Search

• Narrowband metalens enable high-definition projection and imaging in portable devices. • A high integration design scheme that combines filtering and focusing into one. • The proposed narrowband metalens is almost unaffected by negative dispersion. • The numerical value of the modulation transfer function at the receiving end is almost unaffected by angular variations. • The light spot matrix at the projection end is almost unaffected within the operating bandwidth. In recent years, three-dimensional (3D) optical imaging has played a significant role in rapid 3D modeling fields, including applications such as cellphone camera-assisted 3D imaging and facial recognition. However, commonly used portable near-infrared vertical-cavity surface-emitting lasers (VCSELs) often have a wide wavelength bandwidth, which makes it challenging to mitigate the effects of dispersion on high numerical aperture metalenses. This can result in a sudden drop in optical performance. Here, we proposed the utilization of multi-layer coating to construct a one-dimensional photonic crystal (1D PhC) cavity, which provide a narrow working wavelength band. A narrowband focusing is achieved by cascading an all-dielectric metalens at the end of the 1D PhC crystal. The proposed narrowband metalens exhibits a 1.6-nm bandwidth at a 1540-nm telecom band, and which was nearly 12 times smaller when compared to normal portable flat lasers. In addition, the operational wavelength position can be tuned by adjusting the scale of the 1D PhC cavity within the wavelength range of 800–1700 nm. Furthermore, narrowband metalenses significantly outperform normal metalenses for a 4 × 4 array light source array focusing dot projection with 100-degree field of angle. We proposed this device to enhance the performance of portable VCSEL-integrated metalenses, which holds great potential for the future of portable high-definition 3D imaging and display. A 940-nm VCSEL is a standard light source for dot projections in 3D imaging reconstruction. The detailed information of the metalenses design for a 940-nm VCSEL is also investigated and reported. [ABSTRACT FROM AUTHOR]

Duck follicles enter different reproductive phases throughout life, and follicle gene expression patterns differ according to these phases. In particular, differentially expressed genes and related to development of follicle (mRNAs) play an important role to explore the key genes in this process; however, the expression profiles of these genes remain unclear. In this study, transcriptome sequencing was used to investigate the expression levels of duck ovarian genes, and comparative transcriptional analysis was carried out to identify differential genes, and cluster them into groups and function identification. The results showed differential expression of 593 coding genes between young and laying ducks, and of 518 coding genes between laying and old ducks. In further GO analysis, 35 genes from the comparison between old ducks and laying ducks have significant been changed involved in hormones related to follicle development. They include up-regulated genes StAR, CYP17, EPOX, 3β-HSD, CYP1B1 CYP19A1 and down-regulated genes SR-B1 in laying ducks hormone synthesis than old ducks. Among which EPOX is a key gene for time special highly expression during egg laying stage, and other key regulatory genes’ highly expression showed in young and laying stage, and lower expression showing with follicular development stopping. Therefore, EPOX is a key regulator for duck follicle development in laying period, its expression level increase 100 times higher than in youth and decrease 98% than stop laying period in duck life cycle. [ABSTRACT FROM AUTHOR]

In China, aquatic ecosystems have been highly disturbed by the introduction and spread of non-native invasive species. Unfortunately, problems of biological invasions in aquatic ecosystems have been largely overlooked and lessons from known disasters are learned slowly, despite that negative effects are frequently detected and reported. Here, we review the available literature to generate a list of invasive species in aquatic ecosystems in China. We summarize five major negative effects caused by invasive species, including habitat damage, community change, pests of agriculture and aquaculture, biodiversity loss, and genetic pollution/extinction. We discuss three major vectors (aquaculture, shipping, and aquarium and ornamental trades) responsible for the introduction and spread of aquatic invasive species. Finally, we propose and call for management of vectors responsible for the introduction and spread of invasive species in China. [ABSTRACT FROM AUTHOR]

Deep learning prediction of metasurface has been a widely discussed issue in recent years. However, the prediction accuracy is still one of the challenges to be solved. In this work, we proposed using the ResNets-10 model to predict plasmonic metasurface S11 parameters. The two-stage training was performed by the k-fold cross-validation and small learning rate. After the training was complete, the predicted logarithmic losses for aluminum, gold, and silver metal–insulator–metal metasurfaces were −48.45, −46.47, and −35.54, respectively. Due to the ultralow error value, the proposed network can efficiently replace the traditional computing methods within a certain structural range. The ResNets-10 can complete training within 1100 iterations, which is highly efficient. The ResNets-10 model we proposed can also be used to design meta-diffractive devices and meta-resonance biosensors, thereby reducing the time required for the simulation process. The ultralow lose value of the network indicates that this work contributes to the development of future artificial intelligence electromagnetic devices computing software. [ABSTRACT FROM AUTHOR]

