Search Results (475)

Objective: To investigate long-term prognosis and impact factors in children with vasovagal syncope (VVS) receiving metoprolol therapy. Method: This retrospective study included children with VVS who underwent metoprolol therapy at the Pediatric Syncope Unit of Peking University First Hospital between January 2012 and November 2023. Baseline demographic data, pre-treatment indices, including head-up tilt test (HUTT) and 24 h Holter monitoring, were collected. All participants received standardized metoprolol therapy for a minimum duration of one month. Follow-up was conducted between June and July 2025, with syncope recurrence as the primary endpoint. Multivariable Cox proportional hazards regression analysis was performed to identify independent impact factors of prognosis and to construct a Prognostic Risk Score (PRS) model. The model’s performance was rigorously validated through receiver operating characteristic (ROC) curve analysis, decision curve analysis (DCA), and Bootstrap resampling (1000 iterations). Furthermore, children were stratified into high- and low-risk groups based on median PRS values. Kaplan–Meier survival analysis was then performed to assess the model’s discriminative efficacy. Result: This study included 97 children diagnosed with VVS. The median duration of metoprolol therapy was 2.5 months (interquartile range [IQR]: 2.0–3.0 months), with a median follow-up period of 59 months (IQR: 25.5–72 months). During follow-up, syncope recurrence was observed in 37 patients, while 60 patients remained symptom-free. COX regression analysis showed that time-domain indices of heart rate variability (HRV), including the standard deviation of all NN intervals (SDNN) and the triangular index (TR), as well as the frequency-domain index of HRV very low frequency (VLF), were relative factors of the long-term prognosis in children with VVS treated with metoprolol. Based on the above three identified factors, the PRS model was calculated as: PRS = 0.03 × SDNN − 0.02 × VLF − 0.1 × TR. ROC showed that the area under the curve (AUC) for discriminative power related to long-term prognosis was 0.808 (p < 0.01). The cumulative recurrence rate of symptoms in the high-risk score group was significantly higher than that in the low-risk score group (p < 0.01). The DCA curve demonstrated the clinical applicability of the model. Bootstrap internal verification indicated high stability, with the bias-corrected and accelerated (Bca) confidence interval (CI) of the C index ranging from 0.71 to 0.89. Conclusions: After metoprolol treatment, 38.1% of children with VVS experienced syncope recurrence during a median follow-up period of 59 months. Baseline HRV index, SDNN, TR, and VLF were identified as factors associated with the long-term prognosis of children with VVS treated with metoprolol. The PRS model based on the above indices demonstrated good value in linking to the individual long-term prognosis. Full article

Heat stress caused a stagnation in the growth and development of Passiflora edulis Sims. To investigate the effects of high-temperature stress, this study subjected P. edulis to 40 °C treatment for different durations; the changes in chlorophyll content, chlorophyll fluorescence parameters, photosynthetic parameters, transcriptome profiles, and photosynthesis-related genes of P. edulis under high-temperature stress were analyzed. The results showed that after 5 h of heat stress, the chlorophyll content of the leaves decreased by 31%, variable fluorescence/maximum fluorescence (Fv/Fm) decreased by 26.91%, photochemical performance index (PI_abs) by 99.28%, comprehensive performance index (PI_total) by 94.20%, light energy absorbed per unit area (ABS/CSm) by 13.56%, light energy captured per unit area (TRo/CSm) by 17.90% and quantum yield of electron transfer per unit area (ETo/CSm) by 92.61%. The net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) decreased by 47%, 41% and 38%, respectively, while intercellular CO₂ concentration (Ci) increased by 1.34 times. Transcriptome sequencing results of P. edulis under heat stress identified 2336 differentially expressed genes (DEGs), which were significantly enriched in pathways including chloroplast function and plant hormone signal transduction. GO enrichment analysis demonstrated that DEGs were significantly enriched in terms related to catalytic activity and chloroplast components. Concurrently, KEGG pathway analysis revealed that carbon fixation in photosynthetic organisms was among the key pathways showing significant enrichment of these DEGs. The expression levels of photosynthesis-related genes, including PePSAE, PeMADs, PebHLH, PeFAR1, PePSBS, PePnsB4, PebZIP and PeC2H2, exhibited a significant increase after 3 h of high-temperature stress and rapidly declined following 5 h. These findings lay a foundation for further research on the high-temperature stress response mechanism and photosynthetic regulation of heat tolerance in P. edulis. Full article

