J Am Soc Mass Spectrom
Department of Chemistry, Washington University, St Louis, Missouri 63130, USA.
Published: January 2002
We investigated a spectral-contrast-angle (theta) method to determine whether mass spectra of structural isomers are the same or significantly different. This method represents collisionally activated dissociation (CAD) spectra as vectors in space. Mass spectra of different isomers are represented as different vectors, having characteristic lengths and direction. The derived spectral contrast angle, which is a measure of the angle between two vectors corresponding to two closely related spectra, is a measure of whether the mass spectra are the same or significantly different. We compare this method with the similarity index (SI) method and show that the spectral contrast angle method is superior and can differentiate between very similar spectra in cases where the SI cannot. Both methods can be implemented simply in situations where the analyst is called on to decide, on the basis of mass or product-ion spectra, whether reference and unknown compounds are the same or to evaluate the reproducibility of spectra comprised of many peaks.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/S1044-0305(01)00327-0 | DOI Listing |
Eur J Radiol
January 2025
Department of Diagnostic and Interventional Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany; Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, USA. Electronic address:
Purpose: To evaluate the feasibility of aortoiliac CT-Angiography (CTA) using dual-source photon-counting detector (PCD)-CT with minimal iodine dose.
Methods: This IRB-approved, single-center prospective study enrolled patients with indications for aortoiliac CTA from December 2022 to March 2023. All scans were performed using a first-generation dual-source PCD-CT.
Eur J Immunol
January 2025
Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
Many human autoimmune diseases (AIDs) are hallmarked by the presence and persistence of autoreactive B-cells. While autoreactive B-cells may frequently encounter antigens, the signals required to balance and maintain their activation and survival are mostly unknown. Understanding such signals may be important for strategies aimed at eliminating human B-cell autoreactivity.
View Article and Find Full Text PDFAppl Spectrosc
January 2025
Department of Chemistry, University of Utah, Salt Lake City, Utah, USA.
Crystallization from the melt is a critical process governing the properties of semi-crystalline polymeric materials. While structural analyses of melting and crystallization transitions in bulk polymers have been widely reported, in contrast, those in thin polymer films on solid supports have been underexplored. Herein, in situ Raman microscopy and self-modeling curve resolution (SMCR) analysis are applied to investigate the temperature-dependent structural changes in poly(ethylene oxide) (PEO) films during melting and crystallization phase transitions.
View Article and Find Full Text PDFDiagn Interv Imaging
January 2025
Department of Cardiovascular and Thoracic Radiology, Hôpital Louis Pradel, Hospices Civils de Lyon, Lyon 69002, France; CREATIS, CNRS UMR 5220, INSERM U1206, INSA-Lyon, University Claude Bernard Lyon 1, Villeurbanne 69100, France.
Biosens Bioelectron
December 2024
Biophotonic Nanosensors Laboratory, Centro de Física Aplicada y Tecnología Avanzada (CFATA), Universidad Nacional Autónoma de México (UNAM), Querétaro, 76230, Mexico. Electronic address:
Smartphone-based colorimetric (bio)sensing is a promising alternative to conventional detection equipment for on-site testing, but it is often limited by sensitivity to lighting conditions. These issues are usually avoided using housings with fixed light sources, increasing the cost and complexity of the on-site test, where simplicity, portability, and affordability are a priority. In this study, we demonstrate that careful optimization of color space can significantly boost the performance of smartphone-based colorimetric sensing, enabling housing-free, illumination-invariant detection.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.