The work is devoted to the consideration of methods for determining the strain of objects using fiber Bragg gratings under a high-frequency vibration or pulsed mechanical action, which is difficult to perform using widespread methods and devices. The methods are based on numerical processing of the time dependence of the radiation power reflected from the fiber Bragg grating at various wavelengths, which makes it possible to measure strain parameters in a wide range of magnitude and frequencies. The efficiency of the proposed methods is demonstrated by numerical simulation. It is shown that it is possible to restore the strain dependence on time in the range ± 1000   μ ϵ or more from simultaneously measured power dependencies reflected by the fiber Bragg grating using common fiber-optic components. The case of sequential registration of reflected radiation power at different wavelengths to determine the probability density of the distribution of the strain values is also considered. The results of signal processing obtained both by numerical simulation and experimentally for the case of a linear vibration are presented. The technical problems of using the proposed methods are discussed. [ABSTRACT FROM AUTHOR]

Twelve polymorphic and informative microsatellite markers were isolated and characterized for the Yesso scallop, Mizuhopecten yessoensis. We characterized these loci by genotyping 48 individuals; the number of alleles ranged from two to eight, and the values of observed heterozygosity and expected heterozygosity varied from 0 to 0.8333 and from 0.2546 to 0.8231, respectively. No significant linkage disequilibrium between pairs of loci was found and three loci showed significant heterozygote deficiency from the Hardy-Weinberg equilibrium. These markers are potential for studies of the population structure, individual or hybrid identification of the species. [ABSTRACT FROM AUTHOR]

Presents information on the practical methods for improving the photoelastic optical fiber pressure sensor. Description of the installment method of the graded index lens; Implementation of several compensation methods in one optical system; Static characteristics based on the compensation methods.

Ground settlement (GS) in an oil tank determines its structural integrity and commercial service. However, GS monitoring faces challenges, particularly due to the significant temperature differences induced by solar radiation around the tank in daytime. To address this problem, this paper digs out a prior and proposes a temperature uncertainty reduction algorithm based on that. This prior has a spatial Gaussian distribution of temperature around the tank, and numerical simulation and practical tests are conducted to demonstrate it. In addition, combining uniformly packaged sensor probes and the spatial prior of temperature, the temperature uncertainty is verified to be Gaussian-distributed too. Then, the overall temperature uncertainty can be captured by Gaussian fitting and then removed. The practical test verified a 91% reduction rate in temperature uncertainty, and this approach enables GS sensors to effectively perform daytime monitoring by mitigating temperature-related uncertainties. [ABSTRACT FROM AUTHOR]

Two-dimensional layered ferroelectric materials, such as CuInP2S6 (CIPS), are promising candidates for novel and high-performance photocatalysts, owing to their ultrathin layer thickness, strong interlayer coupling, and intrinsic spontaneous polarization, while how to control the photocatalytic activity in layered CIPS remains unexplored. In this work, we report for the first time, the photocatalytic activity of ferroelectric CIPS for the chemical deposition of silver nanostructures (AgNSs). The results show that the shape and spatial distribution of AgNSs on CIPS are tunable by controlling layer thickness, environmental temperature, and light wavelength. The ferroelectric polarization in CIPS plays a critical role in tunable AgNS photodeposition, as evidenced by layer thickness and temperature dependence experiments. We further reveal that AgNS photodeposition process starts from active site creation, selective nanoparticle nucleation/aggregation, to continuous film formation. Moreover, AgNS/CIPS heterostructures prepared by photodeposition exhibit excellent resistance switching behavior and good surface enhancement Raman Scattering activity. Our findings provide new insight into the photocatalytic activity of layered ferroelectrics and offer a new material platform for advanced functional device applications in smart memristors and enhanced chemical sensors. [ABSTRACT FROM AUTHOR]

Two-dimensional layered ReX2 (X = Se, S) has attracted researcher's great interest due to its unusual in-plane anisotropic optical and electrical properties and great potential in polarization-sensitive optoelectronic devices, while the clean, energy-saving, and ecological synthesis of highly crystalline ReSe2 with controlled domains remains challenging. Here, we develop a space-confined solid-phase approach for growing high-quality two-domain 1T′-ReSe2 with tunable optoelectronic properties by using pure Re powder as a Re precursor. The results show that ReSe2 can be grown at a temperature as low as 550 °C in a small-tube-assisted space-confined reactor, with its size and shape well-tailored via temperature control. A solid-phase two-domain ReSe2 growth mechanism is proposed, as evidenced by combining in situ optical monitoring, ex situ electron microscope, elemental mapping, and polarized optical imaging. Moreover, two-domain ReSe2 transistors are fabricated, which exhibit a switchable transport behavior between n-type and ambipolar character via grain boundary orientation control. This modulation phenomenon is attributed to the different doping levels between grain boundary and single domain. Furthermore, our two-domain ReSe2 photodetectors exhibit a highly gate-tunable current on–off ratio (with a maximum value of ∼8.2 × 103), a polarization-sensitive photo-response, and a high-speed response time (∼300 μs), exceeding most of the previously reported ReX2 photodetectors. Our work, thus, provides a low-consumption, energy-saving growth strategy toward high-quality, domain-controlled ReX2 for highly tunable and high-performance optoelectronics. [ABSTRACT FROM AUTHOR]

