Simultaneous monitoring of multiple prohibited drugs in various aquatic products.

Both sedative and antipathogenic drugs are often found to be illegally used in aquaculture, but there is a lack of simultaneous monitoring methods. A method for simultaneously monitoring multiple prohibited drugs in various aquatic product samples was developed in this work, including fish, shrimp, crab, and shellfish. Sulfonic acid-functionalized magnetic graphitic carbon nitride (S-MGCN) was synthesized and validated to efficiently co-extract all targets (adsorption efficiency over 90.07%) through various adsorption mechanisms such as electrostatic interaction, hydrogen bonding, and π-π interaction while demonstrating good sample matrix purification ability (matrix effect below 13.60%). A new magnetic solid-phase extraction method based on S-MGCN was subsequently established. Coupled with UPLC-MS/MS, the detection limits were 0.030.075 µg /kg, and the recoveries ranged from 88.76% to 111.74% with the RSDs lower than 14.60%, indicating that the developed method has good sensitivity, accuracy, and precision. Further validation of its practicality was achieved through actual sample analysis.

Exploring the optimal lower blood pressure boundary during endovascular thrombectomy in patients with large vessel occlusion.

BACKGROUND: Current guidelines advocate for maintaining BP level below 180/105 mmHg during EVT, determining the safe lower boundary remains primarily consensus-driven by experts. This study aims to delve into the correlation between various targets of lower boundary for systolic and diastolic BP (SBP and DBP) during EVT and 3-month functional outcomes. METHODS: A cohort study was conducted across two EVT-capable centers, enrolling patients with large artery occlusion undergoing EVT within 8 h of stroke onset. Mean BP values during EVT were meticulously recorded, and logistic regression models were utilized to evaluate the correlation between outcomes and diverse lower boundary targets for SBP and DBP. Additionally, logistic regression models investigated the relationship between periprocedural BP variability and subsequent outcomes. RESULTS: Among the 201 patients included, having a SBP higher than 130 or 140 mmHg showed an independent association with increased good functional outcomes at 3 months (adjusted odds ratio, aOR 2.80, 95% Cis, 1.26-6.39 for 140 mmHg; aOR 2.34, 95% Cis, 1.03-5.56 for 130 mmHg). Additionally, an SBP exceeding 130 mmHg was correlated with decreased 3-month mortality (aOR, 0.24, 95% CI 0.07-0.74). No significant relationship was observed between DBP and functional outcomes. Patients with higher periprocedural SBP coefficient variance exhibited a decreased rate of good functional outcomes at 3 months (aOR, 0.42, 95% CI, 0.18-0.96). CONCLUSIONS: A SBP range above 130-140 mmHg could potentially serve as a safe lower boundary during EVT, while minimizing BP fluctuations may correlate with improved post-EVT functional outcomes.

A simple, organized web-based system improved the transfer efficiency and patient outcomes for endovascular thrombectomy in regional stroke network.

BACKGROUND: Endovascular thrombectomy (EVT) is a time-sensitive treatment for acute ischemic stroke with large vessel occlusion. To optimize transfer efficiency, a web-based platform was introduced in the Tainan Stroke Network (TSN). We assessed its application and effectiveness in regional stroke care. METHOD: This new web-based platform containing a questionnaire-style interface was introduced on October 1, 2021. To assess the transfer efficiency and patient outcomes, acute stroke patients transferred from PSCs to CSC for EVT from April 01, 2020, to December 30, 2022, were enrolled. The patients were classified into the traditional transferal pathway (TTP) group and the new transferal pathway (NTP) group depending on mode of transfer. Patient characteristics, time segments after stroke onset and outcome were compared between groups. RESULT: A total of 104 patients were enrolled, with 77 in the TTP group and 27 in the NTP group. Compared to the TTP group, the NTP group had a significantly shorter onset-to-CSC door time (TTP vs. NTP: 267 vs. 198 min; p = 0.041) and a higher EVT rate (TTP vs. NTP: 18.2% vs. 48.1%, p = 0.002). Among EVT patients, those in the NTP group had a significantly shorter CSC door-to-puncture time (TTP vs. NTP: 131.5 vs. 110 min; p = 0.029). The NTP group had a higher rate of good functional outcomes at 3 months (TTP vs. NTP: 21% vs. 61.5%; p = 0.034). CONCLUSION: This new web-based EVT transfer system provides notable improvements in clinical outcomes, transfer efficiency, and EVT execution for potential EVT candidates without markedly changing the regional stroke care paradigm.

