Purpose: This work describes the first implementation and in vivo study of ultrahigh-dose-rate radiation (>37 Gy/s; FLASH) effects induced by kilovoltage (kV) x-ray from a rotating-anode x-ray source.
Methods And Materials: A high-capacity rotating-anode x-ray tube with an 80-kW generator was implemented for preclinical FLASH radiation research. A custom 3-dimensionally printed immobilization and positioning tool was developed for reproducible irradiation of a mouse hind limb. Calibrated Gafchromic (EBT3) film and thermoluminescent dosimeters (LiF:Mg,Ti) were used for in-phantom and in vivo dosimetry. Healthy FVB/N and FVBN/C57BL/6 outbred mice were irradiated on 1 hind leg to doses up to 43 Gy at FLASH (87 Gy/s) and conventional (CONV; <0.05 Gy/s) dose rates. The radiation doses were delivered using a single pulse with the widths up to 500 ms and 15 minutes at FLASH and CONV dose rates. Histologic assessment of radiation-induced skin damage was performed at 8 weeks posttreatment. Tumor growth suppression was assessed using a B16F10 flank tumor model in C57BL6J mice irradiated to 35 Gy at both FLASH and CONV dose rates.
Results: FLASH-irradiated mice experienced milder radiation-induced skin injuries than CONV-irradiated mice, visible by 4 weeks posttreatment. At 8 weeks posttreatment, normal tissue injury was significantly reduced in FLASH-irradiated animals compared with CONV-irradiated animals for histologic endpoints including inflammation, ulceration, hyperplasia, and fibrosis. No difference in tumor growth response was observed between FLASH and CONV irradiations at 35 Gy. The normal tissue sparing effects of FLASH irradiations were observed only for high-severity endpoint of ulceration at 43 Gy, which suggests the dependency of biologic endpoints to FLASH radiation dose.
Conclusions: Rotating-anode x-ray sources can achieve FLASH dose rates in a single pulse with dosimetric properties suitable for small-animal experiments. We observed FLASH normal tissue sparing of radiation toxicities in mouse skin irradiated at 35 Gy with no sacrifice to tumor growth suppression. This study highlights an accessible new modality for laboratory study of the FLASH effect.
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http://dx.doi.org/10.1016/j.ijrobp.2023.06.006 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Department of Electronic Engineering, Hanyang University, Seoul 04763, Republic of Korea.
For potential application in advanced memory devices such as dynamic random-access memory (DRAM) or NAND flash, nanolaminated indium oxide (In-O) and gallium oxide (Ga-O) films with five different vertical cation distributions were grown and investigated by using a plasma-enhanced atomic layer deposition (PEALD) process. Specifically, this study provides an in-depth examination of how the control of individual layer thicknesses in the nanolaminated (NL) IGO structure impacts not only the physical and chemical properties of the thin film but also the overall device performance. To eliminate the influence of the cation composition ratio and overall thickness on the IGO thin film, these parameters were held constant across all conditions.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznanskiego 8, 61-614 Poznan, Poland.
In the course of 266 nm nanosecond laser flash photolysis of carbazole (CBL) in acetonitrile, we discovered a new transient absorption band centered at 360 nm that has been heretofore unreported despite numerous reports on similar topics. To put some limits on possible transients responsible for this absorption band and thus to solve the mechanism of CBL photolysis, we employed the strategy of selectively blocking the CBL active sites by various modifications in the structure. This strategy was supported by the use of the solvent effect and triplet quenching by molecular oxygen.
View Article and Find Full Text PDFJ Invasive Cardiol
January 2025
Minneapolis Heart Institute and Minneapolis Heart Institute Foundation, Abbott Northwestern Hospital, Minneapolis, Minnesota. Email:
Background: The use of the Ostial Flash balloon (Ostial Corporation) has received limited study in aorto-ostial chronic total occlusion (CTO) percutaneous coronary artery intervention (PCI).
Methods: The authors evaluated the outcomes of Ostial Flash balloon use in a large CTO-PCI registry (PROGRESS-CTO, NCT02061436).
Results: The Ostial Flash balloon was used in 54 of 907 aorto-ostial CTO PCIs in 905 patients (6.
Invest Ophthalmol Vis Sci
January 2025
School of Psychology and Public Health, La Trobe University, Melbourne, Australia.
Purpose: Prolonged exposure to broadband light with a short-wavelength (blue) or long-wavelength (orange/red) bias is known to impact eye growth and refraction, but the mechanisms underlying this response are unknown. Thus, the present study investigated the effects of broadband blue and orange lights with well-differentiated spectrums on refractive development and global flash electroretinography (gfERG) measures of retinal function in the chick myopia model.
Methods: Chicks were raised for 4 days with monocular negative lenses, or no lens, under blue, orange, or white light.
Dig Dis Sci
January 2025
Division of Gastroenterology, University of California, San Francisco, CA, USA.
Background: Pouchitis is common among patients with ulcerative colitis (UC) who have had colectomy with ileal pouch-anal anastomosis. Antibiotics are first-line therapy for pouch inflammation, increasing the potential for gut colonization with multi-drug resistant organisms (MDRO). Fecal microbial transplant (FMT) is being studied in the treatment of pouchitis and in the eradication of MDRO.
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