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1.
Sensors (Basel) ; 23(2)2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36679729

RESUMEN

Stable, water-soluble titanium complexed with mandelic acid was used as a precursor for titanium phosphorus double oxide obtained in hydrothermal conditions in the presence of phosphoric acid. Surprisingly, hydrolysis of organic complexes provided a microstructured sphere with narrow size distribution, low aggregation and a small fraction of morphological irregularities. Obtained microspheres had a complex structure comprised of flakes, whose size could be manipulated with temperature conditions. Samples were found to be electrochemically active against sulcotrione, a well-recognized herbicide. Electrochemical sensors based on the synthesized microspheres were successfully adapted for natural water reservoir analysis and exhibited low levels of detection of 0.61 µM, limit of quantification of 1.86 µM, wide dynamic linear range from 2 to 200 µM, good selectivity, excellent reproducibility and in-time stability.


Asunto(s)
Fósforo , Titanio , Titanio/química , Reproducibilidad de los Resultados , Óxidos/química , Agua
2.
Int J Mol Sci ; 23(15)2022 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-35897677

RESUMEN

With the ever-growing concern for human health and wellbeing, the prenatal period of development requires special attention since fetuses can be exposed to various metals through the mother. Therefore, this study explored the status of selected toxic (Pb, Cd, Ni, As, Pt, Ce, Rb, Sr, U) and essential trace metals (Mn, Co, Cu, Zn, Se) in the umbilical cord (UC) sera, maternal sera, and placental tissue samples of 92 healthy women with normal pregnancies. A further aim focuses on the potential transplacental transfer of these trace metals. Based on the obtained levels of investigated elements in clinical samples, it was observed that all of the trace metals cross the placental barrier and reach the fetus. Furthermore, statistical analysis revealed significant differences in levels of toxic Ni, As, Cd, U, Sr, Rb, and essential Mn, Cu, and Zn between all three types of analyzed clinical samples. Correlation analysis highlighted As to be an element with levels that differed significantly between all tested samples. Principal component analysis (PCA) was used to enhance these findings. PCA demonstrated that Cd, Mn, Zn, Rb, Ce, U, and Sr were the most influential trace metals in distinguishing placenta from maternal and UC serum samples. As, Co, and Cu were responsible for the clustering of maternal serum samples, and PCA demonstrated that the Pt level in UC sera was responsible for the clustering of these samples. Overall, the findings of this study could contribute to a better understanding of transplacental transfer of these trace metals, and shed a light on overall levels of metal exposure in the population of healthy pregnant women and their fetuses.


Asunto(s)
Metales Pesados , Oligoelementos , Cadmio , Femenino , Humanos , Metales Pesados/toxicidad , Placenta/química , Embarazo , Análisis de Componente Principal
3.
Angew Chem Int Ed Engl ; 60(14): 7686-7690, 2021 03 29.
Artículo en Inglés | MEDLINE | ID: mdl-33410245

RESUMEN

The effects of photobleaching on electrochemiluminescence (ECL) was investigated for the first time. The plasma membrane of Chinese Hamster Ovary (CHO) cells was labeled with a [Ru(bpy)3 ]2+ derivative. Selected regions of the fixed cells were photobleached using the confocal mode with sequential stepwise illumination or cumulatively and they were imaged by both ECL and photoluminescence (PL). ECL was generated with a model sacrificial coreactant, tri-n-propylamine. ECL microscopy of the photobleached regions shows lower ECL emission. We demonstrate a linear correlation between the ECL decrease and the PL loss due to the photobleaching of the labels immobilized on the CHO membranes. The presented strategy provides valuable information on the fundamentals of the ECL excited state and opens new opportunities for exploring cellular membranes by combining ECL microscopy with photobleaching techniques such as fluorescence recovery after photobleaching (FRAP) or fluorescence loss in photobleaching (FLIP) methods.


