RESUMEN
Quasi-2D (Q-2D) perovskites with typical varied n-phase structures deserve promising candidates in pursuing high-performance perovskite light-emitting diodes (PeLEDs). Whereas their weakness in precise n-phase distribution control disables the optical property of PeLEDs since the n = 1 phase is dominated by severe nonradiative recombination. Here, an effective phase distribution tailoring strategy is developed for pure blue PeLEDs by introducing taurine (TAU) into mixed halide Q-2D perovskites. The sulfonic acid group in TAU can coordinate with Pb2+ to suppress the formation of the n = 1 phase while promoting the growth of Q-2D perovskites into domains with the graded distribution of n = 2 and 3. The amino group in TAU forms hydrogen bonds with electronegative halide ions, suppressing the formation of halide vacancies and reducing the defect density in the Q-2D perovskite films. As a result, optimized blue Q-2D perovskite films boosted PLQY to 92%. Target blue PeLED was endowed with a peak EQE of 14.82% (average 12.6%) at 475 nm and a maximum luminance of 1937 cd m-2 , which is among the reported high-level pure blue PeLEDs. This work demonstrates a feasible approach to regulate the phase distribution of Q-2D perovskites for high-performance blue PeLEDs.
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Metalaxyl-M and azoxystrobin have been used to control various fungal diseases on scallion and other crops. In view of the adverse toxic effects of both on the mammalian liver, it is necessary to conduct a cumulative risk assessment of their dietary exposure to consumers. The residues of metalaxyl-M and azoxystrobin on scallion were determined by a quick, easy, cheap, effective, rugged, and safe method (QuEChERS) combined with high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The half-lives were about 1.15 and 3.89 days, respectively, and the final residues after a seven-day harvest interval were <0.001−0.088 mg/kg and 0.190−4.687 mg/kg, respectively. The cumulative dietary risk quotient of the two fungicides to Chinese consumers calculated by the probability model is 13.94%~41.25%. According to the results of the contribution analysis, the risk posed by azoxystrobin is much greater than that of metalaxyl-M. Although metalaxyl-M and azoxystrobin do not pose a cumulative risk to Chinese consumers, the risk to children and adolescents is significantly higher than that to adults. This suggests that in future research, more consideration should be given to the cumulative risk of compounds to vulnerable groups.
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Enfermedad Hepática Inducida por Sustancias y Drogas , Fungicidas Industriales , Residuos de Plaguicidas , Adolescente , Alanina/análogos & derivados , Niño , Cromatografía Liquida/métodos , Exposición Dietética/efectos adversos , Exposición Dietética/análisis , Fungicidas Industriales/química , Humanos , Residuos de Plaguicidas/análisis , Pirimidinas , Medición de Riesgo , Estrobilurinas , Espectrometría de Masas en Tándem/métodosRESUMEN
A ratiometric fluorescence method based on carboxylated graphitic carbon nitride nanosheets (C-g-C3N4) and Eu3+ (C-g-C3N4-Eu3+) is described for the detection of tetracyclines (TCs), a broad-spectrum antibiotic. C-g-C3N4, which was used as a fluorescence enhancer of Eu3+, was prepared by direct pyrolysis of melamine and post-functionalization. In the presence of TCs, the fluorescence intensity of Eu3+ at 616 nm increased, accompanied by a decrease of fluorescence intensity of C-g-C3N4 at 435 nm. Under the optimal conditions, the ratio of fluorescence intensity at 616 nm to the one at 435 nm (I616/I415) increases linearly in the 10 nM to 40 µM TC concentration range with a detection limit of 7.7 nM (S/N = 3). It has been successfully applied in the detection of TCs in spiked tap water and soil samples with satisfactory recovery (96.6-107.2%) and high precision. Furthermore, a test paper and smartphone can assist in rapidly detecting TCs due to the emission color change from blue to red with the addition of TCs. This shows that the proposed method has great potential for the rapid detection TCs in real samples.
