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1.
J Hazard Mater ; 421: 126805, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34388929

RESUMO

Superoxide radicals (O2•-) produced by the reaction of Fe(III) with H2O2 can regenerate Fe(II) in Fenton-like reactions, and conditions that facilitate this function enhance Fenton treatment. Here, we developed an efficient Fenton-like system by using calcium peroxide/biochar (CaO2/BC) composites as oxidants and tartaric acid-chelated Fe(III) as catalysts, and tested it for enhanced O2•--based Fe(II) regeneration and faster sulfamethoxazole (SMX) degradation. SMX degradation rates and peroxide utilization efficiencies were significantly higher with CaO2/BC than those with CaO2 or H2O2 lacking BC. The CaO2/BC system showed superior activity to reduce Fe(III), while kinetic analyses using chloroform as a O2•- probe inferred that the O2•- generation rate by CaO2/BC was one-half of that by CaO2. Apparently, O2•- is utilized more efficiently in this system to regenerate Fe(II) and enhance SMX degradation. Additionally, a positive correlation between SMX degradation rate constants and EPR signal intensities of biochar-derived persistent free radicals (PFRs) in CaO2/BC was obtained. We postulate that PFRs enhanced Fe(III) reduction by shuttling electrons donated by O2•-. This represents a new strategy to augment the ability of superoxide to accelerate Fe(III)/Fe(II) cycling for increased hydroxyl radical production and organic pollutant removal in Fenton-like reactions.


Assuntos
Compostos Férricos , Superóxidos , Carvão Vegetal , Compostos Ferrosos , Peróxido de Hidrogênio , Oxirredução
2.
J Hazard Mater ; 421: 126806, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34388930

RESUMO

Under anoxic conditions, aqueous Fe(II) (Fe(II)aq)-induced recrystallization of iron (oxyhydr)oxides changes the speciation and geochemical cycle of trace elements in environments. Oxidation of trace element, i.e., As(III), driven by Fe(II)aq-iron (oxyhydr)oxides interactions under anoxic condition was observed previously, but the oxidative species and involved mechanisms are remained unknown. In the present study, we explored the formed oxidative intermediates during Fe(II)aq-induced recrystallization of goethite under anoxic conditions. The methyl phenyl sulfoxide-based probe experiment suggested the featured oxidation by Fe(IV) species in Fe(II)aq-goethite system. Both the Mössbauer spectra and X-ray absorption near edge structure spectroscopic evidenced the generation and quenching of Fe(IV) intermediate. It was proved that the interfacial electron exchange between Fe(II)aq and Fe(III) of goethite initiated the generation of Fe(IV). After transferring electrons to goethite, Fe(II)aq was transformed to labile Fe(III), which was then transformed to Fe(IV) via a proton-coupled electron transfer process. This highly reactive transient Fe(IV) could quickly react with reductive species, i.e. Fe(II) or As(III). Considering the ubiquitous occurrence of Fe(II)-iron (oxyhydr)oxides reactions under anoxic conditions, our findings are expected to provide new insight into the anoxic oxidative transformation processes of matters in non-surface environments on earth.


Assuntos
Compostos Férricos , Compostos de Ferro , Compostos Ferrosos , Minerais , Oxirredução
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 265: 120380, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34562863

RESUMO

The pressing need to develop a specific analytical sensor that can identify and quantify Fe(II) without a cytotoxic response was the major motivation drive in this work. The turn-on fluorescent sensor here described can successfully detect Fe(II) and discriminate this ion from other analytes that commonly act as interferents in biological media. Moreover, this reduced fluoresceinamine-based sensor has a high photostability and high dissociation constant, which is an indication that the complex obtained between reduced fluoresceinamine (RFL) and Fe(II) is highly stable. This fluorescence-based sensor has a binding mechanism of 1:1 and a positive cooperativity was found between analyte and sensor. The detection, quantification and sensitivity parameters of the sensor were determined: 21.6 ± 0.1 µM; 65.6 ± 0.1 µM and 48 ± 3 (×107) µM, respectively. To evaluate a possible cytotoxicity effect an erythrocyte assay was performed and the obtained data were evaluated considering CdTe Quantum Dots (QDs) passivated with mercaptoacetic acid has experimental control. According to the resulting data RFL is not cytotoxic even when used in high concentrations, 660 mM. On the other hand QDs are quite different. Indeed it was proven that these heavy metal-based nanoparticles are responsible for 40% erytrocytes hemolysis in concentrations of 600 mM.


