Koji Koyama

3.1k total citations
166 papers, 2.4k citations indexed

About

Koji Koyama is a scholar working on Reproductive Medicine, Molecular Biology and Public Health, Environmental and Occupational Health. According to data from OpenAlex, Koji Koyama has authored 166 papers receiving a total of 2.4k indexed citations (citations by other indexed papers that have themselves been cited), including 69 papers in Reproductive Medicine, 47 papers in Molecular Biology and 47 papers in Public Health, Environmental and Occupational Health. Recurrent topics in Koji Koyama's work include Sperm and Testicular Function (53 papers), Reproductive Biology and Fertility (38 papers) and Animal Genetics and Reproduction (23 papers). Koji Koyama is often cited by papers focused on Sperm and Testicular Function (53 papers), Reproductive Biology and Fertility (38 papers) and Animal Genetics and Reproduction (23 papers). Koji Koyama collaborates with scholars based in Japan, United States and India. Koji Koyama's co-authors include Akiko Hasegawa, S. Isojima, Minoru Shigeta, Shinji Komori, Yoshiyuki Tsuji, Hiroaki Shibahara, A. Hasegawa, Gupta Sk, Hiroshi Tsubamoto and Hideaki Sawai and has published in prestigious journals such as SHILAP Revista de lepidopterología, The Journal of Clinical Endocrinology & Metabolism and Cancer.

In The Last Decade

Koji Koyama

152 papers receiving 2.2k citations

Peers — A (Enhanced Table)

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

Name h Career Trend Papers Cites
Koji Koyama Japan 30 1.2k 853 702 517 452 166 2.4k
Hiroaki Shibahara Japan 31 1.8k 1.5× 1.2k 1.4× 684 1.0× 602 1.2× 324 0.7× 207 3.1k
J. Martal France 30 507 0.4× 899 1.1× 484 0.7× 1.9k 3.7× 606 1.3× 77 3.4k
Divya Shah United States 25 475 0.4× 296 0.3× 611 0.9× 352 0.7× 385 0.9× 83 2.2k
Vernon C. Stevens United States 24 603 0.5× 359 0.4× 400 0.6× 695 1.3× 230 0.5× 79 1.7k
Subbi Mathur United States 29 1.3k 1.1× 462 0.5× 252 0.4× 900 1.7× 182 0.4× 90 2.2k
Deepak Modi India 33 1.4k 1.2× 1.0k 1.2× 906 1.3× 1.0k 2.0× 795 1.8× 134 3.3k
Inmaculada Moreno Spain 25 866 0.7× 524 0.6× 981 1.4× 1.4k 2.7× 148 0.3× 60 2.9k
Jonathan E. Boyson United States 27 412 0.3× 408 0.5× 383 0.5× 2.6k 5.0× 92 0.2× 55 3.2k
László Szereday Hungary 27 463 0.4× 509 0.6× 166 0.2× 1.5k 3.0× 130 0.3× 79 2.1k
Tal I. Arnon Israel 25 483 0.4× 421 0.5× 605 0.9× 4.3k 8.3× 158 0.3× 33 5.1k

Countries citing papers authored by Koji Koyama

Since Specialization
Citations

This map shows the geographic impact of Koji Koyama'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 Koji Koyama with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Koji Koyama more than expected).

Fields of papers citing papers by Koji Koyama

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Koji Koyama. 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 Koji Koyama. The network helps show where Koji Koyama may publish in the future.