Galvanized steel sheets are vital anti-corrosion materials, yet their surface quality is prone to defects that impact performance. Manual inspection is inefficient, while conventional machine vision struggles with complex, small-scale defects in industrial settings. Although deep learning offers promising solutions, standard object detection models like YOLOv5 (which is short for ‘You Only Look Once’) exhibit limitations in handling the subtle textures, scale variations, and reflective surfaces characteristic of galvanized sheet defects. To address these challenges, this paper proposes S-C-B-YOLO, an enhanced detection model based on YOLOv5. First, a Squeeze-and-Excitation (SE) attention mechanism is integrated into the deep layers of the backbone network to adaptively recalibrate channel-wise features, improving focus on defect-relevant information. Second, a Transformer block is combined with a C3 module to form a C3TR module, enhancing the model’s ability to capture global contextual relationships for irregular defects. Finally, the original path aggregation network (PANet) is replaced with a bidirectional feature pyramid network (Bi-FPN) to facilitate more efficient multi-scale feature fusion, significantly boosting sensitivity to small defects. Extensive experiments on a dedicated galvanized sheet defect dataset show that S-C-B-YOLO achieves a mean average precision (mAP@0.5) of 92.6% and an inference speed of 62 FPS, outperforming several baseline models including YOLOv3, YOLOv7, and Faster R-CNN. The proposed model demonstrates a favorable balance between accuracy and speed, offering a robust and practical solution for automated, real-time defect inspection in galvanized steel production. Full article

Phospholipase D (PLD) genes play key roles in plant abiotic stress responses, but the systematic identification of the maize (Zea mays) PLD family and its cold tolerance mechanism remain unclear. Using 26 maize genomes (pangenome), we identified 21 ZmPLD members via Hidden Markov Model (HMM) search (Pfam domain PF00614), including five private genes—avoiding gene omission from single reference genomes. Phylogenetic analysis showed ZmPLD conservation with Arabidopsis and rice PLDs; Ka/Ks analysis revealed most ZmPLDs under purifying selection, while three genes (including ZmPLD15) had positive selection signals, suggesting roles in maize adaptive domestication. For ZmPLD15, five shared structural variations (SVs) were found in its promoter; some contained ERF/bHLH binding sites, and SVs in Region1/5 significantly regulated ZmPLD15 expression. Protein structure prediction and molecular docking showed conserved ZmPLD15 structure and substrate (1,2-diacyl-sn-glycero-3-phosphocholine) binding energy across germplasms. Transgenic maize (B73 background) overexpressing ZmPLD15 was generated. Cold stress (8–10 °C, 6 h) and recovery (24 h) on three-leaf seedlings showed transgenic plants had better leaf cell integrity than wild type (WT). Transgenic plants retained 45.8% net photosynthetic rate (Pn), 47.9% stomatal conductance (Gs), and 55.8% transpiration rate (Tr) versus 7.6%, 21.3%, 13.8% in WT; intercellular CO₂ concentration (Ci) was maintained properly. This confirms ZmPLD15 enhances maize cold tolerance by protecting photosynthetic systems, providing a framework for ZmPLD research and a key gene for cold-tolerant maize breeding. Full article

Thermal runaway (TR) in lithium-ion batteries presents a significant safety hazard for electric vehicles (EVs), often resulting in fire or explosion. Mitigating TR requires thermal-protection strategies capable of delaying or suppressing heat propagation within battery pack cases (BPCs). This study proposes a flame-retardant BPC design and evaluates its effectiveness through a combined approach using CFD-based thermal analysis and multiscale experimental validation. In the CFD model, a heat-source temperature of 1107 °C was applied to simulate the thermal load during TR, together with a coolant flow rate of 17 L/min. Material-level verification was conducted through high temperature specimen tests, in which flame-retardant pads were heated to a target of 1100 °C with an allowable tolerance of ±10% for 5 min; the unheated (backside) temperature remained below 160 °C. Full-scale assessment involved heating the BPC upper case at temperatures exceeding 500 °C for 10 min, where the backside temperature remained below 150 °C. Module-level TR experiments further confirmed that the flame-retardant layer reduced the external temperature from 240–260 °C to below 150 °C. The results demonstrate that the proposed design effectively delays thermal penetration and maintains external safety thresholds, offering practical guidelines for developing safer EV battery systems. Full article

