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1.
Food Chem ; 338: 127800, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798815

RESUMO

For the first time, a method is proposed for colorimetric determination of reducing sugars in cachaça employing digital image and a smartphone as detector. The method was based on the reduction of Cu(II) to Cu(I) by sugars and followed by the formation of a colored Cu(I)-Neocuproine complex. A calibration curve was linear from 0.1 to 15 g L-1 for glucose and fructose with limits of detection of 0.012 g L-1 and 0.010 g L-1, respectively. It was observed that the non-aged cachaças, known for having inferior flavors and aromas, had a reducing sugar content three times higher than the aged cachaças, once a common practice among producers is to add sugar to adjust sensory deficits in the final product. Furthermore, the method is simple, does not require complex technical knowledge and it could be used as a tool to check possible fraud, adulteration or non-compliance to the law.


Assuntos
Bebidas Alcoólicas/análise , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Smartphone , Açúcares/análise , Colorimetria/instrumentação , Colorimetria/métodos , Cobre/química , Desenho de Equipamento , Contaminação de Alimentos/análise , Frutose/análise , Glucose/análise , Fenantrolinas/química , Saccharum
2.
Food Chem ; 340: 127919, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889210

RESUMO

Non-enzymatic electrochemical sensors for the monitoring of reducing sugars in foods has great potential as a rapid in-situ detection method. This development involved the assembly of a nanoporous platinum structure on a screen-printed carbon electrode (SPCE). The modified electrode was then employed as an amperometric sensing element in a flow injection analysis (FIA) manifold. The system was successfully applied to the rapid detection of reducing sugars in potatoes, without the need for sample preparation. Optimal signals were achieved in phosphate buffer (pH 7.4) at a flow rate of 0.5 mL min-1 and an applied potential of 0.6 V. Experimental results demonstrated the sensor's long-term stability and high selectivity for reducing sugars. This method provides high sample throughput due to a rapid response time of less than five seconds. Reducing sugar values determined were in good agreement with those recorded using a commercially available enzymatic assay kit.


Assuntos
Técnicas Eletroquímicas/métodos , Eletrodos , Análise de Injeção de Fluxo/métodos , Análise de Alimentos/métodos , Solanum tuberosum/química , Açúcares/análise , Carbono/química , Técnicas Eletroquímicas/instrumentação , Análise de Injeção de Fluxo/instrumentação , Análise de Alimentos/instrumentação , Frutose/análise , Sucos de Frutas e Vegetais/análise , Glucose/análise , Nanoestruturas/química , Platina/química , Propriedades de Superfície
3.
Medicine (Baltimore) ; 99(46): e23211, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33181703

RESUMO

Dietary intake influences gut microbiota activity. Nevertheless, there is a lack of evidence available that illustrates the acute effects of high glucose meal on metabolic endotoxemia. The present study assessed the acute impact of high glucose meal on endotoxemia and other clinical parameters in Saudi females with varying degrees of glycemia.The subjects were 64 consenting pre-menopausal women, grouped into 3: control [n = 14 lean, non-T2DM, BMI = 22.2 ±â€Š2.2 kg/m]; overweight [n = 16, non-T2DM, BMI = 28.5 ±â€Š1.5 kg/m] and T2DM [n = 34, BMI = 35.2 ±â€Š7.7 kg/m]. After an overnight fast, all subjects were given a standardized high-glucose (75 g) meal. Anthropometrics were taken and blood samples were withdrawn at baseline and postprandial (0, 2 and 4-hours), serum glucose, endotoxin and lipid profile were quantified.At baseline, total cholesterol, LDL-cholesterol, triglycerides and serum glucose levels were significantly higher (P values <.01) whereas significantly lower HDL-cholesterol levels (P < .01) were observed in T2DM subjects compared to other groups. Baseline endotoxin levels were highest in the overweight group (3.2 ±â€Š1.1 mmol/L) as compared to control (2.0 ±â€Š0.5 mmol/L) and T2DM (2.7 ±â€Š1.2 mmol/L) (P = .046). HDL-cholesterol, LDL-cholesterol and triglycerides, significantly decreased in the T2DM group after 2 hours (P values <.05), whereas unremarkable changes observed in other groups. Lastly, endotoxin levels significantly increased only in the overweight group (3.2 ±â€Š1.1 vs 4.2 ±â€Š1.4 mmol/L; P < .05), 4 hours postprandial.High glucose meal elevates endotoxemia only among overweight subjects and impairs dysbiosis.


