A novel PTFE-based proton-conductive membrane

Abstract The demand for a solid polymer electrolyte membrane (SPEM) for fuel-cell systems, capable of withstanding temperatures above 130 • C, decreasing the electrode-catalyst loadings and reducing poisoning by carbon monoxide, has prompted this study. A novel, low-cost, highly conductive, nanoporous proton-conducting membrane (NP-PCM) based on a polytetrafluoroethylene (PTFE) backbone has been developed. It comprises non-conductive nano-size ceramic powder, PTFE binder and an aqueous acid. The preparation procedures were studied and the membrane was characterized with the use of: SEM, EDS, pore-size-distribution measurements (PSD), TGA-DTA and electrochemical methods. The ionic conductivity of a membrane doped with 3 M sulfuric acid increases with the ceramic powder content and reaches 0.22 S cm −1 at 50% (v/v) silica. A non-optimized direct-methanol fuel cell (DMFC) with a 250 m thick membrane has been assembled. It demonstrated 50 and 130 mW cm −2 at 80 and 130 • C, respectively. Future study will be directed to improving the membrane-preparation process, getting thinner membranes and using this membrane in a hydrogen-fed fuel cell

Out of Sight but Not out of Mind: Alternative Means of Communication in Plants

Current knowledge suggests that the mechanisms by which plants communicate information take numerous forms. Previous studies have focussed their attention on communication via chemicals, contact and light; other methods of interaction between plants have remained speculative. In this study we tested the ability of young chilli plants to sense their neighbours and identify their relatives using alternative mechanism(s) to recognised plant communication pathways. We found that the presence of a neighbouring plant had a significant influence on seed germination even when all known sources of communication signals were blocked. Furthermore, despite the signalling restriction, seedlings allocated energy to their stem and root systems differently depending on the identity of the neighbour. These results provide clear experimental evidence for the existence of communication channels between plants beyond those that have been recognized and studied thus far

Postoperative Delirium after Urological Surgery: A Literature Review

Purpose: We aimed to thoroughly search and identify studies referring to risk factors associated with postoperative delirium (POD) in patients undergoing open as well as en-doscopic urological surgery. Methods: The review after a systematic literature search included 5 studies. Results: The incidence of POD was reported to be between 7.8 and 30% depending on the type of the urologic surgery, while in the majority of the studies the onset happened on the first postoperative day and the symptoms lasted 3 ± 0.8 days. Seventeen different risk factors for POD were identified and presented in detail. Conclusion: The Mini-Mental State Examination score and older age were significantly associated with the development of POD. However, the Confusion Assessment Method is very well validated against the diagnosis of delirium from the specialists. © 2019 S. Karger AG, Basel

Single lower calyceal percutaneous tract combined with flexible nephroscopy: A valuable treatment paradigm for staghorn stones

Introduction: We evaluated the efficacy and safety of single lower calyceal tract combined with flexible nephroscopy for the management of staghorn renal stones by percutaneous nephrolithotomy. Methods: The medical records of patients who underwent percutaneous nephrolithotomy for the management of staghorn stones were analyzed. We included patients aged >18 years, while patients with incomplete data and renal anatomical anomalies were excluded from the study. Stone-free rate, postoperative complications, procedure duration, fluoroscopy time, and length of hospitalization were recorded. Postoperative outcomes were evaluated by non-contrast computed tomography scan 4-6 weeks after the operation. Stonefree status was defined as the absence of residual stones >4 mm. Results: The study cohort consisted of 103 consecutive patients. Stonefree rate was 65.0%. No complications were observed in 69.9% of the cases; most postoperative complications were Grade 1 (13.6%) and 2 (10.7%). Five patients (4.9%) suffered a Grade 3a complication and another patient (1.0%) suffered a Grade 3b complication. Conclusions: Percutaneous nephrolithotomy through a single lower calyceal tract combined with flexible nephroscopy can be a valuable treatment option for the treatment of staghorn calculi, providing efficacy and safety. Nevertheless, the present study is limited by both its retrospective nature and being conducted at a single centre and, thus, proper prospective studies with head-on comparisons are needed to prove or disprove the advantages and disadvantages of either approach. © 2018 Canadian Urological Association