Comparing Efficacy and Safety Between Patients With Atrial Fibrillation Taking Direct Oral Anticoagulants or Warfarin After Direct Oral Anticoagulant Failure.

BACKGROUND: An increased risk of recurrent stroke is noted in patients with atrial fibrillation despite direct oral anticoagulant (DOAC) use. We investigated the efficacy and safety of treatment with each of 4 different DOACs or warfarin after DOAC failure. METHODS AND RESULTS: We retrospectively analyzed patients with atrial fibrillation with ischemic stroke despite DOAC treatment between January 2002 and December 2016. The different outcomes of patients with DOAC failure were compared, including recurrent ischemic stroke, major cardiovascular events, intracranial hemorrhage and subarachnoid hemorrhage, mortality, and net composite outcomes according to switching to different DOACs or vitamin K antagonist after index ischemic stroke. We identified 3759 patients with DOAC failure. A total of 84 patients experienced recurrent ischemic stroke after switching to different oral anticoagulants, with a total follow-up time of 14 years. Using the vitamin K antagonist group as a reference, switching to any of the 4 DOACs was associated with a 69% to 77% reduced risk of major cardiovascular events (adjusted hazard ratio [aHR], 0.25 [95% CI, 0.16-0.39] for apixaban, 0.23 [95% CI, 0.14-0.37] for dabigatran, 0.23 [95% CI, 0.09-0.60] for edoxaban, and 0.31 [95% CI, 0.21-0.45] for rivaroxaban), and a 69% to 83% reduced risk of net composite outcomes (aHR, 0.25 [95% CI, 0.18-0.35] for apixaban, 0.17 [95% CI, 0.11-0.25] for dabigatran, 0.31 [95% CI, 0.17-0.56] for edoxaban, and 0.31 [95% CI, 0.23-0.41] for rivaroxaban). CONCLUSIONS: In Asian patients with DOAC failure, continuing DOACs after index stroke was associated with fewer undesirable outcomes than switching to a vitamin K antagonist. Alternative pharmacologic and nonpharmacologic strategies warrant investigation.

The relationships between plasma advanced glycation end products level and cognitive function in middle-aged and elderly Chinese subjects.

OBJECTIVES: To determine the relationships between circulating representative advanced glycation end products (AGEs) and cognitive performance in middle-aged and elderly Chinese adults. METHOD: A cross-sectional study with 1834 participants were included. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE). Plasma free AGEs including Nε-carboxymethyl-L-lysine (CML), Nε-(1-carboxyethyl) lysine (CEL), S-carboxymethyl-L-cysteine (CMC) and Nδ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Multivariate adjusted linear and logistic regression analysis were used to explore the associations between plasma AGEs and cognitive function. RESULTS: The prevalence of mild cognitive impairment (MCI) was 17.94%. Plasma CMC and MG-H1 level were negatively associated with MMSE score (ß = -0.42, p < 0.001 for all) in the multivariate linear regression analysis. In the multivariate logistic regression analysis, compared to the lowest tertile, participants within the highest tertile of CMC and MG-H1 had increased risk of MCI [ORs (95% CI): 1.62 (1.21-2.17), P trend <0.001, and ORs (95% CI): 1.30 (0.97-1.76), P trend = 0.069, respectively]. In addition, the weighted quantile sum (WQS) index was negatively associated with MMSE (ß = -0.48, P < 0.001) and increased risk of MCI [ORs (95% CI): 1.35 (1.20-1.52), P < 0.001]. CONCLUSION: Combined exposure of plasma free AGEs including CML, CEL, CMC and MG-H1 were associated with increased risk of cognitive impairment. Plasma CMC and MG-H1 might the main contributors for cognitive impairment, while further longitudinal studies are required to verify the associations.

