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1.
Biosens Bioelectron ; 169: 112604, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32980805

RESUMO

Virus severely endangers human life and health, and the detection of viruses is essential for the prevention and treatment of associated diseases. Metal-organic framework (MOF), a novel hybrid porous material which is bridged by the metal clusters and organic linkers, has become a promising biosensor platform for virus detection due to its outstanding properties including high surface area, adjustable pore size, easy modification, etc. However, the MOF-based sensing platforms for virus detection are rarely summarized. This review systematically divided the detection platforms into nucleic acid and immunological (antigen and antibody) detection, and the underlying sensing mechanisms were interpreted. The nucleic acid sensing was discussed based on the properties of MOF (such as metal ion, functional group, geometry structure, size, porosity, stability, etc.), revealing the relationship between the sensing performance and properties of MOF. Moreover, antibodies sensing based on the fluorescence detection and antigens sensing based on molecular imprinting or electrochemical immunoassay were highlighted. Furthermore, the remaining challenges and future development of MOF for virus detection were further discussed and proposed. This review will provide valuable references for the construction of sophisticated sensing platform for the detection of viruses, especially the 2019 coronavirus.


Assuntos
Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Viroses/virologia , Vírus/isolamento & purificação , Animais , Anticorpos Antivirais/análise , Antígenos Virais/análise , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Humanos , Imunoensaio/instrumentação , Imunoensaio/métodos , Modelos Moleculares , Impressão Molecular/instrumentação , Impressão Molecular/métodos , Ácidos Nucleicos/análise , Espectrometria de Fluorescência/instrumentação , Espectrometria de Fluorescência/métodos , Viroses/diagnóstico
2.
Environ Pollut ; 265(Pt A): 115052, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806424

RESUMO

Dissolved organic matter (DOM) is recognized as a good indicator of water quality as its concentration is influenced by land use, rainwater, windborne material and anthropogenic activities. Recent technological advances make it possible to characterize fluorescent dissolved organic matter (FDOM), the fraction of DOM that fluoresces. Among these advances, portable fluorometers and benchtop fluorescence excitation and emission spectroscopy coupled with a parallel factor analysis (EEM-PARAFAC) have shown to be reliable. Despite their rising popularity, there is still a need to evaluate the extent to which these techniques can assess DOM dynamics at the watershed scale. We compare the performance of in-situ measurements of FDOM with laboratory measurements of fluorescence spectroscopy within the context of two distinct glacierized watersheds in Peru. Glacierized watersheds represent unique testing environments with contrasting DOM conditions, flowing from pristine, vegetation-free headwaters through locations with obvious anthropogenic influences. We used an in-situ fluorometer and a portable multimeter to take 38 measurements of FDOM, pH and turbidity throughout the two catchments. Additionally, samples were analyzed in the laboratory using the EEM-PARAFAC method. Results were compared to dissolved organic carbon (DOC) measurements using standard high-temperature catalytic oxidation. Our results show that the three techniques together were able to capture the DOM dynamics for both studied watersheds. Taken individually, all three methods allowed detection of the watershed DOM main points of sources but in a more limited way. Due to the narrow bandwidth of the portable fluorometer used in the study, FDOM measurements were almost non-detectable to protein-like substances. Indeed, the more demanding EEM-PARAFAC was able to both differentiate between potential sources of DOM and provide an estimate of relative concentrations of different organic components. Finally, similar to FDOM but to a lesser extent, the DOC measurements showed some limits where protein-like substances make up most of the DOM composition.


Assuntos
Rios , Qualidade da Água , Análise Fatorial , Peru , Espectrometria de Fluorescência
3.
J Chromatogr A ; 1628: 461440, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822980

RESUMO

A selective and highly sensitive high performance liquid chromatography (HPLC) with fluorescence derivatization method was developed for determination of ethinyl estradiol (EE); one of endocrine-disrupting compounds (EDCs). The fluorescence derivatization procedure was based on Sonogashira coupling reaction using 4-(4, 5-diphenyl-1H-imidazole-2-yl) iodobenzene (DIB-I), a fluorescence labeling reagent, to derivatize EE in presence of copper and palladium ions. The formed fluorescent product was separated on Cosmosil 5C18 MS-II by an isocratic elution with a mobile phase composed of acetonitrile: 5.0 mM Tris-HNO3 buffer, pH 7.4 (60:40, v/v %). The detection wavelengths were set at 310 and 400 nm as excitation and emission wavelengths, respectively. Various parameters affecting derivatization reaction were optimized. Further, the proposed method was validated and a good linearity with low detection limit (S/N=3) 7.4 ng L-1 was obtained in water sample after a simple solid-phase disk extraction (C18 SPE disk) method. The proposed method was successfully applied for detection of EE in river water samples in order to monitor EE concentration and to distinguish its effect on the ecosystem and human health.


