Search Results (593)

This study proposes a multi-objective optimization scheduling method for edible oil transportation in smart manufacturing, focusing on centralized control and addressing challenges such as complex pipelines and shared resource constraints. The method employs the A* and Dijkstra pathfinding algorithm to determine the shortest pipeline route for each task, and estimates pipeline resource usage to derive a node cost weight function. Additionally, the transport time is calculated using the Hagen–Poiseuille law by considering the viscosity coefficients of different oil types. To minimize both cost and time, task execution sequences are optimized based on a Pareto front approach. A 3D digital model of the pipeline system was developed using C#, SolidWorks Professional, and the Helix Toolkit V2.24.0 to simulate a realistic production environment. This model is integrated with a 3D visual human–machine interface(HMI) that displays the status of each task before execution and provides real-time scheduling adjustment and decision-making support. Experimental results show that the proposed method improves scheduling efficiency by over 43% across various scenarios, significantly enhancing overall pipeline transport performance. The proposed method is applicable to pipeline scheduling and transportation management in digital factories, contributing to improved operational efficiency and system integration. Full article

γ-tocopherol is an important antioxidant compound associated with anticancer activity in several plants. This study aimed to analyze the γ-TMT (γ-tocopherol methyltransferase) gene sequence and predict its protein structure in mutant rodent tuber (Typhonium flagelliforme Lodd.) plants. Degenerate primers were designed from homologous sequences in monocot species and used to amplify the γ-TMT gene. Amplification of the γ-TMT gene was observedin the mutant and the wild-type plants. The amplified region partially covers the γ-TMT gene, which has undergone mutations due to a combination of somaclonal variation and gamma irradiation. Sequence analysis revealed notable variations between mutant and wild-type lines, including base substitutions and deletions. Predicted protein structures based on the coding DNA sequence (CDS) revealed notable differences in helix and loop orientation, particularly in the C-terminal domain and central regions of the protein. These structural differences suggest potential links to increased tocopherol biosynthesis or biological activity; however, further experimental validation is required to confirm these functional implications. This study provides foundational insights into the link between the expression of the γ-TMT gene and tocopherol biosynthesis and supports the development of specific molecular markers in T. flagelliforme. Full article

Seed germination is a critical phase in the plant lifecycle of Camellia oleifera (oil tea), directly influencing seedling establishment and crop reproduction. In this study, we examined transcriptomic and physiological changes across five defined germination stages (G0–G4), from radicle dormancy to cotyledon emergence. Using RNA sequencing (RNA-seq), we assembled 169,652 unigenes and identified differentially expressed genes (DEGs) at each stage compared to G0, increasing from 1708 in G1 to 10,250 in G4. Functional enrichment analysis revealed upregulation of genes associated with cell wall organization, glucan metabolism, and Photosystem II assembly. Key genes involved in cell wall remodeling, including cellulose synthase (CESA), phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), caffeoyl-CoA O-methyltransferase (COMT), and peroxidase (POD) showed progressive activation during germination. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed dynamic regulation of phenylpropanoid and flavonoid biosynthesis, photosynthesis, carbohydrate metabolism, and hormone signaling pathways. Transcription factors such as indole-3-acetic acid (IAA), ABA-responsive element binding factor (ABF), and basic helix–loop–helix (bHLH) were upregulated, suggesting hormone-mediated regulation of dormancy release and seedling development. Physiologically, cytokinin (CTK) and IAA levels peaked in G4, antioxidant enzyme activities were highest in G2, and starch content increased toward later stages. These findings provide new insights into the molecular mechanisms underlying seed germination in C. oleifera and identify candidate genes relevant to rootstock breeding and nursery propagation. Full article

Cold environments challenge the structural and functional integrity of membrane proteins, requiring specialized adaptations to maintain activity under low thermal energy. Here, we investigate the molecular basis of cold tolerance in the peptide transporter PepT1 from the Antarctic icefish (Chionodraco hamatus, ChPepT1) using molecular dynamics simulations, binding free energy calculations (MM/GBSA), and dynamic network analysis. We compare ChPepT1 to its human ortholog (hPepT1), a non-cold-adapted variant, to reveal key features enabling psychrophilic function. Our simulations show that ChPepT1 displays enhanced global flexibility, particularly in domains adjacent to the substrate-binding site and the C-terminal domain (CTD). While hPepT1 loses substrate binding affinity as temperature increases, ChPepT1 maintains stable peptide interactions across a broad thermal range. This thermodynamic buffering results from temperature-sensitive rearrangement of hydrogen bond networks and more dynamic lipid interactions. Importantly, we identify a temperature-responsive segment (TRS, residues 660–670) within the proximal CTD that undergoes an α-helix to coil transition, modulating long-range coupling with transmembrane helices. Dynamic cross-correlation analyses further suggest that ChPepT1, unlike hPepT1, reorganizes its interdomain communication in response to temperature shifts. Our findings suggest that cold tolerance in ChPepT1 arises from a combination of structural flexibility, resilient substrate binding, and temperature-sensitive interdomain dynamics. These results provide new mechanistic insight into thermal adaptation in membrane transporters and offer a framework for engineering proteins with enhanced functionality in extreme environments. Full article

