Differential effects of specific emotions on spatial decision-making: evidence from cross-frequency functionally independent brain networks.

Emotions significantly shape the way humans make decisions. However, the underlying neural mechanisms of this influence remain elusive. In this study, we designed an experiment to investigate how emotions (specifically happiness, fear, and sadness) impact spatial decision-making, utilizing EEG data. To address the inherent limitations of sensor-level investigations previously conducted, we employed standard low-resolution brain electromagnetic tomography and functional independent component analysis to analyze the EEG data at the cortical source level. Our findings showed that across various spectral-spatial networks, positive emotion activated the decision-making network in the left middle temporal gyrus and inferior temporal gyrus, in contrast to negative emotions. We also identified the common spectral-spatial networks and observed significant differences in network strength across emotions. These insights further revealed the important role of the gamma-band prefrontal network. Our research provides a basis for deciphering the roles of brain networks in the impact of emotions on decision-making.

High Performance Nacre Fibers by Engineering Interfacial Entanglement.

Biological materials exhibit fascinating mechanical properties for intricate interactions at multiple interfaces to combine superb toughness with wondrous strength and stiffness. Recently, strong interlayer entanglement has emerged to replicate the powerful dissipation of natural proteins and alleviate the conflict between strength and toughness. However, designing intricate interactions in a strong entanglement network needs to be further explored. Here, we modulate interlayer entanglement by introducing multiple interactions, including hydrogen and ionic bonding, and achieve ultrahigh mechanical performance of graphene-based nacre fibers. Two essential modulating trends are directed. One is modulating dynamic hydrogen bonding to improve the strength and toughness up to 1.58 GPa and 52 MJ/m3, simultaneously. The other is tailoring ionic coordinating bonding to raise the strength and stiffness, reaching 2.3 and 253 GPa. Modulating various interactions within robust entanglement provides an effective approach to extend performance limits of bioinspired nacre and optimize multiscale interfaces in diverse composites.

Canagliflozin regulates metabolic reprogramming in diabetic kidney disease by inducing fasting-like and aestivation-like metabolic patterns.

AIMS/HYPOTHESIS: Sodium-glucose co-transporter 2 (SGLT2) inhibitors (SGLT2i) are antihyperglycaemic drugs that protect the kidneys of individuals with type 2 diabetes mellitus. However, the underlying mechanisms mediating the renal benefits of SGLT2i are not fully understood. Considering the fuel switches that occur during therapeutic SGLT2 inhibition, we hypothesised that SGLT2i induce fasting-like and aestivation-like metabolic patterns, both of which contribute to the regulation of metabolic reprogramming in diabetic kidney disease (DKD). METHODS: Untargeted and targeted metabolomics assays were performed on plasma samples from participants with type 2 diabetes and kidney disease (n=35, 11 women) receiving canagliflozin (CANA) 100 mg/day at baseline and 12 week follow-up. Next, a systematic snapshot of the effect of CANA on key metabolites and pathways in the kidney was obtained using db/db mice. Moreover, the effects of glycine supplementation in db/db mice and human proximal tubular epithelial cells (human kidney-2 [HK-2]) cells were studied. RESULTS: Treatment of DKD patients with CANA for 12 weeks significantly reduced HbA1c from a median (interquartile range 25-75%) of 49.0 (44.0-57.0) mmol/mol (7.9%, [7.10-9.20%]) to 42.2 (39.7-47.7) mmol/mol (6.8%, [6.40-7.70%]), and reduced urinary albumin/creatinine ratio from 67.8 (45.9-159.0) mg/mmol to 47.0 (26.0-93.6) mg/mmol. The untargeted metabolomics assay showed downregulated glycolysis and upregulated fatty acid oxidation. The targeted metabolomics assay revealed significant upregulation of glycine. The kidneys of db/db mice undergo significant metabolic reprogramming, with changes in sugar, lipid and amino acid metabolism; CANA regulated the metabolic reprogramming in the kidneys of db/db mice. In particular, the pathways for glycine, serine and threonine metabolism, as well as the metabolite of glycine, were significantly upregulated in CANA-treated kidneys. Glycine supplementation ameliorated renal lesions in db/db mice by inhibiting food intake, improving insulin sensitivity and reducing blood glucose levels. Glycine supplementation improved apoptosis of human proximal tubule cells via the AMP-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway. CONCLUSIONS/INTERPRETATION: In conclusion, our study shows that CANA ameliorates DKD by inducing fasting-like and aestivation-like metabolic patterns. Furthermore, DKD was ameliorated by glycine supplementation, and the beneficial effects of glycine were probably due to the activation of the AMPK/mTOR pathway.

