Interaction beteween the visible clectromagnetic Field and the living Matter: Experimental basis for a biophysical approach


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INTERNATIONAL INSTITUTE OF BIOPHYSICS

Interaction between the visible electromagnetic Field and the living Matter: Experimental basis for a biophysical approach
F.Musumeci, A.Scordino, A.Triglia
Instituto di Fisica della Facolta' di Ingegneria - Universita' di Catania
Vle A Doria 6 - 95129 - Catania - Italia

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Introduction

Material and Methods

Experimental Results and Discussion

Experimental Results and Discussion (cont.)

Conclusion

References

Page 3 of 7

Experimental Results and Discussion First of all we examine the typical time trend of the DL shown in fig. 1 : it appears that this trend significantly differs from an exponential decay.

fig. 1 - Typical trend of D.L. decay: ( X ) experimental data, (-----) fit according eq. 1.

Nevertheless in about all cases is possible to fit the experimental data to a hyperbolic trend described by

(1)

as reported in figure 1a.

It must be pointed out that the hyperbolic fitting of the experimental trend is an extremely practical way for expressing the experimental results by using the three parameters Io to and m.

Nevertheless is important to understand why it works so well and in this respect three possible interpretations were proposed :

a) Hyperbolic relaxation is due to the decaying of an excited full coherent field that plays an important role in promotion and control of living processes [14,16].

b) Hyperbolic relaxation is due to the decay of a continuous set of many equilibrium states with different decay constants exponentially distributed [17]. In this case one could write:

(2)

Where A is a normalising factor having the same physical dimensions of I(t). The weights p(g) to be attributed to the single decay rates are obtainable by the analytical Laplace transform of the hyperbolic fitting function , that represents the distribution probability for the decay rates.

c) Hyperbolic relaxation is due to a bimolecular process in which luminescence is due to the recombination of one excited electron with one empty recombination centre : this phenomenon is common in solid state systems [18] as it is shown in fig 2.

fig. 2 - Trends of D.L. decay of a solid state system illuminated with red light (650 nm) of different intensity
(n) 2A 2s, (+) 1A 1s, (*) .5A 4s, (X) .5A 2s,
for comparison also the decay of an acetabularia sample (o) is reported

Interpretations b) and c) are based on a description of the phenomenon that foresees the population and the following depletion of electronic levels.

In such case , however complex the structure of such levels is, the dynamics of decay will be described from an equation of the type

In these conditions the time evolution of the system is a function only of N and once achieved a certain number of filled levels the system will evolve in a unique way.

On the contrary interpretations a) take in account the presence of the electromagnetic field coming out from depletion of electronic levels and then foresees that the time evolution of the system will be a function of both the number N of excited levels and the intensity I of the field inside the system.

Starting from this consideration a graph of I Vs N will give us information about the number of parameters that influence the time evolution of the system and so will test the proposed interpretations.

Is not so easy to calculate I and N because N represents the energy stored in the excited electronic levels while I will represents the energy stored in the electromagnetic field. Nevertheless as a first approximation one can consider that I is proportional to the number of photons coming out from the system at time t while N is proportional to the total number of photons coming out from the system after the time t.

fig. 3 - Trends of D.L. decay ( the same of fig 2) of a solid state system reported on a I Vs N plot :
(n) 2A 2s, (o) 1A 1s, (+) .5A 4s, (*) .5A 2s.

In fig 3 are reported the I Vs N plots of the samples showed in fig. 2: one can easily see that the different trends of fig. b2 correspond to the same path on the IN plane in fig. b3: this means that, for a solid state system, showing an hyperbolic decay according to interpretation c), the time evolution of the system is a function only of N and once achieved a certain number of filled levels the system will evolve in a unique way.

fig. 4 - Behaviour of two biological samples illuminated with blue light (450 nm) of different intensity :
(n) 5 10¹⁴phot/s/cm², (o) 2.5 10¹⁴phot/s/cm², (+) 1.2 10¹⁴phot/s/cm², (*) 6 10¹³phot/s/cm²
a) Acetabularia sample
b) dried yeast cells.

A different behaviour is shown in fig 4a and 4b in which is reported the behaviour of two biological samples illuminated with blue light (450 nm) of different intensity : it is possible to see that in the case of biological systems both N and I seems to be independent parameters that define the state of the system and his evolution.

A problem is if this parameters are sufficient to fully define the behaviour of the system.

An answer to this question could be furnished only by experiments.

In order to increase the number of experimental information which are preliminary to any attempt of comprehension of the phenomenon, the followings points will be presented:

a) the behaviour of the excitation and emission spectrum

b) the dependence of the dynamics on the wavelength and the intensity of the source

c) the dependence of the dynamics on the temperature

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