This study proposes an iterative method based on thermal equilibrium equations to calculate the radial temperature distribution of long-span overhead transmission lines under forced convection. This paper takes the ACSR 500/280 conductor as the research object, establishes the three-dimensional finite element model considering the helix angle of the conductor, and carries out the experimental validation for the LGJ 300/40 conductor under the same conditions. The model captures internal temperature distribution through contour analysis and examines the effects of current, wind speed, and ambient temperature. Unlike traditional models assuming uniform conductor temperature, this method reveals internal thermal gradients and introduces a novel three-stage radial attenuation characterization. The iterative method converges and accurately reflects temperature variations. The results show a non-uniform radial distribution, with a maximum temperature difference of 8 °C and steeper gradients in aluminum than in steel. Increasing current raises temperature nonlinearly, enlarging the radial difference. Higher wind speeds reduce both temperature and radial difference, while rising ambient temperatures increase conductor temperature with a stable radial profile. This work provides valuable insights for the safe operation and optimal design of long-span transmission lines and supports future research on dynamic and environmental coupling effects. Full article

This article deals with drilling, the most common and simultaneously most important traditional machining operation, and which is significantly influenced by the properties of the machined material itself. To fully understand this process, both from a theoretical and practical perspective, it is essential to examine the influence of technological and tool-related factors on its various parameters. Based on the evaluation of experimentally obtained data using advanced statistical methods and machine learning decision trees, we present a detailed analysis of the effects of technological factors (f_n, v_c) and tool-related factors (D, ε_r, α₀, ω_r) on variations in torque (M_c) during drilling of two types of engineering steels: carbon steel (C45) and case-hardening steel (16MnCr5). The experimental verification was conducted using CTS20D cemented carbide tools coated with a Triple Cr SHM layer. The analysis revealed a significant influence of the material on torque variation, accounting for a share of 1.430%. The experimental verification confirmed the theoretical assumption that the nominal tool diameter (D) has a key effect (53.552%) on torque variation. The revolution feed (f_n) contributes 36.263%, while the tool’s point angle (ε_r) and helix angle (ω_r) influence torque by 1.189% and 0.310%, respectively. No significant effect of cutting speed (v_c) on torque variation was observed. However, subsequent machine learning analysis revealed the complexity of interdependencies between the input factors and the resulting torque. Full article

Activating mutations in the epidermal growth factor receptor (EGFR) are key oncogenic drivers across multiple cancers, yet the structural mechanisms by which these mutations promote persistent receptor activation remain elusive. Here, we investigate how three clinically relevant mutations—T790M, L858R, and the T790M_L858R double mutant—reshape EGFR’s conformational ensemble and regulatory network architecture. Using multiscale molecular simulations and kinetic modeling, we show that these mutations, particularly in combination, enhance flexibility in the αC-helix and A-loop, favoring activation-competent states. Markov state modeling reveals a shift in equilibrium toward active macrostates and accelerated transitions between metastable conformations. To resolve the underlying coordination mechanism, we apply neural relational inference to reconstruct time-dependent interaction networks, uncovering the mutation-induced rewiring of allosteric pathways linking distant regulatory regions. This coupling of conformational redistribution with network remodeling provides a mechanistic rationale for sustained EGFR activation and suggests new opportunities for targeting dynamically organized allosteric circuits in therapeutic design. Full article

