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Authors = Heng Ren ORCID = 0000-0003-1526-7843

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11 pages, 1401 KiB  
Communication
Graphene-Enhanced FePO4 Composites with Superior Electrochemical Performance for Lithium-Ion Batteries
by Jinde Yu, Shuchun Hu, Yaohan Zhang, Yin Liu, Wenjuan Ren, Aipeng Zhu, Yanqi Feng, Zhe Wang, Dunan Rao, Yuqin Yang, Heng Zhang, Runhan Liu and Shunying Chang
Materials 2025, 18(15), 3604; https://doi.org/10.3390/ma18153604 - 31 Jul 2025
Viewed by 226
Abstract
In this study, we successfully synthesized olivine-type FePO4 via an in situ oxidation method and further developed two composite cathode materials (o-FePO4-1/GR-1 and o-FePO4-1/GR-2) by incorporating graphene. The composites were characterized using scanning electron microscopy (SEM), X-ray diffraction [...] Read more.
In this study, we successfully synthesized olivine-type FePO4 via an in situ oxidation method and further developed two composite cathode materials (o-FePO4-1/GR-1 and o-FePO4-1/GR-2) by incorporating graphene. The composites were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray Photoelectron Spectroscopy (XPS), revealing a three-dimensional porous layered structure with an enhanced surface area and strong interaction between FePO4 nanoparticles and graphene layers. Electrochemical tests demonstrated that the composite electrodes exhibited significantly improved performance compared to pristine FePO4, with discharge capacities of 147 mAh g−1 at 1C and 163 mAh g−1 at 0.1C for o-FePO4-1/GR-2, approaching the level of LiFePO4. The incorporation of graphene effectively enhanced the electrochemical reaction kinetics, highlighting the innovation of our method in developing high-performance cathode materials for lithium-ion batteries. Full article
(This article belongs to the Section Electronic Materials)
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27 pages, 2276 KiB  
Review
Fault Detection of Li–Ion Batteries in Electric Vehicles: A Comprehensive Review
by Heng Li, Hamza Shaukat, Ren Zhu, Muaaz Bin Kaleem and Yue Wu
Sustainability 2025, 17(14), 6322; https://doi.org/10.3390/su17146322 - 10 Jul 2025
Viewed by 792
Abstract
Lithium–ion (Li–ion) batteries are fundamental for advancing intelligent and sustainable transportation, particularly in electric vehicles, due to their long lifespan, high energy density, and strong power efficiency. Ensuring the safety and reliability of EV batteries remains a critical challenge, as undetected faults can [...] Read more.
Lithium–ion (Li–ion) batteries are fundamental for advancing intelligent and sustainable transportation, particularly in electric vehicles, due to their long lifespan, high energy density, and strong power efficiency. Ensuring the safety and reliability of EV batteries remains a critical challenge, as undetected faults can lead to hazardous failures or gradual performance degradation. While numerous studies have addressed battery fault detection, most existing reviews adopt isolated perspectives, often overlooking interdisciplinary and intelligent approaches. This paper presents a comprehensive review of advanced battery fault detection using modern machine learning, deep learning, and hybrid methods. It also discusses the pressing challenges in the field, including limited fault data, real-time processing constraints, model adaptability across battery types, and the need for explainable AI. Furthermore, emerging AI approaches such as transformers, graph neural networks, physics-informed models, edge computing, and large language models present new opportunities for intelligent and scalable battery fault detection. Looking ahead, these frameworks, combined with AI-driven strategies, can enhance diagnostic precision, extend battery life, and strengthen safety while enabling proactive fault prevention and building trust in EV systems. Full article
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22 pages, 2576 KiB  
Article
Multi-Indicator Environmental Impact Assessment of Recycled Aggregate Concrete Based on Life Cycle Analysis
by Heng Zhang, Xiaochu Wang, Peng Ren and Linlin Yang
Buildings 2025, 15(13), 2301; https://doi.org/10.3390/buildings15132301 - 30 Jun 2025
Viewed by 374
Abstract
With the ongoing acceleration in urban development, the volume of construction and demolition waste continues to rise, while the availability of natural aggregates is steadily declining. Utilizing recycled aggregates in concrete has become a vital approach to fostering sustainability within the construction sector. [...] Read more.
