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1.
Sensors (Basel) ; 21(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207306

RESUMO

Reliable diagnosis of early-stage Parkinson's disease is an important task, since it permits the administration of a timely treatment, slowing the progression of the disease. Together with non-motor symptoms, other important signs of disease can be retrieved from the measurement of the movement trajectory and from tremor appearances. To measure these signs, the paper proposes a magnetic tracking system able to collect information about translational and vibrational movements in a spatial cubic domain, using a low-cost, low-power and highly accurate solution. These features allow the usage of the proposed technology to realize a portable monitoring system, that may be operated at home or in general practices, enabling telemedicine and preventing saturation of large neurological centers. Validation is based on three tests: movement trajectory tracking, a rest tremor test and a finger tapping test. These tests are considered in the Unified Parkinson's Disease Rating Scale and are provided as case studies to prove the system's capabilities to track and detect tremor frequencies. In the case of the tapping test, a preliminary classification scheme is also proposed to discriminate between healthy and ill patients. No human patients are involved in the tests, and most cases are emulated by means of a robotic arm, suitably driven to perform required tasks. Tapping test results show a classification accuracy of about 93% using a k-NN classification algorithm, while imposed tremor frequencies have been correctly detected by the system in the other two tests.


Assuntos
Doença de Parkinson , Tremor , Humanos , Fenômenos Magnéticos , Monitorização Fisiológica , Movimento
2.
Talanta ; 233: 122526, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215029

RESUMO

Herein, a novel magnetic porous carbon nanocomposite derived from a cobalt based-metal-organic framework was synthesized and evaluated for simultaneous preconcentration of homo and hetero-polycyclic aromatic hydrocarbons. Briefly, magnetite nanoparticles (MNPs) were synthesized and then were coated with a metal-organic framework layer. Finally, the magnetic nanocomposite was carbonized under an inert atmosphere to obtain the magnetic porous carbon (MPC). Various characterization techniques such as FT-IR spectroscopy, transmission and scanning electron microcopies, vibrating sample magnetometry, and X-ray diffraction were employed. Applicability of the MPC was explored using benzothiophene, dibenzothiophene, 9,10-dimethylanthracene, and benz[α]anthracene as the model analytes. Limits of detection and linearities were achieved in the range of 0.06-0.18 µg L-1 and 0.25-500 µg L-1, respectively. Precision of the method as RSDs was evaluated which was in the range of 4.2-7.0% (within-day, n = 5) and 8.2-11.3% (between-day, n = 3). Ultimately, the method was applied to analyze two seawater samples and satisfactory results (RSDs%, 5.0-9.0%; relative recoveries, 89-104%) were obtained.


Assuntos
Estruturas Metalorgânicas , Nanocompostos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Carbono , Cobalto , Limite de Detecção , Fenômenos Magnéticos , Hidrocarbonetos Policíclicos Aromáticos/análise , Porosidade , Extração em Fase Sólida , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise
3.
Talanta ; 233: 122471, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215105

RESUMO

Development of novel functionalized adsorbents for efficient magnetic solid phase extraction (MSPE) is essential for promoting their versatile applications in sample pretreatment. Herein, we report the fabrication of a new polyethyleneimine-600 decorated magnetic microporous organic network nanosphere (Fe3O4@MON-PEI600) for effective MSPE of trace non-steroidal anti-inflammatory drugs (NSAIDs) from different water samples. The core-shelled Fe3O4@MON-PEI600 integrates the synergistic effects of Fe3O4, MON and PEI600, providing facile and effective extraction to NSAIDs via multiple hydrogen bonding, π-π and hydrophobic interactions. The inner MON shell employs π-π and hydrophobic interaction sites and the outer PEI-600 coat acts as the hydrogen bonding doner/receptor, which affords good extraction performance for NSAIDs. Under optimal conditions, the Fe3O4@MON-PEI600-MSPE-HPLC-UV method gives wide linear range (0.14-400 µg L-1), low limits of detection (0.042-0.149 µg L-1), good precisions (intra-day and inter-day RSDs < 4.5%, n = 6), and large enrichment factors (97.0-98.2). Extraction mechanisms and selectivity of Fe3O4@MON-PEI600 are evaluated in detail. Moreover, Fe3O4@MON-PEI600 is successfully applied to enrich the trace NSAIDs in different water samples with the concentrations of 0.7 and 0.8 µg L-1 for 1-naphthylacetic acid, 0.5 and 0.1 µg L-1 for naproxen as well as 0.7 µg L-1 for ibuprofen, respectively. The developed method not only affords a novel and efficient magnetic adsorbent for NSAIDs in aqueous media at trace level, but also provides a new strategy for the rational design and synthesis of multiple functionalized MON composites in sample pretreatment.


