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1.
IEEE Trans Cybern ; PP2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34637387

RESUMO

Human-robot-collaboration requires robot to proactively and intelligently recognize the intention of human operator. Despite deep learning approaches have achieved certain results in performing feature learning and long-term temporal dependencies modeling, the motion prediction is still not desirable enough, which unavoidably compromises the accomplishment of tasks. Therefore, a hybrid recurrent neural network architecture is proposed for intention recognition to conduct the assembly tasks cooperatively. Specifically, the improved LSTM (ILSTM) and improved Bi-LSTM (IBi-LSTM) networks are first explored with state activation function and gate activation function to improve the network performance. The employment of the IBi-LSTM unit in the first layers of the hybrid architecture helps to learn the features effectively and fully from complex sequential data, and the LSTM-based cell in the last layer contributes to capturing the forward dependency. This hybrid network architecture can improve the prediction performance of intention recognition effectively. One experimental platform with the UR5 collaborative robot and human motion capture device is set up to test the performance of the proposed method. One filter, that is, the quartile-based amplitude limiting algorithm in sliding window, is designed to deal with the abnormal data of the spatiotemporal data, and thus, to improve the accuracy of network training and testing. The experimental results show that the hybrid network can predict the motion of human operator more precisely in collaborative workspace, compared with some representative deep learning methods.

2.
Anal Chem ; 92(9): 6734-6740, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32285667

RESUMO

A new photoelectrochemical (PEC) "signal-on" sensing platform based on photoactive material Bi2O3-ZnO and CdS quantum dots (QDs) sensitizer was fabricated for ultrasensitive determination of thrombin by constructing supersandwich nanowires. The CdS/ZnO/Bi2O3 sensitization structure with excellent energy level arrangement remarkably improved photoelectric conversion efficiency because of the efficient separation of the electron-hole. Moreover, the DNA supersandwich nanowire is ingeniously synthesized in one step by simple dislocation hybridization, which could carry a large amount of sensitized material CdS QDs. More importantly, with Exonuclease III (Exo III)-assisted multiple amplification, the proposed "signal-on" platform demonstrated a detection range of 10 fM to 1 µM with the detection limit of 1.41 fM for thrombin. Impressively, the PEC platform can successfully detect human serum samples with good accuracy. Above all, the CdS/ZnO/Bi2O3 sensitization photoelectric biosensing platform by using DNA nanowire in combination with Exo III-multiple amplification opens new sensitized amplification paths for supersensitive biosensing and bioanalysis.


Assuntos
Compostos de Cádmio/química , DNA/química , Técnicas Eletroquímicas , Nanofios/química , Pontos Quânticos/química , Sulfetos/química , Trombina/análise , Humanos , Tamanho da Partícula , Processos Fotoquímicos , Propriedades de Superfície
3.
Biosens Bioelectron ; 147: 111778, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655382

RESUMO

In this work, a new 3D DNA nanosphere was ingeniously designed and fabricated, which was used to combine with multiple enzyme-free amplification strategy to develop a photoelectrochemical (PEC) biosensing platform for ultrasensitive detection of carcinoembryonic antigen (CEA). The 3D DNA nanostructure was self-assembled by base complementary pairing in a few minutes and rolling circle amplification (RCA) reaction. The intense photocurrent derived from Au NPs/ZnSe QDs can be effectively decreased by 3D DNA nanospheres assembled on the electrode, making photoelectric signal present "off" state. The specific binding of target CEA with its hairpin (HP1) aptamer opens HP1 structure, which initiated multiple enzyme-free strand displacement amplification (SDA) reaction and generated a large number of single strands DNA S1. Then S1 competitively binds to capture DNA on the electrode to release 3D DNA nanospheres, thus the photocurrent signal became "on" state for achieving amplified assay of target CEA. The proposed PEC biosensor exhibits excellent performance with a wide linear range of 1.0 fg/mL to 10 ng/mL and a low detection limit of 0.12 fg/mL for CEA, which was successfully applied for the assay of real serum samples with good precision. The reported strategy opens a new simple way for PEC biosensor using DNA nanostructure, showing huge potential in clinical application research.


Assuntos
Biomarcadores Tumorais/isolamento & purificação , Técnicas Biossensoriais , Técnicas Eletroquímicas , Neoplasias/diagnóstico , Biomarcadores Tumorais/química , Biomarcadores Tumorais/genética , DNA de Cadeia Simples/química , Ouro/química , Humanos , Nanopartículas Metálicas/química , Nanosferas/química , Nanoestruturas/química , Neoplasias/genética , Pontos Quânticos/química
4.
Anal Chem ; 91(21): 14117-14124, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31642671

