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1.
ACS Nano ; 18(1): 581-591, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38126349

RESUMO

Neural networks based on low-power artificial synapses can significantly reduce energy consumption, which is of great importance in today's era of artificial intelligence. Two-dimensional (2D) material-based floating-gate transistors (FGTs) have emerged as compelling candidates for simulating artificial synapses owing to their multilevel and nonvolatile data storage capabilities. However, the low erasing/programming speed of FGTs renders them unsuitable for low-energy-consumption artificial synapses, thereby limiting their potential in high-energy-efficient neuromorphic computing. Here, we introduce a FGT-inspired MoS2/Trap/PZT heterostructure-based polarized tunneling transistor (PTT) with a simple fabrication process and significantly enhanced erasing/programming speed. Distinct from the FGT, the PTT lacks a tunnel layer, leading to a marked improvement in its erasing/programming speed. The PTT's highest erasing/programming (operation) speed can reach ∼20 ns, which outperforms the performance of most FGTs based on 2D heterostructures. Furthermore, the PTT has been utilized as an artificial synapse, and its weight-update energy consumption can be as low as 0.0002 femtojoule (fJ), which benefits from the PTT's ultrahigh operation speed. Additionally, PTT-based artificial synapses have been employed in constructing artificial neural network simulations, achieving facial-recognition accuracy (95%). This groundbreaking work makes it possible for fabricating future high-energy-efficient neuromorphic transistors utilizing 2D materials.

2.
Nano Lett ; 23(22): 10196-10204, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37926956

RESUMO

Low-power electronic devices play a pivotal role in the burgeoning artificial intelligence era. The study of such devices encompasses low-subthreshold swing (SS) transistors and neuromorphic devices. However, conventional field-effect transistors (FETs) face the inherent limitation of the "Boltzmann tyranny", which restricts SS to 60 mV decade-1 at room temperature. Additionally, FET-based neuromorphic devices lack sufficient conductance states for highly accurate neuromorphic computing due to a narrow memory window. In this study, we propose a pioneering PZT-enabled MoS2 floating gate transistor (PFGT) configuration, demonstrating a low SS of 46 mV decade-1 and a wide memory window of 7.2 V in the dual-sweeping gate voltage range from -7 to 7 V. The wide memory window provides 112 distinct conductance states for PFGT. Moreover, the PFGT-based artificial neural network achieves an outstanding facial-recognition accuracy of 97.3%. This study lays the groundwork for the development of low-SS transistors and highly energy efficient artificial synapses utilizing two-dimensional materials.

3.
RSC Adv ; 12(37): 23912-23921, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-36093240

RESUMO

In this paper, a core-shell structure nickel disulfide and ZIF-67 composite electrode material (NiS2/ZIF-67) was synthesized by a two-step method. Firstly, spherical NiS2 was synthesized by a hydrothermal method, dispersed in methanol, then reacted and coated by adding cobalt ions and 2-methylimidazole to obtain the NiS2/ZIF-67 core-shell composite. The NiS2/ZIF-67 composite shows a high specific capacitance (1297.9 F g-1 at 1 A g-1) and excellent cycling durability (retaining 110.0% after 4000 cycles at 5 A g-1). Furthermore, the corresponding hybrid supercapacitor (NiS2/ZIF-67//AC HSC) has an energy density of 9.5 W h kg-1 at 411.1 W kg-1 (6 M KOH) and remarkable cycling stability (maintaining 133.3% after 5000 cycles). Its excellent electrochemical performance may be due to the core-shell structure and the synergistic effect between the transition metal sulfide and metal-organic framework. These results indicate that the NiS2/ZIF-67 composite as an electrode material with a core-shell structure has potential application in high-efficiency supercapacitors.

4.
Anal Chem ; 94(3): 1626-1636, 2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35025203

RESUMO

(Mi)RNAs are important biomarkers for cancers diagnosis and pandemic diseases, which require fast, ultrasensitive, and economical detection strategies to quantitatively detect exact (mi)RNAs expression levels. The novel coronavirus disease (SARS-CoV-2) has been breaking out globally, and RNA detection is the most effective way to identify the SARS-CoV-2 virus. Here, we developed an ultrasensitive poly-l-lysine (PLL)-functionalized graphene field-effect transistor (PGFET) biosensor for breast cancer miRNAs and viral RNA detection. PLL is functionalized on the channel surface of GFET to immobilize DNA probes by the electrostatic force. The results show that PGFET biosensors can achieve a (mi)RNA detection range of five orders with a detection limit of 1 fM and an entire detection time within 20 min using 2 µL of human serum and throat swab samples, which exhibits more than 113% enhancement in terms of sensitivity compared to that of GFET biosensors. The performance enhancement mechanisms of PGFET biosensors were comprehensively studied based on an electrical biosensor theoretical model and experimental results. In addition, the PGFET biosensor was applied for the breast cancer miRNA detection in actual serum samples and SARS-CoV-2 RNA detection in throat swab samples, providing a promising approach for rapid cancer diagnosis and virus screening.


