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1.
Chemosphere ; 253: 126658, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32259680

RESUMO

The objective of the present study was to determine the susceptibility of entomopathogenic nematodes to ivermectin and thiabendazole. Soil samples collected from the municipalities of Irapuato and León, Guanajuato, Mexico, were obtained, from which the entomopathogenic nematodes (EPNs) of the Steinernematidae and Heterorhabditidae families were isolated. The samples were classified from livestock and nonlivestock soils, and the susceptibility of EPNs to anthelmintics was determined with the larval motility assay (LMA, 24 h) and the larval migration inhibition assay (LMI assay, 48 h). Sterile distilled water (T1) and treatments with 1% ivermectin diluted in 5% DMSO (dimethyl sulfoxide) (T2) and 5% thiabendazole diluted in 5% DMSO (T3) were applied to infective juvenile larvae. Analysis of variance was performed with a factorial design and Tukey's test at 0.05 probability. In addition, different concentrations of ivermectin (0.1, 0.5, 1, 1.2, 1.5, and 2 µg) and thiabendazole (1, 5, 10, 12, 15, and 20 mg) were evaluated to perform a Probit analysis to determine their LC50. All strains of EPNs were susceptible to ivermectin in both the LMA and LMI assay. The results show that EPNs are susceptible to ivermectin and thiabendazole, and the degree depends on the type of test performed, the chemical product used, and the origin of the strain of EPN.


Assuntos
Anti-Helmínticos/toxicidade , Ivermectina/toxicidade , Rabditídios/fisiologia , Tiabendazol/toxicidade , Animais , Larva/efeitos dos fármacos , México , Solo
2.
PLoS One ; 15(3): e0229943, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32142527

RESUMO

Cassava (Manihot esculenta Crantz) is an important food security crop in many parts of the developing world. The crop's high yield potential and multitude of uses-both for nutrition and processing-render cassava a promising driver for the development of rural value chains. It is traditionally propagated from stem cuttings of up to 30 cm in length, giving a multiplication rate as low as 1:10. Propagating cassava traditionally is very inefficient, which leads to challenges in the production and distribution of quality planting material and improved cultivars, greatly limiting the impact of investments in crop breeding. The work described in the present study aimed to develop a seed treatment approach to facilitate the use of shorter seed pieces, increasing the multiplication rate of cassava and thus making the crop's seed systems more efficient. After several tests, formulation was identified, consisting of thiamethoxam 21 g ha-1, mefenoxam 1.0 g ha-1, fludioxonil 1.3 g ha-1, thiabendazole 7.5 g ha-1 and Latex 2% as a binder. Plant growing from seed pieces treated with this formulation displayed increased crop establishment and early crop vigor, leading to an improved productivity throughout a full growing cycle. This allowed to reduce the cassava seed piece size to 8 cm with no negative effects on germination and crop establishment, leading to yields comparable to those from untreated 16 cm pieces. This, in turn, will allow to increase the multiplication ratio of cassava by a factor of up to 3. Notably, this was possible under regular field conditions and independently of any specialised treatment facilities. Compared with existing seed production protocols, the increased multiplication rates allowed for efficiency gains of between 1 to 1.9 years compared to conventional five-year cycles. We believe that the technology described here holds considerable promise for developing more reliable and remunerative delivery channels for quality cassava planting material and improved genetics.


Assuntos
Manihot/crescimento & desenvolvimento , Melhoramento Vegetal , Caules de Planta/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Alanina/análogos & derivados , Alanina/farmacologia , Dioxóis/farmacologia , Látex/farmacologia , Manihot/efeitos dos fármacos , Caules de Planta/efeitos dos fármacos , Pirróis/farmacologia , Sementes/efeitos dos fármacos , Tiabendazol/farmacologia , Tiametoxam/farmacologia
3.
Food Chem ; 310: 125923, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31837530

