Hydrophilic interaction chromatographic evaluation of zwitterionic polymer grafted silica gel via multiple binding sites.

A novel zwitterionic polymer grafted silica stationary phase, Sil-PZIC, was prepared by bonding poly(ethylene maleic anhydride) molecules on the surface of silica via multiple binding sites, followed by ammonolysis of maleic anhydride through a nucleophilic substitution reaction with ethylenediamine. The stationary phase was characterized by solid-state 13C nuclear magnetic resonance, zeta potential, and elemental analysis and the results show the successful encapsulation of zwitterionic polymer on the surface of silica. The chromatographic performance of Sil-PZIC was investigated by using nucleosides and nucleic bases as test analytes The variation of retention and separation performance of these model compounds were investigated by varying the chromatographic conditions such as the components of mobile phase, salt concentration, and pH. The results show that the retention of the Sil-PZIC phase was dominated by a hydrophilic partitioning mechanism accompanied by secondary interactions such as electrostatic and hydrogen bonding. In addition, saccharides and Amadori compounds were also well separated on the Sil-PZIC, indicating that the Sil-PZIC column has potential application for separation of the polar compound.

Regulatory Basis of Adipokines Leptin and Adiponectin in Epilepsy: from Signaling Pathways to Glucose Metabolism.

Epilepsy is a common and severe neurological disorder in which impaired glucose metabolism leads to changes in neuronal excitability that slow or promote the development of epilepsy. Leptin and adiponectin are important mediators regulating glucose metabolism in the peripheral and central nervous systems. Many studies have reported a strong association between epilepsy and these two adipokines involved in multiple signaling cascades and glucose metabolism. Due to the complex regulatory mechanisms between them and various signal activation networks, their role in epilepsy involves many aspects, including the release of inflammatory mediators, oxidative damage, and neuronal apoptosis. This paper aims to summarize the signaling pathways involved in leptin and adiponectin and the regulation of glucose metabolism from the perspective of the pathogenesis of epilepsy. In particular, we discuss the dual effects of leptin in epilepsy and the relationship between antiepileptic drugs and changes in the levels of these two adipokines. Clinical practitioners may need to consider these factors in evaluating clinical drugs. Through this review, we can better understand the specific involvement of leptin and adiponectin in the pathogenesis of epilepsy, provide ideas for further exploration, and bring about practical significance for the treatment of epilepsy, especially for the development of personalized treatment according to individual metabolic characteristics.

Triglyceride-glucose index and short-term functional outcome and in-hospital mortality in patients with ischemic stroke.

BACKGROUND AND AIMS: The triglyceride-glucose (TyG) index has been demonstrated as an independent marker of ischemic stroke. Whether TyG index predicts short-term outcomes in patients with ischemic stroke remains uncertain. The aim of the study was to investigate the early prognosis value of TyG index in ischemic stroke patients. METHODS AND RESULTS: A total of 3216 acute ischemic stroke patients from 22 hospitals were included in this analysis. The TyG index was calculated as ln (fasting triglyceride [mg/dL] × fasting glucose [mg/dL]/2). Logistic regression model was performed to estimate the relationship between TyG index and unfavorable functional outcome of death or disability (modified Rankin Scale score of 4-6) at discharge. Risk reclassification with TyG index to predict unfavorable functional outcome was analyzed. During hospitalization, 748 patients (23.3%) experienced poor functional outcome and 105 patients (3.3%) died from all causes. The multivariable adjusted odds ratios for the highest versus lowest quartile of TyG index was 1.62 (95% CI 1.15-2.29) for unfavorable functional outcome at discharge. The addition of TyG index to the conventional model improved the risk reclassification (net reclassification improvement 10.37%; integrated discrimination improvement 0.27%; both p < 0.05) for poor functional outcome. Moreover, TyG index was associated with an odds ratio (95% CI) of 1.26 (1.02-1.55) for an ordinal shift in mRS score and 2.49 (1.21-5.12) for in-hospital mortality. CONCLUSIONS: Higher TyG index was associated with higher risk of unfavorable functional outcome at discharge and in-hospital mortality, implicating the significant short-term prognostic effect of TyG index in patients with ischemic stroke.

Prognostic significance of international normalised ratio and prothrombin time in Chinese acute ischaemic stroke patients.