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Grafito , Tetraciclinas , Antibacterianos , Fluorescencia , Compuestos de NitrógenoRESUMEN
Tracing the herbicide bixlozone and its metabolites in food is necessary to assess their risks to human health. In the study, a rapid and effective analytical method using the quick, easy, cheap, effective, rugged, and safe method for the simultaneous determination of bixlozone and its metabolites (2,4-dichlorobenzoic acid, 3-hydroxy-propanamide-bixlozone, and 5'-hydroxy-bixlozone) in plant and animal samples (tomato, cucumber, apple, wheat flour, meat, milk, and egg) was developed based on ultra high performance liquid chromatography-tandem mass spectrometry. The method was validated based on the linearity (R2 > 0.99), sensitivity (limit of quantification = 0.01 mg/kg), recovery (70.2-115.1%), and precision (intraday 1.2-17.6%, interday 0.3-16.0%). Detection was achieved within 6.0 min. The method is reliable for the determination of four target compounds in all seven matrices. The satisfactory validation criteria and successful application show that the proposed methodology is suitable for the detection of four target compounds in real matrices.
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Herbicidas/análisis , Animales , Cromatografía Líquida de Alta Presión , Cucumis sativus/química , Cucumis sativus/metabolismo , Herbicidas/metabolismo , Solanum lycopersicum/química , Solanum lycopersicum/metabolismo , Malus/química , Malus/metabolismo , Carne/análisis , Leche/química , Leche/metabolismo , Óvulo/química , Óvulo/metabolismo , Espectrometría de Masas en TándemRESUMEN
DNA damage can occur naturally or through environmental factors, leading to mutations in DNA replication and genomic instability in cells. Normally, natural d-nucleotides were selected by DNA polymerases. The template l-thymidine (l-T) has been shown to be bypassed by several types of DNA polymerases. However, DNA replication fidelity of nucleotide incorporation opposite l-thymidine in vivo remains unknown. Here, we constructed plasmids containing a restriction enzyme (PstI) recognition site in which the l-T lesion was site-specifically located within the PstI recognition sequence (CTGCAG). Further, we assessed the efficiencies of nucleotide incorporation opposite the l-T site and l-T lesion bypass replication in vitro and in vivo. We found that recombinants containing the l-T lesion site inhibited DNA replication. In addition, A was incorporated opposite the l-T lesion by routine PCR assay, whereas preference for nucleotide incorporation opposite the l-T site was A (13%), T (22%), C (46%), and G (19%), and no nucleotide insertion and deletions were detected in E. coli cells. In particular, a novel restriction enzyme-mediated method for detection of the mutagenic properties of DNA lesion was established, which allows us to readily detect restriction-digestion of the l-T-bearing plasmids. The study provided significant insight into how mirror-image nucleosides perturb the fidelity of DNA replication in vivo and whether they elicit mutagenic effects, which may help to understand both how DNA damage interferes with the flow of genetic information during DNA replication and development of diseases caused by gene mutation.
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Replicación del ADN/efectos de los fármacos , ADN Bacteriano/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Timidina/farmacología , Daño del ADN , Replicación del ADN/genética , ADN Bacteriano/genética , Escherichia coli/citologíaRESUMEN
To discern the distinctive effect of the C[double bond, length as m-dash]C bond and the phenyl bridge on the photophysical and chemical properties of D-π-A molecular systems, three new dicyanovinyl substituted push-pull chromophores 1-3 containing either a C[double bond, length as m-dash]C bond or a phenyl ring as the central π-linker were synthesized by the Suzuki-Miyaura and Knoevenagel reactions. Together with the counterpart of 1 developed by Zhang's group (TPE-z), their optical properties and single crystal structures were systematically and comparatively investigated. Notably, the simple π-extension of a C[double bond, length as m-dash]C linker to a phenyl ring between electron donor and electron acceptor moieties could greatly affect the photophysical properties of chromophores, particularly leading to significant hypsochromic shifts in both absorption and emission spectra. Meanwhile, as a node of twisted sections in chromophores, the C[double bond, length as m-dash]C bond was demonstrated to play an important role in the nonradiative relaxation of excited states, as compared to the rigid phenyl spacer. Moreover, the three chromophores were found to display spectral responses to hydrazine with slightly different sensitivities, and visual detection of hydrazine in the gaseous state was achieved via using readily fabricated paper test strips.