Assuntos
Nanosferas , Preparações Farmacêuticas , Adsorção , Anti-Inflamatórios não Esteroides , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Fenômenos Magnéticos , Polietilenoimina , Extração em Fase Sólida , Águas Residuárias
4.
Talanta ; 233: 122472, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215106

RESUMO

Direct identification of bacteria in blood cultures using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is interfered with by a variety of non-bacterial proteins derived from blood cells and culture media. Thus, appropriate pre-treatments are needed for successful identification. Here, the bacteria in blood culture bottles were enriched using co-magnetic beads and processed for MALDI-TOF MS profiling. In this strategy, the Fc-containing mannose-binding lectin-coated Fe3O4 (Fc-MBL@Fe3O4) is incorporated with human IgG-coated Fe3O4 (IgG@Fe3O4) to form co-magnetic beads, which can recognize both Gram-positive and Gram-negative bacteria. Compared to single magnetic beads Fc-MBL@Fe3O4 or IgG@Fe3O4, co-magnetic beads resulted in better bacterial capture efficiency and, therefore, could decrease the false-negative results. Our proposed strategy is much more suitable for enrichment of clinically unknown bacteria from blood culture bottles for MALDI-TOF MS database identification.


Assuntos
Antibacterianos , Hemocultura , Bactérias , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Humanos , Fenômenos Magnéticos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
5.
Talanta ; 233: 122496, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34215114

RESUMO

In this work, a synergistic imprinting strategy combined with metal coordination based on ligand-free Fe3O4-Cu was proposed to fabricate molecularly imprinted polymers (MIPs) for the recognition and isolation of bovine hemoglobin (BHb) specifically in biological samples. Copper doped magnetic microspheres prepared solvothermally in a one-pot pathway act as both magnetic core and metal affinity substrate. Upon anchoring BHb to Fe3O4-Cu through metal coordination, the imprinted layer was formed via dopamine self-polymerization. Profiting from the synergistic effect, the obtained imprinted microspheres exhibited an enhanced adsorption performance with the adsorption capacity of 400.86 mg g-1, imprinting factor of 11.88, selectivity coefficient above 5.8, superior to most of other reported BHb-MIPs. Furthermore, kinetic adsorption analyses pointed to a chemisorption-limited process as described by the pseudo-second-order model, and the isothermal adsorption analyses implied monolayer adsorption, as described by the Langmuir model. In addition, the resultant magnetic MIPs can be used at least six adsorption-desorption cycles without re-incubation in the metallic salt solution, avoiding secondary environmental pollution. Furthermore, the well-defined materials showed selectivity both in individual protein samples and bovine serum, providing a promising potential in bioseparation.


