Search

An isotope dilution ultra-performance liquid chromatography–triple quadrupole mass spectrometry method was developed to simultaneously detect two typical kinds of α,β-unsaturated aldehydes, namely 4-hydroxy-2-hexenal (4-HHE) and 4-hydroxy-2-nonenal (4-HNE), in foods. The proposed method exhibited a linear range of 10–1000 ng/mL with a limit of detection of 0.1–2.0 ng/g and a limit of quantification of 0.3–5.0 ng/g. The recovery rates of these typical toxic aldehydes (i.e., 4-HHE, 4-HNE) and their d3-labeled analogues were 91.54%–105.12% with a low matrix effect. Furthermore, this proposed method was successfully applied to a real frying system and a simulated digestion system, wherein the contents of 4-HHE and 4-HNE were determined for both. Overall, the obtained results provide strong support for further research into the production of 4-HHE and 4-HNE resulting from foods during oil digestion and frying.

Abstract Near‐infrared (NIR) luminescent metal halide (LMH) materials have attracted great attention in various optoelectronic applications due to their low‐temperature solution‐processable synthesis, abundant crystallographic/electronic structures, and unique optoelectronic properties. However, some challenges still remain in their luminescence design, performance improvement, and application assignments. This review systematically summarizes the development of NIR LMHs through classifying NIR luminescent origins into four major categories: band‐edge emission, self‐trapped exciton (STE) emission, ion emission, and defect‐related emission. The luminescence mechanisms of different types of NIR LMHs are discussed in detail by analyzing typical examples. Reasonable strategies for designing and optimizing luminescence/optoelectronic properties of NIR LMHs are summarized, including bandgap engineering, self‐trapping state engineering, chemical composition modification, energy transfer, and other auxiliary strategies such as improvement of synthesis scheme and post‐processing. Furthermore, application prospects based on the optoelectronic devices are revealed, including phosphor‐converted light‐emitting diodes (LEDs), electroluminescent LEDs, photodetectors, solar cells, and x‐ray scintillators, as well as demonstrations of some related practical applications. Finally, the existing challenges and future perspectives on the development of NIR LMH materials are critically proposed. This review aims to provide general understanding and guidance for the design of high‐performance NIR LMHs materials.

Peach gum polysaccharide (PGP) is a natural compound known for its anti-inflammatory and antioxidant properties. This study aimed to investigate the potential protective effect of PGP against Enterococcus faecium E745-induced pneumonia and elucidate its underlying mechanism. It demonstrated that PGP exert antioxidant effects by activating the Nrf2 signaling pathway, as evidenced by the normalization of MDA, SOD and GSH levels. Notably, PGP inhibited the NF-κB signaling pathway, reduced IL-6 and TNF-α levels in serum, colon and lung, and enhanced the expression of tight junction proteins. In addition, PGP affected the synthesis of short-chain fatty acids (SCFAs), especially increased the content of propionate and butyrate. These results suggest that PGP alleviates pneumonia by restoring the integrity of the intestinal barrier, increasing the production of SCFAs, reducing the inflammatory response and oxidative stress. In conclusion, our study provides valuable insights into the potential application of PGP in the treatment of inflammatory diseases.

Abstract Achievement of high photoluminescence quantum efficiency and thermal stability is challenging for near-infrared (NIR)-emitting phosphors. Here, we designed a “kill two birds with one stone” strategy to simultaneously improve quantum efficiency and thermal stability of the NIR-emitting Ca3Y2-2x (ZnZr) x Ge3O12:Cr garnet system by chemical unit cosubstitution, and revealed universal structure-property relationship and the luminescence optimization mechanism. The cosubstitution of [Zn2+–Zr4+] for [Y3+–Y3+] played a critical role as reductant to promote the valence transformation from Cr4+ to Cr3+, resulting from the reconstruction of octahedral sites for Cr3+. The introduction of [Zn2+–Zr4+] unit also contributed to a rigid crystal structure. These two aspects together realized the high internal quantum efficiency of 96% and excellent thermal stability of 89%@423 K. Moreover, information encryption with “burning after reading” was achieved based on different chemical resistance of the phosphors to acid. The developed NIR-emitting phosphor-converted light-emitting diode demonstrated promising applications in bio-tissue imaging and night vision. This work provides a new perspective for developing high-performance NIR-emitting phosphor materials.

