How the pro-apoptotic Bax protein permeabilizes the mitochondrial outer membrane is not fully understood. Previously, using cryo-electron microscopy (cryo-EM), we showed that activated Bax forms large, growing pores. Whether formed in liposomes or in mitochondrial outer membranes, Bax-induced pores exhibit the same morphology, with negative curvature flanking the edges and with no visible prote...

During the mitochondrial permeability transition, a large channel in the inner mitochondrial membrane opens, leading to the loss of multiple mitochondrial solutes and cell death. Key triggers include excessive reactive oxygen species and mitochondrial calcium overload, factors implicated in neuronal and cardiac pathophysiology. Examining the differential behavior of mitochondrial Ca(2+) overloa...

BACKGROUND AND PURPOSE The blood-brain barrier (BBB) is a selectively permeable cerebrovascular endothelial barrier that maintains homeostasis between the periphery and the central nervous system. BBB disruption is a consequence of ischemic stroke and BBB permeability can be altered by infection/inflammation, but the complex cellular and molecular changes that result in this BBB alteration need...

Determination of porosity, permeability, and pore volume compressibility of reservoir rocks and those variations with effective stress changes are of great interest in petroleum engineering. This paper has studied the influence of pore types of carbonate reservoir rocks on pore volume compressibility as well as Klinkenberg permeability and porosity at different stress values. In the current stu...

Polyurethane shape memory polymer (SMP) foams are proposed for use as thrombogenic scaffolds to improve the treatment of vascular defects, such as cerebral aneurysms. However, gas blown SMP foams inherently have membranes between pores, which can limit their performance as embolic tissue scaffolds. Reticulation, or the removal of membranes between adjacent foam pores, is advantageous for improv...

Extremely low permeability due to nano-scale pores is a distinctive feature of gas transport in a shale matrix. The permeability of shale depends on pore pressure, porosity, pore throat size and gas type. The pore network model is a practical way to explain the macro flow behavior of porous media from a microscopic point of view. In this research, gas flow in a shale matrix is simulated using a...

A model for determining the permeability of fractural porous media based on the double percolation model is presented. The results are close to that by fractural permeability tensor model. The non-uniformity of the permeability and the pore pressure are investigated by parameter study. It is shown that rocks could be divided into “pore-controlling” permeability and “fracture-controlling” permea...

Mitochondrial outer membrane permeability is conferred by a family of porin proteins. Mitochondrial porins conduct small molecules and constitute one component of the permeability transition pore that opens in response to apoptotic signals. Because mitochondrial porins have significant roles in diverse cellular processes including regulation of mitochondrial ATP and calcium flux, we sought to d...

Synaptic mechanisms of plasticity are calcium-dependent processes that are affected by dysfunction of mitochondrial calcium buffering. Recently, we observed that mice deficient in mitochondrial voltage-dependent anion channels, the outer component of the mitochondrial permeability transition pore, have impairments in learning and hippocampal synaptic plasticity, suggesting that the mitochondria...

We have provided evidence that mitochondrial membrane permeability transition induced by inorganic phosphate, uncouplers or prooxidants such as t-butyl hydroperoxide and diamide is caused by a Ca(2+)-stimulated production of reactive oxygen species (ROS) by the respiratory chain, at the level of the coenzyme Q. The ROS attack to membrane protein thiols produces cross-linkage reactions, that may...