An insight into the gene expression evolution in Gossypium species based on the leaf transcriptomes.

BACKGROUND: Gene expression pattern is associated with biological phenotype and is widely used in exploring gene functions. Its evolution is also crucial in understanding species speciation and divergence. The genus Gossypium is a bona fide model for studying plant evolution and polyploidization. However, the evolution of gene expression during cotton species divergence has yet to be extensively discussed. RESULTS: Based on the seedling leaf transcriptomes, this work analyzed the transcriptomic content and expression patterns across eight cotton species, including six diploids and two natural tetraploids. Our findings indicate that, while the biological function of these cotton transcriptomes remains largely conserved, there has been significant variation in transcriptomic content during species divergence. Furthermore, we conducted a comprehensive analysis of expression distances across cotton species. This analysis lends further support to the use of G. arboreum as a substitute for the A-genome donor of natural cotton polyploids. Moreover, our research highlights the evolution of stress-responsive pathways, including hormone signaling, fatty acid degradation, and flavonoid biosynthesis. These processes appear to have evolved under lower selection pressures, presumably reflecting their critical role in the adaptations of the studied cotton species to diverse environments. CONCLUSIONS: In summary, this study provided insights into the gene expression variation within the genus Gossypium and identified essential genes/pathways whose expression evolution was closely associated with the evolution of cotton species. Furthermore, the method of characterizing genes and pathways under unexpected high or slow selection pressure can also serve as a new strategy for gene function exploration.

An update on chronic complications of diabetes mellitus: from molecular mechanisms to therapeutic strategies with a focus on metabolic memory.

Diabetes mellitus, a chronic metabolic disease, often leads to numerous chronic complications, significantly contributing to global morbidity and mortality rates. High glucose levels trigger epigenetic modifications linked to pathophysiological processes like inflammation, immunity, oxidative stress, mitochondrial dysfunction, senescence and various kinds of cell death. Despite glycemic control, transient hyperglycemia can persistently harm organs, tissues, and cells, a latent effect termed "metabolic memory" that contributes to chronic diabetic complications. Understanding metabolic memory's mechanisms could offer a new approach to mitigating these complications. However, key molecules and networks underlying metabolic memory remain incompletely understood. This review traces the history of metabolic memory research, highlights its key features, discusses recent molecules involved in its mechanisms, and summarizes confirmed and potential therapeutic compounds. Additionally, we outline in vitro and in vivo models of metabolic memory. We hope this work will inform future research on metabolic memory's regulatory mechanisms and facilitate the development of effective therapeutic compounds to prevent diabetic complications.

Transcriptome analysis reveals the potential lncRNA-mRNA modules involved in genetic male sterility and fertility of Chinese cabbage (brassica rapa L. ssp. pekinensis).

