Matching electron beams without secondary collimators (applicators) were used for treatment of extensive, recurrent chest-wall carcinoma. Due to the wide penumbra of such beams, the homogeneity of the dose distribution at and around the junction point is clinically acceptable and relatively insensitive to positional errors. Specifically, dose around the junction point is homogeneous to within +/- 4% as calculated from beam profiles, while the positional error of 1 cm leaves this number essentially unchanged. The experimental isodose distribution in an anthropomorphic phantom supports this conclusion. Two electron beams with wide penumbra were used to cover the desired treatment area with satisfactory dose homogeneity. The technique is relatively simple yet clinically useful and can be considered a viable alternative for treatment of extensive chest-wall disease. The steps are suggested to make this technique more universal.
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http://dx.doi.org/10.1016/0958-3947(94)90029-9 | DOI Listing |
Sci Rep
January 2025
Accelerator Operations and Technology Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545, USA.
The pursuit to operate photocathodes at high accelerating gradients to increase brightness of electron beams is gaining interests within the accelerator community, particularly for applications such as free electron lasers (FEL) and compact accelerators. Cesium telluride (CsTe) is a widely used photocathode material and it is presumed to offer resilience to higher gradients because of its wider band gap compared to other semiconductors. Despite its advantages, crucial material properties of CsTe remain largely unknown both in theory and experiments.
View Article and Find Full Text PDFNat Commun
January 2025
Center for Electron Microscopy, South China University of Technology, Guangzhou, China.
Electron ptychography, recognized as an ideal technique for low-dose imaging, consistently achieves deep sub-angstrom resolution at electron doses of several thousand electrons per square angstrom (e/Å) or higher. Despite its proven efficacy, the application of electron ptychography at even lower doses-necessary for materials highly sensitive to electron beams-raises questions regarding its feasibility and the attainable resolution under such stringent conditions. Herein, we demonstrate the implementation of near-atomic-resolution ( ~ 2 Å) electron ptychography reconstruction at electron doses as low as ~100 e/Å, for metal-organic frameworks (MOFs), which are known for their extreme sensitivity.
View Article and Find Full Text PDFJ Phys Condens Matter
January 2025
South China Normal University, School of Physics, Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, Guangzhou, 510631, CHINA.
With the continuous development of digital information and big data technologies, the ambient temperature and heat generation during the operation of magnetic storage devices play an increasingly crucial role in ensuring data security and device stability. In this study, we examined the lattice thermal conductivity of the van der Waals magnetic semiconductor CrSBr from bulk to monolayer structures using first-principles calculations and the phonon Boltzmann transport equation. Our results indicated that lattice thermal conductivity show anisotropy and CrSBr bilayer exhibits lower thermal conductivity at all temperatures.
View Article and Find Full Text PDFBraz Oral Res
January 2025
Universidade de São Paulo - USP, School of Dentistry, Department of Operative Dentistry, São Paulo, SP, Brazil.
The aim of this study was to assess the effect of a chlorhexidine digluconate solution (CHX) applied as an antiproteolytic agent for controlling erosive tooth wear or as part of the adhesive treatment on long-term bond strength to eroded dentin. Dentin specimens were abraded with a 600-grit silicon carbide (SiC) paper for 1 min (sound dentin - S), subsequently treated with 2% CHX for 1 min (with excess removed, followed by a 6-hour rest), and eroded by exposure to Coca-Cola for 5 min, three times a day, for 5 days (CHX-treated and eroded dentin - CHXE), or only eroded (eroded dentin - E). The specimens were acid-etched (15 s), rinsed (30 s), dried (15 s), and rehydrated with 1.
View Article and Find Full Text PDFInorg Chem
January 2025
Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China.
Atomically precise nanoclusters, distinguished by their unique nuclearity- and structure-dependent properties, hold great promise for applications of energy conversion and electronic transport. However, the relationship between ligands and their properties remains a mystery yet to be unrevealed. Here, the influence of ligands on the electronic structures, optical properties, excited-state dynamics, and transport behavior of ReS dimer clusters with different ligands is explored using density functional theory combined with time-domain nonadiabatic molecular dynamic simulations.
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