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In the "method of four coefficients," electrical resistivity (ρ), Seebeck coefficient (S), Hall coefficient (RH), and Nernst coefficient (Q) of a material are measured and typically fit or modeled with theoretical expressions based on Boltzmann transport theory to glean experimental insights into features of electronic structure and/or charge carrier scattering mechanisms in materials. Although well-defined and readily available reference materials exist for validating measurements of ρ and S, none currently exists for RH or Q. We show that measurements of all four transport coefficients—ρ, S, RH, and Q—can be validated using a single reference sample, namely, the low-temperature Seebeck coefficient Standard Reference Material® (SRM) 3451 (composition Bi2Te3+x) available from the National Institute for Standards and Technology (NIST) without the need for inter-laboratory sample exchange. RH and Q data for NIST SRM 3451 reported here for the temperature range 80–400 K complement the data already available for ρ and S and will therefore be of interest to researchers desiring to validate new or existing galvanomagnetic and thermomagnetic transport properties measurement systems. [ABSTRACT FROM AUTHOR]

The WATCHMAN device (Boston Scientific; Marlborough, MA, USA) is noninferior to warfarin in preventing ischemic strokes while reducing bleeding risks associated with long term anticoagulation in nonvalvular atrial fibrillation (AFib). The device's performance compared to direct oral anticoagulants (DOAC) is less well known. To compare 5-year major bleeding and ischemic stroke rates in patients with nonvalvular AFib who received a WATCHMAN device or DOAC therapy after a major bleeding event. This retrospective, multicenter, 1:1 matched cohort study was derived from the PearlDiver Mariner database from 2010 to 2020. Patients with nonvalvular AFib on oral anticoagulation who had a major bleeding event were identified. Those who received either WATCHMAN or DOAC after resolution of the bleeding event were selected. The two groups were exactly matched 1:1 based on various comorbidities. Rates of ischemic stroke, transient ischemic attack (TIA), major bleeding, and hemorrhagic stroke were compared over 5 years. Each cohort consisted of 2248 patients after 1:1 matching. The mean CHADS2-VASC score was 4.81 ± 1.25. At 5 years, the WATCHMAN cohort had significantly lower rates of major bleeding events [OR 0.24 (0.21, 0.27)], TIAs [OR 0.75 (0.58, 0.95)], and ischemic strokes [OR 0.72 (0.61, 0.86)]. There was no significant difference in hemorrhagic strokes [OR 1.14 (0.83, 1.58)]. Even in a high-risk population, the WATCHMAN is comparable to DOAC therapy in the primary prevention of hemorrhagic strokes and may provide benefit in the rates of bleeding events, TIAs, and ischemic strokes. [Display omitted] • Atrial fibrillation increases individual stroke risk by up to 5 times. • Stroke risk can be mitigated with direct oral anticoagulant (DOACs) or the WATCHMAN device. • Ischemic stroke rates were lower with the WATCHMAN device compared to DOACs. • Major bleeding event rates were lower with the WATCHMAN device compared to DOACs. [ABSTRACT FROM AUTHOR]

Context: Regulatory approaches to COVID-19 vaccine authorizations varied substantially across countries. Facing a common public health threat, what accounts for regulatory variation? This study focuses on emergency pharmaceutical and vaccine regulatory procedures and whether and how regulators' emergency pharmaceutical regulatory procedures going into the pandemic shaped regulatory processes and decisions during the pandemic. Methods: The authors conducted an analysis of seven high-impact national and international pharmaceutical regulators with case studies from Brazil, China, India, Russia, the United Kingdom, the United States, and the European Medicines Agency. The authors analyzed evidence from primary source executive and legislative branch regulations and statutes as well as national and international scientific and general press reporting; they also drew on the secondary analysis of scholars, practitioners, and international organizations. Findings: Inherited emergency pharmaceutical and vaccine regulatory procedures substantially shaped COVID-19 vaccine regulation during the pandemic. Variation in the presence and content of emergency regulatory procedures affected the quality of pandemic regulatory processes, outcomes, and procedural updates and differentially empowered policy-making experts and elected politicians. Conclusions: Emergency regulatory procedures affect key features of regulatory political economy and public health practices during crises. To improve future public health crisis responses, the authors provide policy recommendations for (1) establishing clear emergency pharmaceutical regulatory procedures, and (2) international collaboration. [ABSTRACT FROM AUTHOR]

This paper describes an area and power-efficient VLSI approach for implementing the discrete wavelet transform on streaming multielectrode neurophysiological data in real time. The VLSI implementation is based on the lifting scheme for wavelet computation using the symmlet4 basis with quantized coefficients and integer fixed-point data precision to minimize hardware demands. The proposed design is driven by the need to compress neural signals recorded with high-density microelectrode arrays implanted in the cortex prior to data telemetry. Our results indicate that signal integrity is not compromised by quantization down to 5-bit filter coefficient and 10-bit data precision at intermediate stages. Furthermore, results from analog simulation and modeling show that a hardware-minimized computational core executing filter steps sequentially is advantageous over the pipeline approach commonly used in DWT implementations. The design is compared to that of a B-spline approach that minimizes the number of multipliers at the expense of increasing the number of adders. The performance demonstrates that in vivo real-time DWT computation is feasible prior to data telemetry, permitting large savings in bandwidth requirements and communication costs given the severe limitations on size, energy consumption and power dissipation of an implantable device. Index Terms--B-spline, brain machine interface, lifting, microelectrode arrays, neural signal processing, neuroprosthetic devices, wavelet transform.