S-nitrosocaptopril nanoparticles as nitric oxide-liberating and transnitrosylating anti-infective technology

Nitric oxide (NO) is an essential agent of the innate immune system which exhibits multi-mechanistic antimicrobial activity. Previously, increased antimicrobial activity against E. coli with nitric oxide releasing nanoparticles (NO-np) was demonstrated when combined with glutathione, versus NO-np alone, due to formation of S-nitrosoglutathione (GSNO), a potent transnitrosylating agent. To capitalize on this finding, the thiol-containing ACE-inhibitor, captopril, was incorporated into the NO-np system to form SNO-CAP-nps, nanoparticles that can both release NO as well as form S-nitrosocaptopril. SNO-CAP-nps demonstrated sustained release of NO and GSNO production in the presence of GSH over time. Both E. coli and MRSA were highly susceptible to SNO-CAP-np in a dose-dependent fashion, with E. coli being highly sensitive, while demonstrating no toxicity when exposed to zebrafish embryos. Given the significance of E. coli in urosepsis, as well as the ability of nanotechnology to overcome biofilm formation, SNO-CAP-np may prove useful against catheter-associated urinary tract infection.This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/nanomedicine-nanotechnology-biology-and-medicineKeywords: Antibacterial, Nitric oxide, Nanotechnology, Nitrosothiols, E. col

DEVELOPMENT OF A DYNAMIC TORSIONAL ACTUATOR FOR TORQUE CONVERTER CLUTCH CHARACTERIZATION

This thesis outlines the development of a torsional shaker test stand capable of testing damping and isolation capabilities of torque converter clutch assemblies in automotive torque converters. By utilizing an electric motor typically found in hybrid electric vehicles, the desired torque fluctuations can be achieved for these measurements. The electric motor can be used as a “torsional shaker” to impose torsional vibrations originating from an internal combustion engine. A synchronous model was developed to evaluate the electric motor to ensure it could produce the required dynamic torque behavior. AMESim models were developed and used to correlate analytical and experimental vibration measurements. The measurements of interest are primarily associated with the damper clutch assembly and its respective stiffness and damping properties. The developed system was found capable of reasonably producing dynamic torsional vibration similar to an internal combustion engine and finding the dominating converter clutch resonance

Nanomaterials for wound healing

Purpose of Review Despite the emergence of various new wound care products, millions of people continue to suffer from complications associated with acute and chronic wounds. Nanomaterials offer a variety of strategies to accelerate wound closure and promote appropriate progression through the stages of healing, which will be detailed in this review

Measurement methods for evaluating the frequency response function of a torque converter clutch

In developing new torque converter clutch (TCC) technology, it is desirable to have accurate models to have confidence in performance predictions. To develop and calibrate TCC models, a test cell has been developed to measure the torsional vibration isolation performance of TCCs. The isolation performance is defined as the ratio of output torque to input torque, or torque transmissibility. This test cell uses an electric motor as a torsional exciter and a secondary motor (absorbing dyno) to control the output speed of the TCC. This loading condition, input torque-output speed, replicates the loading seen in a vehicle drivetrain where the engine provides a torque to the input of the torque converter and the vehicle’s wheels provide the speed boundary condition to the output. The torque transmissibility plot is acquired using a stepped sine approach with three frequencies per measurement. Two other excitation methods will be investigated to further reduce testing time. Step inputs (both up and down) Pseudo-random excitation (constant amplitude, random phase) The torque transmissibility results of the new excitation methods will be compared to the previous measurement method for validation