Fuzhou UniversityFujian

Fuzhou, China

Fuzhou UniversityFujian

Fuzhou, China

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Fang Q.,Fuzhou UniversityFujian | Dong Y.,Fuzhou UniversityFujian | Chen Y.,Fuzhou UniversityFujian | Lu C.-H.,Fuzhou UniversityFujian | And 3 more authors.
Carbon | Year: 2017

Carbon based dots (CDs) have attracted broad attention exhibit due to the unique optical properties. However, the exact origins of their optical properties are still controversial. Citric acid (CA) coupled with some amino group-containing small molecules are believed to be ideal precursors for the synthesis of high luminescent CDs through various thermal treatment processes. Herein, CA coupled with four amino group-containing small molecules are chosen as models to synthesize CDs for a systematical study on the photoluminesce (PL) properties. It is found that the PL properties of CDs are resulted from the synergistic effect of the contained luminescent pyridine-derivatives and the defect states. A reasonable mechanism of PL emission from the CDs has been proposed. The results presented here must be critical for understanding the origins of PL, and also for preparing CDs with strong and wavelength tunable PL emission. © 2017 Elsevier Ltd

Zeng S.,Fuzhou UniversityFujian | Ye J.,Fuzhou UniversityFujian | Cui Z.,Fuzhou UniversityFujian | Cui Z.,Fujian University of TechnologyFujian | And 11 more authors.
Materials Science and Engineering C | Year: 2017

As one of the stimulators on bone formation, osteogenic growth peptide (OGP) improves both proliferation and differentiation of the bone cells in vitro and in vivo. The aim of this work was the preparation of three dimensional porous poly(lactic acid) (PLA) scaffold with high porosity from PLA-dioxane-water ternary system with the use of vacuum-assisted solvent casting, phase separation, solvent extraction and particle leaching methods. Then, by surface coating of PLA scaffold with chitosan (CS)/OGP solution, biofunctionalization of PLA scaffold had been completed for application in bone regeneration. The effects of frozen temperature (− 20, − 50, − 80 °C) and PLA solution concentration (10, 12, 14 wt%) on the microstructure, water absorption, porosity, hydrophilicity, mechanical properties, and biocompatibility of PLA and CS/OGP/PLA scaffold were investigated. Results showed that both PLA and CS/OGP/PLA scaffolds have an interconnected network structure and a porosity of up to 96.1% and 91.5%, respectively. The CS/OGP/PLA scaffold exhibited better hydrophilicity and mechanical properties than that of uncoated PLA scaffold. Moreover, the results of cell culture test showed that CS/OGP coating could stimulate the proliferation and growth of osteoblast cells on CS/OGP/PLA scaffold. These finding suggested that the surface biofunctionalization by CS/OGP coating layer could be an effective method on enhancing cell adhesion to synthetic polymer-based scaffolds in tissue engineering application and the developed porous CS/OGP/PLA scaffold should be considered as alternative biomaterials for bone regeneration. © 2017 Elsevier B.V.

Peng K.-P.,Fuzhou UniversityFujian | Mou X.-P.,Fujian Inspection and Research Institute for Product Quality | Ma Y.-S.,Fujian Qianda Heavy Machinery Co LtdFujian
Cailiao Rechuli Xuebao/Transactions of Materials and Heat Treatment | Year: 2014

Cu-35Zn alloy deformed by constrained groove pressing (CGP) up to 10 passes and 30% cold rolling was annealed at different temperatures. The thermal stability of Cu-35Zn processed by CGP and cold rolling was studied. The results show that the grains of Cu-35Zn alloy are refined by CGP and cold rolling. After the deformation of CGP and cold rolling, the hardness and strength of the samples are improved. The recovery process of specimens deformed by CGP and cold rolling is dominants when annealing below 200 ℃. The crystallites with large angle grain boundary are formed at 220 ℃. The recrystallization and grain growth are completed at 300-400 ℃.

Huang F.,Tongji University | Huang F.,Fuzhou UniversityFujian | Huang F.,University of Nevada, Reno | Yu X.,Fuzhou UniversityFujian | And 3 more authors.
Thin-Walled Structures | Year: 2016

In general, the calculation of ultimate load capacity (UL) of a concrete-filled steel tubular (CFST) column is based on the assumption that the load is resisted by both the steel tube and the concrete core simultaneously as a composite member. However, steel tubes of CFST columns are preloaded due to self-weight, wet concrete weight as well as temporary construction loads before the composite action is formed. There is still no consensus on how the preload affects the loading resistance of CFST columns and how to quantify the effect of preload on the ultimate strength. The paper reported an experimental study on circular CFST columns subjected to preload. The testing results showed that the preloading effect increased with the increase of slenderness, decreased the ultimate load capacity and increased the deformation significantly at high preloading ratio, but did not have much influence on the ultimate load capacity at light preload. Then, a parametric analysis of coupled effects of preloading ratio with other parameters, such as slenderness ratio, eccentric ratio, as well as material properties, is presented. Finally, a simplified method is proposed to predict the ultimate load capacity of CFST columns with preload. The preloading reduction factor of simplified methods of UL based on regressive analysis can be used to evaluate the UL of CFST columns with preload after verified by overall comparison of total preloading tests. © 2015 Elsevier Ltd. All rights reserved.