BACKGROUND: We investigated the association between international normalised ratio (INR) and prothrombin time (PT) levels on hospital admission and in-hospital outcomes in acute ischaemic stroke (AIS) patients. METHODS: A total of 3175 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included. We divided patients into four groups according to their level of admission INR: (<0.92), Q2 (0.92-0.98), Q3 (0.98-1.04) and Q4 (≥1.04) and PT. Logistic regression models were used to estimate the effect of INR and PT on death or major disability (modified Rankin Scale score (mRS)>3), death and major disability (mRS scores 4-5) separately on discharge in AIS patients. RESULTS: Having an INR level in the highest quartile (Q4) was associated with an increased risk of death or major disability (OR 1.69; 95% CI 1.23 to 2.31; P-trend = 0.001), death (OR, 2.64; 95% CI 1.12 to 6.19; P-trend = 0.002) and major disability on discharge (OR, 1.56; 95% CI 1.13 to 2.15; P-trend = 0.008) in comparison to Q1 after adjusting for potential covariates. Moreover, in multivariable logistic regression models, having a PT level in the highest quartile also significantly increased the risk of death (OR, 2.38; 95% CI 1.06 to 5.32; P-trend = 0.006) but not death or major disability (P-trend = 0.240), major disability (P-trend = 0.606) on discharge. CONCLUSIONS: High INR at admission was independently associated with death or major disability, death and major disability at hospital discharge in AIS patients and increased PT was also associated with death at hospital discharge.

Prognostic significance of serum globulin in patients with acute ischemic stroke.

BACKGROUND AND PURPOSE: We investigated the association between serum globulin levels upon hospital admission and in-hospital short-term outcomes in acute ischemic stroke (AIS) patients. METHODS: A total of 3,127 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included in the present study. We divided patients into 4 groups according to their level of admission serum globulin: Q1 (<23.5 g/L), Q2 (23.5-26.4 g/L), Q3 (26.4-29.9 g/L), and Q4 (≥29.9 g/L). Logistic regression models were used to estimate the effect of serum globulin on the short-term outcomes, including all cause in-hospital mortality, poor outcome upon discharge (modified Rankin Scale score ≥3) and in-hospital pneumonia in AIS patients. RESULTS: The median National Institutes of Health Stroke Scale (NIHSS) score was 4.0 (IQR, 2.0-7.0). The risk of in-hospital mortality was significantly higher in patients with highest serum globulin level (Q4) compared to those with lowest (Q1) (adjusted odds ratio [OR] 2.30; 95% confidence interval [CI], 1.12-4.70; P-trend =0.026). The highest serum globulin level (Q4) was associated with a 1.32-fold and 1.62-fold increase in the risk of poor outcome upon discharge (adjusted OR 1.32; 95% CI, 1.00-1.75; P-trend = 0.070) and in-hospital pneumonia (adjusted OR 1.62; 95% CI, 1.18-2.23; P-trend = 0.001) in comparison to Q1 after adjustment for potential covariates. CONCLUSIONS: A high level of serum globulin upon hospital admission was independently associated with all cause in-hospital mortality, poor outcome upon discharge and in-hospital pneumonia in relative mild AIS patients.

Triglyceride-glucose index and common carotid artery intima-media thickness in patients with ischemic stroke.

BACKGROUND: Triglyceride glucose (TyG) index was recently reported to be associated with an increased risk of the development and recurrence of cardiovascular events, and atherosclerosis is a main speculative mechanism. However, data on the relationship between TyG index and atherosclerosis, especially in the setting of ischemic stroke, is rare. We aimed to explore the association between TyG index and carotid atherosclerosis in patients with ischemic stroke. METHODS: A total of 1523 ischemic stroke patients with TyG index and carotid artery imaging data were enrolled in this analysis. The TyG index was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Carotid atherosclerosis was measured by common carotid artery intima-media thickness (cIMT), and abnormal cIMT was defined as a mean cIMT and maximum cIMT value ≥ 1 mm. Multivariable logistic regression models and restricted cubic spline models were used to assess the relationships between TyG index and abnormal cIMT. Risk reclassification and calibration of models with TyG index were analyzed. RESULTS: The multivariable-adjusted odds ratios (95% CIs) in quartile 4 versus quartile 1 of TyG index were 1.56 (1.06-2.28) for abnormal mean cIMT and 1.46 (1.02-2.08) for abnormal maximum cIMT, respectively. There were linear relationships between TyG index and abnormal mean cIMT (P for linearity = 0.005) and abnormal maximum cIMT (P for linearity = 0.027). In addition, the TyG index provided incremental predictive capacity beyond established risk factors, shown by an increase in net reclassification improvement and integrated discrimination improvement (all P < 0.05). CONCLUSIONS: A higher TyG index was associated with carotid atherosclerosis measured by cIMT in patients with ischemic stroke, suggesting that TyG could be a promising atherosclerotic marker.

