• Title/Summary/Keyword: Freezing method

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Cryo-Ability of Boar Sperm sorted by Percoll Containing of Antioxidative Enzyme (항산화 효소가 첨가된 Percoll에 의해 분리한 돼지 정액의 동결-융해 능력)

  • Lee, Kyung-Jin;Lee, Sang-Hee;Joo, Seon-Ho;Kim, Yu-Jin;Yang, Jin-Woo;Lee, Yeon-Ju;Hwangbo, Yong;Lee, Seunghyung;Lee, Seung Tae;Lee, Eunsong;Park, Choon-Keun
    • Journal of Embryo Transfer
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    • v.30 no.3
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    • pp.121-128
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    • 2015
  • The objective of this study was to evaluate the efficiency of sperm cryosurvival in boar sperm separated by Percoll containing antioxidant enzymes. The boar semen was collected into a pre-warmed ($37^{\circ}C$) thermos bottle by gloved-hand method and was separated by 65% Percoll with superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) before freezing. The frozen sperm was thawed at $38.5^{\circ}C$ for 45 sec in water-bath for sperm characteristic analysis. The sperm were estimated with SYBR14/PI double staining for viability, FITC-PNA/PI double staining for acrosome reaction, Rhodamine123/PI double staining for mitochondrial integrity and were analyzed using flow cytometry. In results, sperm viability, acrosome reaction and mitochondrial integrity were improved in separated sperm groups compared with unseparated sperm by Percoll (UP) group. Especially, viability was significantly higher in sperm separated by Percoll containing 400 IU CAT group compared with other groups (P<0.05). And acrosome reaction was decreased in sperm separated by Percoll with 300 IU SOD, 400 IU CAT and 0.5 mM GSH groups compared with other groups, however, there were no significantly difference mitochondrial integrity among sperm separated by Percoll with antioxidant enzymes. In conclusion, we suggest that use of Percoll containing antioxidant enzymes for sperm separation will be beneficial for sperm cryopreservation in pigs.

A Geomorphological Study on the Locational Characteristics and Construction Method of Dolmens in Hyosanri·Daesinri (지석묘의 입지특성과 축조방식에 대한 지형학적 고찰 - 효산리·대신리를 중심으로 -)

  • PARK, Cheol-Woong;KIM, In-Cheol
    • Journal of The Geomorphological Association of Korea
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    • v.19 no.3
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    • pp.23-36
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    • 2012
  • This study aims to think about the problem of dolmens: the reasons for the presence of dolmens and how to construct it, at the point of view of geographical and geomorphological. The subjects of this study is the dolmens which locate between at Dogok Hyosanri and Chunyang Daesinri Hwasoon-gun, Jeonlanamdo. The study areas in Hyosanri, Daesinri has been observed as follows. First, the long axis direction of Dolmen upper stone and the slope one are the same. Second, tor, block stream, hockey stick, etc. Third, Composition of the soil silt> sand> clay is distributed in the order. Forth, The soil of high quality silt and the roundness of angular, sub-angular-level and the high frequency, peaks of quarts and illite clay minerals show. Fifth, in the result of $SiO_2/Al_2O_3$, $SiO_2/R_2O_3$, and CIA(Chemical Index of Alteration), Hyosanri, Daesinri areas show mechanical weathering was dominant and chemical weathering environment was not being progressed. The blocks used in construction of dolmens had moved to the bottom of slopes by mass movement such as solifluction then them which had been placed in the position seem to be used by people of Bronze. Based on the above results, the process of construction of dolmens can be estimated as follows. They would dig up the ground under the upper stone of dolmens, put the supporting stone in the place, then dig up earth, place into remains, close the obturating stones, then heal up earth.

Angiopoietin-1 and -2 and vascular endothelial growth factor expression in ovarian grafts after cryopreservation using two methods