Assuntos
Impressão Molecular , Adsorção , Animais , Bovinos , Hemoglobinas , Fenômenos Magnéticos , Microesferas , Polímeros
6.
Artigo em Russo | MEDLINE | ID: mdl-34223754

RESUMO

In the conditions of increasingly stringent anti-doping rules, the development of new non-drug methods of treatment and rehabilitation of athletes is of particular importance. OBJECTIVE: Development of new methods of medical rehabilitation of athletes after injury. MATERIAL AND METHODS: Thirty-three athletes with knee injuries were examined. The main complaints were the presence of pronounced edema in the area of injury. All patients were randomly divided into 2 groups: in group 1 (16 patients) lymphatic drainage kinesis-taping was performed; in the 2nd group (17 patients) - complex treatment including lymphatic drainage kinesis-taping and low-frequency pulse magnetic therapy. Using laser Doppler flowmetry a study of microcirculatory disorders in the area of injury was carried out. The severity of edema was assessed by measuring the circumference of the knee joint of the diseased and healthy limbs. The assessment of the subjective feelings of athletes using questionnaires CIVIQ2 andVAS. RESULTS AND CONCLUSION: Based on the obtained subjective and objective data, a medical complex was developed using lymphatic drainage kinesis-taping and low-frequency pulse magnetic therapy, which affects different steps in the pathogenesis of edema formation. Data obtained resultedin more pronounced positive effect during complex treatment compared with monotherapy with kinesis-taping.


Assuntos
Fita Atlética , Cinese , Atletas , Edema/etiologia , Edema/terapia , Humanos , Extremidade Inferior , Fenômenos Magnéticos , Microcirculação
7.
Mater Sci Eng C Mater Biol Appl ; 127: 112238, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34225878

RESUMO

Fenton-based therapy is emerging as an effective and selective strategy against cancer. However, a low concentration of transition metal ions, insufficient endogenous H2O2, and a high level of antioxidant activity within the cancer cells have hindered the therapeutic efficacy of this strategy. To address these issues, in this study, the Fenton reagent (magnetic hydroxyapatite, mHAP) was accompanied with chemotherapy drugs (cisplatin (CDDP) and methotrexate (MTX)) and static magnetic field (SMF), in such a way to be a pH-, redox-, and magnetic-responsive nanoplatform. In vitro and in vivo experiments revealed higher toxicity of the final construct, MTX.CDDP@mHAP, toward colon cancer cells, as compared with that of free drugs. The most effective antitumor activity was observed as MTX.CDDP@mHAP-treated tumor cells were exposed to SMF (0.9 T) and no noticeable damage was observed in the normal cells and tissues. Active targeting by MTX and magnetic targeting by mHAP under magnetic field increased the tumor selectivity and enhanced the tumor site accumulation and cellular uptake of MTX.CDDP@mHAPs. The released iron ions within the cancer cells trigger the Fenton reaction while the release of chemotherapy drugs, reduction of intracellular glutathione, and application of SMF aggravated the Fenton reaction, subsequently leading to the generation of reactive oxygen species (ROS) and induction of apoptosis. Therefore, Fenton magnetic-based therapy-mediated by MTX.CDDP@mHAP could be considered as a promising strategy against colon cancer with high therapeutic efficiency and biosafety.


Assuntos
Antineoplásicos , Neoplasias do Colo , Nanopartículas , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linhagem Celular Tumoral , Neoplasias do Colo/tratamento farmacológico , Durapatita , Humanos , Campos Magnéticos , Fenômenos Magnéticos
8.
Int J Mol Sci ; 22(9)2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-34063119

RESUMO

One of the promising strategies for improvement of cancer treatment is application of a combination therapy. The aim of this study was to investigate the anticancer activity of nanoformulations containing doxorubicin and iron oxide particles covered with polymeric shells bearing cholesterol moieties. It was postulated that due to high affinity to cell membranes, particles comprising poly(cholesteryl acrylate) can sensitize cancer cells to doxorubicin chemotherapy. The performed analyses revealed that the developed systems are effective against the human breast cancer cell lines MCF-7 and MDA-MB-231 even at low doses of the active compound applied (0.5 µM). Additionally, high compatibility and lack of toxicity of the tested materials against human red blood cells, immune (monocytic THP-1) cells, and cardiomyocyte H9C2(2-1) cells was demonstrated. Synergistic effects observed upon administration of doxorubicin with polymer-iron oxide hybrids comprising poly(cholesteryl acrylate) may provide an opportunity to limit toxicity of the drug and to improve its therapeutic efficiency at the same time.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Colesterol/química , Doxorrubicina/uso terapêutico , Fenômenos Magnéticos , Polímeros/química , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Doxorrubicina/farmacologia , Doxorrubicina/toxicidade , Difusão Dinâmica da Luz , Feminino , Humanos , Teste de Materiais , Ratos , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Termogravimetria
9.
J Environ Sci (China) ; 105: 173-183, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34130834

