Search Results (221)

This study proposes an autonomous recognition and approach method for unmanned aerial vehicles (UAVs) targeting linear splicing sleeves. By integrating deep learning and active stereo vision, this method addresses the navigation challenges faced by UAVs during the identification, localization, and docking of splicing sleeves on overhead power transmission lines. First, a two-stage localization strategy, LC (Local Clustering)-RB (Reparameterization Block)-YOLO (You Only Look Once)v8n (OBB (Oriented Bounding Box)), is developed for linear target splicing sleeves. This strategy ensures rapid, accurate, and reliable recognition and localization while generating precise waypoints for UAV docking with splicing sleeves. Next, virtual reality technology is utilized to expand the splicing sleeve dataset, creating the D_SS dataset tailored to diverse scenarios. This enhancement improves the robustness and generalization capability of the recognition model. Finally, a UAV approach splicing sleeve (UAV-ASS) visual navigation simulation platform is developed using the Robot Operating System (ROS), the PX4 open-source flight control system, and the GAZEBO 3D robotics simulator. This platform simulates the UAV’s final approach to the splicing sleeves. Experimental results demonstrate that, on the D_SS dataset, the RB-YOLOv8n(OBB) model achieves a mean average precision (mAP0.5) of 96.4%, with an image inference speed of 86.41 frames per second. By incorporating the LC-based fine localization method, the five rotational bounding box parameters (x, y, w, h, and angle) of the splicing sleeve achieve a mean relative error (MRE) ranging from 3.39% to 4.21%. Additionally, the correlation coefficients (ρ) with manually annotated positions improve to 0.99, 0.99, 0.98, 0.95, and 0.98, respectively. These improvements significantly enhance the accuracy and stability of splicing sleeve localization. Moreover, the developed UAV-ASS visual navigation simulation platform effectively validates high-risk algorithms for UAV autonomous recognition and docking with splicing sleeves on power transmission lines, reducing testing costs and associated safety risks. Full article

Background: Recently, pyrido[2,3-d] pyrimidine, triazolopyrimidine, thiazolopyrimidine, quinoline, and pyrazole derivatives have gained attention due to their diverse biological activities, including antimicrobial, antioxidant, antitubercular, antitumor, anti-inflammatory, and antiviral effects. Objective: The synthesis of new heterocyclic compounds including 5-quinoline-pyrido[2,3-d] pyrimidinone (1–2, 4, 6–7), 6-quinoline-pyrido[2,3-d]thiazolo[3,2-a]pyrimidinone (3, 5, 8–10), 1,2,4-triazole-6-quinoline-pyrido[2,3-d]thiazolo[3,2-a]pyrimidinone (11–13), and pyrido[2,3-d]thiazolo[3,2-a]pyrimidine-ethyl-(pyridine)-9-thiaazabenzo[cd]azulenone (14) derivatives was performed with high yields while evaluating antimicrobial activities. Methods: A new series of quinoline-pyrido[2,3-d]thiazolo[3,2-a]pyrimidine derivatives were prepared using a modern style and advanced technology, resulting in high yields of these new compounds. Various reagents were utilized, specifically tailored to the production needs of each compound, through reactions that included alkylation, addition, condensation, acylation, the formation of Schiff bases, and intramolecular cyclization. Results: The chemical structures of the new compounds were determined using spectroscopy analyses, including IR, NMR, and MS, achieving good yields ranging from 68% to 90% under mild conditions in a regular system. All compounds were tested for in vitro antimicrobial activity and compared to standard drugs, specifically cefotaxime sodium and nystatin. The results showed that compounds 10 to 14 exhibited excellent antimicrobial activity, with a minimum inhibitory concentration (MIC) of 1 to 5 µmol/mL, compared to that of the standard drugs, which had MIC values of 1 to 3 µmol/mL. Furthermore, molecular docking studies were conducted to explore the interactions of specific compounds with antimicrobial target proteins. The findings revealed that compounds 10 to 14 displayed significant binding energies, with ΔG values ranging from −7.20 to −11.70 kcal/mol, indicating effective binding to the active sites of antimicrobial protein receptors. Conclusions: The SAR study confirmed a relationship between antimicrobial activity and the tested compounds. Molecular docking demonstrated that compounds 10, 11, 12, 13, and 14 exhibited significant binding energy, effectively interacting with the active sites of antimicrobial protein receptors. This consistent finding supports that these new compounds’ practical and theoretical studies align regarding their antimicrobial activity. Full article

