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1.
Environ Monit Assess ; 191(12): 779, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31784811

RESUMO

This work aims to evaluate the different water sources available in Mahayel Aseer, KSA, chemically, toxicology and microbiologically. Several water samples, such as tap water, differentially desalinated water and bottled water, were analysed. Moreover, different metal ions and anions, including sodium, potassium, calcium, lead, cadmium, manganese, bicarbonate, fluoride, chloride, sulphate, nitrate and nitrite, were evaluated and assessed for human health. Bacterial and fungal pollutions arising from various water sources were also investigated. This study was conducted on polymer bottles and the best storage conditions. In order to acquire purified water safe for human consumption, certain recommendations pertaining to the steps of water treatment can be recommended.


Assuntos
Água Potável , Substâncias Perigosas , Poluentes Químicos da Água , Água , Ânions/análise , Cálcio/análise , Água Potável/química , Substâncias Perigosas/análise , Substâncias Perigosas/toxicidade , Humanos , Minerais/análise , Nitratos/análise , Nitritos/análise , Arábia Saudita , Água/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Abastecimento de Água
2.
Huan Jing Ke Xue ; 40(7): 3195-3200, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854718

RESUMO

This study investigated the inhibitory effect of free nitrous acid (FNA) on the activity of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) under anoxic conditions with different mixed liquid suspended solids (MLSS). Sequencing batch reactors were used to study the changes in the activity of AOB and NOB in nitrifying activated sludge based on four different MLSS (8398, 11254, 15998, and 19637 mg·L-1), after treatment, under anoxic conditions with FNA (at an initial concentration of 1.3 mg·L-1) for 48 h. The results showed that the pH increased by approximately 0.9, but the concentration of NO2--N did not decrease significantly. With over-aeration, the concentration of NH4+-N gradually degraded to 0 mg·L-1, and the removal rate of NH4+-N gradually increased to a maximum of 4.4-6.8 mg·(L·h)-1 which time used was shorter with the increase of the inhibition MLSS. The nitrite accumulation rate was more than 92% when the sludge concentration was 8398, 11254, 15998, and 19637 mg·L-1 and with over-aeration for 0-396 h, 0-396 h, 0-372 h, and 0-168 h, respectively. When aerated for 468 h, 468 h, 444 h, and 264 h, the NO2--N concentration and NAR decreased to 0, and NO3--N concentrations increased to their highest with the values of 42.6, 49.9, 42.9, and 47.9 mg·L-1 respectively.


Assuntos
Bactérias/metabolismo , Nitritos/análise , Ácido Nitroso/química , Esgotos/microbiologia , Amônia/análise , Reatores Biológicos/microbiologia , Nitrificação
3.
Environ Sci Pollut Res Int ; 26(33): 34377-34387, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31637614

RESUMO

Nitrous oxide (N2O) accumulation in biological nitrogen removal has drawn much attention in recent years; however, nitric oxide (NO) accumulation in denitrification was rarely studied. In this study, NO and N2O accumulation during nitrite denitrification in a lab-scale sequencing batch reactor (SBR) were investigated. Results showed that low pH (< 7) and high influent loading (> 360:90) (COD:NO2--N) caused serious NO and N2O accumulation. The maximal NO accumulation of 4.96 mg L-1 was observed at influent loading of 720:180 and the maximal N2O accumulation of 46.29 mg L-1 was found at pH of 6. The NO accumulation was far higher than the values reported in previous studies. In addition, the high NO accumulation could completely inhibit the activities of reductases involved in denitrification. High NO and N2O accumulation were mainly caused by significant free nitrous acid (FNA) and NO inhibition at low pH and high influent loading. There were significant differences on NO and N2O accumulation at different carbon to nitrogen (COD/N). Low COD/N (≤ 4) could mitigate NO accumulation, but led to high N2O accumulation. It is speculated that NO accumulation is related to the rapid denitrification with accumulated electron in anaerobic stage at high COD/N. N2O accumulation is attributed to intense electron competition at low COD/N. High dissolved oxygen (DO) of 4.04 mg L-1 was detected during NO detoxification in this experiment, which is speculated to be partly caused by NO dismutation.


