Ryoichi Hirayama

2.6k total citations
103 papers, 2.1k citations indexed

About

Ryoichi Hirayama is a scholar working on Pulmonary and Respiratory Medicine, Molecular Biology and Radiology, Nuclear Medicine and Imaging. According to data from OpenAlex, Ryoichi Hirayama has authored 103 papers receiving a total of 2.1k indexed citations (citations by other indexed papers that have themselves been cited), including 56 papers in Pulmonary and Respiratory Medicine, 43 papers in Molecular Biology and 36 papers in Radiology, Nuclear Medicine and Imaging. Recurrent topics in Ryoichi Hirayama's work include Radiation Therapy and Dosimetry (54 papers), DNA Repair Mechanisms (26 papers) and Effects of Radiation Exposure (25 papers). Ryoichi Hirayama is often cited by papers focused on Radiation Therapy and Dosimetry (54 papers), DNA Repair Mechanisms (26 papers) and Effects of Radiation Exposure (25 papers). Ryoichi Hirayama collaborates with scholars based in Japan, China and France. Ryoichi Hirayama's co-authors include Yoshiya Furusawa, Koichi Andō, Ryuichi Okayasu, Akiko Uzawa, Yoshitaka Matsumoto, Miho Noguchi, Atsushi Ito, Hiroshi Ide, Takeshi Fukawa and Nobuo Kubota and has published in prestigious journals such as Proceedings of the National Academy of Sciences, Nucleic Acids Research and Journal of Biological Chemistry.

In The Last Decade

Ryoichi Hirayama

97 papers receiving 2.0k citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name	h						Papers	Cites
Ryoichi Hirayama Japan	26	983	834	631	454	334	103	2.1k
Yoshitaka Matsumoto Japan	25	1.2k 1.2×	716 0.9×	706 1.1×	820 1.8×	230 0.7×	98	2.4k
Kheng‐Wei Yeoh Singapore	3	612 0.6×	686 0.8×	592 0.9×	314 0.7×	284 0.9×	5	2.4k
Mizuho Aoki Japan	18	1.1k 1.1×	365 0.4×	767 1.2×	557 1.2×	158 0.5×	29	1.5k
Roger F. Martin Australia	28	590 0.6×	1.5k 1.8×	726 1.2×	203 0.4×	491 1.5×	85	2.8k
L. D. Skarsgard Canada	23	817 0.8×	541 0.6×	789 1.3×	429 0.9×	460 1.4×	75	1.7k
Ryuichi Okayasu Japan	37	1.2k 1.2×	2.4k 2.8×	968 1.5×	284 0.6×	1.0k 3.0×	113	3.7k
Shin‐ichiro Masunaga Japan	29	764 0.8×	514 0.6×	2.2k 3.5×	1.0k 2.3×	341 1.0×	172	3.2k
C.K. Hill United States	22	660 0.7×	525 0.6×	605 1.0×	263 0.6×	333 1.0×	73	1.7k
R. Roots United States	14	553 0.6×	903 1.1×	416 0.7×	192 0.4×	426 1.3×	21	1.7k
Patricia M. Price United Kingdom	22	362 0.4×	590 0.7×	1.1k 1.7×	287 0.6×	426 1.3×	46	2.3k

Countries citing papers authored by Ryoichi Hirayama

Since Specialization

Citations

This map shows the geographic impact of Ryoichi Hirayama's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Ryoichi Hirayama with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Ryoichi Hirayama more than expected).

Fields of papers citing papers by Ryoichi Hirayama

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Ryoichi Hirayama. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Ryoichi Hirayama. The network helps show where Ryoichi Hirayama may publish in the future.

Co-authorship network of co-authors of Ryoichi Hirayama

This figure shows the co-authorship network connecting the top 25 collaborators of Ryoichi Hirayama. A scholar is included among the top collaborators of Ryoichi Hirayama based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Ryoichi Hirayama. Ryoichi Hirayama is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

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20 of 20 papers shown

Gao, Yuting, Boyi Yu, Linjing Li, et al.. (2025). mtDNA/RNA boosts radiation-induced abscopal effect via M1 macrophage polarization-promoted IFN-β-dependent inflammatory response. International Immunopharmacology. 155. 114673–114673.

Iwasaki, A, et al.. (2024). Piceatannol reduces radiation-induced DNA double-strand breaks by suppressing superoxide production and enhancing ATM-dependent repair efficiency. SHILAP Revista de lepidopterología. 13. 100114–100114. 1 indexed citations

Seksek, Olivier, Judith Bergs, Ryoichi Hirayama, et al.. (2024). Synchrotron-based infrared microspectroscopy unveils the biomolecular response of healthy and tumour cell lines to neon minibeam radiation therapy. The Analyst. 150(2). 342–352.

