Search Results (927)

Excessive sodium intake is a public health concern, although sodium chloride is technologically essential in comminuted meat systems due to its role in protein solubilization, water binding, and gel formation. This study evaluated the extent to which progressive sodium reduction combined with nutritional yeast supplementation preserves physicochemical stability, structural integrity, and sensory quality in cooked sausages. Four formulations were produced: a referent and three reduced-salt (NaCl) treatments (−15%, −25%, −35%) containing 2% nutritional yeast (1% in the referent). Water activity increased significantly with salt reduction (0.969–0.977; p < 0.05), accompanied by higher lightness (CIE L*) and yellowness (CIE b*), whereas instrumental redness (CIE a*) remained stable. Proximate composition was unaffected except for the expected decrease in ash and salt content (p < 0.05), while free glutamic acid increased significantly in reduced-salt treatments (0.67 vs. 0.87–0.91 g/kg; p < 0.05). Instrumental texture parameters indicated preserved cutting resistance, although repeated compression revealed reduced structural resilience at the 35% reduction level. Sensory evaluation showed that reductions up to 25% maintained overall typicality and balance, whereas 35% reduction decreased saltiness, slice coherence, aroma harmony, and texture typicality (p < 0.05). Principal component analysis confirmed a multivariate shift from a salt-stabilized structural domain to a softer, yeast-associated sensory domain at the highest reduction level. Moderate sodium reduction combined with nutritional yeast is therefore technologically and sensorially feasible in this product category. Full article

Drought and salt stresses severely impair plant growth and development worldwide. DEHYDRATION-RESPONSIVE ELEMENT BINDING proteins (DREBs), as a subfamily of the AP2/ERF transcription factor superfamily, play critical regulatory roles in plant biological processes including growth and development, as well as the adaptive response to various abiotic stresses. Based on the transcriptome data analysis of Medicago truncatula under saline-alkali stress previously conducted in our laboratory, a gene responsive to saline-alkali stress, Medtr3g110205, was identified, and its homologous gene in Arabidopsis thaliana, AtERF41 (AT5G11590), was obtained via BLAST (version BLAST+ 2.17.0.). The mutant erf41 was used to explore its biological functions in response to drought and salt stresses. The results showed that under salt and drought stress conditions, the seed germination rate, and growth status of the erf41 mutant were all better than those of the wild type. Further determination of physiological and biochemical indicators revealed that the leaf contents of superoxide dismutase (SOD) and proline (Pro) in the leaves of the mutant plants were significantly higher than those in the wild type, while the malondialdehyde (MDA) content was significantly decreased. In conclusion, the AtERF41 gene negatively regulates salt and drought tolerance in Arabidopsis thaliana, providing a potential target for the genetic improvement of crop stress tolerance. This study not only deepens our understanding of the role of DREB transcription factors in plant stress response but also provides a theoretical basis for improving crop stress tolerance using genetic engineering technology in the future. Full article

The SARS-CoV-2 Omicron variant and its descendants accumulated unprecedented numbers of spike substitutions yet remained transmissible, implying compensatory mechanisms that preserve entry while eroding humoral immunity. We analyzed 32 variants for sequence-level mutation, physicochemical profiling, and epitope disruption; 25 had growth-advantage estimates, and 18 underwent molecular dynamics/MM-PBSA simulations. We applied a systems-virology framework to the SARS-CoV-2 receptor-binding domain (RBD), integrating immunodominance-weighted epitope conservation (567 B-cell and 97 T-cell epitopes) across variants (Wuhan-Hu-1 to KP.3) with molecular dynamics, molecular mechanics Poisson–Boltzmann surface area (MM-PBSA) binding energetics, and deep mutational scanning (DMS) benchmarking. B-cell epitope conservation declined from a median of 72.7% in pre-Omicron variants to 28.8% in BA.1 and 10.6% in KP.3, and was strongly inversely associated with a breakthrough-infection proxy (Spearman ρ = −0.8246, p < 0.001), whereas RBD T-cell epitopes remained comparatively conserved (91.5% to 87.2%). Despite the loss of the ancestral K417–ACE2 D30 salt bridge, Omicron reconfigured the interface via alternative electrostatic contacts (Q493R–E35 and Q498R–D38), producing compensatory interactions captured by MM-PBSA, but with only modest agreement with DMS affinity changes (r = 0.682, p = 0.007), consistent with enthalpy–entropy compensation. Finally, mutation tolerance shifted toward stronger epistatic buffering in Omicron (two-fold higher epistasis than pre-Omicron; p = 0.0093), enabling extensive antigenic change without structural collapse. Together, these results support a multi-objective evolutionary strategy—epitope erosion, interface rewiring, and epistatic compensation—that can be operationalized to prioritize emerging lineages for surveillance and to inform vaccine designs that emphasize conserved T-cell targets. Full article

