Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21.238
Filtrar
1.
Chemosphere ; 287(Pt 2): 132163, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34509014

RESUMO

A structural switching in Single-stranded DNA (ssDNA) fluorescence biosensor for quick turn-on/off detection of Pb2+ ions and pesticide was reported. The design strategy of Hex-labelled ssDNA consists of two types of aptamer probe, G-rich base pair sequence forms G-quadruplex confirmation with Pb2+ ions. While other part of base pair sequence exhibits affinity to fold isocarbophos pesticide. MoS2 nanosheets were identified as quick quencher of Hex fluorescence intensity via Vander-Waals interaction and its significance was compared with other nanomaterials. This sensing mechanism proposes a specific affinity of GA-rich ssDNA with Pb2+ to form G-quadruplex via G-Pb2+-G sequences. Consequently, ssDNA relived from MoS2 nanosheets to restore the fluorescence intensity (turn-on). Subsequent addition of pesticide shows stronger affinity towards unfolded aptamer probe to form a random coil like structure. This causes Hex-labelled 5' end closer to the G-quadruplex connected at the 3' end of ssDNA resulting in a remarkable fluorescence quenching (turn-off) owing to PET process. Moreover, the sensing probe (Hex-labelled GA-rich ssDNA) was recycled by introducing acetylcholinesterase enzyme and thiocoline into the reaction mixture. The detection limits of Pb2+ and isocarbophos pesticide was estimated to be 0.6 nM and 0.018 µg/L respectively. Moreover, this study reveals a high sensitivity and selectivity towards target molecules in environmental samples.


Assuntos
Técnicas Biossensoriais , Praguicidas , Acetilcolinesterase , DNA de Cadeia Simples , Chumbo , Limite de Detecção , Compostos Organofosforados
2.
Chemosphere ; 286(Pt 3): 131837, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34399266

RESUMO

The presence of highly toxic and persistent pesticides in water bodies causes serious problems to human beings as well as aquatic life. Quinalphos is one such widely used organophosphorus pesticide in agricultural fields. Herein, for degradation and mineralization of quinalphos, ZnO nanoflowers and their hybrid nanocomposite with graphene oxide have been synthesized. FESEM analysis confirmed the formation of ZnO nanoflowers over nanosheets of graphene oxide having a thickness of 20 ± 10 nm. GO-ZnO composite exhibited remarkable photocatalytic activity in comparison to pure ZnO. 98 % degradation of quinalphos was achieved using GO-ZnO nano-catalyst at 6 pH within 45 min of irradiations, whereas it was 80 % for bare ZnO nanoflowers. Higher degradation with hybrid nanocomposite was attributed to improved surface area (36 m2 g-1), a substantial reduction in bandgap energy from 3.10 to 2.90 eV and enhanced charge separation (e-/h+ pairs) after the addition of GO. Reaction kinetics study followed pseudo-first-order behaviour. Further, mineralization to the extent of 90 % in 90 min was confirmed by TOC analysis. Based on identified intermediates, using LCMS analysis, degradation pathways were proposed. The plausible pathways confirmed the presence of smaller and safer reaction intermediates supported by excitation of e- from nanocomposite followed by oxidation of quinalphos with huge free radicals. Overall, this study is significant in terms of using photocatalysis as a tertiary treatment of quinalphos pesticide wastewater at pH 6 in a short duration.


Assuntos
Praguicidas , Óxido de Zinco , Catálise , Humanos , Cinética , Compostos Organofosforados , Compostos Organotiofosforados
3.
Food Chem ; 371: 130997, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34537611

RESUMO

In this study, we report the synthesis and application of a nanocomposite comprising metal-organic framework MIL-101(Cr) and graphene nanopowder (GNP) as a promising sorbent for the extraction of organophosphorus pesticides (OPPs) in juices, water, vegetables and honey samples. A syringe filter, for the first time, was used to host the synthesized nanocomposite and extract the OPPs followed by GC-MS analysis. Different characterization methods including XRD, FTIR, TGA, BET and SEM were employed to confirm the formation of studied nanocomposite. The results indicated that the GNP/MIL-101(Cr) could provide higher capacity for adsorption of OPPs and lower detection limit compared to pristine MIL-101(Cr). The detection limits were 0.005 to 15.0 µg/Kg and the linear range found between 0.05 and 400 µg/Kg. The proposed method showed very good repeatability with the RSD values ranging from 2.9% to 7.1%. The recoveries were between 84% -110% with the spiked levels of 2.0-100.0 µg/Kg.