Co-authorship network of co-authors of Koji Koyama

This figure shows the co-authorship network connecting the top 25 collaborators of Koji Koyama. A scholar is included among the top collaborators of Koji Koyama 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 Koji Koyama. Koji Koyama is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Koyama, Koji, et al.. (2023). Effect of Using a Spine Mat on Chest Expansion, Respiratory Function, and Respiratory Muscle Strength. Rigakuryoho Kagaku. 38(1). 78–83.
2.
Koyama, Koji, et al.. (2023). Effects of Spine Mat Use on the Interscapular Distance of Children in the Upright Position. Rigakuryoho Kagaku. 38(4). 268–272.
3.
4.
Masumoto, Shuji, Koji Koyama, T. KATO, et al.. (2016). Discovery of SMP-304, a novel benzylpiperidine derivative with serotonin transporter inhibitory activity and 5-HT1A weak partial agonistic activity showing the antidepressant-like effect. Bioorganic & Medicinal Chemistry. 25(1). 293–304. 4 indexed citations
5.
Sk, Gupta, Koji Koyama, Peter Johnson, & Sarah A. Robertson. (2009). Preface. Journal of Reproductive Immunology. 83(1-2). 1–1. 1 indexed citations
6.
Shibahara, Hiroaki, et al.. (2009). Diagnosis and treatment of immunologically infertile women with sperm-immobilizing antibodies in their sera. Journal of Reproductive Immunology. 83(1-2). 139–144. 13 indexed citations
7.
Hasegawa, Akiko & Koji Koyama. (2007). In vitro growth and maturation of mouse oocyte‐granulosa cell complex from cryopreserved ovaries and achievement of pup birth. Reproductive Medicine and Biology. 6(2). 77–83. 3 indexed citations
8.
Hasegawa, Akiko, et al.. (2007). Comparison of urinary and recombinant follicle-stimulating hormone in in vitro growth, maturation, and fertilization of mouse preantral follicles. Fertility and Sterility. 89(5). 1482–1489. 9 indexed citations
9.
Koyama, Koji & A. Hasegawa. (2006). Premature Ovarian Failure Syndrome May Be Induced by Autoimmune Reactions to Zona Pellucida Proteins. Journal für Kardiologie (Krause & Pachernegg GmbH). 3(2). 94–97. 6 indexed citations
10.
Komori, Shinji, et al.. (2003). Diagnostic Laparoscopy in Infertility: A Retrospective Study. Journal of Laparoendoscopic & Advanced Surgical Techniques. 13(3). 147–151. 8 indexed citations
11.
Komori, Shinji, et al.. (2003). Prevention of multiple pregnancies by restricting the number of transferred embryos: randomized control study. Archives of Gynecology and Obstetrics. 270(2). 91–3. 7 indexed citations
12.
Shibahara, Hiroaki, et al.. (2000). Successful Pregnancies in a Case of Retrograde Ejaculation Associated with Tethered Spinal Cord Syndrome. Journal of Assisted Reproduction and Genetics. 17(4). 233–233. 3 indexed citations
13.
14.
Hasegawa, Akiko, et al.. (1997). Induction of autoantibody against rabbit zona pellucida by immunization of 18-mer synthetic peptide. 11. 49–50. 1 indexed citations
15.
Shibahara, Hiroaki, et al.. (1997). Evaluation of sperm fertilizing ability using the Sperm Quality Analyzer. International Journal of Andrology. 20(2). 112–117. 33 indexed citations
16.
Koyama, Koji, et al.. (1997). Effect of respiratory acidosis on body movements in the chronically instrumented fetal lamb. Acta Obstetricia Et Gynecologica Scandinavica. 76(4). 200–204. 1 indexed citations
17.
Hasegawa, A., M. Inoue, Koji Koyama, & S. Isojima. (1993). DETERMINATION OF A EPITOPE SEQUENCE RECOGNIZED BY A MONOCLONAL ANTIBODY (5H4) TO PORCINE ZONA PELLUCIDA. 7. 125–128.
18.
Koyama, Koji, et al.. (1986). Affinity to lectin, biological and immunological characteristics of human chorionic gonadotropins from pregnant women and trophoblastic tumour patients. European Journal of Endocrinology. 112(4). 579–585. 2 indexed citations
19.
20.
Horikoshi, Masaru, et al.. (1979). Establishment of a Cell Line (RTG) Derived from Foetal Rat Tooth Germs. THE JOURNAL OF THE STOMATOLOGICAL SOCIETY JAPAN. 46(3). 211–219. 1 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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