RESUMO

The design of a novel and reliable plasmonic platform for detecting multiple chemical contaminants in the complex matrix is an exciting topic in the food industry. Herein, a high-performance surface-enhanced Raman scattering (SERS) two-dimensional (2D) nanodot array was designed through liquid-liquid interfacial self-assembly of the core-shell nanoparticles (Au@Ag NPs) and exploited for assessment of dual-fungicides in pear, apple, and orange juices. The 2D Au@Ag nanodot array delivered good uniformity and reproducibility with the substrate-to-substrate relative standard deviation values of 10.51%. This substrate could be used for detecting thiram and thiabendazole in aqueous solutions with the limit of detection of 0.0011 and 0.051 ppm, respectively. Furthermore, satisfactory recoveries ranging from 76-134% for the juices were obtained, demonstrating that the high-throughput 2D Au@Ag nanodot arrays are promising for their applications as sensitive SERS platforms for monitoring chemical contaminants in food products, especially in the beverage industry.


Assuntos
Análise de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Fungicidas Industriais/análise , Nanopartículas Metálicas/química , Análise Espectral Raman/métodos , Citrus sinensis , Análise de Alimentos/instrumentação , Contaminação de Alimentos/análise , Ouro/química , Malus , Reprodutibilidade dos Testes , Prata/química , Análise Espectral Raman/instrumentação , Tiabendazol/análise , Tiram/análise
4.
Food Chem ; 310: 125812, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31734008

RESUMO

An eco-friendly method was used to synthesize carbon dots (CDs) from Rosemary leaves, as a carbon source. The as-synthesized CDs was applied as a fluorophore in an optical sensor after modification with molecularly imprinted polymers (MIPs) for determination of thiabendazole (TBZ). For this purpose, a silica shell using tetraethoxysilane (TEOS), as a Si source, was stabilized on the surface of CDs via reverse microemulsion technique. Following, MIPs were synthesized in the presence of TBZ as a template, using 3-aminopropyl triethoxysilane and TEOS as a functional monomer and a crosslinker, respectively. After optimization of the experimental parameters, a linear dynamic range of 0.03-1.73 µg/mL TBZ with a detection limit as 8 ng/mL were obtained for the suggested method. Finally, the proposed sensor was successfully applied for the determination of TBZ in apple, orange, and tomato juices. This sensor is a simple, rapid, selective, and non-expensive method for TBZ measurement.


Assuntos
Fluorometria/instrumentação , Sucos de Frutas e Vegetais/análise , Polímeros/síntese química , Pontos Quânticos/química , Tiabendazol/análise , Carbono/química , Corantes Fluorescentes/química , Fluorometria/métodos , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Química Verde , Limite de Detecção , Impressão Molecular/métodos , Silanos/química , Dióxido de Silício/química , Espectrometria de Fluorescência/métodos
5.
Sci Total Environ ; 688: 1145-1154, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31726545

RESUMO

Carbon-based nanomaterials exhibit unique properties that make them suitable for a wide variety of industrial and biomedical applications. In this work, we studied the acute toxicity of graphite-diamond nanoparticles (GDN) combined with the fungicide thiabendazole (TBZ) to the immobilization of the cladoceran Daphnia magna in the presence and absence of the micro green algae Raphidocelis subcapitata, supplied as food source. The toxicity of GDN to D. magna decreased in the presence of R. subcapitata, while that of TBZ increased, the latter suggesting a carrier effect to TBZ. GDN-TBZ mixtures were fitted to the most common conceptual models applied to mixture toxicity: Concentration Addition (CA), Independent Action (IA) and Combination Index (CI). For GDN-TBZ mixtures in the absence of food the best fit was obtained with dose ratio deviation from CA model, while in the presence of food, dose level deviation from CA gave a better fit. The binary mixtures of GDN and TBZ showed synergistic toxic interactions at low concentrations, which could be attributed to the increased bioavailability of TBZ adsorbed on GDN. For higher concentrations of GDN, the binary mixtures turned antagonistic due to particle agglomeration. Our study provides evidence that deviations from additivity are dose dependent and relevant for the risk assessment of mixtures of nanoparticles with other chemical pollutants.