Assuntos
Estruturas Metalorgânicas , Nanocompostos , Praguicidas , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Compostos Organofosforados/análise , Praguicidas/análise , Extração em Fase Sólida , Seringas
4.
Sci Total Environ ; 804: 150159, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34509846

RESUMO

Rice is the main staple food for more than half of the world's population. Yet, rice cultivation is subjected to criticism because of its important role in methane (CH4) emissions. Although several agronomic practices such as controlled irrigation and conservation tillage have been widely adopted to mitigate CH4 emissions from rice cultivation, the benefits gained by these practices are highly dependent on site-specific soil and climate conditions, and often offset by yield reduction. The use of plant growth regulating compounds having the potential to increase the crop yield and mitigate CH4 emissions may be an innovative approach to sustainable agriculture. Ethylene (C2H4), a plant growth regulator is known to have a strong inhibitory effect on methanogenesis. However, due to gaseous form and low water solubility, C2H4 has not been used to suppress methanogenesis in paddy fields. To develop C2H4 as a prospective soil amendment for reducing methane (CH4) emissions, ethephon (2-Chloroethylphosphonic acid), a precursor of C2H4 was tested. We found that ethephon reduced CH4 formation by 43%, similar to other well known methanogenic inhibitors (2-Bromoethanesulfonate, 2-Chlomoethanesulfonate, 2-Mercaptoethanesulfonate). However, ethephon rapidly hydrolyzed to C2H4 and methanogenic activity recuperated completely after C2H4 removal. To slow down the release of C2H4, ethephon was mixed with bio-degradable polymers such as cellulose acetate and applied to paddy soils. We found that compared with the control, the C2H4 release of ethephon slowed down to 90 days, and the CH4 emissions were reduced by 90%. The application of ethephon at lower concentrations did not significantly alter bacterial communities, their relative abundance, and the abundance of methanotrophs, but it significantly reduced archaeal communities and the relative abundance and expression level of methanogens in paddy soils. Results suggest that cellulose acetate-mixed ethephon has great promise to suppress CH4 emissions in rice paddies while ensuring sustainable yields.


Assuntos
Metano , Oryza , Agricultura , Óxido Nitroso/análise , Compostos Organofosforados , Estudos Prospectivos , Solo
5.
Food Chem ; 368: 130835, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34416487

RESUMO

A novel deep eutectic solvents (DES) was successfully applied as an emulsifier in vortex assisted liquid-liquid microextraction (VALLME) coupled with gas chromatography-mass spectrometry for the determination of organophosphorus pesticides in honey and fruit samples. Based on the result of toxicity study, DES provides new opportunities for the safe delivery and application. The predominant parameters affecting extraction efficiency were thoroughly optimized and studied in detail. Under optimum parameters, the calibration curve was determined in the concentration range of 0.1 to 200 µgL-1 with excellent determination coefficients values of 0.9989 to 0.9999. Limit of detection and limit of quantification were found to be 0.01 - 0.09 µgL-1 and 0.03 - 0.2 µgL-1, respectively. Application of the developed method to honey and fruit samples gave acceptable recovery values 83 - 109% with relative standard deviation below than 9.5%. The suggested approach has also proven to be simple, cost-effective, rapid, and non-toxic in nature.