BACKGROUND: Long non-coding RNAs (lncRNAs) play a crucial role in regulating gene expression vital for the growth and development of plants. Despite this, the role of lncRNAs in Chinese cabbage (Brassica rapa L. ssp. pekinensis) pollen development and male fertility remains poorly understood. RESULTS: In this study, we characterized a recessive genic male sterile mutant (366-2 S), where the delayed degradation of tapetum and the failure of tetrad separation primarily led to the inability to form single microspores, resulting in male sterility. To analyze the role of lncRNAs in pollen development, we conducted a comparative lncRNA sequencing using anthers from the male sterile mutant line (366-2 S) and the wild-type male fertile line (366-2 F). We identified 385 differentially expressed lncRNAs between the 366-2 F and 366-2 S lines, with 172 of them potentially associated with target genes. To further understand the alterations in mRNA expression and explore potential lncRNA-target genes (mRNAs), we performed comparative mRNA transcriptome analysis in the anthers of 366-2 S and 366-2 F at two stages. We identified 1,176 differentially expressed mRNAs. Remarkably, GO analysis revealed significant enrichment in five GO terms, most notably involving mRNAs annotated as pectinesterase and polygalacturonase, which play roles in cell wall degradation. The considerable downregulation of these genes might contribute to the delayed degradation of tapetum in 366-2 S. Furthermore, we identified 15 lncRNA-mRNA modules through Venn diagram analysis. Among them, MSTRG.9997-BraA04g004630.3 C (ß-1,3-glucanase) is associated with callose degradation and tetrad separation. Additionally, MSTRG.5212-BraA02g040020.3 C (pectinesterase) and MSTRG.13,532-BraA05g030320.3 C (pectinesterase) are associated with cell wall degradation of the tapetum, indicating that these three candidate lncRNA-mRNA modules potentially regulate pollen development. CONCLUSION: This study lays the foundation for understanding the roles of lncRNAs in pollen development and for elucidating their molecular mechanisms in regulating male sterility in Chinese cabbage.

Two-dimensional fullerene-based monolayer materials assembled by C80 and Sc3N@C80.

Construction of two-dimensional (2D) materials using fullerenes as building blocks has attracted particular attention, primarily due to their ability to integrate desired functionalities into devices. However, realization of stable 2D phases of polymerized fullerenes remains a big challenge. Here, we propose two stable 2D monolayer phases with covalently bridged C80 cages, namely α-C80-2D and ß-C80-2D, which are semiconductors with strong absorption in the long wave range and appreciable carrier mobility, respectively. The high stability originates from the bond energy released by the [2+2] cycloaddition polymerization of C80 is greater than the deformation energy of a cage. Starting from α-C80-2D, endohedral incorporation of the Sc3N molecule into each C80 cage leads to 2D semiconductors of α-Sc3N@C80-2D and α'-Sc3N@C80-2D, which possess exceptional stability and diverse physical properties, including unique electronic band structures, strong optical absorption in the visible (VIS) to near-infrared (NIR) regime, and anisotropic optical characteristics. Remarkably, a temperature-induced order-disorder transition in the α-Sc3N@C80-2D phase has been observed at elevated temperatures above 600 K. These findings expand the family of 2D carbon materials and provide useful clue for the potential applications of fullerene-assembled monolayer networks.

Tin-oxo nanoclusters for extreme ultraviolet photoresists: Effects of ligands, counterions, and doping.

The extreme ultraviolet (EUV) nanolithography technology is the keystone for developing the next-generation chips. As conventional chemically amplified resists are approaching the resolution limit, metal-containing photoresists, especially tin-oxo clusters, seize the opportunity to embrace this challenge owing to their small sizes, precise atomic structures, and strong EUV absorption. However, atomistic insights into the mechanism for regulating their photolithographic behavior are lacking. Herein, we systematically explored the effects of ligands, counterions, and endohedral doping on the photophysical properties of tin-oxo cage clusters by first-principles calculations combined with molecular dynamics simulations. Photoresists assembled by allyl-protected clusters with small-size OH- or Cl- counterions have a high absorption coefficient at the EUV wavelength of 13.5 nm and a low energy cost for ligand detachment and superior stability to ensure high sensitivity and strong etch resistance, respectively. The photoresist performance can further be improved by endohedral doping of the metal-oxo nanocage with Ag+ and Cd2+ ions, which exhibit superatomic characteristics and are likely to be synthesized in laboratory. These theoretical results provide useful guidance for modification of metal-oxo clusters for high-resolution EUV photolithography.

Exposure to microcystin-LR promotes astrocyte proliferation both in vitro and in vivo via Hippo signaling pathway.