Asunto(s)
Membrana Celular/química , Colorantes Fluorescentes/química , Compuestos Organometálicos/química , Animales , Técnicas Biosensibles , Células CHO , Membrana Celular/ultraestructura , Cricetulus , Técnicas Electroquímicas , Mediciones Luminiscentes , Microscopía Confocal , Fotoblanqueo , Propilaminas/química
4.
Environ Res ; 186: 109538, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32334172

RESUMEN

Our previous investigation showed significantly increased arsenic (As) content in thyroid tissue samples of patients with Hashimoto's thyroiditis (HT). This research aimed to extend previous findings and provide reliable insight into the close relationship between As and other trace elements with HT by considering a greater number of thyroid tissue samples, accompanied by blood and urine samples. The essential trace elements for thyroid homeostasis (Mn, Cu, Zn, Se) and the main threatening toxic trace elements (Ni, As, Pb, Cd, U) was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Relevant parameters that could affect the concentration of trace elements were considered. This research showed that there was a difference in the elemental profile between HT and control samples. The most important findings were related to the elevated As and Pb content in the thyroid tissue and HT blood samples. The obtained negative correlations between As and Pb with Se may explain the antagonistic effect of As and Pb on the extrusion of essential Se from the HT tissue. The reduced Se content in the blood and its increased content in urine samples may further confirm this hypothesis and explain the lack of Se in HT. Furthermore, the reported results may highlight the unresolved molecular basis of HT and could indicate the role of trace element effects on thyroid homeostasis.


Asunto(s)
Arsénico , Tiroiditis , Oligoelementos , Arsénico/toxicidad , Humanos , Plomo
5.
J Environ Sci Health B ; 55(12): 1069-1079, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32880524

RESUMEN

Bentazone degradation efficiency and mineralization in water solutions using chlorine dioxide treatment were evaluated. Double distilled water and a river water sample spiked with bentazone were studied and compared after chlorine dioxide treatment. Degradation efficiency was determined using high-performance liquid chromatography (HPLC). Daphnia magna toxicity testing and total organic carbon (TOC) analysis were used to ascertain the toxicity of the degraded solutions and mineralization degree. Bentazone degradation products were identified using gas chromatography with a triple quadrupole mass detector (GC-MS-MS). A simple mechanistic scheme for oxidative degradation of bentazone was proposed based on the degradation products that were identified. Decrease in D. magna mortality, high degradation efficiency and partial bentazone mineralization were achieved by waters containing bentazone degradation products, which indicate the formation of less toxic compounds than the parent bentazone and effective removal of bentazone from the waters. Bentazone degraded into four main degradation products. Humic acid from Sava River water influenced bentazone degradation, resulting in a lower degradation efficiency in this matrix (about 10% lower than in distilled water). Chlorine dioxide treatment of water to degrade bentazone is efficient and offers a novel approach in the development of new technology for removal of this herbicide from contaminated water.


Asunto(s)
Benzotiadiazinas/química , Herbicidas/química , Contaminantes Químicos del Agua/química , Animales , Benzotiadiazinas/toxicidad , Carbono/análisis , Compuestos de Cloro/química , Cromatografía Líquida de Alta Presión , Daphnia/efectos de los fármacos , Cromatografía de Gases y Espectrometría de Masas , Herbicidas/toxicidad , Sustancias Húmicas , Oxidación-Reducción , Óxidos/química , Ríos , Pruebas de Toxicidad , Contaminantes Químicos del Agua/toxicidad , Purificación del Agua/métodos
6.
Environ Monit Assess ; 192(7): 422, 2020 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-32519186

