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1.
Environ Res ; 239(Pt 2): 117410, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37858693

RESUMO

BACKGROUND: Previous researches have assessed the relationships of urinary arsenic metabolism with type 2 diabetes (T2D) and glucose-insulin homeostasis, but the results were controversial, and potential mechanisms remain largely unclear. OBJECTIVES: This study aimed to investigate the cross-sectional and longitudinal associations of urinary arsenic metabolism with T2D prevalence and glucose changes in relatively higher arsenic exposure, and further to evaluate the underlying roles of oxidative damage in these relationships. METHODS: We included 796 participants at baseline, among them 509 participants were followed up after 2 years. Logistic regression model and leave-one-out approach were applied to evaluate the associations of arsenic metabolism with T2D prevalence. Linear mixed model was conducted to estimate the relationship of arsenic metabolism with glycemic changes over two years. The associations between arsenic metabolism and indicators of oxidative stress were assessed with a linear regression model. We further performed mediation analysis to investigate the role of oxidative stress in the associations of arsenic metabolism with 2-year change of glucose levels. RESULTS: Higher urinary MMA% increased T2D prevalence and baseline glucose levels. MMA% was positively associated with 2-year change of glucose levels. Moreover, we observed significant dose-response relationship between MMA% and 8-hydroxy-2-deoxyguanosine (8-OHdG). However, the mediating role of 8-OHdG in the association of MMA% and 2-year change of glucose levels was not observed in this population. CONCLUSIONS: In this population exposure to relatively higher arsenic levels, higher MMA% contributed to increased T2D prevalence and glucose homeostasis disorder. Arsenic metabolism also affected oxidative stress levels, especially 8-OHdG. Further studies are required to investigate the potential mechanisms.


Assuntos
Arsênio , Diabetes Mellitus Tipo 2 , Humanos , Arsênio/metabolismo , Diabetes Mellitus Tipo 2/epidemiologia , Exposição Ambiental , Estudos Transversais , 8-Hidroxi-2'-Desoxiguanosina , Homeostase , Glucose
2.
Sensors (Basel) ; 23(6)2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36991815

RESUMO

A photodetector based on a hybrid dimensional heterostructure of laterally aligned multiwall carbon nanotubes (MWCNTs) and multilayered MoS2 was prepared using the micro-nano fixed-point transfer technique. Thanks to the high mobility of carbon nanotubes and the efficient interband absorption of MoS2, broadband detection from visible to near-infrared (520-1060 nm) was achieved. The test results demonstrate that the MWCNT-MoS2 heterostructure-based photodetector device exhibits an exceptional responsivity, detectivity, and external quantum efficiency. Specifically, the device demonstrated a responsivity of 3.67 × 103 A/W (λ = 520 nm, Vds = 1 V) and 718 A/W (λ = 1060 nm, Vds = 1 V). Moreover, the detectivity (D*) of the device was found to be 1.2 × 1010 Jones (λ = 520 nm) and 1.5 × 109 Jones (λ = 1060 nm), respectively. The device also demonstrated external quantum efficiency (EQE) values of approximately 8.77 × 105% (λ = 520 nm) and 8.41 × 104% (λ = 1060 nm). This work achieves visible and infrared detection based on mixed-dimensional heterostructures and provides a new option for optoelectronic devices based on low-dimensional materials.

3.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(4): 428-432, 2023 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-37580295

RESUMO

Animal study plays a key role to evaluate the safety and effectivity of medical devices. This study aims to share evaluated consideration on the role, general principles, necessity, study design and quality management system of animal study, in order to improve the quality of animal study and reduce unnecessary study.


