Retraction mechanics of Finochietto-style self-retaining thoracic retractors.

Objectives: Analyze the mechanics of Finochietto-style retractors, including the responses of thoracic tissues during thoracotomy, with an emphasis on tissue trauma and means for its reduction.

Methods: Mechanical analyses of the retractor were performed, including analysis of deformation under load and kinematics of the crank mechanism. Thoracotomies in a porcine model were performed in anesthetized animals (7) and fresh cadavers (17) using an instrumented retractor.

Expansion channels for low-pass filtering of axial concentration gradients in microfluidic systems.

Chemical gradients that run axially in a microfluidic channel often contain undesirable high-frequency concentration variations, or noise, that results from mechanical and thermal fluctuations in the system. In this paper, we describe a passive microfluidic component called an 'expansion channel' (EC), that removes high frequency noise through axial dispersion. We show that the behavior of the filter can be modeled analytically, using an expression for the transfer function of the microfluidic channel, derived by Xie et al.

A low-cost, manufacturable method for fabricating capillary and optical fiber interconnects for microfluidic devices.

Microfluidic chips require connections to larger macroscopic components, such as light sources, light detectors, and reagent reservoirs. In this article, we present novel methods for integrating capillaries, optical fibers, and wires with the channels of microfluidic chips. The method consists of forming planar interconnect channels in microfluidic chips and inserting capillaries, optical fibers, or wires into these channels.

Analysis of the three-dimensional trajectories of organisms: estimates of velocity, curvature and torsion from positional information.

Most biological motions are three-dimensional. This includes the trajectories of whole organisms and of their appendages. While recordings of three-dimensional trajectories are sometimes published, quantitative analysis of these trajectories is uncommon, primarily because there are no standard techniques or conventions in biology for the analysis of three-dimensional trajectories.

Hydrostatic pressure has different effects on the assembly of tubulin, actin, myosin II, vinculin, talin, vimentin, and cytokeratin in mammalian tissue cells.

Hydrostatic pressures in the range of hundreds of atmospheres are known to disrupt cytoskeletal organization in tissue culture cells, with profound changes in cell shape. The molecular mechanisms of these effects are poorly understood. To determine the effect of pressure on the cytoskeleton, and thus to provide better indicators of the molecular mechanisms, we used fluorescent antibody staining to compare the organizations of seven different cytoskeletal proteins in HeLa cells and rat osteosarcoma cells (ROS-17/2.