• Journal of Microbiology and Biotechnology
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• v.22 no.12
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• pp.1653-1658
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• 2012

We have reported previously that a recombinant Escherichia coli co-expresses aminolevulinic acid (ALA) synthase, an NADP-dependent malic enzyme, and a dicarboxylate transporter-produced heme, an iron-chelated porphyrin, in a succinate-containing complex medium. To develop an industrially plausible process, a chemically defined medium was formulated based on M9 minimal medium. Heme synthesis was enhanced by adding sodium bicarbonate, which strengthened the C4 metabolism required for the precursor metabolite, although a pH change discouraged cell growth. Increasing the medium pH buffering capacity (100mM phosphate buffer) and adding sodium bicarbonate enabled the recombinant E. coli to produce heme at rates 60% greater than those in M9 minimal medium. Adding growth factors (1 mg/l thiamin, 0.01 mg/l biotin, 5 mg/l nicotinic acid, 1 mg/l pantothenic acid, and 1.4 mg/l cobalamin) also induced positive heme production effects at levels twice of heme production in M9-based medium. Porphyrin derivatives and heme were found in the chemically defined medium, and their presence was confirmed by liquid chromatography/mass spectroscopy (LC/MS). The formulated medium allowed for the production of $0.6{\mu}M$ heme, $29{\mu}M$ ALA, $0.07{\mu}M$ coproporphyrin I, $0.21{\mu}M$ coproporphyrin III, and $0.23{\mu}M$ uroporphyrin in a 3 L pH-controlled culture.

• Journal of Convergence for Information Technology
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• v.9 no.11
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• pp.55-61
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• 2019

This study was conducted to identify the predictors of the choice of regional small and medium hospitals by identifying the job preference, recognition of small and medium hospitals. For this purpose, data were collected from September 2018 to October 2018 for nursing students attending 4 universities in Gwangju and Jeollanam - do, and total of 476 questionnaires were analyzed using the SPSS / WIN 24.0 program. The results showed that 66.0% of nursing students selected region local small and medium hospitals. The factors influencing the choice of region small and medium hospitals were high school region, nursing school performance and recognition of small and medium hospitals. In order to increase the employment rate of nursing students to the region small and medium hospitals, nursing educators should provide personalized career guidance to students who want to work in small and medium hospitals and hospital personnel should establish various public relations activities and marketing strategies to raise recognition of small and medium hospitals.

• Journal of Veterinary Science
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• v.22 no.6
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• pp.86.1-86.13
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• 2021

Background: Conditioned medium is the medium obtained from certain cultured cells and contained secretome from the cells. The secretome, which can be in the form of growth factors, cytokines, exosomes, or other proteins secreted by the cells, can induce the differentiation of cells that still have pluripotent or multipotent properties. Objectives: This study examined the effects of conditioned medium derived from E17 rat brain cells on cells with pluripotent properties. Methods: The conditioned medium used in this study originated from E17 rat brain cells. The CM was used to induce the differentiation of primary colonies of mice blastocysts. Primary colonies were stained with alkaline phosphatase to analyze the pluripotency. The morphological changes in the colonies were examined, and the colonies were stained with GFAP and Neu-N markers on days two and seven after adding the conditioned medium. Results: The conditioned medium could differentiate the primary colony, beginning with the formation of embryoid-body-like structure; round GFAP positive cells were identified. Finally, neuron-like cells testing positive for Neu-N were observed on the seventh day after adding the conditioned medium. Conclusions: Conditioned medium from different species, in this case, E17 rat brain cells, induced and promoted the differentiation of the primary colony from mice blastocysts into neuron-like cells. The addition of CM mediated neurite growth in the differentiation process.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.1
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• pp.26-32
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• 2022

