• 한국수정란이식학회지
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• 제32권3호
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• pp.81-86
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• 2017

The Somatic cell nuclear transfer (SCNT) method can be applied to various fields such as species conservation, regenerative medicine, farming industries and drug production. However, the efficiency using SCNT is very low for many reasons. One of the troubles of SCNT is that it is highly dependent on the researcher's competence. For that reason, four somatic cell nuclear injection methods were compared to evaluate the effect of hole-sealing process and existence of cytochalasin B (CB) on efficiency of murine SCNT protocol. As a results, the microinjection with the hole-sealing process, the oocyte plasma membrane is inhaled with injection pipette, in HCZB with CB was presented to be the most efficient for the reconstructed in SCNT process. In addition, we demonstrated that the oocytes manipulated in Hepes-CZB medium (HCZB) with CB does not affect the developmental rate and the morphology of the blastocyst during the pre-implantation stage. For this reason, we suggest the microinjection involving hole-sealing in HCZB with CB could improve SCNT process efficiency.

• Nuclear Engineering and Technology
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• 제56권6호
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• pp.2324-2331
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• 2024

The current study investigated Saudi Arabian oil fly ash impacts on Egyptian clay bricks' structural and radiation shielding properties. To produce the required bricks, crushed clay minerals from the Hafafit area were mixed with 0, 10, 20, 30, and 40 % wt.% Saudi Arabian oil fly ash and pressed at a pressure rate of 68.55 MPa. Identification of the minerals in the chosen clay was achieved via X-ray diffraction. Additionally, the material's morphology and chemical composition were determined through scanning electron microscope and energy-dispersive X-ray. The fabricated bricks' density was reduced by 36.3 % through increasing the concentration of fly ash from 0 to 40 wt%. Then, the fly ash addition's influence on the fabricated clay bricks' γ-ray shielding properties was investigated by Monte Carlo simulation, which found a reduction in the fabricated bricks' linear attenuation coefficient (LAC) by 41.2, 36.0, 33.8, and 33.8 % at the 0.059, 0.103, 0.662, and 1.252 MeV γ-ray energies, respectively. The LAC reduction caused an increase in the fabricated bricks' half-value thickness, transmission factor, and the equivalent thickness of the lead. Moreover, the thicker fabricated sample thicknesses were found to have high γ-ray shielding capacity and can thus be used in radiation shielding applications.

• 한국응용곤충학회지
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• 제34권3호
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• pp.218-223
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• 1995

담배와 고추의 주요해충인 담배나방 [Helicoverpa assulta(Guenee)]의 미생물적 방제법을 개발하기 위하여, 아직 국내에서 보고되지 않은 담배나방 핵다각체병 바이러스 담배나방 사충으로 부터 분리하고, 바이러스의 전자현미경 관찰 및 바이러스 DNA의 제한효소 분석 등을 통한 생화학적 특성을 조사하였다. 담배나방 핵다각체병 바이러스의 다각체는 구형에 가까운 20면체로서 크기는 평균 약 1.0$\mu$m 정도이고, 다수의 바이러스 입자가 다각체 단백질에 포매되어 있었다. 포매된 바이러스 입자는 한개의 봉상 nucleocapsid가 하나의 envelope 내에 매립된 형태의 SNPV(single embedded nuclear polyhedrosis virus)로, 형태는 전형적인 봉상으로서 그 크기는 약 $65nm\times300nm$ 였다. 또한 다각체 단백질의 SDS-PAGE 분석 결고, 분자량은 약 31 Kd이었으며, 담배나방 핵다각체병바이러스 DNA를 분리하여 EcoRI. HindIII 등 수종의 제한효소로 처리분석한 결과, 그 genome의 크기는 약 120Kb 정도였다. 본 핵다각체병바이러스는 담배나방 유충에만 병원성을 나타내 기주특이성을 보였다.

• Corrosion Science and Technology
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• 제6권2호
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• pp.37-43
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• 2007

Iodine sulfur (IS) process is one of the promising processes for a hydrogen production by using a high temperature heat generated by a very high temperature gas cooled reactor(VHTR) in the nuclear power industries. Even though the IS process is very efficient for a hydrogen production and it is not accompanied by a carbon dioxide evolution, the highly corrosive environment of the process limits its application in the industry. Corrosion tests of selected materials were performed in sulfuric acid to select appropriate materials compatible with the IS process. The materials used in this work were Fe-Cr alloys, Fe-Ni-Cr alloys, Fe-Si alloys, Ni base alloys, Ta, Ti, Zr, SiC, Fe-Si, etc. The test environments were 50 wt% sulfuric acid at $120^{\circ}C$ and 98 wt% at $320^{\circ}C$. Corrosion rates were measured by using a weight change after an immersion. The surface morphologies and cross sectional areas of the corroded materials were examined by using SEM equipped with EDS. Corrosion behaviors of the materials were discussed in terms of the chemical composition of the materials, a weight loss, the corrosion morphology, the precipitates in the microstructure and the surface layer composition.