Microcystins (MCs) are toxic to the central nervous system of mammals. However, the direct toxicity of MCs on mammalian brain cells and the involved molecular mechanisms are not fully elucidated. Here, we incubated primary astrocytes, the major glial cell-type in the brain, with 0-12.5 µM concentrations of MC-LR for 48 h, and the impairment was evaluated. We found that MC-LR caused significant increases in the cell viability at the range of 0.05-1 µM concentrations with the highest density at 0.1 µM concentration. Treatment with 0.1 µM MC-LR induced YAP nuclear translocation and decreased the ratio of p-YAP to YAP. It also decreased mRNA levels of the upstream regulator (AMOT), and enhanced expressions of YAP interacted genes (Egfr, Tead1, and Ctgf) in primary astrocytes. Overexpression of AMOT significantly attenuated the increase of MC-LR-induced astrocyte proliferation and the expression of YAP downstream genes. These results indicate that Hippo signaling contributed to MC-LR-caused astrocyte proliferation. Further, reactive astrogliosis was observed in the mice brain after MC-LR exposure to environmentally relevant concentrations (20 or 100 µg/L) through drinking water for 16 weeks. Pathological observations revealed that 100 µg/L MC-LR exposure caused neuronal damages with characteristics of shrunken or vacuolation in the region of the cerebral cortex, striatum and cerebellum. These results were accompanied with increased oxidative stress and inflammatory response. Our data reveal the potential astrocytic mechanisms in MC-induced neurotoxicity and raise an alarm for neurodegenerative disease risk following daily exposure to MC-LR.

Progress in the Regulation of Immune Cells in the Tumor Microenvironment by Bioactive Compounds of Traditional Chinese Medicine.

The tumor microenvironment (TME) can aid tumor cells in evading surveillance and clearance by immune cells, creating an internal environment conducive to tumor cell growth. Consequently, there is a growing focus on researching anti-tumor immunity through the regulation of immune cells within the TME. Various bioactive compounds in traditional Chinese medicine (TCM) are known to alter the immune balance by modulating the activity of immune cells in the TME. In turn, this enhances the body's immune response, thus promoting the effective elimination of tumor cells. This study aims to consolidate recent findings on the regulatory effects of bioactive compounds from TCM on immune cells within the TME. The bioactive compounds of TCM regulate the TME by modulating macrophages, dendritic cells, natural killer cells and T lymphocytes and their immune checkpoints. TCM has a long history of having been used in clinical practice in China. Chinese medicine contains various chemical constituents, including alkaloids, polysaccharides, saponins and flavonoids. These components activate various immune cells, thereby improving systemic functions and maintaining overall health. In this review, recent progress in relation to bioactive compounds derived from TCM will be covered, including TCM alkaloids, polysaccharides, saponins and flavonoids. This study provides a basis for further in-depth research and development in the field of anti-tumor immunomodulation using bioactive compounds from TCM.

Modulation of fried spring roll wrapper quality upon treatment of batter with maltogenic amylase, transglutaminase and bromelain.

BACKGROUND: Fried foods are favored for their unique crispiness, golden color and flavor, but they also face great challenge because of their high oil content, high calories and the existence of compounds such as acrylamide and polycyclic aromatic hydrocarbons. Long-term consumption of fried foods may adversely affect health. Therefore, it is necessary to explore fried foods with lower oil contents and a high quality to meet the demand. RESULTS: A method of enzyme treatment was explored to investigate the effects of maltogenic amylase (MA), transglutaminase (TG) and bromelain (BRO) on the physicochemical properties of the batter and the quality of fried spring roll wrapper (FSRW). The results showed that the MA-, TG- or BRO-treated batters had a significant shear-thinning behavior, especially with an increase in viscosity upon increasing TG contents. FSRW enhanced its fracturability from 419.19 g (Control) to 616.50 g (MA-6 U g-1), 623.49 g (TG-0.75 U g-1) and 644.96 g (BRO-10 U g-1). Meanwhile, in comparison with BRO and MA, TG-0.5 U g-1 endowed batter with the highest density and thermal stability. MA-15 U g-1 and TG-0.5 U g-1 displayed FSRW with uniform and dense pores, and significantly reduced its oil content by 18.05% and 25.02%, respectively. Moreover, compared to MA and TG, BRO-50 U g-1 improved the flavor of FSRW. CONCLUSION: MA, TG or BRO played a key role in affecting the physicochemical properties of the batter and the quality of FSRW. TG-0.5 U g-1 remarkly reduced the oil content of FSRW with a great potential in practical application. © 2024 Society of Chemical Industry.

