The complex of yeast cytochrome c peroxidase and cytochrome c is a paradigm of the biological electron transfer (ET). Building on seven decades of research, two different models have been proposed to explain its functional redox activity. One postulates that the intermolecular ET occurs only in the dominant, high-affinity protein-protein orientation, while the other posits formation of an addit...

The thylakoid membranes of cyanobacteria are the major sites of respiratory electron transport as well as photosynthetic light reactions. The photosynthetic and respiratory electron transport chains share some components, and their presence in the same membrane opens up the possibility for a variety of "unorthodox" electron transport routes. Many of the theoretically possible electron transport...

We have studied the electron-transport properties of strained-Si on relaxed Si12xGex channel MOSFETs using a Monte Carlo simulator adapted to account for this new heterostructure. The low-longitudinal field as well as the steadyand nonsteady-state high-longitudinal field transport regimes have been described in depth to better understand the basic transport mechanisms that give rise to the perf...

An alternative in vitro model of human follicle-associated epithelium (FAE) to study nanoparticle transport mechanisms by M cells was developed and characterized. The previous in vitro model of human FAE has been improved by inverting inserts after Caco-2 cell seeding. Raji and M cells were identified only in inverted co-culture cell monolayers by immunohistochemistry, confocal microscopy, and ...

The regulation of the mitochondrial electron transport chain is central to the control of cellular homeostasis. There are significant gaps in our understanding of how the expression of the mitochondrial and nuclear genome-encoded components of the electron transport chain are co-ordinated, and how the assembly of the protein complexes that constitute the electron transport chain are regulated. ...

Because of its large nucleus, the Xenopus laevis oocyte offers an excellent system to study nucleocytoplasmic transport. This system, in combination with electron microscopy, has provided much of our insight into the mechanisms of nuclear import and export. In a typical experiment, the nuclear transport substrate is first labeled with colloidal gold, and the resulting complex is injected into t...

We propose a transport blockade mechanism in quantum dot arrays and conducting molecules based on an interplay of Coulomb repulsion and the formation of edge states. As a model we employ a dimer chain that exhibits a topological phase transition. The connection to a strongly biased electron source and drain enables transport. We show that the related emergence of edge states is manifest in the ...

The changes in pigment composition, photosynthesis and PSII photochemistry were investigated in cells of Spirulina platensis adapted to salt stress (!0±75 M NaCl). A decrease in the phycocyanine}chlorophyll and no significant change in the carotenoid}chlorophyll ratio were observed in salt-adapted cells. Salt stress inhibited the apparent quantum efficiency of photosynthesis and PSII activity w...

In order to provide accurate predictions for state-of-the-art devices, the quantum mechanical (QM) theory gradually upgrades (by including concepts such as tunnelling, quantization,..) the different approaches used for modelling electron transport. Recently, CMOS has been demonstrated to be a viable technology for very-high-bit-rate broadband and wireless communication systems up to 40 Gb/s and...

Mitochondria maintain a constant rate of aerobic respiration over a wide range of oxygen levels. However, the control strategies underlying oxygen homeostasis are still unclear. Using mathematical modeling, we found that the mitochondrial electron transport chain (ETC) responds to oxygen level changes by undergoing compensatory changes in reduced electron carrier levels. This emergent behavior,...