The results of applications of various methods for measuring the parameters of high-speed loading using a strain gauge, a fiber Bragg grating located on a metal measuring rod and an interferometer monitoring the movement of the free boundary of the end of the rod are presented. Numerical simulation confirmed the adequacy of the description of the shock-wave process according to experimental data and showed that, with the thickness of the adhesive layer fixing the fiber Bragg grating and the strain gauge on a dimensional rod up to 100 µm, the deformation parameters of the sensors correspond to the parameters of the stress–strain state of the rod. Experimentally, a good correspondence of the results of measuring the magnitude of the relative deformation at a pulse duration of 10–100 µs using sensors of various types is shown, and an estimate of the limit values of the measured values of the deformation wave parameters is given. [ABSTRACT FROM AUTHOR]

Nanostructured optical field enhancements have become more attractive in recent years. In this work, we proposed a surface electric field enhancement device based on the combined effect of surface plasmons resonance and surface plasmon polariton. By optimizing the relationship between the morphology of the nanostructures and the Z-direction electric field components, the intensity of the surface polarized plasmons of the meta-atom can be further enhanced. The 633 nm left-circularly polarized light excitation for this device was examined and worked well. It was used as the operating wavelength. A comparison of the results obtained from right-circularly polarized and linearly polarized lights demonstrated only a strong optical field enhancement of the structure with left-handed polarized light. The polarization-selective parameters were also considered. Finally, by designing meta-atoms with different arrangements, we achieved electric field enhancements up to 177.5. It is worth mentioning that this method can control the degree of electric field enhancement by controlling the number of meta-atoms that excite surface plasmon polaritons, which means that obtaining the desired electric field amplitude becomes tunable in the design. With the proper format, the enhancement factor of the surface-enhanced Raman spectroscopy can be increased to approximately 109. In the research of surface-enhanced Raman spectroscopy and optical tweezers, it would be a straightforward and effective design method to create the desired optical field enhancements. [ABSTRACT FROM AUTHOR]

A nonuniform temperature field can deteriorate the performance of sensors, especially those working in the field, such as an optical sensor for oil-tank ground settlement (GS) monitoring. In this case, the GS monitoring employs hydraulic-level-based sensors (HLBS), which are uniformly installed along with the oil-tank basement perimeter and are all connected by hydraulic tubes. Then, the cylinder structure of the oil tank itself can create a strong temperature difference between the sensors installed in the sunlit front and those in the shadow. Practically, this sunlight-dependent difference can be over 30 °C, by which the thermal expansion of the measuring liquid inside the connecting hydraulic tubes keeps on driving a movement and, thereby, leads to fluctuations in the final result of the oil-tank GS monitoring system. Now, this system can work well at night when the temperature difference becomes negligible. However, temperature uncertainty is generated in the GS sensors due to the large temperature difference between the sensors in the daytime. In this paper, we measured the temperature where the sensor was located. Then, we compared the results of the GS sensors with their corresponding temperatures and fitted them with two separate curves, respectively. After observing the similarity in the tendency of the two curves, we found that there was a qualitative correlative relationship between the change in temperature and the uncertainty in the sensor results. Then, a curve similarity analysis (CSA) principle based on the minimum mean square error (MMSE) criteria was employed to establish an algorithm, by which the temperature uncertainty in the GS sensors was reduced. A practical test proved that the standard deviation was improved by 73.4% by the algorithm. This work could be an example for reducing the temperature uncertainty from in-field sensors through the CSA method. [ABSTRACT FROM AUTHOR]