Assuntos
Endotoxemia/complicações , Glucose/análise , Obesidade/complicações , Administração Oral , Adulto , Árabes/classificação , Árabes/estatística & dados numéricos , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Endotoxemia/fisiopatologia , Jejum/sangue , Jejum/metabolismo , Feminino , Humanos , Lipídeos/análise , Lipídeos/sangue , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Prevalência , Arábia Saudita
4.
JAMA Netw Open ; 3(10): e2023934, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33125498

RESUMO

Importance: The coronavirus disease 2019 (COVID-19) pandemic has placed unprecedented stress on health systems across the world, and reliable estimates of risk for adverse hospital outcomes are needed. Objective: To quantify admission laboratory and comorbidity features associated with critical illness and mortality risk across 6 Eastern Massachusetts hospitals. Design, Setting, and Participants: Retrospective cohort study of all individuals admitted to the hospital who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by polymerase chain reaction across these 6 hospitals through June 5, 2020, using hospital course, prior diagnoses, and laboratory values in emergency department and inpatient settings from 2 academic medical centers and 4 community hospitals. The data were extracted on June 11, 2020, and the analysis was conducted from June to July 2020. Exposures: SARS-CoV-2. Main Outcomes and Measures: Severe illness defined by admission to intensive care unit, mechanical ventilation, or death. Results: Of 2511 hospitalized individuals who tested positive for SARS-CoV-2 (of whom 50.9% were male, 53.9% White, and 27.0% Hispanic, with a mean [SD ]age of 62.6 [19.0] years), 215 (8.6%) were admitted to the intensive care unit, 164 (6.5%) required mechanical ventilation, and 292 (11.6%) died. L1-regression models developed in 3 of these hospitals yielded an area under the receiver operating characteristic curve of 0.807 for severe illness and 0.847 for mortality in the 3 held-out hospitals. In total, 212 of 292 deaths (72.6%) occurred in the highest-risk mortality quintile. Conclusions and Relevance: In this cohort, specific admission laboratory studies in concert with sociodemographic features and prior diagnosis facilitated risk stratification among individuals hospitalized for COVID-19.


Assuntos
Infecções por Coronavirus/complicações , Estado Terminal , Mortalidade Hospitalar/tendências , Pneumonia Viral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Betacoronavirus/patogenicidade , Nitrogênio da Ureia Sanguínea , Proteína C-Reativa/análise , Técnicas de Laboratório Clínico , Estudos de Coortes , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/urina , Creatinina/análise , Creatinina/sangue , Estado Terminal/epidemiologia , Eosinófilos , Contagem de Eritrócitos/métodos , Feminino , Glucose/análise , Hospitalização/estatística & dados numéricos , Humanos , Hidroliases/análise , Hidroliases/sangue , Contagem de Linfócitos/métodos , Masculino , Massachusetts/epidemiologia , Pessoa de Meia-Idade , Monócitos , Neutrófilos , Pandemias , Contagem de Plaquetas/métodos , Pneumonia Viral/epidemiologia , Pneumonia Viral/fisiopatologia , Reação em Cadeia da Polimerase/métodos , Curva ROC , Estudos Retrospectivos , Troponina T/análise , Troponina T/sangue
5.
Sci Rep ; 10(1): 16747, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028896

