Structure optimization of heterogeneous compound eye camera for improving the detection performance.

To achieve fast location, precise tracking and accurate identification over a large field of view (FOV), we have proposed a heterogeneous compound eye camera (HeCECam), which consists of a heterogeneous compound eye array, an optical relay system and a CMOS detector. However, the current HeCECam can hardly acquire high-precision 3D information of the targets to realize these applications. To solve this challenge, we propose a scheme on optimizing the structure of the HeCECam to improving the detection performance, including the optimization of the distribution uniformity of the sub-eyes with the proposed "Three-direction center-of-gravity subdivision (TGS)" and the enhancement of the compatibility between heterogeneous compound eyes and the optical relay system with the proposed compensation method for tilt. The TGS significantly reduces the distribution unevenness of sub-eyes down to 117% from the previous 152%, and provides symmetry to the heterogeneous compound eye array. The tilt compensation effectively addresses previous imaging defects, such as distortion of sub-images, increased stray light, and support structures being imaged, and it improves the imaging clarity of the system, especially in external FOV. Based on two proposed methods, we re-design and fabricate the heterogeneous compound eye array to obtain a high-performance prototype. To verify the imaging capacities of the optimized HeCECam, a series of comparison experiments are performed, including blank scene imaging, FOV tests, resolution verification and real-world scene imaging. The results show that the previous imaging defects have been well eliminated, and the optimized prototype has stronger resolving power and wider FOV. This allow the HeCECam to perform better in subsequent practical applications, such as wide-area surveillance, forewarning, and navigation.

Downregulation of NUP93 aggravates hypoxia-induced death of cardiomyocytes in vitro through abnormal regulation of gene transcription.

Nuclear pore complex in the nuclear envelope plays an important role in controlling the transportation of RNAs, proteins and other macromolecules between the nucleus and cytoplasm. The relationship between abnormal expression of nucleoporins and cardiovascular diseases is unclear. In this study we investigated how myocardial infarction affected the expression and function of nucleoporins in cardiomyocytes. We separately knocked down 27 nucleoporins in rat primary myocardial cells. Among 27 nucleoporins, knockdown of Nup93, Nup210 and Nup214 markedly increased the expression of ANP and BNP, two molecular markers of cardiomyocyte function. We showed that Nup93 was significantly downregulated in hypoxic cardiomyocytes. Knockdown of Nup93 aggravated hypoxia-induced injury and cell death of cardiomyocytes, whereas overexpression of Nup93 led to the opposite effects. RNA-seq and bioinformatics analysis revealed that knockdown of Nup93 did not affect the overall transportation of mRNAs from the nucleus to the cytoplasm, but regulated the transcription of a large number of mRNAs in cardiomyocytes, which are mainly involved in oxidative phosphorylation and ribosome subunits. Most of the down-regulated genes by Nup93 knockdown overlapped with the genes whose promoters could be directly bound by Nup93. Among these genes, we demonstrated that Nup93 knockdown significantly down-regulated the expression of YAP1. Overexpression of YAP1 partially rescued the function of Nup93 knockdown and attenuated the effects of hypoxia on cell injury and cardiomyocyte death. We conclude that down-regulation of Nup93, at least partially, contributes to hypoxia-induced injury and cardiomyocyte death through abnormal interaction with the genome to dynamically regulate the transcription of YAP1 and other genes. These results reveal a new mechanism of Nup93 and might provide new therapeutic targets for the treatment of ischemia-induced heart failure.

Influence of the thermodynamic properties of the Internal Occulter inside the coronagraph on coronal observations.

To detect good quality coronal spectra images, the continuous optimization of stray light suppression techniques for coronagraphs is required. The internal occulter (IO) serves as the main tool for the Internally Occulted Coronagraph to suppress the direct light from the photosphere layer, and thermal stress displacements with thermodynamic properties will overcover the information of the internal corona. In this paper, a reflective distribution function model is established according to Kirchhoff's principle which is based on a ground-based Lyot coronagraph, the aperture is 200 mm, detection wavelength is 637.4 nm (Fe X) and the work field range is ±1.05-2.0 RS (RS is the solar radius), thus the absorption rate is inverted. The irradiance at different positions received by the ground is simulated, and then the temperature change of the occulter during the time of the strongest radiation is calculated. The thermal stress displacement change of the two materials was analyzed by the finite element method. Comparison of the experiment shows that the displacement variation of the conical bottom plane results in losing 0.34% RS corona information for the 2a12-t6 aluminum alloy, and losing 0.11% RS coronal information for oxygen-free copper. This way provides a new idea for the thermodynamic modeling of the IO and the direct light suppression technology in the coronagraph.

Heterogeneous compound eye camera for dual-scale imaging in a large field of view.