Assuntos
Compostos de Cádmio , Pontos Quânticos , Compostos Ferrosos , Corantes Fluorescentes , Ferro , Pontos Quânticos/toxicidade , Espectrometria de Fluorescência , Telúrio
4.
FEMS Microbiol Ecol ; 97(11)2021 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-34724047

RESUMO

Autotrophic nitrate reduction coupled to Fe(II) oxidation is an important nitrate removal process in anoxic aquifers. However, it remains unknown how changes of O2 and carbon availability influence the community structure of nitrate-reducing Fe(II)-oxidizing (NRFeOx) microbial assemblages and what the genomic traits of these NRFeOx key players are. We compared three metabolically distinct denitrifying assemblages, supplemented with acetate, acetate/Fe(II) or Fe(II), enriched from an organic-poor, pyrite-rich aquifer. The presence of Fe(II) promoted the growth of denitrifying Burkholderiaceae spp. and an unclassified Gallionellaceae sp. This Gallionellaceae sp. was related to microaerophilic Fe(II) oxidizers; however, it did not grow under microoxic conditions. Furthermore, we explored a metagenome and 15 metagenome-assembled genomes from an aquifer-originating, autotrophic NRFeOx culture. The dominant Gallionellaceae sp. revealed the potential to oxidize Fe(II) (e.g. cyc2), fix CO2 (e.g. rbcL) and perform near-complete denitrification leading to N2O formation (e.g. narGHJI,nirK/S and norBC). In addition, Curvibacter spp.,Methyloversatilis sp. and Thermomonas spp. were identified as novel putative NRFeOx taxa. Our findings provide first insights into the genetic traits of the so far only known autotrophic NRFeOx culture originating from an organic-poor aquifer, providing the genomic basis to study mechanisms of nitrate removal in organic-poor subsurface ecosystems.


Assuntos
Gallionellaceae , Água Subterrânea , Processos Autotróficos , Desnitrificação , Ecossistema , Compostos Ferrosos , Gallionellaceae/genética , Nitratos , Oxirredução
5.
Indian J Med Res ; 154(1): 78-84, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34782532

RESUMO

Background & objectives: Iron-deficiency anaemia (IDA) is a common nutritional deficiency among pregnant women in India. It has a significant impact on the health of the mother as well as that of the foetus. IDA generally responds well to treatment with oral iron supplementation. However, oral iron supplements are toxic to the gastrointestinal mucosa and intolerance is common, resulting in poor compliance and failure of treatment. The iron salts such as iron hydroxide polymaltose complex (IPC) and ferrous ascorbate (FeA) are claimed to have low gastrointestinal intolerance, therefore better patient compliance than the conventionally used ferrous sulphate (FS). These preparations also claim to increase haemoglobin level faster as well as improve the iron storage better than FS. This study was done to compare the efficacy and safety of FS with IPC and FeA. Methods: It was a randomized, parallel, open label, study among pregnant women of gestational age between 12 to 26 wk with moderate anaemia. Patients were randomly allocated to receive either FS, IPC or FeA. They were then followed up for 90 days to observe for improvement in the haemoglobin levels and other haematological parameters or any adverse drug reaction. Results: The haemoglobin levels were comparable in the three groups except at day 90 when FeA group had significantly higher haemoglobin level as compared to FS group (P<0.05). The overall adverse effect profiles were also comparable among the study groups except epigastric pain which was more commonly reported in the FS group. Interpretation & conclusions: The results of the study showed that FS, IPC and FeA have comparable efficacy and safety profile in the treatment of IDA of pregnancy.


