and RSP-T semen and extender containing 2~8% glycerol, and ability of frozen-thawed sperm to penetrate homologous oocytes. 1. The concentration, motility and abnormality of epididymal WES, RSP-S and RSP-T sperm were 4.25 $\pm$ 0.25($\times$10$^{6}$ Cells/$m\ell$), 3.85$\pm$0.20($\times$10$^{6}$ Cells/$m\ell$), 4.05 $\pm$ 0.28($\times$10$^{6}$ Cells/$m\ell$), 50.55 $\pm$ 2.75%, 67.25 $\pm$ 2.55%, 78.75 $\pm$ 3.55 and 9.45 $\pm$ 2.25%, 37.75 $\pm$ 2.10%, 24.25 $\pm$ 1.55%, respectively. 2. The survival rates of slow and rapid frozen epididymal RSP-S and RSP-T sperm were 35.00 $\pm$ 2.35%, 45.50 $\pm$ 2.15％ and 16.50 $\pm$ 3.55%, 22.55 $\pm$ 3.95%, respectively. The survival rate of epididymal WES and RSP-T sperm after freezing following dilution with tris-buffer containing 2~8% glycerol were 9.25 $\pm$ 1.55%~17.50 $\pm$ 2.50%. 3. The percentage of capacitated and acrosome-reacted sperm prier to culture for fresh and frozen -thawed epididymal RSP-T semen were 45.25 $\pm$ 5.75%, 7.06 $\pm$ 0.25%, 48.20 $\pm$ 6.80% and 13.00 $\pm$ 2.35%, 3.55 $\pm$ 0.85%, 15.50 $\pm$ 1.90%, respectively. The penetration rate the number of sperm per penetrated for fresh and frozen-thawed epididymal RSP-T sperm were 39.25 $\pm$ 4.72%, 34.24 $\pm$ 3.93% and 1.30 $\pm$ 0.33, 1.10 $\pm$ 0.50., respectively.

• Applied Microscopy
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• v.39 no.1
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• pp.65-72
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• 2009

Cryo-SEM which enables specimens to be observed in frozen form has been used to study liquid specimens in their native states. Cryo-methods, sample preparation for cryo-SEM, are quite complex and involve several discrete but vitally interconnected steps which are rapid cooling, fracturing, sectioning, etching and coating. It is important to select practical techniques and to optimize conditions of each steps considering analytic purpose and specimen characters, viz., sample dimension, water contents. In this study, etching methods and sample preparation before freezing had been studied for observation of cyanobacteria, Synechocystis sp. PCC 6803 using cryo-SEM and their cryo-SEM images were compared to Conventional SEM (CSEM) images treated by chemical fixation. We could observe the improved morphological images of the pili of the surface and membranes of Synechocystis sp. PCC 6803 and the three-dimensional architectures of their biofilm, which were difficult to observe using chemical fixation and CSEM. These results suggest that cryo-methods/cryo-SEM are useful techniques for morphological study of biological specimen.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.4
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• pp.311-319
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• 2009

Objective: Human embryonic stem cells (hESCs) have the capacity to differentiate into all of the cell types and therefore hold promise for cell therapeutic applications. In order to utilize this important potential of hESCs, enhancement of currently used technologies for handling and manipulating the cells is required. The cryopreservation of hESC colonies was successfully performed using the vitrification and slow freezing-rapid thawing method. However, most of the hESC colonies were showed extremely spontaneous differentiation after freezing and thawing. In this study, we were performed to rapidly collect of early passage hESCs, which was thawed and had high rate of spontaneously differentiation of SNUhES11 cell line. Methods: Four days after plating, partially spontaneously differentiated parts of hESC colony were cut off using finely drawn-out dissecting pipette, which is mechanical separation method. Results: After separating of spontaneously differentiated cells, we observed that removed parts were recovered by undifferentiated cells. Furthermore, mechanical separation method was more efficient for hESCs expansion after thawing when we repeated this method. The recovery rate after removing differentiated parts of hESC colonies were 55.0%, 74.5%, and 71.1% when we have applied this method to three passages. Conclusion: Mechanical separation method is highly effective for rapidly collecting and large volumes of undifferentiated cells after thawing of cryopreserved early passage hESCs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.618-625
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• 2018

With the passing of time, exposed concrete structures are affected by a range of environmental, chemical, and physical factors. These factors seep into the concrete and have a deleterious influence compared to the initial performance. The importance of identifying and preventing further performance degradation due to the occurrence of deterioration has been greatly emphasized. In recent years, evaluations of the target life have attracted increasing interest. During the freezing-melting effect, a part of the concrete undergoes swelling and shrinking repeatedly. At these times, chloride ions present in seawater penetrate into the concrete, and accelerate the deterioration due to the corrosion of reinforced bars in the concrete structures. For that reason, concrete structures located onshore with a freezing-melting effect are more prone to this type of deterioration than inland structures. The aim of this study was to develop a high performance mortar mixed with a mineral admixture for the durability properties of concrete structures near sea water. In addition, experimental studies were carried out on the strength and durability of mortar. The mixing ratio of the silica fume and meta kaolin was 3, 7 and 10 %, respectively. Furthermore, the ultra-fine fly ash was mixed at 5, 10, 15, and 20%. The mortar specimens prepared by mixing the admixtures were subjected to a static strength test on the 1st and 28th days of age and degradation acceleration tests, such as the chloride ion penetration resistance test, sulfuric acid resistance test, and salt resistant test, were carried out at 28 days of age. The chloride diffusion coefficient was calculated from a series of rapid chloride penetration tests, and used to estimate the life time against corrosion due to chloride ion penetration according to the KCI, ACI, and FIB codes. The life time of mortar with 10% meta kaolin was the longest with a service life of approximately 470 years according to the KCI code.

