Search Results (156)

In the field of interferometric fiber-optic sensing, the phase-shifting technique is well known as a highly efficient method for retrieving the phase signal from the interference light intensity. The rectangular-pulse binary phase modulation (RPBPM) method is a typical phase-shifting method with the advantages of high efficiency, low complexity, and easy array multiplexing. Exploring the impact of the parameters on the performance is of great significance for guiding its application in practical systems. In this study, the influence of the sampling interval and modulation depth deviation involved in the method is analyzed in detail. Through a comparative simulation analysis with the traditional heterodyne and phase-generated carrier methods, the superiority of the RPBPM method is effectively validated. Meanwhile, an improved method based on the ellipse fitting of the Lissajous figure is proposed to compensate for the error and improve the signal-to-noise-and-distortion ratio (SINAD) from 26.3 dB to 37.1 dB in a specific experiment. Finally, the experimental results guided by the above method show excellent performance in a practical vibration system. Full article

Background/Objectives: Food-related memory influences appetite regulation, with memory inhibition potentially reducing cravings. While obesity is linked to inhibitory deficits, how restrained eating affects memory suppression in healthy-weight individuals remains unclear. This study examined the cognitive and neural mechanisms of food-memory suppression in young women. Methods: Forty-two female participants completed a think/no-think task with high-/low-calorie food cues while an EEG was recorded. Event-related potentials (ERPs) were assessed and time–frequency analyses (theta/beta oscillations) were performed. Results: Restrained eaters showed reduced memory control for both food types. The ERP analysis revealed significant N200 amplitude differences between think/no-think conditions (p = 0.03) and a significant interaction between food calories and think/no-think conditions (p = 0.032). Theta oscillations differed by group, food calories, and conditions (p = 0.038), while beta oscillations reflected food-cue processing variations. Conclusions: In conclusion, restrained eaters exhibit distinct neural processing and attenuated food-memory suppression. These results elucidate the neurocognitive mechanisms underlying dietary behavior, suggesting that targeted interventions for maladaptive eating could strengthen memory inhibition. Full article

Background/Objectives: Chemically or genetically detoxified pertussis toxin (PTx) is a crucial antigen component of the acellular pertussis vaccine. Chemical detoxification using glutaraldehyde generally causes significant structural changes to the toxin. However, how these structural changes in PTx affect its antigenic properties remains unclear. Additionally, there is limited knowledge regarding how many alterations in antigenic properties impact immunogenicity. Methods: To investigate the impact of structural changes on antigenic properties, we developed a sandwich ELISA to quantify the neutralizing epitopes on PTx. Subsequently, we analyzed different PTx toxoid (PTd) preparations with the assay. Additionally, we assessed the immunogenicity of various acellular pertussis vaccine candidates containing these PTd preparations. Finally, the assay was applied to evaluate the consistency of commercial batches of PTx and PTd intermediates. Results: The assay demonstrated reasonable specificity, accuracy, and precision, and it was sensitive enough to quantify variations in neutralizing epitopes among different PTd samples that shared the same protein concentration. Importantly, we found a positive correlation between the number of neutralizing epitopes in detoxified PTx and its immunogenicity, indicating that the amount of neutralizing epitopes present determines the immunogenicity of glutaraldehyde-inactivated PTx. Moreover, commercial batches of PTx and PTd intermediates exhibited minor variations in neutralizing epitopes. Conclusions: These findings have significant implications for developing acellular pertussis vaccines as they highlight the importance of preserving the neutralizing epitopes of PTx during detoxification to ensure the vaccine’s effectiveness. This assay is also valuable for the quality control of PTd as it more accurately represents the actual antigenic changes of PTx. Full article

