• Computers and Concrete
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• v.25 no.3
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• pp.205-214
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• 2020

Cytoskeleton components in living cell bear large compressive force and are responsible in maintaining the cell shape. Actually these filaments are surrounded by viscoelastic media within the cell. This surrounding, viscoelastic media affects the buckling behavior of these filaments when external force is applied on these filaments by exerting continuous pressure in opposite directions to the incipient buckling of the filaments. In this article a mechanical model is applied to account the effects of this media on the buckling behavior of intermediate filaments network of cytoskeleton. The model immeasurably associates; filament's bending rigidity, adjacent system elasticity, and cytosol viscosity with buckling wavelength, buckling growth rate and buckling amplitude of the filaments.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.74-74
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• 2001

난자 동결방법의 선별은 보다 효과적인 난자은행의 개발에 필수 불가결한 중요한 요소이다. 이전의 연구에서 마우스의 난자를 ethylene glycol과 electron microscope grid를 이용한 유리화 동결법으로 동결 융해한 결과 기존의 slow freezing 방법에서보다 높은 생존율과 배발달율이 나타남을 관찰하였다. 그러나 동결융해후의 난자는 방추사와 염색체의 이상성이 대조군에 비해 높은 빈도로 나타나 융해후의 배발달율을 감소시키는 것으로 보고되었다. 이에 본 연구에서는 유리화동결법동안 항동해제에 Cytoskeleton system을 안정화시키는 cytoskeleton stabilizer인 taxol을 첨가시킨후 동결시켰을때 생존율과 발달율을 개선시킬 수 있는지 알아보고자 본 실험을 시행하였다. ICR mouse의 성숙란을 채취하여 연구목적에 따라 taxol을 첨가시키지 않은 대조군과 첨가시킨 실험군으로 분류하였다. 동결방법은 난자를 1.5 M ethylene glycol (EG)에 2분 30초간 노출시킨후 5.5 M EG와 1 M sucrose가 첨가된 동결액에 20초간 노출시킨 후 Grid에 난자를 부착시킨후 직접 액체질소에 침지하여 동결하였다. 동결후 난자는 5단계로 융해를 실시한 후 정자와 체외수정을 시킨 후 수정된 난자는 modified P1 배약액에 124 h까지 발달율을 관찰하였고, 배양 후 발달된 배반포는 대조군과 실험군, 각각 4마리의 발정동기화된 recipient에 이식을 시행하였다. 배발달율은 대조군에 비해 실험군에서 4세포기 (48 vs. 84.4%), 8세포기 (34% vs. 70.6%), 상실배 (26% vs. 58.6%) 그리고 배반포 발달율은 (24% vs. 58.6%)로 높게 관찰되었다. 배아이식후 대조군과 실험군에서 각각 2 마리가 임신이되어 정상적인 산자를 분만하였다. 따라서 항동해제에 taxol의 첨가는 동결 융해후의 난자의 배발달율을 증진시킬 수 있었다..8%로 나타나 난할율 및 배반포 발생율에 있어서 융합조건에 따라 큰 차이는 없었으나 1.9㎸/cm, 30$\mu\textrm{s}$ 2회의 조건이 다른 조건들에 비하여 유의적으로 낮았다. 따라서, 체세포와 수핵란 세포질간의 융합율과 배반포 발생에 미치는 영향은 전압보다는 시간에 더 크게 받음을 알 수 있었으며, 이와 같은 결과에서 융합시 시간을 오래 주는 것보다 전압을 높이는 것이 수핵난자의 세포질에 상해를 줄이고 이후 배반포 발생에 유리할 것으로 사료되었다.면에서도 더욱 더 활발할 것으로 기대된다. 배란후 72시간째에 초음파진단기를 이용하여 난소의 난포발달을 조사한 결과 , 대조구와 bFF처리구에 비해 AI처리구에서 발달난포가 유의적으로 많은 것을 확인하였다. 이상과 같은 결과로, Anti-inhibin serum은 한우 자체에서 분비하는 Inhibin을 특이하게 억제하여 Inhibin에 의해 억제되는 FSH분비가 촉진됨으로써 난포발달과 estrogen의 농도가 촉진되는 것으로 사료되어 anti-inhibin serum이 한우의 과배란유기 효과가 있는 것으로 사료된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수록 현저했다. 주상에서 관측된 이러한 특성은 서브스톰 확장기 활동이 자기폭풍의 발달과 밀접한 관계가 있음을 시사한다.se that were all low in two aspects, named "the Nonsignificant group". And the issues were high risk perception in general setting and

