Publications by authors named "Maria Conceicao B S M Montenegro"

Article Synopsis
  • The study explores the modification of polysulfone (PSU) hemodialysis membranes with bioactive compounds to improve the management of chronic kidney disease (CKD).
  • Two synthesized inhibitors (D4L-1 and D4L-2) and a commercial inhibitor (Sivelestat) were tested for their ability to inhibit human neutrophil elastase (HNE).
  • Results showed that the modified membranes were both bioactive and hemocompatible, with D4L-1 demonstrating the strongest inhibitory effect, suggesting improvements over traditional methods for CKD treatment.
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Cow's milk is currently the most consumed product worldwide. However, due to various direct and indirect contamination sources, different chemical and microbiological contaminants have been found in cow's milk. This review details the main contaminants found in cow's milk, referring to the sources of contamination and their impact on human health.

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End-stage renal disease is a growing health problem with increasing prevalence and high health care costs. Patients suffering from end-stage renal disease exhibit higher morbidity and mortality rates compared to the general population. These patients, who are treated using hemodialysis, typically suffer from anemia, inflammation, and oxidative stress.

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In this paper two fast and highly sensitive ultra-high performance liquid chromatography (UHPLC) methods for the determination of tetracycline antibiotics (oxytetracycline, tetracycline, doxycycline, demeclocycline, chlortetracycline, minocycline and degradation product epitetracycline) in surface waters have been developed using fluorescence (FL) and mass spectrometry (MS) detection. ACQUITY UPLC BEH C8 and ACQUITY CSH C18 columns were employed for FL and MS detection, respectively, both packed with 1.7μm particles.

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The porous monolithic columns show high performance at relatively low pressure. The coupling of short monoliths with sequential injection technique (SIA) results in a new approach to implementation of separation step to non-separation low-pressure method. In this contribution, a new separation method for simultaneous determination of ambroxol, methylparaben and benzoic acid was developed based on a novel reversed-phase sequential injection chromatography (SIC) technique with UV detection.

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Two quasi-independent methods for potentiometric and optical determination of chloride were simultaneously implemented in a flow system, providing real-time assessment of the quality of results. A potentiometric and an optical polymeric membrane doped with the same indium(III) octaethyl-porphyrin were used as sensor ionophore. The working mechanism and the analytical characteristics of these porphyrin-based sensors with respect to dynamic range, selectivity, repeatability and lifetime are discussed.

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In the proposed procedure, the determination of bopindolol using a flow injection analysis (FIA) technique, with spectrophotometric detection at 635 nm, is described. The method is based on the production of a green, water-soluble complex with ferric ions in acid medium. The automated lab-made FIA system was used for the direct determination of bopindolol in tablets.

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The amperometric determination of dopamine (Do) in pharmaceuticals formulations by flow injection analysis (FIA) is proposed. An enzymatically modified carbon paste electrode constituted by 25% (w/w) of polyphenol oxidase obtained from Annona muricata L. tissue, 30% (w/w) of graphite, 30% (w/w) of silicone and 15% (w/w) of 7,7,8,8 tetracyanoquinodimethane (TCNQ), was used as flow-through detector.

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This work describes an FIA potentiometric procedure for the quantification of dipyrone in pharmaceutical products. For the detector, a tubular electrode comprising a polymeric membrane containing tetraoctylammonium as an electroactive material (5% w/w), dibutylphtalate as a mediator solvent (65% w/w) and PVC (30% w/w) directly applied above a graphite conductor support was used. This unit was incorporated into a monochannel FI-system with a 0.

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Two almost independent potentiometric methods were implemented in a multi-task flow system based on the concept of sequential injection analysis for the analytical control of potassium clavulanate in pharmaceutical formulations. In addition to in-line preparation of the solutions submitted to the analysis, the system simultaneously detected the clavulanate anion and the potassium cation using two potentiometric detectors selective to each of the species referred. For the two determinations, the system developed presented an analytical range of 2 mM-0.

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