Objective To investigate the phenomenon of coherence resonance(CR)in a nonlinear integrate-and-fire neuronal model(NIF)induced with correlated voltage-gated channel noise and synaptic noise.Meanwhile,the effects of intensity of the voltage-gated channel noise,intensity of the synaptic noise and the strength of the correlation between noises on coherence resonance are discussed.Methods Based on the adiabatic approximation theory and the two-state theory,the approximate expressions of the probability distribution of neuron first fire(FPD)and the coefficient of variation(CV)of the inter-spike intervals of neuron discharging were obtained.Results It was shown that the FPD and the CV were the function of intensities of the voltage-gated channel noise,intensities of the synaptic noise and the strength of the correlation between noises.Conclusion By choosing appropriate the intensity of noise and the strength of the correlation between noises,the minimum of the CV can be obtained,to make the maximum coherence of system and the phenomenon of coherence resonance will occur.

OBJECTIVE:To establish a method to distinguish between synthetic caffeine and natural caffeine METHODS:To identify the related substances obtained from synthetic caffeine and natural caffeine by HPLC,TLC,fluorescence spectrophotometry and X-ray powder diffraction RESULTS:Synthetic caffeine and natural caffeine can be identified by testing the related substances in them CONCLUSION:Using the described method,synthetic caffeine and natural caffeine can be discriminated accurately

With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.
Animals ; Brain ; physiopathology ; Electrocardiography ; radiation effects ; Electroencephalography ; radiation effects ; Electromagnetic Fields ; adverse effects ; Electromyography ; radiation effects ; Female ; Male ; Radiation Injuries, Experimental ; etiology ; Random Allocation ; Rats ; Rats, Wistar ; Spectroscopy, Fourier Transform Infrared ; Time Factors

The testicle tissue's pathological changes of Wistar rats in low frequency electromagnetic fields were observed and analyzed by Fourier transform infrared (FTIR) spectroscopy. The components of secondary structure were examined by use of derivative and curve-fitting techniques. The results showed some significant differences between the exposed group and the sham-exposed group on spectra. Especially, the analysis on the components of secondary structure of amide link I bond revealed a marked decrease in the ordered secondary structure of the exposed group. These findings indicate there will be damage to the testicle tissues that have been exposed to extremely low frequency electromagnetic fields for a long time.
Animals ; Electromagnetic Fields ; adverse effects ; Male ; Protein Structure, Secondary ; radiation effects ; Random Allocation ; Rats ; Rats, Wistar ; Spectroscopy, Fourier Transform Infrared ; Testis ; chemistry ; pathology ; radiation effects

Objective To observe the effect of curcumin on behavior,blood brain barrier(BBB)and ex-pression of glial fibrillary acidic protein(GFAP)and cyclic nucleotide 3′phosphohydrolase(CNPase)in hippocam-pus of radiation injured brain(RIB)rats. Methods SD rats were divided into radiation group,treatment group and negative control group. RIB rats model were established by X ray,and rats in treatment group were treated by curcumin. Morris water maze test were taken to study learning memory of rats in each group. The expression of Ev-ans blue(EB)in brain tissue and the expression of GFAP and CNPase in hippocampus were detected to observe the effect of curcumin on the BBB of RIB rats. Results In RIB rats,learning memory were decreased significant-ly,permeability of BBB were increased. GFAP expression in brain tissue was increased,and CNPase was de-creased(P < 0.05). After the treatment of curcumin,learning memory of rats were improved,the permeability of BBB was decreased,GFAP was decreased,and CNPase expression was increased(P < 0.05). Conclusion Cur-cumin can significantly reduce the damage of BBB in RIB rats,decrease the expression of GFAP and increase the expression of CNPase in hippocampal,which indicate that curcumin has curative effect on radiation injured brain.