Background/Objectives: Ziziphus jujuba var. spinosa (sour jujube) is a traditional medicinal plant with remarkable tolerance to abiotic stresses, particularly salinity. However, the regulatory mechanisms underlying its salt stress tolerance remain unclear. NHX genes play a crucial role in plant adaptation to salt stress by mediating Na⁺/K⁺ transport to maintain intracellular ion homeostasis and pH balance. Although the NHX gene family has been characterized in many plant species, its functional characteristics in sour jujube have not yet been systematically investigated. Methods: In this study, using Arabidopsis thaliana as a reference, we identified NHX genes in sour jujube through genome-wide analysis and molecular approaches, and systematically analyzed their phylogenetic relationships, chromosomal locations, conserved motifs, gene structures, cis-regulatory elements in promoter regions, and expression patterns under abiotic stresses, particularly salt stress. Results: The results revealed the presence of eight NHX genes distributed across six chromosomes in sour jujube, which were classified into three subfamilies: Vac-class, Endo-class, and PM-class. Members within the same evolutionary clade exhibited high structural conservation in motif composition and gene architecture. Except for the PM-class, all other clades contained amiloride-binding sites (FF(I/L)(Y/F)LFLLPPI). Analysis of cis-regulatory elements indicated that the promoter regions of these genes were enriched with elements related to defense responses, stress adaptation, and phytohormone signaling, further supporting their role in plant environmental adaptation. Additionally, the qRT-PCR analysis showed that most of the ZjNHX genes in both roots and leaves are up-regulated by salt. Notably, ZjNHX1 expression in roots increased approximately 40-fold within 3 h, whereas ZjNHX2 and ZjNHX3 were strongly induced in leaves under prolonged salt exposure. Conclusions: Taken together, this work gives a detailed overview of the ZjNHX genes and their important roles in response to salt stress in sour jujube. Our findings also provide a foundation for further functional characterization of this gene family. Full article

Background/Objectives: Adeno-associated viruses (AAVs) are widely used gene therapy vectors; yet their physicochemical stability and chromatographic behavior are highly sensitive to the solution conditions they are in. Effective separation of full (F), empty (E), and partially filled (P) capsids—most commonly achieved by anion exchange (AEX) chromatography—is essential for standard analytical characterization, process development, and product safety. However, conventional AEX methods rely on low-conductivity alkaline mobile phases with low salt, which promote capsid binding and therefore higher resolution, at the expense of structural stability. Conversely, formulations such as near-neutral buffers might preserve capsid integrity but often impair AEX retention and separation resolution. Methods: Here, we extend a mechanistic investigation using AAV8 capsids as a model system, focusing on detailed capsid interactions with strong AEX, and present novel AAV8 separation strategies on a weak AEX stationary phase. Results: By systematically varying buffer pH and ionic strength, we identify operational regimes that balance capsid stability with chromatographic separation efficiency. In parallel, we introduce an integrated two-dimensional (2D) in-line buffer exchange configuration that decouples AEX performance from sample formulation, enabling robust separation of stability-optimized, high-salt matrices without off-line desalting. Conclusions: By elucidating the roles of capsid charge modulation, ligand physicochemical properties, and local microenvironmental buffering, this study establishes practical design principles for stability-preserving chromatography. It lays a foundation for more reliable analytical and future preparative AAV workflows. Full article