Assuntos
Cromatografia Líquida de Alta Pressão , Monitoramento Ambiental/métodos , Etinilestradiol/análise , Rios/química , Espectrometria de Fluorescência , Disruptores Endócrinos/análise , Fluorescência , Extração em Fase Sólida , Poluentes Químicos da Água/análise
4.
Ecotoxicol Environ Saf ; 204: 111129, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32805505

RESUMO

Anaerobic digestate has been widely used for agricultural activities as an organic fertilizer product. Dissolved organic matter (DOM) derived from anaerobic digestate plays a key role in the speciation, bioavailability and ultimate fate of metals that is related to agriculture and food safety as well as the soil environment. Hence, the binding properties of Cu, Pb and Zn with digestate DOM are investigated using two-dimensional correlation spectroscopy (2D-COS) in combination with ultraviolet absorption, synchronous fluorescence spectra (SFS) and Fourier transform infrared (FTIR) spectroscopy. The 2D absorption COS shows that the DOM at 200 nm is most susceptive with the addition of Pb, followed by Zn and Cu. The log-transformed absorption spectra can also obtain more valuable signals than that from conventional absorption spectra. The 2D-SFS-COS indicates that protein-like peak is more sensitive to the variation of the concentration of metal ions, and fulvic-like substances can preferentially interact with the three heavy metals (HMs). The 2D-FTIR-COS reveals that Cu(II) and Zn(II) ions can be bonded preferentially to the N-H of secondary amide (II), and phenolic OH groups shows a favorable binding with Pb(II). Humic-like peaks with Cu(II) and Zn(II) obtains relatively higher log KM values than fulvic- and protein-like substances. However, the proportion of initial fluorescence (f) for DOM-Cu(II) and DOM-Zn(II) decreased with an increase in wavelength. Protein-like materials have more fluorescent substances that can combine with Cu(II) and Zn(II). This study provides a guide for understanding the geochemical behavior of metal ions in agricultural soils when anaerobic digestate is applied as an organic fertilizer product.


Assuntos
Substâncias Húmicas/análise , Esterco/microbiologia , Metais Pesados/química , Anaerobiose , Animais , Galinhas , Fertilizantes , Fluorescência , Solo/química , Espectrometria de Fluorescência/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
5.
PLoS One ; 15(8): e0237730, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857799

RESUMO

Freshwater ecosystems play a key role in shaping the global carbon cycle and maintaining the ecological balance that sustains biodiversity worldwide. Surficial water bodies are often interconnected with groundwater, forming a physical continuum, and their interaction has been reported as a crucial driver for organic matter (OM) inputs in groundwater systems. However, despite the growing concerns related to increasing anthropogenic pressure and effects of global change to groundwater environments, our understanding of the dynamics regulating subterranean carbon flows is still sparse. We traced carbon composition and transformations in an arid zone calcrete aquifer using a novel multidisciplinary approach that combined isotopic analyses of dissolved organic carbon (DOC) and inorganic carbon (DIC) (δ13CDOC, δ13CDIC, 14CDOC and 14CDIC) with fluorescence spectroscopy (Chromophoric Dissolved OM (CDOM) characterisation) and metabarcoding analyses (taxonomic and functional genomics on bacterial 16S rRNA). To compare dynamics linked to potential aquifer recharge processes, water samples were collected from two boreholes under contrasting rainfall: low rainfall ((LR), dry season) and high rainfall ((HR), wet season). Our isotopic results indicate limited changes and dominance of modern terrestrial carbon in the upper part (northeast) of the bore field, but correlation between HR and increased old and 13C-enriched DOC in the lower area (southwest). CDOM results show a shift from terrestrially to microbially derived compounds after rainfall in the same lower field bore, which was also sampled for microbial genetics. Functional genomic results showed increased genes coding for degradative pathways-dominated by those related to aromatic compound metabolisms-during HR. Our results indicate that rainfall leads to different responses in different parts of the bore field, with an increase in old carbon sources and microbial processing in the lower part of the field. We hypothesise that this may be due to increasing salinity, either due to mobilisation of Cl- from the soil, or infiltration from the downstream salt lake during HR. This study is the first to use a multi-technique assessment using stable and radioactive isotopes together with functional genomics to probe the principal organic biogeochemical pathways regulating an arid zone calcrete system. Further investigations involving extensive sampling from diverse groundwater ecosystems will allow better understanding of the microbiological pathways sustaining the ecological functioning of subterranean biota.