Understanding remote sensing imagery is vital for object observation and planning. However, the acquisition of optical images is inevitably affected by shadows and occlusions, resulting in local discrepancies in object representation. To address these challenges, this paper proposes AFNE-Net, a general network architecture for remote sensing image segmentation. First, the model introduces an attention-based feature fusion module. Through the use of weighted fusion of multi-resolution features, this effectively expands the receptive field and enhances semantic associations between categories. Subsequently, a feature enhancement module based on the consistency of neighborhood semantic representation is introduced. This aims to improve the feature representation and reduce segmentation errors caused by local perturbations. Finally, evaluations are conducted on the ISPRS Potsdam, UAVid, and LoveDA datasets to verify the effectiveness of the proposed model. Full article

Pear (Pyrus pyrifolia) is an important deciduous fruit tree that requires a specific period of low-temperature accumulation to trigger spring flowering. The warmer winter caused by global warming has led to insufficient winter chilling, disrupting floral initiation and significantly reducing pear yields in Southern China. In this study, we integrated targeted phytohormone metabolomics, full-length transcriptomics, and proteomics to explore the regulatory mechanisms of dormancy in ‘Mixue’, a pear cultivar with an extremely low chilling requirement. Comparative analyses across the multi-omics datasets revealed 30 differentially abundant phytohormone metabolites (DPMs), 2597 differentially expressed proteins (DEPs), and 7722 differentially expressed genes (DEGs). Integrated proteomic and transcriptomic expression clustering analysis identified five members of the dormancy-associated MADS-box (DAM) gene family among dormancy-specific differentially expressed proteins (DEPs) and differentially expressed genes (DEGs). Phytohormone correlation analysis and cis-regulatory element analysis suggest that DAM genes may mediate dormancy progression by responding to abscisic acid (ABA), gibberellin (GA), and salicylic acid (SA). A dormancy-associated transcriptional regulatory network centered on DAM genes and phytohormone signaling revealed 35 transcription factors (TFs): 19 TFs appear to directly regulate the expression of DAM genes, 18 TFs are transcriptionally regulated by DAM genes, and two TFs exhibit bidirectional regulatory interactions with DAM. Within this regulatory network, we identified a novel pathway involving REVEILLE 6 (RVE6), DAM, and CONSTANS-LIKE 8 (COL8), which might play a critical role in regulating bud dormancy in the ‘Mixue’ low-chilling pear cultivar. Furthermore, lncRNAs ONT.19912.1 and ONT.20662.7 exhibit potential cis-regulatory interactions with DAM1/2/3. This study expands the DAM-mediated transcriptional regulatory network associated with bud dormancy, providing new insights into its molecular regulatory mechanisms in pear and establishing a theoretical framework for future investigations into bud dormancy control. Full article

Antibiotic resistance has emerged as a critical global public health challenge. In this study, we employed metagenomic sequencing to analyze fecal samples from giant pandas (Ailuropoda melanoleuca) across three distinct stages—semi-wild, released, and wild populations—to investigate shifts in antibiotic resistance genes (ARGs) and virulence factors (VFs) during the reintroduction process. Our findings revealed significant variations in the composition of ARG and VF across different stages, with released and wild giant pandas exhibiting similar ARG and VF profiles. Further analyses identified that the increased abundance of ARGs and VFs in both released and wild individuals compared to semi-wild individuals was mainly from Pseudomonas. We hypothesized that the same geographic environment in which ARGs and VFs are transmitted between a host and the environment via mobile genetic elements (MGEs) may be responsible for the similar structure of ARGs and VFs in released and wild giant pandas. Additionally, diet may modulate the gut microbial community, thereby influencing the distributions of ARG and VF. This study elucidated the impact of geographic and dietary factors on ARGs and VFs dynamics in giant pandas, offering valuable insights for mitigating antibiotic resistance and virulence gene dissemination. Full article