• Clinical and Experimental Reproductive Medicine
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• v.24 no.3
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• pp.281-292
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• 1997

The objective of this study was to compare retrospectively the survival and pregnancy rates(PR) of cryopresered-thawed embryos obtained from intracytoplasmic sperm injection (ICSI) or conventional in vitro fertilization (IVF). Ninety-six cycles of cryopresered-thawed embryo transfer (ET) were performed in 79 patients from June, 1996 to September, 1997 and grouped as followings: 20 cycles (16 patients) inseminated by ICSI (ICSI Group) and 76 cycles (63 patients) by conventional IVF (IVF Group). Slow-freezing and rapid-thawing protocol was used with 1.5M propanediol (PROH) and 0.1M sucrose as cryoprotectant. All embryos were frozen-thawed at the two pronuclear (2 PN) stage excluding four cycles in which the early cleavage stage embryos were frozen, and allowed to cleave in vitro for one day before ET. The duration from freezing to thawing was comparable in both groups ($mean{\pm}SD$, $112.1{\pm}80.0$ vs. $124.8{\pm}140.1$ days). The age of female ($31.2{\pm}3.4$ vs. $32.6{\pm}3.3$ years) and the endometrial thickness prior to progesterone injection ($9.4{\pm}2.0$ vs. $9.3{\pm}1.8$ mm) were also comparable in both groups. There was no significant difference in the outcomes of cryopreserved-thawed ET between two groups: survival rate ($85.2{\pm}16.1%$ vs. $82.2{\pm}19.7%$), cleavage rate ($96.9{\pm}6.7%$ vs. $94.7{\pm}13.0%$), cumulative embryo score (CES, $54.5{\pm}31.1$ vs. $49.0{\pm}20.0$), preclinical loss rate (5.0% vs. 5.3%), clinical miscarriage rate (0% vs 29.4%), clinical PR per transfer (35.0% vs. 22.4%), implantation rate (9.9% vs. 5.6%), and multifetal PR (42.9% vs. 17.6%). In conclusion, human embryos resulting from ICSI can be cryopreserved-thawed and transferred successfully, and the survival rate and PR are comparable to conventional IVF.

• BMB Reports
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• v.37 no.5
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• pp.538-545
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• 2004

A new CRT binding factor (CBF) gene designated Cbcbf25 was cloned from Capsella bursa-pastoris, a wild grass, by the rapid amplification of cDNA ends (RACE). The full-length cDNA of Cbcbf25 was 898 bp with a 669 bp open reading frame (ORF) encoding a putative DRE/CRT (LTRE)-binding protein of 223 amino acids. The predicted CbCBF25 protein contained a potential nuclear localization signal (NLS) in its N-terminal region followed by an AP2 DNA-binding motif and a possible acidic activation domain in the C-terminal region. Bioinformatic analysis revealed that Cbcbf25 has a high level of similarity with other CBF genes like cbf1, cbf2, and cbf3 from Arabidopsis thaliana, and Bncbf5, Bncbf7, Bncbf16, and Bncbf17 from Brassica napus. A cold acclimation assay showed that Cbcbf25 was expressed immediately after cold triggering, but this expression was transient, suggesting that it concerns cold acclimation. Our study implies that Cbcbf25 is an analogue of other CBF genes and may participate in cold-response, by for example, controlling the expression of cold-regulated genes or increasing the freezing tolerance of plants.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1527-1533
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• 2001

Garole is a prolific, rare, less known and small size Indian sheep breed found in low and humid Sunderban region of West Bengal. Although information on stored Garole ram liquid semen upto 24 h is available, but there is a need to further investigate the short-term and long-term preservability of Garole ram semen for extensive utilization of this valuable germplasm by artificial insemination. The aim of the present study was to apply computer-assisted sperm analysis technique for assessing the motion characteristics of Garole ram semen stored (i) in liquid state at refrigeration temperature for short-term preservation upto 48 h and (ii) in frozen state at $-196^{\circ}C$ for long-term preservation after packaging in mini straws. Short-term preservation had a significant effect on motility (p<0.01) as the motility progressively decreased from 90.1% at 0 h to 85.5% and 73.2% after 24 and 48 h of storage, respectively. Although the decline in rapid moving sperms was also significant (p<0.01) on storage but the decrease was more pronounced at 48 h as compared to 24 h of storage period. Storage of chilled semen had also a significant effect on % linearity (p<0.05), % straightness (p<0.01), sperm velocities (p<0.01), amplitude of lateral head displacement (p<0.01) and beat frequency (pO.Ol) of spermatozoa. The replication had a significant effect for all the variables except average path and straight line velocity. However, the interactions of short-term storage and replication were non-significant for most of the variables except % of medium moving sperms, sperm velocities and beat frequency. On long-term preservation of Garole ram spermatozoa under controlled conditions the mean post-thaw recovery of 70.4 and 71.4% motile spermatozoa was achieved having 48.8 and 48.9% of rapidly motile spermatozoa, respectively in both the replicates. The effect of replication on cryopreservation was significant (p<0.05) on amplitude of lateral head displacement and beat frequency, but there was no significant effect on motility, rapidly motile spermatozoa, linearity, straightness and sperm velocities of frozen-thawed spermatozoa. It can be concluded from these results that an average 70% motility can be achieved on storage of Garole ram semen in chilled liquid state upto 48 h or in liquid nitrogen after freezing under controlled conditions in straws. However, further studies are required to evaluate the fertility of short-term and long-term preserved Garole ram semen for extensive use of this prolific sheep breed.