Liquid crystal based active wavelength filter for phase-sensitive optical time domain reflectometry.

This study proposes a liquid-crystal-based active wavelength filter for phase-sensitive optical time domain reflectometry to mitigate the amplified spontaneous emission (ASE) noise and accurately match the passband with the light source. The validity of the proposed system was verified using comparative experiments with conventional passive optical filters. The experiment showed an increase in signal-to-noise ratio (SNR) of up to 2.21 dB compared with passive filters. Additionally, the proposed system can effectively eliminate ASE noise, resulting in an SNR of 12.99 dB.

A Sensing Device with the Optical Temperature Sensors-Based Quad-RX Module and a Security Module.

In this paper, we present a sensing device with the optical temperature sensors-based quad receiver (Quad-RX) module and a security module. In addition, in order to prevent cyberattacks on critical national infrastructures and key facilities, we implemented symmetric-key and secure hash algorithm-based hardware security modules in the key elements of the sensing device. A preliminary test was conducted prior to a field trial to verify the performance of the developed sensing device. The accuracy and stability of the sensing device were then verified for 1 month in a field test at facilities for energy storage systems and photovoltaic converters in sewage treatment plants.

Molecular characterisation and expression analysis of a fish-egg lectin in rock bream, and its response to bacterial or viral infection.

A fish-egg lectin, RbFEL, was identified from rock bream (Oplegnathus fasciatus) and its expression analysed. In both vertebrates and invertebrates, carbohydrate-binding proteins (lectins) play an important role in innate immunity against microbial invasion. Here, we report the cloning of a fish-egg lectin from rock bream using a combination of expression sequence tag (EST) analyses. The full-length cDNA of RbFEL is composed of 1512-bp with a 780-bp ORF that encodes 259 amino acid residues. The deduced polypeptide exhibits six conserved residues of the FEL family. All cysteine positions in each domain were completely conserved. Reverse transcription quantitative real-time PCR analysis of the tissues revealed that RbFEL mRNA was abundantly expressed in liver, moderately expressed in head kidney and rarely expressed in other tissues. Expression analyses of time series sampled fertilised eggs showed that expression gradually increased 1, 3, 12, 24 and 36 h after fertilisation. In addition, RbFEL expression was significantly up-regulated in rock bream challenged with Edwardsiella tarda, Streptococcus iniae and red sea bream iridovirus (RSIV). These results suggest that RbFEL is a member of the egg-lectin family and is involved in the innate immune response in rock bream.

Molecular identification and expression analysis of cathepsins O and S from rock bream, Oplegnathus fasciatus.

Cathepsins are lysosomal cysteine proteases belonging to the papain family, members of which play important roles in normal metabolism for maintenance of cellular homeostasis. Rock bream (Oplegnathus fasciatus) cathepsin O and S (RbCTSO and RbCTSS, respectively) cDNAs were identified by expressed sequence tag (EST) analysis of a lipopolysaccharide (LPS)-stimulated rock bream liver cDNA library. The full-length RbCTSO cDNA (1698 bp) contained an open reading frame (ORF) of 1017 bp encoding 338 amino acids. The full-length RbCTSS cDNA was 1401 bp in length and contained an ORF of 1014 bp encoding 337 amino acids. RbCTSO was significantly expressed in the liver, peripheral blood lymphocytes (PBLs) and spleen. On the other hand, RbCTSS showed significant expression in the liver, trunk kidney, muscle and gills. Real-time RT-PCR was used to examine RbCTSO and RbCTSS mRNA expression in several tissues (kidney, spleen, liver and gill) under conditions of bacterial and viral challenge. Experimental infection of rock bream with Streptococcus iniae and red sea bream iridovirus (RSIV) resulted in significant increases in RbCTSO and RbCTSS mRNA levels in the tissues.

Molecular cloning and characterisation of the rock bream, Oplegnathus fasciatus, Fas (CD95/APO-1), and its expression analysis in response to bacterial or viral infection.

Fas belongs to the tumour necrosis factor (TNF) receptor superfamily and can transmit a death signal leading to apoptosis. In the present study, we isolated the full-length cDNA for rock bream (Oplegnathus fasciatus) Fas (RbFas). The full-length RbFas cDNA was 1770 bp long and contained an open reading frame of 957 bp that encoded 319 amino acid residues with a predicted molecular mass of 35.1 kDa. The 319 amino-acid predicted RbFas sequence is homologous to other Fas sequences, contains three cysteine-rich domains and a death domain (DD) and two potential N-glycosylation sites. Expression of RbFas mRNA was detected in nine different tissues from healthy rock bream and was the highest in red blood cells. In analyses of mitogen-stimulated RbFas expression in peripheral blood leucocytes, expression of RbFas mRNA was observed between 1 and 36 h after stimulation with LPS, and 1 and 3 h stimulation with poly I:C. In the case of bacterial injection, the RbFas transcript peaked 6 h after injection in both the kidney and the spleen. Otherwise, the RbFas transcript peaked after 1 h in spleen and 6 h in kidney following injection with RSIV.

Linear FBG Temperature Sensor Interrogation with Fabry-Perot ITU Multi-wavelength Reference.

The equidistantly spaced multi-passbands of a Fabry-Perot ITU filter are used as an efficient multi-wavelength reference for fiber Bragg grating sensor demodulation. To compensate for the nonlinear wavelength tuning effect in the FBG sensor demodulator, a polynomial fitting algorithm was applied to the temporal peaks of the wavelength-scanned ITU filter. The fitted wavelength values are assigned to the peak locations of the FBG sensor reflections, obtaining constant accuracy, regardless of the wavelength scan range and frequency. A linearity error of about 0.18% against a reference thermocouple thermometer was obtained with the suggested method.

Accuracy improvement in peak positioning of spectrally distorted fiber Bragg grating sensors by Gaussian curve fitting.

To improve measurement accuracy of spectrally distorted fiber Bragg grating temperature sensors, reflection profiles were curve fitted to Gaussian shapes, of which center positions were transformed into temperature information. By applying the Gaussian curve-fitting algorithm in a tunable bandpass filter demodulation scheme, approximately 0.3 degrees C temperature resolution was obtained with a severely distorted grating sensor, which was much better than that obtained using the highest peak search algorithm. A binary search was also used to retrieve the optimal fitting curves with the least amount of processing time.