Spectral imaging based on custom-made multi-strip filter arrays.

Spectral imaging technology based on on-chip spectroscopy can find applications in areas including aerospace, industrial and consumer electronics, and so on. Since each application normally requires a different set and number of spectral bands, the development of customized spectroscopy solutions with more compact size and lower cost becomes quite important. In this paper, we demonstrate a compact, highly customizable imaging spectrometer scheme based on custom-made multi-strip filter arrays, which maintains an average high transmission of ∼85%, narrow bandwidth of ∼30n m, and high optical density of ∼O D2 in the blocking regions across the visible to near-infrared waveband. Spectral imaging experiments are conducted, and the accurate reconstruction of sparse spectral image data is demonstrated as well to prove the validity of the proposed scheme. As a result, the work reported in this paper allows researchers to develop customized spectral imaging equipment in a relatively easy way and also has a great potential to be engineered further for scalable production with a quite low cost.

Optimal design of a gravitational wave telescope system for the suppression of stray light.

For gravitational wave detection, the telescope is required to have an ultra-low wavefront error and ultra-high signal-to-noise ratio, where the power of the stray light should be controlled on the order of less than 10-10. In this work, we propose an alternative stray light suppression method for the optical design of an off-axis telescope with four mirrors by carefully considering the optimal optical paths. The method includes three steps. First, in the period of the optical design, the stray light caused by the tertiary mirror and the quaternary mirror is suppressed by increasing the angle formed by the optical axes of the tertiary mirror and the quaternary mirror and reducing the radius of curvature of the quaternary mirror as much as possible to make sure the optical system provides a beam quality with a wavefront error less than λ/80. Next, the stray light could satisfy the requirement of the order of 10-10 when the level of roughness reaches 0.2 nm, and the pollution of mirrors is controlled at the level of CL100. Finally, traditional stray light suppression methods should also be applied to mechanics, including the use of the optical barrier, baffle tube, and black paint. It can be seen that the field stop can efficiently reduce stray light caused by the secondary mirror by more than 55% in the full field of view. The baffle tube mounted on the position of the exit pupil can reduce the overall stray light energy by 5%, and the difference between the ideal absorber (absorption coefficient is 100%) and the actual black paint (absorption coefficient is 90%) is 3.2%. These simulation results are confirmed by the Monte Carlo method for a stray light analysis. Based on the above results, one can conclude that the geometry structure of the optical design, the quality of mirrors, and the light barrier can greatly improve the stray light suppression ability of the optical system, which is vital when developing a gravitational wave telescope with ultra-low stray light energy.

Design of Mantis-Shrimp-Inspired Multifunctional Imaging Sensors with Simultaneous Spectrum and Polarization Detection Capability at a Wide Waveband.

The remarkable light perception abilities of the mantis shrimp, which span a broad spectrum ranging from 300 nm to 720 nm and include the detection of polarized light, serve as the inspiration for our exploration. Drawing insights from the mantis shrimp's unique visual system, we propose the design of a multifunctional imaging sensor capable of concurrently detecting spectrum and polarization across a wide waveband. This sensor is able to show spectral imaging capability through the utilization of a 16-channel multi-waveband Fabry-Pérot (FP) resonator filter array. The design incorporates a composite thin film structure comprising metal and dielectric layers as the reflector of the resonant cavity. The resulting metal-dielectric composite film FP resonator extends the operating bandwidth to cover both visible and infrared regions, specifically spanning a broader range from 450 nm to 900 nm. Furthermore, within this operational bandwidth, the metal-dielectric composite film FP resonator demonstrates an average peak transmittance exceeding 60%, representing a notable improvement over the metallic resonator. Additionally, aluminum-based metallic grating arrays are incorporated beneath the FP filter array to capture polarization information. This innovative approach enables the simultaneous acquisition of spectrum and polarization information using a single sensor device. The outcomes of this research hold promise for advancing the development of high-performance, multifunctional optical sensors, thereby unlocking new possibilities in the field of optical information acquisition.