RESUMO

Glutathione (GSH) serves vital functions in biological systems and associates with various human diseases. In this work, a versatile electrochemiluminence (ECL) and a photoelectrochemical (PEC) "signal on" biosensing platform were developed for a sensitive assay of GSH by a Mn2+-powered DNAzyme amplification strategy combined with DNA-walker-triggered allosteric conversion. First, MnO2 nanosheets were reduced to Mn2+ by GSH; then, Mn2+ as a substitute target triggered DNAzyme-assisted cleavage-cycling amplification to generate numerous DNA output (s3). Meanwhile, the DNA molecular machine was introduced to bridge signal probes for versatile biosensing, which included hairpin DNA as a track and an arm as a walker. The presence of DNA output (s3) activated the swing arm to hybridize with hairpin DNA and then cut it by Nt.BbvCI, which initiated autonomous walking of the arm for forming a large number of streptavidin (SA) aptamers. Thus, a large number of CdS:Mn-SA tags as versatile signal probes was linked to the electrode by specific SA-aptamer binding, generating highly enhanced ECL and PEC signals for sensitive detection of the target. The present biosensing system take advantage of metal ion-based DNAzyme amplification, a DNA walker machine, multi-signals of QDs, and specificity of aptamers, which can provide a universal and efficient biosensing method for detecting various targets. The designed strategy demonstrated good performance for a GSH assay in human serum samples, showing more promising applications than other reported methods.


Assuntos
Técnicas Biossensoriais , DNA/química , Técnicas Eletroquímicas , Glutationa/sangue , Medições Luminescentes , Compostos de Manganês/química , Regulação Alostérica , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , DNA/metabolismo , DNA Catalítico/química , DNA Catalítico/metabolismo , Glutationa/metabolismo , Humanos , Compostos de Manganês/metabolismo , Hibridização de Ácido Nucleico , Processos Fotoquímicos
5.
Biosens Bioelectron ; 143: 111602, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31442756

RESUMO

Herein, a novel biosensing platform for versatile electrochemiluminescence (ECL) "off" and fluorescence (FL) "on" detection of lipopolysaccharide (LPS) with multiple-amplification strategy is proposed. The specific recognition of target to aptamer on the magnetic beads (MB) firstly released abundant DNA sequences of three kinds. The sequences hybridized with multifunctional molecular beacon (MMB) and initiated numerous bidirectional polymerization and shearing reactions, generating a large number of DNA fragments (a1) by multiple cycling amplification. Then a1 was introduced to the triple-helix sensing system, opening the triple-helix structure. In ECL system, the G-rich chains S2 were exposed to form G-quadruplex-hemin complex in the presence of hemin, which could efficiently quench ECL for "off" detection of LPS. In FL system, the fluorophore FAM and quencher BHQ on S1 chain were separated with opening of triple-helix structure, achieving fluorescence "on" signal for LPS assay. So the versatile platform can achieve greatly amplified ECL and FL signal changes for sensitive assay of LPS, showing wide linear ranges (0.1 fg/mL-0.1 ng/mL by ECL and 10 fg/mL-1-1 µg/mL by FL) and low detection limits (0.012 fg/mL by ECL and 1.269 fg/mL by FL). Therefore, the present ECL "Off" and FL "On" dual-signal detection patterns for LPS displayed many advantages over other reported methods, which provided an outlook for future applications in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Lipopolissacarídeos/isolamento & purificação , Medições Luminescentes , Aptâmeros de Nucleotídeos/química , DNA Catalítico/química , Fluorescência , Quadruplex G , Ouro/química , Hemina/química , Humanos , Lipopolissacarídeos/química , Nanopartículas Metálicas/química
6.
Mikrochim Acta ; 186(2): 85, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30627800

RESUMO

A multifunctional DNA nanocage containing CdTe quantum dots (QDs) was prepared. It was applied to the fluorometric detection of human 8-oxoG DNA glycosylase 1 (hOGG1) by exonuclease-assisted cycling amplification technique. When loaded with the cancer drug doxorubicin (Dox), the nanocage is also a versatile probe for fluorescence imaging of cancer cells, and drug delivery to them. The presence of hOGG1 leads to the division of DNA HP1 (containing 8-oxo-dG) and formation of DNA fragments 1 and 2. Then, HP2 is added to hybridize with DNA 1 and produced lots of trigger DNA (containing nucleolin aptamer) by Exo III-aided cycling amplification. The DNA nanocage was fabricated by linking the trigger DNA to multiple specific DNA strands, and the fluorescent CdTe QDs were further conjugated to the DNA nanocage for sensitive detection of hOGG1 activity. After Dox is incorporated into the DNA nanocage, the fluorescence of Dox is turned off. Once the DNA nanocage enters the MCF-7 cells, the Dox is released and its fluorescence (measured at excitation/emission wavelengths of 480/560 nm) is turned on. The DNA nanocage containing fluorescent QDs and Dox was successfully applied to the fluorometric detection of hOGG1, fluorescence imaging, and therapy of cancer cells, which has great promise in clinical application and treatment of cancer. Graphical abstract A multifunctional DNA nanocage containing CdTe quantum dots and acting as a signalling probe was prepared. It was applied to fluorometric determination of human 8-oxoG DNA glycosylase 1 using cycling amplification technique. It also enables drug delivery to cancer cells if loaded with doxorubicin.