RESUMO

Magnetic particles were coupled with a flocculant to enhance the demulsification and separation of waste cutting emulsions. The optimal magnetic particle size and critical magnetic field conditions were investigated to achieve large-scale engineering application of magnetic demulsification separation for waste cutting emulsion treatment. The micro-scale magnetic particles were found to show comparable effects to nano-scale magnetic particles on enhancing the demulsification and separation of cutting emulsions, which are beneficial for broadening the selectivity of low-cost magnetic particles. The critical magnetic separation region was determined to be an area 40 mm from the magnetic field source. Compared to the flocculant demulsification, the magnetic demulsification separation exhibited a significant advantage in accelerating flocs-water separation by decreasing the separation time of flocs from 180-240 min to less than 15 min, compressing the flocs by reducing the floc volume ratio from 60%-90% to lower than 20%, and showing excellent adaptability to the variable properties of waste cutting emulsions. Coupled with the design of the magnetic disk separator, continuous demulsification separation of the waste cutting emulsion was achieved at 1.0 t/hr for at least 10 hr to obtain clear effluent with 81% chemical oxygen demand removal and 89% turbidity reduction. This study demonstrates the feasibility of applying magnetic demulsification separation to large-scale continuous treatment of waste emulsion. Moreover, it addresses the flocs-water separation problems that occur in practical flocculant demulsification engineering applications.


Assuntos
Fenômenos Magnéticos , Água , Emulsões , Tamanho da Partícula , Fenômenos Físicos
10.
ACS Sens ; 6(6): 2191-2201, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34124887

RESUMO

In clinical practice, a variety of diagnostic applications require the identification of target cells. Density has been used as a physical marker to distinguish cell populations since metabolic activities could alter the cell densities. Magnetic levitation offers great promise for separating cells at the single cell level within heterogeneous populations with respect to cell densities. Traditional magnetic levitation platforms need bulky and precise optical microscopes to visualize levitated cells. Moreover, the evaluation process of cell densities is cumbersome, which also requires trained personnel for operation. In this work, we introduce a device (HologLev) as a fusion of the magnetic levitation principle and lensless digital inline holographic microscopy (LDIHM). LDIHM provides ease of use by getting rid of bulky and expensive optics. By placing an imaging sensor just beneath the microcapillary channel without any lenses, recorded holograms are processed for determining cell densities through a fully automated digital image processing scheme. The device costs less than $100 and has a compact design that can fit into a pocket. We perform viability tests on the device by levitating three different cell lines (MDA-MB-231, U937, D1 ORL UVA) and comparing them against their dead correspondents. We also tested the differentiation of mouse osteoblastic (7F2) cells by monitoring characteristic variations in their density. Last, the response of MDA-MB-231 cancer cells to a chemotherapy drug was demonstrated in our platform. HologLev provides cost-effective, label-free, fully automated cell analysis in a compact design that could be highly desirable for laboratory and point-of-care testing applications.


Assuntos
Holografia , Microscopia , Animais , Processamento de Imagem Assistida por Computador , Fenômenos Magnéticos , Magnetismo , Camundongos
11.
J Chromatogr A ; 1651: 462301, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34107399