Histone H3Y99sulf regulates hepatocellular carcinoma responding to hypoxia.

Histone H3 tyrosine-99 sulfation (H3Y99sulf) is a recently identified histone mark that can cross-talk with H4R3me2a to regulate gene transcription, but its role in cancer biology is less studied. Here, we report that H3Y99sulf is a cancer-associated histone mark that can mediate hepatocellular carcinoma (HCC) cells responding to hypoxia. Hypoxia-stimulated SNAIL pathway elevates the expression of PAPSS2, which serves as a source of adenosine 3'-phosphate 5'-phos-phosulfate for histone sulfation and results in upregulation of H3Y99sulf. The transcription factor TDRD3 is the downstream effector of H3Y99sulf-H4R3me2a axis in HCC. It reads and co-localizes with the H3Y99sulf-H4R3me2a dual mark in the promoter regions of HIF1A and PDK1 to regulate gene transcription. Depletion of SULT1B1 can effectively reduce the occurrence of H3Y99sulf-H4R3me2a-TDRD3 axis in gene promoter regions and lead to downregulation of targeted gene transcription. Hypoxia-inducible factor 1-alpha and PDK1 are master regulators for hypoxic responses and cancer metabolism. Disruption of the H3Y99sulf-H4R3me2a-TDRD3 axis can inhibit the expression and functions of hypoxia-inducible factor 1-alpha and PDK1, resulting in suppressed proliferation, tumor growth, and survival of HCC cells suffering hypoxia stress. The present study extends the regulatory and functional mechanisms of H3Y99sulf and improves our understanding of its role in cancer biology.

Advanced Biomimetic Multispectral Curved Compound Eye Camera for Aerial Multispectral Imaging in a Large Field of View.

In this work, we demonstrated a new type of biomimetic multispectral curved compound eye camera (BM3C) inspired by insect compound eyes for aerial multispectral imaging in a large field of view. The proposed system exhibits a maximum field of view (FOV) of 120 degrees and seven-waveband multispectral images ranging from visible to near-infrared wavelengths. Pinhole imaging theory and the image registration method from feature detection are used to reconstruct the multispectral 3D data cube. An airborne imaging experiment is performed by assembling the BM3C on an unmanned aerial vehicle (UAV). As a result, radiation intensity curves of several objects are successfully obtained, and a land type classification is performed using the K-means method based on the aerial image as well. The developed BM3C is proven to have the capability for large FOV aerial multispectral imaging and shows great potential applications for distant detecting based on aerial imaging.

Broadband Achromatic Metalens for Tunable Focused Vortex Beam Generation in the Near-Infrared Range.

Vortex beams accompanied with orbital angular momentum have attracted significant attention in research fields due to their formidable capabilities in various crucial applications. However, conventional devices for generating vortex beams still suffer from bulky sizes, high cost, and confined performances. Metalens, as an advanced platform to arbitrarily control the optical waves, has promising prospects to address the predicament for conventional devices. Although great progress has been demonstrated in the applications of vortex beams, they are still confronted with fixed functionality after fabrication that severely hinders their application range. In this work, the phase-change material of Ge2Sb2Te5 (GST) is employed to design the meta-atoms to realize tunable optical responses. Moreover, the focused vortex beam can be accomplished by superimposing a helical phase and hyperbolic phase, and the chromatic aberrations in near-infrared (NIR) range can be corrected by introducing an additional phase compensation. And the design strategy is validated by two different metalenses (BAMTF-1 and BAMTF-2). The numerical results indicate that the chromatic aberrations for two metalens can be corrected in 1.33-1.60 µm covering the telecom range. Moreover, the average focusing efficiency of BAMTF-1 is 51.4%, and that of BAMTF-2 is 39.9%, indicating the favorable performances of designed BAMTF. More importantly, their average focal lengths have a relative tuning range of 38.82% and 33.17% by altering the crystallization ratio of GST, respectively. This work may provide a significant scheme for on-chip and tunable devices for NIR imaging and communication systems.