The occurrence of anthocyanins in rice (Oryza sativa) and barley (Hordeum vulgare) varies among cultivars, with pigmented varieties (e.g., black rice and purple barley) accumulating higher concentrations due to genetic and environmental factors. The biosynthesis of anthocyanins is regulated by a complex network of structural and regulatory genes. Key enzymes in the pathway include chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), and UDP-glucose flavonoid 3-O-glucosyltransferase (UFGT). These genes are tightly controlled by transcription factors (TFs) from the MYB, bHLH (basic helix–loop–helix), and WD40 repeat families, which form the MBW (MYB-bHLH-WD40) regulatory complex. In rice, OsMYB transcription factors such as OsMYB3, OsC1, and OsPL (Purple Leaf) interact with OsbHLH partners (e.g., OsB1, OsB2) to activate anthocyanin biosynthesis. Similarly, in barley, HvMYB genes (e.g., HvMYB10) coordinate with HvbHLH TFs to regulate pigment accumulation. Environmental cues, such as light, temperature, and nutrient availability, further modulate these TFs, influencing the production of anthocyanin. Understanding the genetic and molecular mechanisms behind the biosynthesis of anthocyanins in rice and barley provides opportunities for the development of biofortification strategies that enhance their nutritional value. Full article

This study investigates the influence of geometric parameters of internally threaded tubes on heat transfer and resistance characteristics. Experimental analyses were conducted on pressure drop for 9.52 mm outer diameter tubes with various industry-standard geometric parameter combinations. Using R410A as the working fluid under turbulent flow conditions (Re = 20,000–60,000), experimental parameters included the following: mass velocity 50–600 kg/(m²·s), condensation temperature 45 ± 0.2 °C, and geometric ranges of thread height (e = 0.0001–0.0003 m), helix angle (α = 17–46°), crest angle (β = 16–53°), and number of ribs (Ns = 50–70). Results demonstrate that the newly developed correlation based on Webb and Ravigururajan friction factor models shows improved prediction accuracy for R410A condensation pressure drop in ribbed tubes. Model II achieved a mean absolute percentage error (MAPE) of 7.08%, with maximum and minimum errors of 27.66% and 0.76%, respectively. The standard deviation decreased from 0.0619 (Webb-based Model I) to 0.0362. Integration of SVR machine learning further enhanced tube selection efficiency through optimized correlation predictions. Full article

In this paper, we introduce null Cartan normal helices in Minkowski space ${\mathbb{E}}_1^3$. We obtain explicit expressions for their torsions by considering the cases when the C-constant vector field is orthogonal to their axis or not orthogonal to it. We find that the tangent vector field of a null Cartan normal helix satisfies the third-order linear homogeneous differential equation and obtain its general solution in a special case. We prove that null Cartan helices are the only normal helices having two axes and, in a particular case, three axes. Finally, we provide the necessary and sufficient conditions for null Cartan normal helices lying on a timelike surface to be isophotic curves, silhouettes, normal isophotic curves and normal silhouettes with respect to the same axis and provide some examples. Full article

Clostridium butyricum Argonaute (CbAgo) can achieve DNA-guided DNA recognition and cleavage at physiological temperatures (~37 °C), making it a promising tool for gene editing. However, its significant off-target effects, particularly associated with the seed region (sites 2–8), pose challenges for precise gene therapy. This study focuses on enhancing the specificity of the seed region recognition to mitigate these off-target effects. We investigated the molecular recognition process between the CbAgo-gDNA complex and the seed region of the target DNA using molecular dynamics simulations and automated path searching. Our findings reveal that positively charged residues located in an α-helix domain at the DNA–protein interface (R279, H285, K287, K288, K291, K298) facilitate rapid binding to the DNA phosphate backbone. Such interaction enhances the pre-formation of the DNA double helix, reducing the reliance on base complementarity during duplex pairing. Further simulations showed that alanine replacement of these positively charged residues led to significantly improved sequence specificity for the target DNA seed region. Collectively, these results offered critical insights into the origin of off-target recognition by CbAgo in its seed region, shedding lights on its fidelity enhancement. Full article

Type IV pili (T4Ps) are multifunctional surface fibers essential for bacterial motility, adhesion, and virulence, found across Gram-negative and Gram-positive bacteria and archaea. Detailed descriptions of T4P structural biology are allowing progress in understanding T4P biogenesis. Secretins, large outer membrane channels, are crucial for T4P extrusion in Gram-negative bacteria. Using cryo-EM and AlphaFold, we modeled the structure of BfpB, the secretin of the Bundle-Forming Pilus (BFP) of enteropathogenic Escherichia coli. BfpB exhibits a unique 17-fold symmetry, correlating with the thicker BFP filaments, and diverging from the 12–15 subunits typical of T4P, type 2 secretion (T2S), and type 3 secretion (T3S) systems. Additionally, we identified an extended β-hairpin loop in the N3 domain, resembling features of distantly related T3SS secretins, and an N-terminal helix where a C-terminal S-domain is seen in some T2S and T3S secretins. These findings reveal evolutionary parallels and structural adaptations in secretins, highlighting the link between oligomerization and pilus structure. This work advances our understanding of T4P biogenesis, secretin evolution, and bacterial secretion systems, offering insights into pathogenic diversity and future research directions. Full article