With the ongoing acceleration in urban development, the volume of construction and demolition waste continues to rise, while the availability of natural aggregates is steadily declining. Utilizing recycled aggregates in concrete has become a vital approach to fostering sustainability within the construction sector. This research develops a life cycle-based environmental impact evaluation model for recycled aggregate concrete, applying the Life Cycle Assessment (LCA) framework. Through the eFootprint platform, a quantitative evaluation is carried out for C30-grade concrete containing varying levels of recycled aggregate replacement. Four replacement ratios of recycled coarse aggregate (30%, 50%, 70%, and 100%) were evaluated. The assessment includes six key environmental indicators: Global Warming Potential (GWP), Primary Energy Demand (PED), Abiotic Depletion Potential (ADP), Acidification Potential (AP), Eutrophication Potential (EP), and Respiratory Inorganics (RI). The findings reveal that higher substitution rates of recycled aggregate lead to noticeable reductions in RI, EP, and AP, indicating improved environmental performance. Conversely, slight increases are observed in GWP and PED, especially under long transport distances. Analysis of contributing factors and sensitivity indicates that cement manufacturing is the principal driver of these increases, contributing over 80% of the total GWP, PED, and ADP impacts, with aggregate transport as the next major contributor. This study offers methodological insights into the environmental evaluation of recycled aggregate concrete and supports the green design and development of low-carbon strategies in construction. Full article
(This article belongs to the Section Building Materials, and Repair & Renovation)
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33 pages, 16266 KiB  
Article
Integrated Bioinformatics Analysis and Cellular Experimental Validation Identify Lipoprotein Lipase Gene as a Novel Biomarker for Tumorigenesis and Prognosis in Lung Adenocarcinoma
by Wanwan He, Meilian Wei, Yan Huang, Junsen Qin, Meng Liu, Na Liu, Yanli He, Chuanbing Chen, Yali Huang, Heng Yin and Ren Zhang
Biology 2025, 14(5), 566; https://doi.org/10.3390/biology14050566 - 19 May 2025
Viewed by 761
Abstract
Lung adenocarcinoma (LUAD) is one of the leading causes of death worldwide, and thus, more biomarker and therapeutic targets need to be explored. Herein, we aimed to explore new biomarkers of LUAD by integrating bioinformatics analysis with cell experiments. We firstly identified 266 [...] Read more.
Lung adenocarcinoma (LUAD) is one of the leading causes of death worldwide, and thus, more biomarker and therapeutic targets need to be explored. Herein, we aimed to explore new biomarkers of LUAD by integrating bioinformatics analysis with cell experiments. We firstly identified 266 druggable genes that were significantly differentially expressed between LUAD tissues and adjacent normal lung tissues. Among these genes, SMR analysis with p-value correction suggested that declining lipoprotein lipase (LPL) levels may be causally associated with an elevated risk of LUAD, which was corroborated by co-localization analysis. Analyses of clinical data showed that LPL in lung cancer tissues has considerable diagnostic value for LUAD, and elevated LPL levels were positively associated with improved patient survival outcomes. Cell experiments with an LPL activator proved these findings; the activator inhibited the proliferation and migration of lung cancer cells. Next, we found that LPL promoted the infiltration of immune cells such as DCs, IDCs, and macrophages in LUAD by mononuclear sequencing analysis and TIMER2.0. Meanwhile, patients with low levels of LPL expression demonstrated superior immunotherapeutic responses to anti-PD-1 therapy. We conclude that LPL acts as a diagnostic and prognostic marker for LUAD. Full article
(This article belongs to the Special Issue Disease Biomarker Discovery and Validation)
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19 pages, 5708 KiB  
Article
An Investigation of the Mechanical Properties and Thermal Insulation of Foamed Rubberised Polypropylene Fibre Concrete That Incorporates a High Quantity of Crumb Rubber Granules
by Zhi Heng Lim, Foo Wei Lee, Kim Hung Mo, Ren Jie Chin, Kim Ho Yeap and Ming Kun Yew
Polymers 2025, 17(7), 967; https://doi.org/10.3390/polym17070967 - 2 Apr 2025
Cited by 1 | Viewed by 640
Abstract
Disposing of waste tyres in landfills poses significant environmental hazards, making recycling a crucial alternative. Rubberised concrete has been found to exhibit lower density and better thermal insulation performance than conventional concrete. In order to maximise the potential of thermal insulation of rubberised [...] Read more.