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The purpose of this study was to investigate the influence of four kinds of Lactic acid bacteria (LAB) on stereoselective degradation of theta-cypermethrin (CYP), including Lactobacillus plantarum, Lactobacillus casei, Lactobacillus delbrueckii, and Streptococcus thermophilus. An effective analytical method for (±)-theta-CYP in medium was developed by high-performance liquid chromatography with cellulose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase. theta-Cypermethrin was spiked to LAB medium with different inoculation rates and sampled at 0, 2, 8, 24, 36, 48, 72, 120, 168, and 240 hours. The results showed that LAB influenced the half-lives and enantiomer fractions of theta-CYP enantiomers, which lead a closer degradation rate between the 2 stereoisomers, and no obvious difference was found among 4 LABs. Besides, the stereoselective degradation of theta-CYP was closely related to pH. The lower the pH (pH of 3, 5, 7, and 9), the lower the enantiomer fraction (from 4.88 to 6.69). At pH of 3, 7, and 9, significant differences of half-lives between enantiomers were observed. (-)-theta-Cypermethrin decreased faster than (+)-theta-CYP under pH of 3, while opposite results were indicated under pH of 7 and 9. Moreover, the acidic condition contributed to the higher chiral configuration stability of (±)-theta-CYP. (+)-Enantiomer was influenced by pH in a greater degree than (-)-enantiomer.
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Lactobacillales/metabolismo , Piretrinas/química , Piretrinas/metabolismo , Biodegradación Ambiental , Concentración de Iones de Hidrógeno , Lactobacillales/crecimiento & desarrollo , Estereoisomerismo , Especificidad por SustratoRESUMEN
Dissipation behavior, final residue, and risk assessment of butralin in soybean, green soybean, plant, and soil were investigated. Butralin residues were extracted with acetonitrile and then soybean samples were detected with gas chromatography-mass spectrometer (GC-MS) and soil samples were determined with GC with nitrogen phosphorous detector (GC-NPD). The limit of quantification (LOQ) of the method was 0.01 mg/kg for soybean, green soybean, plant, and soil. Average recoveries ranged from 90.4 ~ 98.2% for green soybean, 86.2 ~ 86.6% for soybean, 86.0 ~ 98.8% for plant, and 85.0 ~ 106.8% for soil. The relative standard deviations (RSDs) were 2.0 ~ 7.2% for green soybean, 2.0 ~ 3.0% for soybean, 3.1 ~ 8.1% for plant, and 1.8 ~ 6.6% for soil. Half-lives of butralin in soil samples varied in the range of 11-22 days. At harvest time, final residues of butralin in soybean and green soybean were lower than LOQ. Risk assessment demonstrated that, at recommended dosage and frequency, butralin would not induce significant harm on humans. The study could be used as a quantitative basis for application of butralin on soybean.