Assuntos
Anemia Ferropriva , Adolescente , Adulto , Anemia Ferropriva/tratamento farmacológico , Ácido Ascórbico/efeitos adversos , Criança , Feminino , Compostos Férricos , Compostos Ferrosos , Humanos , Gravidez , Gestantes , Adulto Jovem
6.
Int J Mol Sci ; 22(19)2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34638742

RESUMO

Glioblastoma (GBM) is the most frequent and deadliest primary brain cancer in adults, justifying the search for new treatments. Some members of the iron-based ferrocifen family have demonstrated a high cytotoxic effect on various cancer cell lines via innovative mechanisms of action. Here, we evaluated the antiproliferative activity by wst-1 assay of six ferrocifens in 15 molecularly diverse GBM patient-derived cell lines (PDCLs). In five out of six compounds, the half maximal inhibitory concentration (IC50) values varied significantly (10 nM < IC50 < 29.8 µM) while the remaining one (the tamoxifen-like complex) was highly cytotoxic against all PDCLs (mean IC50 = 1.28 µM). The pattern of response was comparable for the four ferrocifens bearing at least one phenol group and differed widely from those of the tamoxifen-like complex and the complex with no phenol group. An RNA sequencing differential analysis showed that response to the diphenol ferrocifen relied on the activation of the Death Receptor signaling pathway and the modulation of FAS expression. Response to this complex was greater in PDCLs from the Mesenchymal or Proneural transcriptomic subtypes compared to the ones from the Classical subtype. These results provide new information on the mechanisms of action of ferrocifens and highlight a broader diversity of behavior than previously suspected among members of this family. They also support the case for a molecular-based personalized approach to future use of ferrocifens in the treatment of GBM.


Assuntos
Biomarcadores Tumorais/biossíntese , Compostos Ferrosos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma , Tamoxifeno/farmacologia , Transcriptoma/efeitos dos fármacos , Linhagem Celular Tumoral , Glioblastoma/tratamento farmacológico , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Relação Estrutura-Atividade
7.
Water Res ; 206: 117731, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34626885

RESUMO

Biogenic ferrous sulfide nanoparticles (bio-FeS) as low-cost and green-synthesized nanomaterial are promising for heavy metals removal, but the need for complicated extraction, storage processes and the production of iron sludge still restrict their practical application. Here, a self-regenerable bio-hybrid consisting of bacterial cells and self-assembled bio-FeS was developed to efficiently remove chromium (Cr(VI)). A dense layer of bio-FeS was distributed on the cell surface and in the periplasmic space of Shewanella oneidensis MR-1, endowing the bacterium with good Cr(VI) tolerance and unusual activity for bio-FeS-mediated Cr(VI) reduction. An artificial transmembrane electron channel was constituted by the bio-FeS to facilitate extracellular electron pumping, enabling efficient regeneration of extracellular bio-FeS for continuous Cr(VI) reduction. The bio-hybrid maintained high activity within three consecutive treatment-regeneration cycles for treating both simulated Cr(VI)-containing wastewater (50 mg/L) and real electroplating wastewater. Importantly, its activity can be facilely and fully restored through bio-FeS re-synthesis or regeneration with replenished fresh bacteria. Overall, the bio-hybrid merges the self-regeneration ability of bacteria with high activity of bio-FeS , opening a promising new avenue for sustainable treatment of heavy metal- containing wastewater.


Assuntos
Cromo , Nanopartículas , Cromo/análise , Compostos Ferrosos , Shewanella , Águas Residuárias
8.
Isr Med Assoc J ; 23(10): 662-664, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34672450

RESUMO

BACKGROUND: Iron deficiency anemia is a widespread problem. Although oral and intravenous therapy are available, iron malabsorption is a distinct possibility. OBJECTIVES: To evaluate the applicability of the oral iron absorption test (OIAT) as a simple and effective means of determining the degree of oral iron absorption. METHODS: The study comprised 81 patients diagnosed with iron deficiency anemia who were referred to a hematology outpatient clinic. Participants were given two ferrous sulphate tablets. Iron levels in the blood were evaluated at intervals from 30 to 180 minutes after iron administration. RESULTS: We divided patients into three distinct groups. The first group consisted of patients with little iron absorption with a maximum iron increment (Cmax) in the blood of 0-49 ug/dl. The second group had a moderate maximum absorption of 50-100 ug/dl, while a third group had considerable absorption of with maximum iron increase of over 100 ug/dl. CONCLUSIONS: The oral iron absorption test, although not clearly standardized, is easy to conduct in any outpatient clinic. This test can readily and clearly determine absorption or nonabsorption of iron. This test can have major implications on the need of oral or intravenous iron therapy and can also determine the need for further gastrointestinal evaluation of the small intestine, where iron absorption takes place and the success of therapy on subsequent iron absorption.