RESUMO

Chronotype has been mostly assessed with subjective scales. Objective assessment has been undertaken with actigraphy, although problems may occur in classifying chronotype. The aims of the study were to assess chronotype in school-age children using a novel integrative measurement (TAP) derived from non-invasive assessments of wrist temperature (T) physical activity (A) and body position (P) and to explore associations between chronotype, sleep disturbances, and metabolic components. Four-hundred-thirty-two children of 8-12 years were recruited from a Mediterranean area of Spain. Measurements were: (a) Chronotype objectively (7-day-rhythms of TAP) and subjectively measured (Munich-chronotype-self-reported questionnaire); (b) sleep rhythms and light exposition; (c) 7-day-diaries of food intake; (d) anthropometry and metabolic parameters; (e) academic scores. TAP acrophase was able to assess eveningness. As compared to more morning-types, more evening-types displayed lower amplitude in temperature rhythms, increased physical activity in the evening, delayed sleep and midpoint of intake and had more frequent social jet lag (P < 0.05). More evening-types had higher light intensity at 2 h before sleep and lower melatonin values (01:00 h). Eveningness associated with higher BMI and metabolic risk (higher values of insulin, glucose, triglycerides and cholesterol). Evening-types presented better grades in art. In conclusion, more evening-types, as objectively assessed, presented sleep alterations, social jet lag, obesity and higher metabolic risk.


Assuntos
Sucesso Acadêmico , Ritmo Circadiano/fisiologia , Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Individualidade , Comportamento Social , Actigrafia , Criança , Colesterol/análise , Feminino , Glucose/análise , Humanos , Insulina/análise , Masculino , Melatonina/análise , Saliva/química , Sono , Espanha , Inquéritos e Questionários , Triglicerídeos/análise
6.
Sci Rep ; 10(1): 15633, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973226

RESUMO

The authors examine study participants who have Type 2 diabetes to determine whether cognition affects glucose levels in contrast to widely held suppositions. Thirty participants who have type 2 diabetes consume beverages that have identical ingredients but have deceptive nutrition facts labels. Blood glucose levels measured four times before and after beverage consumption show that blood glucose levels increase when participants believe the beverage has high sugar content as portrayed on the labels. Also, individual eating behaviors and nutritional satisfaction are linked to changes in blood glucose levels. The study results support the concept of anticipatory budgeting on glucose metabolism. The findings provide pressing evidence for the psychobiological model of chronic disease, suggesting that psychological intervention programs may be important for diabetes management, beyond current programs in which type 2 diabetes is managed through diet, exercise, and medications only.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/psicologia , Ingestão de Alimentos/psicologia , Ingestão de Energia , Glucose/análise , Glucose/metabolismo , Açúcares/administração & dosagem , Dieta , Humanos , Estado Nutricional , Edulcorantes/administração & dosagem
7.
Int J Nanomedicine ; 15: 6619-6629, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32982222

RESUMO

Background: Diabetes is a complex metabolic disorder known to induce a high blood glucose level that fluctuates outside the normal range. Diabetes affects and damages the organs in the body and causes heart issues, blindness and kidney failure. Continuous monitoring is mandatory to keep the blood glucose level within a healthy range. Materials and Methods: This research was focused on diagnosing diabetes mellitus on zeolite nanoparticle-polyethylene glycol complex-immobilized interdigitated electrode sensor (IDE) surfaces. Zeolite nanoparticles were extracted from the fly ash of a thermal power plant by alkaline extraction. The surface morphology of the synthesized nanoparticles was observed by field-emission scanning electron microscopy and transmission electron microscopy, and the presence of certain elements and the particle size were determined by energy-dispersive X-ray spectroscopy and particle size analysis, respectively. Results: The crystalline PEG-zeolite nanoparticles were synthesized with a size of 40±10 nm according to high-resolution microscopy. A particle size analyzer revealed the sizes of the fly ash and PEG-zeolite particles as 60±10 µm and 50±10 nm, respectively. The IDE surface was evaluated for its ability to display antifouling properties and sense glucose levels on the abovementioned nanoparticle-modified surface. Glucose oxidase was probed on the PEG-zeolite-modified IDE surface, and glucose was detected. PEG zeolite performed well with excellent antifouling properties on the IDE sensor surface and improved the glucose detection limit to 0.03 mg/mL from 0.08 mg/mL, as determined by linear regressions [y = 5.365x - 6.803; R2 = 0.9035 (zeolite surface) and y = 5.498x + 5.914R2 = 0.9061 (PEG-zeolite surface)]. This enhancement was ~3-fold, and sensitivities were found to be 0.03 and 0.06 mg/mL glucose for the PEG-zeolite- and zeolite-modified surfaces, respectively, showing a 2-fold difference. Conclusion: The excellent biocompatible surface modified by PEG zeolite exhibited high performance and is useful for medical diagnosis.


