World's Best Scientists 2026 revealed!

D-Index & Metrics

Discipline name D-Index World Ranking Current World Ranking National Ranking Current National Ranking Publications Citations
Biology and Biochemistry 43 19390 17768 1398 1294 149 7122

Tomoichiro Oka publications per year

The chart shows the history of publications by Tomoichiro Oka between 1994 and 2021, highlighting the no. of papers published in each year and offering an overview of the publication velocity of this scholar. Tomoichiro Oka published across 28 years, from 1994 to 2021, averaging 5.1 papers a year. Output peaked at 11 publications in 2009. 15 of the 144 publications appeared in the last two years.

No. of publications
2 4 6 8 10
Bar chart. Horizontal axis: year, 1994 to 2021. Vertical axis: number of publications, 0 to 11. Peak 11 publications in 2009. 1994: 2 publications 1995: 0 publications 1996: 0 publications 1997: 1 publication 1998: 1 publication 1999: 3 publications 2000: 10 publications 2001: 0 publications 2002: 4 publications 2003: 1 publication 2004: 4 publications 2005: 6 publications 2006: 8 publications 2007: 10 publications 2008: 8 publications 2009: 11 publications 2010: 9 publications 2011: 5 publications 2012: 6 publications 2013: 9 publications 2014: 5 publications 2015: 4 publications 2016: 8 publications 2017: 7 publications 2018: 3 publications 2019: 4 publications 2020: 7 publications 2021: 8 publications
1994 2021

144 publications in total across all disciplines

View publications per year as a table
Tomoichiro Oka: publications per year, 1994 to 2021
Year Publications
1994 2
1995 0
1996 0
1997 1
1998 1
1999 3
2000 10
2001 0
2002 4
2003 1
2004 4
2005 6
2006 8
2007 10
2008 8
2009 11
2010 9
2011 5
2012 6
2013 9
2014 5
2015 4
2016 8
2017 7
2018 3
2019 4
2020 7
2021 8
Total 144
Download as CSV

Tomoichiro Oka publication distribution in Biology and Biochemistry in 2026

The chart shows the distribution of publications by all Research.com ranked scientists in the field of Biology and Biochemistry in 2026. The highlighted bar marks where Tomoichiro Oka sits on this spectrum.

No. of scientists
200 400 600 800
Bar chart with 100 bars. Horizontal axis: publications, 47–56 to 1,028+. Vertical axis: number of scientists, 0 to 980. Most scientists, 980, have 127–136 publications. The last bar groups every scientist with 1,028 publications or more. The highlighted bar, 147–156 publications, is where this scientist sits. 47–56 publications: 8 scientists 57–66 publications: 35 scientists 67–76 publications: 106 scientists 77–86 publications: 231 scientists 87–96 publications: 413 scientists 97–106 publications: 546 scientists 107–116 publications: 704 scientists 117–126 publications: 848 scientists 127–136 publications: 980 scientists 137–146 publications: 942 scientists 147–156 publications: 969 scientists 157–166 publications: 949 scientists 167–176 publications: 951 scientists 177–186 publications: 915 scientists 187–196 publications: 787 scientists 197–206 publications: 840 scientists 207–216 publications: 733 scientists 217–226 publications: 708 scientists 227–236 publications: 651 scientists 237–246 publications: 605 scientists 247–256 publications: 510 scientists 257–266 publications: 524 scientists 267–276 publications: 434 scientists 277–286 publications: 417 scientists 287–296 publications: 350 scientists 297–306 publications: 363 scientists 307–316 publications: 315 scientists 317–326 publications: 296 scientists 327–336 publications: 261 scientists 337–346 publications: 240 scientists 347–356 publications: 219 scientists 357–366 publications: 196 scientists 367–376 publications: 154 scientists 377–386 publications: 161 scientists 387–396 publications: 155 scientists 397–406 publications: 145 scientists 407–416 publications: 124 scientists 417–426 publications: 112 scientists 427–436 publications: 132 scientists 437–446 publications: 116 scientists 447–456 publications: 99 scientists 457–466 publications: 81 scientists 467–476 publications: 91 scientists 477–486 publications: 80 scientists 487–496 publications: 80 scientists 497–506 publications: 59 scientists 507–516 publications: 36 scientists 517–526 publications: 46 scientists 527–536 publications: 54 scientists 537–546 publications: 44 scientists 547–556 publications: 43 scientists 557–566 publications: 43 scientists 567–576 publications: 42 scientists 577–586 publications: 25 scientists 587–596 publications: 34 scientists 597–606 publications: 23 scientists 607–616 publications: 33 scientists 617–626 publications: 31 scientists 627–636 publications: 27 scientists 637–646 publications: 25 scientists 647–656 publications: 28 scientists 657–666 publications: 34 scientists 667–676 publications: 18 scientists 677–686 publications: 16 scientists 687–696 publications: 10 scientists 697–706 publications: 12 scientists 707–716 publications: 21 scientists 717–726 publications: 12 scientists 727–736 publications: 12 scientists 737–746 publications: 10 scientists 747–756 publications: 7 scientists 757–766 publications: 13 scientists 767–776 publications: 15 scientists 777–786 publications: 13 scientists 787–796 publications: 9 scientists 797–806 publications: 9 scientists 807–816 publications: 7 scientists 817–826 publications: 4 scientists 827–836 publications: 9 scientists 837–846 publications: 7 scientists 847–856 publications: 3 scientists 857–866 publications: 5 scientists 867–876 publications: 5 scientists 877–886 publications: 11 scientists 887–896 publications: 3 scientists 897–906 publications: 4 scientists 907–916 publications: 7 scientists 917–926 publications: 5 scientists 927–936 publications: 6 scientists 937–946 publications: 6 scientists 947–956 publications: 3 scientists 957–966 publications: 7 scientists 967–976 publications: 2 scientists 977–986 publications: 2 scientists 987–996 publications: 1 scientist 997–1,006 publications: 5 scientists 1,007–1,016 publications: 2 scientists 1,017–1,026 publications: 2 scientists 1,027 publications: 1 scientist 1,028+ publications: 100 scientists
47–56 publications 1,028+

