• 제목/요약/키워드: Cellular layers

검색결과 95건 처리시간 0.031초

Comparison of unprocessed silk cocoon and silk cocoon middle layer membranes for guided bone regeneration

  • Kim, Seong-Gon;Kim, Min-Keun;Kweon, HaeYong;Jo, You-Young;Lee, Kwang-Gill;Lee, Jeong Keun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제38권
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    • pp.11.1-11.8
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    • 2016
  • Background: Silk cocoon is composed of multiple layers. The natural silk cocoon containing all layers was cut as a rectangular shape as defined as total group. The inner and outermost layers were removed from the total group and the remained mat was defined as the middle group. The objectives of this study was to compare the total group with the middle group as a barrier membrane for the guided bone regeneration. Methods: The effects of these materials on the cellular proliferation and alkaline phosphatase (ALP) expression of MG63 cells were explored. For comparing bone regeneration ability, bilateral bone defects were created in calvarial areas in ten adult New Zealand white rabbits. The defects were covered with silk membranes of the middle group, with silk membrane of the total group used as the control on the contralateral side. The defects were allowed to heal for 4 and 8 weeks. Micro-computerized tomography (${\mu}CT$) and histological examination were performed. Results: The middle group exhibited a higher MTT value 48 and 72 h after treatment compared to the total group. ALP expression was also higher in the middle group. The results of ${\mu}CT$ and histologic examination showed that new bone formation was significantly higher in the middle group compared to the total group 8 weeks postoperatively (P < 0.05). Conclusions: In conclusion, the middle layer of the silk cocoon supports guided bone regeneration better than unprocessed silk cocoon.

다층 배양된 암세포에서 파크리탁셀의 항증식효과 분석 (Anti-proliferative Effect of Paclitaxel in Multicellular Layers of Human Cancer Cells)

  • 강춘모;이주호;차정호;구효정
    • Journal of Pharmaceutical Investigation
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    • 제36권1호
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    • pp.1-9
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    • 2006
  • Human solid tumors exhibit a multicellular resistance (MCR) resulting from limited drug penetration and decreased sensitivity of tumor cells when interacting with their microenvironments. Multicellular cultures represent solid tumor condition in vivo and provide clinically relevant data. There is little data on antitumor effect of paclitaxel (PTX) in multicellular cultures although its MCR has been demonstrated. In the present study, we evaluated antiproliferative effects of PTX in multicellular layers (MCL) of DLD-1 human colorectal carcinoma cells. BrdU labeling index (LI), thickness of MCL, cell cycle distribution and cellular uptake of calcein were measured before and after exposure to PTX at 0.1 to 50 ${\mu}M$ for 24, 48 and 72 hrs. BrdU LI and thickness of MCL showed a concentration- and time-dependent decrease and the changes in both parameters were similar, i.e., 34.2% and 40.6% decrease in BrdU LI and thickness, respectively, when exposed to $50\;{\mu}M$ for 72 hr. The DLD-1 cells grown in MCL showed increase in $%G_{0}/G_{1}$ and resistance to cell cycle arrest and apoptosis compared to monolayers. Calcein uptake in MCL did not change upon PTX exposure, indicating technical problems in multicellular system. Overall, these data indicate that antitumor activity of PTX may be limited in human solid tumors (a multicellular system) and MCL may be an appropriate model to study further pharmacodynamics of PTX.