Assuntos
Mel , Microextração em Fase Líquida , Praguicidas , Frutas/química , Mel/análise , Limite de Detecção , Compostos Organofosforados/toxicidade , Praguicidas/análise , Praguicidas/toxicidade , Solventes
6.
Sci Total Environ ; 805: 150384, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818755

RESUMO

The bioaccumulation and depuration of seven organophosphorus flame retardants (OPFRs) in marine mussel Mytilus galloprovincialis were studied. OPFRs showed to be bioavailable in aquatic environments. When mussels are exposed to environmentally relevant concentrations of OPFRs, uptake kinetics fit well to a first-order model with a single compartment; in contrast depuration rates were generally underestimated by that model, most likely because it does not take into account the biotransformation of OPFRs by the organisms. The highest bioaccumulation rates were observed for tricresyl phosphate (TCrP), triphenyl phosphate (TPhP) and 2-ethylhexyldiphenylphosphate (EHDPP). This could be due to the presence of aryl groups in these compounds, their low solubility in water, and their affinity for fat tissues. According to these findings TCrP, with a BCF value of 4042 L kg-1 wet weight, should be classified in environmental regulations as an accumulative chemical.


Assuntos
Retardadores de Chama , Mytilus , Animais , Bioacumulação , Cinética , Organofosfatos , Compostos Organofosforados
7.
Artif Intell Med ; 121: 102180, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34763802

RESUMO

Glioma is a relatively common brain tumor disease with high mortality rate. Humans have been seeking a more effective therapy. In the course of treatment, the specific location of the tumor needs to be determined first in any case. Therefore, how to segment tumors from brain tissue accurately and quickly is a persistent problem. In this paper, a new dual-stream decoding CNN architecture combined with U-net for automatic segmentation of brain tumor on MR images namely DDU-net is proposed. Two edge-based optimization strategies are used to enhance the performance of brain tumor segmentation. First, we design a separate branch to process edge stream information. Here, high level edge features are reduced in dimension of channel and integrated into the conventional semantic stream in the way of residual. Second, a regularization loss function is used to encourage the predicted segmentation mask to align with ground truth around the edge mainly by penalizing pixels where the predicted segmentation masks and labels do not match around the edge. In training, we employ a novel edge extraction algorithm for providing edge labels with higher quality. Moreover, we add a self-adaptive balancing class weight coefficient into the cross entropy loss function for solving the serious class imbalance problem in the backpropagation of edge extraction. Our experiments show that this leads to a very efficient architecture which can produce clearer prediction at the edge of the tumor. Our method achieves ideal performance on BraTS2017 and BraTS2018 in terms of Dice coefficient.


Assuntos
Neoplasias Encefálicas , Aprendizado Profundo , Algoritmos , Neoplasias Encefálicas/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador , Compostos Organofosforados , Triazóis
8.
Pestic Biochem Physiol ; 179: 104977, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802527

RESUMO

Chlorpyrifos (0,0-diethyl 0-(3,5,6-trichloro-2-pyridinyl)-phosphorothioate; (CPF)) is a widely used lipophilic organophosphorus insecticide that primarily manifests into central and peripheral nervous system toxicity. However, it is poorly investigated as a developmental neurotoxicant and thus remains less explored for pharmacological interventions as well. Berberine (BBR) is a benzylisoquinoline alkaloid, primarily found in the plants of Berberidaceae family, and is used for the synthesis of several bioactive derivatives. The goal of this study was to evaluate the CPF-induced neuronal damage through lactational route and analyze the neuroprotective efficacy of berberine (BBR), a potent antioxidant compound in the F1 generation. The environmentally relevant dose of CPF (3 mg/kg b.wt.) was administered via gavage to pregnant dams from postnatal day 1 to day 20 (PND 1-20). BBR (10 mg/kg b.wt.) was administered concurrently with CPF for the same duration as a co-treatment. Levels of reactive oxygen species, lipid peroxidation, membrane bound ATPases (Na+K+ATPase, Ca2+ATPase, and Mg2+ATPase), DNA damage, histomorphological alterations, cellular apoptosis were increased, and activities of glutathione reductase, endogenous antioxidant enzymes (SOD, CAT, GST, and GR) were decreased in cerebellum and cerebrum regions of CPF exposed pups. CPF triggered neuronal apoptosis by upregulating Bax and caspase-3 and downregulating Bcl-2. Co-treatment of BBR significantly attenuated these effects of CPF signifying oxidative stress mediated chlorpyrifos induced neuronal apoptosis. Berberine treatment ameliorated the CPF-induced downregulation of Bcl-2, Bax translocation, and up-regulation of caspase-3 in F1 pups. Therefore, BBR owing to its multiple pharmacological properties can be further explored for its therapeutic potential as an alternative neuroprotective agent against lactational exposure of chlorpyrifos-induced developmental neurotoxicity.