Ferrite-martensite (F/M) dual-phase ductile iron with different relative amounts of martensite was fabricated via intercritical quenching in the present study. The mechanical properties and tribological behavior were investigated. The strength of ductile iron increased linearly with the increase of martensite level, while the ductility decreased rapidly. Fracture surface morphology analysis indicated that ductile fracture was predominant when the proportion of martensite in ductile iron was less than 20%. However, the samples with more than 40% martensite exhibited brittle fractures. Wear tests indicated that F/M dual-phase ductile iron exhibited a significantly lower friction coefficient compared with directly quenched ductile iron. Additionally, the martensite amounts affected the tribological behavior of ductile iron significantly. Abrasive wear was predominant in ductile iron with small amounts of martensite, while delamination wear was the main wear mechanism in case of ductile iron with high amounts of martensite.

BackgroundRadiofrequency ablation (RFA) is the primary curative treatment for hepatocellular carcinoma (HCC) patients who are not eligible for surgery. However, the effects of RFA on the global tumor immune response remain unclear.MethodIn this study, we examined the phenotypic and functional changes in peripheral blood mononuclear cells (PBMCs) from recurrent HCC patients who had undergone two RFA treatments using mass cytometry and high-throughput mRNA assays. ResultsWe observed significant increase in monocytes and decrease in T cell subpopulations three days after the first RFA treatment and three days after the second RFA treatment. The down-regulation of GZMB, GZMH, GZMK, and CD8A, which are involved in the cytotoxic function of T cells, was observed following RFA. Furthermore, the population of CD8 effector and memory T cells (CD8 Teff and CD8 Tem) significantly decreased after RFA. The expression of CD5 and CD161 in various T cell subpopulations also showed significant reductions. Additionally, elevated secretion of VEGF was observed in monocytes, B cells, regulatory T cells (Tregs), and CD4 naive T cells. ConclusionIn recurrent HCC patients, serum components derived from radiofrequency therapy can enhance the antigen-presenting capacity of monocytes. However, they also inhibit the anti-cancer immune response by reducing the population of CD8 effector and memory T cells and suppressing the activation of T cells, as well as down-regulating the expression of CD161 and CD5 in various T cell subpopulations. These tumor-derived components also contribute to an immunosuppressive microenvironment by promoting the secretion of VEGF in monocytes, Tregs, B cells, and CD4 naive T cells.

In this study, the effects of slow freezing (−20 ℃) and quick freezing (−80 ℃) on the cell wall structure of waxberry fruits were investigated, and the changes of main nutrient quality components during storage were also studied. The moisture content and migration of waxberry fruits during storage were observed by low field NMR. The results showed that the cell wall morphology of quick-frozen waxberry fruits maintained well, and there were obvious gaps in the cross section of the cell wall of slow-frozen waxberry fruits. During the storage period of 25 days, the water content of fruit gradually decreased, but the range of water transfer of quick-frozen waxberry was small, and the total lateral relaxation time was larger than the relaxation time of slow-frozen waxberry, indicating that quick-frozen waxberry could effectively maintain fruit water activity. The free water signal value of quick-frozen waxberry decreased only by 18%, while the free water signal value of slow-frozen waxberry decreased by 47.75%, indicating that quick-frozen waxberry was beneficial to maintaining fruit water content. In addition, fruit nutrients decreased gradually, but the total sugar content, titratable acid content, total phenols and anthocyanins contents were 13.64 mg/g, 13.43 g/L, 15.43 mg/mL and 0.53 μmol/g, respectively, at the end of storage stage of quick-frozen waxberry. The retention rates of main nutritional indexes were higher than those of slow frozen waxberry. Therefore, quick-freezing can effectively delay the loss of nutrients in waxberry fruits.