  • Cho, In Ae;Lee, Yeon Jee;Lee, Hee Jung;Choi, In Young;Shin, Jeong Kyu;Lee, Soon Ae;Lee, Jong Hak;Choi, Won Jun
    • Clinical and Experimental Reproductive Medicine
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    • v.45 no.3
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    • pp.143-148
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    • 2018
  • Objective: The favored method of preserving fertility in young female cancer survivors is cryopreservation and autotransplantation of ovarian tissue. Reducing hypoxia until angiogenesis takes place is essential for the survival of transplanted ovarian tissue. The aim of this study was to investigate the role of angiopoietin-1 (Angpt-1), angiopoietin-2 (Angpt-2), and vascular endothelial growth factor (VEGF) in ovarian tissue grafts that were cryopreserved using two methods. Methods: Ovarian tissues harvested from ICR mice were divided into three groups: group I (control), no cryopreservation; group II, vitrification in EFS (ethylene-glycol, ficoll, and sucrose solution)-40; and group III, slow freezing in dimethyl sulfoxide. We extracted mRNA for VEGF, Angpt-1, and Angpt-2 from ovarian tissue 1 week following cryopreservation and again 2 weeks after autotransplantation. We used reverse transcriptase-polymerase chain reaction to quantify the levels of VEGF, Angpt-1, and Angpt-2 in the tissue. Results: Angpt-1 and Angpt-2 expression decreased after cryopreservation in groups II and III. After autotransplantation, Angpt-1 and Angpt-2 expression in ovarian tissue showed different trends. Angpt-1 expression in groups II and III was lower than in group I, but Angpt-2 in groups II and III showed no significant difference from group I. The vitrified ovarian tissues had higher expression of VEGF and Angpt-2 than the slow-frozen ovarian tissues, but the difference was not statistically significant. Conclusion: Our results indicate that Angpt-2 may play an important role in ovarian tissue transplantation after cryopreservation although further studies are needed to understand its exact function.

Optimal Design Standard and Application of Low Cost, High Performance Scrubber for Absorbing Hazardous Gas (유해가스 흡수처리를 위한 저비용 고효율 스크러버의 최적 설계기준 및 현장적용 방안)

  • Jung, Ga-Young;Lim, Kyung-Min;Ma, Byung-Chol
    • Journal of the Korean Institute of Gas
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    • v.25 no.3
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    • pp.39-45
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    • 2021
  • Scrubbers that treat hazardous materials at workplaces have high treatment efficiency; however, the design is complex, and pumps need to be operated 24 hours a day, which can be costly. Therefore, to minimize the operating costs, small businesses do not install scrubbers, or operate them while circulation pumps are suspended. Hence, this study investigated the application of low-cost, high-performance scrubbers that can be used economically in small businesses. Low-cost, high-efficiency scrubbers are applied to bubble columns to utilize devices for hazardous chemical absorption treatment purposes, and for the development of these scrubbers, absorption performance was reviewed and the optimal application method was studied under certain conditions. The changes in the absorption performance of hazardous gas were studied in certain environments by varying the physical conditions, and the optimal application methods were analyzed. The results showed that, while it was possible to treat some of the gas flowing into the low cost, high performance scrubber, the treatment capacity was reduced. Performance degradation was prevented by supplying an absorption liquid, and a certain level of absorption was maintained depending on the amount of circulation. Based on this, three types of site application methods of low cost, high performance scrubbers were presented. In addition, the appropriate timing of circulation and anti freezing measures were also discussed.

Predicting Road Surface Temperature using Solar Radiation Data from SOLWEIG(SOlar and LongWave Environmental Irradiance Geometry-model): Focused on Naebu Expressway in Seoul (태양복사모델(SOLWEIG)의 복사플럭스 자료를 활용한 노면온도 예측: 서울시 내부순환로 대상)

  • AHN, Suk-Hee;KWON, Hyuk-Gi;YANG, Ho-Jin;LEE, Geun-Hee;YI, Chae-Yeon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.23 no.4
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    • pp.156-172
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    • 2020
  • The purpose of this study was to predict road surface temperature using high-resolution solar radiation data. The road surface temperature prediction model (RSTPM) was applied to predict road surface temperature; this model was developed based on the heat-balance method. In addition, using SOLWEIG (SOlar and LongWave Environmental Irradiance Geometry-model), the shadow patterns caused by the terrain effects were analyzed, and high-resolution solar radiation data with 10 m spatial resolution were calculated. To increase the accuracy of the shadow patterns and solar radiation, the day that was modeled had minimal effects from fog, clouds, and precipitation. As a result, shadow areas lasted for a long time at the entrance and exit of a tunnel, and in a high-altitude area. Furthermore, solar radiation clearly decreased in areas affected by shadows, which was reflected in the predicted road surface temperatures. It was confirmed that the road surface temperature should be high at topographically open points and relatively low at higher altitude points. The results of this study could be used to forecast the freezing of sections of road surfaces in winter, and to inform decision making by road managers and drivers.

