• 생명과학회지
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• 제14권2호
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• pp.368-373
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• 2004

광범위 제초제인 Bast $a^{(R)}$에 대해 저항성을 가지는 형질전환체 벼를 개발하였다. Bar유전자를 함유하고 있는 플라스미드 pCaMV35S::Bar를 embryogenic 현탁 배양체로부터 분리한 벼의 원형질체에 도입하였다. Phosphinotricin에 대해 저항성을 가지는 형질전환체 식물체들이 재분화되었고, 이들을 15 mg/l phosphinotricin이 함유한 배지에서 다시 선별하였다. 형질전환체 벼에서 bar유전자의 삽입과 발현을 Southern과 Northern blot분석으로 확인하였고, 또한 $R_1$ 형질전환 식물체들을 PAT 활성 assay로 재차 유전자 발현을 확인하였다. Bar 유전자는 다음 세대인 $R_1$ 식물체에서 3:1 멘델 유전 양상을 나타내었고, 형질전환체 $R_1$과 $R_2$ 식물체들은 fieild에서 살포되는 제초제 양만큼 Bast $a^{(R)}$ 를 살포했을 때 제초제 저항성을 나타내었다..

• Structural Engineering and Mechanics
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• 제54권5호
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• pp.1017-1044
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• 2015

This study aimed to investigate the random vibration characteristic of train-slab track-bridge interaction system subjected to both track irregularities and earthquakes by use of pseudo-excitation method (PEM). Each vehicle subsystem was modeled by multibody dynamics. A three-dimensional rail-slab- girder-pier finite element model was created to simulate slab track and bridge subsystem. The equations of motion for the entire system were established based on the constraint condition of no jump between wheel and rail. The random load vectors of equations of motion were formulated by transforming track irregularities and seismic accelerations into a series of deterministic pseudo-excitations according to their respective power spectral density (PSD) functions by means of PEM. The time-dependent PSDs of random vibration responses of the system were obtained by step-by-step integration method, and the corresponding extreme values were estimated based on the first-passage failure criterion. As a case study, an ICE3 high-speed train passing a fifteen-span simply supported girder bridge simultaneously excited by track irregularities and earthquakes is presented. The evaluated extreme values and the PSD characteristic of the random vibration responses of bridge and train are analyzed, and the influences of train speed and track irregularities (without earthquakes) on the random vibration characteristic of bridge and train are discussed.

• 한국전산구조공학회논문집
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• 제14권3호
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• pp.267-276
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• 2001

이 논문은 회전식 수문(radial gate)의 구조해석에 근거하여 지지점 위치에 따른 모멘트 분배를 최적화하는 것에 관심을 두고 있다. 회전식 수문(radial gate)의 경제적인 관점에서의 중요성에도 불구하고 이의 지지점 위치에 따른 최적설계에 관한 자료를 찾기 어려운 실정이다. 그래서 본 연구에서는 주판(skin plate)의 곡률 반경, 수심, 동압 등의 주어진 자료를 이요약하여 지지점(gate arm)의 수가 2개인 경우와 3개인 경우에 대하여 곡선형태의 주판(skin plate)에서 지지점 (arm)의 최적 위치를 얻어서 설계자료에 의한 것들과 비교한다. 그 결과 최적 설계에 의한 회전식 수문 (radial gate)의 치수가 설계자료에 의한 것에 비해 현저히 감소되는 것을 알 수 있다.

• 한국세라믹학회지
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• 제50권4호
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• pp.263-268
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• 2013

Porous biphasic calcium phosphate scaffolds were fabricated by a freeze-gel casting technique using a tertiary-butyl alcohol (TBA)-based slurry. After sintering, unidirectional macropore channels of scaffolds aligned regularly along the TBA ice growth direction were tailored simultaneously with micropores formed in the outer wall of the pore channels. The crystallinity, micro structure, pore configuration, bulk density, and compressive strength for the scaffolds were investigated with X-ray diffractometery, scanning electron microscopy analysis, a water immersion method, and a universal test machine. The results revealed that the sintered porosity and pore size generally resulted in a high solid loading which resulted in low porosity and small pore size, which relatively increased the higher compressive strength. After being sintered at $1100-1300^{\circ}C$, the scaffolds showed an average porosity and compressive strength in the range 35.1-74.9% and 65.1-3.0 MPa, respectively, according to the processing conditions.