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.4
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• pp.290-299
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• 2020

Purpose: Here, we verified that the actin cytoskeletal gene expression of human gingival fibroblasts was altered by the administration of trichloroacetic acid (TCA) and epidermal growth factor (EGF) using the nano-controlled releasing system. Materials and methods: The control and experimental groups were divided into 3 groups: the group with the TCA-only nano-controlled releasing system (EXP1), the group with the TCA- and EGF nano-controlled releasing system (EXP2), and the control group (CON) with 48-h incubation. Expression of 26 genes involved in the regulation of actin cytoskeleton were analyzed by real-time PCR followed by the determination of correlations and influential factors using the Pearson correlation analysis and multiple regression analysis. Results: Among 23 genes upregulated in EXP1 and EXP2, expression of 14 genes were significantly increased in EXP2 compared to EXP1. On the other hand, LPAR1 was downregulated only in EXP1, GNA13 was upregulated only in EXP2, and F2R was downregulated only in EXP2. Three Rac1-related genes and CDC42 were identified as the influential factors of the actin gene upregulation. Conclusion: The actin cytoskeleton genes in human gingival fibroblast were upregulated by the administration of TCA and EGF using HGC-based nano-controlled releasing system.

• BMB Reports
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• v.29 no.5
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• pp.405-410
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• 1996

Previous studies have shown that transforming growth factor beta ($TGF-{\beta}$) is a potent regulator of cell growth and differentiation. To study the effects of $TGF-{\beta}$ on cell morphology and cytoskeleton reorganization, we conducted a survey using Mv1Lu mink lung epithelial cells with antibodies to cytoskeletal proteins and an extracellular matrix protein. While the untreated cells showed a cuboidal shape of typical epithelia, the Mv1Lu cells displayed a drastic shape change in the presence of $TGF-{\beta}$. This alteration was most prominent when near-confluent cells were treated with $TGF-{\beta}$. Since the morphology alteration is known to be accompanied by the reorganization of cytoskeletal proteins in other cell types, we investigated the intracellular distribution of the three major cytoskeletal structures: microfilaments, microtubules, and intermediate filaments. In the microfilament system, $TGF-{\beta}$ induced new stress fiber formation, which was caused primarily by the polymerization of cytoplasmic G-actin. However, $TGF-{\beta}$ appeared not to induce any significant changes in microtubular structures and vimentin filaments as determined by indirect fluorescence microscopy. Finally we confirmed the rapid accumulation of fibronectin by immunoblot analysis and chased the protein locations by immunofluorescence microscopy.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.67-74
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• 2003

Nervous system is clinically important, and involved in most disorders directly or indirectly. It could be injury and be a source of symptoms. Injury of central or peripheral nervous system injury may affect that mechanism and interrupt normal function. An understanding of the concepts of axonal transport is important for physical therapist who treat injury of nerves. Three connective tissue layers are the endoneurium, perineurium, epineurium. Each has its own special structural characteristics and functional properties. The blood supply to the nervous system is well equipped in all dynamic and static postures with intrinsic and extrinsic vasculation. After nerve injury, alternations in the ionic compression or pressures within this environment may interfere with blood flow and, consequently conduction and the flow of axoplasm. The cytoskeleton are not static. On the contrary, elements of the cytoskeleton are dynamically regulated and are very likely in continual motion. It permits neural mobility. There are different axonal transport systems within a single axon, of which two main flows have been identified : First, anterograde transport system, Secondly, retrograde transport system. The nervous system adapts lengthening in two basic ways. The one is that the development of tension or increased pressure within the tissues, increased intradural pressure. The other is movements that are gross movement and movement occurring intraneurally between the connective tissues and the neural tissues. In this article, we emphasize the biologic aspects of nervous system that influenced by therapeutic approaches. Although identified scientific information in basic science is utilized at clinic, we would attain the more therapeutic effects and develop the physical therapy science.