Disposing of waste tyres in landfills poses significant environmental hazards, making recycling a crucial alternative. Rubberised concrete has been found to exhibit lower density and better thermal insulation performance than conventional concrete. In order to maximise the potential of thermal insulation of rubberised concrete, this study investigates the mechanical and thermal properties of foamed rubberised polypropylene fibre concrete (FRPFC). FRPFC was produced using a mix of crumb rubber (CR) granules, polypropylene fibres, and foam, targeting a density of 800 kg/m3, with CR substituting sand at varying levels. Compressive strength, flexural strength, splitting tensile strength, and thermal conductivity of FRPFC were evaluated. The results demonstrate that increasing CR granule content enhances compressive strength due to reduced porosity from lower foam usage. For instance, compressive strength improved by 55% (2.64 to 4.10 MPa) as CR granule content increased from 0% to 80%. Similarly, flexural strength and splitting tensile strength increased by 55% (1.61 MPa to 2.49 MPa) and 39% (0.41 MPa to 0.57 MPa), respectively, when CR content rose from 0% to 100% at a water-to-cement ratio of 0.50. Furthermore, thermal conductivity decreased by 34% (0.3608 W/mK to 0.2376 W/mK) when sand was fully replaced with CR granules, showcasing improved thermal insulation. Statistical analysis using ANOVA confirmed that the crumb rubber content significantly influences the mechanical and thermal properties of FRPFC, with higher CR content (80% and 100%) leading to superior performance. These findings highlight FRPFC’s potential as an environmentally sustainable and thermally efficient construction material, contributing to enhanced mechanical properties compared to conventional foamed polypropylene fibre concrete. Full article
(This article belongs to the Section Polymer Fibers)
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25 pages, 9694 KiB  
Article
Orthogonal Experimental Study on Layout Parameters of Ventilation Equipment in Tunnel Construction Based on TOPSIS Theory
by Guofeng Wang, Fayi Deng, Kaifu Ren, Yongqiao Fang, Bo Wang and Heng Zhang
Buildings 2025, 15(7), 1151; https://doi.org/10.3390/buildings15071151 - 1 Apr 2025
Viewed by 303
Abstract
Based on the Daozhen–Wulong Zimuyan tunnel, the distance from the outlet of the air duct to the tunnel face and the diameter of the air duct are studied through an orthogonal experimental design. Aiming at the influence of the position of the air [...] Read more.