RESUMEN

Chlorine dioxide has been reported as very efficiently removing pesticides and other organic compounds from water matrixes. Due to pesticide toxicity and potential toxicity of their degradation products, it is important to monitor these compounds as environmental pollutants in ground and surface waters. Evaluating the effects of chlorine dioxide treatment is necessary, and toxicity studies are used to ascertain the severity of effects of intermediates due to incomplete degradation of the parent compounds. In this paper, for the first time, chlorine dioxide is applied and evaluated for the removal of chloroacetamide herbicides (pethoxamid and metazachlor) from waters (deionized water and Sava River water). The degradation degree of herbicides was measured by high-performance liquid chromatography, the main degradation products were identified using gas chromatography with a triple quadrupole mass detector, and the degree of mineralization was monitored by total organic carbon analysis. Four and two degradation products were identified after pethoxamid and metazachlor degradation, respectively. Total organic carbon analysis showed mineralization occurred, but it was incomplete. The mineralization and the characteristics of the degradation products obtained were tested using Daphnia magna and showed lower toxicity than the parent herbicides. The advantage of the applied treatment was a very high degradation percentage for pethoxamid removal from deionized water and Sava River water (100% and 97%, respectively), with higher mineralization efficiency (65%) than metazachlor. Slightly lower degradation efficiency in the Sava River water was due to chlorine dioxide oxidizing the herbicides and dissolved organic matter simultaneously.


Asunto(s)
Acetamidas , Compuestos de Cloro , Óxidos , Contaminantes Químicos del Agua , Purificación del Agua , Acetamidas/análisis , Acetamidas/química , Acetamidas/metabolismo , Acetamidas/toxicidad , Animales , Compuestos de Cloro/química , Daphnia/efectos de los fármacos , Ecotoxicología , Óxidos/química , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/toxicidad , Purificación del Agua/métodos
7.
Ecotoxicol Environ Saf ; 169: 402-409, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30469025

RESUMEN

The purpose of this study was to establish reference values (RVs) for the occupationally- and environmentally-important toxic elements in the whole blood of adult Serbian population for the first time. Contaminated drinking water with arsenic, high share of smokers in the country, removing tetraethyl lead from the gasoline and war attack at the end of the twentieth century were some of the reasons to provide background information for arsenic (As), cadmium (Cd), lead (Pb), thorium (Th), and uranium (U) in the blood of the Serbian population. The whole blood samples were collected from the healthy respondents living in the Belgrade and surrounding areas of the capital (n = 305; w/m ratio = 154/151; mean age: 41 ±â€¯2). The concentrations of toxic metals were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Reference values were estimated as the lower limit (LL) and upper limit (UL) of the 95% confidence interval (CI), together with the selected percentiles (P2.5-P97.5). The obtained geometric mean (GM) for As, Cd, Pb, Th, and U were: 0.50 ng/g, 0.32 ng/g, 20.94 ng/g, 0.30 ng/g, and 0.06 ng/g, respectively. The influences of age, sex and lifestyle on results were considered. Women have significantly higher levels of Cd and Th than men. The increased level of Th was observed in the aged group below 40 years, while smokers had significantly higher levels of Pb and double higher level of Cd in the blood than non-smokers (p < 0.05). In comparison with other population groups worldwide, the Serbian population had significantly higher levels of Th and U (up to 100 times higher). These findings could contribute to better understanding of the molecular basis for the development of various health hazards, including the increased incidence of cancer among the Serbian population which need be confirmed by clinical studies.


Asunto(s)
Arsénico/sangre , Cadmio/sangre , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/sangre , Plomo/sangre , Torio/sangre , Uranio/sangre , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Serbia
8.
Ecotoxicol Environ Saf ; 183: 109479, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31365889

