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Imaging through scattering media holds great promise for biomedical and measurement applications. In this study, we explore a line-scan imaging strategy through strong scattering media based on epipolar constraints. The implemented setup consists mainly of three parts, namely, the laser source, galvo scanner, and the industrial camera. With pre-calibrated system parameters, a set of epipolar lines are easily generated and projected in sequence with the laser and the galvo scanner projection module, while the epipolar lines on the original images corresponding to the illuminating epipolar lines can be effectively extracted. By stitching the extracted epipolar lines together, a whole image less affected by scattering media can be obtained. We validate our approach using a customized letter pattern obscured by a strong diffuser. Experimental result shows that part of the original signal can be recovered whereas almost no information is shown in the comparison image obtained with the conventional method. Furthermore, the proposed system and algorithm are easier to implement than most existing approaches for imaging through scattering media.

Convolutional neural networks (CNN) with their deep feature extraction capability have recently been applied in numerous image fusion tasks. However, the image fusion of infrared and visible images leads to loss of fine details and degradation of contrast in the fused image. This deterioration in the image is associated with the conventional “averaging” rule for base layer fusion and relatively large feature extraction by CNN. To overcome these problems, an effective fusion framework based on visual saliency weight map (VSWM) combined with CNN is proposed. The proposed framework first employs VSWM method to improve the contrast of an image under consideration. Next, the fine details in the image are preserved by applying multi-resolution singular value decomposition (MSVD) before further processing by CNN. The promising experimental results show that the proposed method outperforms state-of-the-art methods by scoring the highest over different evaluation metrics such as Q0, multiscale structural similarity (MS_SSIM), and the sum of correlations of differences (SCD).

Integrated zoom and image stabilization system based on deformable mirrors (DMs) has advantages of miniaturization, rapid response and low energy consumption. Integrating the two capabilities on one DM-based imaging system poses considerable challenges. First, limited DM stroke will result in limited changeable aberration correction value for zoom and image stabilization. Second, the DM-based off-axis imaging system suffers a simple relative movement between optical axis and objects caused by carrier vibration may result in complicated optical system aberrations. To address these challenges, a reasonable assignment of the changeable aberration correction value for zoom and image stabilization is needed. Image stabilization and aberration correction in DM-based off-axis imaging system, should be considered when translation or rotation occurs. To troubleshoot the assignment issues of the correcting aberrations, we propose a graded optimization method which comprises two steps. To troubleshoot the image stabilization and aberration correction issues, we introduce vectorial ray tracing method and image point freezing principle to transform the aberration correction problem into an optimization problem of image coordinates. With the proposed method, we construct practical integrated freeform surfaces of DMs for a space camera with three mirrors. The sagittal heights of designed DM surface profiles are limited within their available stroke.

Oceanographic plankton classification for many images is time consuming, especially for low-contrast images obtained when the water is dirty and opaque due to impurities. A novel, overcomplete dictionary algorithm is studied by analyzing the sparse characteristics of the image matrix using pixel values. The features in hyperspace are mapped onto a specifically designed vector space. Thus, mathematically, the algorithm exhibits faster calculating convergence and has a strong expressivity for the selective signal in the vector space with a lower signal loss rate. The clustering method based on the dictionary can classify planktons for species counting, which can enable high-speed, multi-object recognition of planktons in turbid water. The experimental results demonstrate that if less data (up to 60%) is processed for each image, a recall rate and accuracy greater than 75% and a structural similarity for the reconstructed image greater than 0.9 can be achieved.

We have developed a graph-based Variational Autoencoder with Gaussian Mixture hidden space (GraphGMVAE), a deep learning approach for controllable magnitude of scaffold hopping in generative chemistry. It can effectively and accurately generate molecules from a given reference compound, with excellent scaffold novelty against known molecules in the literature or patents (97.9% are novel scaffolds). Moreover, a pipeline for prioritizing the generated compounds was also proposed to narrow down our validation focus. In this work, GraphGMVAE was validated by rapidly hopping the scaffold from FDA-approved upadacitinib, which is an inhibitor of human Janus kinase 1 (JAK1), to generate more potent molecules with novel chemical scaffolds. Seven compounds were synthesized and tested to be active in biochemical assays. The most potent molecule has 5.0 nM activity against JAK1 kinase, which shows that the GraphGMVAE model can design molecules like how a human expert does but with high efficiency and accuracy.