Assuntos
Ciclo do Carbono , Isótopos de Carbono/análise , Monitoramento Ambiental/métodos , Água Subterrânea/química , Microbiota/fisiologia , Solo/química , Austrália , Isótopos de Carbono/metabolismo , Código de Barras de DNA Taxonômico , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Água Subterrânea/microbiologia , RNA Ribossômico 16S/genética , Chuva , Salinidade , Microbiologia do Solo , Espectrometria de Fluorescência
6.
Environ Monit Assess ; 192(8): 526, 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32676790

RESUMO

Trichodesmium, a marine cyanobacterium, plays a significant role in the global nitrogen cycle due to its nitrogen fixing ability. Large patches of Trichodesmium blooms were observed in the coastal waters, off Goa during spring intermonsoon (SIM) of 2014-2018. Zeaxanthin was the dominant pigment in the bloom region. Here, we present the spectral absorption and fluorescence characteristics of colored dissolved organic matter (CDOM) during these blooms. CDOM concentration was much higher in the bloom patches as compared with nonbloom regions. During the bloom spectral CDOM absorption had distinct peaks in the UV region due to the presence of UV-absorbing/screening compounds, mycosporine-like amino acids (MAAs) and in the visible region due to phycobiliproteins (PBPs). The spectral fluorescence signatures by the traditional peak picking method exhibited three peaks, one was protein-like, and the other two were humic-like. Apart from these, Trichodesmium exhibited strong protein-like fluorescence with 370/460 nm (Ex/Em), which is a signature of cyanobacteria. A parallel factor analysis (PARAFAC) on the fluorescence excitation-emission matrix (EEM) of Trichodesmium dataset fitted a 3-component model of which one was protein-like, and two were humic-like. The fluorescence index (FI) values during Trichodesmium bloom was very high (~ 3) compared with the typical range of 1.2-1.8 observed for the natural waters. Bloom degradation experiments proved that increase in tryptophan fluorescence enhances the CDOM absorption. Our study indicates that Trichodesmium blooms provide a rich source of organic matter in the coastal waters and long-term monitoring of these blooms is essential for understanding the health of ecosystem.


Assuntos
Trichodesmium , Ecossistema , Monitoramento Ambiental , Análise Fatorial , Espectrometria de Fluorescência
7.
Int J Nanomedicine ; 15: 4139-4149, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606669

RESUMO

Introduction: A correlation is established between the efficacy of Chinese herbal medicine and its charcoal drugs. Lonicerae japonicae Flos (LJF) is commonly used to treat fever, carbuncle, and tumors, among others. LJF Carbonisatas (LJFC) is preferred for detoxifying and relieving dysentery and its related symptoms. However, the mechanisms underlying the effects of LJFC remain unknown. Aim: The aim of this study was to explore the effects of LJFC-derived carbon dots (LJFC-CDs) on lipopolysaccharide (LPS)-induced fever and hypothermia rat models. Methods: LJFC-CDs were characterized using transmission electron microscopy, high-resolution transmission electron microscopy, Fourier-transform infrared, ultraviolet, fluorescence, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. The anti-inflammatory effects of LJFC-CDs were evaluated and confirmed using rat models of LPS-induced fever or hypothermia. Results: The LJFC-CDs ranged from 1.0 to 10.0 nm in diameter, with a yield of 0.5%. LJFC-CDs alleviated LPS-induced inflammation, as demonstrated by the expression of tumor necrosis factor-α, interleukin (IL)-1ß, and IL-6 and the recovery of normal body temperature. Conclusion: LJFC-CDs may have an anti-inflammatory effect and a potential to alleviate fever and hypothermia caused by inflammation.


