• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.879-886
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• 2000

Background : Thyroid Transcription Factor-1(TTF-1) acts as a tissue specific transcription factor in the regulation of lung specific gene expression and as morphogenic protein during lung organogenesis. Currently, there is very little information on the cis-acting sequences and transcription factors that direct the TTF-1 gene expression. DNAse 1 hypersensitive (DH) sites represent a marker for active or potentially active chromatin and are likely to be especially important in gene regulation, being associated with many DNA sequences that regulate gene expression. It is clear that DH regions correlate with genetic regulatory loci and binding for sequence-specific DNA-binding proteins. Methods : We have used DH site assays to identify putative distal regulatory elements in H441 lung adenocarcinoma cells, which express the TTF-1 gene and HeLa cells. Results : There are four DH sites 5' of the TTF-1 gene. These sites are located at base pair approximately +150, -450, -800, and -1500 from the start of transcription. Conclusion : These data suggest that there may be at least one intragenic site and regulatory region 5' prime to the promotor region.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1451-1456
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• 2012

A novel tetrathiafulvalene (TTF)-based main-chain polymer (6TTF-polymer) was successfully synthesized via a condensation polymerization between a newly synthesized dihydroxy TTF derivative and a malonyl chloride, and its chemical structure was characterized by spectroscopic techniques. Molecular weight of the 6TTF-polymer (9,030 g/mol by gel permeation chromatography) was large enough to form the ductile film. The electrochemical and optical properties of the 6TTF-polymer were further estimated by cyclic voltammetry, ultraviolet and photoluminescence spectroscopes. The highest occupied molecular orbital level ($E_{HOMO}$=-4.79 eV) and band-gap energy ($E_g$=1.91 eV) of the 6TTF-polymer suggested that TTF-based polymer could act as a good electron donating material for the optoelectronic applications.

• Biomedical Science Letters
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• v.12 no.3
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• pp.171-176
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• 2006

Sodium iodide symporter (NIS) plays a key role in thyroid hormone production by efficiently accumulating iodide from the circulating blood into the thyocytes, and this is done against an electrochemical gradient. Thyroid transcription factor-l (TTF-l) is a homeodomain-containing protein expressed in embryonic diencephalons, thyroid, and lung and has been found to bind to thyroid specific promoters and to activate their transcriptional activity. TTF-l may be one of the factors capable of activating NIS gene expression in the thyroid gland, thus it accounts for the lower levels of NIS gene expression that are seen in the extrathyroidal tissues. However, a high frequency of TTF-l expression has been observed, especially in primary lung adenocarcinoma. The present study was undertaken in order to elucidate the relationship between the expression of NIS and TTF-l in primary lung adenocarcinoma. Immunohistochemical studies for NIS and TTF-l were performed in 64 primary lung adenocarcinomas. Immunoreactivities for NIS and TTF-l were found in 49 (76.6%) and 45 (70.3%) out of 64 cases, respectively. Forty-one (83.7%) of the 49 cases with positive NIS immunoreactivity showed positive TTF-l expression, whereas 11 (73.3%) of the 15 cases with negative NIS immunoreactivity showed negative TTF-l expression (P<0.05). So the NIS expression was significantly associated with the TTF-l expression. These findings suggest that TTF-l may be one of the factors capable of activating NIS gene expression in primary lung adenocarcinoma. Further studies are needed to define the relation between NIS and TTF-l for examining the mechanisms of tissue-specific NIS expression.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1477-1479
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• 2008

We report the first TTF compounds having columnar LC phase at room temperature. Based on the thermal, structural, and morphological observations, it was concluded that TTF derivative with long alkyl chains has highly ordered oblique columnar LC at room temperature. The new TTF derivatives have excellent oxidative stability which is desirable for a p-type (hole transport) materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.509-509
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• 2013