• 한국항해항만학회지
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• 제40권3호
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• pp.97-103
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• 2016

최적의 선박 운항 항로를 찾기 위해서는 선박의 정확한 추진성능을 추정하는 것이 매우 중요하다. 본 논문은 선박 최적운항시스템의 추진성능 데이터베이스를 생성하기 위한 전산프로그램의 개발에 대해 기술하고 있다. 실해역에서의 추진성능은 표류와 표면 거칠기 등 선체 상태뿐 만 아니라 파랑과 바람 등 해상 상태의 영향을 받는다. 이 부가저항 추정 방법들은 ISO 15016:2002 표준의 실선 속력시운전 해석법을 근간으로 하고 있으며, 추가로 바람과 선체 표면 거칠기에 대한 몇 가지 추정 방법이 보완되었다. 이 추정 방법들은 종합적인 전산프로그램으로 만들어졌다. 그리고 향후 최적 운항경로 계산에 활용될 쇄빙연구선 아라온 호에 대해서 데이터베이스 계산이 수행되었다. 이 프로그램은 모든 선박의 항로 최적화 계산에 유용하게 사용될 수 있을 것으로 판단된다.

• 한국수정란이식학회지
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• 제18권3호
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• pp.179-186
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• 2003

Human embryonic stem (hES) cell lines have been derived from human blastocysts and are expected to have far-reaching applications in regenerative medicine. The objective of this study is to improve freezing method with less cryo-injuries and best survival rates in hES cells by comparing various vitrification conditions. For the vitrifications, ES cells are exposed to the 4 different cryoprotectants, ethylene glycol (EG), 1,2-propanediol (PROH), EG with dime-thylsulfoxide (DMSO) and EG with PROH. We compared to types of vehicles, such as open pulled straw (OPS) or electron microscopic cooper grids (EM grids). Thawed hES cells were dipped into sequentially holding media with 0.2 M sucrose for 1 min, 0.1 M sucrose for 5 min and holding media for 5 min twice and plated onto a fresh feeder layer. Survival rates of vitrified hES cells were assessed by counting of undifferentiated colonies. It shows high survival rates of hES cells frozen with EG and DMSO (60.8％), or EG and PROH(65.8％) on EM grids better than those of OPS, compared to those frozen with EG alone (2.4％) or PROH alone (0％) alone. The hES cells vitrified with EM grid showed relatively constant colony forming efficiency and survival rates, compared to those of unverified hES cells. The vitrified hES cells retained the normal morphology, alkaline phosphates activity, and the expression of SSEA-3 and 4. Through RT-PCR analysis showed Oct-4 gene expression was down-regulated and embryonic germ layer markers were up-regulated in the vitrified hES cells during spontaneous differentiation. These results show that vitrification method by using EM grid supplemented with EG and PROH in hES cells may be most efficient at present to minimize cyto-toxicity and cellular damage derived by ice crystal formation and furthermore may be employed for clinical application.

• 대한지역사회영양학회지
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• 제21권5호
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• pp.426-439
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• 2016

Objectives: This study was performed to measure the food allergy (FA) awareness and management by the parents of preschool children. Methods: A questionnaire survey was conducted with the parents of preschool children. The questionnaire was designed to identify the prevalence of food allergies, requirements of food allergy support and differences in food management according to the presence or absence allergic diseases, using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. After excluding incomplete responses, the data of 158 parents of preschool children (90.3%) was used for statistical analysis. Results: The rate of the preschool children who had experienced food allergy (FA, ever) was 38.6% while diagnosed for food allergy by doctor (Diagnosis of FA, ever) was 17.7%. Forty nine preschool children (80.3%) had food restriction, and twenty three of them (37.7%) had self-restriction without diagnosis. The consumption frequencies of allergenic foods in FA group, such as ramyeon, noodles, bread, eggs, yogurt and ice cream were significantly (p<0.001) lower than those of the other two groups. The major allergenic foods were eggs, milk, wheat and processed foods in FA group. The overall food allergy-related knowledge level of parents was insufficient. Only 26 parents (16.5%) had received training about food allergies. All parents wanted to receive food allergy-related supports. In addition, most of parents wanted information on substitute menu for children with food allergy. Conclusions: This study identified a lack of food allergy training for the parents of preschool children and the necessity for food allergy education. Food allergy-related supports, such as menus without allergenic ingredients, guidelines for managing food allergy & anaphylaxis emergency care plan etc, should be provided to the parents in order to avoid events related to food allergies.

