Determination of insecticide residues in beverages based on MIL-100(Fe) dispersive solid-phase microextraction in combination with dispersive liquid-liquid microextraction followed by HPLC-MS/MS.

A novel dispersive solid-phase microextraction method based on a metal-organic framework (MIL-100(Fe)) combined with a dispersive liquid-liquid microextraction technique was proposed for the extraction and enrichment of four insecticides in beverages. The qualitative and quantitative analysis of these insecticides was conducted using HPLC-MS/MS. To optimize the extraction process, several parameters were investigated, and the main variables were optimized using CCD-based RSM. The developed method displayed a wide linear range of 1.000-1000 ng/L and R2 values >0.993 for all four calibration curves. The method demonstrated high sensitivity, with LODs and LOQs of 0.3-0.6 ng/L and 0.8-1.0 ng/L, respectively. In addition, the greenness of the proposed method was assessed using the Complex GAPI tool, and the results showed that the proposed method exhibits benefits, such as minimal usage of organic solvents and negligible matrix influence, making it a suitable method for the detection of insecticide residues in beverages.

Separation and Detection of Catechins and Epicatechins in Shanxi Aged Vinegar Using Solid-Phase Extraction and Hydrophobic Deep Eutectic Solvents Combined with HPLC.

This research presents a new, eco-friendly, and swift method combining solid-phase extraction and hydrophobic deep eutectic solvents (DES) with high-performance liquid chromatography (SPE-DES-HPLC) for extracting and quantifying catechin and epicatechin in Shanxi aged vinegar (SAV). The parameters, such as the elution solvent type, the XAD-2 macroporous resin dosage, the DES ratio, the DES volume, the adsorption time, and the desorption time, were optimized via a one-way experiment. A central composite design using the Box-Behnken methodology was employed to investigate the effects of various factors, including 17 experimental runs and the construction of three-dimensional response surface plots to identify the optimal conditions. The results show that the optimal conditions were an HDES (tetraethylammonium chloride and octanoic acid) ratio of 1:3, an XAD-2 macroporous resin dosage of 188 mg, and an adsorption time of 11 min. Under these optimal conditions, the coefficients of determination of the method were greater than or equal to 0.9917, the precision was less than 5%, and the recoveries ranged from 98.8% to 118.8%. The environmentally friendly nature of the analytical process and sample preparation was assessed via the Analytical Eco-Scale and AGREE, demonstrating that this method is a practical and eco-friendly alternative to conventional determination techniques. In summary, this innovative approach offers a solid foundation for the assessment of flavanol compounds present in SAV samples.

Determination of Flavonoid Compounds in Shanxi Aged Vinegars Based on Hydrophobic Deep Eutectic Solvent VALLME-HPLC Method: Assessment of the Environmental Impact of the Developed Method.

This research presents a novel, eco-friendly, vortex-assisted liquid-liquid microextraction (VALLME) approach, integrating hydrophobic deep eutectic solvents (DESs) with HPLC for the identification and quantification of nine specific flavonoids in Shanxi aged vinegar (SAV). The parameters of DES-VALLME, including the ratio of trioctylmethylammonium chloride to 1,4-butanediol (1:6), DES volume (150 µL), vortex duration (5 min), the concentration of NaCl (0.40 g), and centrifugation time (10 min), were optimized to achieve the maximum extraction efficiency of target substances. Under these optimal conditions, quantitative analyses performed via HPLC demonstrated a broad linear range of 0.20-50.00 µg/mL and correlation coefficients (r2) greater than 0.9944 for all nine calibration curves. The limits of detection (LOD) and limits of quantitation (LOQ) were 0.09-0.18 µg/mL and 0.30-0.60 µg/mL, respectively, ensuring high sensitivity. The relative standard deviations for intra-day and inter-day variability were within the acceptable range, 2.34-3.77% and 3.04-4.96%, respectively, demonstrating the method's reliability. The recovery rates ranged from 85.97% to 108.11%, underscoring the method's precision. This technique exhibited a significant enrichment effect (enrichment factor: 43 to 296) on SAV flavonoids. Notably, the eco-friendliness of this procedure was evaluated using the Analytical Eco-Scale, Green Analytical Procedure Index, and Analytical Greenness Metric. The results suggested that this technique is a viable green alternative to traditional flavonoid determination methods in SAV. In summary, this novel method provides a theoretical basis for assessing flavonoid content in SAV samples and tracing SAV products. This contribution has significant implications for enhancing analytical techniques in food chemistry and environmental science and the sustainable development of the food industry.

A Novel Monopolar Cross-Scale Nanopositioning Stage Based on Dual Piezoelectric Stick-Slip Driving Principle.