Assuntos
Berberina , Clorpirifos , Inseticidas , Animais , Berberina/toxicidade , Clorpirifos/toxicidade , Inseticidas/toxicidade , Compostos Organofosforados , Estresse Oxidativo , Ratos , Ratos Wistar
9.
Anal Chim Acta ; 1186: 339128, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34756263

RESUMO

A magnetic dual-template molecularly imprinted polymer (DMIP) was successfully prepared in an aqueous medium and used as a sorbent for the selective extraction of organophosphorus pesticides prior to analysis by high-performance liquid chromatography (HPLC). The binding properties and selectivity of DMIP toward organophosphorus were evaluated and compared with those of a non-imprinted polymer. The established magnetic dispersive solid-phase extraction (MDSPE) method using DMIP exhibited fast enrichment of the target analytes within 60 s for adsorption and 30 s for desorption. Good linearities in the range of 0.5-2000 µg L-1 with coefficients of determination (R2) greater than 0.9930 were observed. The method provides low limits of detection of 0.062-0.195 µg L-1 and limits of quantification of 0.210-0.640 µg L-1 with relative standard deviations of less than 9.5% for intra- and inter-day analyses. The enrichment factors ranged from 464 to 621. Satisfactory recoveries ranged from 81.3 to 110.0% with relative standard deviations below 11%.


Assuntos
Impressão Molecular , Praguicidas , Cromatografia Líquida de Alta Pressão , Frutas/química , Limite de Detecção , Fenômenos Magnéticos , Polímeros Molecularmente Impressos , Compostos Organofosforados , Praguicidas/análise , Extração em Fase Sólida , Verduras
10.
Anal Chim Acta ; 1187: 339135, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34753563

RESUMO

Molecularly imprinted polymers (MIPs) have become an important class of materials for selective and efficient adsorption of target analytes. Despite versatility of MIPs for fabrication in numerous formats, these materials have been primarily reported as solid phase extraction packing materials. An effective thin film MIP prepared on stainless steel substrate is reported here for high throughput enrichment of organophosphorus pesticides (OPPs) from water and beverage samples followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. The key factors controlling performance as well as best practices for optimized fabrication of thin film MIPs are presented. A pseudo-phase diagram is introduced to evaluate and predict the effect of the ratio of porogen (solvent, 1-octanol) volume to relative crosslinker mass on the desired polymer features (i.e., porosity, surface area, capacity, and selectivity). At low porogen ratios, a macroporous polymer with insignificant selectivity is formed, whereas at high porogen ratios a micro-gel polymer with superior selectivity towards targets is obtained. The porosity and morphology determined with nitrogen adsorption and scanning electron microscopy were attributed to specific regions in the pseudo-phase diagram. Other factors influencing selectivity and stability of the polymer, such as type of the template and its ratios with monomer (methacrylic acid) and crosslinker (ethylene glycol dimethacrylate) were optimized. The prepared thin film MIPs were characterized using adsorption isotherms and adsorption kinetics, and evaluated for matrix effects (high humic acid content) and cross-reactivity in presence of other pesticides and pharmaceuticals. The optimized method provided limits of quantitation (LOQs) ranged from 0.002 to 0.02 ng mL-1 in water and from 0.095 to 0.48 ng g-1 in apple juice. Regarding inter-device variability (CV∼10% without normalization), excellent linearity (R2 > 0.99), satisfactory accuracies (90-110%) and precisions (<15%) were obtained.


