Imaging lifetime

Fig. 5.59 Fluorescence of a mouse bearing tumors. Left to right Photo, CW image, Lifetime image, fluorescence decay curves in different pixels of the image. [174] and courtesy of ART, Montreal, Canada...

Fig. 5.78 Two-photon autofluorescence lifetime image of aortic tissue. Top Intensity image, lifetime image of average lifetime, lifetime distribution. Bottom Fluorescence decay in indicated pixel and double exponential fit with 81% of 294 ns and 18.7% of 2.26 ns. From [39]...

Fig. 5.87 HEK cell expressing two interacting proteins labelled with CFP and YFP. Singleexponential lifetime images, lifetime distributions in a region of interest, and decay functions in the selected spot. Left CFP channel, blue to red corresponds to 1.5 to 2.2 ns. Right YFP channel, blue to red corresponds to 1.5 to 2.7 ns...

Figure Cl.5.4. Comparison of near-field and far-field fluorescence images, spectra and lifetimes for the same set of isolated single molecules of a carbocyanine dye at a PMMA-air interface. Note the much higher resolution of the near-field image. The spectmm and lifetime of the molecule indicated with the arrow were recorded with near-field excitation and with far-field excitation at two different excitation powers. Reproduced with pennission from Trautman and Macklin [125].

Dunn R C, Holtom G R, Mets L and Xie X S 1994 Near-field fluorescence imaging and fluorescence lifetime measurement of light harvesting complexes in intact photosynthetic membranes J. Chem. Phys. 98 3094-8... 

The small (<1 cm) sizes and brief (<1 //s) lifetimes of the fusion research plasmas preclude the use of most probe techniques. Laser pulse imaging... 

Fluorescence Lifetime Imaging Study on Living Cells with Particular Regard to Electric Field Effects and pH Dependence 607... 

The centric scan, one-dimensional, DHK SPRITE measurement was used to study the ingress of lithium. This measurement technique was selected due to the low absolute sensitivity of 7Li (27% of [36]), the small amounts that are present and the short signal lifetimes (bulk Tx of 10 ms and T2 of 120 ps). In addition to the robust, quantitative nature of this technique, lithium is a quadrupolar nucleus and interpretation of the image intensity is more complex than spin % nuclei. Once again Eq. (3.4.2) is quantitatively correct for even quadrupolar nuclei due to the fact the longitudinal steady state does not influence the image intensity. 

The SPI and SPRITE class of measurements for imaging short MR signal lifetimes are quantitative and have signal equations that are readily understood. The centric SPRITE methods are much faster and feature signal equations that are easier to interpret. This feature makes these measurements more readily density weighted and better suited to imaging quadrupolar nuclei. 

Fig. 5. Effect of the dissociation rate on the ion image intensity distribution, (a) Simulated translational energy distribution, (b), (c) Image intensity distributions that would result from (a) if the dissociation lifetime was 0.1/rs and 15/l

Liebsch G, Klimant I, Krause C, Wolfbeis OS (2001) Fluorescent imaging of pFl with optical sensors using time domain dual lifetime referencing. Anal Chem 73 4354 -363... 

Dialkylanthracene-containing squaraine dyes 17 show intense absorption and emission in the NIR region (720-810 nm) [74]. They are compatible with aqueous environments and show substantial enhancement of quantum yields and fluorescence lifetimes in hydrophobic and micellar media, suggesting that these dyes can be potentially useful as fluorescent probes in biological applications, e.g., for imaging of hydrophobic domains such as cell membranes. 

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