Assuntos
Técnicas Biossensoriais , Neoplasias da Mama , COVID-19 , Grafite , MicroRNAs , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , COVID-19/diagnóstico , Feminino , Humanos , Polilisina , RNA Viral/genética , SARS-CoV-2
5.
RSC Adv ; 11(20): 11786-11792, 2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-35423764

RESUMO

New carbon-loaded nickel chalcogenide electrode materials (NiS2/GO and NiSe2/rGO) have been synthesized through an easy-to-operate process: NiSe2 was obtained based on NiS2 hollow spheres, and was successfully synthesized with l-cysteine assistance under the hydrothermal method at 120 °C. GO of different mass fraction was added together with l-cysteine. The electrochemical performance of NiS2/GO and NiSe2/rGO has been greatly improved because the formation of a carbon-loaded layer effectively increased the specific surface area and reduced the charge transport resistance. Compared with pure NiS2 and NiSe2, NiS2/GO and NiSe2/rGO presented much better specific capacitance (1020 F g-1 and 722 F g-1 respectively at a current density of 1 A g-1) and more superior rate capability (when the current density was raised to 5 A g-1 the specific capacitance remained at 569 F g-1 and 302 F g-1). This work highlights the advantages of nickel compounds through a very simple experimental method, and contributes to providing a good reference for preparation of superior supercapacitor materials with high performance.

6.
BMC Genomics ; 20(1): 524, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-31242853

RESUMO

Following the publication of this article.

7.
BMC Genomics ; 19(1): 175, 2018 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-29499650

RESUMO

BACKGROUND: Obtaining complete gene structures is one major goal of genome assembly. Some gene regions are fragmented in low quality and high-quality assemblies. Therefore, new approaches are needed to recover gene regions. Genomes are widely transcribed, generating messenger and non-coding RNAs. These widespread transcripts can be used to scaffold genomes and complete transcribed regions. RESULTS: We present P_RNA_scaffolder, a fast and accurate tool using paired-end RNA-sequencing reads to scaffold genomes. This tool aims to improve the completeness of both protein-coding and non-coding genes. After this tool was applied to scaffolding human contigs, the structures of both protein-coding genes and circular RNAs were almost completely recovered and equivalent to those in a complete genome, especially for long proteins and long circular RNAs. Tested in various species, P_RNA_scaffolder exhibited higher speed and efficiency than the existing state-of-the-art scaffolders. This tool also improved the contiguity of genome assemblies generated by current mate-pair scaffolding and third-generation single-molecule sequencing assembly. CONCLUSIONS: The P_RNA_scaffolder can improve the contiguity of genome assembly and benefit gene prediction. This tool is available at http://www.fishbrowser.org/software/P_RNA_scaffolder .


Assuntos
Algoritmos , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Software , Humanos , RNA/genética
8.
Bioinformatics ; 32(20): 3193-3195, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27334475

RESUMO

MOTIVATION: Recovering the gene structures is one of the important goals of genome assembly. In low-quality assemblies, and even some high-quality assemblies, certain gene regions are still incomplete; thus, novel scaffolding approaches are required to complete gene regions. RESULTS: We developed an efficient and fast genome scaffolding method called PEP_scaffolder, using proteins to scaffold genomes. The pipeline aims to recover protein-coding gene structures. We tested the method on human contigs; using human UniProt proteins as guides, the improvement on N50 size was 17% increase with an accuracy of ∼97%. PEP_scaffolder improved the proportion of fully covered proteins among all proteins, which was close to the proportion in the finished genome. The method provided a high accuracy of 91% using orthologs of distant species. Tested on simulated fly contigs, PEP_scaffolder outperformed other scaffolders, with the shortest running time and the highest accuracy. AVAILABILITY AND IMPLEMENTATION: The software is freely available at http://www.fishbrowser.org/software/PEP_scaffolder/ CONTACT: lijt@cafs.ac.cnSupplementary information: Supplementary data are available at Bioinformatics online.


Assuntos
Genoma , Análise de Sequência de DNA , Algoritmos , Animais , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Homologia de Sequência , Software
9.
Int J Mol Sci ; 16(9): 21310-29, 2015 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-26370964

RESUMO

Teleosts have more types of chromatophores than other vertebrates and the genetic basis for pigmentation is highly conserved among vertebrates. Therefore, teleosts are important models to study the mechanism of pigmentation. Although functional genes and genetic variations of pigmentation have been studied, the mechanisms of different skin coloration remains poorly understood. The koi strain of common carp has various colors and patterns, making it a good model for studying the genetic basis of pigmentation. We performed RNA-sequencing for red skin and white skin and identified 62 differentially expressed genes (DEGs). Most of them were validated with RT-qPCR. The up-regulated DEGs in red skin were enriched in Kupffer's vesicle development while the up-regulated DEGs in white skin were involved in cytoskeletal protein binding, sarcomere organization and glycogen phosphorylase activity. The distinct enriched activity might be associated with different structures and functions in erythrophores and iridophores. The DNA methylation levels of two selected DEGs inversely correlated with gene expression, indicating the participation of DNA methylation in the coloration. This expression characterization of red-white skin along with the accompanying transcriptome-wide expression data will be a useful resource for further studies of pigment cell biology.