Neuropeptide B (NPB) and NPB receptor 2b (NPBWR2b) in the ricefield eel Monopterus albus: expression and potential involvement in the regulation of gonadotropins.

The neuropeptide B/W signaling system is composed of neuropeptide B (NPB), neuropeptide W (NPW), and two cognate receptors, NPBWR1 and NPBWR2, which are involved in diverse physiological processes, including the central regulation of neuroendocrine axes in vertebrates. The components of this signaling system are not well conserved during vertebrate evolution, implicating its functional diversity. The present study characterized the ricefield eel neuropeptide B/W system, generated a specific antiserum against the neuropeptide B/W receptor, and examined the potential roles of the system in the regulation of adenohypophysial functions. The ricefield eel genome contains npba, npbb, and npbwr2b but lacks the npw, npbwr1, and npbwr2a genes. The loss of npw and npbwr1 probably occurred at the base of ray-finned fish radiation and that of npbwr2a species specifically in ray-finned fish. Npba and npbb genes are produced through whole-genome duplication (WGD) in ray-finned fish. The ricefield eel npba was expressed in the brain and some peripheral tissues, while npbb was predominantly expressed in the brain. The ricefield eel npbwr2b was also expressed in the brain and in some peripheral tissues, such as the pituitary, gonad, heart, and eye. Immunoreactive Npbwr2b was shown to be localized to Lh and Fsh cells but not to Gh or Prl cells in the pituitary of ricefield eels. Npba upregulated the expression of fshb and cga but not lhb mRNA in pituitary fragments of ricefield eels cultured in vitro. The results of the present study suggest that the NPB system of ricefield eels may be involved in the neuroendocrine regulation of reproduction.

Histone tyrosine sulfation by SULT1B1 regulates H4R3me2a and gene transcription.

Tyrosine sulfation is a common posttranslational modification in mammals. To date, it has been thought to be limited to secreted and transmembrane proteins, but little is known about tyrosine sulfation on nuclear proteins. Here we report that SULT1B1 is a histone sulfotransferase that can sulfate the tyrosine 99 residue of nascent histone H3 in cytosol. The sulfated histone H3 can be transported into the nucleus and majorly deposited in the promoter regions of genes in chromatin. While the H3Y99 residue is buried inside octameric nucleosome, dynamically regulated subnucleosomal structures provide chromatin-H3Y99sulf the opportunity of being recognized and bound by PRMT1, which deposits H4R3me2a in chromatin. Disruption of H3Y99sulf reduces PRMT1 binding to chromatin, H4R3me2a level and gene transcription. These findings reveal the mechanisms underlying H3Y99 sulfation and its cross-talk with H4R3me2a to regulate gene transcription. This study extends the spectrum of tyrosine sulfation on nuclear proteins and the repertoire of histone modifications regulating chromatin functions.

Long-working-distance 3D measurement with a bionic curved compound-eye camera.

The bionic curved compound-eye camera is a bionic-inspired multi-aperture camera, which can be designed to have an overlap on the field of view (FOV) in between adjacent ommatidia so that 3D measurement is possible. In this work, we demonstrate the 3D measurement with a working distance of up to 3.2 m by a curved compound-eye camera. In that there are hundreds of ommatidia in the compound-eye camera, traditional calibration boards with a fixed-pitch pattern arrays are not applicable. A batch calibration method based on the CALTag calibration board for the compound-eye camera was designed. Next, the 3D measurement principle was described and a 3D measurement algorithm for the compound-eye camera was developed. Finally, the 3D measurement experiment on objects placed at different distances and directions from the compound-eye camera was performed. The experimental results show that the working range for 3D measurement can cover the whole FOV of 98° and the working distance can be as long as 3.2 m. Moreover, a complete depth map was reconstructed from a raw image captured by the compound-eye camera and demonstrated as well. The 3D measurement capability of the compound-eye camera at long working distance in a large FOV demonstrated in this work has great potential applications in areas such as unmanned aerial vehicle (UAV) obstacle avoidance and robot navigation.