Salvia miltiorrhiza seeds (SMS) are the main by-product of the production processing of Radix Salviae Miltiorrhizae. The main purposes of this work are to analyse the nutritional components in SMS, to explore the antioxidant activity of the chemical components in SMS and to evaluate the possibility of SMS as a raw material for functional foods. The contents of crude fibre, total protein, carbohydrates, total phenolics and flavonoids in SMS and the composition and relative content of fatty acids in SMS oil were determined. The results suggested that SMS has high contents of crude fibre (28.68 ± 4.66 g/100 g), total protein (26.65 ± 2.51 g/100 g), total phenolics (6.45 ± 0.55 mg of gallic acid equivalent/g) and total flavonoids (3.28 ± 0.34 mg of rutin equivalent/g), as well as a high level of α-linolenic acid (33.774 ± 4.68%) in their oil. Twenty-two secondary metabolites were identified in SMS residue, and nine compounds were isolated. The IC50 values of the total phenolic content in SMS on an ABTS radical, DPPH radical, superoxide radical and hydroxyl radical were 30.94 ± 3.68 μg/mL, 34.93 ± 4.12 μg/mL, 150.87 ± 17.64 μg/mL and 230.19 ± 24.47 μg/mL, respectively. The results indicate that SMS contain many nutrients and have high utilization value as a promising functional food.

Abstract Background Polyunsaturated fatty acid (PUFA) synthase is a multi-domain mega-enzyme that effectively synthesizes a series of PUFAs in marine microorganisms. The dehydratase (DH) domain of a PUFA synthase plays a crucial role in double bond positioning in fatty acids. Sequencing results of the coccolithophore Emiliania huxleyi (E. huxleyi, Eh) indicated that this species contains a PUFA synthase with multiple DH domains. Therefore, the current study, sought to define the functions of these DH domains (EhDHs), by cloning and overexpressing the genes encoding FabA-like EhDHs in Escherichia coli (E. coli) and Arabidopsis thaliana (A. thaliana). Results A complementation test showed that the two FabA-like DH domains could restore DH function in a temperature-sensitive (Ts) mutant. Meanwhile, overexpression of FabA-like EhDH1 and EhDH2 domains increased the production of unsaturated fatty acids (UFAs) in recombinant E. coli by 43.5–32.9%, respectively. Site-directed mutagenesis analysis confirmed the authenticity of active-site residues in these domains. Moreover, the expression of tandem EhDH1-DH2 in A. thaliana altered the fatty acids content, seed weight, and germination rate. Conclusions The two FabA-like DH domains in the E. huxleyi PUFA synthase function as 3-hydroxyacyl-acyl carrier protein dehydratase in E. coli. The expression of these domains in E. coli and A. thaliana can alter the fatty acid profile in E. coli and increase the seed lipid content and germination rate in A. thaliana. Hence, introduction of DH domains controlling the dehydration process of fatty acid biosynthesis in plants might offer a new strategy to increase oil production in oilseed plants.

Chargeback fraud is a fast-growing threat to e-commerce, bringing huge losses to online sellers, but there is still a lack of effective technical counter measures. To combat chargeback fraud, this paper proposes a consortium blockchain based chargeback fraud data sharing mechanism — CFLedger, which includes multi-source reporting, anti-tamper accounting, and post-supervision. This paper also analyzes the efficiency, effectiveness, and practicality of CFLedger, proving that it is an effective and feasible mechanism to prevent chargeback fraud.

To solve the problem of environmental pollution, Distiller's dried grains (DDGS), a biomass, is used as a clean reducing agent for the leaching process of pyrolusite. Experimental results have shown that the leaching rate of manganese can reach 92.1% with the optimized conditions including a sulfuric acid concentration of 3.5 mol/L, a DDGS to pyrolusite ratio of 0.4, a liquid–solid ratio of 3 mL/g, a temperature of 363K, a time of 3 h, and a rotation speed of 400 rpm. This article explored the mechanism of the entire leaching process: the crude fiber in DDGS is hydrolyzed into reducing sugars, and the MnO2 in pyrolusite undergoes an oxidation–reduction reaction to generate Mn2+ and studied the kinetics of the leaching process following the unreacted shrinkage nuclear reaction model controlled by the surface chemical reaction (1-(1-X)1/3 = kt). The equation of leaching kinetics is 1−1−X13=3738.06·[H2SO4]0.57·[LS]0.78·[DDGSpyrolusite]0.25·[rpm]0.09·exp(−48.448/(RT)) This work provides a green and effective leaching process for the leaching of pyrolusite.