We study basis-independent structures in the Type-I seesaw mechanism for light Majorana neutrinos, assuming the canonical scenario with three heavy right-handed (sterile) neutrinos. Let $m_{\nu }$ denote the $3\times 3$ mass matrix of light neutrinos, obtained at tree level from heavy Majorana singlets with a diagonal mass matrix $D_N=\mathrm{diag}(M_1,M_2,M_3)$ and a Dirac matrix $m_D$. We show that all right actions F on the seesaw matrix that leave $m_{\nu }$ unchanged form the group $G=D_N^{1/2}O(3,\mathbb{C})D_N^{-1/2}$. While oscillation data determine the PMNS matrix $U_{\mathrm{PMNS}}$ and the mass-squared splittings, they do not fix the F-class within G. We classify basis-invariant quantities into those that are class-blind (e.g., $det \eta$) and class-sensitive (e.g., $\mathrm{Tr}\eta$, $\mathrm{Tr}{\eta }^2$, an alignment measure, and CP-odd traces relevant to leptogenesis), where $\eta$ denotes the non-unitarity matrix of the light sector. We provide explicit formulas and both high-scale and GeV-scale benchmark examples that illustrate these invariant fingerprints and their scaling with $D_N$. This converts the degeneracy at fixed $m_{\nu }$ into measurable, basis-invariant fingerprints. Full article

A water-soluble hydroxypropyl cellulose (HPC) polymer matrix has been filled with different weight percentages (wt.%) of multiwalled carbon nanotubes (MWCNTs), fullerenes C₆₀, fullerenols C₆₀(OH)_24, and their combinations. We study the potential of the 0D nanoparticles for improving electrical properties of the conductive MWCNT network in a biocompatible matrix. Physicochemical effects of fillers content, both individually and in combinations (MWCNTs/C₆₀ and MWCNTs/C₆₀(OH)₂₄), for these composite systems, have been investigated. The performed SAXS analysis shows improved nanofiller dispersion for films with two fillers. The electrical percolation threshold (P_c) in MWCNTs composites occurs at ≈1.0 wt.%. A synergistic effect for binary filler composites on the electrical conductivity has been evaluated by keeping a constant amount of 0.5 wt.% MWCNTs (σ ≈ 3 × 10⁻⁹ S·m⁻¹) and increasing the amount of C₆₀ or C₆₀(OH)₂₄. A large increase in the electrical conductivity is obtained for the bifiller composites with 0.5 wt.% MWCNTs and 1.5 wt.% of C₆₀(OH)₂₄, reaching σ ≈ 0.008 S·m⁻¹. Further, the sensing properties of 4.0/1.0 MWCNT/C₆₀ nanocomposites were demonstrated by measuring both piezoresistive (PR) and thermoresistive (TR) responses. The combination of semiconductive fullerene/fullerenols combined with MWCNTs allows obtaining more homogeneous composites in comparison to single MWCNTs composites and also gives possibilities for tuning the electrical conductivity of the system. Overall, it is demonstrated that the use of bifillers with a water soluble biopolymeric matrix allows the development of eco-friendly high-performance electroactive materials for sustainable digitalization. Full article

Light intensity strongly influences the morphological development and photoprotective responses of in vitro plantlets, yet the optimal conditions for hydrangea remain undefined. This study investigated the effects of five light intensity gradients (TrA: 80–120 lux, TrB: 380–480 lux, TrC: 1500–1800 lux, TrD: 3800–4000 lux, TrE: 6000–6400 lux) on Hydrangea macrophylla ‘Qingtian’ plantlets. Plantlets exhibited optimal growth at TrB, showing maximal biomass, leaf expansion, chlorophyll content, and root activity, accompanied by low antioxidant enzyme activities and soluble sugar levels. Nutrient accumulation was greater under low light than under high light conditions. Transcriptome analysis of treatments (TrB and TrE) with marked phenotypic differences revealed 7119 differentially expressed genes (DEGs). Of these, 4582 genes were up-regulated and 2537 were down-regulated. The up-regulated genes were significantly enriched in pathways related to cell walls, the microtubule cytoskeleton, and developmental processes, which are involved in the plant growth and development process, such as photosynthesis, nutrient ion transport and regulation, as well as plant hormone responses and transport; whereas the down-regulated genes were significantly enriched in pathways related to carbohydrate metabolism, oxidoreductase activity, and glutathione metabolism, suggesting that high light stress impairs growth by disrupting carbon and antioxidant processes. These results demonstrated that 380–480 lux is the optimal light intensity for ‘Qingtian’ Hydrangea macrophylla in vitro plantlets. This study provides a foundation for optimizing culture conditions and offers new insights into the molecular regulation of light-responsive genes. Full article