Increased admission serum total bile acids can be associated with decreased 3-month mortality in patients with acute ischemic stroke.

BACKGROUND: Bile acids (BAs) not only play an important role in lipid metabolism and atherosclerosis but also have antiapoptotic and neuroprotective effects. However, few studies have focused on the relationship of the total bile acid (TBA) levels with the severity and prognosis of acute ischemic stroke (AIS). OBJECTIVES: The aim of this study was to investigate the potential associations of the fasting serum TBA levels on admission with the stroke severity, in-hospital complication incidence and 3 -month all-cause mortality in patients with AIS. METHODS: A total of 777 consecutive AIS patients were enrolled in this study and were divided into four groups according to the quartiles of the serum TBA levels on admission. Univariate and multivariate logistic regression analyses were used to explore the relationship between the fasting TBA levels and the stroke severity, in-hospital complications, and 3-month mortality in AIS patients. RESULTS: Patients in group Q3 had the lowest risk of severe AIS (NIHSS > 10) regardless of the adjustments for confounders (P < 0.05). During hospitalization, 115 patients (14.8%) had stroke progression (NIHSS score increased by ≥ 2), and 222 patients (28.6%) developed at least one complication, with no significant difference among the four groups (P > 0.05). There was no significant difference in the incidence of pneumonia, urinary tract infection (UTI), hemorrhagic transformation (HT), gastrointestinal bleeding (GIB), seizures or renal insufficiency (RI) among the four groups (P > 0.05). A total of 114 patients (14.7%) died from various causes (including in-hospital deaths) at the 3-month follow-up, including 42 (21.3%), 26 (13.3%), 19 (9.9%) and 27 (13.9%) patients in groups Q1, Q2, Q3 and Q4 respectively, with significant differences (P = 0.013). After adjusting for confounding factors, the risk of death decreased (P -trend < 0.05) in groups Q2, Q3, and Q4 when compared with group Q1, and the OR values were 0.36 (0.16-0.80), 0.30 (0.13-0.70), and 0.29 (0.13-0.65), respectively. CONCLUSIONS: TBA levels were inversely associated with the 3-month mortality of AIS patients but were not significantly associated with the severity of stroke or the incidence of complications.

Prognostic significance of international normalised ratio and prothrombin time in Chinese acute ischaemic stroke patients.

BACKGROUND: We investigated the association between international normalised ratio (INR) and prothrombin time (PT) levels on hospital admission and in-hospital outcomes in acute ischaemic stroke (AIS) patients. METHODS: A total of 3175 AIS patients enrolled from December 2013 to May 2014 across 22 hospitals in Suzhou city were included. We divided patients into four groups according to their level of admission INR: (<0.92), Q2 (0.92-0.98), Q3 (0.98-1.04) and Q4 (≥1.04) and PT. Logistic regression models were used to estimate the effect of INR and PT on death or major disability (modified Rankin Scale score (mRS)>3), death and major disability (mRS scores 4-5) separately on discharge in AIS patients. RESULTS: Having an INR level in the highest quartile (Q4) was associated with an increased risk of death or major disability (OR 1.69; 95% CI 1.23 to 2.31; P-trend = 0.001), death (OR, 2.64; 95% CI 1.12 to 6.19; P-trend = 0.002) and major disability on discharge (OR, 1.56; 95% CI 1.13 to 2.15; P-trend = 0.008) in comparison to Q1 after adjusting for potential covariates. Moreover, in multivariable logistic regression models, having a PT level in the highest quartile also significantly increased the risk of death (OR, 2.38; 95% CI 1.06 to 5.32; P-trend = 0.006) but not death or major disability (P-trend = 0.240), major disability (P-trend = 0.606) on discharge. CONCLUSIONS: High INR at admission was independently associated with death or major disability, death and major disability at hospital discharge in AIS patients and increased PT was also associated with death at hospital discharge.