Assuntos
Equipamentos e Provisões , Modelos Animais , Animais
4.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(6): 684-689, 2023 Nov 30.
Artigo em Chinês | MEDLINE | ID: mdl-38086729

RESUMO

The ossicular replacement prosthesis should have good biocompatibility, stability, easy to install, and excellent sound transmission capacity. In this study, the characteristics of ideal materials for the ossicular replacement prosthesis were analyzed by searching the types of materials used in clinical practice and comparing the advantages and disadvantages of various materials and structures. At the same time, in combination with the current evaluation requirements and evaluation experience, the focus of the performance research project of ossicular replacement prosthesis in the process of registration is discussed to clarify the performance evaluation requirements of these products, so as to provide reference for the future work of manufacturers and regulators. The performance evaluation of ossicular replacement prosthesis focuses on its mechanical properties, fixation stability, sound transmission characteristics, biological characteristics, and magnetic resonance compatibility.


Assuntos
Prótese Ossicular , Substituição Ossicular , Som , Desenho de Prótese , Resultado do Tratamento
5.
Zhongguo Yi Liao Qi Xie Za Zhi ; 47(5): 550-556, 2023 Sep 30.
Artigo em Chinês | MEDLINE | ID: mdl-37753896

RESUMO

In recent years, new orthopaedic implantable devices continue to emerge, which require higher requirements for technical evaluation. Animal study is an important part of the research and development process for the new orthopedic implantable devices, which provides relevant evidence for product design and stereotyping. By introducing the purpose of animal study, and the application of 3R principle (replacement, reduction, refinement) in this field, we summarize the concern on the animal study, in order to provide reference for the development and research of new orthopedic implantable devices and biomaterials. At the same time, the application of evidence-based research methods such as systematic review in the field is introduced, which provides new tools and approaches for the technical review and regulatory science.


Assuntos
Ortopedia , Animais , Materiais Biocompatíveis , Próteses e Implantes , Projetos de Pesquisa
6.
Neuroimage ; 264: 119678, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36261057

RESUMO

Head motion presents a continuing problem in brain PET studies. A wealth of motion correction (MC) algorithms had been proposed in the past, including both hardware-based methods and data-driven methods. However, in most real brain PET studies, in the absence of ground truth or gold standard of motion information, it is challenging to objectively evaluate MC quality. For MC evaluation, image-domain metrics, e.g., standardized uptake value (SUV) change before and after MC are commonly used, but this measure lacks objectivity because 1) other factors, e.g., attenuation correction, scatter correction and parameters used in the reconstruction, will confound MC effectiveness; 2) SUV only reflects final image quality, and it cannot precisely inform when an MC method performed well or poorly during the scan time period; 3) SUV is tracer-dependent and head motion may cause increases or decreases in SUV for different tracers, so evaluating MC effectiveness is complicated. Here, we present a new algorithm, i.e., motion corrected centroid-of-distribution (MCCOD) to perform objective quality control for measured or estimated rigid motion information. MCCOD is a three-dimensional surrogate trace of the center of tracer distribution after performing rigid MC using the existing motion information. MCCOD is used to inform whether the motion information is accurate, using the PET raw data only, i.e., without PET image reconstruction, where inaccurate motion information typically leads to abrupt changes in the MCCOD trace. MCCOD was validated using simulation studies and was tested on real studies acquired from both time-of-flight (TOF) and non-TOF scanners. A deep learning-based brain mask segmentation was implemented, which is shown to be necessary for non-TOF MCCOD generation. MCCOD is shown to be effective in detecting abrupt translation motion errors in slowly varying tracer distribution caused by the motion tracking hardware and can be used to compare different motion estimation methods as well as to improve existing motion information.


Assuntos
Processamento de Imagem Assistida por Computador , Tomografia por Emissão de Pósitrons , Humanos , Processamento de Imagem Assistida por Computador/métodos , Tomografia por Emissão de Pósitrons/métodos , Movimento (Física) , Algoritmos , Encéfalo/diagnóstico por imagem
7.
Planta ; 256(4): 65, 2022 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-36036331

