Is constant needle motion during soft tissue filler injections a safer procedure? A theoretical mathematical model for evaluating patient safety.

Background: The safety rationale behind the constant needle motion injection technique is based on the assumption that due to the constant needle motion and simultaneous soft tissue filler material administration a smaller amount of product per area may be injected into an artery if an artery within the range of the moving needle is inadvertently entered.

Objective: To perform mathematical calculations for determining the probability for causing intra-arterial product administration when constantly moving the needle during facial aesthetic soft tissue filler injections.

Methods: This study was designed as a theoretical investigation into the probabilities for causing adverse events due to intravascular injection of soft tissue filler material when constantly moving a 27-G needle during facial soft tissue filler administration.

Ultrafast Force-Clamp Spectroscopy of Microtubule-Binding Proteins.

Optical trapping has been instrumental for deciphering translocation mechanisms of the force-generating cytoskeletal proteins. However, studies of the dynamic interactions between microtubules (MTs) and MT-associated proteins (MAPs) with no motor activity are lagging. Investigating the motility of MAPs that can diffuse along MT walls is a particular challenge for optical-trapping assays because thermally driven motions rely on weak and highly transient interactions.