Assuntos
Carpas/genética , Regulação da Expressão Gênica , Pigmentação da Pele/genética , Animais , Análise por Conglomerados , Biologia Computacional/métodos , Ilhas de CpG , Metilação de DNA , Perfilação da Expressão Gênica , Locos de Características Quantitativas , Transcriptoma
10.
Huan Jing Ke Xue ; 33(7): 2244-50, 2012 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-23002597

RESUMO

For the safety of the water environment in Jiashan county in Zhejiang Province, one-dimensional hydrodynamic and water quality models are established based on three large-scale monitoring of hydrology and water quality in Jiashan county, three water environmental sensitive spots including Hongqitang dam Chijia hydrological station and Luxie pond are selected to investigate weight parameters of water quality impact and risk grade determination. Results indicate as follows (1) Internal pollution impact in Jiashan areas was greater than the external, the average weight parameters of internal chemical oxygen demand (COD) pollution is 55.3%, internal ammonia nitrogen (NH(4+)-N) is 67.4%, internal total phosphor (TP) is 63.1%. Non-point pollution impact in Jiashan areas was greater than point pollution impact, the average weight parameters of non-point COD pollutions is 53.7%, non-point NH(4+)-N is 65.9%, non-point TP is 57.8%. (2) The risk of Hongqitang dam and Chijia hydrological station are in the middle risk. The risk of Luxie pond is also in the middle risk in August, and in April and December the risk of Luxie pond is low. The strategic decision will be suggested to guarantee water environment security and social and economic security in the study.


Assuntos
Monitoramento Ambiental/métodos , Água Doce , Poluição da Água/prevenção & controle , Qualidade da Água , China , Hidrologia , Modelos Teóricos , Medição de Risco , Abastecimento de Água/análise
11.
Zhonghua Xue Ye Xue Za Zhi ; 32(11): 752-7, 2011 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-22339911

RESUMO

OBJECTIVE: To assess complete remission (CR), the overall survival (OS), event-free survival (EFS) and adverse events of newly diagnosed acute promyelocytic leukemia (APL) with homoharringtonine (HHT) plus ATRA, to evaluate the therapeutic effect by comparing HHT plus ATRA with daunorubicin plus ATRA as induction regimen (HA with DA as post-remission regimen). METHODS: 115 APL patients (54 in HHT group, 61 in DNR group) after long-term follow-up were enrolled in the analyses of clinical feature, chromosome karyotype, molecular biology, OS and EFS. RESULTS: The overall CR of 115 patients was 100%, the median interval to achieve hematological CR was 32 (22 - 43) days, the overall median OS was within 0.23 - 77.34 months, median EFS was within 0.23 - 77.34 months. 3-year OS rate was 93%, 5-year OS rate 93%, 3-year EFS rate 85% and 5-year RFS rate 75% respectively. Converting to PML-RARα PCR-negative after the induction therapy in the HHT and DNR group was 31.3% and 15.5% respectively, at the end of 1 consolidation course was 68.6% and 77.6% respectively, while the remaining 4 patients tested PML-RARα PCR-negative at the end of 2 consolidation courses in the DNR group. While both groups obtained the identical molecular biology relapse rate (9.8% and 8.6%, respectively). Survival analysis indicated that no significant difference was found on OS and EFS between the HHT group and the DNR group (P = 0.206 and 0.506). 5-year OS rate was 87% for the HHT group while 98% for the DNR group, 5-years EFS rate was 80% for the HHT group while 71% for the DNR group. And the risk group was not the factor affecting OS and EFS (P = 0.615 and 0.416). Grade 2 fever in the HHT group was less than in the DNR group during induction therapy. And no difference was found in terms of liver dysfunction, renal dysfunction, cardiac dysfunction, and hematologic toxicity between two groups. CONCLUSION: Our study demonstrated comparable therapeutic effect of HHT or DNR on APL. HHT was also well tolerated and didn't cause serious adverse events.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Promielocítica Aguda/tratamento farmacológico , Adolescente , Adulto , Idoso , Feminino , Harringtoninas/administração & dosagem , Mepesuccinato de Omacetaxina , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Resultado do Tratamento , Tretinoína/administração & dosagem , Adulto Jovem
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