MODIFICATION OF METAL MATERIALS BY HIGH TEMPERATURE PULSED PLASMA FLUXES IRRADIATION

  • Vladimir L. Yakushin;Boris A. Kalin;Serguei S. Tserevitionov
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2000년도 춘계학술발표회 초록집
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    • pp.1-1
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    • 2000
  • The results of the modification of metal materials treated by high temperature pulst:d plasma fluxes (HTlPPF) with a specific power of incident flux changing in the $(3...100)10^5{]\;}W/cm^2$ range and a pulse duration lying from 15 to $50{\;}\mu\textrm{s}$ have been presented. The results of HTPPF action were studied on the stainless steels of 18Cr-l0Ni, 16Cr- 15Ni, 13Cr-2Mo types; on the structural carbon steels of (13...35)Cr, St. 3, St. 20, St. 45 types; on the tool steels of U8, 65G, ShHI5 types, and others; on nickel and high nickel alloy of 20Cr-45Ni type; on zirconium- and vanadium-base alloys and other materials. The microstructure and properties (mechanical, tribological, erosion, and other properties) of modified materials and surface alloying of metals exposed to HTPPF action have been investigated. It was found that the modification of materials by HTPPF resulted in a simultaneous increase of several properties of the treated articles: microhardness of the surface and layers of 40...60 $\mu\textrm{m}$ in depth, tribological characteristics (friction coefficient, wear resistance), mechanical properties ({\sigma_y}, {\;}{\sigma_{0.2}}.{\;}{\sigma_r}) on retention of the initial plasticity ($\delta$), corrosion resistance, radistanation erosion under ion irradiation, and others. The determining factor of the changes observed is the structural-phase modification of the near-surface layers, in particular, the formation of the fine cellular structure in the near-surface layers at a depth of $20{\;}{\mu\textrm{m}}$ with dimension of cells changing in the range from 0.1 to $1., 5{\;}\mu\textrm{m}$, depending on the kind of material, its preliminary treatment, and the parameters of plasma fluxes. The remits obtained have shown the possibility of purposeful surface alloying of metals exposed to HTPPF action over a depth up to 20...45 $\mu\textrm{m}$ and the concentration of alloying element (Ni, Cr, V) up to 20 wt.%. Possible industrial brunches for using the treatment have been also considered, as well as some results on modifying the serial industrial articles by HTPPF.

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Cell Population Changes in Transplanted Olfactory Placodes of Chimerae of Xenopus Iaevis and Xenopus borealis

  • 구혜영
    • Animal cells and systems
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    • 제1권3호
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    • pp.491-496
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    • 1997
  • When olfactory placodes are transplanted at stages 23/24 from Xenopus laevis to Xenopus borealis hosts of the same age, it is possible to distinguish the cell populations of the host and donor due to the peculiar nuclear Q bands specific to X. borealis. I have replaced the eye anlage in each of a number of X. borealis with the transplanted olfactory placode of an individual X. laevis, or vice versa. In most instances, the placode of the donor fuses with that of the host. When fusion occurs, but not when the host and donor orqans grow separately, the cells of the donor were replaced gradually and according to a characteristic pattern by cells of the host. The basal cells of the donor were the first to be replaced, followed by the more matured cells of the sensory epithelium. This cellular substitution, proceeding in an orderly fashion from bottom to upper layers of the epithelium, depends on the fusion of the two organs. This observation suggests intercellular contacts in the mitotic zone of the two organs favor the host's cells over those of the donor.

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Fabrication of Three-Dimensionally Arrayed Polyaniline Nanostructures

  • 권혜민;류일환;한지영;임상규
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.220-220
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    • 2012
  • The supercapacitors with extraordinarily high capability for energy storage are attracting growing attention for their potential applications in portable electronic equipments, hybrid vehicles, cellular devices, and so on. The nanostructuring of the electrode surface can provide large surface area and consequently easy diffusion of ions in the capacitors. In addition, compared to two-dimensional nanostructures, the three-dimensional (3D) nano-architecture is expected to lead to significant enhancement of mechanical and electrical properties such as capacitance per unit area of the electrode. Polyaniline (PANi) is known as promising electrode material for supercapacitors due to its desirable properties such as high electro activity, high doping level and environmental stability. In this context, we fabricated well-ordered 3D PANi nanostructures on 3D polystyrene (PS) nanospheres which was arrayed by layer-by-layer stacking method. The height of the PANi nanostructures could be controlled by the number of PS layers stacked. 3D PANi hollow nanospheres were also fabricated by dissolving inner PS nanospheres, which resulted in further enhancement of the surface area and capacitance of the electrode.

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Establishment of Mouse Pluripotent Stem Cells Generated from Primordial Germ Cells

  • Shim, Sang-Woo;Song, Sang-Jin;Hosup Shim;Lee, Bo-Yon;Huh, Choo-Yup;Hyuk Song;Chung, Kil-Saeng;Lee, Hoon-Taek
    • 한국동물번식학회:학술대회논문집
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    • 한국동물번식학회 2004년도 춘계학술발표대회
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    • pp.276-276
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    • 2004
  • Pluripotent stem cells have been generated from two embryonic sources. ES cells are generated from ICM of blastocyst stage embryos, and embryonic germ (EG) cells are generated from primordial germ cells (PGCs). Both ES and EG cells are pluripotent and present important characteristics such as high levels of alkaline phosphatase (AP) activity, multi-cellular colony formation, normal and stable karyotypes, continuously passaging ability, and the capability of differentiation into all three embryonic germ layers. (omitted)