This scientist: 149 publications — 26th percentile

26% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 1,028 publications or more.

View publications distribution as a table
Number of Biology and Biochemistry scientists by publication count, Research.com 2026 ranking edition. Based on 19,587 ranked scientists.
Publications Scientists This scientist
47–56 8
57–66 35
67–76 106
77–86 231
87–96 413
97–106 546
107–116 704
117–126 848
127–136 980
137–146 942
147–156 969 149
157–166 949
167–176 951
177–186 915
187–196 787
197–206 840
207–216 733
217–226 708
227–236 651
237–246 605
247–256 510
257–266 524
267–276 434
277–286 417
287–296 350
297–306 363
307–316 315
317–326 296
327–336 261
337–346 240
347–356 219
357–366 196
367–376 154
377–386 161
387–396 155
397–406 145
407–416 124
417–426 112
427–436 132
437–446 116
447–456 99
457–466 81
467–476 91
477–486 80
487–496 80
497–506 59
507–516 36
517–526 46
527–536 54
537–546 44
547–556 43
557–566 43
567–576 42
577–586 25
587–596 34
597–606 23
607–616 33
617–626 31
627–636 27
637–646 25
647–656 28
657–666 34
667–676 18
677–686 16
687–696 10
697–706 12
707–716 21
717–726 12
727–736 12
737–746 10
747–756 7
757–766 13
767–776 15
777–786 13
787–796 9
797–806 9
807–816 7
817–826 4
827–836 9
837–846 7
847–856 3
857–866 5
867–876 5
877–886 11
887–896 3
897–906 4
907–916 7
917–926 5
927–936 6
937–946 6
947–956 3
957–966 7
967–976 2
977–986 2
987–996 1
997–1,006 5
1,007–1,016 2
1,017–1,026 2
1,027 1
1,028+ 100
Download as CSV

Tomoichiro Oka D-index placement in Biology and Biochemistry in 2026

The chart shows the D-index (discipline H-index) distribution of Biology and Biochemistry scientists ranked by Research.com in 2026. The highlighted bar marks where Tomoichiro Oka sits on this spectrum.

