Copyright (C) 2008 John Wiley & Sons, Ltd.”
“Bio-inspired designs can provide an answer to engineering problems such as swimming strategies
at the micron or nano-scale. Scientists are now designing artificial micro-swimmers that can mimic flagella-powered swimming of micro-organisms. In an application such as lab-on-a-chip in which micro-object manipulation in small flow geometries could be achieved by micro-swimmers, control of the swimming direction becomes an important aspect for retrieval and control of the micro-swimmer. A bio-inspired approach for swimming direction reversal (a flagellum bearing mastigonemes) can be used to design such a system and is being explored in the present work. We analyze the system using a computational framework in which the equations of solid mechanics and fluid dynamics are solved simultaneously. The fluid dynamics of Stokes flow is represented by a 2D Stokeslets approach while the solid mechanics behavior selleck kinase inhibitor is realized using Euler-Bernoulli beam elements. The working principle of a flagellum bearing mastigonemes can be broken up into two parts: (1) the contribution of the base flagellum and (2) the contribution
of mastigonemes, which act like cilia. These contributions are counteractive, and the net motion (velocity and direction) is a superposition of the two. In the present work, we also perform a dimensional analysis to understand the underlying physics associated with the system parameters such as the height of the
mastigonemes, the number of mastigonemes, the flagellar wave length and amplitude, the flagellum length, and mastigonemes rigidity. Our results provide fundamental physical insight GDC-0941 ic50 on the swimming of a flagellum with mastigonemes, and it provides guidelines for the design of artificial flagellar systems. (C) 2011 American Institute of Physics. [doi:10.1063/1.3608240]“
“Major spine surgery with multilevel instrumentation is followed by large amount of opioid consumption, significant pain and difficult mobilization in a population of predominantly chronic pain patients. This case-control study investigated if a standardized comprehensive pain and postoperative nausea and vomiting (PONV) treatment protocol would improve pain treatment in this population.
A GSK2879552 new regimen with acetaminophen, NSAIDs, gabapentin, S-ketamine, dexamethasone, ondansetron and epidural local anesthetic infusion or patient controlled analgesia with morphine, was introduced in a post-intervention group of 41 consecutive patients undergoing multilevel (median 10) instrumented spinal fusions and compared with 44 patients in a pre-intervention group.
Compared to patients in the pre-intervention group, patients treated according to the new protocol consumed less opioid on postoperative day (POD) 1 (P = 0.024) and 2 (P = 0.048), they were mobilized earlier from bed (P = 0.003) and ambulation was earlier both with and without a walking frame (P = 0.027 and P = 0.027, respectively).