Physiotherapeutic effects of infrared lasers have been proved in clinic. These infrared-based regulations of the bioelectrical activities can roughly be classified into enhancement and suppression of action potential (AP), which are described by sodium (Na) and potassium (K) transmembrane current equations, named as Hodgkin and Huxley (HH)-model. The enhancement effect is able to evoke or strengthen the AP when infrared light is applied. Its corresponding mechanism is commonly ascribed to the changes of the cell membrane capacitance, which is transiently increased in response to the infrared radiation. The distinctive feature of the suppression effect is to inhibit or reduce the AP by the designed protocols of infrared radiation. However, its mechanism presents more complexity than that in enhancement cases. HH-model describes how the Na current determines the initial phase of AP. So, the enhancement and suppression of AP can be also ascribed to the regulations of the corresponding Na currents. Here, a continuous infrared light at the wavelength of 980 nm (CIS-980) was employed to stimulate a freshly isolated hippocampal neuron in vitro and a suppression effect on the Na currents of the neuron cell was observed. Both Na and K currents, which are named as whole cell currents, were simultaneously recorded with the cell membrane capacitance current by using a patch clamp combined with infrared irradiation. The results demonstrated that the CIS-980 was able to reversibly increase the capacitance currents, completely suppressed Na currents, but little changed K currents, which forms the steady outward whole cell currents and plays a major role on the AP repolarization. A confirmation experiment was designed and carried out by synchronizing tens of milliseconds of infrared stimulation on the same kinds of hippocampal neuron cells. After the blocked K channel, a reduction of Na current amplitude was still recorded. This proved that infrared suppression of Na current was irrelevant to K channel. A membrane capacitance mediation process was preliminarily proposed to explain the Na channel suppression process. [ABSTRACT FROM AUTHOR]

Development of a model for the analysis of strain transfer mechanism in Brillouin-based sensors with strain singularities is provided in this study. The main objective of the research pertained to the development of a method for accurate detection of cracks and their locations in sensing with Brillouin-based fiber optic distributed sensors. The work involved formulation of a shear lag-based model considering the elastic as well as elastoplastic stages of the fiber optic coating strains. Feasibility of the proposed approach is evaluated through an experimental program. The experimental program involved use of a Brillouin optical time domain reflectometer (BOTDR) for distributed measurement of strain and detection of simulated cracks in a 15-m-long beam. The results indicate that the discontinuities in the strain distribution based on the theoretical analysis provide the means to accurately pinpoint the location of simulated cracks. On the other hand, the distortion effect of the BOTDR system due to averaging of the strains over the spatial resolution of the system masked the influence of strain discontinuities. In contrast to the strains acquired through the averaging process in BOTDR, the theoretical computations pertain to the actual distribution of strain along the length of the beam. Optomechanical relationships were also used to simulate the effect of spatial resolution on the theoretical results. The apparent strains obtained in this way were compared with the BOTDR measured values. Because of the measurement noise, the apparent strains based on the theoretical computations provided better information about the location of the cracks. [ABSTRACT FROM AUTHOR]

Molluscs, the second largest animal phylum on earth, primarily rely on cellular and humoral immune responses to fight against pathogen infection. Although antimicrobial peptides (AMPs) such as big defensin play crucial roles in the humoral immune response, it remains largely unknown in the ecological and economic important blood clam (Tegillarca granosa). In this study, a novel big defensin gene (TgBD) was identified in T. granosa through transcripts and whole genome searching. Bioinformatic analyses were conducted to explore the molecular characteristics of TgBD, and comparisons of TgBD with those reported in other molluscs were performed by multiple alignments and phylogenetic analysis. In addition, the expression patterns of TgBD in various tissues and upon bacterial challenge were investigated while the antimicrobial activity of synthetic N-terminal domain of TgBD was confirmed in vitro by radial diffusion experiment. Results obtained showed TgBD had an open reading frame (ORF) of 369 bp, encoding a prepropeptide containing a signal peptide and a propeptide. Similar to big defensins reported in other species, TgBD consists of a hydrophobic N-terminal domain containing β1-α1-α2-β2 folds and a cysteine-rich cationic C-terminal domain with three disulfide bonds between C1–C5, C2–C4, and C3–C6. Phylogenetic analysis showed that TgBD shared 76.80% similarity to its close relative ark shell (Scapharca broughtoni). In addition, TgBD expression was observed in all tissues investigated under normal conditions and was significantly induced by injection of Vibrio parahaemolyticus. Furthermore, synthetic N-terminal peptide of TgBD exhibited strong antimicrobial activity against Gram-positive bacteria tested. Our results indicated that TgBD is a constitutive and inducible acute phase AMP, which provides a universal and prompt protection for T. granosa. • A novel big defensin (TgBD) was identified in the blood clam, Tegillarca granosa. • TgBD shares common structural characteristics with big defensins reported in other bivalves. • TgBD expressed normally in all tissues tested and was significantly induced by bacterial challenge. • Synthetic TgBD peptide exhibited strong antimicrobial activity against Gram-positive bacteria. [ABSTRACT FROM AUTHOR]

In most of flexible production schemes, the flexible manufacturing cells (FMCs) are more economical and feasible. So, an important task is to establish the correct reliability analysis model for the FMCs. However, with the increasing of system complexity, some reliability analysis modes can hardly describe the actual situation. Besides, due to the lack of test-data and field-data during the design stage of FMC' system, the reliability modeling will be more complicated. In order to deal with the deficient data and the uncertainty occurred from analysis and judgment, this article analyzes the reliability of FMCs system through the method of fuzzy fault tree, which is based on triangular fuzzy membership. At last, a practical example is illustrated. The reliability analysis model indicates that it can offer a diagnostic tool for FMCs system and improve the efficiency of operation and production in FMCs system. [ABSTRACT FROM AUTHOR]

