• 제목/요약/키워드: Cell division cycle

검색결과 332건 처리시간 0.022초

Effects of Oriental Medicinal Drugs on Axonal Regeneration in the Spinal Cord Neurons

  • An Joung-Jo;NamGung Uk;Seo In-Chan;Kim Yoon-Sik
    • 동의생리병리학회지
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    • 제19권6호
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    • pp.1640-1646
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    • 2005
  • An oriental medicinal drugs Jahageo (JHG, Hominis placenta) were examined to determine its effects on the responsiveness of central nervous system neurons after injury. We found that JHG was involved in neurite outgrowth of DRG sensory axons. JHG treatment also increased expression of axonal growth-associated protein GAP-43 in DRG sensory neurons after sciatic nerve injury and in the injured spinal cord. JHG treatment during the spinal cord injury increased induction levels of cell division cycle 2 (Cdc2) protein in DRG as well as in the spinal cord. Histochemical investigation showed that induced Cdc2 in the injured spinal cord was found in non-neuronal cells. These results suggest that JHG regulates activities of non-neuronal cells such as oligodendrocyte and astrocyte in responses to spinal cord injury and protects neuronal responsiveness after axonal damage.

Hydrogen Storage Properties of Hydriding-Dehydriding Cycled Magnesium-Nickel-Iron Oxide Alloy

  • Song, Myoung Youp;Kwon, Sung Nam;Park, Hye Ryoung;Kim, Byoung-Goan
    • 대한금속재료학회지
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    • 제50권2호
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    • pp.171-175
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    • 2012
  • By measuring the absorbed hydrogen quantity as a function of the number of cycles, the cycling properties of the Mg-15 wt%Ni-5 wt%$Fe_2O_3$ alloy were investigated. The absorbed hydrogen quantity decreased as the number of cycles increased. The $H_a$ value varied almost linearly with the number of cycles. The maintainability of absorbed hydrogen quantity at n=100 was 89.0% for the hydriding reaction time of 10 min. After the $150^{th}$ hydriding-dehydriding cycle, Mg, $Mg_2Ni$, $Mg(OH)_2$, MgO, and Fe were observed. The phases were analyzed by Rietveld analysis from the XRD patterns of the Mg-15 wt%Ni-5 wt%$Fe_2O_3$ alloy after 150 hydriding-dehydriding cycles. The crystallite size and strain of Mg were then estimated with the Williamson-Hall technique.

Hydrogen Storage Property Comparison of Pure Mg and Iron (III) Oxide-Added Mg Prepared by Reactive Mechanical Grinding

  • Song, Myoung Youp;Kwon, Sung Nam;Park, Hye Ryoung
    • 대한금속재료학회지
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    • 제50권5호
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    • pp.383-387
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    • 2012
  • The activation of Mg-10 wt%$Fe_2O_3$ was completed after one hydriding-dehydriding cycle. Activated Mg-10 wt%$Fe_2O_3$ absorbed 5.54 wt% H for 60 min at 593 K under 12 bar $H_2$, and desorbed 1.04 wt% H for 60 min at 593 K under 1.0 bar $H_2$. The effect of the reactive grinding on the hydriding and dehydriding rates of Mg was weak. The reactive grinding of Mg with $Fe_2O_3$ is believed to increase the $H_2$-sorption rates by facilitating nucleation (by creating defects on the surface of the Mg particles and by the additive), by making cracks on the surface of Mg particles and reducing the particle size of Mg and thus by shortening the diffusion distances of hydrogen atoms. The added $Fe_2O_3$ and the $Fe_2O_3$ pulverized during mechanical grinding are considered to help the particles of magnesium become finer. Hydriding-dehydriding cycling is also considered to increase the $H_2$-sorption rates of Mg by creating defects and cracks and by reducing the particle size of Mg.