Assuntos
Impressão Molecular , Praguicidas , Adsorção , Bebidas , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Polímeros Molecularmente Impressos , Compostos Organofosforados/análise , Praguicidas/análise , Extração em Fase Sólida , Espectrometria de Massas em Tandem , Água
11.
Medicine (Baltimore) ; 100(39): e27385, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34596160

RESUMO

RATIONALE: Although anaplastic lymphoma kinase (ALK) inhibitors are effective treatment options for ALK-positive non-small cell lung cancer (NSCLC) with central nervous system (CNS) metastasis, achieving long-term survival in patients with NSCLC with meningeal carcinomatosis resistant to ALK inhibitors is difficult. Lorlatinib, a third-generation ALK inhibitor, was designed for selective CNS penetration, and exerts potent antitumor activity against tumors resistant to first- and/or second-generation ALK inhibitors. However, there is limited information about the activity of lorlatinib in ALK inhibitor-resistant meningeal carcinomatosis. Here, we report a case of ALK-positive lung adenocarcinoma with meningeal carcinomatosis in which lorlatinib was used after resistance to alectinib and brigatinib. PATIENTS CONCERNS: A 55-year-old woman with no history of smoking presented to our hospital with a swelling on the left neck. Clinical imaging and histopathological examination revealed a tumor of adenocarcinoma histology in the left upper lung with no CNS metastasis. DIAGNOSES: The patient was diagnosed with ALK-positive lung adenocarcinoma (cT3N3M1b: stage IVA). INTERVENTIONS: She received the second-generation ALK inhibitors, alectinib and brigatinib, in the first and second-line settings, respectively. However, she developed meningeal carcinomatosis. Hence, treatment with lorlatinib was initiated in the third-line setting. OUTCOMES: The symptoms associated with meningeal carcinomatosis, such as disturbance of consciousness and diplopia, improved dramatically. At 8 months from the initiation of lorlatinib, the patient remained well without disease progression. LESSONS: Lorlatinib is an effective treatment option for patient with ALK-positive NSCLC who develop meningeal carcinomatosis resistant to second-generation ALK inhibitors. Therefore, lorlatinib should be considered in such cases, even when patients exhibit serious symptoms associated with meningeal carcinomatosis.


Assuntos
Aminopiridinas/uso terapêutico , Quinase do Linfoma Anaplásico/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Lactamas/uso terapêutico , Carcinomatose Meníngea/tratamento farmacológico , Carcinomatose Meníngea/secundário , Proteínas Tirosina Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/uso terapêutico , Pirazóis/uso terapêutico , Quinase do Linfoma Anaplásico/antagonistas & inibidores , Carbazóis/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Carcinomatose Meníngea/diagnóstico por imagem , Pessoa de Meia-Idade , Compostos Organofosforados/uso terapêutico , Piperidinas/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Pirimidinas/uso terapêutico
12.
Artigo em Chinês | MEDLINE | ID: mdl-34624949

RESUMO

Objective: To explore the value of soluble growth stimulation expression gene 2 protein (soluble suppression of tumorigenicity 2; sST2) and N terminal B type brain natriuretic peptide (N-terminal probrainnatriuretic peptide, NT-proBNP) in evaluating the short-term prognosis of acute organophosphorus pesticide poisoning. Methods: select 228 patients with acute organophosphorus pesticide poisoning in our hospital from October 2017 to March 2020. According to the grade of poisoning degree, it was divided into 82 cases in mild and moderate group and 146 cases in severe group. hs-cTnI、CK-MB、sST2、NT-proBNP、APACHE Ⅱ score and cholinesterase activity were detected 4 h、12 h、24 h after admission. ROC curve was used to evaluate sST2 and NT-proBNP to predict the prognosis of AOPP. Results: 4 hours after admission, there was no significant difference in the scores of hs-cTnI, APACHE Ⅱ, cholinesterase and CK-MB between the Severe Group and the mild and moderate Group (P<0.05) . At 12 and 24 hours after admission, the scores of hs-cTnI, CK-MB and APACHE Ⅱ in severe group were higher than those in mild and moderate group, and the changes of Cholinesterase were more significant than those in 12 hours after Admission (P<0.05) . 4 hours after admission, SST2 and NT-proBNP levels were significantly higher in severe group than those in mild and moderate Group (P<0.05) . The level of SST2 and NT-proBNP in the severe group was significantly higher than that in the mild and moderate group 12 and 24 hours after Admission (P<0.01) , and the level of SST2 and NT-proBNP was significantly higher than that in the mild group 12 hours after Admission (P<0.05) . Correlation analysis showed that 24 hours after admission, sST2, NT-proBNP were positively correlated with APACHE-Ⅱ scores (R=0.634, 0.723, P<0.01) . The area under sST2 combined with NT-proBNP was 0.891, higher than that under sST2 and NT-proBNP at 12 h after admission. The 24 h APACHE Ⅱ score after admission area under the curve was 0.838. Conclusion: sST2 and NT-proBNP combined detection can early predict the occurrence of recent complications in AOPP patients.