Based on the Daozhen–Wulong Zimuyan tunnel, the distance from the outlet of the air duct to the tunnel face and the diameter of the air duct are studied through an orthogonal experimental design. Aiming at the influence of the position of the air duct of the axial flow fan in the tunnel on the ventilation flow field, the improved TOPSIS theory is adopted for detailed data analysis, and the flow field characteristics are thoroughly checked to identify the optimal working condition configuration. The results show that with the increase in the distance between the air duct and the tunnel face, the local CO concentration will first decrease and then increase, indicating that too large or too small a distance will weaken the effective CO emission ability of the tunnel face, and the distance between the air duct outlet and the tunnel face is the best scheme; by combining the TOPSIS theory, entropy weight method, and analytic hierarchy process, the optimization scheme is obtained. When the distance between the outlet of the air duct and the working face is 15 m, the side wall of the air duct is 4 m away from the air, the diameter of the air duct is 1.8 m, the flow field in the tunnel shows a high degree of stability, the wind speed is significantly increased, and the vortex area that may hinder the air flow is effectively eliminated. The ventilation efficiency is greatly improved and the overall stability of the tunnel is enhanced. Full article
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17 pages, 4483 KiB  
Article
The Aroma, Taste Contributions, and Flavor Evaluation Based on GC-IMS, E-Nose, and E-Tongue in Soybean Pastes: A Comparative Study
by Bing Yang, Heng Wang, Zhenxia Cao, Jing Yan, Zijie Dong, Fazheng Ren, Wanli Zhang and Lishui Chen
Foods 2025, 14(7), 1178; https://doi.org/10.3390/foods14071178 - 27 Mar 2025
Cited by 1 | Viewed by 749
Abstract
The objective of this study was to assess and compare the characteristics of different soybean pastes by using intelligent sensory analysis. In this study, color, flavor, texture, and taste were regarded as four factors affecting the sensory quality of soybean pastes and the [...] Read more.
The objective of this study was to assess and compare the characteristics of different soybean pastes by using intelligent sensory analysis. In this study, color, flavor, texture, and taste were regarded as four factors affecting the sensory quality of soybean pastes and the sensory quality of four different soybean pastes was evaluated using fuzzy mathematics. The sensory evaluation scores of samples L, Z, and W were very similar and significantly higher than that of sample Y. Gas chromatography–ion mobility spectrometry (GC-IMS) detected 111 volatile flavor compounds, with acids, alcohol, and ketones having a significantly higher relative content than other compounds, indicating their vital role in the flavor formation process of soybean pastes. Furthermore, partial least squares discriminant analysis (PLS-DA) model analysis identified 41 marker compounds that could differentiate the four types of soybean pastes. The overall odor and flavor profile were detected by the E-nose and E-tongue. These fundamental results lay the groundwork for future research on the similarities and differences between the flavor characteristics of different brands of soybean paste. Full article
(This article belongs to the Section Food Analytical Methods)
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13 pages, 2156 KiB  
Article
Analysis of the Interaction Between the Attenuated HSV-1 Strain M6 and Macrophages Indicates Its Potential as an Effective Vaccine Immunogen
by Zhenxiao Zhang, Xiaohong Ren, Ying Zhang, Jingjing Zhang, Xinghang Li, Fengyuan Zeng, Rong Yue, Qi Li, Haobo Zhang, Danjing Ma, Yuansheng Liao, Yun Liao, Dandan Li, Li Yu, Guorun Jiang, Heng Zhao, Huiwen Zheng, Heng Li, Xin Zhao, Longding Liu and Qihan Liadd Show full author list remove Hide full author list
Viruses 2025, 17(3), 392; https://doi.org/10.3390/v17030392 - 10 Mar 2025
Viewed by 757
Abstract
Herpes simplex virus type 1 (HSV-1) is a very concerning pathogen due to its ability to persist in the host’s nervous system and continuously interfere with the immune system, which complicates treatment. Therefore, the development of an effective HSV-1 vaccine is crucial. In [...] Read more.