RESUMO

In this work, a core-shell structured magnetic covalent organic framework named as M-TpDAB was constructed with 3,3'-diaminobenzidine (DAB) and 1,3,5-triformylphloroglucinol (Tp) as building units. M-TpDAB was characterized by infrared spectroscopy, nitrogen adsorption-desorption isotherms, powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Using the M-TpDAB as adsorbent, a simple and highly effective method was proposed for preconcentrating phenylurea herbicides before high performance liquid-phase chromatography analysis. In the optimized conditions, a good linearity was achieved within the range of 0.15-100 ng mL-1 for water sample, 1.0-100.0 ng mL-1 for tea drink samples. The limits of detection for the analytes were 0.05-0.15 ng mL-1 for water sample and 0.30-0.50 ng mL-1 for drink samples. Satisfactory recoveries of spiked target compounds were in the range of 84.6%-105% for water sample and 80.3%-102% for tea drink samples. Finally, the M-TpDAB based method was successfully used to determine phenylurea herbicides in tea drinks and water samples, demonstrating a good alternative for analyzing trace level of phenylurea herbicides in water samples.


Assuntos
Herbicidas/isolamento & purificação , Estruturas Metalorgânicas/química , Compostos de Fenilureia/isolamento & purificação , Extração em Fase Sólida/métodos , Água/química , Adsorção , Cromatografia Líquida de Alta Pressão , Água Potável/química , Herbicidas/análise , Fenômenos Magnéticos , Magnetismo/métodos , Compostos de Fenilureia/análise , Difração de Raios X
12.
J Chromatogr A ; 1651: 462347, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34166861

RESUMO

Herein, we report the fabrication of a novel, well-defined core-double-shell-structured magnetic Fe3O4@polydopamine@naphthyl microporous organic network (MON), Fe3O4@PDA@NMON, for the efficient magnetic extraction of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and p-nitrophenol (p-Npn) from wastewater samples. The hierarchical nanospheres were designed and constructed with the Fe3O4 nanoparticle core, the inner shell of a polydopamine (PDA) layer, and the outer shell of a porous naphthyl MON (NMON) coating, allowing efficient and synergistic extraction of OH-PAHs and p-Npn via hydrophobic, hydrogen bonding, and π-π interactions. The Fe3O4@PDA@NMON nanospheres were well characterized and employed as an efficient sorbent for magnetic solid-phase extraction (MSPE) coupled with high performance liquid chromatography (HPLC) for analyzing of OH-PAHs and p-Npn. Under optimal conditions, the Fe3O4@PDA@NMON-based-MSPE-HPLC-UV method afforded wide linear range (0.18-500 µg L-1), low limits of detection (0.070 µg L-1 for p-Npn, 0.090 µg L-1 for 2-OH-Nap, 0.090 µg L-1 for 9-OH-Fluo and 0.055 µg L-1 for 9-OH-Phe, respectively), large enrichment factors (92.6-98.4), good precisions (intra-day and inter-day relative standard deviations (RSDs); <6.4%, n=6) and less consumption of the adsorbent. Furthermore, trace OH-PAHs and p-Npn with concentrations of 0.29-0.80 µg L-1 were successfully detected in various wastewater samples. Fe3O4@PDA@NMON also functioned as a good adsorbent to enrich a wide scope of trace contaminants containing hydrogen bonding sites and aromatic structures, highlighting the potential of functional MONs in sample pretreatment.


Assuntos
Indóis/química , Nanosferas/química , Nitrofenóis/isolamento & purificação , Hidrocarbonetos Policíclicos Aromáticos/isolamento & purificação , Polímeros/química , Extração em Fase Sólida/métodos , Águas Residuárias/química , Cromatografia Líquida de Alta Pressão , Interações Hidrofóbicas e Hidrofílicas , Limite de Detecção , Fenômenos Magnéticos , Nitrofenóis/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Porosidade
13.
Sci Total Environ ; 783: 147083, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34088131