Quantifying carbon sequestration in cultivated land ecosystems is essential for achieving carbon neutrality and ensuring food security, yet current models often fail to capture the complex interactions between crop phenology and environmental factors at regional scales. This paper proposed an improved CASA-CGC model that couples crop phenological parameters with photosynthetic physiological processes, enabling precise carbon sink accounting at the growth cycle scale of cultivated land ecosystems. Results indicate that the carbon sequestration capacity of cultivated land in the province significantly increased from 2010 to 2022, with an average increase of 163.04 g C m⁻², and the spatial pattern showed a centralized evolution characteristic. Model validation showed that the accuracy of the CASA-CGC model is significantly better than traditional methods. Compared with remote sensing inversion products and 93 ground measurement point data, the improved CASA-CGC model increased the R² by 0.155 and reduced the RMSE by 4.19 compared with the tr-CASA model. The innovative introduction of the GeoDetector model reveals that the nonlinear interaction between natural and human factors dominates the carbon sequestration process (accounting for 60%), with the interaction effect between altitude and cropping system configuration being the strongest (q = 0.312), confirming that humans can significantly amplify the potential of natural carbon sinks by optimizing cropping systems. Full article

(1) Background: Repeated planting cycles and monoculture practices have led to widespread magnesium (Mg) deficiency in Chinese fir (Cunninghamia lanceolata) plantations. To gain clarity on how different Mg concentrations affect seedling growth and physiology, we designed the following experiment. (2) Methods: One-year-old seedlings were exposed to three Mg concentration treatments: High (HM), Medium (MM), and Low (LM). Their responses were evaluated in terms of growth traits, photosynthetic activity, and chloroplast structure. (3) Results: Both HM and LM significantly affected leaf development, with LM having the strongest impact. LM disrupted chloroplast structure, causing thylakoid membrane rupture, mitochondrial damage, accumulation of osmiophilic granules, and increased spacing between chloroplasts and cell walls. LM also impaired photosynthesis, lowering the net photosynthetic rate (Pn) and peroxidase (POD) activity, while increasing malondialdehyde (MDA) levels. Leaf growth was reduced, as shown by smaller leaf area and lower biomass. In contrast, HM temporarily enhanced some physiological traits, including intercellular CO₂ concentration (Ci), transpiration rate (Tr), leaf dry matter content (LDMC), and ATPase activity, though it also reduced Fv/Fo compared to MM. (4) Conclusions: Both high and low Mg concentration negatively affected photosynthesis, with Mg deficiency causing the most severe damage. These findings highlight the importance of managing soil Mg levels to maintain healthy growth and productivity in C. lanceolata plantations. Full article

In response to the International Maritime Organization (IMO)’s greenhouse gas reduction targets and the growing demand for decarbonization in the maritime sector, the development of hydrogen-fueled ship technologies has gained increasing attention. Liquid hydrogen (LH₂) is regarded as a promising marine fuel due to its high energy density per unit volume when liquefied at −253 °C, enabling large-scale storage and transportation. However, critical technical challenges remain in cryogenic storage, transfer, vaporization processes, and safety assurance. This study proposes a conceptual pre-standardization framework for land-based evaluation of LH₂ fuel tank and supply systems, supported by preliminary validation using LN₂ surrogate tests. The protocol is established through a reinterpretation of existing international and domestic standards (KGS AC111, ISO/TR 15916, CGA H-3) and adapted to Korean demonstration environments. Test items were categorized into (i) supply performance (flow and pressure), (ii) vaporization and heating performance (temperature), and (iii) safety functions, with acceptance criteria benchmarked against international guidelines. To overcome the significant safety and cost constraints of handling actual LH₂, liquid nitrogen (LN₂) was applied as a surrogate medium to enable preliminary validation under safe and practical conditions, and process simulations are proposed as a future pathway for comprehensive verification. The results highlight not only the application but also the localization and refinement of global standards into a practical protocol for small- to medium-sized ship applications. This protocol is expected to serve as a critical reference for subsequent sea trials and commercialization, thereby contributing to the advancement of eco-friendly marine fuel technologies and strengthening international competitiveness in the hydrogen powered shipping sector. Full article

Polymer-dispersed liquid crystal (PDLC), as an electrically controlled dimming material, has broad application prospects in various fields, including smart glass, display technology, and optical devices. However, traditional PDLC materials still face some challenges in practical applications, such as a high driving voltage and insufficient optical contrast, which limit their further application in high-performance optoelectronic devices. In this study, PDLC composite films exhibiting low-voltage operation (23 V), high contrast ratios (135), and rapid response times (T_R ~1.28 ms, T_D ~48 ms) were developed. This was achieved by modifying the chain length of the crosslinking agent and polymer monomer as well as by incorporating molybdenum disulfide (MoS₂) nanosheets. It shows a good regulation ability in the sunlight range (ΔT_sol = 63.92%, ΔT_lum = 73.97%). Simultaneously, the various chemical bonds inside the film and its special network structure enable it to exhibit a good radiative cooling effect. The indoor sunlight simulation tests showed that the indoor temperature decreased by 5 °C. This study provides valuable ideas for the development and preparation of smart windows with high efficiency and energy savings. Full article