RESUMEN

Evaluation of trace metals at level of solid tissue can provide better information than blood or urine and, therefore, could highlight the role of metals in the etiology of organ-specific disease. The current study aimed to establish the baseline content of four essential (Mn, Cu, Zn, Se) and four toxic metals (As, Cd, Pb, U) in the healthy thyroid tissues (HTTs) by considering sex, age and smoking habits. A further aim was to examine whether differences in the content of metals exist in regard to the thyroid diseases, such as benign tumor (BT), Hashimoto's thyroiditis (HT), multinodular goiter (MNG) and thyroid cancer (TC). A total number of investigated tissue samples were 423. All metals were quantified by inductively coupled plasma-mass spectrometry (ICP-MS). It was found that the content of Cu and U was higher in HTTs of women, while the content of Zn was higher in HTTs of men. Increased content of Zn and decreased content of U was found in the group of HTTs above 50 years compared to a younger group (<50 years). Increased content of Cd, Pb and U distinguish smokers from the non-smokers. In comparison with other population groups worldwide, investigated Serbian population had up to 15 times reduced content of Se. Despite the difference in metal's profile according to biological variables, this study also demonstrated, for the first time, that each thyroid disease has its unique metal's profile. The most altered metal's content was found in tissues with HT. Contrarily, the greatest similarity in metal's content with HTTs was found in BT tissues. Based on the increased content, metal's that dominantly discriminated HTTs from the HT, MNG and TC was As, Pb and Cd, respectively. Reported results could highlight the role of toxic and essential trace metals in the not very well clarified etiology of thyroid diseases and, moreover, could provide a molecular basis for pathophysiological changes of metal's hazardous effects on thyroid health at the tissue level.


Asunto(s)
Metales/análisis , Enfermedades de la Tiroides/metabolismo , Glándula Tiroides/química , Neoplasias de la Tiroides/química , Femenino , Humanos , Masculino , Metales/metabolismo , Persona de Mediana Edad , Oligoelementos/análisis
9.
Undersea Hyperb Med ; 46(5): 635-646, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31683362

RESUMEN

We aimed to assess the effects of intermittent hyperbaric oxygenation (HBO2 at 2 bars for 120 minutes a day for four successive days) on acetylcholine-induced vasorelaxation (AChIR) in female Sprague-Dawley (SD) rats (N=80) that were randomized into four groups: healthy controls (CTR); diabetic rats (DM); and control and diabetic rats that underwent hyperbaric oxygenation (CTR+HBO and DM+HBO), respectively. AChIR was measured in vitro in aortic rings, with/without L-NAME, MS-PPOH, HET0016 or indomethacin. mRNA expression of eNOS, iNOS, COX-1, COX-2, thromboxane A synthase 1 (TBXAS1), CYP4A1, CYP4A3 and CYP2J3 was assessed by qPCR. Systemic oxidative stress and plasma antioxidative capacity were determined with the thiobarbituric acid-reactive substances (TBARS) and the ferric reducing ability of plasma (FRAP) assays, respectively. There was no significant difference in AChIR among experimental groups of rats. In CTR and DM group of rats, AChIR was mediated by NO and EETs pathway, while in the CTR+HBO and DM+HBO groups, NO-pathway prevailed. iNOS expression was upregulated in the DM group compared to CTR, while HBO2 upregulated eNOS in CTR group and TBXAS1 in DM group of rats. In both, CTR and DM group of rats, the sensitivity to ACh in the presence of L-NAME or in the presence of MSPPOH was significantly decreased compared to the response to ACh in the absence or presence of indomethacin or HET0016. DM and DM+HBO rats had increased TBARS compared to their respective controls. In conclusion, HBO2 presumably alters vasorelaxation in response to ACh from NO-EETs mediated pathways to solely NO-pathway, without affecting oxidative status of DM rats.


Asunto(s)
Acetilcolina/farmacología , Inhibidores Enzimáticos del Citocromo P-450/farmacología , Diabetes Mellitus Experimental/fisiopatología , Oxigenoterapia Hiperbárica , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Análisis de Varianza , Animales , Aorta/efectos de los fármacos , Aorta/fisiopatología , Glucemia/análisis , Peso Corporal , Sistema Enzimático del Citocromo P-450/fisiología , Cartilla de ADN , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Tipo 1/inducido químicamente , Diabetes Mellitus Tipo 1/fisiopatología , Femenino , Oxigenoterapia Hiperbárica/métodos , Estrés Oxidativo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Estreptozocina , Factores de Tiempo , Vasodilatación/fisiología
10.
Artículo en Inglés | MEDLINE | ID: mdl-30587075

