• 제목/요약/키워드: DNL

검색결과 156건 처리시간 0.028초

Lipogenesis와 adipose expansion의 전사조절 (Transcriptional Regulation of Lipogenesis and Adipose Expansion)

  • 장영훈
    • 생명과학회지
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    • 제32권4호
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    • pp.318-324
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    • 2022
  • PPARγ와 C/EBPα는 adipose tissue 발생에 필요한 핵심 adipogenic TFs이다. 두 TFs는 adipose tissue의 배아 발생에 있어 초기 adipogenesis와 adipocytes 유전자 발현을 조절한다. Adipose expansion은 adipose tissue가 태어난 뒤에도 계속 팽창이 지속되는 것을 말한다. 이러한 adipose expansion은 후기 adipogenesis의 과정인 lipogenesis가 요구된다. 특히 간과 adipose tissue은 탄수화물이 기본적으로 fatty acids으로 전환되는 de novo lipogenesis (DNL)의 주요 장기이다. Fatty acids는 이어서 glycerol-3-phosphate에 에스테르화되어 adipocytes의 lipid droplets 생성을 위해 triglycerides로 전환된다. 간의 DNL이 활발하게 연구가 된 반면, in vivo에서 adipocytes의 DNL은 아직 잘 알려져 있지 않다. 그러므로, adipose expansion과 DNL에 대한 이해는 비만, 2형 당뇨 그리고 대사성 질환을 위한 치료제 개발에 도움을 줄 수 있다. Adipocytes에서 DNL 유전자 발현은 ChREBP나 SREBP1a와 같은 lipogenic TFs 뿐 아니라, lipogenesis coactivator에 의해 전사 수준에서 조절된다. 최근 in vivo 연구에 의해 lipogenesis 유전자 발현과 adipose expansion의 새로운 측면이 밝혀졌다. 향후 구체적인 분자기전 연구는 어떻게 영양분이 DNL과 adipose expansion을 조절하는 지를 규명해 줄 것이다. 본 리뷰논문은 전사조절 관점에서 adipocytes와 adipose expansion에 있어 DNL에 대한 최신 연구결과를 요약정리 할 것이다.

하우스킵핑 A/D 변환기의 테스트 알고리즘과 측정 (Test Algorithm and Measurement of Housekeeping A/D Converter)

  • 박용수;유흥균
    • 반도체디스플레이기술학회지
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    • 제3권4호
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    • pp.19-27
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    • 2004
  • The characteristic evaluation of A/D converter is to measure the linearity of the converter. The evaluation of the linearity is to measure the DNL, INL, gain error and offset error in the various test parameters of A/D converter. Generally, DNL and INL are to be measured by the Histogram Test Algorithm in the DSP-based ATE environment. And gain error and offset error are to be measured by the calculation equation of the measuring algorithm. It is to propose the new Concurrent Histogram Test Algorithm for the test of the housekeeping A/D converter used in the CDMA cellular phone. Using the proposed method, it is to measure the DNL, INL, gain error and offset error concurrently and to show the measured results.

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DNL1 에서 반복류프처리장치의 설계 (Implementation of Iteration Loop in DNL1)

  • 김원섭;박희순
    • 대한전기학회논문지
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    • 제35권8호
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    • pp.309-315
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    • 1986
  • We proposed a preliminary Data Flow Machine Model(DNL1) operating on the basis of Node Label. In this model, all the PMs(Processing Modules) were synchronized with the content of LC(Level Counter) and were not implemented dy the processing cability on conditional nodes. This paper presents an architecture of a concurrent multiprocessor system which was developed from DNL1 with two additional types of memories, CF(Control Flag) and ETF (Enabled Token Flag). The CF memory holds the control condition flag ('1' or '0') to be referenced to when a node is fired and the ETF represents the firability of a certain node. Firable nodes are fetched to the PU(Processing Unit) and processed. This Data Flow system can be extended hierarchically by a network of simple modules. The principle working elements of the machine are a set of PMs, each of which performs the execution of the data flow procedures held in a local memory, NTM(Node Token Memory) within the PM.

