• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.249-254
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• 2016

In this study, we investigated the main characteristics of off-gas generated from melting process and off-gas treatment system operation example to provide some primary data for commercial vitrification facility design. The purpose of vitrification facility operation is to treat hazardous materials in the radioactive wastes and harmful off-gas containing a variety of chemical species generated in the glass melting process. Constructing and operating vitrification facility essentially need to be licensed through safety analysis; it is very important to treat radionuclide and hazardous materials below the legal environment emissions regulation level. We must accurately understand the characteristics of off-gas and apply an appropriate off-gas treatment process accordingly. Thus, to design the appropriate off-gas treatment there must be a wide range of elements taken into account such as characteristics of waste and melter, regulation guidance of off-gas, characteristics of generated off-gas and off-gas treatment system performance assessment.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.385-391
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• 2006

In vitro-grown axillary buds of Melia aredarach were successfully cryopreserved by vitrification. On the MS medium supplemented with BA 1 mg/L, multiple shoots were developed within $4{\sim}5$ weeks. Plantlets of Melia azedarach were cold-hardened at $10^{\circ}C$ for a 16-hr photo-period for 6 weeks. Excised axillary shoot-tips from hardened plantlets were precultured on a solidified Murashige & Skoog agar medium (MS) supplemented with 0.7 M sucrose for 1 day at $25^{\circ}C$. Axillary shoot-tip meristems wert dehydrated using a highly concentrated vitrification solution (PVS2) for 60 min at $0^{\circ}C$ prior to a direct plunge into liquid nitrogen (LN). The PVS2 vitrification solution consisted of 30% glycerol (w/v), 15% ethylene glycol (w/v), 15% DMSO (w/v) in MS medium containing 0.4M sucrose. After short-term warming in a water bath at $40^{\circ}C$, the meristems were transferred into 2 ml of MS medium containing 1.2M sucrose for 15 min and then planted on solidified MS culture medium. Successfully vitrified and warmed meristems resumed growth within 2 weeks and directly developed shoots without intermediary callus formation. The survival rate of cold-hardened plantlets for 3 and 4 weeks was 90%. We did not find any difference in PCR-band patterns between control and cryopreserved plants. This method appears to be a promising technique for cryopreserving axillary shoot-tips from in vitro-grown plantlets of Medicinal plants.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.155-161
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• 1996

For a large sclase production of genetically identical or cloned animals, the effect of cryopreservation by vitrification on the post-thaw viability of nuclear transplant rabbit embryos were investigated. The embryos of 16-cell stage were collected from the mated does at 48 hours post-hCG injection, and they were synchronized to G1 phase of 32-cell stage were injected into enucleated recipient cytoplasms by micromanipulation. After culture until 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation. After in vitro culture for 48h, the nuclear transplant embryos developed to morula stage were cryoperserved with EFS solution by vitrification method. The forzen nuclear transplant embryos were thawed and cultured for 72h and the nuclear transplant of blastomeres under a fluorescence microscopy. The in vitro development to blastocyst of intact-fresh and intact-frozen 16-cell embryos was found to be 96.9 and 63.9%, respectively. The in vitro development to blastocyst of nuclear transplant and frozen-thawed nuclear transplant embryos was found to be 74.5 and 42.9%, respectively. Also, their mean blastomere numbers and mean cell cycles/day was 153 and 105, 145 and 1.34, respectively. From the above results it was concluded that the present cryopreservation by vitrification of nuclear transplant rabbit embryos might be useful though was decreased significantly.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.333-339
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• 2018

The mature zygotic embryos of the Hevea brasiliensis were cryopreserved through the use of the vitrification and encapsulation/dehydration techniques. In all the experiments, the zygotic embryos were pre-cultured for three days in the MS medium supplemented with 0.3 M sucrose before they were used for the cryopreservation technique. In the vitrification procedure, the effect of the plant vitrification solutions (PVS2 and PVS3) and exposure time were studied. The highest survival rate (88.87%) and regrowth (66.33%) were achieved when the precultured zygotic embryos were incubated in a loading solution for 20 minutes at $0^{\circ}C$. They were subsequently exposed to PVS2 for 120 minutes at $0^{\circ}C$ and plunged directly into liquid nitrogen. Cryopreservation by the encapsulation-dehydration method was successfully done by leaving the encapsulated zygotic embryos in a laminar flow for 4 hours prior to plunging into a LN. The survival rate and regrowth of the encapsulated zygotic embryos were 37.50% and 27.98%, respectively. The cryopreserved zygotic embryos were able to develop into whole plants.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.23-28
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• 2003

