• Clinical and Experimental Reproductive Medicine
• /
• 제31권4호
• /
• pp.209-215
• /
• 2004

Objective: Embryonic stem (ES) cells could be differentiated into the specific cell types by alternation of culture condition and modification of gene expression. This study was performed to evaluate the differentiation protocol for mouse and human ES cells to insulin secreting cells. Methods: Undifferentiated mouse (JH-I) and human (Miz-hESI) ES cells were cultured on STO feeder layer, and embryoid bodies (EBs) were formed by suspension culture. For the differentiation, EBs were cultured by sequential system with three stage protocol. The differentiating ES cells were collected and marker gene expressions were analyzed by seIni-quantitative RT-PCR in each stage. Amount of secreted insulin levels in culture media of human ES cells were measured by human insulin specific RIA kit. Results: During the differentiation process of human ES cells, GATA-4, a-fetoprotein, glucose transporter-2 and Ngn-3 expression were increased whereas OctA was decreased progressively. Insulin and albuInin mRNAs were expressed from stage IT in mouse ES cells and from stage III in human ES cells. We detected 3.0~7.9 IlU/rnl secretion of insulin from differentiated human ES cells by in vitro culture for 36 days. Conclusion: The sequential culture system could induce the differentiation of mouse and human ES cells into insulin secreting cells. This is the fIrst report of differentiation of human ES cells into insulin secreting cells by in vitro culture with serum and insulin free medium.

• 문화기술의 융합
• /
• 제10권4호
• /
• pp.357-365
• /
• 2024

본 연구는 그림책 감상을 통한 유아의 로봇 활용 놀이가 순서적 사고에 미치는 영향을 알아보고자 한다. 이를 위해 서울시에 위치한 각 유치원 만 5세 15명의 유아를 대상으로 J유치원(실험집단)은 '그림책 감상 로봇 활용 놀이'를 지원하였으며, C유치원(비교집단)은 '그림책 감상 자유놀이'를 지원하였다. 두 집단의 놀이 경험의 차이를 알아보기 위해 순서적 사고 검사도구를 활용하여 놀이지원 전과 후에 대한 점수자료를 수집하였으며, 수집된 자료는 SPSS 28.0프로그램을 활용하여 사전점수를 공변인으로 한 사후점수를 ANCOVA(공분산분석)를 실시하였다. 그 결과, 그림책 감상을 통한 로봇 활용 놀이를 경험한 실험집단은 비교집단에 비해 순서적 사고의 총점과 하위 영역인 역학, 행동, 의도에서 모두 유의미하게 향상된 것으로 나타났다. 이러한 연구결과는 유아 주도의 창의적인 놀이매체로서 로봇의 가치를 발견하고, 미래사회의 역량으로 그 중요성이 강조되고 있는 순서적 사고 역량을 증진할 수 있도록 지원하는 놀이연구로서 가치가 있다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권7호
• /
• pp.969-976
• /
• 2009

Use of oocytes from prepubertal animals for in vitro embryo production holds potential application for reducing generation intervals and increasing genetic progress through embryo transfer. The objective of these studies was to compare the effect of three sperm pretreatments (prior to in vitro fertilization) and seven embryo culture protocols on fertilization rate and (or) subsequent development of in vitro fertilized embryos derived from oocytes harvested from ovaries of 1-6 month old prepubertal Boer goats in China. Cleavage rates were highest for embryos fertilized with heparin-treated versus calcium ionophore- or caffeine-treated sperm. Similar rates of blastocyst development were observed using heparin- and ionophore-treated sperm, which were higher than obtained with caffeine-treated sperm. No differences in cleavage or blastocyst rates were observed following embryo culture in basal medias (synthetic oviductal fluid (SOF), Charles Rosenkrans 1 (CR1) or tissue culture medium-199 (TCM-199)) containing 10% fetal bovine serum (FBS). Cumulus or oviductal cell co-culture did not enhance cleavage or blastocyst rates relative to culture in SOF+10% FBS. Replacement of FBS in SOF medium with 0.3% BSA increased cleavage rates, but did not increase rates of blastocyst development. Sequential culture in SOF+0.3% BSA followed by SOF+10% FBS increased blastocyst yield versus continuous culture in SOF+10% FBS and tended to increase blastocyst yield versus continuous culture in SOF+0.3% BSA. These results demonstrate a pronounced effects of sperm pretreatments and in vitro embryo culture systems on rates of blastocyst development and provide a potential protocol (sperm pretreatment with heparin and sequential embryo culture in SOF+0.3% BSA followed by SOF+10% FBS) for generation of the significant numbers of in vitro produced blastocysts from oocytes of prepubertal Boer goats necessary for application of embryo transfer in rural regions of China for distribution of Boer goat genetics.