Assuntos
Daphnia/fisiologia , Fungicidas Industriais/toxicidade , Grafite/toxicidade , Nanopartículas/toxicidade , Tiabendazol/toxicidade , Animais , Diamante , Poluentes Químicos da Água/toxicidade
6.
Behav Processes ; 166: 103905, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31310793

RESUMO

Globally, native predators and scavengers are threatened through the incidence of illegal poisoning due to increasing human-wildlife conflicts. The use of conditioned taste aversion (CTA) may mitigate such conflicts. CTA is a robust learning paradigm that occurs when animals associate a food with a discomfort induced by a chemical, thereby avoiding that food in subsequent encounters. We reviewed the potential of 167 chemical compounds to be used in CTA, considering effects, margin of safety, accessibility, and detectability. After the review, 15 compounds fulfilled the required characteristics, but only five (thiabendazole, thiram, levamisole, fluconazole and fluralaner) were finally selected to be tested in CTA assays with dogs. Of the tested compounds, thiabendazole, thiram and levamisole caused target food rejection by dogs and reduced the time spent eating during post-conditioning. However, despite being microencapsulated, levamisole appeared to be detectable by dogs, whereas thiram and thiabendazole were not. Fluconazole and fluralaner did not produce any CTA effect. Thiabendazole, thiram and levamisole can therefore induce CTA, and thus are potential candidates as aversive compounds for wildlife management. Thiram is an undetectable, relatively safe and accessible compound that can induce CTA in canids, and opens new possibilities to develop methods of non-lethal predation control.


Assuntos
Aprendizagem da Esquiva/efeitos dos fármacos , Comportamento Predatório/efeitos dos fármacos , Paladar , Animais , Animais Selvagens , Condicionamento Clássico/efeitos dos fármacos , Cães , Fluconazol/farmacologia , Isoxazóis/farmacologia , Levamisol/farmacologia , Masculino , Tiabendazol/farmacologia , Tiram/farmacologia
7.
Rev Soc Bras Med Trop ; 52: e20180229, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31340353

RESUMO

Sarcoidosis is a rare multisystem chronic inflammatory disease in children. We present a case of a five-year-old child with clinical features mimicking several diseases, including tuberculosis. After failure of treatment based on the suspected diagnosis, an axillary lymph node biopsy showed noncaseating granulomas compatible with sarcoidosis and appropriate treatment was then started.


Assuntos
Sarcoidose/diagnóstico , Anti-Helmínticos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Biópsia , Brasil , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Linfoma/diagnóstico , Prednisolona/uso terapêutico , Sarcoidose/tratamento farmacológico , Tiabendazol/uso terapêutico , Tomografia Computadorizada por Raios X , Tuberculose/diagnóstico
8.
Chemosphere ; 232: 152-163, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31154175

RESUMO

Agriculture is considered as the main source of water contamination by pesticides. However, food packaging or processing industries are also recognised as relevant point sources of contamination by these compounds, not yet investigated in depth. The objective of this work has been to improve current knowledge about the presence and concentration of pesticides in the effluent of a food processing industry, as well as to investigate their main transformation products (TPs). An analytical strategy combining target and suspect analysis has been applied to provide an evaluation of the effluents. The methodology involves solid-phase extraction (SPE) of wastewater samples followed by (i) liquid chromatography quadrupole-linear ion trap tandem mass spectrometry (LC-QqLIT-MS/MS) for quantitative target analysis and (ii) liquid chromatography coupled to quadrupole-time-of-flight high resolution mass spectrometry (LC-QTOF-HRMS) to identify non-target pesticides and possible TPs. The results revealed the presence of 17 of the target pesticides analysed and 3 additional ones as a result of the suspect screening performed by HRMS. The TPs were investigated for the pesticides found at the highest concentrations: imazalil (7038-19802 ng/L), pyrimethanil (744-9591 ng/L) and thiabendazole (341-926 ng/L). Up to 14 TPs could be tentatively identified, demonstrating the relevance of this type of studies. These data provide a better understanding of the occurrence of pesticides and their TPs in agro-food industrial effluents.