[Expert consensus on the genetic counseling for Dystrophinopathies].

Dystrophinopathies caused by variants of DMD gene are a group of muscular diseases including Duchenne muscular dystrophy, Becker muscular dystrophy, and DMD-associated dilated cardiomyopathy. With the advancement of genetic testing techniques and wider implementation of genetic screening, especially the expanded carrier screening, more and more individuals carrying DMD gene variants have been identified, whereas the genetic counseling capacity is relatively insufficient. Currently there is still a lack of professional norms for genetic counseling on dystrophinopathies. In this consensus, the main points to be covered in the pre- and post-test consultation have been discussed, with an aim to provide genetic counseling guidance for the disease diagnosis, treatment, and family reproduction.

Detection of Small-Molecule Interactions with Fibrillar Tau Protein Aggregates Using Microscale Thermophoresis.

Aggregated fibrillar tau protein is a pathological hallmark of several neurodegenerative diseases. Small molecules that bind to tau fibrils may be applied for their detection and quantification. This is of great importance as they can potentially be used for earlier diagnosis of disease and disease progression. Microscale thermophoresis (MST) enables the detection of biomolecular interactions in an aqueous environment in which no immobilization of either reaction partner is required. Here, an MST assay methodology is described for the detection of the interaction between a variety of small molecules and tau fibrils. The results of this study demonstrate that MST is a practical methodology to quantify interactions between small molecules and tau fibrillar aggregates.

Optical Activity and Excitonic Characteristics of Chiral CdSe Quantum Dots.

Introduction of chirality to colloidal semiconductor quantum dots (QDs) triggers a chiroptical effect. However, there remains a knowledge gap in the mechanism of chirality transfer and amplification from molecules to QDs. By time-dependent density functional theory calculations combined with a correlated electron-hole picture, we explored the chiroptical activity of CdSe QDs decorated with different chiral monocarboxylic acids from an excitonic perspective. Our calculations showed strong circular dichroism (CD) signals in the visible region for the chiral CdSe QDs. The excitonic states with large CD originate from QDs, while the chiral molecules break the orthogonality between electric and magnetic transition dipoles, which synergistically facilitates the prominent dissymmetric effect. The considered monocarboxylic acid chiral molecules all favor the bidentate adsorption configuration of the carboxyl group on the CdSe surface, endowing an identical CD signature but distinct excitonic characteristics. These findings are crucial for the regulation of chirality and excitons in semiconductor QDs to develop excitonic devices.

ITGB4 is a prognostic biomarker and correlated with lung adenocarcinoma brain metastasis.

BACKGROUND: The aim of this study is to explore the prognostic value and immune signature of ITGB4 expression in lung adenocarcinoma (LUAD) brain metastasis. METHODS: We comprehensively screened genes associated with LUAD brain metastasis by integrating datasets from the GEO database and TMT-based quantitative proteomics profiles. Univariable survival and Multivariate Cox analysis was used to compare several clinical characteristics with survival, and a risk model was constructed. The biological functions were explored via GO and KEGG analysis. Gene set enrichment analysis (GSEA) was performed using the TCGA dataset. In addition, we use TIMER to explore the collection of ITGB4 Expression and Immune Infiltration Level in LUAD. The ability of ITGB4 to regulate tumor metastasis was further assessed by migration, invasion assay and Western-blot in H1975-BrM4 cells. RESULTS: We found that ITGB4 was the only gene with high clinical diagnostic and prognostic value in LUAD. Enrichment analysis indicated that ITGB4 is associated with brain metastasis, infiltration of immune cells, and the response to immunotherapy. ITGB4 expression can effectively predict the outcomes of patients with LUAD who are receiving anti-PD-1 therapy. ITGB4 knockdown inhibited the invasion, migration of H1975-BrM4 brain metastasis cells, as well as epithelial-mesenchymal transition (EMT) abilities. The heightened expression of ITGB4 protein was shown to promote EMT and enhance the metastatic potential. ITGB4 promotes the progression in H1975-BrM4 cells via MEK/ERK signaling pathway. CONCLUSIONS: Our findings indicate that the expression of ITGB4 is linked to the occurrence of brain metastasis and infiltration of immune cells, suggesting that ITGB4 might be a clinical treatment target for LUAD.