Understanding the molecular targets of natural products is crucial for elucidating their mechanisms of action, mitigating toxicity, and uncovering potential therapeutic pathways. Icaritin (ICT), a bioactive flavonoid, demonstrates significant anti-tumor activity but lacks defined molecular targets. This study employs an advanced strategy integrating proteolysis targeting chimera (PROTAC) technology with quantitative proteomics to identify ICT’s key targets. A library of 22 ICT-based PROTAC derivatives were synthesized, among which LJ-41 exhibited a superior IC50 of 5.52 μM against Burkitt lymphoma (CA-46) cells. Then, differential proteomic analysis identified Bax inhibitor-1 (BI-1) as a potential target. Target validation techniques, including cellular thermal shift assay (CETSA), drug affinity responsive target stability (DARTS) assay, surface plasmon resonance (SPR) assay, and molecular docking, confirmed LJ-41’s high specificity for BI-1. Mechanistic investigations revealed that LJ-41 induces apoptosis through BI-1 degradation, triggering endoplasmic reticulum stress and activating inositol-requiring enzyme 1 α (IRE1α), activating transcription factor 6 (ATF6), and nuclear factor erythroid 2-related factor transcription factor heme oxygenase 1 (NRF2-HO-1) signaling pathways. This study establishes a refined methodological framework for natural product target discovery and highlights ICT-PROTAC derivatives’ potential for clinical application in Burkitt lymphoma treatment. Full article

Background: L-Shikonin, an active component of Arnebia euchroma (Royle) Johnst., has remarkable pharmacological effects, particularly in its anti-tumour activity. Nonetheless, the specific targets and mechanisms of action remain to be further explored. Methods: A novel Fe₃O₄@L-Shikonin was designed and synthesized in this study by linking Fe₃O₄ and L-Shikonin through benzophenone. Fe₃O₄@L-Shikonin was characterized using several techniques, including scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and drug removal methods, to determine the content of L-Shikonin on the surface of the magnetic particles. Target hooking technology was utilized to identify the target proteins of the compound in melanoma. The synthesized Fe₃O₄@L-Shikonin was co-incubated with A375 cell lysate, followed by the target proteins, which were purified by magnetic enrichment using magnetic microspheres and identified by high-resolution mass spectrometry. Results: AutoDock Vina software was employed for molecular docking analysis, where it was found that L-Shikonin targets RPN1, CPEB4, and HNRNPUL1 proteins. Subsequently, A375 cells were treated with L-Shikonin at different concentrations (2.5, 5.0, 10.0 μM) for 48 h, and the expressions of the three proteins were observed. The results showed a significant reduction in the relative expression of CPEB4 in the high-dose group compared to the control group (p < 0.01). Moreover, the relative expression of HNRNPUL1 was decreased in the medium- and high-dose groups (p < 0.05). Conclusions: This study initially revealed from the source that L-Shikonin may regulate melanoma-specific markers, melanosomes, tyrosine kinases related to abnormal tyrosine metabolism, and melanoma through multiple targets such as CPEB4 and HNRNPUL1. Proliferation and metastasis work together to exert an anti-melanoma mechanism, which provides a new idea for the follow-up study of the molecular pharmacological mechanism of the complex system of total naphthoquinones in Arnebia euchroma (Royle) Johns. Full article