Assuntos
Praguicidas/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Agricultura , Cromatografia Líquida/métodos , Monitoramento Ambiental , Indústria Alimentícia , Indústria de Processamento de Alimentos , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos , Tiabendazol/análise , Águas Residuárias/análise , Poluição Química da Água/estatística & dados numéricos
9.
PLoS One ; 14(3): e0214214, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30921394

RESUMO

Morphological characterization and multi-locus DNA sequence analysis of fungal isolates obtained from 32 clinical cases of equine fungal keratitis (FK) was performed to identify species and determine associations with antifungal susceptibility, response to therapy and clinical outcome. Two species of Aspergillus (A. flavus and A. fumigatus) and three species of Fusarium (F. falciforme, F. keratoplasticum, and F. proliferatum) were the most common fungi isolated and identified from FK horses. Most (91%) equine FK Fusarium nested within the Fusarium solani species complex (FSSC) with nine genetically diverse strains/lineages, while 83% of equine FK Aspergillus nested within the A. flavus clade with three genetically diverse lineages. Fungal species and evolutionary lineage were not associated with clinical outcome. However, species of equine FK Fusarium were more likely (p = 0.045) to be associated with stromal keratitis. Species of Aspergillus were more susceptible to voriconazole and terbinafine than species of Fusarium, while species of Fusarium were more susceptible to thiabendazole than species of Aspergillus. At the species level, A. fumigatus and A. flavus were more susceptible to voriconazole and terbinafine than F. falciforme. Natamycin susceptibility was higher for F. falciforme and A. fumigatus compared to A. flavus. Furthermore, F. falciforme was more susceptible to thiabendazole than A. flavus and A. fumigatus. These observed associations of antifungal sensitivity to natamycin, terbinafine, and thiabendazole demonstrate the importance of fungal identification to the species rather than genus level. The results of this study suggest that treatment of equine FK with antifungal agents requires accurate fungal species identification.


Assuntos
Antifúngicos/farmacologia , Infecções Oculares Fúngicas , Doenças dos Cavalos , Ceratite , Tiabendazol/farmacologia , Animais , Infecções Oculares Fúngicas/tratamento farmacológico , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/veterinária , Doenças dos Cavalos/tratamento farmacológico , Doenças dos Cavalos/microbiologia , Cavalos , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Ceratite/veterinária , Sudeste dos Estados Unidos , Especificidade da Espécie
10.
Int J Parasitol ; 49(5): 397-406, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30771359

RESUMO

Soil-transmitted nematodes infect over a billion people and place several billion more at risk of infection. Hookworm disease is the most significant of these soil-transmitted nematodes, with over 500 million people infected. Hookworm infection can result in debilitating and sometimes fatal iron-deficiency anemia, which is particularly devastating in children and pregnant women. Currently, hookworms and other soil-transmitted nematodes are controlled by administration of a single dose of a benzimidazole to targeted populations in endemic areas. While effective, people are quickly re-infected, necessitating frequent treatment. Widespread exposure to anthelmintic drugs can place significant selective pressure on parasitic nematodes to generate resistance, which has severely compromised benzimidazole anthelmintics for control of livestock nematodes in many areas of the world. Here we report, to our knowledge, the first naturally occurring multidrug-resistant strain of the canine hookworm Ancylostoma caninum. We reveal that this isolate is resistant to fenbendazole at the clinical dosage of 50 mg/kg for 3 days. Our data shows that this strain harbors a fixed, single base pair mutation at amino acid 167 of the ß-tubulin isotype 1 gene, and by using CRISPR/Cas9 we demonstrate that introduction of this mutation into the corresponding amino acid in the orthologous ß-tubulin gene of Caenorhabditis elegans confers a similar level of resistance to thiabendazole. We also show that the isolate is resistant to the macrocyclic lactone anthelmintic ivermectin. Understanding the mechanism of anthelmintic resistance is important for rational design of control strategies to maintain the usefulness of current drugs, and to monitor the emergence of resistance. The isolate we describe represents the first multidrug-resistant strain of A. caninum reported, and our data reveal a resistance marker that can emerge naturally in response to heavy anthelminthic treatment.