Assuntos
Desnitrificação , Óxido Nítrico/análise , Nitritos/análise , Dióxido de Nitrogênio/análise , Reatores Biológicos , Nitrogênio , Ácido Nitroso , Óxido Nitroso
4.
Chemosphere ; 236: 124835, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31549673

RESUMO

In this contribution, the electrocatalytic abatement of bisphenol A (BPA) with boron-doped diamond (BDD) anode had been conducted in NaNO2 electrolytes. Central composite design was used as statistical multivariate method to optimize the operating parameters adopted (applied current density, flow rate, concentration of NaNO2 and initial pH). The results from response surface analysis indicated that pH was the most influential factor for TOC decay, and a maximum TOC decay of 63.7% was achieved under the optimized operating conditions (9.04 mA cm-2 of applied current density, 400 mL min-1 of flow rate, 10 mM of NaNO2, 4.0 of initial pH and 60 min of electrolysis time). Besides, LC/MS technique was applied to identify the main reaction intermediates, and plenty of nitrated oligomers were detected at the end of the degradation. These by-products were generated via the coaction of coupling reaction of nitrated phenol and electrophilic substitution mediated by nitrogen dioxide radicals. Moreover, our results showed that the degree of nitration depended heavily on the employed initial nitrite concentration. This was one of the very few investigations dealing with nitrophenolic by-products in nitrite medium, and thus the findings exhibited important implications for electrochemical degradation of BPA and its related phenolic pollutants.


Assuntos
Compostos Benzidrílicos/química , Técnicas Eletroquímicas/métodos , Nitratos/química , Nitritos/química , Fenóis/química , Poluentes Químicos da Água/química , Boro/análise , Diamante , Eletrodos , Eletrólise , Concentração de Íons de Hidrogênio , Nitratos/análise , Nitritos/análise , Oxirredução , Fenóis/análise , Poluentes Químicos da Água/análise
5.
J Agric Food Chem ; 67(39): 10930-10936, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31496247

RESUMO

The stability of lipids in meat products depends on the initial concentration of hydroperoxides, the catalytic involvement of metal ions and myoglobin, endogenous antioxidants, and biological and technological factors. Ground meat was treated with additives, sealed in vacuum bags, heated to 75 °C, and stored opened to air at 4 °C. S-Nitroso-N-acetylcysteine (NAC-SNO) at concentration like nitrite used by the industry prevents lipid peroxidation in the product, even after storage for 1 month at 4 °C. The same simulated treatments at different concentrations of both compounds show that NAC-SNO acts as an antioxidant ∼4-fold better than nitrite at pH 6.2 or 3.0. Ascorbic acid significantly improves nitrite antioxidant effect. NAC-SNO was found to prevent, much better than nitrite, accumulation of reactive aldehydes and hydroxynonenal protein modification. In condition like those used by the industry for meat products processing, NAC-SNO acts better than nitrite to provide antioxidant protection without the side effect of N-nitrosation, oxidation, and the loss of nutrient generated by nitrite.


Assuntos
Acetilcisteína/análogos & derivados , Antioxidantes/análise , Conservantes de Alimentos/análise , Mucosa Gástrica/metabolismo , Produtos da Carne/análise , Acetilcisteína/análise , Acetilcisteína/metabolismo , Animais , Antioxidantes/metabolismo , Conservantes de Alimentos/metabolismo , Temperatura Alta , Peroxidação de Lipídeos , Nitritos/análise , Oxirredução , Perus
7.
Environ Sci Pollut Res Int ; 26(28): 28737-28748, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31376124

RESUMO

Several parts of the world have been facing the problem of nitrite and nitrate contamination in ground and surface water. The acute toxicity of nitrite has been shown to be 10-fold higher than that of nitrate. In the present study, aminated silica carbon nanotube (ASCNT) was synthesised and tested for nitrite removal. The synergistic effects rendered by both amine and silica in ASCNT have significantly improved the nitrite removal efficiency. The IEP increased from 2.91 for pristine carbon nanotube (CNT) to 8.15 for ASCNT, and the surface area also increased from 178.86 to 548.21 m2 g-1. These properties have promoted ASCNT a novel adsorbent to remove nitrite. At optimum conditions of 700 ppm of nitrite concentration at pH 7 and 5 h of contact with 15 mg of adsorbent, the ASCNT achieved the maximal loading capacity of 396 mg/g (85% nitrite removal). The removal data of nitrite onto ASCNT fitted the Langmuir isotherm model better than the Freundlich isotherm model with the highest regression value of 0.98415, and also, the nonlinear analysis of kinetics data showed that the removal of nitrite followed pseudo-second-order kinetic. The positive values of both ΔS° and ΔH° suggested an endothermic reaction and an increase in randomness at the solid-liquid interface. The negative ΔG° values indicated a spontaneous adsorption process. The ASCNT was characterised using FESEM-EDX and FTIR, and the results obtained confirmed the removal of nitrite. Based on the findings, ASCNT can be considered as a novel and promising candidate for the removal of nitrite ions from wastewater.