RESUMEN

This study reports the contents and sources of chromium, nickel and cobalt, as well as Al, Ca, Mg, K, Fe and Mn in Vojvodina regions Srem and Central Banat area soil samples. Different methods were applied to identify the sources of the studied elements and to classify the latter as geogenic and/or anthropogenic: modified Tessier sequential extraction, calculation ratio of E/Al, XRPD, correlations and cluster analysis. The sampling methodology was according to the GEMAS project. The results show that increasing content of chromium, cobalt and nickel detected in studied soils can be explained by a distribution pattern and the presence of ultramafic and mafic parent rocks, as well as by significant anthropogenic pollution, mainly originating from the industry at some localities. The statistically significant difference between the content of Cr and Ni in soils of Srem and C. Banat is observed. The content of the studied elements is higher in soils of Srem. The normalization to Al indicating a presence of the anthropogenic sources which my significantly affect the content of Cr and Ni in the soils from Beocin, Ruma and Stara Pazova. There is no shown influence of eventual agrochemicals application on the Cr, Ni and Co content.


Asunto(s)
Cromo/análisis , Cobalto/análisis , Monitoreo del Ambiente/métodos , Níquel/análisis , Contaminantes del Suelo/análisis , Suelo/química , Agricultura , Industrias , Serbia
11.
Environ Monit Assess ; 191(3): 133, 2019 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-30726528

RESUMEN

This study reports the contents and sources of Cu, Hg, Cr, Ni, Co, Zn, Pb, Cd, As, and B pollution in soil samples from Srem in the province of Vojvodina (Republic of Serbia). They are collected in the vicinity of local industrial facilities. The main objective of this study is evaluating the impact of the industrial facilities on the eventual contamination of soils used mostly for agricultural manufacturing. This paper describes the implementation of the combination of methods to estimate the ecological status and determine potential ecological risk. This study applies sequential extraction, pollution indices, comparison with the guidelines, and statistical analysis. Other soil parameters, such as organic matter content, pH, and clay content were measured to evaluate their influence on the trace element content. The investigated soil samples exhibited the raised contents of Ni, Hg, and Cu. Elevated contents of toxic elements observed in localities accommodated within an impact zone affected by industrial complexes, indicating a correlation between the contamination of surrounding soil and potential impact on plants. The most mobile elements are Hg, Cd, and B, while Cr is the least mobile and potential least bioavailable. The results indicate Cr and Ni content increase marking the presence of bedrock, notably in the area of underlying ultramafic rocks and the surface zones influenced by diluvial-proluvial and alluvial processes. The second source of Cr and Ni in the soils of Srem is industrial activities such as leather, cement industry, as well as the metal processing factory.


Asunto(s)
Agricultura , Monitoreo del Ambiente/métodos , Industrias , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Suelo/química , Oligoelementos/análisis , Serbia
12.
Environ Monit Assess ; 190(4): 208, 2018 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-29525886

RESUMEN

Content of potentially toxic elements was examined in soils from Srem (Vojvodina), to evaluate industrial facilities as pollution sources. Based on the distribution of the elements, the results of sequential extraction, enrichment factor (EF), ecological risk factor (Er), ecological risk index (RI), and statistical analysis, the current ecological status of the soils was determined. Elements in soils around the industrial facilities can be grouped into the five significant components derived by the principal component analysis (PCA), which explains 78.435% of the total variance. Al, Fe and Mg, and K and Mn are associated with two lithogenic components, respectively. Anthropogenic origin is identified for Hg and Cd. Mixed sources, geogenic and anthropogenic, are identified within two PCA components; one wich includes As, Pb, B, Zn, and the other: K and Cr, Ni and Cu. Cluster analysis (CA) corroborated the results obtained by PCA. The preliminary results revealed that the soils studied in a vicinity of industrial facilities in Srem have been exposed to different degrees of pollution. Among the characterized studied elements, Pb, Cd, Hg, Cu, Ni, and Cr are the main contaminants. Based on calculated EF, the studied soils show minor to severe enrichment with heavy metals. Ecological risk assessment results indicate that Cd and Hg carry the highest ecological risk level, and Zn and Cr the lowest.