Gram-scale synthesis of nitrogen-doped carbon dots from locusts for selective determination of sunset yellow in food samples.

Locust powder was converted into water-soluble fluorescent nitrogen-doped carbon dots (N-CDs) with gram-scale yield through a self-exothermic reaction between nitric acid and diethylenetriamine (DETA) within 10 min. The morphology, elemental information, and optical properties of the N-CDs were characterized using high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier-transform infrared, ultraviolet-visible and fluorescence spectroscopy. Spectroscopic investigation indicated that the fluorescence emission behaviour of N-CDs is excitation wavelength dependent, with the strongest emission peak at 470 nm using a 390 nm excitation wavelength. The strong absorption peak of sunset yellow (SY) at 482 nm overlaps substantially with the blue emission peak (470 nm) of N-CDs. This enables the fluorescence emission of N-CDs to be obviously quenched by SY through the inner filter effect. There was a good linear relationship between the fluorescence quenching degree and the concentrations of SY within the range 0.5-40 µM. The detection limit of developed fluorescence assay for SY is 28 nM, and the relative standard deviation is 2.3% (c = 10 µM). The N-CDs derived from locusts by the self-exothermic reaction are highly selective and sensitive fluorescent probes for SY, which were applied to the fluorescence sensing of SY in different food samples with satisfactory results.

Nano-amylose-2,3-bis(3,5-dimethylphenylcarbamate)-silica hybrid sol immobilized on open tubular capillary column for capillary electrochromatography enantioseparation.

The chiral organic-inorganic hybrid materials can exhibit a high loading, and the chiral selector nanoparticles can create efficient stationary phases for open-tubular capillary electrochromatography (OT-CEC). Hence, a novel protocol for the preparation of an OT column coated with nano-amylose-2,3-bis(3,5-dimethylphenylcarbamate) (nano-ABDMPC)-silica hybrid sol through in situ layer-by-layer self-assembly method was developed for CEC enantioseparation. By controlling the assembly cycle number of nano-ABDMPC-silica hybrid sol, a homogeneous, dense and stable coating was successfully prepared, which was confirmed by SEM and elemental analysis. As the main parameter influencing the chiral separating effect, the nano-ABDMPC bearing 3-(triethoxysilyl)propyl residues concentration was investigated. The experimental results showed that 10.0 mg/mL nano-ABDMPC bearing 3-(triethoxysilyl)propyl residues coated OT capillary column possessed chiral recognition ability toward the six enantiomers (phenylalanine, tyrosine, tryptophan, phenethyl alcohol, 1-phenyl-2-propanol, and Tröger's base) at some of the different conditions tested. Additionally, the coated OT column revealed adequate repeatability concerning run-to-run, day-to-day and column-to-column. These results demonstrated the promising applicability of nano-ABDMPC-silica hybrid sol coated OT column in CEC enantioseparations.

Neutrophil to lymphocyte ratio and the hematoma volume and stroke severity in acute intracerebral hemorrhage patients.

BACKGROUND: Neutrophil to lymphocyte ratio (NLR) serves as a powerful inflammatory marker for predicting cardiovascular events. Here, we investigate whether admission NLR is associated with hematoma volume, stroke severity, and 3-month outcomes in patients with acute intracerebral hemorrhage (ICH). METHODS: 352 patients with acute ICH were prospectively identified in this study. Demographic characteristics, lifestyle risk factors, NIHSS score, hematoma volumes, and other clinical features were recorded for all participants. Patients was divided into quartiles based on the admission NLR levels (Q1: <2.78; Q2: 2.78-4.08; Q3: 4.08-7.85; Q4: ≥7.85). Multivariable linear regression models and logistic regression models were used to evaluate the association between NLR and hematoma volume, admission severity, or the outcomes after ICH. RESULTS: Median NIHSS scores for each quartile (Q1 to Q4) were 6.0, 6.0, 6.0, and 11.0 (P=.001), and median hematoma volumes were 9.5, 9.3, 9.1, and 15.0ml (P=.005), respectively. After adjusting the age, sex, and other potential risk factors, the patients in Q4 had higher NIHSS scores (P=.042) and larger hematoma volume (P=.014). After 3-month follow-up, 148 poor outcomes (mRS, 3-6) and 47 all-cause deaths were documented. There were more patients with poor outcomes in Q4 than Q1. However, compared with the patients in Q1, those in Q4 were not associated with poor outcomes (P-trend=0.379), and all-cause mortality (P-trend=0.843) after adjust for other risk factors. CONCLUSIONS: Higher admission NLR are associated with larger hematoma volume and more serious stroke, but not 3-month outcomes in patients with acute ICH.