No. of scientists
250 500 750 1,000 1,250
Bar chart with 65 bars. Horizontal axis: D-Index, 40–41 to 167+. Vertical axis: number of scientists, 0 to 1,253. Most scientists, 1,253, have 58–59 D-Index. The last bar groups every scientist with 167 D-Index or more. The highlighted bar, 42–43 D-Index, is where this scientist sits. 40–41 D-Index: 80 scientists 42–43 D-Index: 183 scientists 44–45 D-Index: 316 scientists 46–47 D-Index: 504 scientists 48–49 D-Index: 718 scientists 50–51 D-Index: 899 scientists 52–53 D-Index: 1,025 scientists 54–55 D-Index: 1,149 scientists 56–57 D-Index: 1,235 scientists 58–59 D-Index: 1,253 scientists 60–61 D-Index: 1,162 scientists 62–63 D-Index: 1,130 scientists 64–65 D-Index: 1,031 scientists 66–67 D-Index: 897 scientists 68–69 D-Index: 814 scientists 70–71 D-Index: 714 scientists 72–73 D-Index: 709 scientists 74–75 D-Index: 596 scientists 76–77 D-Index: 512 scientists 78–79 D-Index: 473 scientists 80–81 D-Index: 412 scientists 82–83 D-Index: 373 scientists 84–85 D-Index: 358 scientists 86–87 D-Index: 285 scientists 88–89 D-Index: 273 scientists 90–91 D-Index: 227 scientists 92–93 D-Index: 208 scientists 94–95 D-Index: 193 scientists 96–97 D-Index: 153 scientists 98–99 D-Index: 157 scientists 100–101 D-Index: 148 scientists 102–103 D-Index: 120 scientists 104–105 D-Index: 113 scientists 106–107 D-Index: 100 scientists 108–109 D-Index: 86 scientists 110–111 D-Index: 67 scientists 112–113 D-Index: 71 scientists 114–115 D-Index: 73 scientists 116–117 D-Index: 64 scientists 118–119 D-Index: 53 scientists 120–121 D-Index: 60 scientists 122–123 D-Index: 54 scientists 124–125 D-Index: 43 scientists 126–127 D-Index: 38 scientists 128–129 D-Index: 49 scientists 130–131 D-Index: 26 scientists 132–133 D-Index: 18 scientists 134–135 D-Index: 23 scientists 136–137 D-Index: 32 scientists 138–139 D-Index: 32 scientists 140–141 D-Index: 27 scientists 142–143 D-Index: 19 scientists 144–145 D-Index: 22 scientists 146–147 D-Index: 12 scientists 148–149 D-Index: 16 scientists 150–151 D-Index: 14 scientists 152–153 D-Index: 10 scientists 154–155 D-Index: 13 scientists 156–157 D-Index: 10 scientists 158–159 D-Index: 7 scientists 160–161 D-Index: 9 scientists 162–163 D-Index: 13 scientists 164–165 D-Index: 4 scientists 166 D-Index: 4 scientists 167+ D-Index: 98 scientists
40–41 D-Index 167+

This scientist: 43 D-Index — 1st percentile

1% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 167 D-Index or more.

View D-Index distribution as a table
Number of Biology and Biochemistry scientists by D-index, Research.com 2026 ranking edition. Based on 19,587 ranked scientists.
D-Index Scientists This scientist
40–41 80
42–43 183 43
44–45 316
46–47 504
48–49 718
50–51 899
52–53 1,025
54–55 1,149
56–57 1,235
58–59 1,253
60–61 1,162
62–63 1,130
64–65 1,031
66–67 897
68–69 814
70–71 714
72–73 709
74–75 596
76–77 512
78–79 473
80–81 412
82–83 373
84–85 358
86–87 285
88–89 273
90–91 227
92–93 208
94–95 193
96–97 153
98–99 157
100–101 148
102–103 120
104–105 113
106–107 100
108–109 86
110–111 67
112–113 71
114–115 73
116–117 64
118–119 53
120–121 60
122–123 54
124–125 43
126–127 38
128–129 49
130–131 26
132–133 18
134–135 23
136–137 32
138–139 32
140–141 27
142–143 19
144–145 22
146–147 12
148–149 16
150–151 14
152–153 10
154–155 13
156–157 10
158–159 7
160–161 9
162–163 13
164–165 4
166 4
167+ 98
Download as CSV

Overview

What is he best known for?

The fields of study he is best known for:

  • Gene
  • DNA
  • Virus

His main research concerns Virology, Sapovirus, Norovirus, Genotype and Capsid. His Virology research incorporates elements of Phylogenetics and Microbiology. His Phylogenetics study which covers Genome that intersects with Recombinant DNA.

