X-ray and neutron scattering

Abstract:

BACKGROUND: The COVID-19 pandemic disproportionately impacted long-term care and assisted living (LTC/AL) facilities in Canada, where infection prevention and control (IPAC) programs had been suboptimal. We aimed to identify barriers affecting healthcare workers' (HCW) adherence to IPAC practices during the pandemic in British Columbia in LTC/AL compared to acute care settings. METHODS: We conducted a web-based survey of direct care providers and IPAC professionals across BC from August to September 2021, focused on knowledge and attitudes toward IPAC within the context of the COVID-19 pandemic, and barriers that affected respondents' abilities to follow IPAC practices throughout the pandemic. RESULTS: The final analysis included 896 acute care respondents and 441 from LTC/AL. More LTC/AL respondents reported experiencing the following barriers: following IPAC guidance was of lower priority compared to other tasks (29.1% vs. 14.7%, FDR = 0.001) and not their responsibility (28.0% vs. 11.2%, FDR = 0.001); limited supplies for personal protective equipment (PPE) (49.0% vs. 33.6%, FDR = 0.001), hand hygiene products (42.2% vs. 28.8%, FDR = 0.001), and cleaning/disinfection products (44.1% vs. 30.3%, FDR = 0.001); deficits in IPAC leadership support (46.2% vs. 38.9%, FDR = 0.012), IPAC education and training (46.9% vs. 32.0%, FDR = 0.001), and patient care knowledge for managing COVID-19 infections (46.6% vs. 36.0%, FDR = 0.001). CONCLUSIONS: This survey found that barriers to HCWs' adherence to IPAC practices during the COVID-19 pandemic were different in LTC/AL settings compared to acute care. Improvement efforts should focus on strengthening IPAC programs in LTC/AL, particularly enhanced IPAC staffing/leadership, increased training and education, and improving access to PPE, hand hygiene, and cleaning products.

Abstract:

Inelastic neutron scattering is used to study the magnetic excitations of the S=1 square-lattice antiferromagnet La₂NiO₄. We find that the spin waves cannot be described by a simple classical (harmonic) Heisenberg model with only nearest-neighbor interactions. The spin-wave dispersion measured along the antiferromagnetic Brillouin-zone boundary shows a minimum energy at the (1/2,0) position as is observed in some S=1/2 square-lattice antiferromagnets. Thus, our results suggest that the quantum dispersion renormalization effects or longer-range exchange interactions observed in cuprates and other S =1/2 square-lattice antiferromagnets are also present in La₂NiO₄. We also find that the overall intensity of the spin-wave excitations is suppressed relative to linear spin-wave theory, indicating that covalency is important. Two-magnon scattering is also observed.