Assuntos
Cinza de Carvão/química , Eletrodos , Glucose/análise , Nanopartículas/química , Zeolitas/química , Diabetes Mellitus/diagnóstico , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Limite de Detecção , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Polietilenoglicóis/química , Soroalbumina Bovina/química , Espectrometria por Raios X
8.
Food Chem ; 331: 127348, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32619908

RESUMO

Information concerning food composition, including information on its glucose content, is essential for modern food industry due to greater consumer awareness and expectations. In this work, the gene encoding d-glucose dehydrogenase (GDH) from Bacillus Natto was expressed in Escherichia coli BL21(DE3) firstly. Ni-IDA column was used for the purification of GDH. Then, the purified GDH was used to construct a color system with stable and effective measurement of concentration of d-glucose. The smart phone photographing and the software Microsoft Photoshop have been used in the system for determination of the color. The enzymatic analysis system can detect the concentration of d-glucose from 5 mM to 40 mM, and other various sugars has no interference to the system. The system was used to quantitatively detect the concentration of d-glucose in honey. The system can be used for convenient and rapid detection of d-glucose in food, especially for large numbers of samples.


Assuntos
Análise de Alimentos/métodos , Glucose/análise , Mel/análise , Smartphone , Bacillus/genética , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cor , Escherichia coli/genética , Análise de Alimentos/instrumentação , Glucose 1-Desidrogenase/genética , Glucose 1-Desidrogenase/metabolismo , Concentração de Íons de Hidrogênio , Limite de Detecção , Software
10.
J Vis Exp ; (158)2020 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-32364543

RESUMO

Lignocellulosic materials are plant-derived feedstocks, such as crop residues (e.g., corn stover, rice straw, and sugar cane bagasse) and purpose-grown energy crops (e.g., miscanthus, and switchgrass) that are available in large quantities to produce biofuels, biochemicals, and animal feed. Plant polysaccharides (i.e., cellulose, hemicellulose, and pectin) embedded within cell walls are highly recalcitrant towards conversion into useful products. Ammonia fiber expansion (AFEX) is a thermochemical pretreatment that increases accessibility of polysaccharides to enzymes for hydrolysis into fermentable sugars. These released sugars can be converted into fuels and chemicals in a biorefinery. Here, we describe a laboratory-scale batch AFEX process to produce pretreated biomass on the gram-scale without any ammonia recycling. The laboratory-scale process can be used to identify optimal pretreatment conditions (e.g., ammonia loading, water loading, biomass loading, temperature, pressure, residence time, etc.) and generates sufficient quantities of pretreated samples for detailed physicochemical characterization and enzymatic/microbial analysis. The yield of fermentable sugars from enzymatic hydrolysis of corn stover pretreated using the laboratory-scale AFEX process is comparable to pilot-scale AFEX process under similar pretreatment conditions. This paper is intended to provide a detailed standard operating procedure for the safe and consistent operation of laboratory-scale reactors for performing AFEX pretreatment of lignocellulosic biomass.