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Leukoencephalopathy and Disseminated Necrotizing Leukoencephalopathy Following Intrathecal Methotrexate Chemotherapy and Radiation Therapy for Central Nerve System Lymphoma or Leukemia

  • Kim, Ji-Yeon;Kim, Sung-Tae;Nam, Do-Hyun;Lee, Jung-Il;Park, Kwan;Kong, Doo-Sik
    • Journal of Korean Neurosurgical Society
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    • 제50권4호
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    • pp.304-310
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    • 2011
  • Objective : Intrathecal methotrexate (MTX) therapy combined with whole brain radiotherapy (WBRT) is one of the major treatment modalities for leukemia and lymphoma involving the central nervous system (CNS). The purpose of this study was to retrospectively determine the incidences of leukoencephalopathy and disseminated necrotizing leukoencephalopathy (DNL) following intrathecal MTX therapy for CNS lymphoma or leukemia and to assess the potential risk factors. Methods : Between January 2000 and August 2009, 143 patients with CNS lymphoma or leukemia received intrathecal MTX therapy alone or in combination with WBRT at a single institution. Patients were followed up clinically and radiologically at regular two- or three-month intervals. Medical records were reviewed to obtain information regarding the patients' demographics, medical histories, radiologic characteristics, treatments, and clinical courses. Results : On follow-up MR images, leukoencephalopathy was found in 95 of 143 patients (66.4%). The median time to develop leukoencephalopathy was 6.6 months. Among those with leukoencephalopathy, four patients showed seven extensive white-matter changes with strongly enhancing lesions demonstrating DNL. Histological confirmation was done in six lesions of three patients and radiological diagnosis alone in one patient. Four lesions spontaneously disappeared on MR images without any treatment, with a mean duration of 14 months before disappearance of DNL. Conclusion : Leukoencephalopathy is a common phenomenon that occurs following intrathecal MTX therapy; however, DNL occurs at a very low incidence. For newly developed enhancing lesions, consideration for the occurrence of DNL should be taken to avoid unnecessary invasive procedures or therapies.

낮은 DNL 특성을 가진 8b 2단 Folding A/D 변환기 (An 8b Two-stage Folding A/D Converter with Low DNL)

  • 최지원;도잔그엉;염창윤;이형규;김경원;김남수
    • 한국전기전자재료학회논문지
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    • 제21권5호
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    • pp.421-425
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    • 2008
  • In this research, a 8-bit CMOS 2 stage folding A/D converter is designed, For low power consumption and small chip size, the A/D converter is designed by using folding and interpolation circuit. Folding circuit is composed of the transistor differential pairs which are connected in parallel. It reduces the number of comparator drastically. The analog block composed of folding block, current interpolation circuit, and three stage current comparator is designed with differential-mode for high speed operation. The simulation in a $0.35\;{\mu}m$ CMOS process. shows DNL and SNDR of 0.5LSB and 47 dB at 250 MHz/s sampling frequency.

고속 샘플링 8bit 100MHz DAC 설계 (8bit 100MHz DAC design for high speed sampling)

  • 이훈기;최규훈
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2005년도 추계종합학술대회
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    • pp.1241-1246
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    • 2005
  • 본 장은 100MHz 수준의 고속 신호 샘플링을 위해 글리치 최소화 기법을 적용한 8비트 100MHz CMOS D/A 변환기 (Digital - to - Analog Converter : DAC) 회로를 제안한다. 제안하는 DAC는 0.35um Hynix CMOS 공정을 사용하여 설계 및 레이아웃을 하였으며, 응용되는 시스템의 속도, 해상도 및 면적 등의 사양을 고려하여 전류 모드 구조로 적용되었다. D/A 변환기의 선형 특성은 원래의 Spec. 과 유사하였으며, ${\pm}0.09LSB$ 정도의 DNL과 INL오차가 측정되었다. 제작된 칩 테스트 결과에 대한 오동작의 원인을 분석하였으며, 이를 통하여 칩 테스트를 위한 고려사항 등을 제안하였다.