Target tracking and imaging through scattering media are challenges that must be overcome for important applications in various fields. The fundamental problem is the randomly diffused light in scattering media that prevents the formation of diffraction-limited images. In recent years, speckle correlation has emerged as a powerful approach for restoring targets through scattering media and tracking targets with high scattering. However, this method fails to achieve high-accuracy target tracking in multidimensional motion. Furthermore, retrieving the deterministic phase of a target in a low-resolution speckle pattern is limited. Here, a method based on speckle-difference-combined bispectrum analysis (SDCBA) is presented to simultaneously track and image targets. The proposed SDCBA requires no high-resolution pattern, randomly assigned initial values, nor numerous iterations. The target is tracked simultaneously in multidimension by using speckle difference autocorrelation and restored with the deterministic phase via bispectrum analysis of the low-resolution speckle pattern. This work carries out simulations and experiments to demonstrate simultaneous multidimensional target tracking and imaging in low-resolution speckle pattern through scattering media via the SDCBA. This work will benefit various fields, including biomedical applications, materials science, and military security.

Antibiotics in breeding industry can enter the environment through multiple pathways, thus accelerating the emergence and spread of antibiotic resistance genes (ARGs), among which aerosol transmission is easily achieved and often overlooked. To elucidate the role of aerosols in this situation, the present study investigated the distribution characteristics of 107 ARG subtypes (targeting to eight different ARG types) and nine mobile genetic elements (MGEs) and bacterial community in animal (chicken cloaca), environment (aerosols) and human (nasopharynx) of a chicken farm (n = 42) in Henan Province. In total, 116 ARG subtypes and MGEs were identified in the poultry farm. The total bacterial concentration of aerosols inside the chicken house (3.117 × 104 CFU/m3) exceeded the corresponding limit. The microbial communities in the samples of cloaca swab (C) and the workers’ nasopharyngeal swab (N) were closer, while the abundance distribution of ARGs/ MGEs in cloacal swab (C) and aerosol (AI) in chicken house were much similar. There were certain consistency of the microbial community structure and the distribution of ARGs among the three groups of chicken cloaca, air aerosol, and workers’ nasopharynx. Our results highlighted that animal breeding does have a certain impact on the surrounding environment and human, and aerosols play an important role in this process.

Lead (Pb) poses a potential environmental risk factor for cognitive dysfunction during early life and childhood. Resveratrol is considered a promising antioxidant with respect to the prevention of cognitive deficits and act as a potent SIRT1 agonist. Herein, this study aims to investigate the profile of neurogenesis markers following Pb exposure and to determine the regulatory role of resveratrol in this process. We confirmed firstly the protective effects of resveratrol against Pb-induced impairments of hippocampal neurogenesis in Male SD rats. Pb exposure early in life caused the altered expression of Ki-67, NeuN, caspase-3 and SIRT1 signaling, thereby resulting in spatial cognitive impairment of adolescent rats. As expected, resveratrol reduced cognitive damage and promoted neurogenesis in Pb-induced injury by regulation of SIRT1 pathway. Collectively, our study establishes the efficacy of resveratrol as a neuroprotective agent and provides a strong rationale for further studies on SIRT1-mediated mechanisms of neuroprotective functions.

Aspheric lenses help meet the most demanding optical requirements while the precision injection molding technique hits the target for precision and cost. We developed a method of analyzing aberration terms in the transmitted “wavefront measurement,” determined by Shack–Hartmann wavefront sensing to estimate the fabrication errors of injection-molded aspheric elements. Considering aspheric element fabrication using a small training data set and F-measure fuzzy cluster analysis, an unsupervised learning method was applied to extract typical aberration terms from the wavefront polynomial. The experimental results suggest that these aberration terms, which are related to spherical (third-, fifth-, and seventh-order) and coma (third-order) aberration terms in the transmitted wavefront polynomial expansion, can be employed to estimate the surface error and decenter, respectively, of a lens from a specific mold cavity. The sampling lenses evaluated in the proposed measuring process were collected from different mold cavities according to their total working performance in the modulated transfer function measurement for the whole camera module. The performances of the typical aberration terms were discussed by comparing to the ones obtained from an interferometer and a profilometer. The proposed method could provide high detection efficiency and can thus be applied for the quality control of aspheric elements for mobile phones, where the existing errors are mainly spherical, coma, and astigmatism aberrations.