Assuntos
Amônia/farmacologia , Biomassa , Lignina/metabolismo , Biocombustíveis , Reatores Biológicos , Glucose/análise , Poaceae , Temperatura , Xilose/análise
11.
Sci Rep ; 10(1): 8254, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427894

RESUMO

Glucose level is a primary indicator in the diagnosis and treatment of diabetes mellitus. According to the correlation between glucose concentration in blood and tears, measuring tear glucose can be an alternative to traditional strips test for blood glucose. Thus, measuring tear glucose levels could provide noninvasive monitoring of blood glucose. As a biocompatible biosensor, a nanoparticle embedded contact lens (NECL) is developed which is composed of glucose oxidase and cerium oxide (III). Using spectroscopy, we found the detectable changes in reflection spectrum of contact lenses with respect to the glucose concentration, and developed correlation curve of the reflection spectrum with known glucose level. Furthermore, we assessed tear glucose level and compared blood glucose level with the diabetic mouse model to evaluate this approach. Our algorithm for regular monitoring of glucose using contact lens biosensor may lead to noninvasive monitoring of tear glucose level. NECL may provide simple and noninvasive glucose monitoring based on the spectral changes in contact lens biosensor.


Assuntos
Técnicas Biossensoriais/métodos , Automonitorização da Glicemia/métodos , Lentes de Contato , Diabetes Mellitus/metabolismo , Glucose/análise , Animais , Técnicas Biossensoriais/instrumentação , Automonitorização da Glicemia/instrumentação , Diabetes Mellitus/diagnóstico , Feminino , Glucose/metabolismo , Glucose Oxidase/química , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nanopartículas/análise , Lágrimas/química
12.
Chem Commun (Camb) ; 56(40): 5393-5396, 2020 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-32285901

RESUMO

A cytochrome c (Cyt c)-modified glass nanopore sensing platform was constructed to sensitively detect glucose in single cells based on changes in the ionic current rectification (ICR) of the system. A difference in glucose content between single H8 and HeLa cells in their satiety or starvation states was clearly able to be detected using this method.


Assuntos
Vidro/química , Glucose/análise , Nanoporos , Análise de Célula Única/métodos , Citocromos c/química , Técnicas Eletroquímicas/métodos , Glucose/química , Glucose Oxidase/química , Células HeLa , Humanos , Peróxido de Hidrogênio/química , Proteínas Imobilizadas/química , Limite de Detecção , Oxirredução
13.
Mikrochim Acta ; 187(5): 276, 2020 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-32307592

RESUMO

A bimetallic nanostructure of Co/Cu for the non-enzymatic determination of glucose is presented. The heterostructure includes cobalt thin film on a porous array of Cu nanocolumns. Glancing angle deposition (GLAD) method was used to grow Cu nanocolumns directly on a fluorine-doped tin oxide (FTO) substrate. Then a thin film of cobalt was electrodeposited on the Cu nanostructures. Various characterization studies were performed in order to define the optimum nanostructure for the determination of glucose. The results showed remarkable boosting of the electrocatalytic activity of Co/Cu bimetallic structure compare to the responses achieved by the monometallic structures of Co or Cu. The sensor showed two linear response ranges for the determination of glucose at 0.55 V in 0.1 M NaOH, from 5 µM-1 mM and 2-9 mM. The sensitivity was 1741 (µA mM-1 cm-2) and 626 (µA mM-1 cm-2), respectively, while the detection limit for a signal-to-noise ratio of 3 was found to be 0.4 µM. The sensor exhibited excellent selectivity and was successfully applied to the determination of glucose in real human blood serum samples. Graphical Abstract Schematic representation of fabrication process of the glucose sensor of Co (Cobalt)/Cu (Copper) on Fluorine doped Tin Oxide (FTO). The current voltage plots show higher electrooxidation activity of the bimetallic nanostructure of Co/Cu/FTO relative to the bare Co/FTO.