[Sulfonated magnetic graphite carbon nitride solid-phase extraction-ultra performance liquid chromatography-tandem mass spectrometry for screening malachite green and leucomalachite green in freshwater fish].

Malachite green (MG) and its metabolite, leucomalachite green (LMG), exert toxic effects on the human body. The use of these dyes is illegal, but they are still detected in aquatic products. Freshwater fish are aquatic products with the high non-qualified rates. Therefore, the sensitive screening of MG and LMG in freshwater fish is of great importance to ensure the safety of aquatic products. Owing to the low contents of MG and LMG in fish and the complex matrix of actual samples, sample preparation is required before detection to purify impurities and enrich the target compounds. Graphite carbon nitride (GCN), a polymer material composed of C, N, and H, has good chemical and thermal stability, a large specific surface area, and a large number of active sites. It has a wide range of application prospects in adsorption and can be used in food safety testing when compounded with Fe3O4 to form magnetic graphite carbon nitride (MGCN). In this study, sulfonated magnetic graphite carbon nitride (S-MGCN) was prepared by further functionalizing MGCN with sulfonic acid. After characterization by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM), a magnetic solid-phase extraction (MSPE) method based on S-MGCN was established to extract MG and LMG from freshwater fish. The targets were screened using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Following sulfonic acid functionalization, S-MGCN showed increased electrostatic interactions based on the MGCN adsorption mechanism, which includes hydrogen bonds and π-π interactions; thus, its adsorption efficiency was significantly improved. The matrix effects were -42.21% and -33.77% before functionalization, -11.40% and -7.84% after functionalization, thus confirming that S-MGCN has significant matrix removal ability. Given that S-MGCN demonstrated excellent efficiency as an MSPE adsorbent, the adsorption conditions for S-MGCN were optimized. The optimal conditions were as follows: adsorbent dosage, 15 mg; adsorption time, 2 min; solution pH, 5; and ionic strength, not adjusted. Under these conditions, the adsorption efficiency of S-MGCN could reach 94.2%. Different organic solvents were used to elute adsorbed MG and LMG, and the desorption efficiency peaked when 1%(v/v) ammonia acetonitrile was used as the elution solvent. The elution volume was also optimized, and a maximum desorption efficiency of 93.2% was obtained when 1 mL of 1%(v/v) ammonia acetonitrile was added to S-MGCN. The limits of detection (LODs) and quantification (LOQs) of the two targets were determined at signal-to-noise ratios (S/N) of 3 and 10, respectively. The LODs and LOQs were 0.075 µg/kg and 0.25 µg/kg, respectively. The linear ranges of the two target compounds were 0.25-20.0 µg/kg with correlation coefficients (r) greater than 0.998. To assess accuracy and precision, we prepared spiked samples at three levels (low, medium, and high) with six parallel samples per level (n=6). The recoveries ranged from 88.8% to 105.9%. The intra- and inter-day relative standard deviations were 5.4%-13.7% (n=6) and 3.3%-11.1% (n=3), respectively. Compared with the national standard method, the proposed method features simpler sample pretreatment procedures, less use of organic reagents (5 mL), and a shorter extraction time (2 min); moreover, the method does not require complicated elution steps, and the eluent can be directly analyzed by UPLC-MS/MS. The test results of actual samples were consistent with those obtained via the national standard method, thus confirming the practical feasibility of the developed method. The proposed MSPE method based on S-MGCN is an efficient and environmentally friendly method that could provide a new methodological reference for the sensitive screening of MG and LMG in actual samples.

Efficient adsorptive removal of aminoglycoside antibiotics from environmental water.