Assuntos
Ancylostoma/efeitos dos fármacos , Ancylostoma/isolamento & purificação , Doenças do Cão/parasitologia , Resistência a Medicamentos , Infecções por Uncinaria/veterinária , Ancylostoma/genética , Ancylostoma/crescimento & desenvolvimento , Animais , Anti-Helmínticos/farmacologia , Sequência de Bases , Cães , Feminino , Proteínas de Helminto/genética , Infecções por Uncinaria/parasitologia , Ivermectina/farmacologia , Masculino , Filogenia , Tiabendazol/farmacologia , Tubulina (Proteína)/genética
11.
J Sep Sci ; 42(9): 1786-1793, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30805997

RESUMO

A new sample preparation method based on SBA-15 assisted electromembrane extraction coupled with corona discharge ion mobility spectrometer was developed for the determination of Thiabendazole as a model basic pesticide in fruit juice samples. The addition of SBA-15 in the supported liquid membrane in electromembrane extraction system not only can lead to enhancement of the effective surface area, but also introducing the negatively charged silanol groups into supported liquid membrane might improve migration of positively charged analytes toward the supported liquid membrane and finally into the acceptor solution. To investigate the effect of the presence of SBA-15 in the supported liquid membrane on the extraction efficiency, a comparative study was carried out between the conventional electromembrane extraction and SBA-15/electromembrane extraction methods. Under the optimized conditions, SBA-15/electromembrane extraction method showed higher extraction efficiencies in comparison with conventional electromembrane extraction method. SBA-15/electromembrane extraction method exhibited a low limit of detection (0.9 ng/mL), high preconcentration factor (167) and high recovery (83%). Finally, the applicability of SBA-15/electromembrane extraction method was studied by the extraction and determination of Thiabendazole as a model basic pesticide in fruit juice samples.


Assuntos
Técnicas Eletroquímicas/métodos , Sucos de Frutas e Vegetais/análise , Praguicidas/isolamento & purificação , Tiabendazol/isolamento & purificação , Animais , Técnicas Eletroquímicas/instrumentação , Limite de Detecção , Membranas Artificiais , Praguicidas/análise , Dióxido de Silício/química , Tiabendazol/análise
12.
Colloids Surf B Biointerfaces ; 176: 249-255, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30623812

RESUMO

Clay minerals are commonly used in pharmaceutical products as excipients and active agents. New drug vehicles based on clay minerals have been developed. In this work, sodium (BentNa), calcium (BentCa) and magnesium (BentMg) exchanged bentonites were used for the sorption of thiabendazole (TBZ), and their potential use as controlled release systems was evaluated. Pristine bentonite and exchanged bentonites were characterized by X-ray diffraction, infrared spectroscopy, thermogravimetry and transmission electron microscopy (TEM), and the influence of the different parameters such as pH, contact time and initial concentration of the drug was investigated. The maximum adsorption reached after 45 min period with 2000 mg L-1 of thiabendazole to BentNa and after 105 min with 1300 mg L-1 to BentCa and BentMg, respectively. The maximum adsorbed quantities of thiabendazole were 164.4; 152.3 and 133.3 mg g-1 for BentNa, BentCa and BentMg, respectively. The emission profiles obtained for the bentonite/drug hybrids were similar when simulated body fluids were used and these emission profiles were fitted according to the Korsmeyer-Peppas kinetic model.


Assuntos
Bentonita/química , Preparações de Ação Retardada/farmacologia , Tiabendazol/química , Adsorção , Liberação Controlada de Fármacos , Concentração de Íons de Hidrogênio , Cinética , Modelos Teóricos , Espectroscopia de Infravermelho com Transformada de Fourier , Fatores de Tempo , Difração de Raios X
13.
Talanta ; 195: 841-849, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30625626

RESUMO

Thiabendazole (TBZ) is a kind of pesticide that is widely used in agriculture, and its residue may pose a threat to human health. In order to measure TBZ residues in food samples, a surface-enhanced Raman spectroscopy (SERS) method combined with a homogeneous and reusable gold nanorods (GNR) array substrate was proposed. GNR with a high uniformity was synthesized and then applied to the self-assembly of a GNR vertically aligned array. The relative standard deviation (RSD) of the array for SERS could reach 15.4%, and the array could be reused for more than seven times through the treatment of plasma etching. A logarithmic correlation between TBZ concentration and Raman intensity was obtained, with the best determination coefficient (R2) and the corresponding limit of detection (LOD) of 0.991 and 0.037 mg/L in methanol solution, and 0.980 and 0.06 ppm in apple samples, respectively. The recoveries of TBZ in apple samples ranged from 76% to 107%. This study provided a rapid and sensitive approach for detecting TBZ in apples based on SERS coupled with GNR array substrate, showing great potential for analyzing other trace contaminants in food matrices.


