Reduced donor

CFP-YFP donor-acceptor pair, YFP is several times brighter than CFP [62]. Lastly, for studying dynamic protein associations in plants, the presence of chlorophyll pigments in leaf and stem cells is an additional limitation. These pigments directly absorb the fluorescence, which decreases blue fluorescence intensity for BFP and CFP donors that can be erroneously interpreted as reduced donor fluorescence quantum yield caused by FRET [18]. If sensitized emission or FSPIM is the only available method for quantifying FRET, then it is very important to restrict measurements to chlorophyll free areas within the cells. 

Nicotinic acid derivatives occur in biologic materials as the free acid, as nicotinamide, and in two coenzymatic forms nicotinamide adenine dinucleotide (NAD), and nicotinamide adenine dinucleotide phosphate (NADP). These coenzymes act in series with flavoprotein enzymes and, like them, are hydrogen acceptors or, when reduced, donors. Several plants and bacteria use a metabolic pathway for the formation of nicotinic acid that is different from the tryptophan pathway used by animals and man (B39). 

Cytochromes, as components of electron transfer chains, must interact with the other components, accepting electrons from reduced donor molecules and transferring them to... 

The reduced donor ability of the phosphinite complexes such as 5e and 5f has an impact beyond the catalyst activation stipulated above. Apparently, the decreased tendency to undergo oxidative addition reactions also disfavors catalyst deactivation via oxidative olefin addition. Accordingly, (vinyl) (hydride) complexes such as 3 are less relevant. Simultaneously, product oxidative addition is restricted and, as... 

Boyce ST, Kagan RJ, Yakuboff KP, Meyer NA, Rieman MT, Greenhalgh DG, Warden GD (2002) Cultured skin substitutes reduce donor skin harvesting for closure of excised, fullthickness bums. Ann Surg 235(2) 269-279... 

The chemical structure dependence of electronic hyperpolarizability is discussed. Strategies for developing structure-function relationships for nonlinear optical chromo-phores are presented. Some of the important parameters in these relationships, including the relative ionization potential of reduced donor and acceptor and the chain length, are discussed. The correspondence between molecular orbital and classical anharmonic oscillator models for nonlinear polarizability is described. 

The four-electron ligand 11 (57), obtained from 12 (X = CH3) and [(CH3)3Sn]2NCH3, is a weak ligand in comparison with borole (2) and thiadiborolene (12). Due to the reduced donor and acceptor properties of 11, complexes 48, 49, and 50 are only accessible, photochemically or thermally, in moderate yields. From the upfield UB-NMR shift (A8 = 28-34 ppm), it is obvious that the 1,2,5-azadiborolene ligand is pentahapto-bonded to the metal (57). In the IR spectrum, the at mode for the Fe(CO)3 group in 48 is found at KCO) 2045 cm 1, which indicates the weaker electron-acceptor properties of 11 in comparison with 12 (a, = 2058 cm-1 in 41 X = CH3). The complexes 48-50 exhibit lower thermal stability than the analogous thiadiborolene compounds. (See Fig. 12.)... 

Exciton migration experiments on isotopic naphthalene crystals reveal a universal behavior with reduced donor concentra-... 

Phenyl groups in 3 and 4 position inductively reduce donor ability in 2 and 5 position this effect is not observed as these phenyls are most likely not conjugated with the phosphorus. 

Cytochromes, as components of electron transfer chains, must interact with the other components, accepting electrons from reduced donor molecules and transferring them to appropriate acceptors. In the respiratory chain of the mitochondria, the ubiquinolxytochrome c oxidoreductase, QCR or cytochrome bc complex, transfers electrons coming from Complexes 1 and 11 to cytochrome c. The bc complex oxidises a membrane-localised ubiquinol the redox process is coupled to the translocation of protons across the membrane, in the so-called proton-motive Q cycle, which is presented in a simplified form in Figure 13.14. This cycle was first proposed by Peter Mitchell 30 years ago and substantially confirmed experimentally since then. The Q cycle in fact consists of two turnovers of QH2 (Figure 13.14). In both turnovers, the lipid-soluble ubiquinol (QH2) is oxidized in a two-step reoxidation in which the semiquinone CoQ is a stable intermediate, at the intermembrane face of the mitochondrial inner membrane. It transfers one electron to the Rieske iron—sulfur protein (ISP), one electron to one of the two cytochrome b haems (bi), while two protons are transferred to the intermembrane space. In both of the Q cycles, the cytochrome bi reduces cytochrome bfj while the Reiske iron—sulfur cluster reduces cytochrome c/. The cytochrome ci in turn reduces the water-soluble cytochrome c, which transfers its electrons to the terminal oxidase, cytochrome c oxidase, described above. In one of the two Q cycles, reduced cytochrome bf reduces Q to the semiquinone, which is then reduced to QH2 by the second reduced cytochrome bn- The protons required for this step are derived from the matrix side of the membrane. The overall outcome of the two CoQ cycles (10) (/ — matrix o — intermembrane space) is... 

Analogous face-directing effects are also observed with 5-alkoxyfuran-2(5//)-ones. Even with phosphanes of increased steric demand and reduced donor capability, such as tris(2-phenyl-phenyl) phosphite, to modify the nickel catalyst, only low yields and product selectivities are obtained. Whereas complete face selectivity is observed in the reaction of MCP with 5-methoxy-furan-2(5//)-one, a mixture of products arising from proximal 25 and distal 26 ring cleavage of the MCP is formed. 

In Fig. 9 we show the results of a 30-ps simulation for the donor-acceptor distance, i.e. the distance between the C2 carbon of substrate and carbon C4N of the nicotinamide ring of the cofactor NAD + /NADH. Fig. 9 shows that the average donor-acceptor distance is shorter for the heart isoform when lactate and NAD + are bound, and for the muscle isoform when pyruvate and NADH are bound. We propose that the different kinetic activity of the two isoforms is due to the reduced donor-acceptor distance when lactate is bound to the heart isoform and pyruvate is bound to the muscle isoform. 

In ab initio calculations a transition state for the proton transfer was found which is indeed characterized by a reduced donor-acceptor distance [53] and it was concluded that a strong coupling to the skeletal in-plane bending mode exists... 

Cervellin M, De Girolamo L, Bait C et al (2012) Autologous platelet-rich plasma gel to reduce donor-site morbidity after patellar tendon graft harvesting for anterior cruciate ligament reconstruction a randomized, controlled clinical study. Knee Surg Sports Traumatol Arthrosc 20(1) 114-120... 

In Fig. 5a QD quenching expressed as FqIF — 1 from the series in Hg. 4a is plotted versus the dye/QD ratio (where Fq and F are the fluorescence intensity of QD in the absence and presence of the dye, respectively). Because reduced donor emission and sensitized acceptor emission and strong spectral overlap between QD emission and dye absorption was observed, the quenching of QD emission was described by the following expression with transfer efficiency E ... 

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