The α, β, γ, and δ polymorphs of Y2Si2O7 were synthesized using sol-gel and solid-state methods. The structures of the α and γ polymorphs were determined by identification of isostructural rare-earth disilicates, and the structures were refined using Rietveld analysis of X-ray powder diffraction data. The α polymorph crystallizes in space group P1, with a=6.5872(6) Å, b=6.6387(7) Å, c=12.032(1) Å, α=94.501(7)°, β=90.984(8)°, γ=91.771(7)°, and volume=524.16(9) Å3. The γ form is described by space group P21/c, a=4.68824(5) Å, b=10.84072(9) Å, c=5.58219(6) Å, and γ=96.0325(3)°. The anisotropic thermal expansion of each phase was measured using high temperature diffraction up to 1200 or 1400 °C, depending on the stability of the polymorph. The thermal expansion is highly anisotropic for all polymorphs, with the low-expansion direction normal to the long axis of the corner-shared SiO4 tetrahedra.

Bioactive glass fibres can be used as tissue engineering scaffolds. In this investigation, the bioactive response of 45S5 glass fibres was assessed in simulated body fluid (SBF). Preliminary attachment of osteoblasts to the fibre surface was assessed, as were the fibre tensile strength and fracture toughness. Fourier transform infrared spectroscopy (FTIR) analysis revealed that hydroxyapatite (HA) was formed on the fibres' surface after 2-4 days in SBF. Raman micro-spectroscopic analysis was used to monitor development of the HA layer during immersion. A correlation was found between increase in intensity of the PO4(3-) peak near 964cm(-1) and appearance of crystalline HA (P-O bending peaks) using FTIR. Such results are encouraging for in situ bioactivity monitoring, as Raman spectra are insensitive to the presence of water, unlike FTIR. Average tensile strength of 45S5 fibres (79 microm diameter) was 340+/-140 MPa. Fracture toughness, determined using fracture surface analysis, was 0.7+/-0.1 MPa m1/2. Confocal microscopy revealed osteoblasts attached and spread along the fibres after 15-90 min culture. Scanning electron microscopy analysis showed that cells with filopodia and dorsal ruffles remained attached after 14 days in culture. These results are encouraging, as cell adhesion is an important first step prior to proliferation and differentiation.

A designed compositional series of 22 devitrifiable glasses for sealing solid oxide fuel cell components was studied. Candidate oxides were selected on the basis of chemical compatibility with the fuel cell environment. The influence of each component on viscosity, thermal expansion, and crystallization were evaluated through systematic addition to a base composition. The most promising results were achieved within the system BaO–SrO–normalB2normalO3–Al2normalO3–Ta2normalO5–SiO2 . Additions of SrO and BaO maximize the thermal expansion of the bulk glass, achieving a coefficient of thermal expansion ranging from 10.8 to 13.9ppm∕K (200–500°C) . Devitrification of the glasses yielded similar thermal expansion coefficients ranging from 10.7 to 14.4ppm∕K . The addition of Al2normalO3 and Ta2normalO5 allows a critical sealing viscosity to be achieved at 900°C in a glass with just 6mol% of normalB2normalO3 . Five promising candidate sealing glasses have been identified.

The attenuation of an in vitro inflammatory response in RAW 264.7 murine macrophages stimulated with lipopolysaccharide (LPS) endotoxin was tested using sol-gel-derived bioactive glasses. Three general types of sol-gel-derived samples were evaluated: 58S, zinc-containing glasses, and copper-containing glasses. Distinct experimental procedures were used to test the potential of bioactive glasses to attenuate the inflammatory response in three situations: (1) therapeutically following LPS stimulation, (2) prophylactically before LPS stimulation of macrophages, and (3) indirectly via the glass dissolution products after stimulation with LPS. A sandwich enzyme-linked immunosorbent assay (ELISA) was used to monitor the concentration of tumor necrosis factor-alpha (TNF-alpha) secreted by macrophage cells. The strongest reduction in TNF-alpha concentration was observed when macrophage cells were first incubated with bioactive glass powder and then stimulated with LPS. This suggests a possible prophylactic application of these bioactive glasses for the prevention of inflammation. The 58S glass was capable of reducing the expression of TNF-alpha by macrophages, although the zinc- and copper-containing were more effective at suppressing the inflammatory response. The additional benefit of using zinc- and copper-doped bioactive glasses may be explained by the direct interactions of zinc and copper ions in key regulatory pathways for the inflammation response.

Direct oral anticoagulants are now commonplace, and reversal agents are recently becoming available. Andexanet alfa (AnXa), approved by the United States Food and Drug Administration in 2018, is a novel decoy molecule that reverses factor Xa inhibitors in patients with major hemorrhage. We present a case of a 70-year-old man taking rivaroxaban with hemodynamic instability from a ruptured abdominal aortic aneurysm. He received AnXa prior to endovascular surgery, and intraoperatively he could not be heparinized for graft placement. Consideration should be given to the risks and benefits of AnXa administration in patients who require anticoagulation after hemorrhage has been controlled.

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Introduction: Patient handoffs from emergency physicians (EP) to internal medicine (IM) physicians may be complicated by conflict with the potential for adverse outcomes. The objective of this study was to identify the specific types of, and contributors to, conflict between EPs and IM physicians in this context. Methods: We performed a qualitative focus group study using a constructivist grounded theory approach involving emergency medicine (EM) and IM residents and faculty at a large academic medical center. Focus groups assessed perspectives and experiences of EP/IM physician interactions related to patient handoffs. We interpreted data with the matrix analytic method. Results: From May to December 2019, 24 residents (IM = 11, EM = 13) and 11 faculty (IM = 6, EM = 5) from the two departments participated in eight focus groups and two interviews. Two key themes emerged: 1) disagreements about disposition (ie, whether a patient needed to be admitted, should go to an intensive care unit, or required additional testing before transfer to the floor); and 2) contextual factors (ie, the request to discuss an admission being a primer for conflict; lack of knowledge of the other person and their workflow; high clinical workload and volume; and different interdepartmental perspectives on the benefits of a rapid emergency department workflow). Conclusions: Causes of conflict at patient handover between EPs and IM physicians are related primarily to disposition concerns and contextual factors. Using theoretical models of task, process, and relationship conflict, we suggest recommendations to improve the EM/IM interaction to potentially reduce conflict and advance patient care.

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