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Compuestos de Anilina/análisis , Monitoreo del Ambiente/métodos , Glycine max/química , Residuos de Plaguicidas/análisis , Contaminantes del Suelo/análisis , Suelo/química , Cromatografía de Gases y Espectrometría de Masas , Semivida , Medición de RiesgoRESUMEN
Based on the dissipation and residual level in cabbage determined by gas chromatography coupled with an electron capture detector (GC-ECD), chronic and acute risk assessments of the novaluron and bifenthrin were investigated. At different spiked levels, mean recoveries were between 81 and 108 % with relative standard deviations (RSDs) from 1.1 to 6.8 %. The limit of quantification (LOQ) was 0.01 mg kg(-1), and good linearity with correlation coefficient (>0.9997) were obtained. The half-lives of novaluron and bifenthrin in cabbage were in the range of 3.2~10 days. Based on the consumption data in China, the risk quotients (RQs) of novaluron and bifenthrin were all below 100 %. The chronic and acute risk of novaluron in cabbage was relatively low, while bifenthrin exerts higher acute risk to humans than chronic risk. The obtained results indicated that the use of novaluron-bifenthrin mixture does not seem to pose any chronic or acute risk to humans even if cabbages are consumed at high application dosages and short preharvest interval (PHI).
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Brassica/química , Residuos de Plaguicidas/análisis , Compuestos de Fenilurea/análisis , Piretrinas/análisis , China , Cromatografía de Gases , Monitoreo del Ambiente/métodos , Semivida , Medición de RiesgoRESUMEN
In this study, the dissipation, terminal residue levels, and risk assessment of fluopicolide and its metabolite (2,6-dichlorobenzamide) in cucumber and soil under field conditions were investigated. An analytical method for the simultaneous quantification of fluopicolide and its metabolite in cucumber and soil using gas chromatography coupled with electron capture detection (GC-ECD) was developed. Recoveries were between 78 and 111%, with relative standard deviations (RSDs) from 1.6 to 10.2% at different spiked levels (0.01, 0.025, 0.5, and 2 mg kg(-1)). The limit of quantification (LOQ) was 0.01 mg kg(-1). Fluopicolide exhibited half-lives ranging from 2.0 to 3.3 days and 35 to 63 days, in cucumber and soil under field ecosystem, respectively. The results suggested that the degradation of fluopicolide to 2,6-dichlorobenzamide was quite limited. During harvest, the terminal residues of fluopicolide and its metabolite were both below 0.13 mg kg(-1), which were lower than the established temporary maximum residue limits (MRLs), 0.5 mg kg(-1). The risk quotients (RQs) ranged from 0.0033 to 0.0078, which showed low risk for different groups of people in China. The present study may provide guidance on reasonable use of this pesticide and serve as a reference for establishment official MRLs in China.
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Benzamidas/análisis , Cucumis sativus/metabolismo , Monitoreo del Ambiente , Residuos de Plaguicidas/análisis , Contaminantes del Suelo/análisis , China , Cromatografía de Gases , Ecosistema , Semivida , Medición de Riesgo , Suelo/químicaRESUMEN
Pyraclostrobin is a new broad-spectrum methoxyacrylic acid fungicide. Cyazofamid is a new selective foliar spray acaricide. Here, we studied the degradation rate and final residues of pyraclostrobin and cyazofamid in grape and evaluated their dietary risk to consumers. The average recoveries of pyraclostrobin ether ester, cyazofamid and cyazofamid metabolite (CCIM) in grapes were 84-94%, 92-98% and 99-104%, respectively. The relative standard deviations (RSDs) were 6.0-20.3%, 2.4-10.5% and 1.3-4.0%, respectively, and the LOQs were all 0.05 mg/kg. The digestion dynamics of the experimental sites were in accordance with the first-order kinetic equation. The degradation half-lives of pyraclostrobin ether ester and cyazofamid were 17.8 d-28.9 d and 4.3 d-7.8 d, respectively. The final residues of pyraclostrobin ether ester, cyazofamid and CCIM in grapes were <0.05-1.88 mg/kg, <0.05-0.31 mg/kg and <0.05-0.47 mg/kg, respectively. Using probability models, the total chronic risk values for pyraclostrobin and cyazofamid were calculated to be 0.112-189.617% and 0.021-1.714%, respectively. The results of the contribution analysis indicate that pyraclostrobin poses a much greater risk to Chinese consumers than cyazofamid, especially to children and adolescents, who have a significantly greater risk than adults. This suggests that more consideration should be given to the cumulative risk of compounds for vulnerable groups in the future.
