γ射线损伤脑神经系统的物理机理

高 峰1，2，肖德涛2，张登玉1

（1.衡阳师范学院 物理与电子信息科学系，湖南 衡阳 421008；2.南华大学 科学技术学院，湖南 衡阳 421001）

0 Introduction

In 1896，A.H.Becguerel discovered the phenomenon of radioactivity，was soon applied to production and practices，whether natural radioactive，or artificial radioactive Accelerator and the ray that accelerator directly produced are the benefit of mankind，and had made an unexpected effects and influences.With the process of using various rays，people realize the harm of nuclear radiation to human health.After W.K.Rontgen discovered xγ－rays for just one year in 1895，Stone－Scott reported 96cases of skin injuries，which caused Xγ－ray.It can cause skin ulcers and also lead to skin cancer.In 1898，Maria Curie discovered polonium and Radium，but radium led to death among women workers.The atomic bomb was used at the end of the World War Two，moreover，which made unclear disaster and make people sick.Today，the radiation and nuclear energy has been more extensive and widely used in isotope trace，Launch Immunoassay，Nuclear Imaging，Nuclear Medicine，and so on.Nearly every socio－economic aspect，such as physical，chemical，biological and other basic science and agricultural，medical，aerospace，energy，geology and mining，chemical and electronics，Modern nuclear technology has played a significant role，which other methods can not reach to that level.The nuclear technology had a high economic and social benefit to human society.However，for the benefit of the extensive use of nuclear energy，mankind increased dramatic－ally nuclear radiation opportunities.Therefore，when deeply studied nuclear radiation and interaction physical body，chemical and biological mechanism，mankind should maximize the use of nuclear radiation at the same time［1］.

Over a long period of study，people found that the Central nervous system is most sensitive part of the nuclear irradiation which can decline learning and memory ability and destruct brain tissue structure［2－3］.Nuclear radiation on the body＇s biological effects depend on the nature of the effect of gamma rays，time，strength，and individual differences.In general，its biological activity increased with the wavelength of the decrease or the frequent increases［4］.After the organism absorbed radiant energy，the body can generate two biological effects：the Effect of heat and non－thermal Effect.Thermal effect refers to the body＇s tissues absorb electromagnetic radiation can make organs of temperature rise，caused by physiological or pathological effects；non－thermal effects cannot be explain the changes in the organism State of exception.The interaction between the organism to the radiation and heat mechanism have proved that organisms of polar molecules in the electromagnetic radiation generated force vibration and produced heat，causing tissue temperature rise，vasodilatation，enzyme deactivation，protein denaturation，thereby leading to circulation disorders，metabolic disorders，tissue destruction or death.On the other hand，people mainly conducted nonthermal effect research from biology and chemistry.Now considered to be of molecules and ions in external electromagnetic field induction under vibrations occur，caused cell membrane fluidity，membrane potential and membrane permeability，which in turn by intracellular second Messenger，resulting in a series of protein kinases and signal path of change，which ultimately detracted from your gene transcription or lead to DNA mutations that cause apoptosis or necrosis［5－6］.

Brain is the most sophisticated，most complex organs，people＇s feelings，sports，skills，languages，thinking and emotion，personality，etc.All mental activity and cognitive function are brain′s function.Uncovering the workings of the brain is the major task of contemporary science for a long time，people from the cell，molecular，nuclei，each level on a system of the brain，but until today，the people＇s understanding of the brain is still at a very preliminary stage，for psychological and cognitive function of the brain mechanism，is not possible to give a satisfactory explanation.From the perspective of quantum physics，this article pursuant to the basic theory of quantum information research in radiation fields and the interaction of cranial nerve system and physical mechanism.

