• Advances in nano research
• /
• v.13 no.3
• /
• pp.297-312
• /
• 2022

Coughing and breath shortness are common symptoms of nano (small) cell lung cancer. Smoking is main factor in causing such cancers. The cancer cells form on the soft tissues of lung. Deformation behavior and wave vibration of lung affected when cancer cells exist. Therefore, in the current work, phase velocity behavior of the small cell lung cancer as a main part of the body via an exact size-dependent theory is presented. Regarding this problem, displacement fields of small cell lung cancer are obtained using first-order shear deformation theory with five parameters. Besides, the size-dependent small cell lung cancer is modeled via nonlocal stress/strain gradient theory (NSGT). An analytical method is applied for solving the governing equations of the small cell lung cancer structure. The novelty of the current study is the consideration of the five-parameter of displacement for curved panel, and porosity as well as NSGT are employed and solved using the analytical method. For more verification, the outcomes of this reports are compared with the predictions of deep neural network (DNN) with adaptive optimization method. A thorough parametric investigation is conducted on the effect of NSGT parameters, porosity and geometry on the phase velocity behavior of the small cell lung cancer structure.

• International Journal of Oral Biology
• /
• v.32 no.3
• /
• pp.93-101
• /
• 2007

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of ${\alpha}\;and\;{\beta}$ integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although ${\alpha}v{\beta}6$ integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, ${\alpha}v$ integrin subunit and ${\alpha}v{\beta}6$ integrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

• Advances in concrete construction
• /
• v.10 no.2
• /
• pp.141-149
• /
• 2020

In the present study, a mechanical model is applied to account the effects of the surrounding viscoelastic media on the buckling behavior of single microfilament within the cell. The model immeasurably associates filament's bending rigidity, neighboring system elasticity, and cytosol viscosity with buckling wavelengths, buckling growth rates and buckling amplitudes of the filament. 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 consisting of other filaments network and viscous cytosole within the cell. This surrounding, viscoelastic media affects the buckling behavior of these filaments when external force is applied on these filaments. The obtained results, indicate that the coupling of viscoelastic media with the viscous cytosol greatly affect the buckling behavior of microfilament. The buckling forces increased with the increase in the intensity of surrounding viscoelastic media.

• Journal of the Korean institute of surface engineering
• /
• v.48 no.1
• /
• pp.23-26
• /
• 2015

What causes the transformation of a solar cell is the behavior difference of thermal expansion occurred between the substrate and the layer of semiconductor used in the solar cell. Therefore, the substrate has to possess a behavior of thermal expansion that is similar with that of semiconductor layer. This study employed electroforming to manufacture Fe-Ni alloy materials of different compositions. To verify the result from a finite element analysis, a two-dimensional Mo substrate was calculated and its verification experiment was conducted. The absolute values from the finite element analysis of Mo/substrate structure and its verification experiment showed a difference. However, the size of residual stress of individual substrate compositions had a similar tendency. Two-dimensional CIGS/Mo/$SiO_2$/substrate was modeled. Looking into the residual stress of CIGS layer occurred while the temperature declined from $550^{\circ}C$ to room temperature, the smallest residual stress was found with the use of Fe-52 wt%Ni substrate material.

• Journal of Advanced Marine Engineering and Technology
• /
• v.35 no.7
• /
• pp.881-890
• /
• 2011

Analyses of performance and behavior of the individual PEM fuel cells (PEMFC) under different operating conditions are of importance optimally to design and efficiently to operate the stack. The paper focuses on experimental analyses of a two-cell stack under different operating conditions, which performance and behavior are measured by the voltage of a cell as well as the stack. Experimental parameters include stoichiometric ratio, temperature of the air supplied under different working stack temperatures and loads. Results showed that the cell voltages are dominantly influenced by the temperature of the air supplied among others. In addition, an inherent difference between the first and the second cell voltage exists because of the tolerances of the cell components and the resulting different over-potentials at different equilibrium states. Furthermore, it is shown that the proton conductivity in the membranes conditioned by the humidity in the cathode channel highly affects the voltage differences of the two cells.