Sleep quality and mental health among Chinese nurses after the COVID-19 pandemic: A moderated model.

INTRODUCTION AND AIMS: In the specialized nursing setting, nurses are susceptible to developing negative mental health issues. Such conditions among nurses can potentially result in unfavorable medical outcomes. Consequently, this study aims to explore the role of social support in regulating between sleep and mental health in nurses. METHODS: A cross-sectional study was carried out in September 2022 on 1219 nurses in Quanzhou. The study comprised general demographic information and utilized various questionnaires, namely the Social Support Rate Scale (SSRS), Pittsburgh Sleep Quality Index Questionnaire (PSQI), Generalized Anxiety Disorder Questionnaire (GAD-7), and Patient Health Questionnaire-9 (PHQ-9). The data analysis was performed using t-tests, ANOVAs, Pearsons correlations and hierarchical regression analyses in SPSS software. RESULTS: Results show that significant associations of sleep quality and social support with anxiety and depression. Simple slope analysis shows that under low levels of social support, sleep quality has a positive impact on anxiety(ß = 0.598) and depression(ß = 0.851), and the impact is significant. Under high levels of social support, sleep quality also has a positive impact on anxiety(ß = 0.462) and depression(ß = 0.578), but the impact is smaller. This indicates that as the level of social support increases, the positive predictive effect of sleep quality on anxiety and depression gradually diminishes. CONCLUSIONS: Social support has the potential to alter the impact of sleep quality on anxiety and depression. Therefore, healthcare policymakers need to focus on enhancing the level of social support and mitigating the impact of poor sleep on anxiety and depression.

Physical education consumption and executive function among older empty nesters in urban community: A double mediation effects.

OBJECTIVE: The main aim of this research was to determine the relationships among executive function, fitness mobile applications (APPs), physical exercise activity and physical education consumption in community-dwelling older empty nesters. METHODS: A cross-sectional design was applied to evaluate the relationships. A sample of 1104 community-dwelling older empty nesters completed the experiments. Physical education consumption scale, fitness APPs by smartphone application scale, physical exercise activity scale, and executive function scale were applied for the evaluation of the elderly alone in urban communities in southeast China. To explore mediating effects, structural equation modeling of AMOS 23.0, SPSS 25.0 and Process V3.5 software packages were applied for statistical processing. RESULT: Physical education consumption positively predicted executive function. Meanwhile, it was also found that physical education consumption and executive function were continuously mediated by fitness APP application and physical exercise activity, with indirect effect value of 0.267, accounting for 76 %. CONCLUSION: This research revealed how physical education consumption affected executive function of older empty nesters. The obtained results had certain implications for older empty nesters to better balance their executive function and life quality. Community managers should provide older empty nesters with favorable physical education environments in terms of positive physical and psychological environments, to improve their use ratio of fitness APPs usage and physical exercise activity, ultimately enhancing their executive function and life satisfaction.

Integrative Transcriptomics and Proteomics Analysis of a Cotton Mutant yl1 with a Chlorophyll-Reduced Leaf.