Assuntos
Nanotubos de Carbono/química , Nitritos/química , Poluentes Químicos da Água/química , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Nanocompostos/química , Nitritos/análise , Dióxido de Silício , Termodinâmica , Águas Residuárias/análise , Água/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos
8.
Sci Total Environ ; 694: 133702, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31386948

RESUMO

Coastal wetlands accumulate enormous quantities of nitrogen due to their position at the interface between land and sea and high trapping capacity. Fortunately, they have high nitrogen (N) purifying (removal) capacity, which means that they likely play an important role in mitigating against coastal eutrophication. However studies that empirically measure the degree to which wetlands purify nitrogen and their removal pathways (e.g. denitrification, anammox, plant uptake, microbial immobilization, etc.) are rare. In this study, the N purification potential (denitrification and anammox) and enzyme activities related to denitrification in different subtropical wetlands types were conducted in nitrogen-enriched wetlands of Daya Bay, Southern China. We found the average N purification rate was 11.4 µmol N·kg-1·h-1, with denitrification accounting for 84.2%-100% of the total N2 production in the wetlands of Daya Bay. The N purification potential in the wet season, subtidal areas and mangrove forests were generally observed to be higher than that in the dry season, high and low tidal areas, barren and estuary habitats, respectively. Correspondingly, these differences were mainly driven by the temperature, Eh and NH4-N, respectively. Additionally, the nitrate reductase (Nar) and nitrite reductase (Nir) activities tended to be similar among different seasons and tidal areas, however, Nir activity in mangrove forest was 1.5-fold and 2-fold of the estuarine and barren areas, respectively. Meanwhile, Nir showed a positive correlation with denitrification rate. These results indicate that NO2-N reduction, the key control mechanism for N purification, should be the rate-limiting step of the denitrification process in Daya Bay wetlands. Notably, mangroves could improve N removal rates by 48.0% compared to other wetlands. Therefore, protecting and restoring mangrove ecosystems could be an effective way to reduce the risk of coastal eutrophication.


Assuntos
Biodegradação Ambiental , Nitritos/metabolismo , Nitrogênio/metabolismo , Áreas Alagadas , Monitoramento Ambiental , Eutrofização , Nitritos/análise
9.
Anal Chim Acta ; 1079: 212-219, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387714

RESUMO

This study examined the efficiency of pH-dependent, fluorescent carbon dots for the sensing of hazardous anions in aqueous media and cell imaging. The nitrite anion, an important water-soluble element for environmental and biological systems, requires continuous monitoring because a high concentration can affect the systems severely. The as-synthesized carbon dots efficiently detected the nitrite anion in aqueous solution through a fluorescent 'Turn Off' phenomenon. The quenching mechanism was investigated through proper microscopic and spectroscopic studies. The limit of detection and linear detection range were 7.9 nM and 2.3µM-7.7 mM, respectively. The sensitivity was tested with different water samples. In a parallel experiment, the as-synthesized carbon dots were used as a cell-imaging probe for HeLa cells, highlighting their potential in different biological studies.


Assuntos
Corantes Fluorescentes/química , Nitritos/análise , Pontos Quânticos/química , Poluentes Químicos da Água/análise , Ácidos Borônicos/química , Carbono/química , Água Potável/análise , Células HeLa , Humanos , Limite de Detecção , Microscopia de Interferência/métodos , Nitrogênio/química , Espectrometria de Fluorescência/métodos
10.
J Sci Food Agric ; 99(14): 6608-6619, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31347167

