Solvent and temperature effects on the dipole-allowed SZ -SO and the symmetry-forbidden SI -SO transitions of all-trans-carotenes, with 5 (m-5), 7 (m-7), 8 (m-8), 9 (m-9), 11 (all-trans-p-carotene), 15 (decapreno-/?-carotene), and 19 (dodecapreno-8-carotene) conjugated double bonds (N), have been investigated by steadystate and time-correlated single-photon counting (SPC) experiments. The measured fluorescence quantum yields of the SI -SO emission (@I) decrease from 7 x at room temperature when going from m-5 to p-carotene. For the longest compounds N = 15 and 19 only the S2 emission was observed, with fluorescence yields (@a) of about 5 x lo-*. The measured S1 fluorescence lifetime of m-5, m-7, m-8, and m-9 was found to decrease with decreasing energy gap between SI and SO (AE(SI-S0)), in accordance with the energy gap law (EGL). @a indicates that the SZ lifetime is on the order of 100 fs for all compounds.Fluorescence emission from the S I state of p-carotene in room temperature liquids was observed with the 0-0 transition located at 14 200 f 500 cm-l. The intensity ratio 12/11, where I 2 represents the integrated SZ -SO emission and 11 the S I -SO emission spectrum determined by time-resolved methods, depends on the AQSI-SO) in a similar way as @&&I (=kr2kl/(krlk21)). When N increases from 5 to 11, 12/11 (%@&&I) increases about 2000 times, while the rate of internal conversion between S I and SO (kl) increases by a factor of 300. Thus, the term kr2/(krlk21) is also affected by N , where kr2 and krl are the radiative rate constants of the SZ and SI state, respectively, and k21 is the rate of internal conversion between SZ and S I . The solvent polarizability (a) affects the dual emission pattern (@n/@fl), as was clearly observed for m-8 and m-9. This is mainly due to an enhancement of k21 at larger a, since the larger the a, the smaller is the s 2 -S~ energy gap (AE(Sz-Sl)). zfl is about 2-3 times longer for m-7, m-8, and m-9 in 77 K glasses than in room-temperature liquids. The weak temperature dependence indicates that no large-amplitude vibronic motion couples the S 1 and SO states. The steady-state anisotropy of the SI -SO transition of m-7 and m-8 in 77 K glasses is about 0.38 and 0.37, respectively. At room temperature the anisotropy is lower, as a result 6f rotational diffusion motion. Because of the short Sz lifetime, the fluorescence anisotropy of the S2 -SO transition is always close to 0.4, irrespective of the temperature.to about 4 x
Recently, many variational models involving high order derivatives have been widely used in image processing, because they can reduce staircase effects during noise elimination. However, it is very challenging to construct efficient algorithms to obtain the minimizers of original high order functionals. In this paper, we propose a new linearized augmented Lagrangian method for Euler's elastica image denoising model. We detail the procedures of finding the saddle-points of the augmented Lagrangian functional. Instead of solving associated linear systems by FFT or linear iterative methods (e.g., the Gauss-Seidel method), we adopt a linearized strategy to get an iteration sequence so as to reduce computational cost. In addition, we give some simple complexity analysis for the proposed method. Experimental results with comparison to the previous method are supplied to demonstrate the efficiency of the proposed method, and indicate that such a linearized augmented Lagrangian method is more suitable to deal with large-sized images.
Recombinant Fab antibodies (rFabs) specific for coplanar polychlorinated biphenyls (PCBs) were derived from a hybridoma cell line (Chiu et al. Anal. Chem. 1995, 67, 3829-3839). Immunoglobulin V(H)-C(H1) and V(L)-C(L) sequences from S2B1 messenger RNA were amplified by PCR and cloned into the M13 phagemid vector pComb3H. Phage displaying rFab were enriched by panning on a PCB hapten conjugate and expressed as soluble rFabs in Escherichia coli XL-1 Blue. Two rFab clones competitively bound PCBs 77 and 126 with half-maximal inhibition (I(50)) of 10-13 ppb in indirect and direct enzyme immunoassays (EIAs), with selectivity nearly identical to that of whole S2B1 IgG and its Fab fragments prepared by papain digestion. These results, and comparison of N-terminal amino acid sequences of MAb S2B1 and the rFab, indicated that rFab S2B1 is a functional copy of the MAb. The rFab S2B1 sequences have 75-89% sequence identity with antibodies that bind nitrophenyl haptens and are being used to construct a three-dimensional computational model of the PCB binding site.
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