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벽지노선의 지속적 운행을 통한 공익적 가치 측정 : 영동선과 동해남부선을 사례로 (Measuring Public Service Values of Rural Railways : A Case Study of Young Dong and Donghae Nambu Lime)

  • 엄영숙;김채원
    • 한국경영과학회지
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    • 제41권4호
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    • pp.1-13
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    • 2016
  • In response to the government's recent attempts to introduce competition and efficiency criteria in the rural railway service provision, this study is to empirically estimate public service values on continuous operation of two rural railways-Young Dong Line (YDL) and Donghae Nambu Line (DNL)-that will be realized beyond the passengers' use values. Based on a contingent valuation survey conducted on 600 passengers and local residents, YDL respondents were willing to pay significantly higher amount compared to those of DNL respondents. Especially tourists traveling on YDL were willing to pay the highest amount, and local residents of DNL were willing to pay relatively high amount. The results will provide useful information in makings decisions on the selection of PSO railways, the amount of PSO compensation and which railways to close, so on.

고속 샘플링 8Bit 100MHz DAC 설계 (8bit 100MHz DAC design for high speed sampling)

  • 이훈기;최규훈
    • 전자공학회논문지 IE
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    • 제43권3호
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    • pp.6-12
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    • 2006
  • 이 논문은 100MHz 수준의 고속 신호 샘플링을 위해 글리치 최소화 기법을 적용한 8비트 100MHz CMOS D/A 변환기 (Digital to Analog Converter : DAC) 회로를 제안한다. 제안하는 DAC는 $0.35{\mu}m$ Hynix CMOS 공정을 사용하여 설계 및 레이아웃을 하였으며, 응용되는 시스템의 속도, 해상도 및 면적 등의 사양을 고려하여 전류 모드 구조로 적용되었다. D/A 변환기의 선형 특성은 설계한 Spec. 과 유사하였으며, $\pm$0.09LSB 정도의 DNL과 INL 오차가 측정되었다. 제작된 칩 테스트 결과에 대한 오동작의 원인을 분석하였으며, 이를 통하여 칩 테스트를 위한 고려사항 등을 제안하였다.

Metformin Induces Lipogenesis and Apoptosis in H4IIE Hepatocellular Carcinoma Cells

  • Deokbae Park;Sookyoung Lee;Hyejin Boo
    • 한국발생생물학회지:발생과생식
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    • 제27권2호
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    • pp.77-89
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    • 2023
  • Metformin is the most widely used anti-diabetic drug that helps maintain normal blood glucose levels primarily by suppressing hepatic gluconeogenesis in type II diabetic patients. We previously found that metformin induces apoptotic death in H4IIE rat hepatocellular carcinoma cells. Despite its anti-diabetic roles, the effect of metformin on hepatic de novo lipogenesis (DNL) remains unclear. We investigated the effect of metformin on hepatic DNL and apoptotic cell death in H4IIE cells. Metformin treatment stimulated glucose consumption, lactate production, intracellular fat accumulation, and the expressions of lipogenic proteins. It also stimulated apoptosis but reduced autophagic responses. These metformin-induced changes were clearly reversed by compound C, an inhibitor of AMP-activated protein kinase (AMPK). Interestingly, metformin massively increased the production of reactive oxygen species (ROS), which was completely blocked by compound C. Metformin also stimulated the phosphorylation of p38 mitogen-activated protein kinase (p38MAPK). Finally, inhibition of p38MAPK mimicked the effects of compound C, and suppressed the metformin-induced fat accumulation and apoptosis. Taken together, metformin stimulates dysregulated glucose metabolism, intracellular fat accumulation, and apoptosis. Our findings suggest that metformin induces excessive glucose-induced DNL, oxidative stress by ROS generation, activation of AMPK and p38MAPK, suppression of autophagy, and ultimately apoptosis.