RESUMO

BACKGROUND: Understanding plant responses to light quantity in indoor horticultural systems is important for optimising lettuce growth and metabolism as well as energy utilisation efficiency. Light intensity and photoperiod sufficient for normal plant growth parameters might be not efficient for nitrate assimilation. Therefore, this study explored and compared the effects of different light intensities (100-500 µmol m-2 s-1 ) and photoperiods (12-24 h) on the growth and nitrate assimilation in red and green leaf lettuce (Lactuca sativa L.). RESULTS: For efficient nitrate assimilation, 300-400 µmol m-2 s-1 photosynthetic photon flux density (PPFD) and 16-18 h photoperiod is necessary for red and green lettuces. The insufficient light quantity resulted in reduced growth and remarkable increase in nitrate and nitrite contents in both cultivars. Short photoperiods, similarly to low PPFD, growth parameters, chlorophyll indices and nitrate assimilation indices showed the shortage of photosynthetic products for normal plant physiological processes. Short photoperiods had the least pronounced effect on nitrate and nitrite contents in lettuce leaves. CONCLUSION: Light intensity was superior compared to photoperiods for efficient nitrate assimilation in both lettuce cultivars. Under short photoperiods, similarly to low intensity, growth parameters, chlorophyll index and nitrate assimilation indices showed a shortage of photosynthetic products for normal physiological processes. The free amino acid concentration increased, but it was not efficiently incorporated in proteins, as their level in lettuce was lower compared to those for moderate photoperiods. © 2019 Society of Chemical Industry.


Assuntos
Alface/metabolismo , Alface/efeitos da radiação , Nitratos/metabolismo , Clorofila/análise , Clorofila/metabolismo , Cor , Alface/química , Alface/crescimento & desenvolvimento , Luz , Nitratos/análise , Nitritos/análise , Nitritos/metabolismo , Fotoperíodo , Fotossíntese , Folhas de Planta/química , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/efeitos da radiação
11.
Anal Chim Acta ; 1077: 167-173, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31307706

RESUMO

Nitrite is a naturally occurring species present in various food samples and also present in our bodies as a product of nitric oxide (NO) oxidation. Considering the ubiquity of nitrite, its determination is of great importance in both biological and food samples. Herein, a very facile indirect method of nitrite determination in meat samples via selective reduction to nitric oxide (NO) is presented. The resulting gaseous product is quantified via portable and cost-effective electrochemical sensors. Both a novel laboratory prepared Pt-Nafion based NO sensor and a commercially available amperometric NO sensor are compared. Excellent correlations between the nitrite amount found in tested samples using both of the electrochemical sensors and a reference chemiluminescence method are demonstrated (r = 0.997 and r = 0.999 for Pt-Nafion based and commercially available NO-B4 electrochemical sensors, respectively, n = 12). Moreover, the slope of the linear regression curves are very close to unity for the comparison of the three systems tested. The amperometric sensors compared within this work exhibit good precision and accuracy and are shown to be an attractive alternative to the costly chemiluminescence detection method for accurately determining nitrite levels in food samples.


Assuntos
Contaminação de Alimentos/análise , Produtos da Carne/análise , Óxido Nítrico/análise , Nitritos/análise , Técnicas Eletroquímicas/métodos , Luminescência , Medições Luminescentes/métodos , Nitritos/química , Oxirredução
12.
Artigo em Inglês | MEDLINE | ID: mdl-31274053

RESUMO

In the Portuguese Geriatric Study of the Health Effects of Indoor Air Quality in Senior Nursing Homes, we aimed to evaluate the impact of indoor air contaminants on the respiratory symptoms and biomarkers in a sample of elderly living in nursing homes. A total of 269 elderly answered a health questionnaire, performed a spirometry and 150 out of these collected an exhaled breath condensate sample for pH and nitrites analysis. The study included the evaluation of indoor chemical and microbiological contaminants. The median age of the participants was 84 (78-87) years and 70.6% were women. The spirometric data indicated the presence of airway obstruction in 14.5% of the sample. Median concentrations of air pollutants did not exceed the existing standards, although increased peak values were observed. In the multivariable analysis, each increment of 100 µg/m3 of total volatile organic compounds was associated with the odds of respiratory infection in the previous three months ( OR̂ =1.05; 95% CI: 1.00-1.09). PM2.5 concentrations were inversely associated with pH values ( ß̂ = -0.04, 95%: -0.06 to -0.01, for each increment of 10 µg/m3). Additionally, a direct and an inverse association were found between total bacteria and FEV1/FVC and FVC, respectively.