Highly efficient Fe3+-activated Sr2-y Ca y (InSb)1-z Sn2z O6 near-infrared-emitting phosphors exhibit tunable emission from 885 to 1005 nm with cation substitution of Ca2+ for Sr2+ and further cosubstitution of [Sn4+–Sn4+] for [In3+–Sb5+].

Abstract In a cell-free massive MIMO system, multiple users arrive at multiple access points at separate times, while in an OFDM system, different delays can be equivalent to delay spread differences (DSDs). Since DSDs are not all the same, in the downlink transmission process, it is necessary to consider its impact on transmission techniques, such as channel estimation and downlink precoding. In this paper, aiming at the performance loss caused by DSDs in cell-free massive MIMO-OFDM system, we propose a multi-RB precoding optimization algorithm that maximizes the downlink sum rate. We derive the sum rate maximization problem into an iterative second-order cone programming form to achieve convex approximation. Then, considering the impact of DSDs on the accuracy of cell-free massive MIMO-OFDM channel estimation, we propose a downlink channel estimation method, which jointly uses channel state information reference signal and demodulation reference signal. The simulation results show that the proposed multi-RB optimal precoding can effectively improve the downlink sum rate, and the proposed downlink channel estimation can obtain accurate multi-RB frequency-domain channel parameters.

The olecranon honey peach is China’s national geographic identification product because of its crisp texture and high sweetness. In recent years, new field management practices have been developed. In this study, fruits (‘SJH’) grown through new planting methods, i.e., black bags combined with bio-organic fermentation fertilizer, were compared with those (‘SBY’) grown by conventional planting methods, i.e., using a chemical fertilizer without bagging, to determine their effects on improving fruit quality. At maturity, the ‘SJH’ was significantly higher than ‘SBY’ in terms of weight, hardness, and sugar content by 14.43%, 19.55% and 9.66%, respectively. RNA sequencing (RNA-seq) technology analysis was performed on ‘SJH’ and ‘SBY’ to identify the main regulatory pathways involved in fruit development, especially focusing on cell-wall biogenesis and sugar metabolism. We identified a total of 1660 differentially expressed genes (DEGs) in ‘SJH’ and 5673 genes in ‘SBY’ throughout the development. A clustering analysis of DEGs revealed that the expression patterns of key genes involved in cell-wall biogenesis and sugar metabolism pathways in ‘SJH’ differed from those in ‘SBY’, such as cellulose synthase-like protein D (CS-LPD), sucrose-phosphate synthase (SPS) and sucrose synthase (SUS). The new cultivation technology promoted soluble sugar accumulation and cell-wall synthesis through molecular regulation, which improved the sweetness and sensory quality of the fruit. These findings contribute towards to the development of novel ideas for the better cultivation of peaches and provide a deeper investigation into the molecular mechanism of their development.

This study aimed to assess the morphometry of enterocytes as well as the goblet cell-to-enterocyte ratio in different intestinal segments of dogs with chronic enteropathies (CE). Histopathological intestinal samples from 97 dogs were included in the study (19 healthy juveniles, 21 healthy adults, 24 dogs with protein-losing enteropathy (PLE), and 33 CE dogs without PLE). Healthy adult small intestinal enterocytes showed progressively reduced epithelial cell height in the aboral direction, while juvenile dogs showed progressively increased epithelial cell height in the aboral direction. CE dogs had increased epithelial cell height in the duodenum, while PLE dogs had decreased epithelial cell heights compared to healthy adult dogs. Both the CE and PLE dogs showed decreased enterocyte width in the duodenal segment, and the ileal and colonic enterocytes of CE dogs were narrower than those of healthy adult dogs. CE dogs had a lower goblet cell-to-enterocyte ratio in the colon segment compared to healthy dogs. This study provides valuable morphometric information on enterocytes during canine chronic enteropathies, highlighting significant morphological enterocyte alterations, particularly in the small intestine, as well as a reduced goblet cell-to-enterocyte ratio in the colon of CE cases compared to healthy adult dogs.

