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1.
Front Nutr ; 11: 1415743, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38962441

RESUMEN

Objective: Sleep disorders is a worldwide public health problem. We sought to examine the association between sarcopenia, a decline in skeletal muscle mass and function, and sleep disorders within the adult demographic of the United States during the period spanning 2011 to 2018. Methods: Diagnosis of sarcopenia and sleep disorders was ascertained through appropriate calculations and a structured questionnaire. The primary correlation analysis was conducted using a weighted multivariate logistic regression model. Furthermore, to confirm the presence of a potential non-linear association between sarcopenia and sleep disorders, additional analyses were performed using multivariate logistic regression and restricted cubic spline (RCS) regression with dose-response curve analysis. Subgroup analyses were also conducted to explore the influence of relevant socio-demographic factors and other covariates. Results: The final analysis encompassed 5,616 participants. Model 4, inclusive of all pertinent covariates, revealed a positive correlation between sarcopenia and sleep disorders, yielding an odds ratio (OR) of 1.732 (95% CI: 1.182-2.547; P = 0.002). Further analysis, utilizing the restricted cubic spline model, indicated a decreasing trend in sleep disorders as sarcopenia indices rose. Stratified analyses across diverse variables underscored the significant impact of sarcopenia on sleep disorders prevalence in several subgroups. Specifically, males, individuals aged 40 and above, non-Hispanic whites, those with high school education or equivalent, unmarried individuals, obese individuals (BMI ≥ 30), alcohol drinkers, former smokers, diabetics, and those engaging in less rigorous recreational activities exhibited a more pronounced association between sarcopenia and sleep disorders. The incidence of sleep disorders exhibited an upward trend as the incidence of sarcopenia declined among study participants. Conclusions: In summary, our study provides evidence of an association between sarcopenia and the prevalence of sleep disorders, with a negative correlation observed between the sarcopenia index and the odds ratio of sleep disorders. These findings suggest that maintaining optimal muscle mass may have a beneficial impact on sleep-related issues. In terms of exploring the mechanisms underlying the relationship between sarcopenia and sleep disorders, more in-depth research is warranted to ascertain the definitive causal relationship.

2.
Front Oncol ; 13: 1145953, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37324000

RESUMEN

Background: Opioid-free anesthesia (OFA) provides adequate analgesia and can reduce postoperative opioid consumption, but its efficacy in spontaneous ventilation video-assisted thoracic surgery (SV-VATS) has not been demonstrated. We aimed to investigate the hypothesis that OFA could provide the same perioperative pain control as opioid anesthesia (OA), maintain safe and stable respiration and hemodynamics during surgery, and improve postoperative recovery. Methods: Sixty eligible patients (OFA group: n=30; OA group: n=30) treated between September 15, 2022, and December 15, 2022, at The First Hospital of Guangzhou Medical University were included. They were randomized to receive standard balanced OFA with esketamine or OA with remifentanil combined with sufentanil. The primary outcome was the pain numeric rating score (NRS) at postoperative 24 h, and the secondary outcomes were intraoperative respiratory and hemodynamic data, opioid consumption, vasoactive drug dosage, and recovery in the post-anesthesia care unit and ward. Results: There was no significant difference in the postoperative pain scores and recovery quality between the two groups. The OFA group had a significantly lower dose of phenylephrine (P=0.001) and a lower incidence of hypotension (P=0.004) during surgery. The OFA group resumed spontaneous respiration faster (P<0.001) and had a higher quality of lung collapse (P=0.02). However, the total doses of propofol and dexmetomidine were higher (P=0.03 and P=0.02), and the time to consciousness was longer (P=0.039) in the OFA group. Conclusions: OFA provides the same level of postoperative pain control as OA, but it is more advantageous in maintaining circulatory and respiratory stability and improving the quality of pulmonary collapse in SV-VATS.