Aminoglycoside antibiotics (AGs) in environmental water are emerging pollutants that must be removed to protect human health and the ecosystem. However, removing AGs from environmental water remains a technical challenge due to high polarity, stronger hydrophilicity and unique characteristics of polycation. Herein, a thermal-crosslinked polyvinyl alcohol electrospun nanofiber membrane (T-PVA NFsM) is synthesized and firstly leveraged as the adsorptive removal of AGs from environmental water. The thermal crosslinking strategy is demonstrated to enhance both the water resistance and hydrophilicity of T-PVA NFsM, thereby effectively interacting with AGs with high stability. Experimental characterizations and analog calculations indicate that T-PVA NFsM utilizes multiple adsorption mechanisms, including electrostatic and hydrogen bonding interactions with AGs. As a result, the material achieves 91.09%-100% adsorption efficiencies and a maximum adsorption capacity of 110.35 mg g-1 in less than 30 min. Furthermore, the adsorption kinetics follow the pseudo-second-order model. After eight consecutive adsorption-desorption cycles, T-PVA NFsM with a simplified recycling process maintains a sustainable adsorption capability. Compared with other forms of adsorption materials, T-PVA NFsM has significant advantages such as less consumption of adsorbent, high adsorption efficiency and fast removal speed. Therefore, T-PVA NFsM-based adsorptive removal holds promise for eliminating AGs from environmental water.

Polyvinyl alcohol electrospun nanofiber membrane based solid-phase extraction for monitoring administered aminoglycoside antibiotics in various animal-derived foods.

This work aims to develop a widely applicable method to monitor administered AGs in various animal-derived food samples to ensure food safety. A polyvinyl alcohol electrospun nanofiber membrane (PVA NFsM) was synthesized and employed as solid-phase extraction (SPE) sorbent, in combination with UPLC-MS/MS, for the simultaneous detection of ten AGs in nine types of animal-derived food samples. PVA NFsM exhibited excellent adsorption performance for the targets (with an adsorption rate of over 91.09%), good matrix purification ability (with a reduction of 7.65%-77.47% in matrix effect after SPE), and good recyclability (can be reused 8 times). The method displayed a linear range of 0.1-25000 µg/kg and attained limits of detection for AGs were 0.03-15 µg/kg. Spiked samples demonstrated a recovery of 91.72%-100.04% with a precision of<13.66%. The practicality of the developed method was verified by testing multiple actual samples.

Simultaneous determination of multiple mycotoxins in corn and wheat by high efficiency extraction and purification based on polydopamine and ionic liquid bifunctional nanofiber mat.

Due to the universality and harmfulness of mycotoxin co-contamination in cereals, it is of great significance to simultaneously monitor various mycotoxins co-polluted to ensure food safety and public health. In this work, a nanofiber mat modified by polydopamine and ionic liquid (PDA-IL-NFsM) was prepared and utilized as a solid-phase extraction (SPE) adsorbent for the simultaneous quantitative detection of multiple mycotoxins in corn and wheat. The PDA-IL-NFsM can form multiple retention mechanisms with the targets through hydrogen bond, π-π interaction, electrostatic or hydrophobic interaction, it shows favorable simultaneous adsorption performance (adsorption efficiency mostly higher than 88.27%) for fifteen mycotoxins in seven classes. Moreover, it can significantly reduce the matrix effect (lower than -13.69%), showing a good purification effect on the sample matrix. Based on the superior performance of PDA-IL-NFsM, a simple sample preparation method was established. The sample extract is simply diluted with water for SPE, and the eluent can be directly collected for ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analysis. The detection limit can reach 0.04-4.21 µg kg-1, the recovery was 80.09%-113.01%, and the relative standard deviations of intra-day and inter-day precision were 2.80%-14.81% and 0.68%-13.80% respectively. The results show that the proposed method has good sensitivity, accuracy and precision, and has practical application potential.

Efficient and simple simultaneous adsorption removal of multiple aflatoxins from various liquid foods.

In this study, a polydopamine modified nanofibers membrane (PDA-PS NFsM) was prepared and evaluated as the adsorbent for simultaneous removal of a variety of aflatoxins in various liquid foods, including edible oil, soy sauce and milk, rice vinegar and liquor. The removal efficiency for every single aflatoxin from all samples involved above was more than 76.5% within 1 h at 25 °C, except the liquors with higher ethanol content, for which the efficiency was lower. Moreover, PDA-PS NFsM can be removed directly after the adsorption process without any subsequent separation. The results suggested that the adsorption mechanism of the aflatoxins onto PDA-PS NFsM was chemisorption-based spontaneous endothermic reaction and aflatoxins were adsorbed by electrostatic interaction, hydrogen bonding and π-π interaction. This study confirmed that the PDA-PS NFsM has a good practical application potential in the simultaneous removal of a variety of aflatoxins from various liquid foods.