An electrochemical sensor based on cellulose nanocrystal for the enantioselective discrimination of chiral amino acids.

A novel electrochemical sensor based on 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanocrystals (TOCNCs) and l-cystines (l-Cys) modified Au electrode (TOCNC/l-Cys/Au) has been fabricated for detection and discrimination of the enantiomers of phenylalanine (Phe), leucine (Leu), and valine (Val). The three amino acids are in connection with metabolism diseases. The TOCNC/l-Cys/Au electrode exhibited obvious peak current difference for the amino acid enantiomers by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The TOCNCs on the electrode surface expressed different interactions with d- and l-amino acids, so the electrochemical recognitions of the three amino acid enantiomers were achieved. TOCNCs were characterized by Fourier transform infrared (FT-IR) and scanning electron microscopy (SEM). The modified electrodes were characterized by SEM and electrochemical techniques. According to DPV, peak currents of the two enantiomers decreased linearly with their concentrations. Furthermore, satisfactory results were obtained when this electrode was applied to measure the d- and l-Phe mixture. The experimental results show that TOCNCs are suitable material for chiral sensor. The contrast of serum sample of healthy people and patients with type 2 diabetes also was proposed, and significant difference was exhibited on the modified electrode. This work is significant for the screening, diagnosis, and treatment of multiple metabolic diseases.

Graphene quantum dots as additives in capillary electrophoresis for separation cinnamic acid and its derivatives.

A facile capillary electrophoresis (CE) method for the separation of cinnamic acid and its derivatives (3,4-dimethoxycinnamic acid, 4-methoxycinnamic acid, isoferulic acid, sinapic acid, cinnamic acid, ferulic acid, and trans-4-hydroxycinnamic acid) using graphene quantum dots (GQDs) as additives with direct ultraviolet (UV) detection is reported. GQDs were synthesized by chemical oxidization and further purified by a macroporous resin column to remove salts (Na2SO4 and NaNO3) and other impurities. Transmission electron microscopy (TEM) indicated that GQDs have a relatively uniform particle size (2.3 nm). Taking into account the structural features of GQDs, cinnamic acid and its derivatives were adopted as model compounds to investigate whether GQDs can be used to improve CE separations. The separation performance of GQDs used as additives in CE was studied through variations of pH, concentration of the background electrolyte (BGE), and contents of GQDs. The results indicated that excellent separation can be achieved in less than 18 min, which is mainly attributed to the interaction between the analytes and GQDs, especially isoferulic acid, sinapic acid, and cinnamic acid.

Simple and rapid ionic liquid-based one-, two-, three-phase transition microextraction for efficient extraction of trace organic pollutants and elimination of lipid co-extractives from fatty food matrices.

Extraction of trace contaminants from fatty food matrices is challenging in food analysis. Herein, a new ionic liquid-based one-, two-, three-phase transition microextraction (IL-OTTPTME) was proposed to efficiently extract trace targets while simultaneously eliminating lipid co-extractives. The method performance was illustrated through the determination of chrysoidine in fatty soybean products using high-performance liquid chromatography-ultraviolet/visible detection. The strong interactions and infinite contact between IL and chrysoidine in the one-phase system ensured ultra-high extraction efficiency (∼100 %). Density functional theoretical calculations confirmed the presence of strong hydrogen bonding and π-π interactions. The formation of the three-phase system during extraction could completely eliminate lipid co-extractives. The IL-OTTPTME integrated extraction, enrichment and cleanup steps into one step, making it rapid and extremely easy to operate. The method had a wide linear range of 0.5-5000 µg/kg and low limit of detection (0.15 µg/kg). It also had satisfactory relative recoveries (95.1 %-104.0 %) and low RSDs (≤5.0 %, n = 5).

Ionic liquid-functionalized mesoporous multipod silica for simultaneously effective extraction of aflatoxin B1 and its two precursors from grain.

