A.J. Speek

1.2k total citations
16 papers, 975 citations indexed

About

A.J. Speek is a scholar working on Molecular Biology, Biochemistry and Nutrition and Dietetics. According to data from OpenAlex, A.J. Speek has authored 16 papers receiving a total of 975 indexed citations (citations by other indexed papers that have themselves been cited), including 4 papers in Molecular Biology, 4 papers in Biochemistry and 3 papers in Nutrition and Dietetics. Recurrent topics in A.J. Speek's work include Antioxidant Activity and Oxidative Stress (4 papers), Retinoids in leukemia and cellular processes (3 papers) and Vitamin C and Antioxidants Research (2 papers). A.J. Speek is often cited by papers focused on Antioxidant Activity and Oxidative Stress (4 papers), Retinoids in leukemia and cellular processes (3 papers) and Vitamin C and Antioxidants Research (2 papers). A.J. Speek collaborates with scholars based in Netherlands, Tanzania and Thailand. A.J. Speek's co-authors include J. Schrijver, W.H.P. Schreurs, Sastri Saowakontha, Michel Wedel, Martin W. Bloem, J. Lindeman, Diny van Zoeren‐Grobben, Howard Berger, Ben J. H. M. Poorthuis and V.J. Feron and has published in prestigious journals such as American Journal of Clinical Nutrition, Food Chemistry and Journal of Chromatography A.

In The Last Decade

A.J. Speek

16 papers receiving 900 citations

Peers — A (Enhanced Table)

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

Name h Career Trend Papers Cites
A.J. Speek Netherlands 13 338 222 180 163 98 16 975
G. Khoschsorur Austria 19 287 0.8× 229 1.0× 213 1.2× 119 0.7× 67 0.7× 44 1.3k
William N. Pearson United States 17 441 1.3× 164 0.7× 214 1.2× 60 0.4× 51 0.5× 48 1.1k
Denis Blache France 21 304 0.9× 232 1.0× 453 2.5× 124 0.8× 77 0.8× 35 1.8k
Serge Renaud France 18 290 0.9× 237 1.1× 165 0.9× 40 0.2× 57 0.6× 36 1.4k
O Zaharia Romania 9 328 1.0× 199 0.9× 255 1.4× 30 0.2× 58 0.6× 17 1.2k
J. J. Strain United Kingdom 21 687 2.0× 101 0.5× 187 1.0× 94 0.6× 54 0.6× 40 1.5k
Meira Fields United States 19 604 1.8× 68 0.3× 134 0.7× 163 1.0× 53 0.5× 78 1.2k
C Manso Portugal 19 119 0.4× 97 0.4× 325 1.8× 36 0.2× 60 0.6× 53 1.1k
Joachim Ziegenhorn United States 13 197 0.6× 102 0.5× 358 2.0× 30 0.2× 70 0.7× 22 1.5k
Omer Pelletier Canada 16 255 0.8× 67 0.3× 95 0.5× 94 0.6× 30 0.3× 42 723

Countries citing papers authored by A.J. Speek

Since Specialization
Citations

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

Fields of papers citing papers by A.J. Speek

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by A.J. Speek. 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 A.J. Speek. The network helps show where A.J. Speek may publish in the future.

