Human melanoma cells that are resistant to gamma rays were irradiated with 14 MeV neutrons given at low doses ranging from 5 cGy to 1.12 Gy at a very low dose rate of 0.8 mGy min(-1) or a moderate dose rate of 40 mGy min(-1). The biological effects of neutrons were studied by two different methods: a cell survival assay after a 14-day incubation and an analysis of chromosomal aberrations in metaphases collected 20 h after irradiation. Unusual features of the survival curve at very low dose rate were a marked increase in cell killing at 5 cGy followed by a plateau for survival from 10 to 32.5 cGy. The levels of induced chromosomal aberrations showed a similar increase for both dose rates at 7.5 cGy and the existence of a plateau at the very low dose rate from 15 to 30 cGy. The existence of a plateau suggests that a repair process after low-dose neutrons might be induced after a threshold dose of 5-7.5 cGy which compensates for induced damage from doses as high as 32.5 cGy. These findings may be of interest for understanding the relative biological effectiveness of neutrons and the effects of environmental low-dose irradiation.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1667/0033-7587(2000)154[0406:eoldna]2.0.co;2 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Validity of one-time phantomless patient-specific quality assurance in proton therapy with regard to the reproducibility of beam delivery.
Med Phys
January 2025
OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany.
Background: Patient-specific quality assurance (PSQA) is a crucial yet resource-intensive task in proton therapy, requiring special equipment, expertise and additional beam time. Machine delivery log files contain information about energy, position and monitor units (MU) of all delivered spots, allowing a reconstruction of the applied dose. This raises the prospect of phantomless, log file-based QA (LFQA) as an automated replacement of current phantom-based solutions, provided that such an approach guarantees a comparable level of safety.
View Article and Find Full Text PDFDeep learning-based Monte Carlo dose prediction for heavy-ion online adaptive radiotherapy and fast quality assurance: A feasibility study.
Med Phys
January 2025
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China.
Background: Online adaptive radiotherapy (OART) and rapid quality assurance (QA) are essential for effective heavy ion therapy (HIT). However, there is a shortage of deep learning (DL) models and workflows for predicting Monte Carlo (MC) doses in such treatments.
Purpose: This study seeks to address this gap by developing a DL model for independent MC dose (MCDose) prediction, aiming to facilitate OART and rapid QA implementation for HIT.
Analysis of the effect of platelet function and different doses of ticagrelor after flow diverter treatment of intracranial aneurysms.
Neurosurg Rev
January 2025
Neurosurgery Center, Department of Cerebrovascular Surgery, Engineering Technology Research Center of Education Ministry of China on Diagnosis and Treatment of Cerebrovascular Disease, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
Ticagrelor has become the standard drug for the treatment of intracranial aneurysms (IAs) with flow diverters (FDs), but the dosage has not been standardized. The effect of platelet function on clinical and imaging prognosis remains unclear. This study aimed to show the effects of different doses of ticagrelor and platelet aggregation function on the clinical and imaging prognosis after FDs treatment of aneurysms.
View Article and Find Full Text PDFUnveiling the potential of Aspergillus terreus SJP02 for zinc remediation and its driving mechanism.
Sci Rep
January 2025
Department of Biological Sciences, Birla Institute of Technology and Sciences, Pilani, 333031, Rajasthan, India.
In present study, 15 morphologically different fungi isolated from rhizopheric soils of an industrial area were screened for their Zn removal efficiency from aqueous solution. Isolate depicting highest potential was molecularly identified as Aspergillus terreus SJP02. Effect of various process parameters viz.
View Article and Find Full Text PDFRelationship between neutropenia caused by nanoliposomal irinotecan/fluorouracil/leucovorin and treatment outcomes in the NAPOLEON-2 study (NN-2301).
Sci Rep
January 2025
Department of Medical Oncology, Sasebo Kyosai Hospital, Sasebo, Japan.
The relationship between nanoliposomal irinotecan/fluorouracil/leucovorin (NFF) treatment outcomes and neutropenia in patients with pancreatic cancer has not been thoroughly examined. Thus, we conducted a retrospective analysis of data from patients with pancreatic cancer who were treated with NFF to investigate this relationship. Neutropenia was assessed according to the Common Terminology Criteria for Adverse Events across three cutoffs: A (grade 0 versus grade 1-4), B (grades 0-1 versus 2-4), and C (grades 0-2 versus 3-4).
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!