• Animal Bioscience
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• 제35권6호
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• pp.858-868
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• 2022

Objective: This study was conducted to evaluate the effects of dietary yeast hydrolysate (YH) supplementation on intestinal morphology, barrier, and anti-inflammatory functions of broilers. Methods: A total of 320 one day old male broilers were randomly allocated into four groups with eight replicates of ten broilers each. The broilers were supplemented with a basal diet (the control group) or basal diets adding 50, 100, 150 mg/kg YH, respectively. This trial lasted for 42 days. The orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing levels of YH. Results: In our previous research, supplementing YH improved growth performance by enhancing body weight gain but decreased feed-to-gain ratio. In this study, compared with the control group, dietary YH addition linearly and quadratically decreased serum diamine oxidase activity (p<0.05). Additionally, supplementing YH linearly and/or quadratically decreased jejunal crypt depth (CD), tumor necrosis factor-alpha (TNF-α) concentration as well as mucin 2, interleukin-6 (IL-6), IL-1β, TNF-α, nuclear factor kappa B, and myeloid differentiation factor 88 gene expression levels (p<0.05). Whereas the jejunal villus height (VH), VH/CD, IL-10 concentration as well as zonula occludens-1 and IL-10 gene expression levels were linearly and/or quadratically increased by YH supplementation (p<0.05). Conclusion: Dietary YH supplementation improved intestinal morphology, barrier and anti-inflammatory functions while decreased intestinal permeability of broilers, which might be related with altering pertinent genes expression. This study provides evidence of YH as a promising feed additive for broilers.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2006년도 The 6th Intermational Symposium on Developmental Biotechnology
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• pp.22-23
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• 2006

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(3)
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• pp.225-230
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• 1996

탄화규소(SiC)가 도포된 핵연료 제조를 위해 고온 연소 합성법(Self-propagating High Temperature Synthesis, SHS)이 적용되었으며, 반응물로 규소(Si) 분말, 규소 박막 (Si-thin film), 흑연 분말과 카본(C) 화이버가 사용되었다. 규소 박막은 프라즈마가 강화된 화학증착법(a microwave pulsed electron cyclotron resonance plasma enhanced chemical vapor deposition)으로 준비되었다. 그 결과 규소와 탄소의 고온 연소 합성반응 생성물은 반응물이 분말이거나 박막에 관계없이. 탄화규소(SiC)가 합성되었으며, 생성물의 형상(morphology)은 초기 탄소의 형상에 의존하였다. 본 연구를 통해 고온 연소 합성법이 탄화규소와 탄소가 도포된 핵연료 제조에 적용 가능함을 알 수 있었다.

• Nuclear Engineering and Technology
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• 제4권3호
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• pp.203-213
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• 1972

$760^{\circ}C에서$ 최고 200시간까지 시효열처리한 Inconel 718 합금의 석출과정을 전자현미경적방법과 X선회절법으로 조사하였다. 이 합금의 주경화상은 작은 석상으로 된, 준안정적인 체심정방계의 $Ni_3Nb상이었며,$ 그밖에 판별된 석출상은 (Ni,T)C와 침상으로 된, 안정상인 사방계의 NifNb상 이었다. 미시효상태에서 전위와 석출상과의 상호작용을 관찰했으며, 그 결과 석출상의 변형과 석출상의 [110]면에 형성된 적층결함층을 관측할 수 있었다.

• Membrane and Water Treatment
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• 제4권2호
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• pp.83-93
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• 2013

In the present investigation, were synthesized composite membranes prepared by simultaneous casting of two polymer solutions using the technique of phase inversion by immersion / precipitation. The support layer was prepared using polyethersulfone and polysulfone as base polymer and for the top layer was used sulfonated polysulfone (SPSU) with 50% sulfonation degree. The morphology of the resulting membranes were characterized by scanning electron microscopy (SEM). The final results showed that it is possible to prepare composite membranes by simultaneous casting of two polymer solutions with adherence between the two layers. Regarding the permeation tests, the developed membranes presented values of hydraulic permeability within the range of commercial nanofiltration (NF) membranes. Values rejection of 80% ammonium ions can be increased by using a SPSU with a greater degree of sulfonation.

• 한국가축번식학회지
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• 제17권3호
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• pp.249-255
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• 1993

Canine follicular oocytes were used to establish a reliable system for maturation and fertilization in vitro. Ovaries were obtained from either slaughter house or hormone-primed bitches of mixed breeds. The oocytes were recovered by mincing the ovaries in M2＋BSA. Good quality of oocyte-cumulus complexes (OCCs) were selected and cultured in TCM 199 containing 15% fetal calf serum(FCS) for 24~56 h in an atmosphere of 5% CO2 at 39$^{\circ}C$. Maturation rate of follicular oocytes was >87% showing metaphase I. Unlike other domestic animals the cumulus expansion did not occur fully in canine OCCs although minimum expansion was found between the cumulus cells and corona radiata cells, the clear nuclear morphology was presented for the first time by rapid staining. The IVM system used in this study may be useful to obtain fully maturated metaphase I oocyte in dog.