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1.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(2): 228-236, 2024 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-38686402

RESUMO

Conventional maximum intensity projection (MIP) images tend to ignore some morphological features in the detection of intracranial aneurysms, resulting in missed detection and misdetection. To solve this problem, a new method for intracranial aneurysm detection based on omni-directional MIP image is proposed in this paper. Firstly, the three-dimensional magnetic resonance angiography (MRA) images were projected with the maximum density in all directions to obtain the MIP images. Then, the region of intracranial aneurysm was prepositioned by matching filter. Finally, the Squeeze and Excitation (SE) module was used to improve the CaraNet model. Excitation and the improved model were used to detect the predetermined location in the omni-directional MIP image to determine whether there was intracranial aneurysm. In this paper, 245 cases of images were collected to test the proposed method. The results showed that the accuracy and specificity of the proposed method could reach 93.75% and 93.86%, respectively, significantly improved the detection performance of intracranial aneurysms in MIP images.


Assuntos
Algoritmos , Imageamento Tridimensional , Aneurisma Intracraniano , Angiografia por Ressonância Magnética , Aneurisma Intracraniano/diagnóstico por imagem , Humanos , Angiografia por Ressonância Magnética/métodos , Imageamento Tridimensional/métodos , Sensibilidade e Especificidade , Processamento de Imagem Assistida por Computador/métodos
2.
J Invertebr Pathol ; 190: 107752, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35367462

RESUMO

Macrobrachium rosenbergii is an important economic aquatic animal and has been cultivated worldwide. However, it has suffered a disease of precocious puberty and growth retardation. This disease was also called iron prawn syndrome (IPS) in recent years. However, the cause of this disease has thus far remained a mystery . The present work utilized transcriptome sequencing technology to acquire gene expression information of gonads and to find the differentially expressed genes(DEGs) between diseased and normal male prawn. Finally, 426 significantly expressed genes were identified(p less than 0.01, |log2FC|≥1), of which 171 genes were up-regulated and 255 were down-regulated. Furthermore, DEGs were annotated to 36 GO terms and 202 KEGG pathways. Enrichment analysis of DEGs resulted in 10 significantly enriched GO terms and a total of 12 significantly enriched KEGG pathways. Analysis of the transcriptome sequences and DEGs identified several unigenes and pathways involved in precocious puberty and growth retardation. Quantitative PCR was performed to validate accuracy of the RNA-seq and the expression level of 10 genes, calculated by two analysis method, was mostly consistent. This is the first time to report precocious puberty and growth retardation male M. rosenbergii by transcriptome sequencing. The data presented here reveals key insights into the genetic markers of precocious puberty and growth retardation of male M. rosenbergii.


Assuntos
Decápodes , Palaemonidae , Animais , Decápodes/genética , Perfilação da Expressão Gênica , Transtornos do Crescimento , Masculino , Palaemonidae/genética , Transcriptoma
3.
Mikrochim Acta ; 188(11): 381, 2021 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-34654957

RESUMO

Vibrio parahaemolyticus (V. parahaemolyticus) is the causative agent for acute hepatopancreatic necrosis disease (AHPND) of shrimp, and it is also a common seafood-borne pathogen for humans. Rapid and accurate identification of V. parahaemolyticus is helpful to diagnose the AHPND and ensure food safety. Common detection methods suffer the deficiency of time-consuming and complexed operation. Based on the increased development of aptamer and our previous study, a new detection assay of V. parahaemolyticus was introduced, in which the aptamer combined with magnetic nanoparticles (MNPs) was the recognizer, hybridization chain reaction (HCR) was the signal amplifier, and lateral flow nucleotide biosensor (LFNB) was the signal exporter. The assay possessed high specificity of distinguishing the target with other bacteria, and the calculated limit of detection was 2.6 × 103 cells. Furthermore, the whole process just needs 67 min, free of thermocycle instruments and signal readout instruments, which means it is suitable for low-resource laboratories or districts.