He S.-H.,CAS Fujian Institute of Research on the Structure of Matter | He S.-H.,Fuzhou UniversityFujian | Liu P.-F.,CAS Fujian Institute of Research on the Structure of Matter | Liu P.-F.,University of Chinese Academy of Sciences | And 6 more authors.
Acta Materialia | Year: 2015

Lead-free In4Se3 is a newly established promising middle temperature n-type thermoelectric (TE) material candidate. Series of Yb-substituted In4-xYbxSe3 (x = 0.01-0.09) samples are prepared herein and their TE properties and the structure-property relationship are investigated. Magnetic molar susceptibility measurements indicate that Yb is nonmagnetic. However, the Yb doped samples behave abnormally in transport properties. The unit cell volume variations and the carrier concentration (ne) changes reveal that Yb substitutes the In4+ site when x < 0.05 in the unitcell of In4Se3 and behaves in transport property as an +1 ion leading to a slow ne decrease; differently, Yb substitutes the In35+ sites in the unitcell of In4Se3 when x > 0.05, and behaves as an acceptor leading to a sharp ne decline. These are considered to be attributed to the Fermi level pinning of the f and d orbitals of Yb. Such Yb substitution preference is also supported by our primary formation energy calculation. Besides, the carriers that on the pinning level are highly localized, thus contribute very little to the electrical conductivity, but contribute to some degree to the thermal conductivity as shown by property-temperature plots. In addition, the Yb atoms produce resonate states around EF that enhance the Seebeck coefficient. As a heavy atom, Yb effectively scatter phonons resulting in the thermal conductivity reduction. All these factors together give In3.95Yb0.05Se3 a significant 30% ZT at 703 K relevant to that of the pure In4Se3. © 2015 Acta Materialia Inc. All rights reserved.

Xu H.,Fuzhou UniversityFujian | Xu H.,Fujian University of Traditional Chinese Medicine | Zhu X.,Fujian Agriculture and forestry University | Dong Y.,Fuzhou UniversityFujian | And 3 more authors.
Sensors and Actuators, B: Chemical | Year: 2016

Graphite carbon nitride nanosheets (g-C3N4 NSs) are the promising metal-free polymer-like semiconductor nanomaterials, which exhibit excellent electrochemiluminescence (ECL) behavior. The g-C3N4 NSs modified the glass carbon electrode showed the obvious ECL response using 10 mM S2O8 2− as the co-reactant at the scan rate of 0.1 V/s. The presence of Cu2+ would quench ECL emission due to the photo induced electron transfer (PET). Pyrophosphate anion (PPi), an important anion in several bioenergetics and metabolic processes, can chelate with Cu2+ with a strong affinity. The introduction of PPi could release Cu2+ from Cu2+-g-C3N4 NSs system, resulting in the ECL recovery. The dosage of Cu2+ and the ECL recover time were further investigated. Under the optimized condition PPi can be detected in the range of 2.0–800 nM with the detection limit of 75 pM based on 3ơ/slope. This ECL sensor also possessed good selectivity to PPi, and has been used to detect PPi in the synovial fluid. © 2016 Elsevier B.V.

Dong H.,Fuzhou UniversityFujian | Sun H.,Fuzhou UniversityFujian | Zheng J.,Fujian Provincial HospitalFujian
Talanta | Year: 2016

With the development of large-scale biologic databases, precision medicine is becoming a frontier in biomedical research. As a main focus of precision medicine study, cancer has been widely accepted as a disease born out of inherited genetic variations or accumulating genomic damage. At the single-cell level, microfluidics or lab-on-a-chip technology for cancer study is an emerging tool for improving risk assessment, diagnostic categories and therapeutic strategies. This work presents a multi-layer microchip for single-cell gene expression profiling. Treated by three drug reagents (i.e. methyl methanesulfonate, docetaxel and colchicine) with varied concentrations and time lengths, individual human breast cancer cells (MCF-7) are then lysed on-chip, and the released mRNA templates are captured and reversely transcribed into cDNA on microbead surface. Three genes (GAPDH, CDKN1A, AURKA) are amplified and quantified simultaneously through triplex real-time polymerase chain reactions (qPCR). Readout per run is set to be eighteen, and can be further improved following same approach. The microchip is able to integrate all steps of single-cell gene expression profiling, and provide precision study of drug induced genotoxicity with reduced reagents consumption per reaction and instrumental cost. © 2016 Elsevier B.V.