To study the degenerative process of concrete subjected to freezing-thawing (F-T) cycles in real-time, the strain behavior of concrete cylinder was monitored by a fiber optic F-T testing method based on the white light interferometer (WLI) technique. The principle of the WLI technique was described in detail and the design of the fiber optic testing method. Two mixed proportions of concrete immersed in 3.5% NaCl solution were tested in a freeze-thaw testing machine. The theory and method of temperature compensation were stated in detail. The results indicated that the variation of strain decreases in the cooling stage and increases in the heating stage in a F-T cycle. The residual strain was generated in the test. [ABSTRACT FROM AUTHOR]

The metasurface devices with high electric field enhancement factor values have been widely discussed in recent years. However, these types of metasurface devices usually have very strict minimum spacing limitations, which seriously affect the difficulty of device fabrication and the reproducibility of experiments. In this work, we proposed a metasurface based on a metal-insulator-metal configuration that significantly enhances the electric field enhancement factor of the surface plasmon resonance structure on the upper surface by utilizing a bottom metal-SiO 2 spiral lens. The results indicated that the gain bandwidth of this proposed device is more than 100 nm with a maximum electric field gain of 377 within the orange-red wavelength range. Furthermore, the electric field enhancement factor can be adjusted based on the number of rings in the spiral lens. Moreover, the minimum fabrication scale of this device is 130 nm, which facilitates easier fabrication and experimental replication. The focal pattern of the electric field generated inside the spiral lens with different polarization states of light was also examined. • Spiral lens excites surface plasmon polaritons for inward focusing is introduced. • The tunable electric field enhancement factor is controlled by SPP waves. • The device can achieve high electric field enhancement factors over a wideband of wavelengths. • The incident light polarization state is decoupled from the electric field enhancement factor. [ABSTRACT FROM AUTHOR]

Techniques based on plasmonic resonance can provide label-free, signal enhanced, and real-time sensing means for bioparticles and bioprocesses at the molecular level. With the development in nanofabrication and material science, plasmonics based on synthesized nanoparticles and manufactured nano-patterns in thin films have been prosperously explored. In this short review, resonance modes, materials, and hybrid functions by simultaneously using electrical conductivity for plasmonic biosensing techniques are exclusively reviewed for designs containing nanovoids in thin films. This type of plasmonic biosensors provide prominent potential to achieve integrated lab-on-a-chip which is capable of transporting and detecting minute of multiple bio-analytes with extremely high sensitivity, selectivity, multi-channel and dynamic monitoring for the next generation of point-of-care devices. [ABSTRACT FROM AUTHOR]

This article proposes a novel white-light interference (WLI) force-monitoring ring for bridge cable force monitoring and temperature compensation. The WLI force-monitoring ring employs a sensing optical fiber wrapped around the outer surface of an elastomer to measure the expansion caused by applied load and temperature. By installing WLI force-monitoring ring between the anchor plate and the spherical plate of the cable, cable force can be captured by the sensing optical fiber and thus measured after temperature compensation. Based on white-light interferometry, two force-monitoring rings with resolution of 0.25 µ are designed. To find a route to temperature compensation, laboratory experiments are carried to study the effects of temperature on WLI force-monitoring ring both in free and forced states. Theoretical analysis and calibration experiments are implemented to verify the effectiveness of the proposed WLI force-testing ring, and the experiment results expose that the temperature-induced strain can be compensated using a WLI force-monitoring ring in free state. As a comparison, similar work is made for four fiber Bragg grating sensors attached to the elastomer evenly near the sensing optical fiber. The comparison results verify that the WLI method achieves better linear relation and repeatability than fiber Bragg grating. The WLI force-monitoring ring provides a high-precision and low-cost method for bridge cable force monitoring. [ABSTRACT FROM AUTHOR]

A fiber-optic low-coherent interferometry sensor was developed to measure the ground settlement (GS) in an accuracy of the micrometer. The sensor combined optical techniques with liquid-contained chambers that were hydraulically connected together at the bottom by using a water-filled tube. The liquid surface inside each chamber was at the same level initially. The optical interferometry was employed to read out the liquid level changes, which following the GS happened at the place where the chamber was put on and, thereby, the GS information was calculated. The laboratory effort had demonstrated its potential in the practical application. Here, the denoising algorithms on the measurement signal were carried out based on the specific environment to ensure the accuracy and stability of the system in field applications. After that, we extended this technique to the high-speed railway. The 5-days continuous measurement proved that the designed system could be applied to monitor the GS of the high-speed railway piers and approached an accuracy of ±70 μm in the field situation with a reference compensation sensor. So the performance of the sensor was suitable to the GS monitoring problem in the high-speed railway. There, the difficulties were to meet the monitoring requirement of both a large span in space and its quite tiny and slow changes. [ABSTRACT FROM AUTHOR]