Background The intellectual loss induced by fluoride exposure has been extensively studied, but the association between fluoride exposure in different susceptibility windows and children’s intelligence is rarely reported. Hence, we conducted a cross-sectional study to explore the association between fluoride exposure in prenatal and childhood periods and intelligence quotient (IQ). Methods We recruited 633 local children aged 7–13 years old randomly from four primary schools in Kaifeng, China in 2017. The children were divided into four groups, of which included: control group (CG, n = 228), only prenatal excessive fluoride exposure group (PFG, n = 107), only childhood excessive fluoride exposure group (CFG, n = 157), both prenatal and childhood excessive fluoride exposure group (BFG, n = 141). The concentrations of urinary fluoride (UF) and urinary creatinine (UCr) were determined by fluoride ion-selective electrode assay and a creatinine assay kit (picric acid method), respectively. The concentration of UCr-adjusted urinary fluoride (CUF) was calculated. IQ score was assessed using the second revision of the Combined Raven’s Test-The Rural in China (CRT-RC2). Threshold and saturation effects analysis, multiple linear regression analysis and logistic regression analysis were conducted to analyze the association between fluoride exposure and IQ. Results The mean IQ score in PFG was respectively lower than those in CG, CFG and BFG (P OR = 0.489, 95% CI: 0.279, 0.858). For all the children, CUF concentration of ≥1.7 mg/L was negatively associated with IQ scores (β = − 4.965, 95% CI: − 9.198, − 0.732, P = 0.022). In children without prenatal fluoride exposure, every 1.0 mg/L increment in the CUF concentration of ≥2.1 mg/L was related to a reduction of 11.4 points in children’s IQ scores (95% CI: − 19.2, − 3.5, P = 0.005). Conclusions Prenatal and childhood excessive fluoride exposures may impair the intelligence development of school children. Furthermore, children with prenatal fluoride exposure had lower IQ scores than children who were not prenatally exposed; therefore the reduction of IQ scores at higher levels of fluoride exposure in childhood does not become that evident.

Currently, there are various calibration methods available to reduce the errors caused by the polarizing section of a dual-rotating-retarder polarimeter. Although these methods have high measurement accuracy, their robustness must be improved and the influence of the imaging section needs be discussed when they are applied in Mueller matrix microscopes. In this paper, a method of error source analysis and element calibration for the Mueller matrix microscope is proposed by using error transform coefficient matrices to account for the polarizing effect of the imaging section. Using Taylor expansion, an approximate linear relationship is established between the sources of errors and the Mueller matrix elements of the measured sample. From this relationship, error magnification coefficient matrices are calculated to determine the specific parameter errors in both the polarizing and imaging sections. Furthermore, elements in the fourth row or column of the error magnification coefficient matrix are especially important for the imaging section. The measurement and simulation results for an air sample and a quarter-wave plate sample as the standard samples, as well as a Daphnia organism sample with complex internal structure, are investigated and discussed. Furthermore, the comparison results reveal the effect of the imaging section on the birefringence characteristics of the Mueller matrix. With the proposed method, the maximum error can be reduced to be less than 0.01 for all the matrix elements and for the amplitude parameter of birefringence, even when the two system parameters a 2

In this study, we propose a method for training convolutional neural networks to make them identify and classify images with higher classification accuracy. By combining the Cartesian and polar coordinate systems when describing the images, the method of recognition and classification for plankton images is discussed. The optimized classification and recognition networks are constructed. They are available for in situ plankton images, exploiting the advantages of both coordinate systems in the network training process. Fusing the two types of vectors and using them as the input for conventional machine learning models for classification, support vector machines (SVMs) are selected as the classifiers to combine these two features of vectors, coming from different image coordinate descriptions. The accuracy of the proposed model was markedly higher than those of the initial classical convolutional neural networks when using the in situ plankton image data, with the increases in classification accuracy and recall rate being 5.3% and 5.1% respectively. In addition, the proposed training method can improve the classification performance considerably when used on the public CIFAR-10 dataset.

3D localization of point source is widely used in many fields, such as bioimaging and autonomous driving fields. However, the localization is hard to perform under scattering conditions because of the diffuse effect of the scattering. We propose a novel method for 3D localization of point source under scattering conditions based on light field imaging and deep learning by only one shot. First, we introduce the description of the point source in a light field wise and how to localize a point source by its light field. On the basis, we elaborate on the effect of scattering on a light field and how to retrieve the location of a point source from a light field with scattering. Then, the effect of aberration on a light field will be introduced. We also build an artificial scene and a deep learning framework to perform a 3D localization practically, and the feasibility and accuracy of our method have been evaluated.

This study describes various methods for optical imaging through scattering media based on compression detection. In these methods, low-intensity micro-structured light patterns are launched sequentially onto an object by using a digital micro-mirror device. The corresponding light intensity information is collected and an intensity correlation algorithm is used to recover the information of the object in the scattering media. For each specific sampling reconstruction method, its related systems are listed and its parameter indicators and application scenarios are analyzed. Prospects for the development of single-pixel imaging through scattering media are also discussed.

The deformation measurement of a specular surface is of great importance during the quality inspection and installation of optical elements or wafers, especially those with large apertures. We propose a deflectometry method with speckle digital image correlation (DeSDIC) to realize the dynamic and high-accuracy measurement of the deformation on specular surfaces, with a simple system structure and robustness to noises and environmental vibrations. Random speckle pattern displayed on liquid crystal display is reflected by the original surface under test (SUT), and the distorted pattern is recorded by a camera. This originally distorted pattern is taken as the reference image, and the patterns captured afterwards are digitally correlated with the reference image to calculate the gradient change and deformation of the SUT. The theoretical relationships and an experimental one-step calibration scheme are proposed. Both static and dynamic deformations of a deformable mirror were experimentally measured to demonstrate the feasibility and accuracy of DeSDIC, which is comparable to phase-measuring deflectometry and interferometry.