• 한국작물학회지
• /
• 제47권4호
• /
• pp.328-334
• /
• 2002

A Lindernia dubia (L.) Pennell var. dubia accession from Jeonnam province, Korea was tested for resistance to sulfonylurea (SU) herbicides, imazosulfuron and pyrazosulfuron-ethyl in whole-plant response bioassay. The accession was confirmed resistant to both herbicides. The $GR_{50}$ (herbicide concentration that reduced shoot dry weight by 50%) values of resistant accession were 264 and 19 times higher to imazosulfuron and pyrazosulfuronethyl, respectively, than that of the standard susceptible accession. The surviving resistant L. dubia after pyrazosulfuron-ethyl + molinate application can be controlled by sequential applications of soil-applied herbicides, butachlor, dithiopyr, pyrazolate, and thiobencarb and foliar herbicides, bentazon. Sulfonylurea-based mixtures such as mixtures of azimsulfuron + anilofos, bensulfuron-methyl + oxadiazon, pyrazosulfuron-ethyl + fentrazamide, and pyrazosulfuron-ethyl + anilofos + carfentrazon can also be used to control the surviving resistant L. dubia. However, use of these mixtures should be restricted to a special need basis. Thus, we suggest that sequential applications of non-SU-based mixtures such as butachlor + pyrazolate and MCPB + molinate + simetryne be used to control the surviving resistant L. dubia after SU herbicide applications. Rice yield was reduced 24 % by resistant L. dubia that survived after the pyrazosulfuron-ethyl + molinate application compared with pyrazolate + butachlor in transplanted rice culture. In vitro ALS activity of the resistant biotype was 40 and 30 times more resistant to imazosulfuron and pyrazosulfuron-ethyl, respectively, than the susceptible biotype. Result of in vitro ALS assay that the resistance mechanism of L. dubia to SU herbicides may be due, in part, to an alteration in the target enzyme, ALS.

• International Journal of Advanced Culture Technology
• /
• 제9권4호
• /
• pp.363-375
• /
• 2021

The purpose of this study is to analyze the safety of evacuation using the Pathfinder program for the alert at once, the priority alarm method, the priority alarm method for the four floors above, and the sequential priority alarm method, which is a modification of the priority alarm method specified in the tourist hotel building. Currently, in Korea's National Fire Safety Codes (NFSC), fire alarm methods are compulsorily applied differently depending on the number of floors and total floor area of a building. Although the growth rate is getting faster due to the diversification of building structures, it is still an obstacle to improving evacuation safety to comply with the standardized fire alarm method in NFSC. As a result of the experiment, the evacuation time was found to be faster with the priority alarm method for the four floors above than the priority alarm method applied to the specific firefighting object. Compared to the priority alarm method applied to the tourist hotel, which is a specific firefighting target with 5 or more floors and a total floor area of more than 3,000m2, the time was shortened by 3.7 seconds when measured by applying the priority alarm method for the four floors directly above. This indicates that it is necessary to take measures to select a fire alarm method suitable for the structure and environmental conditions of the building rather than applying the uniform NFSC regulations.

• 복식문화연구
• /
• 제31권5호
• /
• pp.607-626
• /
• 2023

This study analyzes consumer fashion purchase patterns from a big data perspective. Transaction data from 1 million transactions at two Korean fashion brands were collected. To analyze the data, R, Python, the SPADE algorithm, and network analysis were used. Various consumer purchase patterns, including overall purchase patterns, seasonal purchase patterns, and age-specific purchase patterns, were analyzed. Overall pattern analysis found that a continuous purchase pattern was formed around the brands' popular items such as t-shirts and blouses. Network analysis also showed that t-shirts and blouses were highly centralized items. This suggests that there are items that make consumers loyal to a brand rather than the cachet of the brand name itself. These results help us better understand the process of brand equity construction. Additionally, buying patterns varied by season, and more items were purchased in a single shopping trip during the spring season compared to other seasons. Consumer age also affected purchase patterns; findings showed an increase in purchasing the same item repeatedly as age increased. This likely reflects the difference in purchasing power according to age, and it suggests that the decision-making process for pur- chasing products simplifies as age increases. These findings offer insight for fashion companies' establishment of item-specific marketing strategies.

• Journal of Microbiology and Biotechnology
• /
• 제17권11호
• /
• pp.1772-1781
• /
• 2007