RESUMO

Magnetic measurement was provided to substitute for time-consuming conventional methods for determination of potentially toxic elements. Both the concentrations of 12 elements and 9 magnetic parameters were determined in 700 muscle tissue samples from the snail Bellamya aeruginosa, shrimp species Exopalaemon modestus and Macrobrachium nipponense, and fish species Hemisalanx prognathous Regan, Coilia ectenes taihuensis, and Culer alburnus Basilewsky collected from Chaohu Lake during different hydrological periods. Spherical and irregular iron oxide particles were observed in the muscle tissues of the studied aquatic products. A field survey of the exposure parameters in humans, such as per capita intake dose of local aquatic products, found no evidence that consumption of the tested species poses a potential health risk. Redundancy analysis revealed different degrees of correlation between the magnetic parameters and concentrations of elements in aquatic products. Back-propagation artificial neural network (BP-ANN) and support vector machine (SVM) models were applied to predict elemental concentrations in aquatic products, using magnetic parameters as input. SVM models performed well in predicting the presence of Cr and Ni, with R and index of agreement values of >0.8 in both training and validation stages as well as relatively low errors. The BP-ANN and SVM models both performed relatively poorly in predicting the presence of Cd and Zn in aquatic products, with R values between 0.333 and 0.718 for Cd and between 0.454 and 0.664 for Zn in training and validation stages. For most of the elements, a better R value was obtained with the SVM than with BP-ANN model. The R of Co, Cr, Cu, Ni, and Ti in the training and validation stages of snail in the SVM model were >0.8. This study is a first step in developing a novel approach allowing the rapid monitoring of potentially toxic elements concentrations in aquatic products.


Assuntos
Aprendizado de Máquina , Redes Neurais de Computação , Animais , Humanos , Lagos , Fenômenos Magnéticos , Máquina de Vetores de Suporte
14.
Mater Sci Eng C Mater Biol Appl ; 126: 112117, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34082934

RESUMO

Controlled pulmonary drug delivery systems employing non-spherical particles as drug carriers attract considerable attention nowadays. Such anisotropic morphologies may travel deeper into the lung airways, thus enabling the efficient accumulation of therapeutic compounds at the point of interest and subsequently their sustained release. This study focuses on the fabrication of electrospun superparamagnetic polymer-based biodegradable microrods consisting of poly(l-lactide) (PLLA), polyethylene oxide (PEO) and oleic acid-coated magnetite nanoparticles (OA·Fe3O4). The production of magnetite-free (0% wt. OA·Fe3O4) and magnetite-loaded (50% and 70% wt. Fe3O4) microrods was realized upon subjecting the as-prepared electrospun fibers to UV irradiation, followed by sonication. Moreover, drug-loaded microrods were fabricated incorporating methyl 4-hydroxybenzoate (MHB) as a model pharmaceutical compound and the drug release profile from both, the drug-loaded membranes and the corresponding microrods was investigated in aqueous media. In addition, the magnetic properties of the produced materials were exploited for remote induction of hyperthermia under AC magnetic field, while the possibility to reduce transport losses and enhance the targeted delivery to lower airways by manipulation of the airborne microrods by DC magnetic field was also demonstrated.


Assuntos
Calefação , Nanopartículas de Magnetita , Sistemas de Liberação de Medicamentos , Pulmão , Fenômenos Magnéticos , Magnetismo
15.
Sensors (Basel) ; 21(10)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064597

RESUMO

Food texture is one of the important quality indicators in foodstuffs, along with appearance and flavor, contributing to taste and odor. This study proposes a novel magnetic food texture sensor that corresponds to the tactile sensory capacity of the human tooth. The sensor primarily consists of a probe, linear slider, spring, and circuit board. The probe has a cylindrical shape and includes a permanent magnet. Both sides of the spring are fixed to the probe and circuit board. The linear slider enables the smooth, single-axis motion of the probe during food compression. Two magnetoresistive elements and one inductor on the circuit board measured the probe's motion. A measurement system then translates the measurement data collected by the magnetoresistive elements into compression force by means of a calibration equation. Fundamental experiments were performed to evaluate the range, resolution, repetitive durability of force, and differences in the frequency responses. Furthermore, the sensor was used to measure seven types of chicken nuggets with different coatings. The difference between the force and vibration measurement data is revealed on the basis of the discrimination rate of the nuggets.