3.
Mikrochim Acta ; 189(11): 431, 2022 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-36284001

RESUMEN

A highly sensitive kanamycin electrochemiluminescence (ECL) switch sensor was constructed. A signal element consisting of ordered mesoporous carbon loaded with indium oxide nanoparticles/carbon quantum dots (OMC/In2O3/C-dots) was assembled on the surface of a gold electrode. Then, a molecularly imprinted polymer (MIP) was prepared on the modified electrode surface using kanamycin as the template molecule and o-aminophenol as the functional monomer. After kanamycin elution, the prepared sensor retained specific kanamycin recognition sites. OMC/In2O3 effectively amplified the ECL signal of the C-dots, thereby enhancing the detection sensitivity, whereas kanamycin quenched the signal. Therefore, the imprinted sites acted as a switch, providing a new method for detecting kanamycin. Under the optimal experimental conditions, the concentration of kanamycin was proportional to the degree of ECL quenching within a linear range of 5-4500 × 10-12 mol L-1 at 0.8 V (vs. Ag/AgCl electrode electrode), and the detection limit was 5.8 × 10-13 mol L-1. When applied to the detection of kanamycin in actual samples, such as chicken, duck, pork, and milk, the recovery for spiked samples was in the range 92.7-110%.


Asunto(s)
Impresión Molecular , Nanopartículas , Puntos Cuánticos , Kanamicina , Carbono , Impresión Molecular/métodos , Polímeros Impresos Molecularmente , Oro
4.
Mikrochim Acta ; 189(10): 383, 2022 09 14.
Artículo en Inglés | MEDLINE | ID: mdl-36102974

RESUMEN

A photoelectrochemical sensing platform based on ligand-variable metal clusters charge transfer was established for the quantitative assay of ronidazole (RNZ) using Ce-porphyrin-metal-organic frameworks/silver nanowires (Ce-Por-MOFs/AgNWs). Rod-like Ce-Por-MOFs and well-dispersed sub-50 nm AgNWs were prepared using a hydrothermal method and polyol strategy, and then through simple drop coating to yield Ce-Por-MOFs/AgNWs nanocomposites. We investigated the intrinsic semiconducting properties of the composites. More importantly, it was found that the variable-valence metal node can provide electronic defect states similar to those caused by multi-metal doping, synergizing with the surface plasmon effect of AgNWs, which significantly improved the photoelectric conversion efficiency, thereby resulting in excellent optoelectronic properties. In combination with molecular imprinting, a competitive type trace photoelectrochemical sensor for RNZ was constructed using Fe2+ as the electron donor and probe. Under optimal conditions, the sensor response is proportional to the logarithm of RNZ concentration in the range 0.1-104 nM with a detected limit of 0.038 nM. The recoveries ranged from 87.2 to 116% with relative standard deviations (RSDs) < 6.5% (n = 3) in milk sample. This work reveals the charge-transfer process of variable-valence metal nodes in MOFs during photoelectrochemical processes, which will provide new insights for the sensing application of variable-valence metal MOFs.


Asunto(s)
Estructuras Metalorgánicas , Nanocables , Ligandos , Estructuras Metalorgánicas/química , Ronidazol , Plata
5.
Mikrochim Acta ; 189(9): 347, 2022 08 24.
Artículo en Inglés | MEDLINE | ID: mdl-36001192

RESUMEN

Considering the limitations associated with existing methods for the detection of trace amounts of trichlorfon, this paper proposes a novel molecularly imprinted electrochemiluminescence (ECL) sensor for the detection of trichlorfon by utilizing the double enhancement effect of trichlorfon and Ag nanoparticles supported by multi-walled carbon nanotubes (MWCNTs/Ag NPs) in a luminol-H2O2 ECL system. Here, trichlorfon was electropolymerized on the surface of the MWCNT/Ag NP-modified gold nanoelectrode with o-phenylenediamine to prepare the molecularly imprinted polymer-based sensor. After eluting the trichlorfon, imprinted holes for the identification of trichlorfon were retained on the sensor, which were used as signal switches to obtain different ECL intensities through the adsorption of different concentrations of trichlorfon. The ECL signal of the sensitized luminol-H2O2 was doubly enhanced by the MWCNTs/Ag and trichlorfon, improving the sensitivity of the sensor. The trichlorfon concentration was positively correlated with the enhanced ECL intensity of the sensor in the range 5.0 × 10-8-5.0 × 10-11 mol L-1, and the detection limit of trichlorfon was 3.9 × 10-12 mol L-1. Moreover, the proposed sensor was successfully applied to the detection of trichlorfon residues in real samples, and the recovery ranged between 91.8 and 109%. A molecularly imprinted electrochemiluminescence sensor for trichlorfon detection by utilizing the double enhancement effect of trichlorfon and Ag nanoparticles supported by multi-walled carbon nanotubes in a luminol-H2O2 ECL system. The dual enhancement of the ECL signal improved the sensitivity of the sensor.