Activated sludge was sequentially adapted to benzene, toluene, and o-xylene (BTX) to study the effects on the change of microbial community. Sludge adapted to BTX separately degraded each by various rates in the following order; toluene>o-xylene>benzene. Degradation rates were increased after exposure to repeated spikes of substrates. Eleven different kinds of sludge were prepared by the combination of BTX sequential adaptations. Clustering analyses (Jaccard, Dice, Pearson, and cosine product coefficient and dimensional analysis of MDS and PCA for DGGE patterns) revealed that acclimated sludge had different features from nonacclimated sludge and could be grouped together according to their prior treatment. Benzene- and xylene-adapted sludge communities showed similar profiles. The sludge profile was affected from the point of the final adaptation substrate regardless of the adaptation sequence followed. In the sludge adapted to 50 ppm toluene, Nitrosomonas sp. and bacterium were dominant, but these bands were not dominant in benzene and benzene after toluene adaptations. Instead, Flexibacter sp. was dominant in these cultures. Dechloromonas sp. was dominant in the culture adapted to 50 ppm benzene. Thauera sp. was the main band in the sludge adapted to 50 ppm xylene, but became vaguer as the xylene concentration was increased. Rather, Flexibacter sp. dominated in the sludge adapted to 100 ppm xylene, although not in the culture adapted to 250 ppm xylene. Two bacterial species dominated in the sludge adapted to 250 ppm xylene, and they also existed in the sludge adapted to 250 ppm xylene after toluene and benzene.

• 한국심리학회지 : 문화 및 사회문제
• /
• 제27권4호
• /
• pp.351-389
• /
• 2021

이 연구는 코로나19 팬데믹에 처한 사람들이 심리적 수준에서 어떻게 적응하고, 결과적으로 어떤 심리적 변화를 겪고 있는지를 이해하고 설명하는 구조적 틀을 도출하고자 하였다. 팬데믹 경험에 관한 선행 연구를 고찰하여 잠정적인 분석의 틀을 설정한 후, 이를 확인하고 수정하는 방향의 질적 연구를 수행하였다. 일반 성인 6명으로부터 인터뷰 자료를 구하였고, 근거이론의 절차를 부분적으로 차용한 내용분석 방법으로 자료를 해석하고 정리하였다. 최종적으로 코로나19 팬데믹에 대한 심리적 적응과 변화 과정의 패러다임 구조 모형을 확장, 도출하였다. 이 패러다임 구조 틀은 '원인적 조건 ⇨ 중심 현상 ⇨ 연쇄적 결과'로 이어지는 심리학적 인과 과정을 중심으로 하고, 개인의 심리적 특성 범주를 '중개 조건'으로 추가한 패러다임 형태로 묘사되었다. 팬데믹 위기와 사회적 거리두기 및 결정적 사건 등이 '원인적 조건' 범주에 해당되고, '중심 현상' 범주는 긍정/부정/복합적 심리 경험을 포함하고, '연쇄적 결과' 범주에는 가치관/행동양식 변화 등이 분류되었다. 중개조건 중 '맥락조건'으로서 직장과 가족관계 특성이 확인되었고, '조절적 중개 조건'으로서 공동체책임의식, 여가능력 및 긍정심리자본 등 다양한 심리적 특성이 확인되었다. 논의 및 결론에서는 분석 결과의 의미를 해석하고, 연구 결과의 이론적, 실무적 시사점과 향후 연구 과제 등을 제시하였다.

• Coupled systems mechanics
• /
• 제5권1호
• /
• pp.87-100
• /
• 2016

In this work, an improved semi-analytical technique is adopted to track the dynamic response of thin rectangular plates excited by sequential traveling masses. This technique exploits a so-called indirect definition of inertial interaction between the moving masses and the plate and leads to a reduction, in the equations of motion, of the number of time-varying coefficients linked to the changing position of the masses. By employing this optimized method, the resonance of the plate can be obtained according to a parametric study of relevant maximum dynamic amplification factor. For the case of evenly spaced, equal masses travelling along a straight line, the resonance velocity of the masses themselves is also approximately predicted via a fast methodology based on the fundamental frequency of the system only.

• Clinical and Experimental Pediatrics
• /
• 제55권11호
• /
• pp.424-429
• /
• 2012

Purpose: Methods for quick and reliable detection of Streptococcus pneumoniae are needed for the diagnosis of pneumococcal disease and vaccine studies. This study aimed to show that sequential multiplex polymerase chain reaction (PCR) is more efficient than conventional culture in achieving S. pneumoniae -positive results. Methods: Nasopharyngeal (NP) secretions were obtained from 842 pediatric patients admitted with lower respiratory infections at Severance Children's Hospital in Korea between March 2009 and June 2010. For identification and serotype determination of pneumococci from the NP secretions, the secretions were evaluated via multiplex PCR technique with 35 serotype-specific primers arranged in 8 multiplex PCR sets and conventional bacteriological culture technique. Results: Among the results for 793 samples that underwent both bacterial culture and PCR analysis for pneumococcal detection, 153 (19.3%) results obtained by PCR and 81 (10.2%) results obtained by conventional culture technique were positive for S. pneumoniae. The predominant serotypes observed, in order of decreasing frequency, were 19A (23%), 6A/B (16%), 19F (11%), 15B/C (5%), 15A (5%), and 11A (4%); further, 26% of the isolates were non-typeable. Conclusion: As opposed to conventional bacteriological tests, PCR analysis can accurately and rapidly identify pneumococcal serotypes.