Assuntos
Carbono/química , Febre/tratamento farmacológico , Hipotermia/tratamento farmacológico , Lonicera/química , Extratos Vegetais/uso terapêutico , Animais , Temperatura Corporal/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , AMP Cíclico/metabolismo , Citocinas/metabolismo , Dinoprostona/metabolismo , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/química , Mediadores da Inflamação/sangue , Lipopolissacarídeos , Masculino , Camundongos , Extratos Vegetais/toxicidade , Células RAW 264.7 , Ratos Sprague-Dawley , Espectrometria de Fluorescência
8.
Vestn Otorinolaringol ; 85(3): 36-42, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32628381

RESUMO

OBJECTIVE: The article demonstrates the experience of using laser fluorescence spectrometry (LFS) in the diagnosis of inflammatory diseases of pharynx, describes a method for recording spectra of pharyngeal tissues using the EnSpectr L405 hardware-software complex operating on the basis of laser radiation with a wavelength of 405 nm, and identifies characteristic features of spectral curves. PATIENTS AND METHODS: The authors presented the characteristics of the spectra from the surface of the pharynx tissue of healthy volunteers, patients with chronic tonsillitis and granular pharyngitis. RESULTS: The most informative parameters of the spectral curves were calculated, analyzing which it is possible to identify the morphometric, metabolic, functional features of the tissue of the tonsils and posterior pharyngeal wall in normal and pathological conditions. CONCLUSION: The article illustrates the importance of developing highly sensitive and highly specific methods for the rapid diagnosis of inflammatory diseases of the pharynx. The presented technology can be used in clinical practice in future.


Assuntos
Faringite , Tonsilite , Humanos , Tonsila Palatina , Faringe , Espectrometria de Fluorescência
9.
Environ Sci Pollut Res Int ; 27(28): 35712-35723, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32601876

RESUMO

Dissolved organic matter (DOM) will be increasingly monitored by means of in situ fluorescence spectroscopy devices in order to supervise wastewater treatment plant efficiency, due to their ease of implementation and high-frequency measurement capacity. However, fluorescence spectroscopy measurements are reported to be sensitive to the sample matrix effects of temperature, the inner filter effect (IFE), and turbidity. Matrix effect estimation tests and signal correction have been developed for DOM (tyrosine-like, tryptophan-like, and humic substances-like fluorescent compounds) fluorescence measurements in unfiltered urban sewage samples. All such tests are conducted in temperature, absorbance, and turbidity ranges representative of urban sewage. For all fluorophores studied, an average of 1% fluorescence intensity decrease per degree (°C) of temperature increase could be observed. Protein-like fluorescent compound signals were found to be significantly affected by turbidity (0 to 210 NTU) and IFE (absorbance 254 nm > 0.200). Only temperature needs to be corrected for humic substances-like fluorescent compounds since other effects were not observed over the studied ranges of absorbance and turbidity. The fluorescence intensity correction method was applied first to each matrix effect separately and then combined by using a sequential mathematical correction methodology. An efficient methodology for determining the matrix effect correction equations for DOM fluorescence analysis into unfiltered urban sewage samples has been highlighted and could be used for in situ fluorescence measurement devices.


Assuntos
Substâncias Húmicas/análise , Esgotos , Espectrometria de Fluorescência , Temperatura , Águas Residuárias
10.
Water Sci Technol ; 81(8): 1786-1796, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32644971

RESUMO

The increase of fluorescent natural organic matter (fNOM) fractions during drinking water treatment might lead to an increased coagulant dose and filter clogging, and can be a precursor for disinfection by-products. Consequently, efficient fNOM removal is essential, for which characterisation of fNOM fractions is crucial. This study aims to develop a robust monitoring tool for assessing fNOM fractions across water treatment processes. To achieve this, water samples were collected from six South African water treatment plants (WTPs) during winter and summer, and two plants in Belgium during spring. The removal of fNOM was monitored by assessing fluorescence excitation-emission matrices datasets using parallel factor analysis. The removal of fNOM during summer for South African WTPs was in the range 69-85%, and decreased to 42-64% in winter. In Belgian WTPs, fNOM removal was in the range 74-78%. Principal component analysis revealed a positive correlation between total fluorescence and total organic carbon (TOC). However, TOC had an insignificant contribution to the factors affecting fNOM removal. Overall, the study demonstrated the appearance of fNOM in the final chlorinated water, indicating that fNOM requires a customised monitoring technique.


