Molecular dynamics study on the diffusion behavior of water inside functionalized carbon nanotubes

To describe the diffusion of atoms in the crystal lattice of a metal, we use the statistical model, which was previously well tested for the description of thermionic emission [1]. Atoms in the crystal lattice of a metal are held by large attractive forces, therefore the potential energy of moving, i.e. diffusing atoms is greater than the potential energy of the atoms of the crystal lattice by the value of u — the activation energy of the diffusion process

Graphene oxide functionalized long period grating for ultrasensitive label-free immunosensing

We explore graphene oxide (GO) nanosheets functionalized dual-peak long period grating (dLPG) based biosensor for ultrasensitive label-free antibody-antigen immunosensing. The GO linking layer provides a remarkable analytical platform for bioaffinity binding interface due to its favorable combination of exceptionally high surface-to-volume ratio and excellent optical and biochemical properties. A new GO deposition technique based on chemical-bonding in conjunction with physical-adsorption was proposed to offer the advantages of a strong bonding between GO and fiber device surface and a homogeneous GO overlay with desirable stability, repeatability and durability. The surface morphology of GO overlay was characterized by Atomic force microscopy, Scanning electron microscope, and Raman spectroscopy. By depositing the GO with a thickness of 49.2 nm, the sensitivity in refractive index (RI) of dLPG was increased to 2538 nm/RIU, 200% that of non-coated dLPG, in low RI region (1.333–1.347) where bioassays and biological events were usually carried out. The IgG was covalently immobilized on GO-dLPG via EDC/NHS heterobifunctional cross-linking chemistry leaving the binding sites free for target analyte recognition. The performance of immunosensing was evaluated by monitoring the kinetic bioaffinity binding between IgG and specific anti-IgG in real-time. The GO-dLPG based biosensor demonstrates an ultrahigh sensitivity with limit of detection of 7 ng/mL, which is 10-fold better than non-coated dLPG biosensor and 100-fold greater than LPG-based immunosensor. Moreover, the reusability of GO-dLPG biosensor has been facilitated by a simple regeneration procedure based on stripping off bound anti-IgG treatment. The proposed ultrasensitive biosensor can be further adapted as biophotonic platform opening up the potential for food safety, environmental monitoring, clinical diagnostics and medical applications

Fibre optic chemical sensor based on graphene oxide-coated long period grating

In this work, a graphene oxide-coated long period fibre grating (GO-LPG) is proposed for chemical sensing application. Graphene oxide (GO) has been deposited on the surface of long period grating to form a sensing layer which significantly enhances the interaction between LPG propagating light and the surrounding-medium. The sensing mechanism of GO-LPG relies on the change of grating resonance intensity against surrounding-medium refractive index (SRI). The proposed GO-LPG has been used to measure the concentrations of sugar aqueous solutions. The refractive index sensitivities with 99.5 dB/RIU in low refractive index region (1.33-1.35) and 320.6 dB/RIU in high index region (1.42-1.44) have been achieved, showing an enhancement by a factor of 3.2 and 6.8 for low and high index regions, respectively. The proposed GO-LPG can be further extended to the development of optical biochemical sensor with advantages of high sensitivity, real-time and label-free sensing

Identification of HSP90 gene from the Chinese oak silkworm, Antheraea pernyi

The heat shock proteins (Hsp) play an important role in protein folding and protection of cells from stress. To investigate the role of Hsp90 in silk-producing insect Antheraea pernyi (Lepidoptera: Saturniidae), a full-length cDNA encoding Hsp90 from A. pernyi was cloned, sequenced and characterized. The complete cDNA (2,482 bp) contained a 2,154 bp open reading frame encoding 717 amino acid residues and had 94.5% identity with Antheraea yamamai Hsp90. The relative expression levels of Hsp90 in five different tissues at normal and high temperatures were evaluated with real-time fluorescence quantitative RT-PCR. The expression of Hsp90 was obviously changed in the examined tissues except for fat bodies after induced by high temperature. SDS-PAGE of purified protein demonstrated that an 86 KD recombinant protein was successfully expressed in transformed Escherichia coli cells. These results shed light on studying the mechanism of tolerance in A. pernyi.Key words: Antheraea pernyi, HSP90, sequence analysis, expression

An adaptive evolutionary algorithm for bi-level multi-objective VRPs with real-time traffic conditions

The file attached to this record is the author's final peer reviewed version.The research of vehicle routing problem (VRP) is significant for people traveling and logistics distribution. Recently, in order to alleviate global warming, the VRP based on electric vehicles has attracted much attention from researchers. In this paper, a bi-level routing problem model based on electric vehicles is presented, which can simulate the actual logistics distribution process. The classic backpropagation neural network is used to predict the road conditions for applying the method in real life. We also propose a local search algorithm based on a dynamic constrained multi-objective optimization framework. In this algorithm, 26 local search operators are designed and selected adaptively to optimize initial solutions. We also make a comparison between our algorithm and 3 modified algorithms. Experimental results indicate that our algorithm can attain an excellent solution that can satisfy the constraints of the VRP with real-time traffic conditions and be more competitive than the other 3 modified algorithms

Reducing Crosstalk of Silicon-based Optical Switch with All-optical Multi-wavelength Regenerator

Improving crosstalk performance of Mach–Zehnder-interferometer-type optical switches is experimentally investigated by use of an all-optical multi-wavelength regenerator. Extinction ratio and bit error rate of WDM signals are simultaneously improved in proposed regenerative optical switching