Asunto(s)
Nanopartículas del Metal , Nanotubos de Carbono , Peróxido de Hidrógeno , Mediciones Luminiscentes/métodos , Luminol/química , Nanopartículas del Metal/química , Nanotubos de Carbono/química , Plata , Triclorfón
6.
Sci Rep ; 12(1): 5523, 2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35365691

RESUMEN

The presence of pesticide residues in cowpea raises serious health concerns. In this study, a novel, sensitive, high-performance method was developed to simultaneously analyze the residues of 35 pesticides in cowpea samples from growing areas in the Hainan province of China, from November 2018 to June 2021. The method employs modified QuEChERS sample pretreatment coupled with gas chromatography-tandem mass spectrometry. The limits of quantification of the 35 pesticides in the cowpea matrix ranged from 1.0 to 8.0 µg/kg. Twenty-seven of the 35 pesticides were detected, twelve of which are banned for use on legumes in China. Residues for ten pesticides in 17.1% of the samples exceeded their MRLs, with the highest exceedance of 380% observed in difenoconazole. Moreover, 80.8% of the samples contained one or more pesticide residues, with the most frequently detected pesticide being chlorfenapyr with a detection rate of 46.3%. In addition, the pesticide triazophos was detected through different years and regions. Notably, the chronic dietary exposure risk (%ADI) of the detected pesticides, evaluated from the national estimated acceptable daily intake, was lower than 100% in Chinese people of different age groups.


Asunto(s)
Residuos de Plaguicidas , Vigna , China , Ingestión de Alimentos , Contaminación de Alimentos/análisis , Cromatografía de Gases y Espectrometría de Masas , Humanos , Residuos de Plaguicidas/análisis , Medición de Riesgo
7.
Environ Monit Assess ; 193(9): 578, 2021 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-34398280

RESUMEN

Risks from combined exposure to multiple chemicals in food have prompted a growing concern for their effect on human health. Risk management of chemical mixtures should be based on developing and harmonizing methodologies to scientifically evaluate their cumulative adverse effects. In this study, a simplified tiered approach of cumulative exposure assessment is described along with a case study of vegetables in China's Hainan province during 2012-2014. This case study could be a reference for the Chinese National Risk Assessment Programs for vegetable and fruit products. In the proposed assessment approach, Tier 1 acts as a screening tier to categorize and evaluate chemicals under a conservative scenario, and it prioritizes the pesticides of most concern. Tier 2 refines the grouping of substances from Tier 1 and normalizes the toxic potency of the chemicals to sum the exposure of chemical mixtures in a given assessment group. Tier 3 applies the refined exposure model and the input parameter distribution to create probabilistic models using Monte Carlo simulation. This approach will be helpful in the cumulative exposure assessment where data on pesticide residues are sufficient, but the individual dietary consumption is inadequate.


Asunto(s)
Residuos de Plaguicidas , China , Monitoreo del Ambiente , Contaminación de Alimentos/análisis , Humanos , Residuos de Plaguicidas/análisis , Medición de Riesgo , Estaciones del Año , Verduras
8.
ACS Appl Mater Interfaces ; 13(35): 41987-41996, 2021 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-34436854

RESUMEN

Metal-organic frameworks (MOFs) prepared via typical procedures tend to exhibit issues like poor water stability and poor conductivity, which hinder their application in electrochemical sensing. Herein, we report a strategy for the preparation of mixed-valence ultrafine one-dimensional Ce-MOF nanowires based on a micelle-assisted biomimetic route and subsequent investigation into their growth mechanism. The prepared mixed-valence Ce-MOF nanowires exhibited a typical size of ∼50 nm and were found to present good water stability and high conductivity. On this basis, we examined the introduction of these nanowires into the luminol hydrogen peroxide luminescence system and proposed a novel dual-route self-circulating electrochemiluminescence (ECL) catalytic amplification mechanism. Finally, in combination with molecular imprinting, a MOF-based ECL sensor was developed for the detection of trace amounts of imidacloprid in plant-derived foods. This sensor exhibited a linearity of 2-120 nM and a detection limit of 0.34 nM. Thus, we proposed not only a novel route to MOF downsizing but also a facile and robust methodology for the design of a MOF-based molecular imprinting ECL sensor.


