scholarly journals Investigations on Average Fluorescence Lifetimes for Visualizing Multi-Exponential Decays

2020 ◽  
Vol 8 ◽  
Author(s):  
Yahui Li ◽  
Sapermsap Natakorn ◽  
Yu Chen ◽  
Mohammed Safar ◽  
Margaret Cunningham ◽  
...  
Keyword(s):  
Fluorescence Lifetimes ◽  
Average Fluorescence

Intrinsic gramicidin fluorescence lifetimes in bilayer lipid membranes and in vesicles

1990 ◽  
Vol 68 (6) ◽  
pp. 888-896 ◽  
Author(s):  
Jose-Miguel Camaleńo-Delgado ◽  
Xiao Kang Zhao ◽  
Janos H. Fendler
Keyword(s):  
Lipid Membranes ◽  
Gramicidin A ◽  
Time Dependent ◽  
Bilayer Lipid Membranes ◽  
Fluorescence Lifetimes ◽  
Iodide Ions ◽  
Bilayer Lipid ◽  
Solid States ◽  
Liquid States ◽  
Average Fluorescence

Intrinsic Gramicidin A′ tryptophan steady-state fluorescence anisotropies and fluorescence lifetimes have been determined in bilayer lipid membranes (BLMs) prepared from glyceryl monooleate (GMO). In GMO BLMs, fluorescence anisotropy, the r value, was found to be 0.05 ± 0.02. Decays of Gramicidin A′ fluorescence intensities were fitted to the sum of three exponentials (τ1, τ2, and τ3) and appropriate pre-exponentials (A1, A2, and A3). These values allowed for the assessment of average fluorescence lifetimes, [Formula: see text]. These values related to those determined in vesicles prepared from dipalmitoylphosphatidylcholine (DPPC), dioleoylphosphatidylcholine (DOPC), distearoylphosphatidylcholine (DSPC), and diphytanoylphosphatidylcholine (DPhPC). In BLMs, [Formula: see text], 3.6 ns, and 2.3 ns were determined for vertically, horizontally, and unpolarized average fluorescence lifetimes, respectively. Increasing the applied potential across the BLM from 0 to 80 mV increased [Formula: see text] from 2.2 ns to 4.9 ns and τ1 from 0.43 ± 0.05 to 0.73 ± 0.06 ns, as well as the contributions and lifetimes of the longer lived fluorescence (A2 and A3, τ2 and τ3). The emission maximum of Gramicidin A′ (334 nm in DPPC) and the absence of quenching by iodide ions indicated complete incorporation of the polypeptide into vesicles. The r values were of the order of 0.10 in vesicles prepared from DPPC and DSPC, both in the absence and in the presence of added 1.2 × 10−4 M CsCl. In vesicles prepared from DOPC and DPhPC, r values increased to 0.13 and 0.14 in water and to 0.15 and 0.20 in 1.2 × 10−4 M CsCl, respectively. At 25.0 °C, the temperature of the measurements, DPPC and DSPC are in their "solid" states, but DOPC and DPhPC are in their "liquid" states, [Formula: see text] values for Gramicidin A′ in vesicles prepared from DPPC, DOPC, and DSPC were all in the 3.0 ± 0.3 ns range. In DPhPC vesicles, [Formula: see text] was determined. Time-dependent anisotropics became observable in DOPC and DPhPC vesicles, particularly in the presence of 1.2 × 10−4 M CsCl. Keywords: gramicidin, fluorescence lifetimes, vesicles, bilayer lipid membranes, time-dependent anisotropics.

scholarly journals Corrigendum: Investigations on Average Fluorescence Lifetimes for Visualizing Multi-Exponential Decays

2021 ◽  
Vol 8 ◽  
Author(s):  
Yahui Li ◽  
Sapermsap Natakorn ◽  
Yu Chen ◽  
Mohammed Safar ◽  
Margaret Cunningham ◽  
...  
Keyword(s):  
Fluorescence Lifetimes ◽  
Average Fluorescence

Dimensionally-Controlled Hydrothermal Tm3+-doped Oxidic Nanocrystals and Their Photoluminescence Properties

2010 ◽  
Vol 1247 ◽  
Author(s):  
Rocío Calderón-Villajos ◽  
Carlos Zaldo ◽  
Concepción Cascales
Keyword(s):  
Single Crystals ◽  
Fluorescence Lifetimes ◽  
Photoluminescence Properties ◽  
Reaction Conditions ◽  
Hydrothermal Processes ◽  
Bulk Single Crystals ◽  
Template Free ◽  
Reaction Media

AbstractControlled reaction conditions in simple, template-free hydrothermal processes yield Tm-Lu2O3 and Tm-GdVO4 nanocrystals with well-defined specific morphologies and sizes. In both oxide families, nanocrystals prepared at pH 7 reaction media exhibit photoluminescence in ∼1.95 μm similar to bulk single crystals. For the lowest Tm3+ concentration (0.2 % mol) in GdVO4 measured 3H4 and 3F4 fluorescence lifetimes τ are very near to τrad.