• 농업과학연구
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• 제46권2호
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• pp.315-322
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• 2019

In this study, the contents of ${\beta}$-carotene and cholesterol were evaluated in various types of agricultural and processed foods (vegetables, legume products, dairy products, and eggs). Certified reference material (CRM) with an assigned value was used for the validation of the ${\beta}$-carotene and cholesterol analytical methods. High recoveries (accuracy) of ${\beta}$-carotene (96%) and cholesterol (97%) were obtained from the quantitative analysis of the CRM, with a relative standard deviation (%) of 1.86 and 3.35% for the ${\beta}$-carotene and cholesterol, respectively. Vegetables contained relatively high concentrations of ${\beta}$-carotene (raw Toona sinensis, $1650.97{\mu}g/100g$, a raw small onion, $879.09{\mu}g/100g$, and a raw lettuce stem, $591.89{\mu}g/100g$). The ${\beta}$-carotene values in dried chickpeas ($22.94{\mu}g/100g$) and dried brown lentils ($21.98{\mu}g/100g$) were similar. The highest ${\beta}$-carotene value among the analyzed dairy products was found in banana milk ($234.21{\mu}g/100g$) while other flavored products (strawberry milk and chocolate milk) did not contain any ${\beta}$-carotene. Furthermore, ${\beta}$-carotene was not detected in goat milk and high calcium milk in this study. With regard to cholesterol among the analyzed samples, the highest cholesterol value was found in egg yolk (629.30 mg/100 g), and cooking methods (boiling and frying) had little effect on the cholesterol levels of eggs. In addition, the cholesterol content in vanilla ice cream was 28.77 mg/100 g which was the highest value among the analyzed dairy products.

• 지질공학
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• 제31권3호
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• pp.257-267
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• 2021

Constraints on the structure and composition of the active layer are important for understanding permafrost evolution. Soil convection owing to repeated moisture-induced freeze-thaw cycles within the active layer promotes the formation of self-organized patterned ground. Here we present the results of ground penetrating radar (GPR) surveys across a selected sorted circle near King Sejong Station, Antarctica, to better delineate the active layer and its relation to the observed patterned ground structure. We acquire GPR data in both bistatic mode (common mid-points) for precise velocity constraints and monostatic mode (common-offset) for subsurface imaging. Reflections are derived from the active layer-permafrost boundary, organic layer-weathered soil boundary within the active layer, and frozen rock-fracture-filled ice boundary within the permafrost. The base of the imaged sorted circle possesses a convex-down shape in the central silty zone, which is typical for the pattern associated with convection-like soil motion within the active layer. The boundary between the central fine-silty domain and coarse-grained stone border is effectively identified in a radar amplitude contour at the assumed active layer depth, and is further examined in the frequency spectra of the near- and far-offset traces. The far-offset traces and the traces from the lower frequency components dominant on the far-offset traces would be associated with rapid absorption of higher frequency radiowave due to the voids in gravel-rich zone. The presented correlation strategies for analyzing very shallow, thin-layered GPR reflection data can potentially be applied to the various types of patterned ground, particularly for acquiring time-lapse imaging, when electric resistivity tomography is incorporated into the analysis.

• Journal of Animal Science and Technology
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• 제63권2호
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• pp.417-425
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• 2021

The use of edible insects to replace meat protein is important to ensure future global food security. However, processed foods using edible insects require development to enhance consumer perception. Here, we examined the physicochemical characteristics and rheological properties of emulsions prepared from different edible insect larvae. Three edible insect species (Tenebrio molitor, Allomyrina dichotoma and Protaetia brevitarsis seulensis) were used to prepare larval emulsions that were formulated with 65% of insect larvae, 20% of pork back fat, and 15% ice. The A. dichotoma emulsion had the highest pH and lightness, redness, and yellowness values, while the T. molitor emulsion had the lowest pH and lightness, redness, and yellowness values. The T. molitor emulsion had the highest hardness, gumminess, chewiness, and apparent viscosity values but the lowest springiness and cohesiveness values. According to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, T. molitor had the thickest bands, followed by P. brevitarsis seulensis. The differential scanning calorimetry distributions for the T. molitor and A. dichotoma emulsions showed one peak, while that of the P. brevitarsis seulensis emulsion had two peaks. The collective results suggest that T. molitor was the most suitable candidate (of the three tested species) for use as a meat replacement in terms of its physicochemical and rheological properties. It is important that such properties of insect-based emulsions are maintained using various technologies.