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1.
Front Neurorobot ; 17: 1269447, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37811356

RESUMO

With the development of machine perception and multimodal information decision-making techniques, autonomous driving technology has become a crucial area of advancement in the transportation industry. The optimization of vehicle navigation, path planning, and obstacle avoidance tasks is of paramount importance. In this study, we explore the use of attention mechanisms in a end-to-end architecture for optimizing obstacle avoidance and path planning in autonomous driving vehicles. We position our research within the broader context of robotics, emphasizing the fusion of information and decision-making capabilities. The introduction of attention mechanisms enables vehicles to perceive the environment more accurately by focusing on important information and making informed decisions in complex scenarios. By inputting multimodal information, such as images and LiDAR data, into the attention mechanism module, the system can automatically learn and weigh crucial environmental features, thereby placing greater emphasis on key information during obstacle avoidance decisions. Additionally, we leverage the end-to-end architecture and draw from classical theories and algorithms in the field of robotics to enhance the perception and decision-making abilities of autonomous driving vehicles. Furthermore, we address the optimization of path planning using attention mechanisms. We transform the vehicle's navigation task into a sequential decision-making problem and employ LSTM (Long Short-Term Memory) models to handle dynamic navigation in varying environments. By applying attention mechanisms to weigh key points along the navigation path, the vehicle can flexibly select the optimal route and dynamically adjust it based on real-time conditions. Finally, we conducted extensive experimental evaluations and software experiments on the proposed end-to-end architecture on real road datasets. The method effectively avoids obstacles, adheres to traffic rules, and achieves stable, safe, and efficient autonomous driving in diverse road scenarios. This research provides an effective solution for optimizing obstacle avoidance and path planning in the field of autonomous driving. Moreover, it contributes to the advancement and practical applications of multimodal information fusion in navigation, localization, and human-robot interaction.

2.
Nanotechnology ; 32(48)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34359058

RESUMO

Development of simple and accurate methods for the detection of As3+is highly desirable and technically important. In this work, a highly sensitive and selective long-period fiber gratings sensor based on surface plasmon resonance was developed for As3+detection by designing glutathione-functionalized Au nanoparticles as a signal amplification tag. Based on the chemical interaction between As3+and glutathione, the self-assembling glutathione on the surface of the gold film combines selectively with As3+, and then anchors the glutathione-functionalized Au nanoparticles, which changes the refractive index of the surrounding environment, resulting in a shift of the transmission spectrum. Results show that the sensor could detect As3+with concentrations ranging from 0.02 to 2 ppb. The sensor exhibited excellent specificity for As3+against other metal ions, such as Na+, Fe3+, Mg2+, Cu2+, Pb2+, Ni2+, Ba2+, and Co3+. The fiber sensor was successfully employed to detect As3+in pond water samples, demonstrating that it has the potential for As3+detection with the advantages of low cost, high sensitivity, and a simple structure.

3.
Molecules ; 24(20)2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31652500

RESUMO

Saponins in the Camellia sinensis seeds have a broad spectrum of biological properties and application potentials. However, up to now, no chromatographic methods have been developed to provide full fingerprinting and quality assurance for these saponins. This research aimed to develop a novel method to tentatively identify and quantify saponins in C. sinensis seeds by ultra-high-performance liquid chromatography coupled with photo-diode array detector and quadrupole time-of-flight mass spectrometry (UPLC-PDA-QTOF-MS/MS), and compare it with the classic vanillin-sulfuric acid assay. Fifty-one triterpene saponins, including six potentially new compounds, were simultaneously detected by UPLC-PDA-MS/MS, and their chemical structures were speculated according to the retention behavior and fragmentation pattern. The total saponin content in the crude extract and the purified saponin fraction of C. sinensis seeds were quantified to be 19.57 ± 0.05% (wt %) and 41.68 ± 0.09% (wt %) respectively by UPLC-PDA at 210 nm, while the corresponding values were determined to be 43.11 ± 3.17% (wt %) and 56.60 ± 5.79% (wt %) respectively by the vanillin-sulfuric acid assay. The developed UPLC-PDA -MS/MS method could determine specified saponins, and is more reliable for quantifying the C. sinensis seed saponins than the classic spectrophotometric method. It is of great significance for the future investigations and applications of these saponins.