Assuntos
Ligas/química , Técnicas Biossensoriais , Técnicas Eletroquímicas , Glucose/análise , Nanoestruturas/química , Cobalto/química , Cobre/química , Eletrodos , Flúor/química , Humanos , Tamanho da Partícula , Propriedades de Superfície , Compostos de Estanho/química
14.
Mikrochim Acta ; 187(5): 286, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32328802

RESUMO

Rosette-shaped graphitic carbon nitride (rosette-GCN) is described as a promising alternative to natural peroxidase for its application to fluorescence-based glucose assays. Rosette-GCN was synthesized via a rapid reaction between melamine and cyanuric acid for 10 min at 35 °C, followed by thermal calcination for 4 h. Importantly, rosette-GCN possesses a peroxidase-like activity, producing intense fluorescence from the oxidation of Amplex UltraRed in the presence of H2O2 over a broad pH-range of, including neutral pH; the peroxidase activity of rosette-GCN was ~ 10-fold higher than that of conventional bulk-GCN. This enhancement of peroxidase activity is presumed to occur because rosette-GCN has a significantly larger surface area and higher porosity while preserving its unique graphitic structure. Based on the high peroxidase activity of rosette-GCN along with the catalytic action of glucose oxidase (GOx), glucose was reliably determined down to 1.2 µM with a dynamic linear concentration range of 5.0 to 275.0 µM under neutral pH conditions. Practical utility of this strategy was also successfully demonstrated by determining the glucose levels in serum samples. This work highlights the advantages of GCNs synthesized via rapid methods but with unique structures for the preparation of enzyme-mimicking catalysts, thus extending their applications to the diagnostics field and other biotechnological fields. Graphical abstract.


Assuntos
Fluorescência , Glucose Oxidase/química , Glucose/análise , Grafite/química , Peróxido de Hidrogênio/química , Compostos de Nitrogênio/química , Peroxidases/química , Biocatálise , Glucose/metabolismo , Glucose Oxidase/metabolismo , Grafite/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Estrutura Molecular , Compostos de Nitrogênio/metabolismo , Tamanho da Partícula , Peroxidases/metabolismo , Porosidade , Propriedades de Superfície
16.
Anal Chim Acta ; 1111: 49-59, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32312396

RESUMO

Here, an ultrasensitive non-enzymatic glucose sensor was fabricated using a facile and low price electro-deposition method. At first, thiol-functionalized magnetic nanoparticles cast onto the glassy carbon electrode (GCE) surface to provide a stable substrate with the high surface area. Then, CuO nanoparticles and Ag nanoparticles electrodeposit on the surface of Fe3O4-SH/GCE to obtain the final modified GCE. The characterization of electro-synthesized nanoparticles and the modified GCE was done by different related techniques such as field emission scanning electronic microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The proposed electrode was applied to the electrochemical sensing of glucose. By employing the optimum conditions on the preparation of modified electrode such as time and potential for electrosynthesis of two different nanoparticles, high reproducibility of measurement and sensor preparation were achieved. The thus optimized simple glucose sensor could be provided stable responses in a wide linear range from 0.06 to 1000 µM with detection limit 15 nM, indicating its potential application for real biological samples.


Assuntos
Cobre/química , Glucose/análise , Nanopartículas Metálicas/química , Nanocompostos/química , Prata/química , Técnicas Biossensoriais , Teoria da Densidade Funcional , Espectroscopia Dielétrica , Eletrodos , Humanos , Fenômenos Magnéticos , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Propriedades de Superfície
17.
Anal Chim Acta ; 1111: 8-15, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32312400

