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Chainika Jangu Jing‐Han Helen Wang Dong Wang Sharon Sharick James R. Heflin Karen I. Winey Ralph H. Colby Timothy E. Long 《Macromolecular chemistry and physics.》2014,215(13):1319-1331
Nitroxide‐mediated polymerization (NMP) affords the synthesis of well‐defined ABA triblock copolymers with polystyrene external blocks and a charged poly(1‐methyl‐3‐(4‐vinylbenzyl)imidazolium bis(trifluoromethane sulfonyl)imide central block. Aqueous size‐exclusion chromatography (SEC) and 1H NMR spectroscopy studies confirm the control of the composition and block lengths for both the central and external blocks. Dynamic mechanical analysis (DMA) reveals a room temperature modulus suitable for fabricating these triblock copolymers into electroactive devices in the presence of an added ionic liquid. Dielectric relaxation spectroscopy (DRS) elucidates the ion‐transport properties of the ABA triblock copolymers with varied compositions. The ionic conductivity in these single‐ion conductors exhibits Vogel–Fulcher–Tammann (VFT) and Arrhenius temperature dependences, and electrode polarization (EP) analysis determines the number density of simultaneously conducting ions and their mobility. The actuators derived from these triblock copolymer membranes experience similar actuation speeds at an applied voltage of 4 V DC, as compared with benchmark Nafion membranes. These tailorable ABA block copolymers are promising candidates for ionic‐polymer device applications.
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Marcie Harris-Hayes Karen Steger-May Christine Koh Nat K. Royer Valentina Graci Gretchen B. Salsich 《Journal of Athletic Training》2014,49(3):304-310
Context:
Abnormal movement patterns have been implicated in lower extremity injury. Reliable, valid, and easily implemented assessment methods are needed to examine existing musculoskeletal disorders and investigate predictive factors for lower extremity injury.Objective:
To determine the reliability of experienced and novice testers in making visual assessments of lower extremity movement patterns and to characterize the construct validity of the visual assessments.Design:
Cross-sectional study.Setting:
University athletic department and research laboratory.Patients or Other Participants:
Convenience sample of 30 undergraduate and graduate students who regularly participate in athletics (age = 19.3 ± 4.5 years). Testers were 2 experienced physical therapists and 1 novice postdoctoral fellow (nonclinician).Main Outcome Measure(s):
We took videos of 30 athletes performing the single-legged squat. Three testers observed the videos on 2 occasions and classified the lower extremity movement as dynamic valgus, no change, or dynamic varus. The classification was based on the estimated change in frontal-plane projection angle (FPPA) of the knee from single-legged stance to maximum single-legged squat depth. The actual FPPA change was measured quantitatively. We used percentage agreement and weighted κ to examine tester reliability and to determine construct validity of the visual assessment.Results:
The κ values for intratester and intertester reliability ranged from 0.75 to 0.90, indicating substantial to excellent reliability. Percentage agreement between the visual assessment and the quantitative FPPA change category was 90%, with a κ value of 0.85.Conclusions:
Visual assessments were made reliably by experienced and novice testers. Additionally, movement-pattern categories based on visual assessments were in excellent agreement with objective methods to measure FPPA change. Therefore, visual assessments can be used in the clinic to assess movement patterns associated with musculoskeletal disorders and in large epidemiologic studies to assess the association between lower extremity movement patterns and musculoskeletal injury.Key Words: movement analysis, screening, athletic injuries, knee valgusKey Points
- With training and the use of standardized techniques, both experienced and novice testers reliably classified lower extremity movement patterns based on visual assessment.
- Movement-pattern category-based visual assessments were in excellent agreement with objective methods to measure changes in frontal-plane projection angle.
- Visual assessment based on the methods described in this study may be used in the clinical setting, as well as in large epidemiologic studies and screening assessments for sport participation, to identify distinct categories of lower extremity movement patterns.
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Sara Heebll Karen Louise Thomsen Steen B Pedersen Hendrik Vilstrup Jacob George Henning Grnbk 《World journal of hepatology》2014,6(4):188-198
The prevalence of obesity and related conditions like non-alcoholic fatty liver disease(NAFLD) is increasing worldwide and therapeutic options are limited.Alternative treatment options are therefore intensively sought after.An interesting candidate is the natural polyphenol resveratrol(RSV) that activates adenosinmonophosphate-activated protein kinase(AMPK) and silent information regulation-2 homolog 1(SIRT1).In addition,RSV has known anti-oxidant and anti-inflammatory effects.Here,we review the current evidence for RSVmediated effects on NAFLD and address the different aspects of NAFLD and non-alcoholic steatohepatitis(NASH) pathogenesis with respect to free fatty acid(FFA) flux from adipose tissue,hepatic de novo lipogenesis,inadequate FFA β-oxidation and additional intra- and extrahepatic inflammatory and oxidant hits.We review the in vivo evidence from animal studies and clinical trials.The abundance of animal studies reports a decrease in hepatic triglyceride accumulation,liver weight and a general improvement in histological fatty liver changes,along with a reduction in circulating insulin,glucose and lipid levels.Some studies document AMPK or SIRT1 activation,and modulation of relevant markers of hepatic lipogenesis,inflammation and oxidation status.However,AMPK/SIRT1-independent actions are also likely.Clinical trials are scarce and have primarily been performed with a focus on overweight/obese participants without a focus on NAFLD/NASH and histological liver changes.Future clinical studies with appropriate design are needed to clarify the true impact of RSV treatment in NAFLD/NASH patients. 相似文献
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Morassa Mohseni Justin Cidado Sarah Croessmann Karen Cravero Ashley Cimino-Mathews Hong Yuen Wong Rob Scharpf Daniel J. Zabransky Abde M. Abukhdeir Joseph P. Garay Grace M. Wang Julia A. Beaver Rory L. Cochran Brian G. Blair D. Marc Rosen Bracha Erlanger Pedram Argani Paula J. Hurley Josh Lauring Ben Ho Park 《Proceedings of the National Academy of Sciences of the United States of America》2014,111(49):17606-17611