A fiber-optic low-coherent interferometry sensor was developed to measure the ground settlement (GS) in an accuracy of the micrometer. The sensor combined optical techniques with liquid-contained chambers that were hydraulically connected together at the bottom by using a water-filled tube. The liquid surface inside each chamber was at the same level initially. The optical interferometry was employed to read out the liquid level changes, which following the GS happened at the place where the chamber was put on and, thereby, the GS information was calculated. The laboratory effort had demonstrated its potential in the practical application. Here, the denoising algorithms on the measurement signal were carried out based on the specific environment to ensure the accuracy and stability of the system in field applications. After that, we extended this technique to the high-speed railway. The 5-days continuous measurement proved that the designed system could be applied to monitor the GS of the high-speed railway piers and approached an accuracy of ±70 μm in the field situation with a reference compensation sensor. So the performance of the sensor was suitable to the GS monitoring problem in the high-speed railway. There, the difficulties were to meet the monitoring requirement of both a large span in space and its quite tiny and slow changes. [ABSTRACT FROM AUTHOR]

There are many studies revealed that metal-based nanoparticles (NPs) possess excellent bactericidal effect on multitudinous bacteria and fungi. However, the control effect of NPs as antimicrobial agents to against Vibrio parahaemolyticus infection remain in poorly understood for blood clam, Tegillarca granosa. In order to evaluate the effect, the changes in six physiological parameters and the immune-related genes expression of clams exposed to V. parahaemolyticus alone or along with NPs (nZnO or nCuO) were investigated in present study. Results showed that both tested NPs exerted prominent redemptive or mitigative effect in an inverse dose-dependent way on physiological indexes of clam, especially in the total counts, phagocytosis and the cell viability of haemocytes, as well as the concentration and activity of lysozymes, when co-exposed with Vibrio. Gene expression analysis showed NPs at a concentration of 0.1 mg/L generally mitigated the downregulation of immune-related genes after clam exposure to V. parahaemolyticus. The combination of 0.1 mg/mL nZnO and nCuO additives has been shown to significantly enhance the humoral immunity of blood clam, suggesting its potential as a protective measure against V. parahaemolyticus infection in T. granosa. • Vibrio parahaemolyticus infection inhibits Tegillarca granosa immune response. • NPs exert rescue effect on physiological signs of T. granosa exposed to Vibrio. • Co-exposure of Vibrio with high doses (1 mg/L) of NPs has certain immunotoxicity to T. granosa. • Toxicity caused by Vibrio was alleviated by 0.1 mg/L nZnO and nCuO to T. granosa. [ABSTRACT FROM AUTHOR]

In order to monitor the residual strain of concrete, which is caused by freezing-thawing (F-T) cycles, a fiber optic F-T sensor based on white light interferometer (WLI) technique is proposed, designed, and tested. The single-mode optical fiber is enwound on the middle surface of concrete cylinder as strain gauge, and WLI technique is used as the acquisitive means of data. To study the feasibility of the proposed F-T sensor, a dry concrete cylinder (T-sensor) was fabricated and exposed it in F-T condition without any solution. The result shows that the strain of T-sensor has a good repeatability with F-T cycles. Two types of mixed proportions of concrete were also fabricated to study the changes of residual strain of concrete which subject to F-T cycles and chloride salt attack. The results indicate that the residual strain increases with F-T cycles, which gives a perspective to understand the damage of concrete exposed in F-T cycles and chloride salt attack. [ABSTRACT FROM AUTHOR]

Corrosion of rock bolts is a major cause for deterioration of the anchor-reinforced concrete slopes structures. In order to evaluate this corrosion-based deterioration in an early stage, a nondestructive technique was required. However, until now, there are no commercialized solutions that are straightforwardly available. Here, a low-coherent fiber-optic sensing technique was developed. This method can carry out the monitoring of the corrosion-caused expansion at the accuracy of sub-microstrains by circled the sensing optical fiber in two ways. One was wound the fiber on the surface of steel rock bolt directly, and thereby generated a nonuniformity in the interface of cement with rock bolt. The other was circled the fiber on a cement mortar cushion without destroying the interface any way. The sensing fiber was configured as one arm of the fiber-optic Michelson interferometer. The acceleration corrosion experiments demonstrated that a uniform interface between cement and rock bolt determined the progress of corrosion development. An early stage evaluation of the corrosion development in rock bolts was monitored. [ABSTRACT FROM AUTHOR]

