Radiation Sources and Interaction with Skin
Henry W. Lim, Herbert Hönigsmann, John L. M. Hawk in Photodermatology, 2007
The correct way to accurately characterize and compare light emitted from various radiation sources is to determine their emission spectra. In an emission spectrum, the irradiance of the source is measured and plotted as a function of wavelength. Figure 4 depicts the emission spectrum of a narrowband TL-01 UVB lamp. This lamp was engineered to produce light maximally at 311 nm. It is also apparent from the emission spectrum that other UV wavebands, including UVA, are emitted by this lamp (although not shown on the spectrum, some visible light is also produced by this lamp). The same holds true for UVA and broadband UVB lamps; they are not necessarily spectrally pure, and their nominal designation as being “UVA” or “UVB” light sources only refers to the fact that their spectral emission and biologic activity is predominantly that of a certain waveband. The emission spectrum of a light source is rarely measured directly in the clinical setting, since spectroradiometers are expensive. Fortunately for regular clinical use, commerical lamp manufactures maintain relatively consistent standards for lamp operating characteristics such as spectral emission.
Fluorescence in Histochemical Reactions
Victoria Vladimirovna Roshchina in Fluorescence of Living Plant Cells for Phytomedicine Preparations, 2020
The emission spectra have been recorded by various types of spectrofluorimeter or the microspectrofluorimeter MSF-2 depending on the object of the study. The registration of fluorescence intensity was expressed in relative units in three to four samples per variant. The results underwent statistical analysis. The mean ± standard error (SEM) was shown in table data or graphically on histograms, and the relative standard deviation (RSD) was also estimated.
Analysis and Interpretation
John M. Wayne, Cynthia A. Schandl, S. Erin Presnell in Forensic Pathology Review, 2017
Answer C is incorrect. Flame photometry is based on the principle that certain elements such as sodium, potassium, and lithium emit energy after they are excited by heat and return to their ground state. The emission spectrum is measured and quantified. Flame photometry has been replaced in the current measurement of sodium and potassium as these are usually measured with some type of ion-selective electrode. Lithium can be measured with colorimetric methods.
Pendant HDAC inhibitor SAHA derivatised polymer as a novel prodrug micellar carrier for anticancer drugs
Published in Journal of Drug Targeting, 2018
Jieni Xu, Jingjing Sun, Pengcheng Wang, Xiaochao Ma, Song Li
The critical micelle concentration (CMC) of POEG-b-PSAHA was measured by fluorescence spectrometry using nile red as a fluorescence probe. Briefly, thirty microlitres of nile red (0.05 mg/mL in DCM) were added to each tube and the solvent was removed by nitrogen flow. POEG-b-PSAHA micelles ranging from 6.1 × 10−5 to 5 × 10−1 mg/mL were prepared with serial dilution as described above and then added into the tubes with nile red. The final concentration of nile red was kept at 6.0 × 10−7 M. The micelles were vortexed and kept overnight at room temperature to reach the equilibrium of solubilisation. The samples were excited at an excitation wavelength of 550 nm and fluorescence intensities were recorded at an emission spectrum from 600 to 700 nm. The peak intensities at 647 nm were plotted versus polymer concentrations. The CMC value was calculated as the cross-point where a sharp increase in fluorescence intensity was observed.
Development of tibulizumab, a tetravalent bispecific antibody targeting BAFF and IL-17A for the treatment of autoimmune disease
Published in mAbs, 2019
Robert J. Benschop, Chi-Kin Chow, Yu Tian, James Nelson, Barbra Barmettler, Shane Atwell, David Clawson, Qing Chai, Bryan Jones, Jon Fitchett, Stacy Torgerson, Yan Ji, Holly Bina, Ningjie Hu, Mahmoud Ghanem, Joseph Manetta, Victor J. Wroblewski, Jirong Lu, Barrett W. Allan
ANS titrations were conducted to investigate whether disulfide bond stabilization reduced the exposure of the variable heavy and light chain hydrophobic interface residues. Anti-IL-17 scFv with or without an H44-L100 disulfide bond was diluted to 0.28 mg/mL in PBS buffer at pH 7.4. ANS was prepared as 1 mM stock solution in PBS buffer. The fluorescence emission spectrum was collected at 25°C from 400 nm to 700 nm, with a step size of 3 nm following excitation at 360 nm. Fluorescence measurements were made using an ISS PC1 fluorometer (Champaign, IL) equipped with a xenon lamp. The emission spectrum was recorded as a function of increasing concentration of ANS from 2 μM to 300 μM. Sequential ANS additions were performed followed by a brief mixing step, incubation, and collection of the emission spectra at approximately 2 min. intervals. A similar protocol was followed for the parent and H44-L100 scFv. The background of the buffer was subtracted from the sample spectrum at each corresponding concentration of ANS.
Updated insight into the characterization of nano-emulsions
Published in Expert Opinion on Drug Delivery, 2023
Xinyue Wang, Halina Anton, Thierry Vandamme, Nicolas Anton
Another phenomenon widely used for the characterization of NE is the FRET. It is an electrodynamic phenomenon occurring between a donor (D) fluorophore in the excited state and an acceptor (A) fluorophore in the ground state [112]. When the transfer of energy occurs, the intensity of the donor emission decreases, while that of the acceptor increases. The prerequisites of FRET are (i) the overlap of the emission spectrum of the donor with the absorption spectrum of the acceptor, (ii) the distance between donor and acceptor molecules being within ~1–10 nm, (iii) relative orientation of the fluorophore dipoles (as shown in Figure 12). The efficacy of the energy transfer E indicates the percentage of the excitation photons that contribute to FRET and is defined as:
Related Knowledge Centers
- Chemical Compound
- Fluorescence
- Gamma Ray
- Spectroscopy
- Perturbation Theory
- Flame Test
- Optical Spectrometer
- Particle-Induced X-Ray Emission
- Energy-Dispersive X-Ray Spectroscopy
- X-Ray Fluorescence