RESUMO

MAIN CONCLUSION: TaATLa1 was identified to respond to nitrogen deprivation through transcriptome analysis of wheat seedlings. TaATLa1 specifically transports Gln, Glu, and Asp, and affects the biomass of Arabidopsis and wheat. Nitrogen is an essential macronutrient and plays a crucial role in wheat production. Amino acids, the major form of organic nitrogen, are remobilized by amino acid transporters (AATs) in plants. AATs are commonly described as central components of essential developmental processes and yield formation via taking up and transporting amino acids in plants. However, few studies have reported the detailed biochemical properties and biological functions of these AATs in wheat. In this study, key genes encoding AATs were screened from transcriptome analysis of wheat seedlings treated with normal nitrogen (NN) and nitrogen deprivation (ND). Among them, 21 AATs were down-regulated and eight AATs were up-regulated under ND treatment. Among the homoeologs, TaATLa1.1-3A, TaATLa1.1-3B, and TaATLa1.1-3D (TaATLa1.1-3A, -3B, and -3D), belonging to amino acid transporter-like a (ATLa) subfamily, were significantly down-regulated in response to ND in wheat, and accordingly were selected for functional analyses. The results demonstrated that TaATLa1.1-3A, -3B, and -3D effectively transported glutamine (Gln), glutamate (Glu), and aspartate (Asp) in yeast. Overexpression of TaAILa1.1-3A, -3B, and -3D in Arabidopsis thaliana L. significantly increased amino acid content in leaves, storage protein content in seeds and the plant biomass under NN. Knockdown of TaATLa1.1-3A, -3B, and -3D in wheat seedlings resulted in a significant block of amino acid remobilization and growth inhibition. Taken together, TaATLa1.1-3A, -3B, and -3D contribute substantially to Arabidopsis and wheat growth. We propose that TaATLa1.1-3A, -3B, and -3D may participate in the source-sink translocation of amino acid, and they may have profound implications for wheat yield improvement.


Assuntos
Arabidopsis , Triticum , Sistemas de Transporte de Aminoácidos , Aminoácidos , Regulação da Expressão Gênica de Plantas , Nitrogênio , Proteínas de Plantas , Plântula
8.
Eur J Nucl Med Mol Imaging ; 49(9): 3086-3097, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35277742

RESUMO

A novel deep learning (DL)-based attenuation correction (AC) framework was applied to clinical whole-body oncology studies using 18F-FDG, 68 Ga-DOTATATE, and 18F-Fluciclovine. The framework used activity (λ-MLAA) and attenuation (µ-MLAA) maps estimated by the maximum likelihood reconstruction of activity and attenuation (MLAA) algorithm as inputs to a modified U-net neural network with a novel imaging physics-based loss function to learn a CT-derived attenuation map (µ-CT). METHODS: Clinical whole-body PET/CT datasets of 18F-FDG (N = 113), 68 Ga-DOTATATE (N = 76), and 18F-Fluciclovine (N = 90) were used to train and test tracer-specific neural networks. For each tracer, forty subjects were used to train the neural network to predict attenuation maps (µ-DL). µ-DL and µ-MLAA were compared to the gold-standard µ-CT. PET images reconstructed using the OSEM algorithm with µ-DL (OSEMDL) and µ-MLAA (OSEMMLAA) were compared to the CT-based reconstruction (OSEMCT). Tumor regions of interest were segmented by two radiologists and tumor SUV and volume measures were reported, as well as evaluation using conventional image analysis metrics. RESULTS: µ-DL yielded high resolution and fine detail recovery of the attenuation map, which was superior in quality as compared to µ-MLAA in all metrics for all tracers. Using OSEMCT as the gold-standard, OSEMDL provided more accurate tumor quantification than OSEMMLAA for all three tracers, e.g., error in SUVmax for OSEMMLAA vs. OSEMDL: - 3.6 ± 4.4% vs. - 1.7 ± 4.5% for 18F-FDG (N = 152), - 4.3 ± 5.1% vs. 0.4 ± 2.8% for 68 Ga-DOTATATE (N = 70), and - 7.3 ± 2.9% vs. - 2.8 ± 2.3% for 18F-Fluciclovine (N = 44). OSEMDL also yielded more accurate tumor volume measures than OSEMMLAA, i.e., - 8.4 ± 14.5% (OSEMMLAA) vs. - 3.0 ± 15.0% for 18F-FDG, - 14.1 ± 19.7% vs. 1.8 ± 11.6% for 68 Ga-DOTATATE, and - 15.9 ± 9.1% vs. - 6.4 ± 6.4% for 18F-Fluciclovine. CONCLUSIONS: The proposed framework provides accurate and robust attenuation correction for whole-body 18F-FDG, 68 Ga-DOTATATE and 18F-Fluciclovine in tumor SUV measures as well as tumor volume estimation. The proposed method provides clinically equivalent quality as compared to CT in attenuation correction for the three tracers.