To assess the association between fluoride exposure and children���s behavioural outcomes, we recruited 325 resident school-age children (7���13 years old) lived in Tongxu County of Henan Province in China. We measured urinary fluoride (UF) concentrations using the ion-selective electrode method. Children���s behavioural outcomes were assessed by Conners��� Parent Rating Scale-Revised, including conduct problems, learning problems, psychosomatic problems, impulsive-hyperactive, anxiety, and ADHD index. It turned out that each 1.0 mg/L increment in UF concentration corresponded with an elevation in the psychosomatic problem score of 4.01 (95% CI: 2.74, 5.28) and a 97% (OR = 1.97, 95% CI: 1.19, 3.27) increase in the prevalence of psychosomatic problems after adjusting for potential influencing factors. The sensitivity analysis results were consistent with those observed in our preliminary analysis. Our study suggests that fluoride exposure is positively related to the behavioural problem in school-age children, psychosomatic problem in particular.

Livestock farms are recognized as the main sources of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) with potential implications for human health. In this study, we systematically analyzed microbiome composition, distribution of ARGs and mobile genetic elements (MGEs) in the oropharynx and gut of workers in cattle farms and surrounding villagers, cattle feces and farm air, and the relationship of microbial communities among farm air, cattle feces and farmworkers (oropharynx and gut). Exposure to the farm environment may have remodeled farmworkers' oropharynx and gut microbiota, with reduced microbial diversity (P 0.05) and enrichment of some opportunistic pathogenic bacteria like Shigella, Streptococcus, and Neisseria in the oropharynx. Meanwhile, compared with villagers, ARG abundance in oropharynx of farmworkers increased significantly (P 0.05), but, no significant difference in gut (P 0.05). Microbial composition and ARG profile in farmworkers might be influenced by working time and work type, ARG abundance in farmworkers' gut was positively correlated with working time (P 0.01), and higher ARG abundance was found in the oropharynx of drovers. The network analysis revealed that 4 MGEs (tnpA-01, tnpA-04, Tp614, and IS613), 5 phyla (e.g. Bacteroidetes, Fusobacteria, and TM7), and 6 genera were significantly associated with 37 ARGs (ρ 0.6, P 0.01). Overall, our results indicated that farm exposure may have affected the microbial composition and increased ARG abundance of farmworkers. Transmission of some ARGs may have occurred among the environment, animals and humans via host bacteria, which might pose a potential threat to human health.

Microcystins (MCs) are produced by certain bloom-forming cyanobacteria that can induce toxicity in various organs, including renal toxicity, reproductive toxicity, cardiotoxicity, and immunosuppressive effects. It has been a significant global environmental issue due to its harm to the aquatic environment and human health. Numerous investigators have demonstrated that MC exposure can induce a widespread epidemic of enterogastritis with symptoms similar to food poisoning in areas close to lakes. Both in vivo and in vitro studies have provided evidence of positive associations between MC exposure and gastrointestinal toxicity. The toxicity of MCs on the gastrointestinal tract is multidimensional. MCs can affect gastrointestinal barrier function and shift the structure of gut microbiota in different gut regions. Furthermore, MCs can inhibit the secretion of gastrointestinal digestive enzymes and the release of inflammatory cytokines, which affects the expression of immune-related genes in the intestine. The damage of the intestine is closely correlated to MC exposure because the intestine is the main site for the digestion and absorption of nutrients. The damage to the gastrointestinal tract due to MCs was summarized from different aspects, which can be used as a foundation for further exploration of molecular damage mechanisms.

Excessive exposure to fluoride has been reported to affect bone mineral density (BMD). CALCA expression plays a critical part in bone formation. However, the role of CALCA in the association between fluoride and BMD is not known. We conducted a cross-sectional study and recruited 722 women in rural areas of Henan Province, China, to assess the relationship between fluoride exposure, CALCA methylation, and BMD. Urinary levels of fluoride, CALCA methylation, and BMD were measured by a fluoride ion-selective electrode, standalone ultrasound bone densitometer, and quantitative methylation-specific polymerases chain reaction, respectively. The association among fluoride exposure, CALCA methylation, and BMD was age-specific. Specifically, BMD was negatively correlated with methylation (β: -0.008; 95% CI: -0.016, 0.000) and fluoride exposure (β: -0.063; 95% CI: -0.129, -0.002) in women over 45 years and 50-54 years of age, respectively, whereas methylation was positively correlated with fluoride exposure (β: 4.953; 95% CI: 1.162, 8.743) in women aged 40-44 years. Besides, increased BMD in women aged 45-49 years induced by the interactive effect of the highest methylation of CALCA exon 1 (tertile 3) and fluoride exposure was observed (P for interaction 0.05). Our findings suggest an age-specific association between exposure to excessive fluoride, CALCA methylation, and BMD in a rural population of women in China. Notably, the susceptibility of BMD to fluoride exposure may be modified by CALCA methylation.

