Desiccation-induced changes of photosynthetic transport in Parmelina tiliacea (Hoffm.) Ach. analysed by simultaneous measurements of the kinetics of prompt fluorescence, delayed fluorescence and modulated 820 nm reflection

2018 ◽  
Vol 198 ◽  
pp. 302-308 ◽  
Author(s):  
Abdallah Oukarroum ◽  
Ahmed Lebrihi ◽  
Mohamed El Gharous ◽  
Vasilij Goltsev ◽  
Reto J. Strasser
Keyword(s):  
Delayed Fluorescence ◽  
Simultaneous Measurements ◽  
Prompt Fluorescence ◽  
Induced Changes ◽  
Kinetics Of

scholarly journals Kinetics of oxygen consumption and light-induced changes of nucleotides in solitary rod photoreceptors.

1996 ◽  
Vol 108 (2) ◽  
pp. 75-87 ◽  
Author(s):  
S Poitry ◽  
M Tsacopoulos ◽  
A Fein ◽  
M C Cornwall
Keyword(s):  
Oxygen Consumption ◽  
Mitochondrial Respiration ◽  
Rod Photoreceptors ◽  
Transmembrane Current ◽  
Simultaneous Measurements ◽  
Atp Levels ◽  
Rate Of Oxygen Consumption ◽  
Induced Changes ◽  
Kinetics Of ◽  
Rod Cell

We made simultaneous measurements of light-induced changes in the rate of oxygen consumption (QO2) and transmembrane current of single salamander rod photoreceptors. Since the change of PO2 was suppressed by 2 mM Amytal, an inhibitor of mitochondrial respiration, we conclude that it is mitochondrial in origin. To identify the cause of the change of QO2, we measured, in batches of rods, the concentrations of ATP and phosphocreatine (PCr). After 3 min of illumination, when the QO2 had decreased approximately 25%, ATP levels did not change significantly; in contrast, the amount of PCr had decreased approximately 40%. We conclude that either the light-induced decrease of QO2 is not caused by an increase in [ATP] or [PCr], or that the light-induced change of [PCr] is highly heterogeneous in the rod cell.

Kinetics of alkali ion exchange of irradiated glasses

2003 ◽  
Vol 792 ◽  
Author(s):  
Michael I. Ojovan ◽  
William E. Lee
Keyword(s):  
Ion Exchange ◽  
External Irradiation ◽  
Glass Temperature ◽  
Ion Exchange Kinetics ◽  
Radiation Induced ◽  
Exchange Kinetics ◽  
Induced Changes ◽  
Kinetics Of ◽  
Alkali Ion

ABSTRACTThe kinetics of alkali ion exchange of irradiated glasses were investigated using the structural energy barrier model for ion exchange of glasses. Derived rates of alkali ion exchange depend both on irradiation dose D(Gy) and dose rate q(Gy/s) illustrating that some effects cannot be simulated by external irradiation and require in-situ measurements. Higher D and q lead to increased ion exchange rates. Significant changes occur in the activation energies demonstrating a 4 – 6 times decrease depending on glass composition. Radiation-induced changes are higher at relatively low temperatures and are diminished by increased glass temperature. Numerical estimations show that changes in alkali ion exchange kinetics occur at D far below damaging doses.

Das Spektrum der verzögerten Fluoreszenz in Anthracen-und Naphthalin-Kristallen

1970 ◽  
Vol 25 (5) ◽  
pp. 657-664 ◽  
Author(s):  
K. W. Benz ◽  
W. Hacker ◽  
H. C. Wolf
Keyword(s):  
Temperature Dependence ◽  
High Purity ◽  
Trap Depth ◽  
Delayed Fluorescence ◽  
Mixed Crystals ◽  
Pure Crystal ◽  
Guest Molecules ◽  
Prompt Fluorescence ◽  
Broad Continuum

The spectra of delayed fluorescence of high purity anthracene and naphthalene crystals have been measured as a function of temperature. Below 50 °K they are very different from the spectra of prompt fluorescence. The spectra of delayed fluorescence are the superposition of three types of subspectra: different X-traps-spectra, a broad continuum, and the pure crystal spectrum. From the temperature dependence of the relative intensities of these spectra one can measure the trap depth. - It is shown that the delayed fluorescence is at least 100 times more sensitive against traps and guest molecules than the prompt fluorescence. This is demonstrated using naphthalene-anthracene mixed crystals.

scholarly journals In Healthy Young Men, a Short Exhaustive Exercise Alters the Oxidative Stress Only Slightly, Independent of the Actual Fitness

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Maya Finkler ◽  
Ayala Hochman ◽  
Ilya Pinchuk ◽  
Dov Lichtenberg
Keyword(s):  
Physical Fitness ◽  
Serum Lipids ◽  
Ex Vivo ◽  
Young Men ◽  
Exhaustive Exercise ◽  
Progressive Exercise ◽  
Exercise Induced ◽  
Induced Changes ◽  
Kinetics Of ◽  
Apparent Disagreement

The aim of the present study was to evaluate the apparent disagreement regarding the effect of a typical cycling progressive exercise, commonly used to assessVO2max, on the kinetics ofex vivocopper induced peroxidation of serum lipids. Thirty-two (32) healthy young men, aged 24–30 years, who do not smoke and do not take any food supplements, participated in the study. Blood was withdrawn from each participant at three time points (before the exercise and 5 minutes and one hour after exercise). Copper induced peroxidation of sera made of the blood samples was monitored by spectrophotometry. For comparison, we also assayed TBARS concentration and the activity of oxidation-related enzymes. The physical exercise resulted in a slight and reversible increase of TBARS and slight changes in the activities of the studied antioxidant enzymes and the lag preceding peroxidation did not change substantially. Most altered parameters returned to baseline level one hour after exercise. Notably, the exercise-induced changes in OS did not correlate with the physical fitness of the subjects, as evaluated in this study (VO2max= 30–60 mL/min/kg). We conclude that in healthy young fit men a short exhaustive exercise alters only slightly the OS, independent of the actual physical fitness.

Evolution of Charged Gap Statesin a- Si:H Under Light Exposure

2003 ◽  
Vol 762 ◽  
Author(s):  
M. Zeman ◽  
V. Nádaždy ◽  
R.A.C.M.M. van Swaaij ◽  
R. Durný ◽  
J.W. Metselaar
Keyword(s):  
Deep Level ◽  
Light Exposure ◽  
Dark Conductivity ◽  
Initial Energy ◽  
Energy Distributions ◽  
Transient Spectroscopy ◽  
Induced Changes ◽  
Hydrogenated Amorphous ◽  
Kinetics Of ◽  
Positively Charged

AbstractThe charge deep-level transient spectroscopy (Q-DLTS) experiments on undoped hydrogenated amorphous silicon (a-Si:H) demonstrate that during light soaking the states in the upper part of the gap disappear, while additional states around and below midgap are created. Since no direct correlation is observed in light-induced changes of the three groups of states that we identify from the Q-DLTS signal, we believe that we deal with three different types of defects. Positively charged states above midgap are related to a complex formed by a hydrogen molecule and a dangling bond. Negatively charged states below midgap are attributed to floating bonds. Various trends in the evolution of dark conductivity due to light soaking indicate that the kinetics of light-induced changes of the three gap-state components depend on their initial energy distributions and on the spectrum and intensity of light during exposure.

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