Assuntos
Técnicas Biossensoriais/métodos , Colorimetria/métodos , Reação em Cadeia da Polimerase/métodos , Alimentos Marinhos/efeitos adversos , Vibrio parahaemolyticus/metabolismo , Humanos
4.
Invest New Drugs ; 38(2): 500-506, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31650447

RESUMO

Background Esophageal cancer is a very common malignant tumor in China, especially esophageal squamous cell carcinoma (ESCC), but there is currently no effective treatment for patients after first-line chemotherapy failure. Apatinib has shown promising outcomes in treatment with various solid tumors. Objectives To evaluate the clinical efficacy and safety of apatinib combined with S-1 in the treatment of advanced ESCC patients after first-line chemotherapy failure. Methods In this prospective study, fifteen patients with advanced ESCC who failed first-line chemotherapy were enrolled from Nov 2016 to Apr 2019. Patients received the combination therapy with apatinib (250-500 mg, once daily) plus S-1 (40-60 mg based on body surface area, twice daily). Primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), disease control rate (DCR) and objective response rate (ORR). Adverse events (AEs) were recorded to evaluate the safety. Results A total of 12 patients were included in the efficacy analysis. The median PFS was 6.23 months, and the median OS was 8.83 months. Two (16.67%) patients achieved partial remission, 9 patients (75.00%) achieved stable disease and 1 (8.33%) patient achieved progressive disease. DCR and ORR was 91.67%and 16.67%, respectively. Most frequent AEs were hypertension, myelosuppression, weakness, hemorrhage, hand-foot syndrome, total bilirubin elevation, sick, proteinuria, oral ulcer, loss of appetite, and transaminase elevation. The most AEs were in grade I~II. Conclusion The combination therapy of apatinib plus S-1 was effective and well tolerated in the treatment of advanced ESCC patients after first-line chemotherapy failure. The combination therapy has the potential to be a potent therapeutic option for advanced ESCC patients after first-line chemotherapy failure.


Assuntos
Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Esofágicas/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Ácido Oxônico/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/uso terapêutico , Tegafur/uso terapêutico , Idoso , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Combinação de Medicamentos , Neoplasias Esofágicas/mortalidade , Carcinoma de Células Escamosas do Esôfago/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Oxônico/efeitos adversos , Inibidores de Proteínas Quinases/efeitos adversos , Piridinas/efeitos adversos , Análise de Sobrevida , Tegafur/efeitos adversos , Resultado do Tratamento
5.
Nanotechnology ; 27(45): 455605, 2016 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-27727146

RESUMO

SiO2-Ag-SiO2, a sandwiched core/shell structure with a layer of Ag nanoparticles (∼4 nm) encapsulated between a shallow SiO2 surface layer and a SiO2 submicrosphere substrate (∼200 nm), has been synthesized from [Formula: see text] and SiO2 spheres by a facile one-pot hydrothermal method. The composite is proposed to result from the dynamic balance between the [Formula: see text] reduction and the dissolution-redeposition of SiO2 in mild basic media. The synthetic mechanism and the roles of the reaction time, temperature, and the amount of ammonia in the formation of this unique structure are investigated and discussed. The composite structure shows superior catalytic performance in CO oxidation to the control Ag/SiO2 structure prepared by impregnation. Pre-treatment by O2 at 600 °C significantly improves the catalytic performance of the composite structure and preserves the nanocomposite structure well.

6.
Small ; 10(11): 2270-9, 2014 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-24577801

RESUMO

Self-assembled α-Fe2O3 mesocrystals/graphene nanohybrids have been successfully synthesized and have a unique mesocrystal porous structure, a large specific surface area, and high conductivity. Mesocrystal structures have recently attracted unparalleled attention owing to their promising application in energy storage as electrochemical capacitors. However, mesocrystal/graphene nanohybrids and their growth mechanism have not been clearly investigated. Here we show a facile fabrication of short rod-like α-Fe2O3 mesocrystals/graphene nanohybrids by self-assembly of FeOOH nanorods as the primary building blocks on graphene under hydrothermal conditions, accompanied and promoted by concomitant phase transition from FeOOH to α-Fe2O3. A systematic study of the formation mechanism is also presented. The galvanostatic charge/discharge curve shows a superior specific capacitance of the as-prepared α-Fe2O3 mesocrystals/graphene nanohybrid (based on total mass of active materials), which is 306.9 F g(-1) at 3 A g(-1) in the aqueous electrolyte under voltage ranges of up to 1 V. The nanohybrid with unique sufficient porous structure and high electrical conductivity allows for effective ion and charge transport in the whole electrode. Even at a high discharge current density of 10 A g(-1), the enhanced ion and charge transport still yields a higher capacitance (98.2 F g(-1)), exhibiting enhanced rate capability. The α-Fe2O3 mesocrystal/graphene nanohybrid electrode also demonstrates excellent cyclic performance, which is superior to previously reported graphene-based hematite electrode, suggesting it is highly stable as an electrochemical capacitor.