1 The Interaction model

In 1963，according to the neural membrane potential changes in the result，in neural signaling in action potential，Hodgkin and Huxley，their experimental observations and differential equations precisely and exactly the action potential occurrence of dynamic processes－neural signal transduction equation.In 1980，Neher and Sakmann invented and applied to the patch clamp technique，and discovered the embrane in the single－particle channel，the result of the research function of nerve cells is very important for controlling mechanism ，and revealed the nervous system ，muscular system and cardiovascular system and many other disease pathogenesis.Based on this finding，the people puted forward a variety of neural network model in order to simulate the functionality of the large brain［7］，such as neurons and the hierarchical model，the nervous system－level model，network－level model，and intelligent model.In 1974，according to the Xγ－ray crystal diffraction experiment，Amos pointed out that nerve cells contain affluent microtubule（MT）［8］，which is an important component of the cytoskeleton，microtube diameter of about 25nm，inner diameter of about 14nm，moreover，the polymer constitute 80%microtubules total protein.The dimmer is connected to the aggregation and composition and formed to tail strand fiber.In 1982，Hameroff noted microtubules are the center of cell organization and information processing can regulate and control of cell ac－tivity，maintain cell structure stability［9］.

Fruitful work of Amos and Hameroff believe neuronal microtubules of the brain exist in quantum information and quantum computation.In recent years，some of the scholars in the area have done a lot of research，such as Mavromato view cell MT system of water molecules is very similar to quantum computing in the Cavity quantum electrodynamics（QED）scheme，so since MT system of water molecules is considered as cavity QED model，they have studied energy transfer and quantum coherence of MT［10－11］.Chiang Yee，Chiu His－Kwan，who transformed quantum logic gate into water subsystem in MT，offered the microtubule in a possible quantum computation［12］；Chen Ying pointed out，due to the interaction of moisture subsystem and fields in the MT，may very faint free electric dipole laser radiation［13］.Based on those finding，we thought the brain cells，two geometric configurations（αarchitecture andβconfiguration）are formed into the election spin in two spatial orientation（up and down），so two electronic states can be used to act as a carrier of brain information，known as big brain information bits－cerebral neural bit，which can assemble hundreds of logic gates，assume the neural signal for the storage，delivery and processing tasks.

The Hamiltonian for the radiation field is given by［14］

For a neuronal microtubules of information bits，the interaction Hamiltonian（1）take a simple form as（ħ＝1）［15］

2 The evolution of the brain information bits

We use density operators to describe the state of the brain information bits，according to the principle of quantum mechanics，the entire system of density operators meet the following equation：

where

At t＝0moment，γrays interact with brain cells，and we can find

we used an iterative method for solving（5），and also by Markov approximate

then we can obtained

set

In accordance with the principle of quantum physics，only the density matrix of the non－diagonal elements reflect the system coherence properties，and informed of the radiation on the brain damage，resulting in the calculation can be ignored for non－diagonal elements of the items had no effect.Use［16］

where

The first item of Eq（11）can be calculated as

The fourth item be written as

Substituting Eqs.（12），（13），and（14）into Eq（11）gives

From Eq（4）we can calculate

then we can obtain

where

completed the integration of Eqs（16）and（17），then we can get the non－diagonal elements of the cnbit density operator.

3 The results of the analysis and discussion

As to the macroscopic world，quantum system is very fragile，it sensitive to the outside［17］.As to the nervous system in the normal case，brain cells MT in cnbit must maintain good quantum coherence，as well as its evolution must be a unitary evolution.If this kind of quantum coherence is compromised，the brain will lead to disorder［18］，such as the event logic errors，confusion and insanity.Quantum coherence can reflected simply by density matrix non－diagonal elements if the density matrix of the non－diagonal elements is zero，which means that does not have quantum coherence；if the density matrix of the non－diagonal elements is not equal to zero，it indicates that the system has a quantum coherence.

In our analysis，the brain of the radiation dose is not involved，high doses of radiation，the situation will become more serious and complex，because it will produce the physiological brain injury.In addition，we in the above study and draw cranial nerve system is broken.However，in any case，the angle from the quantum physics has proven.What is more，high－doseγradiation or low－doseγradiation，will damage the victim＇s brain function，and make it appear spirit.

It is important to note that the above research analysis did not consider the influence of the ambient temperature，for animals，not only the nervous system，other organizations，but also ambient temperature changed in a wide variety of biological performance or pathological changes.In the radiation field，brain tissue temperature changes caused neurological functional changes，this is a very interesting issues.

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