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1.
Chem Sci ; 13(45): 13409-13417, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36507186

RESUMO

Electrocatalytic conversion of formic acid oxidation to CO2 and the related CO2 reduction to formic acid represent a potential closed carbon-loop based on renewable energy. However, formic acid fuel cells are inhibited by the formation of site-blocking species during the formic acid oxidation reaction. Recent studies have elucidated how the binding of carbon and hydrogen on catalyst surfaces promote CO2 reduction towards CO and formic acid. This has also given fundamental insights into the reverse reaction, i.e. the oxidation of formic acid. In this work, simulations on multiple materials have been combined with formic acid oxidation experiments on electrocatalysts to shed light on the reaction and the accompanying catalytic limitations. We correlate data on different catalysts to show that (i) formate, which is the proposed formic acid oxidation intermediate, has similar binding energetics on Pt, Pd and Ag, while Ag does not work as a catalyst, and (ii) *H adsorbed on the surface results in *CO formation and poisoning through a chemical disproportionation step. Using these results, the fundamental limitations can be revealed and progress our understanding of the mechanism of the formic acid oxidation reaction.

2.
Anal Chim Acta ; 1186: 339121, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34756269

RESUMO

This work addresses the electrocatalytic activity of a binary metal oxide catalyst of NiMn2O4 for electroxidation of sarcosine, the well-known prostate cancer biomarker. The nanocatalyst described was prepared via hydrothermal synthesis route, followed by calcination at 800 °C. Field emission scanning electron microscopy and X-ray diffraction were applied to obtain information about the material morphology and structure. A carbon paste electrode modified with nano-NiMn2O4 showed unique catalytic activity in sarcosine electroxidation which led to a significant rise in oxidation current (about four times) in comparison with the blank electrode. However, the carbon paste electrodes containing single oxides of NiO and Mn2O3 exhibited no considerable enhancement in sarcosine signal. The cyclic voltammetry results indicated that the Mn3+/Mn4+ couple was responsible for sarcosine oxidation, and NiO may enhance the content of Mn4+species in NiMn2O4 material. The carbon paste-based NiMn2O4 electrode was applied in the sensitive determination of sarcosine in the concentration range of 0.01-5.0 µM with the relative standard deviation of 3.49% (n = 5). The detection limit and quantification limit of the probe were determined to be 3.8 and 12 nM, respectively. The remarkable sensitivity and high selectivity of the method approved the sensor applicability in measurement of sarcosine content in urine samples.


Assuntos
Carbono , Neoplasias , Biomarcadores Tumorais , Eletrodos , Humanos , Masculino , Próstata , Sarcosina
3.
J Res Pharm Pract ; 8(4): 202-207, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31956633

RESUMO

OBJECTIVE: Increased risk of infection following hyperglycemia has been reported in hospitalized patients. Sliding-scale insulin protocol is an out-of-date method; therefore, it is necessary to examine new approaches in this regard. This study aimed to evaluate the efficacy of sliding-scale protocol versus basal-bolus insulin protocol, which supervised by clinical pharmacists in an infectious disease ward. METHODS: In this prospective randomized clinical trial, 90 hyperglycemic patients who hospitalized in Loghman Hakim Hospital Infectious Disease Ward (Tehran, Iran) were randomized into two groups: sliding-scale insulin protocol (the control group) and the basal-bolus protocol groups that were under supervision clinical pharmacists. Some demographic, laboratory, and clinical variables, as well as patient's blood glucose were measured four times daily. FINDINGS: The results indicated significant improvement among the patients in the intervention group. General indicators including fever, blood glucose level, the duration of hospitalization, incidence of hypoglycemia, days to achieve normal blood glucose, and leukocyte count improved in intervention group. CONCLUSION: According to this study, basal-bolus insulin protocol, which supervised by clinical pharmacy service, showed better blood glucose control and infection remission compared to the sliding-scale protocol.

4.
Eur J Med Chem ; 114: 14-23, 2016 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-26974371

RESUMO

A new series of 2-aryl-trimethoxyquinoline analogues was designed and synthesized as tubulin inhibitors using methoxylated flavones as the lead compounds. The cytotoxic activity of the synthesized compounds was evaluated against four human cancer cell lines including MCF-7, MCF-7/MX, A-2780, and A-2780/RCIS. All the alcoholic derivatives (6a-6e) showed significant cytotoxic activity with IC50 in the range of 7.98-60 µM. The flow cytometry analysis of the four human cancer cell lines treated with 6e and 5b showed that 6e induced cell cycle arrest at G2/M phase and apoptosis as well. The effect of quinolines on tubulin polymerization was also evaluated. Compound 6e that demonstrated the best antiproliferative activity in the series was identified as the most potent inhibitor of tubulin polymerization as well. Molecular docking studies of 6e into the colchicine-binding site of tubulin displayed possible mode of interaction between this compound and tubulin.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Flavonas/farmacologia , Quinolinas/farmacologia , Moduladores de Tubulina/farmacologia , Tubulina (Proteína)/metabolismo , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Flavonas/química , Humanos , Modelos Moleculares , Estrutura Molecular , Polimerização/efeitos dos fármacos , Quinolinas/síntese química , Quinolinas/química , Relação Estrutura-Atividade , Moduladores de Tubulina/síntese química , Moduladores de Tubulina/química , Células Tumorais Cultivadas
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