7.
Nanotechnology ; 24(20): 205401, 2013 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-23598519

RESUMO

Novel hierarchical hybrids, tin dioxide@carbon hollow spheres with encapsulated tin nanoparticles (SnO2@HCS@Sn), were fabricated by combining solution and vapor phase techniques. The phase composition, morphological evolution and porosity of the hierarchical hybrids were characterized by x-ray diffraction, energy dispersive x-ray spectroscopy, scanning and transmission electron microscopy, and N2 adsorption-desorption analysis. The significantly improved electrochemical performance of this functional material is attributed to its heterogeneous architecture which unifies hollow carbon spheres with tin nanoparticles with a diameter of less than 20 nm, which are further conformally covered by ultra-small tin dioxide nanoplates. The ultrathin SnO2 nanoplates grown on the carbon spheres effectively increase the charge-transfer properties and shorten the transport lengths for both electrons and lithium ions. The mesoporous carbon spheres offer excellent conductivity and abundant void space to buffer the large volume change during cycling. High initial capacity (∼1766 mAh g⁻¹ at 0.1 Ag⁻¹), high initial Coulombic efficiency (56.4%), and long cycle life (100 cycles with ∼710 mAh g⁻¹) have been realized in the hierarchical hybrid tin-based anodes.

8.
Nano Lett ; 12(1): 198-202, 2012 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-22141577

RESUMO

We present a simple micromanipulation technique to transfer suspended graphene flakes onto any substrate and to assemble them with small localized gates into mechanical resonators. The mechanical motion of the graphene is detected using an electrical, radio frequency (RF) reflection readout scheme where the time-varying graphene capacitor reflects a RF carrier at f = 5-6 GHz producing modulation sidebands at f ± f(m). A mechanical resonance frequency up to f(m) = 178 MHz is demonstrated. We find both hardening/softening Duffing effects on different samples and obtain a critical amplitude of ~40 pm for the onset of nonlinearity in graphene mechanical resonators. Measurements of the quality factor of the mechanical resonance as a function of dc bias voltage V(dc) indicates that dissipation due to motion-induced displacement currents in graphene electrode is important at high frequencies and large V(dc).


Assuntos
Condutometria/instrumentação , Grafite/química , Sistemas Microeletromecânicos/instrumentação , Impressão Molecular/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Radiometria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Teste de Materiais , Tamanho da Partícula , Doses de Radiação , Ondas de Rádio
9.
Rev Sci Instrum ; 94(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37695115

RESUMO

This paper tackles the problem of noise suppression during vital sign signal monitoring. Physiological signal monitoring is a significant and promising medical monitoring method, and wearable medical monitoring devices based on piezoelectric polymer sensors are a trending way for their advantages of being flexible in the shape, portable to use, and comfortable to wear. However, this raises the question that the measured signal contains much more noise components. To avoid the following shortcoming of low signal to noise ratio (SNR), a noise suppression method based on improved wavelet threshold and empirical mode decomposition combined with singular value decomposition (SVD) screening the intrinsic mode function (IMF) components is proposed. A wavelet transform is first used under the combination of hard and soft thresholds to focus the target range in the low-frequency region where the energy of the physiological signal is concentrated. Then, a complete ensemble empirical mode decomposition is used to decompose the signal effectively, which can resist the influence of random noises. Meanwhile, a SVD decomposition procedure was used to filter out the lower correlated IMF components to retain the validity of the original signal. We verified the effectiveness of the proposed method through simulated and measured experiments as well as the advantages and disadvantages of the algorithm compared with other physiological signal denoising algorithms through SNR filtering results, power spectrum distribution, and other perspectives. The results proved that the proposed method could effectively remove more detailed noise and improve the SNR of the signal efficiently, which is more conducive to the demand for auxiliary medical diagnosis in the future.

10.
ACS Nano ; 17(1): 657-667, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36542067

RESUMO

Black phosphorus (BP) has been demonstrated as a promising electrode material for supercapacitors. Currently, the main limitation of its practical application is the low electrical conductivity and poor structure stability. Hence, BP-based supercapacitors usually severely suffer from low capacitance and poor cycling stability. Herein, a chemically bridged BP/conductive g-C3N4 (BP/c-C3N4) hybrid is developed via a facile ball-milling method. Covalent P-C bonds are generated through the ball-milling process, effectively preventing the structural distortion of BP induced by ion transport and diffusion. In addition, the overall electrical conductivity is significantly enhanced owing to the sufficient coupling between BP and highly conductive c-C3N4. Moreover, the imbalanced charge distribution around the C atom can induce the generation of a local electric field, facilitating the charge transfer behavior of the electrode material. As a result, the BP/c-C3N4-20:1 flexible supercapacitor (FSC) exhibits an outstanding volumetric capacitance of 42.1 F/cm3 at 0.005 V/s, a high energy density of 5.85 mW h/cm3, and a maximum power density of 15.4 W/cm3. More importantly, the device delivers excellent cycling stability with no capacitive loss after 30,000 cycles.