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The polymerase chain reaction (PCR) has become an indispensable technique in molecular biology, however, it suffers from low efficiency and specificity problems. Developing suitable additives to effectively avoid nonspecific PCR reactions and explore the mechanism for PCR enhancing is a significant challenge. In this paper, we report three different modified gold nanoparticles (AuNPs) with different surface charge polarities and poly (diallyl dimethylammonium) chloride (PDDA) for use as novel PCR enhancers to improve the efficiency and specificity. These AuNPs included the positively charged PDDA protected AuNPs (PDDA-AuNPs), the neutral PDDA-AuNPs modified with excess chloride ion (PDDA.C-AuNPs), and the negatively charged sodium citrate (Na(3)Ct) protected AuNPs (Na(3)Ct-AuNPs). Our data clearly suggests that the positively charged PDDA-AuNPs with an optimum concentration as low as 1.54 pM could significantly enhance the specificity and efficiency of PCR, however, the optimum concentration of the negatively charged Na(3)Ct-AuNPs (2.02 nM) was more than 3 orders of magnitude higher than that of positively charged PDDA-AuNPs. The PCR specificity and efficiency are also improved by the neutral PDDA.C-AuNPs with an optimum concentration, much more than that of the PDDA-AuNPs. This suggests that there should be an electrostatic interaction between the positively charged PDDA-AuNPs and the negatively charged PCR components, and the surface charge polarities of PDDA-AuNPs may play an important role in improving the PCR specificity and efficiency.
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ADN/química , Nanopartículas del Metal , Polietilenos/química , Reacción en Cadena de la Polimerasa/métodos , Compuestos de Amonio Cuaternario/química , Electricidad Estática , Oro/química , Técnicas de Amplificación de Ácido NucleicoRESUMEN
Na1/2Eu1/2Cu3Ti4O12 and Na1/2Sm1/2Cu3Ti4O12 dielectric ceramics were synthesized at different sintering temperatures (950, 975 and 1000 °C) by a solid-state reaction method. Phase structure, cation valence state, and dielectric properties of all sintered ceramics were systematically investigated. When the preparation temperature was changed, the Cu+ ion concentration of (Na+, Eu3+) co-doped ceramics changed faster than that of (Na+, Sm3+) co-doped ceramics. Abnormally high dielectric constants of ~ 3.17 × 104 and ~ 1.06 × 104 (at 10 Hz and 303 K) were achieved in Na1/2Sm1/2Cu3Ti4O12 and Na1/2Eu1/2Cu3Ti4O12 ceramics prepared at 950 °C, respectively. However, Na1/2Sm1/2Cu3Ti4O12 and Na1/2Eu1/2Cu3Ti4O12 prepared in high sintering temperature (1000 °C) exhibited a good frequency stability of dielectric permittivity. It was demonstrated that an increasing number of charge carriers induced by the increase of sintering temperature could lead to a competitive coexistence of two polarization mechanisms (surface barrier layer capacitor and internal barrier layer capacitor), further changing the dielectric properties of CaCu3Ti4O12-based ceramics.
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Transmission electron microscopy (TEM) is an excellent characterization method to analyze the size, morphology, crystalline state, and microstructure of perovskite quantum dots (PeQDs). Nevertheless, the electron beam of TEM as an illumination source provides high energy, which causes morphological variation (fusion and melting) and recession of the crystalline structure in low radiolysis tolerance specimens. Hence, a novel and facile strategy is proposed: electron beam peel [PbBr6]4- octahedron defects from the surface of QDs to optimize the crystal structure. TEM and high-angle annular dark-field scanning TEM (HAADF) tests indicate that the [PbBr6]4- octahedron would be peeled from the surface of QDs when QDs samples were irradiated under high-power irradiation, and then a clear image would be obtained. To avoid interference from a protective film of "carbon deposits" on the surface of the sample when using high resolution TEM, amorphous carbon film (15-20 nm) was deposited on the surface of QDs film and then characterized by TEM and HAADF. The detection consequences showed that the defection of PbBr2 on the surface of QDs will gradually disappear with the extension of radiation time, which further verifies the conjecture.