Assuntos
Administração Oral , Anemia Ferropriva , Monitoramento de Medicamentos/métodos , Compostos Ferrosos , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/fisiopatologia , Disponibilidade Biológica , Feminino , Compostos Ferrosos/administração & dosagem , Compostos Ferrosos/sangue , Absorção Gastrointestinal/fisiologia , Hematínicos/administração & dosagem , Hematínicos/sangue , Humanos , Síndromes de Malabsorção/diagnóstico , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
9.
Water Sci Technol ; 84(6): 1464-1476, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34559080

RESUMO

The effects of thermally and Fe(II) activated potassium persulfate (PPS) on sludge dewatering performance were compared systematically. Sludge dewaterability was monitored by measuring capillary suction time (CST) and sludge specific resistance to filtration (SRF), and the degradation effect was characterized by chemical oxygen demand (COD), total organic carbon (TOC), ammonia nitrogen (NH4+-N) and extracellular polymeric substances (EPS). The change of extracellular polymer substance (EPS) including soluble, loosely bound and tightly bound EPS (S-EPS, LB-EPS and TB-EPS) with time and PPS dosage was monitored to discuss the oxidation efficiency of thermally and Fe(II) activated PPS. Sludge supernatant was analyzed by three-dimensional fluorescence excitation-emission spectra (3D-EEM) to confirm the protein transformation. The result showed that sludge dewaterability in terms of CST and SRF were enhanced with increasing PPS dosage and condition time of two activated methods. While Fe(II) activated PPS could reduce sludge CST and SRF to preferred values at low PPS dosage and short condition time. Meanwhile, sludge degradation effect was also more obvious. Mechanically, sludge TB-EPS in proteins and polysaccharides converted to SB-EPS was faster with Fe(II) activated PPS. In addition, thermally activated PPS tended to oxidize the protein in the supernatant first.


Assuntos
Esgotos , Água , Matriz Extracelular de Substâncias Poliméricas , Compostos Ferrosos , Oxirredução
10.
Analyst ; 146(20): 6187-6192, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34558582

RESUMO

Triacetone triperoxide (TATP) explosives, a popular choice for terrorists, have been used in many violent terrorist attacks all over the world. However, simple, rapid, and on-site detection methods of TATP are still lacking. Herein, we present a visual colorimetric method for on-site and rapid detection of TATP based on a Fe(II)-promoted thermal decomposition process of TATP. We discovered that TATP can be decomposed into H2O2 under heating conditions, and it reacts with Fe2+ to produce hydroxyl radicals (˙OH) and Fe3+via the Fenton reaction. The resulting ˙OH and Fe3+ further oxidize colorless 3,3',5,5'-tetramethylbenzidine (TMB) to a yellow oxidized product (oxTMB). These reaction processes remarkably promote the chemical equilibrium shift and decrease the activation energy. Using the TATP-Fe2+-TMB ternary chromogenic system, the present colorimetric assay for TATP shows a dynamic range of 0.5-30 µM with a low detection limit of 0.12 µM. Additionally, common substances (e.g., inorganic salts, small organic substances, and polymers) do not interfere with TATP detection. This assay can be used for analyzing TATP in real water and camouflage samples. Furthermore, a test-paper-based method was also successfully developed for visual, rapid and on-site detection of TATP.


