John Edwar Diaz

Dr. John Edwar Diaz

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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28 January 2020 in Water
Verified
Journal Article
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LLLorena Lugo
Lorena Lugo
AMAlison Martín
Alison Martín
JDJohn Edwar Diaz
John Edwar Diaz
APAlejandro Pérez
Alejandro Pérez
CCCrispin Celis
Crispin Celis
The modified tannin by Mannich reaction was investigated for wastewater treatment. The removal of heavy metals, such as copper, chromium and mercury, in industrial wastewater was evaluated through the coagulation–flocculation technique, using modified Acacia tannin (MAT) as a coagulant agent. The successful tannin modification was evaluated by infrared spectopometry (FTIR), nuclear magnetic resonance (NMR); monitoring the removal of heavy metals was performed by atomic absorption (AA) and a direct mercury analyzer (DMA). Additionally, the parameters of water quality, total suspended solids (TSS), turbidity and chemical oxygen demand (COD) were assessed. Different doses of MAT were evaluated (375 ppm, 750 ppm, 1250 ppm and 1625 ppm) and three different levels of pH (4, 7 and 10). The highest percentages of removal obtained were copper 60%, chromium 87%, mercury 50%–80%, COD 88%, TSS 86% and turbidity 94%, which were achieved with the dose of 375 ppm of MAT at pH 10. The coagulation–flocculation process with the modified Acacia tannin is efficient for the removal of conventional parameters and for a significant removal of the metals studied.


7 June 2018 in Molecular Neurobiology
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Journal Article
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JJJuan Camilo Jurado-Coronel
Juan Camilo Jurado-Coronel
ALAlix E. Loaiza
Alix E. Loaiza
JDJohn Edwar Diaz
John Edwar Diaz
RCRicardo Cabezas
Ricardo Cabezas
Ghulam M. AshrafGhulam M. Ashraf
Ghulam M. Ashraf
GBGeorge E. Barreto
George E. Barreto

20 December 2021 in Metabolites
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Journal Article
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NPNINNA FERNANDA PULIDO-OCHOA
NINNA FERNANDA PULIDO-OCHOA
JGJohana Guevara
Johana Guevara
ARAlexander Rodriguez-Lopez
Alexander Rodriguez-Lopez
ÁPÁlvaro Pulido
Álvaro Pulido
JDJohn Edwar Diaz
John Edwar Diaz
OEOlga Echeverri
Olga Echeverri
The utility of low-resolution 1H-NMR analysis for the identification of biomarkers provided evidence for rapid biochemical diagnoses of organic acidemia and aminoacidopathy. 1H-NMR, with a sensitivity expected for a field strength of 400 MHz at 64 scans was used to establish the metabolomic urine sample profiles of an infant population diagnosed with small molecule Inborn Errors of Metabolism (smIEM) compared to unaffected individuals. A qualitative differentiation of the 1H-NMR spectral profiles of urine samples obtained from individuals affected by different organic acidemias and aminoacidopathies was achieved in combination with GC–MS. The smIEM disorders investigated in this study included phenylalanine metabolism; isovaleric, propionic, 3-methylglutaconicm and glutaric type I acidemia; and deficiencies in medium chain acyl-coenzyme and holocarboxylase synthase. The observed metabolites were comparable and similar to those reported in the literature, as well as to those detected with higher-resolution NMR. In this study, diagnostic marker metabolites were identified for the smIEM disorders. In some cases, changes in metabolite profiles differentiated post-treatments and follow-ups while allowing for the establishment of different clinical states of a biochemical disorder. In addition, for the first time, a 1H-NMR-based biomarker profile was established for holocarboxylase synthase deficiency spectrum.

1 January 2017 in Journal of the Brazilian Chemical Society
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Journal Article
Open access
JDJohn Edwar Diaz
John Edwar Diaz
DMDiana Martinez
Diana Martinez
LLLina López
Lina López
GMGina Mendez
Gina Mendez
RVRicardo Vera
Ricardo Vera
ALAlix E. Loaiza
Alix E. Loaiza

2 February 2017 in Neotropical Entomology
Verified
Journal Article
Closed access
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AAA Amarillo-Suárez
A Amarillo-Suárez
ARA Repizo
A Repizo
JRJ Robles
J Robles
JDJohn Edwar Diaz
John Edwar Diaz
SBS Bustamante
S Bustamante