N-Heterocyclic carbenes (NHCs) have been widely utilized over the past three decades due to their broad applications, yet synthetic methods for their preparation remain limited. A promising approach for NHC generation involves the thermolysis of NHC adducts. Herein, we report the synthesis of NHC pentafluorobenzene adducts featuring an o-carboranyl group in the backbone (2), which, unlike previously studied systems, resists thermal decomposition. Density functional theory (DFT) calculations were used to investigate the discrepancy, revealing that the decomposition reaction is kinetically controlled. For widely studied NHC systems like IMes and SIMes, the activation barriers were calculated to be 246.3 kJ/mol and 267.3 kJ/mol, respectively, aligning with reactions requiring heating. In contrast, the o-carborane system exhibited a significantly higher barrier of 320.5 kJ/mol, primarily due to the structural influence of the o-carborane backbone. Further analysis indicates that delocalization of π-electrons from the backbone into the NHC’s p-orbitals lowers the activation barrier, whereas delocalization into an exo-NHC ring increases it. These findings provide new insights into the thermal generation of NHCs and we hope it can offer guidance for future NHC design and synthesis. Full article

Federated learning is a distributed machine learning framework that allows multiple clients to collaborate on training global models without sharing raw data, thereby protecting data privacy. However, it is still a challenge to construct an efficient federated learning method for the semantic segmentation task of automated driving street view. On the one hand, the complexity of the semantic segmentation model is high, resulting in huge computing and communication overhead of client local training. On the other hand, the client data distribution is significantly different and has Non-Independent and Identically Distributed (non-IID) characteristics, which easily leads to the difficulty of global model convergence or the deterioration of generalization performance. Therefore, this paper proposes a Federal Street View segmentation method, Federal Street View Segmentation (FedSS), which optimizes model training by improving the cross-entropy loss function and designing a gradient compensation strategy and a gradient sparse compression strategy to alleviate the high communication overhead in federation learning. Extensive experiments show that our approach can consume fewer computational resources and achieve higher communication efficiency while improving semantic segmentation performance. Full article

We present a novel approach to generating a cooperative guidance strategy using deep reinforcement learning to address the challenge of cooperative multi-missile strikes under uncontrollable velocity conditions. This method employs the multi-agent proximal policy optimization (MAPPO) algorithm to construct a continuous action space framework for intelligent cooperative guidance. A heuristically reshaped reward function is designed to enhance cooperative guidance among agents, enabling effective target engagement while mitigating the low learning efficiency caused by sparse reward signals in the guidance environment. Additionally, a multi-stage curriculum learning approach is introduced to smooth agent actions, effectively reducing action oscillations arising from independent sampling in reinforcement learning. Simulation results demonstrate that the proposed deep reinforcement learning-based guidance law can successfully achieve cooperative attacks across a range of randomized initial conditions. Full article

In this work, 1,3-diketone synthesized via the Claisen condensation method and nano-copper particles modified by the Brust–Schiffrin method were added into a commercial marine medium-speed diesel engine cylinder piston oil to evaluate their effects on boundary lubrication performance. Friction and wear tests conducted on CKS-coated piston ring and cast-iron cylinder liner samples demonstrated significant reductions in both friction and wear with the addition of 1,3-diketone and nano-copper particles. Compared to the original oil without additives, the friction force was reduced by up to 16.7%, while the wear of the piston ring and cylinder liner was decreased by up to 21.6% and 15.1% at 150 °C, respectively. A worn surface analysis indicated that the addition of 1,3-diketone and functionalized nano-copper particles influenced the depolymerization and tribo-chemical reactions of the anti-wear additive ZDDP (zinc dialkyldithiophosphate) in the original engine oil. This modification enhanced the oil’s anti-friction and anti-wear properties, offering valuable insights into the development of eco-friendly lubricants for energy-efficient systems. Full article