Assuntos
Colorimetria , Peróxido de Hidrogênio , Compostos Ferrosos , Compostos Heterocíclicos com 1 Anel , Peróxidos
11.
Int J Mol Sci ; 22(18)2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34576090

RESUMO

Iron deficiency is the most common mammalian nutritional disorder. However, among mammalian species iron deficiency anemia (IDA), occurs regularly only in pigs. To cure IDA, piglets are routinely injected with high amounts of iron dextran (FeDex), which can lead to perturbations in iron homeostasis. Here, we evaluate the therapeutic efficacy of non-invasive supplementation with Sucrosomial iron (SI), a highly bioavailable iron supplement preventing IDA in humans and mice and various iron oxide nanoparticles (IONPs). Analysis of red blood cell indices and plasma iron parameters shows that not all iron preparations used in the study efficiently counteracted IDA comparable to FeDex-based supplementation. We found no signs of iron toxicity of any tested iron compounds, as evaluated based on the measurement of several toxicological markers that could indicate the occurrence of oxidative stress or inflammation. Neither SI nor IONPs increased hepcidin expression with alterations in ferroportin (FPN) protein level. Finally, the analysis of the piglet gut microbiota indicates the individual pattern of bacterial diversity across taxonomic levels, independent of the type of supplementation. In light of our results, SI but not IONPs used in the experiment emerges as a promising nutritional iron supplement, with a high potential to correct IDA in piglets.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Suplementos Nutricionais , Compostos Férricos/administração & dosagem , Compostos Férricos/uso terapêutico , Nanopartículas Magnéticas de Óxido de Ferro/administração & dosagem , Nanopartículas Magnéticas de Óxido de Ferro/química , Administração Oral , Anemia Ferropriva/sangue , Animais , Animais Recém-Nascidos , Biomarcadores/metabolismo , Duodeno/metabolismo , Compostos Férricos/farmacologia , Compostos Ferrosos/uso terapêutico , Hepcidinas/sangue , Hepcidinas/genética , Masculino , Microbiota , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Suínos
12.
Environ Sci Technol ; 55(19): 13366-13375, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34551244

RESUMO

Hydroxyl radical (•OH) production by electron transfer from Fe(II)-bearing clay minerals to oxygen has been increasingly reported. However, the influence of ubiquitous coexisting humic acid (HA) on this process is poorly understood. Here, we investigated the effect of different HA on •OH production during the oxygenation of reduced nontronite NAu-2 (rNAu-2), montmorillonite, and sediment. Results showed that HA could enhance •OH production, and the enhancement was related to the content of reactive Fe(II) in rNAu-2 and the electron-accepting capacity of HA. Coexisting HA leads to a new electron-transfer pathway from Fe(II) in rNAu-2 to HA (instead of the HA-Fe complex) and then to O2, changing the first step of O2 reduction from one- to two-electron transfer process with H2O2 as the main intermediate. Reduced HA decomposes H2O2 to •OH at a higher yield (13.8%) than rNAu-2 (8.8%). Modeling results reveal that the HA-mediated electron-transfer pathway contributes to 12.6-70.2% of H2O2 generation and 13.2-62.1% of •OH formation from H2O2 decomposition, with larger contributions at higher HA concentrations (5-100 mg C/L). Our findings implicate that HA-mediated electron transfer can expand the area of •OH production from the mineral surface to the aqueous phase and increase the yield of •OH production.


Assuntos
Substâncias Húmicas , Radical Hidroxila , Argila , Compostos Férricos , Compostos Ferrosos , Substâncias Húmicas/análise , Peróxido de Hidrogênio , Minerais , Oxirredução
13.
J Phys Chem Lett ; 12(37): 9020-9025, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34516127

RESUMO

Ribonucleotide reductase (RNR), which supplies the building blocks for DNA biosynthesis and its repair, has been linked to human diseases and is emerging as a therapeutic target. Here, we present a mechanistic investigation of triapine (3AP), a clinically relevant small molecule that inhibits the tyrosyl radical within the RNR ß2 subunit. Solvent kinetic isotope effects reveal that proton transfer is not rate-limiting for inhibition of Y122· of E. coli RNR ß2 by the pertinent 3AP-Fe(II) adduct. Vibrational spectroscopy further demonstrates that unlike inhibition of the ß2 tyrosyl radical by hydroxyurea, a carboxylate containing proton wire is not at play. Binding measurements reveal a low nanomolar affinity (Kd ∼ 6 nM) of 3AP-Fe(II) for ß2. Taken together, these data should prompt further development of RNR inactivators based on the triapine scaffold for therapeutic applications.


