417 research outputs found
The Effects of Cyclic Strain on Rat Tail Tenocytes
The purpose of this study was to examine the effects of cyclic tension on the expression of hyaluronic acid, its receptor (CD44), and total glycosaminoglycan content in tendon fibroblasts. An in vitro model was used to analyze tenocytes from the tail tendons of rats. Tenocytes in the experimental group were exposed to cyclic mechanical stress, and using ELISA, western blot, and colormetric dye-binding assays, the effect of strain on cultured tenocytes was examined. Tenocytes exposed to mechanical strain produced 1528 ± 58 ng/mL (mean ± SEM) of hyaluronic acid, while those in a control environment produced only 730 ± 27 ng/mL; nearly a two-fold difference (p\u3c.0001, n=44). CD44, the receptor for hyaluronic acid, was also detected in higher concentrations. Tenocytes under mechanical strain increased their concentration of CD44 by 62.5%, with tenocytes exposed to strain having an optical density of 26 . 103 ± 2 . 103 compared with 15 . 103 ± 1 . 103 in controls (p\u3c.05, n=6). The total glycosaminoglycan content of the two groups did not differ significantly; strained cells produced 10.2 ± 0.6 µg/mL and controls producing 15.3 ± 3 µg/mL (p=0.103, n=44). We conclude that mechanical strain in tendon fibroblasts is sufficient to induce the production of hyaluronic acid and increase the expression of its receptor, CD44. The results of our study suggest that the beneficial effects on tendon adhesion formation seen with both mechanical strain and hyaluronic acid may be related in their mechanism
Ayer & Crockett Dry Goods Advertising Broadside
Large-format broadside advertisement promoting Ayer & Crockett\u27s Dry Goods located at 32 and 34 Main Street, Bangor, Maine, ca. 1840.https://digitalcommons.library.umaine.edu/mainebicentennial/1103/thumbnail.jp
Autonomous space processor for orbital debris
The development of an Autonomous Space Processor for Orbital Debris (ASPOD) was the goal. The nature of this craft, which will process, in situ, orbital debris using resources available in low Earth orbit (LEO) is explained. The serious problem of orbital debris is briefly described and the nature of the large debris population is outlined. The focus was on the development of a versatile robotic manipulator to augment an existing robotic arm, the incorporation of remote operation of the robotic arms, and the formulation of optimal (time and energy) trajectory planning algorithms for coordinated robotic arms. The mechanical design of the new arm is described in detail. The work envelope is explained showing the flexibility of the new design. Several telemetry communication systems are described which will enable the remote operation of the robotic arms. The trajectory planning algorithms are fully developed for both the time optimal and energy optimal problems. The time optimal problem is solved using phase plane techniques while the energy optimal problem is solved using dynamic programming
Bison (Bison Bison) Fecal Pats as a Small-scale Disturbance on Tallgrass Prairie
Environmental Scienc
Eighteen Years in the Judicial Catbird Seat
My legal career began with the Florida Supreme Court in September of 1938 as the sole law clerk for the court\u27s six justices
An Unsplit Godunov Method for Ideal MHD via Constrained Transport in Three Dimensions
We present a single step, second-order accurate Godunov scheme for ideal MHD
which is an extension of the method described by Gardiner & Stone (2005) to
three dimensions. This algorithm combines the corner transport upwind (CTU)
method of Colella for multidimensional integration, and the constrained
transport (CT) algorithm for preserving the divergence-free constraint on the
magnetic field. We describe the calculation of the PPM interface states for 3D
ideal MHD which must include multidimensional ``MHD source terms'' and
naturally respect the balance implicit in these terms by the condition. We compare two different forms for the CTU integration
algorithm which require either 6- or 12-solutions of the Riemann problem per
cell per time-step, and present a detailed description of the 6-solve
algorithm. Finally, we present solutions for test problems to demonstrate the
accuracy and robustness of the algorithm.Comment: Extended version of the paper accepted for publication in JC
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