• Journal of Embryo Transfer
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• v.12 no.3
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• pp.259-267
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• 1997

To improve the efficiency of production of cloned embryos and animals by nuclear transplantation in the rabbit, the effect of cell cycle of donor nuclei and type of recipient cytoplasm on the in vitro developmental potential and production efficiency of offspring was determined. The embryos of 16-cell stage were collected from the mated does at 48h post-hCG injection and they were synchronized to G$_1$ phase of 32-cell stage. The oocytes collected at 14h post-hCG injection were freed from cumulus cells and then enucleated. One group of the enucleated cytoplasms was activated by electrical stimulation prior to injection of donor nucleus, and the other group was not pre-activated. The separated G$_1$phase blastomeres of 32-cell stage embryos were injected into the perivitelline space of recipient cytoplasms. After culture for 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation and the fused nuclear transplant embryos were co-cultured for 120h and the nuclear transplant embryos developed to blastocyst stage were stained with Hoechst 33342 dye and their blastomeres were counted. Some of the nuclear transplant embryos developed in vitro to 2- to 4-cell stage were transferred into the oviducts of synchronized recipient does. The electrofusion rate was similar between the types of donor nuclei and recipient cytoplasms used. However, the nuclear transplant embryos using G$_1$ phase donor nuclei were developed to blastocyst at higher rate(60.3%) than those using S phase ones(24.7%). Also, when non-preactivated oocytes were used as recipient cytplasms, the develop-mental rates of nuclear transplant embryos to blastocysts were significantly(P< 0.05) higher(57.1%) than those using preactivated ones(20.8%). The cell counts of nuclear transplant embryos developed to blastosyst stage were increased signficantly(P<0.05) more in the non-preactivated recipient cytoplasm(163.7 cells), as compared whit the preactivated recipient cytoplasm(85.4 cells), A total of 49 nuclear transplant embryos were tranferrid into 5 recipient does, of which two offsprings were produced from a foster mother 31 days after embryo transfer. these results showed that the blastomeres of G1 phase and non-preactivated oocytes might be utillzed efficiently as donor nuclei and recipient cytoplasms in the nuclear transplant procedure, thought the offspring production remained still low.

• Journal of the Society of Disaster Information
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• v.15 no.4
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• pp.597-606
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• 2019

Purpose: This paper is for the improvement of the safety education system in the construction industry, which has become a great threat to domestic industrial safety. Among the industrial sectors, the accident rate and death rate in the construction industry are the highest, and measures for falls in the litigation work are needed. Method: The application of the Analytic Hierarchy Process(AHP) resulted in the following conclusions. Results: The management group of the construction industry was divided into a group of on-site workers. In addition, the practical education system was reviewed by analyzing differences in perceptions of safety education. The survey results of the two groups were analyzed through AHP by dividing the construction safety education system into three layers. Conclusion: The results showed that managers showed a great deal of importance, such as actual conditions for implementation related to education, while on-site workers indicated importance for items that were somewhat site-oriented compared to managers. In addition, the two groups did not place much weight on the effectiveness of AR and VR, which have been expanding into safety education recently.

• ALGAE
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• v.35 no.1
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• pp.45-59
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• 2020

To investigate the spatio-temporal distributions of the mixotrophic dinoflagellate Yihiella yeosuensis in Korean coastal waters and its grazing impact on prey populations, water samples were seasonally collected from 28 stations in the East, West, and South Seas of Korea and Jeju Island from April 2015 to October 2018. The abundances of Y. yeosuensis in the water samples were quantified using quantitative real-time polymerase chain reaction (qPCR). Simultaneously, the physical and chemical properties of water from all sampled stations were determined, and the abundances of the optimal prey species of Y. yeosuensis, the prasinophyte Pyramimonas sp. and the cryptophyte Teleaulax amphioxeia, were quantified using qPCR. Y. yeosuensis has a wide distribution, as is reflected by the detection of Y. yeosuensis cells at 23 sampling stations; however, this distribution has a strong seasonality, which is indicated by its detection at 22 stations in summer but only one station in winter. The abundance of Y. yeosuensis was significantly and positively correlated with those of Pyramimonas sp. and T. amphioxeia, as well as with water temperature. The highest abundance of Y. yeosuensis was 48.5 cells mL^-1 in Buan in July 2017, when the abundances of Pyramimonas sp. and T. amphioxeia were 917.6 and 210.4 cells mL^-1, respectively. The growth rate of Y. yeosuensis on Pyramimonas sp., calculated by interpolating the growth rates at the same abundance, was 0.49 d^-1, which is 37% of the maximum growth rate of Y. yeosuensis on Pyramimonas sp. obtained in the laboratory. Therefore, the field abundance of Pyramimonas sp. obtained in the present study can support a moderate positive growth of Y. yeosuensis. The maximum grazing coefficient for Y. yeosuensis on the co-occurring Pyramimonas sp. was 0.42 d^-1, indicating that 35% of the Pyramimonas sp. population were consumed in 1 d. Therefore, the spatio-temporal distribution of Y. yeosuensis in Korean coastal waters may be affected by those of the optimal prey species and water temperature. Moreover, Y. yeosuensis may potentially have considerable grazing impacts on populations of Pyramimonas sp.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1776-1788
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• 2019