BACKGROUND: Aflatoxin B1 (AFB1) and its precursors contaminate food and agricultural products, posing a significant risk to food safety and human health, but simultaneous and effective extraction and determination of AFB1 and its precursors with varied structures is still a challenging task. RESULTS: In this study, a bisimidazolium-type ionic liquid functionalized mesoporous multipod silica (SiO2@mPMO-IL(im)2) was fabricated to extract AFB1 and its two precursors, i.e., averantin and sterigmatocystin. The SiO2@mPMO-IL(im)2 could simultaneously extract three targets with varied structures based on the multipods, mesopores, and multifunctional groups. The density functional theory calculations further verified the multiple interactions between SiO2@mPMO-IL(im)2 and targets. The fabricated SiO2@mPMO-IL(im)2 could effectively extract and determine three targets in grains by combing with dispersive solid-phase extraction and high-performance liquid chromatography. Good linearity (r2 > 0.9978), low LODs (0.9-1.5 µg kg-1) and LOQs (3.0-4.5 µg kg-1), satisfactory spiked recoveries (92.5%-106.8%) and high precisions (RSD<6.4%) were observed. SIGNIFICANCE AND NOVELTY: This work demonstrates the feasibility of SiO2@mPMO-IL(im)2 for simultaneous and effective extraction of toxins with varied structures and provides a promising sample preparation for the analysis of AFB1 and its precursors in grain samples.

Construction of MOFs@COFs composite material as stationary phase for efficient separation of diverse organic compounds.

BACKGROUND: The development of efficent chromatographic stationary phases (SP) with mixed-mode or multiple interactions in high-performance liquid chromatography (HPLC) for the separation of complex samples is a challenging task. Metal organic frameworks (MOFs)-based SP can provide desired multiple interactions and enable the separation of a diverse range of solutes, but have limitations of low column efficiency and poor stability. RESULTS: Herein, the hybrid MOFs@Covalent organic frameworks (COFs) materials were used as SP in HPLC due to their synergistic structural features. The SiO2@NH2-UiO-66@CTF SP was synthesized by integration of NH2-UiO-66 and covalent triazine framework (CTF) onto silica surface. Due to the unique structure of SiO2@NH2-UiO-66@CTF with hierarchical-pores, this column showed higher column efficiency (up to 49,369 plates m-1 for alkylbenzenes) than the reported columns packed with MOFs-based SP. Owing to the Zr4+-N coordination bonding between CTF and NH2-UiO-66, the structural stability of SiO2@NH2-UiO-66@CTF can be improved. Furthermore, this new column exhibited remarkable column stability with relative standard deviation of retention time of <0.40% after 400 injections. With the combined advantages of multifunctional properties, high column efficiency, and good stability, SiO2@NH2-UiO-66@CTF SP showed excellent selectivity for the separation of a variety of hydrophobic, aromatic, heteroatomic, and hydrophilic analytes. SIGNIFICANCE AND NOVELTY: This work not only offers a promising SP with multiple retention mechanisms for HPLC, but also provides an efficient strategy for development of high column efficiency MOFs-based SP with good stability. Moreover, the MOFs@COFs hybrid materials were expanded in application area through this study, and the research results can also afford the foundation for further explore its structural characteristics.

A Novel and Highly Efficient Microextraction Method for the Determination of Aflatoxin Precursor Averantin in Fatty Grain Samples.

Averantin (AVN) is an important aflatoxin biosynthetic precursor and has been listed in the screening range of mycotoxins. Herein, a novel ionic liquid-based one-, two-, and three-phase transition microextraction (IL-OTTPTME) method was combined with high-performance liquid chromatography for the extraction and determination of AVN in fatty grain samples. The formation of a homogeneous solution and three-phase system during the IL-OTTPTME process allowed both efficient extraction and coextracted lipid cleanup. Density functional theory calculations and distribution coefficient determination results demonstrated that AVN extraction by IL mainly occurred through hydrogen-bond and π-π interactions. Under optimized conditions, the LOD and LOQ of the proposed method were 0.5 and 1.5 ng/g, respectively. Finally, the method was used to determine AVN in several grains with different fat contents, achieving satisfactory relative recoveries (86.0-107.8%) and RSDs (1.2-6.2%, n = 3).

Preparation and characterization of glucose-based covalent organic polymer coated silica as stationary phase for high-performance liquid chromatography.

