Copyright (C) 2010 S. Karger AG, Basel”
“Background: Icodextrin, a glucose polymer with a polydispersity [ratio of weight-average molecular weight (Mw) to number-average molecular weight] of approximately 2.6, has been shown, compared with glucose, to provide superior ultrafiltration (UF) efficiency [ratio of UF to carbohydrate (CHO) absorbed] when used as an osmotic agent during a long-dwell peritoneal dialysis exchange. In an experimental rabbit model, we evaluated the effect of Mw on the UF and UF efficiency of glucose
polymers with low polydispersity.
Methods: A crossover trial in female New Zealand White rabbits (2.20 – 2.65 kg) with surgically implanted PD-1/PD-L1 Inhibitor 3 cell line peritoneal catheters evaluated two glucose polymers at nominal concentrations of
7.5 g/dL: a 6K polymer (Mw: 6.4 kDa; polydispersity: 2.3) and a 19K polymer (Mw: 18.8 kDa; polydispersity: 2.0). Rabbits were randomized to receive either the 6K (n = 11) or the 19K (n = 12) solution during the first exchange (40 mL/kg body weight). The alternative solution was evaluated in a second exchange 3 days later. During each 4-hour dwell, the UF and total glucose polymer CHO absorbed were determined.
Results: The UF was higher for the 6K (p < 0.0001) than for the 19K polymer (mean +/- standard deviation: 73.6 +/- 30.8 mL vs. 43.0 +/- 20.2 mL), as was the amount of CHO absorbed (42.5% +/- 9.8% vs. 35.7% BAY 63-2521 concentration +/- check details 11.0%, p = 0.021). In spite of higher CHO absorption, an approximately 50% higher (p = 0.029) UF efficiency was achieved with the 6K polymer (28.3 +/- 18.8 mL/g) than with the 19K polymer (19.0 +/- 11.3 mL/g). The results were independent of the order of the experimental exchanges.
Conclusions: Glucose polymers with low polydispersity are effective osmotic agents in a rabbit model. The low-Mw polymer was more effective at generating UF and had a higher UF efficiency,
but those results came at the expense of the polymer being more readily absorbed from the peritoneal cavity. Perit Dial Int 2013; 33(2):124-131 www.PDIConnect.com epub ahead of print: 01 Nov 2012 doi:10.3747/pdi.2012.00009″
“The idea of localized resonance in phononic crystals is introduced to improve the low-frequency acoustic absorption of viscoelastic materials, which are widely used underwater to absorb the unwanted noise and meet a difficult challenge to enhance low-frequency absorption. Experimental measurements for acoustic absorptances of various viscoelastic polymer slabs embedded with locally resonant scatterers, i.e., heavy spheres coated by soft silicon rubber, are reported. Theoretical investigations using a layer-multiple-scattering method show good agreement with the experiment results, which supports unambiguously the observed low-frequency absorption phenomenon. The physical mechanism for the low-frequency absorption is also investigated by referring the elements of the Mie scattering matrix.