Assuntos
Proteína 1 Semelhante a Receptor de Interleucina-1 , Peptídeo Natriurético Encefálico , Praguicidas , Biomarcadores , Humanos , Compostos Organofosforados , Fragmentos de Peptídeos , Praguicidas/envenenamento , Prognóstico
13.
Anal Chim Acta ; 1184: 339026, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34625266

RESUMO

In this work, boron carbon oxynitride quantum dots (BCNO QDs) were prepared by a one-step hydrothermal process of ethanolamine and boric acid. BCNO QDs exhibited blue fluorescence with the optimal excitation/emission fluorescence peak at 335 and 420 nm, respectively. As an efficient fluorescence quencher, manganese dioxide (MnO2) nanosheets can effectively quench the fluorescence of BCNO QDs via the inner filter effect (IFE). Acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylcholine (ATCh) to produce thiocholine (TCh). TCh can reductively degrade MnO2 nanosheets to generate Mn2+, thereby recovering the fluorescence of BCNO QDs. Organophosphorus pesticides (OPs) can inhibit the activity of AChE enzymes, thereby preventing the production of TCh and the decomposition of MnO2 nanosheets, resulting in the fluorescence "turn-off". Therefore, the concentration of OPs can be detected by measuring the fluorescence intensity change of AChE-ATCh-MnO2-BCNO-QDs system. Under optimal experimental conditions, the dynamic detection range of paraoxon is 0.1-250 ng mL-1, and the detection limit is 0.03 ng mL-1. Meanwhile, the reaction system also showed concentration-dependent visual color changes from colorless to brownish. Furthermore, we prepared a portable BCNO QDs test paper. By using a smartphone to identify the RGB values of the reaction solution and the corresponding test paper, we carried out the digital image chromaticity analysis, which can shorten the detection time and reduce the detection cost, and provide an effective solution for the rapid detection of OPs on site.


Assuntos
Técnicas Biossensoriais , Praguicidas , Pontos Quânticos , Acetilcolinesterase , Boro , Carbono , Colorimetria , Compostos de Manganês , Compostos Organofosforados , Óxidos , Praguicidas/análise , Smartphone
14.
Sensors (Basel) ; 21(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34640680

RESUMO

Decreased oxygen saturation (SO2) at high altitude is associated with potentially life-threatening diseases, e.g., high-altitude pulmonary edema. Wearable devices that allow continuous monitoring of peripheral oxygen saturation (SpO2), such as the Garmin Fenix® 5X Plus (GAR), might provide early detection to prevent hypoxia-induced diseases. We therefore aimed to validate GAR-derived SpO2 readings at 4559 m. SpO2 was measured with GAR and the medically certified Covidien Nellcor SpO2 monitor (COV) at six time points in 13 healthy lowlanders after a rapid ascent from 1130 m to 4559 m. Arterial blood gas (ABG) analysis served as the criterion measure and was conducted at four of the six time points with the Radiometer ABL 90 Flex. Validity was assessed by intraclass correlation coefficients (ICCs), mean absolute percentage error (MAPE), and Bland-Altman plots. Mean (±SD) SO2, including all time points at 4559 m, was 85.2 ± 6.2% with GAR, 81.0 ± 9.4% with COV, and 75.0 ± 9.5% with ABG. Validity of GAR was low, as indicated by the ICC (0.549), the MAPE (9.77%), the mean SO2 difference (7.0%), and the wide limits of agreement (-6.5; 20.5%) vs. ABG. Validity of COV was good, as indicated by the ICC (0.883), the MAPE (6.15%), and the mean SO2 difference (0.1%) vs. ABG. The GAR device demonstrated poor validity and cannot be recommended for monitoring SpO2 at high altitude.


