• KSBB Journal
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• v.13 no.3
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• pp.272-278
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• 1998

Cell recovery from high cell density broths of Alcaligenes eutrophus by pretreatment with aluminum-based coagulants such as aluminum sulfate, polyaluminum hydrooxide chloride silicate (PACS), and polyaluminum hydrooxide chloride (Hi-PAX) was carried out. Cells coagulated with coagulants could be successfully recovered above 95-99% by centrifugation or filtration. The optimum initial pH of fermentation broths for cell recovery was in the range of 10 to 12. Optimum coagulants dosage for cell recovery increased with increasing of cell concentrations (21-160 g/L). The optimum coagulant dosages to recover cells with more than 95% cell recovery by centrifugation for the cell concentrations ranged 21-160 g/L were as follows: aluminum sulfate, 416-1708 mg Al/L; PACS, 211-826 mg Al/L; Hi-PAX, 320-960 mg Al/L. At optimum conditions for the coagulation of cells, centrifugal forces for 95% of cell recovery were dependent on the cell concentration. The centrifugal forces at 82 g/L and 160 g/L of cell concentration were only 45${\times}$g and 1600${\times}$g, respectively.

• KSBB Journal
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• v.15 no.4
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• pp.405-407
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• 2000

A novel recovery method was developed to obtain the plant cell and its debris from Taxus chinensis cell cultures By pH control of plant cell cultures plant cell and debris was precipitated. The best pH is between 1.8 and 2.2 to obtain the precipitate of the plant cell and debris. Also paclitaxel is stable in this acidic conditions. This method is very simple an efficient to recover the plant cell and debris from plant cell cultures.

• Korean Journal of Environmental Biology
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• v.23 no.4
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• pp.390-397
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• 2005

The inhibition of cell recovery might be proceeded via either the damage of the mechanism of the recovery itself or via the formation of irreversible damage which could not be repaired at all. Both these processes may take place at the same time. Any of these possibilities would result in a decrease in both the rate and extent of cell recovery. To distinguish them, a quantitative approach describing the process of recovery as a decrease in the effective radiation dose was applied to experimental data on the recovery from potentially lethal damage in Chinese hamster cells exposed to X-rays alone or combined with various chemicals (pyruvate, novobiocin, lactate, nalidixic acid, 3-aminobenzamide). For these particular cases, it is concluded that the recovery process itself is not damaged and the inhibition of the recovery is entirely due to the enhanced yield of the irreversibly damaged cells.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.199-204
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• 2016

The dependence of cell survival on exposure dose and the duration of the liquid-holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage.

• Journal of the Korean Solar Energy Society
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• v.35 no.5
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• pp.57-65
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• 2015

The Potential Induced Degradation(PID) in PV module mainly affected by various performance conditions such as a potential difference between solar cell and frame, ambient temperature and relative humidity. The positive charges as sodium ions in front glass reach solar cell in module by a potential difference and are accumulated in the solar cell. The ions accelerate the recombination of generation electrons within solar cell under illumination, which reduces the entire output of module. Recently, it was generally known that PID generation is suppressed by controlling the thickness of SiNx AR coating layer on solar cell or using Sodium-free glass and high resistivity encapsulant. However, recovery effects for module with PID are required, because those methods permanently prevent generating PID of module. PID recovery method that voltage reversely applies between solar cell and frame contract to PID generation begins to receive attention. In this paper, PID recovery tests by using voltage under various outdoor conditions as humidity, temperature, voltage are conducted to effectively mitigate PID in module. We confirm that this recovery method perfectly eliminates PID of solar cell according to repeative PID generation and recovery as well as the applied voltage of three factors mainly affect PID recovery.

• KSBB Journal
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• v.31 no.4
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• pp.284-290
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• 2016

In this research, recombinant human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) was produced by transgenic rice cells. RAmy3D promoter was used for overcome the limitation of low expression level in transgenic plant cells, and the secretion of target protein was accomplished by signal peptide. However, the RAmy3D promoter system which can be induced only by sugar starvation causes the decrease of cell viability. As a result, cell death promotes the release of protease which degrades the target proteins. The protein stability and productivity can be significantly influenced by proteolysis activity. Therefore, development of new strategies are necessary for the in situ recovery of target proteins from cell culture media. In this study, in situ recovery was performed by various strategies. Direct addition of Protein A resin with nylon bag leads to cell death by increased shear stress and decrease in production of hCTLA4Ig by protease. Medium exchange through modified flask could recover hCTLA4Ig with high cell viability and low protease activity, on the other hand, the productivity was lower than that of control. When in situ recovery was conducted at day 7 after induction in air-lift bioreactor, 1.94-fold of hCTLA4Ig could be recovered compared to control culture without in situ recovery. Consequently, in situ recovery of hCTLA4Ig from transgenic rice cell culture could enhance productivity significantly and prevent degradation of target proteins effectively.

