Abstract. We present Monte Carlo simulations of a coarse-grained model for Langmuir monolayers of amphiphile molecules on a polar substrate. The molecules are modelled as chains of Lennard-Jones beads, with one slightly larger end bead confined in a planar surface. They are simulated in continuous space under conditions of constant pressure, using a simulation box of variable size and shape. Th...

This article describes a nanomanipulation technique that makes it possible to mechanically and quantitatively stretch and supercoil a single linear DNA molecule. We show how this technique can be extended to the study of protein–DNA interactions that lead to DNA untwisting, particularly to the study of promoter unwinding by RNA polymerase during the initiation of transcription. In our system, a...

We recently reported the use of a biphasic approach to generate topologically segregated bilayer beads. In generating 'one-bead one-compound' (OBOC) combinatorial libraries, novel encoding methods have been applied to these beads such as the testing library compound and the coding tags residing on the outer layer and inner core of each bead, respectively. In this report, we further exploit thes...

VASP comet sightings ess is more when it comes to actin-fueled propulsion. Julie Plastino, Stéphane Olivier, and Cécile Sykes (Institut Curie, Paris, France) show that hollow actin comets propel beads faster than a more filament-packed comet. Actin comets, which drive bead or bacteria movement, are thought to depend strongly on Arp2/3–built, branched actin networks. Now, Plastino et al. show th...

Protocols for characterizing cellular phenotypes commonly use chemical fixatives to preserve anatomical features, mechanically stabilize tissue, and stop physiological responses. Formaldehyde, diluted in either phosphate-buffered saline or phosphate buffer, has been widely used in studies of neurons, especially in conjunction with dyes and antibodies. However, previous studies have found that t...

Mallows and Shepp (2008) developed the following necklace processes. Start with a necklace consisting of one white bead and one black bead, and insert, one at a time, under a deterministic rule, a white bead or a black bead between a randomly chosen adjacent pair. They studied the statistical properties of the number of white beads by investigating the nature of the moments and the expected num...

We describe a new method for calibrating optical trapping measurements in which tension is applied in the direction of the laser beam to a molecule tethered between a surface and an optically trapped bead. Specifically, we present a generally-applicable procedure for converting from the measured scattering intensity and the measured stage displacement to applied tension and bead-coverslip separ...

due to the fact that many application processes take place at different temperature, better examining and understanding of swelling properties as a function of temperature is essential for such application. the temperature effect on the swelling properties of commercial polyacrylic acid (paa) hydrogel beads was investigated as a function of time and temperature. gel bead size, swelling equilibr...

Dielectrophoresis was used to stretch and suspend actin filaments across a trench etched between two electrodes patterned on a glass slide. Optical tweezers were used to bring a motor protein-coated bead into close proximity to a pre-selected, suspended actin filament, facilitating the attachment of the myosin-coated bead to the filament. The clearance beneath the filament allowed the bead to m...

To investigate influence of welding parameters on weld bead geometry in underwater wet flux cored arc welding (FCAW), orthogonal experiments of underwater wet FCAW were conducted in the hyperbaric chamber at water depth from 0.2 m to 60 m and mathematical models were developed by multiple curvilinear regression method from the experimental data. Sensitivity analysis was then performed to predic...