Supposing that polydextrose molecules could improve the hard texture of cooked rice based on intermolecular interactions and forming a hydrogel-like network structure, this study added polydextrose (moisture content 1%) at 0%, 3%, 5%, 7%, and 10% concentrations to rice (cv. Super Qianhao, SQ) milled from a 3-year-stored paddy and compared their cooking properties, their cooked rice texture, the pasting and thermal properties of their flours, the thermo-mechanical characteristics of their flour dough, and the microstructure of their cooked rice grains with a newly harvested japonica rice cv. Nanjing 5 (NJ5). With an increase in polydextrose addition, a General Linear Model (GLM) analysis showed that the cooking times of two japonica rice varieties was significantly (p < 0.05) reduced, and their gruel solid loss increased. Adding polydextrose significantly reduced the hardness, springiness, gumminess, and chewiness of cooked rice and increased the cohesiveness and resilience. By increasing polydextrose addition in rice flours, the peak, breakdown, and setback viscosities of pasting were significantly decreased, but the pasting temperature and peak time increased. Adding polydextrose reduced the gelatinization enthalpy and increased gelatinization peak temperature of the rice flour and significantly decreased the ageing of the retrograded rice flour paste stored at 4 °C when measured at 21 days. A Mixolab test showed that the stability time of the rice flour dough increased, and the protein weakening, gelatinization peak torque, and starch breakdown, as well as the starch setback and the speeds of heating, gelatinization, and enzymatic degradation all decreased. The addition of 5–10% polydextrose significantly reduced the amorphous and crystalline regions of starch and relative percent of β-sheet in cooked rice grains, with an increase in the relative percent of α-helix, random coil, and β-turn. Observing the microstructure, we confirmed that polydextrose addition facilitated the formation of a soft and evenly swollen honeycomb structure of the cooked rice. These results suggest that polydextrose might decrease the cooked rice hardness and improve the eating quality of sea rice through intermolecular interactions. Full article

Endogenous α-amylase activity is crucial for determining the end-use value of glutinous rice flour (GRF), and controlling it is a key goal in the milling process. Although the structure and properties of starch and protein in GRF have been extensively studied, there is little information on endogenous α-amylase in GRF. In this study, endogenous α-amylase isolated from GRF was purified and characterized. It was found to have a molecular weight of about 32 kDa, with the highest specific activity at 60 °C and a pH of 6.0. The enzyme is stable below 50 °C and in the pH range of 4.0–7.0. Its activity is Ca²⁺-independent but inhibited by Cu²⁺, Zn²⁺, Mg²⁺, Mn²⁺, and Ba²⁺. Its activity is also reduced by β-mercaptoethanol. The enzyme hydrolyzes amylopectin most efficiently. Circular dichroism spectroscopy showed that the enzyme contains 7.9% α-helix, 35.4% β-folding, 21.1% β-turning, and 35.9% random coils, with a T_m value of 63.68 °C. These results suggest that temperature control may be the best strategy for reducing amylase activity in dry-milled GRF, providing a new approach for the development of GRF dry-milling techniques. Full article

A covalent complex of okra seed protein (OSP) and rutin was prepared using the alkali-induced method and characterized. Its application in nanoemulsions was also evaluated. Multi-spectral analysis confirmed the formation of the covalent complex, with OSP as the main body. With an increasing rutin dosage during the preparation process, the amount of rutin in the complex progressively ascended, and the α-helix structure and surface hydrophobicity of the complex gradually declined. The complex exhibited remarkable ABTS radical scavenging capacity and reducing power, which were proportional to the total phenolic content. The OSP/rutin complex could be utilized for the fabrication of O/W nanoemulsions, which remained stable in terms of droplet size and appearance after 28 days of storage at both 4 °C and 25 °C. Furthermore, lipid oxidation in the nanoemulsion stabilized by the OSP/rutin covalent complex could be effectively inhibited, and the emulsion could enhance the UV irradiation resistance of lutein loaded in the oil phase. Our results can provide a reference for the development of protein–polyphenol covalent complexes. Full article