John J. Usher

440 total citations
20 papers, 351 citations indexed

About

John J. Usher is a scholar working on Pharmacology, Molecular Biology and Organic Chemistry. According to data from OpenAlex, John J. Usher has authored 20 papers receiving a total of 351 indexed citations (citations by other indexed papers that have themselves been cited), including 14 papers in Pharmacology, 9 papers in Molecular Biology and 8 papers in Organic Chemistry. Recurrent topics in John J. Usher's work include Microbial Natural Products and Biosynthesis (10 papers), Antibiotic Resistance in Bacteria (5 papers) and Antimicrobial Resistance in Staphylococcus (4 papers). John J. Usher is often cited by papers focused on Microbial Natural Products and Biosynthesis (10 papers), Antibiotic Resistance in Bacteria (5 papers) and Antimicrobial Resistance in Staphylococcus (4 papers). John J. Usher collaborates with scholars based in United States, United Kingdom and Germany. John J. Usher's co-authors include E. P. Abraham, Jack E. Baldwin, Joyce A. Huddleston, Edward P. Abraham, Robert L. White, Robert M. Adlington, Gulam Bahadur, Gamini S. Jayatilake, Leslie D. Field and Mankil Jung and has published in prestigious journals such as Journal of the American Chemical Society, Applied and Environmental Microbiology and Analytical Biochemistry.

In The Last Decade

John J. Usher

19 papers receiving 330 citations

Peers — A (Enhanced Table)

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

Name h Career Trend Papers Cites
John J. Usher United States 12 208 138 85 60 45 20 351
Joel G. Whitney United States 9 198 1.0× 173 1.3× 194 2.3× 62 1.0× 22 0.5× 15 425
Hong-Hoi Ting United Kingdom 13 216 1.0× 124 0.9× 103 1.2× 56 0.9× 82 1.8× 29 343
J. A. Mabe United States 13 300 1.4× 204 1.5× 140 1.6× 31 0.5× 30 0.7× 25 534
Olga Z. Sarre United States 12 259 1.2× 188 1.4× 196 2.3× 27 0.5× 17 0.4× 31 444
Norio Ezaki United Kingdom 15 212 1.0× 247 1.8× 218 2.6× 37 0.6× 16 0.4× 25 503
Yoshikazu Wada Japan 12 173 0.8× 105 0.8× 176 2.1× 17 0.3× 9 0.2× 28 380
Ross R. Herr United States 11 234 1.1× 110 0.8× 204 2.4× 15 0.3× 27 0.6× 18 478
Jack Tadanier United Kingdom 11 234 1.1× 120 0.9× 245 2.9× 32 0.5× 20 0.4× 41 415
John T. Sime United States 12 173 0.8× 72 0.5× 86 1.0× 9 0.1× 43 1.0× 24 321
Hermann Führer Switzerland 14 207 1.0× 145 1.1× 232 2.7× 15 0.3× 19 0.4× 29 430

