Further analysis of delayed luminescence of plants

Yan, Yu; Popp, Fritz-Albert; Sigrist, Sibylle; Schlesinger, Daniel; Dolf, A.; Yan, Zhongchen; Cohen, S.; Chotia, Amodsen

doi:10.1016/j.jphotobiol.2004.11.012

Cited by 36 publications

(21 citation statements)

References 21 publications

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“…DF has a monotonic decay kinetics in the first seconds, which is sometimes followed by a transient peak [16][17][18]. DF is affected by chemical and physical parameters, such as different chemicals [19][20][21] or temperature [22,23].…”

Section: Introductionmentioning

confidence: 99%

Delayed fluorescence in algal growth inhibition tests

et al. 2007

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A series of 72-hour growth inhibition tests with green alga Desmodesmus (Scenedesmus) subspicatus (ISO 8692) has been performed to test the delayed fluorescence (DF) parameters as possible endpoint measurements. Sensitivity to five toxicants with direct and indirect effects on photosynthesis was tested, and the median effective concentration (EC 50 ) values derived from the cell concentration, absorbance and DF were compared. The sensitivity of DF intensity (DFI) was comparable with the two endpoints suggested in ISO 8692 for all five toxicants: potassium dichromate, 3,5-dichlorophenol (3,5-DCP), DCMU, copper and cadmium. In the case of potassium dichromate and copper, DFI was more sensitive than the other endpoints in this study. The analysis of DF relaxation kinetics showed a specific response to the herbicide DCMU. Additionally, a 24-hour test was performed with the same toxicant concentrations (except copper), where DFI was measured 30 minutes, one hour and 24 hours after the exposure. The influence of toxicants on DFI after a 24-hour exposure was comparable with the effects after 72 hours. Only 3,5-DCP influenced DFI after 30 minutes. DF proved to be a simple, reliable and rapid measurement to assess toxicity in algal tests, which can to some extent differentiate among various toxicants.

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Section: Introductionmentioning

confidence: 99%

Delayed fluorescence in algal growth inhibition tests

et al. 2007

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“…Prior to the measurement, the hands of the subjects were covered for 45 min with black gloves to reduce delayed luminescence [13]. The subjects then positioned their hands in the dark chamber.…”

Section: Measurement Proceduresmentioning

confidence: 99%

The Effect of Venous and Arterial Occlusion of the Arm on Changes in Tissue Hemodynamics, Oxygenation, and Ultra-Weak Photon Emission

Scholkmann

Schraa²,

Wijk³

et al. 2012

Advances in Experimental Medicine and Biology

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Ultra-weak photon emission (UPE) is a general feature of living -biological systems. To gain further insights into the origin of UPE and its physiological significance, the aim of the present study was to investigate the connection between hemodynamics (HD), oxygenation (OX), and UPE. Therefore, during venous and arterial occlusion (VO, AO), changes of UPE and surrogates of HD as well as OX were measured simultaneously using two photomultipliers and near-infrared spectroscopy, respectively. We showed that (1) changes in UPE correlate significantly nonlinearly with changes in oxyhemoglobin, indicating a complex association between UPE and tissue HD/OX; (2) UPE decreases significantly during AO but not during VO; (3) UPE increases significantly after AO; and (4) the view that ROS are the source of UPE is generally supported by the present study, although some findings remain unexplained in the context of the theory of ROS-mediated UPE generation. In conclusion, the present study revealed new insights into the interplay between HD, OX, and UPE and opens up new questions that have to be addressed by future studies. Abstract: Ultra-weak photon emission (UPE) is a general feature of living biological systems. To gain further insights into the origin of UPE and its physiological significance, the aim of the present study was to investigate the connection between hemodynamics (HD), oxygenation (OX), and UPE. Therefore, during venous and arterial occlusion (VO, AO), changes of UPE and surrogates of HD as well as OX were measured simultaneously using two photomultipliers and near-infrared spectroscopy, respectively. We showed that (1) , indicating a complex association between UPE and tissue HD/OX; (2) UPE decreases significantly during AO but not during VO; (3) UPE increases significantly after AO; and (4) the view that ROS are the source of UPE is generally supported by the present study, although some findings remain unexplained in the context of the theory of ROS-mediated UPE generation. In conclusion, the present study revealed new insights into the interplay between HD, OX, and UPE and opens up new questions that have to be addressed by future studies.

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“…There are several proposed phenomenological models of long-term DF decay kinetics: the "multiexponential models" (Schmidt & Schneckenburger, 1992), the "hyperbolic models" (Lavorel & Dennery, 1982;Scordino et al, 1993), the "coherence models" (Yan et al, 2005). Recently, Qiang Li and co-workers presented a very interesting mathematical-physical analysis where they modeled the electron reflux for photosynthetic electron transport chain (Li et al, 2007).…”

Section: Modelling Of Delayed Fluorescence Kineticsmentioning

confidence: 99%

“…With increasing temperature, peak position is moving towards the beginning of the relaxation curve ( Figure 10a) and average delayed fluorescence intensity increases until a maximum around 28 -30°C (Wang et al, 2004;Yan et al, 2005;. Due to changes in the kinetics, the temperature dependence of DFI is more complicated because it also depends on the time interval on which it is averaged.…”

Section: Temperature and Illumination Intensity Dependencementioning

confidence: 99%