RESUMO

Recently, the use of atomic spectrometry (AS) for biochemical analysis has attracted considerable attention due to its high sensitivity, selectivity and anti-interference ability. In this work, we conducted a detailed study on a phenomenon of thiol inhibition of mercury (Hg2+) cold vapor generation (CVG) and found L-cysteine (L-Cys), glutathione (GSH), dithiothreitol, N-Acetyl-L-cysteine, 3-mercaptopropionic acid, ß-mercaptoethanol, and NaI can inhibit the CVG of Hg2+, while EDTA has no inhibitory effect. Furthermore, changing the content of -SH can effectively adjust the CVG atomic fluorescence spectrometer (CVG-AFS) signal of Hg2+. As as a consequence, an AS-based homogeneous bioassay was constructed by adjusting the oxidation ratio and production quantity of -SH in the system. The quantitative analysis of the system was demonstrated by using AFS as a representative detector. Hydrogen peroxide (H2O2) and glucose were used as representative analytes for the validation of Hg2+ atomic fluorescence signal turn-off strategy, and butyrylcholinesterase (BChE) as well as parathion (organophosphorus pesticides, OPs) as utilized as representative targets for the signal turn-on strategy. Under optimal experimental conditions, the homogeneous CVG-AFS sensor can be successfully used to detect 3 µM H2O2, 30 µM glucose, 0.25 U/L BChE, and 0.4 µg/mL parathion. In addition, the detection results of glucose and BChE in human serum samples agreed well with those obtained by using glucometer and kit, showing the promising potential of this method for practical applications. Therefore, this work provides a perspective for the construction of AS-based homogeneous bioassays and shows great potential for the detection of biomarkers.


Assuntos
Butirilcolinesterase/análise , Glucose/análise , Peróxido de Hidrogênio/análise , Praguicidas/análise , Bioensaio , Boroidretos/química , Butirilcolinesterase/metabolismo , Humanos , Mercúrio/química , Espectrofotometria Atômica , Compostos de Sulfidrila/química , Compostos de Estanho/química , Volatilização
18.
Mater Sci Eng C Mater Biol Appl ; 109: 110575, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32228910

RESUMO

We report a straightforward route for the preparation of flexible, electrochemically stable and easily functionalizable poly(3,4-ethylenedioxythiophene) (PEDOT) composite films deposited on PET foils as biosensing platforms. For this purpose, poly(allylamine) hydrochloride (PAH) was blended with PEDOT to provide amine-bearing sites for further biofunctionalization as well as to improve the mechanical properties of the films. The conducting PEDOT-PAH composite films were characterized by cyclic voltammetry, UV-vis and Raman spectroscopies. An exhaustive stability study was carried out from the mechanical, morphological and electrochemical viewpoint. Subsequent sugar functionalization of the available amine groups from PAH allowed for the specific recognition of lectins and the subsequent self-assembly of glycoenzymes (glucose oxidase and horseradish peroxidase) concomitant with the prevention of non-specific protein fouling. The platforms presented good bioelectrochemical performance (glucose oxidation and hydrogen peroxide reduction) in the presence of redox mediators. The developed composite films constitute a promising option for the construction of all-polymer biosensing platforms with great potential owing to their flexibility, high transmittance, electrochemical stability and the possibility of glycosylation, which provides a simple route for specific biofunctionalization as well as an effective antifouling strategy.


Assuntos
Aspergillus niger/enzimologia , Técnicas Biossensoriais , Compostos Bicíclicos Heterocíclicos com Pontes/química , Técnicas Eletroquímicas , Proteínas Fúngicas/química , Glucose Oxidase/química , Glucose/análise , Membranas Artificiais , Poliaminas/química , Polímeros/química , Peroxidase do Rábano Silvestre/química
19.
Talanta ; 215: 120922, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32312464

RESUMO

We present here wearable devices for continuous monitoring of diabetes and hypoxia based on continuous analysis of sweat. To induce sweating the clinically relevant procedure (pilocarpine electrophoresis) is used. Being a sufficient requirement for diagnostics, positive correlations in variation rates between glucose and lactate concentrations in sweat and the corresponding values in blood are shown. Continuous monitoring of human condition is possible only with the use of flow-through wearable devices providing a delivery of sweat to the biosensor almost immediately after secretion. Evaluating blood glucose through continuous sweat analysis upon glucose tolerance test, we clearly show that diabetics can actually be monitored reliably via non-invasive approach.