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A rapid, sensitive, and effective multiresidue analytical method was established to investigate the degradation rate and final residues of bifenthrin, bifenazate, and its metabolite bifenazate-diazene in apples, and the dietary risk of consumers was evaluated. The residues of bifenthrin, bifenazate, and bifenazate-diazene in apple samples from 12 different apple-producing areas of China were determined by high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The average recoveries of the three compounds in apples were 88.4-104.6%, and the relative standard deviations (RSDs) were 1.3-10.5%. The limit of quantification (LOQ) for each compound was 0.01 mg/kg. Although the degradation half-lives of bifenthrin, bifenazate, and bifenazate-diazene were 17.8-28.9, 4.3-7.8, and 5.0-5.8 days, under good agricultural practice (GAP) conditions, the final residues of bifenthrin, bifenazate, and the sum of bifenazate and its metabolite bifenazate-diazene in apples were <0.01-0.049, < 0.01-0.027, and <0.02-0.056 mg/kg, respectively, which were lower than the maximum residue limit (MRL) in China. By comparing the deterministic model with the probabilistic model, the results of the probabilistic model at the P95 level (12.91-48.9% for bifenthrin, 17.48-52.01% for bifenazate including its metabolite) were selected as reasonable assessment criteria for chronic dietary risk, and the acute risk was at the P99.9 level (3.00-15.59% for bifenthrin). Although the exposure risk calculated by both the deterministic model and the probabilistic model was less than 100%, the risk to children is significantly higher than that of the general population. This suggests that in future research and policy making, we should pay more attention to the risk of vulnerable groups such as children.
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Malus , Residuos de Plaguicidas , Carbamatos , Niño , China , Cromatografía Liquida , Semivida , Humanos , Hidrazinas , Imidas , Residuos de Plaguicidas/análisis , Piretrinas , Medición de Riesgo , Espectrometría de Masas en TándemRESUMEN
Elucidating the enantiomeric chemistry and enantioselective fate of the novel chiral triazole fungicide mefentrifluconazole is of vital importance for agroecosystem safety and human health. The absolute configuration of mefentrifluconazole was identified firstly as S-(+)-mefentrifluconazole and R-(-)-mefentrifluconazole on a cellulose tris(3-chloro-4-methylphenylcarbamate) chiral phase. A baseline resolution (Rs, 2.51), favorable retention (RT ≤ 2.24 min), and high sensitivity (LOQ, 0.5 µg/kg) of enantiomer pair were achieved by reversed-phase liquid chromatography tandem mass spectrometry combined with a 3D response surface strategy. Nationwide field trials were undertaken to clarify the enantiomer occurrence, enantioselective dissipation, terminal concentrations, and storage stability of S-mefentrifluconazole and R-mefentrifluconazole in watermelon across China. The original deposition of the sum of enantiomer pair was estimated to be 14.4-163.7 µg/kg, and terminally decreased to < LOQ-59.3 µg/kg 10 days after foliage application. S-mefentrifluconazole preferentially degraded (T1/2, 3.3-6.0 days), resulting in the relative enrichment of R-mefentrifluconazole (T1/2, 3.9-6.6 days) in watermelon. A probabilistic model is recommended for the dietary risk assessment, although both acute (%ARfD, 0.435-22.188%) and chronic (%ADI, 1.697-9.658%) risks are acceptable for associated population. The long-term exposures should be continuously emphasized given the increasing applications and persistent fate of mefentrifluconazole, especially for urban children.