The MERS-CoV (Middle East respiratory syndrome coronavirus) is a zoonotic virus with a high mortality rate and a lack of antiviral drugs, underscoring the need for effective therapeutic methods. Viral entry depends on interactions between viral surface proteins and human receptors, with Dipeptidyl Peptidase-4 (DPP4), a transmembrane glycoprotein, acting as the receptor for MERS-CoV. We employed Molecular Dynamics (MD) Simulations to identify critical interface residues under a high-performance computing (HPC) workflow for accelerated results. Target residue pairs were identified through analysis of salt bridge and hydrogen bond occupancy. The stability of these residues was confirmed through three independent MD Simulations at human body temperature and constant pressure. Additionally, binding affinity predictions were calculated to determine the interaction strength between the virus and human receptors. Applying the scientific threshold criteria, we narrowed our results to seven key interaction pairs; two of the identified pairs (Asp510-Arg317, and Arg511-Asp393) are consistent with findings published in previous research studies, and five novel interactions are proposed for future experimental studies with our active collaborators in Pharmacology. The results provide a molecular basis for targeted mutation-based experiments and support the rational design of structure-based inhibitors aimed at disrupting the MERS-CoV-DPP4 complex, thereby facilitating the translation of computational findings into antiviral drug discovery. Full article

Soil salinization severely restricts the sustainable development of the pear industry. Pyrus betulifolia, a vital native salt-tolerant rootstock in China, holds great significance for investigating stress resistance mechanisms. Plant-specific DNA-binding One Zinc Finger (Dof) transcription factors act as pivotal regulators in stress adaptation. However, their functions in P. betulifolia remain largely unexplored. In this study, we identified 43 PbeDof members within the P. betulifolia genome and classified them into eight subfamilies via phylogenetic analysis. Gene structure and conserved motif analyses revealed that PbeDof members within the same subfamily share similar exon-intron organizations and protein architecture, suggesting evolutionary conservation. Promoter analysis indicated that PbeDof genes are rich in cis-acting elements related to light, phytohormones (especially ABA and MeJA), and stress responses, implying their potential roles in diverse biological processes. Chromosomal localization and collinearity analyses revealed that segmental duplication was the primary driver of this family’s expansion. Combined transcriptomic profiling and qRT-PCR assays demonstrated that PbeDof9.1 is predominantly expressed in roots and is strongly induced by salt stress. Subcellular localization confirmed that PbeDof9.1 targets the nucleus. Functional characterization indicated that heterologous overexpression of PbeDof9.1 in Arabidopsis thaliana significantly enhances salt tolerance at germination and seedling stages. Notably, under 175 mM NaCl stress, the transgenic lines exhibited a superior root system architecture, with primary root length and lateral root numbers being approximately 1.5-fold higher than those of the wild type. Furthermore, homologous overexpression in pear calli confirmed that PbeDof9.1 mitigates oxidative damage by boosting the activities of peroxidase (POD) and catalase (CAT) to scavenge reactive oxygen species (ROS), thereby reducing malondialdehyde (MDA) accumulation. Collectively, this study characterizes the PbeDof family and establishes PbeDof9.1 as a key candidate gene for the genetic improvement of salt tolerance in pear rootstocks. Full article