Assuntos
Técnicas Biossensoriais , Diabetes Mellitus/diagnóstico , Glucose/análise , Hipóxia/diagnóstico , Monitorização Fisiológica , Suor/química , Dispositivos Eletrônicos Vestíveis , Diabetes Mellitus/metabolismo , Glucose/metabolismo , Humanos , Hipóxia/metabolismo , Tamanho da Partícula , Propriedades de Superfície
20.
Endocrinol. diabetes nutr. (Ed. impr.) ; 67(4): 235-244, abr. 2020. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-194799

RESUMO

INTRODUCCIÓN: En México, en los últimos años, se ha incrementado la prevalencia de sobrepeso y obesidad, condición que favorece el desarrollo de enfermedades crónico-degenerativas. Implementar estrategias para incrementar en la población el consumo diario de vegetales, leguminosas, cereales de grano entero y frutas implicará una ingesta adecuada de fibra soluble, antioxidantes, proteínas de origen vegetal y vitaminas. OBJETIVO: Evaluar el efecto de un producto alimenticio comercial elaborado a base de 6 leguminosas sobre determinados parámetros antropométricos y bioquímicos en sujetos sanos. MÉTODOS: Ensayo aleatorizado de intervención dietética, en el que los sujetos del grupo de estudio recibieron durante 3 meses 15 g del producto, administrados diariamente en periodos de 5 días con 2 días de descanso. Antes y después de la intervención se realizó una valoración antropométrica y dietética, así como una cuantificación sérica de glucosa, perfil de lípidos, insulina, proteína C reactiva ultrasensible, malondialdehído y resistencia a la insulina (índice HOMA). Se utilizó la prueba U de Mann Whitney y una significación estadística de p < 0,05. RESULTADOS: Se incluyeron 60 estudiantes universitarios (53% hombres). Al término de la intervención, en el grupo de estudio se obtuvo una disminución en los niveles séricos de glucosa (p = 0,001), malondialdehído (p = 0,001) e índice HOMA (p = 0,017), sin cambios significativos en el resto de los parámetros. CONCLUSIONES: La ingesta diaria de 15 g de un producto a base de leguminosas mejoró en el grupo estudiado los niveles séricos de glucosa y malondialdehído, así como la resistencia a la insulina, lo cual podría atribuirse al contenido de polifenoles e isoflavonas como la genisteína, presente en las leguminosas


INTRODUCTION: Prevalence of overweight and obesity, a condition that promotes development of chronic degenerative diseases, has increased in Mexico in recent years. Implementation of strategies to increase daily consumption of vegetables, legumes, whole grain cereals, and fruits by the population will result in an adequate intake of soluble fiber, antioxidants, protein of vegetable origin, and vitamins. OBJECTIVE: To assess the effect of a commercial food product prepared using 6 legumes on some anthropometric and biochemical parameters in apparently healthy subjects. METHODS: A randomized dietary intervention trial where subjects in the study group received for three months 15g of the product, administered daily in periods of five days with two days of rest. Before and after intervention, anthropometric and dietary assessments were performed, and serum glucose, lipid profile, insulin, ultrasensitive C-reactive protein, malondialdehyde (MDA) and insulin resistance (HOMA index) were measured. A Mann-Whitney U test was used and values of P < 0.05 were considered statistically significant. RESULTS: Sixty university students were included in the study (53% males). At the end of the intervention, decreases were seen in serum glucose levels (P = 0.001), MDA (P = 0.001) and HOMA index (P = 0.017), but there were no significant changes in all other parameters. CONCLUSIONS: Daily intake of 15g of the legume-based food product improved serum glucose and malondialdehyde levels in the study group, as well as insulin resistance; which could be attributed to the presence of polyphenols and isoflavones such as genistein in legumes


Assuntos
Adulto , Fabaceae , Malondialdeído/sangue , Lipídeos/sangue , Resistência à Insulina , Glucose/análise , Antropometria , Alimentos Formulados , Sucos de Frutas e Vegetais , Dietética , Biomarcadores/sangue
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