Assuntos
Poluentes Atmosféricos/análise , Testes Respiratórios , Casas de Saúde , Sistema Respiratório/efeitos dos fármacos , Doenças Respiratórias/etiologia , Idoso , Idoso de 80 Anos ou mais , Poluentes Atmosféricos/toxicidade , Poluição do Ar em Ambientes Fechados/efeitos adversos , Poluição do Ar em Ambientes Fechados/análise , Feminino , Humanos , Concentração de Íons de Hidrogênio , Masculino , Nitritos/análise , Material Particulado/análise , Material Particulado/toxicidade , Portugal/epidemiologia , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/microbiologia , Espirometria , Inquéritos e Questionários , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/toxicidade
13.
J Agric Food Chem ; 67(29): 8074-8084, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31299152

RESUMO

Consumers often malign conventional curing agents while concomitantly accepting the natural forms of the same constituents in numerous food products. This paradox ostensibly exceeds all other food-related controversies to date and likely contributes to the rapid expansion of meat products that utilize natural nitrate derivatives. While there is high demand for these products, a fundamental lack of understanding regarding the safety and chemical implications of curing agents, whether derived from synthetic or natural sources, continues to persist. This manuscript elucidates the variations among curing preparations with particular emphasis pertaining to the associated safety, chemical, and regulatory ramifications encompassing these product categories.


Assuntos
Rotulagem de Alimentos/legislação & jurisprudência , Produtos da Carne/análise , Nitratos/análise , Nitritos/análise , Extratos Vegetais/análise , Plantas/química , Animais , Aditivos Alimentares/efeitos adversos , Aditivos Alimentares/análise , Manipulação de Alimentos , Rotulagem de Alimentos/normas , Inocuidade dos Alimentos , Humanos , Nitratos/efeitos adversos , Nitritos/efeitos adversos , Extratos Vegetais/efeitos adversos
14.
Meat Sci ; 156: 139-145, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31158600

RESUMO

Several strategies were examined for incorporating chia products (seeds, flour and a coproduct from cold-press oil extraction) in frankfurters. The nutritional composition, technological properties and sensory attributes of the resulting products were studied in relation to the formulation used and, lipid oxidation, pH, residual nitrite level and microbiological properties were evaluated during chilled storage. Application of these chia products (3%) was seen to enhance the nutritional composition of frankfurters, without adversely affecting the technological properties of the final product. In general, although differences were detected in the sensory attributes of the frankfurters reformulated with chia products (most of them when chia coproduct was added), all of them were judged acceptable. Besides the quality aspects, these reformulation strategies had beneficial effects on some technological properties during chilled storage: better resistance to oxidation (controlling the TBARS increase during storage) and lower residual nitrite levels than control (both effects presumably because the chia polyphenols content) and no effect on microbiological safety.


Assuntos
Armazenamento de Alimentos , Produtos da Carne/análise , Salvia , Adulto , Animais , Feminino , Qualidade dos Alimentos , Humanos , Masculino , Produtos da Carne/microbiologia , Pessoa de Meia-Idade , Nitritos/análise , Sementes , Suínos , Substâncias Reativas com Ácido Tiobarbitúrico/análise
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 221: 117211, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31158765

RESUMO

Doping graphene quantum dots (GQDs) with heteroatoms can change their band gap and electronic density, thus enhancing their fluorescence quantum yield (QY). In this work, we for the first time reported a nontoxic, rapid, and one-pot hydrothermal method to synthesize sulfur and phosphorus co-doped GQDs (S, P-GQDs). Citric acid was functioned as a carbon source, whereas sodium phytate and anhydrous sodium sulfate are used as the P and S sources, respectively, in this bottom-up synthesis. The resulting S, P-GQDs exhibit high heteroatomic doping ratios of 9.66 at.% for S and 3.34 at.% for P, and higher QY than those obtained from monoatomic doped GQDs. Additionally, the as-prepared S, P-GQDs exhibit excitation-dependent behavior, pH sensitivity between 8.0 and 13.0, high tolerance of ionic strength. More importantly, the as-synthesized S, P-GQDs show a sensitive and selective behavior for sensing nitrite (NO2-) in the concentration range of 0.7-9 µmol/L, and the detection limit was as low as 0.3 µmol/L. Additionally, the S, P-GQDs was successfully used in detecting NO2- in pickled foods, showing their promise for potential applications in realistic analysis.