His study in Norovirus is interdisciplinary in nature, drawing from both Molecular epidemiology and Rotavirus. His research in Genotype is mostly concerned with Genotyping. The study incorporates disciplines such as Molecular typing, Pathogen, Mink and Disease in addition to Outbreak.

His most cited work include:

  • Coexistence of Multiple Genotypes, Including Newly Identified Genotypes, in Outbreaks of Gastroenteritis Due to Norovirus in Japan (371 citations)
  • Phylogenetic analysis of the complete genome of 18 Norwalk-like viruses. (279 citations)
  • Detection of human sapovirus by real-time reverse transcription-polymerase chain reaction (194 citations)

What are the main themes of his work throughout his whole career to date?

His primary scientific interests are in Virology, Sapovirus, Genotype, Norovirus and Genetics. Tomoichiro Oka combines subjects such as Recombinant DNA and Microbiology with his study of Virology. His Sapovirus research includes themes of Pathogen, Feces, Viral replication, Caliciviridae Infections and Sequence analysis.

His biological study spans a wide range of topics, including Phylogenetics and Whole genome sequencing. Tomoichiro Oka focuses mostly in the field of Norovirus, narrowing it down to topics relating to Molecular epidemiology and, in certain cases, Caliciviridae. His research investigates the connection between Capsid and topics such as Molecular biology that intersect with problems in Reverse transcription polymerase chain reaction.

He most often published in these fields:

  • Virology (78.72%)
  • Sapovirus (54.61%)
  • Genotype (34.04%)

What were the highlights of his more recent work (between 2015-2021)?

  • Virology (78.72%)
  • Sapovirus (54.61%)
  • Genome (21.28%)

In recent papers he was focusing on the following fields of study:

His primary areas of study are Virology, Sapovirus, Genome, Genetics and Phylogenetic tree. His Virology research integrates issues from Strain, Recombination and Pathogenesis. Genotype and Norovirus are inextricably linked to his Sapovirus research.

His Genotype study combines topics in areas such as Reverse transcription polymerase chain reaction, Cysteine protease, Outbreak, Complementary DNA and Primer. His work deals with themes such as Feces and Sequence analysis, which intersect with Genome. Tomoichiro Oka interconnects Wild boar, Phylogenetics, Virus and Metagenomics in the investigation of issues within Phylogenetic tree.

Between 2015 and 2021, his most popular works were:

  • Genetic Characterization and Classification of Human and Animal Sapoviruses. (42 citations)
  • Genetic Characterization and Classification of Human and Animal Sapoviruses. (42 citations)
  • Attempts to grow human noroviruses, a sapovirus, and a bovine norovirus in vitro. (26 citations)

In his most recent research, the most cited papers focused on:

  • Gene
  • DNA
  • Virus

The scientist’s investigation covers issues in Sapovirus, Virology, Genetics, Genome and Polymerase chain reaction. His Sapovirus study improves the overall literature in Genotype. He has researched Genotype in several fields, including GenBank, Outbreak and Capsid.

Norovirus and Viral replication are the primary areas of interest in his Virology study. His Polymerase chain reaction research incorporates themes from Amino acid, Sequence analysis, NS3, Mink and Protein sequencing. The various areas that he examines in his Coding region study include Peptide sequence, Strain, Genetic diversity and Phylogenetics.

Best Publications

  • Coexistence of Multiple Genotypes, Including Newly Identified Genotypes, in Outbreaks of Gastroenteritis Due to Norovirus in Japan

    Tsutomu Kageyama;Michiyo Shinohara;Kazue Uchida;Shuetsu Fukushi

  • Phylogenetic analysis of the complete genome of 18 Norwalk-like viruses.

    Kazuhiko Katayama;Haruko Shirato-Horikoshi;Shigeyuki Kojima;Tsutomu Kageyama

  • Comprehensive Review of Human Sapoviruses

    Tomoichiro Oka;Tomoichiro Oka;Qiuhong Wang;Kazuhiko Katayama;Linda J. Saif

  • Detection of human sapovirus by real-time reverse transcription-polymerase chain reaction

    Tomoichiro Oka;Kazuhiko Katayama;Grant S. Hansman;Tsutomu Kageyama

  • Norovirus Infections in Symptomatic and Asymptomatic Food Handlers in Japan

    Kazuhiro Ozawa;Tomoichiro Oka;Naokazu Takeda;Grant S. Hansman

  • Cell culture isolation and sequence analysis of genetically diverse US porcine epidemic diarrhea virus strains including a novel strain with a large deletion in the spike gene.