Co-authorship network of co-authors of A.J. Speek

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

All Works

16 of 16 papers shown
1.
Bloem, Martin W., et al.. (1990). Vitamin A intervention: short-term effects of a single, oral, massive dose on iron metabolism. American Journal of Clinical Nutrition. 51(1). 76–79. 115 indexed citations
2.
Bloem, Martin W., Michel Wedel, A.J. Speek, et al.. (1989). Iron metabolism and vitamin A deficiency in children in northeast Thailand. American Journal of Clinical Nutrition. 50(2). 332–338. 126 indexed citations
3.
Lindeman, J., Diny van Zoeren‐Grobben, J. Schrijver, et al.. (1989). The Total Free Radical Trapping Ability of Cord Blood Plasma in Preterm and Term Babies. Pediatric Research. 26(1). 20–24. 142 indexed citations
4.
Speek, A.J., et al.. (1986). Urinary Excretion of 3-Methylhistidine and Creatinine by Healthy Dutch Children During Day and Night. The Influence of Age and Sex. Clinical Chemistry and Laboratory Medicine (CCLM). 24(7). 465–70. 9 indexed citations
5.
6.
Schrijver, J., et al.. (1986). Persistent low plasma vitamin E levels in premature infants surviving respiratory distress syndrome. European Journal of Pediatrics. 145(3). 170–171. 15 indexed citations
7.
Speek, A.J., et al.. (1986). Microdetermination of vitamin A in human plasma using high-performance liquid chromatography with fluorescence detection. Journal of Chromatography B Biomedical Sciences and Applications. 382. 284–289. 13 indexed citations
8.
Speek, A.J., J. Schrijver, & W.H.P. Schreurs. (1985). Vitamin E Composition of Some Seed Oils as Determined by High‐Performance Liquid Chromatography with Fluorometric Detection. Journal of Food Science. 50(1). 121–124. 136 indexed citations
9.
Speek, A.J., J. Schrijver, & W.H.P. Schreurs. (1984). Fluorimetric determination of menadione sodium bisulphite (vitamin K3) in animal feed and premixes by high-performance liquid chromatography with post-column derivatization. Journal of Chromatography A. 301(2). 441–447. 31 indexed citations
10.
Speek, A.J., J. Schrijver, & W.H.P. Schreurs. (1984). Fluorometric determination of total vitamin C in whole blood by high-performance liquid chromatography with pre-column derivatization. Journal of Chromatography B Biomedical Sciences and Applications. 305(1). 53–60. 154 indexed citations
11.
Speek, A.J., J. Odink, J. Schrijver, & W.H.P. Schreurs. (1983). High-performance liquid chromatographic determination of urinary free catecholamines with electrochemical detection after prepurification on immobilized boric acid. Clinica Chimica Acta. 128(1). 103–113. 30 indexed citations
12.
Speek, A.J., et al.. (1982). けい光検出を行う高性能液体クロマトグラフィーによる全血中のB 2 ビタマ フラビン-アデニンジヌクレオチドの定量. Journal of Chromatography A. 228. 311–316. 27 indexed citations
13.
Speek, A.J., F van Schaik, J. Schrijver, & W.H.P. Schreurs. (1982). Determination of the B2 vitamer flavin—adenine dinucleotide in whole blood by high-performance liquid chromatography with fluorometric detection. Journal of Chromatography B Biomedical Sciences and Applications. 228. 311–316. 39 indexed citations
14.
Feron, V.J., Coenraad Hendriksen, A.J. Speek, H.P. Til, & B.J. Spit. (1981). Lifespan oral toxicity study of vinyl chloride in rats. Food and Cosmetics Toxicology. 19(3). 317–333. 50 indexed citations
15.
Feron, V.J., et al.. (1975). Observations on the oral administration and toxicity of vinyl chloride in rats. Food and Cosmetics Toxicology. 13(6). 633–638. 10 indexed citations
16.
Leegwater, D. C. & A.J. Speek. (1972). Study on the Faecal Metabolites of Hydroxypropyl Starch in the Rat. Starch - Stärke. 24(11). 373–374. 8 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.

Explore authors with similar magnitude of impact

Breakdown of academic impact, for papers by G. Khoschsorur Breakdown of academic impact, for papers by William N. Pearson Breakdown of academic impact, for papers by Denis Blache Breakdown of academic impact, for papers by Serge Renaud Breakdown of academic impact, for papers by O Zaharia Breakdown of academic impact, for papers by J. J. Strain Breakdown of academic impact, for papers by Meira Fields Breakdown of academic impact, for papers by C Manso Breakdown of academic impact, for papers by Joachim Ziegenhorn Breakdown of academic impact, for papers by Omer Pelletier
Rankless by CCL
2026