Oxidosqualene cyclases (OSCs) are enzymes responsible for converting linear triterpenes into tetracyclic ones, which are known as precursors of other important and bioactive metabolites. Two OSCs genes encoding parkeol synthase and lanostadienol synthase have been found in representatives of the genera Apostichopus and Stichopus (family Stichopodidae, order Synallactida). As a limited number of sea cucumber OSCs have been studied thus far, OSCs encoding gene(s) of the sea cucumber Eupentacta fraudatrix (family Sclerodactylidae, order Dendrochirotida) were investigated to fill this gap. Here, we employed RACEs, molecular cloning, and Oxford Nanopore Technologies to identify candidate OSC mRNAs and genes. The assembled cDNAs were 2409 bp (OSC1) and 3263 bp (OSC2), which shared the same CDS size of 2163 bp encoding a 721-amino-acid protein. The E. fraudatrix OSC1 and OSC2 had higher sequence identity similarity to each other (77.5%) than to other holothurian OSCs (64.7–71.0%). According to the sequence and molecular docking analyses, OSC1 with L436 is predicted to be parkeol synthase, while OSC2 with Q439 is predicted to be lanostadienol synthase. Based on the phylogenetic analysis, E. fraudatrix OSCs cDNAs clustered with other holothurian OSCs, forming the isolated branch. As a result of gene analysis, the high polymorphism and larger size of the OSC1 gene suggest that this gene may be an ancestor of the OSC2 gene. These results imply that the E. fraudatrix genome contains two OSC genes whose evolutionary pathways are different from those of the OSC genes in Stichopodidae. Full article

Visual recognition and localization of underwater optical beacons are critical for AUV docking, but traditional beacons are limited by fixed directionality and light attenuation in water. To extend the range of optical docking, this study designs a novel omnidirectional rotating optical beacon that provides 360-degree light coverage over 45 m, improving beacon detection probability through synchronized scanning. Addressing the challenges of light centroid detection, we introduce a parallel deep learning detection algorithm based on an improved YOLOv8-pose model. Initially, an underwater optical beacon dataset encompassing various light patterns was constructed. Subsequently, the network was optimized by incorporating a small detection head, implementing dynamic convolution and receptive-field attention convolution for single-stage multi-scale localization. A post-processing method based on keypoint joint IoU matching was proposed to filter redundant detections. The algorithm achieved 93.9% AP at 36.5 FPS, with at least a 5.8% increase in detection accuracy over existing methods. Moreover, a light-source-based measurement method was developed to accurately detect the beacon’s orientation. Experimental results indicate that this scheme can achieve high-precision omnidirectional guidance with azimuth and pose estimation errors of -4.54° and 3.09°, respectively, providing a reliable solution for long-range and large-scale optical docking. Full article

This paper presents the design process and resulting technical concept for an integrated hyperloop system, aimed at realizing efficient high-speed ground transportation. This study integrates various functions into a coherent and technically feasible solution, with key design decisions that optimize performance and cost-efficiency. An iterative design process with domain-specific experts, regular reviews, and a dataset with a single source of truth were employed to ensure continuous and collective progress. The proposed hyperloop system features a maximum speed of 600 $\frac{\mathrm{km}}{h}$ and a capacity of 21 passengers per pod (vehicle). It employs air docks for efficient boarding, electromagnetic suspension (EMS) combined with electrodynamic suspension (EDS) for high-speed lane switching, and short stator motor technology for propulsion. Cooling is managed through water evaporation at an operating pressure of 10 $\mathrm{m}$$\mathrm{bar}$, while a 300 $\mathrm{k}$$\mathrm{W}$ inductive power supply (IPS) provides onboard power. The design includes a safety system that avoids emergency exits along the track and utilizes separated safety-critical and high-bandwidth communication. With prefabricated concrete parts used for the tube, construction costs can be reduced and scalability improved. A dimensioned cross-sectional drawing, as well as a preliminary pod mass budget and station layout, are provided, highlighting critical technical systems and their interactions. Calculations of energy consumption per passenger kilometer, accounting for all functions, demonstrate a distinct advantage over existing modes of transportation, achieving greater efficiency even at high speeds and with smaller vehicle sizes. This work demonstrates the potential of a well-integrated hyperloop system to significantly enhance transportation efficiency and sustainability, positioning it as a promising extension to existing modes of travel. The findings offer a solid framework for future hyperloop development, encouraging further research, standardization efforts, and public dissemination for continued advancements. Full article

