A kinetic model of the interactions between operators and regulators is developed to study the stabilities of genetic states and lysogeny/lysis switch in Eschemchia coli infected by bacteriophage lambda. Using adiabat...A kinetic model of the interactions between operators and regulators is developed to study the stabilities of genetic states and lysogeny/lysis switch in Eschemchia coli infected by bacteriophage lambda. Using adiabatic approximation, the kinetic evolutions of mRNA and regulator concentrations can be deduced from operators＇ equations. Furthermore, the stability of each state of the system is studied. The results show that the lysogenic state switches to the lytic state through two bifurcations： one from a single stable state to a three-point state, and the other from a three-point state to a single stable state. Then we indicate that the property of the lysogeny/lysis switch satisfies the topological characteristics theorem. Finally, the influence of the left operators on the lysogeny/lysis switch is briefly discussed. The results show that the cooperativity of the CI2 bound to left and right operators makes the lysogenic state more stable.展开更多
We put forward a new method for measuring the entropy production in the living cell.It involves heating the sample by alternating the electric field and recording the outward heat flow.The entropy production in a norm...We put forward a new method for measuring the entropy production in the living cell.It involves heating the sample by alternating the electric field and recording the outward heat flow.The entropy production in a normal cell MCF10A and a cancerous cell MDA-MB-231 were measured and compared.The results show that the method is effective for the entropy measurement of a living organism.The scaled electro-induced entropy production rate(SEEP)of MDA-MB-231 monotonically increases with the electric field strength at 5–40 V/cm.While that of MCF10A changes non-monotonically and there exists a peak at 5–30 V/cm.The electro-induced entropy production ratio(EEPR)is smaller than 1 in a large range of field strengths,from 5 to 25 V/cm,which reveals that under 5–25 V/cm electric field exposure,the direction of the entropy flow may be changed from normal tissue to cancerous cells.We present a facile and effective strategy for experimentally investigating the thermodynamic properties of the cell and give a deeper insight into the physical difference between normal and cancerous cells under electric field exposure.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 90403010 and 200408020102
文摘A kinetic model of the interactions between operators and regulators is developed to study the stabilities of genetic states and lysogeny/lysis switch in Eschemchia coli infected by bacteriophage lambda. Using adiabatic approximation, the kinetic evolutions of mRNA and regulator concentrations can be deduced from operators＇ equations. Furthermore, the stability of each state of the system is studied. The results show that the lysogenic state switches to the lytic state through two bifurcations： one from a single stable state to a three-point state, and the other from a three-point state to a single stable state. Then we indicate that the property of the lysogeny/lysis switch satisfies the topological characteristics theorem. Finally, the influence of the left operators on the lysogeny/lysis switch is briefly discussed. The results show that the cooperativity of the CI2 bound to left and right operators makes the lysogenic state more stable.
基金Supported by the National Natural Science Foundation of China(Nos 90403010 and 60963015)Distinguished Scientist Award 2008 of Inner Mongolia Autonomous Region and Inner Mongolia Autonomous Region Natural Science Foundation(No 2009BS0102).
文摘We put forward a new method for measuring the entropy production in the living cell.It involves heating the sample by alternating the electric field and recording the outward heat flow.The entropy production in a normal cell MCF10A and a cancerous cell MDA-MB-231 were measured and compared.The results show that the method is effective for the entropy measurement of a living organism.The scaled electro-induced entropy production rate(SEEP)of MDA-MB-231 monotonically increases with the electric field strength at 5–40 V/cm.While that of MCF10A changes non-monotonically and there exists a peak at 5–30 V/cm.The electro-induced entropy production ratio(EEPR)is smaller than 1 in a large range of field strengths,from 5 to 25 V/cm,which reveals that under 5–25 V/cm electric field exposure,the direction of the entropy flow may be changed from normal tissue to cancerous cells.We present a facile and effective strategy for experimentally investigating the thermodynamic properties of the cell and give a deeper insight into the physical difference between normal and cancerous cells under electric field exposure.