Herpes simplex virus type 1 (HSV-1) is a very concerning pathogen due to its ability to persist in the host’s nervous system and continuously interfere with the immune system, which complicates treatment. Therefore, the development of an effective HSV-1 vaccine is crucial. In this study, we focused on an HSV-1 mutant strain, M6, which includes several deleted genes associated with viral infection virulence and latent infection function, and explored its infection of macrophages and immunological characteristics. The study found that both the attenuated strain M6 and the wild-type strain infect macrophages through the binding of the gD protein to the HVEM receptor on the macrophage surface. Compared to the wild-type strain, the attenuated M6 strain induced a milder immune response, characterized by the lower expression of immune signaling molecules and inflammatory cytokine levels. Upon reintroducing macrophages infected with the two strains into mice, the M6 strain induced lower levels of inflammatory cytokines and higher levels of chemokines in spleen cells and also slightly lower humoral and cellular immune responses than the wild-type strain. Further histopathological analysis revealed that mice in the attenuated M6 group showed more stable body weight changes and milder pathological damage in immune organs such as the liver, spleen, and lymph nodes. In conclusion, the attenuated M6 strain exhibits good immunogenicity and mild pathological side effects, suggesting its potential as an effective immunogen. Full article
(This article belongs to the Special Issue Herpesviruses and Associated Diseases)
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28 pages, 15742 KiB  
Essay
Comparing Grassland Fire Drivers and Models in Inner Mongolia Using Field and Remote Sensing Data
by Heng Zhang, Yansen Liang, Haiyan Ren and Qingyu Ban
Fire 2025, 8(3), 93; https://doi.org/10.3390/fire8030093 - 25 Feb 2025
Cited by 1 | Viewed by 829
Abstract
Frequent and intense grassland fires represent a significant threat to the stability and sustainability of grassland ecosystems. Therefore, understanding the driving factors of grassland fire and the occurrence of fire is key to formulating effective fire management policies and management plans. Based on [...] Read more.
Frequent and intense grassland fires represent a significant threat to the stability and sustainability of grassland ecosystems. Therefore, understanding the driving factors of grassland fire and the occurrence of fire is key to formulating effective fire management policies and management plans. Based on the fire dataset (manually recorded data, satellite remote sensing data) from 2001 to 2022, this study uses six models to analyze the differences in grassland fire driving factors in different regions and fire prevention periods in the study area, determine the relative importance of fire driving factors, and draw a probability map of grassland fire. The results show that both types of data selected the Boosted Regression Trees (BRT) model as the optimal model for predicting grassland fires in the Inner Mongolia Autonomous Region. Meteorological factors are the main driving factors of grassland fire in the Inner Mongolia Autonomous Region, and topographic factors and socio-economic factors are important factors. The number and probability of fires gradually decreased from east to west, and fires were mainly concentrated in the northeast and middle of the study area. Therefore, our study functioned to explore the spatio-temporal pattern of grassland fire, accurately predict the probability of grassland fire at different scales, and provide a scientific basis for the rational allocation of grassland fire prevention resources in the study area. Full article
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14 pages, 460 KiB  
Article
Prevalence of Homologous Recombination Repair Mutations and Association with Clinical Outcomes in Patients with Solid Tumors: A Study Using the AACR Project GENIE Dataset
by Changxia Shao, Heng Zhou, Cai Chen, Elisha J. Dettman, Yixin Ren, Razvan Cristescu, Alexander Gozman and Fan Jin
Cancers 2025, 17(4), 577; https://doi.org/10.3390/cancers17040577 - 8 Feb 2025
Viewed by 1137
Abstract
Background/Objectives: Mutations in BRCA1 and/or BRCA2 (BRCAm) and other homologous recombination repair genes (HRRm) are associated with several cancers. We evaluated the prevalence and association with overall survival (OS) of somatic BRCAm and HRRm among patients with advanced solid tumors. Methods: We used [...] Read more.