The rapid development of nanotechnology boosts the massive production and utilization of various nanoparticles (NPs). However, the NPs escaped into environments form emergent pollutants, which pose a potential threat to marine organisms and ecosystems. Due to their sessile filter-feeding lifestyle, marine bivalves live in pollution-prone coastal areas are more susceptible to land-sourced pollutants such as NPs. However, the impacts of many NPs on the metabolism, one of the most critical physiological processes of an organism, still remain largely unknown in bivalve species. To fill up this knowledge gap, in this study the impacts of four commonly used NPs (nZnO, nFe 2 O 3 , nCuO, and multi-walled carbon tube (MWCNT)) on the filtration rate, oxygen consumption rate, ammonia excretion rate, and O:N ratio were investigated in the blood clam, Tegillarca granosa. In addition, the expressions of ten key metabolism-related genes upon exposure to these NPs were also analyzed. The results demonstrated that exposure of blood clams to the NPs resulted in a reduction in the food intake (indicated by declined filtration rate), a shift in the metabolism substance, and disruptions in key metabolism-related molecular pathways (i.e., glycolysis and tricarboxylic acid cycle), which may render blood clam in energy shortage and thus pose significant threat to the health of this important bivalve species. [Display omitted] • NPs exposure led to reductions in filtration rates and oxygen consumption rates of blood clams. • NPs exposure resulted in a shift in the metabolism substance. • NPs exposure disrupted the key molecular metabolic processes of blood clams. • NPs exposure may hamper the energy-generating efficiency. • NPs exposure may pose a significant threat to the health of bivalve species. [ABSTRACT FROM AUTHOR]

DNA methylation plays a vital role in tissue development and differentiation in eukaryotes. Epigenetic studies have been seldom conducted in the extremely diverse and evolutionarily highly successful bilaterian lineage Mollusca. In the present study, we conducted the genome-wide profiling of DNA methylation for five tissues of a bivalve mollusc, Chlamys farreri using the methylation-sensitive amplification polymorphism (MSAP) technique. The methylation levels were quite similar among tissues, ranging from 20.9% to 21.7%. CG methylation was the dominant type (14.9%–16.5%) in the C. farreri genome, but CHG methylation also accounted for a substantial fraction of total methylation (5.1%–6.3%). Relatively high methylation diversity was observed within tissues. Methylation differentiation between tissues was evaluated and 460 tissue-specific epiloci were identified. Kidney differs from the other tissues in DNA methylation profiles. Our study presents the first look at the tissue-specific DNA methylation patterns in a bivalve mollusc and represents an initial step towards understanding of epigenetic regulatory mechanism underlying tissue development and differentiation in bivalves. [ABSTRACT FROM AUTHOR]

Non-lethal DNA sampling has long appealed to researchers studying population and conservation genetics, as it does not necessitate removing individuals permanently from their natural environment or destroying valuable samples. However, such an approach has not yet been well established in bivalves. In this study, we demonstrate that the gill represents a good source of tissue for non-lethal sampling in scallops. Removal of a few gill filaments caused no noticeable behavioral abnormalities or increased mortality rates in Zhikong scallop (Chlamys farreri) during a three-month period of observation. To facilitate rapid gill-based DNA extraction, six methods (MA-MF) were designed and evaluated, each requiring less than one hour of processing time. The optimal method was identified as MF, in terms of maintaining DNA integrity and genotyping accuracy. Further optimization of MF method by orthogonal experimental design suggested that the utilization of gills could be limited to 2 mg of sample, which is sufficient for performing up to 20,000 PCR reactions. We also demonstrate the excellent cross-species utility of MF in two additional scallop species, Yesso scallop (Patinopecten yessoensis) and bay scallop (Argopecten irradians). Taken together, our study provides a rapid and efficient approach for applying non-lethal DNA sampling in bivalve species, which would serve as a valuable tool for maintaining bivalve populations and conservation genetics, as well as in breeding studies. [ABSTRACT FROM AUTHOR]

The razor clam Sinonovacula constricta , one of most important mariculture bivalve species in China, suffered from the variable challenges such as ammonia stress, drastic salinity fluctuation, highly variable temperature. Ammonia stress represents a common stressor and now considered to be the main limiting factor in intensive culture systems of S. constricta , a potential strategy for the challenge is selecting strain that are genetically resistant to the ammonia stress. Here, we constructed full-sib families and performed two challenge experiments in different life stages to estimate genetic parameters of ammonia tolerance and growth traits in S. constricta. A total of 45 families including 26 families at 5-month-old and 19 families at 10-month-old were used to test the ammonia tolerance, as well as the growth-related traits (Shell length, Shell height, Shell width and Body weight) of individuals. The heritability estimates of the two experiments were similar and comparable, moderate estimates were observed for heritability of ammonia tolerance (0.20 ± 0.07–0.28 ± 0.04), while moderate to high heritability (0.36 ± 0.13–0.64 ± 0.37) were found for growth-related traits. Slightly low genetic (0.34 ± 0.32–0.42 ± 0.30) and phenotypic (0.01 ± 0.05–0.15 ± 0.04) correlations were detected between ammonia tolerance and growth traits in the early life style, while the correlations were also low in genetic (0.13 ± 0.29–0.39 ± 0.25) and in phenotypic (0.03 ± 0.04–0.13 ± 0.04) in the later life style. These findings confirm the existence of genetic variation for ammonia tolerance and growth traits and provide important information to guide effective selection of S. constricta. • Heritabilities of ammonia tolerance were estimated by two challenge experiments in different growth stages in S. constricta. • Moderate heritability for ammonia tolerance indicates potential prospects for genetic improvement. • Correlation between ammonia tolerance and growth-related traits was low. • The heritabilities were in a moderate-to-high level and correlation were high among growth-related traits. [ABSTRACT FROM AUTHOR]