Asunto(s)
Técnicas Electroquímicas/métodos , Mediciones Luminiscentes/métodos , Estructuras Metalorgánicas/química , Nanocables/química , Neonicotinoides/análisis , Nitrocompuestos/análisis , Adsorción , Cerio/química , Contaminación de Alimentos/análisis , Peróxido de Hidrógeno/química , Insecticidas/análisis , Insecticidas/química , Límite de Detección , Sustancias Luminiscentes/química , Luminol/química , Solanum lycopersicum/química , Malus/química , Musa/química , Neonicotinoides/química , Nitrocompuestos/química , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/química
9.
Biosens Bioelectron ; 176: 112944, 2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33421761

RESUMEN

Combining electrochemiluminescence (ECL) with nanozyme amplification provides unique advantages for the detection of antibiotic residues. Herein, a molecularly imprinted chloramphenicol (CAP) sensor was established based on aggregation-induced (AI)-ECL and nanozyme amplification. Covalent organic framework materials with AI-ECL groups (COF-AI-ECL) and nanozyme Co3O4 were synthesised as the signal element and the amplification element, respectively. Subsequently, using CAP as a template molecule, a molecularly imprinted polymer (MIP) was fabricated on the electrode surface modified with COF-AI-ECL and Co3O4. The ECL signal of COF-AI-ECL was catalytically amplified by Co3O4, whereas CAP effectively quenched this signal. Consequently, the ECL signal was controlled by the elution and adsorption of CAP by the MIP, thus establishing a new method for CAP detection. Unlike traditional ECL reagent, COF-AI-ECL exhibited a stable and strong ECL signal. Therefore, COF-AI-ECL in combination with the MIP provided greater sensitivity and enhanced selectivity. The linear range of the developed CAP sensor was 5 × 10-13 to 4 × 10-10 mol/L, with a detection limit of 1.18 × 10-13 mol/L. Moreover, the recoveries range of 85.0%-106.2% were obtained for the detection of CAP in real honey, milk, and chicken samples, indicating the potential of this sensor design for the detection of trace antibiotic residues in food safety applications.


Asunto(s)
Técnicas Biosensibles , Impresión Molecular , Cloranfenicol , Electrodos , Mediciones Luminiscentes
10.
Anal Chim Acta ; 1127: 69-78, 2020 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-32800139

RESUMEN

The use of dual recognition and multiple detection modes is an attractive strategy for realising sensors with improved selectivity and accuracy. Herein, a molecularly imprinted polymer (MIP)-based sensor is developed for amoxicillin detection based on two detection modes (fluorescence and electrochemiluminescence) and dual recognition. First, graphene oxide loaded with CdTe quantum dots/gold nanoparticles (GO/CdTe/Au NPs) is coated onto an indium tin oxide (ITO) electrode. Then, 4-mercapto-calix[6]arene is bonded to GO/CdTe/Au NPs as the first recognition element, which then form a host-guest complex with the target molecule amoxicillin. Subsequently, as the second recognition element, an MIP is prepared on the ITO electrode. After amoxicillin is removed from the MIP, specific identification sites for amoxicillin are obtained. Furthermore, the GO/CdTe/Au NPs can generate fluorescence and electrochemiluminescence signals that are effectively quenched by amoxicillin. Therefore, on/off switching of these signals can be achieved through the elution or adsorption of amoxicillin. The dual detection modes are complementary and provide mutual authentication, which can improve the detection accuracy and application scope. Moreover, the dual recognition sites for amoxicillin, improve detection selectivity. The fluorescence and electrochemiluminescence modes have detection ranges of 5-1000 × 10-11 mol L-1 and 5-1500 × 10-11 mol L-1, respectively, with detection limits of 9.2 × 10-12 mol L-1 and 8.3 × 10-12 mol L-1, respectively.