A highly efficient red-emitting Cs3EuGe3O9 phosphor for high-performance pc-WLEDs is discovered with non-concentration quenching, favourable thermal stability, high colour purity and negative thermal expansion.

Although a variety of techniques to detect malicious websites have been proposed, it becomes more and more difficult for those methods to provide a satisfying result nowadays. Many malicious websites can still escape detection with various Web spam techniques. In this paper, we first summarize three types of Web spam techniques used by malicious websites, such as redirection spam, hidden IFrame spam, and content hiding spam. We then present a new detection method that adopts the perspective of users and takes screenshots of malicious webpages to invalidate Web spams. The proposed detection method uses a Convolutional Neural Network, which is a class of deep neural networks, as a classification algorithm. In order to verify the effectiveness of the method, two different experiments have been conducted. First, the proposed method was tested based on a constructed complex dataset. We present comparison results between the proposed method and representative machine learning-based detection algorithms. Second, the proposed method was tested to detect malicious websites in a real-world Web environment for three months. These experimental results illustrate that the proposed method has a better performance and is applicable to a practical Web environment.

Phosphor materials with narrow emission bands are highly interesting for light-emitting diode (LED) lighting and display applications. However, designing novel Bi3+-doped phosphors with desirable narrow band emission, high luminous efficiency and good thermal stability is a challenging task. Here, two novel violet- and blue-emitting narrow-band M10P6O25:Bi3+ (M = Ca, Sr) phosphors are designed based on the small Stokes shift and introduction of Bi3+ into highly symmetric lattice sites. Both phosphors exhibit a broad absorption band in 300–380 nm, matching well with the n-UV LED chip. Under UV light excitation, Ca10P6O25:Bi3+ shows a violet emission peaking at 392 nm with a narrow full width at half-maximum (FWHM) of 36 nm and high color purity of 98%. Sr10P6O25:Bi3+ emits a blue light (400–550 nm) with FWHM of 66 nm and color purity of 88%. More importantly, the as-prepared M10P6O25:Bi3+ (M = Ca, Sr) phosphors show good thermal stability (>82%@150 °C) and relatively high photoluminescence quantum yields (PLQY >50%). Moreover, violet LED fabricated with Ca10P6O25:Bi3+ can be used in anti-counterfeiting. The as-fabricated white LED utilizing Sr10P6O25:Bi3+ possesses a CIE chromaticity coordinates of (0.345, 0.363), color rendering index (CRI) of 87.5 and correlated color temperature (CCT) of 4992 K. The above investigations indicate that M10P6O25:Bi3+ (M = Ca, Sr) are promising violet and blue phosphor candidates for LED with wide-color-gamut display and potential anti-counterfeiting applications.

ABE can be used as an alternative fuel for engines. This paper studies the combustion and emission performances of an SI engine with GPI plus ABEDI at different engine speeds and loads. The engine operating conditions included speeds of 1000–2600 rpm at the MAP = 50 kPa and loads of MAP = 30–70 kPa at a speed of 1800 rpm. The ABEDIr contained 0%, 20%, 40%, 60%, 80%, and 100%. At speeds = 1000–1800 or 2200–2600 rpm, the testing results showed the ABEDIr corresponding to the maximum IMEP at 80% or 100%. When the ABEDIr = 60%, HC and NOx emissions were the lowest at speeds of 1000–2600 rpm. Meanwhile, NPN and APN both decreased with the increasing of ABEDIr. As the MAP increased, CA0-90 decreased. At different loads, ABE-added fuels had lower HC and NOx emissions and higher IMEP values than pure gasoline. PN was lower than 4 × 104 n/cm3 when the ABEDIr was over 80%. Overall, 80% ABEDIr is a great choice for engine performance at the test range of loads and speeds, and pure ABE fuel is better if the power performance is the main requirement at high speeds and loads.