Assuntos
Inibidores Enzimáticos/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli/enzimologia , Compostos Ferrosos/química , Piridinas/química , Ribonucleotídeo Redutases/metabolismo , Tiossemicarbazonas/química , Inibidores Enzimáticos/metabolismo , Proteínas de Escherichia coli/antagonistas & inibidores , Radicais Livres/química , Radicais Livres/metabolismo , Hidroxiureia/química , Ligação Proteica , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Ribonucleotídeo Redutases/antagonistas & inibidores , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Anal Chim Acta ; 1180: 338862, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34538316

RESUMO

Rapid emergence of new strains of drug-resistant H1N1 influenza viruses calls for effective drugs for the controls prior to their outbreaks. In the present work, electrochemical H1N1 RNA beacons have been newly designed for exploring the potentiality of an anticancer agent of Bleomycin (BLM) with Fe (ΙΙ) ions (BLM-Fe(ΙΙ)) alternatively the treatment of drug-resistant H1N1 strains with H274Y gene mutation. Herein, biotinylated (-) ssRNA of H1N1 virus and its complementary (+) ssRNA were labeled with electrochemical signal probes of ferrocene and anthraquinone, respectively. The resultants were hybridized and conjugated with avidin-modified magnetic beads to create electrochemical RNA beacons. The electrochemical signal variation of the H1N1 RNA beacon treated with the RNA degradation agent of BLM-Fe(ΙΙ) were monitored. Results indicate that the BLM-Fe(ΙΙ) agent could effectively cleave both H1N1 dsRNAs and ssRNAs at selective cutting sites, as evidenced by the mass spectrometry analysis. This indicates that the BLM-Fe(II) agent could be utilized to block the viral-host infection process by curbing the host-cell viral RNA-mRNA transcription or inactivate the viruses through the cleavage of viral genomes. The efficiency of the BLM-Fe(ΙΙ) agent was verified with clinical seasonal H1N1 samples using real-time polymerase chain reaction. The therapeutic gene drug of BLM-Fe(ΙΙ) holds great potential for controlling new strains of H1N1 virus resistant to clinical antiviral drugs. More importantly, the so designed RNA beacons may provide a rapid, sensitive and cost-effective platform of drug screening by monitoring the drug-DNA/RNA interactions.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Preparações Farmacêuticas , Bleomicina , Farmacorresistência Viral/genética , Compostos Ferrosos , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Neuraminidase , Oseltamivir , RNA Viral/genética
15.
J Hazard Mater ; 416: 126262, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492997

RESUMO

Cadmium (Cd) and tetracycline (TC) cause serious environmental risks. Nanomaterials have been extensively applied for environmental remediation. The size and content of nanoparticles directly affect the removal of contaminants. However, size regulation and quantitative determination of nanoparticles cannot be easily realized. In this study, hydrogels with different polymerization degrees were prepared by adjusting the contents of acrylamide (AM) and sodium lignosulfonate polymeric monomers. Ferrous sulfide (FeS) nanoparticles of different sizes were synthesized in situ within the hydrogels. The nanoparticle size decreased from 600 to 200 nm with increasing hydrogel polymerization degree, and an incomplete crystalline state was observed at the highest polymerization degree. By combining energy dispersive spectroscopy (EDS) images with the maximum between-class variance (Otsu) method, the content of nanoparticles was calculated to be 7.81%, 15.05%, 22.62%, 27.10%, 21.97%, and 23.95%. The distribution state of FeS compounds was also obtained. A low polymerization degree resulted in high FeS dispersal, and a high polymerization degree affected the uniformity distribution based on irregular ion diffusion. The obtained nanocomposites with different polymerization degrees were applied to the removal of Cd and TC in water. The removal capacity for both contaminants revealed a trend of initially increasing and then decreasing. The initial increase was related to the increasing content and decreasing size of the FeS nanoparticles, while the following decrease was due to the decreasing content and incomplete crystallization of the FeS nanoparticles. Overall, changing the proportion of polymeric monomers is an effective way to regulate particle size, and the Otsu method combined with EDS mapping images is a feasible method for calculating the content of nanoparticles.