Objective: We investigated the effect of supplementing fertilization medium and/or culture medium with astaxanthin (AST) on the two phases of in vitro fertilization: gamete fertilization and embryo development. Methods: Mouse cumulus-oocyte complexes were divided into four groups with 5 µM AST added to the fertilization medium (group 3, n=300), culture medium (group 2, n=300), or both media (group 4, n=290). No AST was added to the control group (group 1, n=300). Results: The fertilization rate was significantly higher (p<0.001) in the groups using AST supplemented fertilization medium (group 3, 79.0%; group 4, 81.4%) than those without AST (group 1, 56.3%; group 2, 52.3%). The blastocyst rate calculated from the two-cell stage was significantly lower (p<0.001) in the groups using AST-supplemented embryo culture medium (group 2, 58.0%; group 4, 62.3%) than in those without AST (group 1, 82.8%; group 3, 79.8%). The blastocyst rate calculated from the number of inseminated oocytes was highest in group 3 (189/300, 63.0%) and lowest in group 2 (91/300, 30.3%) with statistical significance compared to other groups (p<0.001). There were significantly higher numbers of cells in the inner cell mass and trophectoderm, as well as significantly higher total blastocyst cell counts, in group 3 than in the control group. Conclusion: An increased blastocyst formation rate and high-quality blastocysts were found only in the fertilization medium that had been supplemented with AST. In contrast, AST supplementation of the embryo culture medium was found to impair embryo development.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.3
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• pp.143-150
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• 2023

Background: The successful production of superior or transgenic offspring from in vitro produced embryos in cattle relies heavily on the quality of blastocyst stage embryos. In order to enhance the developmental competency of these embryos, a novel culture method was devised. Methods: This study utilized stem cell culture medium (SCM) from hESCs as a supplement within the culture medium for bovine in vitro produced embryos. To gauge the efficacy of this approach, in vitro fertilized embryos were subjected to culture in CR1aa medium enriched with one of three supplements: 0.3% BSA, 10% FBS, or 10% SCM. Results: The blastocyst development and hatching rates of one-cell zygotes cultured in CR1aa medium supplemented with SCM (23.9% and 10.2%) surpassed those cultured in CR1aa medium supplemented with BSA (9.3% and 0.0%) or FBS (3.1% and 0.0%) (p < 0.05). Furthermore, post-zygotic gene activation, cleaved embryos cultured in CR1aa medium supplemented with SCM (57.8% and 34.5%) exhibited notably higher rates (p < 0.05) compared to those cultured with BSA (12.9% and 0.0%) or FBS (45.7% and 22.5%) supplementation. Furthermore, the microinjection of SCM into the cytoplasm or pronucleus of fertilized zygotes resulted in elevated blastocyst development and hatching rates, particularly when the microinjected embryos were subsequently cultured in CR1aa medium supplemented with SCM from the 8-cell embryo stage onwards (p < 0.05), in contrast to those cultured with FBS supplementation. Conclusions: In conclusion, this study conclusively demonstrated that the incorporation of SCM into the culture medium significantly enhances the developmental progress of preimplantation embryos.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.53-61
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• 1995

The experiments were performed to determine whether the cardiac depressant action of lidocaine is directly associated with the utilization of endogenous substrates in isolated rat atria, by using citrate and bicarbonate-free medium known as potent inhibitors of phosphofructokinases (PFK) enzyme step. Citrate and bicarbonate-free medium produced negative inotropic action of isolated rat atria incubated in normal Krebs-Ringer bicarbonate glucose medium. Pyruvate and acetate increased the force of contraction of atria depressed by citrate or bicarbonate-free medium, whereas fructose was without effect indicating the inhibitory effect of citrate and bicarbonate-free medium at some point in the glycolytic pathway such as the PFK step in atria. In the absence of exogenous substrate, citrate and bicarbonate-free medium produced a marked depression of the force of substrate-depleted atria indicating that utilization of endogenous substrate above the PFK step, probably cardiac glycogen, is also impaired by citrate or bicarbonate-free medium. Lidocaine produced further depression of the contractile force of atria depressed by citrate. These results argue strongly for an additional mechanism of cardiac depression caused by lidocaine involving the sites below the PFK.