11.
Int J Syst Evol Microbiol ; 62(Pt 12): 2927-2933, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22268075

RESUMO

The bacterial strain LH2-2(T) was isolated from freshwater of Longhu Lake, a slightly alkaline lake (pH 8.8) in north-east China. Cells of strain LH2-2(T) were Gram-staining-negative, non-spore-forming rods, 0.3-0.5 µm wide and 2.0-4.0 µm long. Cells were motile by means of a single polar flagellum. The strain was strictly aerobic and heterotrophic and oxidase- and catalase-positive. Growth occurred at 0-36 °C (optimum, 26-34 °C), pH 6.5-11 (optimum, pH 8.0-8.6) and in the presence of 0-2 % (w/v) NaCl (optimum, 1%). Strain LH2-2(T) contained Q-8 as the major respiratory quinone. The major fatty acids were summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH; 21.9%), C(17:1)ω8c (18.9%), C(18:1)ω7c (16.4%) and C(16:0) (12.7%) after growth on marine agar 2216. The DNA G+C content was 47 mol% (T(m)). The 16S rRNA gene and a conserved portion of the gyrB gene were sequenced and used for phylogenetic analyses. Phylogenetic trees based on 16S rRNA gene and gyrB sequences showed that strain LH2-2(T) was associated with the genus Rheinheimera and closely related to the type strains of Rheinheimera species, and showed the highest 16S rRNA gene sequence similarity to Rheinheimera pacifica KMM 1406(T) (97.4%), R. aquimaris SW-353(T) (97.1%) and R. chironomi K19414(T) (96.5%). The DNA-DNA relatedness of strain LH2-2(T) to R. pacifica NBRC 103167(T), R. aquimaris JCM 14331(T) and R. chironomi LMG 23818(T) was 39, 31 and 23%, respectively. Based on these results, it is concluded that strain LH2-2(T) represents a novel species of the genus Rheinheimera, for which the name Rheinheimera longhuensis sp. nov. is proposed. The type strain is LH2-2(T) ( = CGMCC 1.7003(T)  = NBRC 105632(T)). An emended description of the genus Rheinheimera is also provided.


Assuntos
Chromatiaceae/classificação , Lagos/microbiologia , Filogenia , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , China , Chromatiaceae/genética , Chromatiaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/análise , Genes Bacterianos , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análise
12.
Nanomaterials (Basel) ; 12(15)2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35957156

RESUMO

Graphene resonant sensors have shown strong competitiveness with respect to sensitivity and size. To advance the applications of graphene resonant sensors, the damage behaviors of graphene harmonic oscillators after thermal annealing and laser irradiation were investigated by morphology analysis and frequency domain vibration characteristics. The interface stress was proven to be the key factor that directly affected the yield of resonators. The resulting phenomenon could be improved by appropriately controlling the annealing temperature and size of resonators, thereby achieving membrane intactness of up to 96.4%. However, micro-cracks were found on the graphene sheets when continuous wave (CW) laser power was more than 4 mW. Moreover, the fluctuating light energy would also cause mechanical fatigue in addition to the photothermal effect, and the threshold damage power for the sinusoidally modulated laser was merely 2 mW. In this way, based on the amplitude-frequency surface morphology of the graphene resonator, the thermal time constant of the order of a few microseconds was confirmed to evaluate the damage of the graphene oscillator in situ and in real time, which could be further extended for those resonators using other 2D materials.