유기발광소자는 빠른 응답속도, 높은 색재현성 및 높은 명암비의 장점을 가지며 차세대 디스플레이로서 소형 및 대형 디스플레이로 각광 받고 있다. 저전압구동 유기발광소자를 제작하기 위해 p-i-n 유기발광소자에 대한 연구가 진행되고 있다. 그러나 p형 물질에 대한 연구는 많이 진행 되었으나 n형 유기물질에 대한 연구는 아직까지 진행되고 있지 않다. n형 무기물질로 알칼리 금속을 많이 사용하고 있지만, 공기 중에 쉽게 산화되고 금속 이온의 확산에 의한 발광층 여기자 소멸 효과에 의한 효율 감소문제가 있다. 또한, 무기물질의 높은 증착온도에 따른 유기층의 손상 문제가 있다. 이러한 문제점을 해결하기 위해 유기물 n형 물질에 관한 연구가 필요하다. 본 연구에서는 n형 유기물 도펀트인 bis (ethylenedithio)-tetrahiafulene (BEDT-TTF)를 4,7-diphenyl-1,10-phenanthroline (BPhen) 전자수송층에 도핑하여 유기발광소자의 전자 수송 능력을 향상하였다. BEDT-TTF의 낮은 증착온도와 공기 중에 산화가 되지 않으며, 유기물을 사용하기 때문에 발광층 여기자 소멸을 방지할 수 있다. 전자수송층에 도핑된 BEDT-TTF 분자는 산화 반응에 의한 전자 증가에 따른 에너지 장벽을 감소시켜 전자의 주입을 향상하였다. BEDT-TTF의 농도에 따른 유기발광소자의 광학적 및 전기적 특성을 각각 관찰하여 BEDT-TTF의 농도에 따른 전자 수송 향상에 따른 저전압 유기발광소자 구동을 관측하였다.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.1
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• pp.50-55
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• 2007

In this paper, we present an analytical method that provides fast and efficient evaluation of the conversion efficiency for Two transistor forward (TTF) DC-DC converter In the proposed method, the conduction losses are evaluated by calculating the effective values of the ideal current waveform first and incorporating them into an exact equivalent circuit model of the TTF converter that includes all the parasitic resistances of the circuit components. While the conduction losses are accurately accounted for the diode rectification, the core losses are assumed to be negligible in order to simplify the analysis. The validity and accuracy of the proposed method are verified with experiments on a prototype TTF converter An excellent correlation between the experiments and theories are obtained for the input voltages of 390V, output voltage 12V and maximum power 480W.

• Journal of Distribution Science
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• v.20 no.5
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• pp.85-96
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• 2022

Purpose: This study aims to dissemination a new concept based on empirical research on enhancing entrepreneurship intention (EI) in the theory of planned behavior (TPB) through entrepreneurship mindset (EM) and task technology fit (TTF). The TTF is a moderating variable in strengthening the relationship between EM and EI. Research design, data, and methodology: This research design was quantitative research. The respondents were 202 students from Malaysia and Indonesia who had filled out and collected an online questionnaire in Microsoft form. Three hypotheses examined the direct influence and the indirect impact of EM on EI through antecedent variables of TPB, and the effect of TTF as moderating variable to enhance the relationship between EM and EI. The data was analyzed using the WarpPLS version 7.0. Results: The result showed that EM had a significant impact on the students' EI. The interaction of EM and TTF was significantly able to improve EI. Conclusions: The findings contributed new ideas to develop the theoretical framework of the TPB model and were able be utilized by lecturers to consider the integration of EM and TTF in the model. The novelty of this study elaborated the EM and TTF variables as an extended model of the TPB.

• Journal of Life Science
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• v.25 no.12
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• pp.1439-1444
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• 2015