Assuntos
Galinhas , Produtos da Carne , Animais , Manipulação de Alimentos , Humanos , Fenômenos Magnéticos , Produtos da Carne/análise , Paladar
16.
J Hazard Mater ; 415: 125701, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34088189

RESUMO

This study aims to synthesize a magnetic activated carbon nanocomposite from green tea leaf waste (MNPs-GTAC) for evaluation of adsorption efficiency of 4 priority polycyclic aromatic hydrocarbons (PAHs). MNPs-GTAC contained spherically-shaped MNPs with cubic spinel structure, surface area at 118.8 m2/g, particle size at 8.6 nm and saturation magnetization at 34.2 emu/g. PAH adsorption reached a plateau at an MNPs-GTAC dose of 50 or 60 mg/L, pH of 2-4 and ionic strength of 0.1-10%, with PAH reduction in the presence of humic acid being compensated by addition of 0.1% sodium chloride. Kinetics was rapid attaining 80% removal within 5 min and the pseudo-second-order rate decreased in this order: Benzo[a]anthracene>Chrysene>Benzo[b]fluoranthene>Benzo[a]pyrene. Isotherm modeling revealed a Langmuir type-2 shape with the maximum adsorption capacity being 28.08, 22.75, 19.14 and 15.86 mg/g for Benzo[b]fluoranthene, Benzo[a]pyrene, Chrysene and Benzo[a]anthracene, respectively. Temperature study showed the PAH adsorption to be an endothermic and spontaneous process with increased randomness at solid-solution interface. Acetonitrile could completely recover the adsorbed PAH and MNPs-GTAC was successfully recycled 5 times with a minimum loss. Application to mineral water showed 86-98% and 72-89% removal for PAHs spiked respectively at 0.1 and 1 mg/L, while a complete removal was attained in tap and river waters.


Assuntos
Nanocompostos , Hidrocarbonetos Policíclicos Aromáticos , Carvão Vegetal , Fenômenos Magnéticos , Hidrocarbonetos Policíclicos Aromáticos/análise , Chá , Água
17.
Sensors (Basel) ; 21(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071520

RESUMO

Colorectal cancer (CRC) is the third leading cause of cancer death and the fourth most common cancer in the world. Colonoscopy is the most sensitive test used for detection of CRC; however, their procedure is invasive and expensive for population mass screening. Currently, the fecal occult blood test has been widely used as a screening tool for CRC but displays low specificity. The lack of rapid and simple methods for mass screening makes the early diagnosis and therapy monitoring difficult. Extracellular vesicles (EVs) have emerged as a novel source of biomarkers due to their contents in proteins and miRNAs. Their detection would not require invasive techniques and could be considered as a liquid biopsy. Specifically, it has been demonstrated that the amount of CD147 expressed in circulating EVs is significant higher for CRC cell lines than for normal colon fibroblast cell lines. Moreover, CD147-containing EVs have been used as a biomarker to monitor response to therapy in patients with CRC. Therefore, this antigen could be used as a non-invasive biomarker for the detection and monitoring of CRC in combination with a Point-of-Care platform as, for example, Lateral Flow Immunoassays (LFIAs). Here, we propose the development of a quantitative lateral flow immunoassay test based on the use of magnetic nanoparticles as labels coupled to inductive sensor for the non-invasive detection of CRC by CD147-positive EVs. The results obtained for quantification of CD147 antigen embedded in EVs isolated from plasma sample have demonstrated that this device could be used as a Point-of-Care tool for CRC screening or therapy monitoring thanks to its rapid response and easy operation.