Citrus cultivars are propagated asexually through methods such as layering, cutting, and grafting. Grafting plays a critical role in regulating citrus fruit quality by optimizing stock–scion combinations. This study evaluated the grafting compatibility of two interstocks with Cocktail grapefruits (Citrus paradisi Macf. cv. Cocktail) by analyzing physiological and volatile traits of the fruits. We used Changshanhuyou (Citrus paradisi cv. Changshanhuyou) and Ponkan (Citrus reticulata Blanco cv. Ponkan), which are traditional citrus varieties in Quzhou, Zhejiang Province, as interstocks. Our results showed that the grapefruit fruits grafted onto Changshanhuyou exhibited higher total soluble solids (12.3 °Brix) and a brighter, more uniform peel color. The acidity of fruits grafted onto Changshanhuyou was lower than that of fruits grafted onto Ponkan and similar to the fruits from the control group that were grafted directly onto trifoliate orange. In terms of volatile organic compounds (VOCs), 974 and 577 unique VOCs were identified in the peel and pulp, respectively. In the peel, 34 (26 upregulated and 8 downregulated) and 14 (13 upregulated and 1 downregulated) differentially accumulated VOCs were identified when comparing the trifoliate orange group with Changshanhuyou and Ponkan groups, respectively. The pulp exhibited greater VOC diversity, with 272 (24 upregulated and 248 downregulated) and 199 (4 upregulated and 195 downregulated) differentially accumulated VOCs detected for the same comparisons. In conclusion, compared with direct grafting onto trifoliate orange or on Ponkan as an interstock, grafting onto Changshanhuyou resulted in better fruit quality and distinct differences in flesh flavor. These findings suggest that Changshanhuyou is a more suitable interstock for Cocktail grapefruit (Citrus paradisi Macf. cv. Cocktail) cultivation. Full article

Wildlife behavior can be influenced by the deployment of sensory cues in a landscape, but different cues vary in the strength and duration of their effectiveness. We aimed to identify the most effective and cost-efficient countermeasures (sensory cues) to deter wild boar (Sus scrofa) entry and damage to cornfields in Hunchun, Jilin Province, China. These cornfields have experienced severe damage by wild boars during the critical 30-day period when this crop was ripening. From 2016 to 2021, different countermeasures were applied sequentially seeking to control this damage by using either (1) visual deterrents, i.e., solar blinkers of different colors; (2) auditory deterrents, i.e., playbacks of Amur tiger (Panthera tigris altaica) calls, wild boar calls, or wolf (Canis lupus) calls; (3) tactile deterrents, i.e., electric fencing; (4) olfactory deterrents, i.e., Adult Amur tiger feces; or (5) various combined deterrents. We first evaluated the effectiveness of these broad categories, then performed a detailed analysis of the individual countermeasures to assess their specific deterrence effectiveness and duration. A cost-effective analysis was subsequently performed on the most effective countermeasures to evaluate the best option for practical applications. Across the broad categories of deterrents, the tactile group proved the most effective overall. For individual deterrents, the seven countermeasures showing significantly higher effectiveness than the others tested included the following: (1) 1000 mA red solar blinker (32.25 ± 4.22 days), (2) 1000 mA yellow solar blinker (29.67 ± 4.58 days), (3) 1000 mA green solar blinker (29.58 ± 5.60 days), (4) electric fencing with three wires (29.67 ± 0.58 days), (5) electric fencing with two wires (28.00 ± 2.00 days), (6) Adult Amur tiger calls for 15 s and wild boar calls for 15 s plus a combined 30 s plus a blank recording for 5 min (26.50 ± 2.38 days), and (7) Adult Amur tiger feces and calls (27.34 ± 2.94 days). Except for the Adult Amur tiger feces and calls, each countermeasure would cover most of the period over which control is necessary (30 days). The 1000 mA red solar blinker of achieved the highest repellency per cost ratio (0.31) at 30.29 IUS$/hm² but showed reduced effectiveness over time. Although electric fencing with three wires offers longer deterrence, its cost-effectiveness ratio was lower (0.27) due to higher installation and maintenance costs at 319.69 IUS$/hm². The 1000 mA red solar blinker offers a highly cost-effective short-term deterrent, while the electric fencing with three wires provides durable, long-term protection despite its higher costs. Balancing cost and duration can optimize wild boar deterrence strategies across different management needs. Full article

