300 publications from this institution
The profiles of phenolic acids and flavan-3-ols for the selected Chinese red wines and the potential of using phenolic acids and flavan-3-ols to differentiate the geographic origin and grape variety of wines from China are investigated in this study. Significant differences and markers could be found according to the geographical origin and grape variety. Through a canonical discriminant analysis a good differentiation was developed according to the geographic origin or grape variety, and the accuracy of the discriminant model was 88.9% and 100%, respectively. According to the phenolic acid and flavan-3-ols profiles of the wine samples and good differentiation in the region and the variety discriminant analysis, minimal fraudulent claims were noted for the Chinese red wines investigated.This study provides some help for the protection of geographical origin and monovarietal wine claims.
= 2). Extensive evaluation using nine kits demonstrated 100% concordance for both positive and negative samples. The materials exhibited excellent repeatability (coefficient of variation, CV <5%) and consistent detectability (≥95% positivity rate) at the claimed limit of detection across all kits. In summary, this study developed a well-characterized reference material system to support the standardization, development, and quality control of CHIKV nucleic acid assays. The availability of this reference material system addresses a longstanding limitation of results across different platforms and geographical regions. Their implementation is expected to facilitate assay optimization and improve the consistency of surveillance data, thereby strengthening preparedness and the accurate identification of cases, especially in non-endemic areas at risk of importation.IMPORTANCEThe absence of a World Health Organization (WHO) international standard for Chikungunya virus (CHIKV) nucleic acid testing has long compromised result comparability and global outbreak response. Here, we established a national reference material system derived from intact, inactivated CHIKV particles-authentically mirroring the entire clinical workflow. Covering both Asian and East/Central/South African (ECSA) genotypes, this system mitigates false-negative risks caused by viral genetic diversity. Assigned via multi-laboratory dPCR and validated across nine commercial kits, it demonstrated 100% concordance, ≥95% detectability at LoD, and coefficient of variation (CV) <5%. This traceable, genotype-inclusive, workflow-authentic benchmark enables, for the first time, unified performance alignment for regulatory review, manufacturer quality control, and inter-laboratory comparison. It fills a critical gap in domestic quality assurance while providing a technical template for future WHO standardization efforts. Widespread adoption will accelerate reliable diagnostics, strengthen surveillance comparability, and support timely clinical decisions in both endemic and importation-prone settings.
Cellulose nanofibers (CNFs) were isolated from lettuce peel using specific chemical treatments, i.e., NaOH alkali solution treatment, NaClO 2 bleaching and sulfuric acid hydrolysis.Both cellulose and cellulose nanofibers were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD).The morphological features and particle size distribution of cellulose and nanostructures were explored using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and a Malvern laser particle size analyzer.The results showed that the particle diameters of the majority of nanofibrillated celluloses were in the range from 10 to 20 nm, and the length between 190 and 460 nm.The crystallinity index reached 41.57%, which increased by 117.3%, compared with the raw material.The crystalline lettuce peel nanofibers belong to cellulose type I.Moreover, the thermal degradation temperature of CNFs is 271.7 °C, which is 47.3 °C higher than that of the untreated peel.The CNFs obtained from these treatments can be used as additional reinforcement in biocomposites in composite manufacturing processes or in the food industry.
In this paper, a novel adaptive-gain sliding mode observer (SMO) is designed for sensorless control of permanent magnet linear synchronous motors (PMLSMs). By the proposed adaptive-gain algorithm, the gain can dynamically adapt to a changing operation condition of the PMLSMs and reach an appropriate value in finite time. Stability of the SMO is proved by using Lyapunov stability theory. Compared with the traditional SMO, the adaptive-gain SMO can improve the control precision, especially when the operation condition is not invariant. Simulation results are given to show the advantages of the proposed method.
Mesoporous multiwalled carbon nanotubes/titanium dioxide (CNTs/TiO2) nanocomposites with low loading amounts (0–0.5 wt%) of CNTs embedded inside mesoporous TiO2 aggregates has been prepared by a simple one-pot hydrothermal method using titanium sulfate as titanium source. The as-prepared CNTs/TiO2 samples are carefully characterized, analyzed and discussed. In contrast to previous reports with high CNT loading, our results indicate that a low CNT loading slightly influences the textural properties (including crystallite size, degree of crystallinity, specific surface areas, and pore volume etc.) and UV-light absorption of the mesoporous TiO2 aggregates. The SEM and TEM results demonstrate that the CNTs are mostly embedded in the mesoporous TiO2 aggregates. Moreover, chemical bonds are formed at the interface between CNTs and TiO2, which is confirmed by the Raman, IR and XPS analyses. Significantly, we point out that PL analysis in terms of intensity of PL signals seems to not be a reliable way to monitor the recombination rate in the CNTs/TiO2 composite, due to the quenching effect of CNTs. Instead, the analysis of transient photocurrent responses is introduced, which definitely reflects CNTs as fast electron transfer channels in chemically-bonded CNTs/TiO2 composites with low CNT loading. Notably, the positive synergy effects of CNTs and TiO2 depend on both the CNT loading amount and the state of interfacial contacts. In our study, only these chemically bonded CNTs/TiO2 nanocomposites with appropriate loading amounts (<0.1 wt%) favor the separation of photogenerated electron-hole pairs and decrease their recombination rate and thus display significantly enhanced photocatalytic activity for degrading acetone in air under UV irradiation, as compared with pristine TiO2 counterparts and commercial P25 photocatalyst. In contrast, a high CNT loading (>0.1 wt%) results in a decrease in photocatalytic activity; a simple mechanical mixing of CNTs and TiO2 without forming chemical bonds at the interface also results in inferior photocatalytic performance.
Permanent magnet synchronous motors (PMSMs) has been gradually applied to space electromechanical products with high-precision and high-stability, the influence of drive circuit on drive performance has attracted more attention. Traditional control strategies for PMSMs are fed by inverter, which can lead to torque ripple due to the chopping of its switching devices, thus limiting the scope of their application. This paper studies the high-precision linear drive circuit based on power operational amplifier for the three-phase open-winding permanent magnet synchronous motor (OW-PMSM), and designs both single-ended and double-ended drive circuits. Based on simulation software PSIM, a closed-loop simulation system of OW-PMSM is established, and the correctness of the drive circuits is simulated and verified. In addition, the performance of single-ended and double-ended drive circuits is compared, which lays a foundation for the application of three-phase OW-PMSMs in high-precision drive control in aerospace.
Melatonin has recently been detected in fermented beverages and foods, in which microorganism metabolism is highly important. The existing literature knowledge discusses the direction for future studies in this review. Evidence shows that many species of microorganisms could synthesize melatonin. However, the actual concentrations of melatonin in fermented foods and beverages range from picograms per milliliter to nanograms per milliliter. Different types of microorganisms, different raw materials, different culture environments, the presence or absence of precursors, high or low alcohol content, and different detection methods are all possible reasons for the huge difference of melatonin levels. Thus far, there have been relatively few studies on the melatonin synthesis pathway microorganisms. Thus, referring to the synthetic pathway of plants and animals, the putative melatonin biosynthesis pathway of microorganisms is presented. It will be significant to discuss whether all species of microorganisms have the capacity to synthesize melatonin and what the biological functions of melatonin are in microorganisms. Melatonin plays a lot of important roles in microorganisms, particularly in enhancing the tolerance of environment stress. Also, the loss of melatonin concentration in commercially available fermented foods and beverages is a ubiquitous trend, and how to solve this problem is a new field to be further explored.