Carbohydrate is a renewable, sustainable, hydrophilic, and biodegradable natural product, which is widely used in the field of adsorption. In this study, a glucose-based covalent organic polymer (COP) coated silica was fabricated by facile solvent knitting reaction between tetrabenzylglucose and silica-phenyl with anhydrous aluminum trichloride as catalyst, forming a core-shell stationary phase (donated as SiO2@COPBn-glu) for high performance liquid chromatography. The prepared SiO2@COPBn-glu was characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectrometry, solid-state 13C nuclear magnetic resonance spectrometry, X-ray photoelectron spectroscopy, and N2 adsorption-desorption experiments. Owing to the coexistence of benzene units and alkyl, hydroxyl and ether groups in the skeleton of COPBn-glu shell, the developed chromatographic packing exhibited reversed-phase/hydrophilic interaction mixed-mode with multiple retention mechanisms, such as hydrophobic, π-π, hydrogen bonding, and electron donor-acceptor interactions. The results revealed that the SiO2@COPBn-glu column demonstrated excellent selectivity and retention behavior for both hydrophilic and hydrophobic compounds with good repeatability and stability. Meanwhile, the chromatographic performance of the prepared SiO2@COPBn-glu column was compared with a C18 column to assess the role of the coating COPBn-glu shell. Therefore, the development of the SiO2@COPBn-glu stationary phase expands the potential application of COPs in separation field.

Fe3O4/ZIFs-based magnetic solid-phase extraction for the effective extraction of two precursors with diverse structures in aflatoxin B1 biosynthetic pathway.

The aflatoxin B1 (AFB1) early warning technique based on precursors is an effective strategy for the prevention of AFB1 contamination risk. The determination of precursors is imperative to ensure the efficiency of the early warning technique. Herein, a controllable magnetic adsorbent Fe3O4/ZIFs was first introduced for the effective extraction and determination of averantin (AVN) and sterigmatocystin (ST) precursors in cereal by combining magnetic solid-phase extraction (MSPE) and high-performance liquid chromatography (HPLC). Benefiting from the abundant adsorption sites and multifunctional groups matching the analytes, Fe3O4/ZIFs effectively and simultaneously extracted AVN and ST with great differences in polarity and structure via multiple interactions. AVN was extracted by Fe3O4/ZIFs mainly through π-π and hydrophobic interactions, while ST was extracted predominantly by electrostatic interactions and surface complexation. The limits of detection were 0.08 µg kg-1 (AVN) and 0.36 µg kg-1 (ST). The developed method exhibited satisfactory spiked recoveries (79.1%-105.4%) in the determination of AVN and ST in rice. This work provides a novel analytical strategy for further studying AFB1 early warning technique and the formation and transformation of aflatoxins.

The association between serum phosphorus and common carotid artery intima-media thickness in ischemic stroke patients.

Purpose: An elevated concentration of phosphorus is associated with an increased risk of atherosclerosis and cardiovascular diseases. Common carotid artery intima-media thickness (cIMT) is an imaging marker of atherosclerosis. However, data on the relationship between phosphorus and cIMT in ischemic stroke are scarce. We aimed to evaluate the association between serum phosphorus levels and cIMT in patients who had experienced ischemic stroke. Patients and methods: A total of 1,450 ischemic stroke patients were enrolled. Participants were divided into four groups (quartiles) according to baseline serum phosphorus level. Carotid atherosclerosis was identified by measurement of cIMT; abnormal cIMT was defined as a maximum cIMT or mean cIMT ≥ 1 mm. Multivariable logistic regression models were used to assess the association between serum phosphorus level and the presence of abnormal cIMT. Results: In the multivariable adjusted analysis, falling into the highest quartile for serum phosphorus (Q4) was associated with a 2.00-fold increased risk of having abnormal maximum cIMT [adjusted odds ratio (OR) 2.00; 95% confidence interval (CI) 1.44-2.79] and a 1.76-fold increased risk of having abnormal mean cIMT (adjusted OR 1.76; 95% CI 1.22-2.53) in comparison to Q1. Furthermore, the association between serum phosphorus and abnormal cIMT was confirmed in analyses treating serum phosphorus as a continuous variable and in subgroup analyses. Conclusion: In acute ischemic stroke patients, baseline elevated serum phosphorus level was found to be independently associated with carotid atherosclerosis, as measured by cIMT.