Tunneling pathway

Exit-site infections present with purulent drainage at the site. Erythema may or may not be present with an exit-site infection. Tunnel infections are generally an extension of the exit-site infection and rarely occur alone. Symptoms of a tunnel infection may include tenderness, edema, and erythema over the tunnel pathway, but are often asymptomatic. Ultrasound can be used to detect tunnel infections in asymptomatic patients. Exit-site infections caused by S. aureus and P. aeruginosa often spread to tunnel infections and are the most common causes of catheter-infection-related peritonitis. 

Fig. 8 Local transmission pictures in a superposed benzenoid structure. As the two rings change geometry from an eclipsed pseudo para geometry (upper left) through an eclipsed pseudo meta geometry to a slip-stacked structure to a single tunneling pathway, the transmission at the Fermi energy increases hy roughly a factor of ten. Reprinted with permission from G. C. Solomon et al. J. Am. Chem. Soc. (2010) 132, 7887-7889. Copyright 2011 American Chemical Society...

Troisi A, Ratner MA (2007) Inelastic insights for molecular tunneling pathways bypassing the terminal groups. PCCP 9(19) 2421-2427... 

Apart from electron promoters a large number of electron mediators have long been investigated to make redox enzymes electrochemically active on the electrode surface. In the line of this research electron mediators such as ferrocene and its derivatives have successfully been incorporated into an enzyme sensor for glucose [3]. The mediator was easily accessible to both glucose oxidase and an electron tunnelling pathway could be formed within the enzyme molecule [4]. The present authors [5,6] and Lowe and Foulds [7] used a conducting polymer as a molecular wire to connect a redox enzyme molecule to the electrode surface. 

In contrast to the molecular wire of molecular interface, electron mediators are covalently bound to a redox enzyme in such a manner as an electron tunneling pathway is formed within the enzyme molecule. Therefore, enzyme-bound mediators work as molecular interface between an enzyme and an electrode. Degani et al. proposed the intramolecular electron pathway of ferrocene molecules which were covalently bound to glucose oxidase [ 4 ]. However, few fabrication methods have been developed to form a monolayer of mediator-modified enzymes on the electrode surface. We have succeeded in development of a novel preparation of the electron transfer system of mediator-modified enzyme by self-assembly in a porous gold-black electrode as schematically shown in Fig.12 [14]. 

Figure 8.22. A possible tunneling pathway leading to the NH3 inversion in the excited state. (From Fraser H3 and Suenram [1992].)... 

Since the Marcus model was initially a classical or later a semi-classical theory, the introduction of quantum effects was considered to account for these observations. In particular, tunnelling pathways of e.t. would increase the rates of some reactions. A closer analysis has, however, led to the conclusion that this could not be a general explanation [80]. 

Winkler JR. Electron tunneling pathways in proteins. Curr Opin Chem Biol 2000 4 192-8. 

This type of analysis enables one to find the optimal tunnelling pathways within a particular protein.155... 

Beth, J.N., Beratan, J.N., and Onuchic, J.N. (1992) Mapping electron tunneling pathways an algorithm that finds the minimum length Vmaximum coupling pathway between electron donors and acceptors in proteins, J. Am. Chem. Soc. 114, 4043-4046. 

Figure 2. Top Dominant tunneling pathways in Ru(bpy)2(im)(HisX)-modified cytochrome c (X = 33, 39, 58, 62, 66, and 72). Bottom Variation of maximum ET rates with tunneling length (of...

Figure 6. Comparison of dominant tunneling pathways (left) and residues identified in EH searches (right) of Ru(NH3)5(HisX)-modified Zn-substituted Mb [X = 70 (A), 48 (B), and 83 (C). ...

Wilson, E. K., Mathews, F. S., Packman, L. C., and Scmtton, N. S., 1995, Electron tunneling in substrate-reduced trimethylamine dehydrogenase Kinetics of electron transfer and analysis of the tunneling pathway. Biochemistry 34 2584n2591. 

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