Objective: The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF). Methods: ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells ($M{\Phi}$) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B ($NF-{\kappa}B$) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 $M{\Phi}$ cells was evaluated by the colony forming unit assay. Results: ASF upregulated the cell viability and growth rate of 3D4/31 $M{\Phi}$, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of $NF-{\kappa}B$ protein, tumor necrosis factor $(TNF){\alpha}$ mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of $NF-{\kappa}B$, $TNF{\alpha}$, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 $M{\Phi}$ against Escherichia coli. Conclusion: This study provides a novel insight into the regulation of $NF-{\kappa}B$ activity and lipid metabolism in $M{\Phi}$, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.

• Environmental Engineering Research
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• v.24 no.2
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• pp.254-262
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• 2019

The impact of free cyanide ($CN^-$) and thiocyanate ($SCN^-$) on the $CN^-$ (CDO) and $SCN^-$ degraders (TDO) to nitrify and denitrify aerobically was evaluated under alkaline conditions. The CDO's were able to nitrify under cyanogenic conditions, achieving $NH_4{^+}-N$ removal rates above 1.66 mg $NH_4{^+}-N.L^{-1}.h^{-1}$, except when $CN^-$ and $SCN^-$ loading was 15 mg $CN^-/L$ and 50 mg $SCN^-.L^{-1}$, respectively, which slightly inhibited nitrification. The TDO's were able to achieve a nitrification rate of 1.59 mg $NH_4{^+}-N.L^{-1}.h^{-1}$ in the absence of both $CN^-$ and $SCN^-$, while the presence of $CN^-$ and $SCN^-$ was inhibitory, with a nitrification rates of 1.14 mg $NH_4{^+}-N.L^{-1}.h^{-1}$. The CDO's and TDO's were able to denitrify aerobically, with the CDO's obtaining $NO_3{^-}-N$ removal rates above 0.67 mg $NO_3{^-}-N.L^{-1}.h^{-1}$, irrespective of the tested $CN^-$ and $SCN^-$ concentration range. Denitrification by the TDO's was inhibited by $CN^-$, achieving a removal rate of 0.46 mg $NO_3{^-}-N.L^{-1}.h^{-1}$ and 0.22 mg $NO_3{^-}-N.L^{-1}.h^{-1}$ when $CN^-$ concentration was 10 and 15 mg $CN^-.L^{-1}$, respectively. However, when the CDO's and TDO's were co-cultured, the nitrification and aerobic denitrification removal rates were 1.78 mg $NH_4{^+}-N.L^{-1}.h^{-1}$ and 0.63 mg $NO_3{^-}-N.L^{-1}.h^{-1}$ irrespective of $CN^-$ and $SCN^-$ concentrations.

• The Journal of Engineering Geology
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• v.28 no.4
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• pp.541-552
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• 2018

The implementation of drought measures in the upstream areas of river basins is seldom considered with respect to water supply. However, the demand for such measures is increasing rapidly owing to the occurrence of severe droughts, and interventions on streams and the water supply are needed. Physical interventions are an option to prevent streams from becoming dry and to maintain stream water flow, but dam construction is challenging because of environmental and ecological considerations. Here, a feasibility study was conducted to assess the potential effects of sand dams, which are widely used in arid regions in Africa. The SWAT-K model, which is a hydrologic model used for Korean watersheds, is used to estimate the flow rate of water in an ungauged watershed. The changes in water storage of the sand-dammed reservoir and in downstream flow rates are estimated for two types of sand dam (natural and dredged). The results show that sand dams are capable of increasing the downstream flow rate during normal conditions and of mitigating water supply problems caused by the withdrawal of water during drought periods.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.6
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• pp.571-576
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• 1994

This study was conducted to determine the effects of embryo age, growth regulators, low temperature treatment on regeneration, plant growth, and heading in immature embryo culture of Barley. Shoot and root development was more in older than in younger excised embryos, and more in a medium without kinetin than in one with kinetin. The rate of survival was higher on medium without growth regulators and lower on medium with kinetin 5 mg/L because of retarded plant growth. Embryo age and media did not completely replace low temperature treatment. Twenty- and 14 day-old embryos responded by flowering after 4 weeks of vernalization. Embryo culture at 14- and 20 days after anthesis coupled with 4-week cold treatment shortens generation time of barley. When 20 day immature embryos of barley (cv. Olbori) was treated low temperature treatment for 4 weeks, the rate of heading was better than the other treatment.