Development of Mg-xFe2O3-yNi Hydrogen-Storage Alloys by Reactive Mechanical Grinding

  • Song, Myoung Youp;Kwon, Sung Nam;Park, Hye Ryoung
    • 대한금속재료학회지
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    • 제50권10호
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    • pp.769-774
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    • 2012
  • Mg-x wt% $Fe_2O_3-y$ wt% Ni samples were prepared by reactive mechanical grinding in a planetary ball mill, and their hydrogen-storage properties were investigated and compared. Activations of $Mg-5Fe_2O_3-5Ni$ was completed after one hydriding (under 12 bar $H_2$) - dehydriding (in vacuum) cycle at 593 K. At n = 2, $Mg-5Fe_2O_3-5Ni$ absorbed 3.43 wt% H for 5 min, 3.57 wt% H for 10 min, 3.76 wt% H for 20 min, and 3.98 wt% H for 60 min. Activated $Mg-10Fe_2O_3$ had the highest hydriding rate, absorbing 2.99 wt% H for 2.5 min, 4.86 wt% H for 10 min, and 5.54 wt% H for 60 min at 593 K under 12 bar $H_2$. Activated $Mg-10Fe_2O_3-5Ni$ had the highest dehydriding rate, desorbing 1.31 wt% H for 10 min, 2.91 wt% H for 30 min, and 3.83 wt% H for 60 min at 593 K under 1.0 bar $H_2$.

Hydrogen Desorption and Absorption Properties of MgH2, LiBH4, and MgH2 + LiBH4 Composite

  • Park, Hye Ryoung;Song, Myoung Youp
    • 대한금속재료학회지
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    • 제50권12호
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    • pp.955-959
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    • 2012
  • To increase the hydrogen storage capacity of Mg-based materials, a sample with a composition of 69.7 wt% $MgH_2$ + 30.3 wt% $LiBH_4$ was prepared by planetary ball milling under hydrogen. The absorption and desorption properties of unmilled $MgH_2$, unmilled $LiBH_4$, and 69.7 wt% $MgH_2$ + 30.3 wt% $LiBH_4$ were examined. At 648 K the unmilled $MgH_2$ desorbed 5.70 wt% for 60 min. The unmilled $LiBH_4$ desorbed 6.40 wt% H for 780 min at 673 K. The 69.7 wt% $MgH_2$ + 30.3 wt% $LiBH_4$ sample desorbed 3.10 wt% H for 50 min, and 3.32 wt% H for 300 min at 623 K at the second cycle.

Metabolome-Wide Reprogramming Modulated by Wnt/β-Catenin Signaling Pathway

  • Soo Jin Park;Joo-Hyun Kim;Sangtaek Oh;Do Yup Lee
    • Journal of Microbiology and Biotechnology
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    • 제33권1호
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    • pp.114-122
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    • 2023
  • A family of signal transduction pathways known as wingless type (Wnt) signaling pathways is essential to developmental processes like cell division and proliferation. Mutation in Wnt signaling results in a variety of diseases, including cancers of the breast, colon, and skin, metabolic disease, and neurodegenerative disease; thus, the Wnt signaling pathways have been attractive targets for disease treatment. However, the complicatedness and large involveness of the pathway often hampers pinpointing the specific targets of the metabolic process. In our current study, we investigated the differential metabolic regulation by the overexpression of the Wnt signaling pathway in a timely-resolved manner by applying high-throughput and un-targeted metabolite profiling. We have detected and annotated 321 metabolite peaks from a total of 36 human embryonic kidney (HEK) 293 cells using GC-TOF MS and LC-Orbitrap MS. The un-targeted metabolomic analysis identified the radical reprogramming of a range of central carbon/nitrogen metabolism pathways, including glycolysis, TCA cycle, and glutaminolysis, and fatty acid pathways. The investigation, combined with targeted mRNA profiles, elucidated an explicit understanding of activated fatty acid metabolism (β-oxidation and biosynthesis). The findings proposed detailed mechanistic biochemical dynamics in response to Wnt-driven metabolic changes, which may help design precise therapeutic targets for Wnt-related diseases.