Image enhancement technique is utilized to emphasize the overall or local characteristics of pictures and widely used in aerospace, and machine vision application. However, most of these techniques are mathematical algorithms based on captured pictures instead of the imaging process. Fourier ptychographic microscopy (FPM) is a recently developed computational imaging approach which stitches together low-resolution images acquired under different angles of illumination with the same intensity in Fourier space to produce a wide-field, high-resolution complex sample image. In this article, a theoretical model about the illumination intensity is proposed. The effect of uneven illumination intensity can be reduced significantly based on our model. Furthermore, the quality of the reconstructed image can be enhanced by adjusting the intensity of the illumination light corresponding to the high frequency components of the original spectrum.

Fourier ptychography microscopy (FPM) is a recently developed computational imaging approach which surpasses the resolution barrier of a low numerical aperture (NA) imaging system. It is a powerful tool due to its ability to achieve super resolution of complex sample function, pupil aberration, LED misalignment, and beyond. However, recent studies have focused more on the optimization algorithms and set-ups instead of its theoretical background. Although some imaging laws about FPM have already been set forth, the formulas and laws are not fully defined, and the connection between diffraction theory and Fourier optics has a gap. Therefore, there exist a need for comprehensive research on physical and mathematical basis of FPM for future applications. Keeping this goal in mind, this manuscript utilizes scalar field diffraction theory to rigorously study the relationship between wavelength, the propagation mode, illumination direction of the incident wave, sample structure information and the direction of the output wave. The theoretical analysis of diffraction imaging in FPM provides a clear physical basis for not only the FPM systems, but also for the ptychography iterative engine (PIE) and any other coherent diffraction imaging techniques and systems. It can help to find the source of noise and therefore improve image quality in FPM technique and systems.

The aspheric optical plastic injection molding technology has many advantages such as lightweight, low cost, saving assembly work, easy mass production and so on. It is the main processing method for aspheric optical plastic lenses. This paper systematically summarizes the error sources in the process of optical plastic injection molding, and displays the current development status of error detection technologies. A method based on wavefront sensing technology for transmission aspheric optical lens error detection is proposed. Finally, this paper gives the prospects for the development of error detection technologies applied in aspheric optical lens.

Major breakthroughs in the fields of image processing, pattern recognition, and scene classification have recently been made through the using of convolutional neural networks (CNNs) and deep learning. If the training set is sufficient, a CNN performs better than traditional machine learning algorithms and differs from them in many ways. In CNNs, feature extraction is more intelligent, so researchers no longer require extensive knowledge about the specific topic. They can focus on the CNN itself, including the structural design of the network, the model optimization, and the numerical solution. The many articles on CNNs published over the past few years propose many neural network models. Methods of training and optimization for CNNs have also been proposed. This paper reviews the history of CNNs, introduces the commonly established CNN structure, and summarizes methods and tips for CNN training.

The polarization state of light is somewhat affected by propagation in a broad-spectrum, high numerical aperture (NA) and other optical systems with oblique incident angles. Changes in the polarization state, known as polarization aberrations, may result in severe deterioration of the imaging quality. This paper reviews the theory of polarization aberration, including the definition of polarization aberration, polarization ray tracing, analysis of the function of polarization aberration, and some new theories related to calculation and analysis procedures. Increasingly, the theory of polarization aberration has been analyzed and applied in optical systems such as interferometers, microscopes, telescopes, and lithography devices. In optical design, the combined calculation and simulation of a polarization aberration can contribute to the efficient optimization of optical system performance.

Since the performance of binary optical element (BOE) is affected vastly by etching depth error, mask misalignment and feature rounding introduced by the fabrication process, it becomes important to analyze the effects of fabrication errors on the BOE. The phase pattern of binary optical lens will not be symmetrical when the misalignment error exists, and it is very complicate to analyze the diffraction efficiency. Based on the relationship between the diffraction efficiency and the modulation transfer function (MTF), the MTF of a binary optical lens with different fabrication errors is calculated, and the effects on diffraction efficiency are also obtained.

The description of deformable mirror (DM) surface, which is usually a complex freeform surface, affects the measurement speed and accuracy in a real-time interferometric measurement system with a DM as the dynamic compensator. We propose an accurate and fast description method with automatically configurable Gaussian radial basis function. The distribution and shape factors of GRBFs are related to the complexity of the surface with sufficient flexibility to improve the accuracy, and the fitting results are automatically obtained using a traversal optimization algorithm, which can improve the fitting speed by reducing the number of time-consuming calculations. The feasibility is verified by numerical and practical experiment.