13.
Cancer Commun (Lond) ; 42(4): 314-326, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35212487

RESUMO

BACKGROUND: There is no consensus on whether triplet regimen is better than doublet regimen in the first-line treatment of advanced gastric cancer (AGC). We aimed to compare the efficacy and safety of oxaliplatin plus capecitabine (XELOX) and epirubicin, oxaliplatin, plus capecitabine (EOX) regimens in treating AGC. METHODS: This phase III trial enrolled previously untreated patients with AGC who were randomly assigned to receive the XELOX or EOX regimen. The primary endpoint was non-inferiority in progression-free survival (PFS) for XELOX as compared with EOX on an intention-to-treat basis. RESULTS: Between April 10, 2015 and August 20, 2020, 448 AGC patients were randomized to receive XELOX (n = 222) or EOX (n = 226). The median PFS (mPFS) was 5.0 months (95% confidence interval [CI] = 4.5-6.0 months) in the XELOX arm and 5.5 months (95% CI = 5.0-6.0 months) in the EOX arm (hazard ratio [HR] = 0.989, 95% CI = 0.812-1.203; Pnon-inferiority = 0.003). There was no significant difference in median overall survival (mOS) (12.0 vs. 12.0 months, P = 0.384) or objective response rate (37.4% vs. 45.1%, P = 0.291) between the two groups. In patients with poorly differentiated adenocarcinoma and liver metastasis, the EOX arm had a significantly longer mOS (P = 0.021) and a trend of longer mPFS (P = 0.073) than the XELOX arm. The rate of grade 3/4 adverse events (AEs) was 42.2% (90/213) in the XELOX arm and 72.5% (156/215) in the EOX arm (P = 0.001). The global health-related quality of life (QoL) score was significantly higher in the XELOX arm than in the EOX arm during chemotherapy. CONCLUSIONS: This non-inferiority trial demonstrated that the doublet regimen was as effective as the triplet regimen and had a better safety profile and QoL as a first-line treatment for AGC patients. However, the triplet regimen might have a survival advantage in patients with poorly differentiated adenocarcinoma and liver metastasis.


Assuntos
Adenocarcinoma , Neoplasias Hepáticas , Neoplasias Gástricas , Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Capecitabina , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Oxaliplatina , Oxaloacetatos , Estudos Prospectivos , Qualidade de Vida , Neoplasias Gástricas/patologia
14.
Int J Syst Evol Microbiol ; 61(Pt 2): 408-411, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20348325

RESUMO

A Gram-negative bacterium, designated B2-9(T), was isolated from water of a slightly alkaline lake, Longhu Lake in Daqing, north-east China. Strain B2-9(T) was an aerobic rod, heterotrophic, catalase- and oxidase-positive and motile by means of a single polar flflagellum. The isolate grew well on n-alkanes C(9)-C(17) and weakly on C(6)-C(8), C(18) and C(19). Growth occurred at 10-37 °C (optimum 20-25 °C), at pH 5.5-9.5 (optimum pH 7.0) and with ≤1.0 % (w/v) NaCl. The major fatty acids were C(18 : 1)ω7c (41.4 %), summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)ω7c; 18.5 %) and C(16 : 0) (10.9 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain B2-9(T) belonged to the genus Hydrocarboniphaga of the class Gammaproteobacteria and shared 97.0 % 16S rRNA gene sequence similarity with Hydrocarboniphaga effusa AP103(T). DNA-DNA relatedness between strain B2-9(T) and H. effusa DSM 16095(T) was 24 %. The DNA G+C content of strain B2-9(T) was 66 mol%. Strain B2-9(T) is considered to represent a novel species of the genus Hydrocarboniphaga, for which the name Hydrocarboniphaga daqingensis sp. nov. is proposed. The type strain is B2-9(T) (=CGMCC 1.7049(T) =NBRC 104238(T)).


Assuntos
Água Doce/microbiologia , Gammaproteobacteria/classificação , Filogenia , Alcanos/metabolismo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Gammaproteobacteria/genética , Gammaproteobacteria/isolamento & purificação , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia da Água
15.
Nanomaterials (Basel) ; 11(9)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34578600

RESUMO

In order to enhance the sensitivity of a Fabry-Perot (F-P) acoustic sensor without the need of fabricating complicated structures of the acoustic-sensitive diaphragm, a mini-type external sound pressure amplification structure (SPAS) with double 10 µm thickness E-shaped diaphragms of different sizes interconnected with a 5 mm length tapered circular rod was developed based on the acoustic sensitive mechanism of the ossicular chain in the human middle ear. The influence of thickness and Young's modulus of the two diaphragms with the diameters of 15 mm and 3 mm, respectively, on the amplification ratio and frequency response were investigated via COMSOL acoustic field simulation, thereby confirming the dominated effect. Then, three kinds of dual-diaphragm schemes relating to steel and thermoplastic polyurethanes (TPU) materials were introduced to fabricate the corresponding SPASs. The acoustic test showed that the first scheme achieved a high resonant response frequency with lower acoustic amplification due to strong equivalent stiffness; in contrast, the second scheme offered a high acoustic amplification but reduced frequency range. As a result of sensitivity enhancement, adapted with the steel/TPU diaphragm structure, an optical fiber Fabry-Perot sensor using a multilayer graphene diaphragm with a diameter of 125 µm demonstrated a remarkable sensitivity of 565.3 mV/Pa @1.2 kHz due to the amplification ratio of up to ~29.9 in the range of 0.2-2.3 kHz, which can be further improved by miniaturizing structure dimension, along with the use of microstructure packaging technology.