Asunto(s)
Monitoreo del Ambiente/métodos , Instalaciones Industriales y de Fabricación , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Suelo/química , Medición de Riesgo , Serbia
13.
Anal Biochem ; 504: 20-6, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-27059753

RESUMEN

In this study, a novel electrochemical sensor for quantification of ascorbic acid with amperometric detection in physiological conditions was constructed. For this purpose, cobalt and nickel ferrites were synthesized using microwave and ultrasound assistance, characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray powder diffraction (XRPD), and used for modification of glassy carbon paste electrode (GCPE). It was shown that introducing these nanoparticles to the structure of GCPE led to increasing analytical performance. Co ferrite modified GCPE (CoFeGCPE) showed better characteristics toward ascorbic acid sensing. The limit of detection (LOD) obtained by sensor was calculated to be 0.0270 mg/L, with linear range from 0.1758 to 2.6010 mg/L. This sensor was successfully applied for practical analysis, and the obtained results demonstrated that the proposed procedure could be a promising replacement for the conventional electrode materials and time-consuming and expensive separation methods.


Asunto(s)
Ácido Ascórbico/análisis , Carbono , Técnicas Electroquímicas , Compuestos Férricos/química , Vidrio , Níquel/química , Electrodos , Compuestos Férricos/síntesis química , Microondas , Nanopartículas , Tamaño de la Partícula , Propiedades de Superficie , Ondas Ultrasónicas
14.
Anal Bioanal Chem ; 408(25): 7085-94, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27039202

RESUMEN

Nanoelectrode arrays (NEAs) are increasingly applied for a variety of electroanalytical applications; however, very few studies dealt with the use of NEAs as an electrochemical generator of electrogenerated chemiluminescence (ECL). In the present study, arrays of nanodisc and nanoband electrodes with different dimensions and inter-electrode distances were fabricated by e-beam lithography on a polycarbonate layer deposited on boron-doped diamond (BDD) substrates. In particular, NEAs with 16 different geometries were fabricated on the same BDD sample substrate obtaining a multiple nanoelectrode and ultramicroelectrode array platform (MNEAP). After electrochemical and morphological characterization, the MNEAP was used to capture simultaneously with a single image the characteristic behaviour of ECL emission from all the 16 arrays. Experiments were performed using Ru(bpy)3 (2+) as the ECL luminophore and tri-n-propylamine (TPrA) as the co-reactant. With a relatively limited number of experiments, such an imaging procedure allowed to study the role that geometrical and mechanistic parameters play on ECL generation at NEAs. In particular, at high concentrations of TPrA, well-separated individual ECL spots or bands revealed an ECL signal which forms a pattern matching the nanofabricated structure. The analysis of the imaging data indicated that the thickness of the ECL-emitting zone at each nanoelectrode scales inversely with the co-reactant concentration, while significantly stronger ECL signals were detected for NEAs operating under overlap conditions.

15.
Anal Chem ; 87(24): 12080-7, 2015 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-26556023

RESUMEN

We report here the design of a novel immunosensor and its application for celiac disease diagnosis, based on an electrogenerated chemiluminescence (ECL) readout, using membrane-templated gold nanoelectrode ensembles (NEEs) as a detection platform. An original sensing strategy is presented by segregating spatially the initial electrochemical reaction and the location of the immobilized biomolecules where ECL is finally emitted. The recognition scaffold is the following: tissue transglutaminase (tTG) is immobilized as a capturing agent on the polycarbonate (PC) surface of the track-etched templating membrane. It captures the target tissue transglutaminase antibody (anti-tTG), and finally allows the immobilization of a streptavidin-modified ruthenium-based ECL label via reaction with a suitable biotinylated secondary antibody. The application of an oxidizing potential in a tri-n-propylamine (TPrA) solution generates an intense and sharp ECL signal, suitable for analytical purposes. Voltammetric and ECL analyses evidenced that the ruthenium complex is not oxidized directly at the surface of the nanoelectrodes; instead ECL is generated following the TPrA oxidation, which produces the TPrA•+ and TPrA• radicals. With NEEs operating under total overlap diffusion conditions, high local fluxes of these reactive radicals are produced by the nanoelectrodes in the immediate vicinity of the ECL labels, so that they efficiently generate the ECL signal. The radicals can diffuse over short distances and react with the Ru(bpy)32+ label. In addition, the ECL emission is obtained by applying a potential of 0.88 V versus Ag/AgCl, which is about 0.3 V lower than when ECL is initiated by the electrochemical oxidation of Ru(bpy)3(2+). The immunosensor provides ECL signals which scale with anti-tTG concentration with a linearity range between 1.5 ng·mL­1 and 10 µg·mL­1 and a detection limit of 0.5 ng·mL­1. The sensor is finally applied to the analysis of anti-tTG in human serum samples, showing to be suitable to discriminate between healthy and celiac patients.