• DNAzyme modified TFBG-SPR biosensor for ultratrace lead ion detection on the basis of "hot spot" effect. • A large dynamic measurement range (10−11 M–10−6 M) and a competitive low limit of detection (8.56 pM). • High stability and excellent selectivity towards lead ion over other environmentally related metal ions. • Lead ion detection was successfully validated in clinical human serum samples. Heavy metal lead ion (Pb2+) detection takes more and more attention due to its synergistic toxicity to human health and undegradability in environment. Currently, there are urgent demands for portable, anti-interference and economical Pb2+ sensors with high sensitivity and selectivity for environmental monitoring as well as modern healthcare in clinic. In this article, via compact and high performed titled fiber Bragg grating (TFBG) surface plasmon resonance (SPR) sensing platform, we present a novel DNAzyme biosensor for ultratrace Pb2+ detection on the basis of "hot spot" effect in near-infrared band. A gold nanoparticle (GNP)-on-Au film construction was built by DNAzyme and its substrate strand. When Pb2+ with high catalytic activity cleave the DNAzyme linked rA (ribonucleotide adenosine) containing substrate strand, making DNA double helix structure transform to a single strand, the GNPs that connected with DNAzyme fall down to the sensor surface. By FDTD simulation, we have demonstrated that the appearing "hot spot" effect due to the narrow gap (<2 nm) will eventually result in enhancement of the spectrum signal response which is directly related to the Pb2+ concentration. In experiments, the proposed fiber biosensor exhibits a competitive low limit of detection ∼ 8.56 pM, excellent selectivity against other environmentally related metal ions and the large dynamic response range from 10−11 M to 10−6 M. More significantly, clinical human serum samples were used to verify the practicability of this TFBG-SPR-DNAzyme-GNPs biosensor showing great potential value in various clinical applications as a high efficiency, portable and easy to miniaturization point-of-care testing technology. [ABSTRACT FROM AUTHOR]

A high performance humidity sensor using tilted fiber Bragg grating (TFBG) and functional graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) hybrid nano-materials was proposed. The humidity-sensitive material with three-dimensional (3D) structure was synthesized by the MWCNTs and GOs. Comparing with traditional two dimensional (2D) GOs film, water molecules could be absorbed effectively due to the larger ripples and more holes in GO/MWCNTs layers. The water molecule will fill the entire space in the 3D structure instead of air, which further enhances the absorption efficiency of the hybrid nanomaterial. TFBG as a compact and robust surrounding complex dielectric constant sensing platform was utilized. The mode coupling coefficient or the amplitude of TFBG cladding mode will vary sharply with the imaginary part of permittivity of the hybrid nanomaterial, realizing the high performance RH sensing. In the experiments, we successfully demonstrated that this 3D structural nanomaterial composed by the MWCNTs and GOs has significant advantages for expanding the range of humidity detection (range from 30% to 90%) and enhancing the detection sensitivity (0.377 dB/% RH is twice more than humidity sensor with 2D GO film). The TFBG-based RH sensor also exhibits good repeatability and stability. Our proposed humidity sensor has potential application in environmental and healthy monitoring fields. [ABSTRACT FROM AUTHOR]

Low-coherent fiber-optic sensors combined with neural network algorithms were designed to carry out a load-sensitizing spherical bearing. Four sensing fibers were wound around the outside of the pot support of the spherical bearing uniformly deployed from upper to bottom. The upper three were configured in a distributed way to respond to the applied load as a function of the three strain sensors. The bottom one was employed as a temperature compensation sensor. A loading experiment was implemented to test the performance of the designed system. The results showed that there was a hysteresis in all the three sensors between loading and unloading process. The neural network algorithm is proposed to set up a function of the three sensors, treated as a set of input vectors to establish the input-output relationship between the applied loads and the constructed input vectors, in order to overcome the hysteresis existing in each sensor. An accuracy of 6% for load sensing was approached after temperature compensation. [ABSTRACT FROM AUTHOR]