The stability/instability behavior of polystyrene (PS) films with tunable thickness ranging from higher as-cast to lower residual made on Si substrates with and without native oxide layer was studied in this paper. For further extraction of residual PS thin film (hresi) and to investigate the polymer–substrate interaction, Guiselin’s method was used by decomposing the polymer thin films in different solvents. The solvents for removing loosely adsorbed chains and extracting the strongly adsorbed irreversible chains were selected based on their relative desorption energy difference with polymer. The PS thin films rinsed in chloroform with higher polarity than that of toluene showed a higher decrease in the residual film thickness but exhibited earlier growth of holes and dewetting in the film. The un-annealed samples with a higher oxide film thickness showed a higher decrease in the PS residual film thickness. The effective viscosity of PS thin films spin-coated on H-Si substrates increased because of more resistance to flow dynamics due to the stronger polymer–substrate interaction as compared to that of Si-SiOx substrates. By decreasing the film thickness, the overall effective mobility of the film increased and led to the decrease in the effective viscosity, with matching results of the film morphology from atomic force microscopy (AFM). The polymer film maintained low viscosity until a certain period of time, whereupon further annealing occurred, and the formation of holes in the film grew, which ultimately dewetted the film. The residual film decrement, growth of holes in the film, and dewetting of the polymer-confined thin film showed dependence on the effective viscosity, the strength of solvent used, and various involved interactions on the surface of substrates.

Interfacial interactions within a multi-phase polymer solution play critical roles in processing control and mass transportation in chemical engineering. However, the understandings of these roles remain unexplored due to the complexity of the system. In this study, we used an efficient analytical method—a nonequilibrium molecular dynamics (NEMD) simulation—to unveil the molecular interactions and rheology of a multiphase solution containing cetyltrimethyl ammonium chloride (CTAC), polyacrylamide (PAM), and sodium salicylate (NaSal). The associated macroscopic rheological characteristics and shear viscosity of the polymer/surfactant solution were investigated, where the computational results agreed well with the experimental data. The relation between the characteristic time and shear rate was consistent with the power law. By simulating the shear viscosity of the polymer/surfactant solution, we found that the phase transition of micelles within the mixture led to a non-monotonic increase in the viscosity of the mixed solution with the increase in concentration of CTAC or PAM. We expect this optimized molecular dynamic approach to advance the current understanding on chemical−physical interactions within polymer/surfactant mixtures at the molecular level and enable emerging engineering solutions.

To improve the corrosion performance of magnesium alloys in the marine environment, the MAO, MAO−Cu2CO3(OH)2·H2O and MAO−Cu2P2O7 ceramic coatings were deposited on AZ91D magnesium alloys in basic electrolyte and the discoloration mechanism of the Cu-doped MAO coatings and the corrosion behavior of the three MAO coatings in the artificial seawater solution were investigated by SEM, EDS and XPS. The results indicated that the formation and discoloration mechanism of the brown MAO ceramic coatings were attributable to the formation of Cu2O in the coatings. Though the three MAO coatings had a certain protective effect against the corrosion of AZ91D substrate in the artificial seawater, the distinctive stratification phenomenon was found on the MAO−Cu2P2O7 coated sample and the corrosion model of the MAO−Cu2P2O7 coatings in the immersion experiment was established. Therefore, the brown Cu-doped MAO coatings were speculated to significantly reduce the risk of the magnesium parts in marine environments.

Aquatic foods are nutritious, enjoyable, and highly favored by consumers. In recent years, young consumers have shown a preference for prefabricated food due to its convenience, nutritional value, safety, and increasing market share. However, aquatic foods are prone to microbial spoilage due to their high moisture content, protein content, and unsaturated fatty acids. Furthermore, traditional processing methods of aquatic foods can lead to issues such as protein denaturation, lipid peroxidation, and other food safety and nutritional health problems. Therefore, there is a growing interest in exploring new technologies that can achieve a balance between antimicrobial efficiency and food quality. This review examines the mechanisms of cold plasma, high-pressure processing, photodynamic inactivation, pulsed electric field treatment, and ultraviolet irradiation. It also summarizes the research progress in nonthermal physical field technologies and their application combined with other technologies in prefabricated aquatic food. Additionally, the review discusses the current trends and developments in the field of prefabricated aquatic foods. The aim of this paper is to provide a theoretical basis for the development of new technologies and their implementation in the industrial production of prefabricated aquatic food. [ABSTRACT FROM AUTHOR]