Acetyl-CoA Carboxylases and Diseases.

Acetyl-CoA carboxylases (ACCs) are enzymes that catalyze the carboxylation of acetyl-CoA to produce malonyl-CoA. In mammals, ACC1 and ACC2 are two members of ACCs. ACC1 localizes in the cytosol and acts as the first and rate-limiting enzyme in the de novo fatty acid synthesis pathway. ACC2 localizes on the outer membrane of mitochondria and produces malonyl-CoA to regulate the activity of carnitine palmitoyltransferase 1 (CPT1) that involves in the ß-oxidation of fatty acid. Fatty acid synthesis is central in a myriad of physiological and pathological conditions. ACC1 is the major member of ACCs in mammalian, mountains of documents record the roles of ACC1 in various diseases, such as cancer, diabetes, obesity. Besides, acetyl-CoA and malonyl-CoA are cofactors in protein acetylation and malonylation, respectively, so that the manipulation of acetyl-CoA and malonyl-CoA by ACC1 can also markedly influence the profile of protein post-translational modifications, resulting in alternated biological processes in mammalian cells. In the review, we summarize our understandings of ACCs, including their structural features, regulatory mechanisms, and roles in diseases. ACC1 has emerged as a promising target for diseases treatment, so that the specific inhibitors of ACC1 for diseases treatment are also discussed.

Biomimetic multispectral curved compound eye camera for real-time multispectral imaging in an ultra-large field of view.

In this work, we demonstrate a prototype of a biomimetic multispectral curved compound eye camera (BMCCEC). In comparison with traditional multispectral imaging systems, the BMCCEC developed in this work has the distinct features of multi-spectral imaging on multiple targets in real time in an ultra-large field of view (FOV), which can be attributed to its biomimetic curved compound eye structure as well as the multispectral cluster network. Specifically, the BMCCEC has a total of 104 multispectral ommatidia and a FOV of 98°×98°, which is able to realize 7-band multispectral imaging with center wavelengths of 500 nm, 560 nm, 600 nm, 650 nm, 700 nm, 750 nm and 800 nm and a spectral resolution of 10 nm. A prototype of BMCCEC was then manufactured and multispectral imaging experiments were performed based on it. As a result, the red edge feature of the spectrum of green plants has been successfully obtained and retrieved with a good accuracy.

Performance of SOFA, qSOFA and SIRS to predict septic shock after percutaneous nephrolithotomy.

OBJECTIVE: The new clinical criteria termed SOFA and qSOFA were demonstrated to be more accurate than SIRS in screening patients at high risk of sepsis. We aim to evaluate the ability of SOFA, qSOFA and SIRS to predict septic shock after PCNL. PATIENTS AND METHODS: Consecutive patients undergoing PCNL were included to assess the performance of SOFA, qSOFA and SIRS in predicting septic shock, the AUC of ROC curve and decision curve analysis were used, and the optimal cutoff values and their achieving time were calculated. RESULTS: Of the 431 included patients, 12 (2.7%) cases developed septic shock. Compared with non-septic shock patients, patients with septic shock were more likely to be female, have positive history of urine culture and higher urine leukocyte count, and show increased postoperative serum creatinine, PCT and decreased leukocyte. The optimal cutoff of SOFA, qSOFA and SIRS was > 2, > 0 and > 1, respectively. All of the 12 patients with verified septic shock met SOFA and SIRS criteria, while only 11 cases met qSOFA criterion. SOFA had the identical highest sensitivity (100%) and greater specificity (87% vs. 81%) than SIRS. qSOFA had higher specificity (92%) than both SOFA and SIRS at the expense of lower sensitivity (92%). The AUC of SOFA (0.973) to predict septic shock was greater than that of qSOFA (0.928) and SIRS (0.935). When combined with SIRS, SOFA outperformed qSOFA for discrimination of septic shock (AUC 0.987 vs. 0.978). Decision curve analysis indicated SOFA was clearly superior to both qSOFA and SIRS with a higher net benefit and net reduction in intervention. The qSOFA achieved the best time-based predictive efficiency, with the shortest median time to meet its cutoff, followed by SOFA and SIRS. CONCLUSION: The performance of SOFA in predicting septic shock after PCNL was slightly greater than qSOFA and SIRS. The comprehensive application of various criteria is recommended to assist early detection of septic shock following PCNL.