Assuntos
Aprendizado Profundo , Neoplasias , Fluordesoxiglucose F18 , Humanos , Processamento de Imagem Assistida por Computador/métodos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Cintilografia , Compostos Radiofarmacêuticos
9.
Nanotechnology ; 34(1)2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36174390

RESUMO

Interfacial properties of van der Waals (vdW) heterostructures dominate the durability and function of their booming practical and potential applications such as opoelectronic devices, superconductors and even pandemics research. However, the strain engineering modulates of interlayer friction of vdW heterostructures consisting of two distinct materials are still unclear, which hinders the applications of vdW heterostructures, as well as the design of solid lubricant and robust superlubricity. In the present paper, a molecular model between a hexagonal graphene flake and a rectangular SLMoS2sheet is established, and the influence of biaxial and uniaxial strain on interlayer friction is explored by molecular dynamics. It is found that the interlayer friction is insensitive to applied strains. Strong robustness of superlubricity between distinct layers is owed to the structure's intrinsic incommensurate characteristics and the existence of Moiré pattern. In engineering practice, it is of potential importance to introduce two distinct 2D materials at the sliding contact interface to reduce the interfacial friction of the contact pair and serve as ideal solid lubricants. Our research provides a further basis to explore the nanotribology and strain engineering of 2D materials and vdW heterostructures.

10.
Proc Natl Acad Sci U S A ; 116(27): 13293-13298, 2019 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-31209050

RESUMO

The linear ubiquitin assembly complex (LUBAC) comprises 3 components: HOIP, HOIL-1, and Sharpin, of which HOIP and HOIL-1 are both members of the RBR subfamily of E3 ubiquitin ligases. HOIP catalyses the formation of Met1-linked ubiquitin oligomers (also called linear ubiquitin), but the function of the E3 ligase activity of HOIL-1 is unknown. Here, we report that HOIL-1 is an atypical E3 ligase that forms oxyester bonds between the C terminus of ubiquitin and serine and threonine residues in its substrates. Exploiting the sensitivity of HOIL-1-generated oxyester bonds to cleavage by hydroxylamine, and macrophages from knock-in mice expressing the E3 ligase-inactive HOIL-1[C458S] mutant, we identify IRAK1, IRAK2, and MyD88 as physiological substrates of the HOIL-1 E3 ligase during Toll-like receptor signaling. HOIL-1 is a monoubiquitylating E3 ubiquitin ligase that initiates the de novo synthesis of polyubiquitin chains that are attached to these proteins in macrophages. HOIL-1 also catalyses its own monoubiquitylation in cells and most probably the monoubiquitylation of Sharpin, in which ubiquitin is also attached by an oxyester bond. Our study establishes that oxyester-linked ubiquitylation is used as an intracellular signaling mechanism.