Improvement of Temperature Constancy of Direct Refrigerator for Supercooled Storage (직냉식 냉장고의 과냉각 저장을 위한 항온 특성 개선 연구)

  • Kim, Jinse;Nam, Soyoung;Jung, Hyun Kyung;Son, Jae Yong;Choi, Dong Soo;Kim, Yong Hoon;Lee, Soo Jang;Park, Chun Wan;Kim, Ha Yoon;Park, Seok Ho
    • Food Engineering Progress
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    • v.23 no.4
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    • pp.270-277
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    • 2019
  • Commercial direct refrigerators have good energy efficiency, but are difficult to use for supercooled storage due to their large temperature deviation. Placing insulators and conductors inside the refrigerator could reduce these temperature deviations to within 0.3 degrees, allowing for the supercooled storage. The supercooled storage of salted Chinese cabbages during ten weeks was progressed to compare the other low temperature storages. The nucleation temperatures of salted Chinese cabbage were around -2.5℃ and the freezing points were around -0.4℃, so -2℃ was selected for the supercooled storage. The growth rate of lactic acid bacteria and yeast at -2℃ storage was lower than that at 2℃ storage. The reducing sugar was maintained higher due to the growth rate of lactic acid bacteria. The supercooled storage had an effect of delaying the fermentation of the salted Chinese cabbage, which may have the effect of delaying the fermentation of kimchi. This enhancement method of the direct refrigerator was effective for the supercooled storage and would be promising for commercial use.

Monitoring of Residual Pesticides in Grape Seed Oil being Sold in Gyeonggi Province (경기도 내 판매되고 있는 포도씨유의 잔류농약 모니터링)

  • Mi-Hui Son;Jae-Kwan Kim;You-Jin Lee;Ji-Eun Kim;Eun-Jin Baek;Byeong-Tae Kim;Myoung-Ki Park;Bo-yeon Kwon
    • Journal of Food Hygiene and Safety
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    • v.39 no.2
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    • pp.128-133
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    • 2024
  • Using the freezing removal method, we investigated residual pesticides in 50 grape seed oils distributed in Gyeonggi Province, South Korea. The fat was mixed with acetonitrile and then frozen at ≤-20℃ for 24 h. Fats and oils were removed by separating those in solid state and the extract acetonitrile in liquid state. Ten residual pesticides were detected 161 times in 49 of 50 cases. The detected pesticides were boscalid, cyclufenamide, deltamethrin, difenoconazole, fluxapyroxad, fenpyrazamine, kresoxim-methyl, piperonyl butoxide, tebuconazole, and trifluoxysorbin. Boscalid, a fungicide, was most frequently detected (44 times), followed by fluxapiroxad (35 times). The detection range was 0.01-1.10 mg/kg, which was within the legal limit of residual pesticide for grapes. The recovery rate of the detected pesticides was 72.6-129.8% and the ratio of estimated daily intake/acceptable daily intake was calculated to determine the risk of the detected pesticides, which was <0.0028%. This indicated that the risk caused by pesticide residues in grape seed oil is at a safe level.

A Study on Risk Assessment of extreme Cold Waves in Energy Storage Facilities According to Climate Change (기후변화에 따른 에너지 저장시설 극한 한파 위험성 평가에 관한 연구)

  • Han-Duk Kim;Eun-Gu Ham;Se-Young Ko
    • Journal of the Society of Disaster Information
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    • v.20 no.3
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    • pp.584-592
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    • 2024
  • Purpose: The biggest concern in cold wave situations is that the fire extinguishing water initially supplied through dry pipes with empty pipes consumes enthalpy and freezes as it rapidly approaches the surface temperature of steel pipes that have been exposed to sub-zero outdoor air for a long time. It has no choice but to be. Method: Therefore, the study found that ice crystals were generated during transport, making it difficult to transport fire extinguishing water, and as a result of the review, when the heat load passed through the piping material, the heat loss per unit length from the piping to the surroundings was 0.946. Results: When calculating the volume of the main pipe, it was calculated that the fire extinguishing water supplied at a temperature of 15 degrees from the underground pipe would have a volume of 3.33m3 to reach the first branch point. If we calculate the heat required until this volume reaches below zero, we get 316.350 kcal. When the results were reviewed using the related formula, the time required for the fire extinguishing water to completely freeze up to the first branch of the steel pipe was found to be 3,412 seconds. Conclusion: Fire-fighting water, which must reach from the main pipe to the branch pipe and nozzle in good condition, must minimize heat loss through the pipe surface along the transfer path. To achieve this, it is necessary to supplement insulation of the main pipe and branch pipes. In this study, the use of inorganic perlite material or flame-retardant rubber foam insulation was proposed through analysis of insulation properties.