• Journal of Embryo Transfer
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• v.16 no.3
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• pp.239-243
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• 2001

Selection of oocyte cryopreservation method is a prerequisite factor for developing an effective bank system. Compared with slow freezing method, the vitrification has various advantages such as avoiding intracellular ice crustal formation. In our previous, we attempted to employ a vitrification method using ethylene glycol and an electron microscope grid for cryopreservation of mouse oocytes. However, A high incidence of spindle and chromosome abnormalities was detected in thawed oocytes after vitrification. We examined whether the addition of a cystoskeleton stabilizer Taxol $^{TM}$, to the vitrification solution could promote the post-thawed survival and subsequent development of stored oocytes. More oocytes developed to the 4-cell (44.7% vs. 69.7%), 8-cell (31.8% vs. 64.2%), morula (24.7% vs. 54.3%), and blastocyst (20.3% vs. 49.2%) stages after the addition of Taxol$^{TM}$ to the cryoprotectant than after no addition. 21 and 26 mouse pups were born after transfer of blastocyst derived from oocytes vitrified without and with Taxol. The addition of Taxol to vitrification solution greatly promoted post-thaw preimplantation development of ICR morose oocytes.tes.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.531-540
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• 2022

Due to the high incidence of malignant melanoma, the establishment of in vitro models that recapitulate the tumor microenvironment is of great biological and clinical importance for tumor treatment and drug research. In this study, 3D printing technology was used to prepare GelMA/PEGDA composite scaffolds that mimic the microenvironment of human malignant melanoma cell (A375) growth and construct in vitro melanoma micro-models. The GelMA/PEGDA hybrid scaffold was tested by the mechanical property, cell live/dead assay, cell proliferation assay, cytoskeleton staining and drug loading assay. The growth of tumor cells in two- and three-dimensional culture systems and the anti-cancer effect of luteolin were evaluated using the live/dead staining method and the Cell Counting Kit-8 (CCK-8) method. The results showed a high aggregation of tumor cells on the 3D scaffold, which was suitable for long-term culture. Cytoskeleton staining and immunofluorescent protein staining were used to evaluate the degree of differentiation of tumor cells under 2D and 3D culture systems. The results indicated that 3D bioprinted scaffolds were more suitable for tumor cell expansion and differentiation, and the tumor cells were more aggressive. In addition, luteolin was time- and dose-dependent on tumor cells, and tumor cells in the 3D culture system were more resistant to the drug.

• Journal of Life Science
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• v.19 no.7
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• pp.866-870
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• 2009

Fascin, a cytoskeleton actin binding protein, functions in cell adhesion and cell migration. Fascin is also known as a candidate biomarker for various cancers, however, regulatory mechanisms of fascin expression remains little understood. In this study, we found an abnormal bristle phenotype, which is similar to that of the Drosophila fascin mutant, in Drafmutant flies. Hence, we investigated whether fascin expression is regulated by Raf signaling. RT-PCR and Western blot analysis showed that Drosophila fascin expression was down-regulated in Draf mutant flies and the level was increased in larvae expressing the oncogenic form of Draf (Draf$^{got}$) under the GAL4-UAS system. Immunostaining analysis showed increased fascin in the hemocytes over-expressing Draf$^{got}$. Our results indicate that fascin expression is regulated by Raf signaling and suggest that Raf signaling may play an important role in the actin cytoskeleton-associated developmental process and tumor progression via regulation of fascin gene.

• IMMUNE NETWORK
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• v.12 no.3
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• pp.71-83
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• 2012

T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.3
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• pp.263-268
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• 2012

It is important to know the mechanism of cell membrane fluctuation because it can be readout for the nanomechanical interaction between cytoskeleton and plasma membrane. Traditional techniques, however, have drawbacks such as probe contact with the cell surface, complicate analysis, and limit spatial and temporal resolution. In this study, we developed a new system for non-contact measurement of nano-scale localized-cell surface dynamics using modified-scanning ion-conductance microscopy. With 2 nm resolution, we determined that endothelial cells have local membrane fluctuations of ~20 nm, actin depolymerization causes increase in fluctuation amplitude, and ATP depletion abolishes all membrane fluctuations.