scholarly journals Modeling of single cell cancer transformation using phase transition theory: application of the Avrami equation

Author(s):  
Krzysztof W. Fornalski ◽  
Ludwik Dobrzyński

AbstractThe nucleation and growth theory, described by the Avrami equation (also called Johnson–Mehl–Avrami–Kolmogorov equation), and usually used to describe crystallization and nucleation processes in condensed matter physics, was applied in the present paper to cancer physics. This can enhance the popular multi-hit model of carcinogenesis to volumetric processes of single cell’s DNA neoplastic transformation. The presented approach assumes the transforming system as a DNA chain including many oncogenic mutations. Finally, the probability function of the cell’s cancer transformation is directly related to the number of oncogenic mutations. This creates a universal sigmoidal probability function of cancer transformation of single cells, as observed in the kinetics of nucleation and growth, a special case of a phase transition process. The proposed model, which represents a different view on the multi-hit carcinogenesis approach, is tested on clinical data concerning gastric cancer. The results also show that cancer transformation follows DNA fractal geometry.

2021 ◽  
pp. 014459872110153
Author(s):  
Qingsong Li ◽  
Jinlei Fu ◽  
Xianwei Heng ◽  
Xiaoqian Xu ◽  
Shu Ma

To study crack propagation around the fracture hole in the coal body induced by high-pressure CO2 gas produced by CO2 phase transition fracturing, the mechanism of permeability enhancement of fractured coal induced by liquid CO2 phase transition fracturing was studied from two aspects, the process of coal gas displacement by competitive adsorption and physical characteristics of fractured coal induced by phase transition. Crack propagation pattern in coal under different lateral coefficients was explored by using discrete-element numerical simulation software. Distribution characteristics of hoop stress of fractured coal were analyzed through theoretical calculation. The results show that: (1) Micro-cracks in damaged coal body generated during phase transition process are mainly crack_tension type, which are formed by the composite action of tension and compression. The crack propagation is the result of the continuous release of compressive stress from concentrated area to the surrounding units. Micro-cracks are radially distributed in a pattern of “flame”. (2) The main crack formed above the fracture hole grows in the direction of vertical minimum initial stress, and the main crack formed below the fracture hole develops in the direction of horizontal initial stress. As the lateral compression coefficient increases, the extension distance of the second crack will not change after reducing to a certain length. (3) As the distance from the fracture hole increases, the peak compression loaded at the monitoring point decays, and the loop stress in the cracked coal is distributed in a pattern of “peanut”. It provides practical methods and ideas for studying the macroscopic and microscopic development of cracks, as well as theoretical support for the on-site hole layout.


2018 ◽  
Vol 427 ◽  
pp. 304-311 ◽  
Author(s):  
Yifan Meng ◽  
Kang Huang ◽  
Zhou Tang ◽  
Xiaofeng Xu ◽  
Zhiyong Tan ◽  
...  

Langmuir ◽  
2016 ◽  
Vol 32 (26) ◽  
pp. 6691-6700 ◽  
Author(s):  
Zhangxin Ye ◽  
Youcheng Li ◽  
Zesheng An ◽  
Peiyi Wu

2019 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Yu.V. Yudin ◽  
M.V. Maisuradze ◽  
A.A. Kuklina ◽  
P.D. Lebedev

An algorithm was developed for the simulation of a phase transition in solid state whichmakes it possible to obtain the kinetic curves of transformation under different initialconditions (the number and arrangement of new phase nuclei, the distance betweenthe nearest nuclei). The simulation results were analyzed using the Kolmogorov-Johnson-Mehl-Avrami equation and the corresponding coefficients were determined.The correlation between the simulation results and the experimental kinetics of theaustenite isothermal transformation in alloyed steels was shown.


Author(s):  
Longjian Li ◽  
Jianbang Zeng ◽  
Quan Liao ◽  
Wenzhi Cui

A new lattice Boltzmann model, which is based on Shan-Chen (SC) model, is proposed to describe liquid-vapor phase transitions. The new model is validated through simulation of the one-component phase transition process. Compared with the simulation results of van der Waals fluid and the Maxwell equal-area construction, the results of new model are closer to the analytical solutions than those of SC model and Zhang model. Since the range of temperature and the maximum density ratio are increased, and the value of maximum spurious current is between those of SC and Zhang models, it is believed that this new model has better stability than SC and Zhang models. Therefore, the application scope of this new model is expanded. According to the principle of corresponding states in Engineering Thermodynamics, the simulations of water and ammonia phase transition process are implemented by using this new model with different equations of state. Compared to the experimental data of water and ammonia, the results show that the Peng-Robinson equation of state is more suitable to describe the water, ammonia and other substances phase transition process. Therefore, these simulation results have great significance for the real engineering applications.


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