Background and Objectives: Left ventricular diastolic dysfunction (LVDD) is a known precursor of heart failure with preserved ejection fraction (HFpEF), particularly in patients with metabolic comorbidities. Acute coronary syndrome (ACS) and percutaneous coronary interventions (PCI) may exacerbate LVDD via systemic inflammation. This study aimed to explore the association between post-procedural systemic inflammation and the severity of diastolic dysfunction in patients with ACS and metabolic comorbidities. Materials and Methods: A retrospective observational study was conducted in 181 patients with ACS who underwent PCI. Inflammatory markers (leukocytes, neutrophils, and C-reactive protein [CRP]) measured at 24–48 h post-intervention were analyzed in relation to diastolic dysfunction, assessed by echocardiography. Multivariable ordinal logistic regression and correlation analyses were performed. Results: CRP showed a non-significant trend toward association with more advanced diastolic dysfunction (p = 0.081). Hypertension had a positive but nonsignificant coefficient. Other metabolic comorbidities (diabetes, dyslipidemia, and obesity) were not significantly associated. The correlation between N-terminal pro-B-type natriuretic peptide (NT-proBNP) and troponin was exploratory. NT-proBNP was the only marker significantly correlated with high-sensitivity troponin (TrHS) at 48 h, indicating a link between myocardial injury and wall stress. Conclusions: CRP may be weakly associated with the severity of diastolic dysfunction post-PCI. However, classical metabolic comorbidities were not independently predictive. Post-PCI inflammation showed only modest, non-significant trends toward diastolic impairment, warranting confirmation in larger prospective studies. Full article

The increasing prevalence of lithium-ion batteries in energy storage and electric transportation has led to a rise in overcharge-induced thermal runaway (TR) incidents. Particularly, the TR of Lithium Iron Phosphate (LFP) batteries demonstrates distinct evolutionary stages and multimodal hazard signals. This study investigated the TR process of LFP batteries under various charging rates through five sets of gradient C-rate experiments, collecting multimodal data (temperature, voltage, gas, sound, and deformation). Drawing on the collected data, this study proposes a three-stage evolution model that systematically identifies key characteristic signals and tracks their progression pattern through each stage of TR. Subsequently, fusion-based models (for both single- and multi-rate scenarios) and a time-series-based LSTM model were developed to evaluate their classification accuracy and feature importance in the classification of TR stages. Results indicate that the fusion-based models offer greater generalization, while the LSTM model excels at modeling time-dependent dynamics. These models demonstrate complementary strengths, providing a comprehensive toolkit for risk assessment. Furthermore, for the severe TR stage, this study proposes an innovative three-dimensional dynamic emergency decision matrix comprising a toxicity index (TI), flammability index (FI), and visibility (V) to provide quantitative guidance for rescue operations in the post-accident phase. Ultimately, this study establishes a comprehensive, closed-loop framework for LFP battery safety, extending from multimodal signal acquisition and intelligent early warning to quantified emergency response. This framework provides both a robust theoretical basis and practical tools for managing TR risk throughout the entire battery lifecycle. Full article

Electric aircraft powered by lithium batteries (LIBs) have seen rapid development in recent years, making research into their thermal runaway (TR) characteristics crucial for ensuring flight safety. This study focused on the individual battery cells of a specific electric aircraft power battery system, conducting TR experiments under both the aircraft’s service ceiling temperature (−8.5 ± 2 °C) and ground ambient temperature (30 ± 2 °C). The experiments analyzed changes in battery temperature, voltage, and mass during TR. Experimental results indicate that the peak TR temperatures reached 589.6 °C and 654 °C under the two environments, respectively, with maximum heating rates of 8.6 °C/s and 16.9 °C/s. At ambient ground temperatures, battery voltage drops more rapidly, with the voltage of a 100% SOC battery decreasing over just 10 s. Peak mass loss during TR reached 265.48 g and 247.52 g, respectively. Combining TR temperature data with the Semenov thermal runaway model, the minimum ambient temperature causing TR in this electric aircraft power battery under sustained external heating was determined to be approximately 39 °C. Finally, a multi-level protection strategy covering the “airframe–battery compartment–cabin” was established. The findings from this research can serve as a reference for subsequent safety design of this aircraft type and the formulation of relevant airworthiness standards. Full article