We studied the effects of insulin-like growth factor I on Achilles tendon healing in a rat model. Rats were randomized into groups of six each: sham surgery, transection alone, and transection plus growth factor. Postoperatively, rats treated with growth factor had a significantly smaller maximum functional deficit and a decreased time to functional recovery than rats in the untreated groups. Biomechanical testing revealed no significant differences in the measured parameters between the treated and the untreated groups after transection. To study the mechanism of action, six additional animals received an Achilles tendon injection of the inflammatory agent carrageenan alone and six received carrageenan plus growth factor. Rats treated with growth factor did not show the inflammation-induced functional deficit experienced by the control rats. Spectrometric myeloperoxidase assays on the remaining eight rats after Achilles tendon transection demonstrated no significant difference between the untreated and the growth factor-treated groups, indicating a mechanism other than neutrophil recruitment by which the growth factor limits inflammation. Histologic studies were performed on carrageenan-injected rats at postinjection day 2 and on surgically treated rats at postoperative day 15. No gross histologic differences were seen between untreated and growth factortreated groups. This study demonstrated that via a possible antiinflammatory mechanism, insulin-like growth factor I reduces maximum functional deficit and accelerates recovery after Achilles tendon injury.
Human cadaver thumbs were tested to evaluate stability of the radial side of the MP joint. The contributions of the dorsal capsule, radial collateral ligament, accessory collateral ligament, and volar plate were examined with the joint in 0 degrees and 30 degrees of flexion. At 0 degrees flexion, the average joint angulation increased 4 degrees following isolated radial collateral ligament transection and 6 degrees following isolated accessory collateral ligament transection. Release of both the accessory and radial collateral ligaments produced marked instability with joint angulation of at least 46 degrees. The accessory collateral ligament helped to stabilize the extended MP joint. There were no significant contributions to stability from the dorsal capsule and volar plate when the collateral ligaments were intact. In the laboratory setting, radial-side instability of the MP joint of the thumb requires transection of both the proper and accessory radial collateral ligament.
Accurate calculation of pump performance margins relative to test acceptance criteria are driven by a variety of requirements and constraints. Inputs including design basis required performance, acceptance criteria assumptions, test conditions, and field versus vendor data are required. Test margin with respect to safety analysis limits may be more limiting than ASME Operations and Maintenance (OM) Code [1] inservice testing (IST) requirements. In response to component design basis inspection (CDBI) and design basis assurance inspection (DBAI) findings of potentially non-conservative equipment performance when operating at the extremes of Emergency Diesel Generator (EDG) Technical Specification (TS) limits of frequency and voltage, Westinghouse and the Pressurized Water Reactor Owner’s Group (PWROG) developed WCAP-17308-NP-A [2] to provide a simplified approach to incorporate these limits, by treating them as uncertainties, into design basis pump test acceptance criteria. The basic methodology provides a general approach to account for uncertainties by adjusting pump curves and test acceptance criteria. Depending on the magnitude of the EDG and instrument uncertainties, adjusted design basis related test acceptance criteria may challenge the tested performance of the pumps. Margin can be recovered by reducing uncertainties and taking credit for any available margin in the safety analyses.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.