Assuntos
Contaminação de Alimentos/análise , Frutas/química , Fungicidas Industriais/análise , Ouro/química , Malus/química , Nanotubos/química , Tiabendazol/análise , Fungicidas Industriais/química , Análise Espectral Raman , Tiabendazol/química
14.
Chemosphere ; 214: 111-122, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30261417

RESUMO

Brazil is one of the world's largest producers of animal protein, requiring the large-scale use of veterinary drugs. The administration of antimicrobials and antiparasitics is a common practice. However, there is a lack of information on how these drugs impact the environment. Antimicrobials are capable of altering the soil microbial population and are responsible for the development of multidrug-resistant microbial strains. Therefore, it is important to evaluate the fate and transport of these compounds in the environment, and one parameter used for this purpose is the soil-water partition coefficient. In this work, an assessment was made of the soil sorption behaviors of 18 drugs from seven different families, including antimicrobials (sulfonamides, fluoroquinolones, amphenicols, and macrolides) and antiparasitic drugs (milbemycin, avermectins, and benzimidazoles). Seven subtropical soils of different textural classes were tested. The Freundlich sorption coefficients, expressed as µg1-1/n (cm3)1/n g-1, were in the following ranges: 0.45 to 19 (sulfonamides), 72 to 2410 (fluoroquinolones), 9 to 58 (thiabendazole), 0.03 to 0.48 (florfenicol), 105 to 424 (moxidectin), 14 to 184 (avermectins), and 1.5 to 74 (macrolides). The results showed that the drugs belonging to the same family, with chemical structures in common, presented similar behaviors regarding sorption and desorption, for the different soils tested and are generally in agreement with soils from temperate regions. The data set obtained in this work give an overview of the fate of the veterinary drugs in Brazilian subtropical soils with different textures and composition and can be very helpful for exposure risk assessments.


Assuntos
Poluentes do Solo/análise , Solo/química , Drogas Veterinárias/farmacologia , Adsorção , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antiparasitários/farmacologia , Brasil , Fluoroquinolonas , Ivermectina/análogos & derivados , Sulfonamidas , Tiabendazol
15.
Carbohydr Polym ; 205: 596-600, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30446146

RESUMO

This study aimed to develop a jellylike flexible substrate based on nanocellulose decorated with Ag nanoparticles (Ag/NC substrate) and explore its applications for rapid in-situ pesticide detections in fruits and vegetables by surface-enhanced Raman spectroscopy (SERS). The performances of Ag/NC substrate were characterized by rhodamine 6G (R6G). The limit of detection recorded by a portable Raman spectrometer is 10-8 M. The substrate still exhibited satisfactory sensitivity after 60-day preservation. Jellylike and slightly sticky Ag/NC substrate demonstrated good adaptabilities in attaching to sample surfaces and is suitable for in-situ SERS detection. Two types of pesticides on apple peels and cabbages were detected by rapid in-situ and non-invasive SERS method coupled with Ag/NC substrate. The lowest detectable level was 0.5 ng/cm2 for thiram and 5 ng/cm2 for thiabendazole, which were well below the maximum residue levels. These results demonstrate that Ag/NC substrate is sensitive for rapid in-situ multi-pesticide detection in food.