Assuntos
Cádmio , Nanopartículas , Compostos Ferrosos , Hidrogéis , Lignina , Tetraciclina
16.
Sensors (Basel) ; 21(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502671

RESUMO

In recent years, the general and scientific interest in nutrition, digestion, and what role they play in our body has increased, and there is still much work to be carried out in the field of developing sensors and techniques that are capable of identifying and quantifying the chemical species involved in these processes. Iron deficiency is the most common and widespread nutritional disorder that mainly affects the health of children and women. Iron from the diet may be available as heme or organic iron, or as non-heme or inorganic iron. The absorption of non-heme iron requires its solubilization and reduction in the ferric state to ferrous that begins in the gastric acid environment, because iron in the ferric state is very poorly absorbable. There are chemical species with reducing capacity (antioxidants) that also have the ability to reduce iron, such as ascorbic acid. This paper aims to develop a sensor for measuring the release of encapsulated active compounds, in different media, based on dielectric properties measurement in the radio frequency range. An impedance sensor able to measure the release of microencapsulated active compounds was developed. The sensor was tested with calcium alginate beads encapsulating iron ions and ascorbic acid as active compounds. The prediction and measurement potential of this sensor was improved by developing a thermodynamic model that allows obtaining kinetic parameters that will allow suitable encapsulation design for subsequent release.


Assuntos
Ácido Ascórbico , Ferro , Antioxidantes , Criança , Dieta , Feminino , Compostos Férricos , Compostos Ferrosos , Heme , Humanos
17.
PLoS One ; 16(9): e0257766, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34555113

RESUMO

The aim of this study was to assess the dose- and time-dependent in vitro effects of ferrous sulphate (FeSO4.7H2O) on the motility parameters, viability, structural and functional activity of bovine spermatozoa. Spermatozoa motility parameters were determined after exposure to concentrations (3.90, 7.80, 15.60, 31.20, 62.50, 125, 250, 500 and 1000 µM) of FeSO4.7H2O using the SpermVisionTM CASA (Computer Assisted Semen Analyzer) system in different time periods. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide (MTT) assay, and the Annexin V-Fluos was applied to detect the membrane integrity of spermatozoa. The initial spermatozoa motility showed increased average values at all experimental concentrations compared to the control group (culture medium without FeSO4.7H2O). After 2 h, FeSO4.7H2O stimulated the overall percentage of spermatozoa motility at the concentrations of ≤ 125 µM. However, experimental administration of 250 µM of FeSO4.7H2O significantly (P < 0.001) decreased the spermatozoa motility but had no negative effect on the cell viability (P < 0.05) (Time 2 h). The lowest viability was noted after the addition of ≥ 500 µM of FeSO4.7H2O (P < 0.001). The concentrations of ≤ 62.50 µM of FeSO4.7H2O markedly stimulated (P < 0.001) spermatozoa activity after 24 h of exposure, while at high concentrations of ≥ 500 µM of FeSO4.7H2O the overall percentage of spermatozoa motility was significantly inhibited (P < 0.001) and it elicited cytotoxic action. Fluorescence analysis confirmed that spermatozoa incubated with higher concentrations (≥ 500 µM) of FeSO4.7H2O displayed apoptotic changes, as detected in head membrane (acrosomal part) and mitochondrial portion of spermatozoa. Moreover, the highest concentration and the longest time of exposure (1000 µM of FeSO4.7H2O; Time 6 h) induced even necrotic alterations to spermatozoa. These results suggest that high concentrations of FeSO4.7H2O are able to induce toxic effects on the structure and function of spermatozoa, while low concentrations may have the positive effect on the fertilization potential of spermatozoa.


Assuntos
Anexina A5/metabolismo , Compostos Ferrosos/efeitos adversos , Motilidade Espermática/efeitos dos fármacos , Espermatozoides/fisiologia , Animais , Bovinos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Compostos Ferrosos/farmacologia , Masculino , Espermatozoides/efeitos dos fármacos , Fatores de Tempo
18.
Nutrients ; 13(9)2021 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-34579127