Asunto(s)
Compuestos de Cadmio , Nanopartículas del Metal , Impresión Molecular , Puntos Cuánticos , Amoxicilina , Oro , Límite de Detección , Telurio
11.
Mikrochim Acta ; 187(7): 394, 2020 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-32556561

RESUMEN

A luminescent double recognition nanoprobe is described as a new strategy for the selective determination of chiral molecules. C-dots/Ir/Au fluorescent nanoparticles, synthesised under hydrothermal conditions, are used as a high-performance probe in combination with a molecularly imprinted polymer (MIP) and calix[6]arene as a double recognition element. Thiolated calix[6]arene is grafted on C-dots/Ir/Au as the first recognition element, which then forms a host-guest complex with the target molecule levodopa (L-DOPA). Subsequently, an MIP is prepared on the C-dots/Ir/Au (MIP/C-dots/Ir/Au) by chemical polymerisation. After the removal of L-DOPA, double recognition imprinting cavities are formed. The fluorescence intensity at 478 nm of the nanoprobe is effectively quenched by adsorption of L-DOPA on MIP/C-dots/Ir/Au, which provides a method for L-DOPA determination. Owing to the double recognition strategy, this method has excellent selectivity which can effectively avoid interference from enantiomer D-DOPA, and a imprinting factor of 7.1 is obtained for L-DOPA. This accurate and reliable method, with a wide linear range (5 × 10-10 to 1.2 × 10-7 mol L-1) and a low limit of detection (1.45 × 10-10 mol L-1), was successfully applied to the determination of L-DOPA in real samples, giving standard recoveries of 89.7-110.0%. Thus, the proposed sensing method provides a viable approach for the determination of a single enantiomer. Graphical abstract Schematic presentation of the MIP/C-dots/Ir/Au for L-DOPA detection. A fluorescence double chiral recognition nanoprobe is prepared of C-dots/Ir/Au nanoparticles as signal probe, and a molecularly imprinted polymer (MIP) and calix[6]arene as a double recognition element. Owing to the double recognition strategy, this method has strong specificity and can effectively avoid interference from enantiomers and racemates.

12.
Biosens Bioelectron ; 146: 111734, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-31586759

RESUMEN

Highly-conductive two-dimensional covalent organic framework (COF) displays prominent applications in various fields of science and technology. This paper reports the design and liquid-liquid interface synthesis of a novel Zr-coordinated amide porphyrin-based 2D COF (Zr-amide-Por-based 2D COF). The COF adopts a graphene-like multilayer structure with the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) band gap of 1.6 eV. The ordered multilayer structure of the amide COF was confirmed through a series of characterization techniques, including scanning electron microscopy, high-resolution transmission electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. In particular, the inherent-ordered structure of Zr-amide-Por-based 2D COF with Zr as the catalytically active center confers several distinct advantages to the material, such as high conductivity and high electrocatalysis performance. A molecularly imprinted tetracycline electrochemiluminescence sensor was constructed based on the Zr-amide-Por-based 2D COF, and gate control effect was used as a signal-generation mechanism. Under optimal conditions, the sensor showed a good linear relationship with tetracycline in the concentration range of 5-60 pM, with a detection limit of 2.3 pM. Because the sensor is rapid, cost-efficient, highly sensitive, and specific, it can be considered as a viable platform for veterinary drug residue monitoring.


Asunto(s)
Antibacterianos/análisis , Estructuras Metalorgánicas/química , Porfirinas/química , Tetraciclina/análisis , Circonio/química , Animales , Técnicas Electroquímicas/métodos , Análisis de los Alimentos/métodos , Estructuras Metalorgánicas/síntesis química , Leche/química , Porfirinas/síntesis química , Difracción de Rayos X
13.
Molecules ; 24(13)2019 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-31269647

RESUMEN

The structure of hapten determines the performance of the antibody and the corresponding detection method. A new type of antigen was designed and synthesized to expose the spatial and characteristic structure of dinotefuran molecule, and a type of high-quality antibody was obtained. The IC50 value of the monoclonal antibody was 5.30 ng/mL and its cross-reactivity (CRs) was less than 2% when reacting with other structurally related analytes. The effects of spatial configurations of hapten on the antibody were visually analyzed while using the appropriate software according to the quality of the antibodies, which showed that the specificity of the antibody is closely related with the exposed structure of hapten. An ELISA assay with an IC50 of 5.66 ng/mL and a linear range of 1.95 to 16.29 ng/mL was developed. The results that were obtained from the ELISA and HPLC methods were equivalent. The results showed that spatial simulation is a crucial method that is used in the designing of hapten to obtain a sensitive and specific antibody. The application of this method will highlight the potential aim and improve the detection efficiency of ELISA.