The paper highlights the potential of cross-docking to reduce storage time and costs. The study addresses evolving market demands that push logistics providers to adopt new technologies for operational efficiency, emphasizing the often-overlooked importance of optimizing cross-docking layouts. The research, conducted in two phases, first analyzed the current warehouse layout (Variant I) to identify inefficiencies and then designed a new layout (Variant II) that was simulated using FlexSim 2022 software. The results showed significant improvements with the new layout, including a 35% increase in deliveries and a 3.23% reduction in forklift travel distances, leading to lower operational costs. Even minor adjustments in the warehouse design proved to enhance logistics efficiency, particularly during peak demand periods like holidays. The study demonstrates how FlexSim software can be applied in cold chain logistics to optimize warehouse operations, underscoring the benefits of cross-docking for cost-effective logistics management. Full article

Algae, despite being labeled as an underexplored biological source of chemical constituents, remain inadequately studied in terms of their metabolism. Metabolomics has emerged as a high-throughput technology to investigate the full metabolic profile of samples that could aid in the understanding and characterization of algae. By delving into their primary composition, particularly polysaccharides and phycobiliproteins, alongside secondary metabolites like polyphenols and pigments, researchers can uncover not only their rheological and nutritional properties but also their diverse biological activities. Given the growing interest in algae in food and related industries, innovative approaches should be explored to enhance the value of their functional components. In this sense, in the context of contemporary in-silico studies, metabolomics should be paired with computational methodologies, to develop novel techniques for studying biomolecular interactions. Molecular docking has emerged, with the function of predicting the atomic-level interaction between small molecules (ligands) and target proteins (proteins). This synergistic approach integrating both technologies could allow us to characterize algal profiles, evaluate their potential for bioactive properties, and better understand their metabolism. This work explores the development of metabolomic and computational strategies targeted toward the functional characterization of algae. By harnessing these technologies, we can unlock new possibilities for using algae in various industrial applications, paving the way for sustainable and innovative solutions in the future. Full article

Background: The goal of the current study was to investigate the inhibitory activity of six phenolic compounds, i.e., rosmarinic acid, gallic acid, oleuropein, epigallocatechin gallate (EGCG), 3-hydroxytyrosol, and quercetin, against β-site amyloid precursor protein cleaving enzyme-1 (BACE1), also known as β-secretase or memapsin 2, which is implicated in the pathogenesis of Alzheimer’s disease (AD). Methods and Results: The inhibitory potential against BACE1, molecular docking simulations, as well as neurotoxicity and the effect on the AD-related gene expression of the selected phenolics were tested. BACE1 inhibitory activity was carried out using the ELISA microplate assay via fluorescence resonance energy transfer (FRET) technology. Molecular docking experiments were performed in the human BACE1 active site (PDB code: 2WJO). Neurotoxicity of the compounds was carried out in SH-SY5Y, a human neuroblastoma cell line, by the Alamar Blue method. A gene expression analysis of the compounds on fourteen genes linked to AD was conducted using the real-time polymerase chain reaction (RT-PCR) method. Rosmarinic acid, EGCG, oleuropein, and quercetin (also used as the reference) were able to inhibit BACE1 with their respective IC₅₀ values 4.06 ± 0.68, 1.62 ± 0.12, 9.87 ± 1.01, and 3.16 ± 0.30 mM. The inhibitory compounds were observed to occupy the non-catalytic site of the BACE1. However, hydrogen bonds were found to be present between rosmarinic acid and EGCG and aspartic amino acid D228 in the catalytic site. Oleuropein and quercetin effectively suppressed the expression of PSEN, APOE, and CLU, which are recognized to be linked to the pathogenesis of AD. Conclusions: The outcomes of the work bring quercetin, EGCG, and rosmarinic acid to the forefront as promising BACE1 inhibitors. Full article

