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A magnetic graphene-like molybdenum disulfide nanocomposite was prepared by liquid-phase exfoliation and hydrothermal synthesis. The morphology, structure, and magnetic behavior of the nanocomposite were characterized by X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis, vibrating sample magnetometry, scanning electron microscopy and transmission electron microscopy. The nanocomposite was employed as a sorbent for magnetic solid-phase extraction (MSPE) of eight triazine and ten sulfonylurea herbicides from environmental water and corn samples. Specifically, this was studied with cyanazine, simetryn, atrazine, methoprotryne, ametryn, prometryn, terbutryn, dipropetryn, metsulfuron-methyl, sulfometuron-methyl, amidosulfuron, rimsulfuron, nicosulfuron, bensulfuron-methyl, halosulfuron-methyl, pyrazosulfuron-ethyl, chlorimuron-ethyl, and cyclosulfamuron. The parameters affecting extraction efficiency (sorbent amount, pH value of the sample, extraction and elution conditions) were studied and optimized. Following MSPE, the multi-residue herbicides were quantified by ultra-high performance liquid chromatography combined with ion trap mass spectrometry and electrospray ionization. The limits of detection range between 20 and 170 ng·L−1. The extraction recoveries of eighteen herbicides from corn samples were in the range between of 64.7% and 103.1%, with RSDs of <17.6%. [ABSTRACT FROM AUTHOR]

Background: With the recent advances in the treatment of heart failure (HF), it is intriguing that a very small number of patients with dilated cardiomyopathy (DCM) have been observed as being fully recovered. However, knowledge of the progression and prognosis of patients with recovered DCM remains sparse. Herein, we conducted this study to investigate the clinical characteristics and prognosis of patients with recovered DCM., Methods: Consecutive patients with recovered DCM referred to our hospital between March 2009 and May 2021 were included. The recovered DCM patients were categorized into relapse and non-relapse groups. The primary endpoint was all-cause death, and the secondary endpoint was HF re-hospitalization during follow-up. Multivariate analyses were performed to identify predictors of relapse among recovered DCM patients. Kaplan-Meier analyses were used to assess the prognostic significance of relapse., Results: A comparatively large cohort of 122 recovered DCM patients from 10,029 DCM patients was analyzed. During a median follow-up duration of 53.5 months, the relapse rate among recovered DCM patients was 15.6% (19/122). Age (odds ratio, OR 1.079, 95% confidence interval, CI: 1.014-1.148; p = 0.017), systolic blood pressure (SBP) at diagnosis (OR 0.948, 95% CI: 0.908-0.990; p = 0.015) and changes in left ventricular ejection fraction from diagnosis to recovery ( Δ LVEF) (OR 0.898, 95% CI: 0.825-0.978; p = 0.013) were identified as predictors of relapse. Furthermore, among 122 patients, 5 (4.1%) experienced death, and 12 (9.8%) underwent HF re-hospitalization. Four deaths occurred in the relapse group, with one in the non-relapse group. All deaths were attributed to cardiovascular events. The long-term prognosis of the relapse group was significantly worse compared to the non-relapse group by Kaplan-Meier analysis ( p < 0.001 based on the log-rank test). Multivariate analyses significantly associated relapse with all-cause mortality in recovered DCM patients (hazard ratio, HR 7.738, 95% CI: 1.892-31.636; p = 0.004)., Conclusions: Recovered DCM patients are at risk of relapse. Older age, lower SBP, and smaller Δ LVEF were independently associated with relapse in recovered DCM patients. Relapse after recovery was related to an unfavorable long-term prognosis., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2024 The Author(s). Published by IMR Press.)

A method for the separation, identification, and determination of fructose and various aldehyde monosaccharides was established by precolumn labeling with 1-phenyl-3-methyl-5-pyrazolone (PMP) and high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The separation was performed on a Kromasil-C18 column (100 mm×4.6 mm, 3.5 μm) with gradient elution. The detection was performed by electrospray ionization mass spectrometry in selected ion monitoring (SIM) mode. In this study, the derivatization mechanism of PMP-labeled fructose was proposed under mild NH 3 ·H 2 O conditions. The suggested method showed good linearity in the corresponding mass concentration ranges, with the correlation coefficients ( r 2 ) > 0.9947. The limits of detection (LODs) and limits of quantification (LOQs) were in the ranges 0.003 to 0.05 mg/L and 0.01 to 0.15 mg/L, respectively. The recoveries in spiked Lycium barbarum L. samples were 65.1% to 116.2%, with relative standard deviations (RSDs) of less than 10.2%. By virtue of its simplicity, high sensitivity, and good repeatability, the method could be successfully applied to the analysis of the monosaccharide composition in polysaccharides of Lycium barbarum L. from four planting areas. Results showed that the isolated polysaccharides comprise mannose, fructose, rhamnose, galactose, glucose, xylose, arabinose, and ribose. The concentration distribution of various monosaccharides differed notably depending on the planted environmention. The proposed method is expected to be of great significance in standardizing the quality control of polysaccharides.

A method for the confirmation and quantification of metformin hydrochloride and its relative substances melamine and dicyandiamide using tandem dual solid phase extraction (SPE) cartridges and high performance liquid chromatography-electrospray ionization multi-stage mass spectrometry (HPLC-ESI-MS n ) was developed. The samples were extracted with anhydrous ethanol containing 0.1% (v/v) acetic acid under ultrasound-assisted conditions. The extracts were concentrated and purified using Cleanert PCX and C18 tandem dual solid phase extraction cartridges, and eluted with 5% (v/v) ammonia methanol solution. The separation was performed on a Kromasil-C18 column (100 mm×4.6 mm, 3.5 μm) with gradient elution. The detection was performed in selected ion monitoring (SIM) mode using electrospray ionization multi-stage mass spectrometry. The external standard method was used for quantification. The extraction solvents, types of SPE cartridges and eluents were optimized by comparing the recoveries under different conditions. The results showed that the detector response of each target compound was linear in corresponding mass concentration ranges with the correlation coefficients ( r 2 ) ≥ 0.9992. The limits of detection (LODs) and the limits of quantification (LOQs) of the three analytes were 1.48-13.61 μg/kg and 5.96-45.67 μg/kg, respectively. The recoveries of the three analytes were 65.02%-118.33% spiked at low, medium and high levels. The relative standard deviations (RSDs) were no more than 13.41%. The method is reliable, easy, and has a better purification effect. The method can be applied to the routine analysis of metformin hydrochloride and its relative substances melamine and dicyandiamide in different preparations of metformin hydrochloride.