Assuntos
Água Potável , Poluentes Químicos da Água/análise , Purificação da Água , Bélgica , Desinfecção , Análise Fatorial , Substâncias Húmicas/análise , Espectrometria de Fluorescência
11.
Nucleic Acids Res ; 48(14): 7623-7639, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32644123

RESUMO

RNA therapeutics are a promising strategy to treat genetic diseases caused by the overexpression or aberrant splicing of a specific protein. The field has seen major strides in the clinical efficacy of this class of molecules, largely due to chemical modifications and delivery strategies that improve nuclease resistance and enhance cell penetration. However, a major obstacle in the development of RNA therapeutics continues to be the imprecise, difficult, and often problematic nature of most methods used to measure cell penetration. Here, we review these methods and clearly distinguish between those that measure total cellular uptake of RNA therapeutics, which includes both productive and non-productive uptake, and those that measure cytosolic/nuclear penetration, which represents only productive uptake. We critically analyze the benefits and drawbacks of each method. Finally, we use key examples to illustrate how, despite rigorous experimentation and proper controls, our understanding of the mechanism of gymnotic uptake of RNA therapeutics remains limited by the methods commonly used to analyze RNA delivery.


Assuntos
RNA/metabolismo , RNA/uso terapêutico , Aptâmeros de Nucleotídeos/uso terapêutico , Núcleo Celular/metabolismo , Citosol/metabolismo , Doenças Genéticas Inatas/tratamento farmacológico , Técnicas Genéticas , Humanos , MicroRNAs/uso terapêutico , Microscopia Eletrônica , Oligonucleotídeos Antissenso/uso terapêutico , RNA/química , RNA/farmacocinética , RNA Interferente Pequeno/uso terapêutico , Espectrometria de Fluorescência
12.
Water Res ; 182: 116005, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32645457

RESUMO

Terrestrial organic matter occupies an important position in the oceanic organic carbon pool. Some terrestrial proxies, like the Branched and Isoprenoid Tetraether (BIT) index, have been applied successfully to indicate the relative abundance of terrestrial organic matter in marine sediments. A new terrestrial proxy derived from sediment pore water fluorescent dissolved matter (fluorescent dissolved organic matter (FDOM)) was developed in this study. Surface sediment samples were collected from forty-two sites in the coastal region of the East China Sea (ECS) to examine the distributional patterns of FDOM. Three protein-like components (C1, C4 and C5) and two humic-like components (C2 and C3) of FDOM were identified using fluorescence excitation-emission matrices parallel factor analysis (EEMs-PARAFAC). Spatially, the intensity of these five components generally increased from the coast to the ocean with protein-like components showing a more obvious trend, which suggested that all five components had autochthonous contribution. However, the C2 and C3 proportions, especially C2 that mainly corresponds to the proportion of peak A in fluorescence excitation-emission matrices, significantly decreased from the coast to the ocean and significantly correlated with the BIT index from corresponding solid fractions. We posit that part of the humic-like components from terrestrial organic matter in sediments are released into the C2 and C3 pools in pore waters, which may be constrained by specific environmental conditions. Thus, the FDOM from pore waters can be integrated with BIT index to validate the nature of FDOM and use it as a biomarker to reflect the terrestrial input of organic matter mediated by different biogeochemical processes in coastal oceans. The proportion of peak A responsible for the fluorescence of C2 was suggest as a new terrestrial derived from FDOM.


Assuntos
Corantes , China , Análise Fatorial , Oceanos e Mares , Espectrometria de Fluorescência
13.
Water Res ; 183: 116125, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32650297

RESUMO

This study aims to extend and demonstrate the application of fluorescence spectroscopy for monitoring the water quality of three differently operated full-scale drinking water treatment plants located in the Shenzhen city (China). A ratio of fluorescent dissolved organic matter (FDOM), which describes relative changes in humic-like to protein-like fluorescence, was used to explain mechanisms behind the physicochemical processes. The fluorescence components obtained through individual and combined parallel factor analysis (PARAFAC) modeling revealed the presence of humic-like (C1) and protein-like (C2) structures in the DOM. The C1/C2 ratio provided a direct relationship between the seasonal variations and DOM composition. Wet season generated DOM enriched with humic-like fluorescence, while dry season caused a higher release of protein-like fluorescence. The fluorescence ratio presented unique patterns of DOM in treatment trains. The chemical pretreatment and disinfection unit processes showed a higher tendency to remove the humic-like fluorescence. However, the C1/C2 ratio increased during physical treatment processes such as coagulation-precipitation and sand filtration, indicating preferential removal of protein-like fluorescence. The DOM composition in influent directly (R2 = 0.77) influenced the relative intensities of fluorescence components in the treated water. Compared to the dry season, the wet season caused significant changes in DOM composition and produced treated water enriched with humic-like fluorescence. This fluorescence ratio offers an approach to explore the role of different treatment units and determine the factors affecting the composition of DOM in the surface water and drinking water treatment plants.