[Determination of tetracycline and fluoroquinolone residues in fish by polydopamine nanofiber mat based solid phase extraction combined with ultra performance liquid chromatography-tandem mass spectrometry].

Tetracyclines and fluoroquinolones are common antibacterial drugs used in aquaculture, and their residues may pose a risk to human health. The low concentration of drug residues and complex matrixes such as fats and proteins in aquatic products necessitate the urgent development of efficient sample pretreatment methods. Solid phase extraction (SPE) is the most common sample pretreatment method, in which the core is an adsorbent. Compared with traditional SPE adsorbents, nanofiber mat (NFsM) has more interaction sites because of their large specific surface area. Furthermore, NFsMs modified with specific functional groups can significantly improve the extraction efficiency of tetracyclines and fluoroquinolones. Polydopamine (PDA) is spontaneously synthesized by the oxidative self-polymerization of dopamine-hydrochloride in alkaline solutions (pH>7.5). Because of its rich amino and catechol groups, PDA can form π-π stacking, electrostatic attraction, hydrophobic interaction, and hydrogen bonding interactions with target molecules. By exploiting the above advantages, polystyrene (PS) NFsM, as a template, was prepared by the electrostatic spinning method, and PDA-PS NFsM was obtained by functional modification of PDA through self-polymerization. Fourier transform infrared spectroscopy (FT-IR) and field-emission scanning electron microscopy (FESEM) were used to characterize the synthesized PS NFsM and PDA-PS NFsM. It was proved that PDA was successfully modified on the PS NFsM, with the SEM images revealing a rough outer core shell structure and an inner honeycomb structure. Subsequently, the handmade SPE column with PDA-PS NFsM was completed. A novel and efficient screening analytical method based on PDA-PS NFsM for the simultaneous determination of three tetracyclines (tetracycline (TET), chlortetracycline (CTC), and oxytetracycline (OTC)) and three fluoroquinolones (enrofloxacin (ENR), ciprofloxacin (CIP), and norfloxacin (NOR)) in fish by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. The SPE procedure was optimized to develop an efficient method for sample preparation. Evaluate parameters including the amount of NFsM usage, ionic strength, flow rate of the sample solution, composition of eluent, and breakthrough volume were investigated. Only (20±0.1) mg of PDA-PS NFsM was sufficient to completely adsorb the targets, and the analytes retained on NFsM could be eluted by 1 mL of formic acid-ethyl acetate (containing 20% methanol) (1∶99, v/v). The residues were redissolved in 0.1 mL 10% methanol aqueous solution containing 0.2% formic acid. In addition, no adjustment of the pH and ionic strength of the sample solutions was required, and the breakthrough volume was 50 mL. The limits of detection (LODs) and limits of quantification (LOQs) of the six target compounds were measured at 3 times and 10 times the signal-to-noise ratio (S/N), respectively. The LODs and LOQs were 0.3-1.5 µg/kg and 1.0-5.0 µg/kg, respectively. The linear ranges of the six target compounds were LOQ-1000 µg/kg, and the coefficient of determination (R2) was greater than 0.999. To evaluate the accuracy and precision, blank spiked samples at three levels (low, medium, and high) were prepared for the recovery experiments, and each level with six parallel samples (n=6). The recoveries ranged from 94.37% to 102.82%, with intra-day and inter-day relative standard deviations of 2.38% to 8.06% and 4.10% to 9.10%, respectively. To evaluate the purification capacity of PDA-PS NFsM, the matrix effects before and after SPE were calculated and compared. Matrix effects before SPE were -12.98% to -38.68%. After the completion of SPEbased on PDA-PS NFsM, the matrix effect of each target analyte was significantly reduced to -2.15% to -7.36%, which proved the significant matrix removal capacity of PDA-PS NFsM. Finally, the practicality of this method was evaluated by using it to analyze real samples. This SPE method based on PDA-PS NFsM is efficient, practical, and environmentally friendly, and it has great potential for use in the routine monitoring of drug residues in fish.

