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Variations in the structure of gamma-alumina (γ-Al 2 O 3 ), derived from well-crystalline boehmite, calcined at various temperatures in air were investigated. Consistent distribution of cation coordination, ∼69% octahedral and ∼31% tetrahedral, was observed for material calcined between 500 and 900 °C. Gamma alumina was found to be present between 450 and 750 °C. Its structure was tetragonally distorted but showed a reduced tetragonal distortion with increasing temperature. A cubic γ-Al 2 O 3 phase was never detected. Above 750 °C, δ-Al 2 O 3 was not observed, but instead a new phase was identified and designated gamma-prime-alumina (γ′-Al 2 O 3 ). Similarly to δ-Al 2 O 3 , γ′-Al 2 O 3 was determined to be a triple cell of γ-Al 2 O 3 and was described using the P4 hm2 space group. The cation ordering in this structure is more obvious than that for γ-Al 2 O 3 , with fewer site positions being occupied with increasing calcination temperature.

BackgroundIn Canada, 4,400 cases of oral cancer are diagnosed yearly. Surgical resection is a key component of treatment in many of these cancers. Reconstruction of defects, with the goal of preserving function, is of utmost importance. Several choices are possible for reconstruction of larger defects, including both free and pedicled flaps. Free flap reconstruction is reliable and effective, but requires additional personnel and peri-operative resources. Pedicled flaps remain an important alternative to free flaps, and are less resource intensive. This paper reviews our inaugural experience with the submental island flap (SIF) and compares costs incurred to a matched cohort of oral cancer patients reconstructed with forearm free flaps.MethodsCharts of patients who underwent SIF and RFFF reconstruction from January 1st 2013 to April 1st 2015 were retrospectively examined. Associated costs were obtained via online database and previously reported costs at the study institution.ResultsMean length of ICU stay in glossectomy RFFF reconstruction was 4.7 days. Only one patient required ICU stay for one night in the SIF group. Mean length of hospital stay was not significantly different in SIF patients vs RFFF patients (12.4 vs 15.4 days, p > 0.05). Mean operative time was significantly lower in the SIF group compared to the RFFF group (347 vs 552 min, p < 0.05). Total mean intraoperative costs were found to be $4780.59 for RFFF operations, versus $2307.94 for SIF. Total mean cost of post-operative stay was $18158.40 in the SIF group and $43617.60 in the RFFF group. Total cost savings were therefore $27931.85 per patient for the SIF group.ConclusionsWe have demonstrated the use of the submental island flap as an alternative to radial forearm free flaps, showing both decreased hospital costs and comparable patient outcomes. Pedicled flaps are making a resurgence in head and neck reconstruction, and the submental island flap offers an excellent alternative to more labour intensive and costly free flap alternatives.

Eutrophication of coastal waters is a serious environmental problem with high costs for society globally. In eastern Skagerrak, reductions in eutrophication are planned through reduction of nitrogen inputs, but it is unclear how this can be achieved. One possible method is the cultivation of filter-feeding organisms, such as blue mussels, which remove nitrogen while generating seafood, fodder and agricultural fertilizer, thus recycling nutrients from sea to land. The expected effect of mussel farming on nitrogen cycling was modeled for the Gullmar Fjord on the Swedish west coast and it is shown that the net transport of nitrogen (sum of dissolved and particulate) at the fjord mouth was reduced by 20%. Existing commercial mussel farms already perform this service for free, but the benefits to society could be far greater. We suggest that rather than paying mussel farmers for their work that nutrient trading systems are introduced to improve coastal waters. In this context an alternative to nitrogen reduction in the sewage treatment plant in Lysekil community through mussel farming is presented. Accumulation of bio-toxins has been identified as the largest impediment to further expansion of commercial mussel farming in Sweden, but the problem seems to be manageable through new techniques and management strategies. On the basis of existing and potential regulations and payments, possible win-win solutions are suggested.

While extracorporeal membrane oxygenation (ECMO) is an effective method of oxygenation for patients with respiratory failure, further refinement of its incorporation into airway guidelines is needed. We present a case of severe glottic stenosis from advanced thyroid carcinoma in which gas exchange was facilitated by veno-arterial ECMO prior to achieving a definitive airway. We also conducted a systematic review of the MEDLINE, EMBASE, CINAHL, and Web of Science databases, using the keywords "airway/ tracheal obstruction", "anesthesia", "extracorporeal", and "cardiopulmonary bypass" to identify reports where ECMO was initiated as the a priori method of oxygenation during difficult airway management.Thirty-six papers were retrieved discussing the use of ECMO or cardiopulmonary bypass (CPB) for the management of critical airway obstruction. Forty-five patients underwent pre-induction of anesthesia institution of CPB or ECMO for airway obstruction. The patients presenting with critical airway obstruction had a range of airway pathologies with tracheal tumours (31%), tracheal stenosis (20%), and head and neck cancers (20%) being the most common. All cases reported a favourable patient outcome with all patients surviving to hospital discharge without significant complications.While most practitioners are familiar with the fundamental airway techniques of bag-mask ventilation, supraglottic airway use, tracheal intubation, and front-of-neck airway access for oxygenation, these techniques have limitations in managing patients with pre-existing severe airway obstruction. The use of ECMO should be considered in patients with severe (or near-complete) airway obstruction secondary to anterior neck or tracheal disease. This approach can provide essential tissue oxygenation while attempts to secure a definitive airway are carried out in a controlled environment.

Arrays of nanoscale interfaces between immiscible electrolyte solutions were formed using silicon nitride nanopore array membranes. Nanopores in the range from 75 nm radius down to 17 nm radius were used to form the nano-interfaces. It was found that the liquid organic phase electrolyte solution filled the pores so that inlaid nano-interfaces were formed with the aqueous phase. Cyclic voltammetry at these nano-interface arrays demonstrated steady-state behaviour at the larger interfaces but the voltammetric wave-shape became progressively worse as the interface size decreased. It was found that the ion transfer currents were ca. 50% of those expected based on theoretical calculations, which is attributed to overlap of diffusion zones at adjacent nano-interfaces. Here, the separation between adjacent nano-interfaces was 20-times the interface radius. The analytical sensitivity for ion transfer from the aqueous to the 1,6-dichlorohexane organic phase was estimated from calibration plots of current density versus concentration of aqueous tetraethylammonium cation. The sensitivity was in the range of 65 μA cm(-2) μM(-1) (at 75 nm radius interfaces) to 265 μA cm(-2) μM(-1) (at 17 nm radius interfaces). The sensitivity depended directly on the inverse of the nano-interface radius, implying that smaller interfaces will provide better sensitivity, due to the enhanced flux of analyte arising from convergent diffusion to smaller electrochemical interfaces.

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Patients undergoing major head and neck surgery are at high risk of PPCs. Advanced age and hypertension significantly correlated with PPCs. PPCs correlate with prolonged ICU and hospital stays, and increased mortality. Further research is needed to define risk factors, useful investigations, and effective optimization strategies to mitigate PPCs.