    Tomoichiro Oka;Linda J. Saif;Douglas Marthaler;Malak A. Esseili

  • Genetic and antigenic diversity among noroviruses.

    Grant S. Hansman;Katsuro Natori;Haruko Shirato-Horikoshi;Satoko Ogawa

  • Human sapoviruses: genetic diversity, recombination, and classification

    Grant S. Hansman;Tomoichiro Oka;Kazuhiko Katayama;Naokazu Takeda

  • Distribution of phospholipid transfer protein in human plasma: presence of two forms of phospholipid transfer protein, one catalytically active and the other inactive.

    Tomoichiro Oka;Takeshi Kujiraoka;Mayumi Ito;Tohru Egashira

  • Antigenic Relationships among Porcine Epidemic Diarrhea Virus and Transmissible Gastroenteritis Virus Strains

    Chun-Ming Lin;Xiang Gao;Tomoichiro Oka;Anastasia N Vlasova

  • Isolation and partial characterization of the inactive and active forms of human plasma phospholipid transfer protein (PLTP).

    Minna Kärkkäinen;Tomoichiro Oka;Vesa M. Olkkonen;Jari Metso

  • Human sapovirus classification based on complete capsid nucleotide sequences

    Tomoichiro Oka;Tomoichiro Oka;Kohji Mori;Nobuhiro Iritani;Seiya Harada

  • Divergent Evolution of Norovirus GII/4 by Genome Recombination from May 2006 to February 2009 in Japan

    Kazushi Motomura;Masaru Yokoyama;Hirotaka Ode;Hiromi Nakamura

  • Identification of Monomorphic and Divergent Haplotypes in the 2006-2007 Norovirus GII/4 Epidemic Population by Genomewide Tracing of Evolutionary History

    Kazushi Motomura;Tomoichiro Oka;Masaru Yokoyama;Hiromi Nakamura

  • Intergenogroup recombination in sapoviruses.

    Grant S. Hansman;Naokazu Takeda;Tomoichiro Oka;Mitsukai Oseto

  • Prevalence of Porcine Noroviruses, Molecular Characterization of Emerging Porcine Sapoviruses from Finisher Swine in the United States, and Unified Classification Scheme for Sapoviruses

    Kelly A. Scheuer;Tomoichiro Oka;Armando E. Hoet;Wondwossen A. Gebreyes

  • Outbreak of Gastroenteritis Due to Sapovirus

    Grant S. Hansman;Hiroyuki Saito;Chihiro Shibata;Shizuko Ishizuka

  • Two novel missense mutations in the CETP gene in Japanese hyperalphalipoproteinemic subjects: high-throughput assay by Invader assay.

    Makoto Nagano;Shizuya Yamashita;Ken-ichi Hirano;Mayumi Ito

  • A sandwich enzyme-linked immunosorbent assay for human serum paraoxonase concentration.

    Takeshi Kujiraoka;Tomoichiro Oka;Mitsuaki Ishihara;Tohru Egashira

  • Novel recombinant sapovirus.

    Kazuhiko Katayama;Tatsuya Miyoshi;Kiyoko Uchino;Tomoichiro Oka

Frequent Co-Authors

Kazuhiko Katayama
Kazuhiko Katayama Kitasato University
Naokazu Takeda
Naokazu Takeda National Institutes of Health
Grant S. Hansman
Grant S. Hansman Griffith University
Takaji Wakita
Takaji Wakita National Institute of Infectious Diseases
Tetsuya Mizutani
Tetsuya Mizutani Tokyo University of Agriculture and Technology
Hirokazu Kimura
Hirokazu Kimura RMIT University
Tatsuo Miyamura
Tatsuo Miyamura National Institutes of Health
Vesa M. Olkkonen
Vesa M. Olkkonen University of Helsinki
Kwonil Jung
Kwonil Jung The Ohio State University
Tetsuya Hosaka
Tetsuya Hosaka Toranomon Hospital

If you think any of the details on this page are incorrect, let us know.

Report an issue

We appreciate your kind effort to assist us to improve this page, it would be helpful providing us with as much detail as possible in the text box below:

Best Scientists Citing Tomoichiro Oka

Trending Scientists

Recently Published Articles