Assuntos
Água Potável/análise , Purificação da Água , China , Análise Fatorial , Substâncias Húmicas/análise , Espectrometria de Fluorescência , Qualidade da Água
14.
Chemosphere ; 259: 127396, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32645596

RESUMO

The performance of the UV/H2O2 advanced oxidation process (AOP) is dependent on water quality parameters, including the UV absorbance coefficient at 254 nm and hydroxyl radical (•OH) water background demand (scavenging factor, s-1). The •OH scavenging factor represents the •OH scavenging rate of the background substances in the water matrix, and it is known to be one of the key parameters to predict the performance of the UV/H2O2 process. The •OH scavenging factor has been determined experimentally by using a probe compound such as pCBA and rhodamine B. The experimental method has been validated to accurately predict the micropollutants removal in the UV/H2O2 process, but there is a need for an easier and simple method of determining the OH scavenging factor. We evaluated the alternative method to analyze the •OH scavenging factor using fluorescence excitation-emission matrix and parallel factor analysis (F-EEM/PARAFAC). The correlation between •OH scavenging factor and the spectroscopic characteristics and structure of different organic matter types was evaluated. Organic matter was characterized using a fluorescence excitation-emission matrix, parallel factor analysis, and liquid chromatography-organic carbon detection. Second-order reaction rates of humic acid sodium salt, sodium alginate, Suwannee River humic acid and bovine serum albumin were calculated as 1.30 × 108 M-1 s-1, 1.39 × 108 M-1 s-1, 1.03 × 108 M-1 s-1, and 3.17 × 107 M-1 s-1, respectively. Results of PARAFAC analysis, the ratio of humic and fulvic fluorescence component 2 to terrestrial humic-like fluorescence component 1 (C2/C1), and •OH scavenging factor showed high linearity. A predictive model, which combines with the F-EEM/PARAFAC method, predicted the optimal UV and H2O2 dose to achieve target compound removal.


Assuntos
Poluentes Químicos da Água/química , Purificação da Água/métodos , Análise Fatorial , Fluorescência , Substâncias Húmicas/análise , Peróxido de Hidrogênio/análise , Radical Hidroxila/química , Oxirredução , Rios/química , Espectrometria de Fluorescência/métodos , Água/análise , Poluentes Químicos da Água/análise , Qualidade da Água
15.
Food Chem ; 333: 127432, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32659661

RESUMO

The sensory qualities and shelf life of tea beverage strongly affected by tea cream that forms by the interaction of polyphenols and protein. The study aimed to investigate the effects of the interactions between tea polyphenols (TPs) and bovine serum albumin (BSA) on tea cream formation at different concentrations. The tea cream formation increased with TPs and BSA concentration increased. The optimal concentration (TPs: 800 mg/L, BSA: 40 mg/L), for high clarities and contents of phytochemicals, was selected by the technique for order preference by similarity to ideal solution (C = 0.7572). The interaction mechanism of TPs-BSA was investigated by fluorescence spectroscopy, UV-visible absorption spectroscopy, synchronous fluorescence spectroscopy, and molecular docking. TPs interacted with BSA via static quenching process, affecting tryptophan and tyrosine residue microenvironment of BSA. Ester catechins had more binding affinity than non-ester catechins. Hydrogen bonds were the main interaction forces of TPs-BSA.