Assuntos
Imunidade Inata , Complexos Multiproteicos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina/metabolismo , Animais , Catálise , Técnicas de Introdução de Genes , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Macrófagos/metabolismo , Camundongos , Camundongos Transgênicos , Complexos Multiproteicos/fisiologia , Serina , Treonina , Ubiquitinação
11.
Sensors (Basel) ; 22(2)2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35062451

RESUMO

It is challenging to obtain wafer-scaled aligned films for completely exploiting the promising properties of semiconducting single-walled carbon nanotubes (s-SWCNTs). Aligned s-SWCNTs with a large area can be obtained by combining water evaporation and slow withdrawal-induced self-assembly in a dip-coating process. Moreover, the tunability of deposition morphology parameters such as stripe width and spacing is examined. The polarized Raman results show that s-SWCNTs can be aligned in ±8.6°. The derived two terminal photodetector shows both a high negative responsivity of 41 A/W at 520 nm and high polarization sensitivity. Our results indicate that aligned films with a large area may be useful to electronics- and optoelectronics-related applications.

12.
Zhongguo Yi Liao Qi Xie Za Zhi ; 46(6): 659-663, 2022 Nov 30.
Artigo em Chinês | MEDLINE | ID: mdl-36597395

RESUMO

With the development of additive manufacturing, the advantages of this type implant devices in the treatment of acetabular defects and reconstruction are becoming more and more prominent. The number of registration and declaration of such products is increasing day by day. According to the relevant requirements of the National Medical Products Administration for registration and application documents, combined with the characteristics of acetabular reconstruction implant products made of additive manufacturing, this study analyzes and summarizes the relevant requirements on raw material control, product performance research, product manufacturing, clinical evaluation, et al. We should pay more attention to in the registration and application materials submitted by the applicant. Provide opinions and suggestions for the next registration applicant to standardize product R&D and registration application documents, in order to help them optimize product R&D process, improve product quality and registration application efficiency.


Assuntos
Comércio , Próteses e Implantes
13.
Zhongguo Yi Liao Qi Xie Za Zhi ; 45(4): 424-428, 2021 Jul 30.
Artigo em Chinês | MEDLINE | ID: mdl-34363371

RESUMO

With the advantages of inflatable bone expander in the treatment of osteoporotic vertebral compression fractures, the number of applications for registration of such products is increasing. Based on the characteristics of the medical device, this article analyzed and summarized the relevant requirements for the basic information, product performance research, product manufacturing, clinical evaluation, and product instructions that should be focused on the registration application dossiers, as well as comply with the requirements of CMDE. The focus of the registration application for Inflatable Bone Expander should be the standardization of the application dossiers, while the difficulty was the scientific rationality of the research data. Comments and suggestions are provided to relevant practitioners on standardization of registration application dossiers. It may help them to optimize the quality of registration application dossiers while improve the efficiency of registration applications.


Assuntos
Fraturas por Compressão , Fraturas da Coluna Vertebral , Cimentos Ósseos , Humanos , Resultado do Tratamento
14.
Zhongguo Yi Liao Qi Xie Za Zhi ; 45(2): 200-204, 2021 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-33825382

RESUMO

OBJECTIVE: This paper introduces the key content and background of Technical Review Guidance for the Registration of Personalized Additive Manufacturing Medical Devices of Passive Implantable Bone, Joint and Oral Hard Tissues. METHODS: The core contents and importance of the construction of personalized design validation and verification and additive manufacturing system are described respectively. RESULTS: The personalized design needs to be carried out under the control of interactive cooperation between healthcare professional and engineer. And the performance of personalized device must be validated and verified completely. At the same time, in view of the particularity of the quality management system of additive manufacturing, the technical focus is expounded. CONCLUSIONS: New ideas and methods shall be used in evaluate and administrate personalized additive manufacturing medical device.