Asunto(s)
Antígenos/análisis , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/normas , Guanidinas/análisis , Neonicotinoides/análisis , Nitrocompuestos/análisis , Animales , Anticuerpos/inmunología , Reacciones Cruzadas , Femenino , Guanidinas/química , Haptenos/química , Hibridomas , Ratones Endogámicos BALB C , Neonicotinoides/química , Nitrocompuestos/química
14.
Biosens Bioelectron ; 139: 111321, 2019 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-31125833

RESUMEN

A dual selection/recognition effect is described for cobalt (II) ions (Co2+). It is based on bovine serum albumin-metal-Co2+ coordination (BSA-Co2+) and the use of a molecularly imprinted polymer (MIP). An electrochemiluminescence (ECL) switch sensor was designed for detecting nanomolar levels of Co2+. The BSA-Co2+ coordination complex was chosen as a template to prepare a MIP modified switch sensor. The coordination reaction between BSA and Co2+ provides the first step in recognition, and MIP provides the second step for Co2+. This leads to a strong improvement in selectivity of the sensor. A multi-walled carbon nanotube/Cu nanoparticles/carbon quantum dots nanocomposite (MWCNT/Cu/C-dots) acts as an ECL device, and the BSA-Co2+ complex quenches the ECL signal. Therefore, the elution and resorption of BSA-Co2+ can be used as a switch to control ECL. Additionally, a method was established to detect Co2+, with the detection limit as low as 3.07 × 10-10 mol/L. The method was applied to the analysis of spiked environmental water, soil samples, and agricultural products. The recovery rates of the method were in the range of 87.5-111.3%.


Asunto(s)
Técnicas Biosensibles , Cobalto/aislamiento & purificación , Técnicas Electroquímicas/métodos , Impresión Molecular , Cobalto/química , Monitoreo del Ambiente , Humanos , Mediciones Luminiscentes , Nanopartículas/química , Polímeros/química , Puntos Cuánticos/química , Suelo/química , Agua/química
15.
RSC Adv ; 9(34): 19354, 2019 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-35702260

RESUMEN

[This corrects the article DOI: 10.1039/C8RA00251G.].

16.
Mikrochim Acta ; 185(6): 295, 2018 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-29752543

RESUMEN

An electrochemical microfluidic chip is described for the determination of the insecticide carbofuran. It is making use of a molecularly imprinted film (MIP) and a DNA aptamer as dual recognition units. The analyte (carbofuran) is transported to the MIP and captured at the identification site in the channel. Then, carbofuran is eluted with carbinol-acetic acid and transported to the DNA aptamer on the testing position of the chip. It is captured again, this time by the aptamer, and detected by differential pulse voltammetry (DPV). The dual recognition (by aptamer and MIP) results in outstanding selectivity. Additionally, graphene oxide-supported gold nanoparticles (GO-AuNPs) were used to improve the sensitivity of electrochemical detector. DPV response is linear in the 0.2 to 50 nM carbofuran concentration range at a potential of -1.2 V, with a 67 pM detection limit. The method has attractive features such as its potential for high throughput, high degree of automation, and high integration. Conceivably, the method may be extended to other analytes for which appropriate MIPs and aptamers are available. Graphical abstract Schematic of an electrochemical microfluidic chip for carbofuran detection based on a molecularly imprinted film (MIP) and a DNA aptamer as dual recognition units. In the chip, targets were recognized by MIP and aptamer, respectively. It shows promising potential for the design of electrochemical devices with high throughput, high automation, and high integration.

17.
Chem Biodivers ; 15(5): e1800059, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29633499

RESUMEN

The synthesis of celastrol analogues containing amino acid ester at the C(29) position and their evaluation for cytotoxic activities in vitro were reported. The MTT test showed that a set of derivatives with lower IC50 values than that of the positive control group cisplatin and the parent compound celastrol, which exhibited greater antiproliferative activities. The most potent title compounds 2a and 2e exhibited cytotoxic activities in vitro against HeLa and A549 cell lines with IC50 values of 0.371 and 0.237 µm, 0.235 and 0.109 µm, respectively. The apoptosis assay demonstrated that 2a and 2e can induces of A549 cell apoptosis in low concentrations. These results showed that 2a and 2e may be promising for further research as antitumor agents.