Assuntos
Doença da Altitude , Dispositivos Eletrônicos Vestíveis , Gasometria , Humanos , Compostos Organofosforados , Oxigênio
15.
Sud Med Ekspert ; 64(5): 32-35, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34644031

RESUMO

Objective - to identify the morphological equivalents of the cardiotoxic action of organophosphate poisoning. It was studied 110 fatal organophosphate poisonings in toxicogenic and somatogenic stages. The study of the heart was a comprehensive in term of clinical, biochemical, histological, micromorphometric, histochemical and histoenzymological approaches. We have identified a complex of deep metabolic disorders and necrobiotic changes in the heart muscle and the level of cholinesterase activity inhibition in the cholinergic structures of the heart in the toxicogenic and somatogenic stages of fatal organophosphate poisoning.


Assuntos
Intoxicação por Organofosfatos , Compostos Organofosforados , Acetilcolinesterase , Humanos , Compostos Organofosforados/toxicidade
16.
Environ Sci Technol ; 55(20): 14037-14050, 2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34663070

RESUMO

Precision biotransformation is an envisioned strategy offering detailed insights into biotransformation pathways in real environmental settings using experimentally guided high-accuracy quantum chemistry. Emerging pollutants, whose metabolites are easily overlooked but may cause idiosyncratic toxicity, are important targets of such a strategy. We demonstrate here that complex metabolic reactions of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) catalyzed by human CYP450 enzymes can be mapped via a three-step synergy strategy: (i) screening the possible metabolites via high-throughout (moderate-accuracy) computations; (ii) analyzing the proposed metabolites in vitro by human liver microsomes and recombinant human CYP450 enzymes; and (iii) rationalizing the experimental data via precise mechanisms using high-level targeted computations. Through the bilateral dialogues from qualitative to semi-quantitative to quantitative levels, we show how TDCIPP metabolism especially by CYP3A4 generates bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) as an O-dealkylation metabolite and bis(1,3-dichloro-2-propyl) 3-chloro-1-hydroxy-2-propyl phosphate (alcoholß-dehalogen) as a dehalogenation/reduction metabolite via the initial rate-determining H-abstraction from αC- and ßC-positions. The relative yield ratio [dehalogenation/reduction]/[O-dealkylation] is derived from the relative barriers of H-abstraction at the ßC- and αC-positions by CYP3A4, estimated as 0.002 to 0.23, viz., an in vitro measured ratio of 0.04. Importantly, alcoholß-dehalogen formation points to a new mechanism involving successive oxidation and reduction functions of CYP450, with its precursor aldehydeß-dehalogen being a key intermediate detected by trapping assays and rationalized by computations. We conclude that the proposed three-step synergy strategy may meet the increasing challenge of elucidating biotransformation mechanisms of substantial synthesized organic compounds in the future.


Assuntos
Poluentes Ambientais , Retardadores de Chama , Biotransformação , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos , Compostos Organofosforados , Fosfatos
17.
Appl Microbiol Biotechnol ; 105(21-22): 8241-8253, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34665276

RESUMO

In the past decades, the organophosphorus compounds had been widely used in the environment and food industries as pesticides. Owing to the life-threatening and long-lasting problems of organophosphorus insecticide (OPs), an effective detection and removal of OPs have garnered growing attention both in the scientific and practical fields in recent years. Bacterial organophosphorus hydrolases (OPHs) have been extensively studied due to their high specific activity against OPs. OPH could efficiently hydrolyze a broad range of substrates both including the OP pesticides and some nerve agents, suggesting a great potential for the remediation of OPs. In this review, the microbial identification, molecular modification, and practical application of OPHs were comprehensively discussed.Key points• Microbial OPH is a significant bioremediation tool against OPs.• Identification and molecular modification of OPH was discussed in detail.• The applications of OPH in food, environmental, and therapy fields are presented.


