Loctite super glue

Cartilage-bone specimens were tested under unconfined cyclic compression. They were mounted with a thin layer of cyanoacrylate glue (Henkel Loctite Super Glue, 161942 SG3) on a custom fitting comprised of a stainless-steel base and a clear plastic chamber. This was attached to an ElectroForce® 3500 load cell (TA Instruments, New Castle, Delaware, USA), and specimens were then submerged in physiologic saline [Compound Sodium Lactate solution (Hartmann's), Fresenius Kabi Deutschland, Friedberg, Germany]. A small preload of 20 N (~0.65 MPa) for 5 min was applied to ensure good contact between the platen and specimen. Testing was performed with sinusoidal waveforms of 1 to 30 MPa for dorsal MCIII specimens and 1 to 40 MPa for palmar MCIII and proximal sesamoid specimens. This load is approximately equivalent to that experienced by the joint when a horse is trotting (24 (link)). It was chosen to minimize the accumulation of microdamage during ex vivo testing and is comparable to a previous study (16 (link)). One hundred cycles were performed at a frequency of 2 Hz. One hundred compressive cycles were chosen to provide sufficient cycles for initial rapid stiffening to occur, followed by a more gradual increase without causing undue ex vivo damage (25 ). Displacement and load data points were collected at a frequency of 500 Hz for the duration of the test.

Before insertion, a 25 μm tungsten wire was attached at the tip of the optical fiber with Loctite super glue (Henkel Corporation, Rocky Hill, CT), opposite to the site where the radiation beam exited the optical fiber (Fig. 1B,E). The tungsten wire has a high contrast in the X-ray imaging and can be easily identified. At the end of each experiment, the optical fiber was left in the cochlea at the position of the maximum response. The fluid in the cochlea was wicked away and replaced by a viscous solution of dental acrylic. After the acrylic had cured, the animals were euthanized with an overdose of sodium pentobarbital (Euthasol^®) and followed by cardiac perfusion with 2.5% glutaraldehyde and 1.5% paraformaldehyde (pH 7.4) in Ringer’s Lactate (RL). After fixation, the animals were decapitated and the bullae were harvested with the optical fiber in place. The specimens were imaged using microCT (Scanco Medical, Wayne, PA) and synchrotron radiation at 2-BM at the Advanced Photon Source (APS), Argonne National Laboratory. From the tomographic reconstruction, a plane across the center of the optical fiber and the tungsten wire and the target structure was selected. The distance between the optical fiber and the target structure was then measured in this plan.