Hypoperfusion Index Ratio as a Surrogate of Collateral Scoring on CT Angiogram in Large Vessel Stroke.

BACKGROUND: This study was to evaluate the correlation of the hypoperfusion intensity ratio (HIR) with the collateral score from multiphase computed tomography angiography (mCTA) among patients with large vessel stroke. METHOD: From February 2019 to May 2020, we retrospectively reviewed the patients with large vessel strokes (intracranial carotid artery or proximal middle cerebral artery occlusion). HIR was defined as a Tmax > 10 s lesion volume divided by a Tmax > 6 s lesion volume, which was calculated by automatic software (Syngo.via, Siemens). The correlation between the HIR and mCTA score was evaluated by Pearson's correlation. The cutoff value predicting the mCTA score was evaluated by receiver operating characteristic analysis. RESULT: Ninety-four patients were enrolled in the final analysis. The patients with good collaterals had a smaller core volume (37.3 ± 24.7 vs. 116.5 ± 70 mL, p < 0.001) and lower HIR (0.51 ± 0.2 vs. 0.73 ± 0.13, p < 0.001) than those with poor collaterals. A higher HIR was correlated with a poorer collateral score by Pearson's correlation. (r = -0.64, p < 0.001). The receiver operating characteristic (ROC) analysis suggested that the best HIR value for predicting a good collateral score was 0.68 (area under curve: 0.82). CONCLUSION: HIR is a good surrogate of collateral circulation in patients with acute large artery occlusion.

Elevated plasma trimethylamine-N-oxide levels are associated with diabetic retinopathy.

AIMS: To determine the relationship between plasma levels of trimethylamine-N-oxide (TMAO) and odds of diabetic retinopathy (DR). METHODS: A cross-sectional study was conducted. Blood samples were obtained from 122 type 2 diabetes mellitus (T2DM) patients with or without DR. Multivariable logistic regression analyses were performed to identify the association between plasma TMAO and DR. The diagnostic value of plasma TMAO was assessed by the area under the receiver operating characteristic curve (AUROC) and integrated discrimination improvement (IDI). RESULTS: In the T2DM patients, plasma levels of TMAO were significantly higher in patients with DR compared with those without DR (P = 0.001). As logarithmic (ln) transformation of TMAO increased per standard deviation (SD), there was higher probability to have DR [odds ratio (OR) = 2.31; P = 0.005]. As ln-transformed TMAO increased per SD, the severity of DR was more likely to get worse (OR = 2.05; P = 0.004). In the diagnostic model, the addition of TMAO contributed to the improvement in AUROC from 0.646 to 0.734 (P = 0.043), and the IDI was 10.7% (P < 0.001). CONCLUSION: Elevated levels of plasma TMAO were associated with higher odds and worse severity of DR in T2DM patients, and further investigation is required for the causality of this association.

Rapid, simple and green solid phase extraction based on polyaniline nanofibers-mat for detecting non-steroidal anti-inflammatory drug residues in animal-origin food.

In this study, polyaniline modified polyacrylonitrile nanofibers mat (PANI NFsM) was prepared as a novel adsorbent for the solid-phase extraction (SPE) of non-steroidal anti-inflammatory drug residues in meat or egg samples. The solvent extracts of samples were simply diluted with water to perform the SPE, and then the eluent was directly analyzed. Significant reduction of the matrix effect was obtained after SPE using only 5 mg of PANI NFsM. The entire sample preparation time is 5-10 times lower than the existing methods. The limits of detection of the target analytes ranging from 0.6 to 12.2 µg kg-1 had already met the demand of food safety monitoring by only 1 g sample. The recoveries ranged from 85.18% to 107.31%, with the intra-day and inter-day relative standard deviations of 2.74% to 16.01%, revealing satisfactory accuracy and precision. Finally, real samples analyses were applied to verify the practicability of the method.