Hydrogel fluorescent microspheres function as versatile tracers with applications spanning across biomedicine, complex plasma systems, hydrodynamics, and drug delivery. However, the controlled release of fluorescent material in hydrogel microspheres is challenging to achieve. The fluorescent hydrogel microsphere (namely poly(ethylene glycol) diacrylate@rhodamine B-tannic acid, PEGDA@RhB-TA) was fabricated by incorporating tannic acid and RhB into PEGDA microspheres. The stable encapsulation and responsive release of RhB can be achieved by leveraging the non-covalent interactions between TA and RhB. RhB was stably encapsulated within PEGDA microspheres through noncovalent interactions (hydrophobic interactions, hydrogen bonding, π–π, and ion–π interactions) between RhB and TA. Both molecular dynamics simulations by GROMACS and experimental results confirmed the noncovalent binding mechanisms between RhB and TA. The microspheres retained RhB following 24 h immersion in a highly concentrated salt solution (1 M NaCl) and exhibited minimal RhB release (7.1%) under heating at 80 °C for 24 h. However, PEGDA@RhB-TA microspheres underwent rapid RhB release in a 50% v/v ethanol–water solution, liberating 73% of the encapsulated dye within 24 h. TA within the PEGDA@RhB-TA microsphere acts as a molecular lock by forming non-covalent interactions with RhB, significantly enhancing the stability of encapsulated RhB, and enabling the responsive release of RhB under specific conditions. Upon introduction into a microfluidic chip, PEGDA@RhB-TA microspheres enable the calculation of flow velocity through position tracking using high-speed camera imaging and fluorescence microscopy. These microspheres overcome the dual challenges of tracer stability and controlled release, making them suitable for fluid tracing and measuring flow rates. Full article

Crust Ash Triad Clay (CATC) is a traditional construction material commonly used for jointing coastal stone masonry in Southeast China. Its surface is prone to blackening in coastal environments. This study focused on traditional stone masonry residences within the protection area of Quanzhou Shihu Ancient Wharf. A systematic detection and analysis were conducted using combined technologies: XRD, Raman, SEM-EDS, and 16S rRNA sequencing. The results revealed that the CATC substrate is mainly composed of quartz and feldspar minerals, with calcite and other substances as binding components. The black coating on the surface is a loose material attached to the substrate, retaining some of the original minerals. The core mechanism of blackening lies in the coastal environment’s abundance of salt spray and humidity. The sulfate substances carried by rainwater react synergistically with metal ions such as Cu, Fe, and Mn in the substrate under the metabolic action of anaerobic bacteria, producing metal sulfide minerals. Photoautotrophic bacteria generate oxygen through photosynthesis, promoting the oxidation and acidification of metal sulfide. This process directly triggers the chain deterioration of the CATC substrate. Based on the principle of “minimal intervention”, physical waterproofing or laser stain removal can be implemented. This study provides scientific support for optimizing the durability and achieving precise protection of traditional building materials in coastal stone structure heritage. Full article

Umami taste in lager beer not only determined body fullness and the backbone of aftertaste, but also affected the controllability and interpretability of flavor expression across the entire brewing process. Based on stage-wise sampling, peptidomic profiles were established on wort fermentation day 0, day 1, day 3, and day 9. A total of 25,592 peptides were identified by reversed-phase liquid chromatography–quadrupole time-of-flight mass spectrometry (RPLC-QTOF-MS). Molecular informatics screening was performed using UMPred-FRL (a feature representation learning-based meta-predictor for umami peptides) and TastePeptides-Meta (a one-stop platform for taste peptides and prediction models), yielding 7255 potential umami peptides. From these, 145 peptides were further selected for molecular docking. In addition, 6 representative umami peptides were selected for receptor-level validation and structural analysis. Mechanistically, the umami receptor taste receptor type 1 member 1/taste receptor type 1 member 3 (T1R1/T1R3) belonged to class C G protein-coupled receptor (GPCR) and relied on the extracellular Venus flytrap (VFT) domain for ligand capture. Ligand-induced VFT conformational convergence transmitted changes to the transmembrane region and triggered signal transduction. Docking and energy decomposition indicated that the ionic group primarily contributed to orientation and anchoring. Salt-bridge or hydrogen-bond networks were formed around Lys228, Arg240, Glu206, Asp210, Asn141, and Gln138, thereby reducing conformational freedom. Meanwhile, hydrophobic side chains obtained major binding gains within a hydrophobic microenvironment formed by Val135, Ile137, Leu165, Tyr166, Trp78, and His79. These results reflected a synergistic mode in which charge pairing enabled positioning and hydro-phobic complementarity promoted VFT closure. To experimentally confirm sensory relevance, 6 representative peptides were individually spiked into 4 brewing-stage beer samples, which produced a clear stratification pattern across stages. Notably, peptides with favorable docking-derived binding propensity did not necessarily enhance umami perception, and several longer peptides showed persistent negative sensory shifts, supporting that binding affinity alone could not be treated as a proxy for perceived umami in the beer matrix. At the node level, the cumulative abundance of umami peptides showed a significant positive correlation with umami scores, with a Pearson correlation coefficient of r = 0.963 and p = 0.037. This result indicated good linear consistency between umami peptide content and the upward shift in umami taste in lager beer. Umami peptide clusters were further proposed as a more appropriate functional unit, and an umami peptide cluster database spanning the full process was constructed. This database provided a reusable resource for process control and flavor prediction. Full article