Biomimetic curved compound-eye camera with a high resolution for the detection of distant moving objects.

In this Letter, we demonstrate the design and fabrication of a biomimetic curved compound-eye camera (BCCEC) with a high resolution for detecting distant moving objects purpose. In contrast to previously reported compound-eye cameras, our BCCEC has two distinct features. One is that the ommatidia of the compound eye are deployed on a curved surface which makes a large field of view (FOV) possible. The other is that each ommatidium has a relatively large optical entrance and long focal length so that a distant object can be imaged. To overcome the mismatch between the curved focal plane formed by the curved compound eye and the planar focal plane of the CMOS image sensor (CIS), an optical relay subsystem is introduced between the compound eye and the CIS. As a result, a BCCEC with 127 ommatidia in the compound eye is designed and fabricated to achieve a large FOV of up to 98∘×98∘. The experimental results show that objects with a size of 100 mm can be clearly resolved at a distance of 25 m. The capture of the motion trajectories of a moving object is also demonstrated, which makes it possible to detect and track the moving targets in a huge FOV for security surveillance purposes.

Colourful imaging and self-reconstruction properties of modified single-focus fractal zone plates.

A modified single-focus fractal zone plate (MSFFZP) is proposed to generate a single main focus with many subsidiary foci or two equal-intensity main foci with many subsidiary foci. Widths of high-transmission zones, which have influence on the number of the high-order diffraction foci, such as the second-order focus and the fourth-order focus, can adjust first-order fractal focal intensities, but have no influence on first-order focal positions. Moreover, the MSFFZPs have the first-order foci or the first and second order foci only along the optic axis. It is proved numerically and experimentally that the MSFFZP can generate one or two colourful images with the low chromatic aberrations at the focal planes, and the MSFFZP beam has the self-reconstruction property. In addition, the MSFFZP produces a series of foci at the different focal planes along the optic axis in the simulations and experiments. The method of constructing the MSFFZP is illustrated. The proposed zone plate can be used to produce the multiple clear images, trap particles at the multiple planes simultaneously, and generate the images with the low chromatic aberration.

Experimental study on the repair of ureteral functional regeneration with highly bioactive extracellular matrix stent.

BACKGROUND: The research of extracellular matrix stent (ECM) has made some progress in the repair of urethra and bladder defects. OBJECTIVES: To observe the effects of highly bioactive ECM scaffold on the regeneration and repair of defects in long-segment ureteral replacement. MATERIAL AND METHODS: An animal model of long-segment ureteral defect was established and four-layer tubular highly bioactive ECM materials were prepared. After the ureteral defect was repaired through surgery, the rabbits in the negative control group were administered a non-bioactive stent, and rabbits in the observation group were treated with an ECM stent. RESULTS: Comparison of macro-indicators: The negative control group had a higher infection rate, a lower survival rate and more complications than the observation group (p < 0.05). The frequency of ureteral peristalsis in the negative control group was lower than in the observation group. In addition, the rate of urinary dysfunction was higher, and the ratio of ureteral diameter was lower in the negative control group than in the observation group (all p < 0.05). Comparison of histopathology: Three months after the operation, the vascular, smooth muscle and mucous membrane of the ureter in the observation group regenerated to close to normal ureteral tissue. There was no significant difference between the ureter regeneration in the repair area and the normal ureter tissue in the observation group 3 months after the operation. The number of regenerated muscle fibers in the observation group was significantly higher than that of the negative control group. Compared with the negative control group, the fibrous capsule was thicker, the percentages of CD31, CD3, CD68, CD80+, and CD163+ were higher, the scope of new smooth muscle fiber was expanded, fusion with the host muscle fibers was higher, and the neuromuscular junction (NMJ) structure was stronger in the observation group (all p < 0.05). CONCLUSIONS: A highly bioactive ECM stent can better regenerate the local anatomical structure and physiological function.