Simultaneous extraction of four plant growth regulators residues in vegetable samples using solid phase extraction based on thiol-functionalized nanofibers mat.

A simple and environmentally friendly sample pretreatment method was established for extraction of four plant growth regulators (PGRs) residues in vegetable samples. In order to effectively extract targets from complex sample matrices, three types of polar groups (COOH, NH2, or SH) functionalized polyacrylonitrile nanofibers mats (PAN NFsM) were prepared and evaluated, respectively. The superior -SH functionalized PAN NFsM was further selected as a novel adsorbent of solid phase extraction (SPE). Under optimal conditions, the proposed method could achieve high sensitivity (0.2-2 ng g-1) and acceptable recovery (88.94%-106.42%) by consuming lower amount of adsorbent (only 5 mg) and organic reagent (only 1.4 mL), and performing much fewer steps than current methods. In addition, the prepared SH-PAN NFsM possessed excellent reusability which could be reused for 6 times without degradation in adsorption capability. These results presented the great potential of the established method for environmental-friendly and efficiently detecting PGRs residues.

The essential role of CYP2E1 in metabolism and hepatotoxicity of N,N-dimethylformamide using a novel Cyp2e1 knockout mouse model and a population study.

N,N-Dimethylformamide (DMF) is a widespread contaminant of leather factories and their surrounding environment. There is a lack of direct in vivo evidence supporting CYP2E1 as a primary enzyme responsible for DMF metabolism and hepatotoxicity. In this study, a novel Cyp2e1 knockout (KO) mouse model was generated and used to assess whether DMF metabolism and hepatotoxicity is CYP2E1 dependent using an acute toxicity protocol with a single dose of 1500 mg DMF/kg. An epidemiological study in 698 DMF-exposed workers and 188 non-DMF-exposed controls was conducted to investigate the associations between functional polymorphisms of CYP2E1 (rs6413432/rs2031920) and DMF metabolite (N-methylcarbmoylated-hemoglobin [NMHb]). We successfully established Cyp2e1 KO mice with evidence from DNA sequence analysis, which showed 1-bp insertion at 65 bp (C) site of Cyp2e1 Exon 1. In addition, western blot and in vivo pharmacokinetic study also showed a complete absence of CYP2E1 protein and a 92% and 88% reduction in CYP2E1 activity among males and females, respectively. DMF metabolism as evidenced by increased blood NMHb, and hepatotoxicity as evidenced by elevated liver/body weight ratio, activity of liver enzymes and massive liver necrosis were detected in wild-type (WT) mice but were completely abrogated in KO mice, strongly supporting a CYP2E1-dependent pattern of DMF metabolism and hepatotoxicity. Moreover, variant allele of CYP2E1-rs6413432 was also significantly associated with higher NMHb levels in DMF-exposed workers (P = 0.045). The increase of glucose-regulated protein 94 detected in WT mice but not in KO mice suggested CYP2E1-dependent endoplasmic reticulum stress may be a key mechanism underlying DMF-induced hepatotoxicity.

Simple, efficient, and eco-friendly sample preparation for simultaneous determination of paracetamol and chloramphenicol in meat.

We have developed and validated a simple, eco-friendly, and reliable method to simultaneously determine paracetamol and chloramphenicol in meat with ultra performance liquid chromatography and tandem mass spectrometry. The samples were firstly extracted with ethylenediaminetetraacetic acid-McIlvaine's buffer and then purified by solid-phase extraction by using a novel core-shell polyaniline/polyacrylonitrile nanofibers mat. Compared with existing methods for the two analytes, the proposed method was simplified greatly with much fewer sample preparation steps, consumed much less time (< 2 min per sample) and organic solvent (0.7 mL per sample). Low detection levels (0.15-0.20 µg/kg for paracetamol, 0.01 µg/kg for chloramphenicol) with good precision and recoveries of the target compounds were obtained. The proposed method was applied to determine the residual paracetamol and chloramphenicol in pork, chicken, and beef samples, and the test results were consistent with those using the Chinese national standard methods, which demonstrates the reliability and practicality of the new method.