Assuntos
Celulose/química , Contaminação de Alimentos/análise , Frutas/química , Nanopartículas Metálicas/química , Praguicidas/análise , Verduras/química , Brassica/química , Limite de Detecção , Malus/química , Prata/química , Análise Espectral Raman/métodos , Tiabendazol/análise , Tiram/análise
16.
Food Chem ; 270: 494-501, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30174078

RESUMO

A novel and highly sensitive metastable state nanoparticle-enhanced Raman spectroscopy (MSNERS) was reported in this work, which employed an amphiphilic polymer polyurethane-Ag nanoparticle (AgNPs) as the MSNERS substrate. Polyurethane could form micelle to incorporate nanoparticles and analytes, where targets could be in close contact with the metal surface, which was effective for further enhancing the detection sensitivity. Time-dependent visible absorption spectra and time-dependent Raman spectra indicated that polyurethane could greatly enhance the stability of AgNPs aggregates during the volatilization process, which was a great improvement of MSNERS substrate. Combining this MSNERS substrate with the rapid separation method of thin layer chromatography (TLC), this TLC-MSNERS was successfully applied to analyze mixed pesticides on fruit skin and the detection limits of thiabendazole, triazophos and phosmet were 0.02 µg/mL, 0.8 µg/mL, and 0.6 µg/mL, respectively. It enhanced 1 order of magnitude the signals of analytes in comparison to that of traditional TLC-SERS method.


Assuntos
Cromatografia em Camada Delgada/métodos , Praguicidas/análise , Análise Espectral Raman/métodos , Nanopartículas Metálicas , Nanopartículas , Tiabendazol
17.
Rev Paul Pediatr ; 37(1): 121-125, 2019.
Artigo em Português, Inglês | MEDLINE | ID: mdl-30066826

RESUMO

OBJECTIVE: To describe an uncommon case of infection by Strongyloides stercoralis (S. stercoralis) in a 4-month-old child and to highlight the importance of early diagnosis. CASE DESCRIPTION: The patient was a male child from the city of Videira, State of Santa Catarina, Southern Brazil, who was born preterm by Cesarean-section, weighing 1,655 g, and stayed in the neonatal intensive care unit for 20 days. At four months of age, the child started presenting blood in stools and the possibility of cow's milk protein allergy was considered, given the symptoms and the use of infant formula in his 1st semester of life, which was then replaced by infant formula with hydrolyzed protein. White blood cell count and a parasitological stool sample were requested. Both tested positive and the stool ova and parasite examination showed a rhabditoid larva of S. stercoralis. The clinician maintained the initial hypothesis and diet, but requested three new stool samples, which tested positive for rhabditoid larvae of S. stercoralis. Since the child presented abdominal pain and vomiting, and there was still blood in stools, treatment with thiabendazole was initiated twice a day for two days. Treatment was repeated after seven days along with a new parasitological examination, which was then negative. COMMENTS: Although strongyloidiasis is usually a mild parasitic infection, it may be severe and disseminated in immunocompromised patients. This agent must be considered in patients who live in endemic areas, and the diagnosis should be established by searching S. stercoralis larvae in tracheal secretions and in stools.


Assuntos
Strongyloides stercoralis/isolamento & purificação , Estrongiloidíase , Tiabendazol/administração & dosagem , Animais , Anti-Helmínticos/administração & dosagem , Fezes/parasitologia , Humanos , Hospedeiro Imunocomprometido , Lactente , Masculino , Estrongiloidíase/diagnóstico , Estrongiloidíase/tratamento farmacológico , Estrongiloidíase/fisiopatologia , Resultado do Tratamento
18.
Environ Sci Pollut Res Int ; 26(3): 2421-2434, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30467755

RESUMO

The simultaneous adsorption of both imazalil (IMZ) and thiabendazole (TBZ) fungicides in a Cu2+-exchanged Mt was studied in this work. Kinetic studies were used to determine the rate law which describes the adsorption of individual fungicides onto the adsorbent. Adsorption isotherm of individual and combined fungicides was done to evaluate synergic or antagonistic effects. The Mt-Cu material considerably improved TBZ and/or IMZ adsorption from aqueous suspensions with respect to raw Mt, leading to removal efficiencies higher than 99% after 10 min of contact time for TBZ and IMZ Ci = 15 and 40 mg/L, respectively, when a solid dosage = 1 g/L was used. The adsorption sites involved were determined by a combination of X-ray diffraction (XRD) determinations and electron paramagnetic resonance (EPR), indicating that fungicides were bonded to Cu2+ cations, while the rate limiting step was the formation of coordination bonds. The adsorption mechanism proposed is that of ligand exchange between water and fungicide molecules in the metal coordination sphere. The single-crystal structure for the IMZ-Cu2+ complex indicated that four molecules were bounded to the copper centers, while two molecules of TBZ are bounded to copper explaining the higher IMZ uptake capacity for the Mt-Cu material. Graphical abstract.


