• Journal of Microbiology and Biotechnology
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• 제22권12호
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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.

• 융합정보논문지
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• 제9권11호
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• pp.55-61
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• 2019

본 연구는 간호대학생을 대상으로 취업선호도, 중소병원에 대한 인지도를 파악하여 지역 중소병원 선택의 예측요인을 파악하기 위하여 시도되었다. 광주광역시와 전라남도 소재 4개 대학교에 재학 중인 간호대학생을 대상으로 2018년 9월부터 2018년 10월까지 자료를 수집하였으며, 부적절한 응답지를 제외한 476명의 설문지를 SPSS/WIN 24.0 프로그램을 이용하여 분석하였다. 연구결과, 간호대학생이 지역 중소병원을 선택한 경우는 66.0%였고, 중소병원 선택의 예측요인은 고등학교 졸업지역, 학업성취도, 중소병원에 대한 인지도였다. 본 연구결과를 통해 간호대학생이 지역 중소병원으로의 취업률을 높이기 위해서는 간호교육자들은 중소병원취업을 희망하는 학생들에게는 역량을 고려한 맞춤형 진로지도 및 상담을 해야겠으며, 병원 관계자들은 중소병원에 대한 인지도를 높이기 위한 다양한 홍보활동 및 마케팅 전략을 수립해야겠다.

• Journal of Veterinary Science
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• 제22권6호
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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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• 제49권1호
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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.

• 한국동물생명공학회지
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• 제38권3호
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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.

• 대한약리학회지
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• 제31권1호
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• pp.53-61
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• 1995

Lidocaine의 심근 수축력 억제 기전이 적출 심장에서 내인성 기질의 사용과 관련이 있는가를 규명하기 위하여, 심장의 phosphofructokinase (PFK)에 대한 강력한 억제 작용을 나타내는 citracte와 bicarbonate-free medium을 이용하여 쥐의 적출 심방 수축성에 대한 lidocaine의 영향을 연구하여 다음과 같은 실험 결과를 얻었다. Citrate와 bicarbonate-free medium은 쥐의 적출 심방의 수축력을 현저히 저하시켰다. Pyruvate나 acetate는 citracte와 bicarbonate-free medium에서 저하된 심방 수축력을 현저히 증가시키는 반면, fructose는 수축력을 증가시키지 못했다. 이 결과는 citrate와 bicarbonate-free medium이 Embden-Meyerhof pathway의 일부, 즉 PFK step을 억제함을 시사한다. 외인성 기질이 없을때 citrate와 bicarbonate-free medium은 기질 제거 용액에서 심방 수축력을 현저히 감소시키며, acetate에 의해 수축력이 회복되었다. 이는 PFK step 이전 단계의 내인성 기질 (glycogen)이 citrated에 의해 억제됨을 시사한다. Lidocaine은 citrate에 의해 억제된 수축력을 더욱 감소시켰다. 이 결과는 lidocaine에 의한 심방 수축력 억제가 PFK step 이후 단계의 내인성 기질 억제에 의한 것임을 시사한다. 이상의 결과로 보아 lidocaine의 적출 심방에 대한 수축력 억제 작용은 두가지 (또는 그 이상)의 기전에 의한 것으로 사료된다: 하나는 PFK step 전단계의 해당과정의 억제기전이고 또 다른 기전은 PFK step 이후의 내인성 기질(들)의 억제인 것으로 사료된다.

• 한국균학회지
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• 제11권2호
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• pp.79-84
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• 1983

Armillariella mellea의 2차균사를 potato dextrose medium, yeast extract medium, malt extract medium Hamada medium, 등에 배양해서 생리 생태적 성질을 연구했다. 그 결과를 요약하면 아래와 같다. 1. 사용했던 4종의 배치 중에서 malt extract medium에서 가장 잘 자랐고, 그 다음 yeast extract medium, potato dextrose medium 그리고 Hamada medium 순으로 생육율이 높였다. 2. $27^{\circ}C$에서 가장 잘 자랐고, $36^{\circ}C$에서는 집락의 지름이 $27^{\circ}C$와 비슷하나 균사의 밀도가 매우 낮았다. 3. pH6에서 가장 높은 생육율을 나타내었다. 4. 식물 생장 호르몬을 첨가한 경우에는 Heteroauxin의 5ppm 농도에서 대조군보다 26.2% 증가로 가장 많은 생육 증량을 보이고, 다음으로 gibberellin 100ppm, Tomatoton 10,000배액, 그리고 Adoton 5,000배액의 순서였다. 식물 생장 호르몬을 적당 농도로 사용하면 생장 증량 효과를 얻을 수 있으나, 과량 사용할 경우, 오히려 생장 억제 효과를 나타내었다. 5. Vitamin 첨가경우에 있어 200ppm 농도의 균일한 조건하(下)에서 Vit.A 첨가군에서 대조군보다 18.2%의 가장 많은 생육 증량을 보였고, $Vit{\cdot}D_2\;Vit{\cdot}E,\;Vit{\cdot}B_1\;folic\;accid\;Vit{\cdot}C$ 그리고 $Vit{\cdot}B_2$의 순으로 그 증가가 나타나 지용성 비타민 첨가 배지에서 상당한 생육율을 나타내었다.

• 한국임상수의학회지
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• 제38권3호
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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.

• 산학경영연구
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• 제9권
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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.

• 한국항만경제학회지
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• 제20권1호
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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.