Stabilized zoom systems possess the advantages such as the simplified system layout, improved system stability, enhanced imaging performance, and a high zoom speed. The complex system design to achieve high performances requires calculations or investigations of the initial system for optimization and improvements, and thus, specific design techniques are pursued. In this study, we propose an automatic optical design scheme of synthetic characteristics for the off-axis stabilized zoom systems, which using focal length variable (FLV) opto-electronic elements and with a high zoom ratio. The study aims at evaluating and synthetically achieving the zooming properties and the image quality balance of entire focus imaging. The multi-element stabilized zoom systems are characterized using the Gaussian brackets expressions and their optimal solution ranges for high zoom ratios are deduced to achieve non-defocusing imaging in specific stroke ranges of FLV elements. Then considering the analytical characterization of the off-axis-induced primary aberrations at multi-conjugate positions, we use a conic surface to deduce the basic expression of the nodal aberration. Thereby the nonlinear global merit function is established with a semi-empirical mathematical model based on nodal aberration theory and nonlinear zoom equation for maintaining the stability of focal length and image plane drift. And the theory of Pareto Optimality is employed in the process of verifying the superiority of the solutions. Finally, a series of solutions for a high zoom ratio and aberration compensation are implemented and the optimal configurations with conical surfaces for an off-axis stabilized zoom system are obtained.

Antibiotic resistance (AR) has become a potential concern to public health. It is mainly associated with the overuse and misuse of antibiotics in the environment. Several factors influence the development and dissemination of antibiotic resistance genes (ARGs); however, the relative contribution of these factors has been scarcely characterized. To study the impact of each factor, we examined the effects of five antibiotics, eight heavy metals, five physicochemical properties, and bacterial community on the abundance of 310 ARGs in agricultural soils collected near a smelter. Tetracycline was found in the highest levels of all the samples compared to the other four antibiotics, with the most severe contamination (1738.534 μg/kg) occurring in the sample farthest from the plant (2556 m), whereas the highest copy number of ARGs (sulfonamide resistance genes, 3.63 × 10−1 copies/16SrRNA) and the worst heavy metal pollution (Cd, 18.900 mg/kg; Pb, 1938.000 mg/kg) were detected in the sample closet to the plant (741 m). Pearson and Spearman rank correlation analysis showed that the abundance of 84 ARGs was impacted by these four factors in the soil. The bacterial phyla contributed to 79.76% of ARGs variation, whereas antibiotics, heavy metals, and physicochemical properties contributed 4.76%, 1.19%, and 3.57%, respectively. Bacterial community was the main factor influencing the distribution of ARGs. Antibiotics and heavy metals may affect the distribution of ARGs not only by themselves but also by influencing the structure of bacterial community in the soil. The research provides insights into the different contributions of factors to AR control.

The focal length of a deformable mirror can be changed by altering its mirror profile or refractive index. With the rapid development of microelectromechanical systems technology, the variations in optical power introduced by refractive and reflective deformable mirrors have been improved, and a stabilized zoom system based on these deformable mirrors has thus become a hotspot for quick zooming and better image quality. In this paper, we discuss the domestic and foreign research on these kinds of systems, which can be divided into three categories—refractive zoom systems, all-reflective zoom systems, and catadioptric zoom systems—to indicate the differences in optical path and the deformable mirrors used. The initial theoretical layout, the verification experiment, and the performance of these systems are discussed. Above all, their characteristics and operating temperatures are highlighted, and these three types of deformable mirrors are then compared to find the possible layout for a zoom stabilization system based on two reflective deformable mirrors. Our study can help in the selection of the most suitable types of deformable mirrors and in discussions of a prototype of a stabilized zoom system. A system performance and defects radar chart for these three types of system is drawn to facilitate the selection of deformable mirrors for system design. Finally, ideas for further work to handle the challenges confronted by deformable mirrors are discussed.

Recognizing and classifying plankton in low-contrast images is difficult. A clustering algorithm are proposed to classify plankton and counted them on a compressed sensing frame. The reasonable output is proved in the experiment.

In this paper, we investigate the two-photon recording system in a 50-layer structure with each recording layer contains 4.7GB of data, similar to the capacity of a single layer Digital Versatile Disc, as the total capacity is 235GB/disc. We present a single-laser system to realize recording and reading and propose a new multilayer disc structure in which the groove structure is set on the substrate for servo control, the laser is separated by a PBS to two parts, one for recording and the other for servo in the optical system. Our research shows the feasibility of high density optical data storage using a single laser in a multilayer structure.