• Journal of Microbiology and Biotechnology
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• v.14 no.5
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• pp.932-937
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• 2004

In situ extraction by organic solvent was studied in order to improve the recovery yield of hydrocarbon from the culture of Botryococcus braunii, a green colonial microalga. When the solvent mixture of octanol as an extractive solvent and n-octane as a biocompatible solvent was added to a two-phase column, the algal growth was seriously inhibited, even at a low concentration of polar octanol. Therefore, a two-stage cell-recycle extraction process was proposed to improve the contact area between the organic phase and the aqueous phase. The hydrocarbon recovery with in situ cell-recycle extraction showed a three-fold increase (57% of cell) in yield over that with two-phase extraction. In addition, over 60% of the hydrocarbon could be recovered without serious cell damage by downstream separation when this process was applied to the culture broth after batch fermentation.

• Korean Journal of Veterinary Research
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• v.33 no.1
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• pp.179-188
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• 1993

The developmental capacity of bovine oocytes under three different culture systems was investigated in this experiment ; One was culture in TCM199 with bovine oviductal epithelial cells(BOEC) for in vitro culture, another was culture in TCM199 with BOEC for 2 days and then transfer of 4~8cell embryos to rabbit oviduct(RO) and the other was transfer of 1 or 2cell embryos to RO for in vivo culture. And the other concern of this experiment was to investigate the effect of culture period and transfer site on recovery. Immature bovine oocytes were cultured in TCM199 with granulosa cells for 22-24hrs and then fertilized in vitro using frozen-thawed semen treated with BO-caffine and BO-BSA. Fifteen to 18hrs after in vitro fertilization oocytes were cultured in TCM199 with BOEC or transferred to RO for 5 days. The rate of development to the morula or blastocyst was higher in transfer of 1 or 2cell embryos to RO(23.1%) than culture in TCM199 with BOEC(11.7%). But, there was no difference between transfer of 1 or 2cell embryos and transfer of 4~8cell embryos to RO(12.8%). Recovery under different culture periods in RO was significantly higher in 90~95hrs(70.1%) than 122~125hrs(50.9%, p<0.05) and recovery significantly increased when oocytes were transferred deeper in RO(2.5cm>, 47.7% ; 2.5~4.5cm, 63.9% ; 4.5cm<, 77.3%, p<0.05). The results show that transfer of 1 or 2cell embryos to RO is an effective means of supporting the further development of in vitro matured and fertilized bovine oocytes than culture in TCM199 with BOEC or transfer of 4~8cell embryos to RO, and recovery from RO increases when oocytes are transferred deeper and incubated shorter in RO.

• Clinical and Experimental Pediatrics
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• v.56 no.1
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• pp.26-31
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• 2013

Purpose: Lymphocyte subset recovery is an important factor that determines the success of hematopoietic stem cell transplantation (HSCT). Temporal differences in the recovery of lymphocyte subsets and the factors influencing this recovery are important variables that affect a patient's posttransplant immune reconstitution, and therefore require investigation. Methods: The time taken to achieve lymphocyte subset recovery and the factors influencing this recovery were investigated in 59 children who had undergone HSCT at the Department of Pediatrics, The Catholic University of Korea Seoul St. Mary's Hospital, and who had an uneventful follow-up period of at least 1 year. Analyses were carried out at 3 and 12 months post-transplant. An additional study was performed 1 month post-transplant to evaluate natural killer (NK) cell recovery. The impact of pre- and post-transplant variables, including diagnosis of Epstein-Barr virus (EBV) DNAemia posttransplant, on lymphocyte recovery was evaluated. Results: The lymphocyte subsets recovered in the following order: NK cells, cytotoxic T cells, B cells, and helper T cells. At 1 month post-transplant, acute graft-versus-host disease was found to contribute significantly to the delay of $CD16^+/56^+$ cell recovery. Younger patients showed delayed recovery of both $CD3^+/CD8^+$ and $CD19^+$ cells. EBV DNAemia had a deleterious impact on the recovery of both $CD3^+$ and $CD3^+/CD4^+$ lymphocytes at 1 year post-transplant. Conclusion: In our pediatric allogeneic HSCT cohort, helper T cells were the last subset to recover. Younger age and EBV DNAemia had a negative impact on the post-transplant recovery of T cells and B cells.

• Journal of Korean Neurosurgical Society
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• v.40 no.4
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• pp.267-272
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• 2006

Objective : There have been recent reports that mesenchymal stromal cells that are harvested from adipose tissue are able to differentiate into neurons. In the present study, we administered adipose tissue derived stem cells in rats with cerebral infarction in order to determine whether those stem cells could enhance the recovery of motor function. Methods : Cerebral infarction was induced by intraluminal occlusion of middle cerebral artery in rats. The adipose tissue-derived mesenchymal stem cells were harvested from inguinal fat pad and proliferated for 2 weeks in DMEM media. Approximately $1{\times}10^6$ cells were injected intravenously or into subdural space of the peri-lesional area. The rotor rod test was performed at preoperative state[before MCA occlusion], and 1, 2, 3, 4, 6, 8 and 10 weeks after the cell therapy. Results : The motor functions that were assessed by rotor rod test at 1 week of the cell therapy were nearly zero among the experimental groups. However, there was apparent motor function recovery after 2 weeks and 4 weeks of cell injection in intravenously treated rats and peri-lesionaly treated rats, respectively, while there was no significant improvement till 8 weeks in vehicle treated rats. Conclusion : These results demonstrate that the adipose derived stem cell treatment improves motor function recovery in rats with cerebral infarction.