16.
ACS Appl Mater Interfaces ; 13(17): 20185-20193, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33878873

RESUMO

The methodology of coating electrocatalysts on semiconductor substrates is critical for the catalytic performance of photoelectrochemical electrodes. A weakly bound coating leads to orders of magnitude lower efficiency and reliability compared to those required to meet the commercial demand. Herein, a facile strategy based on the hydrolysis of TiCl4 is developed to solve the coating issue. Mesoporous tungsten phosphide (WP) particles were spin-coated and affixed onto TiO2-protected planar p-Si by the formation of a TiO2 necking layer between the catalyst particles and the substrates. Under 1 sun illumination, the as-prepared WP/TiO2/Si photocathode yields a saturated current density of -35 mA cm-2 and a durability of over 110 h with a current density over -15 mA cm-2 at 0 V versus a reversible hydrogen electrode in a 1.0 M KOH solution, which is among the state-of-the-art performances of commercial planar Si-based photocathodes. The Kelvin probe force microscopy results suggest the successive transfer of photoelectrons from Si to TiO2 and WP. The as-formed TiO2 necking layer plays the key role in ensuring the surface catalytic activity and durability. This necking strategy is also applicable for coating other transition-metal phosphides, for example, MoP and FeP, thus offering a practical approach to meet the commercial requirement of low-cost, highly efficient, and durable photoelectrodes.

17.
Nanotechnology ; 21(9): 095703, 2010 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-20124657

RESUMO

Organic nanowires/fibers have great potential in applications such as organic electronics and soft electronic techniques. Therefore investigation of their mechanical performance is of importance. The Young's modulus of poly(vinyl alcohol) (PVA) nanofibers was analyzed by scanning probe microscopy (SPM) methods. Air plasma treatment was used to reduce the nanofibers to different sizes. Size-dependent mechanical properties of PVA nanofibers were studied and revealed that the Young's modulus increased dramatically when the scales became very small (<80 nm).

18.
Nanotechnology ; 21(9): 095701, 2010 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-20110583

RESUMO

An ultrahigh field emission current density of 10.3 mA cm(-2) was obtained from nitrogen-implanted ZnO nanowires. The sample was characterized and clearly showed a nitrogen doping signal. Field emission properties of the ZnO nanowires were considerably improved after N-implantation with lower turn-on field and a much higher current density. Removal of an amorphous layer, the presence of nanoscale protuberances, and surface-related defects were found to be responsible for the significantly enhanced field emission. Our work is important for the possible applications of ZnO nanowires in flat panel displays and high brightness electron sources.

19.
Mitochondrial DNA B Resour ; 5(1): 972-973, 2020 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33366832

RESUMO

Ctenochaetus flavicauda is one of most important genera of Acanthuridae. However, the systemically classification and taxonomic studies have so far been limited. In this study, we report the complete mitochondrial genome sequence of C. flavicauda. The mitogenome has 15,772 base pairs (55.5% A + T content) and made up of total of 37 genes (13 protein-coding, 22 transfer RNAs and 2 ribosomal RNAs), and a putative control region. This study will provide useful genetic information for future phylogenetic and taxonomic classification of Acanthuridae.

20.
Mitochondrial DNA B Resour ; 5(1): 974-975, 2020 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-33366833

RESUMO

Pomacanthus arcuatus is one of most important genera of Pomacanthidae. However, the systemically classification and taxonomic studies have so far been limited. In this study, we report the complete mitochondrial genome sequence of P. arcuatus. The mitogenome has 16,718 base pairs (54.4% A + T content) and made up of total of 37 genes (13 protein-coding, 22 transfer RNAs and 2 ribosomal RNAs), and a putative control region. This study will provide useful genetic information for future phylogenetic and taxonomic classification of Pomacanthidae.

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