RESUMO

We sought to investigate the effects of resistance training (RT) combined with erythropoietin (EPO) and iron sulfate on the hemoglobin, hepcidin, ferritin, iron status, and inflammatory profile in older individuals with end-stage renal disease (ESRD). ESRD patients (n: 157; age: 66.8 ± 3.6; body mass: 73 ± 15; body mass index: 27 ± 3), were assigned to control (CTL; n: 76) and exercise groups (RT; n: 81). The CTL group was divided according to the iron treatment received: without iron treatment (CTL-none; n = 19), treated only with iron sulfate or EPO (CTL-EPO or IRON; n = 19), and treated with both iron sulfate and EPO (CTL-EPO + IRON; n = 76). The RT group followed the same pattern: (RT-none; n = 20), (RT-EPO or IRON; n = 18), and (RT-EPO + IRON; n = 86). RT consisted of 24 weeks/3 days per week at moderate intensity of full-body resistance exercises prior to the hemodialysis section. The RT group, regardless of the iron treatment, improved iron metabolism in older individuals with ESRD. These results provide some clues on the effects of RT and its combination with EPO and iron sulfate in this population, highlighting RT as an important coadjutant in ESRD-iron deficiency.


Assuntos
Eritropoetina/uso terapêutico , Falência Renal Crônica/terapia , Treinamento de Força , Idoso , Ferritinas/sangue , Compostos Ferrosos/uso terapêutico , Hemoglobinas/análise , Hepcidinas/sangue , Humanos , Inflamação/terapia , Ferro/sangue , Pessoa de Meia-Idade
19.
Sci Total Environ ; 801: 149672, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34438148

RESUMO

The biodegradation of hexachlorocyclohexanes (HCHs) is known to be accompanied by isotope fractionation of carbon (13C/12C), but no systematic studies were performed on abiotic degradation of HCH isomers by iron (II) minerals. In this study, we explored the carbon isotope fractionation of α-HCH during dechlorination by FeS nanoparticles at different pH values. The results of three different experiments showed that the apparent rate constants during dehalogenation of α-HCH by FeS increased with pH. The lowest apparent rate constant value α-HCH during dehalogenation by FeS was 0.009 d-1 at pH value of 2.4, while the highest was 1.098 d-1 at pH 11.8. α-HCH was completely dechlorinated by FeS only at pH values 9.9 and 11.8, while the corresponding apparent rate constants were 0.253 d-1 and 1.098 d-1, respectively. Regardless of the pH used, the 1,2,4-trichlorobenzene (1,2,4-TCB), 1,2-dichlorobenzene (1,2-DCB), and benzene were the dominant degradation products of α-HCH. An enrichment factor (εC) of -4.7 ± 1.3‰ was obtained for α-HCH using Rayleigh model, which is equivalent to an apparent kinetic isotope effect (AKIEC) value of 1.029 ± 0.008 for dehydrohalogenation, and of 1.014 ± 0.004 for dihaloelimination, respectively. The magnitude of isotope fractionation from this study suggests that abiotic isotope fractionation by FeS must be taken into account in anoxic sediments and aquifers contaminated with HCH isomers, when high concentrations of FeS are present in the above-mentioned anoxic environments.


Assuntos
Nanopartículas , Biodegradação Ambiental , Isótopos de Carbono/análise , Compostos Ferrosos , Hexaclorocicloexano , Concentração de Íons de Hidrogênio
20.
Angew Chem Int Ed Engl ; 60(39): 21221-21225, 2021 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-34342117

RESUMO

A novel metal-organic framework (MOF) containing one-dimensional, Fe2+ chains bridged by dipyrazolate linkers and N,N-dimethylformamide (DMF) ligands has been synthesized. The unusual chain-type metal nodes feature accessible coordination sites on adjacent metal centers, resulting in motifs that are reminiscent of the active sites in non-heme diiron enzymes. The MOF facilitates direct reduction of nitric oxide (NO), producing nearly quantitative yields of nitrous oxide (N2 O) and emulating the reactivity of flavodiiron nitric oxide reductases (FNORs). The ferrous form of the MOF can be regenerated via a synthetic cycle involving reduction with cobaltocene (CoCp2 ) followed by reaction with trimethylsilyl triflate (TMSOTf).


Assuntos
Materiais Biomiméticos/química , Compostos Ferrosos/química , Estruturas Metalorgânicas/química , Óxido Nítrico/química , Pirazóis/química , Estrutura Molecular , Oxirredução
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