Steroid receptor coactivators (SRC) are transcriptional coactivators. Among SRCs, SRC-3 is the most studied in relation to different types of tumors. However, the role of SRC-3 in early lung development and lung cancer has not been well studied. The expression profiles of SRC-3 showed that SRC-3 contributed to bronchial and alveolar development in embryonic lung development. SRC-3 was strongly expressed in Clara cells and type II alveolar cells during fetal lung development (E17.5- E18.5), and SRC-3 was expressed in both cell types in the adult lung. TTF-1 was expressed in the lungs of heterozygote SRC-3 mice and Clara cell-specific-CCSP-TAg tumor mice, along with SRC-3 expression. The expression of TTF-1 was localized at transformed Clara cells and multifocal adenocarcinomas in lung cancer mice. However, SRC-3 was not expressed in the multifocal adenocarcinomas, suggesting that SRC-3 might not be involved in the invasiveness of lung cancer. Cotransfection of TTF-1 in Clara cell-specific mtCC cell lines resulted in significant activation of CCSP expression. However, cotransfection of SRC-3 had no significant effects on transient transfection. These in vivo and in vitro results suggest that SRC-3 does not play a significant role in lung tumor progression. In conclusion, SRC-3 is involved in bronchial and alveolar development in fetal and adult lungs, but it does not play an important role in the progression of Clara cell-derived lung cancer.

• Journal of Korea Technology Innovation Society
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• v.10 no.4
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• pp.755-788
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• 2007

This study investigates the effects of individual and group level factors on the use of GSS (Group Support System) and task performance from GSS use. GSS facilitates the group work, so that GSS adoption is not necessarily influenced only by individual perceptions on information systems. Adaptive Structuration Theory (AST) in our study to explain the adoption and success from GSS use. AST contends that the success of IS is not necessarily the technical fit between tasks and technology, instead the political outcome among user socializations. We have the following two research inquires: Are the IS use and performance maximized when information technologies are provided properly?; and, Does TTF always influence positively on IS use (or performance)? To research these issues, we investigate the influence of TTF (Task-Technology Fit) on use and performance of GSS, which is introduced to foster collaboration among organizational members. Drawing insights from the AST, we examine if COA (Consensus on Appropriation) among group members and FOA (Faithfulness of Appropriation) between those who use technology and who design it show any moderating effect. A questionnaire survey was conducted on firms using the GSS for one month from June 2 to June 27 2005 and a sample of 303 responses was used for a statistical analysis. The result demonstrates that TTF exerts a positive influence on use and performance of GSS. We find that the stronger the COA, the greater the effect of W on use of GSS and performance. FOA likewise has a positive effect on both use of GSS and performance. The TTF model has been widely applied to studies on individual performance of information system, whereas the AST theory specifically explains members' adaptation process to information system. By integrating the AST theory with the TTF model, the study contributes to heightening our understanding on if and how individual performance varies with the use of GSS.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.394.1-394.1
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• 2014

고효율 및 낮은 구동 전압을 가지는 유기 발광소자를 제작하기 위한 많은 연구가 진행되고 있다. 고효율 및 낮은 구동전압을 가지는 p-i-n 유기발광소자는 정공수송층에 p형 무기 도펀트를 도핑하고, 전자수송층에 n형 무기 도펀트를 사용하여 제작하지만, 무기 도펀트는 높은 온도에서 증착하기 때문에 챔버 내의 다른 유기 물질들이 함께 증착되거나 유기 박막에 손상을 가져올 수 있는 단점을 가지고 있기 때문에 유기물 n형 도펀트의 경우는 연구가 필요하다. 본 연구에서는 유기 p형 도펀트인 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile과 유기 n형 도펀트인 bis (ethylenedithio)-tetrahiafulene (BEDT-TTF)를 사용하여 p-i-n 구조의 유기 발광소자를 제작하였다. 유기 n형 도펀트인 BEDT-TTF는 전자수송층 사이에서 산화-환원 반응을 통해 많은 전자를 생성하게 되고, 증가한 전자들로 인해서 Al 음극전극과 전자수송층 사이의 에너지장벽이 낮추는 역할을 하게 된다. BEDT-TTF를 도핑하지 않은 유기 발광소자보다 BEDT-TTF를 도핑하였을 때, 100 cd/m2 일때 약 2.4 V 작동 전압의 감소를 관측할 수 있었다. 이 결과는 음극전극으로부터 발광층으로 전자의 주입이 원활하게 되고, 그 결과 낮은 구동전압 및 고효율을 가지는 p-i-n 유기 발광소자를 제작할 수 있다는 것을 보여준다.