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Citrullus , Fungicidas Industriales , Niño , China , Cromatografía Líquida de Alta Presión , Fluconazol/análogos & derivados , Fungicidas Industriales/análisis , Fungicidas Industriales/toxicidad , Humanos , Medición de Riesgo , EstereoisomerismoRESUMEN
Benziothiazolinone is the first independently developed fungicide in China. It has been used to effectively control fungal diseases in a variety of fruits, vegetables, and crops. In this study, the degradation behavior and final residue of benziothiazolinone in apples is discussed, and the dietary risk to consumers was evaluated. High-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine benziothiazolinone residues in apple samples from eight different regions of China. The average recovery of benziothiazolinone in apples was 85.5-100.2%, and the relative standard deviation (RSD) was 0.8-14.9%. The limits of the method of quantification of benziothiazolinone in apples was 0.01 mg/kg. Under good agricultural practices (GAP) conditions, the final residues of benziothiazolinone in apples were below 0.01 mg/kg, lower than the maximum residual limit (MRL) of China. Although the degradation half-lives of benziothiazolinone were 23.9 d-33.0 d, the risk quotient (RQ) of benziothiazolinone was 15.5% by calculating the national estimated daily intake and comparing it with the acceptable daily intake. These results suggested that under GAP conditions, the intake of benziothiazolinone from apples exhibits an acceptably low health risk on consumers.
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Malus , Residuos de Plaguicidas , China , Cromatografía Liquida , Contaminación de Alimentos/análisis , Residuos de Plaguicidas/análisis , Medición de Riesgo , Espectrometría de Masas en TándemRESUMEN
Perovskite-based white-light-emitting devices (WLEDs) are expected to be the potential candidate for the next-generation lighting field due to their scalability and low-cost process. However, simple and adjustable WLED fabrication technology is in urgent need. Here, WLEDs with a single layer of perovskite quantum dots (PQDs) were constructed by combining Zn2+-doped CsPbBr3 PQDs with exciplex emission between poly(9-vinylcarbazole) (PVK) and ((1-phenyl-1H-benzimidazol-2-yl)benzene)) (TPBi). Zn2+-doped CsPbBr3 PQDs with polar ion shells were prepared by means of low temperature and post-treatment. The photoluminescence quantum yield (PLQY) can reach as high as 95.9% at the emission wavelength of 456 nm. The blue shift of its PL (â¼60 nm) is much greater than that of other reported Zn2+-doped CsPbBr3 PQDs (5-10 nm), thus realizing the true blue-emission Zn2+-doped CsPbBr3 PQDs. As a result, just by controlling the thickness of TPBi, the adjustment of cold (CIE (0.2531, 0.2502)) and warm WLEDs (CIE (0.3561, 0.3562)) is realized for the first time.
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Understanding the enantioselective fate of chiral neonicotinoid dinotefuran is of vital importance for accurate dietary exposure assessment and food safety regulation. The study investigated the enantioselectivity in respect to dissipation, metabolism, and removal, of dinotefuran from tomato cultivation to tomato paste processing. The chiral analytical method of dinotefuran, UF and DN was developed in tomato using ultrahigh performance supercritical fluid chromatography/tandem mass spectrometry. Under greenhouse cultivation R-dinotefuran preferentially degraded (T1/2, 9.1-12.6 days), resulting in relative enrichment of S-dinotefuran (T1/2, 10.3-13.3 days) by foliage and root uptake pathways. (-)-UF generated at a faster rate and was more persistent than its antipode in tomato by foliage treatment. Furthermore, changes in the enantiomeric removal and enantioselectivity orientation of dinotefuran and metabolites were evaluated during home canning of tomato paste, including washing, peeling, homogenization, simmering, and sterilization. Peeling played the key role in reducing S-dinotefuran by 67.3% and R-dinotefuran by 69.9% with processing factor of 0.313 and 0.287, respectively. Simmering was the most effective way to remove UF enantiomers (Pf, 0.336-0.421) by elevated temperature. This study sheds light on the chiral profiles of the fate of dinotefuran from cultivation to processing, providing scientific importance to protect human health from hazardous effects.