Asunto(s)
Aminoácidos/farmacología , Antineoplásicos Fitogénicos/farmacología , Triterpenos/farmacología , Aminoácidos/química , Antineoplásicos Fitogénicos/síntesis química , Antineoplásicos Fitogénicos/química , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Células HeLa , Humanos , Estructura Molecular , Triterpenos Pentacíclicos , Relación Estructura-Actividad , Tripterygium/química , Triterpenos/síntesis química , Triterpenos/química , Células Tumorales Cultivadas
18.
Food Chem ; 241: 188-198, 2018 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-28958518

RESUMEN

An ultrahigh-performance liquid chromatography/hybrid quadrupole time-of-fight mass spectrometry (UPLC/QTOF-MS) method for the simultaneous identification and quantification of 50 multi-class pesticides in minor fruits is reported. The method consists of a sample extraction step, followed by analysis of the pesticides by UPLC/QTOF-MS. Satisfactory chromatographic separation was achieved over a 20min runtime. The pesticides were identified by the accurate mass measurements of the protonated molecules ([M+H]+) and their main fragment ions, isotopic pattern analysis and retention time matching. The mass accuracy obtained was below 2ppm error for all the pesticides analysed. The method was validated by spiking starfruit with the 50 analytes. Satisfactory results regarding sensitivity and linearity were obtained. The method was successfully applied to the analysis of 87 real-world starfruit and Indian jujube samples, demonstrating its applicability for the routine analysis of multiple pesticide residues in minor tropical fruits.


Asunto(s)
Frutas/química , Residuos de Plaguicidas/análisis , Cromatografía Líquida de Alta Presión , Espectrometría de Masas , Verduras
19.
RSC Adv ; 8(16): 8671-8677, 2018 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35539853

RESUMEN

To supply actual data for assessing the potential threat from difenoconazole to the ecosystem, its practical environmental behaviors in a mango field were investigated through a novel mode. After optimization, a UPLC-MS/MS determination method with good accuracy and stability was developed that could be used for the residue determination. Difenoconazole residue was in situ sampled, and its degradation and transportation activity, which reflected the actual transfer characteristics in the natural environment, were researched. The results showed that the half-life of difenoconazole in the soil was 15.4 days, which may be accumulated in a year-round agricultural production system. The residue was detected in the rain settled underground, which showed that the residue transported gradually with the rainfall in vertical and horizontal directions. The results showed that difenoconazole would transport with the rainfall, although the process was slow. All the data showed that the soil ecosystem, and probably also the aquatic ecosystem, would be affected by difenoconazole residue.

20.
Biosens Bioelectron ; 91: 687-691, 2017 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-28119249

RESUMEN

In this study, a biosensor with a dual recognition system comprising a molecularly imprinted polymer (MIP) and aptamers selective for lincomycin was fabricated. The MIP was synthesized by electropolymerization of carbon dots (C-dots)-tagged DNA aptamers combined with lincomycin and o-aminophenol on the gold-nanoparticle-functionalized graphene oxide (Au-GO)-modified electrode. Electrogenerated chemiluminescence (ECL) resonance energy transfer was observed between Au-GO and C-dots. After the C-dots accepted the energy, they acted as a signal indicator and exhibited enhanced signal intensity in the presence of target lincomycin. When lincomycin was competitively bound to DNA aptamers and MIP, it blocked the transfer of energy, and a decreased ECL signal was observed. Hence, a dual recognition method for the detection of lincomycin is realized. Using this strategy, the sensor exhibited a linear ECL response to lincomycin at concentrations from 5.0 × 10 -12 mol/L to 1.0 × 10 -9 mol/L. The detection limit of this assay was found to be 1.6 × 10 -13 mol/L. This method was utilized to determine lincomycin residuals in meat samples with satisfactory results.


Asunto(s)
Antibacterianos/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Contaminación de Alimentos/análisis , Lincomicina/análisis , Carne/análisis , Impresión Molecular/métodos , Aminofenoles/química , Animales , Técnicas Electroquímicas/métodos , Electrodos , Transferencia de Energía , Oro/química , Grafito/química , Límite de Detección , Luminiscencia , Mediciones Luminiscentes/métodos , Nanoestructuras/química , Polimerizacion
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