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This chapter does not deal with any practical aspects of light measurement, only with theoretical concepts. The following concepts are explained: energy fluence , energy fluence rate, photon fluence, photon fluence rate and radiance, mol, as well as the following superflu-ous or obsolete terms and synonyms: actinic flux, space irradiance, scalar irradiance, spherical irradiance, vectorial irradian
Theoretical results are presented on the absorption and fluorescence of indole in aqueous solution as well as at the air/water surface. We use a combined quantum chemical statistical mechanical model with explicit solvent. An approximate ab initio complete active space self-consistent field description of the indole molecule is used, coupled to a discrete polarizable water medium. From the bulk si
Anti-proliferative drugs have been used for immunosuppression since the introduction of clinical transplantation. Most transplant centres include azathioprine (Aza) and cyclosporine (CyA) in their standard regimens, despite several controlled studies having failed to confirm the benefit of this combination. Aza is still. the most commonly used anti-proliferative drug, although no major differences
We show how a difference in the correlation length longitudinally and transversely, with respect to the jet axis in e+e− annihilation, arises naturally in a model for Bose-Einstein correlations based on the Lund string model. In genuine three-particle correlations the difference is even more apparent and they provide therefore a good probe for the longitudinal stretching of the string field. The c
Only a small number of protein homologues cause the majority of allergies. There is no consensus structure or other obvious common denominator discriminating the few proteins that are allergens from thousands of other, non-allergenic proteins. By database sequence homology searching, we here show that to date known allergen sequences have no or few bacterial homologues, in contrast to randomly sel
Lipid A (a hexaacylated 1,4' bisphosphate) is a potent immune stimulant for TLR4/MD-2. Upon lipid A ligation, the TLR4/MD-2 complex dimerizes and initiates signal transduction. Historically, studies also suggested the existence of TLR4/MD-2-independent LPS signaling. In this article, we define the role of TLR4 and MD-2 in LPS signaling by using genome-wide expression profiling in TLR4- and MD-2-de
We present rock magnetic and palaeointensity data from Holocene Icelandic lava flows, including historical and pre-historical lavas. Susceptibility versus temperature measurements indicate that the magnetic mineralogy is dominated by primary titanomagnetite that have experienced variable degrees of high-temperature oxidisation. The analyses also demonstrate that virtually all studied samples are t
The size of the anisotropic domains in a lyotropic liquid crystal is estimated using a new protocol for diffusion NMR. Echo attenuation decays are recorded for different durations of the displacement-encoding gradient pulses, while keeping the effective diffusion time and the range of the wave vectors constant. Deviations between the sets of data appear if there are non-Gaussian diffusion processe
Bet-hedging is defined as a strategy that reduces the temporal variance in fitness at the expense of a lowered arithmetic mean fitness. After a few technical points, we will here argue that this definition of bet-hedging is badly suited for models with density- and/or frequency-dependent fitness. A strict interpretation cannot be employed; possibly, a modified definition is necessary.
Excited-state proton transfer has been hypothesized as a mechanism for UV energy dissipation in eumelanin skin pigments. By using time resolved fluorescence spectroscopy, we show that the previously proposed, but unresolved, excited-state intramolecular proton transfer (ESIPT) of the eumelanin building block 5,6-dihydroxyindole-2-carboxylic acid (DHICA) occurs with a time constant of 300 fs in aqu
Two-dimensional electronic spectroscopy (2D) has been applied to beta-carotene in solution to shine new light on the ultrafast energy dissipation network in carotenoids. The ability of 2D to relieve spectral congestion provides new experimental grounds for resolving the rise of the excited state absorption signal between 18,000 and 19,000 cm(-1). In this spectral region, the pump-probe signals fro
Side-chain carboxyl and carbonyl groups play a major role in protein interactions and enzyme catalysis. A series of C-13 relaxation experiments is introduced to study the dynamics of carboxyl and carbonyl groups in protein side chains on both fast (sub-ns) and slower (mu s-ms) time scales. This approach is illustrated on the protein calbindin D-9k. Fast dynamics features correlate with hydrogen- a
We report the signature of an unconventional zwitterion in thick (>40 angstrom) L-cysteine films grown at low temperature (100 K) by means of sublimation in ultrahigh vacuum. Using X-ray photoelectron spectroscopy (XPS) we find that protonated amino groups (57%) are less prevalent than in films grown at higher temperatures. A large majority of the protonated amino groups receive the hydrogen throu
This study explores the influences of steric hindrance and excited state solvent ligation on the excited state dynamics of Cu(I) diimine complexes. Ultrafast excited state dynamics of Cu(I)bis(3,8-di(ethynyltrityl)-1,10-phenanthroline) [Cu(I)(detp)(2)](+) are measured using femtosecond transient absorption spectroscopy. The steady state electronic absorption spectra and measured lifetimes are comp