• The Korean Journal of Mycology
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• v.11 no.2
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• pp.79-84
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• 1983

To study physiological and ecological characters of the secondary mycelia of Armillariella mellea, it was cultivated on the various media. It was grown very well on the malt extract medium compared with its growth on yeast extract medium, potato dextrose medium and Hamada medium. The temperature of $27^{\circ}C$ gave the best condition for it to grow. The highest rate of growth was shown in medium of pH 6. Heteroauxin of 5 ppm concentration showed a increase as 26.2% in growth in compared with the control group. Gibberelline 10ppm, Tomatoton of 10,000 dilution and Adoton of 5,000 dilution showed positive effect. It was shown that the use of above hormones in appropriate concentration brought the effect of growth, but overuse of them brought inhibitory effect. Under the same condition of 200ppm concentration, vitamin A gave the highest growth of 18.2% than that of the control used.

• Journal of Veterinary Clinics
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• v.38 no.3
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• pp.135-142
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• 2021

The aim of this study was to evaluate the contrast effect if a saline flush following low-volume contrast medium bolus improves vascular and parenchymal enhancement using a saphenous vein in abdominal CT for small animals. Six clinically healthy beagle dogs underwent abdominal contrast-enhanced CT. They were divided into nine groups (each group, n = 6), according to the volume of contrast medium 1, 2, and 3 mL/kg, and volume of the saline solution 0, 5, and 10 mL. Dynamic CT scanning was performed at the hepatic hilum level. The maximum contrast enhancement, time to maximum enhancement, and time to equilibrium phase were calculated from the time attenuation curves. Mean attenuation values for all groups were measured in the aorta, portal vein, and liver. After contrast enhancement, grading of image quality regarding surrounding artifacts and evaluation of the hepatic hilum structures was performed. For comparison of the effect of the contrast material and saline solution doses, differences in mean attenuation values between the contrast medium 2 mL/kg without saline flush group and the remaining groups, and between contrast medium 3 mL/kg without saline flush group and the remaining groups, were analyzed for statistical significance. There were no significant differences between with and without saline flushing at the same contrast medium dose groups. There were no significant differences in peak values between the 3 mL/kg dose of contrast medium alone and the 2 mL/kg dose of contrast medium with saline solution flush. However, there was a significant difference in peak values between the 3 mL/kg dose of the contrast medium without the saline flush group and the 2 mL/kg dose of the contrast medium alone group. Grades of the artifacts were not significantly different in the saline flush regardless of the dose of the contrast medium. Using 2 mL/kg of contrast medium with saline solution flush resulted in similar liver parenchyma attenuation, compared with using 3 mL/kg of contrast medium without saline solution flush. In CT evaluation of hepatic parenchymal diseases, using 2 mL/kg of contrast medium with saline solution flush may yield decreased risk of contrast nephropathy and cost-saving.

• Korean Business Review
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• v.9
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• pp.99-121
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• 1996

On the job training is useful : a part of on the job training has increased the marginal productivity of future and rate of wage. Investment in a human capital depends on character of investment and market conditions. The innovation role of small and medium firms has recently received increasing attention in newly industrializing countries as they attempt to transform their industries from labor intensive to technology intensive. It also suggests some implications to the small and medium firms' strategies and public policies accelerating research and development. Lack of qualified scientists and engineers often inhibits the small and medium firms' ability to access and assimilate external technical information. Such technical personnel are particularly scarce in NICs. Therefore, how to employ these technical staff should be an important issue for small and medium firms seeking to acquire distinctive competences. Small and medium firms must invest further education and training to its labor.

• Journal of Korea Port Economic Association
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• v.20 no.1
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• pp.141-151
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• 2004

Although the small and medium ports are actually competing with various strategies, the definition and structural understanding of small and medium ports are not known very much. Therefore this study has launched from this fact, and has the objective of obtaining the structural model for increasing shippers' attraction of small and medium ports. The process began by abstracting the components that composed the success factors through recent research, and grouping it by FA(Factor Analysis) method. Also, by using the FSM(Fuzzy Structural Modeling) method to understand the structure of the grouped components, and the structural model for increasing shippers' attraction of small and medium ports was able to obtain as the result. When analyzing the obtained structural model, easiness of shipment, connection to hubport and efficiency of hinterland network came out to be the most important component groups.