LKB1/STK11 Tumor Suppressor Reduces Angiogenesis by Directly Interacting with VEGFR2 in Tumorigenesis

  • Seung Bae Rho;Hyun Jung Byun;Boh-Ram Kim;Chang Hoon Lee
    • Biomolecules & Therapeutics
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    • 제31권4호
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    • pp.456-465
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    • 2023
  • Cervical tumors represent a prevalent form of cancer affecting women worldwide; current treatment options involve surgery, radiotherapy, and chemotherapy. Angiogenesis, the process of new blood vessel formation, is a crucial factor in cervical tumor growth. The molecular mechanisms underlying the effects of the liver kinase B1 (LKB1/STK11) tumor suppressor protein on tumor angiogenesis have not been elucidated. Therefore, we investigated the role of LKB1 in cervical tumor angiogenesis both in vitro and in vivo in this study. Our results demonstrated that LKB1 inhibited cervical tumor angiogenesis by suppressing the expression of angiogenesis-related factors such as vascular endothelial growth factor (VEGF) and hypoxia inducible factor-1α. LKB1 directly affected both carcinoma and vascular endothelial cells, resulting in a significant reduction in tumor growth and angiogenesis. Furthermore, LKB1 was found to bind to VEGF receptor 2 (VEGFR-2) and target the VEGFR-2-mediated protein kinase B/mechanistic target of rapamycin signaling pathway in endothelial cells, thereby reducing cervical tumor growth and angiogenesis. Our study provides new insights into the molecular mechanisms underlying the anti-tumor and anti-angiogenic effects of LKB1 in cervical cancer. These findings will help develop new therapeutic strategies for cervical cancer.

The enhancing effect of Acanthopanax sessiliflorus fruit extract on the antibacterial activity of porcine alveolar 3D4/31 macrophages via nuclear factor kappa B1 and lipid metabolism regulation

  • Hwang, Eunmi;Kim, Gye Won;Song, Ki Duk;Lee, Hak-Kyo;Kim, Sung-Jo
    • Asian-Australasian Journal of Animal Sciences
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    • 제32권11호
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    • pp.1776-1788
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    • 2019
  • Objective: The demands for measures to improve disease resistance and productivity of livestock are increasing, as most countries prohibit the addition of antibiotics to feed. This study therefore aimed to uncover functional feed additives to help enhance livestock immunity and disease resistance, using Acanthopanax sessiliflorus fruit extract (ASF). Methods: ASF was extracted with 70% EtOH, and total polyphenolic and catechin contents were measured by the Folin-Ciocalteu and vanillin assay, respectively. The 3D4/31 porcine macrophage cells ($M{\Phi}$) were activated by phorbol 12-myristate 13-acetate (PMA), and cell survival and growth rate were measured with or without ASF treatment. Flow-cytometric analysis determined the lysosomal activity, reactive oxygen species levels (ROS), and cell cycle distribution. Nuclear factor kappa B ($NF-{\kappa}B$) and superoxide dismutase (SOD) protein expression levels were quantified by western blotting and densitometry analysis. Quantitative polymerase chain reaction was applied to measure the lipid metabolism-related genes expression level. Lastly, the antibacterial activity of 3D4/31 $M{\Phi}$ cells was evaluated by the colony forming unit assay. Results: ASF upregulated the cell viability and growth rate of 3D4/31 $M{\Phi}$, with or without PMA activation. Moreover, lysosomal activity and intracellular ROS levels were increased after ASF exposure. In addition, the antioxidant enzyme SOD2 expression levels were proportionately increased with ROS levels. Both ASF and PMA treatment resulted in upregulation of $NF-{\kappa}B$ protein, tumor necrosis factor $(TNF){\alpha}$ mRNA expression levels, lipid synthesis, and fatty acid oxidation metabolism. Interestingly, co-treatment of ASF with PMA resulted in recovery of $NF-{\kappa}B$, $TNF{\alpha}$, and lipid metabolism levels. Finally, ASF pretreatment enhanced the in vitro bactericidal activity of 3D4/31 $M{\Phi}$ against Escherichia coli. Conclusion: This study provides a novel insight into the regulation of $NF-{\kappa}B$ activity and lipid metabolism in $M{\Phi}$, and we anticipate that ASF has the potential to be effective as a feed additive to enhance livestock immunity.