Assuntos
Neoplasias Colorretais , Vesículas Extracelulares , Biomarcadores Tumorais , Neoplasias Colorretais/diagnóstico , Detecção Precoce de Câncer , Humanos , Imunoensaio , Fenômenos Magnéticos
18.
Talanta ; 232: 122432, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34074418

RESUMO

The design of simultaneous detection method has broad prospects for cancer diagnosis and prognosis. Herein, we reported a low cost and sensitive SERS sensing platform for simultaneous p21 mRNA and miRNA-21 detection based on duplex-specific nuclease signal amplification (DSNSA) plus multifunctional Fe3O4@SiO2 magnetic nanoparticles (Fe3O4@SiO2 MNPs). Here, Fe3O4@SiO2 MNPs were used as a separation substrate, and Au@AgNPs served as stable and ultrasensitive SERS nanotags. Firstly, Au@AgNPs and Fe3O4@SiO2 MNPs were attached to both ends of capture probe (CP) by covalent bonds. Under the assistance of the target p21 mRNA and miRNA-21, DNA (CP) of the DNA-RNA heteroduplexes could be specifically degraded by DSN and the SERS nanotags that were released from the surface of Fe3O4@SiO2 MNPs. Meanwhile, the target p21 mRNA and miRNA-21 were released and then involved in the next round of signal reactions. The proposed strategy allowed quantitative detection of p21 mRNA and miRNA-21 and the limit of detection (LOD) was 0.12 fM and 0.17 fM, respectively. This method gives a great potential for multiplex detection of biological molecules.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , MicroRNAs , Neoplasias , Ouro , Humanos , Limite de Detecção , Fenômenos Magnéticos , MicroRNAs/genética , Neoplasias/diagnóstico , Neoplasias/genética , RNA Mensageiro/genética , Dióxido de Silício , Análise Espectral Raman
19.
Talanta ; 232: 122449, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34074433

RESUMO

Antibiotics, such as sulfadiazine and sulfathiazole, are widely used in veterinary applications which can result in remains in edible animal products. Therefore, there is an immense need for a reliable, selective, sensitive, and simple analytical technique for monitoring the concentration of sulfadiazine (SDZ) and sulfathiazole (STZ) in edible animal products. In this regard, we developed a magnetic dual template molecularly imprinted polymer (MMIP) to determine the SDZ and STZ in milk samples. For the sensitive and selective extraction and determination of target analytes, MMIPs have been combined with the syringe-to-syringe magnetic solid-phase microextraction (SS-MSPME) method. In addition, we used central composite design (CCD) for the extraction of SDZ and STZ. With optimum conditions, an efficient, rapid, and convenient technique for the preconcentration and determination of SDZ and STZ in milk samples by SS-MSPME coupling with HPLC-UV was developed. Using our combined approach, the limits of detection are 0.9 and 1.3 ng mL-1 for SDZ and STZ, respectively, along with good linearity and determination coefficients higher than 0.98. Our method demonstrates a practical approach for the deduction of antibiotics in milk samples with high recoveries and selectivity.


Assuntos
Impressão Molecular , Sulfadiazina , Animais , Cromatografia Líquida de Alta Pressão , Fenômenos Magnéticos , Leite/química , Polímeros Molecularmente Impressos , Extração em Fase Sólida , Sulfadiazina/análise , Sulfatiazóis , Seringas
20.
Analyst ; 146(13): 4261-4267, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34105527

RESUMO

Glycosylation of proteins plays important roles in the occurrence and development of chronic diseases. In this study, we report an enrichment method of intact N-glycopeptides using a magnetic polyaniline nanomaterial (Fe3O4@PANI). Under the synergistic effect of hydrogen bonding and electrostatic adsorption, Fe3O4@PANI can rapidly and easily enrich N-glycopeptides derived from standard protein (bovine fetuin and transferrin) tryptic digests and serum haptoglobin tryptic digests. Finally we have detected 63 glycopeptides in the glycosylation sites of both N204 and N211 from the serum haptoglobin beta chain using MALDI FTICR MS. Compared with non-magnetic materials, Fe3O4@PANI can achieve complete separation from complex biological samples, meeting the requirement of the high purity of samples for mass spectrometric detection. Overall, Fe3O4@PANI exhibits great application potential in the highly efficient enrichment of intact N-glycopeptides due to its stability and convenient preparation.


Assuntos
Glicopeptídeos , Nanoestruturas , Compostos de Anilina , Animais , Bovinos , Interações Hidrofóbicas e Hidrofílicas , Fenômenos Magnéticos
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