Asunto(s)
Enfermedad Celíaca/diagnóstico , Electroquímica/instrumentación , Electrodos , Mediciones Luminiscentes/instrumentación , Nanotecnología , Anticuerpos/sangre , Biomarcadores/sangre , Humanos , Límite de Detección , Reproducibilidad de los Resultados
16.
ScientificWorldJournal ; 2014: 212506, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25101314

RESUMEN

In power plant, coal ash obtained by combustion is mixed with river water and transported to the dump. Sequential extraction was used in order to assess pollution caused by leaching of elements during ash transport through the pipeline and in the storage (cassettes). A total of 80 samples of filter ash as well as the ash from active (currently filled) and passive (previously filled) cassettes were studied. Samples were extracted with distilled water, ammonium acetate, ammonium oxalate/oxalic acid, acidic solution of hydrogen-peroxide, and a hydrochloric acid. Concentrations of the several elements (Al, As, Cd, Co, Cu, Cr, Fe, Ba, Ca, Mg, Ni, Pb, and Zn) in all extracts were determined by inductively coupled plasma atomic emission spectrometry. Pattern recognition method was carried out in order to provide better understanding of the nature of distribution of elements according to their origins. Results indicate possible leaching of As, Ca, Cd, Cu, Zn, and Pb. Among these elements As, Cd, and Pb are toxicologically the most important but they were not present in the first two phases with the exception of As. The leaching could be destructive and cause negative effects on plants, water pollution, and damage to some life forms.

17.
Biomedicines ; 12(7)2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39062163

RESUMEN

(1) Background: Multiple sclerosis (MS) is a chronic, complex, and demyelinating disease closely associated with altered levels of trace elements. Although the first studies into the role of trace elements in MS were published in the 1970s, for five decades it has remained unknown whether trace elements can be part of this heterogeneous neurological disease. (2) Materials and methods: To drive toward at a potential solution, we conducted a systematic review and meta-analysis to elucidate whether there were differences in circulating levels of neurologically important essential trace elements (Zn, Fe, Co, Cu, Mn, and Se) between MS cases and controls. (3) Results: This study revealed significantly lower serum/plasma Zn and Fe levels and higher Cu levels in MS-affected individuals compared to controls. At the same time, no significant differences were found between the MS cases and controls regarding their serum/plasma levels of Co, Mn, or Se. Thus, the loss of Fe and Zn should be considered in supplementation/nutrition strategies for MS patients. On the other hand, since high serum Cu levels indicate a burden on the bloodstreams of MS patients, Cu should be excluded from mineral supplement strategies. Furthermore, all three trace elements (Fe, Zn, and Cu) should be considered from an etiological point of view, and, most importantly, their levels in the bloodstreams of MS patients should be monitored. (4) Conclusions: This study highlights the way for personalized and targeted strategies in the management of MS.