Assuntos
Polifenóis/química , Polifenóis/metabolismo , Soroalbumina Bovina/química , Chá/química , Animais , Sítios de Ligação , Catequina/química , Catequina/metabolismo , Precipitação Química , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Tamanho da Partícula , Soroalbumina Bovina/metabolismo , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Chá/metabolismo , Termodinâmica
16.
Water Res ; 183: 116096, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32717651

RESUMO

N-nitrosamines have been identified as emerging contaminants with tremendous carcinogenic potential for human beings. This study examined the seasonal changes in the occurrence of N-nitrosamines and N-nitrosodimethylamine formation potential (NDMA-FP) in drinking water resources and potable water from 10 drinking water treatment plants in a southern city of China. The changes in N-nitrosamines are well correlated with dissolved organic matter (DOM), particularly fluorophores, which were measured and compared between traditional fluorescence indices and excitation-emission matrix coupled with parallel factor analysis (EEM-PARAFAC). Four of N-nitrosamine species including N-nitrosodimethylamine (NDMA), N-Nitrosodibutylamine (NDBA), N-Nitrosopyrrolidine (NPYR), and N-Nitrosodiphenylamine (NDPhA) are found to be abundant compounds with an average of 29.5% (26.7%), 20.0% (25.2%), 18.9% (16.0%), and 9.0% (9.9%) in the source (and treated) water, respectively. The sum of N-nitrosamines concentration is recorded to be low in the wet season (July-September), whereas the dry season (October-December) provided opposite impacts. EEM-PARAFAC modeling indicated the predominance of humic-like component (C1) in the wet season while in the dry season the water was dominant in protein-like component (C2). All the N-nitrosamines excluding NDPhA and N-Nitrosomorpholine (NMOR) showed a strong association with protein-like component (C2). In contrast, humic-like C1, which was directly influenced by rainfall, was found to be a suitable proxy for NMOR and NDPhA. The results of this study are valuable to understand the correlation between different N-nitrosamines and DOM through adopting fluorescence signatures.


Assuntos
Água Potável/análise , Nitrosaminas/análise , Poluentes Químicos da Água/análise , China , Cromatografia Líquida , Análise Fatorial , Humanos , Substâncias Húmicas , Estações do Ano , Espectrometria de Fluorescência , Espectrometria de Massas em Tandem
17.
Food Chem ; 333: 127528, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32682231

RESUMO

Endogenous lipase and lipoxygenase play important roles in accelerating lipid oxidation. Polyphenols are a series of commonly used chemicals for preserving fish and seafood products, due to their positive inhibitory effects on lipid oxidation. However, the mechanism involved is still unknown. The inhibitory effects of chlorogenic acid (CGA) on lipase and lipoxygenase were investigated and explored with multi- spectroscopic and molecular docking approaches. Results showed that CGA could inhibit the activities of lipase and lipoxygenase with concentration increased in a highly dose-dependent manner. CGA quenched intrinsic fluorescence intensities of enzymes by static quenching and binding with CGA which led to changes in 3D structures of enzymes. Results of the molecular docking confirmed binding modes, binding sites and major interaction forces between CGA and enzymes, which reduced the corresponding activity. Thus, this study could provide basic mechanisms of the inhibitory effects of polyphenols on lipid oxidation during food preservation.


Assuntos
Ácido Clorogênico/metabolismo , Ácido Clorogênico/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Inibidores de Lipoxigenase/metabolismo , Inibidores de Lipoxigenase/farmacologia , Simulação de Acoplamento Molecular , Animais , Sítios de Ligação , Conservação de Alimentos , Lipase/antagonistas & inibidores , Lipase/química , Lipase/metabolismo , Lipoxigenase/química , Lipoxigenase/metabolismo , Oxirredução/efeitos dos fármacos , Polifenóis/farmacologia , Espectrometria de Fluorescência
18.
An Acad Bras Cienc ; 92(1): e20190819, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32491127

RESUMO

Herbal-flavonoids (HF) as polyphenolic secondary metabolites are taken in the daily diet to join in many metabolic processes in the human organism. Anti-proliferative activities and human serum albumin (HSA) binding capacities of herbal-flavonoids namely 7,5'-dimethoxyisoetin (HF1), homoorientin-6''-4-O-methyl-myo-inositol (HF2), (2R, 3R)-(+)-dihydrokaempferol-7,4'-dimethylether (HF3), eriodictyol-7,4'-dimethylether (HF4) and flavonoids isoorientin (HF5) and genkwanin (HF6) were investigated. Anti-proliferative activities were determined by the xCELLigence system by treatment with human prostate (PC3) and cervical cancer (HeLa) cells. The binding capacities were studied by two-dimensional (2D-FL) and three-dimensional (3D-FL) fluorescence spectroscopy. HeLa and PC3 cell lines were treated with flavonoids at 10, 50 and 100 µg/mL concentrations over a 48 hour period. Stable anti-proliferative efficacy plots were obtained for tested flavonoids. From the flavonoids, HF3 and HF4 showed the strongest anti-proliferative effect against PC3 and HeLa cell line. HF1 and HF2 exhibited the strongest binding capacity to the HSA corresponding to Kb values of 3.81 x 104 M-1 and 6.00 x 104 M-1, respectively. The studies revealed that the flavonoids form the basis of in vivo preclinical studies as important nutraceuticals of the daily diet, as well as modelled in medical and pharmacological applications.