• Journal of Electrochemical Science and Technology
• /
• v.11 no.2
• /
• pp.132-139
• /
• 2020

Solid oxide fuel cells (SOFCs) are among one of the promising technologies for efficient and clean energy. SOFCs offer several advantages over other types of fuel cells under relatively high temperatures (600℃ to 800℃). However, the thermal behavior of SOFC stacks at high operating temperatures is a serious issue in SOFC development because it can be associated with detrimental thermal stresses on the life span of the stacks. The thermal behavior of SOFC stacks can be influenced by operating or material properties. Therefore, this work aims to investigate the effects of the thermal conductivity of each component (anode, cathode, and electrolyte) on the thermal behavior of samarium-doped ceria-based SOFCs at intermediate temperatures. Computational fluid dynamics is used to simulate SOFC operation at 600℃. The temperature distributions and gradients of a single cell at 0.7 V under different thermal conductivity values are analyzed and discussed to determine their relationship. Simulations reveal that the influence of thermal conductivity is more remarkable for the anode and electrolyte than for the cathode. Increasing the thermal conductivity of the anode by 50% results in a 23% drop in the maximum thermal gradients. The results for the electrolyte are subtle, with a ~67% reduction in thermal conductivity that only results in an 8% reduction in the maximum temperature gradient. The effect of thermal conductivity on temperature gradient is important because it can be used to predict thermal stress generation.

• Journal of Biosystems Engineering
• /
• v.39 no.3
• /
• pp.244-252
• /
• 2014

Purpose: The development of an efficient in vitro cell culture device to process various cells would represent a major milestone in biological science and engineering. However, the current conventional macro-scale in vitro cell culture platforms are limited in their capacity for detailed analysis and determination of cellular behavior in complex environments. This paper describes a microfluidic-based culture device that allows accurate control of parameters of physical cues such as pressure. Methods: A microfluidic device, as a model microbioreactor, was designed and fabricated to culture Saccharomyces cerevisiae and Chlamydomonas reinhardtii under various conditions of physical pressure stimulus. This device was compatible with live-cell imaging and allowed quantitative analysis of physical cue-induced behavior in yeast and microalgae. Results: A simple microfluidic-based in vitro cell culture device containing a cell culture channel and an air channel was developed to investigate physical pressure stress-induced behavior in yeasts and microalgae. The shapes of Saccharomyces cerevisiae and Chlamydomonas reinhardtii could be controlled under compressive stress. The lipid production by Chlamydomonas reinhardtii was significantly enhanced by compressive stress in the microfluidic device when compared to cells cultured without compressive stress. Conclusions: This microfluidic-based in vitro cell culture device can be used as a tool for quantitative analysis of cellular behavior under complex physical and chemical conditions.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.1450-1454
• /
• 2008

In the conventional biology, the most of cell studies was carried out by culturing cells in the Petri dish and by investigating cellular behavior under the diverse bio-molecule (cell signalling materials, drugs or etc.) conditions. However, in vivo environments, diverse stimulations including chemical, mechanical and topological environments involved in the proliferation, differentiation and migration of cells and it is almost impossible to provide these conditions with traditional method. We have developed the methods to provide the well defined chemical and mechanical stimulations using microfluidic devices and applied these approaches to the study of environmental effect on cells. In this paper, we will introduce our microfluidic chips to provide microenvironment and its applications using several cells.

• Transactions on Electrical and Electronic Materials
• /
• v.8 no.6
• /
• pp.283-285
• /
• 2007

The molten carbonate fuel cell has conspicuous feature and high potential in being used as an energy converter of various fuel to electricity and heat. However, the molten carbonate fuel cell which use strongly corrosive molten carbonate at $650^{\circ}C$ have many problem. Systematic investigation on corrosion behavior of stainless steels has been done 62 mole% $Li_2CO_3$ and 38 mole% $K_2CO_3$ melt at 923 K by using steady-state polarization method and electrochemical impedance spectroscopy method. It was found that SUS 310L and Al coating specimen may be the best choice among the alloys tested in this study for molten carbonate fuel cell component material.

• KSBB Journal
• /
• v.27 no.1
• /
• pp.45-50
• /
• 2012

In this paper, we investigated the effect of nanostructure on the cell behaviors such as adhesion and growth rate. Nanoporous structures with various diameters (30, 40, 45, 50, 60 nm) and 500 nm of the depth were fabricated using the anodizing method. The water contact angle of the surface consisting of nanopores with 30 nm diameter was 40 degree and those were 60~70 degree in cases of nanopores with over 40 nm diameter. Hela cells were cultivated on various nanoporous structure surface to investigate the cell behavior on nanostructure. As a result, Hela cells preferred 30 nm diameter nanoporous surface that has lower water contact angle. This result was confirmed by protein adsorption experiment and scanning electron microscope investigation.