Assuntos
/análise , Análise de Alimentos/métodos , Nitritos/análise , Pontos Quânticos/química , Ácido Cítrico/química , Grafite/química , Microscopia Eletrônica de Transmissão , Concentração Osmolar , Fósforo/química , Fotodegradação , Ácido Fítico/química , Sensibilidade e Especificidade , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfatos/química , Enxofre/química
16.
J Chromatogr A ; 1603: 8-14, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31151694

RESUMO

A low cost, UV absorbance detector incorporating a 235 nm light emitting diode (LED) for portable ion chromatography has been designed and fabricated to achieve rapid, selective detection of nitrite and nitrate in natural waters. The optical cell was fabricated through micromilling and solvent vapour bonding of two layers of poly (methyl methacrylate) (PMMA). The cell was fitted within a 3D printed housing and the LED and photodiode were aligned using 3D printed holders. Isocratic separation and selective detection of nitrite and nitrate was achieved in under 2.5 min using the 235 nm LED based detector and custom electronics. The design of the new detector assembly allowed for effective and sustained operation of the deep UV LED source at a low current (<10 mA), maintaining consistent and low LED temperatures during operation, eliminating the need for a heat sink. The detector cell was produced at a fraction of the cost of commercial optical cells and demonstrated very low stray light (0.01%). For retention time and peak area repeatability, RSD values ranged from 0.75 to 1.10 % and 3.06-4.19 %, respectively. Broad dynamic linear ranges were obtained for nitrite and nitrate, with limits of detection at ppb levels. The analytical performance of the IC set up with optical cell was compared to that of an ISO-accredited IC through the analysis of five various water samples. Relative errors not exceeding 6.86% were obtained for all samples. The detector was also coupled to a low pressure, low cost syringe pump to assess the potential for use within a portable analytical system. RSD values for retention time and peak area using this simple configuration were <1.15% and <3.57% respectively, highlighting repeatability values comparable to those in which a commercial HPLC pump was used.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Nitratos/análise , Nitritos/análise , Cromatografia Líquida de Alta Pressão/métodos , Raios Ultravioleta
17.
Nutrients ; 11(6)2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31200505

RESUMO

OBJECTIVE: To verify if acute intake of beetroot juice potentiates post-exercise hypotension (PEH) in hypertensive postmenopausal women. METHODS: Thirteen hypertensive postmenopausal women (58.1 ± 4.62 years and 27.4 ± 4.25 kg/m²) were recruited to participate in three experimental sessions, taking three different beverages: Beetroot juice (BJ), placebo nitrate-depleted BJ (PLA), and orange flavored non-caloric drink (OFD). The participants performed moderate aerobic exercise training on a treadmill, at 65-70% of heart rate reserve (HRR), for 40 min. After an overnight fast, the protocol started at 07h when the first resting blood pressure (BP) was measured. The beverage was ingested at 07h30 and BP was monitored until the exercise training started, at 09h30. After the end of the exercise session, BP was measured every 15 min over a 90-min period. Saliva samples were collected at rest, immediately before and after exercise, and 90 min after exercise for nitrite (NO2-) analysis. RESULTS: There was an increase in salivary NO2- with BJ intake when compared to OFD and PLA. A slight increase in salivary NO2- was observed with PLA when compared to OFD (p < 0.05), however, PLA resulted in lower salivary NO2- when compared to BJ (p < 0.001). There were no changes in salivary NO2- with the OFD. Systolic and diastolic BP decreased (p < 0.001) on all post exercise time points after all interventions, with no difference between the three beverages. CONCLUSION: Acute BJ intake does not change PEH responses in hypertensive postmenopausal women, even though there is an increase in salivary NO2-.


Assuntos
Beta vulgaris , Pressão Sanguínea/fisiologia , Exercício/fisiologia , Sucos de Frutas e Vegetais , Hipertensão/fisiopatologia , Raízes de Plantas , Bebidas/análise , Estudos Cross-Over , Método Duplo-Cego , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Pessoa de Meia-Idade , Nitritos/análise , Pós-Menopausa , Saliva/química
18.
J Agric Food Chem ; 67(26): 7205-7222, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31244197

RESUMO

Nitrate and nitrite ions are used as food additives to inhibit the growth of microorganisms in cured and processed meats. Vegetables contain significant quantities of nitrate and nitrite. Actually, the vast majority of consumed nitrate and nitrite comes from natural vegetables and fruits rather than food additives. For years, the cancer risks of these two ions have been discussed, since they potentially convert into the carcinogenic nitrosamines. However, recently, these two ions have been considered essential nutrients which promote nitric oxide production and consequently help cardiovascular health. It seems that the role of these two ions in our diet is important now from a different point of view. In this review, the nitrate and nitrite contents of food products from different countries are displayed globally in order to reinterpret the risks/benefits of our consumption quotations. This review article is based on Science Citation Index (SCI) articles reported between 2008 and 2018.