Assuntos
Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Albumina Sérica Humana/efeitos dos fármacos , Flavonoides/química , Células HeLa , Humanos , Espectrometria de Fluorescência
19.
Sci Total Environ ; 738: 139419, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32521357

RESUMO

We explore in-situ fluorescence spectroscopy as an instantaneous indicator of total bacterial abundance and faecal contamination in drinking water. Eighty-four samples were collected outside of the recharge season from groundwater-derived water sources in Dakar, Senegal. Samples were analysed for tryptophan-like (TLF) and humic-like (HLF) fluorescence in-situ, total bacterial cells by flow cytometry, and potential indicators of faecal contamination such as thermotolerant coliforms (TTCs), nitrate, and in a subset of 22 samples, dissolved organic carbon (DOC). Significant single-predictor linear regression models demonstrated that total bacterial cells were the most effective predictor of TLF, followed by on-site sanitation density; TTCs were not a significant predictor. An optimum multiple-predictor model of TLF incorporated total bacterial cells, nitrate, nitrite, on-site sanitation density, and sulphate (r2 0.68). HLF was similarly related to the same parameters as TLF, with total bacterial cells being the best correlated (ρs 0.64). In the subset of 22 sources, DOC clustered with TLF, HLF, and total bacterial cells, and a linear regression model demonstrated HLF was the best predictor of DOC (r2 0.84). The intergranular nature of the aquifer, timing of the study, and/or non-uniqueness of the signal to TTCs can explain the significant associations between TLF/HLF and indicators of faecal contamination such as on-site sanitation density and nutrients but not TTCs. The bacterial population that relates to TLF/HLF is likely to be a subsurface community that develops in-situ based on the availability of organic matter originating from faecal sources. In-situ fluorescence spectroscopy instantly indicates a drinking water source is impacted by faecal contamination but it remains unclear how that relates specifically to microbial risk in this setting.


Assuntos
Carbono , Microbiologia da Água , Monitoramento Ambiental , Fluorescência , Senegal , Espectrometria de Fluorescência
20.
Environ Sci Pollut Res Int ; 27(26): 32856-32873, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32524401

RESUMO

The source regions of the Yangtze and Yellow Rivers on the Qinghai-Tibet Plateau are extremely important water resources and ecological functional areas in China, and the ecological environment is fragile and sensitive to climate change. Chromophoric dissolved organic matter (CDOM) is an important component that plays a crucial role in the biogeochemical cycle in aquatic ecosystems. However, knowledge of the distribution characteristics of CDOM in this area is limited. In this study, the optical properties, possible sources of CDOM, and their relationships with environmental variables were investigated in the two regions. The results indicated that the CDOM absorption spectra of these two source regions had a high degree of consistency, and the absorption coefficient aCDOM(355) was small, with a mean of 2.07 ± 1.10 m-1. Two fluorescence components (C1 and C2) were identified and grouped into the humic-like component with parallel factor analysis (PARAFAC) of fluorescence excitation-emission matrices (EEMs), which exhibited highly similar (excitations/emission)max positions between each pair of components in the two regions. Comprehensive CDOM spectral absorption and fluorescence parameters suggested that CDOM was mainly derived from externally input humus, and the source region of the Yellow River showed stronger allochthonous sources. The dissolved organic carbon (DOC) gradients in the water affected the fluorescence intensity and indicated that the humic-like component was an important component of DOC. Water temperature (WT) and turbidity (Turb) positively affected the concentration of CDOM and the ability to absorb light in the aquatic ecosystems. Due to global warming, the rising temperature may lead to an increase in meltwater inflow in the source area and will also bring more external inputs through the runoff.


Assuntos
Monitoramento Ambiental , Rios , China , Ecossistema , Espectrometria de Fluorescência , Tibet
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