Calmodulin-binding transcription activators (CAMTAs) are pivotal regulators decoding calcium signals, with crucial roles in plant development, hormone responses, and adaptation to abiotic stresses. Although extensive research has been conducted on CAMTAs in model plants such as Arabidopsis thaliana, a comprehensive genome-wide analysis of the CAMTA gene family across the economically important Brassica U-triangle species has not been performed. In this study, we systematically identified and characterized 64 CAMTA genes from the genomes of Brassica U-triangle species. Phylogenetic analysis classified these genes into four conserved groups, a finding corroborated by analyses of gene structure and conserved motifs. These analyses revealed strong evolutionary preservation of functional domains, especially the calmodulin-binding domain (CaMBD). Chromosomal distribution and collinearity assessment highlighted the significant impact of polyploidization on the expansion of the CAMTA family, with most orthologous pairs being under purifying selection. Cis-element analysis in promoters uncovered an abundance of stress- and hormone-related elements, suggesting diverse regulatory roles for these genes. Furthermore, RNA-Seq and RT-qPCR expression profiling demonstrated that BnaCAMTA genes exhibit tissue-specific expression and are dynamically responsive to various phytohormones (ABA, JA, and GA) and abiotic stresses (salt and drought), particularly in the root. Notably, BnaCAMTA5.2, which was prioritized among several validated candidates, mediates the antagonistic regulation of hypocotyl and root growth under GA and salt stress, indicating its key role in balancing growth promotion and stress adaptation. Additionally, we identified a set of stress-related miRNAs that potentially target BnaCAMTAs, suggesting a potential layer of post-transcriptional regulation. Our results provide valuable insights into the evolutionary and functional diversity of CAMTA genes in Brassica U-triangle species and lay a foundation for further research into their roles in enhancing stress resistance in B. napus. Full article

This study investigates the molecular and mechanical effects of sodium accumulation in myocardial tissue using a combination of physiological measurements and Raman spectroscopy. Male Wistar rats were maintained on normal- and high-salt diets to induce differential sodium loading in cardiac tissue. Hemodynamic and mechanical analyses revealed increased myocardial stiffness and altered contractile parameters in the high-salt group. Raman microspectroscopy of myocardial sections demonstrated distinct spectral changes, particularly in regions corresponding to glycosaminoglycan (GAG), collagen, and its component, proline. Enhanced Raman signals near 1640 cm⁻¹ in the Amide I range, 1246 cm⁻¹ in the Amide III range, and in the 1030–1070 cm⁻¹ range indicated structural modifications of the GAG–collagen complex and an increased contribution of proline-rich collagen, consistent with elevated tissue rigidity. These findings support the concept that sodium deposition in the myocardium alters its molecular architecture and mechanical properties through GAG-mediated binding and collagen remodeling. This study provides new insights into the biophysical mechanisms linking sodium homeostasis to myocardial stiffness and diastolic dysfunction. Full article