Data are accumulating on the hydrolytic activity of serum albumin towards esters and organophosphates. Previously, with the help of the technology of proton nuclear magnetic resonance (¹H NMR) spectroscopy, we observed the yield of acetate in the solution of bovine serum albumin and p-nitrophenyl acetate (NPA). Thus, we showed that albumin possesses true esterase activity towards NPA. Then, using the methods of molecular docking and molecular dynamics, we established site Sudlow I as the catalytic center of true esterase activity of albumin. In the present work, to expand our understanding of the molecular mechanisms of albumin pseudoesterase and true esterase activity, we investigated—in experiments in vitro and in silico—the interaction of anticoagulant warfarin (WRF, specific ligand of site Sudlow I) and benzodiazepine diazepam (DIA, specific ligand of site Sudlow II) with albumins of different species, and determined how the binding of WRF and DIA affects the hydrolysis of NPA by albumin. It was found that the characteristics of the binding modes of WRF in site Sudlow I and DIA in site Sudlow II of human (HSA), bovine (BSA), and rat (RSA) albumins have species differences, which are more pronounced for site Sudlow I compared to site Sudlow II, and less pronounced between HSA and RSA compared to BSA. WRF competitively inhibits true esterase activity of site Sudlow I towards NPA and does not affect the functioning of site Sudlow II. Diazepam can slow down true esterase activity of site Sudlow I in noncompetitive manner. It was concluded that site Sudlow I is more receptive to allosteric modulation compared to site Sudlow II. Full article

This paper presents a study on aircraft engine identification using real-time 3D LiDAR point cloud segmentation technology, a key element for the development of automated docking systems in airport boarding facilities, known as jetbridges. To achieve this, 3D LiDAR sensors utilizing a spinning method were employed to gather surrounding environmental 3D point cloud data. The raw 3D environmental data were then filtered using the 3D RANSAC technique, excluding ground data and irrelevant apron areas. Segmentation was subsequently conducted based on the filtered data, focusing on aircraft sections. For the segmented aircraft engine parts, the centroid of the grouped data was computed to determine the 3D position of the aircraft engine. Additionally, PointNet was applied to identify aircraft engines from the segmented data. Dynamic tests were conducted in various weather and environmental conditions, evaluating the detection performance across different jetbridge movement speeds and object-to-object distances. The study achieved a mean intersection over union (mIoU) of 81.25% in detecting aircraft engines, despite experiencing challenging conditions such as low-frequency vibrations and changes in the field of view during jetbridge maneuvers. This research provides a strong foundation for enhancing the robustness of jetbridge autonomous docking systems by reducing the sensor noise and distortion in real-time applications. Our future research will focus on optimizing sensor configurations, especially in environments where sea fog, snow, and rain are frequent, by combining RGB image data with 3D LiDAR information. The ultimate goal is to further improve the system’s reliability and efficiency, not only in jetbridge operations but also in broader autonomous vehicle and robotics applications, where precision and reliability are critical. The methodologies and findings of this study hold the potential to significantly advance the development of autonomous technologies across various industrial sectors. Full article

In the context of the digital economy, digital technology is an important driving force to promote green development and achieve the “dual-carbon goal”. Taking 1746 Shanghai and Shenzhen A-share enterprises from 2015 to 2022 as research objects, we empirically examine the relationship between government subsidies, digital transformation, and corporate green technology innovation. The study shows that (1) there is an inverted “U”-shaped relationship between government subsidies and corporate green technological innovation, while digital transformation plays a mediating role, and there is a difference between the quality and quantity of digital transformation in promoting green technological innovation. (2) Through the analysis of the moderating effect, it is found that market concentration has an obvious inhibitory effect between enterprise digital transformation and green technology innovation. (3) The study, by classifying the nature of enterprises, shows that the promotion effect of digital transformation on green technology innovation is weaker under heavily polluted enterprises than under non-heavily polluted enterprises, but the promotion interval of the relationship between government subsidies and green technology innovation is larger. Therefore, enterprises should make full use of digital technology to inject new impetus into their innovation activities, and the government should fully consider the appropriate space for enterprises to receive subsidies, make reasonable use of the incentive effect of government subsidies, and smooth the information docking channels for government and enterprise subsidies. Full article