Binary amplitude-only image reconstruction through a MMF based on an AE-SNN combined deep learning model.

The obstacle of imaging through multimode fibers (MMFs) is encountered due to the fact that the inherent mode dispersion and mode coupling lead the output of the MMF to be scattered and bring about image distortions. As a result, only noise-like speckle patterns can be formed on the distal end of the MMF. We propose a deep learning model exploited for computational imaging through an MMF, which contains an autoencoder (AE) for feature extraction and image reconstruction and self-normalizing neural networks (SNNs) sandwiched and employed for high-order feature representation. It was demonstrated both in simulations and in experiments that the proposed AE-SNN combined deep learning model could reconstruct image information from various binary amplitude-only targets going through a 5-meter-long MMF. Simulations indicate that our model works effectively even in the presence of system noise, and the experimental results prove that the method is valid for image reconstruction through the MMF. Enabled by the spatial variability and the self-normalizing properties, our model can be generalized to solve varieties of other computational imaging problems.

Optical trapping of single nano-size particles using a plasmonic nanocavity.

Trapping and manipulating micro-size particles using optical tweezers has contributed to many breakthroughs in biology, materials science, and colloidal physics. However, it remains challenging to extend this technique to a few nanometers particles owing to the diffraction limit and the considerable Brownian motion of trapped nanoparticles. In this work, a nanometric optical tweezer is proposed by using a plasmonic nanocavity composed of the closely spaced silver coated fiber tip and gold film. It is found that the radial vector mode can produce a nano-sized near field with the electric-field intensity enhancement factor over 103 through exciting the plasmon gap mode in the nanocavity. By employing the Maxwell stress tensor formalism, we theoretically demonstrate that this nano-sized near field results in a sharp quasi-harmonic potential well, capable of stably trapping 2 nm quantum dots beneath the tip apex with the laser power as low as 3.7 mW. Further analysis reveals that our nanotweezers can stably work in a wide range of particle-to-tip distances, gap sizes, and operation wavelengths. We envision that our proposed nanometric optical tweezers could be compatible with the tip-enhanced Raman spectroscopy to allow simultaneously manipulating and characterizing single nanoparticles as well as nanoparticle interactions with high sensitivity.

Imaging properties of generalized composite aperiodic zone plates.

Generalized composite aperiodic zone plates (GCAZPs) are proposed to generate clearer images at focal planes. The images can be produced by a target object at infinity based on a collimator. The proposed zone plate consists of the proposed radial zone plate (RZP), whose original radius is not zero, and the common aperiodic zone plate, which has the coincident first-order diffraction area and the same axial first-order diffraction intensity distribution. The GCAZPs are applicable for the other aperiodic zone plates. Moreover, the modulation transfer function curve of the GCAZP is basically above that of the corresponding common aperiodic zone plate. Compared with the common aperiodic zone plates, the GCAZPs have the foci with higher intensity and the images with higher contrast at the same focal planes. In addition, a GCAZP with an arbitrary size can be designed. The construction method of the GCAZP is illustrated in details. Furthermore, it has been also proved numerically and experimentally that the GCAZPs are used to generate the clearer images than the corresponding common aperiodic zone plates. The proposed zone plates are applicable to generate clear images and trap particles stably at multiple planes simultaneously.