Chronobiological data: advantages of telemetric monitoring and prospects of mathematical modeling

Chronobiology and chronomedicine is a special part of biomedical sciences studying rhythmical patterns in physiological and pathological processes. In order to analyse probability of some pathology and to make forecasts concerning possibility of some diseases based on the signs of rhythmicity disorders it is necessary to perform continuous monitoring of different physiological functions for a certain period of time. Since 1984 until now we have had an excellent opportunity of studying biological rhythms and their disorders in animals using the method of radio-telemetric monitoring. A huge amount of continuous data obtained in telemetric monitoring could be used for mathematical modeling of different pathological processes on the basis of rhythmic patterns. In this work we have presented some preliminary results of the chronobiological study in which the effects of bright light on blood pressure and heart rate were investigated. The experiment was carried out on male rats of genetic strains: Wistar-Kyoto – normotensive rats and SHR – spontaneously hypertensive rats. The animals were exposed to 1 hour exposure of ∼ 10000 lux white LED light from 10.00 to 11.00 a.m. For the analysis of daily profiles of blood pressure and heart rate we used the method of radio-telemetric monitoring of blood pressure and heart rate. It was shown that systolic blood pressure significantly increased in both Wistar-Kyoto and SHR rats under the action of bright during the time of bright light exposure (from 10.00 to 11.00 a.m.) and within the whole daytime period. For SHR rats an increase in diastolic blood pressure during the period of bright light action was also typical. But there were no significant changes in heart rate in the animals of either strain. These results require further and more detailed chronobiological studies to provide additional evidence. However traditional statistical methods seem to be important but not sufficient for further investigations. Moreover we could lose a considerable part of data without using contemporary methods of computer and mathematical modeling

Tailoring of the trap distribution and crystal field in Cr³⁺-doped non-gallate phosphors with near-infrared long-persistence phosphorescence

We present a series of efficient near-infrared (NIR) Cr3+-doped non-gallate long-persistence phosphors (Zn2SnO4: Cr and Zn(2-x)Al2xSn(1-x)O4: Cr) and highlight their special optical characteristics of broad emission band (650-1200 nm, peaking at 800 nm) and long afterglow duration (>35h). In the context of materials selection, these systems successfully avoid the existing ubiquitous reliance on gallates as hosts in Cr3+-doped phosphorescent phosphors. Zn2SnO4 is employed as a host to take advantage of its characteristic inverse spinel crystal structure, easy substitution into Zn2+ and Sn4+ sites by Cr3+ in distorted octahedral coordination and non-equivalent substitution. In this work, Al dopant was introduced both to precisely tailor the local crystal field around the activator center, Cr3+, and to redeploy trap distribution in the system. Indeed, such redeployment permits band gap adjustment and the dynamic variation of the annihilation and the formation of defects. The results demonstrate that the method employed here can be an effective way to fabricate multi-wavelength, low-cost, NIR phosphorescent phosphors with many potential multifunctional bio-imaging applications