The present study was undertaken to investigate the effects of PVP concentration and exposure temperature to vitrification solution on the post-thaw survival, in vitro maturation and development of immature bovine oocytes (germinal vesicle stage). The vitrification solution (VS) consisted of 40% ethylene glycol (EG)+0.5 M sucrose (S)+10% FBS. PVP was added to VS: 0%, 5% or 10%. The cumulus-oocyte complexes (COCs) were diluted in VS as one step, after 2 min the COCs were loaded in straw and vitrified by direct immersion into liquid nitrogen. For thawing, the straws were plunged into $30^{\circ}C$ water bath for 10s. After thawing, the oocytes were diluted in 0.5 M (in DPBS with 10% FBS) sucrose solution for 5 min. The survival rate (FDA-test and trypan blue) of immature bovine oocytes was measured. The survival rate was higher in 5% PVP (91.5%) than in 0% (64.2%) or in 10% PVP (79.7%). The proportion of metaphase II formation was 69.35% in control (no vitrified COCs), 9.3% in 40% EG+0.5 M S+0% PVP and 21.05% in 40% EG+0.5 M S+5% PVP (p<0.05). The effect of room temperature ($25^{\circ}C$ for 10 min) and cold temperature ($4^{\circ}C$ for 10 min) on COCs were determined in this study. After IVF, the cleavage and blastocysts rate of oocytes exposed to room temperature and cold temperature in VS+5% PVP was significantly different (2 cell: 63.20% vs 37.97%, blastocysts: 18.40% vs 2.53%). The cleavage rates of frozen-thawed oocytes were 20.53% with PVP and 22.13% without PVP (p>0.05). Two out of 151 oocytes (1.32%) developed to blastocyst stage after frozen-thawed with 5% PVP (p>0.05). Development of oocytes after frozen-thawing to the 2 cell were not significantly affected with or without PVP following IVF. However, the vitrification of immature bovine oocytes with PVP maintained the ability to develop to the blastocyst stage after IVM-IVF and IVC, while no blastocysts were obtained from oocytes vitrified without PVP. These results suggested that PVP has a protective role for vitrification of immature bovine oocytes as far as survival is concerned, however, the protection was not sufficient enough to support blastocyst formation.

• Clinical and Experimental Reproductive Medicine
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• v.29 no.1
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• pp.13-20
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• 2002

Objective: This study was carried out to establish the effectiveness of the vitrification method and the optimal cryoprotectants in the cryopreservation of human embryonic stem cells (ESC). Materials and Methods: Human ESC clumps established at Seoul National University Hospital (SNUhES 1) were cryopreserved with the vitrification method using the EM grid. EDS and EFS40 were used as vitrification solutions. Results: Between the EDS and EFS40 groups, there was no significant difference in the recovery rate after cryopreservation of human ESC. The formation rates of ESC colonies in the vitrified groups were significantly lower than those in the control ESC group (p<0.05, p<0.05). In addition, the formation rate of ESC colonies in the EDS group was significantly higher than that in the EFS40 group (p<0.05). The ESC colonies in the vitrified groups were significantly smaller after culture duration of 2 and 4 days, respectively, compared with the control ESC group (p<0.1, p<0.05). However, these effects could be reduced to nonsignificant level by the additional culture of ESC colonies. The vitrified human ESC retained the properties of pluripotent cells, including the expression of cell surface. markers for the undifferentiated cells such as alkaline phosphatase and SSEA-4 (stage-specific embryonic antigen-4), and the expression of transcription factor Oct-4 (octamer-binding transcription factor-4), and the normal karyotype. Conclusion: The vitrification method using the EM grid and EDS solution was confirmed to be very effective for the cryopreservation of human ESC.

• Journal of Embryo Transfer
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• v.29 no.4
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• pp.397-401
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• 2014

The boar sperm has more lipid droplets and specialty of seminal plasma compared with other species, causing difficulties of freezing sperm and decreases for the utilization of frozen semen into the artificial insemination. However, several studies reported significant results for the recovery of sperm motility and reproductive by addition of cryoprotectants and seminal plasma after thawing. This study was designed to investigate the effects of supplementation of trehalose or glycerol in the LEY (lactose and egg yolk in BTS) solution for the conventional freezing and vitrification process. Two boars aged 16 months were used to collect semen for 2 times in a week. The samples were allotted to 3 freezing solutions (LEY + glycerol 10.5% + OEP 1.5%, LEY + trehalose 1M + OEP 1.5%, and sucrose 1.5M + trehalose 1 M + OEP 1.5%) after centrifugation at 800 g for 10 minutes. Semen was equilibrated in freezing solutions for 10 minutes and injected into plastic straws with 2~3 air bubbles to minimize freezing damages. Vitrification was performed to locate sperm in 5 cm above $LN_2$ for 5 minutes, and the conventional freezing was conducted with an automatic freezer. Motility and survival rates were measured by CASA (Computer assisted sperm an alyzing system) and FITC (Fluorescein isothiocyanate), respectively after thawing semen at $50^{\circ}C$ for 12 seconds. The results were analyzed by ANOVA with STATVIEW statistical program. The vitrificatioin solution (LEY + 10.5% glycerol + 1.5% OEP) presented higher motility (20.9%) than other solutions while the solution (LEY + 1M trehalose + 1.5% OEP) showed the lowest (motility : 5.2%). However, survival rates of vitrified sperms detected by FITC showed 1~4% live sperms in almost of dead sperms at all vitrification solutions' groups, but survival rate of freezing solution of LEY + 1M trehalose + 1.5% OEP LEY and LEY + 10.5% glycerol + 1.5% OEP were showed 49%, and 79%, respectively. There were differences (P<0.05) survival rate of conventional freezing in LEY + 10.5% glycerol + 1.5% OEP and LEY + 1M trehalose + 1.5% OEP and the remaining showed no differences. The results suggested that vitrified boar semen was not enough to be utilized for the artificial insemination, but it showed possibility to utilize for ICSI and conventional freezing with glycerol would be useful method for artificial insemination in pig while we choose the outstanding semen against tolerance to freezing damages.

• Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.417-420
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• 2015

We investigated the relationship between viability and IGF-1 receptor (IGF-1R) activity in D-shaped and umbo larvae of the surf clam Spisula sachalinensis after treatment with vitrification solution (VS) or freezing. In a toxicity assay, VS1, containing 5 M dimethyl sulfoxide (DMSO), was very harmful to D-shaped and umbo larvae. However, VS2, containing 5 M ethylene glycol (EG), was not harmful to either larval stage. Although VS2 had a promising toxicity test outcome, none of the larvae survived vitrification. After immersion into VSs and freezing, IGF-1R ${\beta}$-subunits were detected in all larvae; however, tyrosine phosphorylation of intracellular ${\beta}$-subunits was detected only in the control and live groups. These results suggest that activation of IGF-1R may influence surf clam larvae viability.

• Korean Journal of Plant Resources
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• v.29 no.6
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• pp.635-641
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• 2016

Sweet potato (Ipomoea batatas L.) shoot tips grown in vitro were successfully cryopreserved by encapsulation-vitrification. Encapsulated explants are very easily manipulated, due to the relatively large size of the alginate beads, and a large number of samples can be treated simultaneously. In this study, the effects of sucrose preculture, cryoprotectant preculture, and post-warm recovery media on regrowth, following liquid nitrogen (LN) exposure, were investigated to establish an efficient encapsulation-vitrification protocol for sweet potato. Shoot tips of plants grown in vitro were precultured in 0.3 M sucrose for 2 d before encapsulation. Encapsulated shoot tips were pre-incubated in liquid MS (Murashige and Skoog) medium containing 0.5 M sucrose for 16 h, before preculturing in sucrose-enriched medium (0.7 M sucrose) for 8 h. Shoot tips were osmoprotected with 35% plant vitrification solution 3 (PVS3) for 3 h, before being dehydrated with PVS3 for 2 h at $25^{\circ}C$. The encapsulated and dehydrated shoot tips were transferred to 2 mL cryotubes, suspended in 0.5 mL PVS3, and plunged directly into liquid N. High levels of shoot formation were obtained for the cv. Yeulmi (65.7%) and Yeonwhangmi (80.3%). The regrowth rates of cryopreserved samples in Yeulmi (78.9%) and Yeonwhangmi (91.3%), following culture on ammonium-free MS medium for 5 d, were much higher than those cultured on standard MS medium (65.7% and 80.3%, respectively). This encapsulation-vitrification is a promising method for the long-term preservation of sweet potato.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.123-131
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• 2008

Vitrification methods are convenient for cryopreserving plant specimens, as the specimens are plunged directly into liquid nitrogen (LN) from ambient temperatures. However, tissues and species with poor survival are still not uncommon. The development of vitrification solutions with high survival that cover a range of materials is important. We attempted to develop new vitrification solutions using bromegrass cells and found that VSL, comprising 20% (w/v) glycerol, 30% (w/v) ethylene glycol, 5% (w/v) sucrose, 10% (w/v) DMSO and 10 mM $CaCl_2$, gave the highest survival following cryopreservation, as determined by fluorescein diacetate staining. However, the cryopreserved cells showed little regrowth, for unknown reasons. To check its applicability, VSL was used to cryopreserve gentian axillary buds and the performance was compared with those of conventional vitrification solutions. Excised gentian stem segments with axillary buds (shoot apices) were two-step precultured with sucrose to induce osmotic tolerance prior to cryopreservation. Gentian axillary buds cryopreserved using VSL following the appropriate preculturing approach exhibited 78% survival (determined by the regrowth capacity), which was comparable to PVS2 and PVS1 and far better than PVS3. VSL had a wider optimal incubation time (20-45 min) than PVS2 and was more suitable for cryopreserving gentian buds. The optimal duration of the first step of the preculture was 7-11 days, and preculturing with sucrose and glucose gave a much higher survival than fructose and maltose. VSL was able to vitrify during cooling to LN temperatures, as glass transition and devitrification points were detected in the warming profiles from differential scanning calorimetry. VSL and its derivative, VSL+, seem to have the potential to be good alternatives to PVS2 for the cryopreservation of some materials, as exemplified by gentian buds.