Isolation and Characterization of P450 Gene from the Formosan Subterranean Termite, Coptotermes formosanus (Isoptera: Rhinotermitidae)

A cytochrome P450 gene belonging to family9 was isolated from the midgut transcriptome of the termite Coptotermes formosanus Shiraki, for screening enzymes related to biomass degeneration. Some studies show that insect P450 enzymes have ligninase activities for catalyzing lignin degradation. We employed the RACE method to clone this cytochrome P450 gene, named CYP9AX1 (GenBank accession No.JN969113). To the best of our knowledge, CYP9AX1 is the first member of the CYP9 family cloned from this termite. The full-length CYP9AX1 cDNA was 2242 bp long and included a 1599bp open-reading-frame (ORF), a 61-bp 5’-untranslated region (UTR) and a 592-bp 3’-UTR (excluding the poly-A tail). The CYP9AX1 protein deduced from the ORF contains 532 amino acids with a predicted signal peptide composed of 20 amino acid at its N-terminal and the classic heme-binding domain FXXGXXXCXG (residues 468-477). At position 473, residue Arg (R) changes to Gln (Q), this suggests that CYP9AX1 is a new type of CYP subfamily 9A. The phylogenetic tree showed that C. formosanus has high genetic relationship with Blattella germanica and Diploptera punctata. Quantitative RT-PCR assays demonstrated that CYP9AX1 was expressed most abundantly in malpighian tubules, and slightly lower in the head, foregut, midgut and hindgut. The results suggested that CYP9AX1 may be involved in enzymatic detoxification systems of the delignification process in C. formosanus

Novel Microfiber Sensor and Its Biosensing Application for Detection of hCG Based on a Singlemode-Tapered Hollow Core-Singlemode Fiber Structure

A novel microfiber sensor is proposed and demonstrated based on a singlemode-tapered hollow core -singlemode (STHS) fiber structure. Experimentally a STHS with taper waist diameter of 26.5 μm has been fabricated and RI sensitivity of 816, 1601.86, and 4775.5 nm/RIU has been achieved with RI ranges from 1.3335 to 1.3395 , from 1.369 to 1.378, and from 1.409 to 1.4175 respectively, which agrees very well with simulated RI sensitivity of 885, 1517, and 4540 nm/RIU at RI ranges from 1.3335 to 1.337, from 1.37 to 1.374, and from 1.41 to 1.414 . The taper waist diameter has impact on both temperature and strain sensitivity of the sensor structure: (1) the smaller the waist diameter, the higher the temperature sensitivity, and experimentally 26.82 pm/°C has been achieved with a taper waist diameter of 21.4 μm; (2) as waist diameter decrease, strain sensitivity increase and 7.62 pm/με has been achieved with a taper diameter of 20.3 μm. The developed sensor was then functionalized for human chorionic gonadotropin (hCG) detection as an example for biosensing application. Experimentally for hCG concentration of 5 mIU/ml, the sensor has 0.5 nm wavelength shift, equivalent to limit of detection (LOD) of 0.6 mIU/ml by defining 3 times of the wavelength variation (0.06 nm) as measurement limit. The biosensor demonstrated relatively good reproducibility and specificity, which has potential for real medical diagnostics and other applications

Advanced predication of geological anomalous body ahead of laneway using seismic tomography technique

Advanced predication of geological anomalous body (GAB) of laneway can provide scientific references for mine safety production. It refers to reveal the position, shape and size of GAB in advance. Seismic tomography technology (STT) can realize the prediction of GAB using tunnel surface waves. Tunnel Reflection Tomography (TRT) 6000 system, which is on the basis of STT, has the advantages of convenience and high reliability. In this paper, TRT6000 is introduced to forecast the GAB ahead of laneway in underground metal mine. The operation steps, data processing and notes about TRT6000 are detailed. The research results show that there are two water flowing fractures, separately located at around 50meters and 85meters ahead of laneway. And the prediction results match the actual situation well. Therefore, the seismic tomography technology improves the mine safety management, and the TRT6000 provides a new method for predicting GAB in advance

Mid-infrared Spectral Compression of Soliton Pulse in an Adiabatically Suspended Silicon Waveguide Taper

Spectral compression (SPC) can be used for generating narrow bandwidth and wavelength-tunable light sources, which have important applications in optical communication system, spectroscopy, and nonlinear microscopy. In this paper, we numerically demonstrate the high-degree SPC of the chirp-free femtosecond pulse at wavelength 2.4 μm in a 6-cm long adiabatically suspended silicon waveguide taper. The silicon waveguide taper is designed with a dispersion-increasing profile along the propagation distance z. Simulation results show that the SPC factor can be up to 10.9, along with the brightness-enhanced factor of 8.0 and negligible sidelobe. The impacts of the higher-order dispersion, higher-order nonlinearity, losses (including linear and nonlinear loss), and variation of Kerr nonlinear coefficient along z on the SPC are also investigated. It is found that variation of Kerr nonlinear coefficient γ(z) and linear loss are the dominant perturbation to the degradation of the SPC performance

Wearable optical fiber sensor based on a bend singlemode-multimode-singlemode fiber structure for respiration monitoring

Respiration rate (RR) is an important information related to human physiological health. A wearable optical fiber sensor for respiration monitoring based on a bend singlemode-multimodesinglemode (SMS) fiber structure, which is highly sensitive to bend, is firstly proposed and experimentally demonstrated. The sensor fastened by an elastic belt on the abdomen of a person will acquire the respiration signal when the person breaths, which will introduce front and back movement of the abdomen, and thus bend of SMS fiber structure. Short-time Fourier transform (STFT) method is employed for signal processing to extract characteristic information of both the time and frequency domain of the measured waveform, which provides accurate RR measurement. Six different SMS fiber sensors have been tested by six individuals and the experimental results demonstrated that the RR signals can be effectively monitored among different individuals, where an average Pearson Correlation Coefficient of 0.88 of the respiration signal has been achieved, which agrees very well with that of commercial belt respiration sensor. The proposed technique can provide a new wearable and portable solution for monitoring of respiratory with advantage of easy fabrication and robust to environment

Self-similar Pcosecond Pulse Compression for Supercontinuum Generation at Mid-infrared Wavelength in Silicon Strip Waveguides

Self-similar pulse compression has important application in highly coherent supercontinuum (SC) generation. In this paper, we numerically present the mid-infrared self-similar picosecond pulse compression in a tapered suspended silicon strip waveguide, which is designed with exponentially decreasing dispersion profile along the direction of propagation. When the variation of the Kerr nonlinear coefficient ��(z), linear and nonlinear losses, higher-order nonlinearity, and higher-order dispersion are taken into consideration, the simulation result shows that a 1 ps input pulse centered at wavelength 2.8 μm could be self-similarly compressed to 47.06 fs in a 3.9-cm waveguide taper, along with a compression factor ��c of 21.25, quality factor ��c of 0.78, and negligible pedestal. After that, the compressed pulse is launched into a uniform silicon strip waveguide, which is used for the generation of SC. We numerically demonstrate that the coherence of the generated SC by the compressed pulse can be significantly improved when compared to that generated directly by the picosecond pulse. The simulation results can be used to realize on-chip mid-infrared femtosecond light source and highly coherent supercontinuum, which can promote the development of on-chip nonlinear optic