Wang B.,Fuzhou UniversityFujian | Deng L.,Fuzhou UniversityFujian | Adrien C.,Chongqing University | Guo N.,Chongqing University | And 2 more authors.
Materials Characterization | Year: 2015

The effects of initial texture on the flow behavior, microstructure and texture evolution of Mg-3Al-1Zn alloy hot rolled plate with a strong basal texture during tension at room temperature have been investigated by experiments and simulations. Three kinds of specimens were cut from this plate with their tensile directions aligned 0°, 45°, and 90° to the normal direction (ND), and they were referred as 0ND, 45ND and 90ND specimens, respectively. A crystal plasticity model was developed to demonstrate the relationship between textures and deformation modes. The results show that the general features of flow curves and texture evolutions of AZ31 alloy during tension can be well explained by the relative activities of deformation modes, which exhibit a pronounced orientation dependence on both the starting and current textures. The obvious yielding behaviors in 0ND and 45ND specimens are induced by the initial activity of {10-12} twinning, and the strain hardening behavior is related to the activities of {10-12} twinning, basal slip and prismatic slip. Due to the existence of {10-11} twinning at low strain, the elongation to rupture of 90ND specimen is much lower than those the elongation of 0ND and 45ND specimens. Although prismatic slip activity depends on the initial texture, its activities always increases during tension, affecting the flow curves, microstructure and texture evolutions. The high prismatic slip activities in 0ND and 90ND specimens result in a strong {10-10} prismatic texture, while the activity of pyramidal < c + a > slip is always negligible in all specimens and insensitive to the initial texture during tension. © 2015 Elsevier Inc. All rights reserved.

Dong H.,Fuzhou UniversityFujian | Sun H.,Fuzhou UniversityFujian
Sensors (Switzerland) | Year: 2016

Microfluidics-based single-cell study is an emerging approach in personalized treatment or precision medicine studies. Single-cell gene expression holds a potential to provide treatment selections with maximized efficacy to help cancer patients based on a genetic understanding of their disease. This work presents a multi-layer microchip for single-cell multiplexed gene expression profiling and genotoxicity detection. Treated by three drug reagents (i.e., methyl methanesulfonate, docetaxel and colchicine) with varied concentrations and time lengths, individual human cancer cells (MDA-MB-231) are lysed on-chip, and the released mRNA templates are captured and reversely transcribed into single strand DNA. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), cyclin-dependent kinase inhibitor 1A (CDKN1A), and aurora kinase A (AURKA) genes from single cells are amplified and real-time quantified through multiplex polymerase chain reaction. The microchip is capable of integrating all steps of single-cell multiplexed gene expression profiling, and providing precision detection of drug induced genotoxic stress. Throughput has been set to be 18, and can be further increased following the same approach. Numerical simulation of on-chip single cell trapping and heat transfer has been employed to evaluate the chip design and operation. © 2016 by the author; licensee MDPI, Basel, Switzerland.

Dong Y.,Fuzhou UniversityFujian | Wu H.,Fuzhou UniversityFujian | Shang P.,Fuzhou UniversityFujian | Zeng X.,Fuzhou UniversityFujian | Chi Y.,Fuzhou UniversityFujian
Nanoscale | Year: 2015

Hydrazide-modified graphene quantum dots (HM-GQDs) obtained by refluxing GQDs with hydrazine hydrate were hybridized with gold nanoparticles (AuNPs) through a redox reaction between HM-GQDs and AuCl4 -. The obtained nano-hybrids (HM-GQD-AuNPs) possess the unique electrochemiluminescence (ECL) properties of HM-GQDs and the easy self-assembly with some bio-molecules of AuNPs, which have great potential applications in bio-sensors. HM-GQD-AuNPs were modified on a glassy carbon electrode to develop a novel ECL immunosensor of carcinoembryonic antigen (CEA) as a model target analyte. Due to the increment of electron-transfer resistance after immunoreaction, the ECL intensity decreased as the concentration of CEA was increased. The linear response range was between 0.02 and 80 ng mL-1, and the detection limit was 0.01 ng mL-1. © The Royal Society of Chemistry.

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