Background/Objectives: Mutations in BRCA1 and/or BRCA2 (BRCAm) and other homologous recombination repair genes (HRRm) are associated with several cancers. We evaluated the prevalence and association with overall survival (OS) of somatic BRCAm and HRRm among patients with advanced solid tumors. Methods: We used deidentified data from the AACR GENIE Biopharma Collaborative dataset derived from patients with tumors genotyped using next-generation sequencing between 1 January 2014 and 31 December 2017. Eligible patients were aged ≥18 years diagnosed with non-small-cell lung, colorectal, breast, bladder, prostate, or pancreatic cancer, with documented BRCA/HRR somatic mutation status. The primary analysis was OS (censored at the start of poly[ADP ribose] polymerase inhibitors [PARPi]/immunotherapy) after initiation of second-line therapy since most patients had sequencing after first-line therapy. Results: Among eligible patients, 242/7022 (3.4%) had BRCAm and 477/5474 (8.7%) had HRRm. Adjusted OS HRs (95% CI) for the primary analysis (using the initiation of second-line therapy as index date) were 0.79 (0.61–1.03) with/without BRCAm (n = 116/n = 3394) and 0.83 (0.69–0.99) with/without HRRm (n = 247/n = 2656); in sensitivity analysis of patients with stage IV disease, HRs were 0.97 (0.68–1.38) with/without BRCAm (n = 58/n = 1847) and 0.92 (0.73–1.18) with/without HRRm (n = 132/n = 1488). Conclusions: Overall, BRCAm and HRRm did not show a strong association with OS, with a trend toward longer OS among patients receiving standard second-line therapies excluding PARPi/immunotherapy. Full article
(This article belongs to the Special Issue New Biomarkers in Cancers 2nd Edition)
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19 pages, 2458 KiB  
Article
Safety Design of Rotary Drilling Rig Mast Based on Multi-Condition Analysis
by Heng Yang, Yuhang Ren, Haorong Yang and Gening Xu
Appl. Sci. 2025, 15(4), 1704; https://doi.org/10.3390/app15041704 - 7 Feb 2025
Viewed by 1196
Abstract
To achieve both safety and a lightweight design for rotary drilling rig masts, this study proposes an optimization method incorporating safety evaluation constraints. The method employs the limit state method to validate the mast structure and uses fuzzy comprehensive evaluation to quantify safety [...] Read more.
To achieve both safety and a lightweight design for rotary drilling rig masts, this study proposes an optimization method incorporating safety evaluation constraints. The method employs the limit state method to validate the mast structure and uses fuzzy comprehensive evaluation to quantify safety performance metrics. The optimization objective is to minimize the mast’s self-weight, with design variables defined as the geometric dimensions of key cross-sections, while imposing constraints on the strength, stiffness, stability, and safety scores. The safety score utilizes fuzzy comprehensive evaluation and a weighted aggregation method, considering indicators such as strength, stiffness, stability, and fatigue strength. An improved Salp Swarm Algorithm is utilized to execute the optimization process. Engineering case studies demonstrate that the optimized design reduces the mast’s self-weight by 6.5% under safety constraints. Compared to designs without safety constraints, the material usage increases slightly by 7.3%, but the safety performance improves by 14.74%. The findings indicate that integrating safety evaluation constraints into the optimization process not only enhances the structural safety of the mast but also achieves a favorable balance between safety and economic efficiency. This approach provides a valuable reference for the safety-focused design of rotary drilling rig masts. Full article
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16 pages, 1446 KiB  
Article
A Study on the Dietary Yeast Polysaccharide Supplementation in Growth Performance, Antioxidant Capacity, and Immunity of Juvenile Largemouth Bass (Micropterus salmoides)
by Junjie Qin, Haifeng Mi, Mingchun Ren, Dongyu Huang, Hualiang Liang, Lu Zhang, Tao Teng and Heng Yin
Fishes 2025, 10(1), 26; https://doi.org/10.3390/fishes10010026 - 8 Jan 2025
Viewed by 1368
Abstract
The aim of this study was to investigate the effects of dietary yeast polysaccharide (YPS) supplementation on the growth performance, whole-body composition, antioxidant capacity, and immunity of juvenile largemouth bass (Micropterus salmoides). In this study, five diets with YPS levels of [...] Read more.