The precise characterization and measurement of new nanomaterials and nano devices require in situ SEM nanorobotic instrumentation systems, which put forward further technical requirements on nanopositioning techniques of compact structure, cross-scale, nanometer accuracy, high vacuum and non-magnetic environment compatibility, etc. In this work, a novel cross-scale nanopositioning stage was proposed, which combined the advantages of piezoelectric stick-slip positioner and piezoelectric scanner techniques and adopted the idea of macro/micro positioning. A new structure design of a single flexible hinge shared by a small and large PZT was proposed to effectively reduce the size of the positioning stage and achieve millimeter stroke and nanometer motion positioning accuracy. Then, the cross-scale motion generation mechanism of the dual piezoelectric stick-slip drive was studied, the system-level dynamics model of the proposed positioning stages was constructed, and the mechanism design was optimized. Further, a prototype was manufactured and a series of experiments were carried out to test the performance of the stage. The results show that the proposed positioning stage has a maximum motion range of 20 mm and minimum step length of 70 nm under the small piezoceramic ceramic macro-motion stepping mode, and a maximum scanning range of 4.9 µm and motion resolution of 16 nm under the large piezoceramic ceramic micro-motion scanning mode. Moreover, the proposed stage has a compact structure size of 30 × 17 × 8 mm3, with a maximum motion speed of 10 mm/s and maximum load of 2 kg. The experimental results confirm the feasibility of the proposed stage, and nanometer positioning resolution, high accuracy, high speed, and a large travel range were achieved, which demonstrates that the proposed stage has significant performance and potential for many in situ SEM nanorobotic instrument systems.

Central nervous system hemangioblastomas: An age-stratified analysis.

BACKGROUND: Hemangioblastomas (HBs) are rare and understudied. The impact of age on clinical features, optimal treatment, and postoperative outcome in HBs has not been systemically studied. MATERIALS AND METHODS: We performed an institutional study in the West China Hospital, including patients diagnosed with hemangioblastomas between October 2011 and October 2016. Clinical data and surgical outcomes were compared among three different age groups (0-20, 21-59, and ≥ 60 years). We also studied surgical prognostic factors. RESULTS: 187 patients (102 males and 85 females) were identified. HBs in spinal locations were more prevalent in children and adolescents, while the most common site in young and old-age adults was the cerebellum (P = 0.023). Risk of Von Hippel-Lindau syndrome (VHL) was negatively correlated with patient age (P = 0.003). 47.6 % of patients aged 0-20, 23 % of patients aged 21-59, and 6.45 % of patients aged ≥60 years were diagnosed with VHL. Older aged patients had a significantly lower risk of VHL and had a lower tumor recurrence rate. Surgical resection was an adequate and sufficient procedure in all age groups with a favorable surgical outcome (P = 0.823). Solid tumor, VHL disease, and localization in the brainstem were associated with poor outcome in patients with hemangioblastomas. CONCLUSIONS: Our study showed that HBs in elderly patients were mostly included in the cerebellum and had a solid configuration and large size, while HBs in children were mainly localized in the spinal cord. VHL disease was more common in children and adolescents but rare in patients older than 60 years. The present study found no excess surgical mortality and risks for HBs in elderly patients or children than in younger adults.

TOPP4 Regulates the Stability of PHYTOCHROME INTERACTING FACTOR5 during Photomorphogenesis in Arabidopsis.

In plants, photoreceptors transfer light signals to phytochrome-interacting factors (PIFs), inducing the rapid phosphorylation and degradation of PIFs to promote photomorphogenesis. However, the phosphatase responsible for PIF dephosphorylation remains unknown. In this study, we identified a type 1 protein phosphatase, TOPP4, that is essential for PIF5 protein stability in Arabidopsis (Arabidopsis thaliana). Compared with the wild type, the dominant-negative mutant, topp4-1, displayed reduced hypocotyl length and larger apical hook and cotyledon opening angle under red light. Overexpression of topp4-1 in the wild type led to defects that were similar to those in the topp4-1 mutant. Red light induced phytochrome B (phyB)-dependent TOPP4 expression in hypocotyls. The topp4-1 mutation weakened the closed cotyledon angle of phyB-9 and phyA-211 phyB-9, while overexpression of TOPP4 significantly repressed the short hypocotyls of phyB-green fluorescent protein seedlings, indicating that TOPP4 and phyB function in an antagonistic way during photomorphogenesis. Protein interaction assays and phosphorylation studies demonstrate that TOPP4 interacts directly with PIF5 and dephosphorylates it. Furthermore, TOPP4 inhibits the red light-induced ubiquitination and degradation of PIF5. These findings demonstrate that dephosphorylation of PIF5 by TOPP4 inhibits its ubiquitin-mediated degradation during photomorphogenesis. These data outline a novel phytochrome signaling mechanism by which TOPP4-mediated dephosphorylation of PIF5 attenuates phytochrome-dependent light responses.