Assuntos
Impressão Tridimensional , Próteses e Implantes
15.
Hepatology ; 69(6): 2471-2488, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30748020

RESUMO

Nonalcoholic fatty liver disease (NAFLD) has become a worldwide epidemic. A large and growing unmet therapeutic need has inspired numerous studies in the field. Integrating the published genomic data available in the Gene Expression Omnibus (GEO) with NAFLD samples from rodents, we discovered that interferon regulatory factor 6 (IRF6) is significantly downregulated in high-fat diet (HFD)-induced fatty liver. In the current study, we identified IRF6 in hepatocytes as a protective factor in liver steatosis (LS). During HFD challenge, hepatic Irf6 was suppressed by promoter hypermethylation. Severity of HFD-induced LS was exacerbated in hepatocyte-specific Irf6 knockout mice, whereas hepatocyte-specific transgenic mice overexpressing Irf6 (IRF6-HTG) exhibited alleviated steatosis and metabolic disorder in response to HFD feeding. Mechanistic studies in vitro demonstrated that hepatocyte IRF6 directly binds to the promoter of the peroxisome proliferator-activated receptor γ (PPARγ) gene and subsequently halts the transcription of Pparγ and its target genes (e.g., genes that regulate lipogenesis and lipid acid uptake) under physiological conditions. Conclusion: Irf6 is downregulated by promoter hypermethylation upon metabolic stimulus exposure, which fail to inhibit Pparγ and its targets, driving abnormalities of lipid metabolism.


Assuntos
Regulação da Expressão Gênica , Fatores Reguladores de Interferon/genética , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/patologia , PPAR gama/genética , Animais , Metilação de DNA/genética , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Regulação para Baixo , Hepatócitos/citologia , Humanos , Fatores Reguladores de Interferon/metabolismo , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Distribuição Aleatória , Sensibilidade e Especificidade
16.
Proc Natl Acad Sci U S A ; 114(17): E3481-E3489, 2017 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-28404732

RESUMO

It is widely accepted that the essential role of TRAF6 in vivo is to generate the Lys63-linked ubiquitin (K63-Ub) chains needed to activate the "master" protein kinase TAK1. Here, we report that TRAF6 E3 ligase activity contributes to but is not essential for the IL-1-dependent formation of K63-Ub chains, TAK1 activation, or IL-8 production in human cells, because Pellino1 and Pellino2 generate the K63-Ub chains required for signaling in cells expressing E3 ligase-inactive TRAF6 mutants. The IL-1-induced formation of K63-Ub chains and ubiquitylation of IRAK1, IRAK4, and MyD88 was abolished in TRAF6/Pellino1/Pellino2 triple-knockout (KO) cells, but not in TRAF6 KO or Pellino1/2 double-KO cells. The reexpression of E3 ligase-inactive TRAF6 mutants partially restored IL-1 signaling in TRAF6 KO cells, but not in TRAF6/Pellino1/Pellino2 triple-KO cells. Pellino1-generated K63-Ub chains activated the TAK1 complex in vitro with similar efficiently to TRAF6-generated K63-Ub chains. The early phase of TLR signaling and the TLR-dependent secretion of IL-10 (controlled by IRAKs 1 and 2) was only reduced modestly in primary macrophages from knockin mice expressing the E3 ligase-inactive TRAF6[L74H] mutant, but the late-phase production of IL-6, IL-12, and TNFα (controlled only by the pseudokinase IRAK2) was abolished. RANKL-induced signaling in macrophages and the differentiation of bone marrow to osteoclasts was similar in TRAF6[L74H] and wild-type cells, explaining why the bone structure and teeth of the TRAF6[L74H] mice was normal, unlike TRAF6 KO mice. We identify two essential roles of TRAF6 that are independent of its E3 ligase activity.


Assuntos
Fator 88 de Diferenciação Mieloide/metabolismo , Proteínas Nucleares/metabolismo , Ligante RANK/metabolismo , Transdução de Sinais , Fator 6 Associado a Receptor de TNF/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Substituição de Aminoácidos , Animais , Técnicas de Silenciamento de Genes , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Camundongos , Camundongos Knockout , Mutação de Sentido Incorreto , Fator 88 de Diferenciação Mieloide/genética , Proteínas Nucleares/genética , Poliubiquitina/genética , Poliubiquitina/metabolismo , Ligante RANK/genética , Fator 6 Associado a Receptor de TNF/genética , Ubiquitina-Proteína Ligases/genética
17.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 37(3): 412-418, 2020 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-32597082