Background: Alzheimer’s disease (AD) is a common clinical neurodegenerative disorder, primarily characterized by progressive cognitive decline and behavioral abnormalities. The hallmark pathological changes of AD include widespread neuronal degeneration, plaques formed by the deposition of amyloid β-protein (Aβ), and neurofibrillary tangles (NFTs). With the acceleration of global aging, the incidence of AD is rising year by year, making it a major global public health concern. Due to the complex pathology of AD, finding effective interventions has become a key focus of research. Ouabain (OUA), a cardiac glycoside, is well-known for its efficacy in treating heart disease. Recent studies have also indicated its potential in AD therapy, although its exact mechanism of action remains unclear. Methods: This study integrates bioinformatics, multi-omics technologies, and in vivo and in vitro experiments to investigate the effects of OUA on the pathophysiological changes of AD and its underlying molecular mechanisms. Results: This study analyzed the expression of the triggering receptor expressed on myeloid cells 2 (TREM2) across different stages of AD using bioinformatics. Serum samples from patients were used to validate soluble TREM2 (sTREM2) levels. Using an Aβ_1-42-induced microglial cell model, we confirmed that OUA enhances the PI3K/AKT signaling pathway activation by upregulating TREM2, which reduces neuroinflammation and promotes the transition of microglia from an M1 proinflammatory state to an M2 anti-inflammatory state. To evaluate the in vivo effects of OUA, we assessed the learning and memory capacity of FAD^4T transgenic mice using the Morris water maze and contextual fear conditioning tests. We used real-time quantitative PCR, immunohistochemistry, and Western blotting to measure the expression of inflammation-associated cytokines and to assess microglia polarization. OUA enhances cognitive function in FAD^4T mice and has been confirmed to modulate microglial M1/M2 phenotypes both in vitro and in vivo. Furthermore, through bioinformatics analysis, molecular docking, and experimental validation, TREM2 was identified as a potential target for OUA. It regulates PI3K/Akt signaling pathway activation, playing a crucial role in OUA-mediated M2 microglial polarization and its anti-inflammatory effects in models involving Aβ_1-42-stimulated BV-2 cells and FAD^4T mice. Conclusions: These findings indicate that OUA exerts anti-neuroinflammatory effects by regulating microglial polarization, reducing the production of inflammatory mediators, and activating the PI3K/Akt signaling pathway. Given its natural origin and dual effects on microglial polarization and neuroinflammation, OUA emerges as a promising therapeutic candidate for neuroinflammatory diseases such as AD. Full article

Epoxide hydrolases (EHs) catalyze the conversion of epoxides into vicinal diols. The epoxide hydrolase gene from P. chrysosporium was previously cloned and subjected to site-directed mutation to study its enzyme activity, but the results were unsatisfactory. This study used error prone PCR and DNA shuffling to construct a PchEHA mutation library. We performed mutation-site combinations on PchEHA based on enzyme activity measurement results combined with directed evolution technology. More than 15,000 mutants were randomly selected for the preliminary screening of PchEHA enzyme activity alongside 38 mutant strains with increased enzyme activity or enantioselectivity. Protein expression and purification were conducted to determine the hydrolytic activity of PchEHA, and three mutants increased their activity by more than 95% compared with that of the wt. After multiple rounds of screening and site-specific mutagenesis, we found that F3 offers the best enzyme activity and enantioselectivity; furthermore, the molecular docking results confirmed this result. Overall, this study uncovered novel mutants with potential value as industrial biocatalysts. Full article