Fluorescence lifetimes and predissociation of the A3? state of SH+

1988 ◽  
Vol 7 (4) ◽  
pp. 373-378 ◽  
Author(s):  
O. Gustafsson ◽  
M. Larsson ◽  
P. Sigray
Keyword(s):  
Fluorescence Lifetimes

scholarly journals Effectiveness of photon-initiated photoacoustic streaming in root canal models with different diameters or tapers

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheng Wen ◽  
Yuanyuan Kong ◽  
Jian Zhao ◽  
Yang Li ◽  
Ya Shen ◽  
...  
Keyword(s):  
Fluorescence Intensity ◽  
Root Canal ◽  
Distilled Water ◽  
Canal Irrigation ◽  
Root Canals ◽  
Atp Assay ◽  
Root Canal Irrigation ◽  
Average Fluorescence Intensity ◽  
Different Diameters ◽  
Average Fluorescence

Abstract Background This study aimed to compare the use of photon-initiated photoacoustic streaming (PIPS) and conventional needle irrigation (CNI) in conjunction with different concentrations of sodium hypochlorite (NaOCl) to remove Enterococcus faecalis (E. faecalis) suspended bacteria and biofilms from root canal systems with different diameters or tapers. Methods Artificial root canal samples (n = 480) were randomly divided into three groups (n = 160/group). The canals were prepared to fit file sizes #10/.02, #25/.02, or #25/.06. The size #10/.02 group was incubated for seven days. The size #25/.02 or #25/.06 group was incubated for 2 days. A stable biological model of E. faecalis infection was established. The root canals were washed with distilled water or with 1%, 2%, or 5.25% NaOCl combined with CNI or PIPS. Bacterial suspensions and biofilms were assessed using an ATP assay kit and fluorescence microscopy. Image-Pro Plus was used to analyse the average fluorescence intensity to determine the most suitable root canal irrigation solution. Results In the CNI and PIPS groups, the ATP value of the 5.25% NaOCl subgroup was the lowest, followed by that of the 2% and 1% NaOCl subgroups. The ATP value of the distilled water subgroup was the highest (P < 0.05). When the root canal taper was 0.02, the ATP value of the #10/.02 + PIPS group was significantly lower than that of the #25/.02 + CNI group (P < 0.05). The average fluorescence intensity of the #10/.02 + PIPS group was lower than that of the #25/.02 + CNI group (P < 0.05). When the apical diameter was #25, the ATP value of the 0.02 taper in the PIPS group was lower than that of the 0.06 taper in the CNI group (P < 0.05), and the average fluorescence intensity of the 0.02 taper + PIPS group was lower than that of the 0.06 taper + CNI group (P < 0.05). PIPS combined with 2% and 5.25% NaOCl effectively improved the long-term antibacterial effect after irrigation and re-culture for 6 h. Conclusions Compared with CNI, PIPS has greater ability to remove bacteria in root canals with a small preparation diameter and a small taper. PIPS with 2% and 5.25% NaOCl exhibited superior antibacterial and bacteriostatic effects.

Fluorescence lifetimes of neodymium-doped glasses and glass-ceramics

1973 ◽  
Vol 77 (8) ◽  
pp. 1016-1018 ◽  
Author(s):  
Charles F. Rapp ◽  
John Chrysochoos
Keyword(s):  
Glass Ceramics ◽  
Fluorescence Lifetimes ◽  
Doped Glasses

Influence of the refractive index on EGFP fluorescence lifetimes in mixtures of water and glycerol

2001 ◽  
Author(s):  
Klaus Suhling ◽  
Daniel M. Davis ◽  
Zdenek Petrasek ◽  
Jan Siegel ◽  
David Phillips
Keyword(s):  
Refractive Index ◽  
Fluorescence Lifetimes ◽  
Egfp Fluorescence
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