18.
Food Chem ; 447: 138993, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-38493684

RESUMEN

Excessive pesticide use can harm human health, making it essential to develop new techniques to monitor hazardous pesticides in food. Our study focuses on detecting mesotrione (MST) using an unmodified boron-doped diamond (BDD) electrode. This was the first application of cathodically pretreated BDD electrode for the detection of MST, based on its oxidation at a high potential value of +1.4 V. We theoretically examined the oxidation mechanism of MST trough the utilization of density functional theory (DFT) methodology. The utilized DPV method achieved a detection limit of 0.45 µM and showed satisfactory selectivity. The practical application of this method was demonstrated by examining corn-based food products. To ensure practical application of the method, MST was deliberately added to the samples to evaluate the accuracy of the proposed method. The effectiveness of the method was confirmed by using HPLC method. This environmentally-friendly approach can establish a solid foundation for future use in food analysis.


Asunto(s)
Boro , Ciclohexanonas , Humanos , Electrodos , Oxidación-Reducción , Técnicas Electroquímicas
19.
Chem Sci ; 15(6): 2055-2061, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38332811

RESUMEN

Electrochemiluminescence (ECL) is evolving rapidly from a purely analytical technique into a powerful microscopy. Herein, we report the imaging of single cells by photoinduced ECL (PECL; λem = 620 nm) stimulated by an incident near-infrared light (λexc = 1050 nm). The cells were grown on a metal-insulator-semiconductor (MIS) n-Si/SiOx/Ir photoanode that exhibited stable and bright PECL emission. The large anti-Stokes shift allowed for the recording of well-resolved images of cells with high sensitivity. PECL microscopy is demonstrated at a remarkably low onset potential of 0.8 V; this contrasts with classic ECL, which is blind at this potential. Two imaging modes are reported: (i) photoinduced positive ECL (PECL+), showing the cell membranes labeled with the [Ru(bpy)3]2+ complex; and (ii) photoinduced shadow label-free ECL (PECL-) of cell morphology, with the luminophore in the solution. Finally, by adding a new dimension with the near-infrared light stimulus, PECL microscopy should find promising applications to image and study single photoactive nanoparticles and biological entities.

20.
J Trace Elem Med Biol ; 83: 127421, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38452433

RESUMEN

BACKGROUND: Multiple sclerosis (MS) is a chronic demyelinating disorder intricately linked to perturbations in trace element levels. While previous studies have explored circulating trace elements in a limited sample, understanding the impact of demographic and clinical variables on the elemental profile within a larger cohort remains elusive. METHODS: This study aimed to evaluate essential trace elements (Cr, Mn, Co, Cu, Zn, and Se) in the sera of 215 MS patients compared to a meticulously matched control group of 100 individuals with similar gender and age. Our main objective was to identify potential variations in elemental profiles based on demographic and clinical parameters among MS patients, elucidating the prospective relevance of supplementing specific essential trace elements. RESULTS: Data indicated a significant decrease in serum levels of Mn, Co, Zn, and Se, and an increase in Cr in MS patients compared to controls. These trace elements not only discriminated between MS patients and controls but also exhibited distinctive capabilities among demographic subgroups. Gender, smoking habits, and age strata (20-40 years and 41-60 years) revealed discernible variations in elemental profiles between MS patients and their control counterparts. Se demonstrated the singular ability to stratify cases of extreme MS severity, mild relapsing-remitting MS (RRMS) and highly severe secondary progressive MS (SPMS). In contrast, Co significantly differentiated RRMS from primary progressive MS (PPMS), while Cu significantly differentiated SPMS from PPMS. Additionally, Cu showed a negative correlation with MSSS, while Mn and Zn showed a positive correlation with EDSS. CONCLUSION: These findings underscore a substantive deficiency in Mn, Co, Zn, and Se in the MS cohort, supporting targeted supplementation with these trace elements. This study provides a comprehensive understanding of the intricate relationship between essential trace elements and MS, paving the way for further research into personalized nutritional interventions for this complex neurological disorder.


Asunto(s)
Esclerosis Múltiple , Oligoelementos , Humanos , Adulto Joven , Adulto , Estudios Prospectivos , Suplementos Dietéticos , Demografía
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