Kusumoto, Tamon, Stéphane Roux, Ryoichi Hirayama, et al.. (2024). Increase of OH radical yields due to the decomposition of hydrogen peroxide by gold nanoparticles under X-ray irradiation. RSC Advances. 14(14). 9509–9513. 3 indexed citations

Nakano, Toshiaki, Ken Akamatsu, Masaoki Kohzaki, et al.. (2024). Deciphering repair pathways of clustered DNA damage in human TK6 cells: insights from atomic force microscopy direct visualization. Nucleic Acids Research. 53(1). 2 indexed citations

Kataoka, J., et al.. (2022). Experimental verification of efficacy of pBCT in terms of physical and biological aspects. Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment. 1045. 167537–167537. 5 indexed citations

Yogo, Katsunori, Hidetoshi Shimizu, Ryoichi Hirayama, et al.. (2022). Radiosensitization Effect of Gold Nanoparticles on Plasmid DNA Damage Induced by Therapeutic MV X-rays. Nanomaterials. 12(5). 771–771. 13 indexed citations

Kageyama, Shun‐Ichiro, Hidenari Hirata, Atsushi Motegi, et al.. (2021). Comparative analysis of the immune responses in cancer cells irradiated with X-ray, proton and carbon-ion beams. Biochemical and Biophysical Research Communications. 585. 55–60. 21 indexed citations

Sech, C. Le & Ryoichi Hirayama. (2020). Dual aspect of radioenhancers and free radical scavengers. Free Radical Biology and Medicine. 159. 103–106. 2 indexed citations

10.

Salado‐Leza, Daniela, Erika Porcel, Xiaomin Yang, et al.. (2020). <p>Green One-Step Synthesis of Medical Nanoagents for Advanced Radiation Therapy</p>. PubMed. Volume 13. 61–76. 11 indexed citations

11.

Salado‐Leza, Daniela, Erika Porcel, Xiaomin Yang, et al.. (2020). Green One-Step Synthesis of Medical Nanoagents for Advanced Radiation Therapy. SHILAP Revista de lepidopterología. 1 indexed citations

12.

Matsumoto, Yoshitaka, Yoshiya Furusawa, Akiko Uzawa, et al.. (2018). Antimetastatic Effects of Carbon-Ion Beams on Malignant Melanomas. Radiation Research. 190(4). 412–412. 11 indexed citations

13.

Hirayama, Ryoichi, Akiko Uzawa, Miho Noguchi, et al.. (2015). Determination of the relative biological effectiveness and oxygen enhancement ratio for micronuclei formation using high-LET radiation in solid tumor cells: An in vitro and in vivo study. Mutation Research/Genetic Toxicology and Environmental Mutagenesis. 793. 41–47. 31 indexed citations

14.

Uzawa, Akiko, Koichi Andō, Yuki Kase, et al.. (2015). Designing a ridge filter based on a mouse foot skin reaction to spread out Bragg-peaks for carbon-ion radiotherapy. Radiotherapy and Oncology. 115(2). 279–283. 10 indexed citations

15.

Kanemoto, Ayae, Ryoichi Hirayama, Takashi Moritake, et al.. (2014). RBE and OER within the spread-out Bragg peak for proton beam therapy: in vitro study at the Proton Medical Research Center at the University of Tsukuba. Journal of Radiation Research. 55(5). 1028–1032. 19 indexed citations

16.

SHIMIZU, N., Nakako Izumi Nakajima, Takaaki Tsunematsu, et al.. (2013). Selective Enhancing Effect of Early Mitotic Inhibitor 1 (Emi1) Depletion on the Sensitivity of Doxorubicin or X-ray Treatment in Human Cancer Cells. Journal of Biological Chemistry. 288(24). 17238–17252. 17 indexed citations

17.

Uzawa, Akiko, Koichi Andō, Sachiko Koike, et al.. (2009). Comparison of Biological Effectiveness of Carbon-Ion Beams in Japan and Germany. International Journal of Radiation Oncology*Biology*Physics. 73(5). 1545–1551. 52 indexed citations

18.

Hirayama, Ryoichi, Atsushi Ito, Masanori Tomita, et al.. (2009). Contributions of Direct and Indirect Actions in Cell Killing by High-LET Radiations. Radiation Research. 171(2). 212–218. 130 indexed citations

19.

Masunaga, Shin‐ichiro, Koichi Andō, Akiko Uzawa, et al.. (2008). Radiobiologic Significance of Response of Intratumor Quiescent Cells In Vivo to Accelerated Carbon Ion Beams Compared With γ-Rays and Reactor Neutron Beams. International Journal of Radiation Oncology*Biology*Physics. 70(1). 221–228. 19 indexed citations

20.

Hirayama, Ryoichi, et al.. (1977). . NIPPON KAGAKU KAISHI. 1684–1687. 3 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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