the permeability is a main property of oil reservoirs that shows the ability of rocks in the conduct of fluids such as oil, water and gas through the pore spaces of reservoir. the determination of the permeability is a crucial task in reserve estimation, production and development of oil reservoirs. due to this, an accurate estimate of such important reservoir rock parameter should not be made ...

may give an indication of the wide appeal which this book should have. These headings are: Significance of Permeability Studies; Methods of Studying Membrane Permeability; Equilibrium Conditions of Cells; Some Equations used in Permeability Studies; The Nature of the Process of Diffusion; The Structure of the Plasma Membrane; The Interpretation of Permeability Measurements; Permeability to Non-...

Stress sensitivity is a very important index to understand the seepage characteristics of reservoir. In this study, dedicated experiments and theoretical arguments based on visualization porous media are used assess effects fracture angle, spacing, relevant elastic parameters principal value permeability tensor. The apertures at different angles show change rates, which influence relative for s...

Retention behavior of molecules mostly depends on their chemical structure. Retention data of biologically active molecules could be an indirect relationship between their structure and biological or pharmacological activity, since the molecular structure affects their behavior in all pharmacokinetic stages. In the present paper, retention parameters (RM0) of biologically active 1,2-O-isopropyl...

alpha-Hemolysin of Staphylococcus aureus is a self-assembling toxin that forms a water-filled transmembrane channel upon oligomerization in a lipid membrane. Apart from being one of the best-studied toxins of bacterial origin, alpha-hemolysin is the principal component in several biotechnological applications, including systems for controlled delivery of small solutes across lipid membranes, st...

BACKGROUND The mechanical, rheological and shape properties of red blood cells are determined by their cortical cytoskeleton, evolutionarily optimized to provide the dynamic deformability required for flow through capillaries much narrower than the cell's diameter. The shear stress induced by such flow, as well as the local membrane deformations generated in certain pathological conditions, suc...

The ovarian hyperstimulation syndrome (OHSS) is typically an iatrogenic complication of induction ovulation occurring during the luteal phase or early pregnancy. However, the spontaneous form of OHSS is extremely rare and always reported during pregnancy. Several cases have been observed during multiple pregnancies and other cases were associated with hypothyroidism. Moreover, a few mutations o...

Cut muscle fibers from Rana temporaria (sarcomere length, 3.5-3.9 micro(m); 14-16 degreesC) were mounted in a double Vaseline-gap chamber and equilibrated with an external solution that contained tetraethyl ammonium- gluconate and an internal solution that contained Cs as the principal cation, 20 mM EGTA, and 0 Ca. Fibers were stimulated with a voltage-clamp pulse protocol that consisted of pul...

BACKGROUND Rh glycoproteins (RhAG, RhBG, RhCG) are members of the Amt/Mep/Rh family which facilitate movement of ammonium across plasma membranes. Changes in ammonium transport activity following expression of Rh glycoproteins have been described in different heterologous systems such as yeasts, oocytes and eukaryotic cell lines. However, in these complex systems, a potential contribution of en...