Multi-scale imaging with large field of view is pivotal for fast motion detection and target identification. However, existing single camera systems are difficult to achieve snapshot multi-scale imaging with large field of view. To solve this problem, we propose a design method for heterogeneous compound eye, and fabricate a prototype of heterogeneous compound eye camera (HeCECam). This prototype which consists of a heterogeneous compound eye array, an optical relay system and a CMOS sensor, is capable of dual-scale imaging in large field of view (360°×141°). The heterogeneous compound eye array is composed of 31 wide-angle (WA) subeyes and 226 high-definition (HD) subeyes. An optical relay system is introduced to re-image the curved focal surface formed by the heterogeneous compound eye array on a CMOS sensor, resulting in a heterogeneous compound eye image containing dual-scale subimages. To verify the imaging characteristics of this prototype, a series of experiments, such as large field of view imaging, imaging performance, and real-world scene imaging, were conducted. The experiment results show that this prototype can achieve dual-scale imaging in large field of view and has excellent imaging performance. This makes the HeCECam has great potential for UAV navigation, wide-area surveillance, and location tracking, and paves the way for the practical use of bio-inspired compound eye cameras.

Bio-inspired spherical compound eye camera for simultaneous wide-band and large field of view imaging.

Natural compound eyes have excellent optical characteristics, namely large field of view, small size, no aberration, and sensitive to motion. Some arthropods have more powerful vision. For example, the Morpho butterfly's compound eyes can perceive the near-infrared and ultraviolet light that the human eye cannot see. This wide-band imaging with a large field of view has great potential in wide-area surveillance, all-weather panoramic imaging, and medical imaging. Hence, a wide-band spherical compound eye camera inspired by the Morpho butterfly's eye was proposed. The wide-band spherical compound eye camera which can achieve a large field of view (360° × 171°) imaging over a wide range of wavelengths from 400nm to 1000nm, mainly consists of three parts: a wide-band spherical compound eye with 234 sub-eyes for light collection, a wide-band optical relay system for light transmission, and a wide-band CMOS image sensor for photoelectric conversion. Our experimental results show that the wide-band spherical compound eye camera not only captures a large field of view without anomalous blurring or aberrations but also perceives near-infrared light that is not recognized by the human eye. These features make it possible for distortion-free panoramic vision and panoramic medical diagnosis.

Bio-inspired multimodal 3D endoscope for image-guided and robotic surgery.

Image-guided and robotic surgery based on endoscopic imaging technologies can enhance cancer treatment by ideally removing all cancerous tissue and avoiding iatrogenic damage to healthy tissue. Surgeons evaluate the tumor margins at the cost of impeding surgical workflow or working with dimmed surgical illumination, since current endoscopic imaging systems cannot simultaneous and real-time color and near-infrared (NIR) fluorescence imaging under normal surgical illumination. To overcome this problem, a bio-inspired multimodal 3D endoscope combining the excellent characteristics of human eyes and compound eyes of mantis shrimp is proposed. This 3D endoscope, which achieves simultaneous and real-time imaging of three-dimensional stereoscopic, color, and NIR fluorescence, consists of three parts: a broad-band binocular optical system like as human eye, an optical relay system, and a multiband sensor inspired by the mantis shrimp's compound eye. By introducing an optical relay system, the two sub-images after the broad-band binocular optical system can be projected onto one and the same multiband sensor. A series of experiments demonstrate that this bio-inspired multimodal 3D endoscope not only provides surgeons with real-time feedback on the location of tumor tissue and lymph nodes but also creates an immersive experience for surgeons without impeding surgical workflow. Its excellent characteristics and good scalability can promote the further development and application of image-guided and robotic surgery.

High level of circulating microRNA-142 is associated with acute myocardial infarction and reduced survival.

BACKGROUND: Recent study reported that microRNA-142 (miR-142) were up-regulated in the atherosclerotic plaques, which may be responsible for pathogenesis of atherosclerosis. However, whether it associates with presence of acute myocardial infarction (AMI), and its prognostic value is still unknown. We, therefore, investigated the association between miR-142 expression and presence of AMI, and its prognostic value in AMI patients. METHODS: We included 300 AMI patients and 100 subjects as the control group. MiR-142 content was detected by quantitative real-time polymerase chain reaction. MiR-142 level was identified in all subjects. The multivariate logistic regression analysis were performed to evaluate the risk factors of AMI. The Kaplan-Meier analysis was performed to determine the major adverse cardiovascular and cerebrovascular events (MACCE)-free survival. RESULTS: AMI group had significantly higher miR-142 level in comparison to the controls [4.10 (2.03-7.43) vs. 1.92 (0.91-2.91), p < 0.001], moreover, miR-142 content was significantly associated with cardiac troponin I (cTnI) level (r = 0.707, p < 0.001). The MACCE-free survival was significantly lower over 24-month for patients in miR-142 high expression group (72.4% ± 5.6% vs. 76.4% ± 5.1%) (p = 0.022). After adjusting for the traditional risk factors, the odds ratios of miR-142 was 14.74 (95% CI, 2.15-101.24). The multivariate logistic regression analysis revealed that miR-142 level significantly associated with presence of AMI (p < 0.001). CONCLUSION: The serum level of miR-142 was increased in AMI patients when compared with health population. Furthermore, use of this marker may allow a certain predictor of the MACCE in AMI patients.