PainSci summary of Denning 2014?This page is one of thousands in the PainScience.com bibliography. It is not a general article: it is focused on a single scientific paper, and it may provide only just enough context for the summary to make sense. Links to other papers and more general information are provided at the bottom of the page, as often as possible. ★★★☆☆3-star ratings are for typical studies with no more (or less) than the usual common problems. Ratings are a highly subjective opinion, and subject to revision at any time. If you think this paper has been incorrectly rated, please let me know.
This is about as basic as basic biology gets, a biologically trivial finding: a teensy little microscopic spark of PE when you would need a bonfire to get any biological significance out of it (never mind clinical significance). The researchers found PE effect at molecular scales, but nearly everything at that scale has a mess of interesting electromagnetic properties, and you can find PE all over the place. For instance, hair, some plastics, lots of minerals … nearly any molecularly regular structure will exhibit some PE. For it to be leveraged biologically for anything, it would have to be happening on a much larger scale, electrons would have to actually go somewhere, further than a few nanometres. PE at the scale investigated here is just a little molecular noise.
Their imaging technology and methodology is much more interesting than what they found with it. Really quite impressive tools they were using!
original abstract†Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
Electromechanical coupling, a phenomenon present in collagenous materials, may influence cell-extracellular matrix interactions. Here, electromechanical coupling has been investigated via piezoresponse force microscopy in transparent and opaque membranes consisting of helical-like arrays of aligned type I collagen fibrils self-assembled from acidic solution. Using atomic force microscopy, the transparent membrane was determined to contain fibrils having an average diameter of 76 ± 14 nm, whereas the opaque membrane comprised fibrils with an average diameter of 391 ± 99 nm. As the acidity of the membranes must be neutralized before they can serve as cell culture substrates, the structure and piezoelectric properties of the membranes were measured under ambient conditions before and after the neutralization process. A crimp structure (1.59 ± 0.37 µm in width) perpendicular to the fibril alignment became apparent in the transparent membrane when the pH was adjusted from acidic (pH = 2.5) to neutral (pH = 7) conditions. In addition, a 1.35-fold increase was observed in the amplitude of the shear piezoelectricity of the transparent membrane. The structure and piezoelectric properties of the opaque membrane were not significantly affected by the neutralization process. The results highlight the presence of an additional translational order in the transparent membrane in the direction perpendicular to the fibril alignment. The piezoelectric response of both membrane types was found to be an order of magnitude lower than that of collagen fibrils in rat tail tendon. This reduced response is attributed to less-ordered molecular assembly than is present in D-periodic collagen fibrils, as evidenced by the absence of D-periodicity in the membranes.
- “Two-dimensional nanoscale structural and functional imaging in individual collagen type I fibrils,” Catalin Harnagea, Martin Vallières, Christian P Pfeffer, Dong Wu, Bjorn R Olsen, Alain Pignolet, François Légaré, and Alexei Gruverman, Biophys J, 2010.
- “The structural origin of second harmonic generation in fascia,” Maxime Rivard, Mathieu Laliberté, Antony Bertrand-Grenier, Catalin Harnagea, Christian P Pfeffer, Martin Vallières, Yves St-Pierre, Alain Pignolet, My Ali El Khakani, and François Légaré, Biomed Opt Express, 2010.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Effectiveness of customised foot orthoses for Achilles tendinopathy: a randomised controlled trial. Munteanu 2015 Br J Sports Med.
- A Bayesian model-averaged meta-analysis of the power pose effect with informed and default priors: the case of felt power. Gronau 2017 Comprehensive Results in Social Psychology.
- The neck and headaches. Bogduk 2014 Neurol Clin.
- Agreement of self-reported items and clinically assessed nerve root involvement (or sciatica) in a primary care setting. Konstantinou 2012 Eur Spine J.
- Effect of NSAIDs on Recovery From Acute Skeletal Muscle Injury: A Systematic Review and Meta-analysis. Morelli 2017 Am J Sports Med.