We propose and demonstrate a tunable femtosecond electro-optic optical frequency comb by shaping a continuous-wave seed laser in an all-fiber configuration. The seed laser, operating at 1.5 μm, is first cascade-phase-modulated and subsequently de-chirped to generate low-contrast pulses of approximately 8 ps at a repetition rate of 5.95 GHz. These pulses are then refined into clean, high-quality picosecond pulses using a Mamyshev regenerator. The generated source is further amplified using an erbium–ytterbium-doped fiber amplifier operating in a highly nonlinear regime, yielding output pulses compressed to around 470 fs. Tunable continuously across a 5.7~6 GHz range with a 1 MHz resolution, the picosecond pulses undergo nonlinear propagation in the final amplification stage, leading to output pulses that can be further compressed to a few hundred femtoseconds. By using a tunable bandpass filter, the center wavelength and spectral bandwidth can be flexibly tuned. This system eliminates the need for mode-locked cavities, simplifying conventional ultrafast electro-optic combs by relying solely on phase modulation, while delivering femtosecond pulses at multiple-gigahertz repetition rates. Full article

Background: Environmental and cardiometabolic impacts of adherence to plant-based dietary patterns with different quality are unclear. Objectives: To investigate the associations between adherence to the overall, healthy, and unhealthy plant-based dietary patterns, as assessed by the plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI), respectively, and risk of myocardial infarction (MI), type 2 diabetes (T2D), stroke, and all-cause mortality and greenhouse gas (GHG) emissions. Methods: Data from adults (N = 14,652 for cardiometabolic diseases and 15,318 for all-cause mortality) in the China Health and Nutrition Survey (1997–2015 wave) were analyzed. PDI, hPDI, and uPDI scores were calculated with dietary intake data. The total GHG emissions were calculated by summing the amount of emissions from all food groups included in the index. Cox proportional hazard regression models and linear regression models were used for statistical analysis. Results: Greater adherence to an unhealthy plant-based dietary pattern, as reflected by higher uPDI scores, was positively associated with risk of MI (Q5 vs. Q1: HR = 5.90; 95% CI: 2.59–13.48), T2D (Q5 vs. Q1: HR = 2.18; 95% CI: 1.75–2.73), stroke (Q5 vs. Q1: HR = 5.96; 95% CI: 2.86–12.42) and all-cause mortality (Q5 vs. Q1: HR = 6.87; 95% CI: 4.70–10.03). PDI scores were inversely associated with the risk of MI, T2D, and all-cause mortality, and hPDI scores were inversely and positively associated with the risk of T2D and stroke, respectively. All scores were inversely associated with GHG emissions (all p-trends < 0.001). Conclusions: Long-term adherence to unhealthy plant-based dietary patterns guided by higher uPDI scores may be a risk factor for new-onset cardiometabolic diseases and all-cause death in Chinese adults. Food-based dietary guidelines, clinicians, and dietitians should consider the quality of plant-based dietary patterns prior to making recommendations for both healthy individuals and those with elevated cardiometabolic disease risk. Full article

Citrus is a globally consumed fruit with great popularity, yet systematic analyses of primary metabolites across major varieties remain scarce, with phenolic acids as an auxiliary focus due to their flavor relevance. In this study, the primary metabolites and phenolic acids of five citrus varieties were analyzed via liquid chromatography‒tandem mass spectrometry (LC–MS/MS). The analysis revealed that five different citrus varieties contained 342 primary metabolites and 77 phenolic acids. The PCA clearly distinguished the metabolites of various citrus varieties. Compared with the pomelo group, the lemon group presented the most differentially abundant metabolites, whereas the kumquat and navel orange groups presented the fewest. An examination of metabolic pathways with notable disparities revealed that phenylpropanoid biosynthesis and the biosynthesis of amino acids significantly varied between varieties. This study elucidates primary metabolic networks underlying citrus flavor diversification, with phenolic acids providing secondary modulation insights. Moreover, this study provides a theoretical foundation for enhancing the flavor of citrus fruits. Full article