An image stabilization optical system using deformable freeform mirrors is proposed that enables the ray sets to couple dynamically in the object and image space. It aims to correct image blurring and degradation when there is relative movement between the imaging optical axis and the object. In this method, Fermat’s principle and matrix methods are used to describe the optical path of the entire optical system with a shift object plane and a fixed corresponding image plane in the carrier coordinate system. A constant optical path length is determined for each ray set, so the correspondence between the object and the shift free image point is used to calculate the solution to the points on the surface profile of the deformable mirrors (DMs). Off-axis three-mirror anastigmats are used to demonstrate the benefits of optical image stabilization with one- and two-deformable mirrors.

We previously developed a Mueller matrix microscope by combining a dual-rotating-retarder device with a commercial microscope, which holds promise for pathologic diagnosis applications. In practical applications, the signals to be measured are sensitive to systematic errors, and the measurement accuracy and the instrument calibration affect the capacity to characterize the data. In conventional calibration, the initial positions of the rotating devices are constrained, causing calibration instability. To improve the calibration, we examine the mathematical model of the calibration process using previous studies, and derive a calibration algorithm with reduced error magnification. Our experimental results show the proposed algorithm improves calibration accuracy, and provides more robust results.

Mathematical model for the calibration of Muller matrix polarimeter is discussed. The error propagation coefficients are calculated, and the data deduction equations designed to minimize errors in calibration are presented.

A variety of specialized wavefront detection technologies have been widely used, generally need specialized sensor or device. In this contribution, we proposed an algorithm to calculate the wavefront aberration with two-dimensional modulation transfer function data. The relationship between the wavefront aberration and the modulation transfer function is built based on the optical transfer function and simplified by applying the Newton-cotes quadrature. Thus the wavefront aberration can be numerically calculated by use of the results of the system performance in frequency domain. Numerical calculation result is provided for validating the proposed algorithm.

This paper introduces a compact optical information storage sensing system. Applications of this system include longitudinal surface plasmon resonance detection of gold nanorods with a single femtosecond laser in three-dimensional space as well as data storage. A diffractive optical element (DOE) is applied in the system to separate the recording-reading beam from the servo beam. This allows us to apply a single laser and one objective lens in a single optical path for the servo beam and the recording-reading beam. The optical system has a linear region of 8 λ, which is compatible with current DVD servo modules. The wavefront error of the optical system is below 0.03 λ(rms). The minimum grating period of the DOE is 13.4 µm, and the depth of the DOE is 1.2 µm, which makes fabrication of it possible. The DOE is also designed to conveniently control the layer-selection process, as there is a linear correlation between the displacement of the DOE and the layer-selection distance. The displacement of DOE is in the range of 0-6.045 mm when the thickness of the layer-selection is 0.3 mm. Experiments were performed and the results have been verified.

Distortion typically occurs when images are captured from the surface of a cylindrical object. This problem is obvious in Quick Response (QR) code images, which necessitate distortion correction for subsequent information reading. Based on a detailed analysis of this distortion, we divided it into linear distortion along the generatrix direction and curl distortion perpendicular to the generatrix direction, and proposed a unified method to correct the distortion of both components. Experimental results are given to demonstrate the feasibility and applicability of the method.

This paper introduces a control system based on ARM and WINCE for optical eccentric detector. The system adopts S3C6410 based on ARM11 architecture as the core chip controls the four-phase stepping motor to drive the rotation of mirror being tested, captured by the image sensor OV9650.It can capture the brightest point in each image, and fits multiple points from many images by least square circle fitting to get the optical eccentric value. Test results show that the system works well and gives stable data, with good real-time performance.

In our previous works, we presented a zoom system and image stabilization design based on deformable mirrors (DMs). According to the high bandwidth and free edge characteristics of the piezoelectric deformable mirror (PDM), we tested the system’s image-stable capability. We found the PDM could realize some tilt displacements while keeping a certain stable surface shape, it could obtain higher image stabilizing precision when integrated with the traditional mechanical image stabilization systems. In the design of the image stabilization system, the PDM’s tilt displacement range is a key factor for consideration. So in this paper, we carried out a tilt displacement range testing experiment by using the OKO’s 37-channel PDM. We measured and analyzed the variation of the tilt displacements in optical image stabilization process, and calculated the maximum tilt angle as the PDM surface shape was stabilized. We built an experimental platform consisting of a fixed target, an imaging system based on PDM, and a CCD camera. We used the ZYGO interferometer as an evaluation instrument to measure the surface shape stability. When the PDM surface had a tilt displacement, the image point of the fixed target on the camera sensor shifted correspondingly. The tilt angle of the PDM could be obtained by calculating this shift. The results showed that the maximum tilt angle of the PDM was 0.2mrad. The paper also analyzed the experiment errors when concerning about the off-axis error of the PDM deflection center.