The aim of this study was to investigate the effects of dietary yeast polysaccharide (YPS) supplementation on the growth performance, whole-body composition, antioxidant capacity, and immunity of juvenile largemouth bass (Micropterus salmoides). In this study, five diets with YPS levels of 0.00% (control), 0.05% (0.05Y), 0.10% (0.10Y), 0.15% (0.15Y), and 0.20% (0.20Y) were designed and prepared. A total of 300 healthy fish (3.20 ± 0.03 g) were randomly divided into 15 floating cages (1 × 1 × 1 m) in five different groups, with three replicates per group, for an 8-week culture experiment. The 0.10Y and 0.20Y groups had significantly higher feed conversion ratios compared with the control group. There was no significant effect on any of the other growth indicators. Plasma biochemical indices showed that the 0.10Y group exhibited the highest plasma alkaline phosphatase content and the 0.20Y group exhibited the highest plasma glucose content. Plasma antioxidant indices (total antioxidant capacity, superoxide dismutase, and glutathione) and antioxidant genes (catalase and superoxide dismutase) were elevated in the 0.05Y or 0.10Y groups, and the malondialdehyde content decreased with increasing YPS concentration. Moreover, the 0.05Y group showed significantly higher immune-related gene (nuclear factor-kappa B, interleukin-8, and interleukin-10) mRNA expression. Altogether, our results indicate that dietary YPS supplementation enhances the antioxidant and immune capacity of M. salmoides, but with no positive effect on their growth. Full article
(This article belongs to the Special Issue Fish Nutrition and Immunology)
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24 pages, 7521 KiB  
Article
High-Resolution High-Squint Large-Scene Spaceborne Sliding Spotlight SAR Processing via Joint 2D Time and Frequency Domain Resampling
by Mingshan Ren, Heng Zhang and Weidong Yu
Remote Sens. 2025, 17(1), 163; https://doi.org/10.3390/rs17010163 - 6 Jan 2025
Viewed by 922
Abstract
A frequency domain imaging algorithm, featured as joint two-dimensional (2D) time and frequency domain resampling, used for high-resolution high-squint large-scene (HHL) spaceborne sliding spotlight synthetic aperture radar (SAR) processing is proposed in this paper. Due to the nonlinear beam rotation during HHL data [...] Read more.
A frequency domain imaging algorithm, featured as joint two-dimensional (2D) time and frequency domain resampling, used for high-resolution high-squint large-scene (HHL) spaceborne sliding spotlight synthetic aperture radar (SAR) processing is proposed in this paper. Due to the nonlinear beam rotation during HHL data acquisition, the Doppler centroid varies nonlinearly with azimuth time and traditional sub-aperture approaches and two step approach fail to remove the inertial Doppler aliasing of spaceborne sliding spotlight SAR data. In addition, curved orbit effect and long synthetic aperture time make the range histories difficult to model and introduce space-variants in both range and azimuth. In this paper, we use the azimuth deramping and 2D time-domain azimuth resampling, collectively referred to as preprocessing, to eliminate the aliasing in Doppler domain and correct the range-dependent azimuth-variants of range histories. After preprocessing, the squint sliding spotlight SAR data could be considered as equivalent broadside strip-map SAR during processing. Frequency domain focusing, mainly involves phase multiplication and resampling in 2D frequency and RD domain, is then applied to compensate for the residual space-variants and achieve the focusing of SAR data. Moreover, in order to adapt higher resolution and larger scene cases, the combination of the proposed algorithm and partitioning strategy is also discussed in this paper. Processing results of simulation data and Gaofen-3 experimental data are presented to demonstrate the feasibility of the proposed methods. Full article
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20 pages, 1618 KiB  
Article
Learning-Based Model Predictive Control for Legged Robots with Battery–Supercapacitor Hybrid Energy Storage System
by Boyu Shu, Zhiwu Huang, Wanwan Ren, Yue Wu and Heng Li
Appl. Sci. 2025, 15(1), 382; https://doi.org/10.3390/app15010382 - 3 Jan 2025
Cited by 3 | Viewed by 1178
Abstract
Electrically driven legged robots have become popular in recent years. However, the development of reliable energy supply systems and effective energy management strategies for legged robots with dramatically varying power requirements still needs to be explored. This article proposes a learning-based model predictive [...] Read more.