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Sino-Bronchiectasis 에 대한 임상적 고찰 (Clinical and Pathological Study of Sino-bronchiectasis)

  • 김종원;서정회;최인환
    • Journal of Chest Surgery
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    • 제6권2호
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    • pp.151-158
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    • 1973
  • Author studied the pathogenesis of Sino-bronchiectasis with review of clincal and pathological findings of resected lungs in 24 eases of bronchiectasis,and the results were as follows: 1. Of the 24 eases of bronchiectasis, Sino-bronchiectasis were found in 11 cases and these cases most commonly, developed in first and second decade of life. In a majority of these cases,the main symptoms were the signs of wet bronchiectasis. 2. The typical roentgenograrn changes of plain chest x rays were increase in size and loss of definition of the markings and bronchographically revealed the cylindrical or tubular form in majority of these cases. 3. Pathologically Sino-bronchiectasis involved specific segmental areas of the lungs such as left basal and S4+5 segments and revealed commonly tubular dilatation. The most common findings of bronchial wall of dilated bronchus were the inflammatory cellular infiltration and cylindrical hyperplasia of mucus epithelial layers. 4. It was suspected that there were some causal relations in pathogenesis between chronic sinusitis and bronchiectasis.

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Numerical investigation of geocell reinforced slopes behavior by considering geocell geometry effect

  • Ardakani, Alireza;Namaei, Ali
    • Geomechanics and Engineering
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    • 제24권6호
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    • pp.589-597
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    • 2021
  • The present study evaluates geocell reinforced slope behavior. A three dimensional analysis is carried out to simulate soil and geocell elastoplastic behavior using the finite difference software FLAC3D. In order to investigate the geocell reinforcement effect, the geocell aperture size, thickness, geocell placement condition and soil compaction had been considered as variable parameters. Moreover, a comparison is evaluated between geocell reinforcing system and conventional planar reinforcement. The obtained results showed that the pocket size, thickness and soil compaction have considerable influence on the geocell reinforcement slope performance. Moreover, it was found that the critical sliding surface was bounded by the first geocell reinforcement and the slope stability increases, by increasing the vertical space between geocell layers. In addition, the comparison between geocell and geogrid reinforcement indicates the efficiency of using cellular honeycomb geosynthetic reinforcement.

HiCORE: Hi-C Analysis for Identification of Core Chromatin Looping Regions with Higher Resolution

  • Lee, Hongwoo;Seo, Pil Joon
    • Molecules and Cells
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    • 제44권12호
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    • pp.883-892
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    • 2021
  • Genome-wide chromosome conformation capture (3C)-based high-throughput sequencing (Hi-C) has enabled identification of genome-wide chromatin loops. Because the Hi-C map with restriction fragment resolution is intrinsically associated with sparsity and stochastic noise, Hi-C data are usually binned at particular intervals; however, the binning method has limited reliability, especially at high resolution. Here, we describe a new method called HiCORE, which provides simple pipelines and algorithms to overcome the limitations of single-layered binning and predict core chromatin regions with three-dimensional physical interactions. In this approach, multiple layers of binning with slightly shifted genome coverage are generated, and interacting bins at each layer are integrated to infer narrower regions of chromatin interactions. HiCORE predicts chromatin looping regions with higher resolution, both in human and Arabidopsis genomes, and contributes to the identification of the precise positions of potential genomic elements in an unbiased manner.

Integrative Multi-Omics Approaches in Cancer Research: From Biological Networks to Clinical Subtypes

  • Heo, Yong Jin;Hwa, Chanwoong;Lee, Gang-Hee;Park, Jae-Min;An, Joon-Yong
    • Molecules and Cells
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    • 제44권7호
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    • pp.433-443
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    • 2021
  • Multi-omics approaches are novel frameworks that integrate multiple omics datasets generated from the same patients to better understand the molecular and clinical features of cancers. A wide range of emerging omics and multi-view clustering algorithms now provide unprecedented opportunities to further classify cancers into subtypes, improve the survival prediction and therapeutic outcome of these subtypes, and understand key pathophysiological processes through different molecular layers. In this review, we overview the concept and rationale of multi-omics approaches in cancer research. We also introduce recent advances in the development of multi-omics algorithms and integration methods for multiple-layered datasets from cancer patients. Finally, we summarize the latest findings from large-scale multi-omics studies of various cancers and their implications for patient subtyping and drug development.