Countries citing papers authored by John J. Usher

Since Specialization
Citations

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

Fields of papers citing papers by John J. Usher

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

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

Co-authorship network of co-authors of John J. Usher

This figure shows the co-authorship network connecting the top 25 collaborators of John J. Usher. A scholar is included among the top collaborators of John J. Usher 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 John J. Usher. John J. Usher 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.
Burnett, William, et al.. (1997). Purification and characterization of a cephalosporin esterase from Rhodosporidium toruloides. Applied and Environmental Microbiology. 63(12). 4807–4811. 21 indexed citations
2.
Brown, Joanne R., et al.. (1996). Purification and Characterization of an Extracellular Alkaline Phosphatase fromPenicillium Chrysogenum. Preparative Biochemistry & Biotechnology. 26(3-4). 171–181. 12 indexed citations
3.
Usher, John J., et al.. (1992). Determination of the rate-limiting step(s) in the biosynthetic pathways leading to penicillin and cephalosporin. Journal of Industrial Microbiology & Biotechnology. 10(3-4). 157–163. 8 indexed citations
4.
Usher, John J., et al.. (1988). Development of the cephalosporin C fermentation taking into account the instability of cephalosporin C. Biotechnology Letters. 10(8). 543–548. 9 indexed citations
5.
Usher, John J., et al.. (1985). Determination by high-performance liquid chromatography of some compounds involved in the biosynthesis of penicillin and cephalosporin. Analytical Biochemistry. 149(1). 105–110. 23 indexed citations
6.
Baldwin, Jack E., Edward P. Abraham, Robert M. Adlington, et al.. (1984). Penicillin biosynthesis: active site mapping with aminoadipoylcysteinylvaline variants. Journal of the Chemical Society Chemical Communications. 1225–1227. 18 indexed citations
7.
8.
Baldwin, Jack E., Edward P. Abraham, Robert M. Adlington, et al.. (1983). Penicillin biosynthesis. On the stereochemistry of carbon–sulphur bond formation with modified substrates. Journal of the Chemical Society Chemical Communications. 0(22). 1319–1320. 13 indexed citations
9.
Adlington, Robert M., Jack E. Baldwin, Bulbul Chakravarti, et al.. (1983). Conversion of 3-exomethylene cephalosporin C into deacetyl cephalosporin C in a cell-free extract from Cephalosporium acremonium(CW-19). Journal of the Chemical Society Chemical Communications. 153–153. 2 indexed citations
10.
Baldwin, Jack E., Edward P. Abraham, Robert M. Adlington, et al.. (1983). Penicillin biosynthesis. Dual pathways from a modified substrate. Journal of the Chemical Society Chemical Communications. 1317–1317. 21 indexed citations
11.
Bahadur, Gulam, Jack E. Baldwin, John J. Usher, et al.. (1981). Cell-free biosynthesis of penicillins. Conversion of peptides into new .beta.-lactam antibiotics. Journal of the American Chemical Society. 103(25). 7650–7651. 29 indexed citations
12.
Baldwin, Jack E., Mankil Jung, John J. Usher, et al.. (1981). Penicillin biosynthesis: conversion of deuteriated (L-α-amino-δ-adipyl)-L-cysteinyl-D-valine into isopenicillin N by a cell-free extract of Cephalosporium acremonium. Journal of the Chemical Society Chemical Communications. 246–247. 5 indexed citations
13.
Bahadur, Gulam, Jack E. Baldwin, Leslie D. Field, et al.. (1981). Direct1H n.m.r. observation of the cell-free conversion of δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine and δ-(L-α-aminoadipyl)-L-cysteinyl-D-(–)-isoleucine into penicillins. Journal of the Chemical Society Chemical Communications. 917–919. 10 indexed citations
14.
Baldwin, Jack E., et al.. (1981). On the possible role of the 3-methylene isomer of deacetoxycephalosporin C in the biosynthesis of cephalosporins. Journal of the Chemical Society Chemical Communications. 934–934. 1 indexed citations
15.
Baldwin, Jack E., et al.. (1981). Synthesis of δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valine and some carbon-13 and nitrogen-15 labelled isotopomers. Journal of the Chemical Society Perkin Transactions 1. 2253–2257. 26 indexed citations
16.
Baldwin, Jack E., et al.. (1980). Direct n.m.r. observation of cell-free conversion of (L-α-amino-δ-adipyl)-L-cysteinyl-D-valine into isopenicillin N. Journal of the Chemical Society Chemical Communications. 1271–1273. 14 indexed citations
17.
Usher, John J. & Robin B. English. (1978). Structure of the racemic pair of lactones of (2S,3S)-4-hydroxyvaline and its optical isomer (as their hydrochlorides). Acta Crystallographica Section B. 34(6). 2012–2014.
18.
Usher, John J., et al.. (1976). Synthesis of δ-(α-aminoadipyl)cysteinylvaline and its role in penicillin biosynthesis. Biochemical Journal. 157(3). 651–660. 68 indexed citations
19.
20.
Usher, John J., et al.. (1975). Synthesis of tritium-labelled isopenicillin N, penicillin N and 6-aminopenicillanic acid. Biochemical Journal. 151(3). 729–739. 23 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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