Dissipation, Residue and Human Dietary Risk Assessment of Pyraclostrobin and Cyazofamid in Grapes Using an HPLC-UV Detector.

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.

Effects of multiple cations and sintering temperature on microstructure and dielectric properties in NaLnCuTiO (Ln = Sm and Eu) ceramic materials.

NaEuCuTiO and NaSmCuTiO 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, Eu) co-doped ceramics changed faster than that of (Na, Sm) co-doped ceramics.

Transmission Electron Microscopy Peeled Surface Defect of Perovskite Quantum Dots to Improve Crystal Structure.

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 [PbBr] octahedron defects from the surface of QDs to optimize the crystal structure.

Tailoring Phase Distribution of Quasi-2D Perovskites via Taurine-Assistance Enables Efficient Blue Light-Emitting Diodes.

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.

Dissipation and Residue of Metalaxyl-M and Azoxystrobin in Scallions and Cumulative Risk Assessment of Dietary Exposure to Hepatotoxicity.

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).

Dissipation, Residue, and Dietary Risk Assessment of Bifenthrin, Bifenazate, and Its Metabolite Bifenazate-Diazene in Apples Based on Deterministic and Probabilistic Methods.

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.

Tunable White Light-Emitting Devices Based on Unilaminar High-Efficiency Zn-Doped Blue CsPbBr Quantum Dots.

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 Zn-doped CsPbBr PQDs with exciplex emission between poly(9-vinylcarbazole) (PVK) and ((1-phenyl-1-benzimidazol-2-yl)benzene)) (TPBi).

Enantiomeric profiling of mefentrifluconazole in watermelon across China: Enantiochemistry, environmental fate, storage stability, and comparative dietary risk assessment.

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.

Dissipation Behavior, Residue, and Risk Assessment of Benziothiazolinone in Apples.

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.

Dissipation, residue, dietary, and ecological risk assessment of atrazine in apples, grapes, tea, and their soil.

Atrazine is one of the most used herbicides in China. It is a persistent organic pollutant but has been widely used on Chinese farmlands for a long time. To assess its dietary and ecological risks to human and environment, in this study, atrazine residues were extracted with acetonitrile and then plant samples were detected with gas chromatography coupled with mass spectrometry (GC-MS) and soil samples were determined with gas chromatography coupled with nitrogen-phosphorus detector (GC-NPD).

Enantioselective fate of dinotefuran from tomato cultivation to home canning for refining dietary exposure.

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.

Label-Free Colorimetric Detection of Prothioconazole Using Gold Nanoparticles Based on One-Step Reaction.

One simple, sensitive detection method for pesticide prothioconazole based on citrate-capped gold nanoparticles (AuNPs) in one step at room temperature was presented in this study. Prothioconazole could be easily linked onto the AuNPs through a Au-S covalent bond, and AuNPs undergo aggregation via hydrogen bonds formed among prothioconazole molecules. As a result, the color of AuNP solution changes from wine red to royal purple, which could be monitored by naked eyes and UV-vis spectra.

A ratiometric nanoprobe based on carboxylated graphitic carbon nitride nanosheets and Eu for the detection of tetracyclines.

A ratiometric fluorescence method based on carboxylated graphitic carbon nitride nanosheets (C-g-CN) and Eu (C-g-CN-Eu) is described for the detection of tetracyclines (TCs), a broad-spectrum antibiotic. C-g-CN, which was used as a fluorescence enhancer of Eu, was prepared by direct pyrolysis of melamine and post-functionalization. In the presence of TCs, the fluorescence intensity of Eu at 616 nm increased, accompanied by a decrease of fluorescence intensity of C-g-CN at 435 nm.

Simultaneous determination of the herbicide bixlozone and its metabolites in plant and animal samples by liquid chromatography-tandem mass spectrometry.

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 (R  > 0.

Replication of DNA Containing Mirror-Image Thymidine in Cells.

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.

Electron Paramagnetic Resonance Study on Oxygen Vacancies and Site Occupations in Mg-Doped BaTiO Ceramics.

Nominal (BaMg)TiO ( = 0.015) (BM1T) and (BaMg)TiO ( = 0.03-0.

Dicyanovinyl substituted push-pull chromophores: effects of central C[double bond, length as m-dash]C/phenyl spacers, crystal structures and application in hydrazine sensing.

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.

Influence of lactic acid bacteria on stereoselective degradation of theta-cypermethrin.

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.

Dissipation behavior and risk assessment of butralin in soybean and soil under field conditions.

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.

Chronic and acute risk assessment of human exposed to novaluron-bifenthrin mixture in cabbage.

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.

Dissipation, terminal residues and risk assessment of fluopicolide and its metabolite in cucumber under field conditions.

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.

Effect of surface charge of PDDA-protected gold nanoparticles on the specificity and efficiency of DNA polymerase chain reaction.

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.

Colorimetric detection of Mn2+ using silver nanoparticles cofunctionalized with 4-mercaptobenzoic acid and melamine as a probe.

A facile, selective and highly sensitive method is proposed for colorimetric detection of manganese ions using 4-mercaptobenzoic acid (4-MBA) and melamine (MA) modified silver nanoparticles (AgNPs). The presence of Mn(2+) induces the aggregation of AgNPs through cooperative metal-ligand interaction, resulting in a color change from bright yellow to purple. The cofunctionalized AgNPs showed obvious advantages over the ones functionalized only by 4-MBA or MA in terms of selectivity.