Switchable Asymmetric Water Transport in Dense Nanocomposite Membranes.

Directional water transport is technologically relevant in separation processes, functional clothing, and other applications. While asymmetric water transport characteristics are a vital feature of leaf cuticles, examples of artificial membranes that display this effect are limited. Here, we report compositionally asymmetric membranes that are based on hydrophobic poly(styrene)-block-poly(butadiene)-block-poly(styrene) (SBS) and hydrophilic poly(vinyl alcohol) (PVA) nanofibers and display directional water transport when a high relative humidity (RH) gradient is applied. This effect is caused by the asymmetric structure of the membrane and the fact that the water permeability of PVA depends on the water pressure applied and the extent of plasticization that it causes. The transport characteristics can be tuned by varying the composition of the membranes. Such materials with switchable asymmetric water transport may be useful for smart packaging applications in which the take-up or release of water is regulated as needed.

Water and Oxygen Barrier Properties of All-Cellulose Nanocomposites.

Hydroxypropyl cellulose (HPC) is potentially interesting as a biobased, rigid food packaging material, but its stiffness and strength are somewhat low, and its water and oxygen transport rates are too high. To improve these characteristics, we investigated nanocomposites of HPC and cellulose nanocrystals (CNCs). These high-aspect-ratio nanoparticles display high stiffness and strength, and their high crystallinity renders them virtually impermeable. Exchanging the counterions of sulfate-ester decorated CNCs with cetyltrimethylammonium ions affords particles that are dispersible in ethanol (CTA.CNC) and allows solvent casting of HPC/CTA.CNC nanocomposite films, which, even at a CTA.CNC content of 90 wt %, are highly transparent. The introduction of CTA.CNC considerably increases the Young's modulus (Ey) and upper tensile strength (σUTS). For example, in the nanocomposite with 90% CTA.CNC, Ey = 7.6 GPa is increased 20-fold and σUTS = 42.7 MPa is more than doubled in comparison to HPC, whereas the extensibility (1.1%) remains appreciable. Composites with a CTA.CNC content of 70 wt % or less show a lower water vapor permeability (6.4-9.2 × 10-5 g µm m-2 s-1 Pa-1) than the neat HPC (1.5 × 10-4 g µm m-2 s-1 Pa-1), whereas the oxygen permeability (5.6 × 10-7-1.3 × 10-6 cm3 µm m-2 s-1 Pa-1) is reduced by 1 order of magnitude compared to HPC (3.2 × 10-6 cm3 µm m-2 s-1 Pa-1). The biobased nanocomposites retain their mechanical integrity at a relative humidity of 75% but readily disintegrate in water.

The Impact of Implementation of the European Association of Urology Guidelines Panel Recommendations on Reporting and Grading Complications on Perioperative Outcomes after Robot-assisted Radical Prostatectomy.

The rate of postoperative complications might vary according to the method used to collect perioperative data. We aimed at assessing the impact of the prospective implementation of the European Association of Urology (EAU) guidelines on reporting and grading of complications in prostate cancer patients undergoing robot-assisted radical prostatectomy (RARP). From September 2016, an integrated method for reporting surgical morbidity based on the EAU guidelines was implemented at a single, tertiary center. Perioperative data were prospectively and systematically collected during a patient interview at 30 d after surgery as recommended by the EAU Guidelines Panel Recommendations on Reporting and Grading Complications. The rate and grading of complications of 167 patients who underwent RARP±pelvic lymph node dissection (PLND) after the implementation of the prospective collection system (Group 1) were compared with 316 patients treated between January 2015 and August 2016 (Group 2) when a system based on patient chart review was used. No differences were observed in disease characteristics and PLND between the two groups (all p≥0.1). Postoperative complications were graded according to the Clavien-Dindo classification system. Overall, the complication rate was higher when the prospective collection system based on the EAU guidelines was used (29%) than when retrospective chart review (10%; p<0.001) was used. In particular, a substantially higher rate of grade 1 (8.4% vs 4.7%) and 2 (14% vs 2.8%) complications was detected in Group 1 versus Group 2 (p<0.001). Although the rate of complications occurred during hospitalization did not differ (13% vs 10%; p=0.3), 31 (19%) complications after discharge were detected in Group 1. This resulted into a readmission rate of 16%. Conversely, no complications after discharge and readmissions were recorded for Group 2. The implementation of the EAU guidelines on reporting perioperative outcomes roughly doubled the complication rate after RARP and allowed for the detection of complications after discharge in more than 15% of patients that would have been otherwise missed, where patients assessed with the EAU implemented protocol had a threefold higher likelihood of reporting complications. PATIENT SUMMARY: The implementation of the European Association of Urology guidelines on reporting and grading of complications after urologic procedures in prostate cancer patients roughly doubled the complication rate after robot-assisted radical prostatectomy compared to retrospective patient chart review. Moreover, it allowed for the detection of complications after discharge in more than 15% of patients that would have been otherwise missed.