INTRODUCTION The size of extracellular vesicles (EVs) can be determined with a tunable resistive pulse sensor (TRPS). Because the sensing pore diameter varies from pore to pore, the minimum detectable diameter also varies. The aim of this study is to determine and improve the reproducibility of TRPS measurements. METHODS Experiments were performed with the qNano system (Izon) using beads and ...

Using an algorithm for simulating equilibrium configurations, we study a fluctuating helical polymer either (i) contained in a cylindrical pore or (ii) wound around a cylindrical rod. We work in the regime where both the contour length and the persistence length of the helical polymer are much larger than the diameter of the cylinder. In case (i) we calculate the free energy of confinement and ...

Absorbing sound almost completely at specific frequencies with conventional acoustic materials whose thickness is least 60 times smaller than the wavelength a challenge, particularly low frequencies. Fort this purpose, metamaterials are of great interest. Here, metamaterial called multi-pancake cavities. It composed main pore repetition thin annular cavities (pancake cavities). Previous researc...

A rugate filter based on nanoporous anodic alumina was fabricated using an innovative sinusoidal current profile with small current variation. The resulting structure consisted of highly parallel pores with modulations of the pore diameter along the pore axis and with no branching. The effect of the period time and the pore widening post-treatment was studied. From reflectance measurements, it ...

Although pore formation by protective antigen (PA) is critical to cell intoxication by anthrax toxin (AT), the structure of the pore form of PA (the PA63 pore) has not been determined. Hence, in this study, the PA63 pore was modeled using the X-ray structures of monomeric PA and heptameric alpha-hemolysin (alpha-HL) as templates. The PA63 pore model consists of two weakly associated domains, na...

The diffusion of two similar molecular weight proteins, bovine serum albumin (BSA) and bovine haemoglobin (BHb), through nanoporous charged membranes with a wide range of pore radii is studied at low ionic strength. The effects of the solution pH and the membrane pore diameter on the pore permeability allow quantifying the electrostatic interaction between the charged pore and the protein. Beca...

Encapsulation of molybdenum oxide MoO3 into ordered mesoporous silica materials is demonstrated using different synthetic routes. Either supramolecular polyoxometalates of the “Müller type” or Na2MoO4 were used as precursors. Molybdenum oxide (MoO3)-silica hybrid materials were characterized using nitrogen-sorption experiments, transmission electron microscopy, small-angle X-ray scattering, and...

Hydrous ferric oxides (HFO) are efficient sorbents for inorganic and organic pollutants and therefore have great potentials in environmental science and engineering applications. Freezing and thawing of HFO suspensions leads to the formation of dense HFO aggregates. It facilitates the handling and increases the drying rate of HFO. In this study, we used a combination of pycnometry, gas adsorpti...

A pore-forming protein with an Mr of 40,000 has been extracted from the cell wall of Mycobacterium smegmatis with buffer containing the detergent Zwittergent 3-12 and 0.5 M NaCl and purified on an anion-exchange column. Although the pore diameter was large (2 nm), the specific activity was much lower than those of nonspecific porin channels of enteric bacteria. The channel allowed the permeatio...