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Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work, we report on a fitting technique used to account for different detector responses resulting from photoabsorption in the various avalanche photodiode layers. The use of this technique results in an improvement of the energy resolution at 8.2 keV by up to a factor of 2 and corrects the timing information by up to 25 ns to account for space dependent electron drift time. In addition, this waveform analysis is used for particle identification, e.g., to distinguish between x-rays and MeV electrons in our experiment.
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http://dx.doi.org/10.1063/1.4921195 | DOI Listing |
J Vis Exp
August 2025
School of Marine and Atmospheric Science, Stony Brook University.
The protocol presented here enables the quantification of microplastics (MPs) as small as ~1 µm in diameter, accurate identification of polymer types, and estimation of particle volume, critically allowing for the calculation of MP mass. Representative results from samples collected in the Great South Bay (GSB), NY, showed that particles within the 1-6 µm equivalent spherical diameter (ESD) range were the most abundant, with approximately 75% of particles measuring less than 5 µm. Notably, the pre-sieving step failed to yield any particles larger than 60 µm, suggesting that large MPs were rare at the coastal sites sampled.
View Article and Find Full Text PDFJ Med Chem
September 2025
Repare Therapeutics, 7171 Frederick-Banting, Building 2, H4S 1Z9 Montréal, Québec, Canada.
DNA polymerase theta (Polθ) plays a critical role in repairing DNA double-strand breaks through microhomology-mediated end joining (MMEJ) and has emerged as a key synthetic lethal drug target in cancers with homologous recombination (HR) deficiencies. Its inhibition has shown a strong potential to synergize with PARP inhibitors, particularly in tumors with deleterious or mutations. Here, we describe the discovery and preclinical development of RP-2119, a selective, potent, and bioavailable Polθ ATPase inhibitor.
View Article and Find Full Text PDFACS Omega
September 2025
Mads Clausen Institute, NanoSYD, University of Southern Denmark (SDU), Alsion 2, 6400 Sønderborg, Denmark.
Detection of micro- and nanoplastic particles at extremely low concentrations in complex matrices is a critical goal in environmental science and regulatory frameworks. Surface-enhanced Raman spectroscopy (SERS) offers unique advantages for detecting molecular species in such mixtures, relying solely on their characteristic fingerprints. However, its application for plastic particles has been constrained due to weak analyte-substrate interactions.
View Article and Find Full Text PDFJ Hazard Mater
September 2025
Mining and Minerals Engineering, Virginia Tech, Blacksburg, VA, USA. Electronic address:
Occupational lung disease remains a serious concern among miner workers, underscoring the need for improved characterization of respirable dust. Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) enables high-resolution analysis of filter samples, but accurate identification of complex, multi-constituent particles like agglomerates during direct-on-filter (DOF) analysis remains challenging. This is because standard tools for automated SEM-EDX treat each dust entity as an independent particle.
View Article and Find Full Text PDFJ Photochem Photobiol B
August 2025
Family Delivery Room, Women and Children's Hospital, Zhumadian Central Hospital, Zhumadian 463000, China.
Pelvic infection has emerged as a significant health risk to women, making the accurate identification of possible pathogenic bacteria and pathogens crucial for its prevention and treatment. Photodynamic therapy (PDT) for antibacterial purposes has emerged as an alternative and promising therapeutic approach for pelvic infections. In this investigation, we developed new antibacterial nanomaterials (DCMP NPs) using doxycycline (DCL), chitosan (CH), and mesoporous polydopamine (MPD) nanoparticles.
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