Purpose: To compare the results on DNA fragmentation induced in Chinese hamster V79 cells by various doses of gamma-rays and low-energy protons and helium-4 ions.
Materials And Methods: V79 cells were irradiated as monolayers with monoenergetic protons and helium-4 ions; gamma-rays were used as the reference radiation. DNA double-strand breaks were evaluated by calibrated pulsed-field gel electrophoresis using conditions covering the range 5.7 Mbp-23.1 kbp.
Results: The fragment-counting method gave double-strand breaks yields and the relative biological effectiveness higher than those obtained by the fraction of activity released method. The frequency distribution of fragments showed that protons and helium ions induced more fragments below the Mbp region than did gamma-rays at the same dose. The distributions for both the irradiated and non-irradiated samples clearly appeared to be non-random.
Conclusion: Differences were observed in the yield and spatial correlation, at a molecular size scale characteristic of loop dimensions, of the double-strand breaks induced by gamma-rays and by light ions. These effects may have a role in the observed different cell response to these radiations.
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http://dx.doi.org/10.1080/09553000210123676 | DOI Listing |
Chem Biodivers
January 2025
Shanghai Key Lab of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai, P. R. China.
The widespread application of pyraclostrobin (PYR), an important strobilurin fungicide with low utilization efficiency, urgently requires optimization for sustainable agriculture. In this study, nanoformulated PYR with nano-iron bismuthide (FeBi) was successfully prepared via flash nanoprecipitation, yielding spherical PYR/FeBi nanoparticles (NPs, Φ120 nm) with stable drug loading capacity (67.9%) and controlled release.
View Article and Find Full Text PDFJ Dent
February 2025
Dental College of Georgia, Augusta University, Augusta, GA, USA. Electronic address:
Objectives: To evaluate the efficacy of multi-functional root canal irrigating solutions in the removal of canal wall smear layers, antibacterial activity, cytotoxicity, and tissue dissolution efficacy.
Methods: Forty single-rooted teeth were mechanically instrumented and irrigated with Triton, EndoJuice™, EDTA, and 0.9 % saline.
Phys Med
January 2025
Instituto de Fisica, Pontificia Universidad Catolica de Chile, Santiago, Chile. Electronic address:
Chem Biol Drug Des
November 2024
Center for Research in Product and Development (CEPPED), Lutheran University of Brazil (ULBRA), Canoas, RS, Brazil.
Overexposure to blue light due to the excessive use of electronic devices has been implicated in premature skin aging and eye damage, among other injuries to health. This study aimed to synthesize two azo derivatives of the 2-(amino-2'-hydroxyphenyl) benzoxazole and explore their potential as UV and blue light filters, proposing a new spectral profile. The synthesis of the heterocyclic compounds involved condensation reactions and diazotation.
View Article and Find Full Text PDFInt J Radiat Oncol Biol Phys
November 2024
Department of Radiology, Nagoya City University Graduate School of Medical Sciences.
Purpose: To establish an ultra-high dose-rate (UHDR) radiation system using a synchrotron proton beam accelerator and to compare the effects by irradiation positions on cultured cells and chick embryos.
Methods And Materials: Protons for UHDR were obtained by applying high-frequency power at much higher levels than usual to extract all protons within approximately 50 ms. Subsequently, monitoring with a Faraday cup was performed immediately after synchrotron extraction and the waveform was adjusted accordingly.
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