Assuntos
Nitratos/análise , Nitritos/análise , Animais , Aditivos Alimentares/análise , Aditivos Alimentares/metabolismo , Humanos , Carne/análise , Nitratos/metabolismo , Nitritos/metabolismo , Medição de Risco , Verduras/química
19.
Ecotoxicol Environ Saf ; 181: 395-403, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31212188

RESUMO

The aims of this work was to investigate, in soil microcosms, the effects on soil microbial community structure and function of increasing concentrations of 4-Nonylphenol (NP). The lasts is a product of degradation of NPEOs (Nonylphenol polyethoxylates) with a known toxic and estrogenic capacity able to disrupt animal's hormonal systems. The effect of increasing concentrations of NP (0, 10, 30, 90, and 270 mg NP kg-1 of dry soil) in soil microcosms in three sampling dates (28, 56, and 112 days) over soil microbial activity and function were assessed. Soil microbial activity was estimated by microbial ATP content, and both bacterial and fungal communities composition were estimated using the terminal restriction fragment length polymorphism technique (T-RFLP). Abundance of ammonia-oxidizing bacteria (AOB) was estimated by qPCR of gene encoding for the bacterial ammonia-monoxygenase (amoA). Changes in biologically mediated soil properties were also assessed, namely water-soluble NH+4, NO-2 and NO-3 content, the two last allowing the assessment of mineralization rates. NP-spiking had some unexpected impacts on microbial community structure and functions, since (i) impacted both bacterial and fungal communities structure at the highest NP concentration tested, bacterial communities were resistant to lower concentrations, while fungal communities were increasingly impacted until the end of the incubation at day 112; (ii) no community structure resilience was observed in bacteria at the highest NP concentration nor for fungi at any concentration; (iii) microbial activity decreased with NP after 28 and 56 d, but increased in the last sampling at the highest concentrations tests, coupled to an enrichment in AOB taxa after 56 and 112 days, that at least partly explain also explain the observed speed up of nitrification rates.


Assuntos
Estrogênios não Esteroides/toxicidade , Microbiota/efeitos dos fármacos , Nitrogênio , Fenóis/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Amônia/análise , Amônia/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Fungos/genética , Fungos/isolamento & purificação , Minerais , Nitratos/análise , Nitrificação , Nitritos/análise , Solo/química
20.
Acta Cir Bras ; 34(4): e201900407, 2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31038585

RESUMO

PURPOSE: To evaluate the functional and structural response of tadalafil effects in the intestinal mucosa, using an experimental model of hypoxia and reoxygenation injury in rats. METHODS: The animals were divided into 4 groups: CTL, H/R, H/R+Td and M+Td. The newborn rats allocated in groups H/R, H/R+Td and M+Td were submitted twice a day, to a gas chamber with CO2 at 100% for 10 minutes and afterward reoxygenation with O2 at 98% for 10 minutes, in the three first days of life. Tadalafil dose was given to newborn of group H/R+Td and to the pregnant rat of group M+Td. Histological analysis was made with hematoxylin-eosin technique and oxidative stress through nitrite and nitrate levels and lipid peroxidation. RESULTS: The histological analysis showed a reduction of mucosa alterations in the groups that received tadalafil. In the oxidative stress evaluation, occurred an increase of NO levels and less lipidic peroxidation in the ileum segments that received tadalafil. CONCLUSION: Tadalafil provides tissue protection when administered independently to both, pregnant or newborns.


Assuntos
Hipóxia/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/metabolismo , Inibidores da Fosfodiesterase 5/farmacologia , Tadalafila/farmacologia , Animais , Animais Recém-Nascidos , Feminino , Humanos , Mucosa Intestinal/patologia , Peroxidação de Lipídeos , Malondialdeído/análise , Nitratos/análise , Nitritos/análise , Gravidez , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo
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