Power line artifacts are the bane of animal and human electrophysiology. A number of methods are available to help attenuate or eliminate them, but each has its own set of drawbacks. In this brief note I present a simple method that combines the advantages of spectral and spatial filtering, while minimizing their downsides. A perfect-reconstruction filterbank is used to split the data into two parts, one noise-free and the other contaminated by line artifact. The artifact-contaminated stream is processed by a spatial filter to project out line components, and added to the noise-free part to obtain clean data. This method is applicable to multichannel data such as electroencephalography (EEG), magnetoencephalography (MEG), or multichannel local field potentials (LFP). I briefly review past methods, pointing out their drawbacks, describe the new method, and evaluate the outcome using synthetic and real data.
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http://dx.doi.org/10.1016/j.neuroimage.2019.116356 | DOI Listing |
3D Print Addit Manuf
December 2024
Photo-Acoustics Research Laboratory, Department of Mechanical and Aerospace Engineering, Clarkson University, Potsdam, New York, USA.
Unlike many conventional manufacturing techniques, 3D Printing/Additive Manufacturing (3DP/AM) fabrication creates builds with unprecedented degrees of structural and geometrical complexities. However, uncertainties in 3DP/AM processes and material attributes could cause geometric and structural quality issues in resulting builds and products. Evaluating the sensitivity of process parameters and material properties for process optimization, quality assessment, and closed-loop control is crucial in practice.
View Article and Find Full Text PDFJ Chem Inf Model
December 2024
Department of Chemistry and Institute of Functional Materials, Pusan National University, Busan 46241, South Korea.
The amber-OL21 force field (ff) was developed to better describe noncanonical DNA, including Z-DNA. Despite its improvements for DNA simulations, this study found that OL21's scope of application was limited by embedded ff artifacts. In a benchmark set of seven DNA molecules, including two double-stranded DNAs transitioning between B- and Z-DNA and five single-stranded DNAs folding into mini-dumbbell or G-quadruplex structures, the free energy landscapes obtained using OL21 revealed several issues: Z-DNA was overly stabilized; misfolded states in mini-dumbbell DNAs were most stable; DNA GQ folding was consistently biased toward an antiparallel topology.
View Article and Find Full Text PDFEnviron Sci Technol
December 2024
Institute of Earth Surface Dynamics, University of Lausanne, Lausanne 1015 CH, Switzerland.
Interactions among microbes, minerals, and organic matter are key controls on carbon, nutrient, and contaminant dynamics in soils and sediments. However, probing these interactions at relevant scales and through time remains an analytical challenge due to both their complex nature and the need for tools permitting nondestructive and real-time analysis at sufficient spatial resolution. Here, we demonstrate the ability and provide analytical recommendations for the submicron-scale characterization of complex mineral-organic microstructures using optical photothermal infrared (O-PTIR) microscopy.
View Article and Find Full Text PDFTrials
December 2024
School of Public Health, University of Michigan, 1420 Washington Heights, Ann Arbor, MI, USA.
Current guidelines tend to focus on a p-value threshold of a pre-specified primary endpoint tested in randomized controlled clinical trials to determine a treatment effect for a specific drug. However, a p-value does not always provide evidence on the treatment effect of a drug, especially when stratification of the data does not account for unforeseen variables introduced into the analysis. We report and discuss a rare case in which investigational site stratification in the pre-specified analysis method of a primary endpoint results in a loss of statistical power in the evaluation of the treatment effect due to data attrition of almost 17% of outcome data in the phase III randomized, controlled PANAMO study in critically ill COVID-19 patients.
View Article and Find Full Text PDFMed Phys
December 2024
Research Center for Advanced Detection Materials and Medical Imaging Devices, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China.
Background: Recently, the popularity of dual-layer flat-panel detector (DL-FPD) based dual-energy cone-beam CT (CBCT) imaging has been increasing. However, the image quality of dual-energy CBCT remains constrained by the Compton scattered x-ray photons.
Purpose: The objective of this study is to develop a novel scatter correction method, named e-Grid, for DL-FPD based CBCT imaging.
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