This paper presents an optical stabilization system based on deformable mirrors (DMs) for retina-like sensors. This system achieves image stabilization by changing the reflective plate of the DM's compensating tilt angle. The mathematical model is constructed with relative parameters, and the simulation experiments and parameter analysis are discussed to verify the system's reliability. The experimental results show that this system achieved optical image stabilization. The maximum relative error of the compensation angle is 8.78%. The system is close to the diffraction limit, and the distortion is less than 0.33%. This study presents an image stabilization system and offers possible improvement in the aberrations in the system, which will provide great support to retina-like sensors.

The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1–5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

Many studies have demonstrated that exposure to excess fluoride was associated with a variety of diseases. Little is known about the variation of testosterone (T) levels caused by fluoride exposure. The aim of this study is to explore the association of fluoride exposure and age with serum T and androgen-binding protein (ABP) levels in male farmers. A cross-sectional study was conducted in a county of Henan Province, China, including high fluoride exposure from drinking water villages and control villages. Male farmers aged 18-55 years old who lived in these villages were recruited by cluster sampling and divided into a higher fluoride exposure group (HFG) and a lower fluoride exposure group (LFG) according to the level of urinary fluoride. Levels of T and ABP in serum were measured using chemiluminescence immunoassay (CLIA) and enzyme-linked immunosorbent assay (ELISA) respectively. Markedly lower T levels were observed in male farmers from the HFG than in those from the LFG (t = 2.496, P

The technology of multi-scale optical systems could be used to achieve a balance of the field-of-view and F-number, and helpful enhance the system image quality. This paper designed a multi-scale optical lens, and finished the work of demonstrating theoretically the feasibility of curved image together with the array lens. An idea has been proposed in this paper, using the approximately concentric chief rays combining with balance aberrations in each channel of the array lens to alleviate the aberrations of the whole optical system. Lastly, we designed a specific optical path and completed the experimental analysis. Experimental results show that the optical layout of the multi-scale optical lens can achieve a field of view of 60 degree while the aberration balance is well.

Large aperture convex aspheric optical components are widely used in imaging systems such as astronomy and space telescopes. Measurement of the figure error of the convex aspherical surface with high precision has been a challenge. We have proposed partial compensating interferometry with catadioptric compensating lens to solve the measurement of convex aspherical surface. In this paper, we dig into the problem of retrace error correction and verify the whole measurement process. We do simulation experiment to measure the wavefront at the exit pupil with digital Moire phase-shifting technique. And then we do iterative optimization to calculate the figure error and correct the retrace error. The feasibility and accuracy has been demonstrated, which lays the theoretical foundation for the practical measurement.

International audience

15GB optical disk, or Next Generation Versatile Disk (NVD), is a new type of disk handling the high definition video in China. In this paper, its specifications are optimized for commercialize concerning about the tracking signal. Then a new specification with robust tracking signal and reasonable pit/track ratio is proposed for NVD.

This paper presents a novel method to reduce the crosstalk force in main movement, and improve the sensitivity of the three-axis actuator in super-multi optical pickup. A novel magnetic circuit adopting symmetric driving coils and permanent magnets with special placement is developed. Then, the magnetic circuit is optimized with the help of Taguchi method, so as to dramatically improve the flux density and reduce the nonlinearity. Some actuator samples with the optimized parameters are fabricated and tested, and the results show the good performance of the proposed actuator.

Super-multi DVD drives are assumed to have the largest market share in the near future because of their high compatibility with all kinds of DVD/CD formats and high recording-reading speed at low cost. In this paper, we present a three-axis actuator used in a super-multi drive with a special magnetic circuit, consisting of symmetric driving coils and permanent magnets with proper placement. At first, the lens holder is optimized with sensitivity method to improve the flexible vibration modes in structure parts. Then, electromagnetic circuits are designed and optimized by Taguchi method and response surface methodology (RSM). Consequently, the final model is fabricated and tested by laser vibrometer system. The results verify the proposed actuator and the integrated design methods.

In this paper we propose a ray tracing method in 3-D space. This method, based on ABCD ray transfer matrices in 2-D spacey, is deduced to establish the matrix expression for ray tracing in 3-D space. In order to solve the attitude control problem of the plan mirror in image stabilization system, we construct a mathematical model to describe the ray passing process from incident plane, mirror reflection, to the next optical plane. Two 2*2 ABCD submatrixes, for two 2-D subspaces, have been used to describe the propagation rules of ray in a 3-D space. Furthermore, the stabilization formula has been deduced. In this way, the offset angle for stabilization and coordinate of ray in space can be got. With the simulation experiments, we verified the effectiveness and accuracy of this mathematical model. The method we put forward has the characteristics of universal and simple. This 3-D ray tracing method could be further applied to other optical area.