Assuntos
Bentonita/química , Cobre/química , Fungicidas Industriais/química , Imidazóis/química , Tiabendazol/química , Poluentes Químicos da Água/química , Adsorção , Espectroscopia de Ressonância de Spin Eletrônica , Cinética , Difração de Raios X
19.
Anal Chim Acta ; 1045: 117-122, 2019 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-30454566

RESUMO

In this work, a novel molecularly imprinted stir-bar was developed for the stir-bar sorptive extraction (SBSE) of thiabendazole (TBZ) and carbendazim (CBZ) from orange samples. Magnetic nanoparticles were surface modified with oleic acid and then encapsulated by a silica shell using a conventional sol-gel procedure. Subsequently, nanoparticles were functionalized with methacrylate functionalities by grafting onto the particles surface. Finally, the modified magnetic nanoparticles were entrapped in a polymer monolith synthetized by copolymerization with the imprinting polymerization mixture using a glass vial insert as a mold. Variables affecting the polymerization and rebinding conditions of target analytes were optimized. The uptake capacity for the template (TBZ) was evaluated as well as the cross-reactivity for the related compound CBZ by rebinding experiments. Finally, the proposed magnetic imprinted monolith was applied to the SBSE of TBZ and CBZ from orange sample extracts providing a remarkable clean-up ability. The calculated detection limit were 0.13 and 0.10 mg kg-1 for CBZ and TBZ respectively, low enough to satisfactory analysis of both compounds in orange samples according to current European Union regulations.


Assuntos
Benzimidazóis/isolamento & purificação , Carbamatos/isolamento & purificação , Citrus sinensis/química , Nanopartículas de Magnetita/química , Impressão Molecular , Polímeros/química , Tiabendazol/isolamento & purificação , Adsorção , Benzimidazóis/química , Carbamatos/química , Polímeros/síntese química , Tiabendazol/química
20.
Plant Dis ; 102(12): 2545-2549, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30328758

RESUMO

Gray mold caused by Botrytis cinerea is an emerging postharvest disease affecting stored mandarin fruit in California. To develop effective control programs, fungicide sensitivities to four citrus postharvest fungicides were determined. One hundred B. cinerea isolates each in 2015 and 2016 were obtained from decayed fruit collected within packinghouses and tested for resistance to the fungicides. Sensitivity to azoxystrobin was examined based on the point mutation in the cyt b gene using PCR, while resistance to fludioxonil, pyrimethanil, and thiabendazole was examined on fungicide-amended media. For azoxystrobin, 83 and 98% of the isolates were resistant in 2015 and 2016, respectively. For pyrimethanil, 71 and 93% were resistant in 2015 and 2016, respectively. For thiabendazole, 63 and 68% were resistant in 2015 and 2016, respectively. No fludioxonil resistance was detected in both years. Five fungicide-resistant phenotypes were detected, and the most common phenotype was triple resistance to azoxystrobin, pyrimethanil, and thiabendazole, accounting for 59 and 65% in 2015 and 2016, respectively. Of the 200 B. cinerea isolates, 5, 23.5, and 62% were resistant to one, two, or three classes of fungicides, respectively. Inoculation tests were conducted to evaluate if the fungicides at label rates controlled various resistant phenotypes on fruit. Most fungicides failed to control gray mold on mandarin fruit inoculated with the respective fungicide resistant phenotypes. Our results suggest that alternative control methods need to be integrated into existing decay control programs to target this emerging disease on mandarin fruit.


Assuntos
Botrytis/efeitos dos fármacos , Citrus/microbiologia , Farmacorresistência Fúngica , Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Botrytis/genética , California , Dioxóis/farmacologia , Frutas/microbiologia , Fenótipo , Doenças das Plantas/prevenção & controle , Pirimidinas/farmacologia , Pirróis/farmacologia , Estrobilurinas/farmacologia , Tiabendazol/farmacologia
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