천년초선인장 열매추출물의 폴리페놀, 플라보노이드 함량과 유방암 세포(MCF-7)에 대한 성장 억제효과 (Total Polyphenol and Flavonoid of Fruit Extract of Opuntia humifusa and Its Inhibitory Effect on the Growth of MCF-7 Human Breast Cancer Cells)

  • 윤진아;함상욱;박지은;손용석
    • 한국식품영양과학회지
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    • 제38권12호
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    • pp.1679-1684
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    • 2009
  • 본 연구에서는 천년초선인장 열매의 총 폴리페놀과 플라보노이드 함량을 분석하고, 열매의 추출물이 인간의 유방상피조직에서 유래한 암세포인 MCF-7의 증식과 세포사멸에 미치는 영향을 조사하였다. 천년초선인장 열매의 총 폴리페놀 함량은 약 4.49 g/100 g, 플라보노이드 함량은 약 1.31g/100 g로 나타났다. 열매의 물 추출물 100과 500 ${\mu}$g/mL 농도에서 정상세포인 BJ에 대한 세포독성을 나타내지 않으면서 MCF-7 세포의 살아있는 세포수를 농도 의존적으로 감소시키는 효과를 보였다. 또한 세포배양액에 열매의 물 추출물을 첨가한 경우, G1 arrest가 일어나 세포주기 진행이 지연되었으나, apoptosis에는 영향을 주지 않음이 확인되어 천년초선인장 열매 물 추출물이 apoptosis보다는 G1 arrest를 유도하여 유방암세포를 억제한다는 것을 규명하였다. 이러한 결과들은 천년초선인장 열매의 물 추출물이 세포독성에는 영향을 주지 않으면서 유방암세포의 증식과 세포주기 진행을 억제하는 효과적인 항암물질이 될 수 있는 기능성 소재로 활용 가능하다는 것을 암시한다.

시리얼 데이터 통신을 위한 기준 클록이 없는 3.2Gb/s 클록 데이터 복원회로 (A 3.2Gb/s Clock and Data Recovery Circuit without Reference Clock for Serial Data Communication)

  • 김강직;정기상;조성익
    • 전자공학회논문지SC
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    • 제46권2호
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    • pp.72-77
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    • 2009
  • 본 논문은 별도 기준 클록 없이 고속 시리얼 데이터 통신을 위한 3.2Gb/s 클록 데이터 복원(CDR) 회로를 설명한다. CDR회로는 전체적으로 5부분으로 구성되며, 위상검출기(PD)와 주파수 검출기(FD), 다중 위상 전압 제어 발진기(VCO), 전하펌프(CP), 외부 루프필터(LF)로 구성되어 있다. CDR회로는 half-rate bang-bang 타입의 위상 검출기와 입력 pull-in 범위를 늘릴 수 있도록 half-rate 주파수 검출기를 적용하였다. VCO는 4단의 차동 지연단(delay cell)으로 구성되어 있으며 튜닝 범위와 선형성 향상을 위해 rail-to-rail 전류 바이어스단을 적용하였다 각 지연단은 풀 스윙과 듀티의 부정합을 보상할 수 있는 출력 버퍼를 갖고 있다. 구현한 CDR회로는 별도의 기준 클록 없이 넓은 pull-in 범위를 확보할 수 있으며 기준 클록 생성을 위한 부가적인 Phase-Locked Loop를 필요치 않기 때문에 칩의 면적과 전력소비를 효과적으로 줄일 수 있다. 본 CDR 회로는 0.18um 1P6M CMOS 공정을 이용하여 제작하였고 루프 필터를 제외한 전체 칩 면적은 $1{\times}1mm^2$이다. 3.2Gb/s 입력 데이터 율에서 모의실험을 통한 복원된 클록의 pk-pk 지터는 26ps이며 1.8V 전원전압에서 전체 전력소모는 63mW로 나타났다. 동일한 입력 데이터 율에서 테스트를 통한 pk-pk 지터 결과는 55ps였으며 신뢰할 수 있는 입력 데이터율 범위는 약 2.4Gb/s에서 3.4Gb/s로 나타났다.