Leaf color mutants serve as ideal materials for studying photosynthesis, chlorophyll metabolism, and other physiological processes. Here, we identified a spontaneous yellow-leaf mutant (yl1) with chlorophyll-reduced leaves from G. hirsutum L. cv ZM24. Compare to wild type ZM24 with green leaves, yl1 exhibited patchy yellow leaves and reduced chlorophyll content. To further explore the mechanisms of the patchy yellow phenotype of the mutant plant, the transcriptomics and proteomics profiles were conducted for the mutant and wild types. A total of 9247 differentially expressed genes (DEGs) and 1368 differentially accumulated proteins (DAPs) were identified. Following gene ontology (GO) annotation and KEGG enrichment, the DEGs/DAPs were found to be significantly involved in multiple important pathways, including the obsolete oxidation-reduction process, photosynthesis, light-harvesting, the microtubule-based process, cell redox homeostasis, and the carbohydrate metabolic process. In photosynthesis and the light-harvesting pathway, a total of 39 DAPs/DEGs were identified, including 9 genes in the PSI, 7 genes in the PS II, 9 genes in the light-harvesting chlorophyll protein complex (LHC), 10 genes in the PsbP family, and 4 genes in the cytochrome b6/f complex. To validate the reliability of the omics data, GhPPD1, a DAPs in the PsbP family, was knocked down in cotton using the TRV-based VIGS system, and it was observed that the GhPPD1-silenced plants exhibited patchy yellow color, accompanied by a significant decrease in chlorophyll content. In conclusion, this study integrated transcriptomic and proteomic approaches to gain a deeper understanding of the mechanisms underlying the chlorophyll-reduced leaf phenotype.

Low-frequency alternating magnetic field and CaCl2 influence the physicochemical, conformational and gel characteristics of low-salt myofibrillar protein.

In this study, the improvement mechanism of low-frequency alternating magnetic field (LF-AMF, 5 mT, 3 h) combined with calcium chloride (CaCl2, 0-100 mM) on the gel characteristics of low-salt myofibrillar protein (MP) was investigated. LF-AMF combined with 80 mM CaCl2 treatment increased solubility (32.71%), surface hydrophobicity (40.86 µg), active sulfhydryl content (22.57%), water-holding capacity (7.15%). Besides, the combined treatment decreased turbidity, particle size and intrinsic fluorescence strength of MP. Fourier transform infrared spectroscopy (FT-IR) results indicated that the combined treatment altered the secondary structure of MP by increasing ß-sheet and ß-turn, and reducing α-helix and random coil. The combined treatment also induced a high G' value and shortened T2 relaxation time for forming a homogeneous and compact gel structure. These results revealed that LF-AMF combined CaCl2 treatment could as a potential approach for modifying the gel characteristics of low-salt MP.

Effect of low-frequency alternating magnetic fields on the physicochemical, conformational and rheological properties of myofibrillar protein after iterative freeze-thaw cycles.

In this work, the effects of low-frequency alternating magnetic fields (LF-AMF) on the physicochemical, conformational, and functional characteristics of myofibrillar protein (MP) after iterative freeze-thaw (FT) cycles were explored. With the increasing LF-AMF treatment time, the solubility, active sulfhydryl groups, surface hydrophobicity, emulsifiability, and emulsion stability of MP after five FT cycles evidently elevated and then declined, and the peak value was obtained at 3 h. Conversely, the moderate LF-AMF treatment time can significantly reduce the average particle size, carbonyl content, and endogenous fluorescence intensity of MP. The rheology results showed that various LF-AMF treatment times would elevate the G' value of MP after iterative FT cycles. The FTIR spectroscopy results suggested that LF-AMF influenced the secondary structure of MP after multiple FT cycles, resulting in a depression in α-helix content and an increment in ß-folding proportion. Moreover, LF-AMF treatment induced the gradually lighter and wider myosin heavy chain bands of MP, implying that LF-AMF accelerated the degradation of macromolecular aggregates. Therefore, the LF-AMF treatment efficaciously ameliorates the structural and functional deterioration of MP after iterative FT cycles and could be used as a potential quality-improving technology in the frozen meat industry.