• Korean Journal of Radiology
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• v.21 no.6
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• pp.736-745
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• 2020

Objective: To identify the initial chest computed tomography (CT) findings and clinical characteristics associated with the course of coronavirus disease 2019 (COVID-19) pneumonia. Materials and Methods: Baseline CT scans and clinical and laboratory data of 72 patients admitted with COVID-19 pneumonia (39 men, 46.2 ± 15.9 years) were retrospectively analyzed. Baseline CT findings including lobar distribution, presence of ground glass opacities, consolidation, linear opacities, and lung severity score were evaluated. The outcome event was recovery with hospital discharge. The time from symptom onset to discharge or the end of follow-up (for those remained hospitalized) was recorded. Data were censored in events such as death or discharge without recovery. Multivariable Cox proportional hazard regression was used to explore the association between initial CT, clinical or laboratory findings, and discharge with recovery, whereby hazard ratio (HR) values < 1 indicated a lower rate of discharge at four weeks and longer time until discharge. Results: Thirty-two patients recovered and were discharged during the study period with a median length of admission of 16 days (range, 9 to 25 days), while the rest remained hospitalized at the end of this study (median, 17.5 days; range, 4 to 27 days). None died during the study period. After controlling for age, onset time, lesion characteristics, number of lung lobes affected, and bilateral involvement, the lung severity score on baseline CT (> 4 vs. ≤ 4 [reference]: adjusted HR = 0.41 [95% confidence interval, CI = 0.18-0.92], p = 0.031) and initial lymphocyte count (reduced vs. normal or elevated [reference]: adjusted HR = 0.14 [95% CI = 0.03-0.60], p = 0.008) were two significant independent factors that influenced recovery and discharge. Conclusion: Lung severity score > 4 and reduced lymphocyte count at initial evaluation were independently associated with a significantly lower rate of recovery and discharge and extended hospitalization in patients admitted for COVID-19 pneumonia.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.500-512
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• 2000

Background : To evaluate the efficacy of two methods of obtaining lung recruitment to reduce ventilator-induced lung injury(VILI). Methods : Fifteen New-Zealand white rabbits were ventilated in the pressure-controlled mode while maintaining constant tidal volume(10 ml/kg) and fixed respiration rate. Lung injury was induced by repeated saline lavage (PaO2<100 mmHg), and the pressure-volume curve was drawn to obtain Pflex. The animals were then randomly assigned to three groups and ventilated for 4 hours. In the control group(n=5), positive end-expiratory pressure(PEEP) less than that of Pflex by 3 mmHg was applied throughout the study. In the recruitment maneuver(RM) group(n=5), RM(CPAP of 22.5 mmHg, for 45 seconds) was performed every 15 minutes in addition to PEEP level less than Pflex by 3 mmHg This phrase is unclear. In the Pflex group, PEEP of Pflex was given without RM. Gas exchange, lung mechanics, and hemodynamics parameters as well as pathology were examined. Results : 1) Both the control and RM groups showed decreasing tendency in PaO2 with time. There was significantly decreased PaO2 at 4 hr compared to Ihr(p<0.05). But in the Pflex group, PaO2 did not decrease with time(p<0.05 vs other groups at 3, 4 hr). PaCO2 did not show significant difference among the three groups. 2) There was no significant difference in static compliance and plateau pressure. Mean blood pressure and heart rate also did not show any significant difference among the three groups. 3) The pathologic exam showed significantly less neutrophil infiltration in the Pflex group than in the control group(p<0.05). There was borderline significant difference in hyaline membrane score among the groups (p= 0.0532). Conclusion : Although recruitment maneuver of the injured lung may be important in decreasing VILI, it alone may not be sufficient to minimize VILI.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.6
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• pp.499-503
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• 2013

This study tested the hypothesis that effects of the menstrual cycle on resting blood pressure carry over to dynamic exercise. Eleven healthy females were studied during the early (EP; low estrogen, low progesterone) and late follicular (LP; high estrogen, low progesterone) menstrual phases. Stroke volume (SV), heart rate (HR), cardiac output (CO), systolic blood pressure (SBP), diastolic blood pressure (DBP), and total vascular conductance (TVC) were assessed at rest and in response to mild and moderate cycling exercise during EP and LP. During EP, compared to LP, baseline SBP ($111{\pm}1$ vs. $103{\pm}2$ mmHg), DBP ($71{\pm}2$ vs. $65{\pm}2$ mmHg) and mean arterial pressure (MAP) ($84{\pm}2$ vs. $78{\pm}1$ mmHg) were higher and TVC ($47.0{\pm}1.5$ vs. $54.9{\pm}4.2$ ml/min/mmHg) was lower (p<0.05). During exercise, absolute values of SBP (Mild: $142{\pm}4$ vs. $127{\pm}5$ mmHg; Moderate: $157{\pm}4$ vs. $144{\pm}5$ mmHg) and MAP (Mild: $100{\pm}3$ vs. $91{\pm}3$ mmHg; Moderate: $110{\pm}3$ vs. $101{\pm}3$ mmHg) were also higher, while TVC was lower (Mild: $90.9{\pm}5.1$ vs. $105.4{\pm}5.2$ ml/min/mmHg; Moderate: $105.4{\pm}5.3$ vs. $123.9{\pm}8.1$ ml/min/mmHg) during EP (p<0.05). However, exercise-induced increases in SBP, MAP and TVC at both work intensities were similar between the two menstrual phases, even though norepinephrine concentrations were higher during LP. Results indicate that blood pressure during dynamic exercise fluctuates during the menstrual cycle. It is higher during EP than LP and appears to be due to additive effects of simultaneous increases in baseline blood pressure and reductions in baseline TVC.