Electrically driven legged robots have become popular in recent years. However, the development of reliable energy supply systems and effective energy management strategies for legged robots with dramatically varying power requirements still needs to be explored. This article proposes a learning-based model predictive control (MPC) energy management strategy for legged robots with battery–supercapacitor hybrid energy storage systems containing a power prediction unit and an MPC with learning-based adaptive weights. Firstly, the mathematical model of the legged robot is established, and a dual-layer long short-term memory network is constructed to predict the load power demand, providing the model and measurable disturbance for the MPC. Secondly, a multi-objective optimization objective function is established for the MPC-based energy management strategy. Three normalized terms, battery capacity loss, battery power fluctuation, and supercapacitor state-of-charge regulation, are balanced in the objective function. Finally, a deep learning algorithm is proposed to adaptively adjust the three weighting factors to meet the diverse operation conditions. Hardware-in-the-loop experimental implementations demonstrate that the proposed method can improve the kinematic performance of the legged robot by maintaining the supercapacitor state of charge at a relatively high level and reducing the battery capacity loss by 12.7% compared with the conventional MPC method. Full article
(This article belongs to the Special Issue Recent Advances in Autonomous Systems and Robotics, 2nd Edition)
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13 pages, 10000 KiB  
Article
Impacts of Copper Deficiency on Oxidative Stress and Immune Function in Mouse Spleen
by Xiaocong Li, Xin Zeng, Wanqin Yang, Peng Ren, Hengxiao Zhai and Heng Yin
Nutrients 2025, 17(1), 117; https://doi.org/10.3390/nu17010117 - 30 Dec 2024
Cited by 2 | Viewed by 1780
Abstract
Introduction: Copper is an essential trace element crucial for enzyme synthesis and metabolism. Adequate copper levels are beneficial for maintaining the normal immune function of the spleen. Copper deficiency disrupts the metabolic processes within the spleen and impairs its immune function. This research [...] Read more.
Introduction: Copper is an essential trace element crucial for enzyme synthesis and metabolism. Adequate copper levels are beneficial for maintaining the normal immune function of the spleen. Copper deficiency disrupts the metabolic processes within the spleen and impairs its immune function. This research examines the impact of copper deficiency on the spleen and the potential recovery following copper supplementation. Methods: Weaned mice underwent a 4-week copper-deficient diet, succeeded by 1-week of copper repletion via intraperitoneal copper sulfate injection. Histological examination was used to assess pathological changes in the spleen. Biochemical assays were performed to measure oxidative stress levels in the spleen. ELISA, qPCR, and Western blot were employed to examine alterations in inflammatory markers, immune indicators, and oxidative regulatory factors across various levels. Results: Copper deficiency caused histological damage to the spleen, altered the expression of oxidative stress regulatory pathways (Nrf2, Keap1, and HO-1), and affected the expression of key inflammatory enzymes (iNOS, COX2) and transcription factor NF-κB, leading to oxidative damage. This was reflected by decreased levels of SOD, GSH, and T-AOC, along with increased levels of CAT and MDA. The levels of inflammatory cytokines IL-1β, TNF-α, IL-6, and IL-8 were notably increased. Copper supplementation significantly improved these changes. Conclusions: Copper deficiency leads to spleen tissue damage in mice, affecting the Nrf2 regulatory pathway and inducing oxidative damage. Subsequent copper supplementation with copper sulfate effectively ameliorates the damage caused by copper deficiency. Full article
(This article belongs to the Section Nutritional Immunology)
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