Determination of dynamic threshold for sea-ice detection through relationship between 11 µm brightness temperature and 11-12 µm brightness temperature difference (11 µm 휘도온도와 11-12 µm 휘도온도차의 상관성 분석을 활용한 해빙탐지 동적임계치 결정)

  • Jin, Donghyun;Lee, Kyeong-Sang;Choi, Sungwon;Seo, Minji;Lee, Darae;Kwon, Chaeyoung;Kim, Honghee;Lee, Eunkyung;Han, Kyung-Soo
    • Korean Journal of Remote Sensing
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    • v.33 no.2
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    • pp.243-248
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    • 2017
  • Sea ice which is an important component of the global climate system is being actively detected by satellite because it have been distributed to polar and high-latitude region. and the sea ice detection method using satellite uses reflectance and temperature data. the sea ice detection method of Moderate-Resolution Imaging Spectroradiometer (MODIS), which is a technique utilizing Ice Surface Temperature (IST) have been utilized by many studies. In this study, we propose a simple and effective method of sea ice detection using the dynamic threshold technique with no IST calculation process. In order to specify the dynamic threshold, pixels with freezing point of MODIS IST of 273.0 K or less were extracted. For the extracted pixels, we analyzed the relationship between MODIS IST, MODIS $11{\mu}m$ channel brightness temperature($T_{11{\mu}m}$) and Brightness Temperature Difference ($BTD:T_{11{\mu}m}-T_{12{\mu}m}$). As a result of the analysis, the relationship between the three values showed a linear characteristic and the threshold value was designated by using this. In the case ofsea ice detection, if $T_{11{\mu}m}$ is below the specified threshold value, it is detected as sea ice on clear sky. And in order to estimate the performance of the proposed sea ice detection method, the accuracy was analyzed using MODIS Sea ice extent and then validation accuracy was higher than 99% in Producer Accuracy (PA).

Clinical Appilication of Endobornchial Cryoablation That's Performed through Flexible Bronchoscope for Treating Tracheobronchial Ostruction (기관 및 기관지 폐색환자에서 굴곡형 기관지내시경을 이용한 냉동수술의 임상적용)

  • Lee, Sung-Ho;Kim, Kwang-Taik;Chung, Jae-Ho;Chung, Won-Jae;Kang, Moon-Chul;Kang, Eun-Hae;Lee, Eun-Joo;In, Kwang-Ho
    • Journal of Chest Surgery
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    • v.41 no.4
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    • pp.457-462
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    • 2008
  • Background: Emergency airway access is essential when a patient has dyspnea that's due to tracheal or bronchial obstruction. Such methods as laser therapy and PDT are now being used for the treatment of tracheal obstruction that's due to benign diseases or nonsurgical malignant diseases. Cryotherapy is a method that uses extreme hypothermia for freezing a tumor to cause necrosis. In this study, we have evaluated the clinical effectiveness of performing endobronchial cryoablation through a flexible bronchoscope. Material and Method: 10 patients with tracheal obstruction that was due to endotracheal tumors were evaluated between May 2005 and May 2007. Eight were male and the mean age of the 10 patients was $59.4{\pm}18.4$ years. Three cases of tracheal obstruction were due to benign tumors and 7 were due to malignant tumors. The obstruction sites were 3 at the trachea, 3 at the carina and 4 at the bronchus. A flexible bronchoscope was inserted and the tumor was eliminated using a flexible cryoprobe. Follow up bronchoscopy was performed at 1 week and 1 month after cryoablation, and then we evaluated the decrease of dyspnea, the improvement of the performance and the complications of the procedures. Result: Complete remission was achieved in 4 patients and partial remission was achieved in 6 patients. Complications such as hemoptysis (100%), and cough (50%) were noted. Hemoptysis was spontaneously resolved in 3 to 8 days (mean: 4.9 days). A decrease in dyspnea and improvement in the performance was noted in all patients. Conclusion: Endobronchial stenosis plays a detrimental role in the life quality of a terminal cancer patient. Due to its simplicity and effectiveness for controlling bleeding, endobronchial cryoablation is considered to be a safe method that is clinically applicable to a wide range of tumors, including the removal of large tumors. We concluded that endobronchial cryoablation through a flexible bronchoscope is a safe, effective method for treating tracheobroncheal obstructions.