Assuntos
DNA Glicosilases/análise , Doxorrubicina/análise , Sistemas de Liberação de Medicamentos/métodos , Fluorometria/métodos , Pontos Quânticos/química , Compostos de Cádmio/química , DNA/química , Diagnóstico por Imagem/métodos , Doxorrubicina/administração & dosagem , Fluorescência , Corantes Fluorescentes/química , Humanos , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Telúrio/química
7.
Biosens Bioelectron ; 118: 115-121, 2018 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-30059865

RESUMO

In this work, we designed a new strategy for ultrasensitive detection of CEA based on efficient electrochemiluminescence (ECL) quenching of Ru(bpy)32+-doped SiO2 nanocomposite by ferrocene using target recycling amplification technique. A large number of Ru@SiO2 ECL signal probe were firstly assembled on the novel magnetic core-shell Fe3O4@Au nanoparticles (NPs), then the ferrocene-labeled ECL quenching probe (Fc-probe) was linked to the magnetic NPs. Finally, numerous DNA1 sequences were produced by target CEA-triggered multiple recycling amplification and displaced the Fc-probe on the magnetic NPs, leading to significantly enhanced ECL signal for CEA detection. Because of the designed cascade signal amplification strategy, the newly developed method achieved a wide linear range of 10 fg/mL to 10 ng/mL with a low detection limit of  3.5 fg/mL. Furthermore, taking advantages of the magnetic Fe3O4@Au NPs for carring abundant signal probes, sensing target and ECL detection, the developed ECL strategy is convenient, rapid and displayed high sensitivity for CEA detection, which has great potential for analyzing the clinical samples in practical disease diagnosis applications.


Assuntos
Técnicas Biossensoriais/métodos , Antígeno Carcinoembrionário/análise , Técnicas Eletroquímicas , Medições Luminescentes , Nanopartículas Metálicas/química , Técnicas Biossensoriais/instrumentação , Humanos , Nanocompostos , Dióxido de Silício/química
8.
Biosens Bioelectron ; 110: 239-245, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29627645

RESUMO

Herein, we successfully devised a novel photoelectrochemical (PEC) platform for ultrasensitive detection of adenosine by target-triggering cascade multiple cycle amplification based on the silver nanoparticles-assisted ion-exchange reaction with CdTe quantum dots (QDs). In the presence of target adenosine, DNA s1 is released from the aptamer and then hybridizes with hairpin DNA (HP1), which could initiate the cycling cleavage process under the reaction of nicking endonuclease. Then the product (DNA b) of cycle I could act as the "DNA trigger" of cycle II to further generate a large number of DNA s1, which again go back to cycle I, thus a cascade multiple DNA cycle amplification was carried out to produce abundant DNA c. These DNA c fragments with the cytosine (C)-rich loop were captured by magnetic beads, and numerous silver nanoclusters (Ag NCs) were synthesized by AgNO3 and sodium borohydride. The dissolved AgNCs released numerous silver ions which could induce ion exchange reaction with the CdTe QDs, thus resulting in greatly amplified change of photocurrent for target detection. The detection linear range for adenosine was 1.0 fM ~10 nM with the detection limit of 0.5 fM. The present PEC strategy combining cascade multiple DNA cycle amplification and AgNCs-induced ion-exchange reaction with QDs provides new insight into rapid, and ultrasensitive PEC detection of different biomolecules, which showed great potential for detecting trace amounts in bioanalysis and clinical biomedicine.


Assuntos
Adenosina/sangue , Técnicas Biossensoriais/métodos , Compostos de Cádmio/química , Nanopartículas Metálicas/química , Pontos Quânticos/química , Prata/química , Telúrio/química , Adenosina/análise , DNA/química , Técnicas Eletroquímicas/métodos , Humanos , Troca Iônica , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Hibridização de Ácido Nucleico , Processos Fotoquímicos , Pontos Quânticos/ultraestrutura
9.
Zhonghua Yi Shi Za Zhi ; 37(2): 104-7, 2007 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-17877896

RESUMO

It is said that the alleged author of Qian Jin Yi Fang, a supplement to Bei Ji Qian Jin Yao Fang is SUN Si-miao. It is claimed that, based on the relevant historical materials, there are overlapping contents, principle differences in the academic ideas between the two books. Moreover, there are differences between the texts of Qian Jin Yi Fang cited by Wai Tai Mi Yao and the modern version of Qian Jin Yi Fang, all these texts are not from the original Qian Jin Yi Fang. It can be concluded that the author of Qian Jin Yi Fang is not SUN Si-miao.


Assuntos
Livros , China , Humanos
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