Assuntos
Inseticidas , Praguicidas , Arildialquilfosfatase , Biodegradação Ambiental , Compostos Organofosforados
18.
Analyst ; 146(22): 6944-6954, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34647931

RESUMO

In this study, an innovative rapid detection technology for quickly screening and quantifying organophosphorus pesticides (OPPs) in vegetables was developed based on ambient micro-fabricated glow discharge plasma desorption/ionization mass spectrometry (MFGDP-MS), where Fe3O4/ZrO2 synthesized by a one-step coprecipitation was used for enrichment. It can not only effectively enrich OPPs, but can be separated by an external magnetic field, thereby simplifying the traditional steps of centrifugation and cleanup in sample preparation. The introduction of a temperature control system (TCS) can tackle the problem of the low ionization efficiency in MFGDP and expand its application range. Under optimized experimental conditions, the limits of detection (LODs) of the standard solution as low as 0.0068-0.7500 µg L-1 mm-2 were achieved, with relative standard deviations (RSDs) being less than 17.8%. Moreover, vegetable extracts were spiked to evaluate the accuracy of the method, and good recoveries (76.9-123.5%) were obtained. Remarkably, it took no more than 7 minutes from sample preparation to testing, resulting in significantly improved ability of the quantitative detection of plentiful samples.


Assuntos
Praguicidas , Fenômenos Magnéticos , Espectrometria de Massas , Compostos Organofosforados/análise , Praguicidas/análise , Extração em Fase Sólida , Temperatura , Verduras , Zircônio
19.
Molecules ; 26(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34641318

RESUMO

The development of coastal regions has contributed to the intensification of environmental contamination, which can accumulate in aquatic biota, such as shrimps. These crustaceans, besides being delicious and being a good source of nutrients, can also accumulate environmental pollutants. Amongst others, these include organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs), brominated flame retardants (BFRs), polychlorinated biphenyls (PCBs) and synthetic musks (SMs). These pollutants, classified as endocrine disruptors, are related to adverse effects in humans and since one of the major routes of exposition is ingestion, this is a cause for concern regarding their presence in food. The aim of the present study was to quantify the presence of environmental pollutants in shrimp samples and in the water from their habitat along the northwest Portuguese coast. In seawater samples, only two OCPs (lindane and DDD) and one BFR (BTBPE) were detected, and in shrimp samples, one OCP (DDD) and three SMs (HHCB, AHTN and ketone) were found. Bioaccumulation and the risk assessment of dietary exposure of SMs in shrimp samples were investigated. It was observed that all shrimp samples analyzed significantly presented bioaccumulation of the three SMs found. Concentrations of SMs detected in shrimp samples do not present a health risk for the adult Portuguese population.


Assuntos
Penaeidae/química , Água do Mar/análise , Poluentes Químicos da Água/isolamento & purificação , Animais , Monitoramento Ambiental/métodos , Retardadores de Chama/isolamento & purificação , Hidrocarbonetos Clorados/isolamento & purificação , Compostos Organofosforados/isolamento & purificação , Bifenilos Policlorados/isolamento & purificação , Portugal , Águas Residuárias/análise
20.
J Agric Food Chem ; 69(43): 12654-12660, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34695356

RESUMO

Chiral fosthiazate enters the organisms via environmental exposure and food web enrichment. Liver subcellular fractions of rats (RLM) and cocks (CLM) were prepared to explore the stereoselective metabolism of fosthiazate in vitro. The results indicated that fosthiazate exhibited different stereoselective metabolism behaviors in RLM and CLM. The clearance rate order of RLM to four fosthiazate stereoisomers was (1R,3R)-fosthiazate > (1S,3R)-fosthiazate > (1R,3S)-fosthiazate > (1S,3S)-fosthiazate. However, CLM showed a faster clearance rate to (1S,3S)-fosthiazate and (1S,3R)-fosthiazate than the other two stereoisomers. The molecular docking results revealed that the stereoselectivity was partially due to the stereospecific binding between fosthiazate stereoisomers and cytochrome P450 proteins. The main metabolism pathways of fosthiazate in RLM and CLM were oxidation and hydrolysis with five common metabolites including M299, M243, M227, M103, and M197 being identified by LC-TOF-MS/MS. The present study provides the accurate data on risk assessment of chiral fosthiazate.


Assuntos
Microssomos Hepáticos , Espectrometria de Massas em Tandem , Animais , Simulação de Acoplamento Molecular , Compostos Organofosforados , Ratos , Estereoisomerismo , Tiazolidinas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...