Assuntos
Camellia sinensis/química , Cromatografia Líquida de Alta Pressão/métodos , Saponinas/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Triterpenos/análise , Estrutura Molecular , Extratos Vegetais/química , Saponinas/química , Sementes/química , Espectrometria de Massas em Tandem/métodos , Triterpenos/química
4.
Chem Biodivers ; 15(5): e1800059, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29633499

RESUMO

The synthesis of celastrol analogues containing amino acid ester at the C(29) position and their evaluation for cytotoxic activities in vitro were reported. The MTT test showed that a set of derivatives with lower IC50 values than that of the positive control group cisplatin and the parent compound celastrol, which exhibited greater antiproliferative activities. The most potent title compounds 2a and 2e exhibited cytotoxic activities in vitro against HeLa and A549 cell lines with IC50 values of 0.371 and 0.237 µm, 0.235 and 0.109 µm, respectively. The apoptosis assay demonstrated that 2a and 2e can induces of A549 cell apoptosis in low concentrations. These results showed that 2a and 2e may be promising for further research as antitumor agents.


Assuntos
Aminoácidos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Triterpenos/farmacologia , Aminoácidos/química , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Estrutura Molecular , Triterpenos Pentacíclicos , Relação Estrutura-Atividade , Tripterygium/química , Triterpenos/síntese química , Triterpenos/química , Células Tumorais Cultivadas
5.
Molecules ; 22(10)2017 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-28974006

RESUMO

Ovarian cancer is regarded as one of the most severe malignancies for women in the world. Death rates have remained steady over the past five decades, due to the undeniable inefficiency of the current treatment in preventing its recurrence and death. The development of new effective alternative agents for ovarian cancer treatment is becoming increasingly critical. Tea saponins (TS) are triterpenoidsaponins composed of sapogenins, glycosides, and organic acids, which possess a variety of pharmacological activities, and have shown promise in the anti-cancer field. Through cell CellTiter 96® Aqueous One Solution Cell Proliferation assay (MTS) assay, colony formation, Hoechst 33342 staining assay, caspase-3/7 activities, flow cytometry for apoptosis analysis, and Western blot, we observed that TS isolated from the seeds of tea plants, Camellia sinensis, exhibited strong anti-proliferation inhibitory effects on OVCAR-3 and A2780/CP70 ovarian cancer cell lines. Our results indicate that TS may selectivity inhibit human ovarian cancer cells by mediating apoptosis through the extrinsic pathway, and initiating anti-angiogenesis via decreased VEGF protein levels in a HIF-1α-dependent pathway. Our data suggests that, in the future, TS could be incorporated into a potential therapeutic agent against human ovarian cancer.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Saponinas/química , Saponinas/farmacologia , Triterpenos/química , Triterpenos/farmacologia , Apoptose , Camellia sinensis/química , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Ácido Oleanólico/química , Extratos Vegetais/química , Saponinas/isolamento & purificação , Sementes/química , Transdução de Sinais , Chá/química , Triterpenos/isolamento & purificação , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos
6.
Anal Chim Acta ; 941: 94-100, 2016 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-27692383

RESUMO

In this study, an electrogenerated chemiluminescence (ECL) sensing platform for carbofuran detection was constructed based on ECL energy transfer (ECRET) and carbon dot (C-dot)-tagged aptamers as the recognition element. Fullerene (C60)-loaded gold nanoparticles (C60-Au) were used as the energy donor, modified on a glassy carbon electrode. C-dot-tagged DNA aptamers were used as the receptor, and ECRET then occurred between C60-Au and C-dots. After accepting the energy, the C-dots acted as a signal indicator and showed decreased signal intensity in the presence of targets, which competitively bound to DNA aptamers and blocked energy transfer. Using this robust, straight-forward strategy, the sensor showed a linear ECL response to carbofuran at concentrations from 2.0 × 10-11 mol L-1 to 8.0 × 10-9 mol L-1. The detection limit of this assay was shown to be 8.8 × 10-13 mol L-1. Thus, the sensing approach described in this study could be adapted for use in the detection of various pesticide residue targets.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/métodos , Carbofurano/análise , Transferência de Energia , Luminescência , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Carbofurano/química , Carbofurano/metabolismo , Carbono/química , Eletroquímica , Pontos Quânticos/química
7.
J Sep Sci ; 39(20): 4019-4026, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27550709

RESUMO

We present novel magnetic composite nanospheres for the preparation of a nanoiron oxide/carbon dots/ß-cyclodextrin/molecularly imprinted polymer for the selective solid-phase extraction kelthane and pyridaben from vegetables. The molecularly imprinted polymer was synthesized on the surface of nano-iron oxide/carbon dots via a chemical polymerization procedure, where kelthane-ß-cyclodextrin and pyridaben-ß-cyclodextrin inclusion complexes were used as template molecules, and their adsorption behavior was investigated in detail. Characterization analysis and binding experiments revealed that magnetic composite nanospheres had outstanding magnetic properties, a large adsorption capacity, and high competitive selectivity for kelthane and pyridaben. The magnetic composite nanospheres were employed as an adsorbent in solid-phase extraction for the determination of kelthane and pyridaben in vegetable samples. The recoveries of kelthane and pyridaben were 92.8-105.2 and 94.4-104.6%, respectively.

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