Nuclear Factor Y (NF-Y) transcription factors are evolutionarily conserved regulators that bind the CCAAT box, playing central roles in horticultural plant growth and adaptation. This review summarizes recent progress on NF-Ys in horticultural plants, focusing on their molecular mechanisms in development and stress responses. For development, NF-Ys mediate phase transition, flowering regulation, embryogenesis, and organ development by integrating endogenous signals (gibberellic acid, GA; abscisic acid, ABA) and regulating downstream genes. For stress responses, they enhance tolerance to abiotic stresses (drought, salt, extreme temperatures) via regulating reactive oxygen species (ROS) scavenging, ABA biosynthesis, and stress networks, and mediate biotic stress resistance (e.g., pathogen infection) by activating defense pathways. This review also briefly covers species-specific genomic features (e.g., duplication-driven expansion) and structural traits (conserved core domains, variable termini) underpinning NF-Y specialization. Finally, it highlights key knowledge gaps (e.g., incomplete regulatory networks, limited translational application) and proposes future directions: deciphering NF-Y crosstalk, exploring combined stress responses, accelerating functional validation of uncharacterized NF-Y genes, and translating research into horticultural breeding. This work provides a holistic reference for understanding NF-Y function and improving horticultural plant yield, quality, and stress resilience. Full article

This study investigated the generation of α-glucosidase inhibitory peptides from whey protein fermented by the marine-derived probiotic Lacticaseibacillus casei DS31 (isolated from the intestinal microbiota of the large yellow croaker, Larimichthys crocea) and assessed their potential for practical glycemic management. Fermentation markedly increased inhibitory activity, with the freeze-dried crude supernatant exhibiting an IC50 of 2.115 mg/mL. Activity was further enriched through stepwise purification: ultrafiltration (<3 kDa) improved potency (IC50 = 1.206 mg/mL), and subsequent Sephadex (crosslinked dextran) G-15 gel filtration yielded a more active E fraction (IC50 = 1.145 mg/mL). LC–MS/MS characterized 19 peptides, and integrated in silico screening (PeptideRanker combined with molecular docking) highlighted GEPGPEGPAG as a leading candidate, showing a more favorable predicted binding energy (−82.50 kcal/mol) than the positive control acarbose (−69.31 kcal/mol). Docking analysis suggests that GEPGPEGPAG may inhibit α-glucosidase by forming a stable network of hydrogen bonds, salt bridges, and hydrophobic interactions within the catalytic pocket. Overall, DS31-fermented whey and its enriched fractions show promise as functional ingredients for postprandial glycemic control. Full article

The increasing crisis of antimicrobial resistance requires innovative therapeutic strategies that can overcome the limitations of conventional antibiotics. Based on our previous finding that AP10 (a derivative of AP29) possesses antimicrobial activity but lacks thermal stability, we rationally redesigned ten new AP10 analogues to enhance functional robustness while maintaining efficacy. Among these, AP10RW is identified as the optimal candidate due to its exceptional broad-spectrum activity against both drug-sensitive and multidrug-resistant (MDR) bacterial pathogens. Structural analysis reveals that AP10RW adopts an environmentally responsive conformation, transitioning from random coil to amphiphilic α-helix in membrane-mimicking environments, while demonstrating remarkable stability under challenges including serum exposure, varying pH, high salt concentrations, and thermal stress. Mechanistic studies indicate that AP10RW exerts its effects through multiple bactericidal mechanisms involving initial high-affinity binding to bacterial characteristic molecules (LTA, LPS and PGN), followed by rapid membrane depolarization, ultrastructural damage and the induction of lethal oxidative stress. Notably, this potent antimicrobial efficacy is coupled with exceptional biosafety, demonstrating little hemolysis and negligible cytotoxicity against mammalian cells. This systematic optimization represents a significant advancement in antimicrobial peptide engineering. We have successfully transformed a thermally unstable peptide into a robust therapeutic candidate and positioned AP10RW as a promising clinical candidate for addressing the growing threat of multidrug-resistant infections. Full article