RESUMO

Electroencephalography (EEG) signals are strongly correlated with human emotions. The importance of nodes in the emotional brain network provides an effective means to analyze the emotional brain mechanism. In this paper, a new ranking method of node importance, weighted K-order propagation number method, was used to design and implement a classification algorithm for emotional brain networks. Firstly, based on DEAP emotional EEG data, a cross-sample entropy brain network was constructed, and the importance of nodes in positive and negative emotional brain networks was sorted to obtain the feature matrix under multi-threshold scales. Secondly, feature extraction and support vector machine (SVM) were used to classify emotion. The classification accuracy was 83.6%. The results show that it is effective to use the weighted K-order propagation number method to extract the importance characteristics of brain network nodes for emotion classification, which provides a new means for feature extraction and analysis of complex networks.


Assuntos
Encéfalo , Eletroencefalografia , Emoções , Algoritmos , Encéfalo/fisiologia , Humanos , Processamento de Sinais Assistido por Computador , Máquina de Vetores de Suporte
18.
Small ; 15(52): e1903362, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31736239

RESUMO

Recent years have witnessed rapid progresses made in the photoelectric performance of two-dimensional materials represented by graphene, black phosphorus, and transition metal dichalcogenides. Despite significant efforts, a photodetection technique capable for longer wavelength, higher working temperature as well as fast responsivity, is still facing huge challenges due to a lack of best among bandgap, dark current, and absorption ability. Exploring topological materials with nontrivial band transport leads to peculiar properties of quantized phenomena such as chiral anomaly, and magnetic-optical effect, which enables a novel feasibility for an advanced optoelectronic device working at longer wavelength. In this work, the direct generation of photocurrent at low energy terahertz (THz) band at room temperature is implemented in a planar metal-PtTe2 -metal structure. The results show that the THz photodetector based on PtTe2 with bow-tie-type planar contacts possesses a high photoresponsivity (1.6 A W-1 without bias voltage) with a response time less than 20 µs, while the PtTe2 -graphene heterostructure-based detector can reach responsivity above 1.4 kV W-1 and a response time shorter than 9 µs. Remarkably, it is already exploitable for large area imaging applications. These results suggest that topological semimetals such as PtTe2 can be ideal materials for implementation in a high-performing photodetection system at THz band.

19.
Zhongguo Yi Liao Qi Xie Za Zhi ; 43(2): 126-128, 2019 Mar 30.
Artigo em Chinês | MEDLINE | ID: mdl-30977612

RESUMO

This article summarizes the attribute conditions to the combination products designation from 2009 to 2018 in China,analyzes the common problems of combination products attribution definition.It is hoped to be helpful for researchers and manufacturers of combination products.


Assuntos
Equipamentos e Provisões , China , Terminologia como Assunto
20.
Nanotechnology ; 29(21): 215711, 2018 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-29513272

RESUMO

Metal-catalyzed chemical vapor deposition (CVD) has been broadly employed for large-scale production of high-quality graphene. However, a following transfer process to targeted substrates is needed, which is incompatible with current silicon technology. We here report a new CVD approach to form nanographene and nanographite films with accurate thickness control directly on non-catalytic substrates such as silicon dioxide and quartz at 800 °C. The growth time is as short as a few seconds. The approach includes using 9-bis(diethylamino)silylanthracene as the carbon source and an atomic layer deposition (ALD) controlling system. The structure of the formed nanographene and nanographite films were characterized using atomic force microscopy, high resolution transmission electron microscopy, Raman scattering, and x-ray photoemission spectroscopy. The nanographite film exhibits a transmittance higher than 80% at 550 nm and a sheet electrical resistance of 2000 ohms per square at room temperature. A negative temperature-dependence of the resistance of the nanographite film is also observed. Moreover, the thickness of the films can be precisely controlled via the deposition cycles using an ALD system, which promotes great application potential for optoelectronic and thermoelectronic-devices.

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